Cryptococcus neoformans is common in patients with immunocompromising conditions. Usually, I have this infectious yeast associated with India Ink staining (wherein it presents with a clear halo) but on mucicarmine stain, it presents with a red inner capsule, and the narrow budding can be more easily appreciated.
It causes cryptococcosis, meningitis, and encephalitis ("soap bubble" lesions in the brain).
The treatment is amphotericin B with flucytosine, followed by fluconazole for cryptococcal meningitis.
Anaphylaxis following blood transfusion is mediated by IgA in the new blood product in the IgA deficient patient. This is a high-yield classic presentation.
Bacillus anthracis is a gram-positive, spore-forming rod that produces anthrax toxin (an exotoxin consisting of protective antigen, lethal factor, and edema factor). Has a polypeptide capsule (poly d-glutamate). Colonies show a halo of projections, sometimes referred to as a “medusa head” appearance.
It presents as a cutaneous anthrax and a pulmonary anthrax:
(A) "Are you having any problems that you may be too embarrassed to talk about? Would you be willing to talk about them today?" is wrong because it implies that the topic is too shameful to openly discuss and discourages the patient from mentioning the issue. Physicians should avoid asking vague questions that do not directly assess for urinary incontinence.
"Don't TRI drugs" -> Tricuspid valve endocarditis is typically associated with intravenous drug use.
See this comment and subcomment in NBME 27.
The posterior communicating artery (PCom) communicates between the posterior cerebral artery and the middle cerebral artery in the Circle of Willis.
PCom aneurysm can lead to compression and ipsilateral CN III palsy leading to mydriasis (classically called a "blown pupil") and ptosis. The clinical finding is a "down and out" eye (eye in an inferior and lateral position). Recall that the oculomotor nerve courses beneath the posterior cerebral and PCom and are vulnerable to aneurysms.
If the renal condition has “proliferative” in the name, it has subendothelial deposits. If it doesn’t have “proliferative” in the name, it must not be
subendothelial. So for instance, membranoproliferative glomerulonephritis (MPGN) and diffuse proliferative glomerulonephritis (DPGN); what would you see on biopsy? -> USMLE answer = subendothelial deposits. (from Mehlman Medical Renal)
In this question, this person has irregular subepithelial electron-dense deposits so the correct answer CAN NOT contain the word proliferative. Furthermore, she has 3+ protein in the urine but no evidence of blood indicating that it must be membranous nephropathy.
Taking this from UWorld:
Major functions of the hypothalamic nuclei
This question was testing the ability to know what upper motor and lower motor signs are. A Babinski sign (presence of the plantar reflex which is the dorsiflexion of the large toe and fanning or the other toes with plantar stimulation in an adult) is significant for an Upper motor neuron (UMN) lesion.
Recall that meningiomas can present with seizures or focal neurologic signs. They are malignant arachnoid cells and these tumors can present with psammoma bodies or laminated calcifications of spindle cells concentrically arranged in a whorled pattern.
Consolidation can be ruled out because this happens when the alveoli become filled with material and should be picked if there were signs of pneumonia or pulmonary edema. There would also be a history of proof on a chest X-ray.
Radiation pneumonitis can cause fibrosis and scarring, which is key for contraction atelectasis.
Autoregulation of perfusion pressures
The local metabolites that vasodilate and increase perfusion to skeletal muscle while exercising are CHALK:
During rest, the sympathetic tone in arteries (alpha and beta receptors).
I was confused and thought that ostial had something to do with bone but I guess ostial refers to the opening or the origin of a vessel (like the cervical Os or the coronary Os).
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Most hypertension is essential or physiological or primary and is related to increased cardiac output or increased total peripheral resistance.
Secondary hypertension is secondary to renal/renovascular disease such as fibromuscular dysplasia (a question asking for this would have likely given us an image with a "string of beads" appearance and a vignette with a woman of child-bearing age) OR renal artery stenosis (or as written in this question ostial stenosis of one renal artery) possibly due to atherosclerosis.
The common fibular (peroneal) nerve gives rise to both the deep fibular and superficial fibular nerves.
This person has decreased sensation in the first web space but sensation over the rest of the foot is normal, implying that the Deep fibular (peroneal) nerve is injured.
The superficial fibular (peroneal) nerve supplies the peroneus longus and brevis muscles. These muscles are the main evertors of the foot. Injury to this nerve would cause weakness in eversion as well as a decrease in sensation or paresthesias over the dorsolateral aspect of the foot.
For completeness, the tibial nerve plantarflexes the foot.
The picture shown in the question is a classical description of a mild compression fracture seen in osteoporosis (see pp462 in FA2020). IL-1 is also known as an osteoclast activating factor and leads to an increase in RANK- ligand (RANK-L) signaling and subsequent osteoclast-mediated bone resorption. Recall that this can be treated by denosumab (a monoclonal antibody against RANKL).
Recall that when a question mentions an ulcerated genital lesion, we should be thinking about two things:
This question was testing first that HIV is a sexually transmitted disease and that of the listed organisms, Haemophilus ducreyi is sexually rtansmitted.
See Question 7 in the same block on related paraneoplastic syndromes (especially hypercalcemia due to increased PTHrP).
In these questions, we should recall the TORCH infections.
Congenital syphilis is caused by the maternal transfer of the spirochete Treponema pallidum through the placenta after the first trimester. It often results in stillbirth, or hydrops fetalis (which is also seen in Parvovirus B19) and presents with facial abnormalities (notches teeth, saddle nose, short maxilla), saber shins, and CN VIII impairment or deafness (which is also seen with Rubella, hearing loss is also seen in CMV).
The main symptoms linking it to Treponema pallidum are rhinitis, periorificial fissures, and dental malformations. Note that hearing loss, seizures, petechial rash, and intracranial calcifications can also be seen in CMV.
Why is it not toxoplasmosis?
They took antibiotics meant for treating toxoplasmosis and they presented with only one lesion in the right cerebral cortex.
Congenital and immunocompromised toxoplasmosis
Chorioretinitis (inflammation of the retina and the choroid or the vascular tissue of the eye), diffuse intracranial calcifications, and hydrocephalus (indicated by ventriculomegaly) in a new born.
Caused by Toxoplasma gondii infection during pregnancy. Consumption of contaminated, undercooked pork. Can also be due to contact with contaminated cat feces.
In an immunocompromised patient, multiple ring-enhancing lesions within the subcortical white matter, basal ganglia, and/or thalamus are highly suggestive of cerebral toxoplasmosis. Toxoplasma gondii is an obligate intracellular parasite, contracted via ingestion of cysts in raw meat or oocysts in cat feces. In immunocompetent patients, the presentation is usually asymptomatic.
Cerebral toxoplasmosis is treated with a combination of sulfadiazine and pyrimethamine.