Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review concerns the present state of accomplishments in the study of SEM of human and experimental renal disease. Critical techniques of specimen preparation reviewed include perfusion fixation, razor tissue sectioning, alcohol cryofracture, microtome sectioning of paraffin or styrene embedded tissue, ultraplaning with glass knives of hard carbowax embedded tissues and glomerular isolation. Gold-palladium coating and heavy metal impregnation with osmium, uranium, and silver are discussed. A compendium of SEM observations of human glomerular, vascular and tubular disease is presented. Techniques for SEM of experimental renal disease are reviewed. These include latex vascular injection, freeze drying, x-ray microanalysis and use of backscattered electron imaging. Experimental models previously investigated by SEM are puromycin aminonucleoside nephrosis, daunomycin nephrosis, and N,N1-Diacetylbenzedine glomerulopathy, nephrotoxic serum nephritis, and protamine perfusion glomerulopathy. Reviewed are acute tubular necrosis caused either by angiotensin, hypotension, norepinephrine, glycerol, mercury, and unilateral renal artery occlusion, also potassium depletion nephropathy, alloxan diabetes and diphenylamine-induced polycystic disease.
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PMID:SEM of human and experimental renal disease. 52 33

1. To elucidate the mechanisms by which cyclosporin A diminishes proteinuria, we studied 20 patients with severe nephrotic syndrome. Biopsy-established pathologies included minimal change disease (n = 5), membranous glomerulopathy (n = 6), membranoproliferative glomerulonephritis (n = 5) and focal segmental glomerulosclerosis (n = 4). Before, at the end of a 90 day course of cyclosporin A, and finally 1 month after stopping cyclosporin A we determined 24 h protein excretion. Measurements of glomerular filtration rate, effective renal plasma flow, fractional clearance rates of albumin and immunoglobulins with different charges and the transglomerular sieving of uncharged dextrans of broad size distribution were used to study the effects of cyclosporin A on renal perfusion and the glomerular filtration barrier. The findings were analysed with a theoretical model of solute transport. 2. Among the different forms of glomerulopathy the response to low-dose cyclosporin A (trough levels 32.0-36.9 ng/ml) varied markedly. In minimal change disease, proteinuria decreased from 9.5 +/- 3.1 to 1.3 +/- 0.2 g/24 h (mean +/- SEM, P less than 0.01). This response was due to restoration of the charge selectivity of the glomerular barrier. The depressed value of the glomerular permeability coefficient also returned to normal. Glomerular filtration rate, effective renal plasma flow and renal vascular resistance did not change. Proteinuria returned after stopping cyclosporin A, although it did not reach pretreatment levels. In membranous glomerulopathy, proteinuria fell from 9.9 +/- 1.5 to 1.8 +/- 0.3 g/24 h (P less than 0.01). Changes in protein excretion and dextran sieving were compatible with an increase in glomerular permselectivity and a decrease in filtrate flow through the 'shunt' pathway. Glomerular filtration rate was maintained, although effective renal plasma flow fell significantly. Proteinuria relapsed after stopping cyclosporin A. In membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis proteinuria did not respond to cyclosporin A, although cyclosporin A exerted important haemodynamic effects. 3. In minimal change disease and membranous glomerulopathy cyclosporin A exerts its beneficial effects on proteinuria through changes in the properties of the glomerular barrier, resulting in increased charge and size selectivity, respectively.
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PMID:Effects of cyclosporin A on glomerular barrier function in the nephrotic syndrome. 132 May 44

We studied the effects of symptomatic, antiproteinuric treatment with NSAID's (n = 28) and ACE-inhibitors (n = 14) in patients with proteinuria due to idiopathic membranous glomerulopathy (MGP). These two treatment groups were compared with a group of patients who did not receive antiproteinuric medication (n = 14). Urinary protein loss was effectively lowered by NSAID and ACE inhibitor therapy from 9.5 +/- 1.0 to 4.5 +/- 0.5 g/day (mean +/- SEM) and from 9.8 +/- 1.4 to 3.9 +/- 0.7 g/day respectively, whereas the control group showed a slight fall in proteinuria from 6.9 +/- 0.8 to 5.5 +/- 0.8 g/day. As a result of this treatment hypoalbuminaemia and hypercholesterolaemia improved significantly: serum albumin rose in the NSAID group from 25.4 +/- 1.2 to 29.0 +/- 1.0, and in the ACEi group from 29.9 +/- 1.8 to 32.7 +/- 1.2 g/l (control group from 27.4 +/- 1.6 to 27.8 +/- 1.6 g/l, while cholesterol was lowered in the NSAID group from 8.5 +/- 0.5 to 7.5 +/- 0.4 and in the ACEi group from 8.7 +/- 0.5 to 7.6 +/- 0.4 mmol/l (control group from 9.7 +/- 1.1 to 8.5 +/- 1.0 mmol/l). The antiproteinuric effect of both drugs was well maintained during an 18-month follow-up. Progression towards end-stage renal failure was observed especially in patients with impaired renal function at entry. Remission of proteinuria occurred particularly in patients with lower baseline values of proteinuria, irrespective of the treatment modality.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antiproteinuric drugs in patients with idiopathic membranous glomerulopathy. 133 89

Rats with streptozotocin-induced chronic diabetes mellitus develop a glomerulopathy functionally manifested by proteinuria. The ability of the glomerular capillary wall to retard filtration of macromolecules was examined in 5 chronically diabetic Munich-Wistar rats exhibiting excessive proteinuria (39 +/- 7 mg/24 h, mean +/- SEM) and 5 age-matched normal Munich-Wistar rats without increased proteinuria (4.7 +/- 0.2 mg/24 h). Urinary albumin excretion was not increased in the diabetic rats (2.0 +/- 0.6 mg/24 h vs 1.6 +/- 0.3 mg/24 h) suggesting that the normal net electronegative charge of the glomerular capillary wall was not altered. Fractional clearances of macromolecular neutral dextrans were similar in diabetic and normal rats throughout a wide range of molecular size (18-42 A). Glomerular filtration rate was the same in the two groups of rats (2.77 +/- 0.16 ml/min in diabetics and 2.72 +/- 0.11 ml/min in normals) suggesting that renal haemodynamic factors did not influence fractional clearances of neutral dextrans in diabetic rats. We conclude that the proteinuria exhibited by these chronically diabetic rats is not attributable to alterations of size-selective properties of the glomerular capillary wall, such as increases in the size or the number of pores.
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PMID:Glomerular selective permeability to macromolecular neutral dextrans in experimental diabetes. 616 92

The significance of isolated proteinuria in pediatric patients is uncertain. Therefore, we retrospectively studied all children evaluated for this urinary abnormality during the 6-year period from 1986 to 1992. Thirty-one patients (19 males), age 2 to 20 years, were identified as having isolated proteinuria that had persisted for a mean interval of 9.6 +/- 1.9 (SEM) months. The diagnosis was based upon the presence of a urine protein:creatinine ratio > 0.2 in an early-morning specimen. None of the patients had hematuria, edema, or azotemia. Seventeen children underwent a renal biopsy. There was no difference between the patients who were biopsied and those who were not with respect to age, magnitude of proteinuria, glomerular filtration rate (GFR), or serum albumin and cholesterol concentrations. The renal histopathology revealed focal segmental glomerulosclerosis (FSGS) (n = 8), membranous nephropathy (n = 1), postinfectious nephritis (n = 2), focal global glomerulosclerosis (FGGS) (n = 1), and normal kidney tissue (n = 5). Twelve of the patients who did not undergo a kidney biopsy and four of the five children with a normal renal biopsy were followed for at least 12 months; there was complete resolution of the proteinuria in 11 (69%) of these patients. The level of proteinuria did not predict the presence or absence of important kidney disease. However, if isolated proteinuria persists for more than 1 year, it is then unlikely to spontaneously remit and a renal biopsy is indicated to clarify the nature of any underlying glomerulopathy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Isolated proteinuria in children. Natural history and indications for renal biopsy. 795 87