Ultrastructural Analysis of Major Basement Membrane Types in Rhesus Monkey &lt;i&gt;Macaca mulatta&lt;/i&gt; Acellular Renal Cortex

Surerus

1986

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Previous transmission electron microscopic studies have demonstrated glomerular basement membrane (GBM) thickening and mesangial matrix (MM) expansion in chronic stages of diabetes. It is difficult, however, to achieve an appreciation of GBM surface features and distribution of MM in planar views. In the current study, autopsy human renal cortical tissue from patients with end-stage diabetic nephropathy were minced and rendered acellular with detergents prior to fixation, cryofracture, and preparation for light microscopic (LM), transmission electron microscopic (TEM), and scanning electron microscopic (SEM) observation in an effort to visualize extracellular materials in three dimensions. Our studies demonstrated that although diabetic glomerular changes vary widely within and between individuals, most showed alterations primarily affecting peripheral (epithelial) GBM (with MM increased but diffusely distributed), or they exhibited similar GBM changes but with variable nodular MM expansion leading ultimately to capillary occlusion. Both types showed peripheral GBM thickening and demonstrated external surface irregularities that by SEM appeared as "cauliflower-like" lobulations. In these glomeruli, GBM lamellation or reduplication was common with internal layers frequently thrown into lumenward projections. Glomeruli with diffusely distributed MM generally showed patent capillary channels with little evidence of occlusion. By TEM, highly compact, epithelial GBMs were clearly distinguishable from the electron-lucent MM. In these preparations the matrix was concentrated in relatively small discrete masses sometimes covered by a finely fibrillar material, which extended intermittently onto lumenal surfaces of epithelial GBMs. In more advanced stages of MM involvement, glomeruli typically exhibited smooth-surfaced nodules that were increased at the expense of capillary surface area. By TEM, MM nodules were comprised of a meshwork of very fine (20-A) fibrils surrounding a variety of detergent-resistant structures including collagenous fibrils and non-collagenous 30-nm circular fibrils with 16-nm subunits. By SEM, GBM and MM nodules were not distinguishable and merged to form substantial barriers to capillary blood flow. In those capillary channels remaining patent, inwardly projecting folds and ridges were common GBM features, and frequently thin fenestrated layers, distinctly separate from epithelial GBMs, formed sieve-like linings for the channels. These three-dimensional observations provide unique views of the processes leading to diabetic glomerular occlusion and suggest a potential for this technique in the study of renal BM disease.

Section: Discussionmentioning

confidence: 59%

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confidence: 84%

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confidence: 99%

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SEM studies of acellular glomerular basement membrane in human diabetic glomerulopathy

Surerus

1986

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“…Muscle BL seems to be an exception, however, and followig our isolation procedure, it exhibits a distinctive fibrillar appearance. SEM analyses of acellular BL have been facilitated by the utilization of a cryofracturing technique (Carlson and Hinds, 1983) which in fortuitously prepared specimens renders internal surfaces of various acellular BL available for SEM observations (Carlson and Hinds, 1983;Carlson and Surerus, 1986;Carlson et al, 1986;Carlson, 1988;1989;Carlson and Bjork, 1990). In the current study this procedure was used to demonstrate the topographical features of skeletal muscle internal BL surfaces.…”

Section: Discussionmentioning

confidence: 99%

A method for preparing skeletal muscle fiber basal laminae

1991

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Previous attempts to prepare skeletal muscle basal laminae (BL) for ultrastructural analyses have been hampered by difficulties in successfully removing skeletal muscle proteins and cellular debris from BL tubes. In the present study we describe a two phase method which results in an acellular muscle preparation, the BL of which are examined by light, transmission electron, and scanning electron microscopy. In the first phase, excised rat extensor digitorum longus muscles are subjected to x-radiation and then soaked in Marcaine to inhibit muscle regeneration and to destroy peripheral muscle fibers. The muscles are then grafted back into their original sites and allowed to remain in place 7-14 days to allow for maximal removal of degenerating muscle tissue with minimal scar tissue formation. In the second phase, the muscle grafts are subjected sequentially to EDTA, triton X-100, DNAase, and sodium deoxycholate to remove phagocytizing cells and associated degenerating muscle tissue. These procedures result in translucent, acellular muscle grafts which show numerous empty tubes of BL backed by endomysial collagenous fibers. These preparations should be useful for morphological analyses of isolated muscle BL and for possible in vitro studies by which the biological activity of muscle BL can be examined.

“…Although the detergent method has been employed widely to isolate BMs prior to TEM observations (Meezan et al, 1975(Meezan et al, , 1979Carlson et al, 1978Carlson et al, , 1981Brendel et al, 1978), it has also been modified to include SEM studies of normal Kenney, 1980, 1982;Carlson and Surerus, 1986;Carlson et al, 1986) and diseased BMs (Bonsib, 1985a,b;Weidner and Lorentz, 1986a,b;Carlson et al, 1986;Marion and Carlson, 1989).…”

Section: Fig 14mentioning

confidence: 99%

SEM and TEM analyses of isolated human retinal microvessel basement membranes in diabetic retinopathy

Bjork

1990

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Human retinas from persons with diabetic retinopathy and age-matched controls were rendered acellular by sequential detergent treatment. The resulting network of microvascular extracellular matrix (ECM) materials, including basement membranes (BMs), was compared by TEM and, following cryofracture, by SEM. Our study demonstrates that in diabetics, retinal capillary BM complexes are generally thickened and that their ECM subcomponents, including BM leaflets and BM-like pericytic matrix (PCM), are differentially altered. Two diabetic microvessel types were identified. In type A vessels, ECM expansion is manifested by loosely arranged combinations of concentric PCM layers and collagen fibrils with thickened subendothelial (EBM) and pericyte (PBM) BM leaflets. Type B vessels show densely compact central PCM masses and poorly recognizable EBMs and PBMs. In both types, Müller cell BMs (MBMs) are relatively unaffected. High-resolution SEM shows tissue-specific features in normal EBM and MBM surfaces, but disease-related topographic changes are not evident. It is possible that the ECM arrangements identified in our study relate to different microvessel domains and that their specific morphological features may play important roles in the pathogenesis of diabetic retinopathy including capillary closure and neovascularization.