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  • 1
    ISSN: 1432-1440
    Keywords: Postglomerular capillaries ; Interstitial fibrosis ; Glomerular and tubular function ; Postglomeruläre Kapillaren ; interstitielle Fibrose ; Funktion von Glomerula and Tubuli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Vorliegende Untersuchungen führen in Ergänzung und Bestätigung früherer Untersuchungsergebnisse an einem im Hinblick auf die glomerulären Läsionen heterogenen Untersuchungsgut zu folgenden Resultaten: 1. Eine Zunahme des relativen Nierenrindeninterstitiumvolumens bzw. der Serumkreatininkonzentration zur Zeit der Biopsie geht mit einer statistisch signifikanten Abnahme der Anzahl der intertubulären Kapillaren und der Kapillarfläche pro Flächeneinheit einher. 2. Mit der Zunahme des relativen Nierenrindeninterstitiumvolumens nimmt die Diffusionsstrecke zwischen intertubulären Kapillaren und Tubuli zu und die Tubulusepithelien werden atrophisch. 3. Bei mittelschwerer mesangioproliferativer Glomerulonephritis bzw. membranösen Glomerulonephritiden Schweregrad I–III ist das glomeruläre Kapillarkonvolut und die Bowman'sche Kapsel bei erhöhter Serumkreatininkonzentration signifikant größer als bei gleich schweren Erkrankungen mit normaler Serumkreatininkonzentration. 4. Bei mittelschwerer mesangioproliferativer Glomerulonephritis nimmt das glomeruläre Kapillarkonvolut mit steigender Serumkreatininkonzentration zu. Aus diesen Befunden wird gefolgert, daß es durch die Verbreiterung des Nierenrindeninterstitiums zu einer Erhöhung des Widerstandes in der postglomerulären Kapillarstrecke kommen muß mit Beeinträchtigung des Abflusses aus den Glomerula. Diese Abflußbehinderung führt funktionell zwar zu einer chronischen Steigerung des hydrostatischen Druckes in den Glomerulumkapillaren, jedoch auch zu einer Reduktion der Glomerulumdurchblutung und damit zum Kreatininanstieg. Bedingt durch die chronische Steigerung des hydrostatischen Druckes kommt es ferner zu einer Zunahme des Kapillarkonvolutes (Erweiterung der Kapillaren, vermehrter Einbau von Kollagen, u.a. in die Kapillarwände). Ferner führt die Verbreiterung des Nierenrindeninterstitiums zu einer Zunahme der Diffusionsstrecke zwischen inter- bzw. peritubulären Kapillaren und Harnkanälchen mit konsekutiver Atrophie der Kanälchen und einer Reduktion der Rückresorption und einer dadurch bedingten Beeinträchtigung des effektiven Filtrations-druckes durch Anstieg des hydrostatischen Druckes im Bowman'schen Kapselraum.
    Notes: Summary Our study in a group of patients (heterogeneous in terms of glomerular lesions), supplementing and confirming earlier findings, indicated that 1. An increase of the relative cortical interstitial volume and the serum creatinine concentration at the time ob biopsy is accompanied by a statistically significant reduction in the number of intertubular capillaries and a decrease in capillary area per area unit. 2. The length of diffusion between the intertubular capillaries and tubuli increases and the tubular epithelium becomes atrophic as relative cortical interstitial volume increases. 3. The glomerular capillaries and the Bowman's capsule are significantly larger in moderately severe mesangioproliferative or grades I to III membraneous GN with elevated serum creatinine concentrations than in equally severe renal diseases with normal serum creatinine concentrations. 4. The glomerulus in moderately severe mesangioproliferative GN progressively increases as the serum creatinine concentration rises. On the basis of these findings, it was concluded that the increase of the cortical interstitial volume results in an increase in resistance of the postglomerular capillary network with impairment of the glomerular flow. This impairment leads to a functional or, to be more precise, a chronic rise in hydrostatic pressure and also to a reduction in the glomerular blood flow and therefore a rise in serum creatinine concentration. The chronic rise in hydrostatic pressure also results in an increase in the size of the glomerulus. The increase of the cortical interstitium additionally leads to an increase in the length of diffusion between the tubules and the intertubular and peritubular capillaries. This increase in the length of diffusion subsequently results in atrophy of the tubules, reduction of reabsorption, and therefore impairment of the effective filtration pressure.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1440
    Keywords: Renal amyloidosis ; Nephrotic syndrome ; Renal insufficiency ; Morphometry ; Tubular reabsorption of protein ; Light and electron microscopy ; Nierenamyloidose ; Nephrotisches Syndrom ; Niereninsuffizienz ; Tubuläre Eiweißrückresorption ; Licht- und Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Korrelation von licht- und elektronenmikroskopischen Befunden mit klinischen Parametern von 85 Fällen glomerulärer Nierenamyloidose führte zu folgenden Ergebnissen: 1. Glomerulär abgelagerte Amyloidmassen stellen keine wesentliche Filtrationsbarriere dar, d.h. die Primärharnbildung wird selbst durch ausgedehnte Amyloidablagerungen im glomerulären Kapillarkonvolut nicht signifikant beeinflußt und eine Proteinretention kann erst beobachtet werden, wenn die glomerulären Kapillaren fast vollständig obliteriert sind. 2. Wenn sich bei der Nierenamyloidose erst einmal ein nephrotisches Syndrom entwickelt hat, so zeigt es trotz zunehmender Niereninsuffizienz keine Tendenz zur Rückbildung. 3. Der Grund für das Fortbestehen des nephrotischen Syndroms trotz zunehmender Niereninsuffizienz ist eine zunehmende Abnahme der Rückresorptionskapazität für Proteine durch die Tubuluszellen bei zunehmender interstitieller Fibrose der Nierenrinde. 4. Die interstitielle Fibrose der Nierenrinde führt zu einer progressiven Verschlechterung in der Sauerstoff-und Energieversorgung der Tubuluszellen, was neben anderen metabolischen Störungen zu einer abnehmenden Rückresorptionskapazität für Proteine führt.
    Notes: Summary The following results were obtained by correlating light and electron microscopic findings from 85 cases of glomerular renal amyloidosis with clinical parameters: 1. Amyloid masses deposited in the glomeruli do not represent an effective filtration barrier, i.e., the formation of primary urine is not significantly influenced even by extensive amyloid masses in the glomeruli; protein retention is first observed when the glomerular capillaries are almost totally obliterated. 2. Once the nephrotic syndrome has developed in association with glomerular renal amyloidosis, it shows no tendency for remittance, despite progressing renal insufficiency. 3. The reason for this persistance of the nephrotic syndrome, despite increasing renal insufficiency, is a progressive reduction in the capacity of the tubules for protein reabsorption in the presence of increasing interstitial fibrosis of the kidney. 4. Interstitial fibrosis of the kidney cortex leads to increasing impairment in the oxygen and energy supply to the tubule cells together with considerable functional deterioration which, in addition to other metabolic disturbances, also results in a reduced capacity for protein reabsorption.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 60 (1982), S. 773-786 
    ISSN: 1432-1440
    Keywords: Acute renal failure ; Pathogenesis ; Reinterpretation ; Electron-microscopic findings ; Tubular cell damage ; Renal fluid compartments ; Akutes Nierenversagen ; Pathogenese ; Reinterpretation ; Elektronenmikroskopische Befunde ; Tubuluszellschädigung ; Renale Flüssigkeitskompartimente
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch elektronenmikroskopische Untersuchungen an 8 Fällen menschlicher akuter Nierenversagen konnten die aus tierexperimentellen Beobachtungen bekannten ultrastrukturellen Veränderungen am Nephron auch für das menschliche akute Nierenversagen bestätigt werden. Die Untersuchungen erfolgten unter besonderer Berücksichtigung der Einzelzellveränderungen, insbesondere der proximalen Tubuluszellen. Herausgestellt wurden die aus der Einzelzellschädigung resultierenden Veränderungen im Bereich der renalen Flüssigkeitskompartimente. Die ultrastrukturellen Veränderungen der Tubuluszellen beim akuten Nierenversagen deuten auf eine gravierende Beeinträchtigung der zellulären Transportkapazität für Elektrolyte und metabolischer Prozesse hin. Die durch Tubuluszellnekrosen oder durch Lösung von Gap- bzw. Tight-Junctions entstehenden Shunt-Wege zwischen tubulärem Flüssigkeitskompartiment und funktionellem Interstitium werden in ihrer Bedeutung für die gerichteten aktiven Transportvorgänge der Tubuluszellen für Natriumchlorid und den passiven Wasserstrom diskutiert. Die morphologischen Befunde werden unter besonderer Berücksichtigung neuer Ergebnisse der zellulären Membranprozesse und des Elektrolyttransportes besprochen. Eine Reinterpretation morphologischer und funktioneller Befunde beim akuten Nierenversagen unter besonderer Berücksichtigung der Einzelzellfunktion und der Integrität der renalen Flüssigkeitskompartimente wird vorgeschlagen.
    Notes: Summary The ultrastructural alterations at the nephron established in animal experiments, were also confirmed, by means of an electron-microscopic examination, in eight cases of human acute renal failure (ARF). Special consideration was given in this study to single cell alterations, particularly in proximal tubular cells, with emphasis being placed on alterations due to single cell damage in the region of the renal fluid compartments. The ultrastructural alterations of the tubular cells in ARF, suggest serious impairment of the cellular capacity for electrolyte transport and metabolic processes. The shunt paths between the tubular fluid compartment and the functional interstitium, arising from necrosis of the tubular cells or dissolution of the gap or tight junctions, were discussed in terms of their significance for the directional, active transport processes of the tubular cells for sodium chloride and the passive water flow. The morphologic findings were reviewed in light of recent findings on cellular membrane processes and electrolyte transport. A reinterpretation of the morphologic and functional findings in ARF is suggested. This takes into consideration single cell function and the integrity of the renal fluid compartments.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 63 (1985), S. 371-378 
    ISSN: 1432-1440
    Keywords: Macrohematuria ; Mild mesangioproliferative glomerulonephritis ; Basement membrane defects ; Scanning electron microscopic investigation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to clarify the pathogenesis of gross hematuria in mild forms of mesangioproliferative glomerulonephritis without crescents, systematic light microscopic, immunohistologic, electron microscopic, and some scanning electron microscopic investigations were carried out on 17 cases of this disease, in part on serial sections. The investigations produced the following results: 1. In gross hematuria, erythrocytes pass into Bowman's space in the area of basement membrane ruptures. 2. The basement membrane ruptures occur at sites where the basement membrane is infiltrated in its entire width by aggregated immune complexes. This occurs when these immune complexes are detached from the basement membrane by lysosomal digestion. 3. As a working hypothesis, it is furthermore considered possible that in diseases accompanied by increased IgA production, circulating IgA is deposited at a higher rate in the glomerular filtration barrier and it is there degraded by an excessive reaction of local cells before morphologically identifiable immune complexes appear. In this process the basement membrane undergoes local destruction. 4. It is also assumed that in gross hematuria, immune complexes other than IgA or hitherto unknown substances enter the basement membrane during the filtration process and trigger frustrane phagocytosis at the basement membrane by their presence, with consecutive basement membrane destruction. 5. It is pointed out that gross hematuria occurs most often in mild forms of mesangioproliferative glomerulonephritis with IgA and C3 deposits in the mesangium and sometimes also in the capillary periphery. 6. It could be shown that in mild forms of mesangioproliferative glomerulonephritis, hematuria occurs more often in the male sex. 7. In 12 biopsy specimens from the kidneys of healthy patients who exhibited no erythrocytes in the urine at the time of biopsy, isolated incomplete basement membrane defects, but no basement membrane ruptures, were observed.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1440
    Keywords: Nephrotic syndrome ; Renal insufficiency ; Protein resorption ; Glomerulonephritides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The following data was obtained by morphometric and photometric microscopic studies of renal biopsies from 140 patients with idiopathic perimembranous glomerulonephritis, 108 patients with focally sclerosing glomeruloncphritis and 50 patients with membranoproliferative glomerulonephritis and correlation of the results obtained with available clinical data: 1. In all three diseases proteinuria and serum protein concentration show no tendency to stabilization in spite of increasing renal insufficiency. 2. With increasing renal insufficiency the proximal tubular cells become increasingly atrophic. 3. Protein resorption through the proximal tubulus cells becomes increasingly diminished with advancing renal insufficiency. It is concluded from the present data that proteinuria, which is primarily glomerular caused, is increased by increasingly diminished resorption of proteins in the tubulus system with increasing renal insufficiency. In this way, even under conditions of advanced renal insufficiency with reduced GFR, large amounts of proteins can be excreted and a nephrotic syndrome can persist to a stage of renal insufficiency.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Histopathology 6 (1982), S. 0 
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Eighteen months experience in the use of an automated staining machine for lengthy histological and immunohistochemical stains in a routine pathology laboratory is described. The apparatus yields an important saving in time for technicians and can maintain the quality of staining at a standardized high level. A disadvantage is the larger volumes of reagents required. Introduction of the machine is recommended when at least five different but lengthy stains have to be performed each day. The considerable gain in time for the technicians has important consequences for the management of pathological laboratories in the near future.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 390 (1981), S. 259-272 
    ISSN: 1432-2307
    Keywords: Renal amyloidosis ; Early lesions ; Amyloid by electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Our investigations on early glomerular changes in renal amyloidosis showed the following: 1. In some renal biopsies, amyloid was demonstrated in the mesangial matrix predominantly and could be seen penetrating through the basememt membrane of the mesangial region into the subepithelial space of adjacent glomerular capillaries. 2. In other biopsies, showing the same severity of amyloidosis, deposits were demonstrated in the mesangium and in the capillary walls distant from the mesangium on both sides of the basememt membrane. There was no apparent connection between the deposits in these two areas. 3. On the basis of the morphological changes found in the cytoplasm of the mesangial cells, the glomerular epithelial cells and partly also in the endothelial cells, supported by our electron microscopic findings in the immediate vicinity of these cells, we come to the conclusion that amyloid in the glomerulus is formed from amyloid precursors brought via the blood stream. 4. Amyloid fibrils may be formed in the extracellular space of the glomerulus under the influence of lysosomal enzymes released from epithelial, mesangial and perhaps endothelial cells, by action of these enzymes on extracellularly deposited amyloid precursors.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2307
    Keywords: Perimembranous glomerulonephritis ; Glomerular amyloidosis ; Therapy with D-penicillamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The results of electron microscopic examination of renal biopsies from 3 patients with rheumatoid arthritis treated with penicillamine are presented. All 3 patients developed a nephrotic syndrome upon discontinuation of penicillamine therapy. When viewed with the electron microscope, segmental forms of perimembranous glomerulonephritis (Stages I–II of Ehrenreich and Churg) and glomerular renal amyloidosis Grade I–III were observed. In all three cases the nephrotic syndrome was considered to be due to the simultaneous occurrence of the two disease processes. In 2 cases perimembranous glomerulonephritis with immuno-complex-deposits was assumed to be the dominant factor in the causation of the disease, in the other case amyloidosis was the principle abnormality.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2307
    Keywords: Secondary amyloidosis ; Healing of nephrotic syndrome ; Electron microscopic investigations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report light- and electron microscopic findings in glomerular amyloidosis (secondary amyloidosis), which occured after recurrent empyema of the pleura. After healing of the empyema, the clinical symptoms disappeared, over a period of eight years. During the acute stage of the disease (grade II–III amyloidosis) when the nephrotic syndrome was present, amyloid deposits were seen in the mesangium and on both sides of the basement membrane of the glomerular capillaries. Furthermore, denuded basement membrane areas showing the passage of amyloid into the urinary space, and invaginations of the podocyte by straightened amyloid fibrils were found. After clinical recovery (except for a trace of proteinuria), the renal amyloidosis had electronmicroscopically transformed from an active into an inactive or resting form, while the amount of amyloid present was almost the same. In the areas of amyloid deposits, reparative changes were observed, especially in the area of the mesangial cells and of the podocytes. The podocytes were separated from the persisting amyloid deposits by newly formed basement membrane material.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 379 (1978), S. 131-141 
    ISSN: 1432-2307
    Keywords: Renal amyloidosis ; Basement membrane denudation ; Cause of nephrotic syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Systematic electron microscopic investigation of glomeruli of 35 patients with renal amyloidosis (grade I–III), among them 26 with the nephrotic syndrome, reveals the following: 1. The extent of the area of basement membrane denuded of its epithelial covering is correlated significantly with the reduction of plasma protein concentration at the time of renal biopsy. 2. In amyloid free regions of the glomerular capillary loops, the foot processes of the epithelial cells remain intact despite the presence of the nephrotic syndrome. From these findings we conclude that the high glomerular protein losses in amyloidosis occur in areas of the basement membrane which are penetrated by amyloid and denuded of their epithelial covering. With increasing number of these lesions per unit area, the permeability of the capillary network for protein increases to a degree which is significantly correlated with the reduced plasma protein concentration at the time of biopsy.
    Type of Medium: Electronic Resource
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