Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We measured plasma fibronectin levels by a rocket immunoelectrophoresis in rats with chronic serum sickness induced by repeated injections of ovalbumin and in rats with epithelial nephropathy induced by a single injection of adriamycin. In the early phases of the immune model, rats presented granular deposits of IgG in the mesangial area with no or descrete proteinuria (less than 40 mg/24 h). Fibronectin levels in that group were significantly higher (450 +/- 90 micrograms/mL) than in normal rats of the same age (350 +/- 46; p less than 0.01). When animals presented IgG deposits in the capillary wall, an important nephrotic syndrome developed in most of them. Fibronectin levels then increased very significantly (863 +/- 153 micrograms/mL; p less than 0.0005). In the model of adriamycin nephropathy, fibronectin significantly increased (580 +/- 110 micrograms/mL; p less than 0.0005) from the first week, when proteinuria was in a range 40-60 mg/24 h. However, the levels were higher (860 +/- 175 micrograms/mL; p less than 0.0005) when a complete nephrotic syndrome developed. At this time, plasma fibronectin levels correlated directly in both models with the degree of proteinuria and inversely with the total serum protein concentration. Our results show that plasma fibronectin levels increased very early in animals with immune and toxic damage of the kidney. The highest elevated values found thereafter, when a full nephrotic syndrome was present, suggest an increased synthetic rate of that glycoprotein linked to that situation.
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PMID:Elevated plasma fibronectin levels in rats with immune and toxic glomerular diseases. 210 Aug 26

Twenty-three nonobese KK mice with abnormal tolerance to glucose, hyperinsulinemia with insulin resistance and human diabetic-like nephropathy were treated with either saline (12 mice) or glipizide, an oral hypoglycemic compound, 1 mg/kg, (11 mice) from 120 to 360 days of age. These mice develop significant increases in mesangial volume and matrix by 40 days of age. Oral glucose tolerance (OGTT), glucosyltransferase and N-acetyl-beta-glucosaminidase (enzymes involved in synthesis and degradation of kidney glycoproteins, respectively) in the kidney and serum, 24-hr proteinuria, and light microscopy studies of the kidney were performed. Glipizide-treated mice improved their OGTT. There was no difference in body weight; however, a 16% decrease (P less than 0.05) in kidney weight was observed in glipizide-treated mice. Both enzymes were significantly increased in the kidneys of mice treated with glipizide. No difference in serum enzymes was found between the two groups of mice. About 58% of the saline-treated mice had moderate glomerulosclerosis. By contrast, only 27% of glipizide-treated mice had moderate glomerulosclerosis. Also, a significant decrease in proteinuria was found in glipizide-treated mice. These data suggest that glipizide improves glucose metabolism, decreases kidney size, prevents kidney glycoprotein and mesangial matrix accumulation, and reduces proteinuria in type II diabetic KK mice. This indicates that good glycemic control prevents further progression of established diabetic nephropathy in animals.
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PMID:Diabetic microangiopathy in KK mice. VI. Effect of glycemic control on renal glycoprotein metabolism and established glomerulosclerosis. 214 55

Laminin, a noncollagenous glycoprotein, has been identified as a component of basement membranes. It serves as a multifunctional adhesion protein. Immunoreactive laminin levels determined by a radioimmunoassay were found to increase throughout gestation, obviously due to growth of the placenta, an organ rich in basement membranes. In this study of 92 pregnant women in the third trimester we compared the serum laminin levels of 69 women with an uneventful course of pregnancy to the levels of 23 women with symptoms of pregnancy-induced hypertension. Laminin concentrations were 2.6 U/ml in pregnant women with hypertension and proteinuria, which was significantly higher than in healthy pregnant women (2.0 U/ml). We supposed that immunologic reactions that damage the kidney account for an increase of laminin concentrations in these women. Therefore we suggest that measurements of serum laminin concentrations may serve as a potential marker of renal damage.
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PMID:Serum laminin in pregnancy-induced hypertension--a marker for renal involvement? 224 53

A variety of tubular marker proteins, as compared to healthy controls, are excreted at an increased rate in the urine of patients with renal damage. Beside cytoplasmic glutathione-S-transferase and lysosomal beta-N-acetyl-glucosaminidase (beta-NAG) the majority of kidney-related urine proteins derives from membrane surface components of the most vulnerable proximal tubule epithelia, among them ala-(leu-gly)-aminopeptidase, gamma-glutamyl transpeptidase (GGT), the tubular portion of angiotensinase A, the major brush border glycoprotein 'SGP-240' and adenosine-deaminase-binding protein. Urinary tissue proteins, e.g. brush border (BB) microvilli, are immunologically identical with those antigens prepared from cell membranes of the human kidney itself. BB antigens are shed into the urine of patients with glomerulonephritis, interstitial nephritis, systemic diseases, e.g. systemic lupus erythematosus (SLE), diabetes mellitus and multiple myeloma, arterial hypertension, infectious diseases (malaria, AIDS) and after operations, renal grafting and administration of X-ray contrast media, aminoglycosides or certain cytostatics (cis-platinum). Tissue proteinuria of tubular proteins is determined by enzyme-kinetic or quantitative immunological assays applying either poly- or monoclonal antikidney antibodies. Clinical, ultrastructural and histochemical studies support the idea that both 'soluble' and high-molecular-weight membrane particles (vacuolar blebs, greater than 10(6) dalton) as well as microfilamental components of the epithelial cytoskeleton contribute to tubular 'histuria' which appears as a sensitive parameter in monitoring tubular damage under clinical conditions at a very early phase.
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PMID:Urinary proteins of tubular origin: basic immunochemical and clinical aspects. 225 76

Protein G, an immunoglobulin (Ig)-binding protein isolated from group C or G streptococci, binds to the Fc portion of IgG. Protein L, from the anaerobic bacterium Peptostreptococcus magnus, specifically binds light chains of Ig. In this study, protein G and L were used to measure the production of antibodies in immunized rabbits. Two rabbits were immunized with a mixture of human urinary proteins from a patient with tubular proteinuria, and blood samples were collected regularly from the animals for 6 weeks after the immunization. The antibody levels of the blood samples against six of the proteins in the antigen mixture were then measured by ELISA. Microtiter plates were coated with each of the antigens, incubated with the rabbit serum samples, and the specific antibodies of the IgG class measured by incubation with biotinylated protein G, and antibodies of all Ig classes with biotinylated protein L. Alternatively, Western blotting was employed, where the antibodies which bound to each antigen after separation by SDS-PAGE and transfer to nitrocellulose membranes, were detected by protein G or L. The results showed that antibody production against five of the antigens, albumin, alpha 1 gamma-acid glycoprotein, alpha 1 gamma-microglobulin, Ig light chains, and retinol-binding protein, showed a similar pattern, although the magnitude of the initial IgM response differed somewhat. After 6 weeks, the levels of the protein G-binding antibodies had reached a plateau, while those of protein L-binding antibodies were still increasing. The response to the sixth antigen, beta 2 microglobulin, was considerably different. A dramatic increase of anti-beta 2 gamma-microglobulin antibodies was seen during the 4th week after immunization when protein L was used.
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PMID:Antibody response in immunized rabbits measured with bacterial immunoglobulin-binding proteins. 227 56

In previous studies we demonstrated that antigens with the capacity to bind to the glycoprotein fibronectin (FN), localized in the glomerular mesangium after intravenous (IV) injection. In the present study we sought to determine if the localization of FN-binding antigens in the mesangium is capable of inducing glomerulonephritis. A group of rats were injected IV with the FN-binding antigen phenylated gelatin (DNP-GL) followed 2 hours later by rabbit anti-DNP antibodies. This experimental protocol resulted in the development of a glomerulonephritis characterized by an initial heterologous phase and a late autologous phase. Both phases of the disease were characterized by significant histologic changes, including focal segmental mesangial matrix expansion, inflammatory cell infiltration, and an increase in endothelial and mesangial cells. By immunoperoxidase we demonstrated mesangial deposition of rabbit IgG and rat C3 during the initial heterologous phase and mesangial deposition of rat IgG and C3 during the autologous phase. Significant proteinuria developed during the heterologous phase, but not during the autologous phase of the disease. By contrast, rats injected with DNP-GL alone or anti-DNP antibodies alone did not develop significant histologic glomerular changes or proteinuria. In conclusion, antigens that bind to mesangial FN are capable of inducing glomerulonephritis. This mechanism of localization of antigens in the glomeruli may be relevant to human immune complex (IC)-mediated diseases involving antigens that have the capacity to bind to FN.
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PMID:Experimental glomerulonephritis induced by antigen that binds to glomerular fibronectin. 230 87

The present study was conducted to determine if Fx1A, a renal cortical extract used to induce Heymann nephritis, contains nephritogenic antigens in addition to the brush border-derived glycoprotein gp 330. Of 26 Lewis rats immunized with Fx1A, 24 developed abnormal proteinuria (greater than 20 mg/24 hr) by wk 10, whereas of 15 rats immunized with a partially purified gp 330 preparation (MVH), only one developed proteinuria. Immunofluorescence studies showed that all Fx1A rats developed large, diffuse, granular deposits along the glomerular basement membrane which stained brightly for IgG and C3; only 11 of the 15 MVH rats had definite deposits; in most rats, they were small and stained only moderately for IgG and faintly or not at all for C3. The Fx1A and MVH rats developed comparable levels of antibodies to MVH (gp 330) before the onset of proteinuria in Fx1A rats, after which serum IgG and antibody levels declined. In contrast, antibodies against soluble Fx1A antigens appeared earlier and rose more rapidly in Fx1A than in MVH rats. Larger amounts of IgG could be eluted from the glomeruli of Fx1A rats than from MVH rats. Eluates from the Fx1A rats contained antibodies that reacted with gp 330 and also a 95 kd antigen; the latter reactivity was not demonstrated in eluates of MVH rats. Immunoprecipitation studies showed that both gp 330 and the 95 kd antigen are components of normal glomeruli. The results show that immunization with Fx1A produces a more severe form of Heymann nephritis than does gp 330, and that Fx1A contains at least one nephritogenic antigen in addition to gp 330.
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PMID:Characterization of antigens and antibody specificities involved in Heymann nephritis. 241 95

Alpha-1-microglobulin (alpha-1-m) is a low molecular weight glycoprotein (mw 25-33 KD) that is filtered through the glomeruli and reabsorbed in the proximal parts of the renal tubules where it is catabolized. Normal ranges were established for alpha-1-m (100 healthy controls) in serum (20-42 mg/l) and urine (3.5-8 mg/l). Alpha-1-m was then measured in 341 urine samples whose protein pattern had been classified as "pathologic" and "normal" according to microelectrophoresis. Increased alpha-1-m concentrations were found in 266 out of 280 pathologic urines (5% false negative) and in 3 out of 61 normal urines (4% false positive). Beta-2-microglobulin (beta-2-m), total protein or protein test strips showed a poorer correlation to the electrophoretic results. Measurement of alpha-1-m is, therefore, the most sensitive of these methods for the detection of proteinuria. In 90 patients with low molecular weight proteinuria and either with or without renal insufficiency alpha-1-m concentrations were determined in both urine and serum. While all patients had elevated urinary alpha-1-m concentrations, increased serum values were only found in renal insufficiency (Ccrea less than 100 ml/min). Independently of these results, we were also able to establish that increased alpha-1-m levels are found at decreased glomerular filtration rates (Ccrea less than 70 ml/min). Pathologic alpha-1-m concentrations therefore only allow the conclusion of isolated tubular impairment when the GFR is greater than 70 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Alpha 1-microglobulin in the urine and serum in proteinuria and kidney insufficiency]. 241 44

The role of individual antigenic determinants in the pathogenesis of antibody-mediated glomerular injury is, at present, incompletely understood. This study was designed to compare the effect of monoclonal antibodies upon binding to three distinct antigenic determinants present in the glomerular capillary wall. Ten monoclonal antibodies were tested for their nephrotoxic capacity in the rat. Six antibodies directed against basement membrane laminin and three antibodies with specificity for a 129/117 kd antigenic complex present on endothelial and glomerular visceral epithelial cell surfaces did not induce proteinuria or structural injury. A non-complement binding monoclonal antibody that immunoprecipitates a 115/107 kd sialo-glycoprotein (SGP-115/107) from glomerular cell membrane preparations and a 107 kd component from proximal tubules, intestinal cells and liver cells, induces glomerular epithelial cell alterations consisting of focal obliteration of foot process architecture, vacuolar changes in the cytoplasm, microvillous transformation of the cell surface, and focal retraction of podocytes, resulting in detachment of the epithelium from the underlying basement membrane. These structural changes are accompanied by immediate transient proteinuria only in animals given complete Freund's adjuvant at the time of antibody administration. These studies indicate that direct antibody-mediated glomerular injury can be induced in the rat by administration of monoclonal antibodies specific for cell associated antigens.
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PMID:Induction of proteinuria in the rat by a monoclonal antibody against SGP-115/107. 245 92

Ordinary methods for purification of complex-forming glycoprotein (protein HC) or alpha 1-microglobulin, a protein closely related to protein HC, require either large volumes of urine or special collection of urine specimens from patients with tubular proteinuria. Here we describe a fast, efficient procedure for isolating protein HC in high yield from urines from healthy and diseased subjects, with use of Cibacron blue, hydroxylapatite, and gel chromatography. Using this procedure, we also obtained a considerable amount of polymeric protein HC from the urine of a patient with chronic renal failure. The pattern of charge heterogeneity and immunoreactivity with anti-protein HC differed between the polymeric and monomeric forms of protein HC. We also observed a variability in charge heterogeneity of protein HC among patients with renal disorders. These results demonstrate that this purification method is useful for further studies to elucidate the biochemical properties of protein HC and its clinical significance in renal disorders.
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PMID:High-yield purification of the complex-forming glycoprotein in urine from normal and abnormal subjects. 246 63


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