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Biomedical subjects

B Chandrasekar

Publications and source records attributed to B Chandrasekar.

60 records · Page 4Linked to original sources
PubMed1989

Changes in pancreatic beta cell function during growth and reproductive maturity of rats.

An attempt has been made to study the changes, if any, in the efficiency of pancreatic beta cell function at different ages using one experimental model. For this, pancreatic islets were isolated from albino rats of 3, 8, 12 and 36 weeks of age and challenged with various concentrations of glucose (11.0, 16.7 and 22.2 mM). Significantly higher rate of glucose stimulated (pro)insulin biosynthesis was seen in the islets from 3 week old rats as compared to the islets obtained from 8, 12 and 36 week rats. On the other hand, immunoreactive insulin release was observed to be highest from islets of 8 week old rats followed by that of 12, 36 and 3 week old ones.

Aging↗
PubMed1989

Effects of prednisolone and dexamethasone on (pro)insulin biosynthesis and insulin release by rat islets of Langerhans.

Administration of either prednisolone or dexamethasone (10 mg/kg body wt/day/oral) to rats for 21 days resulted in inhibition of (pro)insulin biosynthesis and immunoreactive insulin release by isolated islets. A gradual reversal of prednisolone's effect was obtained after exposing islets to increasing glucose concentrations but glucose challenges failed to influence dexamethasone's effect.

Animals↗
PubMed1988

Effect of prolonged administration of cyclosporin A on (pro)insulin biosynthesis and insulin release by rat islets of Langerhans.

One group of rats received, an oral dose of 25 mg/kg body weight of Cyclosporin A daily for 21 consecutive days in olive oil, whereas the control group received an equal amount of the vehicle for the same period. On the 22nd day animals selected at random from both the groups were subjected to glucose tolerance (1.5 g/kg body weight/oral). The blood sugar values indicated glucose intolerance in experimental rats compared to vehicle-treated rats. The remaining animals were killed, and the pancreases were separated for islet isolation. After incubation of islets for 3 hr at 37 degrees with different glucose challenges, a highly significant (P less than 0.001) lowering of (pro)insulin biosynthesis, significant decrease in IRI release as well as significant inhibition in activities of acid phosphatase and cathepsin B was seen.

Acid Phosphatase↗
PubMedDate not supplied

Acute effect of balloon mitral valvotomy on serial electrocardiographic changes and their haemodynamic correlation.

The effect of acute haemodynamic changes that occur following balloon mitral valvotomy on the electrocardiogram were studied in 25 patients with isolated rheumatic mitral stenosis. Statistically significant changes were observed in the characteristics of P-wave and QRS axis. Patients who showed changes in P-wave had significantly greater fall in left atrial mean pressure (p < 0.025), lesser residual transmitral gradient (p < 0.025) and greater percentage change in mitral valve area (p < 0.01) following balloon mitral valvotomy. Good correlation was seen between the decrease in right axis deviation of QRS axis and fall in mean pulmonary artery pressure (r = +0.56, p < 0.001) and pulmonary vascular resistance (r = +0.48, p < 0.05). Transient arrhythmias were seen in six patients. All these changes occurred within 72 hours, and in the majority of patients within 24 hours. These results demonstrate that the acute haemodynamic changes following balloon mitral valvotomy produce corresponding changes on electrocardiogram and these changes indicate a significantly greater degree of haemodynamic benefit from the procedure than when these changes are not seen.

Adolescent↗