Rx Qmax Flashcards
How do you calculate attributable risk?
It is the risk difference between the exposed and unexposed group (e.g. lung cancer in smokers vs. non smokers).
Attributable risk = Ie - Iu
*Ie = incidence exposed group and Iu = incidence unexposed group.
What is the area of the brain infarcted in Broca’s aphasia? Wernicke’s?
Broca’s = inferior frontal gyrus of the frontal lobe
Wernicke’s = superior temporal gyrus of the temporal lobe
What is the mechanism of action of fibrates?
Activate PPAR (a nuclear transcription factor) which leads to increased activity of lipoprotein lipase which will lower TG levels.
What does urachus plus the allantois become post-embryonically?
The median umbilical ligament. Note this is different from the medial umbilical ligaments which is what umbilical arteries become.
What is the most appropriate treatment for gatroparesis?
Metoclopromide
What is Sheehan syndrome?
It is post-partum hypopituitarism. Most commonly presents w/ failure to lactate and eventually progresses to hypothyroidism, hypoadrenalism, hyponatremia and hyperkalemia.
What do CD55 and CD59 - flow cytometry results in the setting of dark urine in the morning indicate?
Paraoxysmal nocturnal hemoglobinuria. Due to impaired synthesis of GPI anchor and it results in hemolysis and hemosiderin in the urine.
What is the pathophysiology of G6PD deficiency leading to hemolysis?
NADPH is regenerated by the HMP pathway that G6P functions in and is necessary to keep glutathione reduced which will in turn detoxify free radicals and peroxides. W/o it they build up and the oxidative damage causes RBC lysis.
What characterizes Patau’s sndrome (trisomy 13)?
Cleft lip, microphthalmia (small eyes), mental retardation, polydactyl, congenital heart disease and renal defects.
Why can blood transfusions cause hypocalcemia?
Because blood is anticoagulated w/ sodium citrate and citric acid and this can cause plasma levels of calcium to drop.
What are the zones of the prostate that proliferate in BPH?
Glandular cells of periurethral and transition zones.
What is the equation for GFR using inulin?
GFR = (urine inulin concentration x urine flow rate) / plasma inulin concentration
What are the CT findings indicative of diverticulitis?
Thickened, enhancing colonic wall and pericolic fat stranding.
Histo will show an attenuated (meaning thinned) muscularis propria)
What is the name of the heme synthesis enzymes that are inhibited in lead poisoning?
delta-aminoleuvulinic acid dehydratase (earlier in pathway) and ferrochelatase.
What are the four inactivated or killed vaccines? What is unique about the immune response they induce?
Rabies, influenza (injection, not nasal spray), polio (Salk, not oral), hepatitis A.
They induce only humoral immunity.
How does saliva concentration vary based on high vs. low flow rate?
Saliva is isotonic (and more basic) at high flow rates and hypotonic (and more acidic) at low flow rates as the ductal epithelium has more time to modify the secretion by reabsorbing Na+ and Cl– and secreting K+.
Thus, in a condition like mumps where there is increased flow rate the saliva will have lower concentrations of K+.
Mediastinal lymphadenopathy is often seen in Hodgkin’s lymphoma. Which subtype is it particularly associated with?
Nodular sclerosing subtype. Often seen in young women and usually there are few RS cells seen.
What are the associated sxs of acute intermittent porphyria?
port-colored wine, abdominal pain, neuropathy, increased sympathetic tone, and neuropsych disturbances.
From which aortic arch does the ductus arteriosus develop?
The 6th aortic arch. Also gives rise to proximal part of the pulm arteries.
What are the most common paraneoplastic syndromes that thymomas (tumors of the thymus) cause?
Myasthenia gravis, pure RBC aplasia, hypogammaglobinemia
What does WAGR syndrome stand for?
Wilm’s tumor, Aniridia (complete or partial loss of the iris), Genital anomalies, mental Retardation
What are the signs of Kawasaki disease?
conjunctival injection, rash, adenopathy (cervical), strawberry tongue, hand/foot changes (edema), fever
What is the physiologic mechanism by which exercise improves type 2 DM?
Increases the translocation of GLUT4 (which are insulin dependent) channels to cell surface. This leads to increased insulin sensitivity.
The mesolimbic tract contributes to what type of sxs in schizophrenia? How about the mesocortical? Bonus: what tract is affected that produces amenorrhea?
- Mesolimbic –> positive sxs. Block reduces them
- Mesocortical –> negative sxs. Block produces/exacerbates them
- Amenorrhea is caused by dopamine block of the tuberoinfundibular tract.
Which HLA antigens confer greater risk for T1DM?
DR3 and DR4.
What is the medical management for a GH secreting putuitary tumor (i.e. if pt declined or could not go thru surgery)?
Octreotide - a somatostatin analog. It will inhibit the release of GH at the pituitary.
Note, this med is also used to tx carcinoid tumor and secretory pancreatic tumors.
What is second line tx in BPH is an a1 antagonist is ineffective or intolerable?
5alpha-reductase inhibitors. They work by preventing the conversion of testosterone to DHT, and this prevents prostate gland enlargement. Of note, this therapy typically takes 6-12 months to be effective.
What is the order of hormone loss in something like Sheehan syndrome where you get infarct to the pituitary and have resulting panhypopituitarism?
GH, FSH, LH, ACTH, TSH, PRL
Natural disease history and histo findings for Whipple’s disease?
Early disease has migratory arthralgia of large joints (often misdiagnosed) and then progresses to abdominal pain and watery diarrhea.
On histo you see vacuolated macrophages crowding the lamina propria.
What is the typical presentation of systemic juvenile idiopathic arthritis?
Quotidian fever (characteristically a fever spike once a day during which the child is ill appearing and then normal temp during interval before the next spike), rash, arthralgias, arthritis and rash. It is a diagnosis of exclusion and by definition occurs in kids younger than 16.
What is the presentation of Kartenger syndrome (a form of primary ciliary dyskinesia)?
Bronchiectasis, situs inversus and chronic sinusitis.
What are the four stages of Paget’s disease?
1) an initial osteolytic lesion involving marked bone resorption, (2) a mixed period of disorganized bone formation, (3) a third stage of osteoblastic-induced sclerosis and (4) a final, quiescent stage in which osteoclastic and osteoblastic activity is minimal.
On labs, see an elevated alk phos during periods of increased bone turnover and the phosphorous is normal.
What is the first line pharmacologic agent for septic shock?
Norepinephrine
The pain of gastric ulcers ________ after a meal, whereas the pain of duodenal ulcers _______ after a meal.
Increases, decreases
Why does salicylate (aka aspirin) toxicity initially present with alkalosis in early stages?
Because it stimulates respiratory centers. It progresses to anion gap acidosis over time from acidic metabolites.
What is the end result of niacin therapy for cholesterol lowering?
Decreased hepatic TG and VLDL synthesis (mechanism not understood) causing lowered LDL and total cholesterol levels as well as elevated HDL.
50% of patients with temporal arteritis (aka giant cell arteritis) may also present with what condition?
Polymyalgia rheumatica. It is where you have symmetrical aching of proximal muscles and girdle weakness.
What is the classic presentation of a thyroglossal duct cyst?
A deep, painless, midline anterior neck swelling that moves with swallowing and elevates on tongue protrusion.
What is the classic triad of Wernicke’s encephalopathy?
The classic triad of Wernicke encephalopathy is confusion, ataxia, and ophthalmoplegia.
What are the four primary symptoms portrayed in Gerstmann syndrome? Damage to what area of the brain causes it?
Agraphia (inability to write), acalculia (inability to understand rules for calculation or arithmetic), finger agnosia, and left-right disorientation.
The syndrome results from damage to the dominant visual association cortex, which is located in the left angular gyrus near the temporoparietal junction in the dominant parietal lobe.
How may you distinguish between a patient with homocystinuria (caused by a deficiency in cystathione synthase for example) and a patient with Marfan syndrome?
Elevated levels of homocysteine in the blood. Additionally, these patients have a downward dislocation of the lens as opposed to an upward dislocation. And they are at increased risk of intellectual disability whereas Marfan pts are not. Also, these pts are at increased risk for thromboembolic events.
What is the mechanism of action by which isoniazid works?
Isoniazid causes a decrease in the synthesis of mycolic acids that make up the unique cell envelope of Mycobacterium tuberculosis.
