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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A proliferative glomerulonephritis was induced in rats preimmunised with rabbit IgG by injecting a sub-nephrotoxic dose of rabbit anti-rat GBM IgG. All the rats developed a severe proteinuria within 2-5 days after the injection of anti-GBM IgG. At the same time, many mononuclear phagocytes infiltrated the glomeruli, the colloidal iron staining of the glomerular filtration barrier was altered, and the urinary excretion of laminin and of neutral proteinase strongly increased. However, the pattern and intensity of staining of different collagenous and non-collagenous BM glycoproteins were not modified, as shown by indirect immunofluorescence microscopy. The existence of a direct significant correlation between the proteinuria and the laminin urinary excretion, and between the latter and the urinary neutral proteinase activity suggests that lysosomal proteinase of mononuclear phagocytes may be involved in the damage of the GBM during the course of this experimental glomerulonephritis.
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PMID:Studies on the glomerular filtration barrier and on the urinary excretion of basement membrane glycoproteins during the accelerated model of nephrotoxic serum nephritis. 636 61

The urinary protein excretion rate, the glomerular localization of cationic proteins (CP) derived from platelets and polymorphonuclear neutrophils (PMN) and the loss of fixed anionic charges were studied in rabbits infused with synthetic 1-0-octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine [platelet activating factor (PAF), 1.5 micrograms/kg in 2 ml of saline containing 0.25% bovine serum albumin (BSA)]. The urinary protein excretion rate, unaffected by diphenhydramine, an antihistaminic agent, reached its maximum at 180 min and decreased 24 hr after PAF infusion. The localization of CP derived from platelets and PMN was investigated by immunofluorescence using specific antisera. Platelet-derived CP were detectable in glomeruli at 15 min and, particularly, at 180 min after PAF infusion. Cells positive for CP derived from PMN accumulated within 15 min in the glomerular capillaries and, later (180 min), cytoplasmic depletion and localization in glomerular capillary walls occurred. CP deposits were associated with the loss of fixed anionic charges as detected by ruthenium red and colloidal iron staining. Rabbits infused with 1-0-octadecyl-sn-glyceryl-3-phosphorylcholine (lyso-PAF) or saline-BSA alone had none of the alterations described above. The development of proteinuria, the glomerular localization of platelet- and PMN-derived CP and the concomitant loss of fixed anionic charges suggested the possibility that, once CP were released in the circulation from PAF-stimulated platelets and PMN, they bound to, and neutralized, fixed anionic charges, resulting in enhanced glomerular permeability.
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PMID:Platelet-activating factor-induced loss of glomerular anionic charges. 637 51

In the present study in Munich-Wistar rats during the initial stages of autologous immune complex nephritis (protein excretion 3 to 50 mg/24 hours) we examined the sequential changes in binding of cationized ferritin to anionic sites, as well as alterations in staining with colloidal iron of podocyte membrane sialoglycoprotein and correlated these with changes in glomerular basement membrane permeability to native ferritin. The results are compared with those obtained from rats with advanced autologous immune complex nephritis (protein excretion 100 to 350 mg/24 hours) and with normal control rats. The formation of the smallest detectable immune complex deposits was associated with a concomitant decrease in binding of cationized ferritin to anionic sites in the lamina rara externa in the area of the deposits. This was accompanied by a diminution in staining by colloidal iron of the epithelial cell coat overlying the deposits. The staining of the remainder of the epithelial cell glycocalyx, however, remained unaltered even in the presence of severe proteinuria. Alterations in the permeability of the glomerular basement membrane to native ferritin could not be documented until protein excretion exceeded 10 mg/24 hours. The gradual loss of staining of the epithelial cell glycocalyx adjacent to immune complexes supports the concept that, as immune complexes are formed in situ by the interaction of antibodies with a glycoprotein present on the epithelial cell surface, they are shed and gradually accumulate in the lamina rara externa. Furthermore, as the immune complex deposits enlarge they destroy and/or mask the heparan sulfate anionic sites in the lamina rara externa resulting in a decreased number of anionic binding sites for cationized ferritin.
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PMID:Alterations in glomerular anionic sites in autologous immune complex nephritis. 662 Sep 83

Biochemical, immunological, histochemical and electron microscope morphometric techniques were used to monitor the changes in urinary protein composition, albumin clearance and glomerular ultrastructure induced in female Wistar rats following i.p. injection of puromycin aminonucleoside (PAN) or bovine albumin (BSA). BSA injected rats maintained a high degree of selectivity with albumin constituting 90 per cent. of the total protein excreted even when mean protein excretion was in the order of 500 mg/24 hr. A similar degree of selectivity was only evident in PAN nephrotic rats at low levels of proteinuria. Levels of 500 mg/24 hr only 57 per cent. of the total protein was albumin. These differences correlated well with the increased number of glomeruli from PAN nephrotics compared with hyperalbuminaemic rats which, at these high levels of proteinuria, had bare areas of glomerular basement membrane caused by epithelial cell detachment (88 and 7 per cent. respectively). Detailed electron microscope morphometric and immunohistochemical studies showed that there were also important quantitative differences in a number of superficially similar glomerular structural alterations. In PAN nephrotic rats all glomeruli showed very marked epithelial cell foot process loss and reduced staining with colloidal iron. In glomeruli from hyperalbuminaemic rats there was a wide variation in the extent of epithelial cell foot process loss and reduced colloidal iron staining was only demonstrable in those glomeruli which had swollen epithelial containing large numbers of vacuoles and protein droplets. Similarly, while protein droplets were smaller and less numerous in glomeruli from PAN-injected rats, they were present in most glomeruli whereas their distribution was much more variable in glomeruli from BSA-injected rats. All the data collected therefore indicated that there were important differences in the types of proteinuria and glomerular ultrastructural damage present in PAN nephrotic and hyperalbuminaemic rats and suggested that their induction may have involved entirely different mechanisms. Evidence gathered from one experimental model should thus only be used with extreme caution to aid in interpretation of data obtained from the other.
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PMID:A morphometric, biochemical and histochemical comparison of puromycin aminonucleoside and hyperalbuminaemic induced proteinurias in the female Wistar rat. 682 98

Forty-three spinal cord injured patients with endstage renal disease (ESRD) maintained on hemodialysis were studied. The most prevalent renal lesions consisted of chronic pyelonephritis and amyloidosis while the main renal functional features included nephrotic range proteinuria, high urine output and relatively low serum creatinine for the degree of renal insufficiency. Normocytic, normochromic anemia with low reticulocyte response, low serum iron and iron binding capacity and high transfusion requirement and serum ferritin were noted. Various cardiovascular, pulmonary and gastrointestinal abnormalities were found with considerable frequencies. The incidence of amyloidosis was much higher than that reported previously. This is thought to be due to continued progression of amyloidosis occasioned by longer survival in the present series.
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PMID:Clinicopathological characteristics of dialysis patients with spinal cord injury. 688 88

Rats injected with F(ab')2 and Fab' antibody fragments directed against an antigen in the rat proximal tubular epithelial brushborder (Fx1A) developed immediate proteinuria [F(ab')2 43.2 +/- 6.7, N=6; Fab' 9.5 +/- 2.8, N=5; normal 1.6 +/- 0.9 mg/day, N=20]), that subsided after 3 to 5 days' duration. This reaction is in contrast to one exhibited by rats given intact IgG anti-Fx1A; the rats that did not develop immediate proteinuria (2.2 +/- 0.3 mg/day, N=5), and the glomerular binding of 125I-antibody fragments was significantly less than that of intact IgG [F(ab')2 0.11 +/- 0.01; Fab' 0.03 +/- 0.01; IgG 0.17 +/- 0.01% administered equimolar dose] at 24 hr. No proteinuria resulted from equimolar doses of nonantibody F(ab')2 and Fab'. Less than 8% of the proteinuria induced by antibody fragments represented injected material, and 30 to 38% was albumin. Immunofluorescence revealed faint and diffuse glomerular capillary wall deposits of F(ab')2 and Fab' and tubular brushborder staining. Subepithelial, electron-dense deposits and focal, podocyte effacement were seen by electron microscopy in rats given the F(ab')2 antibody. Light microscopy and colloidal iron-staining were normal. In our study antibody fragments appear to interact directly with components of the outer, glomerular capillary wall to alter permeability in the absence of recognized mediators such as complement and inflammatory cells.
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PMID:Altered glomerular permeability induced by F(ab')2 and Fab' antibodies to rat renal tubular epithelial antigen. 704 51

A 56-year-old man with diffuse cutaneous xanthomatosis had neither mucosal lesions nor diabetes insipidus. Cutaneous lesions were characterised by dermal histiocytic infiltration, without X bodies, associated with Touton's cells and abundant iron deposits. Plasma lipid levels were normal. A lambda G monoclonal dysglobulinemia was present without Bence-Jones proteinuria or myeloma, except for a moderate increase in medullary plasmocytic cell elements. The diagnosis of disseminated xanthomatosis was established, the differential diagnosis from other histiocytic proliferations, particularly diffuse plane xanthoma, being sometimes difficult. The relation between normolipaemic xanthomatosis and dysglobulinemia certainly exists, but no satisfactory pathogenic explanation was possible in this case, in the absence of cryoglobulin, paraprotein antilipoprotein activity, and cutaneous deposits of lipoprotein-paraprotein complexes.
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PMID:[Diffuse normolipemic xanthomatosis and IgG monoclonal dysglobulinemia]. 718 Dec 45

Abnormal myoglobinemia (above 77 microgram/l) and free hemoglobin in plasma were found in 16 runners and in nine non runners immediately following distance running. The same abnormalities were found iun six elite rowers following rowing. In parallel with the rise in myoglobin and free hemoglobin a rise was found in serum concentrations of cellular enzymes (LDH, CK, ASAT, alkaline phosphatase) and of various metabolites. We found no proteinuria nor casts in the urine. Non runners had a higher rise in serum myoglobin than runners. Competitive running caused a rise in the serum concentration of the heart specific fraction of creatine kinase in seven of the nine (healthy) elite runners. The abnormal findings are only explainable on the basis of leakage of proteins from muscle cells to the circulation in otherwise healthy, well trained persons. Myoglobinemia and a transient rhabdomyolysis is a common phenomenon in long distance running, but evidently also occurs in distance rowing. Three months of running training prevented most of the muscle damage from relaxed jogging in the nine previous non runners. Neither the observed myoglobinemia nor the hemoglobinemia resulted in any significant loss of iron in the urine.
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PMID:Muscle cell leakage due to long distance training. 720 6

To study the role of lysosomal enzymes in glomeruli, we examined specific activities of lysosomal hydrolases in isolated glomeruli and, for comparison in isolated tubules, from rat kidney cortex of normal animals and animals with puromycin aminonucleoside nephrosis (PAN). Nephrotic syndrome was induced in rats by a single intraperitoneal injection of aminonucleoside and the rats were sacrificed at the time of peak proteinuria. Colloidal iron staining of renal cortex demonstrated decreased staining for the epithelial polyanion in animals with PAN. Lysosomal enzymes were determined by fluorogenic and colorimetric methods. In normal kidney, total specific activities of cathepsin beta 1, beta-2-fucosidase, acetyl-beta-glucosaminidase, and arylsulfatase were lower in glomeruli compared with tubules and with tissue slices of the same kidney. Total activity of acid phosphatase was higher in glomeruli than tubules. In glomeruli of PAN rats, there were lower activities of N-acetyl-beta-glucosaminidase, D-fucosidase, beta-glucosidase, beta-glucoronidase, and arylsulfatase compared with control rats. Activity of acid phosphatase, on the other hand, was higher in glomeruli of PAN than control rats. All differences were statistically significant. These studies demonstrate that (1) activities of lysosomal enzymes in normal glomeruli and in glomeruli of nephrotic rats have a property distinct from the rest of the kidney, and (2) the specific activities of lysosomal hydrolases are altered in glomeruli of rats with PAN. These studies suggest that changes in activities of lysosomal enzymes may be related to pathogenesis of this glomerulopathy.
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PMID:Activities of lysosomal enzymes in isolated glomeruli. Alterations in experimental nephrosis. 732 25

1. The intrarenal infusion of concentrated urea after clamping of the renal artery produced immediate proteinuria in the dog. The predominant lesion on ultramicroscopy was destruction of the epithelial layer. Colloidal iron staining showed decreased fixed anionic charges in the capillary wall. 2. Sieving studies with neutral macromolecules such as 125I-labelled polyvinylpyrrolidone and [3H]dextran or an electronegatively charged polymer, [3H]dextran sulphate, showed a moderate increase in permeablility to the neutral tracers and a much more severe alteration of the lectrostatic barrier to the anionic polymer. The fractional clearance of dextran sulphate molecules increased to a greater extent than clearance of neutral dextrans of comparable size. 3. The shape of the curve relating the fractional clearance of dextran sulphate to molecular size is also modified in the contralateral kidney. This may be due to elevated plasma angiotensin II concentrations.
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PMID:Sieving studies in 'urea-induced nephropathy' in the dog. 735 55


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