USMLE-Rx: Week of 12/26/16 Flashcards
Familial hypercholesterolemia results from ______________.
defects in LDL receptors
Defective C-II results in ________________.
high triglyceride levels, because C-II is a ligand for the lipoprotein lipase enzyme (resembling LPL deficiency, but less severe)
Apo-E defects result in ________________.
dysbetalipoproteinemia, a syndrome in which triglycerides and cholesterol are elevated
You know that Wilson disease presents with liver failure and psychiatric symptoms (sometimes with Parkinsonian features), but what other lab results can appear?
Type 2 renal tubular acidosis, with low bicarbonate and potassium
Why does fetal hemoglobin have a higher affinity for oxygen?
Because fetal hemoglobin has a lower affinity for 2,3-BPG. (2,3-BPG decreases O2 affinity, so having less of it makes hemoglobin more likely to bind oxygen.)
_____________ is converted to 6-mercaptopurine in the body.
Azathioprine
What is a major side effect of azathioprine?
Immunosuppression
What drug, other than rifampin, can cause orange sweat and urine?
Sulfasalazine (a medication that is given to those with ulcerative colitis; it is thought to act topically because it is poorly absorbed)
There is a great mnemonic for recalling the origins of the contents of the spermatic cord. What is it?
ICE TIE
Internal spermatic fascia = Transversalis fascia
Cremasteric muscle = Internal oblique muscle
External spermatic fascia = External oblique muscle
All of the vessels that supply the testicles are ______________ the spermatic cord.
within
What nerves run to the testes and where do they run?
The cutaneous nerve (supplying the skin of the testes) runs outside the spermatic cord, whereas the cremasteric nerve runs within the spermatic cord.
Salmonella selectively targets ______________.
Peyer’s patches (“Want some salmon pie?”)
The posterior cord of the brachial plexus gives rise to the ________________.
axillary and radial nerves
The lateral cord of the brachial plexus gives rise to the _________________.
musculocutaneous nerve and (with a branch from the medial cord) median nerve
The medial cord of the brachial plexus gives rise to the _____________.
ulnar nerve and (with a branch from the lateral cord) median nerve
Which kind of thyroid carcinoma is found in MEN 2 (both A and B)?
Medullary
Crohn’s disease results in increased incidence of _______. Why?
kidney stones; enhanced absorption of calcium oxalate
Cardiac arrhythmias, vision loss, and multiple sclerosis symptoms should raise suspicion for _______________.
Leber hereditary optic neuropathy, a mitochondrial disorder
In all ulcer questions, look out for things that suggest _______________.
NSAID use (this question included a woman with RA!)
In a patient with ____________, the Brunner glands are likely to be hypertrophic.
an ulcer
True or false: Jehovah’s witnesses can refuse blood transfusions.
True, but they cannot do so for their children!
The signet-ring cancer of the stomach often metastasizes to the _____________ and is called _____________.
ovaries; Krukenberg tumor
Ethanol metabolism converts ______________.
NAD+ to NADH (“Ethanol goes to your Head.”
In addition to erythema, what rash can those with Kawasaki’s present with?
Desquamation of the fingertips
There are three kinds of renal tubular acidosis. Describe each.
The types are I, II, and IV. You would think it would go proximal to distal in order, but that is not the case. Instead, it goes in reverse.
I: Distal tubule acidosis; failure of alpha-intercalated cells to secrete acid into the urine (can be caused by amphotericin B)
II: Proximal convoluted tubule; failure or bicarbonate resorption (can be caused by acetazolamide)
IV: Adrenal gland; failure to secrete aldosterone leading to failed secretion of protons
What drug is used to treat narcolepsy?
Modafinil, an indirect sympathomimetic (your alarm clock is on sleep MODe when you have narcolepsy)
The intercostal neurovascular bundle passes immediately ____________ to the corresponding rib.
inferior (INferior INtercostal nerve)
Hypothyroidism in a child results in bone age _____________.
less than actual age; this occurs because thyroid hormone has a permissive effect on growth (thus, not having will lead to deficient growth and younger bones)
Those with Charcot-Marie-Tooth neuropathy have deficiencies in what?
Myelin, which predominately affects sensory information
Remember that those with Chiari type I can have a distinct loss of spinal function: _______________.
loss of pain sensation in the arms due to syringomyelia
What is the mechanism of the antibiotic that is not often used because it has neurotoxic side effects?
Polymyxin B works by disrupting cell membranes via a detergent-like mechanism
Describe the structures of MHC I and II.
MHC I: 3 alpha and 1 beta subunits
MHC II: 2 alpha and 2 beta subunits
(Think: the 1s go together.)
Again, what four cancers have psammoma bodies?
2 PM Papillary thyroid carcinoma Papillary cystadenocarcinoma of the ovary Meningioma Mesothelioma
Which comes first, granulation tissue or collagen deposition?
Granulation tissue! Recall that granulation tissue is vascularized wound tissue that appears about 1 week after an injury.
What is the treatment for Bruton’s agammaglobulinemia?
IV IG
They might try to trick you by giving “bone marrow transplant” as an option, but BMT is not indicated because boys with Bruton’s still have functional T cells!
What three physical exam maneuvers can indicate acute appendicitis?
Passive psoas sign: pain with extension of the hip beyond the plane of the thorax
Active psoas sign: pain with flexion of the hip against resistance
Obturator sign (more common when the appendix is positioned in the pelvis): pain with medial rotation of the hip
What leg test indicates meningitis?
The Kernig sign: extending the knee when the hip is flexed
What is the best way to distinguish between Niemann-Pick disease and Tay-Sachs?
Those with NP will have hepatomegaly. (This is important to know, because both will present with macular red spots!)
The enzymes that are defective in Krabbe disease and Fabry sound familiar. What are they?
Krabbe: galactocerebrosidase
Fabry: alpha-galactosidase
What bone marrow histologic slide might the NBME show to ask about Niemann-Pick disease?
Macrophages with enlarged cytoplasms with many small vacuoles (overall giving the cytoplasm a smooth, uniform appearance)
What reaction does hexosaminidase A catalyze?
Ganglioside M2 to M3
What reaction is catalyzed by alpha-galactosidase?
Ceramide trihexoside to lactosyl cerebroside
What antipsychotic is often used for its anti-emetic property?
Prochloerperazine (whic blocks D2 receptors in the area postrema)
What cells store vitamin A?
The cells of Ito
True or false: the triptans are serotonin antagonists.
False. They are agonists.
Those with Turner syndrome have broad necks, shield chests, hands that hang at a greater angle, amenorrhea, streak ovaries, and _________________.
renal abnormalities
What syndrome is characterized by anti-Jo antibodies?
Dermatomyositis (think of the woman in the derm clinic attacking Joseph with an antibody-shaped pitchfork)
What antiviral therapy can produce psychiatric symptoms and cytopenia?
Alpha-interferon (which works to degrade viral mRNA and assist in the NK cell and CD8 cell cytotoxicity)
What presentation is typical of 47, XXX?
An asymptomatic woman; this is so because an extra Barr body can silence the additional chromosome
What is the “penis at 12” syndrome?
5-alpha reductase deficiency results in a person who is genetically XY but lacks dihydrotestosterone. The missing hormone leads to female-appearing genitals at birth, but at puberty the genitals get virilized and the body develops male secondary sexual characteristics.
