Evolving trends in the etiopathogenesis of acute renal failure.

Research during the last few years has uncovered the mechanisms responsible for acute renal failure. During the initiation phase of acute tubular necrosis sublethal injury, apoptosis or necrosis of the tubular epithelium, hemodynamic alterations, tubule obstruction and back leakage occur. Hypofiltration persists due to imbalance between endothelins and endothelium derived nitric oxide, medullary congestion and tubuloglomerular feedback. Recovery is characterised by tubular epithelium regeneration. A greater understanding of the pathogenesis of acute renal failure will allow better management of such cases.

Fulminant cerebral infarction in a patient with nephrotic syndrome.

Fulminant cerebral infarction secondary to arterial thrombosis in adults with nephrotic syndrome is rare. We report a 42 year old male with fulminant right anterior cerebral and middle cerebral artery infarction. Minimal change disease of the kidney was documented by renal biopsy. The possible pathogenesis is discussed and pertinent literature reviewed.

Erythrocyte morphology under phase contrast microscopy in haematuria.

Fresh urine samples from twenty patients with macroscopic haematuria were examined by phase contrast microscopy to study the erythrocyte morphology. Other appropriate investigation like - renal biopsy in suspected glomerulonephritis and appropriate urological investigations in other cases to prove the site of origin of erythrocyte were done in all cases. Changes in erythrocyte morphology were observed in all the 12 patients with histological evidence of proliferative glomerulonephritis. These changes included extrusion of cell cytoplasm (39.5%), 'Doughnut' cell (26.5%) budding cell (15%) and cell membrane rupture with loss of cytoplasm (15%). Overall 83.3% of the erythrocytes showed some morphologic change or the other. In 8 patients where bleeding was into the pelvicalyceal system, ureter or bladder, 95% of RBCs showed no discernible morphologic change. It is concluded that the morphological changes in the erythrocyte identified under the phase contrast microscope can help to differentiate between glomerular and non glomerular causes of bleeding.

Paraquat poisoning with acute renal failure--a case report.

Paraquat poisoning is relatively rare and is associated with mortality varying from 35 to 50%. A patient who consumed paraquat developed features of non-oliguric acute renal failure and recovered following haemodialysis. Renal biopsy done during the early recovery phase showed features of acute tubulo-interstitial nephritis with no disruption of tubular basement membrane. On recovery the patient had no evidence of proximal renal tubular dysfunction.