A 68-year old previously healthy male presents with a several week history of weight loss and malaise. Laboratory studies reveal increased serum creatinine and markedly increased urinary protein (14 grams/24hours). Monoclonal light chains are detected in the urine. A renal biopsy is performed (see H&E image). IF and EM are being performed. What would be the next best procedure to perform on the biopsy section to make the diagnosis? 

Anatomically where do medications in clinical use that treat hyperphosphatemia have their effect to reduce the patient’s phosphate levels in their blood?

Electron microscopy of a glomerulus from the kidney biopsy of a 12 year old female patient with the nephritic syndrome is displayed. Which other clinical finding would most likely be expected in this patient? 

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 75 y/o man with the recent diagnosis of acute decompensated heart failure reports little to no urine output. His bladder is empty on ultrasound. What is the most likely cause of his oliguria? 

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? 

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?

Which drug and major site of action is mismatched? 

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?