Biomedical subjects

S Bhadra

Publications and source records attributed to S Bhadra.

At least 73 records · Page 4Linked to original sources

PubMed1991

Incorporation of liposomal phytosterols into human cells in culture: a potential in vitro model for investigating pathological effects of phytosterolemia.

A potential in vitro cell culture model was developed for studies concerning the pathological effect of phytosterolemia in which liposomal phytosterols were incorporated into human skin fibroblasts and hepatoblastoma (HepG2) cells. After incubation with phytosterols, fibroblasts and HepG2 cells contained a significant amount (20-27%) of phytosterols (campesterol and beta-sitosterol). Phytosterol accumulation caused a significant reduction in the cholesterol content of cells. Labeled sitosterol and cholesterol showed similar uptake with lower esterification of sitosterol when compared to cholesterol. Labeled sitosterol incorporated into LDL was esterified to a greater extent than sitosterol added as straight liposome. About 23% of the labeled sitosterol was converted into acidic products and 5.6% was present as 5 alpha-stanols in HepG2 cells.

Cells, Cultured↗

PubMed1991

Multifunctional role for fetuin (fetal protein) in lipid transport.

Recent studies from this laboratory have shown that fetuin 1) is nearly 50-fold more efficient than albumin in incorporating exogenous fatty acids into cultured cells, (JBC, 265: 5883, 1990), and 2) is associated with a lipoprotein-like particle (FASEB J. 3: 2075-2080, 1989). In the present study, this lipid-containing fraction (FLP) was isolated by ultracentrifugation, and its effect on cholesterol efflux from cultured human skin fibroblasts and Hep-G2 cells prelabeled with [14C]cholesterol was investigated. FLP fraction caused a significant efflux of [14C]cholesterol from cells, the same in magnitude as HDL. This effect of fetuin supranatant fraction increased proportionately with concentration and time. Similar results were observed with Hep-G2 cells. This ability to induce efflux of cholesterol was confirmed by a decrease in cholesterol mass of cells after 24 h incubation with FLP. The ultracentrifugal bottom (infranatant) fraction of fetuin (FI) was ineffective in this regard. However, FI was more effective in the incorporation of exogenous fatty acids into cellular triglycerides. These studies suggest that the fetuin molecule is a multifunctional protein (delivery of fatty acids to cells and cholesterol efflux from cells) which may play a role in lipid transport during fetal life.

Animals↗

PubMed1991

Plasma lipoprotein peroxidation potential: a test to evaluate individual susceptibility to peroxidation.

Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we developed a test to determine susceptibility of whole plasma to metal/H2O2-catalyzed peroxidation. Incubation of 300-500 microL of plasma with H2O2/cupric acetate resulted in the formation of products from fatty acids (malonaldehyde, measured by thiobarbituric acid assay) and cholesterol (predominantly cholest-3,5-dien-7-one, measured by gas-liquid chromatography). In the presence of Cu2+, formation of malonaldehyde and cholest-3,5-dien-7-one increased at least 10-fold over basal values. Lipid peroxide (malonaldehyde) and cholesterol oxide concentrations after peroxidation were significantly higher (P less than 0.01) in diabetic plasma than in normal plasma. Because susceptibility to plasma peroxidation represents a balance between pro-oxidant factors and antioxidant protection, this test may be useful in determining individual susceptibility to peroxidation as influenced by nutritional and clinical status.

Adult↗

PubMed1990