Uworld 3,4 Flashcards
What characteristic pathologic changes are seen in Alzheimer dementia?
Intracellular Neurofibrillary tangles and extracellular amyloid-beta plaques
What are neurofibrillary tangles composed of?
Tau proteins - component of intracellular microtubules
What happens to Tau proteins in alzheimer dementia?
Hyperphosphorylated, causing microtubule structures to collapse into tangles
The APP gene is located on what chromosome?
21
Zidovudine is what type of analog?
Thymidine analog - without 3’OH group, making 3’-5’ phosphodiester bond formation impossible
What hormones are responsible for glucose homeostasis during prolonged fasting?
Growth hormone and cortisol
What hormones are responsible for increasing blood glucose due to a rapid drop in glucose?
Glucagon is primary, with Epi acting as a backup
Growth hormone receptors are found where, and what activate what pathway?
Receptors are membrane-bound, result in JAK-STAT pathway
What cells produce the inflammatory response seen in gout?
Neutrophils
What is the best option for rapid reversal of warfarin?
Fresh frozen plasma
What is protamine used for?
Heparin reversal
The basal ganglia are supplied bu what arteries?
Lenticulostriate arteries
What valvular lesion is commonly seen in Turner syndrome? What other common vascular defect is seen?
Bicuspid aortic valve; coarctation of the aorta
What are the gynecologic complications of Turner syndrome?
Streak ovaries, amenorrhea, infertility
What is the site of protrusion for direct inguinal hernia?
Hesselbach triangle
What is the site of protrusion for an indirect inguinal hernia?
Deep inguinal ring
Is an indirect inguinal hernia above or below the inguinal ligament?
Above; the inguinal ligament makes up the lower border
Is a direct inguinal hernia above or below the inguinal ligament?
Above; the inguinal ligament makes up the lower border
Is a femoral hernia above or below the inguinal ligament?
Below
Why do indirect inguinal hernias occur?
Failure of the processus vaginalis to obliterate, allowing adb contents to protrude through deep inguinal ring
What is the location of an inguinal hernia in regards to the inferior epigastric vessels?
Inguinal hernia is lateral to the inferior epigastric vessels
What is the location of a direct inguinal hernia in regards to the inferior epigastric vessels?
Direct inguinal hernia is medial to the inferior epigastric vessels
What type of inguinal hernia can continue into the scrotum?
Indirect inguinal hernia
Deep palpation of the external inguinal ring reveals a hernia, what type of hernia is it most likely to be?
Indirect inguinal hernia
What is the equation for NPV?
TN/ (TN + FN)
What is the equation for specificity?
TN/ (TN + FP)
What is the equation for positive likelihood ratio?
LR+ = sensitivity / (1-specificity)
What is the positive likelihood ratio?
A ratio representing the likelihood of having the disease given a positive result
What is the equation for the negative likelihood ratio?
LR- = (1- sensitivity) / specificity
How do patients with partial nephrogenic DI respond to water deprivation test?
Slow but steady rise in urine osmolality with increasing serum osmolality after water deprivation; there is no further increase in urine osmolality with DDAVP
Where is the MLF located in the brainstem?
Dorsal pons
Where does the frontal eye field project to in conjugate horizontal eye movement?
Projects to contralateral paramedian pontine reticular formation
In internuclear ophthalmoplegia, the lesion occurs on which side, in regards to the affected eye?
Ipsilateral
Patient has internuclear ophthalmoplegia with a lesion on the left side MLF, what eye is unable to adduct? What eye is unable to abduct?
Left eye unable to adduct during right conjugate horizontal gaze, contralateral (right) eye abducts with nystagmus
What is first line treatment for toxoplasmosis in patient with HIV?
Pyrimethamine and sulfadiazine (or clindamycin in case of sulfa allergy); may add leucovorin (folinic acid)
What gene is effect in achondroplasia?
FGFR3 gene; point mutation causes exaggerated inhibition of chondrocyte proliferation
What channel do class IC antiarrhythmics block? What effect do they have on the ECG?
Sodium channels; prolong QRS duration with minimal effect on QT interval
What type of antiarrhythmic is procainamide?
Class IA
What effect do Class IA antiarrhythmics have on the ECG?
Prolong QRS and the QT interval due to moderate K channel blocking
What channels do Class IA antiarrhythmics block?
Na and moderate K channel block
What type of antiarrhythmic is lidocaine?
Class IB
What type of antiarrhythmic is flecainide? Propafenone?
Both Class IC
What is an important virulence factor of E coli causing neonatal meningitis?
K1 capsule
Fever and a sore throat in a patient with hyperthyroidism treated with medical therapy should raise concern for what?
Thionamide-induced agranulocytosis
What are the AEs of thionamides?
Agranulocytosis; methimazole: 1st trimester teratogen, cholestasis; PTU: hepatic failure, ANCA-associated vasculitis
What is the MOA of celecoxib?
Selective COX-2 inhibitor
What is the MOA of rifaximin?
Nonabsorbable antibiotic that alters GI flora and decreases intestinal production and absorption of of ammonia
What is the MOA of lactulose?
Increased conversion of ammonia to ammonium by lowering colonic pH
What effect does high urine citrate have on renal stone formation?
Has stone-preventing effects; citrate binds to free (ionized) calcium, preventing its precipitation and facilitating its excretion
Patients with hypocitraturia are at increased risk for what?
Calcium oxalate precipitation and stone formation
What effect doe higher dietary calcium have on renal stone formation?
Decreases it; calcium binds oxalate in intestine, decreasing absorption of oxalate, and therefore decreasing the amount of oxalate needing to be excreted
At what pH do magnesium ammonium phosphate stones precipitate?
Higher pH
What chromosome is the RB tumor suppressor gene on?
13
What gene is the WT-1 tumor suppressor gene on? What is it associated with?
Chromosome 11; Wilms tumor
What chromosome is c-Myc on? What is it associated with?
Chromosome 8; associated with Burkitts lymphoma
What chromosome is NF-1 on? What is it associated with?
Chromosome 17; associated with neurofibromatosis type 1
Renal blood flow x (1- Hct) calculates what?
Renal plasma flow
How is renal plasma flow calculated using renal blood flow and Hct?
Renal blood flow x (1-Hct)
How is filtration fraction calculated?
GFR/RPF
When creating a DDx for metabolic alkalosis, what is an important test to differentiate the causes?
Urine chloride
In unilateral renal artery stenosis, what is seen on CT?
Atrophy of the affected kidney, while contralateral kidney becomes enlarged
How does acute hemolytic transfusion reaction present?
Fever, hypotension, tachypnea, tachycardia, flank pain, hemoglobinuria
What is the cause of acute hemolytic transfusion reaction?
IgM antibodies to transfused ABO blood, resulting in complement activation
What type of HSR is acute hemolytic transfusion reaction?
Type II HSR
What are the AEs of thiazide diuretics?
Hypokalemia, metabolic alkalosis, hyperGlycemia, hyperLipidemia, hyperUricemia, hyperCalcemia. Sulfa allergy.
What effect do loop diuretics have on calcium?
Loops increase calcium excretion; hypocalcemia
What are the AE of acetazolamide?
Hypokalemia, metabolic acidosis (proximal renal tubular acidosis), sulfa allergy, NH3 toxicity, paresthesias
Gram negative rod, non-lactose fermenting, causing UTI in patient with indwelling catheter
P aeruginosa
Gram negative rod that is lactose-fermenting and causes nosocomial UTI infections
Enterobacter cloacae
What is the MOA of sirolimus?
Binds immunophilin FKBP in cytoplasma, forming a complext that inhibits mTOR; inhibition of mTOR inhibits IL-2 signal transduction
What is the most dangerous AE of amphotericin B?
Nephrotoxicity - can cause damage and result in hypokalemia
How do uric acid stones appear?
Yellow or red brown, diamond/rhombus formation
Uric acid crystals precipitate at what pH?
Low pH
In PSGN, what are the immune complex depositions comprised of?
IgG, IgM, C3
In repidly proliferative crescentic GN, the deposits are comprised of what?
Fibrin
In type 1 membranoproliferative GN, the deposits are comprised of what?
C1q
Subendothelial C1q deposits are characteristic of what renal disease?
Type 1 membranoproliferative GN
Basement membrane splitting is seen in what renal disease?
Alport syndrome and membranoproliferative glomerulonephritis
Uniform, diffuse thickening of glomerular capillary walls on LM is seen in what renal disease?
Membranous glomerulopathy
What drug can be used to treat ganciclovir-resistant CMV?
Foscarnet
What are the AEs of foscarnet use?
Hypocalcemia and hypomagnesemia which can cause seizures
Hyperproteinemia has what effect on GFR?
Increased oncotic pressure in the glomerular capillary, therefore decreased GFR
Urea passively diffuses into what part of the tubule?
Thin ascending limp of the loop of henle
Where is UT1 found? What controls it? What is its function?
Found in medullary collecting tubule; ADH increases expression of UT1; UT1 allows for reabsorption of urea (increasing interstitial concentration and therefor promoting water reabsorption)
Where is UT2 found? What is its function?
UT2 is found on thin ascending limb of the loop of Henle; it allows for secretion of urea (allowing for dilution of the tubular fluid)
What is minimal change disease?
Most common cause of pediatric nephrotic syndrome; see massive proteinuria (selective)
Erythropoiesis-stimulating agents increase the risk for what?
Hypertension an thromboembolic events
What is a urachus?
Remnant of the allantois that connects the bladder with the yolk sac
What effects doe beta-adrenergic antagonists have on renin secretion?
Inhibits renin release
What substance can be used to calculate renal plasma flow?
Para-aminohippuric acid
Acute rejection of an organ is seen in what timeframe?
Usually < 6 months
Secondary hyperparathyroidism due to CKD results in what characteristic lab findings?
Hyperphosphatemia, low 1,25 Vit D, hypocalcemia, increased PTH
