Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Graded dextrans were used as tracers to study glomerular permeability in nephrotic rats. Two narrow range fractions were used, one which was approximately the same size as albumin (62,000 mol wt) and one which was considerably larger (125,000 mol wt). Nephrosis was induced with daily injections of an aminonucleoside of puromycin, and the animals examined after 7 days, when proteinuria is minimal, or after 10 days, when proteinuria has almost reached a maximum. At both stages and with both dextran fractions the following results were obtained: (a) dextran was retained for up to 3 h (the longest interval studied) in the plasma at high concentration; (b) there was a sharp drop in the concentration of tracer between the inner, looser portions of the basement membrane (lamina rara interna) and its outer denser portions (lamina densa), (c) accumulation of dextran was seen in the mesangial areas with time; and (d) no accumulation of dextran was seen in the slits at any time. These results are the same as those reported earlier in normal animals, and they demonstrate that in nephrotics the basement membrane still behaves as the main filtration barrier retaining most of the plasma proteins. Certain differences from the findings in normals were also noted in that increased amounts of the tracer were present on the epithelial side of the basement membrane: (a) in the urinary spaces; (b) in the subepithelial portions of the basement membrane; and (c) within lysosomes (protein absorption droplets) in the epithelial cytoplasm. In addition areas of thinning of the dense portions of the basement membrane (lamina densa) were seen which were accompanied by a corresponding widening of the less dense, subendothelial and subepithelial layers (lamina rara interna and externa, respectively). The presence of increased quantities of dextran on the epithelial side of the basement membrane indicates that the filter, i.e. the basement membrane, is leaky and allows increased passage of dextrans and therefore plasma proteins.
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PMID:The permeability of glomerular capillaries of aminonuceoside nephrotic rats to graded dextrans. 115 Dec 87

The visceral glomerular epithelium of rats made nephrotic by daily injections of puromycin aminonucleoside was examined from the time of onset of proteinuria (day 6) to the time when many animals die (day 15) in order to establish the chronology of the pathologic alterations which occur during the course of the disease. In addition, the structure of the residual epithelial slits was examined using special fixatives and freeze-fracture. Changes seen early in the disease (7 to 9 days) are: (1) a reduction in the number of foot processes and filtration slits; (2) occurrence of occluding junctions in many of the residual slits coupled with displacement of the slit diaphragms; (3) thinning of the dense central portion of the basement membrane (lamina densa) with a corresponding widening of the space (lamina rara externa) between it and the epithelium; (4) heightened epithelial pinocytosis with increased numbers of protein absorption droplets or lysosomes. In freeze-fracture preparations the occluding junctions were seen to be limited in extent and made up of only a few strands, indicating they are incomplete and represent occluding maculae or fasciae rather than zonulae. Later on in the disease (10 to 15 days) no further changes in the number or arrangement of slits is evident, but other alterations occur: (1) denuded regions of basement membrane are seen where there is initially partial and eventually complete detachment of the epithelium from the basement membrane; (2) increasing numbers of large vacuoles or phagosomes and decreasing numbers of fully condensed lysosomes are present; and (3) basement membrane-like material is seen in the spaces between the partially detached epithelium and basement membrane. The new findings in this study are: (1) the clarification of early (reversible) versus late (probably irreversible) changes in the glomerular epithelium in a acute aminonucleoside nephrosis; (2) delineation of the structure of the residual epithelial slits; (3) the description of progressive loosening of the attachment between the epithelium and the basement membrane leading to focal or complete epithelial cell detachment; (4) the presentation of evidence indicating that exhaustion of the lysosomal system of the glomerular epithelium (in protein absorption and concentration) occurs late in the disease. The available evidence is summarized and indicates that the glomerular basement membrane, the main glomerular filter, is defective in aminonucleoside nephrosis and allows increased protein leakage. However, it seems likely that the main site of action of aminonucleoside is on the epithelium leading to the production of defective basement membrane.
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PMID:Alterations of the glomerular epithelium in acute aminonucleoside nephrosis. Evidence for formation of occluding junctions and epithelial cell detachment. 124 24

Ferritin was used as a tracer to investigate glomerular permeability in the nephrotic rat. The results were compared with those previously obtained in normal animals. A nephrotic syndrome was induced by 9 daily injections of the aminonucleoside of puromycin. Ferritin was administered intravenously on the 10th day, and kidney tissue was fixed at intervals of 5 minutes to 44 hours after injection of the tracer and examined by electron microscopy. The observations confirmed that at this stage of the experimental nephrotic syndrome the changes affect predominantly the visceral epithelium (loss of foot processes, reduction and modification of urinary slits, and intracellular accumulation of vacuoles and protein absorption droplets). Less extensive changes were found in other layers (reduction of endothelial fenestrae, an increase in the population of "deep" cells, and a thinning and "loosening" of the basement membrane.) At short intervals (5 to 15 minutes) after ferritin administration, the tracer was found at high concentration in the lumen and endothelial fenestrae, and at decreasing concentrations embedded throughout the basement membrane and incorporated into the epithelium (within cytoplasmic vesicles and within invaginations of the plasmalemma facing the basement membrane). After longer intervals (1 to 3 hours) the distribution of the tracer within the capillary wall was similar except that its concentration in the epithelium was higher, and, in addition to plasma membrane invaginations and small vesicles, ferritin also marked larger vacuoles, dense bodies, and intermediate forms. Large accumulations of tracer typically occurred in the spongy areas of the basement membrane, especially in the axial regions. Ferritin also appeared in the endothelium within membrane-limited vacuoles and dense bodies, particularly in the deep cells. After 6 to 44 hours the tracer still occurred in the lumen and throughout the basement membrane. The ferritin deposits in the spongy areas as well as the ferritin-containing vacuoles of the deep endothelium were larger and more numerous. In the epithelium ferritin was found not only within various membrane-limited bodies, but also "free" within the cytoplasmic matrix. These observations indicate that in the nephrotic glomerulus, as in the normal, the basement membrane functions as the main filtration barrier; however, in nephrosis, the basement membrane is defective and allows leakage of increased quantitites of ferritin and presumably plasma proteins. The basement membrane defect appears to be fine and widespread, occurring at or near the molecular level of organization of the filter. The accumulation of unfiltered ferritin in axial regions together with the demonstration of its subsequent phagocytosis by the "deep" endothelial cells suggest that the latter may function in the removal of filtration residues. Finally, the findings indicate that in the nephrotic, as in the normal animal, the epithelium acts as a monitor that recovers, at least in part, the protein which leaks through the filter, and that in nephrosis, the recovering activities of the epithelium are greatly enhanced because of the increased permeability of the basement membrane.
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PMID:Glomerular permeability. II. Ferritin transfer across the glomerular capillary wall in nephrotic rats. 1389 78

Three hundred 1-day-old Japanese quail (Coturnix coturnix japonica) were divided into two groups of 150 each. One group was maintained on quail mash alone, whereas Fusarium verticillioides culture material (FCM) was added to quail mash in the second group from 5 days of age and supplied 150 mg FB1/kg mash. At day 21, each group was further subdivided into two groups, yielding four groups with 75 birds apiece, which served as the control (group CX), the Salmonella Gallinarum alone group (group CS), the FB1 alone group (group FX), and the group fed FB1 and infected with Salmonella Gallinarum (group FS). An oral challenge with Salmonella Gallinarum organisms (2 x 10(4) colony-forming units [cfu]/ml) was given to groups CS and FS at 21 days of age. Three quail each, were necropsied on day 21 (0 day interval) from groups CX and FX, whereas at subsequent intervals, i.e., 1, 2, 3, 5, 7, 10, 14, and 21 days postinfection (DPI), they were sacrificed from all four groups (CX, CS, FX, and FS) to study the agglutinin response to Salmonella Gallinarum and pathologic changes. The agglutinin titers to Salmonella Gallinarum in the combination group (FS) were generally lower when compared with those in group CS. A reduction in the size of spleen along with depletion of white pulp, thinning of cardiomyocytes, lymphoid cell depletion from bursal follicles, and renal tubular nephrosis were characteristic pathologic changes in group FX. In contrast, there was mild to severe enlargement of spleen accompanied by necrosis and reticuloendothelial cell hyperplasia, pericarditis, myocarditis, and focal interstitial nephritis in groups CS. Similar but more severe lesions were observed in the combination group (FS). In addition, the flabby texture of heart, hydropericardium, and ascites were mainly observed in group FS. It is concluded that continuous presence of fumonisins at 150 mg/kg diet increases the severity of Salmonella Gallinarum infection in young Japanese quail.
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PMID:Pathologic changes in extrahepatic organs and agglutinin response to Salmonella Gallinarum infection in Japanese quail fed Fusarium verticillioides culture material containing known levels of fumonisin B1. 1799 30