SYTM 5506 Week 3 Practice Questions

[3BC] Which of the following are cardiovascular findings in chronic renal failure? A. Hypertension B. Hemorrhagic fibrinous pericarditis C. Congestive heart failure D. Accelerated atherosclerosis

All of the above Chronic renal failure leads to hypertension due to salt retention, hemorrhagic fibrinous pericarditis due to inability to clear toxins (urea, creatinine, PTH, uric acid, etc.), CHF due to volume overload (& salt retention), & accelerated atherosclerosis due to endothelial damage from hypertension & toxins. Chronic renal failure can also cause CHF via myocyte dysfunction & interstitial fibrosis.

[3DE] A sexually active 22-year-old woman develops urinary frequency, dysuria, and urgency. Her urine is grossly turbid. Which lab data are most likely to define the causal agent? A. Gram-negative diplococcus, which is oxidase positive but does not ferment maltose B. Gram-positive coccus, which is catalase positive and coagulase negative C. Gram-positive coccus, optochin resistant, and catalase negative D. Gram-positive bacillus grown on low oxidation-reduction medium E. Gram-negative, non-lactose-fermenting bacterium capable of reducing nitrates to nitrites

B. Gram-positive coccus, which is catalase positive and coagulase negative Staph saprophyticus likes to cause UTIs in young women. It is non-motile, catalase positive, coagulase negative, & produces some urease (like Klebsiella).

[3JK] A 36-year-old woman comes to the clinic because of blood in her urine for the past 4 days. She also complains of painful urination, an increased urge to urinate, and an involuntary loss of urine. Physical examination shows suprapubic tenderness. Blood pressure is 135/90 mm Hg. Urinalysis shows 2+ blood, a positive urine leukocyte esterase test, and a positive nitrate test. Urine Gram stain shows a negative stained organism with a count of 300,000/mm^3. Which of the following is the most likely diagnosis? A. Bladder carcinoma B. Hemorrhagic cystitis C. Urethritis D. Post-streptococcal glomerulonephritis E. Nephritis

B. Hemorrhagic cystitis ??? E. coli

[3DE] Which of the following is a risk factor for developing pyelonephritis? A. History of alcohol abuse B. History of diabetes mellitus C. History of hypertension D. History of genital warts E. History of malaria

B. History of diabetes mellitus ???

[3BC] What is the name of this lesion (see other side)? A. Hyperplastic arteriolosclerosis B. Hyaline arteriolosclerosis

B. Hyaline arteriolosclerosis Benign nephrosclerosis are renal changes due to long-standing benign hypertension. Both kidneys are shrunken w/ finely granular cortical surface. Microscopically, arterioles in renal cortex have undergone hyaline arteriolosclerosis. Due to extra pressure, there is extravasation of plasma proteins which deposit in basement membrane matrix. This causes marked thickening of walls & narrowed lumen. There is also focal ischemia, which causes tubular atrophy, interstitial fibrosis, glomerular sclerosis, & scattered inflammatory infiltrates. Labs show mild proteinuria & hematuria as well as renal azotemia.

[3BC] What is the mass of reactive tissue found in bones of patients with chronic renal failure?

Brown tumor In osteitis fibrosis cystica, calcified supporting structures are replaced w/ fibrous tissue (peritrabecular fibrosis), creating hemorrhagic bone cysts such as Brown tumor. Brown tumor is mass of reactive tissue within bone. It contains microfractures, secondary hemorrhages, influx of macrophages, ingrowth of reparative fibrous tissue, & cystic degeneration. Brown color is due to increased vascularity & hemorrhage, which leads to hemosiderin deposition.

[3BC] What is the sequence of events leading to urate nephropathy in a cancer patient? Chemotherapy, Breakdown of nuclei releases purines, Lysis of tumor cells, Burkitt lymphoma

Burkitt lymphoma -> Chemotherapy -> Lysis of tumor cells -> Breakdown of nuclei releases purines

[3L] A 74-year-old man is hospitalized following a stroke and an indwelling urinary catheter is placed. He subsequently develops a UTI caused by Pseudomonas aeruginosa. Which antibiotic is the best choice for his infection? A. TMP-SMX B. Vancomycin C. Piperacillin-Tazobactam D. Nitrofurantoin E. Colistin

C. Piperacillin-Tazobactam There are several options for treating inpatient acute complicated UTIs: carbapenems, Pip/Taz for Pseudomonas, ceftriaxone, Cipro, or gentamicin.

[3L] A 46-year-old woman is given nitrofurantoin for a UTI. She returns in 2 weeks with flank pain and mild hematuria. Urine is pH 8 with struvite crystals, and kidney ultrasound shows large, staghorn-shaped stone in the renal pelvis. What UTI pathogen is likely responsible? A. E. coli B. Enterobacter C. Proteus D. Group B Strep

C. Proteus

[3BC] What is wrong with this retina (see other side)?

Malignant hypertension causes hypertensive retinopathy, e.g. papilledema, flame hemorrhages, diffuse exudates, macular star, retinal detachment, & cotton wool infarction spots.

[3BC] What is the sequence of events leading to pyelonephritis? Intrarenal reflux, Indwelling urinary catheter, Infection of urine in the bladder, Vesicoureteral reflux

Indwelling urinary catheter -> Infection of urine in the bladder -> Vesicoureteral reflux -> Intrarenal reflux Indwelling urinary catheter, urinary tract obstruction (e.g. BPH, ureteral calculi, neurogenic dysfunction due to diabetes mellitus, pregnancy), or sickle cell trait/disease leads to stasis & infected urine. After urine travels up into kidney via vesicoureteral reflux, there is intrarenal reflux where infected urine enters renal parenchyma thru open ducts in tips of papillae. They most commonly affect upper & lower poles of kidney. Hematogenous spread of S. aureus from endocarditis can also cause acute pyelonephritis, though this route is uncommon.

[3BC] Name a laboratory finding in chronic renal disease.

Patient will have hyperkalemia due to H+/K+ exchange & decreased K+ excretion in urine. There is anion gap metabolic acidosis due to retention of organic acids. Decreased renal excretion causes hyperphosphatemia, which binds calcium & causes hypocalcemia. Moreover, this excess calcium-phosphorus deposits in soft tissue (metastatic calcification). Due to reduction of 1-alpha-hydroxylase in PCTs, there is decreased synthesis of calcitriol (hypovitaminosis D) & decreased Ca2+ absorption. Hyperparathyroidism results from chronic hypocalcemia as well. Normocytic anemia results from decreased synthesis of EPO, & there is prolonged bleeding time due to defects in platelet aggregation. Urine has fixed specific gravity, i.e. there is lack of concentration & dilution due to tubular dysfunction, & free water clearance is zero. There are waxy casts in urine due to excretion of plasma proteins. If patients have been on long-term renal dialysis, they may develop cysts in their non-functional kidneys.

[3BC] This patient has multiple myeloma. What is the cause of this microscopic appearance (see other side)? A. AL amyloidosis B. Light chain casts C. Nephrocalcinosis D. Crystal deposition

A. AL amyloidosis

[3I] A 52-year-old woman who suffers from diabetes mellitus and frequent UTIs presents with a 3-day history of flank pain, fever, and malaise. A CBC shows neutrophilic leukocytosis (16,000/uL). Urine cultures reveal more than 100,000 bacterial colonies, composed predominantly of Gram-negative microorganisms. Blood pressure is 170/100 mm Hg, BUN is 30 mg/dL, and creatinine is 2.0 mg/dL. Fasting serum glucose is 190 mg/dL. Urinalysis shows 2+ sugar and 1+ protein. Microscopic examination of the urine sediment reveals neutrophils and occasional leukocyte casts. Which of the following is the most likely diagnosis? A. Acute pyelonephritis B. Acute tubular necrosis C. Diabetic nephropathy D. Post-infectious glomerulonephritis E. Nephrolithiasis

A. Acute pyelonephritis Acute pyelonephritis is suppurative inflammation of kidney & collecting system. It is usually bacterial in origin, either thru ascending infection or hematogenous spread. Risk factors include urinary tract obstruction, instrumentation (catheter), pregnancy, vesicoureteral reflux, diabetes mellitus, being female, & immunosuppression. Grossly, there are microabscesses in kidney. Microscopically, there is patchy, interstitial inflammation w/ neutrophil aggregates & tubular necrosis. Complications include papillary necrosis, pyonephrosis, & perinephric abscess.

[3I] A 60-year-old man presents with acute renal insufficiency. He treated his garden last week with a number of herbicides and insecticides, some of which may have contained heavy metals. Laboratory studies confirm oliguria and increased levels of BUN (54 mg/dL) and creatinine (3.7 mg/dL). What is the most likely diagnosis? A. Acute tubular necrosis B. Bilateral cortical necrosis C. Papillary necrosis D. Rapidly progressive glomerulonephritis E. Tubulointerstitial nephritis

A. Acute tubular necrosis There are multiple causes of acute tubular injury. Antibiotics, radiographic contrast agents, heavy metals, organic solvents, & poisons cause nephrotoxin acute tubular injury. Massive hemorrhage, septic shock, severe burns, & dehydration cause prerenal acute renal failure. Myoglobin & hemoglobin cause heme protein cast nephropathies.

[3I] A 35-year-old man presents with fever and rash after beginning treatment with penicillin 2 weeks earlier for a sinus infection. Urinalysis shows 3+ hematuria, as well as mononuclear cells, neutrophils, and eosinophils. Which of the following is the most likely diagnosis? A. Acute tubulointerstitial nephritis B. Chronic pyelonephritis C. crescentic glomerulonephritis D. Focal necrotizing glomerulonephritis E. Focal segmental glomerulosclerosis

A. Acute tubulointerstitial nephritis Many drugs can cause acute drug-induced interstitial nephritis, including penicillin, rifampin, thiazide diuretics, NSAIDs, allopurinol, & cimetidine. Symptoms begin about 2 weeks after exposure to drug, including fever, eosinophilia, skin rash, & renal abnormalities such as WBCs, RBCs, & protein in urine. Acute renal failure w/ oliguria develops in half of patients.

[3G] A 60-year-old man complains of chronic back pain and fatigue, excessive urination, and increased thirst. X-ray examination reveals numerous lytic lesions in the lumbar vertebral bodies. Laboratory studies show hypoalbuminemia. Urinalysis displays 4+ proteinuria. A monoclonal immunoglobulin light-chain peak is demonstrated by serum electrophoresis. A bone marrow biopsy discloses foci of plasma cells, which account for 20% of all hematopoietic cells. Which of the following is the most likely cause of nephrotic syndrome in this patient? A. Amyloid nephropathy B. Crescentic glomerulonephritis C. IgA nephropathy (Berger disease) D. Membranous glomerulonephritis E. Nodular glomerulosclerosis

A. Amyloid nephropathy Kidney is most commonly involved organ in systemic amyloidosis. Amyloid deposits in mesangium, resulting in nephrotic syndrome. As usual, it has apple-green birefringence w/ Congo red staining under polarized light. These deposits are found initially in mesangium & eventually in capillary walls. Another systemic disease that can cause nephrotic syndrome is diabetes mellitus; diabetic glomerulosclerosis is most common cause of secondary nephrotic syndrome. High serum glucose leads to NEG of vascular basement membrane & hyaline arteriolosclerosis. Basement membrane becomes leaky, so protein leaks onto wall of blood vessel, which increases thickness & decreases its lumen. Since efferent arterioles are more affected than afferent, there is high glomerular filtration pressure. Initially there is microalbuminuria, followed by eventual sclerosis of mesangium & progression to nephrotic syndrome. This sclerosis of mesangium (as well as Kimmelstiel-Wilson nodules) can be seen on biopsy. ACEi's slow filtration injury in these patients by preventing Ang II from further vasoconstricting efferent arteriole.

[3DE] A 51-year-old woman presents to the emergency department with intense pain in her lower back and a burning sensation upon urination. A urine culture was taken and plated on MacConkey agar, yielding pink colonies. Gram negative rods that produced urease were identified. Which virulence factor of the causal agent is most important for pathogenesis? A. Capsule B. Catalase C. Coagulase D. Exotoxin A E. Urease

A. Capsule Patient is infected w/ Klebsiella pneumoniae. Pseudomonas does not ferment lactose, so it's not option D. Klebsiella produces some urease but in relatively small amts., so it is not as important.

[3JK] A 25-year-old sexually active female presents with a urethral discharge for 2 weeks. She decided to seek medical attention after noticing pain in her left knee joint and right wrist, and a rash on soles one week ago. She also has itching and redness of the eye and a low-grade fever. Upon further evaluation, she admits to having several sex partners in the past year. Vitals include a blood pressure of 115/78 mm Hg, a temperature of 100.2°F, and a pulse of 78 bpm. Infection with which of the following organism could be responsible for her ongoing clinical presentation? A. Chlamydia trachomatis B. Treponema pallidum C. Herpes simplex virus D. Trichomonas vaginalis E. Streptococcus viridans

A. Chlamydia trachomatis Patient has C. trachomatis, which is obligate intracellular organism since it can't create its own ATP. It has poor Gram staining due to lack of muramic acid in cell wall. However, inclusion (reticular) bodies are visible within cells under microscopy using Giemsa stain. Lab diagnosis is performed via NAAT (PCR). Treat w/ macrolides like azithromycin or tetracyclines like doxy.

[3BC] What is the cause of discrete, corticomedullary scars in a kidney? A. Chronic pyelonephritis B. Benign nephrosclerosis C. Diffuse cortical necrosis D. Malignant hypertension

A. Chronic pyelonephritis Chronic pyelonephritis is renal dysfunction secondary to fibrosis & tubular damage and/or chronic inflammation of renal parenchyma. It is preceded by acute pyelonephritis that was not resolved, usually due to vesicoureteral reflux starting in young girls. It is also secondary to urinary tract obstruction & assoc. hydronephrosis, e.g. prostate hyperplasia or renal stones. Grossly, kidneys have irregular, discrete, corticomedullary scars (mostly in upper & lower poles) w/ overlying dilated, blunted, or deformed calyces. Microscopically, there is chronic interstitial inflammation (lymphocytes, plasma cells, & macrophages). There is also fibrosis in cortex & medulla, tubular atrophy, & dilated tubules containing casts of eosinophilic material resembling thyroid tissue. Patient presents w/ history of recurrent acute pyelonephritis, hypertension, & chronic renal failure. Renal scan shows decreased uptake in scarred kidneys.

[3L] A 24-year-old woman presents with urinary frequency and dysuria. She also has a history of long QT syndrome. Which antibiotic has a risk of causing a cardiac arrhythmia? A. Ciprofloxacin B. TMP-SMX C. Nitrofurantoin D. Amoxicillin-Clavulanate E. Cephalexin F. Fosfomycin

A. Ciprofloxacin Cipro & Levo are FQs that inhibit bacterial topoisomerases. They are given orally for 5-7 days or may be administered as IV loading dose + oral FQs for 7-14 days in more severe cases. Its spectrum is broad but resistance is common; although they confidently cover Staph saprophyticus, Citrobacter, & Serratia, they are now wishy-washy on E. coli, Klebsiella, Proteus, Enterobacter, & Pseudomonas. Levo covers Enterococcus faecalis that is not VRE.

[3H] A 30-year-old man with a history of smoking suddenly develops oliguria, hematuria, and hemoptysis. Serologic studies reveal antibodies to the glomerular basement membrane. Which of the following pathologic changes would be visible by light microscopy in this biopsy specimen? A. Crescents in the urinary space B. Leukocytic infiltrates in the glomeruli C. Mesangial cell proliferation D. Thickening of the glomerular basement membrane E. Thrombi in glomerular capillaries

A. Crescents in the urinary space Patient has Goodpasture syndrome, which involves RPGN. RPGN is nephritic syndrome that progresses to renal failure within wks to months. Light microscopy w/ H&E stain shows crescents (composed of fibrin & macrophages) in Bowman space. Immunofluorescence helps narrow down etiology. Linear pattern denotes Goodpasture; granular denotes PSGN or DPGN. DPGN is due to diffuse antigen-antibody complex deposition (usually sub-endothelial). It is most common type of renal disease in SLE. Negative immunofluorescence indicates Wegener granulomatosis (c-ANCA), microscopic polyangiitis (p-ANCA),or Churg-Strauss syndrome (also p-ANCA but w/ granulomatous inflammation, eosinophilia, & asthma).

[3H] A 38-year-old man complains of being lethargic for 4 months. There is no fever and the BP is 140/90 mm Hg. Labs show: Serum creatinine 5.8 mg/dL Complement low C3 nephritic factor positive ANA negative Urine 2+ hematuria 1+ protein A renal biopsy shows hypercellular glomeruli with ribbon like deposits in the lamina densa of the glomerular membrane. What is most likely? A. Dense deposit disease B. Focal segmental glomerulosclerosis C. Chronic glomerulonephritis D. Post-infectious glomerulonephritis E. Rapidly progressive glomerulonephritis

A. Dense deposit disease Type II MPGN, now called C3 glomerulopathy, has intramembranous deposits & is assoc. w/ C3 nephritic factor. C3 nephritic factor is autoantibody that stabilizes C3 convertase & prevents its breakdown, leading to overactivation of complement & inflammatory damage. Lab values will show decreased serum C3 but normal C1 & C4. Immunofluorescence will show C3 deposits only.

[3DE] A 50-year-old male presents with chronic back pain and dysuria on and off for 2 months. X-ray of the abdomen shows multiple calculi in the poles of both kidneys. What is the least likely organism which could cause his condition? A. E. coli B. Proteus mirabilis C. Serratia marcescens D. Klebsiella E. Citrobacter

A. E. coli Proteus is extremely urease positive; all others are slightly urease positive. Only E. coli is absolutely negative for urease. Citrobacter is Gram-negative rod that resembles Salmonella. It ferments lactose & hydrolyzes urea. Serratia is facultatively anaerobic, Gram-negative rods. It grows well on most lab media, showing up as bright red or pink (even if not grown on MacConkey agar). Ironically, they are non-lactose fermenters.

[3JK] A 60-year-old woman is hospitalized following a stroke and develops a high-grade fever with chills. She is catheterized due to urinary incontinence and receives a cephalosporin for treatment of pneumonia. Blood cultures and Gram stain are performed by the laboratory. The organisms isolated are Gram-positive cocci that are catalase negative and capable of growth in 6.5% sodium chloride agar. Which of the following is the most likely causal agent? A. Enterococcus faecalis B. Staphylococcus aureus C. Staphylococcus epidermidis D. Streptococcus pyogenes E. Viridans streptococci

A. Enterococcus faecalis Enterococci are Gram-positive bacteria that grow on 6.5% NaCl. They are bile resistant, & VRE are resistant to almost every antibiotic (except linezolid & tigecycline). They cause UTIs, endocarditis, & biliary tree infections.

[3DE] A 74-year-old woman is evaluated in the emergency department for new onset of confusion and three days of fever and rigors. Medical history is significant for hypertension, diabetes mellitus, and hyperlipidemia. The patient was diagnosed with UTI, and appropriate antibiotic therapy was initiated. She continued to have a fever of day 5 on antibiotics. CT of the abdomen and pelvis showed a renal abscess. What is the most frequently encountered causative organism in the condition described? A. Escherichia coli B. Klebsiella pneumoniae C. Candida albicans D. Staphylococcus aureus E. Streptococcus pyogenes

A. Escherichia coli ??? Most common cause of renal abscess

[3DE] A 32-year-old man comes to the emergency department with road traffic accident injuries of the abdomen. His temperature is 100.1°F, pulse is 128/min, respirations are 22/min, and blood pressure is 70/42 mm Hg. Physical examination shows a clammy and cold skin and dry mucous membranes. Diffuse ecchymoses and distension of the abdomen are also present. A Foley catheter bag collects dark brown urine. Which type of renal cast would most likely be seen on urinalysis? A. Granular casts B. Hyaline casts C. Waxy casts D. White cell casts E. RBC casts

A. Granular casts ???

[3BC] What is the name of this lesion (see other side)? A. Hyperplastic arteriolosclerosis B. Hyaline arteriolosclerosis

A. Hyperplastic arteriolosclerosis Hyperplastic arteriolosclerosis occurs in malignant hypertension to protect blood vessels against enormous pressure. This creates onion-skin lesions involving smooth muscle cell hyperplasia and/or reduplication of basement membrane.

[3A] Reabsorption of filtered sodium at the proximal convoluted tubule requires which of the following? A: Large amounts of ATP and high oxygen consumption B: Large amounts of ATP and normal oxygen consumption C: Normal amounts of ATP and high oxygen consumption D: Normal amounts of ATP and normal oxygen consumption E: No ATP or oxygen

A: Large amounts of ATP and high oxygen consumption PCT requires Na+/K+ ATPase to put in work to reabsorb 67% of all filtered Na+ as well as 100% of glucose & amino acids. Together w/ Na+/K+ ATPase working in ascending LOH, they use large amounts of ATP & have high oxygen demand. Unfortunately, there is decreasing PO2 gradient so that medulla receives much less oxygen than cortex (physiologic medullary hypoxia). This was inevitable price for ability to concentrate urine. On top of that, there is limited blood flow to medulla (only 10% of total RBF) to prevent osmotic gradient from being washed away. Thus, medulla must rely on anaerobic respiration to produce ATP, while cortex relies on oxidative fat metabolism, gluconeogenesis, & aerobic respiration.

[3BC] This patient has malignant hypertension. What causes pinpoint spots on the surface of the renal cortex? A. Microhemorrhages B. Coagulative necrosis C. Scar D. Eosinophilic microabscesses

A. Microhemorrhages Malignant hypertension causes vascular damage to arterioles & small arteries, including pinpoint hemorrhages on surface of both kidneys (flea-bitten appearance). There is also fibrinoid necrosis, necrotizing arteriolitis, & glomerulitis. Clinically, patients present w/ rapid increase in BP, oliguric acute renal failure, & hypertensive encephalopathy. They may have cerebral edema & intracerebral bleed.

[3A] During the normal catabolism of protein, urea and ammonia are produced as waste products. If these waste products are not cleared by the liver and kidneys, hyperammonemia can occur, leading to confusion and delirium. Fortunately, a healthy liver can clear these waste products via the urea cycle. Which of the following reactions is the rate limiting step in the urea cycle? A. NH3 + HCO3- + 2 ATP -> Carbamoyl phosphate + 2 ADP + 2 Pi B. Carbamoyl phosphate + Ornithine -> Citrulline + Pi C. Citrulline + Aspartate + ATP -> Arginosuccinate + AMP + PPi D. Argininosuccinate -> Arginine + Fumarate E. Arginine + H2O -> Ornithine + Urea

A. NH3 + HCO3- + 2 ATP -> Carbamoyl phosphate + 2 ADP + 2 Pi First two reactions of urea cycle take place in mitochondria. (1) NH4+ is added to HCO3- (formed from Co2 & H2O) to form carbamoyl phosphate. This reaction is catalyzed by carbamoyl phosphate synthetase I (CPSI), which uses up 2 ATP. (2) Ornithine transcarbamoylase combines carbamoyl phosphate w/ ornithine to form citrulline. (3) Citrulline leaves mitochondria & enters cytosol, where it combines w/ Asp to form argininosuccinate. This reaction is catalyzed by argininosuccinate synthetase, which uses up 1 ATP. (4) Argininosuccinate lyase splits argininosuccinate into Arg & fumarate. (5) Arginase cleaves Arg to form urea (which is excreted thru urine) & ornithine. Ornithine re-enters mitochondria to be used again.

[3JK] A 60-year-old man from sub-Saharan Africa presents to the clinic for worsening hematuria and weight loss. He reports a recurring history of hematuria for 8 months. Biopsy of the bladder shows oval shaped eggs. What would be the most likely organism responsible for his condition? A. Schistosoma haematobium B. Schistosoma japonicum C. E. coli D. Ascaris lumbricoides E. Taenia solium

A. Schistosoma haematobium Schistosoma is explained on another card.

[3BC] A 62-year-old man with a 20-year-history of poorly controlled hypertension presents to the family clinic with weight loss, fatigue, and bone pain. Laboratory values reveal an elevated BUN and creatinine, and normocytic anemia. What is the most likely cause of the patient's anemia? A: Decreased erythropoietin B: Hyperparathyroidism C: Hypocalcemia D: Chronic metabolic acidosis E: Increased phosphate

A: Decreased erythropoietin Patients w/ CKD have normocytic anemia w/ reticulocyte index < 2%. Decreased synthesis of EPO causes bone marrow response to be insufficient. There are also qualitative (functional) platelet defects that can be corrected by dialysis.

[3BC] A 72-year-old with a 25-year-history of poorly controlled hypertension is found dead in his home. An autopsy reveals a kidney with gross microhemorrhages and microscopic abnormalities such as reduplication of the basement membrane of kidney arterioles. What is the most likely cause of these findings? A: Malignant hypertension B: Benign nephrosclerosis C: Chronic pyelonephritis D: Acute Drug-induced tubulointerstitial nephritis E: Urate nephropathy

A: Malignant hypertension Malignant hypertension is sudden onset of accelerated hypertension < 210/120 mm Hg. This is seen in 5% of hypertensive patients; other risk factors include pre-existing benign nephrosclerosis, HUS, TTP, or systemic sclerosis. Symptoms include oliguric acute renal failure, hypertensive encephalopathy, cerebral edema, & intracerebral bleed. Lab findings show increased serum BUN & Cr (BUN:Cr ratio < 15), hematuria w/ RBC casts, & proteinuria.

[3L] A 47-year-old woman visits an outpatient family medicine clinic and complains of urinary urge and dysuria. A dipstick test shows that her urine has a pH of 8.2 and is positive for nitrite. She is prescribed a 5-day course of oral nitrofurantoin, but returns the following week because her urinary symptoms have not improved. Which UTI pathogen is intrinsically resistant to the antibiotic she was prescribed? A: Proteus mirabilis B: E. coli C: Klebsiella pneumoniae D: Staphylococcus saprophyticus E: Enterococcus faecalis

A: Proteus mirabilis Nitrofurantoin rapidly accumulates in urine & causes DNA damage via ROS generation. It is administered orally w/ food for 5 days in female patients & 7 days in males. It is active against E. coli, Staph saprophyticus, & Enterococcus faecalis. It is wishy-washy on Klebsiella & Enterobacter. It is not active against Proteus or Pseudomonas. Proteus is resistant b/c it produces urease, which alkalizes urine & renders drug useless. Adverse effects include immediate or delayed pulmonary toxicity. Nitrofurantoin, along w/ TMP-SMX & fosfomycin, are first-line drugs for uncomplicated UTIs.

[3DE] A 64-year-old man presents with backache and dysuria of 5 days duration. He also complains of colicky pain of the flanks on and off for the past 2 weeks. On examination he has moderate costochondral angle tenderness. Culture of his urine revealed 5×10^6 colonies of a motile, non-lactose, fermenting, Gram negative bacterium. His urine pH was 8.2. Which of the following organisms is most likely the cause of his illness? A: Proteus mirabilis B: E. coli C: Klebsiella pneumoniae D: Pseudomonas aeruginosa E: Citrobacter freundii

A: Proteus mirabilis Proteus is non-lactose-fermenting, non-encapsulated, Gram-negative bacteria part of Enterobacteriaceae family. It is facultative anaerobic & highly motile w/ flagella, resulting in swarming motility (colonies grow in wave pattern) on blood agar. It produces large amounts of urease that break down urea to produce ammonia, which alkalizes urine & precipitates formation of kidney stones. It also produces H2S & has fish odor. It is one of 7 main uropathogens causing UTIs.

[3JK] Four weeks after his arrival from Egypt, a 24-year-old graduate student presents to his doctor with blood in his urine. Microscopic examination of his urine reveals the presence of oval-shaped eggs with one pointed end. He admits that he has been working on his family's rice field occasionally since his early childhood. What is the most likely etiologic agent of his symptoms? A: Schistosoma haematobium B: Entamoeba histolytica C: Fasciolopsis buski D: Schistosoma japonicum E: Schistosoma mansoni

A: Schistosoma haematobium Main parasitic culprit for bladder infection is S. haematobium, which is found in Africa & Middle East. It first lays eggs that leave human thru feces and/or urine. These eggs hatch in water to release miracidia, which infect snails & form sporocysts. Cercariae are released by snail into water & eventually penetrate swimmer. Once inside, cercariae lose their tails & become schistosomulae. They migrate to portal blood in liver to mature into adults, upon which they migrate back up against portal blood flow to either mesenteric venules of bowel/rectum (S. japonicum & mansoni) or venous plexus of bladder (S. haematobium). Patient presents w/ rash at skin site (schistosome aka swimmer's itch), symptoms of cystitis (dysuria, hematuria, suprapubic pain, hemospermia), & later hematuria & proteinuria. Chronic infection leads to polyp formation, bladder obstruction, & bladder cancer. Diagnosis is based on urine sample to detect eggs, antibody or antigen tests, & molecular detection. Treat w/ praziquantel.

[3A] Which of the following evolved as an adaptation to improve the efficiency of sodium transport in the kidneys? A: The Na/K/2Cl cotransporter in the apical membrane of the Thick Ascending Limb B: The Na/K Pump in the basolateral membrane of the Proximal Tubule C: The Na-Glucose co-transporter in the Proximal Tubule D: The Na-H Antiporter in the Proximal Tubule E: The hydrogen-ATPase pump in the late distal tubule

A: The Na/K/2Cl cotransporter in the apical membrane of the Thick Ascending Limb Na/glucose co-transporter in apical membrane of PCT only transports 3 mEq of Na+ per 1 mM of ATP. NKCC2 cotransporter in apical membrane of thick ascending LOH transports 6 mEq Na+ per 1 mM of ATP. It had evolved in presence of limited supply of oxygen in medulla to be twice as efficient at transporting Na+.

[3BC] A 3-year-old boy is undergoing chemotherapy for Burkitt Lymphoma. 12 hours after starting therapy, he develops anuria. Serum creatinine 6 hours later is 2.5 X baseline. What is the most likely finding in the tubules and interstitium of the kidney? A: Urate crystal deposition B: "AL" amyloidosis C: Mononuclear and eosinophil infiltrate D: Neutrophilic tubulitis E: Irregular dense scars

A: Urate crystal deposition Patient has urate nephropathy, where renal injury is caused by deposition of urate crystals in renal tubules & interstitium. Most common cause is tumor lysis syndrome, where chemotherapy works too well & there is massive cellular necrosis of lymphoma/leukemia cells. Breakdown of cell nuclei releases purines, which are eventually converted to uric acid. Other causes of urate nephropathy include lead poisoning (lead decreases urinary excretion of uric acid) & gout. It can ultimately lead to acute renal failure.

[3BC] A 22-year-old woman presents to the Emergency Department with spiking fevers, flank pain, increased frequency, and dysuria. Physical exam reveals tenderness at the right costovertebral angle. A right nephrectomy is performed, showing multiple microabscesses. Which of the following is a risk factor for this condition? A: Vesicoureteral reflux B: Atrial fibrillation C: Recent course of penicillin D: Multiple myeloma E: Hypertension

A: Vesicoureteral reflux Vesicoureteral reflux can be congenital in children (1-2%) or acquired in adults. Intravesical portion of ureter is not compressed during micturition due to congenital absence or shortening of intravesical portion of ureter. This allows infected urine to ascend up ureter into kidney. This can be corrected via reimplantation of ureters or use of stents.

[3BC] Which of the following are mechanisms of kidney injury in multiple myeloma? A. Foreign body giant cell reaction / inflammation of tubules and interstitium B. Amyloidosis C. Bence-Jones tubular casts D. Nephrocalcinosis

All of the above Multiple myeloma causes Bence-Jones (light chain) proteinuria, which produces tubular casts that obstruct lumen. These light chains are toxic to renal tubular epithelium, causing foreign body giant cell reactions 7 inflammation involving tubules & interstitium. Another way multiple myeloma causes renal damage is nephrocalcinosis, i.e. hypercalcemia secondary to lytic bone lesions. There is metastatic calcification of basement membrane of collecting tubules, leading to polyuria (nephrogenic diabetes insipidus) & renal failure. Multiple myeloma also causes AL amyloidosis, where Ig light chains misfold & bind together to form amyloid fibrils that deposit in glomeruli, arteries, & interstitium. These deposits obliterate glomeruli & produce nephrotic syndrome.

[3DE] A 32-year-old woman G3P3 has been found to have asymptomatic bacteriuria on recent urine culture. the patient says she feels well and prefers to avoid taking medications when pregnant due to concerns that antibiotics and other medications can cause congenital disabilities. Which of the following is most important to discuss with the patient? A. Asymptomatic bacteriuria is common in pregnancy and does not require treatment unless symptoms develop B. Asymptomatic bacteriuria should be treated in pregnancy to prevent the development of pyelonephritis, which can lead to serious maternal and fetal morbidity C. Asymptomatic bacteriuria should be treated in pregnancy to prevent preterm delivery D. Many treatments for asymptomatic bacteriuria can cause birth defects, so she should take a short course of treatment only

B. Asymptomatic bacteriuria should be treated in pregnancy to prevent the development of pyelonephritis, which can lead to serious maternal and fetal morbidity

[3DE] A 54-year-old diabetic, partially paralyzed patient who has been catheterized for 1 week presents with fever and flank and suprapubic pain. Urine culture plate shows pale green colonies. Which of the following microbial components is most likely responsible for his illness? A. Peptidoglycans B. Exotoxin A C. Pyocyanin D. IgA protease E. Pili

B. Exotoxin A Pseudomonas' most important virulence factor is Exotoxin A, which is extracellular protein that inhibits protein synthesis in susceptible cells (mechanism similar to diphtheria toxin). Another important virulence factor is Exoenzyme S, unique T cell mitogen that is powerful immunostimulant that activates large proportion of T cells & induces apoptosis of host cells.

[3BC] Which of the following is a cause of renal infarction? A. Renal artery stenosis B. Atrial fibrillation C. Atherosclerotic plaque D. Polyarteritis nodosa

B. Atrial fibrillation, C. Atherosclerotic plaque, & D. Polyarteritis nodosa Renal infarction is wedge-shaped pale area of coagulation necrosis in renal cortex. It is most often caused by atrial fibrillation, where thrombus formation in L atrium embolizes into systemic circulation. Other causes include atheroembolic renal disease, where atheromatous plaques in aorta or renal artery rupture. This releases cholesterol crystals that plug up renal arteries, esp. in elderly patients w/ diffuse erosive atherosclerosis. Third cause is vasculitis, esp. polyarteritis nodosa. Grossly, there are 1+ irregular wedge-shaped pale infarctions in cortex, while old infarctions form V-shaped scar. Symptoms include sudden onset of severe flank pain & hematuria.

[3A] A 2-day-old boy is brought to the emergency department by his parents after he started vomiting numerous times within 1 hour. His parents say that he was born at home and appeared to be healthy at birth; however, he has become increasingly lethargic over the course of the past 24 hours. They became extremely concerned after he started vomiting copiously both with and without feeding. Physical exam reveals a distressed appearing infant who is hyperventilating, and laboratory tests demonstrate orotic acid in blood and urine. Which of the following metabolites is a substrate of the enzyme that is most likely defective in this patient? A. Ammonia B. Carbamoyl phosphate C. Citrulline D. Orotic acid E. Uridine monophosphate

B. Carbamoyl phosphate Patient has deficiency in ornithine transcarbamoylase (OTCD), which is most common genetic cause of hyperammonemia. It is caused by X-linked recessive mutation. Patient has neurologic symptoms such as seizures, developmental delay, & intellectual disability. More rarely, hyperammonemia can also be caused by deficiency in N-acetylglutamate synthase (NAGS). NAGS produces N-acetylglutamate from acetyl-CoA & Glu. NAG is required for activation of CPSI, so NAGS deficiency would also lead to decreased CPSI activity, hyperammonemia, & neurological complications. Inherited NAGSD is autosomal recessive mutation.

[3L] A 41-year-old woman complains of urinary frequency and burning pain when urinating. Urine dipstick test is positive for nitrates and leukocyte esterase. She has a 6-year history of myasthenia gravis. Which antibiotic should be avoided? A. Amoxicillin-Clavulanate B. Ciprofloxacin C. TMP-SMX D. Fosfomycin E. Nitrofurantoin F. Cefadroxil

B. Ciprofloxacin For uncomplicated UTIs, FQs are reserved for patients w/ no alternative therapy, since they have many serious adverse effects. These include CNS excitation, aortic aneurysm, tendon rupture, QT prolongation, MG exacerbation, phototoxicity, C. diff superinfection, & peripheral neuropathy. For acute complicated UTIs w/ low risk of resistance, they are first line. If there is risk of FQ resistance, add on single dose injection of ceftriaxone. If there is risk of MDR Gram Neg or penicillin allergy, add on deep IM injection or IV ertapenem. However, ertapenem can accumulate in patients w/ renal impairment, causing seizures.

[3A] A 20-year-old male presents with confusion and odd behavior. Very early in the morning, his mother found him urinating on the floor of his bedroom. A detailed history taken from the mother revealed that he has been a vegetarian his entire life but decided to bulk up by working out and consuming whey protein several times a day. A blood test revealed increased levels of ammonia and orotic acid. The patient began treatment and hemodialysis, which improved his condition. Gene therapy of the enzyme producing which product would correct his condition? A. Uridine monophosphate B. Citrulline C. Homocysteine D. Phenylalanine E. Fructose-1-phosphate

B. Citrulline Patient has OTC deficiency, which is discussed on other cards. On another note, MSUD is caused by defect in alpha-keto acid dehydrogenase, which leads to buildup of Val, Ile, Leu, & their corresponding alpha-keto acids. Increased alpha keto acids cause neurologic complications, while both increased branched chain amino acids & their alpha-keto acids contribute urine resembling maple syrup. Degradation of Phe & Tyr also has assoc. pathologies (see picture). PKU involves mental retardation & urine w/ musty odor. Tyrosinemia II involves lesions of eye & skin & neurologic problems. Tyrosinemia I causes liver & kidney failure, nervous system disorders, & increased risk for liver cancer. Alcaptonuria leads to deposition of black pigment (oxidized & polymerized homogentisate) in tissue & urine.

[3L] A 34-year-old woman presents with urinary frequency and a vaginal discharge 10-days after having unprotected intercourse. A cervical exam shows inflammation, erythema, and cloudy mucous. A sample is submitted for analysis. What is the best choice for empiric therapy? (PICK 2) A. Amoxicillin B. Doxycycline C. Cefixime D. Ceftriaxone E. Azithromycin F. TMP-SMX

B. Doxycycline & D. Ceftriaxone See previous card for explanation. On a similar note, non-gonococcal urethritis (NGU) is caused by Mycoplasma genitalium or Chlamydia (can infect on its own or co-infect w/ Mycoplasma). Since both of these pathogens are cell wall deficient, beta lactams will not work. First-line drug for NGU is oral doxy, which is given for 7 days for Chlamydia. If Mycoplasma is sensitive to macrolides, 7 days of doxy should be followed by 3 days of azithromycin (macrolide that binds to 50S subunit to inhibit protein synthesis). If Mycoplasma is resistant or if resistance is unknown, 7 days of doxy should be followed by 7 days of moxifloxacin (FQ that inhibits DNA gyrase).

[3DE] Which of the following actions is most important when evaluating the effectiveness of treatment in a patient with pyelonephritis? A. Monitoring improvement of symptoms B. Evaluating urine culture and antibiotic sensitivity C. Monitoring specific gravity D. Monitoring temperature E. Measuring BUN

B. Evaluating urine culture and antibiotic sensitivity

[3BC] What type of calcification is present in the lungs of a patient with chronic renal failure? A. Dystrophic B. Metastatic

B. Metastatic Elevated levels of serum phosphorus binds calcium & thus lowers serum calcium. This leads to metastatic calcification, i.e. deposition of calcium salts in normal tissue such as blood vessels, lungs, kidneys, & gastric mucosa.

[3BC] In chronic renal failure, what type of anemia is present? A. Microcytic B. Normocytic C. Macrocytic

B. Normocytic

[3DE] A 62-year-old woman with type 2 diabetes mellitus is brought to the emergency room because of a 3-day history of fever and shaking chills. Her temperature is 39.4°C. Examination of the back shows right costovertebral angle tenderness. Analysis of the urine shows WBCs, WBC casts, and Gram-negative rods. Biopsy of the patient's kidney is most likely to show which of the following? A. Polygonal clear cells filled with lipids and carbohydrates B. Polymorphonuclear leukocytes in tubules C. Widespread granulomatous tissue and foamy macrophages D. Cystic dilation of the renal medulla E. Sloughing of necrotic renal papillae

B. Polymorphonuclear leukocytes in tubules ???

[3I] A 60-year-old man undergoes resection of an abdominal aneurysm, which is complicated by massive hemorrhage. Two days after surgery, the patient develops acute renal insufficiency. He is placed on dialysis but suffers a massive heart attack and dies. Microscopic examination of the kidneys at autopsy reveals necrotic epithelial cells within the lumina of some tubules. What is the appropriate diagnosis? A: Acute interstitial nephritis B: Acute tubular necrosis C: Eosinophilic interstitial nephritis D: Fanconi syndrome E: Polyarteritis nodosa

B: Acute tubular necrosis There are many causes of tubulointerstitial nephritis: infections, toxins, metabolic diseases, physical obstruction, neoplasms, immunologic reactions, & vascular diseases. If damage is ischemic in nature, LOH is often involved, showing patchy tubular necrosis. If damage is due to toxins, tubular necrosis is mainly found in proximal tubules. Nephrotoxic prognosis is generally better than ischemic one.

[3DE] Which of the following statements best describes the virulent factors of common uropathogens? A: Uropathogenic E. coli produce protein A for IgG binding B: Klebsiella pneumoniae has a capsule for immune evasion C: Staphylococcus saprophyticus produce LPS which results in immune activation D: Enterococcus faecalis has a thick capsule for inhibition of phagocytosis E: Proteus mirabilis produce an IgA breaking-down enzyme

B: Klebsiella pneumoniae has a capsule for immune evasion Klebsiella is non-motile, Gram-negative bacteria. Along w/ Enterobacter & Serratia, it ferments lactose (pink colonies on MacConkey agar), though Serratia ferments lactose very slowly & may show up as negative. Those three bacteria cause nosocomial pneumonia & UTIs & are MDR. Klebsiella specifically likes to infect alcoholics thru aspiration, forming abscesses. Hallmark of respiratory infection is currant jelly sputum. Klebsiella is urease positive but oxidase negative. It has thick capsule that creates halo surrounding bacterium under Gram staining.

[3I] A 56-year-old woman presents with acute renal failure. A frozen section of a renal biopsy demonstrates birefringent, intra- tubular deposits of uric acid. This finding suggests that the patient has been treated recently for which of the following underlying conditions? A: Chronic hepatitis B B: Leukemia C: Porphyria D: Rheumatoid arthritis E: Ulcerative colitis

B: Leukemia Urate nephropathy presents in 3 forms. Acute uric acid nephropathy is where uric acid crystals precipitate in renal tubules, causing acute renal failure. Chronic urate (gouty) nephropathy is found in hyperuricemic patients, where urate crystals precipitate in acidic environment of interstitium. There can also be uric acid stone formation.

[3A] A 26-year-old female complains of frequent, large volume urination. This negatively affects her sleep, as she must frequently wake up at night to urinate. She also complains of increased thirst. Her past medical history is significant for bipolar disorder that is treated with lithium for 3 years. Lab work shows high serum osmolality of 425 mOsm/kg (normal 280-290) and low urine osmolality of 176 mOsm/kg (normal: 500-800). Which of the following best explains this patient's serum and urine osmolality? A. Hypothalamic overproduction of ADH B. Decreased production of ADH C. ADH resistance in renal collecting ducts D. Increased sodium reabsorption and potassium excretion E. Increased aquaporin expression in the renal collecting ducts

C. ADH resistance in renal collecting ducts Lithium reduces ADH sensitivity in tubules by inhibiting adenylate cyclase (AC); this prevents ADH from activating AC to increase aquaporin localization to plasma membrane. Thus, kidneys cannot reabsorb water in collecting ducts, leading to lithium-induced nephrogenic diabetes insipidus. Option B is consistent w/ neurogenic diabetes insipidus (incorrect).

[3DE] A previously healthy 24-year-old woman comes to the physician because of a 1-day history of nausea and weakness. Her temperature is 101°F. Physical examination shows right costovertebral angle tenderness. Pelvic examination is normal. Which of the following is the most likely cause of this patient's condition? A. Ascending bacteria from the endocervix B. Noninfectious inflammation of the bladder C. Ascending bacteria from the bladder D. Decreased urinary pH E. Decreased renal calcium reabsorption

C. Ascending bacteria from the bladder ???

[3DE] A 26-year-old female presents to her primary care physician concerned that she has contracted an STD. She states that she is having severe pain whenever she urinates and seems to be urinating more frequently than normal. She reports that her symptoms started after she began having unprotected sexual intercourse with 1 partner earlier this week. The physician obtains a urinalysis which demonstrates the following: SG: 1.010 Leukocyte esterase: positive Nitrites: positive Protein: trace pH: 6.4 RBC: negative Urease test: negative Which of the following organisms is most likely responsible for this patient's condition? A. Proteus B. Klebsiella pneumoniae C. Escherichia coli D. Staphylococcus saprophyticus E. Streptococcus pyogenes

C. Escherichia coli ??? Nitrites only positive with Gram neg organisms

[3DE] A 23-year-old woman comes to urgent care because of 2 days of mild fever and painful urination. The patient has increased frequency and sense of incomplete voiding. She denies seeing blood in her urine, abnormal discharge, fatigue, or increased thirst. Physical examination is unremarkable. Urine culture detects the presence of Gram-negative bacterial rods. Upon testing, they were oxidase negative, ferment lactose, and are motile. Which of the following virulence factors contributes to the pathogenesis of the most likely microorganism causing the patient's symptoms? A. Exotoxin A B. IgA protease C. Fimbriae D. P1 antigen E. Protein A

C. Fimbriae ??? E. coli

[3JK] A 59-year-old woman comes to the emergency department because of a 2-day history of increasingly severe fever and back pain. She also has a burning sensation with urination, and there is an aromatic smell to the urine. She has had three urinary tract infections treated with ciprofloxacin during the past year. Her temperature is 102.3°F. Physical examination shows right flank tenderness. Laboratory studies show: Leukocytes: 15,500/mm^3 Urine pH: 6.2 Protein: trace WBC: numerous Bacteria: > 100,000 colonies/mL A urine culture grows a urease-positive organism that displays non-motility on non-selective agar. Which of the following is the most likely causal organism? A. Enterococcus faecalis B. Escherichia coli C. Klebsiella pneumoniae D. Proteus mirabilis E. Staphylococcus saprophyticus

C. Klebsiella pneumoniae Enterococcus & E. coli are urease negative. Staph saprophyticus, Klebsiella & Proteus are urease-positive, but only Staph saprophyticus & Klebsiella are non-motile. However, Staph mostly infects young women, so Klebsiella is more likely in this scenario.

[3G] A 12-year-old boy complains of swelling of his feet for the past 3 weeks. He is otherwise healthy, with no known previous illness. Vital signs are normal. Physical examination reveals pitting edema of the lower legs and a swollen abdomen. Urinalysis shows 4+ protein but no RBCs or WBCs. Which of the following are the most likely diagnoses to consider in your evaluation of this patient? A. Henoch-Schoenlein purpura, lupus nephritis B. Malignant hypertension, renal vein thrombosis C. Minimal change disease, focal segmental glomerulosclerosis D. Pyelonephritis, acute tubular necrosis E. Wilms tumor, renal cell carcinoma

C. Minimal change disease, focal segmental glomerulosclerosis

[3JK] A 22-year-old male presents to the family medicine clinic with complaints of dysuria, urethral pruritis, and discharge for the past three weeks. He has had persistent urethritis despite treating with ceftriaxone and metronidazole. He is sexually active with multiple partners and does not use condoms. His vital signs are stable. The examination of genitalia shows erythema of the urethral meatus and a mucoid urethral discharge. Which of the following is the most likely cause of his urethritis? A. Trichomonas vaginalis B. Adenovirus C. Mycoplasma genitalium D. Herpes simplex virus E. Neisseria gonorrhoeae

C. Mycoplasma genitalium Patient has non-gonococcal urethritis (NGU), which is caused by C. trachomatis, Ureaplasma urealyticum, or Mycoplasma genitalium. Occasionally, it can also be caused by Trichomonas or HSV. Otherwise, cause is unknown in 50% of cases. Compared to gonococcal urethritis, incubation period is much longer (7-28 days vs. 3-5 days). Onset is gradual rather than abrupt, & discharge is mucoid rather than purulent. Gram stain of discharge shows PMN leukocytes in NGU, while gonococcal will show Gram-negative intracellular diplococci.

[3L] A 22-year-old man presents with urethritis. Which of these pathogens is most susceptible to an antibiotic that inhibits cell wall synthesis? A. Mycoplasma genitalium B. Chlamydia trachomatis C. Neisseria gonorrhea D. Trichomonas vaginalis

C. Neisseria gonorrhea Neisseria is only encapsulated bacteria among these answer choices. It is discussed on another card. On another note, oral praziquantel is used to treat urinary schistosomiasis. Its mechanism is based on increasing Ca2+ permeability, which causes worm paralysis & detachment.

[3JK] A 25-year-old male presents with dysuria and fever. He reports that he recently entered a new relationship and is having unprotected sex with a new partner. On examination, you find purulent urethral discharge. He also has right wrist pain and two small pustular lesions on his arm. What is the most likely organism causing this patient's condition? A. Chlamydia trachomatis B. Trichomonas vaginalis C. Neisseria gonorrhoeae D. Mycoplasma hominis E. E. coli

C. Neisseria gonorrhoeae N. gonorrhoeae causes urethritis & cervicitis w/ mucopurulent discharge. It doesn't really cause vaginitis. However, it can cause ano-rectal, pharyngeal, & disseminated disease. It causes urethritis in males, PID in females. One complication of PID is Fitz-Hugh-Curtis syndrome, where inflammation spreads into peritoneum & forms violin-string adhesions on liver capsule. It can also cause asymmetric arthritis, commonly in knee, w/ purulent synovial fluid that doesn't Gram-stain (since infection is intracellular). Mom can pass gonorrheal infection onto baby during delivery, manifesting as early-onset conjunctivitis in newborns.

[3A] a 15-year-old boy is brought to the emergency department by his mother because of fever, severe lethargy, and vomiting. HIs mother mentions that he has a history of similar problems since childhood, and she has recently observed that his symptoms seem to worsen after he eats meat. Temperature is 38.3°C, blood pressure is 120/90 mm Hg, pulse is 90/min, and respiratory rate is 12/min. On physical examination, growth retardation and cognitive impairment are present. Blood analysis shows hyperammonemia. Urine analysis shows increased orotic acid levels. Which of the following enzymes is most likely deficient in this patient? A. Branched acid alpha keto acid B. Hypoxanthine-guanine phosphoribosyltransferase C. Ornithine transcarbamylase D. Phenylalanine hydroxylase E. Uridine monophosphate synthetase

C. Ornithine transcarbamylase Patient has OTC deficiency. Hyperammonemia is toxic to brain b/c it inhibits glutaminase in brain. Glutaminase's job is to convert Gln to Glu. Increased NH3 & Gln inside neurons causes osmotic imbalance & brain edema. Simultaneously, decrease in Glu & GABA (which is produced from Glu) impairs neurotransmission & causes neurologic symptoms.

[3DE] A 22-year-old sexually active female presents to the emergency department in severe pain. She states that she has significant abdominal pain that seems to worsen whenever she urinates. This seems to have progressed over the past day and is accompanied by increased urge and frequency. The emergency room physician obtains a urinalysis which demonstrates the following: SG: 1.010 Leukocyte esterase: positive Protein: trace pH: 8.9 RBC: negative Nitrite: positive Urease test: positive (+++) What is the most likely cause of UTI in this patient? A. Klebsiella pneumoniae B. Staphylococcus saprophyticus C. Proteus mirabilis D. Escherichia coli E. Serratia marcescens

C. Proteus mirabilis Proteus is non-lactose-fermenting, non-encapsulated Gram-negative bacteria. It is highly motile w/ flagella, resulting in swarming motility (colonies grow in wave-like pattern) on blood agar. It produces urease that breaks down urea into CO2 & NH3; this alkalizes urine & precipitates formation of struvite stones. It also produces H2S & has fishy odor.

[3L] A 27-year-old woman who is 8-weeks pregnant presents with a UTI. Which medication should be avoided in the first trimester, due to a risk of developmental defects? A. Nitrofurantoin B. Amoxicillin-Clavulanate C. TMP-SMX D. Fosfomycin E. Cephalexin

C. TMP-SMX Trimethoprim-Sulfamethoxazole are folate antagonist; TMP inhibits DHFR, while SMX inhibits DHPS. They are administered orally for 3 days in females & 7 days in males. They are active against Staph saprophyticus & Enterobacter but wishy-washy on E. coli, Klebsiella, & Proteus. They are not active against Enterococcus faecalis or Pseudomonas. However, they must not be used in pregnant women due to possible risk of neural tube defects. There is also chance of sulfa-drug reaction, which can range from maculopapular eruption to SJS.

[3JK] A 55-year-old man presents with pain in the perineum, penile tip, and scrotum for the past 10 days. He had lower back pain a week ago, but the pain has subsided. A clear milky discharge from the penis and nocturia are also noted. On physical examination, his prostate is boggy and tender to palpation. What is the most likely microbial cause of his condition? A: Herpes simplex virus - 2 B: Chlamydia trachomatis C: E. coli D: Human immunodeficiency virus (HIV) E: Staphylococcus aureus

C: E. coli ???

[3H] A 35-year-old man with a history of smoking presents with hematuria and bloody sputum. Over the next 2 days, he develops oliguria and renal failure, after which he is placed on dialysis. A renal biopsy is stained with fluorescein-conjugated goat antihuman IgG. Which of the following best describes the pattern of direct immunofluorescence observed? A: Discontinuous and peripheral B: Finely granular along the perimesangial reflections C: Linear along the glomerular basement membrane D: Mesangial with a stalk predominance E: Peripheral granular humps

C: Linear along the glomerular basement membrane Patient has Goodpasture Disease, which classically affects young adult males. It involves autoantibody against Type IV collagen in glomerular & alveolar basement membranes. Thus, patients present w/ hematuria from rapidly progressive glomerulonephritis (RPGN) & hemoptysis from pulmonary hemorrhage. Histologically, there are glomerular crescents & diffuse immunostaining for IgG.

[3L] A 24-year-old man visits his family physician with a complaint of painful urination and a purulent urethral discharge. A first-catch urine specimen tests positive for Neisseria gonorrhoeae. He is administered an intramuscular injection of ceftriaxone to cover N. gonorrhoeae. He is also given a 7-day course of oral doxycycline. What is the purpose for prescribing this second, oral antibiotic? A: To cover against cephalosporin-resistant N. gonorrhoeae B: To synergize with ceftriaxone against N. gonorrhoeae C: To cover against possible co-infection with Chlamydia trachomatis D: To continue covering N. gonorrhoeae after ceftriaxone wears off E: To cover against possible misdiagnosis as Mycoplasma genitalium

C: To cover against possible co-infection with Chlamydia trachomatis Patient has gonococcal urethritis, which is treated w/ high single dose IM injection of ceftriaxone. For ceftriaxone, watch out for hypersensitivity. This covers Neisseria, but not Chlamydia, which often co-infects w/ Neisseria. Doxy is given orally for 7 days to cover Chlamydia.

[3BC] Name a risk factor for renal papillary necrosis.

Compression of vessels due to pyelonephritis, acute interstitial nephritis, or urinary tract obstruction. Microvascular disease, e.g. diabetes mellitus, sickle cell disease, NSAIDs, or acute analgesic nephropathy Renal papillary necrosis is any condition causing ischemia of small blood vessels of medulla. Grossly, renal pyramids undergo gray-white or yellow necrosis, & their papillae may slough off. Microscopically, there is coagulative necrosis (hence preservation of outlines of tubules). Patient presents w/ flank pain, fever, gross hematuria, cloudy urine, tissue pieces in urine, dysuria, & frequency.

[3L] A 44-year-old man presents with recurrent symptoms of urinary tract infection, but without bacteriuria or STI. He is treated for a presumed case of chronic bacterial prostatitis and prescribed a ___ course of ciprofloxacin. A. 3-day B. 1-week C. 2-week D. 6-week

D. 6-week Prostatitis is most often caused by E. coli or Proteus mirabilis. Most antibiotics do not penetrate prostate very well, but inflammation in acute prostatitis increases drug penetration. Outpatient acute bacterial prostatitis is treated w/ oral TMP-SMX or FQ such as Cipro or Levo. Inpatient acute bacterial prostatitis is treated w/ IV FQ or beta-lactam (w/ or w/o gentamicin). However, chronic prostatitis requires 6+ weeks of FQ treatment.

[3JK] A 36-year-old man comes to the office because of a 6-month history of suprapubic and penile pain. When asked about his sexual history, the patient mentions that he is in a monogamous relationship and denies unsafe sexual practices. Upon further questioning, the patient complains of burning pain after ejaculation and transient urinating difficulty. Rectal exam shows a normal-sized, moderately tender prostate gland. His temperature is 36.6°C, pulse is 78/min, respirations are 18/min, and blood pressure is 110/70 mm Hg. Urine culture is normal. Prostatic fluid culture on blood and chocolate agar grew nothing. Which of the following organism is the most likely cause of this patient's current condition? A. N. gonorrhoeae B. E. coli C. Proteus mirabilis D. Chlamydia trachomatis E. H. influenzae

D. Chlamydia trachomatis Patient has chronic prostatitis. C. trachomatis is obligatory intracellular bacterium due to its inability to produce ATP. Infections are often asymptomatic. It has dimorphic growth cycle, where elementary bodies are infectious form & reticular bodies are replicating form.

[3JK] A 36-year-old female presents to your clinic complaining of dysuria and hematuria, as well as pain with intercourse. She recently immigrated from Africa. Urinalysis shows 2+ blood, but no other obvious signs of infection. Testing for STIs is negative. CBC is only remarkable for eosinophilia. Cystoscopy shows granular material on bladder wall. What is the likely source of his infection? A. Mosquitoes B. Inhalation C. Exposure to infected body fluids D. Contaminated water E. Black fly

D. Contaminated water Patient has Schistosoma, which is transmitted thru water. Eggs of Schistosoma is that granular material seen on bladder wall. Since testing for STIs is negative, it is unlikely she was exposed via infected body fluids.

[3G] A 4-year-old girl presents with swelling of the legs and ankles. Physical examination reveals pitting edema of the lower extremities. Urinalysis shows 2+ proteinuria. The urinary sediment contains no inflammatory cells or red blood cells. Serum levels of BUN and creatinine are normal. the patient recovers completely after a course of corticosteroids. What would electron microscopy of renal biopsy prior to treatment most likely demonstrate? A. Duplication of capillary basement membranes B. Electron-dense immune deposits in the capillary basement membranes C. electron-dense immune deposits in the mesangium D. Fusion of podocyte foot processes E. Loss of microvilli by the tubular lining cells

D. Fusion of podocyte foot processes

[3L] A 71-year-old man with delirium is admitted to the hospital with pyelonephritis attributed to an ESBL-producing strain of E. coli. Which antibiotic is the best choice? A. Azithromycin B. Vancomycin C. Amoxicillin-Clavulanate D. Imipenem-Cilastatin E. Ciprofloxacin

D. Imipenem-Cilastatin Uncomplicated ESBL is treated w/ fosfomycin, w/ or w/o nitrofurantoin or TMP-SMX. Complicated ESBL is treated w/ carbapenems. Uncomplicated VRE is treated w/ nitrofurantoin, while complicated VRE is treated w/ IV or oral linezolid. MRSA is treated w/ vanco or linezolid (TMP-SMX unreliable for UTIs & systemic infections).

[3G] A 44-year-old man complains of swelling of his legs and puffiness around eyes. His abdomen has become protuberant, and he feels short of breath. Physical examination reveals generalized edema and ascites. Total serum protein is 5.2 g/dL (reference = 5.5 to 8.0 g/dL) and albumin is 1.9 g/dL. Serum cholesterol is elevated at 530 mg/dL. There are 5 g of protein in a 24-hour urine collection. The urinary sediment contains many hyaline casts but no RBCs or inflammatory cells. A renal biopsy stained by direct immunofluorescence for IgG is granular with sub-epithelial immune complex deposition. Which of the following is the most likely diagnosis? A. Amyloid nephropathy B. Focal segmental glomerulosclerosis C. Membranoproliferative glomerulonephritis type I D. Membranous glomerulopathy E. Minimal change disease

D. Membranous glomerulopathy Membranous nephropathy is most common cause of nephrotic syndrome in adults. Though usually idiopathic (primary), it may be assoc. w/ HBV, HCV, solid tumors, SLE, or drugs like NSAIDs & penicillamine (secondary). Idiopathic type is more common in white males over age 40. If found in women, SLE should be suspect. Light microscopy w/ H&E stain shows thick glomerular basement membrane. Immunofluorescence is granular due to sub-epithelial immune complex deposition at base of foot processes. EM shows these deposits w/ spike & dome appearance (podocytes lay down dome of extra basement membrane over deposits, each separated by V-shaped spike). Idiopathic type should see electron-dense deposits in sub-epithelial zone only; secondary type should see deposits in mesangium & sub-epithelium.

[3H] One week after a mild flulike illness, a 9-year-old boy has an episode of hematuria that subsides in 2 days. One month later, he has red urine again. The physical exam is unremarkable. Urine analysis shows specific gravity of 1.1015, 1+ proteinuria, 1+ hematuria, and no ketones or glucose. The serum IgA levels are increased. Which of the following glomerular structures will show structural alterations? A. Basement membranes B. Capillaries C. Parietal epithelium D. Mesangium E. Podocytes

D. Mesangium Patient has IgA nephropathy, i.e. IgA immune complex deposition in mesangium of glomeruli. It is most common nephropathy worldwide, often presenting during childhood w/ episodic gross/microscopic hematuria w/ RBC casts, esp. following mucosal infections. Immunofluorescence is granular due to IgA immune complex deposition in mesangium. It may slowly progress to renal failure.

[3JK] A 58-year-old woman had surgery for ovarian cancer and has an indwelling catheter in place. Three days later, she developed high fever with cloudy urine. Gram-stained urine shows polymorphs and Gram-positive cocci in chains. Which one of the following best explains the causative organism in culture? A. Alpha hemolytic colonies which are optochin sensitive B. Beta hemolytic colonies which are bacitracin sensitive C. Beta hemolytic colonies that hydrolyze hippiurate D. Non-hemolytic colonies that grow on 6.5% NaCl E. Alpha hemolytic colonies which are optochin resistant

D. Non-hemolytic colonies that grow on 6.5% NaCl Patient has Enterococcus (Strep Group B).

[3DE] A 69-yearold woman comes to the emergency department because of a 2-day history of increasingly severe fever and back pain. She has also burning sensation with urination, and there is an aromatic smell to the urine. She has had three UTIs treated with ciprofloxacin during the past year. Her temperature is 39.1°C. Physical examination shows right flank tenderness. Lab studies show: Leukocyte count: 15,500/mm^3 Urine pH: 9 Protein: trace WBC: numerous Bacteria: > 100,000 colonies/mL A urine culture grows a urease-positive organism that displays motility on blood agar. Which of the following is the most likely causal organism? A. Enterococcus faecalis B. Escherichia coli C. Klebsiella pneumoniae D. Proteus mirabilis E. Staphylococcus saprophyticus

D. Proteus mirabilis If urine pH is high, automatically think Proteus. Attributes of Proteus explained on another card.

[3DE] A 65-year-old hospitalized patient has end-stage uterine cancer. Which of the following oxidase positive organisms is most likely to be the cause of a UTI in this patient? A. Neisseria gonorrhoeae B. Salmonella typhi C. Proteus mirabilis D. Pseudomonas aeruginosa E. Escherichia coli

D. Pseudomonas aeruginosa Pseudomonas is most common opportunistic infection & most common cause of nosocomial pneumonia & respiratory failure in CF patients. It causes osteomyelitis in IV drug users & diabetics & infects burn patients. It also causes nosocomial UTIs, hot tub folliculitis, otitis externa (swimmer's ear), & ecthyma gangrenosum (black necrotic lesions on skin following sepsis). Lab tests show that Pseudomonas is indole negative, methyl red negative, Vp negative, & urease negative. It is citrate positive & doesn't ferment lactose (colorless on MacConkey agar). It also has fruity, grape-like odor.

[3I] A 70-year-old diabetic woman presents with sudden onset of excruciating groin and flank pain. Physical examination shows pitting edema of the lower extremities. Laboratory studies reveal decreased serum albumin and increased serum lipids. Urine cultures reveal more than 100,000 bacterial colonies composed predominantly of Gram-negative microorganisms. Which of the following is the most likely diagnosis? A. Acute tubular necrosis B. Crescentic glomerulonephritis C. Diabetic glomerulosclerosis D. Renal papillary necrosis E. Renal vein thrombosis

D. Renal papillary necrosis ???

[3JK] A 30-year-old sexually active man presents to his doctor with dysuria and a mucoid urethral discharge of 5 days duration. The discharge was cultured on a specialized bacterial culture medium (without urea) for 48 hours and the colony appearance shows colonies surrounded by inhibition zones. Which of the following statements best describes the organism which was cultured? A: It has a cell wall made of mannan and chitin B: It is best treated with a first-generation cephalosporin C: It is the only cause of non-gonococcal urethritis in males D: It results urethritis in males and cervicitis in females E: It causes asymptomatic disease unless co-infected with Neisseria species

D: It results urethritis in males and cervicitis in females Patient has N. gonorrhoeae, which is Gram-negative, non-motile, non-spore-forming, non-encapsulated organism. It ferments glucose but not maltose (unlike N. meningitidis, which ferments both). Once phagocytosed by neutrophils, it is found in pairs. Unable to grow on blood agar, it can grow on chocolate agar or VPN (aka Thayer-Martin) agar. Other options for diagnosis include blood culture, PCR, & ELISA. Main virulence factors include pili (enhance attachment to host cells & resistance to phagocytosis), lipooligosaccharide (LOS, which is similar to LPS), & IgA1 protease (inactivates IgA1, which is major mucosal Ig in humans).

[3H] An 8-year-old boy presents with headaches, dizziness, and malaise. He was seen for a severe sore throat 2 weeks ago. Physical examination reveals facial edema. The blood pressure is 180/110mmHg. A 24-hour urine collection demonstrates oliguria, and urinalysis shows hematuria. Which of the following best describes this patient's medical condition? A: IgA nephropathy (Berger disease) B: Membranous glomerulonephritis C: Minimal change nephritic syndrome D: Postinfectious glomerulonephritis E: Focal segmental glomerulosclerosis

D: Postinfectious glomerulonephritis Post-streptococcal glomerulonephritis (PSGN) is nephritic syndrome that arises after group A beta-hemolytic strep infection of skin (impetigo) or pharynx. This occurs w/ nephritogenic strains that carry M protein virulence factor. Nephritis-assoc. plasmin receptor (NAPLr) deposits in glomerulus & binds to plasmin, which proceeds to degrade ECM proteins. However, post-infectious glomerulonephritis can also occur after infection w/ non-strep organisms. PSGN presents 2-3 wks in children after infection w/ hematuria (cola-colored urine), oliguria, hypertension, & periorbital edema. Biopsy shows hypercellular, inflamed glomeruli under light microscopy w/ H&E stain. Immunofluorescence is granular due to immune complex deposition. These deposits contain IgG, IgM, & C3. EM shows sub-epithelial humps; that is, deposits start sub-endothelial & slowly work their way up to sub-epithelial before sloughing off & disappearing. Treatment is supportive, since children rarely progress to renal failure. However, adults that get PSGN can get renal failure.

[3DE] A 39-year-old paralyzed male patient who had been catheterized for the past 3 weeks presents with fever with chills and rigor and cloudy pale green urine for the past 3 days. You are consulted as the hospitalist for urgent antibiotic treatment. Which one of the following organisms would you cover in your prescription? A: Proteus mirabilis B: Klebsiella pneumoniae C: S. epidermidis D: Pseudomonas aeruginosa E: Citrobacter freundii

D: Pseudomonas aeruginosa Pseudomonas is non-spore-forming, Gram-negative bacteria. It is motile w/ flagella but is encapsulated. It is aerobic (though some grow under anaerobic conditions). It is also oxidase & catalase positive. It produces two distinct fluorescent pigments: water soluble yellow-green or yellow-brown Pyoverdin & blue Pyocyanin. It is able to survive in broad range of habitats, including mucus in paranasal sinuses in cystic fibrosis patients. Disruption of mucous membranes, use of urinary or IV catheters, & neutropenia predispose for Pseudomonas infection. It usually enters patient thru intraluminal route (thru catheter), which is often seen in males. PMNs are most important defense against invasive, systemic Pseudomonas infection.

[3DE] A female patient with symptoms of urinary tract infection had a urine culture taken. The laboratory reported it as 10^4 CFU/mL of mixed bacteria. Which of the following is the most clinically appropriate action to take? A: Do no further clinical workup B: Determine if fluorescent microscopy is available for the diagnosis of actinomycosis C: Consider primary treatment with vancomycin D: Repeat urine culture test E: Suggest a repeat antibiotic susceptibility test

D: Repeat urine culture test Microbiological diagnosis of UTIs requires collection of good urine sample or clean catch sample. This can be obtained via (1) mid-stream urine specimen, (2) urinary catheters, or (3) suprapubic aspiration of urine (any number of microorganisms in this scenario should be considered clinically significant). Culture 10 uL of urine on blood or MacConkey agar for 24-48 hrs at 37°C. In females, even 100 CFUs/mL of mid-stream urine should be considered significant, as it may indicate cystitis (females only). 100,000 CFUs or baceria/mL are required for lab diagnosis of UTIs; this may indicate pyelonephritis in females or asymptomatic bacteriuria in males. If urine culture grows multiple bacterial types, it should be considered contaminated & test should be repeated.

[3A] You are examining a 3-day-old newborn who was delivered vaginally without any complications. The newborn presents with vomiting, hyperventilation, lethargy, and seizures. Blood work demonstrates hyperammonemia, elevated glutamine, and decreased BUN. A CT scan demonstrates cerebral edema. Defects in which of the following enzymes would result in a clinical presentation similar to this infant? A. Phenylalanine hydroxylase B. Branched-chain ketoacid dehydrogenase C. Homogentisate oxidase D. Cystathionine synthase E. Carbamoyl phosphate synthetase I

E. Carbamoyl phosphate synthetase I Patient has CPSI deficiency. First step in amino acid metabolism is transamination, i.e. transferring amine group to alpha-ketoglutarate to form Glu. Gln synthetase then transfers amine group to Gln, since Gln has fewer negative charges & crosses cell membranes more easily than Glu. Once inside mitochondria of liver, Gln is converted back into Glu, which then re-forms alpha-ketoglutarate & ammonium. From there CPSI takes over. Thus, having elevated Gln means that reactions are backed up. However, since orotic acid is not present (see next card for details), it must be CPSI that is defective.

[3JK] A 22-year-old sexually active college student presents with dysuria and a penile discharge of 4 days duration. His roommate is an IM resident and treats him with ciprofloxacin for 5 days with little or no improvement of his symptoms. Which of the following is true regarding the most likely etiological agent of his illness? A. It has a cell wall made of peptidoglycan B. It has an ssRNA genome C. It has a cell wall with multiple fimbria D. It has a cell membrane but no cell wall E. It has 4 anterior flagella

E. It has 4 anterior flagella Patient has Trichomonas vaginalis, which causes strawberry cervix cervicitis. Symptoms include burning, itching, & malodorous yellow-green discharge. Vaginal fluid has pH 4.5+, unlike Candida. Lab diagnosis via wet mount shows motile trophozoites. Since it is STI, treatment w/ metro must be administered to both partners.

[3A] A 6-month-old boy is brought to the clinic by his mother because of lethargy, irritability, vomiting, and tremors. He has a positive medical history of drowsiness and poor feeding to both breast milk and formula. On physical examination, the patient appears somnolent, and a flapping tremor is observed. Papilledema is seen on fundoscopic examination. Studies reveal elevated orotic acid in blood and urine, in addition to decreased BUN. Which of the following enzymes is most likely to be deficient in this patient? A. Arginase B. Branched chain alpha-ketoacid dehydrogenase C. Carbamoyl phosphate synthetase I D. N-acetylglutamate synthetae E. Ornithine transcarbamylase

E. Ornithine transcarbamylase Patient has OTC deficiency. This is differentiated from CPSI deficiency by presence of orotic acid. Carbamoyl phosphate that builds up is shunted into pyrimidine synthesis pathway, which produces orotic acid. If there is CPSI deficiency, carbamoyl phosphate would not be produced, so lab findings would show hyperammonemia but no orotic acid abnormalities.

[3I] A 50-year-old woman complains of severe headaches and dizziness. The patient has a history of repeated urinary tract infections. The blood pressure is 180/110 mm Hg. Laboratory studies show elevated levels of BUN (38 mg/dL) and creatinine (2.8 mg/dL). A CT scan of the lower abdomen reveals small, irregularly shaped kidneys with deep coarse scars. A percutaneous renal biopsy is shown. The pathology of the renal disease in the patient is related to which of the following conditions? A. Amyloidosis B. Anti-glomerular basement membrane disease C. Chronic HBV infection D. Hypertension E. Repeated attacks of acute pyelonephritis

E. Repeated attacks of acute pyelonephritis Chronic pyelonephritis is caused by repeated acute pyelonephritis over many years. Grossly, kidneys have multiple cortical scars. Scars are often polar if due to reflux. Microscopically, interstitium is fibrosed due to chronic inflammation. While some tubules undergo atrophy, others undergo compensatory hypertrophy. Dilated tubules may contain eosin-staining proteinaceous material (colloid), giving it the appearance of thyroid follicles (thyroidization).

[3JK] A 17-year-old male presents with urethral discharge and dysuria. On examination, a mucoid discharge was observed. Urinalysis is positive for trace leukocyte esterase. Gram stain did not reveal any organisms. Which of the following statements best describes the most likely organism responsible for his illness? A. Contains RNA genome B. Grows extracellularly C. Contains a cell wall made of chitin D. Reticulate body is the infectious form E. Serovariants D-K are responsible for urethritis

E. Serovariants D-K are responsible for urethritis Patient has non-gonococcal urethritis caused by Chlamydia trachomatis, whose serovariants D-K are STIs. It is characterized by water discharge & can progress to PID in females if left untreated, leading to infertility & ectopic pregnancies. Mom can pass infection onto baby during delivery, presenting as delayed neonatal conjunctivitis (1-2 wks later) & pneumonia w/ staccato cough. Serovariants L1-L3 causes LGV, which presents w/ tender inguinal lymphadenopathy. One complication is Reiter syndrome, which involves reactive arthritis, uveitis, & urethritis (can't see, can't pee, can't climb a tree). Serovariants A-C cause blindness (leading cause worldwide), which is transmitted by hand-to-eye contact or fomites.

[3H] An 8-year-old boy presents with headaches, dizziness, and malaise approximately 2 weeks after a severe sore throat. His mother describes puffiness of his face and darkening of his urine. she also notes that her son is passing less urine and that he is becoming increasingly short of death. On physical examination, there is hypertension (190/130 mm Hg), and tachycardia. The urine is scanty and brownish red. Urinalysis shows 3+ proteinuria. Microscopic examination of the urine discloses numerous RBCs, as well as occasional granular and red cell casts. A renal biopsy is stained by direct immunofluorescence microscopy for complement C3. Which of the following best describes the pattern of immunofluorescence that would be observed in this renal biopsy? A. Dense deposits in glomerular crescents between epithelial cells B. Deposits limited to the mesangium C. Granular deposits along the perimesangial reflections D. Linear staining along the glomerular basement membranes E. Subepithelial and subendothelial deposits

E. Subepithelial and subendothelial deposits Patient has membranoproliferative glomerulonephritis (MPGN). MPGN can cause nephritic alone or nephritic & nephrotic syndromes together. Light microscopy w/ H&E stain show thick capillary membranes & tram-track appearance (cytoplasm of mesangial cells proliferate to cut deposits in two). Immunofluorescence is granular due to immune complex deposition. Primary MPGN is idiopathic, while second MPGN can be caused by infection or neoplasia. Primary MPGN itself is split into two; Type II is discussed on next card. Type I has subendothelial deposits & is assoc. w/ HBV & HCV; it is also more assoc. w/ tram tracks. It involves activation of classical & alternative complement pathways via unknown antigen. Immunofluorescence will stain for C3, IgG, C1q, & C4. Then there is secondary MPGN, which can be caused by infection or neoplasia.

[3DE] A 52-year-old woman comes to the physician because of a 2-day history of fever and right flank pain. She has been treated for multiple episodes of pyelonephritis during the past 3 years. Her temperature is 37.8°C. Physical examination shows left flank tenderness. Urinalysis shows 24-28 WBC/hpf with occasional lymphocytes and mononuclear cells with features of macrophages. Cultures of urine grow 110,000 colonies/mL of Proteus mirabilis. An X-ray of the abdomen shows a 3-cm mass in the lower pole of the right kidney. Gross examination of the mass after it has been resected shows that it is yellow, 3.2 cm in diameter, and centrally but not marginally necrotic. Histologic examination of the mass shows a predominance of epithelioid cells with partially clear and granular-to-foamy cytoplasm. Nuclei are eccentric, normochromic, symmetric, and without significant pleomorphism. Scattered lymphocytes and plasma cells are intermixed. Which of the following is the most likely diagnosis? A. Acute pyelonephritis B. Malacoplakia C. Renal cell carcinoma, clear cell type, intermediate grade D. Renal cell carcinoma, granular cell type E. Xanthogranulomatous pyelonephritis

E. Xanthogranulomatous pyelonephritis Xanthogranulomatous pyelonephritis is special complication of chronic pyelonephritis where there is obstruction by renal stones and/or chronic infection. Patients can have masive unilateral destruction of kidney due to granulomatous tissue formation. Its appearance can be confused w/ renal malignancy. It is more prevalent in middle-aged women w/ history of recurrent UTIs. It clinically presents w/ flank pain, fever, malaise, anorexia, & weight loss. Unilateral renal mass can be palpated on physical exam. Malakoplakia is another potential complication but can be distinguished from xanthogranulomatous pyelonephritis w/ Michaelis-Gutman bodies (basophilic inclusions) on histology.

[3JK] A 23-year-old sexually active female college student presents to her doctor with fever (102.4°F), dysuria, headache and right-hand pain, and joint swelling of 7 days duration. The doctor suggested aspiration of the joint for microbiology laboratory tests but she rejects his suggestion, due to invasive and painful nature of the test. Which one of the following tests would be the best alternative for establishing a diagnosis? A: Stool culture B: Lower vaginal swab culture C: Throat swab culture D: Skin swab from the area of swelling E: Blood Culture

E: Blood Culture Patient likely contracted STI that, undetected & left untreated, became systemic. Therefore, causative organism should be found in blood.

[3G] A 30-year-old man with a history of drug addiction presents with a 6-month history of progressive swelling in his ankles and abdomen. Urinalysis shows heavy proteinuria >4 g per 24 hours but no evidence of inflammatory cells or RBCs. Laboratory studies reveal hyperlipidemia and hypoalbuminemia. Serum creatinine level is normal. The blood test for ANCA is negative. The patient responds well to treatment with corticosteroids, but edema and proteinuria recur the following year. The steroid treatment is repeated with the same results. Upon the third recurrence of edema and proteinuria, the patient becomes steroid resistant. A renal biopsy shows that only certain parts of the glomerulus are affected. Which of the following is the most likely diagnosis for this patient's glomerulopathy? A: Acute glomerulonephritis B: Amyloidosis C: Crescentic glomerulonephritis D: Diffuse proliferative glomerulonephritis E: Focal segmental glomerulosclerosis

E: Focal segmental glomerulosclerosis Focal segmental glomerulosclerosis (FSGS) is most common cause of nephrotic syndrome in Hispanics & African Americans. Though usually idiopathic (primary), it may be assoc. w/ HIV, heroin use, sickle cell disease, & other random conditions (secondary). There is nonspecific binding of IgM & complement (C3, sometimes C1) in sclerotic lesions. Light microscopy w/ H&E stain shows focal & segmental sclerosis, i.e. dense pink deposition of collagen within glomerulus. This sclerosis only involves certain parts of glomerulus (segmental) & certain glomeruli within kidney (focal). EM shows effacement of foot processes (just like MCD). Like MCD, immunofluorescence is negative w/ no immune complex deposits. However, unlike MCD, FSGS doesn't respond to steroids & progresses to chronic renal failure.

[3G] A 12-year-old girl complains of swelling of her eyelids, abdomen, and ankles. She had been in good health until several months ago, when she gained some weight and noted swelling of her lower legs. An X-ray film of the chest shows bilateral pleural effusions, without evidence of lung disease. Urinalysis reveals heavy proteinuria (8 g per 24 hours) without hematuria. A percutaneous needle biopsy of the kidney discloses no morphologic abnormalities by light microscopy. Which of the following best describes this patient's medical condition? A: Amyloid nephropathy B: Focal segmental glomerulosclerosis C: Hereditary nephritis D: Membranous glomerulopathy E: Minimal change glomerulopathy

E: Minimal change glomerulopathy Minimal change disease (MCD) is most common cause of nephrotic syndrome in children. It also causes 10-15% of primary nephrotic syndromes in adults. It is usually idiopathic, though it may be assoc. w/ Hodgkin lymphoma (since Reed-Sternberg cells produce massive amts. of cytokines). That being said, cytokine production mediates damage to food processes, which are effaced/lost. Light microscopy w/ H&E stain show normal glomeruli (though lipids may be seen in PCT cells). However, EM shows effacement of foot processes. Immunofluorescence is negative w/ no immune complex deposits. There is selective proteinuria, i.e. loss of albumin but not Ig. It has excellent response to steroids, since damage is mediated by cytokines secreted by T cells.

[3BC] What is the sequence of events leading to osteitis fibrosa cystica? Chronic hypocalcemia, Increased osteoclastic activity, Hypovitaminosis D & hyperphosphatemia, Release of excess parathyroid hormone (hyperparathyroidism)

Hypovitaminosis D & hyperphosphatemia -> Chronic hypocalcemia -> Release of excess parathyroid hormone (hyperparathyroidism) -> Increased osteoclastic activity Osteitis fibrosa cystica is cystic bone lesions & accelerated bone turnover caused by hypovitaminosis D & hyperphosphatemia. Both of these cause chronic hypocalcemia, which stimulates production of PTH. PTH increases osteoclastic activity, leading to chronic bone resorption. There is subperiosteal bone resorption of phalanges, tooth sockets, & skull (salt & pepper appearance).

[3BC] Name a risk factor for acute pyelonephritis.

Indwelling catheter, urinary tract obstruction, diabetes mellitus or neurogenic bladder, pregnancy, ureteral calculi, bladder calculi, sickle cell disease, being female, vesicoureteral reflux, endocarditis, & bacteremia/sepsis Acute pyelonephritis is acute bacterial infection of kidneys, affecting tubules, interstitium, & renal pelvis. It affects women more than men due to their short urethras & urethral trauma during sexual intercourse. E. coli is most common causative pathogen, followed by Proteus, Klebsiella, & Enterobacter.

[3BC] What hormone is produced by the ischemic kidney in unilateral artery stenosis?

Renin Renal artery stenosis is often unilateral (3% of hypertension cases), in which case it is curable by surgery. This stenosis is often caused by increased production of renin from ischemic kidney. There is narrowing at origin of renal artery by atheromatous plaque, leading to fibromuscular dysplasia (thickening of intima, media, or adventitia). Affected kidney undergoes diffuse, ischemic atrophy. There will be bruit on auscultation.

[3BC] Name a symptom or laboratory finding associated with acute pyelonephritis.

Symptoms: spiking fevers, pain at costovertebral angle, flank pain, increased urinary frequency/urgency, dysuria Lab findings: WBC casts, pyuria, bacteriuria, hematuria Grossly, kidneys have grayish-white areas of inflammation & abscess formation. Histologically, there is patchy tubular & interstitial suppurative inflammation, including neutrophilic tubulitis & microabscesses in tubular lumens & interstitium. These may progress to larger destructive abscesses. Complications include chronic pyelonephritis, perinephric abscess, renal papillary necrosis, & septicemia w/ endotoxic shock (Gram-negative bacteria).