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Biomedical subjects

J Marais

Publications and source records attributed to J Marais.

46 records · Page 3Linked to original sources
PubMed1988

Microvasculature of the feline renal medulla.

The microvascular pattern of the feline renal medulla was studied by scanning electron microscopy using corrosion casts. At the corticomedullary junction, numerous efferent arterioles were observed giving rise to peritubular capillary plexuses and arteriole rectae. Considerable differences in vessel diameters were seen. Arteriolae rectae coursed around interlobar veins before returning to the corticomedullary area, as venulae rectae. Diffuse capillary papillary plexuses were seen protruding into the renal pelvis.

Animals↗
PubMed1988

Ultrastructural morphology of the canine thoracic duct and cisterna chyli.

The ultrastructural morphology of the thoracic duct and cisterna chyli of the dog was examined using scanning and transmission electron microscopy. Examination of the cisterna chyli, reservoir of the lymphatic system, featured a number of afferent lymphatics draining into the cisterna: valves were however absent. The luminal surface of the endothelial lining of both the thoracic duct and cisterna demonstrated ovoid endothelial nuclei with numerous cellular ridges. Considerable variation existed in the number of smooth muscle cells lining the duct and cisterna in the contracted and distended state. Organelles and inclusions characteristic of endothelium and smooth muscle were identified. Reflux of lymph into the thoracic duct was prevented by a mono- and bicuspid valve situated at the lymphaticovenous junction.

Animals↗
PubMed1987

Cortical microvasculature of the feline kidney.

Scanning electron microscopy of corrosion casts was used to study the ultrastructural morphology of the microcirculation in the feline kidney. The technique used enabled us to examine the renal microvasculature by obtaining stable and consistent replicas of the vasculature. Corrosion casts were evaluated at three different levels, namely subcapsular, midcortical and the corticomedullary junction. The interlobular arteries, given off by the arcuate arteries, coursed through the cortex in a radial fashion and afferent arterioles were given off at varying intervals. Large afferent arterioles formed the glomerular capillary lobules which consisted of very tortuous capillaries. Smaller-diameter efferent arterioles were formed at the vascular pole and ran in the opposite direction to the afferent arteriole. The peritubular plexuses were seen as interconnecting capillaries at both the subcapsular, midcortical and corticomedullary junction. Numerous efferent arterioles, derived from the corticomedullary glomeruli, were seen as large, radiating vessels running towards the renal papilla.

Animals↗
PubMed1980

Effect of clofibrate on the enzyme activity of rat liver plasma membranes.

The activity of 3 plasma membranes marker enzymes (5'-nucleotidase, Mg++-ATPase and alkaline phosphodiesterase-I) was determined in plasma membranes isolated from liver of control and of clofibrate-treated rats. A complete indentity of plasma membranes enzyme activity in the 2 groups of experimental animals was observed for the 3 enzymes studied.

5'-Nucleotidase↗
PubMedDate not supplied

Isolation, culture and characterization of adult human hepatocytes from surgical liver biopsies.

A technique is described for isolation and culture of adult human hepatocytes from surgical liver biopsies. The mean cell yield was 1.75 X 10(7) cells per gm liver and viability averaged 80%. Hepatocytes were maintained in primary culture for about 10 days. Cell morphology and histochemical characteristics were similar to hepatocytes in vivo. Bile canaliculi were observed by electron microscopy. Intracellular albumin was demonstrated up to the 7th day of culture; albumin secretion rate was maximal (0.6 +/- 0.33 micrograms per hr per 10(6) cells) 5 days after plating. These studies demonstrate that adult human hepatocytes can be isolated from surgical biopsies with high yield, and differentiated function can be maintained for several days.

Adult↗