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.
True or false: VIPomas can cause hypoglycemia.
False. They can cause hyperglycemia, and thus the best way to distinguish glucagonomas from VIPomas is the rash that presents with glucagonomas.
Those with Hartnup disease will present with what symptoms?
Pellagra, because Hartnup disease results from inability to reabsorb neutral amino acids, including tryptophan. Without tryptophan, there will be less niacin made by the body. Thus, in a well-nourished child with pellagra, suspect Hartnup.
What parts of the 50S subunit are inhibited by chloramphenicol and clindamycin?
Clindamycin: inhibits translocation of the peptide
Chloramphenicol: inhibits peptidyltransferase
Only __________________ vaccines can be given to pregnant women.
inactivated (such as the killed polio vaccine)
Which vaccines only have live versions?
MMR and varicella
During which phase of the cell cycle does bleomycin act?
During the G2 phase. While bleomycin works by forming free radicals and thus affects all cells with DNA, cells with more DNA –like those in G2 with double the amount of chromosomes –will be affected more. Thus, rapidly dividing cells are partially targeted.
What is the best way to differentiate between LPL deficiency and defective VLDL clearance?
VLDL clearance will present with comorbidities, whereas LPL deficiency will present with isolated hypertriglyceridemia.
What infection can cause achalasia?
Chagas’ disease: Trypanosoma cruzi
What nephritic pathology is often caused by lupus?
Proliferative nephritis with subendothelial deposits (the “wire looping” sign –LUPus = LOOPing)
What kidney disease do those with HBV and HCV get?
Membranoproliferative glomerulonephritis (MPGN)
This is characterized by the split (train track) membrane.
(To help you remember this, think MPGN = Morphine Pokers’ GlomeruloNephritis, because heroin addicts often get HBV and HCV. To remember the membrane splitting, just think of how the junkies in the movie TRAINspotting got TRACK marks.)
Which nephritic syndrome is hypercellular?
Post-Streptococcal
Indirect hernias pass __________ to the inferior epigastric artery, while direct hernias pass ________ to the inferior epigastric artery.
lateral; medial
In what cases is it ok to withhold information about a surgical procedure from a patient?
If a patient has a legal guardian (such as a case worker for a mentally challenged adult) and the physician has reason to suspect the patient might harm him- or herself if told about a procedure. (The question that sparked this card discussed a woman who ran away the last time she was told she had to have her uterus removed because of endometrial cancer.)
The AICA branches off of ____________.
the pontine artery
The PICA branches off of ____________.
the vertebral artery
Describe the aortic arches and what each gives rise to.
1st: maxillary artery
2nd: stapedial artery
3rd: common carotid (C is the third letter of the alphabet)
4th: aortic arch (the 4th goes to the 4 limbs)
6th: ligamentum arteriosum and pulmonary arteries
What anticoagulants are only given IV?
Direct thrombin (IIa) inhibitors like argatroban and bivalirudin; heparin.
Which anticoagulants are oral?
Direct Xa inhibitors like apixaban and rivaroxaban; warfarin.
Which anticoagulants are subcutaneous?
LMWH, fondaparinux
Which anticoagulants require monitoring?
Warfarin (PT/INR) and heparin (PTT)
What embryologic structure is often defective in boys with CF?
The mesonephric (Wolffian) duct, which should become the ductus deferens; this is why boys with CF are often infertile
Those with Crohn’s are often given what antibody?
Infliximab (anti-TNFa)
Clopidogrel is often used for _____________ procedures.
stenting
What are the various adverse effects of the inhaled anesthetics?
Halothane: hepatotoxicity
Enflurane: nephrotoxicity, pro-convulsant
Isoflurane: very little (I SaFe)
Describe how ELISAs are used in terms of the timeline of exposure to HIV.
Antibodies to HIV usually take up to two months to develop, so the traditional ELISA (in which antibodies to HIV are detected) will only display its spectacular sensitivity after two months. Prior to two months, ELISAs to viral components can be used.
In the GQ RACKS In AAA Magazines, what are C and S?
C can be cimetidine or ciprofloxacin, and S is sulfonamides
What gives rise to the thyroglossal duct?
The primitive pharynx
Exercise intolerance can result from what enzyme deficiency?
Myophosphorylase (which is needed for glycogen breakdown in muscle); this is missing in McArdle disease, which presents with myoglobinuria with exercise
Babies that survive meningitis often develop ________________.
communicating hydrocephalus: meningeal scarring that prevents some CSF absorption by arachnoid villi
Remember that burn victims are at increased risk of a certain GI malady: ________________.
Curling ulcers
Treat with PPIs
Which branch of the celiac trunk supplies the pancreas?
The common hepatic which gives off the gastroduodenal!
What marker does CD14 recognize?
Lipopolysaccharide (there are 14 letters in polysaccharide)
What information is carried by the VPL and VPM?
VPL: pain and touch sensation from the contralateral body
VPM: pain and touch sensation from the contralateral face
Which of these medications cause gallstones: ezetimibe, statins, cholestyramine, niacin, and gemfibrozil?
Cholestyramine and gemfembrozil
Other than as “hypocellular areas,” how might you hear Kimmelstiel-Wilson nodules described?
Nodular glomerulosclerosis
“Diffuse basement membrane thickening” is a way to describe ________________.
membranous nephropathy
What is First Aid’s mnemonic for remembering which pituitary cells are basophilic?
B-FLAT
Basophilic –FSH, LH, Adrenocorticotrophs, Thyrotrophs
Neurophysin I and II help transport ________________.
oxytocin (I) and vasopressin (II)
One = Oxytocin
What hormones control milk synthesis and secretion?
Synthesis: prolactin
Secretion: oxytocin
What prognosis does a baby born with a 5p deletion have?
Cri-du-chat syndrome can present with intellectual disability, cardiac abnormalities, and microcephaly, but generally lifespan is normal.
What hand abnormalities might present with Patau’s and Edwards’?
Patau’s: polydactyly
Edwards’: clenched, overlapping fingers
What trisomies present with microcephaly and macrocephaly?
Patau’s: microcephaly (Patau’s Petite)
Edwards’: macrocephaly (Edwards’ Eggheads)
How can you differentiate between Crigler-Najjar and biliary atresia?
In biliary atresia, conjugated bilirubin accumulates in the blood and is excreted in the urine. In Crigler-Najjar, however, unconjugated bilirubin accumulates which cannot pass into the urine; thus, babies with CN will have no bilirubin in the urine.
True or false: HCC and HCV can cause extreme elevations in AST and ALT.
False. They can lead to some elevation, but levels greater than 10 times normal are rare.
What is a hapten?
A molecule that induces an autoimmune response by binding to a self-antigen
What is absolutely required for a diagnosis of depression?
Anhedonia; a patient can have five of the SIGECAPS and not be diagnosed with depression if they don’t have anhedonia
What are symptoms of the most common porphyria?
Photosensitive, cutaneous blistering (being uroporphobilinogen decarboxylase deficiency)
What is First Aid’s mnemonic for eosinophilia?
NAACP
- neoplasm
- allergy
- asthma
- collagen vascular disorders
- parasites
Once again, how can you distinguish Hurler and Hunter?
Hurler: AR, corneal clouding
Hunter: XLR, aggressive behavior
What is the rate-limiting step of fatty acid synthesis?
Acetyl co-a carboxylase (regulated by citrate)
What stimulus climbing fibers, parallel fibers, and Purkinje cells use?
Climbing: excitatory glutamate
Purkinje: inhibitory GABA
Parallel: excitatory glutamate
What drug is given to AIDS patients to prophylactically treat PCP pneumonia?
Bactrim
What is the formal name for the bias that arises from not analyzing based on intention to treat?
Selection bias
What disorders are more likely in those with HLA-DR4, HLA-DR3, and HLA-B27?
DR3: DM1
DR4: DM1, Graves, RA
B27: psoriasis, ankylosing spondylitis, IBD, and reactive arthritis
One of the HLA subtypes that is associated with MS is also associated with which other diseases?
HLA-DR2: Goodpasture’s, SLE, and hay fever
What is “wrist drop”?
Inability to extend the wrist caused by impairment of the radial nerve
True or false: Dubin-Johnson is more likely to progress to liver failure than Rotor syndrome.
False. Both are equally benign!
True or false: Gilbert syndrome is associated with lethargy and headache (in addition to jaundice).
False. There are no complications of Gilbert syndrome.
Explain Reye syndrome.
Caused by giving aspirin to kids with viral illness, Reye syndrome results in hepatic encephalopathy. The cause of hepatic damage is impaired beta-oxidation in liver mitochondria.
What disorder presents with elevations of IgE and recurrent abscesses?
Job syndrome! An autosomal dominant disorder of helper T-cells in which they fail to produce interferon-gamma. Without interferon-gamma, neutrophils do not respond to chemotactic signals and the body compensates by increasing IgE
(Good mnemonic: “The biblical Job was FATED to suffer” –Facies [abnormal], Abscesses, Teeth [retained primary], IgE [elevated], and Derm [eczema])
Which antiviral is first-line for HBV?
Tenofovir
True or false: infants typically respond to their own name before being able to speak.
True. They usually respond to their own name by 7-10 months and then speak around 12 months.
True or false: positive Babinski reflex indicates spinal cord lesions in an infant.
False. Infants usually retain a positive Babinski reflex until 12 months.
Explain the utility of HBc-Ab
Antibody to HBV core indicates a past infection that has been overcome or is being overcome
What does HBe-Ag indicate?
Active rEEEPlication (“This infection is rEEEEcent.”)
Which antithyroid medication blocks T3 both centrally and peripherally?
PTU –often given to pregnant women
What physical exam finding is often seen in kids with foreign-body aspiration?
Focal wheezing (as opposed to asthma which is usually found in more than one spot)
Which chromosomes are p53 and retinoblastoma found on?
p53: 17
Rb: 13
True or false: CGD results from a defect in lysosomes.
False. The NADPH oxidase enzyme is found in phagosomes.
Which glomerular injury presents with hypertension?
Nephritic syndromes (also distinguished by oliguria and hematuria)
What might you be thinking if the NBME shows you a slide of an HIV patient with a multinucleated giant cell?
HIV encephalitis, caused by infected microglia
Where, in the lymph nodes, are T cells located?
The paracortex –the region between the follicles and the medulla. Note, in the past you’ve several times thought that T cells were in the medulla –not true. Only macrophages are in the medulla.
What are the three interferons used for?
Alpha: HBV, HCV, and HHV
Beta: multiple sclerosis (mechanism unknown)
Gamma: activates macrophages (so can help with CGD!)
Which is the only muscle of mastication that opens the jaw?
The lateral pterygoids
(First Aid has a phenomenal mnemonic: “The Laterals Lower, and the Ms Munch: Masseter, Medial pterygoids, and teMporalis.”)
Normal grief encompasses all of the symptoms of depression except __________________.
suicidality
