Simultaneous postinfectious glomerulonephritis and thrombotic microangiopathy: a renal biopsy study

The simultaneous occurrence of postinfectious glomerulonephritis and thrombotic microangiopathy is described in renal biopsy specimens from three patients. Each presented with diverse manifestations: two patients had hypertension and acute renal failure, and in the third, it was unclear whether an atypical postinfectious glomerulonephritis or an atypical thrombotic microangiopathy was present. All biopsy specimens disclosed a combination of irregular granular complement and immunoglobulin deposits in mesangial regions and capillary walls along with fibrin in a linear pattern in capillary walls by immunofluorescence. Light microscopy showed diffuse hypercellularity in some glomeruli, endothelial cell swelling, luminal thrombi and mesangiolysis in others, and both types of changes in a third group. Ultrastructurally, subepithelial hump-shaped deposits coexisted with widened and lucent subendothelial spaces. Possible pathogenic mechanisms for the synchronous lesions include endothelial injury, perhaps triggered by infection and immunologic tissue damage.

Effects of magnesium depletion on myocardial high-energy phosphates and contractility

The effect of prolonged magnesium depletion on contractility, phosphorylating activity, and organic phosphates of spontaneously beating isolated rat atria was studied. Rats were fed a Mg-deficient diet for 8 weeks, during which serum Mg fell from 1.85 +/- 0.02 to 0.52 +/- 0.10 mg/dl. Atrial contractile activity was measured for 1 hr and at the end of this period tissue samples were taken for the determination of the phosphorylated intermediates. Mg depletion was associated with (a) reduced intracellular inorganic phosphorus and adenine nucleotides; (b) elevated creatine phosphate; (c) reduction in contractile force (CF) with no change in atrial beat rate (BR). There were no significant differences in the activities of creatine phosphokinase and adenylate kinase in control and Mg-depleted rat atrial homogenates determined in the presence of 5 mM MgCl2. Addition of various concentrations of MgCl2 to the medium resulted in an immediate reduction in both CF and BR of normal and Mg-depleted rat atria. Intraperitoneal administration of MgCl2 to Mg-depleted rats resulted in complete recovery of CF of isolated atria. This improvement in CF occurred without changes in the levels of inorganic phosphate and adenine nucleotides. The reduced intracellular level of high-energy phosphate or inorganic phosphate cannot therefore be responsible for the impaired contractility seen in Mg-depleted heart muscle. On the other hand, the fact that the creatine phosphate levels were higher in magnesium depletion suggests that myofibrillar utilization of creatine phosphate is more impaired than production, analogous to phenomena seen in postanoxic recovery.

Sexual dysfunction associated with hyperprolactinemia in males and females undergoing hemodialysis

Fifty-nine uremic patients (38 males and 21 females) maintained on chronic hemodialysis (CHD) served as the subjects in a study of the relationship between sexual dysfunction and serum prolactin levels (SPL). Sexual desire and activity were evaluated by a self-report sexual function rating scale (SFRS). About half the population of this study reported sexual dysfunction. Males and females reporting disturbance of sexual function had significantly higher SPL than those with normal sexual function. Bromocriptine treatment in five hyperprolactinemic patients reduced SPL to normal range and improved the sexual function. Association between sexual dysfunction and hyperprolactinemia in uremic patients is suggested.

Interstitial nephritis with acute renal failure after erythromycin

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Elevated thrombocyte calcium content in uremia and its correction by 1 alpha(OH) vitamin D treatment

Intracellular calcium plays an important role in the regulation of platelet function. It has also been demonstrated that platelet functions are impaired in uremia. A rise in intracellular calcium has been shown in several tissues and has been held responsible for the impaired function of several organs seen in uremia. This study was undertaken to evaluate whether the calcium (Ca) content of thrombocytes is elevated in uremia and, if so whether treatment with an active vitamin D metabolite might correct this abnormality. In 10 patients on chronic hemodialysis, platelet Ca content was determined by a technique utilizing consecutive freezing and thawing of platelet-rich plasma. The platelet Ca content of uremic patients was found to be markedly higher (20.86 +/- 0.9 ng/200,00 platelets, p less than 0.01) than that of a group of 20 normals (12.8 +/- 1.2 ng/200,000 platelets). 1 months after treatment with 1 alpha (OH) vitamin D at a dosage of 0.5-2.5 microgram/day, the platelet Ca content of the dialysis patients decreased to 14.99 +/- 2.14 ng/200,000 platelets (p less than 0.05). The data show that in dialysis patients the platelet Ca content is markedly elevated in comparison with that of normals, and the treatment with 1 alpha (OH) vitamin D may significantly reverse this abnormality. It is suggested that elevated Ca content may play a role in the pathogenesis of uremic platelet dysfunction, and that 1 alpha (OH) vitamin D administration may be of benefit in correcting this disorder.

Pulmonary function abnormalities in Sjögren's syndrome and the sicca complex

The frequency of pulmonary involvement in a group of 20 patients with Sjögren's syndrome or the sicca complex was evaluated with pulmonary function studies. In 12 patients pulmonary functional abnormalities were demonstrated. The most common abnormality was airway obstruction. Nine out of 13 patients with the limited variant of the disease (sicca complex) and three out of seven patients with the complete syndrome had abnormal pulmonary function.

Hyperprolactinemia: a possible cause of sexual impotence in male patients undergoing chronic hemodialysis

Hyperprolactinemia is known to cause impotence in patients with normal renal function and elevated serum prolactin levels (SPLs) have also been reported in uremia. This study was undertaken to examine a possible role of elevated SPLs in the impotence of male patients undergoing chronic hemodialysis (CHD). SPLs in 16 male patients undergoing CHD were evaluated using a homologous double-antibody radioimmunoassay with prolactin isohormones isolated from human amniotic fluid. Patients were divided in 2 groups: 6 patients were sexually impotent and 10 sexually potent. Patients with emotional disturbances or marital conflicts known to cause impotence were excluded from the study. The SPLs of the impotent patients were found to be significantly elevated in comparison to the levels of the potent patients (136.7 +/- 28.2 vs. 37.3 +/- 2.7 ng/ml, p less than 0.001). Furthermore, in 2 patients who were successfully treated with bromocriptine to suppress hyperprolactinemia, recovery of sexual potency was noted. Thus, sexual impotence in male CHD patients seems to be associated with marked hyperprolactinemia. It is suggested that elevated SPLs may be an important cause of impotence among CHD patients.

Lupus nephritis. Electron-dense and immunofluorescent deposits and their correlation with proteinuria and renal function

Thirteen patients who had systemic lupus erythematosus were studied for the purpose of correlating the findings of light and electron microscopy and immunofluorescent studies with renal function and the presence of proteinuria. Subendothelial deposits of electron-dense material were found in all biopsy specimens, whereas mesangial and subepithelial deposits were not always present. IgG and beta 1c were constant findings in the glomerular membrane. The seven patients who were found to have extensive subendothelial deposits had moderate to massive proteinuria, and four of these patients had decreases in renal function. Most of the patients who had smaller subendothelial deposits had slight or insignificant proteinuria. Massive subendothelial deposits were mainly found in specimens showing histologic evidence of active lesions. Correlation was also found between proteinuria and the overall amount of deposits and their distribution. The prognosis was dependent on the severity of subendothelial deposits, the overall amount of deposits, and the morphologic form of lupus nephropathy.

Systemic lupus erythematosus associated with mixed cryoglobulinaemia and circulating anticoagulant

We describe a 30-year-old woman with systemic lupus erythematosus (SLE), in whom the only evidence of the disease, during the 10 years before diagnosis was established, was an accelerated erythrocyte sedimentation rate and a positive Wassermann test. Her disease was characterized by the presence of an anticoagulant without indication of bleeding, mixed cryoglobulinaemia, steroid-resistant renal damage, and persistent false-positive tests for syphilis. The relationship between these results and the presence of anticoagulant, mixed cryoglobulinaemia and renal damage in patients with SLE are discussed.