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Biomedical subjects

J Chakraborty

Publications and source records attributed to J Chakraborty.

At least 127 records · Page 7Linked to original sources
PubMed1984

Alloxan-induced diabetes in the rat - protective action of (-) epicatechin?

Administration of alloxan (150 mg/kg body weight, i.p.) to male Wistar rats induced a reproducible and persistent diabetes mellitus as evidenced by elevated serum glucose and low serum insulin concentrations. Administration of either (-)epicatechin or (+)catechin (250 mg/kg, i.p. on each occasion) at 36, 24, 12 and 1 hour before and at 12 and 24 hours after alloxan administration did not prevent the induction of the diabetes. Similarly, treatment of animals with (-)epicatechin or (+)catechin (125 mg/kg i.p. twice daily) for 21 days commencing 24 hours after alloxan administration did not reverse the persisting elevated serum glucose and low serum insulin concentrations. Moreover, administration of these compounds did not relieve any of the symptoms of the alloxan-induced diabetes such as poor weight gain, polyuria or polydipsia. Thus, this study does not confirm previous reports of prophylactic and curative effects of (-)epicatechin against alloxan-induced diabetes in rats, in spite of the high dosages of the compounds used in these experiments.

Animals↗
PubMed1984

Determination of caffeine, theophylline and theobromine in serum and saliva using high-performance liquid chromatography.

A method is described for the measurement of theobromine, theophylline and caffeine in serum and saliva by high-performance liquid chromatography (HPLC). A chloroform/isopropanol extract (85:15, v/v) is evaporated to dryness and chromatographed on a 100 X 4.5 mm id Hypersil octadecylsilane column with UV detection at 280 nm. Theobromine, theophylline, caffeine and the internal standard proxyphylline are satisfactorily resolved with an elution system of acetonitrile/tetrahydrofuran/50 mM acetate buffer, pH 4.0, (4:1:95, v/v). No interference is observed from the presence of xanthine metabolites or any of a number of common drugs examined. A good correlation was observed between the concentrations of caffeine in serum and in saliva suggesting that salivary measurements may be useful for the study of caffeine pharmacokinetics in man. Caffeine levels determined by the HPLC procedure described here agreed well with those obtained by a radioimmunoassay method. The method is also suitable for determining the xanthine content of beverages by direct injection of diluted samples.

Caffeine↗
PubMed1984

Quantitative evaluation of guinea pig spermatogenesis: Epon versus paraffin embedding.

A quantitative evaluation of spermatogenesis in the guinea pig was made at the light microscope level following improved methods of fixation and plastic embedding. The pattern of germ cell differentiation was studied by counting the average number of germ cell nuclei per Sertoli cell nucleus during the seminiferous epithelial cycle. Appreciable cell loss occurred during spermatogenesis. As a result, only 20.8% of the theoretically possible number of spermatozoa were produced from each spermatogonium. A slightly better yield of germ cells was obtained from Epon sections in comparison to paraffin sections. Epon sections can be effectively used for quantitative analyses of various cell populations in small biopsy specimens of testis tissue.

Animals↗
PubMed1983

Plasma levels and response to prednisolone therapy in rheumatoid arthritis.

Plasma prednisolone levels were measured in parallel with clinical and laboratory assessments in seven patients with rheumatoid arthritis on single daily doses of prednisolone which were reduced at weekly intervals from 10 mg. to 7, 6 and 5 mg. A significant negative rank correlation was observed between prednisolone dose and the duration of morning stiffness (p less than 0.05). No significant correlation was observed between plasma prednisolone levels, other clinical assessment criteria or laboratory indices.

Adult↗
PubMed1983

Biochemical mode of action of a hepatoprotective drug: observations on (+)-catechin.

(+)-Catechin inhibits the hepatic lipid accumulation resulting from chronic ethanol ingestion in the rat. Experiments have been carried out to determine the mechanisms underlying this effect. Ethanol was administered (2.0 g/kg intraperitoneally) to Wistar rats and 90 min later 1 microCi [U-14C] palmitic acid injected intraperitoneally. Animals were sacrificed 10 min after injection of palmitate and the liver freeze-clamped. Ethanol caused a 250% increase in the hepatic lactate:pyruvate (L:P) ratio and a 100% increase in the amount of [U-14C] palmitate incorporated into the hepatic lipids when compared with controls. Pretreatment of animals with (+)-catechin (200 mg/kg orally) at 24 and 0 hr before ethanol caused significant reductions in the L:P ratio and amount of radioactivity incorporated into hepatic lipids, when compared with animals receiving ethanol alone. (+)-Catechin also stimulated 14CO2 production from [1-14C] palmitate by liver slices taken from rats 90 min after ethanol administration. Thus, (+)-catechin appears to mediate its effect on fat accumulation partly by correcting the ethanol-induced alterations in hepatic redox state as there is no evidence of the drug inhibiting ethanol metabolism.

Animals↗
PubMed1983

Electron microscopic study of testicular tumor in congenital adrenal hyperplasia.

Ultrastructural features of bilateral testicular biopsy materials, obtained from both tumor and nontumor areas of the testis of a 27-year-old man with congenital adrenal hyperplasia, revealed a number of pathologic changes. Germ cell hypoplasia and extratubular cellular hyperplasia were noticed in the nontumor portion of the testis. In some areas of the tumor, dense collagenous materials surrounded the compressed degenerative seminiferous tubule. In other areas at least three different types of cells were identified: 1) branched, irregular giant cells, 2) small cells in clusters, and 3) modified myoid or smooth muscle cells. It is suggested that these three types of cells have different origins. The concept that these types of tumor cells originate from "pluripotential cells" is supported.

Adrenal Hyperplasia, Congenital↗
PubMed1983

Plasma prednisolone studies in rheumatic patients.

Prednisolone concentration in plasma after a daily maintenance steroid dose was monitored in 83 patients with rheumatic diseases. Although no restrictions were imposed on the intake of food or drink, plasma drug levels tended to peak at 1 h after the ingestion of the standard tablets, whereas intestinal absorption of the enteric-coated preparation was found to be most unpredictable. A profound individual variation was observed in plasma prednisolone concentrations, and neither total nor unbound drug levels showed any consistent relationship with the size of the prednisolone dose or the control of the disease activity. The basal cortisol production was suppressed in one-third of the patients. There is no support from this study for the concept of an 'optimum therapeutic range' of plasma prednisolone for the treatment of rheumatic disease.

Adult↗
PubMed1983

Effects of stress on the reproductive system of male rats and mice.

Male rats were immobilized for 2 hr/day, 5 days a week, for varying periods of time (7-31 days) to assess the effects of stress on the reproductive system. Mice were immobilized for 25-38 days. The effectiveness of the stress was demonstrated by assessing the adrenal and body weight. Adrenal weights were significantly increased (p less than .05--t-test) compared to controls. Body weights were decreased compared to controls. No consistent change was noticed in the testicular weight and progressive motility of the spermatozoa drawn from the cauda epididymis and vas deferens. There were no deleterious effects of immobilization stress on the morphology of the differentiating germ cells, peritubular wall, and the interstitial tissues of the testis.

Animals↗
PubMed1982

High dose intravenous methylprednisolone "pulse" therapy in patients with rheumatoid disease. Plasma methylprednisolone levels and adrenal function.

Twenty seven patients with acute rheumatoid disease who had not previously received systemic corticosteroid therapy were given a pulse(s) of high dose methylprednisolone sodium succinate (MPS) intravenously. Of the 27 patients 22 received 1 g MPS once and 5 were given the drug on three consecutive days. Plasma "MP" (total MPS plus hydrolysed methylprednisolone) and cortisol levels were measured at various intervals post infusion. Clinical assessments were made before and at 2 week intervals after each infusion for 12 weeks. Patients showed objective improvement for up to 12 weeks post infusion. Maximum "MP" levels ranging between 16 and 72 mumol/l were obtained after single infusions. In a majority of the patients "MP" concentrations in plasma were reduced to values between 0.12-3.4 mumol/l in 24 h, 0.06 to 0.13 mumol/l in 48 h. Plasma cortisol levels were incompletely suppressed for a few days in all patients, but the drug was removed from plasma and normal adrenal function restored within a fortnight after steroid infusion at the latest.

Adult↗
PubMed1982

Home-administered oral therapy for diarrhoea: a laboratory study of safety and efficacy.

Serum electrolytes were measured for persons treated for diarrhoea at home with prepackaged or locally available sugar and salt oral rehydration therapy (ORT) solutions and for persons with diarrhoea who received no ORT but were treated according to local customs. No detrimental effect was found for persons treated with ORT at home; no significant difference was found in the frequency at which members of the groups had hypernatraemia. The rates of hyponatraemia and hypokalaemia were significantly lower for persons who took estimated appropriate volumes of ORT than for those who took less than appropriate volumes or for persons treated according to local customs without ORT. These laboratory results indicate that ORT administered in rural homes in Bangladesh was safe and effective under the conditions of our study.

Adolescent↗
PubMed1982

The demographic impact of the family planning--health services project in Matlab, Bangladesh.

This paper evaluates the demographic impact of the Family Planning-Health Services Project in Matlab Thana of rural Bangladesh. The project was begun by the International Centre for Diarrhoeal Disease Research, Bangladesh in October 1977. Contraceptive services--including pills, condoms, IUDs, sterilization, and injectables--are supplemented by oral rehydration, tetanus toxoid, and other services. About 33 percent of eligible couples are using contraception. Impact is evaluated by direct measurement of birth rates in the treatment and comparison areas. An overall fertility decline of about 25 percent is observed, concentrated among older women. The impact is two-to-three times that of an earlier project that included fewer methods and used lesser trained workers. The study shows that intensive family planning efforts can affect fertility in the absence of socioeconomic changes.

Adolescent↗
PubMed1982

The demographic impact of the contraceptive distribution project in Matlab, Bangladesh.

This paper evaluates a study fielded in Bangladesh in 1975 to test the hypothesis that ubiquitous availability of pills and condoms in a rural, traditional, noncontracepting population would increase contraceptive use and reduce fertility. Treatment and comparison areas were designated in Matlab, an area with accurate and complete demographic data. Use prevalence peaked at 18 percent in the first three months of the project and declined thereafter. Project activities continued until 1977. Results show that between-treatment fertility differentials were 10 percent in the first year of program impact, but that effects dissipated with time.

Adolescent↗
PubMed1981

Prednisolone concentrations in plasma, saliva and urine.

Prednisolone was measured in plasma, saliva and urine at various times after a single dose. Peak plasma prednisolone levels were observed about 1 h after the dose. Saliva prednisolone levels were measurable for at least 3 h after dosing but showed no consistent relationship to either total or free plasma prednisolone concentrations. Unchanged prednisolone in amounts up to 14% of the dose administered was found in the 24 h urine and most of it was excreted in the first 5 h.

Adult↗
PubMed1981

Molecular and morphological differentiation of the mouse blastocyst after manipulations of compaction with cytochalasin D.

Cleavage stage mouse embryos were incubated with cytochalasin D, which inhibited cytokinesis, intercellular adhesion and junction formation but not aspects of the morphological polarization associated with compaction. If the drug was removed when controls had formed blastocysts, the embryos compacted within 1 hr, assembled junctional complexes at the apices of their cells and accumulated fluid to form "blastocyst-like vesicles" within the next 8 to 12 hr. The molecular and morphological development of these blastocyst-like vesicles and embryos cultured continuously in cytochalasin D followed the same temporal sequence as untreated controls, indicating that they are similar to normal intact blastocysts despite their decreased number of cells, altered ploidy and the absence of an overt inner cell mass. Since maturation of the embryo can take place in the absence of the intercellular features of compaction, the cellular polarization of blastomeres may be important for initiating the differentiation of inner cell mass and trophectoderm in the normal compacting morula.

Animals↗