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

We wish to determine what cellular and functional alterations are associated with the development of glomeruloscierosis when rats with one kidney are fed an excess of salt or protein. Rats with one kidney are more likely to develop pronteinuria and glomerulosclerosis than control animals. Blood pressure recordings indicate that proteinuria and glomerulosclerosis occur before hypertension is evident. Fluorescent antibody studies disclose that albumin accumulates in the epithelial cells of glomeruli and tubules. Ultrastructural examination shows that vacuolozation of epithelial cells and basement membrane thickening precede the sclerotic collapse of capillary loops. Increased concentrations of sodium or urea that are found in urines of these rats favor the point of view that an elevation of solute load when combined with a reduction of renal mass will on some unknown manner accelerate the deterioration of glomeruli.
 ...
PMID:Protein overload nephropathy in rats with unilateral nephrectomy. A correlative light immunogluorescence and electron microscopical analysis. 4 49

The pathogenesis of focal glomerular sclerosis (FGS) and its relation to proteinuria and idiopathic nephrotic syndrome are unknown. Urine protein excretion in Sprague-Dawley rats increased with age. Fifty per cent of 12-month and 90 per cent of 24-month-old animals were proteinuric (greater than 20 mg. per day). Heavily proteinuric old rats manifested biochemical changes characteristic of nephrotic syndrome without significant loss of renal function. Three-month, 6-month, and nonproteinuric 12-month-old animals had mesangial deposits of IgM in occasional lobules of some glomeruli and slight mesangial hyperplasia. Four proteinuric 12-month-old rats had diffuse 4+ deposits of IgM in the mesangium of most glomeruli, basement membrane thickening and epithelial cell foot process fusion without FGS. The mesangial IgM deposits eluted in acid buffer and did not fix complement. Six proteinuric 12-month-old rats had focal and segmental areas of glomerular sclerosis with adhesions to Bowman's capsule, foamy cells, intraluminal eosinophilic deposits and capillary wall wrinkling and collapse. These lesions were more advanced in 24-month-old animals. Nonproteinuric 24-month-old rats did not have detectable FGS. Mesangial uptake of colloidal carbon was normal in proteinuric and nonproteinuric animals without FGS. Mesangial uptake of colloidal carbon was normal in proteinuric and nonproteinuric animals without FGS and reduced in proteinuric animals with FGS. In the aging rat the development of proteinuria and mesangial IgM deposition apparently precede development of a focal sclerotic glomerular lesion with histologic and ultrastructural features similar to FGS in man. The generalized impairment of mesangial phagocytic function in proteinuric rats with FGS suggests that this lesion may result from mesangial overload and dysfunction consequent to the persistent increase in glomerular permeability and proteinuria.
 ...
PMID:Mesangial lesions and focal glomerular sclerosis in the aging rat. 12 75

Structural distortion of glomerular capillaries in chronic rat Masugi nephritis was studied by light, transmission electron, and scanning electron microscopy. A few months after rats were given injections of heterologous nephrotoxic antibodies, focal and local mesangial as well as basement membrane thickenings were observed. Using scanning electron microscopy, glomerular corrosion castings disclosed that definite loop constriction with occasional gaps occurred in such local foci. The local changes were gradually extended to adjacent areas in rats with severe proteinuria, later resulting in a broad disappearance of the loops. Also observed were glomeruli undergoing a collapse with structural simplification resulting from multiple loss of communicating branches. At the terminal stage, almost all glomeruli were involved in varying degrees in either of these changes. In contrast, no progression of the disease process was observed in rats with minimal proteinuria. By scanning electron microscopy, a large number of castings from various angles revealed that morphologically normal glomeruli were involved in local and ultimately global obsolescence under the condition of persistent proteinuria.
 ...
PMID:Structural distortion of glomerular capillary loops in the chronic phase of rat Masugi nephritis. 43 55

Forty cases of focal sclerosing glomerulonephropathy with nephrotic syndrome or proteinuria were studied retrospectively in regard to clinical presentation, response to steroid therapy and clinical course, and histopathology of the lesion. Morphologically there was a focal segmental and global sclerosis with subendothelial hyaline deposits, collapse of the capillary loops, intracapillary hyaline material or foam cells, filling and widening of the mesangium with mesangial matrix, focal tubular atrophy, and focal interstitial fibrosis. Thirty-four patients had been treated with prednisone; initial complete remission of the nephrotic syndrome occurred in only 4 patients and partial remission in 10. Nine of these 14 patients had nephrotic relapse or became resistant to steroids. Thirty-three percent of the patients progressed to end-stage renal failure and an additional 25 percent had impairment of renal function after a mean of 8 years from onset. Three patients received kidney allografts, and in two the disease recurred in the transplanted kidney. Focal sclerosing glomerulonephropathy associated with nephrotic syndrome or proteinuria appears to be a clinicopathologic entity characterized by resistance to steroid treatment, frequent progression to end-stage renal disease, and recurrence in the transplanted kidney.
 ...
PMID:Focal sclerosing glomerulonephropathy: a clinicopathologic study. 109 Jul 90

Although glomerular damage plays a well-established and important role in the pathomechanism of diabetic nephropathy, it alone does not fully explain the progression of renal complications in long-term diabetes mellitus. We discuss experimental evidence showing involvement of the postglomerular microvessels (peritubular capillaries and venules) in diabetic microangiopathy. This involvement is manifest in increased permeability of these vessels to plasma proteins and in highly augmented lymphatic drainage of the extravasated proteins from the renal interstitium. We suggest that in the advanced phase of diabetic nephropathy, proteinuria (corresponding to excess leakage of proteins through the glomerular capillary wall) indicates the probability that postglomerular microvessels have also allowed leakage of plasma proteins. As long as lymphatic drainage is capable of removing the increased quantity of extravasated plasma proteins from the interstitium, renal function should not be deleteriously affected. However, if the excess amount of extravasated proteins exceeds the capacity of lymphatic drainage, increases in interstitial volume and pressure are unavoidable with detrimental consequences for glomerular filtration and tubular reabsorption. Under these conditions, a potential positive-feedback loop can be visualized that involves increased extravasation of plasma proteins leading to increased interstitial pressure that through dilation of the afferent and efferent arterioles results in a further increase in protein extravasation. These conditions combined with glomerular damage should lead to the eventual collapse of renal function.
 ...
PMID:Role of postglomerular microvessels in pathophysiology of diabetic nephropathy. Assessment and hypothesis. 206 Jul 15

Renal mass reduction may lead to glomerular hypertrophy, proteinuria and focal glomerulosclerosis (FGS) in humans and rats. In humans and rats, females are less susceptible than males to these phenomena. This study was undertaken to evaluate the effect of male rat castration on the pathogenesis of proteinuria and FGS. Urinary protein was measured in 60-day-old male and female rats. Uninephrectomy was performed in all rats, and castration in half of the males. After 180 days, proteinuria, glomerular filtration rate (GFR) and blood biochemistry were determined. Kidneys were resected, weighed and subjected to morphologic studies. Following uninephrectomy, male rats developed severe proteinuria: 132.3 +/- 40.9 mg 24 h-1, most of which was accounted for by an albuminuria of 70.9 +/- 19.3 mg 24 h-1. In contrast, protein excretion in female and castrated male rats remained within normal limits: 8.0 +/- 1.8 and 4.2 +/- 0.5 mg 24 h-1, respectively. Mean glomerular volume in male rats was 1.18 +/- 0.08 x 10(6) microns3; much higher than in female rats, 0.84 +/- 0.04 x 10(6) micron3, and castrated male rats, 0.87 +/- 0.03 x 10(6) micron3 (P less than 0.005). On light and electron microscopy, glomeruli of female and castrated male rats were completely normal. In contrast, in four of seven male rats, mild glomerular changes were observed. They consisted mainly of mesangial expansion, electron-dense deposits and collapse of capillary loops. These data suggest that castration confers protection against the development of glomerular hypertrophy and proteinuria in uninephrectomized male rats. Endogenous testosterone may be associated with this development.
 ...
PMID:Castration inhibits glomerular hypertrophy and proteinuria in uninephrectomized male rats. 212 95

Chronic diseases of the kidney are characterized by progression once a certain portion of renal function is lost. End-stage kidneys, the result of progressive chronic renal disease, are characterized by sclerosis, tubulointerstitial scarring, and collapse of glomerular capillary tufts. The mechanisms and risk factors responsible for the progression of renal disease have been studied intensively in the past decade, and it now appears that multiple nonimmunologic factors are responsible. These factors include systemic hypertension, hyperlipidemia, proteinuria, excessive intake of protein, and adaptive changes in nephron function as a consequence of nephron loss. The latter adaptations, increased intraglomerular pressure, increased excretion of ammonia, "hypermetabolism," decreased afferent arteriolar tone, and renal hypertrophy, may also be responsible for the progression of renal disease. A complete understanding of the factors responsible for the progression of renal disease should permit rational development of appropriate therapeutic interventions.
 ...
PMID:Progression of chronic renal disease. 213 99

We studied the clinical features, pathologic findings, and course of 18 patients who were found to have glomerular disease at the time of hospitalization with manifestations of acquired immunodeficiency syndrome or acquired immunodeficiency syndrome-related complex at New York University Medical Center, New York, NY, during 1984 through 1987. Focal glomerulosclerosis, characterized by segmental and/or global collapse of capillary walls, was observed in 15 of these patients; mesangial proliferation in 2, and membranous nephropathy in 1. Those with focal glomerulosclerosis typically demonstrated heavy proteinuria without edema or hypertension and progressed rapidly to renal failure in less than 1 year from the time of discovery. This form of focal glomerulosclerosis is characterized by a fulminant course, the collapse type of sclerosis, and the frequent occurrence of uremia without advanced glomerular obliteration. The absence of widespread glomerular sclerosis and the rapid course suggest that unique renal hemodynamic mechanisms may be responsible for the progression.
 ...
PMID:Rapid renal failure in AIDS-associated focal glomerulosclerosis. 240 96

Injury of the glomerular microvasculature by nonimmunologic processes is often the underlying mechanism of progressive deterioration of renal function in patients with a variety of renal disorders. The structural hallmark of this injury is focal and segmental glomerulosclerosis, often accompanied by entrapment of hyalin. Although such lesions are quite characteristic for diseases that primarily affect the glomerular podocyte, similar damage occurs in association with functional and structural adaptive changes that develop as a consequence of a significant loss of functioning nephrons or other systemic disorders. Experimental studies have revealed that such functional adaptations include intrarenal vasodilatation that through increases in glomerular capillary pressure and plasma flow leads to a significant compensatory hyperfiltration. This functional state is accompanied by a parallel increase in glomerular volume, attained chiefly by expansion of matrix components and an increase in the number of endothelial and mesangial cells, but not of podocytes. The persistence of the adaptive changes results in endothelial, mesangial, and epithelial cell dysfunction revealed clinically by proteinuria and structurally by the development of microthrombosis, microaneurysms, mesangial expansion, and occlusion of capillaries by hyalin accumulation. Although all these pathologic processes can lead to segmental collapse of the capillary tuft, it is the progressive hyalin deposition in capillaries with defective or detached podocytes that represents the major mechanism in the development of segmental and eventually global glomerulosclerosis. The inability of the highly differentiated podocyte to replicate in response to systemic or locally released trophic factors ultimately results in imperfections of the capillary wall that set the stage for permeability defects amplified and accentuated by greatly augmented hydrodynamic forces. These structural and functional microvascular changes acting in concert not only facilitate the transcapillary convection of macromolecules that results in albuminuria, but can also be anticipated to play a key role in the entrapment and accumulation of larger macromolecules in front of the lamina densa in the form of hyalin material. Continuing damage to the glomerular microvasculature exacerbates the adaptive changes in surviving nephrons, closing a positive-feedback loop that culminates in end-stage renal failure.
 ...
PMID:Pathogenesis and significance of nonprimary focal and segmental glomerulosclerosis. 265 58

Although a variety of renal lesions may occur in acquired immune deficiency syndrome (AIDS), a rare but aggressive form of focal and segmental glomerulosclerosis with capillary collapse has been considered a possible component of this disorder. It is manifested by heavy proteinuria and progression to renal failure in a short time. We studied renal biopsies from nine patients with HIV infection and the above clinical features and compared the renal tissues to biopsies from HIV-positive individuals with immune complex glomerulonephritis and to biopsies from patients with heroin abuse nephropathy. The HIV-associated nephropathy was characterized by a combination of lesions: focal and segmental glomerulosclerosis, often in an early stage of evolution and with prominent degenerative changes of visceral epithelium; tubular necrosis without identifiable nephrotoxic or hemodynamic etiology; interstitial edema; large plasma protein-containing tubular casts in all segments of the nephron associated with marked tubular dilatation; and widespread tubuloreticular structures in vascular endothelium. In contrast, neither the sclerosing glomerular changes nor the tubulointerstitial abnormalities were present in HIV-infected patients with immune complex glomerulonephritis. Similarly, the tubular and interstitial changes and widespread tubuloreticular structures were absent in heroin-abuse nephropathy. The lesions of HIV-associated nephropathy occurred in patients with AIDS, AIDS-related complex, and in individuals clinically asymptomatic for HIV infection. Their morphological features in asymptomatic patients are sufficiently specific to allow for accurate diagnosis of HIV infection.
 ...
PMID:HIV-associated nephropathy. A unique combined glomerular, tubular, and interstitial lesion. 307 May 50


1 2 3 4 5 6 7 8 Next >>