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NBME 17 Answers

Question#6 (reveal difficulty score)
A 55-year-old man with chronic bronchitis is ...

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A 6-week-old girl is brought to the physician ...
Immature lower esophageal sphincterπŸ”,πŸ“Ί

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A 21-year-old man comes to the emergency ...
Inferior rectal veinπŸ”,πŸ“Ί

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A 24-year-old man with a history of ...

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A 42-year-old farmer has a 7-mm red scaly ...
Actinic keratosisπŸ”,πŸ“Ί

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A 42-year-old woman comes to the physician ...

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A newborn has male genital ducts but female ...

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A 56-year-old man comes to the physician 4 ...
Right subthalamicπŸ”,πŸ“Ί

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An 80-year-old woman comes to the emergency ...

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A randomized clinical trial is conducted to ...
Neither procedure is superiorπŸ”,πŸ“Ί

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A 13-year-old girl has a grade 2/6, ...

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A 2-month-old boy is given a vaccine that has ...
Haemophilus influenzae type bπŸ”,πŸ“Ί

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A 28-year-old woman at 18 weeks' gestation ...
Free T4πŸ”,πŸ“Ί

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A 21-year-old man is brought to the emergency ...
Streptococcus pneumoniaeπŸ”,πŸ“Ί

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A 60-year-old man comes to the physician ...
Pleural effusionπŸ”,πŸ“Ί

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A 65-year-old woman with ovarian cancer is ...
DNA replicationπŸ”,πŸ“Ί

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In a clinical study, a polymorphic marker ...

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A study is conducted to assess the ...
Placebo effectπŸ”,πŸ“Ί

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A 40-year-old man is evaluated because his ...
Heme synthesisπŸ”,πŸ“Ί

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A 40-year-old woman comes to the physician ...

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An investigator wishes to conduct a study of ...

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Metabolic acidosisπŸ”,πŸ“Ί

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A 16-year-old boy is brought to the physician ...
Luteinizing hormoneπŸ”,πŸ“Ί

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A 14-year-old boy is brought to the physician ...
Inhaled glueπŸ”,πŸ“Ί

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A 65-year-old woman undergoes surgical repair ...
Area labeled with letter 'A'πŸ”,πŸ“Ί

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A physician is sad because he has to inform a ...
Yes, it is.πŸ”,πŸ“Ί

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A 44-year-old woman comes to the physician ...
Ubiquitin ligaseπŸ”,πŸ“Ί

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A 20-year-old man is brought to the emergency ...

Question#36 (reveal difficulty score)
An 18-year-old man with Crohn disease is ...
T-lymphocyte functionπŸ”,πŸ“Ί

Question#37 (reveal difficulty score)
A 4-year-old boy is brought to the physician ...
Congenital ureteral obstructionπŸ”,πŸ“Ί

Question#38 (reveal difficulty score)
Ten healthy human subjects are given a new ...
Phase 1πŸ”,πŸ“Ί

Question#41 (reveal difficulty score)
A 27-year-old woman is admitted to the ...

Question#49 (reveal difficulty score)
A previously healthy 48-year-old nulligravid ...
Endometrial hyperplasiaπŸ”,πŸ“Ί

Question#1 (reveal difficulty score)
An 83-year-old man is brought to the ...
Early septic shockπŸ”,πŸ“Ί

Question#10 (reveal difficulty score)
A 32-year-old woman, gravida 2, para 1, at 7 ...
Ectopic pregnancyπŸ”,πŸ“Ί

Question#14 (reveal difficulty score)
A 55-year-old man is admitted to the hospital ...
0.9% SalineπŸ”,πŸ“Ί

Question#20 (reveal difficulty score)
A 45-year-old man comes to the physician ...
Mallory hyalineπŸ”,πŸ“Ί

Question#27 (reveal difficulty score)
A 20-year-old man with suspected appendicitis ...

Question#30 (reveal difficulty score)
A 45-year-old man comes to the physician ...
Tumor necrosis factorπŸ”,πŸ“Ί

Question#34 (reveal difficulty score)
A 16-year-old girl comes to the physician ...
Dopamine Ξ²-hydroxylaseπŸ”,πŸ“Ί

Question#36 (reveal difficulty score)
A 41-year-old woman is evaluated because of ...
Fibromuscular dysplasiaπŸ”,πŸ“Ί

Question#47 (reveal difficulty score)
A 10-year-old boy has had anemia since birth. ...
Hereditary spherocytosisπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 34-year-old patient with AIDS develops ...

Question#0 (reveal difficulty score)
15-year-old, lesions on neck, acid-fast ...
Temperature SensitivityπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
60-year-old man progressive shortness of ...
Alveolar macrophageπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
22-year-old woman, gravida 1, para 1... ...
Internal iliacπŸ”,πŸ“Ί

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A previously healthy 17-year-old girl is ...

Question#0 (reveal difficulty score)
An 80-year-old man with Type 2 Diabetes ...
Pelvic SplanchnicπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 45-year-old woman comes to the physician ...

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A 56-year-old woman develops a restrictive ...
Beta-Pleated sheet structureπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
45-year-old man with poorly controlled type 2 ...
Enterococcus faecalisπŸ”,πŸ“Ί

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16-year-old girl comes to the physician ...

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A 65-year-old woman with a 20-year history of ...
L-3 to 4πŸ”,πŸ“Ί

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38-year-old man with a 3-year history of type ...

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27-year-old woman comes to the physician... ...
Trophoblastic tissueπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A new compound is taken up by bacterial ...
Carrier-mediated diffusionπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A previously healthy 3-year-old boy is ...
Interleukin-8 (IL-8)πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
59-year-old comes to the physician... lack of ...

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A 24-year-old man comes to the physician, ...

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A 52-year-old man is brought to the physician ...

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A 20-year-old man comes to the physician, ...
Posterior pituitary glandπŸ”,πŸ“Ί

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A 30-year-old woman comes to the physician ...

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35-year-old man is brought to the ED, fatigue ...
Activation of adenylyl cyclaseπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A female newborn is delivered at 38 weeks' ...
15 to 40πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 27-year-old primigravid woman at 34 weeks' ...

Question#0 (reveal difficulty score)
A 30-year-old man is brought to the ED... CT ...
Middle meningeal arteryπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 63-year-old man comes to the physician ...
Calcified 80% stenosisπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 50-year-old man comes to the physician 3 ...

Question#0 (reveal difficulty score)
A 68-year-old man comes to the physician... ...
Inhibition of phosphodiesterase πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 60-year-old man who emigrated from China to ...

Question#0 (reveal difficulty score)
A 38-year-old woman comes to the physician ...

Question#0 (reveal difficulty score)
A 50-year-old man who has smoked 2 packs of ...
Increased blood HCO3-πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 30-year-old primigravid woman at 22 weeks' ...
Listeria monocytogenesπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
In a nuclear transplantation experiment, ...

Question#0 (reveal difficulty score)
A 62-year-old woman with recurrent pulmonary ...
VII (proconvertin)πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 19-year-old man is admitted to the hospital ...
Left achilles tendonπŸ”,πŸ“Ί

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60-year-old man comes to the physician ...
Parietal cellsπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 42-year-old woman comes to the physician ...
Cholesterol synthesisπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 3-year-old boy with sickle cell disease has ...

Question#0 (reveal difficulty score)
Ten years after total gastrectomy, a ...
B12 (cobalamin)πŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 65-year-old woman comes to the physician ...
Lichen sclerosusπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
A 28-year-old woman comes to the physician ...
Parotid gland enlargementπŸ”,πŸ“Ί

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A 75-year-old man comes to the emergency ...
Salicylate poisoningπŸ”,πŸ“Ί

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A 55-year-old woman comes to the physician ...
Major Depressive DisorderπŸ”,πŸ“Ί

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A 40-year-old woman with a 6-month history of ...
Wegener granulomatosisπŸ”,πŸ“Ί

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A 25-year-old woman comes to the physician ...
Rheumatoid arthritisπŸ”,πŸ“Ί

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Trypanosoma cruziπŸ”,πŸ“Ί

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A 53-year-old man, who recently returned from ...

Question#0 (reveal difficulty score)
A 42-year-old man comes to the emergency ...
Infection with HIV-2πŸ”,πŸ“Ί

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A 70-year-old man from China has a poorly ...
Epstein-Barr virusπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
Three days after unprotected sex with a new ...
Herpes Simplex Virus type 2πŸ”,πŸ“Ί

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A 27-year-old woman comes to the physician ...

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A 28-year-old man is brought to the emergency ...
Dissecting aneurysmπŸ”,πŸ“Ί

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A 70-year-old man dies in a motor vehicle ...
Tubular adenomaπŸ”,πŸ“Ί

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A 40-year-old woman comes to the physician ...

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Staphylococcus aureusπŸ”,πŸ“Ί

Question#0 (reveal difficulty score)
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Aortic stenosisπŸ”,πŸ“Ί

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Dynein armsπŸ”,πŸ“Ί

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Vitamin EπŸ”,πŸ“Ί

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9 πŸ”,πŸ“Ί

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Recent comments ...

... cassdawg made a comment on nbme17/block0/q#0 (A 58-year-old woman is brought to the emergency...)
submitted by cassdawg(1400)

I don't like how they are asking this, but I think what they are getting at is that after the stent placement ("subsequent to the stent placement") there will be reperfusion injury to the myocardial tissue which occurs through free radical injury and therefore membrane lipid peroxidation is the best answer (FA2020 p210 mentions membrane lipid peroxidation as a mechansism of free radical damage and lists reperfusion injury after thrombolytic therapy as a type). Elevations in the cardiac enzymes I assume are because of the injury to the cells.

zalzale96  Created an account just to up vote this answer +4
cheesetouch  1998 journal via google " Myocardial injury after cardiac surgery with cardiopulmonary bypass may be related to free oxygen radical-induced lipid peroxidation" +
peteandplop  "Evidence suggests that reactive oxygen species (ROS) may play important roles in the pathogenesis in myocardial infarction [2]. Following ischemia, ROS are produced during reperfusion phase [3, 4]. ROS are capable of reacting with unsaturated lipids and of initiating the self-perpetuating chain reactions of lipid peroxidation in the membranes" ( +1
mittelschmerz  Honestly the wording got me on this one. Great answer +
acerj  Also, you can rule out a few of the options to help justify this. Post MI you expect necrosis, not apoptosis. Remember, apoptosis is suicide, and necrosis is MURDER! Cell swelling is a sign of cellular injury, not cell shrinkage. The heart will undergo coagulative necrosis, not liquefactive necrosis. Also, protease inactivation by cytoplasmic free calcium is kind of nonsensical to me. Free calcium is more likely to cause cell injury via caspases (a form of proteases amongst other things), which is why calcium is usually bound up inside healthy cells. +3
ownersucks  This question presentation is exactly how Sattar said in pathoma Ch2. Raise in cardiac enzyme following reperfusion +
amy  FA2020 305: Reperfusion injury: free radical and increased Ca influx--hypercontraction of myofibrils There is increased cytoplasmic free calcium ions, but it induces hypercontraction, no protease inactivation. +
... cassdawg made a comment on nbme17/block0/q#0 (An 80-year-old man with Type 2 Diabetes Mellitus is...)
submitted by cassdawg(1400)

Pelvic splanchnic nerves carry the parasympathetic fibers that are responsible for hindgut intestinal motility including voiding (image). [FA2020 p364].

Diabetes mellitus can cause nerve damage and gastroparesis, treated with metoclopromide (FA2020 p400).

pakimd  thank you for sharing the image +1
... cassdawg made a comment on nbme17/block2/q#12 (2 month old boy given vaccine which converts T-independent antigens to T-dependent forms)
submitted by cassdawg(1400)

The question stem is referring to a conjugate vaccine. This is because conjugate vaccines convert T-independent antigens (polysaccharides) into T-dependent antigens by conjugating them with a protein. [FA2020 p127]

Remember that in order for a T-cell to be able to respond to an antigen via MHC, it MUST be a protein. Thus, T-dependent (dependent on T-cells) responses are to proteins. T-dependent responses are overall better because then B-cells can then undergo affinity maturation and class switching through interaction with T-cells. So, by conjugating bacterial polysaccharides to proteins, the immune response will be a more robust T-dependent reaction and will yield better protection. [FA2020 p103]

Conjugate vaccines exist for encapsulated bacteria (as the capsules are polysaccharide and would need to be conjugated to protein to improve response). These are Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae

You can remember these encapsulated organisms and their conjugate vaccine because they are THE SAME organisms that you become susceptible to when you have a splenectomy and which necessitate vaccination.

drippinranch  I appreciate this explanation so much. Thank you. +7
j44n  cassdawg you are a beast +2
... cassdawg made a comment on nbme17/block4/q#1 (83 yo man found bedridden and confused)
submitted by cassdawg(1400)


FA2020 p310

This man presents with hypothermia (septic shock can present with hyper or hypothermia), tachycardia, and low blood pressure with increased cardiac output, characteristic of septic shock. Further distributive shock is associated with severe decrease in systemic vascular resistance while other forms of shock have increased systemic vascular resistance.

cheesetouch  FA2018 P305 Shock +
pakimd  hypothermic presentation of septic shock is due to cytokine-induced dysregulation of the temperature control in the hypothalamus and is associated with poorer outcomes +1
... cassdawg made a comment on nbme17/block1/q#21 (42 yo farmer, 7 mm red scaly plaque on ear)
submitted by cassdawg(1400)

Just to add to the explanation here is what you would see in the others (most on FA2020 p484)

  • Basal cell carcinoma:
  • Keratoacanthoma:
    • Resembles squamous cell carcinoma in that it is a rapidly growing dome shaped nodule with a keratin filled center
    • On histology it basically presents as a crater filled with keratin

  • Malignant melanoma:
    • Bad boi, look for the ABCDEs (asymmetry, border irregularity, color variation, diameter >6mm, and evolution)
    • On histology you see melanocyte proliferation below the basement membrane and it just looks uglier

  • Merkel cell carcinoma:
kstebbins  ^Amazing with the links. Thank you! +4
victorlt14  β€œActinic Keratosis Dermatopathology: Large bright-staining keratinocytes, with mild-to-moderate pleomorphism in the basal layer extending into follicles, atypical (dyskeratotic) keratinocytes, and parakeratosis” From Flitzpatrick's atlas of dermatology +
... cassdawg made a comment on nbme17/block4/q#14 (55 yo man, admitted to hospital for treatment of sepsis)
submitted by cassdawg(1400)

This has to do with the algorithm of treating shock. Septic (a type of distributive) shock as well as hypovolemic shock are treated with IV fluid resuscitation (FA2020 p310). Crystalloid fluids are first-line choice, and normal saline (0.9%, isotonic) is first-line specifically in cases of shock.

5% dextrose in water and 0.45% saline is hypertonic and not useful here.

5% dextrose alone is isotonic in the bag but physiologically hypotonic. It is more often given for fluid replacement after severe dehydration.

0.45% saline only is hypotonic and not useful here.

3% saline is hypertonic and not useful here.

... cassdawg made a comment on nbme17/block3/q#31 (20 yo man, 6 hours of difficulty breathing and vomitting)
submitted by cassdawg(1400)

Hormone sensitive lipase (HSL) is the enzyme which degrades triglycerides stored within adipocytes (FA2020 p93). Thus, it makes sense that it is activated in times of fasting and suppressed in the fed state.

Insulin would inhibit HSL, as insulin is a fed state enzyme secreted by the pancreas and would want to trigger storage of triglycerides.

In contrast glucagon is secreted in response to hypoglycemia by the pancreas and will trigger fasted state activation. In terms of the fed/fast state I always think of glucagon and epinephrine kind of like a superhero and their side kick, because they usually work together in the fasting state on similar targets to ensure the body has enough energy (this helps me remember that epinephrine and glucagon are fasting state hormones). Here though is epinephrine's big action away from glucagon, where glucagon has minimal effect and epinephrine has the big action of activating HSL! Glucagon has a minor role and other catecholamines and ACTH can also serve to activate HSL as well.

Another example of the synergistic work of glucagon and epinephrine is in glycogen breakdown (FA2020 p85). Both will trigger cAMP increase and protein kinase A activation which will phosphorylate glycogen phosphporylase and activate it (FAST PHOSPHORYLATE! Hormone sensitive lipase is actually phsophorylated to activate it as well).

FUN FACT: Hormone sensitive lipase actually got its name because it was sensitive to epinephrine!

flapjacks  In Type 1 DM, the glucagon response to hypoglycemia is not functional and these individuals are reliant on the epinephrine-stimulated hepatic glycogenolysis. I recall this by remembering you can administer glucagon to these patients if they're having a hypoglycemic episode. They can respond to it, but they aren't releasing it. +1
passplease  How did you eliminate thyroxine? As it also plays a role in lipolysis. I was thrown off my the low blood pressure and therefore did not select epinephrine. Why would they still have a low blood pressure? +
jackie_chan  ^ they have low blood pressure because DKA causes a lot of dehydration (vomiting, diuresis due to osmotically active glucose in urine) so low BP Thyroxine I eliminated because remember that thyroxine is unique in that it functions similar to a steroid hormone and acts in the nucleus to upregulate expression of many genes. I figured hormone-sensitive lipase needs to be activated, not stimulated to upregulate expression, so I thought about EPI and beta-3 stimulation. fuckPeter +
schep  I figured since he has low BP/dehydrated, his body would try to maintain cardiac output by increasing sympathetic tone (releasing epinephrine). In hypovolemic shock, systemic vascular resistance is up because of this compensation. +
j44n  also thyroxine works like a steroid hormone meaning it takes a while to cause its effect +
flvent2120  That'd be cool if it were called "epinephrine sensitive lipase" +
... cassdawg made a comment on nbme17/block2/q#13 (28 yo woman, 18 weeks gestation and palpitations)
submitted by cassdawg(1400)

In agreement with the other post: (see FA2020 p331)

You would want to check FREE T4 because pregnancy increases Thyroid binding globulin. It is possible she might have increased overall T4, but NOT have hyperthyroidism because the free T4 is normal (i.e. her increases amount of thyroid binding globulin has bound more T4, and since our bodies respond to the concentration of free T4 only, the hypothalamus should ensure that the free T4 is kept constant; this would appear as increased overall T4)

Another way of thinking of this:

  • Overall T4 = bound T4 + free T4

If we increase bound T4 and keep free T4 the same, we would still increase overall T4. Thus to know if she truly has hyperthyroidism we must look at free T4 concentration.

lpp06  Does Overall T4 stay the same because TBG+T4 can last longer in circulation? Cause I always struggle thinking that free T4 is low because its being bound by the extra TBG +
covid_19  I'm not sure if I'm interpreting your question correctly, but I thought overall T4 increases in pregnancy? The way I think of it is that early in pregnancy, Ξ²-HCG (acting like TSH) β†’ ↑ free T4 β†’ ↓ TSH via (-) feedback β†’ TSH back to nml as ↓β-HCG during pregnancy (i.e. gestational thyrotoxicosis). If the mom really has hyperthyroidism, then free T4 remains high and TSH low even as Ξ²-HCG ↓ and ↑TBG. Later in the pregnancy, estrogen β†’ ↑TBG β†’ ↓ free T4 β†’ TSH release β†’ ↑ free T4 to regain equilibrium. (bound T4: free T4) 2:2 (nml) β†’ 3:1 β†’ 3:3 (new nml where there's a relative increase in free T4 AND overall T4). What are your thoughts on this? +
topgunber  Overall t4 increases, but when t4 is bound to thyroid binding globulin it is not active, therefore someone would not show characteristics of hyperthyroidism if they had high thyroid binding globulin and high total t4. Basically, free t4 is the actual amount of thyroid hormone that can cause a physiologic effect. As the first comment says, total thyroid hormone and thyroid binding globulin are increased in pregnancy. Thus to check for hyperthyroid we are concerned only with free t4 (if it is low then the patient would be hypothyroid) +
... waitingonprometric made a comment on nbme17/block0/q#0 (A 70-year-old man dies in a motor vehicle collision....)
submitted by waitingonprometric(224)

From FA2020, pg. 381:

Tubular adenoma--> neoplastic; tubular histology has less malignant potential than villous; tubulovillous has intermediate malignant potential; usually asymptomatic, may present with rectal bleeding. Hence our patient who has been undergoing evaluation for fecal occult blood.

Other answers:

Hyperplastic polyp--> most common, generally smaller and in rectosigmoid region. I'm guessing the picture attached to this question is trying to clue us into this not being a small lesion.

Inflammatory pseudopolyps--> due to mucosal erosion in inflammatory bowel disease. There is no appreciable erosions in this picture, also the mass appears pedunculated, so we know it's not a spot of normal mucosa that just looks raised compared to surrounding erosion.

Juvenile polyp and Peutz-Jeghers syndrome--> these are both genetic disorders with numerous hamartomatous polyps seen in the colon. Peutz-Jeghers also associated with increased risk of breast and other GI cancers. It is unlikely that our patient had either of these b/c he is 70 y/o; therefore, if he had one of these, he would likely have more than one colon lesion and may also present with a history of other cancers at his age.

cheesetouch  great refutation of others, thanks! +3
lpp06  To add - tubular adenomas are pedunculate masses, as seen in the image +2
soccerfan23  great explanation and username lol +
sexymexican888  Also... idk if this helps but it got me the right answer (plus clinical scenario) : golijan said TUBULAR ADENOMA -> STRAWBERRY ON A STICK I know thats for the histology but idk thats what it looked like to me haha +
... cassdawg made a comment on nbme17/block4/q#37 (An 18-year-old man has yellow nodules on the...)
submitted by cassdawg(1400)

Yellow nodules (cholesterol deposits) on the achilles tendons have a very high association with Type II familial dyslipidemia, or familial hypercholesterolemia. This is caused most often by a defect in the LDL receptor function. (FA2020 p94)

cassdawg  NOTE: This patient shows a SELECTIVE increase in LDL so it is a defect in the LDL receptor NOT a defect in ApoB100. A defect in ApoB100 would present with increased VLDL as well! +27
ginachipotle  Note that the answer is ABSENT LDL receptors vs. partial reduction b/c LDL >700 (LDL = 980), indicating individual is likely homozygous for the trait. (FA2020 pg. 94) +10
jdc_md  you trick me nbme. veryy veryy tricky +4
... waitingonprometric made a comment on nbme17/block2/q#22 (60 yo man, 1 month of progressive shortness of breath)
submitted by waitingonprometric(224)

FA2019, pg. 666:

Based on the findings of decreased breath sounds, dull percussion, and decreased tactile fremitus, pleural effusion is your answer.

This was more of a rule-out question than a remember-the-arrows-on-a-page-in-FA question for me!

Breath sounds are decreased, so you can rule out asthmatic bronchitis (wheezing) and pulmonary embolism (normal breath sounds, but tachypneic). Bronchiectasis can have a number of findings--crackles, rhonchi, wheezing, mid-inspiratory squeaks, etc.

Emphysema (loss of alveolar septal tissue) and pneumothorax have increased air in the lungs, therefore, they will be hyperresonant on percussion, so rule those out too.

Tactile fremitus decreases with most everything, but consolidation--low frequency sounds travel well in dense material (lobar pneumonia), but travel poorly through liquid (pleural effusion). Therefore, based on decreased fremitus, rule out pneumonia.'re left with pleural effusion as your answer!

mw126  Physical exam findings related to the FA table for pulmonary embolism are usually normal, may have a pleural friction rub over the area of infarct. +
an1  why are there crackles in the opposite lung? +
srmtn  pleural effusion secondary to HF (bilateral lung involvement). so crackles is the finding before pleural efussion- +2
... bingcentipede made a comment on nbme17/block0/q#0 (A 55-year-old woman has left flank pain and gross...)
submitted by bingcentipede(305)

The classic triad of a renal cell carcinoma is: 1) hematuria; 2) flank pain; and 3) a palpable flank mass. The classic RCC comes from a VHL mutation. No VHL means you can't inhibit HIF (hypoxia inducible factor). This leads to uncontrolled activation of VEGF, leading to the hypervascular mass.

cheesetouch  FA2018 P583 +3
... cassdawg made a comment on nbme17/block3/q#24 (10 yo girl, well-child examination)
submitted by cassdawg(1400)

Here is a great image showing the timeline for the different pubertal changes in males and females. Tanner stages are found in FA2020 p673.

In females, the earliest detectable sign of pubertal change is breast bud development which only slightly precedes pubic hair development. In males, testicular enlargement is the first detectable sign.

flapjacks  You share excellent charts. Thank you! +2
... flapjacks made a comment on nbme17/block2/q#33 (Study conducted to assess effectiveness of lidocaine injections)
submitted by flapjacks(86)

My reasoning for this question:

  • In both situations, you see a cyclical increase in pain before receiving the injection. This could be seen if the effect was wearing off; however, if you notice, there is a decrease in pain before the injection is even given. I believe this implies that something inherent about the injection is providing pain relief.
  • Furthermore, both curves follow the same path with an eventual decrease in pain, regardless of intervention.
  • Maybe an additional point - I am not questioning their pain, but fibromyalgia typically shows no abnormal lab results in addition to typically coexisting with some form of mental pathology. I don't think placebo being demonstrated is far off.
j44n  I agree that was my though process, except i didnt notice the decrease before the injection, good eye! also the other answers didnt really apply regression toward the mean is the phenomenon that arises if a random variable is extreme on its first or first few measurements but closer to the mean or average on further measurements and there was no way for us to know about confounding or their selection procedures so from that we couldn't really know about the types of errors they made +2
... lfcdave182 made a comment on nbme17/block4/q#20 (45 yo man, 4 days of yellow skin)
submitted by lfcdave182(36)

Pg 391, FA 2020

  • Alcoholic hepatitis: Swollen and necrotic hepatocytes with neutrophilic infiltration; Mallory Bodies (Intracytoplasmic eosinophilic inclusions of damaged keratin filaments)
cheesetouch  FA2018 P385 +4
randi  FA2019 p.385 +1
... tinyhorse made a comment on nbme17/block0/q#0 (A 45-year-old woman comes to the physician for a...)
submitted by tinyhorse(9)

Frankly pretty floored that anybody thought that this question contained enough information for someone to confidently answer it.

The question has you assume that both parents are heterozygotes at the locus. Why? I assume I'm missing some esoteric fact about P450 allele frequencies.

flapjacks  I got lucky guessing the same % chance that siblings share HLA markers +4
baja_blast  I agree with OP seriously no idea how anyone could have gotten this right without totally guessing it. Am I missing something here?? +2
sschulz2013  However, if one parent is homozygous and the other is heterozygous, then it works out that the sister will have the same allele 50% of the time, not 25%. So still not sure about the above answer. Don't think assuming the parents are both heterozygotes is something we should have to do. There is probably more to it than just that. +1
j44n  the probability for being the same gene as a sibling thats homozygous is always 25% this has been on just about every practice NBME +
chaosawaits  Because neither of the parents have history breast cancer, it is assumed that neither parent is homozygous. +1
... cassdawg made a comment on nbme17/block0/q#0 (A female newborn is delivered at 38 weeks'...)
submitted by cassdawg(1400)

This child likely has a meningomyelocele (neural tube defect caused by failure of the neuropores to fuse in week 4, FA2020 p491). Neural tube development in general occurs weeks 3-8 (FA2020 p612) which corresponds most closely to days 15-40. Organogenesis and most vital development also occurs during this period.

Days 1-10 are typically "all or nothing" in that a defect would cause fetal demise.

Days 60-75 (~weeks 8-10) are associated with external genital development, palate and teeth.

The most critical periods are typically over by week 10 (see this chart)

... cassdawg made a comment on nbme17/block0/q#0 (A 50-year-old man comes to the physician 3 days after)
submitted by cassdawg(1400)

This individual is suffering from hypocalcemia, which explains the seizures, twitching (reason for Chvostek sign - tapping of the facial nerve causing contraction of the muscles), and spasms (similar to Trousseau sign - inflation of the blood pressure cuff causing carpal spasm). It also may present with QT prolongation and numbness and tingling (as described). It is also important to note that though mild hypocalcemia causes hyporeflexia, extreme hypocalcemia can lead to hyperreflexia, tetany, parasthesias, and seizures (see here). Basically you cannot bank on the reflexes.

Hypercalcemia would present with stones (renal), bones(pain), groans(abdominal pain), thrones( urinary frequency), psychiatric overtones(anxiety, altered mental status).

The others answers are incorrect because:

  • Bicarbonate disturbances are related to acid/base imbalance and would not present with the symptoms described.
  • Chloride:
  • Hypochloremia (associated with excessive vomiting) is typically accompanied by hyponatremia and typically presents with weakness/fatigue and dehydration.
  • Hyperchloremia disturbances are generally related to kidney issues and when signs present they are dehydration, excessive thirst, fatigue, and dry mucus membranes
  • Potassium:
  • Hypokalemia presents with muscle cramps, spasm, and weakness but also with cardiac anomalies (arrhythmias) and flattened T-waves on ECG.
  • Hyperkalemia presents with wide QRS and peaked T waves on ECG, weakness, and arrhythmias.
  • Sodium:
  • Hyponatremia can cause seizures and stupor, but it also typically presents with nausea and vomiting, weakness/fatigue, and confusion. Here is a good hyponatremia pneumonic (SALTLOSS - Stupor, Anorexia[nausea, vomiting], Lethargy, Tendon reflexes decreased, Limp muscles/weakness, Orthostatic hypotension, Seizures, Headache)
  • Hypernatremia presents with irritability and stupor

Electrolyte Disturbances: FA2020 p591

chaosawaits  everything is great except "mnemonic" +
... abkapoor made a comment on nbme17/block0/q#0 (A 56-year-old woman comes to the physician for a...)
submitted by abkapoor(18)

Just to clarify, complete resolution after injury can only occur if the basement membrane remains intact as this below this is where the stem cells are located. If there is damage to the basement membrane, you will have incomplete resolution and scar formation. The best example of this is skin injury.

... cassdawg made a comment on nbme17/block0/q#0 (A 3-year-old boy with sickle cell disease has the...)
submitted by cassdawg(1400)

Osteomyelitis is a common complication of sickle cell disease and can be distinguished here because of the elevated WBC/neutrophil (indicating bacterial infection). It is important to note the most common cause of sickle cell osteomyelitis is Salmonella or Staph aureus (in a healthy individual the most common cause is Staph aureus). [FA2020 p180 and 422]

... cassdawg made a comment on nbme17/block0/q#0 (A 65-year-old woman comes to the physician because of )
submitted by cassdawg(1400)

Lichen sclerosus is a vulvular pathology involving thinning of the epidermis with fibrosis/sclerosing dermis, most commonly presenting with skin fragility (paper-thin) in post-menopausal women (FA2020 p644)

The other answers do not fit:

  • Candidal infection = itchyness and cottage cheese discharge; the excessive itching can lead to lichen sclerosus but would also be treated by the miconazole
  • HPV = genital warts or cervical cancer
  • Trichomoniasis = itchy with green smelly discharge, see organisms on microscopy
  • Urethral prolapse = rare, painful, would not cause these symptoms and would cause swelling in urethral area
... bingcentipede made a comment on nbme17/block1/q#16 (A healthy 70-year-old woman has participated in a...)
submitted by bingcentipede(305)

Changes that happen in aging:

Stays the same: TLC (very important to know this)

Increased: lung compliance, residual volume, V/Q mismatch, A-a gradient

Decreased: chest wall compliance, FVC, FEV1, respiratory muscle strength, ventilatory response to hypoxia/hypoxemia

AKA don't get old

gooooose  FA 2020 p665 +1
sschulz2013  Exception: severe kyphosis can cause decrease in TLC! +3
ownersucks  Even though lung compliance increases there is stiffening of chest wall which balance out increased lung compliance. Thus TLC remains unchanged RV increase and FEV decreases because there’s collapse of out flow tract which weakens with age +1
... lfcdave182 made a comment on nbme17/block1/q#28 (12 yo boy, swimming in mountain stream; immersed in 60-degree water for 20 minutes)
submitted by lfcdave182(36)

Cold temperature: Causes peripheral vasoconstriction and central vasodilation

  • Increased central blood volume --> Lower ADH due to increased blood volume through kidneys
  • Increased central blood volme --> leads to atrial stretching, increased preload --> Increased ANP release
passplease  what organs are considered "central"? I initially thought that the kidneys would not be getting more blood with most of the blood flow going to the lungs and heart +1
brise  Same :( +
drdoom  the kidneys are the lungs for waste products that can't be expelled via your breathe. (another way of saying this is: the lungs are like the kidneys of your mouth: instead of urinating out of your mouth, you "pee out" CO2 in the form of expired air.) tl;dr the kidneys are very vital organs!! +2
mkayman  my dumbass was like alright you pee in cold water so that means central blood volume is up since you're filtering more blood in the kidneys, ADH is down because you wanna pee and ANP is up because you wanna pee... worked out okay +
... waitingonprometric made a comment on nbme17/block2/q#46 (38 yo man, brought to ER 30 minutes after being found near his home, unsbale to stand upright)
submitted by waitingonprometric(224)

Metabolic acidosis because the arterial pH goes in the same direction as the bicarb and pCO2 (i.e. both pH and bicarb/pCO2 are decreased from normal); in primary respiratory acidosis/alkalosis the arterial pH goes in the opposite direction as the bicarb and pCO2.

Once you know that it is a primary metabolic acidosis, you have to check for concomitant respiratory disorders. Do this with Winter's formula:

expected pCO2 = 1.5(HCO3) + 8 +/- 2

so... expected pCO2 = 1.5(11) + 8 +/- 2 --> pCO2 = 24.5 +/- 2 = expected pCO2 is between 22.5-26.5, therefore, 23 is in the expected range, no concomitant respiratory process

baja_blast  Was looking for "Metabolic acidosis and respiratory acidosis" and was wondering why it wasn't a choice. Totally forgot about Winter's formula. Thanks!! +6
... cassdawg made a comment on nbme17/block0/q#0 (22-year-old woman, gravida 1, para 1... vaginal bleeding)
submitted by cassdawg(1400)

Ligation of the internal iliac artery is used to stop postpartum uterine bleeding while preserving fertility as the ovarian arteries provide collateral circulation (FA2020 p640).

Here is an image showing the uterine artery coming off the internal iliac with the ovarian artery collateral.

Other answers:

  • The external iliac gives rise to the femoral artery, inferior epigastric artery, and the deep circumflex iliac artery
  • The internal pudendal artery supplies the external genetalia and perineum via arteries such as the inferior rectal artery (anal canal BELOW the pectinate line), perineal artery, and ldorsal/deep arteries of the clitoris or dorsal/deep arteries of the penis
  • The median sacral artery is small and supplies the coccyx/sacrum/lumbar vertebrae
  • The obturator artery is a branch of the internal iliac which gives off the pubic branch (supplies pelvic muscles) and acetabular branch (supplies head of the femur)
cheesetouch  fa2018 p624 +4
... cassdawg made a comment on nbme17/block0/q#0 (A 19-year-old man is admitted to the hospital...)
submitted by cassdawg(1400)

He has an upper motor neuron lesion which is causing paralysis on his left lower side, so he will have hyperreflexia on this side. Thus the deep tendon reflex will actually be increased/strongest in his left achilles tendon initially after the accident. [FA2020 p529]

jurrutia  Wouldn't he also have hyperreflexia in the right brachioradialis, which is innervated by the radial nerve? Since the patient's right radial nerve was severed, he should also have an UMN lesion with hyperreflexia in the right brachioradials? +
kbizzitt  A radial nerve lesion is a LMN lesion (hyporeflexia). You can basically divide it by pre-anterior horn, and post-anterior horn of the spinal cord. After the synapse at the anterior horn it becomes a lower motor neuron. Before that (along the spinal cord and up back up to the motor cortex) is considered upper motor neuron. +3
jurrutia  Duh, of course! Dumb mistake. Thanks +1
an1  So if it's UMNL, why couldn't the right patellar tendon show hypereflexia as it was also in the initial injury? +4
solangelroma  the only paralysis for right cerebral cortex injury (UMN) is the left lower extremity - the radial lesion (LMN) is for the humeral shaft fracture. the tibial fracture is also right. UMN gives hyperreflexia, LMN hypo. +
... cassdawg made a comment on nbme17/block2/q#1 (A 38-year-old man comes to the physician because of)
submitted by cassdawg(1400)

Loratadine is a second generation antihistamine and thus would be preferred in this patient as it does not cause sedation. [FA2020 p686]

Since he works operating heavy machinery, it would be preferred to put him on a second generation antihistamine. Bropheniramine, hydroxyzine, and diphenhydramine are first generation antihistamines which cause sedation.

Ranitidine is a histamine H2 blocker used to decrease secretion by parietal cells in peptic ulcer disease, gastritis, and gastric reflux [FA2020 p399]

cheesetouch  FA2018 P667 +
... andro made a comment on nbme17/block1/q#8 (6 week old girl, 6 days of vomiting a small amount of milk)
submitted by andro(213)

Differential Diagnosis of Newborn/Neonatal Vomiting

-Benign gastroesophageal reflux ( i.e immature lower esophageal sphincter ) regurgitation of food shortly after feeding .
No further symptoms , healthy children with normal development

-Hypertrophic pyloric stenosis
Regurgitation - projectile nonbilious vomiting electrolyte imbalances ( alkalosis and hypokalemia ) * physical examination may reveal an olive mass on palpation of epigastrium
*typically starts from between 2nd and 7th week of age

-Midgut volvulus /Malrotation /Duodenal atresia * bilious vomiting * abdominal distention * Imaging may reveal signs like the double bubble sign ( duodenal atresia ) etc

Note: The list is not exhaustive as there are many more causes associated with newborn vomiiting

covid_19  To add on to Benign GER, I couldn't find anything in a cursory look through FA and also didn't know that GER was a thing in neonates, so I found this nice and concise article in UpToDate: +
i_hate_it_here  I don't understand why Esophageal spasm isn't right +
topgunber  I would say esophageal spasm would cause immediate regurgitation or inability to swallow properly. so we would be looking for dysphagia. +4
nikitasr27  In general neonates have an immature nervous system (e.g. babinski) and I think that also applies to the ANS. That’s why you see so many YouTube videos of babies vomiting out of the blue without even changing their face expression. I don’t knoow, babies are weird +
pakimd  is immature esophageal sphincter the reason why babies spit up milk when parents burp their babies? +
chaosawaits  babies burp up their milk because they swallow too aggressively when they feed. Burping them helps get rid of some of the air in their stomach and helps prevent distention from too much air, thereby relieving of potential stomach pains. +
... icedcoffeeislyfe made a comment on nbme17/block2/q#5 (56 yo man, sudden onset of uncontrollable irregular movements on left side of body for 4 hours)
submitted by icedcoffeeislyfe(49)

First aid 2020 pg 511-- brain lesion in the subthalamic nucleus = contralateral hemiballismus

cheesetouch  also: Caudate atrophy -> Huntington Disease [causes cognitive issues FA18 p 484 vs putamen has motor role] Dentate nucleus is the most lateral deep nucleus involved in cerebellar output (FA18 p 483) +
... icedcoffeeislyfe made a comment on nbme17/block2/q#34 (40 yo man, skin extremely sensitive to sunlight)
submitted by icedcoffeeislyfe(49)

FA 2020 pg 425

Porphyria cutanea tarda-- defect in UROD in the heme synthesis pathway that causes photosensitivity and blistering

bingcentipede  Most common porphyria, too +4
brise  The thing that got me screwed was the "increases synthesis of compounds"; like what compounds? +
i_hate_it_here  I swear they just love to say shit to throw us off smh +3
sexymexican888  @brise I think they were referring to the previous products of heme synthesis that build up (hydroxymethylbilane, uroporphynogen - or however the fk u spell it) I think those are what cause the blistering photosensitivity, im guessing it is since these dont accumulate in acute intermittent porphyria -> no skin symptoms. but yeah I agree these ppl fucking suck +
chaosawaits  "Disorder caused by the increased synthesis of compounds in the skin that are subject to excitation by visible light" = heme; "Disorder caused by lack of compounds in the skin that are subject to excitation by visible light" = melanin +
... cassdawg made a comment on nbme17/block2/q#41 (Seven hundred healthy women observed for 10 years)
submitted by cassdawg(1400)

FA2020 p256

This would be a prospective cohort as they are looking at two groups with and without risk factors and assessing disease incidence.

UWorld has a super pretty picture which helps visually explain the differences (Copyright UWolrd, blah blah buy UWorld)

... cassdawg made a comment on nbme17/block3/q#33 (Female newborn delivered at 36 weeks, respiratory distress)
submitted by cassdawg(1400)

This is a Congenital Diaphragmatic Hernia (FA2020p370).

Conginital diaphragmatic hernias are caused by a congenital defect of the pleuroperitoneal membrane which allows contents of the abdominal cavity to herniate upward, and displace the contents of the thorax (hence why our baby has displacement of the mediastinal contents to the right). This also leads to lung malformation and respiratory distress (hence the low apgar scores). Because the stomach is likely herniates upward, a nasogastric tube placed would appear in the left mediastinum (because that is where the stomach is). Further, there is an absence of bowel gas in the abdomen likely because the bowels are herniated into the thorax.

cheesetouch  FA2018 P364 CDH +1
randi  FA2019 364 Diaphragmatic Hernia +1
... cassdawg made a comment on nbme17/block4/q#47 (10 yo boy, anemia since birth; spleen is five times normal size)
submitted by cassdawg(1400)

Splenectomy is indicated for hereditary spherocytosis because it is an intrinsic hemolytic anemia where the spleen is destroying the red cells even though they could technically function fine. Thus splenectomy will prevent premature removal by the spleen (FA2020 p422).

Sickle cell disease causes autosplenectomy/splenic infarct/sequestration but splenectomy is not indicated because the spleen is not contributing to the symptoms of sickle cell, the symptoms are caused by the vasoocclusive disease.

jzbjzb  why not thalassemia major? splenectomy reduces the need for blood transfusions and greater Hb levels +1
shieldmaiden  Because of the NBME law of the "Best Answer". Splenectomy is what "cures" HS, because that is the organ that prematurely targets it for removal leading to hemolysis. As for thalassemia, you could do it, but it is not indicated at this time for this 10-year-old. Splenectomy is only indicated for thalassemia when an enlarged spleen increased the frequency of transfusions and/or chelation therapy is not enough to control iron levels. +1
shieldmaiden  For the exam, only consider splenectomy for spherocytosis, refractory autoimmune hemolytic anemia, or massive trauma +1
... cassdawg made a comment on nbme17/block0/q#0 (15-year-old, lesions on neck, acid-fast bacilli,...)
submitted by cassdawg(1400)

Mycobacterium leprae likes cool temperatures (FA2020 p141)

Mycobacterium leprae is an acid-fast bacteria which can cause two skin manifestations:

  • Lepromatous presents diffusely over the skin and with leonine facies and is more serious with a largely Th2 response and high bacteria load
  • Tuberculoid (what our patient has) presents with a few hypoesthetic hairless skin plaques with a largely Th1 response and low bacteria load

Leprosy likes cool temperatures so it infects skin and superficial nerves. Even without knowing the organism, the link could also be potentially inferred!

bingcentipede  In addition, the only other acid-fast bacterium is Nocardia; they would have to describe it as branching/filamentous (NOT a bacillus!). +3
... cassdawg made a comment on nbme17/block0/q#0 (14-year-old boy is brought to the emergency...)
submitted by cassdawg(1400)

Maxillary nerve injury (specifically the infraorbital nerve) is an important potential complication of orbital rim fractures (e.g. blow out fractures) [See here]

Here is a picture of the territories of the different branches of the trigeminal nerve for sensation which could help you answer this question as he has numbness under the eye to the upper lip.

Orbital floor fractures can lead to entrapment of the inferior rectus, which can be a cause of pain on upward gaze and diplopia when asked to look upward. This is an ophthalmologic emergency (

... cassdawg made a comment on nbme17/block0/q#0 (58-year-old man with supraventricular...)
submitted by cassdawg(1400)

This mainly has to do with the location of the SA node (see here). The SA node is located in the atrial wall at the junction of the superior vena cava and right atrium.

The AV node lies near the back of the intraventricular septum near the opening of the coronary sinus (the triangle of Koch defines the AV node location)

Other fun facts from UWorld about ablation and different sites of origin, etc:

  • Between the tricuspid and inferior vena cava (cavotricuspid isthmus) is the most likely location of a reentrant circuit causing atrial flutter
  • The pulmonary vein ostia is the most likely site of origin for AFib and therefore most likely targeted for catheter ablation to correct Afib
  • The right ventricular outflow tract and papillary muscles are the most likely site of origin for Idiopathic VTach (though it is more commonly from ischemic tissue)
  • An accessory pathway bypassing the AV node is the cause of Wolff-Parkinson-White syndrome (characteristic delta wave upstroke) and AV reentrant tachycardia
  • A slow pathway that reenters the AV node is the cause of AV nodal reentrant tachycardia and the slow pathway would be targeted for ablation
... baja_blast made a comment on nbme17/block0/q#0 (A 30-year-old woman comes to the physician for a...)
submitted by baja_blast(151)

Gluconeogenesis primarily occurs in the liver, but enzymes for gluconeogenesis are also found in kidneys and intestinal epithelium. FA2019 p. 78

dermgirl  FA2020 p. 78 +
... cassdawg made a comment on nbme17/block0/q#0 (A protein found in the brown adipose tissue of mice...)
submitted by cassdawg(1400)

This protein is an uncoupling agent (likely thermogenin which is found in brown adipose and serves to increase heat production. Uncoupling agents will cause increased permeability of the mitochondria membrane, necessitating more oxygen consumption in order to generate the same ion gradient. Since more oxygen is consumed to generate the same gradient, more oxygen would be consumed to generate the same amount of ATP, so the ratio of oxygen consumption to ATP generation increases. (FA2020 p78)

Another way of thinking about this is that oxygen will continued to be consumed to attempt to generate the gradient, but the leaky membrane will prevent the gradient from being formed properly and therefore prevent ATP from being formed. Thus there is the same amount of oxygen consumed for little to no ATP being made so again the ratio of oxygen consumption to ATP generation increases. This is closer to what actually happens in the body but I found it easier to think about it the first way.

feochromocytoma  Exactly, the electron transport in the mitochondria will keep going, but ATP synthesis would stop, which causes production of heat. +
thegout  if you're like me, you picked decreased ratio of oxygen to ATP in a brain fart without thinking about what a ratio is, gotta read the answers more carefully in long grueling exam. +13
... cassdawg made a comment on nbme17/block0/q#0 (A 53-year-old man, who recently returned from Africa)
submitted by cassdawg(1400)

Below are links to pictures of what each organism would look like on a stain:

  • Babesiosis is fever and hemolytic disease predominantly in the northeast US, usually presents with classic "maltese cross" in RBCs [FA2020 p157]
  • Leishmaniasis can be cutaneous with ulcer presentation or visceral with spiking fevers, hepatosplenomegaly, and pancytopenia. The amastigotes are present in macrophages not RBCs [FA2020 p158]
  • Malaria is caused by the plasmodium species and presents with trophozoite ring forms in RBCs. It is transmitted by the anopheles mosquito and is endemic in parts of Africa. It causes fever, headache, anemia, and splenomegaly [FA2020 p157]
  • Toxoplasmosis is is an intracellular parasite but a small numbr exist extracellularly as tachyzoites in blood; it can also cause tissue cysts filled with bradyzoites. In immunocompetent hosts it produces mono-like symptoms but in immunocompromised it will dissiminate and cause ring-enhancing brain/tissue abscesses. [FA2020 p156]
  • Trypanosomiasis can be caused by Trypanosoma bruceii (African sleeping sickness, p156) or Trypanosoma cruzii (Chaga's disease, South America, p158). These organisms are extracellular on blood smear.
... lfcdave182 made a comment on nbme17/block1/q#14 (21 yo man, excruciating anal pain for 4 hours)
submitted by lfcdave182(36)

Pg 366 FA 2020.

  • Below pectinate line: External hemorrhoids: Painful if thrombosed: Inferior Rectal Vein.
neovanilla  Note: pg 365 FA 2020 states: anorectal varices: portal <--> systemic: superior rectal <--> middle and inferior rectal. Not sure if that's correct, but definitely the info cited in pg 366 is correct +3
cheesetouch  FA 2018 p360 +
... compasses made a comment on nbme17/block1/q#20 (24 yo man, history of intravenous drug use, brought to ER 30 minutes after he could not be aroused)
submitted by compasses(7)
unscramble the site ⋅ remove ads ⋅ become a member ($39/month)

taotl aoetcrntnocin = m3/0gl.0 x 020L = 6emh0 g ktoo eth rdug 6 ohrsu ago @ fhlat- fo 2 or20=00h=0hmoro== h8 6su=sr1=m2gorgushrmg=6us0gumh=42 44s

... osler_weber_rendu made a comment on nbme17/block1/q#21 (42 yo farmer, 7 mm red scaly plaque on ear)
submitted by osler_weber_rendu(112)
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Whta uoy nac ese is

.rsree1pHastykoi keintdce(h utrmast )asaruei2.omrPcakotnesr yo(u nca ese het enclui yvre lleacry in the tsumart rmoasaieul) 3ypnsc.D cient(o ttkacryeiones oythcepharircm and egalr ilcneu og up mastlo all the ywa ot het .pto hisT tsni so ni roamln sink)

all shit sfti ntciaci eoistsakr

cassdawg  Actinic keratosis is FA2020 p482 if anyone needs it! +5
baja_blast  FA2019 p. 472 +3
cheesetouch  Sweet name @osler_weber_rendu #represent #cureHHT +1
... cassdawg made a comment on nbme17/block2/q#24 (65 yo woman, ovarian cancer treated with cyclophosphamide)
submitted by cassdawg(1400)

Cyclophosphamide is an alkylating agent which cross-links DNA at guanine and interferes with DNA replication (FA2020p441)

Other alkylating agents that interfere with DNA replication include busulfan, isofosfamide, nitrosureas and procarbazine (procarbazine is nonspecific).

Other answers:

  • Imatinib/dasatinib/nilotinib targets the BCR-Abl tyrosine kinase and are used for CML (p443)
  • Caspase 3 is not a direct target of any chemotherapeutic.
  • DNA histone deacetylase is the target of HDAC inhibitors, not in First Aid but approved for some T-cell lymphoma.
  • DNA polymerase alpha is one of the eukaryotic DNA polymerases. It is responsible for initiation and some synthesis of lagging strand but does not have the high processivity of Pol delta. It is not directly targeted in any therapy.
  • DNA topoisomerase II inhibitors include etoposide, teniposide (primarily solid tumor use, p442), doxorubicin, danorubicin (solid tumors, leukemia, lymphoma, p439). DNA Top I inhibitors are also important antitumor agents, including irinotecan and topotecan (p442)
  • Epidermal growth factor receptor tyrosine kinase (EGF tyrosine kinase) inhibitor is Erlotinib, and it is important in combatting non-small cell lung cancer (p442)
pakimd  thank you for the explanation. one question: arent all alkylating agents cell cycle independent/non-specific? thanks +1
... baja_blast made a comment on nbme17/block2/q#39 (40 yo man, interstitial pulmonary fibrosis)
submitted by baja_blast(151)

Fibrosis pulls the airway open, increasing radial traction and decreasing resistance to airflow.

Here is a picture comparing fibrosis (increased traction) to emphysema (decreased traction) to a healthy lung.

... icedcoffeeislyfe made a comment on nbme17/block3/q#9 (40 yo African American woman, 2 weeks of fever, malaise, dyspnea)
submitted by icedcoffeeislyfe(49)

The pt has sarcoidosis via the classic demographic association and the b/l hilar adenopathy

in sarcoid you get increased ACE and you also get hypercalcemia due to increased 1-alpha-hydroxylase (via acitvated macrophages) which leads to increased vitamin D

FA2020 pg 676

jdc_md  black females lungs= sarcoidosis +2
... cassdawg made a comment on nbme17/block3/q#26 (34 yo man, lightheaded after 12 miles of marathon)
submitted by cassdawg(1400)

This question is essentially asking what happens to sympathetic and parasympathetic efferents in the setting of hypovolemia/dehydration. In this setting, there would be lower blood pressure and thus this would cause reduced firing of the carotid baroreceptors, ultimately leading to feedback which stimulates the sympathetic nervous system (to increase heart rate and cause peripheral vasoconstriction in order to compensate for hypovolemia) while also inhibiting the parasympathetics.

saqeer  silly me thought they were asking about heat stroke. +1
... cassdawg made a comment on nbme17/block4/q#3 (46 yo man, recevied cardiac transplant, treated with oral cyclosporine)
submitted by cassdawg(1400)

Cyclosporine is an immunosuppressant that blocks T-cell activation by preventing IL-2 transcription (FA2020 p120)

Even without remembering the mechanism of cyclosporine, the answer could be inferred as most medications used after kidney transplant (cyclosporine, tacrolimus, sirolimus, basiliximab) block T-cell activation. This mechanism MAKES LOGICAL SENSE because T-cells are the primary mediators of acute rejection, which is what we are trying to prevent directly after a kidney transplant.

... cassdawg made a comment on nbme17/block4/q#34 (16 yo girl, 2 years of intermittent fainting while standing)
submitted by cassdawg(1400)

Answering this question requires general knowledge of the catecholamine synthesis pathway (FA2020 p83).

The approach I took to this question was mainly elimination of wrong answers:

  • MAO (monoamine oxidase) could be eliminated because she is lacking epinephrine and since MAO is involved in the breakdown of catecholamines, a deficiency in MAO would increase concentrations of norepinephrine and other catecholamines.
  • Norepinephrine transporter could be eliminated because inhibition of reuptake of norepinephrine would, again, increase norepinephrine concentrations and she has decreased concentration.
  • Tyrosine hydroxylase can be eliminated because it is the first step in catecholamine synthesis and required for dopamine synthesis, and as she has increased dopamine this step is not deficient.
  • Amino acid decarboxylase, or L-amino acid decarboxylase also called DOPA decarboxylase, is also required in dopamine synthesis and can be eliminated because of her increased dopamine concentration.

This leaves the answer, dopamine beta-hydroxylase.

waitingonprometric  Awesome answer, but just to add a bit more about why the correct answer makes sense. Dopamine beta-hydroxylase is the enzyme that converts dopamine to norepinephrine. Therefore, the increase in dopamine conc. when rising from supine to standing, is trying to tell us that her body is ramping up the SNS to compensate for all of the blood rushing to her feet when she stands up. Ramping up the SNS requires production of catecholamines, but without this enzyme, synthesis of NE only gets to the dopamine stage and lots of dopamine backs up behind this enzyme. +14
... waitingonprometric made a comment on nbme17/block0/q#0 (38-year-old man with a 3-year history of type 2...)
submitted by waitingonprometric(224)

FA 2019, pg. 556. Stages of change model.

Precontemplation --> denying the problem (i.e. if this patient didn't think that he needed insulin to control his blood sugar)

Contemplation --> acknowledges the problem, but is unwilling to change (i.e. our patient here, knows that he needs insulin, but not ready to take it b/c it made people in his family sick)

Preparation/determination --> preparing for behavioral change (i.e. patient asking the doctor to prescribe insulin to control his blood sugar)

Action/willpower --> changing behaviors (i.e. patient is taking insulin)

Maintenance --> maintaining changes (i.e. patient has taken his insulin for last 5 years with fidelity)

Relapse --> returning to old behaviors and abandoning changes

dermgirl  FA 2020, pg. 568. +
... waitingonprometric made a comment on nbme17/block0/q#0 (A 63-year-old man comes to the physician because of )
submitted by waitingonprometric(224)

6-month history of exertional chest pain that is relieved by rest = stable angina. Per FA2019, pg. 301--stable angina is usually secondary to atherosclerosis with more than 70% occlusion.

Contrary to what you might think (or at least this is doublethink for me!), plaques that occlude a larger percentage of the lumen are usually older and more stable (i.e. calcified) and this makes them less dangerous. These larger, older occlusions usually have a well-developed fibrous cap that makes them less likely to rupture and cause unstable angina/NSTEMI or STEMI.

B/c this guy has had symptoms that are not increasing in intensity over the past 6 months, he likely has a calcified, lg. plaque.

jdc_md  nice job, further adding NSTEMI is caused by less than 100% obstruction. STEMI= 100% occlusion. For stable angina to present typically you would need at least 70% occlusion for symptoms to emerge. +1