and we’re back! with BRAND SPANKIN' NEW tangents!
welcome redditors!to snoo-finity ... and beyond!
NBME 20 Answers

Block 1/Question#1
A 37-year-old nurse is accidentally stuck with a needle used ...
Inhibits reverse transcriptase

Block 1/Question#2
A mother who has toxoplasmosis gives birth to an asymptomatic ...
Antitoxoplasma IgM antibody concentrations

Block 1/Question#3
A 48-year-old man comes to the physician for a routine ...
Upregulation of the LDL receptors

Block 1/Question#4
A 50-year-old man is brought to the emergency department by ...
Formic acid

Block 1/Question#5
A 24-year-old African American man comes to the physician ...
Pseudofolliculitis barbae

Block 1/Question#6
A 16-year-old student has uncontrollable sleepiness, falling ...
Direct transition from wakefulness to REM sleep

Block 1/Question#7
A 5-year-old girl with AIDS develops a progressive ...
Thymidine kinase

Block 1/Question#8
A 10-year-old girl is brought to the physician by her mother ...
Breast bud development

Block 1/Question#9
A 50-year-old man is brought to the physician by his wife ...
Pick disease

Block 1/Question#10
A 77-year-old woman has been having difficulty fastening ...
C7-T1 foraminal stenosis

Block 1/Question#11
The sequence surrounding the first two exons of the human ...
Disruption of normal splicing by creation of a new 3′ splice site

Block 1/Question#12
A 72-year-old woman with dysphagia is undergoing surgical ...
Right kidney

Block 1/Question#13
A 6-week-old girl is brought to the physician by her mother ...
Immature lower esophageal sphincter

Block 1/Question#14
A 28-year-old man who is a migrant worker comes to the clinic ...
Psoas major

Block 1/Question#15
A 30-year-old man who completed a successful course of ...
Adjustment disorder with anxiety

Block 1/Question#16
A 30-year-old woman with multiple sclerosis comes to the ...
Pons

Block 1/Question#17
A 50-year-old woman comes to the physician because of a ...
Drug effect

Block 1/Question#18
A 36-year-old man comes to the physician because he has not ...
Urine output: increased; Urine potassium: increased

Block 1/Question#19
A 60-year-old man comes to the physician because of a 6-week ...
Urine Na+: increased; Serum osmolality: decreased

Block 1/Question#20
An 8-year-old boy is evaluated for ventricular systolic ...
Coarctation of the aorta

Block 1/Question#21
A 75-year-old woman comes to the physician because of a ...
Multinucleated giant cells and neutrophil infiltrates

Block 1/Question#22
A 38-year-old woman comes to the physician because of a 3-day ...
Vagus

Block 1/Question#23
A 34-year-old man who is HIV positive is brought to the ...
CD4+ T lymphocytes

Block 1/Question#24
A 50-year-old man comes to the physician because of a ...
Omeprazole

Block 1/Question#25
A 25-year-old primigravid woman at 42 weeks’ gestation is ...
Phosphoinositide hydrolysis

Block 1/Question#26
Serum cholesterol concentrations are measured as part of a ...
16%

Block 1/Question#27
A 53-year-old woman comes to the physician because of a ...
Schistosoma mansoni

Block 1/Question#28
A previously healthy 16-year-old girl comes to the physician ...
Trichomonas vaginalis

Block 1/Question#29
During an experiment, an investigator isolates an abnormal ...
Lysine

Block 1/Question#30
A 33-year-old woman comes to the emergency department 1 hour ...
Lunate

Block 1/Question#31
A 66-year-old man has had fatigue, shortness of breath, and ...
Focal pulmonary fibrosis

Block 1/Question#32
A 56-year-old woman is brought to the emergency department ...
Placement of the central line via the left internal jugular vein

Block 1/Question#33
A 17-year-old girl comes to the emergency department because ...
Mitochondrial

Block 1/Question#34
A strain of Escherichia coli produces a temperature-sensitive ...
Missense

Block 1/Question#35
A 70-year-old man dies of coronary artery disease. He had a ...
Spastic hemiparesis on the right

Block 1/Question#36
A 56-year-old man is admitted to the hospital after an ...
Rhabdomyolysis

Block 1/Question#37
A 1-month-old male newborn is brought to the emergency ...
Na+: 132; K+: 3.2; Cl: 90; HCO3: 37

Block 1/Question#38
A 9-year-old girl is brought to the physician because of poor ...
Diverticulum of the roof of the embryonic oral cavity

Block 1/Question#39
A 3-month-old boy is brought to the office by his mother ...
Lateral to the inferior epigastric artery and superior to the inguinal ligament

Block 1/Question#40
Monoclonality of neoplastic cells in endometrial carcinoma ...
X chromosome-linked isoenzymes

Block 1/Question#41
A 45-year-old man has fever, chills, dysuria, and a tender, ...
Escherichia coli

Block 1/Question#42
A 60-year-old man has two-pillow orthopnea, severe dyspnea, ...
Jugular venous pressure of 12 mm Hg

Block 1/Question#43
A randomized clinical trial is conducted to compare wound ...
Neither procedure is superior

Block 1/Question#44
A 35-year-old woman with newly diagnosed hypertension comes ...
MR angiography of the renal arteries

Block 1/Question#45
A 2-year-old boy is brought to the physician because of ...
Amino Acids: decreased; Glucose: decreased; Phosphate: decreased; HCO3–: decreased

Block 1/Question#46
A 55-year-old woman comes to the physician for a follow-up ...
Cholecalciferol

Block 1/Question#47
A 60-year-old woman with type 2 diabetes mellitus is brought ...
Rupture of a papillary muscle

Block 1/Question#48
An otherwise healthy 4-month-old girl is brought to the ...
Spontaneous involution

Block 1/Question#49
A 56-year-old man comes to the physician because of a 6-month ...
Fibromuscular hyperplasia of arterioles

Block 1/Question#50
A 26-year-old man undergoes an abdominal exploratory ...
Splenic

Block 2/Question#1
A 17-year-old girl comes to the emergency department because ...
Speak with the patient and her parents about the findings

Block 2/Question#2
Following a wedding reception that was attended by 75 people, ...
Norovirus

Block 2/Question#3
An investigator compares the DNA sequences of a group of ...
5′ CCGG

Block 2/Question#4
A 56-year-old woman has frequently burned herself while ...
Syrinx of the central region of the spinal cord from C-4 to T-5

Block 2/Question#5
A 32-year-old woman has had fecal incontinence since giving ...
Damage to the anal sphincter

Block 2/Question#6
An 18-year-old boy has just been diagnosed with ...
50%

Block 2/Question#7
A 30-year-old man comes to the physician because of a 3-month ...
Increased osteoclast maturation and activity

Block 2/Question#8
Three elderly residents of an assisted living facility in ...
Legionella pneumophila

Block 2/Question#9
An otherwise healthy 16-year-old girl comes to the physician ...
Cold, dry air

Block 2/Question#10
A 70-year-old woman is transferred to a rehabilitative ...
Activity level before the fracture

Block 2/Question#11
A female newborn delivered at 36 weeks' gestation is in ...
Incomplete formation of pleuroperitoneal membrane

Block 2/Question#12
An 80-year-old man with type 2 diabetes mellitus is brought ...
Pelvic splanchnic

Block 2/Question#13
A 25-year-old woman comes to the physician because of a 2-day ...
A phospholipid (cardiolipin) on charcoal particles

Block 2/Question#14
A 23-year-old woman has had fever, hypotension, and ...
Streptococcus pneumoniae

Block 2/Question#15
A 55-year-old man comes to the physician because of ...
Dextromethorphan

Block 2/Question#16
A 10-year-old boy with mild mental retardation is brought to ...
Tuberous sclerosis

Block 2/Question#17
A 57-year old man has a hemoglobin concentration of 18.5 ...
Chronic obstructive pulmonary disease

Block 2/Question#18
A 65-year-old man is brought to the emergency department ...
ST-segment elevation

Block 2/Question#19
A 66-year-old man is brought to the emergency department 30 ...
Cigarette smoking

Block 2/Question#20
A 19-year-old man who is a college student is brought to the ...
Subcutaneous crepitus

Block 2/Question#21
A 25-year-old woman comes to the physician 2 days after ...
Granulomas containing stellate microabscesses

Block 2/Question#22
A 44-year-old woman comes to the physician for a follow-up ...
Ubiquitin ligase

Block 2/Question#23
Which of the following changes in the cardiovascular system ...
Increased basal systolic blood pressure

Block 2/Question#24
A patient with a 1-week history of diarrhea has reduced ...
Decreased arterial Pco2

Block 2/Question#25
A 14-year-old girl is brought to the physician because of a ...
Mitochondrial tRNALeu

Block 2/Question#26
A male newborn is found to have a decreased blood thyroxine ...
Thyroid hormone-binding globulin deficiency

Block 2/Question#27
A 38-year-old African American man with recently diagnosed ...
It should play a role because the efficacy of certain classes of medications varies among different ethnicities

Block 2/Question#28
At a postnatal checkup, a 6-week-old female newborn weighs 20 ...
Annular pancreas

Block 2/Question#29
A 25-year-old woman has a flu-like illness (fever, myalgias, ...
Picornavirus

Block 2/Question#30
A 78-year-old man is brought to the emergency department by ...
Cortisol

Block 2/Question#31
A 25-year-old man comes to the physician 8 hours after the ...
Rupture of an intervertebral disc

Block 2/Question#32
A 12-year-old girl is brought to the physician by her mother ...
Osteoblasts

Block 2/Question#33
A study is conducted to assess the effect of a new screening ...
Lead-time

Block 2/Question#34
A 28-year-old man has excessive thirst and polyuria. The ...
Hypothalamus

Block 2/Question#35
A 36-year-old woman comes to the office because of a 1-month ...
Splenomegaly

Block 2/Question#36
A 31-year-old man has a large, yellow, soft mass deeply ...
Liposarcoma

Block 2/Question#37
A 28-year-old woman of Eastern European Jewish decent comes ...
Recombinational double-stranded DNA break repair

Block 2/Question#38
A 50-year-old woman with a restrictive pulmonary disorder ...
Functional residual capacity: decreased; Residual volume: decreased; Vital capacity: decreased

Block 2/Question#39
A 29-year-old man comes to the physician because of a 1-week ...
Absence of peptidoglycan

Block 2/Question#40
A 70-year-old man has a 3-month history of weakness and a ...
Squamous cell carcinoma

Block 2/Question#41
Purified serum antibodies elicited by immunization with ...
Proteins X and Y express the same epitopes

Block 2/Question#42
A previously healthy 32-year-old woman is brought to the ...
Preload

Block 2/Question#43
An 18-year-old woman comes to the physician because she has ...
Ovaries

Block 2/Question#44
A 43-year-old woman, gravida 2, para 1, at 10 weeks' ...
Nuchal translucency (fetal ultrasound): increased;
Pregnancy-associated Plasma Protein (maternal serum): decreased;
Human Chorionic Gonadotropin (maternal serum): increased


Block 2/Question#45
A new antiplatelet agent is developed for the prevention of ...
8%

Block 2/Question#46
A physician prescribes a newly marketed drug to 45 patients. ...
Discontinue the new drug in affected patients and file MedWatch reports on the FDA's Web site

Block 2/Question#47
A 35-year-old man comes to the physician to discuss donating ...
1:4

Block 2/Question#48
A sedentary 50-year-old man with hypertension comes to the ...
Antidepressant therapy

Block 2/Question#49
An 82-year-old woman is brought to the physician because of a ...
Decreased slope of diastolic depolarization

Block 2/Question#50
A 27-year-old woman comes to the physician because of a ...
Pheochromocytoma

Block 3/Question#1
The frequency of an autosomal recessive disease in a ...
1/25

Block 3/Question#2
A 23-year-old woman is brought to the emergency department ...
Xanthine oxidase

Block 3/Question#3
A 45-year-old woman has a thyroidectomy because of asymmetric ...
Calcitonin

Block 3/Question#4
An 18-year-old woman comes to the physician because of fever, ...
Reactive T lymphocytes

Block 3/Question#5
A 35-year-old man comes to the physician because of a 2-month ...
Methotrexate

Block 3/Question#6
A new drug has the following effects on the activity of the ...
Pathway labeled 'H' (Conversion of Leukotriene A4 to Leukotriene B4

Block 3/Question#7
A 10-year-old boy has a palpable mass in the ventral midline ...
Endoderm of foramen caecum

Block 3/Question#8
A 12-year-old girl is brought to the physician for a ...
Polyubiquitination

Block 3/Question#9
A 62-year-old man comes to the physician because of pain in ...
Prostate

Block 3/Question#10
A 59-year-old man develops fatigue and decreased appetite 3 ...
Hemolysis

Block 3/Question#11
A 3-year-old boy is brought to the physician because of a ...
Heterozygous mutation in the ankyrin gene

Block 3/Question#12
A 46-year-old man has dyspnea, orthopnea, and a midsystolic ...
Mitral regurgitation

Block 3/Question#13
A 45-year-old woman develops proteinuria and hematuria. She ...
Tubulointerstitial nephritis

Block 3/Question#14
During a clinical study, an investigator tests a new drug for ...
Increase the sample size

Block 3/Question#15
A 23-year-old woman, who was diagnosed with Sjögren syndrome ...
Substance P

Block 3/Question#16
A 41-year-old woman with systemic lupus erythematosus is ...
Ask the attending physician to obtain informed consent

Block 3/Question#17
A 45-year-old man comes to the emergency department because ...
Schizoid personality disorder

Block 3/Question#18
An 18-year-old woman comes to the physician to request ...
50%

Block 3/Question#19
A 23-year-old man comes to the physician because of a 1-month ...
Area labeled ‘B’ (Mitochondrion)

Block 3/Question#20
A 67-year-old woman comes to the physician for a health ...
Low sensitivity

Block 3/Question#21
A newborn is born with a lethal chromosome defect. He is ...
Feed by whatever means necessary to maintain comfort

Block 3/Question#22
In patients with breast cancer, metabolically stable agonists ...
Gonadotropin by the pituitary gland

Block 3/Question#23
A 50-year-old woman is brought to the emergency department by ...
pKa: 6.0; Protein binding in plasma: 20%; Volume of distribution at steady state: 1 L/kg

Block 3/Question#24
A 2-month-old girl is brought to the emergency department by ...
Thyroid function tests

Block 3/Question#25
A 4-week-old infant is brought to the emergency department ...
Hypertrophic pyloric stenosis

Block 3/Question#26
A 3-month-old boy is brought to the physician because of ...
Mannose 6-phosphate

Block 3/Question#27
A 55-year-old man with type 2 diabetes mellitus, ...
Pravastatin

Block 3/Question#28
A 23-year-old woman who is 6 months pregnant develops deep ...
Antiplatelet antibodies

Block 3/Question#29
An 83-year-old man is brought to the emergency department ...
Early septic shock

Block 3/Question#30
A 22-year-old woman who recently emigrated from rural Mexico ...
Obstruction of the right interventricular foramen (foramen of Monro)

Block 3/Question#31
A 62-year-old woman comes to the physician because of ...
β-Tubulin

Block 3/Question#32
A 54-year-old woman with terminal metastatic pancreatic ...
Nonmaleficence

Block 3/Question#33
A 31-year-old woman receives a prescription for tetracycline ...
Formation of complexes with mineral ions

Block 3/Question#34
A 22-year-old woman comes to the emergency department because ...
Release of bacterial products

Block 3/Question#35
A 51-year-old man has the acute onset of fever and ...
Cytomegalovirus infection

Block 3/Question#36
A 4-year-old boy has had fever, abdominal cramping, and ...
Shigella sonnei

Block 3/Question#37
A 62-year-old man with alcohol-induced liver disease develops ...
Spironolactone

Block 3/Question#38
A 23-year-old man with a 3-year history of schizophrenia is ...
Psychogenic polydipsia

Block 3/Question#39
A 19-year-old woman has severe refractory pustular acne that ...
Teratogenic effects in the embryo

Block 3/Question#40
Two days after admission to the hospital because of ...
Do not proceed with the transfusion

Block 3/Question#41
A 2-year-old child undergoes resection of the right kidney ...
Increase in glomerular size

Block 3/Question#42
A 13-year-old girl has an episode of severe cellular ...
Epstein-Barr virus genome

Block 3/Question#43
A 71-year-old man comes to the physician because of a 6-month ...
Cilostazol

Block 3/Question#44
A 56-year-old man is brought to the emergency department 30 ...
Capillary hydrostatic: increased; Interstitial hydrostatic: increased; Interstitial oncotic: decreased

Block 3/Question#45
A 39-year-old man reports bright red spots on the toilet ...
Constipation

Block 3/Question#46
Removal of the thymus at birth results in severely impaired ...
Thymic lymphocytes produced before thymectomy are long-lived

Block 3/Question#47
A 60-year-old woman has prolonged apnea following general ...
Succinylcholine

Block 3/Question#48
A 48-year-old woman comes to the physician because of a ...
Hypothyroidism

Block 3/Question#49
A 92-year-old woman who was recently admitted to a nursing ...
Atrophy of dermal collagen

Block 3/Question#50
A 62-year-old man comes to the physician because of a 1-week ...
Agonist at γ-aminobutyric acid B (GABAB) receptors

Block 4/Question#1
A 32-year-old man comes to the physician because of a 3-month ...
Tissue: testicle; Effect: estradiol production

Block 4/Question#2
A study is conducted to identify healthy women at risk for ...
Liver

Block 4/Question#3
A 23-year-old woman comes to the physician for a follow-up ...
Collagen synthesis

Block 4/Question#4
A 20-year-old man comes to the physician stating that food ...
Olfactory

Block 4/Question#5
Immediately after a cerebral infarction, a 62-year-old ...
Area labeled ‘A’ (Broca’s area)

Block 4/Question#6
A 51-year-old man develops diaphoresis, tachycardia, and a ...
Alcohol withdrawal

Block 4/Question#7
A 33-year-old woman with HIV infection is brought to the ...
Non-Hodgkin lymphoma

Block 4/Question#8
A 58-year-old man is brought to the emergency department ...
Hypertension

Block 4/Question#9
A previously healthy 37-year-old woman comes to the physician ...
Tumor of the adrenal zona fasciculata

Block 4/Question#10
A 65-year-old woman who has a 25-year history of chronic ...
Hydroxylation of proline

Block 4/Question#11
A 37-year-old man who is HIV positive comes to the physician ...
Nortriptyline

Block 4/Question#12
An investigator is conducting a randomized, double-blind, ...
Analyze all nonadherent participants according to the group of the study to which each was randomized

Block 4/Question#13
A 62-year-old woman comes to the physician because of a ...
Bronchogenic carcinoma

Block 4/Question#14
A 60-year-old man has a round, semitransparent nodule on his ...
Basal cell carcinoma

Block 4/Question#15
A 45-year-old man is undergoing a surgical procedure. Which ...
Decreasing respiratory rate

Block 4/Question#16
An investigator wishes to determine the effectiveness of a ...
Ductal ion reabsorption is more efficient at low flow rates

Block 4/Question#17
A previously healthy 55-year-old man has recently been ...
Renal artery stenosis

Block 4/Question#18
A 35-year-old man comes to the physician because of a 6-month ...
Gastrin

Block 4/Question#19
A 55-year-old man with severe emphysema comes to the ...
Percussion: hyperresonant; Tactile fremitus: decreased; Expiratory phase: prolonged

Block 4/Question#20
A 5-year-old boy is brought to the physician for a follow-up ...
Hypophosphatemia

Block 4/Question#21
A 47-year-old woman comes to the physician because of a ...
Contact with parakeets

Block 4/Question#22
A 35-year-old man is given cyclosporine following a liver ...
Decreased synthesis of interleukins

Block 4/Question#23
A 45-year-old woman who is intubated and mechanically ...
β-Glucan carbohydrates in the cell wall

Block 4/Question#24
A 27-year-old man comes to the physician because of weakness ...
Deep branch of the ulnar nerve at the hook of the hamate bone

Block 4/Question#25
A 52-year-old man is brought to the emergency department ...
Increased total peripheral resistance and decreased cardiac output

Block 4/Question#26
A 33-year-old man comes to the physician because of a 3-week ...
Rectus femoris

Block 4/Question#27
An investigator is studying patients with West Nile virus ...
Case series

Block 4/Question#28
A 78-year-old man dies of chronic congestive heart failure. ...
Failure of the Na+–K+ pump

Block 4/Question#29
A 15-year-old girl is brought to the physician by her mother ...
Doxycycline

Block 4/Question#30
A 32-year-old woman is brought to the emergency department 20 ...
Arterial laceration

Block 4/Question#31
A 48-year-old man is brought to the emergency department 12 ...
Cl-: 96 mEq/L; HCO3-: 8 mEq/L

Block 4/Question#32
A 55-year-old man comes to the physician because of a 2-month ...
Partial oxidation of fatty acids

Block 4/Question#33
A 65-year-old woman with cardiovascular disease is found to ...
Increased bile salt

Block 4/Question#34
A 20-year-old man is brought to the physician by his mother ...
How frightening for you to see your son like this. Do you have any idea about what might be causing his behavior?""

Block 4/Question#35
A 62-year-old man comes to the physician for a follow-up ...
Contemplation

Block 4/Question#36
A 25-year-old woman is brought to the emergency department ...
Factitious disorder

Block 4/Question#37
A 16-year-old girl with cystic fibrosis is brought to the ...
Vitamin E

Block 4/Question#38
A 45-year-old man comes to the physician because of ...
Tumor necrosis factor

Block 4/Question#39
A 30-year-old woman develops serum sickness following ...
C3a

Block 4/Question#40
A 6-month-old girl is brought to the emergency department by ...
Ornithine transcarbamylase

Block 4/Question#41
A 56-year-old man with a 20-year history of chronic back pain ...
Naloxone

Block 4/Question#42
A 65-year-old woman dies 6 months after the onset of severe ...
Meningeal

Block 4/Question#43
A physician is assigned to a search and rescue team ...
Negative nitrogen balance

Block 4/Question#44
A 45-year-old man comes to the office for counseling prior to ...
Starchy foods

Block 4/Question#45
A 12-year-old boy is brought to the physician for further ...
Terminal components of complement

Block 4/Question#46
A 28-year-old woman at 32 weeks' gestation comes to the ...
Obstructive uropathy

Block 4/Question#47
A 61-year-old man has erectile dysfunction due to spinal cord ...
Area labeled ‘D’ (Corpus cavernosum)

Block 4/Question#48
A 24-year-old man comes to the emergency department because ...
Lipoprotein lipase

Block 4/Question#49
A 23-year-old woman sustains significant blood loss in a ...
Direct antiglobulin test

Block 4/Question#50
A previously healthy 16-year-old girl is brought to the ...
Prescribe antibiotics without notifying her parents

Recent comments ...

... hayayah made a comment on nbme20/block1/q#1 (A 37-year-old nurse is accidentally stuck with a...)
 +1  upvote downvote
submitted by hayayah(349)

NRTI's are associated with possible side effects of anemia, granulocytopenia, and myelosuppression.

sympathetikey  Especially zidovudine.
... fuckster made a comment on nbme20/block1/q#1 (A 37-year-old nurse is accidentally stuck with a...)
 -11  upvote downvote
submitted by fuckster(-44)

[special]

... hayayah made a comment on nbme20/block1/q#2 (A mother who has toxoplasmosis gives birth to an...)
 +5  upvote downvote
submitted by hayayah(349)

The baby does not get any maternal IgM, IgA or IgE as they do not cross the placenta, so if IgM is found it may suggest the baby has encountered an infection in utero.

IgG is passed down to the baby as a means of passive immunity until the baby can form their own antibodies of different types. So if you see anything other than IgG (e.g. IgM) you know it must be d/t an infection.

... xxabi made a comment on nbme20/block1/q#3 (A 48-year-old man comes to the physician for a...)
 +0  upvote downvote
submitted by xxabi(82)

Statins decrease cholesterol synthesis, which indirectly Statins indirectly cause increased LDL receptor expression on hepatocytes (increases LDL clearance from circulation).

... hayayah made a comment on nbme20/block1/q#4 (A 50-year-old man is brought to the emergency...)
 +5  upvote downvote
submitted by hayayah(349)

Methanol is toxic by two mechanisms:

First, methanol can be fatal due to its CNS depressant properties in the same manner as ethanol poisoning.

Second, in a process of toxication, it is metabolized to formic acid via formaldehyde in a process initiated by the enzyme alcohol dehydrogenase in the liver. Methanol is converted to formaldehyde via alcohol dehydrogenase (ADH) and formaldehyde is converted to formic acid (formate) via aldehyde dehydrogenase (ALDH).

Formate is toxic because it inhibits mitochondrial cytochrome c oxidase, causing hypoxia at the cellular level, and metabolic acidosis, among a variety of other metabolic disturbances.

sugaplum  Good pictograph comparing methanol, alcohol, and ethylene glycol. https://wikem.org/wiki/File:Toxic_alcohol_ingestion.JPG
... hayayah made a comment on nbme20/block1/q#5 (A 24-year-old African American man comes to the...)
 +1  upvote downvote
submitted by hayayah(349)

Foreign body inflammatory facial skin disorder characterized by firm, hyper-pigmented papules and pustules that are painful and pruritic. Located on cheeks, jawline, and neck.

Commonly occurs as a result of shaving (“razor bumps”), primarily affects African-American males.

Images: shorturl.at/fpwY1

... drdoom made a comment on nbme20/block1/q#6 (A 16-year-old student has uncontrollable sleepiness,...)
 +5  upvote downvote
submitted by drdoom(167)

This is an interesting one. I like to remember it this way: in people with narcolepsy, all the “right kinds” of sleep are happening at all the “wrong times” of day. During the day, when a power nap would typically throw you immediately into REM, this kid is only entering Stage 1 or 2 (lightest sleep = slightest noises jar him back to reality). At night, when he should peacefully drift into Stage 1, 2, and so on, he instead completely zonks out. Classic narcolepsy.

From UpToDate: “Narcolepsy can be conceptualized as a disorder of sleep-wake control in which elements of sleep intrude into wakefulness and elements of wakefulness intrude into sleep.”

... hayayah made a comment on nbme20/block1/q#6 (A 16-year-old student has uncontrollable sleepiness,...)
 +4  upvote downvote
submitted by hayayah(349)

In narcolepsy, there is a direct transition from wakefulness to REM sleep. Basically instead of going through the early stages and gradually falling into a deep sleep, you just suddenly go from being awake to being in a deep sleep.

... charcot_bouchard made a comment on nbme20/block1/q#6 (A 16-year-old student has uncontrollable sleepiness,...)
 +1  upvote downvote
submitted by charcot_bouchard(42)

Narcolepsy has one of the following 3 chraracter - 1. Cataplexy 2. dec orexin in csf 3. REM latency <15 min

its ass with (not dx criteria( Hypnagogin/pompic hallcination. Sleep paralysis

charcot_bouchard  oh dx criteria must also include excessive daytime slepeiness for 3 time per week over 3 month
... hayayah made a comment on nbme20/block1/q#7 (A 5-year-old girl with AIDS develops a progressive...)
 +5  upvote downvote
submitted by hayayah(349)

Acyclovir, famciclovir, valacyclovir are guanosine analogs. They undergo conversion to acyclovir monophosphate via virus encoded thymidine-kinase. Ultimately, they inhibit viral DNA polymerase by chain termination.

Mutated viral thymidine kinase can cause resistance.

... hayayah made a comment on nbme20/block1/q#8 (A 10-year-old girl is brought to the physician by...)
 +3  upvote downvote
submitted by hayayah(349)

Earliest detectable secondary sexual characteristic is breast bud development in girls, testicular enlargement in boys.

... strugglebus made a comment on nbme20/block1/q#9 (A 50-year-old man is brought to the physician by his...)
 +1  upvote downvote
submitted by strugglebus(63)

Fronto-temporal dementia characterized by personality change is usually Picks

fuckster  jku
... hayayah made a comment on nbme20/block1/q#9 (A 50-year-old man is brought to the physician by his...)
 +4  upvote downvote
submitted by hayayah(349)

Frontotemporal dementia (formerly known as Pick disease): Early changes in personality and behavior (behavioral variant), or aphasia (primary progressive aphasia). May have associated movement disorders (eg, parkinsonism).

While this presents very similiarly to Hungtington's, you can differentiate it because in this stem it says "atrophy of the frontal lobes bilaterally" whereas Huntington's has atrophy of caudate and putamen with ex vacuo ventriculomegaly.

... hayayah made a comment on nbme20/block1/q#10 (A 77-year-old woman has been having difficulty...)
 +0  upvote downvote
submitted by hayayah(349)

Little finger = ulnar nerve.

C8-T1 are the roots of the ulnar nerve, which is a branch of the medial cord. The ulnar nerve is not found in the carpal tunnel (the medial nerve is).

Ulnar n. damage can lead to loss of wrist flexion and adduction, flexion of medial fingers, abduction and adduction of fingers (interossei), actions of medial 2 lumbrical muscles. Loss of sensation over medial 1 1/2 fingers, including hypothenar eminence.

sugaplum  Also to add: since it is a bilateral sx it is more likely to be coming from the spinal cord then from equal compression of ulnar nerve (in guyons canal) on both sides. unless she is a cyclist
thefoggymist  shouldn't the other nerves of the same roots be affected?
thefoggymist  shouldn't the other nerves of the same roots be affected?
charcot_bouchard  Not really. In klumpeke paralysis ulnar nerve s/s dominates (Almost same cause)
... monoloco made a comment on nbme20/block1/q#11 (The sequence surrounding the first two exons of the...)
 +1  upvote downvote
submitted by monoloco(49)

This has to do with intron splicing. Remember GTAG. This mutation induced an AG closer where it was supposed to be, so some of that intron just became an exon.

... drdoom made a comment on nbme20/block1/q#11 (The sequence surrounding the first two exons of the...)
 +4  upvote downvote
submitted by drdoom(167)

As described in the question stem, this mutation occurs within an intron (a gene segment which is transcribed [DNA->RNA] but not translated). RNA splicing enzyme(s) grab RNA and “loop it”; an intron is cut out and the exons on either side of the intron are adjoined, like this:

exon1—intron—exon2 => exon1—exon2

Typically, this splicing occurs at the very edges of the intron (what I denoted with the “—” character). But in our case, a mutation within the intron is causing RNA splicing enzyme to recognize a new site: the splicer cuts within the intron (instead of at the very edge, as it should). So, we get something that looks like this:

exon1—intr—exon2

That’s a totally different mRNA molecule, and it's going to make our β-globin protein look (and behave) awfully strange.

... onyx made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +2  upvote downvote
submitted by onyx(11)

The mass described is in the posterior mediastinum (see images below). The thoracic duct is damaged “near the mass”, hence drainage of organs distal to that point will be affected. The images below should clarify.

... onyx made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +0  upvote downvote
submitted by onyx(11)

Mediastinal relations.

... onyx made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +3  upvote downvote
submitted by onyx(11)

Thoracic duct relations.

consuela_salon  This was the picture that I liked the most for this question. If you imagine that the injury is at the level of the left subclavian vein (LSV) and thoracic duct (TD) crossing each other, maybe it will help you realize that the left breast & left upper extremity bypass the injury. The right lung is drained by the right lymphatic duct, not the TD (see one of the links bellow). And the heart is where eventually all the drainage is going to end up to be pumped again (TD -> LSV -> SVC -> heart).
... onyx made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +0  upvote downvote
submitted by onyx(11)

Thoracic duct relations.

... hayayah made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +3  upvote downvote
submitted by hayayah(349)

The left upper extremity and breast are drained by the axillary lymph node. The kidney is drained by the thoracic duct. The heart has its own lymph system going on surrounding the heart.

... thomas made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
jointaccount  Left breast & L UE drained by axillary. With the remaining choices, R kidney is the only choice outside the territory of the right lymphatic duct
... consuela_salon made a comment on nbme20/block1/q#12 (72 yo woman with dysphagia)
 +0  upvote downvote
submitted by consuela_salon(0)

This was the picture that I liked the most for this question. If you imagine that the injury is at the level of the left subclavian vein (LSV) and thoracic duct (TD) crossing each other, maybe it will help you realize that the left breast & left upper extremity bypass the injury. The right lung is drained by the right lymphatic duct, not the TD (see one of the links bellow). And the heart is where eventually all the drainage is going to end up to be pumped again (TD -> LSV -> SVC -> heart).

consuela_salon  (I meant the picture posted by onyx)
... hayayah made a comment on nbme20/block1/q#13 (A 6-week-old girl is brought to the physician by her...)
 +1  upvote downvote
submitted by hayayah(349)

No abnormalities, only some vomiting, looks well w/ no failure to thrive. Most likely immature LES.

masonkingcobra  http://www.sedico.net/English/SedicoInformationCenter/Physicians/gerd_e.htm
... suku008 made a comment on nbme20/block1/q#13 (A 6-week-old girl is brought to the physician by her...)
 +1  upvote downvote
submitted by suku008(1)

It’s a common disease that impacts babies and children. GERD stands for gastro esophageal reflux disease. Dr. Viraine Weerasooriya, a pediatric gastroenterologist on the medical staff of Golisano Children’s Hospital of Southwest Florida, says infants are prone to having reflux until their gut matures at about 12 to 18 months. But GERD is more than just reflux. “What this implies is individuals who have problems with gastro contents that move up to the esophagus or into the mouth.

suku008  https://www.youtube.com/watch?v=DFcySw14rIo
... hayayah made a comment on nbme20/block1/q#14 (A 28-year-old man who is a migrant worker comes to...)
 -1  upvote downvote
submitted by hayayah(349)

Of all the options, psoas major is the only one that is really associated with the lumbar vertebrae.

Q. Lumborum involves the transverse process of L1 but Psoas Major originates from L1-L5

imnotarobotbut  QL is connected to L1-L5 vertebrae as well (https://en.wikipedia.org/wiki/Quadratus_lumborum_muscle)
... studentdo made a comment on nbme20/block1/q#14 (A 28-year-old man who is a migrant worker comes to...)
 +1  upvote downvote
submitted by studentdo(2)

The major motion of Psoas major is flexion of hip. This patient is held in "rigid extension", hence he does not want to flex. Psoas is the only muscle on this list that connects the lumbars to lower extremity "holds his right lower extremity"

... aj32803 made a comment on nbme20/block1/q#14 (A 28-year-old man who is a migrant worker comes to...)
 +2  upvote downvote
submitted by aj32803(2)

Uworld specifically says that Psoas abscess means the patient will prefer flexion to avoid stretching the muscle. That's why Psoas did not make sense to me since the patient preferred extension, which would be stretching out the muscle.

On the other hand it's right on the vertebra and it's associated with TB.

... hayayah made a comment on nbme20/block1/q#15 (A 30-year-old man who completed a successful course...)
 +4  upvote downvote
submitted by hayayah(349)

Definition of adjustment disorder:

Emotional symptoms (eg, anxiety, depression) that occur within 3 months of an identifiable psychosocial stressor (eg, divorce, illness) lasting < 6 months once the stressor has ended.

If symptoms persist > 6 months after stressor ends, it is GAD.

hello  Yep, and I think what we are supposed to take from this Q is: The only info. we have for this patient is that he ended chemo 2 months ago and has been calling the doctor a lot -- this is supposed to mean he has been calling a lot since ending chemo 2 months ago. His frequent calls starting after ending chemo and within 3 months of the stressor fits with the above-stated definition of "adjustment disorder" with anxiety. I stressor in this case could possibly be either the actual illness or the ending of chemo/treatment. It probably does not matter much in this case.
charcot_bouchard  I think doing uw done me wrong here. Adjustment disorder isnt diagnosed when symptom match another disorder --- it was like never a right answer. But ofc its right answer in nbme
maxillarythirdmolar  Just to add to that, the tingling in his fingers may seem like a distraction/it probably is. Likely has some relation to his Chemo.
... johnthurtjr made a comment on nbme20/block1/q#15 (A 30-year-old man who completed a successful course...)
 +1  upvote downvote
submitted by johnthurtjr(43)

While I can get on board with Adjustment Disorder, I don't see how this answer is any better than Somatic Symptom Disorder. From FA:

Variety of bodily complaints lasting months to years associated with excessive, persistent thoughts and anxiety about symptoms. May co-appear with illness.

SSD belongs in a group of disorders characterized by physical symptoms causing significant distress and impairment.

savdaddy  I think part of it stems from the fact that this patients symptoms are occurring within the time-frame for adjustment disorder while SSD seems to have a longer timeline. Aside from that I find it difficult to see why SSD wasn't a possible answer.
chillqd  To add to that, I inferred that the obsession with checking temp and with the tingling sensation were signs provided to him by the physicians of recurrence. He is anxious over his cancer recurring, and they are more specific than a variety of body complaints
hello  In somatic symptom disorder, the motivation is unconscious. I think for the patient in this Q-stem, his motivation is conscious -- he wants to make sure that recurrence of cancer is not going "undetected".
cienfuegos  I also had issues differentiating these two and ultimately went with SSD, but upon further review it seems that a key differentiating feature was the timeline. His somatic symptoms would have had to have been present for at least 6 months per the DSM criteria https://www.ncbi.nlm.nih.gov/books/NBK519704/table/ch3.t31/
... strugglebus made a comment on nbme20/block1/q#16 (A 30-year-old woman with multiple sclerosis comes to...)
 +2  upvote downvote
submitted by strugglebus(63)

The pons has nerves 5-8, so the trigeminal would be affected here

masonkingcobra  Thalamic pain syndrome would involve dysesthesias on the entire contralateral body so more than just the face. Also it occurs often after post-stroke. Additoinally, these dysesthesias appear weeks/months later
... whossayin made a comment on nbme20/block1/q#16 (A 30-year-old woman with multiple sclerosis comes to...)
 +1  upvote downvote
submitted by whossayin(3)

The mnemonic I like for remembering the locations of the cranial nerves is the "2,2,4,4 rule"

Above brainstem= CN I + II Midbrain= CN III, IV Pons= CN V, VI, VII, VIII Medulla= CN IX, X, XI, XII

... sympathetikey made a comment on nbme20/block1/q#16 (A 30-year-old woman with multiple sclerosis comes to...)
 +2  upvote downvote
submitted by sympathetikey(260)

Principle Sensory Nucleus of the Trigeminal is located in the Pons, as is the Motor Trigeminal Nucleus of the pons. This presentation is probably dealing more with the Principle Sensory Nucleus.

... feliperamirez made a comment on nbme20/block1/q#16 (A 30-year-old woman with multiple sclerosis comes to...)
 +0  upvote downvote
submitted by feliperamirez(0)

I do understand that the principal nucleus of the trigeminal nerve is located at the pons. But since this patient is having trigeminal neuralgia wouldn't you be disrupting the pathway involved in pain and temperature, which in this case would be the spinal nucleus (located in the medulla)?

Besides, I found this at an article

A recent hypothesis attributes the pain of trigeminal neuralgia to a central mechanism involving the pars oralis of the spinal trigeminal nucleus.[5]

https://www.ncbi.nlm.nih.gov/books/NBK539729/

... woodenspooninmymouth made a comment on nbme20/block1/q#16 (A 30-year-old woman with multiple sclerosis comes to...)
 +0  upvote downvote
submitted by woodenspooninmymouth(0)

MS is a demyelinating disease. That's why I didn't pick cortex or thalamus; they are grey matter. I picked medulla because I the spinotrigeminal nerves traverse the medulla. I guess we are just supposed to assume the demyelination is happening in the pons? I don't know.

woodenspooninmymouth  Sorry, I meant to say that the pons would have the cell bodies for the pain/temp neurons, no?
... strugglebus made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +11  upvote downvote
submitted by strugglebus(63)

Nowhere have I been able to find why the hell this is a thing.

yotsubato  Its not in FA, Sketchy, or Pathoma, or U world. I knew it wasnt cancer because its bilateral. And Diabetes made no sense to me. So I just threw down Drug effect and walked away.
breis  same^^^
feliperamirez  The only possible explanation I think is that she was under a K sparing diuretic, such as spironolactone (which would lead to gynecomastia).
... strugglebus made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +5  upvote downvote
submitted by strugglebus(63)

As an edit: 108,001 people reported to have side effects when taking Hydrochlorothiazide. Among them, 25 people (0.02%) have Breast discharge

neonem  I think the best way to answer this question was by process of elimination.
sympathetikey  That's some bullshit lol
karljeon  Haha I eliminated the answer by process of elimination.
medschul  I eliminated thiazides by process of elimination :(
medstudent65  Shit I eliminated thiazides because of elimination went with HTN thinking intercranial bleed effecting the pituitary
... niboonsh made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +1  upvote downvote
submitted by niboonsh(57)

" Other classes of medications that cause hyperprolactinemia include antidepressants, antihypertensive agents, and drugs that increase bowel motility. Hyperprolactinemia caused by medications is commonly symptomatic, causing galactorrhea, menstrual disturbance, and impotence. It is Important to ensure that hyperprolactinemia in an Individual patient is due to medication and not to a structural lesion in the hypothalamic/pituitary area; this can be accomplished by (1) stopping the medication temporarily to determine whether prolactin levels return to normal, (2) switching to a medication that does not cause hyperprolactinemia "

https://www.ncbi.nlm.nih.gov/pubmed/16092584

"Non-dose-dependent side effects — Although low-dose therapy seems to minimize the metabolic complications induced by a thiazide or thiazide-like diuretic, it may not necessarily eliminate other side effects. As an example, as many as 25 percent of men treated with 25 mg/day of chlorthalidone develop a decline in sexual function [34]. Sleep disturbances can also occur, particularly if the patient is on a low-sodium diet [34]. How these problems occur is not known."

https://www.uptodate.com/contents/use-of-thiazide-diuretics-in-patients-with-primary-essential-hypertension#H2250530998

... namira made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by namira(9)

Possible explanation:

If the pt is taking a thiazide (which is K depleting), it might have also been given with a K sparing drug such as spirinolactone.

Spirinolactone has endocrinologic effects such as gynecomastia and galactorrhea.

sugaplum  I think you could only make this assumption if they said "patient is on standard htn tx" but since they gave the name hctz, would not be fair to assume they are also taking spirinolactone. I went with process of elimination on this one. Even checked access medicine's drug adverse effect profile...galactorrhea not listed for hctz
... hello made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +6  upvote downvote
submitted by hello(52)

Goljan had a lecture that mentioned that "If a patient has galactorrhea, review every drug they're taking since many drugs cause galactorrhea."

The only thing of possible relevance in this Q-stem is that she takes a medication, therefore the answer of "drug effect" is the most likely reason for her galactorrhea.

... sam1 made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by sam1(0)

Thiazides can cause acute interstitial nephritis, a form of renal failure. Without the renal excretion of prolactin, it can build up in the serum and result in galactorrhea.

coccidioinmytitties  Sexual dysfunction [desire based = libido] can be due to drug side effects [antihypertensives], per first aid. Edition: 2018 Page: 551 Section: Psych Per, 1stAid's endocrine section: "excessive amounts of prolactin associated with ↓libido [324]. This goes together with our sexual dysfunction with "antihypertensives." Only logical synthesis I can think of: thiazide = ↑prolactin = ↓libido + galactorrhea. It would also make sense since we are dealing with an expected to be post-menopausal female [milk production would have to be due to exogenous source]. Dug into my lecture notes and found the following: beta-blockers and thiazides cause sexual dysfunction. I also like sam1's explanation. We're reaching here, but its the best I can do.
g8427  Mayo clinic shows clear or bloody nipple discharge as side affect of Thiazides. But doesnt state milky discharge.
... minhphuongpnt07 made a comment on nbme20/block1/q#17 (A 50-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by minhphuongpnt07(0)

Thiazide=> hypercalcemia=> Oxytoxin (Gq coupled protein-> incr Ca2+)=> nipple discharge

... hayayah made a comment on nbme20/block1/q#18 (A 36-year-old man comes to the physician because he...)
 +7  upvote downvote
submitted by hayayah(349)

The tubes are catheters put in for urine to flow into a bag. So urine output is going to increase. The patient is also hyperkalemic. Aldosterone responds to hyperkalemia by increasing K+ excretion.

Hyperkalemia will stimulate aldosterone secretion even if renin is suppressed due to his hypertension. Although Na+ will be reabsorbed, this will be transient (should resolve once the potassium levels normalized) and since his urine output will most likely return to normal, his blood pressure should also normalize.

charcot_bouchard  Postobstructive diuresis Postobstructive diuresis is a polyuric state in which copious amounts of salt and water are eliminated after the relief of a urinary tract obstruction. The incidence of POD is unclear but estimates suggest 0.5% to 52% of patients will experience POD after relief of obstruction.10 It generally occurs after relieving BOO, bilateral ureteric obstruction, or unilateral ureteric obstruction in a solitary kidney.11 Diuresis is a normal physiologic response to help eliminate excess volume and solutes accumulated during the prolonged obstruction. In most patients, the diuresis will resolve once the kidneys normalize the volume and solute status and homeostasis is achieved. Some patients will continue to eliminate salt and water even after homeostasis has been reached, referred to as pathologic POD. These patients are at risk of severe dehydration, electrolyte imbalances, hypovolemic shock, and even death if fluid and electrolyte replacement is not initiated.9
... hayayah made a comment on nbme20/block1/q#19 (A 60-year-old man comes to the physician because of...)
 +6  upvote downvote
submitted by hayayah(349)

This patient has small cell carcinoma. This type of cancer is associated with paraneoplastic syndromes such as: Cushing Syndrome, SIADH, or antibodies against Ca2+ channels (Lambert-Eaton) or neurons. Amplification of myc oncogenes is also common.

SIADH (Syndrome of inappropriate antidiuretic hormone secretion) is characterized by:

  • Excessive free water retention
  • Euvolemic hyponatremia with continued urinary Na+ excretion
  • Urine osmolality > serum osmolality

Body responds to water retention with aldosterone and ANP and BNP. That is what causes the increased urinary Na+ secretion Žwhich leads to normalization of extracellular fluid volume Žand the euvolemic hyponatremia.

hello  Why would body respond to water retention with ALDO? ALDO would increase water retention...
nala_ula  @hello, the body's response is to decrease Aldosterone since there is increased volume retention and subsequently increased blood pressure. This concept confused me a lot, but I ended up just viewing it as separate responses. First, the increased volume retention leads to increase ANP and BNP secretion that lead to decreased Na+ reabsorption in the tubules (page 294 in FA 2019) and second, this increased volume basically leads to increased pressure so lets also decrease aldosterone so there is no Na+ retention (since water comes with it)... I thought it was counterintuitive to secrete so much Na+ since you're already having decreased serum osmolality (decreased Na+ concentration) because of the water retention, but I'm guessing that this is just another way our body's well intentions end up making us worse XD
compasses  see page 344 FA2019 for SIADH.
... hayayah made a comment on nbme20/block1/q#20 (An 8-year-old boy is evaluated for ventricular...)
 +1  upvote downvote
submitted by hayayah(349)

Coarctation of the aorta leads to increased LV overload causing LV hypertrophy and a L axis deviation.

... hayayah made a comment on nbme20/block1/q#21 (A 75-year-old woman comes to the physician because...)
 +2  upvote downvote
submitted by hayayah(349)

This is an example of Shingles. Herpes simplex and herpes zoster viruses cause abnormal cell division in epidermal cells, and this creates multinucleated giant cells.

A Tzank smear showing multinucleated giant cells is characteristic of Varicella Zoster Virus infections. (HSV will have similar findings).

ergogenic22  other identifying terms for herpes: Single dermatome (does not cross the midline), painful (burning and itching),and lesions in multiple stages.
redvelvet  and why neutrophile infiltration, is it a thing? or just a distracting thing?
charcot_bouchard  Neutrophil comes into party always first. but it was distracting for me too.
... hmorela made a comment on nbme20/block1/q#22 (A 38-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by hmorela(3)

Why is it that the answer isn't also glossopharyngeal since you test CN IX by saying "Ah" also? Please help! Thanks!!

sinforslide  I believe that the arrow pointed to the uvula; uvular deviation would be testing for CN X palsy. CN IX's only motor innervation is the stylopharyngeus. (Not testing for gag reflex!)
... hayayah made a comment on nbme20/block1/q#23 (A 34-year-old man who is HIV positive is brought to...)
 -2  upvote downvote
submitted by hayayah(349)

Mycobacterium avium complex infections are a common opportunistic infection in patients with advanced AIDS (CD4 count <50).

realfakedreams  @hayayah you were being lazy.. smh.. Homie started anti-retroviral therapy. HIV infects CD4 T-Cells through either CCR5 or more commonly CXCR4. Because of anti-retrovirals start working, HIV isnt able to infect anymore CD4 T cells. Thus CD4 t lymphocytes levels start to rise and are able to active B cells.
... sympathetikey made a comment on nbme20/block1/q#23 (A 34-year-old man who is HIV positive is brought to...)
 +1  upvote downvote
submitted by sympathetikey(260)

CD4+ cells activate B-cells which form follicles and cause enlargement of lymph nodes. Therefore, in an AIDS patient, to enlarge the lymph nodes, the CD4+ dysfunction must be resolved.

breis  Yea i get that, but if the patients CD4 was ~35, how in the world did the CD4 count rise enough to stimulate B cell proliferation...? I don't get it
namira  The only thing i can think of is that: the cd4 count that is given was taken prior to having started the antiretroviral therapy. Since the question asks about "improved function", maybe its referring to the therapy actually being effective and its managed to increase cd4 count and function so as to be able to contribute to lymph node enlargement due to myco. avium
... strugglebus made a comment on nbme20/block1/q#24 (A 50-year-old man comes to the physician because of...)
 -4  upvote downvote
submitted by strugglebus(63)

This a CYP 450 inhibitor (SICKFACES.COM); its the O.

coccidioinmytitties  Azoles, as a class, are CYP450 inhibitors [fungal > human; to prevent conversion of lanosterol to ergosterol]. Justget is correct- a ↓pH is needed for absorption and PPI/H2RA/antacids are contraindicated.
... hayayah made a comment on nbme20/block1/q#24 (A 50-year-old man comes to the physician because of...)
 -3  upvote downvote
submitted by hayayah(349)

Add on to the other comment: SICKFACES.COM (when I Am drinking Grapefruit juice) is the mnemonic for remembering the CYP450 Inhibitors:

  • S odium valproate
  • I soniazid
  • C imetidine
  • K etoconazole
  • F luconazole
  • A cute alcohol abuse
  • C hloramphenicol
  • E rythromycin/clarithromycin
  • S ulfonamides
  • C iprofloxacin
  • O meprazole
  • M etronidazole

  • A miodarone

  • Grapefruit juice
charcot_bouchard  Its not a cytochrome question. IK because i go t it wrong
... justgettinby made a comment on nbme20/block1/q#24 (A 50-year-old man comes to the physician because of...)
 +9  upvote downvote
submitted by justgettinby(9)

Itraconazole requires the acidic environment of the stomach to be absorbed. Omeprazole inhibits the H+/K+ pump of the stomach, thereby decreasing the acidity of the stomach. So when the patient takes Omeprazole and Itraconazole together, Itraconazole won't be absorbed into the body. That's why it has no effect.

It's recommended to take medications at least 2 hours prior to taking an antacid.

necrotizingfasciitis  Just adding support to the above explanation: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671798/
pakimd  do all azoles or just itraconazole only requires an acidic environment to be absorbed?
... hayayah made a comment on nbme20/block1/q#25 (A 25-year-old primigravid woman at 42 weeks’...)
 +4  upvote downvote
submitted by hayayah(349)

Oxytocin uses IP3 signaling pathway.

GnRH, Oxytocin, ADH (V1-receptor), TRH, Histamine (H1-receptor), Angiotensin II, Gastrin.

FA mnemonic: "GOAT HAG"

... strugglebus made a comment on nbme20/block1/q#26 (Serum cholesterol concentrations are measured as...)
 +2  upvote downvote
submitted by strugglebus(63)

So you know that 65% of the data will fall within 1SD of the mean. So if you subtract 100-65 you will get 35. Which means that about 16% will fall above and 16% will fall below 1 SD. They are asking for how many will fall above 1 SD. I'm sure there is a better way of doing this, but thats how I got it lol.

sympathetikey  Except according to FA, it's 68% within 1 SD, so 34%, which split in half is 17%.
... monoloco made a comment on nbme20/block1/q#27 (A 53-year-old woman comes to the physician because...)
 +2  upvote downvote
submitted by monoloco(49)

When you have a traveler who has intermittent abdominal symptoms and diarrhea, and who has traveled to the likes of northern Africa and such, Schistosomiasis needs to be on your radar. At least, that’s how I’ve incorporated this nugget into my mental space.

... strugglebus made a comment on nbme20/block1/q#27 (A 53-year-old woman comes to the physician because...)
 +2  upvote downvote
submitted by strugglebus(63)

It also looked exactly like schistosome on the slide--it had the little spine. Entamoeba would have had a bunch of RBCs inside.

... hayayah made a comment on nbme20/block1/q#28 (A previously healthy 16-year-old girl comes to the...)
 +1  upvote downvote
submitted by hayayah(349)

Trichomonas:

Clinical findings: thin, yellow-green, malodorous, frothy discharge and vaginal inflammation / itching.

Lab findings: pH >4.5 and motile trichomonads.

... strugglebus made a comment on nbme20/block1/q#29 (During an experiment, an investigator isolates an...)
 +2  upvote downvote
submitted by strugglebus(63)

Lysine is used in elastin and collagen cross linking; it is cross linked by lysyl oxidase to make collagen fibers

charcot_bouchard  Thats my brother from UFAP mother
... notadoctor made a comment on nbme20/block1/q#29 (During an experiment, an investigator isolates an...)
 +3  upvote downvote
submitted by notadoctor(47)

Analysis of the elastin in the question showed a decreased number of desmosine cross-links. Desmosine is made up of four lysine residues. Therefore abnormal elastin is likely missing lysine necessary for the formation of these desmosine cross-links. Wikipedia article on Desmosine.

dbg  how can i trust you, you aint even a doctor
... hayayah made a comment on nbme20/block1/q#30 (A 33-year-old woman comes to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

Capitate and lunate are in the center of the palm. Capitate is not an option, so lunate is the answer.

Dislocation of lunate may cause acute carpal tunnel syndrome.

yotsubato  Lunate is the only carpal bone that is frequently dislocated. Scaphoid is frequently fractured. Hook of hamate is also frequently fractured.
redvelvet  and also point tenderness in the anatomical snuffbox may indicate a scaphoid fracture.
... onyx made a comment on nbme20/block1/q#31 (66 yo man, cavitary lesion in right lower lobe of lung)
 +6  upvote downvote
submitted by onyx(11)

A radiographically visible air-fluid level suggests a pretty large lesion (hence, “cavitary”). That's not going to become normal tissue again. Six months following resolution of symptoms you can expect healing in the form of a scar; that is, fibrosis but only in a single spot.

masonkingcobra  Robbin's: The basic mechanisms of fibrosis are the same as those of scar formation during tissue repair. However, tissue repair typically occurs after a short-lived injurious stimulus and follows an orderly sequence of steps, whereas fibrosis is induced by persistent injurious stimuli such as infections, immunologic reactions, and other types of tissue injury. The fibrosis seen in chronic diseases such as pulmonary fibrosis is often responsible for organ dysfunction and even organ failure.
... monoloco made a comment on nbme20/block1/q#32 (A 56-year-old woman is brought to the emergency...)
 +4  upvote downvote
submitted by monoloco(49)

This is the only choice that comes close to nicking the thoracic duct, specifically at its inlet, the left subclavian.

... strugglebus made a comment on nbme20/block1/q#33 (A 17-year-old girl comes to the emergency department...)
 +3  upvote downvote
submitted by strugglebus(63)

OK, so if I remember correctly this is the one that shows the inheritance pattern. mitochondrial is also passed by the mother; however, it can have variable expressivity and incomplete penetrance, which is why some members were not affected.

hyoscyamine  Also, question said there was a deficiency in NADH dehydrogenase activity which is another fancy way of saying complex I in the mitochondria.
yotsubato  That unaffected male really threw me off... : (
charcot_bouchard  It was pure MELAS description. the unaffected male threw me off
... hayayah made a comment on nbme20/block1/q#34 (A strain of Escherichia coli produces a...)
 +7  upvote downvote
submitted by hayayah(349)

Missense mutations involve a nucleotide substitution resulting in changed amino acids. Sometimes the effects of missense mutations may be only apparent under certain environmental conditions; such missense mutations are called conditional mutations. Many missense mutations result in proteins that are still functional, at least to some degree.

Also, all the other answers would probably leave you with either a greatly altered or non-functional protein.

thefoggymist  I chose nonsense because I thought it'll make the enzyme shorter (since less bonds = more heat liable = can't work at 42 degrees) but yea, probably won't work even at 30 if it's an early nonsense.
... strugglebus made a comment on nbme20/block1/q#35 (A 70-year-old man dies of coronary artery disease....)
 +2  upvote downvote
submitted by strugglebus(63)

It affected the corticospinal tract in the crus cerebri on the L

... hayayah made a comment on nbme20/block1/q#35 (A 70-year-old man dies of coronary artery disease....)
 -7  upvote downvote
submitted by hayayah(349)

The damage is in the L midbrain in the area affecting the corticospinal tract. Because it is in the midbrain, decussation in the pyramids (medulla) so it will show ipsilateral dysfunctional motor signs.

Photo of midbrain and important areas: shorturl.at/myHLR

masonkingcobra  Just for clarification, on the left side, you see where he had the infarction 7 years ago and the tissue is gone.
chefcurry  so is the dysfunction on the contralateral side?
praderwilli  If the decussation is in the pyramids of the medulla, shouldn't it be contralateral hemiparesis if the damage is on the right? It confuses me because of the labeling right and left at the top of the pictures.
endochondral1  that link isnt working @ hayayah....is there any good picture to look at to know where the tracts are on this section?
... sympathetikey made a comment on nbme20/block1/q#35 (A 70-year-old man dies of coronary artery disease....)
 +4  upvote downvote
submitted by sympathetikey(260)

As stated below, the Left crus cerebri was damaged (see what it should normally look like below). This contains the corticospinal tract. Since the corticospinal tract decusates at the medulla, below the midbrain section we're looking at, you would see Contralateral (Right) Spastic Hemiparesis

sympathetikey  http://what-when-how.com/wp-content/uploads/2012/04/tmp15F11_thumb.jpg
hello  What identifies that a cross-section is medulla vs midbrain vs pons?
kernicterusthefrog  @hello I like to pay attention to the Cerebral Aqueduct (diamond/spade shape seen mostly in Midbrain, and transitioning to 4th ventricle in rostral Pons), and then the shape and size of the 4th ventricle as you move down Pons to rostral&middle Medulla, and eventual closing and absence of fluid space at caudal Medulla.
hello  @kernicterusthefrog Thank you.
... hayayah made a comment on nbme20/block1/q#36 (A 56-year-old man is admitted to the hospital after...)
 +1  upvote downvote
submitted by hayayah(349)

Rhabdomyolysis can present looking like a kidney injury (it can lead to acute tubular necrosis as well). The electrolyte findings are just like renal failure (Inc. K+, inc. PO4-, dec. Ca)

To differentiate between rhabdomyolysis and kidney injury, you check the urine to see if there are any RBCs. In rhabdomyolysis there are no free RBCs in the urine.

ergogenic22  "Crush injury" is a buzz word for rhabdo
... hayayah made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +2  upvote downvote
submitted by hayayah(349)

With chronic vomiting, you lose electrolytes and a lot of acid. It triggers metabolic alkalosis which is why all the serum values are low (or on the lower end of the normal range) except for bicarbonate.

ergogenic22  decreased K+ (from increased RAAS due to volume loss) and decreased Cl- (loss of HCl from the stomach), Alkalosis from loss of HCl and thus high bicarb. For this reason high to mid range K is wrong
sbryant6  Wouldn't increased RAAS lead to increased Na+? The answer shows decreased Na+.
sbryant6  Also, remember Bulimia Nervosa is associated with hypokalemia.
sugaplum  so the range they gave for K is 3-6? so 3.2 is WNL then? or are we just operating on "it is on the lower end of normal in peds"
dbg  sodium levels in pyloric stenosis vary, nothing really classic, can be high as in this case simply due to hydration, can low in other cases if aldosterone managed to reverse that to the other extreme
... masonkingcobra made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +2  upvote downvote
submitted by masonkingcobra(56)

In metabolic alkalosis, potassium moves into the cells

The loss in volume through emesis triggers RAAS resulting in increased Aldosterone release and further potassium excretion

http://www.labpedia.net/test/116

... ark110 made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +0  upvote downvote
submitted by ark110(0)

But what is the difference between option A and option C (132; 4.9; 90; 35)

sympathetikey  K+ shouldn't increase. It's moving into cells due to metabolic alkalosis.
home_run_ball  In the parietal cell of the stomach Hydrogen ions are formed from the dissociation of carbonic acid. Water is a very minor source of hydrogen ions in comparison to carbonic acid. Carbonic acid is formed from carbon dioxide and water by carbonic anhydrase. The bicarbonate ion (HCO3−) is exchanged for a chloride ion (Cl−) on the basal side of the cell and the bicarbonate diffuses into the venous blood, leading to an alkaline tide phenomenon.
ergogenic22  RAAS increases from volume loss, and thus more aldosterone leads to low K+
sinforslide  Three reasons for hypokalemia. First, some K+ is lost in gastric fluids. Second, H+ shifts out of cells and K+ shifts into cells in metabolic alkalosis. Third, ECF volume contraction has caused increased secretion of aldosterone.
... apop made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +0  upvote downvote
submitted by apop(0)

These explanations arent great. It doesnt really have much to do with RAAS activation. It has almost everything to do with a phenomenon called the alkaline tide. In chronic vomitting, you would expect Cl- to be low and K= to be low (similar to lab results in someone with bullemia). To compensate for the low Cl-, the stomach has an antiporter which exchanges Cl- for HCO3-. Therefore, Cl- will be replenished in the stomach, while HCO3- will increase in the blood, causing an alkalosis. In alkalotic states, the H+/K+ antiporter will begin to activate, shifting K+ INTO cells (hypokalemia) and increasing pH. RAAS probably plays a role in making the hypokalemia worse but the alkaline tide is more important here.

... iamapotato made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +0  upvote downvote
submitted by iamapotato(0)

No one here bothered to actually discuss what's going on. This is a 1-month old newborn.

He vomits after feedings, 5-day history.

At 1 month old, with vomiting after feedings, it is most likely a case of PYLORIC STENOSIS due to hypertrophy of the pyloric sphincter (usually occurs 6 weeks later).

Due to him vomiting stomach contents, he will LOSE Cl-, K+, and Na+.

He will ALSO lose H+. This is why you go into the metabolic alkalosis with a resultant increase in the HCO3-.

... thefoggymist made a comment on nbme20/block1/q#37 (A 1-month-old male newborn is brought to the...)
 +0  upvote downvote
submitted by thefoggymist(1)

I don't get this. Shouldn't the kidneys start correcting the bicarb levels afer 5 days? The delayed phase of the correction since they take time... and in the question they're asking "now". We have metabolic alkalosis since HCL is lost, so the body will try to correct it first by hyperventilation and later by increased excretion of bicarb. Bicarb should be low... (unless I'm missing something due to being exhausted)

thefoggymist  Nevermind, I think I got it. Beta intercalated cells cannot function and excrete bicarb because we don't have chloride. Yea apparently I was exhausted.
... hayayah made a comment on nbme20/block1/q#38 (A 9-year-old girl is brought to the physician...)
 +5  upvote downvote
submitted by hayayah(349)

Patient has a craniopharyngioma. Most common childhood supratentorial tumor. Derived from remnants of Rathke pouch (oral ectoderm). Calcification is common. Cholesterol crystals found in “motor oil”-like fluid within tumor.

A cystic suprasellar mass with calcifications and enhancement of the wall or solid portions in a child or adolescent is almost always a craniopharyngioma.

May be confused with pituitary adenoma (both cause bitemporal hemianopia).

... hayayah made a comment on nbme20/block1/q#39 (A 3-month-old boy is brought to the office by his...)
 +3  upvote downvote
submitted by hayayah(349)

Inguinal hernias are usually reducible, femoral hernias are not.

This is an indirect inguinal hernia. It enters internal inguinal ring lateral to inferior epigastric vessels and is superior to the inguinal ligament.

Caused by failure of processus vaginalis to close (can form hydrocele). May be noticed in infants or discovered in adulthood. Much more common in males.

yotsubato  Heres a good picture to help with the concept. https://www.google.com/url?sa=i&source=images&cd=&ved=2ahUKEwjVkIi0yN7iAhWLjqQKHbeXCTUQjRx6BAgBEAU&url=https%3A%2F%2Fwww.herniaclinic.co.nz%2Finformation%2Ftypes-of-hernias%2F&psig=AOvVaw2BzGtQLvSmUN8ymhdvETG5&ust=1560244112252834
sbryant6  Note that direct inguinal hernias typically happen in older adults. This question presents a younger baby, so it is more like to be indirect.
... hayayah made a comment on nbme20/block1/q#40 (Monoclonality of neoplastic cells in endometrial...)
 +11  upvote downvote
submitted by hayayah(349)

Neoplasia is new tissue growth that is unregulated, irreversible, and monoclonal.

Clonality can be determined by glucose-6-phosphate dehydrogenase (G6PD) enzyme isoforms. G6PD is X-linked.

*For more information check out Ch. 3 Neoplasia in Pathoma

hello  This is great, thank you.
breis  Pathoma ch. 3 pg 23 "Basic Principles"
charcot_bouchard  Shoutout to Imam Satter! Without him this question wasnt possible for me to answer in 10 sec.
... hayayah made a comment on nbme20/block1/q#41 (A 45-year-old man has fever, chills, dysuria, and a...)
 +1  upvote downvote
submitted by hayayah(349)

Prostatitis is characterized by dysuria, frequency, urgency, low back pain. Warm, tender, enlarged prostate.

Acute bacterial prostatitis—in older men most common bacterium is E. coli.

ergogenic22  In young men it could be chlamydia but the question stem makes no mention of sexual activity, so it is e. coli
charcot_bouchard  First this guy isnt older! He may incite Daddy issue but not older. At this age people tend to be more monogamous so E Coli the more likely answer. But again cont NBME 20 trend this one was pretty vague too.
monkey  They classify at 35 year old (<35 = Chlamydia or Neisseria and > 35 = E.coli)
... hayayah made a comment on nbme20/block1/q#42 (A 60-year-old man has two-pillow orthopnea, severe...)
 +4  upvote downvote
submitted by hayayah(349)

This patient has heart failure. Normal JVP is 6-8 mmHg.

Signs of heart failure are based on cardiac pump dysfunction, Žcongestion, and low perfusion.

Symptoms: include dyspnea, orthopnea, fatigue; signs include S3 heart sound, rales, jugular venous distention (JVD), and pitting edema.

... yotsubato made a comment on nbme20/block1/q#42 (A 60-year-old man has two-pillow orthopnea, severe...)
 +5  upvote downvote
submitted by yotsubato(214)

Bifid carotid pulses are seen in Aortic stenosis or regurgitation

Carotid Bruit is heard with atherosclerosis of common carotid artery

Slow rising decreased volume carotid pulse is characteristic of aortic stenosis.

Cannon waves are seen in complete AV block, as right ventricle and atria contract independently.

... scpomp made a comment on nbme20/block1/q#42 (A 60-year-old man has two-pillow orthopnea, severe...)
 +2  upvote downvote
submitted by scpomp(2)

Cannon A waves occur when the right atrium contracts against a closed tricuspid valve. Classically seen in AV dissociation (complete heart block).

... strugglebus made a comment on nbme20/block1/q#43 (A randomized clinical trial is conducted to compare...)
 +2  upvote downvote
submitted by strugglebus(63)

The CI value contained 1, which means that its insignificant

sympathetikey  Correct. Per first aid: "If the 95% CI for odds ratio or relative risk includes 1, H0 is not rejected."
xxabi  Ah that makes more sense, thanks!
... xxabi made a comment on nbme20/block1/q#43 (A randomized clinical trial is conducted to compare...)
 -3  upvote downvote
submitted by xxabi(82)

I think its that the CI contained the number "0" which makes it statistically insignificant

kernicterusthefrog  You're thinking about CI for a **mean difference** b/w 2 variables. This question talks about **relative risk**, for which 'strugglebus' correctly asserts that *a CI including 1 fails to reject the null hypothesis*. #funwithformatting
xxabi  Ahhhh you're right, I definitely had them mixed up! Thanks!
xxabi  #biostatsisthebaneofmyexistence
... hayayah made a comment on nbme20/block1/q#44 (A 35-year-old woman with newly diagnosed...)
 +3  upvote downvote
submitted by hayayah(349)

Renovascular disease is the most common cause of 2° HTN in adults. Can be d/t ischemia from renal stenosis or microvascular disease. Can hear renal bruits lateral to umbilicus.

Main causes of renal artery stenosis:

  • Atherosclerotic plaques—proximal 1/3rd of renal artery, usually in older males, smokers.

  • Fibromuscular dysplasia—distal 2/3rd of renal artery or segmental branches, usually young or middle-aged females.

Lab values based off:

  1. Stenosis decreases blood flow to glomerulus.
  2. Juxtaglomerular apparatus (JGA) responds by secreting renin, which converts angiotensinogen to angiotensin I.
  3. Angiotensin I is converted to angiotensin II (ATII) by angiotensin converting enzyme (ACE --in lungs)
  4. ATII raises blood pressure by (1) contracting arteriolar smooth muscle, increasing total peripheral resistance and (2) promoting adrenal release of aldosterone, which increases reabsorption of sodium (where Na+ goes H2O will follow) in the distal convoluted tubule (expanding plasma volume). Can lead to hypokalemia (seen in the labs for this question)
  5. Leads to HTN with increased plasma renin and unilateral atrophy (due to low blood flow) of the affected kidney; neither feature is seen in primary hypertension
uslme123  So both causes would result in increased aldo and MR is the only way to differentiate the two?
hello  @USMLE123 I think both are causes of renal artery stenosis and that could be seen via MR angiography. It is asking what could help DIAGNOSE this patient -- and her most likely cause of the findings is fibromuscular dysplasia. So, yes, MR angiography would look different for the 2 different etiologies and thus could can be used to differentiate the two from one another. However, epidemiologically, we are looking to diagnose her with the suspected most probable cause.
yotsubato  @USLME123 I think measuring Aldosterone is an incorrect answer because you already know its increased due to low K. Knowing she has high Aldosterone wouldnt provide you evidence for a final diagnosis.
... hayayah made a comment on nbme20/block1/q#45 (A 2-year-old boy is brought to the physician because...)
 +4  upvote downvote
submitted by hayayah(349)

Fanconi's is a generalized reabsorption defect in PCT causing increased excretion of amino acids, glucose, HCO3–, and PO43–, and all substances reabsorbed by the PCT.

... hayayah made a comment on nbme20/block1/q#46 (A 55-year-old woman comes to the physician for a...)
 +6  upvote downvote
submitted by hayayah(349)

Notice, the stem says "precorsors in the skin"

D3 (cholecalciferol) from exposure of skin (stratum basale) to sun, ingestion of fish, milk, plants.

D2 (ergocalciferol) from ingestion of plants, fungi, yeasts.

Both converted to 25-OH D3 (storage form) in liver and to the active form 1,25-(OH)2 D3 (calcitriol) in kidney.

sympathetikey  C is the 3rd letter in the alphabet. Hence, D3 = Cholecalciferol
karljeon  Thanks for the explanation. The question stem made it sound like "what future step will be decreased?" Actual question: "Decreased production of which... is most LIKELY TO OCCUR in this patient?" Maybe NBME needs a grammar Nazi working for them.
... hayayah made a comment on nbme20/block1/q#47 (A 60-year-old woman with type 2 diabetes mellitus is...)
 +3  upvote downvote
submitted by hayayah(349)

The two most important MI complications that occur within a 2-5 day span are papillary muscle rupture and interventricular septum ruture.

Papillary muscle rupture leads to severe mitral regurgitation, heard as a systolic murmur at the apex.

... strugglebus made a comment on nbme20/block1/q#48 (An otherwise healthy 4-month-old girl is brought to...)
 +2  upvote downvote
submitted by strugglebus(63)

The strawberry hemangiomas tend to grow and then randomly involute.

medschul  My problem with this question is that a strawberry hemangioma should continue to grow until 5-8 yrs old so I did not see the answer choice "Continued enlargement as the child grows" would not be an acceptable answer as well.
... kernicterusthefrog made a comment on nbme20/block1/q#48 (An otherwise healthy 4-month-old girl is brought to...)
 +1  upvote downvote
submitted by kernicterusthefrog(17)

I also had difficulties with this, especially w/FA being so abbreviated. There is one word in FA that helps, and then I have a link for more info: "grows rapidly and regresses spontaneously by 5-8 years old." Which means it's done with its involution phase by then. This NCBI article helps: The Lessons I Learned from a Hemangioma Clinic TLDR: rapid growth occurs for the first few month, followed by a few months of rest, and then years of involution. Since the question is asking what happens over 5 years, the majority of that time is spent in involution phase. Hope this helps.

whossayin  totally not NBME related, but I think you username is brilliant lol
... hayayah made a comment on nbme20/block1/q#49 (A 56-year-old man comes to the physician because of...)
 +3  upvote downvote
submitted by hayayah(349)

Case of arteriolosclerosis.

Hyperplastic arteriolosclerosis involves thickening of vessel wall by hyperplasia of smooth muscle ('onion-skin appearance')

  • Consequence of malignant hypertension (>180/120 w/ acute end-organ damage)
  • Results in reduced vessel caliber with end-organ ischemia
  • May lead to fibrinoid necrosis of the vessel wall with hemorrhage; classically causes acute renal failure (ARF) with a characteristic 'flea-bitten' appearance
masonkingcobra  From Robbin's: Fibromuscular dysplasia is a focal irregular thickening of the walls of medium-sized and large muscular arteries due to a combination of medial and intimal hyperplasia and fibrosis. It can manifest at any age but occurs most frequently in young women. The focal wall thickening results in luminal stenosis or can be associated with abnormal vessel spasm that reduces vascular flow; in the renal arteries, it can lead to renovascular hypertension. Between the focal segments of thickened wall, the artery often also exhibits medial attenuation; vascular outpouchings can develop in these portions of the vessel and sometimes rupture.
asapdoc  I thought this was a weirdly worded answer. I immediately ( stupidly) crossed of fibromuscular dysplasia since it wasnt a younger women =/
uslme123  I was thinking malignant nephrosclerosis ... but I guess you'd get hyperplastic arteries first -_-
hello  The answer choice is fibromuscular HYPERplasia - I think this is different from fibromuscular DYSplasia (seen in young women);
yotsubato  hello is right. Fibromuscular hyperplasia is thickening of the muscular layer of the arteriole in response to chronic hypertension (as the question stem implies)
smc213  Fibromuscular Hyperplasia vs Dysplasia...... are supposedly the SAME thing with multiple names. Fibromuscular dysplasia, also known as fibromuscular hyperplasia, medial hyperplasia, or arterial dysplasia, is a relatively uncommon multifocal arterial disease of unknown cause, characterized by nonatherosclerotic abnormalities involving the smooth muscle, fibrous and elastic tissue, of small- to medium-sized arterial walls. http://www.medlink.com/article/fibromuscular_dysplasia
smc213  *sorry I had to post this because it was confusing!!!*Fibromuscular dysplasia is most common in women between the ages of 40 of and 60, but the condition can also occur in children and the elderly. The majority (more than 90%) of patients with FMD are women. However, men can also have FMD, and those who do have a higher risk of complications such as aneurysms (bulging) or dissections (tears) in the arteries. https://my.clevelandclinic.org/health/diseases/17001-fibromuscular-dysplasia-fmd
momina_amjad  These questions are driving me crazy- fibromuscular dysplasia/hyperplasia is the same thing, and it is NOT this presentation and it doesn't refer to arteriolosclerosis seen in malignant HTN! Is the HTN a cause, or a consequence? I read it as being the cause (uncontrolled HTN for many years) If it was the consequence, the presentation is still not classical! -_-
charcot_bouchard  Poor controlled HTN is the cause here
charcot_bouchard  Also guys if u take it as Fibromuscular dysplasia resulting in RAS none of the answer choice matches
... cry2mucheveryday made a comment on nbme20/block1/q#49 (A 56-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by cry2mucheveryday(7)

Fibromuscular hyperplasia will cause pre renal azotemia. S. BUN/Cr is >20 in pre renal azotemia but in the question its value is indicative of intrinsic renal failure. very confusing!!

charcot_bouchard  Not really, Hypotension cause pre renal azotemia. Here long standing HTN resulting in end organ damage so intrinsic renal failure
cry2mucheveryday  ugh! i just noticed there's a fairly long h/o of poorly controlled HTN which makes this question simpler now. Thanks!!
... hayayah made a comment on nbme20/block1/q#50 (A 26-year-old man undergoes an abdominal exploratory...)
 +0  upvote downvote
submitted by hayayah(349)

Short gastric a. branch from the splenic a.

Branches of the celiac trunk that constitute the blood supply to the stomach: common hepatic, splenic, and left gastric.

... yotsubato made a comment on nbme20/block2/q#1 (A 17-year-old girl comes to the emergency department...)
 +1  upvote downvote
submitted by yotsubato(214)

"physicians should always encourage healthy minor-guardian communication."

Also you're going to do some serious things to cure this girl's disease, leading up to amputation. You cant hide that from her.

djjix  Non sense ... you can hide the amputation from her
charcot_bouchard  Just show her one leg twice.
... beeip made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +2  upvote downvote
submitted by beeip(56)

How to differentiate between Norovirus and Rotavirus here? Must be related to the the contagious nature of the illness?

strugglebus  You know it’s Noro because people are vaccinated against Rota at 2,4,6 months.
beeip  @strugglebus: I didn't know about the vaccine schedule. Thanks!
strugglebus  As an addendum, you know it’s not staph aureus b/c that is rapid onset within 4 hours.
asapdoc  @Beeip If you go to the vaccines page in first aid it gives you all the high yield vaccinations. I didnt realize to correlate that page to a lot of questions until I got this answer wrong
savdaddy  its norovirus b/c it can survive ~2 weeks without a host, which is why we see family members with symptoms 3 days after the initial virus.
savdaddy  ***after the initial outbreak
eacv  for me this was a discart qx: 1.Giardia lamblia not showed steatorrhea and it needs medication to go away. 2. Rotavirus normally in unvaccinated kids. 3. Shiguella VERY inflammatory stool test do not show anything 4.S areus is very FAST 2-6 hr after eat the contaminated food.
link981  Norovirus is the most common cause of viral gastroenteritis in the USA due to vaccination. + Rotavirus is the most common cause of viral gastroenteritis in the rest of the world. In this question you had to know the most common cause.
... strugglebus made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +1  upvote downvote
submitted by strugglebus(63)

[moved to subcomment]

... strugglebus made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +0  upvote downvote
submitted by strugglebus(63)

[moved to subcomment]

... beeip made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +0  upvote downvote
submitted by beeip(56)

[moved to subcomment]

... usmleuser007 made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +1  upvote downvote
submitted by usmleuser007(86)

Norovirus (Sketchy) = Affects where a lot of people are in close quarters - especially common on cruises - 90% of all diarrheal outbreaks on cruises

sbryant6  Rotavirus occurs in unvaccinated children. In order for it to spread, all those kids would have to be unvaxxed.
... link981 made a comment on nbme20/block2/q#2 (Following a wedding reception that was attended by...)
 +0  upvote downvote
submitted by link981(24)

Norovirus is the most common cause of viral gastroenteritis in the USA due to vaccination. + Rotavirus is the most common cause of viral gastroenteritis in the rest of the world. In this question you had to know the most common cause

... hayayah made a comment on nbme20/block2/q#3 (An investigator compares the DNA sequences of a...)
 +1  upvote downvote
submitted by hayayah(349)

Most restriction enzymes bind palindromes.

So both 5'CCGG or 3'GGCC would have been acceptable in this scenario.

meningitis  Yes, correct. The 5'GGCC option could cause some confusion.
guillo12  I really don't understand the question nor the answer. Can someone explain it for dummies like me?
whossayin  yes please.. I'm with guillo12 on this
sugaplum  @guillo12 @whossayin questions says you've created a new cut site, 1. look at the region on the sick vs healthy. The C to G is the change 2. Write out the sick "CCGG" from 5'3'- you could write out the whole thing, but the answer only has 4 letters, so being lazy here 3. write under it, its complement, the dna base pair. So "GGCC" 4. remember both strands are going in opposite directions when you write them out on top of each other. 5. So the bottom strand actually reads 5' CCGG 3' so that is the answer I hope that clears it up
... ergogenic22 made a comment on nbme20/block2/q#4 (A 56-year-old woman has frequently burned herself...)
 +0  upvote downvote
submitted by ergogenic22(28)

classic for Syringomyelia - results in bi-lateral loss of pain and temperature sensation in a "cape-like" distribution

... lebron james made a comment on nbme20/block2/q#4 (A 56-year-old woman has frequently burned herself...)
 +1  upvote downvote
submitted by lebron james(2)

Syringomyelia normally presents with bi-lateral loss of pain/temp in a cape like distribution due to damage of the anterior white commisures of the Spino-Thalamic Tract.

This person also has wasting of the small muscles of her hand, which is due to Syrinx expansion causing damage to LMNs of the anterior horn (from CNS Pathoma)

dbg  you're talented, bball and now this
... ergogenic22 made a comment on nbme20/block2/q#5 (A 32-year-old woman has had fecal incontinence since...)
 +1  upvote downvote
submitted by ergogenic22(28)

A stretch injury during childbirth will result in damage to the external uretheral and anal sphincters and damage to the pudendal nerve (S2-S4). This can lead to decreased sensation in the perineal and genital area and fecal or urinary incontinence

thepacksurvives  I think that there can also be a direct tear to the anal sphincter muscles
sympathetikey  A better answer choice would have been "damage to the nerves innervating the anal sphincter" but eh, ok.
... celeste made a comment on nbme20/block2/q#6 (An 18-year-old boy has just been diagnosed with...)
 +7  upvote downvote
submitted by celeste(27)

While the lifetime risk in the general population is just below 1%, it is 6.5% in first-degree relatives of patients and it rises to more than 40% in monozygotic twins of affected people. Analyzing classic studies of the genetics of schizophrenia done as early as in 1930s, Fischer concludes that a concordance rate for psychosis of about 50% in monozygotic twins seems to be a realistic estimate, which is significantly higher than that in dizygotic twins of about 10–19% (ncbi.nlm.nih.gov/pmc/articles/PMC4623659/#ref3)

imnotarobotbut  How is one supposed to know this before having read this article?
imgdoc  This question falls under the either you know it or you dont category. It isnt in FA or Uworld
jaxx  So why would these A-holes put it on there as if prepping for this exam isn't stressful enough :-|
... babydoc made a comment on nbme20/block2/q#6 (An 18-year-old boy has just been diagnosed with...)
 +1  upvote downvote
submitted by babydoc(1)

Inheritance pattern is autosomal dominant. Patient has 50% chance of inheriting and if she does inherit it, she has about 100% of developing colon cancer. 0.5 x 1 = 0.5 thus, 50% chance.

babydoc  oops wrong Q
usmlephile  This one makes more sense and its pretty direct!
usmlephile  sorry wrong Qs
... killme made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by killme(2)

The concept being tested is "what does PTH do that leads to hypercalcemia" https://i.ibb.co/sKPdVj3/image.png

yotsubato  ugh, bullshit. I was trying to figure out an actual disease process here.
rio19111  its primary hyperparathyroidism caused by parathyroid adenoma. addition of the peptic ulcer suggest Zollinger ---> MEN1 but none of that is imp because that's not what they are asking. All they are asking for is the function of PTH.
... sympathetikey made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by sympathetikey(260)

In addition to PTH = osteoclast activity = increased calcium, this person could also be exhibiting symptoms of MEN1.

... laminin made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by laminin(6)

can someone explain why it says he has an 'intact' PTH concentration...is it to let us know that the PTH concentration is a result of pathology? and what's his dx? thanks!

yotsubato  I swear they make up some of this stuff. Like whats up with the thirst, urination, and peptic ulcer diseases.
redvelvet  hypercalcemia can cause nephrogenic diabetes inspidus; so thirst, urination. hypercalcemia can also cause peptic ulcer disease. His symptoms are all about hypercalcemia due to hyperparathyroidism.
namira  "Hypercalcemia can cause renal dysfunction such as nephrogenic diabetes insipidus (NDI), but the mechanisms underlying hypercalcemia-induced NDI are not well understood." https://www.kidney-international.org/article/S0085-2538(16)30704-9/fulltext
... nwinkelmann made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by nwinkelmann(60)

Does anyone know the significance of monocyte motility?

... cafeaulait made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by cafeaulait(1)

I believe this stem may be inferring MEN 1 syndrome - possible gastrinoma (peptic ulcer disease dx), parathyroid adenoma, and pituitary adenoma (causing SIADH). But, you don't need to even know this to get this right - just asking the effect of high PTH on the system - causes increased osteoclast activity as well as maturation.

... rio19111 made a comment on nbme20/block2/q#7 (A 30-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by rio19111(3)

its primary hyperparathyroidism caused by parathyroid adenoma. addition of the peptic ulcer suggest Zollinger ---> MEN1

but none of that is imp because that's not what they are asking. All they are asking for is the function of PTH.

rio19111  Stones, groans, thrones, psychiatric overtones ---> symptoms
... allinthistogether made a comment on nbme20/block2/q#8 (Three elderly residents of an assisted living...)
 +1  upvote downvote
submitted by allinthistogether(1)

Legionella is common causes of pneumonia superimposed on chronic obstructive pulmonary disease.

asapdoc  Im pretty sure so is strept pneumoniae
usmleuser007  COPD is also exacerbated by Viral infection: Rhinovirus, influenza, parainfluenza; and Bacterial infection: Haemophilus influenzae, Moraxella catarrhalis, Streptococcus. however, the questions gives a hint that it may be legionella = "weekend retreat" which may be associated with this infection
loopers  From FA 2017 pg 139: Legionnaires’ disease—severe pneumonia (often unilateral and lobar A ), fever, GI and CNS symptoms. Common in smokers and in **chronic lung disease.**
kentuckyfan  I also believe that the other attendees showed signs of pontiac fever, which is another hint they tried to get at.
luke.10  i did it wrong and chose influenza virus since it is most common infection in COPD but the clue in the Question is that the other attendee didnt get sick since in legionella there is no person to person transmission
endochondral   but in Uworld s. pneumo is one of the most common bacterial exacerbation of COPD legionella wasn't even mentioned. How do we rule out s. pneumo ?
nala_ula  maybe because in children s.pneumo causes otitis media?
smc213  Another hint made in the Q stem is the location being rural Pennsylvania.... Legionnaires disease was first discovered by the outbreak in 1976 at a convention held in Philadelphia, Pennsylvania. Not sure why I know this fact...
hpsbwz  Biggest hint towards legionella to me was that they all were at a residence hall... i.e. where there'd be air conditioners and such.
... usmle11a made a comment on nbme20/block2/q#8 (Three elderly residents of an assisted living...)
 +0  upvote downvote
submitted by usmle11a(2)

legionella : very common in advanced age, COPD, immunosuppressed patients and " going back from a residence hall" which probably had a contaminated AX system (basically fits every one in the Q)

adeno X : would present with conjunctivitis, throat pain ... flu virus: not everyone got the disease RSV: no children strep pneumo: would target a larger population of healthy people as well.

... andrewk1 made a comment on nbme20/block2/q#9 (An otherwise healthy 16-year-old girl comes to the...)
 +2  upvote downvote
submitted by andrewk1(2)

This girl has exercise induced asthma. It is not well understood why it happens but the triggers are recognized. Normally when breathing occurs air is taken in by the nose and the nasal passages and turbinates act to remove dust and humidify/warm the air. Logically this makes the air denser Pv=nRT. So when exercising, breathing through the nose is decreased and replaced by more vigorous mouth breathing. This means the air is not humidified and warmed up. The air is less dense and the asthma ensues. The question took this same principle except reversed it by asking what external condition could lead to the asthma and that would be cold dry air.

eacv  oooh thank u !!! I choose wrong, cold air hehhe
eacv  moisture air instead!
... monoloco made a comment on nbme20/block2/q#10 (A 70-year-old woman is transferred to a...)
 +5  upvote downvote
submitted by monoloco(49)

This is indirectly asking about peak bone density. That whole thing about weight-bearing exercises, eating right, yada yada, before and during that down-slope phase of life for bone density. All about reducing that 1% per year age-related bone density loss as best as we can. Level of activity is precisely like weight-bearing exercise. (Consider: no activity, bed-ridden -- say goodbye to your bones; highly active, runs every other day -- good amount of weight-bearing / stress to induce remodeling and maintain integrity of the bones.)

sympathetikey  Yeah, I was thinking about that while taking the exam. Just got thrown off because I don't see how that matters, now that they've fractured the femur. How do prior increases in bone density allow for better chances of bone healing?
... sherry made a comment on nbme20/block2/q#10 (A 70-year-old woman is transferred to a...)
 +0  upvote downvote
submitted by sherry(3)

This is the second best choice I was gonna take during the exam. I thought Age was better since FA indicated decreased estrogen and old age are the reasons for bone resorption. Can somebody explain to me why Age could not possibly be the answer?

kard  I solve it like this: So age is 70 (already, nothing we can do to change it), is asking about a predictor of success in the Rehab process (So basically, what this patient did in matter of activity, life style, etc. to have a Good rehab process). So From all the answers the, Activity level is the most likely choice because of the, increase in Bone density(Specially Weigh bearing) and OsteoBlastic activity.
... monoloco made a comment on nbme20/block2/q#11 (A female newborn delivered at 36 weeks' gestation is...)
 +1  upvote downvote
submitted by monoloco(49)

This is a hypoplasia of the pleuroperitoneal membrane. The guts herniate into the thorax, usually on the left side, and result in hypoplasia of the lungs (because they're horribly compressed).

johnthurtjr  Usually on the left because the liver prevents herniation through the right hemidiaphragm
asdfghjkl  aka congenital diaphragmatic hernia
... hayayah made a comment on nbme20/block2/q#12 (An 80-year-old man with type 2 diabetes mellitus is...)
 +0  upvote downvote
submitted by hayayah(349)

Pelvic splanchnic nerves are part of the parasympathetic system.

masonkingcobra  The inferior hypogastric plexus innervates internal pelvic viscera; has both sympathetic and parasympathetic components; parasympathetic contribution helps stimulate detrusor of bladder (along with pelvic splanchnic nerves), sympathetic contribution helps stimulate internal urethral sphincter
... johnthurtjr made a comment on nbme20/block2/q#12 (An 80-year-old man with type 2 diabetes mellitus is...)
 +6  upvote downvote
submitted by johnthurtjr(43)

FA2019 p 357 on Gastrointestinal blood supply and parasympathetic innervation:

  • Foregut --> celiac artery, vagus innervation
  • Midgut --> SMA, vagus
  • Hindgut --> IMA, pelvic innervation
... strugglebus made a comment on nbme20/block2/q#13 (A 25-year-old woman comes to the physician because...)
 +4  upvote downvote
submitted by strugglebus(63)

Any answer with treponemes is used to syphilus only and is very specific. That only leaves cardiolipin, which is also elevated in SLE; this is why its sensitive but not specific in Syph.

... hayayah made a comment on nbme20/block2/q#13 (A 25-year-old woman comes to the physician because...)
 +3  upvote downvote
submitted by hayayah(349)

Diagnosis of Syph: Visualized by immunofluorescence or dark-field microscopy; serology is important – two types of antibodies:

  • Ab binds to cardiolipin: an antigen found in mammalian mitochondrial membranes and in treponemes; a cheap source of antigen is cow heart, which is used in screening tests; very sensitive in primary, except early, and secondary syphilis – titer may decline in tertiary and with treatment; but not specific – must confirm with FTA-ABS.
  • Examples include Venereal Disease Research Lab (VDRL), Rapid plasma Reagin (RPR), Automated Reagin Test (ART), or Recombinant Antigen Test (ICE)

  • Specific tests for treponemal antibody are more expensive; earliest antibodies bind to spirochetes: these tests are more specific and positive earlier; usually remain positive for life, but positive n patients with other treponemal diseases and may be positive in Mono, RF, Lupus, Leprosy, Lime, and Drug users.

  • The most widely used is Fluorescent Treponemal Antibody- Absorption (FTA-ABS) or Treponema pallidum microhemagglutination (MHA-TP)
... xxabi made a comment on nbme20/block2/q#13 (A 25-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by xxabi(82)

Non-treponemal tests are sensitive, but not specific - RPR, VRDL

... monoloco made a comment on nbme20/block2/q#14 (A 23-year-old woman has had fever, hypotension, and...)
 +1  upvote downvote
submitted by monoloco(49)

Encapsulated organisms run rampant in patients who have no spleen, whether physically or functionally. (Recall the wide-array of sequalae sickle cell patients experience thanks to their functional autosplenectomy.)

sympathetikey  Agreed -- went with E. Coli like a dingus, just because I didn't associate DIC with S. Pneumo. Thought it was too easy.
chillqd  Isn't E. Coli also an encapsulated organism? What makes Strep pneumo more likely in this question just because its the more common cause?
studentdo  Pseudomonas aeruginosa is encapsulated as well. I think the right answer has to do with DIC but why?
mgoyo89  The only reason i found was S. pneumo is more common, I went with Pseudomonas because of the "overwhelming sepsis" :(
kard  Everyone is correct about the Encapsulated microbes, but this is one of those of "MOST LIKELY", and by far the most likely is S.Pneumo>>H.infl>N.Mening. (omitting that patients with history of splenectomy must be vaccinated.
... yotsubato made a comment on nbme20/block2/q#14 (A 23-year-old woman has had fever, hypotension, and...)
 +0  upvote downvote
submitted by yotsubato(214)

This question is bullshit. The woman would most likely be vaccinated to Strep pneumo, especially if she had a splenectomy.

E coli is also an encapsulated bacterium that causes pneumonia, so that is more likely IMO.

sugaplum  I agree with you, only possible logic for their answer: the qualifier asplenic makes the "ShIN" pathogens more likely, even though Ecoli can cause gram negative sepsis and DIC. FA 2019 pg 127 Also it says s pneumo causes sepsis specifically in asplenic patients Pg 136
lmfaoayeitslit  To be honest, the only reason I got this right (because I really was thinking E.Coli as well), is that I ended up remembering the MOPS part of the Sketchy, and I couldn't remember if he said that it was the number 1 cause of all of them or not, and ended up clicking it. It's pretty shitty they don't offer explanations for these.
... celeste made a comment on nbme20/block2/q#15 (A 55-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by celeste(27)

Dextromethorphan is an opium alkaloid derivative. Dextromethorphan is a drug of abuse. The main risks associated with dextromethorphan are ataxia, central nervous system (CNS) stimulation, dizziness, lethargy and psychotic behavior. Less frequently with large doses seizures and respiratory depression can occur. Nausea, vomiting, constipation and tachycardia may also occur. (toxnet.nlm.nih.gov)

... sugaplum made a comment on nbme20/block2/q#15 (A 55-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by sugaplum(37)

Synthetic codeine analog, has mild Opioid effects when used in high concentrations. Hence constipation FA 2019 671

... ergogenic22 made a comment on nbme20/block2/q#16 (A 10-year-old boy with mild mental retardation is...)
 +0  upvote downvote
submitted by ergogenic22(28)

See the first aid entry on Tuberous sclerosis. It is associated with increased incidence of subependymal giant cell astrocytoma and many other conditions.

... usmleuser007 made a comment on nbme20/block2/q#16 (A 10-year-old boy with mild mental retardation is...)
 +0  upvote downvote
submitted by usmleuser007(86)

Tuberous sclerosis = "ash-leaf spots" = oval-shaped areas pale areas on skin. often d/t hamartomas

... strugglebus made a comment on nbme20/block2/q#17 (A 57-year old man has a hemoglobin concentration of...)
 -2  upvote downvote
submitted by strugglebus(63)

Pt has polycythemia vera (myeloproliferative disorder) due to chronic hypoxia induced by COPD. Myeloid metaplasia is extra medullary hematopoiesis due to myelofibrosis. Hereditary hemochromatosis would have been proven by a prussian blue stain. Hypersplenism would have caused decreased RBCs, and myelodysplasic syndrome would have shown Auer rods or blasts.

neonem  Right, I think this would be just called "appropriate absolute polycythemia", whereas polycythemia vera is due to a malignant JAK2 mutation and would be termed a type of chronic myeloproliferative disorder.
... hayayah made a comment on nbme20/block2/q#17 (A 57-year old man has a hemoglobin concentration of...)
 +5  upvote downvote
submitted by hayayah(349)

This is reactive polycythemia vera, which is due to high altitude or lung disease. SaO2 is low, and EPO is increased.

Another way to approach the question is looking at the blood smear. It's pretty normal (no megakaryocytes, no increased number of platelets, no rods, nothing blue, etc). A blood smear from a COPD patient will be normal. Just an increased number of RBCs due to the increased EPO leading to increased Hgb.

... alexb made a comment on nbme20/block2/q#17 (A 57-year old man has a hemoglobin concentration of...)
 +0  upvote downvote
submitted by alexb(10)

I confused myelodysplastic syndrome with primary myelofibrosis because I thought 2-3 of those RBCs looked like teardrop cells. Just like when they show an image for bullous pemphigoid and there's some weird second rip through the dermal/subdermal layer making me think it's not BP even though I don't know what else it would be. fml

whoissaad  Made the same mistake
targetusmle  i thought exactly the same!! 2 cells looked like tear drop cells :/
... strugglebus made a comment on nbme20/block2/q#18 (A 65-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by strugglebus(63)

ST will first decrease; however, after 20 min it will increase (elevate)

... hayayah made a comment on nbme20/block2/q#18 (A 65-year-old man is brought to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

This man is showing sxs of an MI.

Initial phase of myocardial infarction leads to subendocardial necrosis involving < 50% of the myocardial thickness (subendocardial infarction); EKG shows ST-segment depression.

Continued or severe ischemia (>20 minutes) leads to transmural necrosis involving most of the myocardial wall (transmural infarction); EKG shows ST-segment elevation.

charcot_bouchard  May i know where do u read this
... monoloco made a comment on nbme20/block2/q#19 (A 66-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by monoloco(49)

Is this the one with the poor kidney that was cut in half against its will and has a dilated distal ureter? If so, probably showing us transitional carcinoma with mild invasion into that distal ureter. Pathoma does a pretty awesome job of talking about GU cancers (and most cancers) ((and most medicine)) IMO.

... hayayah made a comment on nbme20/block2/q#19 (A 66-year-old man is brought to the emergency...)
 +3  upvote downvote
submitted by hayayah(349)

It's transitional cell carcinoma, which smoking is a common risk factor for; it can involve the renal pelvis/calyces. The histo image shows the papillary nature of the tumor (however it can also be flat or nodular according to Pathoma).

Also known as urothelial carcinoma. Most common tumor of urinary tract system (can occur in renal calyces, renal pelvis, ureters, and bladder). Can be suggested by painless hematuria (no casts).

... lancestephenson made a comment on nbme20/block2/q#19 (A 66-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by lancestephenson(5)

This is LITERALLY the same photo they used to describe the 4-year-old boy with diffuse cortical necrosis from NBME 18. Can someone explain what's going on here

lancestephenson  *Tubular atrophy, not cortical necrosis lol
charcot_bouchard  Can u fuckers talk about spoilers
... monoloco made a comment on nbme20/block2/q#20 (A 19-year-old man who is a college student is...)
 +0  upvote downvote
submitted by monoloco(49)

I have regarded crepitus as the rubbing of bone-on-bone. My study partner and I think this is a purely definitional question. Yes, crepitus could also be trapped air. Context, I guess.

medstudent65  Crepitus is used to describe bone-on-bone grinding. Subcutaneous crepitus is very specific sound referencing air finding its way into the skin which you can hear but also feel by rubbing your hand over the affected area. The addition of subcutaneous lets you know we are specifically talking about air in the skin.
... strugglebus made a comment on nbme20/block2/q#20 (A 19-year-old man who is a college student is...)
 +9  upvote downvote
submitted by strugglebus(63)

Bronchophony= pneumonia Expiratory stridor= tracheobronchial obstruction (mass/foreign body) Inspiratory stridor = laryngeal obstruction Succussion splash= test for pyloric stenosis

When there is a fractured rib it will cause a trauma pnemothorax which can cause air to escape and become trapped under the skin leading to crepitus.

charcot_bouchard  Actually when a fractured rib puncture lung then it cause sc emphysema.
... masonkingcobra made a comment on nbme20/block2/q#20 (A 19-year-old man who is a college student is...)
... rio19111 made a comment on nbme20/block2/q#20 (A 19-year-old man who is a college student is...)
 +0  upvote downvote
submitted by rio19111(3)

Diagnosis: Pneumomediastinum (FA 2019, 659)

+Hamman Sign=Crepitus on cardiac auscultation

Etiology: spontaneous (due to rupture of pulmonary bleb) or 2° (eg, trauma, iatrogenic, Boerhaave syndrome).

... neonem made a comment on nbme20/block2/q#21 (A 25-year-old woman comes to the physician 2 days...)
 +1  upvote downvote
submitted by neonem(227)

Cat scratch disease (Bartonella infection in immunocompetent hosts) causes lymphadenitis (especially in the axillary region) characterized by sarcoid-like non-caseating granulomas filled with neutrophils.

... sympathetikey made a comment on nbme20/block2/q#21 (A 25-year-old woman comes to the physician 2 days...)
 +1  upvote downvote
submitted by sympathetikey(260)

Choice A. would have been correct if this patient was immunocompromised. Per First Aid, "If CD4 <100, Bartonella...Findings: Neutrophilic Inflammation.

However, as this patient has a competent immune system, buzz words are stellate necrotizing granulomas.

yotsubato  Everyones choice A is different.
sugaplum  they mean- Diffuse neutrophil infiltration
... sugaplum made a comment on nbme20/block2/q#21 (A 25-year-old woman comes to the physician 2 days...)
 +1  upvote downvote
submitted by sugaplum(37)

B Hensele- Cat Scratch in immuno-compotent - http://www.pathologyoutlines.com/topic/lymphnodescatscratch.html Bartonella henselae in Immuno-compromised- Baciliary angiomatotsis Looks like kaposi sarcoma "Diffuse neutrophilic infiltrate" FA 2019 177

... hayayah made a comment on nbme20/block2/q#22 (A 44-year-old woman comes to the physician for a...)
 +1  upvote downvote
submitted by hayayah(349)

In eukaryotic cells, two major pathways—the ubiquitin-proteasome pathway and lysosomal proteolysis—mediate protein degradation.

The major pathway of selective protein degradation in eukaryotic cells uses ubiquitin as a marker that targets cytosolic and nuclear proteins for rapid proteolysis.

The other major pathway of protein degradation in eukaryotic cells involves the uptake of proteins by lysosomes and digestion by proteases.

missi199  Could I ask why it is not Lysosomal protease
smc213  "Certain viruses have evolved to recruit the cellular E3 ligases to induce the degradation of cellular proteins that might have harmful effects on the viral life cycle. For instance, the protein E6 of Human papillomavirus (HPV) recruits the cellular E3 ubiquitin ligase E6-AP to induce ubiquitination and degradation of p53, thereby allowing viral replication." from: https://www.mdpi.com/1999-4915/9/11/322/htm
smc213  USMLE Kaplan: A majority of cellular proteins are degraded via the ubiquitin proteasome pathway, including many proteins that play a role in maintaining cellular homeostasis. These include proteins that regulate the cell cycle, apoptosis, etc.
... dontwanttofail made a comment on nbme20/block2/q#22 (A 44-year-old woman comes to the physician for a...)
 +0  upvote downvote
submitted by dontwanttofail(-4)

From Amboss on Protein Degradation:

"Endogenous proteins are degraded by proteasomes. Exogenous proteins are degraded by lysosomes"

... ergogenic22 made a comment on nbme20/block2/q#23 (Which of the following changes in the cardiovascular...)
 +0  upvote downvote
submitted by ergogenic22(28)

aging results in increased arterial stiffness (change in Extra Ccellular Mmatrix composition - decreased elastin, increased collagen deposition); ISH is responsible for 60-80% of HTN cases in patients > 60. Also, decreased compliance as a result of aging causes increased pulse pressure

rio19111  why not dev. of coronary atherosclerosis?
pakimd  @rio19111 i think the Q stem is asking in absence of any lesions of blood vessels; the number and severity of which increase with age. So with normal aging SBP should increase in isolation which may then result in the development of coronary atherosclerosis- if that makes sense
... hayayah made a comment on nbme20/block2/q#24 (A patient with a 1-week history of diarrhea has...)
 +2  upvote downvote
submitted by hayayah(349)

Patient has chronic diarrhea leading to metabolic acidosis. Respiratory compensation will lead to decreased CO2 (respiratory alkalosis via hyperventilation).

usmleuser007  Aldo would increase b/c protons are anti-transported with potassium --> leads to hyperkalemia --> aldo activation ADH will also increase b/e of volume loss
... loopers made a comment on nbme20/block2/q#24 (A patient with a 1-week history of diarrhea has...)
 +1  upvote downvote
submitted by loopers(2)

Another quick way to think of this is through the formula: pH = HCO3/CO2. Since pH is low and HCO3 is low, CO2 must also be low.

... mrmassador made a comment on nbme20/block2/q#25 (A 14-year-old girl is brought to the physician...)
 +2  upvote downvote
submitted by mrmassador(2)

I think the point of the question is to recognize that this is a mitochondrial disease (mother and maternal grandmother were affected). Produces wide range of effects, but muscle weakness and some neurologic deficits stood out to me. Also this: https://ghr.nlm.nih.gov/gene/MT-TL1#conditions

sympathetikey  Yes, but doesn't that mean maternal transmission? Men can have these diseases too, they just won't pass them on.
... hayayah made a comment on nbme20/block2/q#25 (A 14-year-old girl is brought to the physician...)
 +2  upvote downvote
submitted by hayayah(349)

This is a presentation of mitochondrial myopathy. They often present with myopathy, lactic acidosis, and CNS disease. 2° to failure in oxidative phosphorylation. Muscle biopsy often shows “ragged red fibers”.

There is variable expression in a population or even within a family due to heteroplasmy in mitochondrial inheritance.

... thomas made a comment on nbme20/block2/q#25 (A 14-year-old girl is brought to the physician...)
 +0  upvote downvote
submitted by thomas(3)

It's a mitochondrial disease. - present in successive generations, always with maternal transmission - damage to high-energy tissues - CSF lactic acidosis (due to increased anaerobic metabolism due to impaired oxidative phosphorylation)

... sympathetikey made a comment on nbme20/block2/q#25 (A 14-year-old girl is brought to the physician...)
 +4  upvote downvote
submitted by sympathetikey(260)

Mutations in MT-TL1 (Mitochondrially encoded tRNA leucine 1)

A common mutation is A3243G. Can result in multiple mitochondrial deficiencies and associated disorders. It is associated with:

  • Mitochondrial encephalomyopathy
  • Lactic acidosis
  • Stroke-like episodes (MELAS)

MELAS is a rare mitochondrial disorder known to affect many parts of the body, especially the nervous system and the brain. Symptoms of MELAS include:

  • Recurrent severe headaches
  • Muscle weakness (myopathy)
  • Hearing loss
  • Stroke-like episodes with a loss of consciousness, seizures, and other problems affecting the nervous system.

Source: https://en.wikipedia.org/wiki/MT-TL1

... monoloco made a comment on nbme20/block2/q#26 (A male newborn is found to have a decreased blood...)
 +1  upvote downvote
submitted by monoloco(49)

Decreased total, normal free (unbound) = Thyroid hormone-binding globulin deficiency

... whossayin made a comment on nbme20/block2/q#26 (A male newborn is found to have a decreased blood...)
 +1  upvote downvote
submitted by whossayin(3)

why can't "organification defect in T3 and T4" be the answer?

sugaplum  I think if it was organification defect you wouldn't have a normal T4 level in the serum.
... sugaplum made a comment on nbme20/block2/q#26 (A male newborn is found to have a decreased blood...)
 +1  upvote downvote
submitted by sugaplum(37)

This is apparently congenital thyroid binding globulin deficiency

"Thyroxine-binding globulin deficiency — Thyroxine-binding globulin (TBG) deficiency is characterized by low serum total T4 but normal free T4 and TSH; the diagnosis is confirmed by measuring TBG concentrations. These infants have normal thyroid function and do not require treatment." - uptodate *can't find in FA, maybe it is in there somewhere?

... jointaccount made a comment on nbme20/block2/q#27 (A 38-year-old African American man with recently...)
 +0  upvote downvote
submitted by jointaccount(0)

"only pharmacokinetic processes which are biologically or biochemically mediated have the potential to exhibit differences between racial or ethnic groups. Thus, the pharmacokinetic factors which can be expected to potentially exhibit racial differences are (1) bioavailability for drugs which undergo gut or hepatic first-pass metabolism, (2) protein binding, (3) volume of distribution, (4) hepatic metabolism, and (5) renal tubular secretion. Absorption (unless active), filtration at the glomerulus, and passive tubular reabsorption would not be expected to exhibit racial differences. "

via: https://www.ncbi.nlm.nih.gov/pubmed/9423140

... drw made a comment on nbme20/block2/q#27 (A 38-year-old African American man with recently...)
 +1  upvote downvote
submitted by drw(2)

According to UTD, it is said that for the young patient, ACEI, ARB, beta-blocker are of better efficacy for primary hypertension as a monotherapy, however, CCB and thiazide are better for the elderly and the black patients.

... monoloco made a comment on nbme20/block2/q#28 (At a postnatal checkup, a 6-week-old female newborn...)
 +1  upvote downvote
submitted by monoloco(49)

Annular pancreas is the only answer that accounts for the bile in the vomit; of the choices, it is the only obstruction distal to where bile enters the GI tract.

ergogenic22  Meckel diverticulum also occurs distal to the CBD but less likely to be associated with bilious vomiting
sympathetikey  Correct. Might cause pain due to ectopic gastic tissue.
... strugglebus made a comment on nbme20/block2/q#28 (At a postnatal checkup, a 6-week-old female newborn...)
 +0  upvote downvote
submitted by strugglebus(63)

Also, Meckels would have describe hematochezia or failure to pass meconium

sugaplum  I believe failure to pass meconium is Hischsprung's Meckels don't present within the first few days of life, so meconium wouldn't be a factor FA 2019 378
... hayayah made a comment on nbme20/block2/q#29 (A 25-year-old woman has a flu-like illness (fever,...)
 +1  upvote downvote
submitted by hayayah(349)

Most important cause of viral myocarditis is Coxsackie (picornavirus).

... luke.10 made a comment on nbme20/block2/q#29 (A 25-year-old woman has a flu-like illness (fever,...)
 +0  upvote downvote
submitted by luke.10(1)

picorna( coxsackie ) is more common than adenovirus but both can caause viral myocarditis

... hayayah made a comment on nbme20/block2/q#30 (A 78-year-old man is brought to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

He's not eating enough.

One of cortisol's functions is to increase gluconeogenesis, lipolysis, and proteolysis.

... asdfghjkl made a comment on nbme20/block2/q#30 (A 78-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by asdfghjkl(1)

Anyone know why IGF-1 wouldn't be increased as well? GHRH is stimulated in hypoglycemic states.

nala_ula  Honestly, it's something that has confused me for a while. Why is it that GH secretion is stimulated by hypoglycemia? I mean, it's literally called growth hormone (for growth!), and hypoglycemia, which is basically a "starvation" state, will stimulate this hormone?
shaeking  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3529368/ This might help answer your question. I basically didn't pick IGF-1 because it would increase the uptake of glucose leading to a worsen hypoglycemic state. Didn't have a true reason otherwise.
temmy  IGF-1 is regulated by insulin. so it will be decreased because insulin levels are also low.
nala_ula  thank you @shaeking!
nwinkelmann  I found this and it also explains to a more genetic/cellular level. Essentially, it says that starvation induces some factors that cause GH resistance and IGF1 suppression.
... dontwanttofail made a comment on nbme20/block2/q#30 (A 78-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by dontwanttofail(-4)

IGF-1 is produced primarily by the liver as an endocrine hormone as well as in target tissues in a paracrine/autocrine fashion. Production is stimulated by growth hormone (GH) and can be retarded by undernutrition, growth hormone insensitivity, lack of growth hormone receptors, or failures of the downstream signaling pathway post GH receptor including SHP2 and STAT5B.

From wikipedia; sourced to: https://academic.oup.com/endo/article-abstract/135/1/472/3036057?redirectedFrom=fulltext

... youssefa made a comment on nbme20/block2/q#30 (A 78-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by youssefa(6)

From Faid 2019 new figure: IGF-1 mainly functions as an anabolic hormone on muscles and bones (pretty much like insulin-> decreases serum glucose). GH acts separately by promoting insulin resistance (increasing serum glucose). Therefore, IGF-1 is not the answer. If GH was among the answers it would have got really confusing.

charcot_bouchard  Can anyone take a little time to curse on that daughter?
dbg  Sure, charcot. Just wished on her to get a couple of charcots (the triad, your aneuryms, marie tooth, etc).
... rio19111 made a comment on nbme20/block2/q#30 (A 78-year-old man is brought to the emergency...)
 +1  upvote downvote
submitted by rio19111(3)

I think a lot of you missed the point. The answer is Cortisol because it helps maintain blood pressure even in the setting where he is malnourished.

rio19111  FA 2019, Pg. 329
pakimd  according to pathoma, cortisol is the hormone neccessary for life. in a condition like the one presented in the Q-stem the most important hormone will be cortisol.
... stepbystep made a comment on nbme20/block2/q#31 (A 25-year-old man comes to the physician 8 hours...)
 +0  upvote downvote
submitted by stepbystep(0)

does some mind explaining why this isn't a tear in the sciatic nerve?

sugaplum  It is a very thick nerve, so I think it is hard to tear without physically cutting it. Also if it tore you would have tibial and common fibular nerve symptoms as well. You would see sensory numbness and tingling along the dermatome also the mechanism of injury is focused on spine so a disc rupture is more likely
... kentuckyfan made a comment on nbme20/block2/q#31 (A 25-year-old man comes to the physician 8 hours...)
 +0  upvote downvote
submitted by kentuckyfan(13)

Since the pain is radicular, a disc herniation is most likely.

charcot_bouchard  Why it cant be a lumbar vertebra fracture
whoissaad  @charcot The patient is young and doesn't have any risk factors for weak bones. Also, disc herniation is a common problem in the young. The disc gets fibrosed and stiff in the elderly so they have less chance for disc herniation. So basically age was the key to answering this question.
... usmle11a made a comment on nbme20/block2/q#31 (A 25-year-old man comes to the physician 8 hours...)
 +1  upvote downvote
submitted by usmle11a(2)

ok here is how i broke it down: a) wrong because most cases would have some risk factor "old female ..." b) "deltoid" c) under pressure it can burst and frankly it is mentioned in FA as a very common cause. D) i think it would need something like a posterior dislocation of hip. e) would probsbly not cause neruo S $S

... monoloco made a comment on nbme20/block2/q#32 (A 12-year-old girl is brought to the physician by...)
 +6  upvote downvote
submitted by monoloco(49)

This is a conditional called craniocleidodysplasia. The kid on Stranger Things with the lisp has the disorder. No collar bones, too many teeth, frontal bossing => craniocleidodysplasia. CBFA1 is a gene highly implicated in osteoblast function.

... hayayah made a comment on nbme20/block2/q#32 (A 12-year-old girl is brought to the physician by...)
 +8  upvote downvote
submitted by hayayah(349)

A big thing here too is noticing that the ALP is decreased. Osteoblast activity is measured by bone ALP. I think that was the main focus here and not that you necessarily need to know the CBFA1 gene mutation.

sympathetikey  Exactly. That's the only way I got to the answer.
pakimd  isnt increased alk phos consistent with increased osteoblastic activity?
... thomas made a comment on nbme20/block2/q#32 (A 12-year-old girl is brought to the physician by...)
 +1  upvote downvote
submitted by thomas(3)

They tell you that the kid has no clavicle. This means the defect is in membranous ossification, NOT endochondral, so the pathology is NOT going to involve the chondro-whatever cells. decreased ALK is consistent with osteoblast defect.

pakimd  isnt increased alk phos consistent with increased osteoblastic activity?
eacv  @pakimd Yes ! ALK phos is a measure of osteoblast work, if the are not working is LOW as in thix px.
... usmleuser007 made a comment on nbme20/block2/q#32 (A 12-year-old girl is brought to the physician by...)
 +0  upvote downvote
submitted by usmleuser007(86)

To answer this question is to note that: 1) alkaline phosphatase activity is linked with osteoblasts.

... xxabi made a comment on nbme20/block2/q#33 (A study is conducted to assess the effect of a new...)
 +1  upvote downvote
submitted by xxabi(82)

Lead time bias is caused by early detection being confused with increased survival. early detection makes it seem as though survival has increased, but the natural history of the disease has not been impacted.

... hayayah made a comment on nbme20/block2/q#34 (A 28-year-old man has excessive thirst and polyuria....)
 +0  upvote downvote
submitted by hayayah(349)

Pt has diabetes inspidus.

If urine concentrates with administration of ADH analog, the kidneys are responsive and the problem is with ADH production in the hypothalamus or release in the post. pituitary.

... sugaplum made a comment on nbme20/block2/q#34 (A 28-year-old man has excessive thirst and polyuria....)
 +0  upvote downvote
submitted by sugaplum(37)

These always tripped me up:
+ Polydipsia= responds to water deprivation, low serum Na
+ Central= responds to vasopressin, high serum Na
+Nephrogenic = responds to nothing, normal serum Na

... medbitch94 made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 -2  upvote downvote
submitted by medbitch94(5)

WHY she has a huge ass liver too? I don't understand how you can choose big spleen over big liver or visa versa

... beeip made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 +5  upvote downvote
submitted by beeip(56)

Liver looks pretty normal-sized to me. Pic here for comparison

... strugglebus made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 +1  upvote downvote
submitted by strugglebus(63)

I thought the liver looked huge af too lol which made me requisition the whole radiograph

... thomas made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 -1  upvote downvote
submitted by thomas(3)

Looked like hepatosplenomegaly, but I went with liver b/c the edema could be due to liver dysfunction.

... sympathetikey made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 +0  upvote downvote
submitted by sympathetikey(260)

Spleen so huge -- look like this girl has 2 livers.

... hello made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 +1  upvote downvote
submitted by hello(52)

Spleen is enlarged. Compare it to CT scan showing normal-sized spleen:

http://www.startradiology.com/uploads/scroll/18/14hiu6b3qot5.jpg

... medschul made a comment on nbme20/block2/q#35 (A 36-year-old woman comes to the office because of a...)
 +0  upvote downvote
submitted by medschul(10)

I can get behind splenomegaly, but what is the disorder?

sup  Felty syndrome, an extraarticular manifestation of RA. Symptoms include a triad of RA, splenomegaly and neutropenia. It's in FA, you just have to squint (look at the fine print under the RA vs OA table in the MSK section).
... hayayah made a comment on nbme20/block2/q#36 (A 31-year-old man has a large, yellow, soft mass...)
 +2  upvote downvote
submitted by hayayah(349)

Benign tumors are usually well-differentiated and well-demarcated, with low mitotic activity, no metastases, and no necrosis.

Malignant tumors (cancers) may show poor differentiation, erratic growth, local invasion, metastasis, and apoptosis. High mitotic activity.

Fat tumors:

  • Lipoma: benign, low mitotic activity
  • Liposarcoma: malignant, increased mitotic activity
whossayin  why can't it be a rhabdomyosarcoma?
charcot_bouchard  Because of histology and gross appearance... very graphic description of fat cell tumor there
... thomas made a comment on nbme20/block2/q#36 (A 31-year-old man has a large, yellow, soft mass...)
 +3  upvote downvote
submitted by thomas(3)

Lipomas/Liposarcomas are the commonest soft-tissue tumors in adults. The high mitotic index & infiltrative nature indicate that the mass is malignant.

... hayayah made a comment on nbme20/block2/q#37 (A 28-year-old woman of Eastern European Jewish...)
 +1  upvote downvote
submitted by hayayah(349)

Defective homologous recombination is seen in breast/ovarian cancers with the BRCA1 gene mutation.

johnthurtjr  Ashkenazi Jews have a higher risk of inheriting the BRCA1 and BRCA 2 gene mutations, just another tip!
lebron james  BRCA1/BRACA2 are involved in the repair of DNA double stranded breaks
... strugglebus made a comment on nbme20/block2/q#38 (A 50-year-old woman with a restrictive pulmonary...)
 -1  upvote downvote
submitted by strugglebus(63)

Ok, so you can reason this by drawing out REIT (sorry I can't draw it here). Anywho, you know its a restrictive disorder and will have a decreased RV, so automatically you know that RV is a component of FRC (FRC= RV+ERV). Thus, FRC should also be decreased. You also know that restrictive diseases are characterized by a steady decrease in FEV1/FVC since both components are decreasing. This leaves you with VC decreasing since FVC= forced vital capacity.

... haliburton made a comment on nbme20/block2/q#39 (A 29-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by haliburton(74)

Mycoplasma pneumoniae cold agglutinins, no response to amoxicillin.

FA 2017: Classic cause of atypical “walking” pneumonia (insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate). X-ray looks worse than patient. High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs. Grown on Eaton agar. Treatment: macrolides, doxycycline, or fluoroquinolone (penicillin ineffective since Mycoplasma have no cell wall). ABC = Africa, Blindness, Chronic infection. D–K = everything else. Neonatal disease can be acquired during passage through infected birth canal. No cell wall. Not seen on Gram stain. Pleomorphic A. Bacterial membrane contains sterols for stability. Mycoplasmal pneumonia is more common in patients < 30 years old. Frequent outbreaks in military recruits and prisons. Mycoplasma gets cold without a coat (cell wall).

johnthurtjr  Have you mixed Chlamydia in with Mycoplasma?
smc213  I mean the Q stem is not about Chlamydiae, but Chlamydiae does lack the classic PTG cell wall d/t decreased muramic acid = beta-lactam abx ineffective. FA 2018 p.148
... sinforslide made a comment on nbme20/block2/q#39 (A 29-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by sinforslide(7)

The question stem is asking what features led to the ineffectiveness of pharmacotherapy. Patient's presentation is consistent with Mycoplasma pneumoniae infection, which doesn't have a cell wall and therefore peptidoglycan, which is the site of action for penicillins. It does require sterols for growth, but that wouldn't explain why amoxicillin is ineffective.

... hayayah made a comment on nbme20/block2/q#40 (A 70-year-old man has a 3-month history of weakness...)
 +1  upvote downvote
submitted by hayayah(349)

Squamous cell carcinoma characteristics: cavitation, hypercalcemia, associated with smoking.

Small cell may actually produce antibodies against presynaptic Ca channels.

smc213  Increased PTHrP seen in squamous cell lung cancer leads to increased Ca2+ levels
... eacv made a comment on nbme20/block2/q#40 (A 70-year-old man has a 3-month history of weakness...)
 +1  upvote downvote
submitted by eacv(2)

to add : it also ARISE FROM BRONCHUS and that is described in the qx.

... rhizopusmucor made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +0  upvote downvote
submitted by rhizopusmucor(0)

I found this, I think it gives kinda of an explanation: If the regression of log ((A'/A) -1) on -log B is linear with a slope of -1, then this indicates that the antagonism is competitive and by definition the agonist and antagonist act at the SAME recognition sites. So basically the more you add Y, the less X is bound, which means they have a same structural component (epitope) and must act on the same site? Don't know if this makes sense...

http://facpub.stjohns.edu/~yoburnb/pages/dictimages/schild1.html

... ilikecheese made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +0  upvote downvote
submitted by ilikecheese(7)

High X is bound when low Y is added, and low X is bound when Y is added. So MAYBE they are competing for the same binding spot/epitope due to this relationship (epitope= antibody binding site) ??????????

... breis made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +0  upvote downvote
submitted by breis(9)

your guess is as good as mine.....................................................................

nala_ula  I spent so long on this question and same... hahaha
... amarousis made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +1  upvote downvote
submitted by amarousis(9)

so how would the graph look for protein x expresses all of the epitopes expressed by protein y, but protein y does not express all of the epitopes expressed by protein x?

drw  then some anti-X cannot relocate to Y even Y is added at whatever high dose. at this condition, the line can never touch the axis-Y. on the contrary, if Y express all epitopes on the X, but X does not express all epitopes on the Y, that means some Y epitopes are not seen on X. at this condition, I don't know what will be the line looked like.
... am.cassandre made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +0  upvote downvote
submitted by am.cassandre(0)

Ran across a question similar to this in another question bank. In that question, there was no change as the concentration of the new protein was added, which meant that the two proteins did not share similar epitopes. In this question, the antibody is just trying to bind its epitope, so adding more or y means less binding of protein x because the antibody favors the proteins the same.

... usmile1 made a comment on nbme20/block2/q#41 (Purified serum antibodies elicited by immunization...)
 +2  upvote downvote
submitted by usmile1(9)

If you look at Uworld question ID 12299 it has a wonderful explanation for this. If they share the same epitopes, it will have a downward slope. If they share none of the same epitopes, the line will be horizontal across the graph (indicating no change as the amount of Y added increases)

eacv  omg YES!! thanks Uworld I got it correct! exactly this qx asked the exact opposite thing! Hahaha I loved it !!
... loopers made a comment on nbme20/block2/q#42 (A previously healthy 32-year-old woman is brought to...)
 +0  upvote downvote
submitted by loopers(2)

Vomiting blood and cool skin indicates this is a type of hypovolemic shock. To understand shock, remember that 1) BP = TPR x CO 2) CO = SV x HR 3) SV = EDV - ESV In hypovolemic shock, you are losing fluid, so stroke volume is decreased and end diastolic volume is decreased. Decreased EDV means that the "filling volume" is decreased, which also means the preload will be decreased (https://www.cvphysiology.com/Cardiac%20Function/CF007). Also, skin is cool because you're decreasing SV --> decreased CO --> Ang II/ADH/etc is released to vasoconstrict increaseing resistance. Since there is increased resistance, there is less blood flow causing skin to be cold/clammy.

hello  Patient in hypovolemic shock - the clues are low BP and COOL skin. Hypovolemic shock is caused by fluid loss. The patient has decreased preload b/c of fluid loss, i.e. there is decreased blood volume returning to heart --> thus decreased preload.
... hello made a comment on nbme20/block2/q#42 (A previously healthy 32-year-old woman is brought to...)
 +0  upvote downvote
submitted by hello(52)

Patient in hypovolemic shock - the clues are low BP and COOL skin. Hypovolemic shock is caused by fluid loss.

The patient has decreased preload b/c of fluid loss, i.e. there is decreased blood volume returning to heart --> thus decreased preload.

endochondral   why not dec SVR?
sup  @endochondral w/ hypovolemic shock you would see increased systemic arterial resistance as arteries will constrict to try and bring BP back up.
eacv  @endochondral dec SVR it typicaly of septic shock.
... step420 made a comment on nbme20/block2/q#43 (An 18-year-old woman comes to the physician because...)
 +2  upvote downvote
submitted by step420(17)

This is mullerian agenesis. Normal ovaries but absent uterus.

endochondral   why not androgen insensitivity?
shaeking  I was wondering the same thing because doesn't androgen insensitivity also have normal female secondary characteristics. Was it the levels of hormones because she doesn't have abnormally high testosterone?
swb  Androgen insensitivity has the same presentation and symptoms. What's the clue that it is mullerian agenesis instead ?
sugaplum  Testosterone would be high if it was androgen insensitivity FA 2019 Pg 625
charcot_bouchard  Testo would be high in AIS. in AIS pubic hair, axillary hair doesnt devlop because of androgen insensitivity. both have normal breast dev and primary amenorrhea
... sympathetikey made a comment on nbme20/block2/q#43 (An 18-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by sympathetikey(260)

Mullerian Agenesis (aka: Mayer-Rokitansky-Kuster-Hauser Syndrome)

Underdevelopment of the Mullerian system leading to congential absence of the vagina. Usually no cervix or uterus.

May present as 1° amenorrhea (due to a lack of uterine development) in females with fully developed 2° sexual characteristics. Functional ovaries allow for normal sexual characteristics and hormone levels.

... temmy made a comment on nbme20/block2/q#43 (An 18-year-old woman comes to the physician because...)
 +1  upvote downvote
submitted by temmy(22)

i think it is not androgen insensitivity because the testosterone levels are normal. They should be high in AIS.

... imgdoc made a comment on nbme20/block2/q#43 (An 18-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by imgdoc(18)

I know it's tempting to think that this may be Androgen insensitivity syndrome but its not, for it to be AIS there needed to be an increase in testosterone. In this case it was in the normal range for a female. Now that we know the person is definitely female -> Mullerian agenesis becomes the best answer.

... hayayah made a comment on nbme20/block2/q#44 (A 43-year-old woman, gravida 2, para 1, at 10 weeks'...)
 +0  upvote downvote
submitted by hayayah(349)

[revised]

... hayayah made a comment on nbme20/block2/q#44 (A 43-year-old woman, gravida 2, para 1, at 10 weeks'...)
 +5  upvote downvote
submitted by hayayah(349)

Down Syndrome Labs:

  • inc. nuchal translucency
  • inc. hCG
  • inc. inhibin
  • decreased AFP
  • decreased PAPPA
celeste  I remember this as Down Syndrome has high HI (hCg and inhibit)
temmy  Thanks celeste. I'll remember Hi
... hayayah made a comment on nbme20/block2/q#45 (A new antiplatelet agent is developed for the...)
 +2  upvote downvote
submitted by hayayah(349)

Absolute risk: the difference in risk (not the proportion) attributable to the intervention as compared to a control.

(.12) - (.04) = .08

ARR = 8%

nwinkelmann  This isn't actually correct. Absolute risk is actually just the incidence, or the same as event rate. Absolute risk reduction = the difference in risk (not the proportion) attributable to the intervention as compared to the control, and thus ARR = incidence unexposed - incidence exposed x 100%. In this example, the incidence of exposed is the incidence in the new treatment group, and incidence unexposed is incidence in standard treatment group.
... strugglebus made a comment on nbme20/block2/q#46 (A physician prescribes a newly marketed drug to 45...)
 +5  upvote downvote
submitted by strugglebus(63)

I chose this solely because it was so damn specific

sympathetikey  Same. Learn something new every day: See more: https://www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program
karljeon  I didn't choose it because it was so damn specific. :(
... hayayah made a comment on nbme20/block2/q#47 (A 35-year-old man comes to the physician to discuss...)
 +2  upvote downvote
submitted by hayayah(349)

You have a 25% chance of inheriting the same HLA markers as your siblings.

masonkingcobra  Two siblings have a 25% chance of being genotypically HLA identical, a 50% chance of being HLA haploidentical (sharing one haplotype), and a 25% chance that they share no HLA haplotypes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2628004/
... strugglebus made a comment on nbme20/block2/q#48 (A sedentary 50-year-old man with hypertension comes...)
 +0  upvote downvote
submitted by strugglebus(63)

Most of the pts values were normal. Drinking wasn't outrageous, LDL was mild, BMI has fine. He did have HTN though. The biggest risk factors are the fact that he had suffered an MI and started suffering severe depression (weight loss/anxiety). Thus, he is more at risk for suicide.

sohaib111  Won't having an MI be a very big risk factor for another one ? And also if they wanted this answer (the anti-depressant), why would they just add that his LDL is inreasing in the last sentence...
dbg  bc they're SOBs and DOBs
... hayayah made a comment on nbme20/block2/q#49 (An 82-year-old woman is brought to the physician...)
 +1  upvote downvote
submitted by hayayah(349)

Beta blockers as antiarrhythmics suppress abnormal pacemakers by decreasing the slope of phase 4 --> prolonging phase 4.

... dbg made a comment on nbme20/block2/q#49 (An 82-year-old woman is brought to the physician...)
 +3  upvote downvote
submitted by dbg(18)

BBs work by decreasing cAMP and Ca2+ thereby slowing SAN & AVN activity. This prolongs phase 4 of depolarization. Therefore, they are known to increase the duration of diastole (predominantly) causing both a rise in heart coronary perfusion and reduction in heart rate.

... meningitis made a comment on nbme20/block2/q#50 (A 27-year-old woman comes to the physician because...)
 +4  upvote downvote
submitted by meningitis(121)

When standing up, the body normally activates sympathetic system to avoid orthostatic hypotension.

But since there is now an additive effect of the pheochromocytoma adrenergics, it will lead to a hypertension

(i.e: Double vasoconstriction = Pheo adrenergics + Sympathetic system)

sympathetikey  Brilliant.
medschul  Would pheo have a normal resting BP though?
meningitis  I was trying to justify these tricky questions but very true medschul.. It shouldn't have normal resting BP. Sometimes it seems these NBME always have a trick up their sleeve. Im getting paranoid lol
nala_ula  The reason why the patient probably has normal HTN is because Pheochromocytoma has symptoms that occurs in "spells" - they come and go. Apparently in that moment, when the physician is examining her, she doesn't have the HTN, but like @meningitis explained, so many adrenergic hormones around leads to double the vasoconstriction when the patient stands up.
meningitis  Thank you @nala_ula for your contribution! Really filled in the gap Iwas missing.
nala_ula  No problem! Thank you for all your contributions throughout this page!
... thechillhill made a comment on nbme20/block3/q#1 (The frequency of an autosomal recessive disease in a...)
 +2  upvote downvote
submitted by thechillhill(2)

p + q = 1 p^2 + 2pq + q^2 = 1 if q^2 = 1/1600 = 0.00063 then q = sqrt(q^2) = 0.025 solve for p to get p = 1 - r = 1 - 0.025 = 0.975 the heterozygous carriers = 2pq = 1 - p^2 = 1 - 0.95 = 0.5 q^2 can be dropped b/c it's much smaller than p^2. The deletion is responsible for 80% of the mutations. 0.8 x 0.5 = 0.04 = 4/100 = 1/25

There might be an easier way to do this, but it worked for me.

thechillhill  So apparently I don't know how to format very well. Sorry!
pakimd  So because i couldnt spend more than a minute on this question and honestly didnt recall the Hardy-Weinberg equation this is how i solved it under a minute: so you know in a given population half of them will be carriers since its an autosomal recessive disease Aa Aa= AA aa Aa Aa so of that half 80% are due to deletion mutations and 20% are due point mutations by that logic 80% of half into 20% of half will give you 1/25
... jotajota94 made a comment on nbme20/block3/q#1 (The frequency of an autosomal recessive disease in a...)
 +9  upvote downvote
submitted by jotajota94(11)

Use the Hardy-Weinberg equation

  1. Take the square root of 1/1600, and that will give you the frequency of the recessive allele = 1/40.
  2. Calculate the frequency of the dominant allele with p+q=1, which is p= 0.975.
  3. They are telling you to calculate the frequency of the disease carriers, which is with the equation 2pq.
  4. They want only the disease carriers in which deletion is present. To calculate this, use the q value (1/40) and multiply by 80% in this should give you 0.02.
  5. Finally, calculate for 2Pq 2 (0.975)(0.02)= 0.04 = 1/25.
yex  Nice! ...and we are supposed to read the stem and do all this in a minute or so? :-/
charcot_bouchard  Allele frequency 1/40. so carrier freq 1/20. 80% of 1/20 is 1/25 (80/100 x 1/20)
... hayayah made a comment on nbme20/block3/q#2 (A 23-year-old woman is brought to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

Allopurinol inhibits xanthine oxidase. It is used for chronic gout as well as prevention of tumor-lysis associated urate nephropathy.

... breis made a comment on nbme20/block3/q#2 (A 23-year-old woman is brought to the emergency...)
 +1  upvote downvote
submitted by breis(9)

Dx: Acute Monocytic Leukemia. Proliferation of monoblasts; lack MPO. CD14 + CD13+ MPO -. blasts characteristically infiltrate the gums.

A Xanthine Oxidase inhibitor is given to prevent adverse reactions of Tumor Lysis Syndrome which results from expulsion of cellular debris/material after the cell dies.

... karljeon made a comment on nbme20/block3/q#2 (A 23-year-old woman is brought to the emergency...)
 +1  upvote downvote
submitted by karljeon(19)

This one was a somewhat simple question since chemotherapy --> tumor lysis --> need xanthine oxidase inhibitor (eg, febuxostat).

BUT WHY IS NBME GRAMMAR SO CRAP? PUT YOUR COMMAS IN THE RIGHT PLACE!

... hayayah made a comment on nbme20/block3/q#3 (A 45-year-old woman has a thyroidectomy because of...)
 +1  upvote downvote
submitted by hayayah(349)

Patient has medullary carcinoma. Malignant proliferation of parafollicular "C" cells that produce calcitonin and have sheets of cells in an amyloid stroma.

xxabi  Just to add - patient likely has MEN 2A or 2B with the presence of medullary thyroid cancer and pheochromocytoma
sympathetikey  @xxabi Was going to say the same thing.
... haliburton made a comment on nbme20/block3/q#4 (An 18-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by haliburton(74)

FA 2017: Infects B cells through CD21. Atypical lymphocytes on peripheral blood smear G —not infected B cells but reactive cytotoxic T cells. ⊕ Monospot test—heterophile antibodies detected by agglutination of sheep or horse RBCs. Use of amoxicillin in mononucleosis can cause characteristic maculopapular rash.

zup  misread the "accounts for" question as what's the reason for the atypical lymphocytes. So I answered "virus infected B lymphocytes." Anyone else misread it like that?
nala_ula  Shit, I misread that too and I noticed it now. Nerves get the best of us!
... katsu made a comment on nbme20/block3/q#4 (An 18-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by katsu(1)

Patient has infectious mono. Atypical lymphocytes (reactive CD8+ T-cells) are seen on blood smear for infectious mono.

... neonem made a comment on nbme20/block3/q#5 (A 35-year-old man comes to the physician because of...)
 +2  upvote downvote
submitted by neonem(227)

Methotrexate would be a drug of choice for psoriasis refractory to topical creams and light therapy; inhibits dihydrofolate reductase in order to decrease skin cell proliferation and reduce inflammatory response.

... neonem made a comment on nbme20/block3/q#6 (A new drug has the following effects on the activity...)
 +0  upvote downvote
submitted by neonem(227)

Leukotriene B4 is a potent chemotactic molecule for neutrophils. Selective loss of this would have no effect on platelets, mast cells, or endothelium - these are more responsive to changes in TXA2, complement/arachidonic acid, and PGI2, respectively.

kernicterusthefrog  FA says: "Neutrophils arrive B4 others"
... xxabi made a comment on nbme20/block3/q#7 (A 10-year-old boy has a palpable mass in the ventral...)
 +2  upvote downvote
submitted by xxabi(82)

This is a thyroglossal duct cyst. The tyroglossal duct may persist and result in a thyroglossal duct cyst (occurring in midline near hyoid bone or at the base of the tongue), thus will classically move up with swallowing or tongue protrusion.

The foramen cecum (of the tongue) is the normal remnant of the thyroglossal duct

... hayayah made a comment on nbme20/block3/q#8 (A 12-year-old girl is brought to the physician for a...)
 +2  upvote downvote
submitted by hayayah(349)

Atrophy is decrease in tissue mass due to decrease in size (increased cytoskeleton degradation via ubiquitin-proteasome pathway and autophagy;  decreased protein synthesis) and/or number of cells (apoptosis). Causes include disuse, denervation, loss of blood supply, loss of hormonal stimulation, poor nutrition.

... katsu made a comment on nbme20/block3/q#8 (A 12-year-old girl is brought to the physician for a...)
 +1  upvote downvote
submitted by katsu(1)

Atrophy in myocytes. Atrophy is due to cytoskeleton degradation via ubiquitin-proteasome pathway.

Polyubiquitination: The binding of many ubiquitin molecules to the same target protein. Polyubiquitination of proteins is the triggering signal that leads to degradation of the protein in the proteasome. It is polyubiquitination that constitutes the "kiss of death" for the protein.

... celeste made a comment on nbme20/block3/q#9 (A 62-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by celeste(27)

If prostate cancer spreads to other parts of the body, it nearly always goes to the bones first (cancer.org/cancer/prostate-cancer/treating/treating-pain.html)

... medschoollovin made a comment on nbme20/block3/q#9 (A 62-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by medschoollovin(5)

Osteoblastic lesions are associated with prostatic adenocarcinoma mets.

Most other cancer mets to the bone are osteolytic lesions.

... jotajota94 made a comment on nbme20/block3/q#10 (A 59-year-old man develops fatigue and decreased...)
 -1  upvote downvote
submitted by jotajota94(11)

When conjugated bilirubin (CB) is less dan, 30% of total bilirubin----> increased the production of unconjugated bilirubin or decreased uptake. Hemolysis is the possible answer choice.

CB is 30%-50% mix-hyperbilirubinemia (Ex. Hepatitis or Alcholol) CB is more than 50% --> Obstruction (intra or extrahepatic)

... lebron james made a comment on nbme20/block3/q#10 (A 59-year-old man develops fatigue and decreased...)
 +0  upvote downvote
submitted by lebron james(2)

this dude had a complication aortic valve replacement which he now presents with a decrescendo diastolic murmur at the left sternal border (Aortic Regurg). The RBCs seem to get sheared as they pass thru the faulty opening of the replaced valve causing intravascular hemolysis

... strugglebus made a comment on nbme20/block3/q#11 (A 3-year-old boy is brought to the physician because...)
 +0  upvote downvote
submitted by strugglebus(63)

Auto dom disease are usually heterozygous (or so they want us to assume)

xxabi  How do you know is autosomal dominant?
scpomp  Hereditary spherocytosis
fshowon  Isnt the mean corpuscular hemoglobin concentration increased in spherocytosis? Thats what through me off.
charcot_bouchard  yes, would be inc in prev NBME. But this is batshit nbme 20. U have to identify spherocytes without central pallor in PBF
charcot_bouchard  yes, would be inc in prev NBME. But this is batshit nbme 20. U have to identify spherocytes without central pallor in PBF
... nala_ula made a comment on nbme20/block3/q#11 (A 3-year-old boy is brought to the physician because...)
 +1  upvote downvote
submitted by nala_ula(33)

The histology is of spherocytes (small spherical cells w/o central pallor). Hereditary spherocytosis is due to defect in proteins interacting with RBC membrane skeleton and plasma membrane (ankyrin, band 3, protein 4.2, spectrin). Mostly autosomal dominant inheritance (so heterozygous mutation since you only need one mutant allele to get the disease).

... xw1984 made a comment on nbme20/block3/q#11 (A 3-year-old boy is brought to the physician because...)
 +0  upvote downvote
submitted by xw1984(0)

I got this Q wrong. I was wondering why this patient “has no personal or family history”. Hereditary spherocytosis should be a AD disease, so, generally speaking, this diz should be seen in each generation, right?

... dr_jan_itor made a comment on nbme20/block3/q#11 (A 3-year-old boy is brought to the physician because...)
 +0  upvote downvote
submitted by dr_jan_itor(6)

Can anyone answer why this one can't be F. Beta thalasemia major? I was thinking becaues of his anemia and the "european descent" which includes the mediteranian europeans. Unless NMBE writers think that european only means the ones with extra white people lol

... breis made a comment on nbme20/block3/q#12 (A 46-year-old man has dyspnea, orthopnea, and a...)
 +1  upvote downvote
submitted by breis(9)

Patient has Midsystolic murmur heard at the cardiac apex. there is also a LEFT ATRIAL abnormality. Echo shows LEFT ATRIUM is enlarged.

Mid systolic... enlarged left atrium...

Best choice: Mitral Regurg

hpsbwz  Why is it regurg instead of stenosis?
minhphuongpnt07  Vague question requires a lot clinical reasoning. mitral regurgitation: holosystolic murmur( this cv: midsystolic), enlarged LA, LV Mitral stenosis: diastolic murmur, enlarged LA, normal LV. only best explanation I can think of: early stage Mitral regur, that's why the murmur is not holosystolic but midsystolic and LV still adequately handle the situation
... hayayah made a comment on nbme20/block3/q#13 (A 45-year-old woman develops proteinuria and...)
 +2  upvote downvote
submitted by hayayah(349)

Acute interstitial renal inflammation. Pyuria (classically eosinophils) and azotemia occurring after administration of drugs that act as haptens, inducing hypersensitivity (eg, diuretics, NSAIDs, penicillin derivatives, proton pump inhibitors, rifampin, quinolones, sulfonamides).

... strugglebus made a comment on nbme20/block3/q#14 (During a clinical study, an investigator tests a new...)
 +1  upvote downvote
submitted by strugglebus(63)

You are aiming to increase power and you can do so by increasing sample size (reduce B error).

... hayayah made a comment on nbme20/block3/q#15 (A 23-year-old woman, who was diagnosed with Sjögren...)
 +0  upvote downvote
submitted by hayayah(349)

Substance P (SP) is an undecapeptide present in the CNS and the peripheral nervous system. A compound thought to be involved in the synaptic transmission of pain and other nerve impulses.

... eacv made a comment on nbme20/block3/q#16 (A 41-year-old woman with systemic lupus...)
 +0  upvote downvote
submitted by eacv(2)

Informed consent should be obtained by a provider who has sufficient knowldge to give accurate description of the intervention, the riska and benefits of tratment, and able to answer all of the px question. This is the explanation for a very similar qx in Uworld.

... lianallado made a comment on nbme20/block3/q#17 (A 45-year-old man comes to the emergency department...)
 +0  upvote downvote
submitted by lianallado(1)

Schizoid personality disorder is characterized by voluntary social withdrawal, limited emotional expression and social isolation.

... hayayah made a comment on nbme20/block3/q#18 (An 18-year-old woman comes to the physician to...)
 +1  upvote downvote
submitted by hayayah(349)

Familial adenomatous polyposis is an autosomal dominant mutation. Thousands of polyps arise starting after puberty; pancolonic; always involves rectum. Prophylactic colectomy or else 100% progress to CRC.

Autosomal dominant diseases have, on average, 50% chance of being passed down to offspring.

sympathetikey  I would say this is Lynch Syndrome (APC is usually thousands of polyps) but lynch syndrome would generally have a family history of other cancers as well, so you might be right. Either way, both autosomal dominant so win win.
smc213  uptodate states: Classic FAP is characterized by the presence of 100 or more adenomatous colorectal polyps
... lianallado made a comment on nbme20/block3/q#19 (A 23-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by lianallado(1)

This patient presents with a mitochondrial myopathy since the disorder is inherited from the mother. Mitochondrial myopathies show “ragged red fibers” on muscle biopsy due to the accumulation of diseased mitochondria in the subsarcolemma of the muscle fiber.

katsu  Mitochondrial myopathies—rare disorders; often present with myopathy, lactic acidosis, and CNS disease, eg, MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). 2° to failure in oxidative phosphorylation. Muscle biopsy often shows “ragged red fibers” (due to accumulation of diseased mitochondria).
... usmle11a made a comment on nbme20/block3/q#19 (A 23-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by usmle11a(2)

https://www.youtube.com/watch?v=k0YqEpA-62A

guys this video explains alot

... usmile1 made a comment on nbme20/block3/q#19 (A 23-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by usmile1(9)

does anyone know what the structure E is pointing to?

thomasburton  Not sure looks like it might be free ribosomes or other such small cytosolic structure (I picked E too, thought B looked way too big!)
targetusmle  same here!! marked e thinking of it as a mitochondria
... hayayah made a comment on nbme20/block3/q#20 (A 67-year-old woman comes to the physician for a...)
 +2  upvote downvote
submitted by hayayah(349)

Sensitivity tests are used for screening. Specificity tests are used for confirmation after positive screenings.

Sensitivity tests are used for seeing how many people truly have the disease. Specificity tests are for those who do not have the disease.

A highly sensitive test, when negative, rules OUT disease. A highly specific test, when positive, rules IN disease. So, a test with with low sensitivity cannot rule out a disease. A test with low specificity can't rule in disease.

The doctor and patient want to screen for colon cancer and rule it out. The doctor would want a test with high sensitivity to be able to do that. He knows that testing her stool for blood will not rule out the possibility of colon CA.

sympathetikey  SeN Out (Snout) --> sensitive test; - test rules out SPec In (Specin) --> specific test; + test rules in
... yotsubato made a comment on nbme20/block3/q#21 (A newborn is born with a lethal chromosome defect....)
 +1  upvote downvote
submitted by yotsubato(214)

"Do no harm"

Starving the baby or withholding food is doing harm. At this point you provide palliative care until the death of the baby. If the parents decide to "pull the plug" then they can do it, but as the doctor thats not your choice.

cry2mucheveryday  Why not 'give foods according to normal caloric requirement'?
hpsbwz  @cry2mucheveryday because feeding to the caloric may be too much or too little for this baby. considering the baby's crying only resolves with food, if you've already reached the limit, are you just not going to feed the baby? that's how i thought of it. "maintain comfort" is the key phrase.
... gasngo711 made a comment on nbme20/block3/q#21 (A newborn is born with a lethal chromosome defect....)
 +1  upvote downvote
submitted by gasngo711(1)

Is this basically just a "maintain quality of life" kind of question?

medstudent65  Its a stupid as shit question. Some of the ethics questions on these new NBMEs are horrible.
... medulla made a comment on nbme20/block3/q#21 (A newborn is born with a lethal chromosome defect....)
 +0  upvote downvote
submitted by medulla(1)

lethal chromosomal defect - > he is going to die -> maintain comfort

... hayayah made a comment on nbme20/block3/q#22 (In patients with breast cancer, metabolically stable...)
 +2  upvote downvote
submitted by hayayah(349)

GnRH agonists like Leuprolide are effective for patients with breast CA because if given in a continuous fashion, they downregulate the GnRH receptor in the pituitary and ultimately decrease FSH and LH.

... monoloco made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +2  upvote downvote
submitted by monoloco(49)

If you want to clear a drug, it is probably best that it not be bound to proteins (so that it gets filtered) and it has a low volume of distribution (so it isn't in the deep, hard to reach tissues).

kingtime9119  But that doesn't make sense. Page 233 of First Aid 2019 edition clearly states that being plasma protein bound creates the lowest volume of distribution, because not being bound to proteins increases the chance it will reach deep into the tissues before it reaches the kidneys. Discrepancy with First Aid?
haliburton  my reasoning was comparing two drugs, both with Vd of 1, the drug with the lower albumin binding would be cleared faster @kingtime. I don't think you're considering that A and B have equal Vd.
... kingtime9119 made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +0  upvote downvote
submitted by kingtime9119(0)

[comment moved to subcomment]

... strugglebus made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +0  upvote downvote
submitted by strugglebus(63)

I was wondering if it was to allow for partial CNS penetration since the drug is supposedly supposed to have CNS effect

... hayayah made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +4  upvote downvote
submitted by hayayah(349)

In order for a drug to be cleared by the kidney, it must first be filtered in the glomeruli. Drugs with a high VD have more of the drug in the tissue that are not available to filtered by the kidney. Drugs with high protein binding won't be filtered either. So you want a drug with low Vd and low binding if you want it cleared via the kidneys and urine.

... haliburton made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +0  upvote downvote
submitted by haliburton(74)

[comment moved to subcomment]

... lispectedwumbologist made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +2  upvote downvote
submitted by lispectedwumbologist(23)

Can somebody please explain why the pKa has to be 6 instead of 10?

masonkingcobra  Since an ionized form is charged (by definition), it will not easily cross a nonpolar lipid membrane. Thus, it is important to recognize the potential of the drug to ionize in order to predict its solubility and the degree to which it can be reabsorbed. The degree of ionization is determined by the drug’s pKa and the pH of its environment. Weak acids and bases are 50% ionized and 50% unionized when the surrounding pH equals the drug’s pKa. At 2 pH units above or below the pKa of the drug, nearly 100% of the drug is ionized or unionized.
masonkingcobra  Basically weak acids are best excreted in alkaline urine, but weak bases are excreted more readily in acid urine.
masonkingcobra  In summary, because this is a weak acid at pKa 6, making the urine alkaline will result it its ionization and excretion. Ionized cant move through lipid membranes so can't get reabsorbed and is pissed out.
yex  Following on masonkingcobra explanation: A pKa 4-9 can be either weak acid or base. Weak acid pKa 4-7; strong acid pKa 1-3 Weak base pKa 7-9; strong base pKa above 9 Differents pHs: stomach: 1-2 duodenum: 3-5 early jejunum: 5-7 late jejunum: 7-9 ileum: >9 urine: 4.5-8 Weak acids (pKa) gets absorbed in acidic (pH) environments and cleared in basic. Weak bases gets absorbed in basic environments and cleared in acidic. THIS DOES NOT APPLY TO STRONG BASES OR ACIDS!!!! The best explanation for this is a Biochem lecture from Pass Program and it is available on YouTube, its long but it is for sure worth it!! Look for 19 Biochemistry 1 from Pass Program on YouTube.
... charcot_bouchard made a comment on nbme20/block3/q#23 (A 50-year-old woman is brought to the emergency...)
 +1  upvote downvote
submitted by charcot_bouchard(42)

pKa is pH at which any drug is at its 50% ionized state.

Now we are alk urine i.e inc pH. when pH>pKa it will have two diff path for acidic drug & basic drug.

Acidic drug will inc its elimination (inc ionized form), basic drug will be more absorbed. so we need to know the drug is basic /acidic.

Now if u alk urine its elimination inc. so it have to be acidic. or u can know its a sodi salt of drug with CNS property i.e most like Phenobarbital (Weak acid)

so if pKa of drug is 6---at pH 7 we will start eliminating

but if pKa is 0 we need to raise pH of urine at 11 to start eliminating.at that point prev drug (pKa=6) would be totally out of system.

thats why A is the right ans (pKa = 6)

charcot_bouchard  Correction : Not 0. i means if pKa is 10
charcot_bouchard  2nd update : cont to learn school grade chem. if pKa > 7 it is base. and if pKa is < 7 it is acid. Since we established the drug have to be a weak acid pKa cant be more than 7.
dbg  thanks, but Pka and PH are not at all the same thing
... hayayah made a comment on nbme20/block3/q#24 (A 2-month-old girl is brought to the emergency...)
 +5  upvote downvote
submitted by hayayah(349)

Patient has congenital hypothyroidism (cretinism). Findings: pot belly, pale, puffy-faced, umbilical hernia, macroglossia, hypotonia, poor brain development (MC cause of treatable mental retardation), large anterior fontanelles.

whossayin  how can you differentiate the symptoms of cretinism from Down syndrome?
... hayayah made a comment on nbme20/block3/q#25 (A 4-week-old infant is brought to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

Most common cause of gastric outlet obstruction in infants. Palpable olive-shaped mass in epigastric region, visible peristaltic waves, and nonbilious projectile vomiting at ∼2–6 weeks old.

Ultrasound shows thickened and lengthened pylorus. Treatment is surgical incision (pyloromyotomy).

katsu  FA 2019 p. 353: Most common cause of gastric outlet obstruction in infants (1:600). Palpable olive-shaped mass in epigastric region, visible peristaltic waves, and nonbilious projectile vomiting at ∼ 2–6 weeks old. More common in firstborn males; associated with exposure to macrolides. Results in hypokalemic hypochloremic metabolic alkalosis (2° to vomiting of gastric acid and subsequent volume contraction). Ultrasound shows thickened and lengthened pylorus. Treatment is surgical incision (pyloromyotomy).
... medbitch94 made a comment on nbme20/block3/q#26 (A 3-month-old boy is brought to the physician...)
 +4  upvote downvote
submitted by medbitch94(5)

FA2019 page 47: I-cell disease (inclusion cell disease/mucolipidosis type II)—inherited lysosomal storage disorder; defect in N-acetylglucosaminyl-1-phosphotransferase → failure of the Golgi to phosphorylate mannose residues (forming mannose-6-phosphate) on glycoproteins → proteins are secreted extracellularly rather than delivered to lysosomes. Results in coarse facial features, gingival hyperplasia, clouded corneas, restricted joint movements, claw hand deformities, kyphoscoliosis, and high plasma levels of lysosomal enzymes. Often fatal in childhood.

... hayayah made a comment on nbme20/block3/q#27 (A 55-year-old man with type 2 diabetes mellitus,...)
 +0  upvote downvote
submitted by hayayah(349)

Statins can have a side effect of rhabdomyolysis.

... hayayah made a comment on nbme20/block3/q#28 (A 23-year-old woman who is 6 months pregnant...)
 +2  upvote downvote
submitted by hayayah(349)

Heparin-induced thrombocytopenia (HIT) is the development of IgG antibodies against heparin bound platelet factor 4 (PF4). Antibody-heparin-PF4 complex activates platelets Ž thrombosis and thrombocytopenia. Highest risk with unfractionated heparin.

drw  could you also help to understand: 1) could anti-heparin-PF4 complex be also called anti-PLT antibody? 2) PLT reduction is due to both PLT thrombosis consumption and elimination in the spleen, then why hypersplenism is not correct?
charcot_bouchard  hypersplenism means bigger spleen eating everything. thats not the case here. here spleen is normal. autoimmune cause
... hayayah made a comment on nbme20/block3/q#29 (An 83-year-old man is brought to the emergency...)
 +1  upvote downvote
submitted by hayayah(349)

Septic shock is a type of distributive shock which is marked by massive vasodilation (d/t inflammatory response) causing decreased SVR, decreased preload / PCWP, and increased CO.

smc213  Septic shock can also present with hypothermia <36C
... hayayah made a comment on nbme20/block3/q#30 (A 22-year-old woman who recently emigrated from...)
 +2  upvote downvote
submitted by hayayah(349)

The right and left ventricle are drained by separate parts of the foramen of monro. (Left side is drained by left monro, right side by right monro). An obstruction of the right foramen of monro will enlarge the right ventricle.

hmorela  My mnemonic for CSF flow: "Little Infants Crying For Food. Sorry, All Done." Lateral ventricle - intraventricular foramen of monro - cerebral aqueduct - forth ventricle - foramen of lusaka/magendie - subarachnoid space - arachnoid granulations - dural venous sinuses
charcot_bouchard  u missed 3rd ventricle, how about " Little Igor the 3rd, Crying for..."
... celeste made a comment on nbme20/block3/q#31 (A 62-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by celeste(27)

Beta-Tubulin is a subunit of tubulin. Tubulin is one of several members of a small family of globular proteins. It is the major constituent of microtubules. There are two of most common members of the tubulin family: alpha-tubulin and beta-tubulin, and together their dimers form microtubules. (origene.com)

... xxabi made a comment on nbme20/block3/q#31 (A 62-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by xxabi(82)

Vinca and plant alkaloids bind B-tubulin, which inhibits the formation or disassembly or microtubules, respectively.

... minhphuongpnt07 made a comment on nbme20/block3/q#32 (A 54-year-old woman with terminal metastatic...)
 +0  upvote downvote
submitted by minhphuongpnt07(0)

super vague question ! Dr denies assisting suicide=> nonmaleficience do everything he can to manage her pain => beneficience

... laminin made a comment on nbme20/block3/q#33 (A 31-year-old woman receives a prescription for...)
 +4  upvote downvote
submitted by laminin(6)

Tetracyclines have a high affinity to form chelates with polyvalent metallic cations such as Fe+++, Fe++, Al+++, Mg++ and Ca++. Many of these tetracycline-metal complexes are either insoluble or otherwise poorly absorbable from the gastro-intestinal tract. Milk and other dairy products, antacids containing polyvalent cations, as well as various iron salts ingested simultaneously with tetracycline derivatives, might interfere with their absorption by 50 to 90% or even more. source: https://www.ncbi.nlm.nih.gov/pubmed/946598

... hayayah made a comment on nbme20/block3/q#34 (A 22-year-old woman comes to the emergency...)
 +4  upvote downvote
submitted by hayayah(349)

Administration of Penicillin for Syphilis may lead to the Jarisch-Herxheimer reaction hours after treatment. Occurs due to lysis of spirochetes (so it can occur with Borrelia and Leptospirosis as well). The reaction is characterized by fever and chills.

The classical explanation of the Herxheimer reaction is that treatment results in the sudden death and destruction of large numbers of treponemes, with the liberation of protein products and toxins.

... hayayah made a comment on nbme20/block3/q#35 (A 51-year-old man has the acute onset of fever and...)
 +2  upvote downvote
submitted by hayayah(349)

CMV is associated with infecting organ transplant patients. CMV is transmitted via sexual contact, organ transplant, or vertically via placenta. Reactivation of CMV occurs in the immunosuppressed.

Organ transplant patients are at an increased risk of CMV pneumonia.

... amorah made a comment on nbme20/block3/q#35 (A 51-year-old man has the acute onset of fever and...)
 +10  upvote downvote
submitted by amorah(22)

Fever -> rule out left ventricular failure TMP-SMX prophylaxis -> rule out Pneumocystis jiroveci Kidney transplant but no WBC/RBC in urine -> rule out transplant rejection

Leaving CMV and atypical mycobacterium as the remaining two options. CMV is more likely in a transplant patient.

... monoloco made a comment on nbme20/block3/q#36 (A 4-year-old boy has had fever, abdominal cramping,...)
 +4  upvote downvote
submitted by monoloco(49)

I think Shigella is the most appropriate, as it is actually regarded as highly inflammatory. Yes, E. coli can be of the EHEC/STEC variety, but E. coli could also be of the ETEC variety or whatever other strains it has. Ergo, E. coli may be plausible, but it is not the 'most likely.' Bleh to these kinds of questions.

... beeip made a comment on nbme20/block3/q#36 (A 4-year-old boy has had fever, abdominal cramping,...)
 +5  upvote downvote
submitted by beeip(56)

Apart from the line in FA referencing PMN infiltrate in Shigella, there is no way to differentiate here between it and E. Coli. Cheap shot.

... louisville made a comment on nbme20/block3/q#36 (A 4-year-old boy has had fever, abdominal cramping,...)
 +6  upvote downvote
submitted by louisville(6)

Methylene-blue stained fecal smear reveled numerous neutrophils (but not any organisms). Shigella is colorless when stained with methylene blue; E coli stains blue with methylene blue because it ferments lactose.

sympathetikey  E. coli stains green (just fyi) otherwise, perfect.
... neonem made a comment on nbme20/block3/q#36 (A 4-year-old boy has had fever, abdominal cramping,...)
 +3  upvote downvote
submitted by neonem(227)

Shigella causes an inflammatory diarrhea; it produces a toxin and can invade tissue directly. In addition, it is resistant to acid, so it has a characteristically low infective dose (~10 organisms), which facilitates its fecal-oral (person-to-person) spread especially in settings where hygiene may be compromised, such as in daycare or institutional housing. It can be differentiated from E. Coli (EHEC) because E Coli doesn't have as much person-to-person spread and only causes GI damage by the shiga-like toxin, not direct invasion. Therefore, EHEC wouldn't facilitate as strong of a neutrophilic response.

yotsubato  I assumed all the kids in the daycare had the same lunch, thus got food poisoning, thus all got EHEC.
... hayayah made a comment on nbme20/block3/q#37 (A 62-year-old man with alcohol-induced liver disease...)
 +0  upvote downvote
submitted by hayayah(349)

Clinical use of K-sparing diuretics:

  • Hyperaldosteronism
  • K+ depletion
  • HF
  • hepatic ascites (spironolactone)
  • nephrogenic DI (amiloride)
  • antiandrogen
redvelvet  Patients with hepatic ascites have hyperaldosteronism; because the intravascular volume is escaped to third space(ascites). So adding spironolactone is a good choice.
... sweetmed made a comment on nbme20/block3/q#37 (A 62-year-old man with alcohol-induced liver disease...)
 +0  upvote downvote
submitted by sweetmed(28)

A rapid reduction of ascites is often accomplished simply with the addition of low-dose oral diuretics in the outpatient setting. First-line diuretic therapy for cirrhotic ascites is the combined use of spironolactone (Aldactone) and furosemide (Lasix) - Clevland Clinic

... masonkingcobra made a comment on nbme20/block3/q#38 (A 23-year-old man with a 3-year history of...)
 +1  upvote downvote
submitted by masonkingcobra(56)

In psychogenic polydipsia, serum sodium is low, and after water deprivation test, urine osmolality is increased. Urine osmolality does not increase with vasopressin injection

In nephrogenic diabetes insipidus, serum sodium is high and there is no change/mild increase in urine osmolality after water deprivation

yotsubato  This patient does not undergo a water deprivation test
niboonsh  Compulsive water drinking or psychogenic polydipsia is now increasingly seen in psychiatric populations. Effects of increased water intake can lead to hyponatremia causing symptoms of nausea, vomiting, seizures, delirium and can even be life threatening if not recognized and managed early. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579464/
missi19998  Just wondering why it in not resistance to ADH action of vasopressin
amarousis  because he would be hypernatremic with no ADH. can't resorb any water
minhphuongpnt07  low osm/urine, low os/plasma => psychogenic polydipsia
... hayayah made a comment on nbme20/block3/q#39 (A 19-year-old woman has severe refractory pustular...)
 +1  upvote downvote
submitted by hayayah(349)

Isotretinoin is used to treat severe cystic acne. It is a teratogen. Can cause multiple severe birth defects. Contraception is mandatory. RXR is a retinoid X receptor.

IsoTERATinoin

... whossayin made a comment on nbme20/block3/q#39 (A 19-year-old woman has severe refractory pustular...)
 +0  upvote downvote
submitted by whossayin(3)

the question was very poorly worded in my opinion, anybody else agree?

niboonsh  yea it was a dumbass question, whoever is writing these questions is undoubtedly a crazy genius but homeboy (or homegirl...homeperson?) needs a few grammar lessons.
yex  I agree. We know that it is a teratogen, but how does that question directs you to think about teratogenic effects instead of something physiologic?
dr_jan_itor  The questions in the NBMEs by default are reject questions. So highly selective to be awful questsions. I am recieving regular heads up that the stems on the real thing lately are like 10-12 lines long. So these questions are not anywhere near like the test. NBME has f'd us good for this particular round of practice forms.
... hayayah made a comment on nbme20/block3/q#40 (Two days after admission to the hospital because of...)
 +3  upvote downvote
submitted by hayayah(349)

The only time you transfuse a Jehovah's Witness patient is when the patient is a minor (<18 years old).

medstudent65  I get why the answer is not to proceed but simply stating at admissions you dont want blood products means nothing without proper paperwork being signed.
... katsu made a comment on nbme20/block3/q#40 (Two days after admission to the hospital because of...)
 +0  upvote downvote
submitted by katsu(1)

It's called patient consent, you've probably heard of it

... step420 made a comment on nbme20/block3/q#41 (A 2-year-old child undergoes resection of the right...)
 +0  upvote downvote
submitted by step420(17)

Other kidney Hypertrophies due to increased stress --> not hyperplasia bc not cancerous

masonkingcobra  Above answer is incorrect because hyperplasia can be either physiological or pathological. Prolonged hyperplasia can set the seed for cancerous growth however. Robbins: Stated another way, in pure hypertrophy there are no new cells, just bigger cells containing increased amounts of structural proteins and organelles. Hyperplasia is an adaptive response in cells capable of replication, whereas hypertrophy occurs when cells have a limited capacity to divide. Hypertrophy and hyperplasia also can occur together, and obviously both result in an enlarged (hypertrophic) organ.
johnthurtjr  FTR Pathoma Ch 1 Dr. Sattar mentions hyperplasia is generally the pathway to cancer, with some exceptions like the prostate and BPH.
sympathetikey  Tubular hypertrophy is the natural compensation post renal transplant. Just one of those things you have to know, unfortunately.
charcot_bouchard  Isnt Kidney a labile a tissue & thus should undergo both. This ques is dipshit
... medbitch94 made a comment on nbme20/block3/q#42 (A 13-year-old girl has an episode of severe cellular...)
masonkingcobra  The pathogenesis of post-transplant lymphoproliferative disorders (PTLD) in most patients relates to the outgrowth of Epstein-Barr virus (EBV)-positive B cell proliferations in the setting of chronic T cell immunosuppression.
... ms2991 made a comment on nbme20/block3/q#42 (A 13-year-old girl has an episode of severe cellular...)
 +2  upvote downvote
submitted by ms2991(2)

FA 2018 page 165--> EBV is "associated with lymphoproliferative disease in transplant patients"

katsu  EBV also targets B lymphocytes
... nickybeezle made a comment on nbme20/block3/q#42 (A 13-year-old girl has an episode of severe cellular...)
 +0  upvote downvote
submitted by nickybeezle(0)

Human B cells are the primary targets of Epstein Barr virus (EBV) infection. In most cases EBV infection is asymptomatic because of a highly effective host immune response but some individuals develop self-limiting infectious mononucleosis, while others develop EBV-associated lymphoid or epithelial malignancies.

... neonem made a comment on nbme20/block3/q#43 (A 71-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by neonem(227)

Cilostazol is a phosphodiesterase inhibitor; leads to increased cAMP which inhibits platelet degranulation/activation while also causing vasodilation. All of the other options work on either vasculature or platelets but not both.

kernicterusthefrog  Just to add: cAMP activates protein kinase A (PKA), which is the more direct mediator of platelet aggregation inhibition, and of myosin light-chain kinase inhibition (which causes inhibition of smooth muscle contraction and thus vasodilation). Just in case there's a question that gets more specific than this one!
... hayayah made a comment on nbme20/block3/q#44 (A 56-year-old man is brought to the emergency...)
 +9  upvote downvote
submitted by hayayah(349)

LV stopped working, pressure backed up into pulm circuit. Pulm circuit roughly is made of 3 "parts" - the capillaries, interstitial space, and the alveoli.

In cardiogenic shock, the extra blood increases capillary hydrostatic pressure, driving fluid into the interstitial space. Compared to the alveoli, the interstitial space now has more fluid (thus more interstitial hydrostatic pressure and less oncotic pressure due to ratio of fluid to protein), and as a result of this unbalancing of forces, fluid moves into the alveoli --> pulmonary edema.

masonkingcobra  https://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Figure%204.1.%20Mechanisms%20of%20enhanced%20transcapillary%20filtration%20in%20response%20to%20elevations%20in%20arterial%20or%20venous%20pressure.&p=BOOKS&id=53445_fig4.1.jpg
... hello made a comment on nbme20/block3/q#44 (A 56-year-old man is brought to the emergency...)
 +4  upvote downvote
submitted by hello(52)

Patient's symptoms began 30 min after mowing lawn (i.e. after doing physical activity). He has severe chest pain and is cool, clammy, diaphoretic. He has increased pulmonary artery pressure and increased left atrial pressure. Taken altogether, this is cardiogenic shock.

Cardiogenic shock is a heart pump problem -- the LV isn't working.

When the LV, isn't working, it causes a back up in the direction opposite to how blood normally flows. Therefore, blood will back up in the lungs.

This causes increased capillary hydrostatic pressure --> this drives more fluid into the interstitium --> this causes increased interstitial hydrostatic pressure --> there is now more fluid than normal in the interstitium --> this affects the protein ratio within the interstitum --> this causes decreased interstitial oncotic pressure.

targetusmle  awesomely explained :)
... hayayah made a comment on nbme20/block3/q#45 (A 39-year-old man reports bright red spots on the...)
 +1  upvote downvote
submitted by hayayah(349)

Large swollen rectal veins --> patient has external hemorrhoids. Swollen and inflamed veins in the rectum and anus that cause discomfort and bleeding. The most common cause of external hemorrhoids is repeated straining while having a bowel movement.

... hayayah made a comment on nbme20/block3/q#46 (Removal of the thymus at birth results in severely...)
 +4  upvote downvote
submitted by hayayah(349)

By age 75, the thymus is little more than fatty tissue. Fortunately, the thymus produces all of your T cells by the time you reach puberty. They are long-lived and that's why you can lose your thymus without impairment of your immune system.

sweetmed  Memory T cells live for six months or less in healthy humans (Westera et al., 2013), whereas naive T cells can live for up to nine years
whossayin  so the bone marrow does not take the role of the thymus?
dr_jan_itor  @sweetmed, does that mean that if someone loses their thymus, they would develop imunodeficiencies appx 9 years later as the naive T cells have died off?
hpsbwz  @dr_jan_itor no, because once all of the thymocytes become T-lymphocytes, they are stored in lymphoid organs until they're needed. this is why removal of the thymus in MG does not cause any immune system deficiency.
... thomas made a comment on nbme20/block3/q#47 (A 60-year-old woman has prolonged apnea following...)
 +0  upvote downvote
submitted by thomas(3)

Not sure about this, but it seems to me that this is referring to "pseudocholinesterase inhibitor deficiency. It's an enzyme defect that is triggered by NMJ blockers - succinylcholine or curare's.

https://en.wikipedia.org/wiki/Pseudocholinesterase_deficiency

usmleuser007  I believe this question was stating that AchE activity was abnormal = it was not lowering the Ach activity. Which suggests that another ligand like Ach was being used.
... niboonsh made a comment on nbme20/block3/q#47 (A 60-year-old woman has prolonged apnea following...)
 +2  upvote downvote
submitted by niboonsh(57)

https://www.youtube.com/watch?v=WGWFFN01qkA succinylcholine usually has v fast duration of action bcuz metabolized by plasma pseudocholinesterase. With atypical pseudocholinesterase, decreased metabolism of succinylcholine and thus causes a prolonged duration of action of succinylcholine ----> APNEA

... xxabi made a comment on nbme20/block3/q#47 (A 60-year-old woman has prolonged apnea following...)
 +3  upvote downvote
submitted by xxabi(82)

The duration of action of Succinylcholine is determined by its metabolism by plasma cholinesterase. So if there is abnormal plasma cholinesterase (=psuedocholinesterase), it will lead to delayed metabolism of succinylcholine as well as mivacirum, heroin, and cocaine.

... celeste made a comment on nbme20/block3/q#48 (A 48-year-old woman comes to the physician because...)
 +1  upvote downvote
submitted by celeste(27)

Amiodarone, a class III antiarrhythmic drug, has multiple effects on myocardial depolarization and repolarization that make it an extremely effective antiarrhythmic drug. However, amiodarone is associated with a number of side effects, including thyroid dysfunction (both hypo- and hyperthyroidism), which is due to amiodarone's high iodine content and its direct toxic effect on the thyroid. (uptodate.com)

celeste  The "**iod**" part of am**iod**arone reminds me of it's high **iod**ine content.
xxabi  I think of it as the trifecta - gotta monitor LFTs, PFTs, and Ts (thyroid) when on amiodarone!
sinforslide  Also, the patient presented with Afib; this might've been caused by transient hyperthyroidism as a prelude to Hashimoto's. In this case, if you give Amio, you'd cause serious hypothyroidism!
... medbitch94 made a comment on nbme20/block3/q#49 (A 92-year-old woman who was recently admitted to a...)
 +3  upvote downvote
submitted by medbitch94(5)

Actinic purpura results from extravasation of blood into the dermis. This phenomenon is due to the skin atrophy and the fragility of the blood vessels in elderly individuals, which is exacerbated by chronic sun exposure. Actinic purpura lesions are located on sun-exposed areas, like the arms, face, and neck.

Skin atrophy in dermatoporosis is due to an alteration of collagen, similar to that which is seen in osteoporosis. This pronounced skin atrophy caused by the photo-aging makes the dermal vascular network very sensitive to the slightest trauma or shearing force.

... medbitch94 made a comment on nbme20/block3/q#49 (A 92-year-old woman who was recently admitted to a...)
... strugglebus made a comment on nbme20/block3/q#50 (A 62-year-old man comes to the physician because of...)
 +2  upvote downvote
submitted by strugglebus(63)

They are talking about Baclofen, a GABA-B agonist known to treat muscle spasticity

... neonem made a comment on nbme20/block3/q#50 (A 62-year-old man comes to the physician because of...)
 +4  upvote downvote
submitted by neonem(227)

This patient likely has some form of upper motor neuron lesion or disease - UMN lesions are characterized by weakness, increased deep tendon reflexes, and spastic paresis. Baclofen is a GABA-B agonist specific to the spinal cord, used ot treat muscle spasticity, dystonia, and MS. GABA-B is a G-protein coupled receptor coupled to Gi, so agonism of this receptor causes hyperpolarization of the neurons and decreased release of excitatory glutamate.

... step420 made a comment on nbme20/block4/q#1 (A 32-year-old man comes to the physician because of...)
 +4  upvote downvote
submitted by step420(17)

B-HCG and LH,FSH,TSH share same alpha subunit, so HCG can activate those receptors if its in high enough quantity. Activating LH receptor will lead to more Testosterone from the Leydig cells. More testosterone can lead to more estrogen formation via aromatase.

... ergogenic22 made a comment on nbme20/block4/q#2 (A study is conducted to identify healthy women at...)
 +0  upvote downvote
submitted by ergogenic22(28)

CRP is an acute phase reactant, these are synthesized primarily by the liver

... celeste made a comment on nbme20/block4/q#3 (A 23-year-old woman comes to the physician for a...)
 +1  upvote downvote
submitted by celeste(27)

Sounds like a hypertrophic scar. "Hypertrophic scars contain primarily type III collagen oriented parallel to the epidermal surface with abundant nodules containing myofibroblasts, large extracellular collagen filaments and plentiful acidic mucopolysaccharides." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3022978/

johnthurtjr  I think it may actually be a keloid, not a hypertrophic scar, as it expands beyond the borders of the original incision.
thepacksurvives  I believe this is a keloid; a hypertrophic scar does not extend past the borders of it's original incision, while a keloid does. regardless, the answer to this question is the same :)
breis  First AID pg 219 Scar formation: Hypertrophic vs. Keloid
charcot_bouchard  They give granulation tissue is a option which is type 3 collagen. so if it was hypertrophic scar it would be ap problem since its only excessive growth of Type 3. while keloid is excessive growth of both 1 and 3
... dbg made a comment on nbme20/block4/q#3 (A 23-year-old woman comes to the physician for a...)
 +2  upvote downvote
submitted by dbg(18)

Imo, this answer choice is wrong, there is no problem in the process of collagen "synthesis" per se. The issue is with excessive synthesis and disorganized deposition. Not an 'abnormal synthetic process' - as would be in EDS, MF, Menkes, etc.

whoissaad  Exactly my reasoning for not choosing collagen "synthesis"
... hayayah made a comment on nbme20/block4/q#4 (A 20-year-old man comes to the physician stating...)
 +2  upvote downvote
submitted by hayayah(349)

A fractured cribriform plate (anterior skull trauma) can result in leaking of cerebrospinal fluid into the nose and loss of sense of smell. Smell plays a large role in the perception of taste. So, in practice, a patient may complain of loss of taste rather than of smell.

brownielove79  can it be a facial nerve??? with lateral head trauma (injury during passage through middle ear, or external auditory canal??) doubt!!!
... xxabi made a comment on nbme20/block4/q#5 (Immediately after a cerebral infarction, a...)
 +0  upvote downvote
submitted by xxabi(82)

Broca’s aphasia: expressive (motor aphasia) with agrammatism (pts aware that they don’t make sense) - area A Wernicke’s aphasia: receptive (sensory) aphasia with impaired comprehension (pts lack insight)

breis  Why would B be incorrect? I realize Broca is "technically lower" but A seems too low to be causing weakness of the lower 2/3 of the face? Am I missing something?
shaeking  @breis B is incorrect because of the lower 2/3 of the face weakness. B isn't located on the motor cortex but in the premotor cortex, plus it isn't low enough for the lower two thirds of the face. https://thebrain.mcgill.ca/flash/a/a_06/a_06_cr/a_06_cr_mou/a_06_cr_mou.html https://www.sciencenews.org/blog/science-ticker/homunculus-reimagined
cienfuegos  @breis, per UW: "a/w r. hemiparesis (face & UE) bc close to primary motor cortex"
... neonem made a comment on nbme20/block4/q#6 (A 51-year-old man develops diaphoresis, tachycardia,...)
 +0  upvote downvote
submitted by neonem(227)

Alcohol withdrawal leads to a sympathetic-hyperactivity-like syndrome with tremors, HTN, insomnia, GI upset, diaphoresis, and mild agitation 3-36 hours after the last drink. There is a similar, but usually slightly later, overlap of withdrawal seizures 6-48 hours after the last drink.

katsu  Alcohol withdrawal sx (p. 554 FA 2018) Time from last drink: 3–36 hr: tremors, insomnia, GI upset, diaphoresis, mild agitation 6–48 hr: withdrawal seizures 12–48 hr: alcoholic hallucinosis (usually visual) 48–96 hr: delirium tremens (DTs) Treatment: benzodiazepine
... radion made a comment on nbme20/block4/q#7 (33 yo woman with HIV, generalized tonic-clonic seizure)
 +2  upvote downvote
submitted by radion(2)

Single enhancing lesion points more towards lymphoma than toxo. Toxo is usually multi-ring enhancing lesions.

... hayayah made a comment on nbme20/block4/q#7 (33 yo woman with HIV, generalized tonic-clonic seizure)
 +4  upvote downvote
submitted by hayayah(349)

This is a primary central nervous system lymphoma. Most commonly associated with HIV/AIDS; pathogenesis involves EBV infection.

Considered an AIDS-defining illness. Variable presentation: confusion, memory loss, seizures. Mass lesion(s) (may be ring-enhancing in immunocompromised patient) on MRI, needs to be distinguished from toxoplasmosis via CSF analysis or other lab tests. Toxo usually has multiple ring enhancing lesions.

... yotsubato made a comment on nbme20/block4/q#7 (33 yo woman with HIV, generalized tonic-clonic seizure)
 +0  upvote downvote
submitted by yotsubato(214)

It cant be Bacterial abscess (Nocardia) because shes taking TMP SMX.

It cant be toxo, because she has one lesion and is also taking TMP SMX which should improve her symptoms.

Glioblastoma is a disease of older individuals

Metastatic disease that mets to the brain is unlikely at this age.

CNS lymphoma is common in HIV AIDS patients, so that is the most likely choice.

... step420 made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by step420(17)

Hypertension can lead to aneurysms like in this patient. Not syphilis because not thoracic aorta.

... haliburton made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 -4  upvote downvote
submitted by haliburton(74)

FA 2017: 3° syphilis disrupts the vasa vasorum of the aorta with consequent atrophy of vessel wall and dilatation of aorta and valve ring. May see calcification of aortic root, ascending aortic arch, and thoracic aorta. Leads to “tree bark” appearance of aorta. Can result in aneurysm of ascending aorta or aortic arch, aortic insufficiency.

... masonkingcobra made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 +1  upvote downvote
submitted by masonkingcobra(56)

Robbin's: The two most important causes of aortic aneurysms are atherosclerosis and hypertension. Atherosclerosis is the more dominant factor in abdominal aortic aneurysms, while hypertension is associated with ascending aortic aneurysms.

... xxabi made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 +4  upvote downvote
submitted by xxabi(82)

I was under the impression that this was an aortic dissection, due to "severe chest pain" as well as the false lumen in the aorta. And HTN is the #1 risk factor for aortic dissection. Someone correct me if i'm wrong, but I think this is aortic dissection rather than aortic aneurysm.

chefcurry  I believe so, FA 2018 pg 299
ergogenic22  It is dissection "extra lumen in the media of the proximal aorta" = "a longitudinal intimal (tunica intima) tear with dissection of blood through the media of the aortic wall" ... answer is still hypertension
breis  FA 2019: 301
... kernicterusthefrog made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by kernicterusthefrog(17)

This is not an aneurysm, which is what makes this question so weird: "x-rays of the chest do not show widening." My understanding was that dissections usually occur in the picture of aneurysm, especially due to hypertension. However, perhaps that's not the case, particularly in these Stanford Type A dissections? The picture in FA sure makes it look like a widened aorta (aneurysm) with a dissection...

... eacv made a comment on nbme20/block4/q#8 (A 58-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by eacv(2)

This is an AORTIC DISSECTION: No. 1 RF is HTA, intimal tear forming a false lumen and the pain sudden onset radiates to the back.

... ergogenic22 made a comment on nbme20/block4/q#9 (A previously healthy 37-year-old woman comes to the...)
 +1  upvote downvote
submitted by ergogenic22(28)

Pt has signs and Sx of hypercortisol. Low/normal ACTH favors elevated cortisol independent of ACTH, confirmed by lack of response to dexamethasone suppression. Zona fasciculata is origin of cortisol production.

... hayayah made a comment on nbme20/block4/q#10 (A 65-year-old woman who has a 25-year history of...)
 +0  upvote downvote
submitted by hayayah(349)

She has a vitamin C deficiency. Scurvy features swollen gums, easy bruising, petechiae, perifollicular and subperiosteal hemorrhages.

... strugglebus made a comment on nbme20/block4/q#11 (A 37-year-old man who is HIV positive comes to the...)
 +4  upvote downvote
submitted by strugglebus(63)

Hydrocodone/Methadone can lead to dependence--you avoid in long term use. NSAIDs you also avoid due to partial ineffectiveness in neuropathic pain as well as ulcer risk. TCA's are known to treat neuropathic pain very well (i.e. diabetes, ART therapy)

... killme made a comment on nbme20/block4/q#12 (An investigator is conducting a randomized,...)
usmleuser007  in a per-protocol analysis,[6] only patients who complete the entire clinical trial according to the protocol are counted towards the final results
sympathetikey  "In an ITT population, none of the patients are excluded and the patients are analyzed according to the randomization scheme."
rio19111  Thx smc213, really helped.
... hpsauce made a comment on nbme20/block4/q#13 (A 62-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by hpsauce(0)

I believe this is Caplan Syndrome (bronchogenic carcinoma + rheumatoid arthritis). Only flaw to that is that the pulmonary findings don't perfectly represent pneumoconioses.

dbg  it's just bronchogenic ca, type of adenoca, which is classically associated with 'hypertrophic osteoarthropathy'
woodenspooninmymouth  To get it for the test, remember that lung adenocarcinoma is associated with clubbing. Mechanistically, this woman probably had RA. Then she was exposed to asbestos. The asbestos in the context of RA lead to caplan syndrome. The asbestos also triggered her bronchogenic carcinoma.
... xxabi made a comment on nbme20/block4/q#13 (A 62-year-old woman comes to the physician because...)
 +2  upvote downvote
submitted by xxabi(82)

Bronchogenic carcinoma = lung cancer

That being said, lung adenocarcinoma specifically is associated with hypertrophic osteoarthropathy, which is a paraneoplastic syndrome characterized by digital clubbing, arthralgia, joint effusions, and periostosis of tubular bones

luke.10  why not systemic scleroderma since i did this question wrong and i chose systemic sclerosis scleroderma , can someone explain that ?
kernicterusthefrog  My best guess answer to that @luke.10 is that: a) there's no mention of any skin involvement (which there would be in order to be scleroderma) b) Scleroderma shows pitting in the nails, not clubbing c) There would be collagen deposition with fibrosis, not hypertrophy of the bone at joints Saying that, I also got this wrong! (but put RA...) so I'm not claiming to "get this" Hope my thought process helps, though!
yotsubato  This is in FA 2019 page 229
larascon  I agree with @kernicterusthefrog on this one, Bronchogenic carcinoma = lung cancer. Squamous cell carcinoma gives you hypercalcemia (new bone formation; maybe?), commonly found in SMOKERS ...
... usmleuser007 made a comment on nbme20/block4/q#14 (A 60-year-old man has a round, semitransparent...)
 +1  upvote downvote
submitted by usmleuser007(86)

All other types are either pigmented or have scales. -- process of elimination

... sympathetikey made a comment on nbme20/block4/q#14 (A 60-year-old man has a round, semitransparent...)
 +2  upvote downvote
submitted by sympathetikey(260)

I believe the biopsy description of "small basophillic cells forming tumor islands" is describing the peripheral palisading that is classically seen in Basal cell carcinoma.

... radion made a comment on nbme20/block4/q#15 (45 yo man undergoing surgical procedure)
 +0  upvote downvote
submitted by radion(2)

Hypercarbia causes cerebral vasodilation. If you have ever seen an intra- or acute post-op neurosurgical patient, or really any patient about to herniate, you can remember this because they will be hyperventilated to pCO2 around 25-30 to decrease ICP via cerebral vasoconstriction; in this case, we have the opposite. The curve of pCO2 vs cerebral blood flow is quite steep in the physiologic range meaning small changes in ventilation make a significant difference in CBF.

smc213  FA 2018 p.486
... drdoom made a comment on nbme20/block4/q#15 (45 yo man undergoing surgical procedure)
 +1  upvote downvote
submitted by drdoom(167)

The more general principle: endothelia vasodilate in the presence of high CO2; you gotta get rid of that acid somehow! Can’t let it accumulate, as lower pH within a “micro-environment” affects structure/efficiency of enzymes, proteins, etc. The more acidic a local environment, the more you expect nearby vasculature to dilate (as a means of increasing flow rate, thereby ferrying off accumulate acid).

The anesthesiologist can exploit this mechanism. By hyperventilating (blowing off CO2), the brain vasculature senses a low CO2 / “hunky-dory state,” which requires no vasodilation. In other words, the vasculature does not need to continue the ATP-consuming practice of synthesizing Nitric Oxide (NO).

hello  But, the Q-stem states the anesthesiologist is HYPOventilating the patient.
drdoom  decreasing respiratory rate = retention of CO2 = vasodilation of brain arteries = more filling of tubes = greater intra-cranial pressure
drdoom  @hello shoot, you're right! i ended my explanation with the example of HYPERventilation when i should have done the opposite! (sorry!) ... edit: "By HYPOventilating (retaining CO2), the brain vasculature senses a high CO2 environment and vasodilates = increases intra-cranial filling and pressure!"
... hayayah made a comment on nbme20/block4/q#15 (45 yo man undergoing surgical procedure)
 +0  upvote downvote
submitted by hayayah(349)

Hyperventilation causes decreased PaCO2 which subsequently leads to arterial vasoconstriction thus lowering cerebral blood flow (CBF), cerebral blood volume, and ICP.

He wants to increase ICP (cerebral vasodilation) which he can do by decreasing the respiratory rate (hypoventilation).

... cienfuegos made a comment on nbme20/block4/q#15 (45 yo man undergoing surgical procedure)
 +0  upvote downvote
submitted by cienfuegos(4)

Couldn't you also decrease the FIO2? Per FA, CPP also increases to hypoxia also decreases CPP when PO2 < 50 mmHg.

cienfuegos  Obviously not the BEST option in this scenario, but seems like it could work unless I'm missing something.
... masonkingcobra made a comment on nbme20/block4/q#16 (An investigator wishes to determine the...)
... usmleuser007 made a comment on nbme20/block4/q#16 (An investigator wishes to determine the...)
 +2  upvote downvote
submitted by usmleuser007(86)

Salivary secretion 1. At low flow = High concentration of potassium; low concentrations of sodium, bicarb, & chloride 2. at high flow = low concentration of potassium; high concentrations of sodium, bicarb, & chloride

sherry  That's exactly what I was thinking when I was taking the test. But I was sidetracked by same HCO3 level. Can somebody explain this part to me??
charcot_bouchard  Because salivary duct removes Na & Cl while secrete K & Hco3 in lumen. In low flow rate HCO3 & K inc because duct is doing its thing for more time. At high flow rate K slightly dec (as cant be secrted as much) but HCO3 stays almost same. the reason is high flow indicates higher metabolism & higher bicarb production.
cienfuegos  Regarding the bicarb (via BRS Physiology, which explains flow rate as coming down to "contact time" where slow flow allows more reabsorption of NaCl): The only ion that does not “fit” this contact time explanation is HCO3−; HCO3− secretion is selectively stimulated when saliva secretion is stimulated.
... sinforslide made a comment on nbme20/block4/q#16 (An investigator wishes to determine the...)
 +1  upvote downvote
submitted by sinforslide(7)

Overview of Saliva production:

  1. Acinar cells secrete initial saliva, which is isotonic to plasma.
  2. Ductal cells modify initial saliva, causing reabsorption of Na+, Cl- and secretion of K+ and HCO-. -> higher K+ and HCO- concentrations, lower Na+ Cl- concentrations in saliva. In this process, MORE NaCl is reabsorbed, meaning that saliva ends up being hypotonic to plasma.

Ductal reabsorption process is hindered in high-flow states, which causes isotonic saliva

... monoloco made a comment on nbme20/block4/q#17 (A previously healthy 55-year-old man has recently...)
 +7  upvote downvote
submitted by monoloco(49)

As a rule of thumb, if you give someone an ACE inhibitor and they get a problem, they had renal artery stenosis (usually bilaterally, or so we were taught at our med school). Probably has to do with decreased GFR thanks to decreased Angiotensin II–selective vasoconstriction of the efferent arteriole => decreased sodium delivery to macula densa => increased renin release.

... hayayah made a comment on nbme20/block4/q#17 (A previously healthy 55-year-old man has recently...)
 +4  upvote downvote
submitted by hayayah(349)

Also, you shouldn't be seeing end-organ damage or increased renin / kidney response with a previously healthy patient that just developed essential HTN. The body doesn't want to increase renin when it has HTN. However, if you have stenosis, the kidneys freak out because they're not getting enough flow and think the whole body isn't either, so they activate the RAAS system. When you give them an ACE-I, the renin is still being produced by the kidney, it just isn't being converted to angiotensin-II.

To eliminate other choices:

  • He has increased renin activity so you can eliminate primary aldosteronism. That has inc. aldosterone, dec. renin.
  • No signs or sxs of Cushing's so that's eliminated.
  • 11-B-hydroxylase deficiency would sxs with the genitalia. You'd have dec. renin activity (aldosterone-like effects still present).
  • Essential HTN: explained above
... hayayah made a comment on nbme20/block4/q#18 (A 35-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by hayayah(349)

Zollinger-Ellison syndrome: Gastrin-secreting tumor (gastrinoma) of pancreas or duodenum.

hello  Can you please explain how gastrin relates to the physical exam findings in the patient?
amorah  I believe the logic behind it is patient has pain and black stool, suggesting peptic ulcer with bleeding. Since pain is not relieved by antiacid and H2 blockers, it suggests ectopic source to stimulate the excessive acid. Among all, gastrin by ZE syndrome fits the most.
... haliburton made a comment on nbme20/block4/q#19 (A 55-year-old man with severe emphysema comes to the...)
 +1  upvote downvote
submitted by haliburton(74)

resonant sound is normal. hyperresonant with overexpansion. tactile fremitus is increased /c solid mass or fluid, and decreased with air/fluid level or overexpansion. prolonged expiratory phase -> obstructive conditions.

... dontwanttofail made a comment on nbme20/block4/q#20 (A 5-year-old boy is brought to the physician for a...)
 -5  upvote downvote
submitted by dontwanttofail(-4)

The answer is actually hypokalemia, according to NBME.

dontwanttofail  JK. Please ignore. The answer is hypophosphatemia
... celeste made a comment on nbme20/block4/q#20 (A 5-year-old boy is brought to the physician for a...)
 +4  upvote downvote
submitted by celeste(27)

This sounds like Fanconi syndrome. The proximal tubular epithelial cells have a hard time reabsorbing filtrate, so you'll see a loss of phosphate, amino acids, bicarbonate, and glucose.

medschul  Wouldn't Fanconi syndrome also cause hypokalemia though?
yotsubato  Especially considering the fact that the DCT will be working in overdrive to compensate for lost solutes???
nala_ula  This question did not make sense to me at all. I knew it was Fanconi syndrome yet didn't select the obvious answer because it said "follow up examination 1 week after diagnosis". I thought it would already be in treatment... I searched (now) and it says that treatment is basically replenishing was is lost in the urine. So definitely the wording is like wtf to me
sugaplum  I was thinking since it affected the PCT that Na resorption would be affected as well? But I guess the other segments will pick up the slack?
... imgdoc made a comment on nbme20/block4/q#20 (A 5-year-old boy is brought to the physician for a...)
 +3  upvote downvote
submitted by imgdoc(18)

You can cross out the top three answer choices, A,B,C. You wont be reabsorbing anything in the PCT in fanconi's syndrome. Looking at hypokalemia, hyponatremia, and hypophosphatemia now. Hypokalemia can't be correct because even though potassium is lost it will be reabsorbed at the later thick ascending loop and if that doesnt make sense, the body will adjust for low serum potassium but activating the H+/K+ pump on cells. It isn't hyponatremia because at the collecting duct principal cells, reabsorption will occur. This leaves hypophosphatemia as the correct and only answer choice.

imgdoc  by*
larascon  Excellent explanation, thank you !
... monoloco made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +3  upvote downvote
submitted by monoloco(49)

This patient is experiencing hypersensitivity pneumonitis from the parakeets. I was thinking M. Avium when I selected parakeets -- I think my logic was flawed given the specifics of the patient's story.

... beeip made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by beeip(56)

I also was thinking M. avium here, but hypersensitivity pneumonitis seems to fit with the reticulogranular changes.

... hayayah made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +3  upvote downvote
submitted by hayayah(349)

Hypersensitivity pneumonitis—mixed type III/IV hypersensitivity reaction to environmental antigen. Causes dyspnea, cough, chest tightness, headache. Often seen in farmers and those exposed to birds. Reversible in early stages if stimulus is avoided.

It's a type of restrictive lung disease.

... masonkingcobra made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
... endochondral1 made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by endochondral1(4)

how do we know parakeets cause hypersensitivy pneumonitis

smc213  FA18 p.657 bird exposure--> HSN pneumonitis (restrictive lung disease) and FA18 p.214 granulomatous diseases: foreign material-->HSN pneumonitis. I had to make sense of it since I didn't know it was HSN pneumonitis at first.
... endochondral1 made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by endochondral1(4)

according to uworld hypersensitivity pneumonitis is due to dust and that was also an option....

amarousis  so it's definitely dust but the specific type of dust was the most important in this question. the fact that they mentioned the birds is important. the dusty books would cause it but the bird dust is more important -.-
charcot_bouchard  Hypersensitivity Pneumonitis - Organic dust (like moldy hay) Pneumocniosis - Inorganic dust none help here though because both will present with same restrictive lung disease picture. i think since dust in library arent neither organic or inorganic and also u dont see many librarians with lung disease but bird ownership is specifically mentioned as cause of HP disease.
... breis made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +1  upvote downvote
submitted by breis(9)

Psittacosis (sometimes called ornithosis or parrot disease or parrot fever) is an infection of the lung (pneumonia) caused by the bacterium Chlamydophila (Chlamydia) psittaci.

Signs and symptoms: fever. cough, usually without much phlegm. headache. rash. muscle aches. chest pain. shortness of breath. sore throat.

charcot_bouchard  Update on my prev comment : Yes this is psittacosis. not hypersensitivity pneumonitis. How do u know? Lymphocyte and Presence of Granuloma - response to intracellular chlamydia. Now HS can also cause loose granuloma too and the clinical picture still more look like HS You know what ......... fuck this ques
shemle  Here Pt. doesn't have fever!
... imnotarobotbut made a comment on nbme20/block4/q#21 (A 47-year-old woman comes to the physician because...)
 +0  upvote downvote
submitted by imnotarobotbut(22)

How would you know that it isn't wool sorters disease?

cienfuegos  FA 2018 137: inhalation of spores leads to flu-like symptoms that progress quickly to fever, pulmonary hemorrhage, mediastinitis and shock, with imaging possibly showing widened mediastinum
... strugglebus made a comment on nbme20/block4/q#22 (A 35-year-old man is given cyclosporine following a...)
 +2  upvote downvote
submitted by strugglebus(63)

Cyclosporine is a calcineurin inhibitor, which aims to decrease IL-2

... strugglebus made a comment on nbme20/block4/q#22 (A 35-year-old man is given cyclosporine following a...)
 +2  upvote downvote
submitted by strugglebus(63)

As a side note, the phosphatase would have activated calcineurin https://www.ecosia.org/images?q=calcineurin+phosphatase#id=2E5AEA65CD7AADC5FADD1C144FFFAD3B7068FDAA

... chillqd made a comment on nbme20/block4/q#23 (A 45-year-old woman who is intubated and...)
 +1  upvote downvote
submitted by chillqd(7)

Patients with fungemia 2/2 to Candida albicans should recieve and Echinocandins antifungal agent idsa practice guidelines

Echinocandins inhibit the synthesis of beta (1,3)-D-glucan, an essential component of the cell wall of susceptible Aspergillus species and Candida species

Caspofungin Package Insert

... celeste made a comment on nbme20/block4/q#24 (A 27-year-old man comes to the physician because of...)
 +4  upvote downvote
submitted by celeste(27)

The adductor pollicis muscle is innervated by the ulnar nerve, giving this guy a difficult time holding a sheet of paper.

... neonem made a comment on nbme20/block4/q#24 (A 27-year-old man comes to the physician because of...)
 +0  upvote downvote
submitted by neonem(227)

Most of intrinsic muscles of the hand are innervated by ulnar nerve - chronic compression at the hook of hamate could lead to nerve ischemia

... xxabi made a comment on nbme20/block4/q#24 (A 27-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by xxabi(82)

Bicycle handlebar injury traditionally damages ulnar nerve @ the hook of the hamate bone

... hello made a comment on nbme20/block4/q#24 (A 27-year-old man comes to the physician because of...)
 +2  upvote downvote
submitted by hello(52)

Guyon Canal Syndrome is due to an Ulnar Nerve lesions and is associated with bicycle handlebar use.

Also FINGER abduction and adduction is mediated by ulnar nerve. The patient is having trouble with FINGER abduction and adduction.

The Froment sign is testing ADDUCTOR POLICIS ACTIVITY, which is mediated by the ULNAR NERVE activity. It is NOT testing thumb opposition, which would be mediated by the median nerve.

See Froment sign

... strugglebus made a comment on nbme20/block4/q#25 (A 52-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by strugglebus(63)

Propanolol is a non-selective Beta blocker. So your HR will decrease (B1), which will cause a compensatory increase in TPR.

home_run_ball  ^ Above is partially right: Propranolol is non-selective Beta blocker: Beta1 stimulation causes inc HR, therefore blocking it will dec HR and dec Cardiac output Beta 2 stimulation causes vasodilation, therefore blocking it will CAUSE UNOPPOSED alpha1 activation --> therefore increasing total peripheral resistance.
amarousis  so why tf do we give beta blockers for hypertension -.-
dr_jan_itor  I would also add that the patient was previously on an a2 inhibitor (clonidine), which he ran out of. So he is rebounding on that with upregulated a1 receptor activity. Adding labetalol would cause a greater degree of unopposed alpha, increasing tpr
... hungrybox made a comment on nbme20/block4/q#25 (A 52-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by hungrybox(176)

So... theoretically an isolated decrease in HR would increase CO due to inc. preload, right?

But CO decreases in this case b/c the effect of inc. TPR is more powerful?

kernicterusthefrog  @hungrybox: No. Isolating HR, you would look at CO like this: CO=HR*SV so if HR or stroke volume go down, CO goes down. The change in preload wouldn't affect the CO as much as the change in rate of flow. So, the decrease in CO is solely due to the beta1 blocking effect on the AV node to decrease HR.
... maxillarythirdmolar made a comment on nbme20/block4/q#25 (A 52-year-old man is brought to the emergency...)
 +0  upvote downvote
submitted by maxillarythirdmolar(0)

Where does the role of B1 stimulation of RAAS come into this? Wouldn't the B1 action cause decrease RAAS? That being said, I can also understand if that's a long term thing and this is a question about the immediate effects...?

... sympathetikey made a comment on nbme20/block4/q#26 (A 33-year-old man comes to the physician because of...)
 +5  upvote downvote
submitted by sympathetikey(260)

Good picture showing the anatomy of the thigh from a T2 MRI perspective.

https://radiologykey.com/wp-content/uploads/2016/01/B9781437707595000073_u007-009-9781437707595.jpg

... sympathetikey made a comment on nbme20/block4/q#27 (An investigator is studying patients with West Nile...)
 +1  upvote downvote
submitted by sympathetikey(260)

Case Series

A group or series of case reports involving patients who were given similar treatment. Reports of case series usually contain detailed information about the individual patients. This includes demographic information (for example, age, gender, ethnic origin) and information on diagnosis, treatment, response to treatment, and follow-up after treatment.

In this question, it looks like they didn't really focus on the treatment part of it but otherwise, makes sense

sympathetikey  Source: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/case-series
ngman  I think another factor is that in case series studies there is no control group vs case-control, cohort...ect
... xxabi made a comment on nbme20/block4/q#28 (A 78-year-old man dies of chronic congestive heart...)
 +1  upvote downvote
submitted by xxabi(82)

Swelling of the cell (e.g., hydropic degeneration): tissue ischemia → decreased ATP production → decreased Na+/K+ ATPase and Ca2+pump activity → diffusion of Na+ and water into the cell → cellular swelling

endochondral1  can someone explain how to cross out the other choices>
endochondral1  what is hydropic degneration and where do i learn about it? why is it not the loss of plasma membrane integrity?
shaeking  Endochondral1, I had the same question. I tried figuring it out and this is what I came up with. The CHF and congestion of the lungs is reducing the amount of oxygen getting to the renal cells. With hypoxia there is decreased aerobic resp in mitochondria with decreased ATP. Without ATPase Na builds up and water follows. As far as the loss of membrane integrity. I think it would cause cellular destruction not just hydropic changes. This is my best guess.
charcot_bouchard  Membrane damage is irreversible stage of cellular injury. if membrane is damaged cell is dying & it will shrink. or totally destroyed by inflammation. they are specifically asking hydropic changes ie cellular swelling. which is the 1st sign of reversible cell injury due to failure of Na/K pump
... nwinkelmann made a comment on nbme20/block4/q#28 (A 78-year-old man dies of chronic congestive heart...)
 +1  upvote downvote
submitted by nwinkelmann(60)

This explains it really well with a picture: https://www.med.illinois.edu/m2/pathology/PathAtlasf/Atlas01.html.

Hydropic change = one of the early signs of cellular degeneration in response to injury that results in accumulation of water in the cell. Hypoxia/ischemia leads to decease in aerobic respiration in the mitochondria and decreased ATP production due to failure of the Na+/K+ ATPase leading to Na+ and water diffusion into the cell. Individual tubule cells appear swollen and "empty" with almost occluded lumen, glomerulus is hypercellular.

... hayayah made a comment on nbme20/block4/q#29 (A 15-year-old girl is brought to the physician by...)
 +0  upvote downvote
submitted by hayayah(349)

An adverse effect of doxycycline is photosensitivity.

rio19111  Why not Cipro?
... drdoom made a comment on nbme20/block4/q#29 (A 15-year-old girl is brought to the physician by...)
 +0  upvote downvote
submitted by drdoom(167)

[deleted]

... breis made a comment on nbme20/block4/q#29 (A 15-year-old girl is brought to the physician by...)
 +2  upvote downvote
submitted by breis(9)

Doxycycline is a Tetracycline (binds 30s subunit) and is used off label for treatment of Acne. Can cause discoloration of teeth, and is known to be PHOTOSENSITIVE.

This patient had diffuse erythema and mild edema over her face and extremities, most likely from sun exposure while being on the med for Acne.

FA 2019: pg 192

... monoloco made a comment on nbme20/block4/q#30 (A 32-year-old woman is brought to the emergency...)
 +6  upvote downvote
submitted by monoloco(49)

Anytime you have a person who bumps their head, gets back up, and then has severe issues or dies like 6 hours later -- you have yourself an epidural hematoma from laceration to the middle MENINGEAL artery. (Goljan really emphasizes that you don't screw up and select middle cerebral.) You know it has to be an arterial laceration since the dura is tightly adhered to the skull's inner surface. Goljan referred to his experience with it as needing pliers to remove the dura from the skull; graphic, but it drives the point home. Tenting seen on CT is because the epidural hematoma gets stuck between the suture lines. When it manages to break past one of the suture lines, it is my understanding that then is when you get severe sequelae, like death or whatever.

usmile1  omg monoloco!! I miss you dude! We used to hang forever ago, hope all is going well in med school!
... hayayah made a comment on nbme20/block4/q#31 (A 48-year-old man is brought to the emergency...)
 +2  upvote downvote
submitted by hayayah(349)

Iron overdose is a cause of a high anion gap metabolic acidosis.

meningitis  I found this to add a little bit more explanation as to how it causes the acidosis if anyone needs it. 1. Mitochondrial toxicity - decreases aerobic respiration and shunts to lactic acid production 2. Cardio toxicity (Secondary to Mitochondrial toxicity) leads to cardiogenic shock (hypoperfusion), which causes lactic acidosis 3. Hepatotoxicity - Decreases lactate metabolism, causing lactic acidosis 4. When in trivalent form (Fe+3), it can react with 3 molecules of H2O --> FeOH3 + 3H+ This will then deplete Bicarb buffering system resulting in non-gap acidosis. Source: https://forums.studentdoctor.net/threads/iron-poisoning-anion-gap-or-non-anion-gap-acidosis.958285/
sympathetikey  None of the other choices were even metabolic acidosis. They threw us a bone with this one.
imnotarobotbut  Don't changes in bicarb take a few days? How did his bicarb drop down to 8 in 12 hours?
charcot_bouchard  its met acidsis. not compensation
... hayayah made a comment on nbme20/block4/q#32 (A 55-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by hayayah(349)

Glucagonoma: Tumor of pancreatic α cells Žcausing an overproduction of glucagon.

Presents with 5D’s:

  • Dermatitis(necrolytic migratory erythema)
  • Diabetes (hyperglycemia)
  • DVT
  • Declining weight
  • Depression
killme  And the sixth D: Diarrhea
ergogenic22  a) CAT1 and CAT2 are important enzymes of fatty acid beta oxidation. Glucagon upregulates this process b) glycogen formation is inhibited by glucagon, so that glucose can be used by cells c) acetyl CoA carboxylase is used for fatty acid synthesis and thus decreased by increased glucagon d) glucagon increases ketogenesis
... xxabi made a comment on nbme20/block4/q#33 (A 65-year-old woman with cardiovascular disease is...)
 +1  upvote downvote
submitted by xxabi(82)

Bile salts help dissolve gallstones that have formed in the gallbladder, used in patients refractory to surgery or prefer to avoid it.

xxabi  To add, bile salts are amphipathic which allows for the emulsification and solubilization of lipids in an aqueous environmen
... eadgar made a comment on nbme20/block4/q#33 (A 65-year-old woman with cardiovascular disease is...)
 +0  upvote downvote
submitted by eadgar(0)

urosodiol increase bile salt. Decreases biliary cholesterol by suppressing hepatic synthesis and secretion of cholesterol as well as inhibiting intestinal absorption.

... thomas made a comment on nbme20/block4/q#34 (A 20-year-old man is brought to the physician by his...)
 +2  upvote downvote
submitted by thomas(3)

The first sentence acknowledges the patient's emotions, which is always good. The second sentence is good because it begins the interview with an open-ended question.

... johnthurtjr made a comment on nbme20/block4/q#35 (A 62-year-old man comes to the physician for a...)
 +1  upvote downvote
submitted by johnthurtjr(43)

In the first stage of overcoming addiction, or precontemplation, the patient denies the presence of a problem.

In the second stage, or contemplation, the patient acknowledges the problem but is unwilling to make a change at the current time.

... johnthurtjr made a comment on nbme20/block4/q#36 (A 25-year-old woman is brought to the emergency...)
 +3  upvote downvote
submitted by johnthurtjr(43)

Low C-peptide, low proinsulin, high plasma free insulin and low glucose, in a nurse, who presents with episodes of symptoms of hypoglycemia without apparent precipitants, is straight out of FA's textbook definition of a factitious disorder. See FA 2019 p554

... katsu made a comment on nbme20/block4/q#36 (A 25-year-old woman is brought to the emergency...)
 +0  upvote downvote
submitted by katsu(1)

In the pancreas' beta cells, proinsulin splits apart to form one molecule of C-peptide and one molecule of insulin.

C-peptide testing can be used to help evaluate the production of insulin made by the body (endogenous) and to help differentiate it from insulin that is not produced by the body but is taken exogenously and so does not generate C-peptide.

... usmleuser007 made a comment on nbme20/block4/q#37 (A 16-year-old girl with cystic fibrosis is brought...)
 -1  upvote downvote
submitted by usmleuser007(86)

Vitamin E deficiency is known to cause similar spinal defects as Vitamin B12 deficiency. However, anemia is not seen.

ergogenic22  Also corticalspinal tract symptoms are not seen, but dorsal column and spinocerebellar tracts are seen
sinforslide  In this case, patient's CF also predisposes fat-soluble vitamin deficiency.
breis  FA pg 70
usmleuser007  Correction: Read more on this Vitamin-E deficiency can in fact cause anemia - hemolytic anemia. This is b/c VitE work as an anti-oxidant; and therefore with reduced anti-oxidation RBCs are more prone to oxidative injuries.
... johnthurtjr made a comment on nbme20/block4/q#38 (A 45-year-old man comes to the physician because of...)
 +1  upvote downvote
submitted by johnthurtjr(43)

Drugs like inflixamab and adalimumab are monoclonal anti-TNF-alpha antibody drugs that can be used to treat inflammatory bowel disease.

Important note - before administering, need to test for latent TB as reactivation can occur (TNF-alpha important in granuloma formation and stabilization)

... johnthurtjr made a comment on nbme20/block4/q#39 (A 30-year-old woman develops serum sickness...)
 +4  upvote downvote
submitted by johnthurtjr(43)

FA 2019 pg 400:

Mast cells... can be activated by tissue trauma, C3a and C5a, surface IgE cross-linking by antigen (IgE receptor aggregation) --> degranulation --> release of histamine, heparin, tryptase, and eosinophil chemotactic factors.

... kentuckyfan made a comment on nbme20/block4/q#40 (A 6-month-old girl is brought to the emergency...)
 +0  upvote downvote
submitted by kentuckyfan(13)

Urea cycle: Decreased citrulline and hyperammonemia can differentiate it from orotic aciduria.

hello  As the poster indicates, the described patient has a defect in the urea cycle, specifically an ornithine transcarbamylase deficiency. Added for clarity to future readers.
... lamhtu made a comment on nbme20/block4/q#40 (A 6-month-old girl is brought to the emergency...)
 +1  upvote downvote
submitted by lamhtu(26)

Unusual that the patient is a young girl, OTCD is XLR inheritance.

eacv  yes !!!!! that make me doubt and choose the wrong one -.-
... usmleuser007 made a comment on nbme20/block4/q#41 (A 56-year-old man with a 20-year history of chronic...)
 +0  upvote downvote
submitted by usmleuser007(86)

https://www.ncbi.nlm.nih.gov/pubmed/301658

Relief of intractable pain was produced in six human patients by stimulation of electrodes permanently implanted in the periventricular and periaqueductal gray matter. The level of stimulation sufficient to induce pain relief seems not to alter the acute pain threshold. Indiscriminate repetitive stimulation produced tolerance to both stimulation-produced pain relief and the analgesic action of narcotic medication; this process could be reversed by abstinence from stimulation. Stimulation-produced relief of pain was reversed by naloxone in five out of six patients. These results suggest that satisfactory alleviation of persistent pain in humans may be obtained by electronic stimulation.

usmleuser007  These questions seem unfair to test because they are based on experimental data. Guess they are there to limit a perfect score.
xxabi  I just read it as patients take opioids to blunt or control pain. So if the electrode does the same thing (decrease pain), then an antagonist of opioids (naloxone) would bring the pain back? Idk if that reasoning is sound but that's the logic I used, I didn't even think of it as experimental.
xxabi  Also its the only one that's an opioid antagonist from the list!
redvelvet  they are writing these questions in an evidence-based manner because the questions in medicine cannot be produced by a self imagination or logic. But that doesn't mean that we have to know their exact evidence like this question. we can use our own basic knowledge and adjust it with logic. so opioids have an analgesic effect in the body and naloxone can revert it.
... thomas made a comment on nbme20/block4/q#42 (A 65-year-old woman dies 6 months after the onset of...)
 -4  upvote downvote
submitted by thomas(3)

Answer is Astrocyte. Patient has glioblastoma multiforme. Although meningiomas may occur at convexities, meningiomas are benign and often asymptomatic. They may cause h/a seizures, but would be unlikely to cause death w/in 6m of onset of h/a. The size of tumor and course of illness is consistent with the course of GBM

masonkingcobra  Above is obviously incorrect because the answer is Meningeal lol. Here is a link to a good picture: http://neuropathology-web.org/chapter7/chapter7fMiscellaneous.html
kernicterusthefrog  Obviously thomas is disagreeing with the presentation of the question, and I agreed with him! This absolutely sounds like GBM, with rapid onset leading to death, and the symptoms. The question stem leads you to GBM, and the gross image to meningioma (I guess).
kernicterusthefrog  Furthermore, where are the meninges on the gross image form which this (meningioma) grew?! It should at least show the tissue from whence it came!
nala_ula  Had the same problem, got confused since it appeared that the growth was malignant :(
sugaplum  FA 2019 pg 514, also agree with everyone. weird presentation. Glios are malignant death within 1 year, meningioma are often asymptomatic or have focal signs. just a gross pathology question at this point
... johnthurtjr made a comment on nbme20/block4/q#42 (A 65-year-old woman dies 6 months after the onset of...)
 +3  upvote downvote
submitted by johnthurtjr(43)

I'm not a fan of gross path images and questions that say "look, what is this thing?" - that said meningiomas are the most common brain tumor and this picture is is a good example of one. I had no idea what these things looked like and got it wrong, too. Take a look at this one

johnthurtjr  [Here's more info](http://www.pathologyoutlines.com/topic/cnstumormeningiomageneral.html)
meningitis  I got it wrong because I didn't see any apparent Dura mater nor other meninges (The veins aren't being covered by any "shiny layer"), so I thought the tumor was coming from inside the brain and not compressing it like meningiomas usually do.
meningitis  But it did follow the common aspect where they are found in between divisions of brain and are circular growths like a ball.
nala_ula  Since it was basically implied that the patient died and "here look at what this is" I thought it was a malignant tumor (glioblastoma)... but I guess it's all about placement.
... smit 24 made a comment on nbme20/block4/q#42 (A 65-year-old woman dies 6 months after the onset of...)
 +0  upvote downvote
submitted by smit 24(0)

Clinical vignette is leading to GBM(astrocyte origin)....not sure about the gross picture.....

Don't know what if such questions appear on real exam😑😑😑

htballer55  I felt the same way. but if you look at autopsy pics on google, you see the meningioma is like a ball coming out of the meninges. compare that to glioblastoma which is within the brain in cerebral hemispheres. so it's mainly one tumor is coming out of the brain and the other is inside the cerebral hemispheres. that's the best i can come up with. but it's confusing
... strugglebus made a comment on nbme20/block4/q#43 (A physician is assigned to a search and rescue team...)
 +2  upvote downvote
submitted by strugglebus(63)

You have negative Nitrogen balance in starvation (lack of protein) and positive Nitrogen in muscle building states (i.e. children/athletes)

celeste  Nitrogen Balance = Nitrogen intake - Nitrogen loss
... guillo12 made a comment on nbme20/block4/q#43 (A physician is assigned to a search and rescue team...)
 +2  upvote downvote
submitted by guillo12(12)

Negative nitrogen balance is associated with burns, serious tissue injuries, fevers, hyperthyroidism, wasting diseases, and during periods of fasting. This means that the amount of nitrogen excreted from the body is greater than the amount of nitrogen ingested.

Positive nitrogen balance is associated with periods of growth, hypothyroidism, tissue repair, and pregnancy. This means that the intake of nitrogen into the body is greater than the loss of nitrogen from the body, so there is an increase in the total body pool of protein.

guillo12  by Wiki
... beeip made a comment on nbme20/block4/q#44 (A 45-year-old man comes to the office for counseling...)
 +2  upvote downvote
submitted by beeip(56)

Thought this would be something regarding "bariatric surgery," but nope, just "no starchy foods, because you're pre-diabetic."

hello  Yep, seems that because the patient has prediabetes, he should avoid eating excessive starchy foods.
yotsubato  such a BS question IMO
yotsubato  such a BS question IMO
breis  I put nuts thinking of "fats" and that with a bariatric surgery they may have problems with absorption..
teetime  This isn't right because the bariatric surgery will cure the prediabetes. It's dumping.
dr_jan_itor  Why should he avoid eating excessive starchy foods? To avoid gaining weight? It doesn't matter what macronutrients he eats if they are calorie controlled.
... strugglebus made a comment on nbme20/block4/q#44 (A 45-year-old man comes to the office for counseling...)
 +2  upvote downvote
submitted by strugglebus(63)

I had put "starches" b/c pts that undergo bariatric surgery are only supposed to eat complex carbs (fruits/vegetables) and avoid simple carbs (i.e. breakfast cereal/baked goods)

... thepacksurvives made a comment on nbme20/block4/q#44 (A 45-year-old man comes to the office for counseling...)
 +5  upvote downvote
submitted by thepacksurvives(5)

I think this one has to do with "late dumping syndrome"-- basically, starchy foods cause hyperglycemia --> release of insulin --> catecholamine surge --> diarrhea, etc.

... xxabi made a comment on nbme20/block4/q#45 (A 12-year-old boy is brought to the physician for...)
 +0  upvote downvote
submitted by xxabi(82)

Terminal Complement (C5-C9) Deficiencies increase susceptibility to recurrent Neisseria bacteremia. Patients most often present with recurrent meningitis.

... neonem made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +0  upvote downvote
submitted by neonem(227)

Obstructive uropathy causes a postrenal azotemia --> when prolonged, tubular damage ensues. This leads to an acute tubular necrosis, characterized by necrotic plugs in the tubular system as seen in the image

meningitis  Does anyone know the relevance of the stem saying: "during this time she also has been crying frequently"?
usmleuser007  Think the postrenal azotemia is d/t her pregnancy. With the increasing in size fetus, the pelvic cavity is being compressed and thus there is pressure on the ureters. This leading to the presentation. As per above --- the crying maybe just d/t her pain and emotional stress caused by worrying about possible complications regarding her fetus.
maxillarythirdmolar  My gut tells me it must be some sort of transient change in placental size with hormonal changes. It's reminiscent of what you might expect for breast changes during the menstrual cycle, imo
... xxabi made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +9  upvote downvote
submitted by xxabi(82)

Also for those of you who are totally clueless like me, urinary tract obstruction = obstructive uropathy.

... sympathetikey made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +2  upvote downvote
submitted by sympathetikey(260)

Hydronephrosis

Distention/dilation of renal pelvis and calyces A . Usually caused by urinary tract obstruction (eg, renal stones, severe BPH, congenital obstructions, cervical cancer, injury to ureter, pregnancy apparently); other causes include retroperitoneal fibrosis, vesicoureteral reflux. Dilation occurs proximal to site of pathology. Serum creatinine becomes elevated if obstruction is bilateral or if patient has an obstructed solitary kidney. Leads to compression and possible atrophy of renal cortex and medulla.

... laminin made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +0  upvote downvote
submitted by laminin(6)

also maybe could do process of elimination...the 'costophrenic angle tenderness' clues us in to it being a renal problem, and the only renal answer choice is obstructive uropathy

... redvelvet made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +0  upvote downvote
submitted by redvelvet(4)

costophrenic angle tenderness and fever WBC casts in tubules on that photo for example All of them is leading us to pyelonephritis. And even minor cystitis can cause pyelonephritis in pregnancy due to obstructive uropathy.

... banieb made a comment on nbme20/block4/q#46 (A 28-year-old woman at 32 weeks' gestation comes to...)
 +3  upvote downvote
submitted by banieb(3)

During the last half of pregnancy dilation of the upper urinary tract can occur due to compression of the ureters by the growing fetus/uterus and the linea terminalis. The compression of these is not allowing fluid passage into the bladder causing urine buildup in the kidney, this leads to dilation of the kidney that ends up causing symptomatic hydronephrosis. this can end up in infection and symptoms such as the ones present in this patient like back pain and CVA tenderness. the crying is mainly due to the pain caused by the obstruction. and just as something extra: double pigtail catheters is a safe and simple way of treating symptomatic hydronephrosis of pregnancy.

banieb  Ureteral obstruction by the pregnant uterus https://www.ncbi.nlm.nih.gov/pubmed/1579937
... xxabi made a comment on nbme20/block4/q#47 (A 61-year-old man has erectile dysfunction due to...)
 +1  upvote downvote
submitted by xxabi(82)

PDE-5 inhibitors (e.g. sildenafil, tadalafil) are indicated for ED by way of increasing blood flow in the corpus cavernosum (labeled D) of the penis

... hayayah made a comment on nbme20/block4/q#48 (A 24-year-old man comes to the emergency department...)
 +0  upvote downvote
submitted by hayayah(349)

Pt. has Familial dyslipidemias. Type I—Hyperchylomicronemia.

estefanyargueta  Lipoprotein lipase: degradation of TGs circulating in chylomicrons and VLDLs.
breis  FA 2019 pg 94
... sympathetikey made a comment on nbme20/block4/q#49 (A 23-year-old woman sustains significant blood loss...)
 +1  upvote downvote
submitted by sympathetikey(260)

Direct Antiglobulin = Direct Coombs Test

Detects antibodies bound directly to RBCs. Hemolysis most likely due to something in the transfused blood (not sure why it took 4 weeks when Type 2 HS is supposed to be quicker but w/e).

ergogenic22  there is a delayed onset hemolytic transfusion reaction which should be evaluated with direct cooms test. https://www.ncbi.nlm.nih.gov/books/NBK448158/
hungrybox  such a dumb question wtf
... strugglebus made a comment on nbme20/block4/q#50 (A previously healthy 16-year-old girl is brought to...)
 +1  upvote downvote
submitted by strugglebus(63)

There are certain situations in which you don't need to notify parents about anything when treating a child--STIs are one of them. The reason being that untreated STIs will cause more spread as well as can lead to PID

... hello made a comment on nbme20/block4/q#50 (A previously healthy 16-year-old girl is brought to...)
 +1  upvote downvote
submitted by hello(52)

The reason "do not prescribe antibiotics until testing results are available" is incorrect is because we already have a gram stain that shows gram-negative diplococci in pairs. This is Neisseria gonorrhoeae. So, no need to wait for test results come back.

The Q-stem stating that "Testing for Neisseria and Chlamydia" is ordered" after already having done the Gram stain seems to be a distractor.

.
.
.


See all comments for NBME 20 Answers (slow load)