An alcoholic man drinks 10 beers per day and does not eat. Note that beer has very little solute (~2 meq/L of Na+; in contrast, Gatorade has 20 meq/L of Na+). He is brought to the ED because his sister (with whom he lives) notes that he is unresponsive except to deep pain. His renal function is normal. Predict his serum sodium concentration (reference interval: 135-145 meq/L) based upon the choices provided.

A 18 year old obese male presents with severe edema. Urinary protein is 8g/24 hr. A renal biopsy is performed. On light microscopy (LM), 20% of the glomeruli have the lesion illustrated in the image. Immunofluorescence (IF) showed some glomerular low intensity IgM staining but electron microscopy (EM) reveals no deposits. What is the best diagnosis? 

Which drug and major site of action is mismatched? 

A patient with hematuria has a family history of kidney disease. A renal biopsy reveals splitting of the glomerular basement membrane (GBM) on EM as the only pathologic finding. If the cause of this disorder is a defect in a type IV collagen (a COL4A3, COL4A4 or COL4A5 gene mutation), what other clinical finding is most likely of the options listed?

The renal response to acid loads is to increase net acid excretion. Which is the quantitatively largest component of net acid excretion?

How does the proximal tubule reabsorb the bulk of Na+ from the filtrate?

A 50 year old previously healthy male presents with lower extremity edema, hypoalbuminemia, hyperlipidemia and severe proteinuria, over 8 grams/24 hours.. A renal biopsy is performed. The light microscopic image is representative of the renal parenchyma observed in the biopsy. What is the BEST preliminary interpretation with the final diagnosis awaiting immunofluorescence and electron microscopy? 

Which one of the following pathophysiological mechanisms is involved in development of hepatorenal syndrome?

Which tubule segment reabsorbs the least amount of filtered sodium?

What is the most important and most frequent risk factor for the development of urothelial carcinomas in men?