Life Sciences Commons^™

Contribution Of Scanning Electron Microscopy And Associated Analytical Techniques To The Study Of Atherosclerotic Disease, R. Laschi

Scanning Electron Microscopy

Human carotid atheroma has been examined by scanning electron microscopy (SEM) utilizing both secondary and backscattered electron detectors and transmission electron microscopy (TEM) both at conventional and high voltage.

Different cytochemical techniques have been used to map elastic fibers, proteoglycans, calcium, non esterified cholesterol. By immunocytochemistry the distribution of factor VIII related antigen and actin has been studied.

With SEM it was possible to detect aspects of carotid plaques not appreciated when using other conventional techniques. With TEM some modifications of the structural and/or functional features of connective tissue macromolecules have been observed. The occurrence of anomalous collagen has been …

Implantation Failure Of Peritoneal Dialysis Catheters: A Scanning Electron Microscopical Study, D. W. Gregory, G. G. Youngson, D. Marshall

Scanning Electron Microscopy

Patients with end stage renal failure may be treated by continuous ambulatory peritoneal dialysis. The transcutaneous portion of the catheters used in this treatment is covered with porous expanded polytetrafluoroethylene (PTFE) to provide a surface suitable for tissue infiltration. Following some instances where catheters failed to become fixed in the abdominal wall, a scanning electron microscopical study was carried out to compare the infiltration of catheters having successful or unsuccessful implantation.

The porous layer of a well-fixed catheter, removed after successful renal transplantation, was infiltrated with collagen fibrils and overlain by layered connective tissue composed of fibroblasts and collagen fibre …

Collagen Deposition During Wound Repair, Charles J. Doillon, Michael G. Dunn, Richard A. Berg, Frederick H. Silver

Scanning Electron Microscopy

Collagen fiber diameters, amount of birefringent collagen (brightness) and birefringence retardation were measured in implanted collagen-based sponges containing hyaluronic acid (HA) and fibronectin (FN). In the presence of HA and FN, increased number of fibroblasts and brightness were observed 6 days after wounding. Increased brightness in the presence of HA and FN reflected increased deposition of oriented collagen fibers. From days 9 to 12, increased fiber diameters were similar in implanted collagen-based sponges with or without HA and FN. Increased birefringence retardation in sponges containing HA and FN was consistent with increased packing density of collagen fibers observed by scanning …

Demonstrable Fixative Interactions, Keith M. Meek, John A. Chapman

Scanning Electron Microscopy

Electron-optical examination of reconstituted collagen fibrils fixed with tannic acid and/or glutaraldehyde and positively stained with heavy metal anions and cations reveals distinct changes in the high resolution staining patterns seen in TEM. Correlation with the known sequence data demonstrates that these changes are caused by (a) interaction of the fixative with certain charged groups in the collagen and (b) localized stain-exclusion effects following fixation. We have analysed the positive and negative staining patterns from glutaraldehyde-treated collagen in detail. In positive staining, uptake of staining ions is shown to be inhibited not only at residues known to interact with glutaraldehyde …