Acute aortic insufficiency associated with Wegener granulomatosis.

Cardiac valvular involvement associated with Wegener granulomatosis is uncommon. We describe a 17-year-old male adolescent who sought medical attention because of a sore throat, arthralgias, low-grade fever, and fatigue of 3 weeks' duration. A rash was noted on his elbows, hands, and ankles; subsequently, a crusting lesion was noted in his internal nares, and infiltrates were detected on chest radiography. Blood cultures were negative for pathogens. An echocardiogram disclosed mild left ventricular enlargement with grade 2 aortic insufficiency, and Wegener granulomatosis was diagnosed based on an antineutrophil cytoplasmic antibody titer of 1:512. When blood cultures are negative for aortic valve endocarditis, a high index of clinical suspicion and antineutrophil cytoplasmic antibody testing may lead to the diagnosis of acute aortic insufficiency associated with Wegener granulomatosis.

Cryptococcal pyelonephritis and disseminated cryptococcosis in a renal transplant recipient.

Symptomatic cryptococcal pyelonephritis, meningitis, and disseminated cryptococcosis are described in a renal cadaver transplant recipient who subsequently died of Klebsiella pneumoniae sepsis. The presence of cryptococcuria and a subsequent positive CSF India ink stain led to the initial diagnosis of disseminated cryptococcosis. Therapy with 0.511 g of amphotericin B and 112.5 g of flucytosine for four weeks did not eradicate Cryptococcus from the kidney and was associated with hepatotoxicity. The importance of urinary examination and culture for C neoformans is emphasized. Cryptococcal pyelonephritis should be considered in the differential diagnosis of allograft rejection in the renal transplant patient.

Mechanism of activation of renal Na+-K+-ATPase in the rat: effects of potassium loading.

The mechanism of activation of Na+-K+-ATPase after chronic potassium loading has been investigated in the rat kidney. Potassium loading stimulated the specific activity of Na+-K+-ATPase in the cortex and medulla of the kidney. This effect was not accompanied by a generalized increase in the cellular contents of RNA and proteins and could not be accounted for by an effect of potassium loading on renal growth. Enzyme induction does not appear to be mediated by changes in the endogenous levels of glucocorticoid or thyroid hormones. Evidence obtained from investigation of the partial reactions (Pi intermediate, ouabain-sensitive pNPPase) of the Na+-K+-ATPase enzymatic reaction is consistent with the interpretation that chronic potassium loading in the rat increases the number of enzyme units (Na+ pumps) in the cortex of the kidney. Analysis of the kinetic parameters (Km, K1/2, Vmax, Hill coefficients) of the enzymatic reaction indicates that K+ loading has little or no effect on the kinetic properties (affinity, cooperativity) of the stimulated transport enzyme.