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S Mondal

Publications and source records attributed to S Mondal.

At least 37 records · Page 2Linked to original sources
PubMed1998

The E2F-family proteins induce distinct cell cycle regulatory factors in p16-arrested, U343 astrocytoma cells.

We previously demonstrated that P16Ink4a (p16) expression in p16-deficient U343 astrocytoma cells causes a G1 cell cycle arrest, profound changes in cytoskeletal proteins and alterations in expression and activity of the pRB and E2F family proteins. We examine here the effects of expressing wild type or mutant versions of the downstream targets of p16 in U343 astrocytomas. We first attempted to block proliferation of U343 cells using the dominant mutant of pRB, deltap34. Expression of this mutant in the human osteosarcoma, SAOS-2, potently blocked proliferation but did not affect the cell cycle of U343 cells. We next showed that expression of E2F-1, E2F-2, E2F-3 and E2F-4 are each able to overcome this p16-dependent cell cycle arrest but exhibit distinct biological activities. Adenoviral-mediated expression of E2F-1, E2F-2, E2F-3, or E2F-4 overcame the p16-dependent cell cycle block and induced alterations in cell morphology. E2F-5, only in conjunction with DP1, promoted cell cycle progression. For both E2F-1 and E2F-2, but not E2F-3 or E2F-5/DP1, cell cycle re-entry was associated with almost quantitative cell death. Only small numbers of dying cells were observed in E2F-4-expressing cultures. Expression of the different E2F's altered the expression of distinct sets of cell cycle regulatory proteins. E2F-1 induced endogenous E2F-4 expression and also caused an increase in pRB, p107 and cyclin E levels. Expression of E2F-4 caused a weak increase in E2F-1 levels but also strongly induced pRB, p107, p130 and cyclin E. However, E2F-1 and E2F-4 clearly regulate expression of distinct genes, demonstrated when E2F-4 caused a threefold increase in the levels of cdk2 whereas E2F-1 failed to increase in this cyclin dependent kinase. Similarly, expression of E2F-1 or E2F-2 were shown to have distinct effects on the expression of cdk2, cyclin E and pRB despite both of these closely related E2F-family members potently inducing cell death. Thus, E2F-1, E2F-2, E2F-3 and E2F-4 are able to overcome the p16-dependent proliferative block in U343 astrocytoma cells. While overcoming this cell cycle block, each of the E2F's uniquely affect the expression of a number of cell cycle regulatory proteins and have distinct abilities to promote cell death.

Adenoviruses, Human↗
PubMed1997

Peripheral inhibin levels in relation to climatic variations and stage of estrous cycle in buffalo (Bubalus bubalis ).

The present study investigated the peripheral plasma inhibin levels in relation to 1) the stage of estrous cycle and the effect of climatic variations. Blood samples were collected from cyclic buffalo (n=5) once daily for 32 consecutive days during the tropical hot humid (summer) and cold (winter) seasons. Estrus was recorded by parading a vasectomized bull as well as by plasma progesterone determination. In the winter season, peripheral inhibin concentrations which were lowest (0.35 +/- 0.02 ng/ml) during the mid-luteal phase of estrous cycle (Day 6 to Day 14, Day 0 = day of estrus) increased significantly (P < 0.02) to 0.47 +/- 0.04 ng/ml during the late luteal phase (Day -4 to Day -2) and then further to 0.52 +/- 0.03 ng/ml (P< 0.02) during the periestrus phase (Day -1 to Day 1). Inhibin concentrations then decreased significantly (P < 0.02) to 0.40 +/- 0.03 ng/ml during the early luteal phase (Day 2 to Day 5). In the summer season the differences in peripheral inhibin concentrations among different phases of estrous cycle were found to be nonsignificant. A comparison of the circulating inhibin concentrations between the two seasons indicated that inhibin concentrations were significantly higher in the late luteal phase (P < 0.01) and periestrus phase (P < 0.05) during the winter season compared with corresponding periods during the summer season. The present study suggests that peripheral inhibin concentrations change in the estrous cycle during cooler breeding season and that environmental heat stress can cause a reduction in peripheral inhibin concentrations.

Journal Article↗
PubMed1997

Inorganic mercury binding to fish oocyte plasma membrane induces steroidogenesis and translatable messenger RNA synthesis.

Both in vitro and in vivo HgCl2 treatment demonstrated a remarkably high rate of progesterone synthesis accompanied by a low rate of conversion to 17 beta-estradiol in the oocyte of Channa punctatus. On depuration, however, there was a reversal of the steroidogenic scenario with a low progesterone and high estradiol level. The accumulation of progesterone was positively correlated with the significant increase in 3 beta-hydroxysteroid dehydrogenase activity in the Hg-treated fish. Thus, it was clear that at the early stage of intoxication Hg does play a role in the induction of 3 beta-hydroxysteroid dehydrogenase in the oocyte of fish at the spawning stage. The induction of this enzyme was found to be mediated by specific binding of Hg to the plasma membrane Na(+)-K(+)-ATPase (Bmax: 14 nmoles mg-1 protein; Ka 1.14 x 10(8) moles) and increase in the specific messenger RNA translating 3 beta-hydroxysteroid dehydrogenase. It is concluded that inorganic mercury is able to initiate translatable messenger RNA synthesis in fish oocyte at a low degree of intoxication.

3-Hydroxysteroid Dehydrogenases↗
PubMed1997

Specific binding of inorganic mercury to Na(+)-K(+)-ATPase in rat liver plasma membrane and signal transduction.

Specific binding of Hg2+ to ouabain-sensitive Na(+)-K(+)-ATPase of rat liver plasma membrane was demonstrated with a Ka of 2.64 x 10(9) and Bmax of 1.6 nmole mg-1 protein. The binding of mercury to the enzyme also causes significant inhibition of the enzyme, which is greater than its ouabain sensitivity. In the cytosol Hg2+ binding to reduced glutathione (GSH) is stimulated by GSH-S-transferase (GST), the activity of which was found to be significantly enhanced by 15 mM Na+ and 10 mM Hg2+. It is proposed that the transport of Hg2+ inside the cell takes place by increased dissociation of Hg2+ from the membrane due to greater avidity of Hg2+ towards cytosolar GSH binding. The GSH-Hg complex enters the nucleus where it dissociates to bind the metal response element (MRE) of the metallothionein (MT) gene to induce MT transcription.

Animals↗
PubMed1997

Effect of premenstrual stress on audiovisual reaction time and audiogram.

A study of weight, auditory reaction time (ART), visual reaction time (VRT) and audiogram was carried out on 105 healthy female subjects between the age of 17-20 years during the premenstrual and post-menstrual phase. A significant increase in weight and prolongation in auditory reaction time (ART) and visual reaction time (VRT) were observed during premenstrual phase. A slight increase in decibel loss was also observed during premenstrual phase in audiogram though not significant. These changes could be attributed to fluid and salt retention due to overain steroids leading to decrease in the processing capability of central nervous system.

Acoustic Stimulation↗
PubMed1997

A study of the distribution of ABO and Rh(D) blood groups amongst Lodha tribe in Midnapore district of West Bengal.

Distribution of ABO and Rh(D) blood group was studied in 206 Lodha subjects living in the Midnapore district of West Bengal. It was observed that incidence of group A was maximum and incidence of group AB was minimum; 99.5% of the subjects were 'Rh' positive. The highest incidence of group A amongst Lodhas indicates that they might belong to the proto-Australoid group anthropologically.

ABO Blood-Group System↗
PubMed1996

Methionine production by microorganisms.

Microbial production of methionine is reviewed with 73 references. The review describes different methionine-producing organisms, as well as analog-resistant regulatory mutants, their optimum cultural conditions and yields. The pathways of methionine biosynthesis and their regulation are discussed.

Amidohydrolases↗
PubMed1994

Outbreak of cholera due to Vibrio cholerae 01 in Orissa state.

During May-June 1993, an outbreak of acute diarrhoea resulting in deaths primarily in adults was reported in two districts of Orissa state. Epidemiological and microbiological investigations revealed that this outbreak was caused by V. cholerae 01 biotype EITor. V. cholerae 01 strains were uniformly resistant to furazolidone.

Adult↗
PubMed1993

Frusemide-induced diabetes mellitus in insulin pretreated rabbits as an experimental model.

Single dose of frusemide 0.1 mg/kg orally was administered in 10 rabbits pretreated with soluble insulin 4 IU intravenously. Induction of diabetes after 24 h was confirmed by an increase in blood sugar and glucosylated haemoglobin and a decrease in serum insulin levels. Ten diabetic rabbits which received only frusemide without insulin pretreatment were used as controls, whereas equal number of insulin-pretreated rabbits receiving hydrochlorothiazide 250 mg/kg orally served as the positive control group. All biochemical parameters remained unaltered in the frusemide-treated test group as well as the positive control group after two weeks. The pancreatotoxic effect of frusemide may induce a stable hyperglycaemic state in rabbits which could lead to a useful diabetic model.

Administration, Oral↗
PubMed1991

Epidemiology of campylobacteriosis in a cohort of rural population near Calcutta.

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at monthly intervals. The overall diarrhoea attack rate was 19 episodes per 100 person-years with peak incidence in the 1- to 4-year-old age group (76/100 person-years). Eight (11.5%) of the total episodes were campylobacter-associated and the overall rate of campylobacter positive diarrhoeal episodes were 2.2 per 100 person-years. Of the 1002 stool samples from healthy individuals 32 (3.2/100 samples) were positive for campylobacter. The organism was most frequently isolated from children under 1 year of age both during diarrhoeal episodes (11.5 per 100 person-years) and non-diarrhoeal (11.1 per 100 samples). Multiple infections in a family were rare. In 19.4% of the occasions one or more animals were campylobacter positive. However, only in 7.7% of these occasions was a human infection recorded within 1 month after the animal was found to be positive. The study showed that the epidemiology of campylobacteriosis in this community was distinct compared to that observed in developed countries.

Adolescent↗
PubMed1991

An operational study on implementation of oral rehydration therapy in a rural community of West Bengal, India.

An operational study of a 3-tier strategy for implementation of oral rehydration therapy (ORT) was conducted in a block of West Bengal with 216,825 population through the existing health services facilities. All the grassroot level, health workers including their supervisors at various levels were trained regarding the management of patients of diarrhoea with mild to moderate degree of dehydration, by ORT. Another block in the same district with similar demographic features where this intervention was not provided served as control. After 22 months of observation, it was evident that despite adequate training, the performance of Community Health Guides (CHGs) and Anganwadi Workers (AWWs) was not encouraging because of the low utilization of both home available fluids (32.0%) and oral rehydration solution (18.0%) in the study area. Similarly, diarrhoea associated mortality could not be reduced significantly. Lack of motivation and failure to maintain sustained level of skill by the CHGs and AWWs constitute the major bottlenecks for the successful implementation of the programme at the community level.

Child, Preschool↗
PubMed1986

Low-dose captopril alone and in combination with hydrochlorothiazide in the treatment of mild to moderate essential hypertension.

In this open, titrated dose clinical trial, captopril, when used in small doses (up to 150 mg daily) for 8 weeks (n = 5) and 4 months (n = 13) in patients suffering from mild to moderate essential hypertension, produced a fall in blood pressure both systolic and diastolic. The end point viz. supine diastolic blood pressure of 90 mmHg or less was reached in 6 out of 18 patients with captopril alone and in another 4 patients after the addition of hydrochlorothiazide (25 mg to 50 mg daily). In 4 more patients, a good response was observed but the end point was not reached. The response was fair in 1 and poor in 3 remaining patients. The side effects produced were only mild in nature and did not require any change in dosage schedule. No significant changes were produced in serum electrolytes, creatinine and blood counts.

Adult↗