Q Banks: Week of 03/06/17 Flashcards
What cardiac manifestations does carcinoid syndrome present with?
Valvular calcifications (most often right-sided)
Don’t forget that ________________ should not be taken with lithium.
NSAIDs, thiazide diuretics, or ACE inhibitors
All of these drugs lead to increased GFR by mild volume depletion. As such, they increase the amount of electrolytes reabsorbed by the nephron, which can lead to excessive lithium levels. Lithium toxicity manifests as nausea, ataxia, and tremors.
(Think of the thiazide pool with the “low clearance” ski lift wires in the Sketchy scene.)
How might you diagnose nocturnal dyspnea in a patient with normal spirometry values?
Methacholine challenge
Asthma can present as episodic cough with nocturnal dyspnea. If the patient has normal spirometry values in the clinic, then methacholine can uncover asthma.
Describe erythema multiforme.
EM is an immune response to an infection that presents about 1 to 2 weeks after the initial infection. The rash presents with circular target macules –not vesicles –often on the extremities. It is classically associated with HSV (remember the red postage stamps on Hermes’ arm) and Mycoplasma.
Note: disseminated HSV, such as in an immunocompromised patient, will present with vesicular rash, not macular target lesions.
Parvovirus can present with ______________ in sickle cell patients.
aplastic anemia (like the sickle on the USSR plane bombing the bone in the Sketchy scene)
Atypical lymphocytes (seen in EBV infection) have CD_.
8
Think of the cross on the knight’s tunic in the Sketchy scene.
IgG and _____ can opsonize bacteria.
C3b
Also, mannose-binding lectin and CRP
How does Clonorchis sinensis cause pigment gallstones?
C. sinensis damages the common bile duct. That damage causes hepatocytes to release beta-glucuronidase into the bile duct. Beta-glucuronidase deconjugates bilirubin, causing it to be less soluble and thus precipitate.
Estrogen increases hepatic uptake of ____________.
cholesterol (this is why estrogen increases the risk of CHOLESTEROL gallstones)
Why does homocysteine increase risk of thrombotic event?
It’s thought to be due to endothelial damage.
A patient has high levels of homocysteine. How can you differentiate which of the two most common genetic conditions he might have?
- Cystathionine beta-synthase deficiency is an AR defect in the enzyme that converts homocysteine to cystathionine. (This reaction uses B6.) This disorder will present with a Marfanoid body habitus and intellectual disability.
- Methyltetrahydrofolate reductase (MTHFR) deficiency presents with decreased ability to methylate homocysteine. Methylation is required to convert homocysteine to methionine. (This reaction uses B12.) This disorder can often be asymptomatic until someone has a clot.
What does S-adenosyl methionine become after it has methylated something (such as DNA)?
S-adenosyl homocysteine
This becomes homocysteine after releasing its S-adenosyl group.
True or false: acute rheumatic fever only results from untreated bullous impetigo with group A Strep.
False. ARF is only caused by pharyngitis –not impetigo.
What is the classic feature of agoraphobia?
Agoraphobia presents with fear in public situations because escape might be impossible or help will not be there if the person has a panic attack or are incapacitated.
Social anxiety disorder presents with what symptoms?
- Avoidance of social gatherings due to fear of scrutiny or embarrassment
- Impairment of life functions (missing school or work due to anxiety)
- Avoidance of eye contact
- Comfort in social situations when the individual is not the center of attention (this is in contrast to agoraphobics who often fear being in social situations even when they are not the focus of attention)
How is histrionic personality disorder different from borderline personality disorder?
Both present with attention-seeking behavior, but BPD presents with self-destructive actions such as promiscuity or interpersonal fights.
The protein that inhibits ferroportin is released from _____________ cells.
hepatic parenchymal
this being HEPcidin
The ____________ thalamic nucleus receives sensory and pain info from the contralateral body (excluding face and head).
ventral posterior lateral
The ___________ thalamic nucleus receives sensory and pain information from the contralateral face.
ventral posterior medial
Explain the process that leads to lacunae in the basal ganglia.
Lipohyalinosis occurs when plasma proteins leak into the artery wall and occlude the lumen. Thus, infarcts occur distal to the narrowing.
In isolated diastolic heart failure, the end-diastolic pressure of the left ventricle is _______________.
increased
Recall that isolated systolic heart failure occurs when the left ventricle becomes stiff. As such, the left atrium has to work a lot harder to push blood in.
The scrotal skin drains to which lymph nodes?
The superficial inguinal
The __________________ drain to the deep inguinal lymph nodes.
glans penis and posterior calf
Neural tube defects present with what two markers in the amniotic fluid?
- Alpha-fetoprotein
* Acetylcholinesterase
What three cytokines are crucial in the pathogenesis of sepsis?
TNF-alpha, IL-1, and IL-6
Leukotriene B4 leads to _____________.
neutrophil chemotaxis
The vast majority of nose bleeds occur on the ___________________.
nasal septum
Specifically, the area known as Kiesselbach’s plexus is the confluence of three arteries and is a common site for nose bleeds.
If a patient has a UTI in the hospital and the micro report notes Gram-positive cocci in chains, what organism should you treat for?
Enterococcus
Note: this is considered a gamma-hemolytic organism.
What is the power of a study?
Power = 1 –Beta
Beta is the probability of making a type II error (saying that there is no difference when there actually is one). As such, beta decreases with increased sample size and therefore power also increases with increased sample size.
What are the two most serious side effects from aminoglycoside usage?
- Ototoxicity (remember the samurai in the Sketchy scene holding his ears after the gong was struck)
- Acute tubular necrosis (the rain gutter in the same Sketchy with the clogged brown mud that resembles brown casts in tubules)
Explain the cycle of tetra- and dihydrofolate.
- Methyltetrahydrofolate donates a methyl group to dUMP to make it dTMP (catalyzed by thymidylate synthase)
- In the process of methyl transfer, tetrahydrofolate becomes dihydrofolate
- Dihydrofolate reductase adds the two hydroxyl groups lost in the methylation process (this is what methotrexate inhibits)
- Tetrahydrofolate gets remethylated
What kind of receptor is the insulin-inducible glucose channel?
Carrier-mediated glucose transport
True or false: CYP450 enzymes are only found in the liver.
False. They are also extensively found in the gut wall.
Which immunosuppressant can cause nephrotoxicity?
Cyclosporine (and any other calcineurin inhibitor such as tacrolimus)
Note: the mechanism by which this occurs is through vasoconstriction of the renal arterioles.
What is pharmacodynamic potentiation?
When two drugs have a total effect greater than the sum of the two separate effects
In terms of microbial genetic differences, explain each of the following: •Interference •Phenotypic mixing •Recombination •Transformation •Reassortment
- Interference: when one virus inhibits the replication of another virus
- Phenotypic mixing: when the genome of one virus can acquire the envelope or capsid of another virus WITHOUT THE GENOME BEING CHANGED
- Recombination: two viral genomes being mixed with resultant phenotypic fusions
- Transformation: when a bacteria absorbs new DNA from the environment
- Reassortment: when a segmented virus rearranges its segments with another strain
What conditions can increase the risk of gout?
- Myeloproliferative disorders like polycythemia vera
- Tumor lysis syndrome
- HGPRT deficiency
All of these lead to the accumulation of purines.
What bone degradation pattern is typical of hyperparathyroidism?
Subperiosteal thinning with cystic degradation
This is because the macrophages activated by PTH are primarily on the periphery of the bone.
Describe Paget’s disease of the bone.
- Disorganized lamellar bone pattern (like the disorganized exhibit in the Sketchy scene)
- Normal Ca
- Normal Phos
- Elevated alkaline phosphatase
What bone pattern is characteristic of osteoporosis?
Trabecular thinning with fewer interconnections
Persistence of the bone spongiosa is a sign of _____________.
osteopetrosis
Macrophages and neutrophils both secrete elastase and matrix metalloproteases. Where are the anti-proteases found?
In the serum and tissue
What organisms causes the most cases of meningitis in those in their 40s?
S. pneumoniae
Why do propofol and thiopental cause quick onset and quick offset anesthesia?
Both thiopental and propofol are highly lipophilic agents. They distribute to the brain initially because the brain has high blood flow and these agents are administered intravenously. They saturate the fatty tissue of the brain initially, but after some time they distribute to the blood and accumulate in organs with less blood flow.
Explain the phenomenon of phenotypic mixing.
Phenotypic mixing is the process in which two viruses infect one cell and then the capsid of one virus encapsulates the genome of the other. Thus, the hybrid would be able to infect the cells that are specific to the capsid, but when new virions are made the genome will recreate the original capsid.
What cellular interactions cause toxic shock syndrome?
Bacteria release a toxin that binds MHC II to CD4. Thus, to have toxic shock syndrome you need an antigen-presenting cell (macrophage, dendrite, or B cell) and a helper T cell. When this interaction occurs, T cells are continuously stimulated and release excessive amounts of IL-1 and IL-2.
What imbalance is the most common cause of kidney stones?
Idiopathic hypercalciuria with normocalcemia
It’s thought that most kidney stones are due to idiopathic increased GI absorption of calcium, increased resorption of calcium from bone, or decreased calcium resorption from the renal tubule. However, because the Ca, vitamin D, PTH system is intact, people with these imbalances will have normal serum calcium levels.
True or false: all dehydrogenases in the TCA cycle utilize niacin as a cofactor.
False. Although most do –pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase all do –succinate dehydrogenase doesn’t.
(“Succinate is the Sole dehydrogenase that doesn’t need niacin.”)
Note: niacin is used to make NAD, and NAD is the form used by these enzymes. Succinate dehydrogenase uses FAD.
Why does a high NADH:NAD+ ratio stimulate lactate production?
Glycolysis makes NADH. Lactate production converts NADH back to NAD so that glycolysis can continue to make ATP.
What are the two most common sites of aspiration pneumonia to develop in SUPINE individuals?
- Superior region of the lower lobe
* Posterior region of the superior lobe
Why is skeletal muscle not blocked by verapamil?
In skeletal myocytes, the voltage-sensitive calcium channels are connected to ryanodine receptors. Thus, depolarization causes release of calcium from the sarcoplasmic reticulum REGARDLESS of if the channel is blocked by verapamil. In cardiac nodal cells, however, there is no physical excitation coupling to ryanodine receptors; calcium from the extracellular environment enters the cell and activates a ligand-gated ion channel on the sarcoplasmic reticulum. Thus, blocking L-type channels in cardiac cells prevents excitation.
Describe the phases of meiosis that the oocyte goes through (1) prior to puberty, (2) during the ovulation cycle, and (3) prior to fertilization.
(1) The oocyte gets paused at prophase I from gestation to puberty.
(2) Each monthly cycle, one oocyte matures from prophase I to metaphase II.
(3) Meiosis II is completed just prior to fertilization.
Why does TPN increase risk of gallstones?
Without stimulation of the intestines, less CCK is released and the gallbladder lacks motility. Similarly, in those who’ve had intestinal resections, there is less CCK released and gallstones may form.
Which kind of hernia is more common?
Indirect > direct
What structures make up the triangle of Hesselbach?
- Medial: rectus abdominis
•Lateral: inferior epigastric vessels - Inferior: inguinal ligament
What does absence of green fluorescence on dihydrorhodamine testing indicate?
Chronic granulomatous disease
Note: this can be a little tricky because myeloperoxidase is what gives sputum its green hue, so you might think MPO is what gives neutrophils their green fluorescence in the dihydrorhodamine assay, but this is not so.
If someone with stable angina cannot tolerate aspirin due to bronchoconstriction, what is the next agent you should offer them?
Clopidogrel, ticagrelor, or ticlodipine (any of the ADP receptor blockers that work similarly to aspirin)
Cardiac output = (_________________)
__________________
Arteriovenous O2 difference
rate of O2 consumption
Ulnar nerve injury most often occurs at which two spots?
- Medial epicondyle of the elbow (funny bone spot)
* Hook of hamate
Ulnar nerve injury presents with defective ______________.
- Sensation of the fourth and fifth digit
- Wrist adduction
- Finger abduction and adduction (lumbricals)
- Flexion of the fourth and fifth digits
What lab distinguishes between obstructive sleep apnea and obesity hypoventilation syndrome?
Arterial blood gas
In OHS, the extra chest weight prevents normal expansion of the chest. As such, people with OHS develop chronic respiratory acidosis.
In OSA, the chest is able to expand normally but the pharyngeal muscles weaken during sleep and lead to brief apneic spells. The ABG will be normal because when they are awake they are breathing normally.
Discuss the risks of aortic stenosis and aortic dissection in those with bicuspid aortic valves.
- Aortic stenosis is very common and typically presents around age 50 (10 years earlier than the average presentation in a patient without BAV).
- Aortic dissection risk is increased, but it occurs in less than 1% of the cases of bicuspid aortic valve.
