Glomerular capsular herniation in focal glomerular sclerosis.

Renal biopsy from a patient with focal segmental sclerosing glomerulopathy (FSSG) and nephrotic syndrome showed localized rupture of Bowman's capsule with herniation of a glomerular loop into the adjacent periglomerular connective tissue. Another glomerulus contained similar changes. Glomerular capsular herniation may be frequent, but unrecognized, in FSSG and would explain many of the morphological features seen in both primary and secondary forms.

Reversible uranyl fluoride nephrotoxicity in the Long Evans rat.

Severity and duration of renal injury produced by low levels of uranyl fluoride (UO2F2) were examined in the rat. Rats received multiple ip injections of UO2F2 (cumulative dose: 0.66 or 1.32 mg U/kg body wt). Renal injury was characterized histologically by cellular and tubular necrosis of pars recta of proximal tubule (S2 and S3), with less severe cellular injury to thick ascending limb of loop of Henle and collecting tubule. Injury was evident when renal uranium levels were between 0.7 and 1.4 micrograms U/g wet kidney and was most severe when renal uranium burden was between 3.4 and 5.6 micrograms U/g. Repair of injury was rapid, with complete restoration within 35 days after exposure. Associated with injury were abnormalities in renal function, including impaired tubular reabsorption, proteinuria, and enzymuria, which appeared temporally related, to variable degrees, to progression of renal injury. Thus, reversible renal injury occurs in the rat at levels of uranium in kidney below the present Nuclear Regulatory Commission standard of 3 micrograms U/g kidney for renal injury in humans.

Proctitis and fatal septicemia caused by Plesiomonas shigelloides in a bisexual man.

A case of proctitis and fatal septicemia caused by Plesiomonas shigelloides in a 42-year-old bisexual male is reported. The medical history of the patient was significant for an aortic valve replacement 3 years before but was otherwise unremarkable. A serum specimen obtained at autopsy was negative for antibody to human immunodeficiency virus by Western blot (immunoblot) analysis. P. shigelloides isolated from blood was susceptible to all antibiotics tested, agglutinated in Shigella group D antiserum, possessed a greater than 100-megadalton plasmid, and was noninvasive in a HeLa cell invasion assay. The previous reports of Plesiomonas bacteremic infections are reviewed, and possible pathogenic mechanisms are discussed.

Increased plasma IgA, sIgA, and C3- and IgA-containing immune complexes with renal glomerular deposits in diabetic rats.

Male Sprague-Dawley rats were fasted 18 h and given streptozocin (STZ; 60 mg/kg body wt i.p.). The resultant diabetes mellitus, not treated with insulin, was associated with persistent manifoldly increased plasma IgA levels, as measured by single-radial immunodiffusion after reduction with dithiothreitol and alkylation with iodoacetamide. Also observed were concurrent increases in plasma levels of secretory IgA (sIgA) and of C3- and IgA-containing immune complexes (C3-IgA-CIC). After 104 days without insulin treatment, six of the diabetic rats were given daily injections of 2 U of insulin for 11 days. Insulin treatment was associated with a precipitous decrease in plasma levels of IgA, sIgA, and C3-IgA-CIC. Cessation of insulin treatment resulted in restoration of greatly increased levels of all three IgA-containing species. Histoimmunofluorescence studies of kidneys from untreated rats with diabetes of 192-324 days revealed glomerular capillary wall and mesangial deposits reacting strongly with anti-IgA (alpha-chain-specific) antiserum. Kidneys from two of the diabetic rats (324 days) were tested with anti-rat C3 and anti-rat secretory component (SC) antisera, and they reacted positively. Control kidneys from normal rats examined simultaneously were negative. The concurrent changes in plasma levels of three IgA-containing species in the untreated STZ-induced diabetic rat and the demonstration of abnormal immunoreactive IgA-containing renal glomerular deposits make this experiment an attractive model for studying the possible role of disturbed IgA metabolism in the pathogenesis of diabetic nephropathy.

Superior vena caval obstruction by lipomatous hypertrophy of the right atrium.

A structural abnormality was suspected when passage of a Swan-Ganz catheter was obstructed at the distal superior vena cava (SVC). At autopsy, lipomatous hypertrophy of the right atrium markedly narrowed the lumen at the SVC-right atrial junction.

Acute idiopathic tubulointerstitial nephritis: report of two cases and review of the literature.

Two patients who presented with severe renal failure and evidence of generalized proximal tubular dysfunction were found to have severe diffuse acute tubulointerstitial nephritis on renal biopsy. No etiology could be found in either case. Both patients had dramatic improvement in renal function following steroid therapy. In the first reported case of its kind, one patient relapsed when steroids were withdrawn, but improved again with reinstitution of steroid therapy. These cases, as well as others in the literature, show that steroids are effective and may be necessary to improve renal function in some patients with acute idiopathic tubulointerstitial nephritis. Evidence of proximal tubular dysfunction is a clue to the presence of this disorder.

The heart in Friedreich's ataxia. Report of a case.

Cardiac abnormalities are a characteristic feature of the autosomal, recessively inherited, spinocerebellar degeneration known as Friedreich's ataxia. We report the pathologic changes in the heart of a 27-year-old woman with Friedreich's ataxia, including ventricular subendocardial fibroelastosis, occlusion of the coronary sinus ostium, individual myofiber loss, myofiber disarray, and markedly enlarged, hyperchromatic myofiber nuclei. A common pathogenetic mechanism may underlie both cardiac and neurological abnormalities.

Effects of contrast media on renal function and subcellular morphology in the dog.

The effects of intravenous contrast media (CM) on renal excretory function and subcellular morphology are examined in this animal investigation. A decrease in GFR (12.0 +/- 1.6 vs. control 30.2 +/- 2.5 ml/min) was observed when renal function was evaluated by means of the artero-venous extraction method with Tc99m DTPA and the anticipated inverse relationship to urinary flow (Vml/min) noted. An artifactual increase in GFR (43.5 +/- 10.0 vs. control 39.1 +/- 3.8 ml/min) was observed using the timed urinary clearance of inulin. V(ml/min) increased four-fold (0.6 +/- 0.16 control vs. 2.7 +/- 0.7 ml/min; P less than .05) over the first five minutes after injection of CM. Urine osmolality initially approached isotonicity and then returned toward preinjection values. Osmolal clearance (Cosm) rose 2.5 times (1.4 +/- 0.3 control vs. 3.7 +/- 1.0 ml/min; P less than .05). The fractional excretion of both Na+ (FENa+) and K+ (FEK+) increased. A comparison of urinary osmolality vs. time after injection of CM confirms a nonspecific osmotic effect on tubular (and hence total urine) flow. The hemodynamic effects of CM on the kidney via the i.v. route reflect a predominant and nonspecific osmotically mediated vasodilation. No significant light or electron microscopic changes were observed. These findings suggest that the major renal physiologic actions of hypertonic CM are a nonspecific response to agent osmolality.

Renal involvement in Refsum's disease.

Renal hemodynamic and tubular functions were measured in a patient with Refsum's disease before and after 12 weeks of twice-weekly plasmaphereses. Percutaneous renal biopsy was performed before initiation of plasmapheresis. These studies were performed to (1) define the nature of the renal lesions and the effects of phytanic acid accumulation on renal functions, and (2) assess the effects of lowering the plasma phytanic acid level on renal functions. The patient, a 39 year old woman, had lipiduria, glycosuria, cylindruria, minimal proteinuria and mild azotemia initially. Renal lesions consist of extensive vacuolization and mitochondrial changes of the tubular epithelial cells, vacuolization of the visceral epithelial cells of the glomeruli, and slight to moderate mesangial sclerosis. The impaired renal hemodynamic function and various tubular functions improved following plasmaphereses associated with reduction of plasma phytanic acid. Over-all clinical improvement was also evident.

Membranous glomerulonephritis: clinical significance of glomerular hypercellularity and parietal epithelial abnormalities.

Quantitative and semi-quantitative morphological analysis of 41 cases of idiopathic membranous glomerulonephritis revealed glomerular hypercellularity in 24 cases and abnormal parietal epithelium in 25 cases. Abnormal parietal epithelium included crescents and prominent parietal epithelium (at least ten enlarged cells with round or ovoid nuclei lining Bowman's capsule of two or more glomeruli per biopsy). The clinical course (mean follow-up = 5.1 years) was correlated with biopsy findings. 8 to 17 patients with normocellular glomeruli, but only 3 of 24 patients with hypercellular glomeruli achieved complete clinical remission. 10 of 16 patients with normal parietal epithelium, but only 1 of 25 patients with abnormal parietal epithelium achieved complete remission. Of 9 urine patients, all but 1 had abnormal parietal epithelium in their biopsies. Glomerular cellularity and parietal epithelium may be useful prognostic indices in idiopathic membranous glomerulonephritis.

Rapidly progressive glomerulonephritis and possible amyloidosis.

In two patients with crescentic glomerulonephritis, coexistence of amyloidosis was considered. In one, electron microscopy failed to show amyloid fibrils despite positive staining and history suggestive of amyloidosis. Glomeruli of the second patient contained amyloid-like fibrils in absence of clinical amyloidosis and with only equivocal or negative stains.

Glomerular lesions in patients with late-onset cystinosis with massive proteinuria.

3 siblings--2 brothers aged 18 and 13 years, and 1 sister, aged 11 years--with adolescent or late-onset cystinosis presented with massive proteinuria. At the time their glomerular filtration rate was normal or only modestly diminished. Though glomerular injury was evident, renal tubular functional abnormalities were also present. Renal biopsy revealed histopathologic features typical of the nephropathic form of cystinosis with the Fanconi syndrome: polykaryocytosis, varying degrees of glomerular sclerosis, thickening and reduplication of basement membrane, fused foot processes, dilated tubules with altered epithelial cell features, and interstitial fibrosis. Fine granular deposits of C3 and IgM are irregularly distributed in the glomeruli, findings which have not been described in cystinosis. These deposits are possibly immune complexes being deposited in the glomeruli unrelated to the cystine-storage disease or they may represent a localized activation of the complement system induced by the glomerular injury of cystinosis.

Bilateral cervical transplantation of canine kidneys for study of canine renal preservation.

Bilateral cervical autotransplantation of canine kidneys is described for comparative study of renal preservation techniques. Data are obtained from kidneys preserved by (1) initial intravascular flushing with modified Collins' C3 solution (Ursol) followed by cold storage, and (2) pulsatile perfusion (MOX 100). Preharvest condition of the donor and ischemia times are identical, thus eliminating major sources of potential data variation. Renal function studies performed at periodic intervals demonstrated better initial function for machine preservation but no difference after one to two-month period.