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Biomedical subjects

S M Sabesin

Publications and source records attributed to S M Sabesin.

72 records · Page 4Linked to original sources
PubMed1976

Minimal hepatic changes in rats fed alcohol and a high casein diet.

This study was designed to determine whether prolonged ingestion of alcohol in combination with a nutritious diet can produce hepatic cirrhosis in the rat. Male Wistar-strain rats were fed a high protein liquid diet in which alcohol comprised 35.5% of total calories. Rats maintained on this diet for 19 months had normal growth. There was no evidence of cirrhosis after 19 months. Histological examination showed no hepatocellular necrosis, inflammation, or increased connective tissue. Ultrastructural study showed no substantial changes, except for occasional mitochondrial enlargement in cells containing increased lipid. Biochemical analyses at 19 months showed moderate increase in hepatic triglyceride levels and slight increase in hepatic collagen content in the experimental groups.

Animals↗
PubMed1975

Lipoprotein and lecithin: cholesterol acyltransferase changes in galactosamine-induced rat liver injury.

Abnormal lipoproteins and drcreased lecithin: cholesterol acyltransferase activity are found in rat plasma following intraperitoneal injection of D-galactosamine. The changes observed, including absence of alpha-lipoprotein and the presence of lipoproteins rich in phospholipid and unesterified cholesterol but deficient in cholesteryl esters, are remarkably similar to changes found in human pathologic states of lecithin: cholesterol acyltransferase deficiency. When examined by electron microscopy, all of the major lipoprotein classes isolated by ultracentrifugation showed morphological abnormalities including the formation of rouleaus consisting of disk-shaped particles.

Acyltransferases↗
PubMed1975

Intestinal lipid absorption: evidence for an intrinsic defect of chylomicron secretion by normal rat distal intestine.

Intracellular triglyceride accumulation and delayed chylomicron secretion were demonstrated in distal but not in proximal rat intestine following prolonged steady state fat absorption. After 1 and 4 hr of intraduodenal triolein infusion, the mucosal triglyceride content in distal intestinal segments was greatly increased compared with proximal segments. Electron microscopy at each time interval disclosed greater quantities of lipid droplets within the distal cells and these were much larger than the intracellular droplets in the proximal cells, some attaining an enormous size (9000 mum). When proximal and distal cells were compared at intervals after cessation of a 4 hr triolein infusion, the differences in intracellular lipid accumulation were also evident because, even after 6 hr the distal cells were still filled with large droplets, whereas the proximal cells were almost devoid of fat. These results indicate a basic cellular difference between proximal and distal intestine in the processing of fat and, in contrast to current concepts, suggest that defective chylomicron secretion is not necessarily associated with limited B-apoprotein availability.

Animals↗
PubMed1975

Toxic effect of puromycin on erythrocyte membranes which is unrelated to inhibition of protein synthesis.

Exposure of rabbit or human erythrocytes to concentrations of puromycin as low as 7 x 10(-4)M for 2 hr causes damage to the cell membrane, as evidenced by increased susceptibility of the cells to hyposmotic lysis, increased cell rigidity, and ultrastructural changes consistent with severe membrane damage. Puromycin causes a concentration-dependent internalization of the erythrocyte membrane, resulting in vacuolization of the cells, at concentrations between 7 x 10(-4) M and 10(-2) M. Since the erythrocyte does not synthesize protein, the data indicate that puromycin has a direct toxic effect on erythroid cell membranes which is unrelated to its action in inhibiting the synthesis of protein.

Animals↗
PubMed1968

Rat intestinal microvillus membranes. Purification and biochemical characterization.

1. A technique is described for the removal of subcellular contaminants from intact rat intestinal brush borders, and for the subsequent separation of a microvillus membrane fraction from a fibrillar residue. 2. Increments in invertase activity, microscopic homogeneity and low nucleic acid content indicate that the microvillus plasma membrane has been extensively purified. Multiple membrane preparations have been shown to be highly reproducible with respect to their invertase specific activity, cholesterol content and phospholipid content. Alkaline phosphatase, leucine aminopeptidase, Mg(2+)- and Ca(2+)-dependent adenosine triphosphatase and seven separate disaccharidases were shown to be predominantly confined to the membrane fraction. 3. The fibrillar fraction has been shown to contain approximately 30% of the total protein of purified brush borders, plus most of the residual nucleic acid contaminant. No evidence was found for the localization of any specific enzyme in this fraction.

Adenosine Triphosphatases↗
PubMed1965

Lymphocytes of small mammals: spontaneous transformation in culture to blastoids.

Small lynmphocytes froni rabbit and guinea pig, grown in tissue culture in the absence of phytohemagglutinin, can transform spontaneously into cytologically immature cells that are indistinguishable morphologically from blast cells. The transformation occurs in 38 to 75 percent of peripheral lymphocytes and 55 to 75 percent of splenic lymphocytes on the 5th day of culture. The altered cells can synthesize RNA and DNA and show mitotic division; synthesis of DNA occurs after the 5th day of culture, whereas RNA is synthesized throughout the duration of culture.

Animals↗