Acute glomerulonephritis: three episodes demonstrated by light and electron microscopy, and immunofluorescence studies--a case report.

The patient, a white boy, had 3 episodes of recurrent acute glomerulonephritis at 7, 12 and 17 years of age. The episodes were preceded by impetigo and there was a good clinical and laboratorial recovery after all of them. Renal biopsies were performed during the acute episodes, and the light, immunofluorescence and electron microscopy studies showed only lesions typical of acute glomerulonephritis. Four months after the third episode another renal biopsy demonstrated only lesions compatible with the subsiding stages of acute glomerulonephritis.

Atrial natriuretic factor and generalized edema in rats.

The natriuretic action of the atrial natriuretic factor (ANF) was studied in massively proteinuric, anti-natriuretic and edematous nephrotic rats with moderate impairment of renal function. Animals were distributed among four groups: NA----NR, NV----NR, NeA----NR and NA----NeR, where normal atrial (NA) or normal ventricular (NV) or "nephrotic" atrial (NeA) extracts were injected (----) into normal rats (NR) or nephrotic rats (NeR). Control (C) clearance measurements were made before iv injection of the extracts and at four 15-min intervals thereafter (E). Mean arterial pressure and glomerular filtration rate did not change consistently in all four groups from the C to the E period. However, during the first 15-min period after extract injection, statistically significant fractional natriuretic peaks of 332, 361 and 662% of preinjection control values were demonstrable for the NA----NR, NeA----NR and NA----NeR groups, respectively, but not for NV----NR. Following the natriuretic peak, natriuresis returned to control values for NA----NR, but remained above control levels for the NeA----NR and NA----NeR groups. We conclude that, since both the atrial extract from nephrotic rats injected into normal rats and the atrial extract from normal rats injected into nephrotic rats elicited marked natriuresis, the anti-natriuretic edematous condition observed in nephrotic animals cannot be attributed either to the absence of ANF in their atria or to the unresponsiveness of their kidneys to ANF.

Distal nephron sodium handling by normal, nephrotic, pyelonephritic and partially nephrectomized rats.

The renal tubular handling of sodium was evaluated in 10 normal (N), 9 edematous nephrotoxic serum nephrotic (Ne), 9 pyelonephritic (Py) and 12 partially nephrectomized (Nx) Wistar rats during maximal free-water clearance induced by intravenous infusion of hypotonic sodium chloride solutions. Fractional deliveries of sodium to distal nephron [(CH2O + CNa)/GFR%] were similar (P greater than 0.05) in N (23.2 +/- 0.69%), Ne (24.3 +/- 1.30%) and Nx (26.9 +/- 2.6%) rats. However, the fractional distal sodium reabsorption [CH2O/(CH2O + CNa)%] was significantly higher (P less than 0.05) in Ne (76.8 +/- 1.80%) and lower (P less than 0.05) in Nx (33.3 +/- 3.1%) rats when compared to normal rats (50.3 +/- 1.80%). Py rats exhibited a higher fractional delivery of sodium to distal nephron (33.5 +/- 3.4%) and a lower fractional distal sodium reabsorption (35.9 +/- 5.9%) when compared to normal rats (P less than 0.05). These data suggest that the distal nephron, by altering sodium reabsorption, contributes to the maintenance of sodium balance in Nx rats, whereas in Ne rats the distal nephron generates a positive sodium balance and edema. At very low glomerular filtration rates (GFR), as is the case for Py rats, sodium balance is maintained both by the proximal and distal portions of the nephron.

Lack of evidence for hepatic control of renal sodium excretion in rats.

Three experimental protocols were used: a) normal and partially hepatectomized rats were expanded with isotonic saline; b) normal rats were expanded with isotonic saline; b) normal rats were infused with hypertonic saline (5%), either by the femoral or portal vein and c) hypertonic saline was sequentially and alternatively infused into normal rats via portal and femoral veins. All the experiments were made under anesthesia. Inulin clearance and absolute and fractional urinary sodium and potassium excretion were measured. Multiple analysis of variance was made to compare normal and partially hepatectomized rats, as well as portal and femoral infusions made either in the same or in different animals. In none of these experiments it was possible to demonstrate an effect of the liver in enhancing the natriuresis induced by saline infusions.

Feocromocitoma maligno: importância do acompanhamento cintilográfico com I131-meta iodo benzilguanidina (I131-MIBG) / Malignant pheochromocytoma: the importance of a scintigraphic investigation with I131 meta iodo benzylguanidine (MIBG I131)

Os autores apresentam um caso de feocromocitoma rastreado com metaiodobenzilguanidina marcada com 131I (MIBG-131I). Esta metodologia identifica a lesäo primitiva, sua recorrência e sua metastatizaçäo. Säo apontadas as vantagens do ensaio pela sua especificidade, sensibilidade e inoqüidade, oferecendo informaçöes ímpares de natureza morfofuncional no diagnóstico e acompanhamento evolutivo dessa doença