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Biomedical subjects

B Bandyopadhyay

Publications and source records attributed to B Bandyopadhyay.

10 recordsLinked to original sources
PubMed2000

2-5A antisense directed against telomerase RNA produces apoptosis in ovarian cancer cells.

OBJECTIVE: RNase L is converted to an active form upon binding short 2',5'-oligoadenylates (2-5A). To direct RNase L to an RNA target, 2-5A is attached to an antisense oligonucleotide (2-5A antisense). This chimera can be directed against telomerase-an RNA-protein complex that elongates telomeric DNA and is involved in cellular immortalization. Our objective is to investigate the effect of 2-5A antisense by targeting telomerase RNA (hTR) in the ovarian cancer cell line, HEY-1B. METHODS: Baseline RNase L levels and telomerase activities were measured in both HEY-1B and normal ovarian epithelial cells (NOE). Cells were treated daily with chimeric oligonuclotides (ODN) directed against four different hTR sites, or control ODNs including nonchimeric antisense, 2-5A fused to a mismatched sequence, or inactive 2-5A fused to antisense. At 48 h, apoptosis was evaluated using the TUNEL assay. After six daily ODN administrations, telomerase activity was redetermined, and at 7 days viability counts were obtained. RESULTS: Both cell lines expressed similar levels of RNase L. Hey-1B displayed telomerase activity while NOE did not. After 7 days of transfection, 2-5A antisense ODNs caused profound cell death in the HEY-1B cells, but not in the NOE cells. This effect was seen regardless of hTR target site, and ODN controls showed no significant decrease in cell viability in either cell line. HEY1B cells treated with 2-5A antisense against hTR showed a decrease in telomerase activity and a profound induction of programmed cell death. CONCLUSIONS: The results suggest that 2-5A antisense directed against telomerase RNA results in apoptotic cell death in ovarian cancer cells, but not normal ovarian epithelial cells. The 2-5A antisense strategy may hold a considerable advantage over the conventional antisense approach in targeting cancer-causing genes.

Adenine Nucleotides↗
PubMed1997

Protective effect of zinc gluconate on chemically induced gastric ulcer.

This study was undertaken in rats to ascertain the role of zinc as an antiulcerogenic agent employing its more bioavailable gluconate derivative. Pretreatment with zinc gluconate 10 mg/kg body wt orally for three consecutive days, protected against alcohol induced gastric epithelial damage and also significantly prevented non-steroidal anti-inflammatory drugs (NSAID) induced gastric ulcer in rats. The enhanced levels of mucus, and hexosamine and decreased acid output in the gastric secretion of zinc treated rats, increased the gastric mucosal barrier. Studies on the mechanism of action suggested the involvement of -SH groups in producing gastric antisecretory effect. Thus, zinc gluconate at > > 100 microM concentrations inhibited H(+)-ion transport which could be reversed by incorporating beta-mercaptoethanol in the secretory solution (luminal side). On the other hand, beta-mercaptoethanol added from the nutrient side showed no effect on the inhibition of H(+)-transport indicting that the implication of -SH groups may not be the sole factor. Zinc appeared to play a vital and multifaceted protective role in chemically induced gastric ulcer disorders.

Animals↗
PubMed1995

Serum zinc level : a possible index in the pathogenesis of peptic ulcer syndrome.

The present investigation shows a possible correlation between serum zinc level and peptic ulcer disease/syndrome and a plausible mechanism for the finding. Clinicopathological study of patients with peptic ulcer diseases followed by confirmed endoscopic findings shows a significant low serum zinc level, 0.846 +/- 0.15 ug/ ml +/- S.D. (P < 0.001) with an exception of approx. 10% of the patients. To understand the cellular mechanism of low zinc levels in serum, tissue zinc content of gastric mucosa was determined. A significant increased value (P < 0.01) of zinc content in gastric mucosa of patients with peptic ulcer diathesis was noted. Carbonic anhydrase, a major zinc containing enzyme was also determined in erythrocytes. However, no change of erythrocyte carbonic anhydrase content was noted. To assess the nutritional status of the patients in relation to the low serum zinc value, serum albumin level was also determined. The low serum zinc level of the peptic ulcer patients is possibly due to the positive shift for the zinc from serum to the gastric mucosa.

Carbonic Anhydrases↗
PubMed1981

Body fat in urban and rural male college students of eastern India.

Male college students (N = 381) residing in several districts of Eastern India, classified into two groups, urban (N = 193) and rural (N = 188), were studied by anthropometric measurements of skinfold thicknesses in several sites of the body to determine their body fat content. The mean value of percentage of body fat was found to be significantly higher (P less than 0.001) in the urban group of students (12.07 +/- 3.04) than in the rurals (11.04 +/- 2.63). The mean values of skinfold thicknesses of the biceps, triceps, and subscapular regions were also found to be higher in urbans (P less than 0.01), but no such significant differences in mean values of supra-iliac and abdominal skinfolds were found between the two groups of students. Most of the subjects of both the groups had a greater thickness of the abdominal skinfold compared to thickness of the biceps, triceps, and suprailiac skinfolds. It was found that the college students of Eastern India were leaner than the youths of North America, Europe, Japan, and Northern India.

Adipose Tissue↗