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Biomedical subjects

S Bhattacharya

Publications and source records attributed to S Bhattacharya.

At least 415 records · Page 23Linked to original sources
PubMed1991

17beta-Estradiol releases thyroxine from the thyroid follicles of a teleost, Channa gachua (Ham.).

To observe a direct effect of 17beta-estradiol (E2) on thyroid activity, thyroid follicles were isolated from hypobranchial muscles of a freshwater murrel, Channa gachua. Thyroid follicles were incubated (5 X 10(6) follicles/well) in vitro at 30 degrees for 2 hr without hormone and then 3 hr with E2 or bovine thyroid-stimulating hormone (bTSH). Addition of 10 and 100 ng of E2 to thyroid follicles resulted in 2- and 3-fold increases in thyroxine (T4) release. When 100 ng of bTSH was added to check the isolated follicular function, it stimulated T4 release to more than 3-fold. Increasing doses of E2 from 1 to 100 ng caused a dose-dependent stimulation of T4 release, while a 1000-ng dose reduced T4 release compared to 100 ng. When thyroid follicles of this experiment were lysed by sonication and T4 content was determined, it corroborated the profile of T4 release in response to varied E2 doses. E2 was ineffective in increasing 125I uptake by the follicles, while bTSH elevated it by 45% over the control. Incubation of varied concentrations of [3H]estradiol with cytosol and nuclear fractions of thyroid follicles in the presence of a 100-fold excess of diethylstilbestrol showed saturable specific binding of E2.

Animals↗
PubMed1991

The medial upper arm fasciocutaneous flap. An alternative flap to cover palmar defects of hand and distal forearm.

Cutaneous defects on the palmar aspect of the hand and distal forearm can usually be covered by split skin grafts or, if the defect is small, by local flaps. However, for larger defects, especially in acute injuries where preservation of functional parts like nerves and tendons is in jeopardy and particularly when further surgery is contemplated, flap coverage becomes essential. Such a flap, besides being uniformly dependable and cosmetically acceptable, must have a reasonable position of immobilization, must be easy to nurse and must not hamper the daily routine of the patient. The medial upper arm fasciocutaneous flap, both distally based and proximally based appears, after a critical evaluation, to be the best answer to this problem short of a microvascular free flap.

Adolescent↗
PubMed1991

Postburn contracture of the neck--our experience with a new dynamic extension splint.

Twenty-eight examples of postburn contracture of the neck managed during the last 5 years gave us a better understanding of the problems of anaesthesia, contracture release, skin grafting, splintage and maintenance of the fully release state. The severe contracture should be incised before intubation under a local anaesthetic agent. The release should include the adjoining contractures of mandibular and pectoral regions lest the skin graft is pulled by the existing contracture. Haemostasis should be meticulously secured to avoid graft loss. Splintage should be a static splint for 4-6 weeks followed by a dynamic splint until the applied graft becomes soft, supple and wrinkle free. Ideally, however, contractures should be prevented by nursing the patient with a neck extension in the acute phase and wearing a cervical collar during the subacute phase of wound healing.

Adolescent↗
PubMed1991

Inhibition of human fetal brain acetylcholinesterase: marker effect of neurotoxicity.

Human fetal brains were obtained after medical termination of pregnancy at 8-10 wk from informed patients. A definite regionalization of AChE was found in the brain of the fetus, with cerebellum recording the highest and cerebral hemisphere the lowest activity. Optimum conditions for the cerebellar AChE activity were determined with respect to molarity of the buffer, pH, temperature, and concentrations of substrate (acetylthiocholine iodide), activators (NaCl, MgCl2), and thiol indicator (dithiobisnitrobenzoic acid). In vitro inhibition of cerebellar AChE with two commercial pesticides, Metacid-50 (O,O-dimethyl p-nitrophenyl phosphorothioate) and carbaryl (N-methyl naphthyl-1-carbamate), were compared with pure anticholinesterase agents, diisopropylfluorophosphate (DFP) and physostigmine (eserine). In general, organophosphates are more neurotoxic than carbamate compounds, as evidenced by higher degree of AChE inhibition by DFP and Metacid-50 as compared to eserine and carbaryl. Assays were also done with psychotropic drugs by employing the procedure of in vitro AChE inhibition kinetics, and it was found that psychotropic drugs are less potent than organophosphate and carbamate compounds. Results indicate that pure and commercial organophosphates and carbamates and psychotropic drugs are all able to significantly alter the AChE activity. Thus exposure of the mother to these environmental toxicants may adversely affect the fetal neural functions.

Acetylcholinesterase↗
PubMed1991

Effect of chronic non-lethal doses of non-metals and metals on hepatic metallothionein in Channa punctatus (Bloch).

Compared to non-metal toxicants (ammonia, 1.56 ppm; and phenol, 10 ppm), the metals (CdCl2, 30 ppm; HgCl2, 16.7 ppb; and ZnCl2, 6 ppm) significantly induced hepatic metallothionein (MT) concentrations in C. punctatus, exposed independently to non-lethal doses of these toxicants for 28 days. It is suggested that hepatic MT serves as a metal-sequestering protein and is involved in the detoxication of metals only and ensures protection from toxic chemicals in ambience.

Ammonium Hydroxide↗
PubMed1990

Heterogeneity of dystrophin expression in patients with Duchenne and Becker muscular dystrophy.

This report documents the results of an integrated biochemical and immunocytochemical investigation into the expression of dystrophin (the protein product of the Duchenne muscular dystrophy gene) in muscle biopsies from 226 patients. It is the first study in which dystrophin has been analysed on blots and on tissue sections in such a large number of patients using the same (monoclonal) antibody. The 140 patients with Xp21 muscular dystrophy who were included in this study represent a continuous spectrum of disease severity and this range was reflected in the heterogeneity of dystrophin expression which was observed with respect to abundance, size and the pattern of tissue localisation. Approximately 40% of biopsies obtained from patients diagnosed as having Duchenne muscular dystrophy (DMD) contained isolated clearly positive fibres and a further 20% had very weak labelling on a large number of fibres. Biopsies from patients with Becker muscular dystrophy (BMD) showed labelling patterns which varied from weak labelling on the majority of fibres to clear labelling on all fibres. Typically, however, there was inter- and intra-fibre variation in labelling intensity. Approximately 85% of the 52 BMD and 54 DMD patients who had unequivocal labelling on blots demonstrated a protein of abnormal size. The remaining 15% had a protein of normal size but reduced abundance. Overall, the estimated abundance of dystrophin correlated well with clinical assessments of the disease severity expressed in patients. We conclude that dystrophin analysis is an essential and dependable technique for the differential diagnosis of patients with Xp21 muscular dystrophy.

Adolescent↗
PubMed1990

The lateral thoracic region flap.

The lateral thoracic region flap is based at the level of the 3rd rib on multiple direct cutaneous perforators. It has an excellent vascularity with a dependable length/width ratio of 3:1. The donor area, which lies in a concealed region, can often be closed primarily. The flap is hairless and can be used anteriorly to cover raw areas over breast and axilla and posteriorly over scapula and chest wall. As a distant flap it can be used to resurface raw areas on the ipsilateral upper arm and forearm and contralateral hand. The successful use of the flap in 40 cases in this series confirms its reliability, versatility and convenience.

Adult↗
PubMed1990

Metabolic labeling of Entamoeba histolytica antigens: characterization of a 28-kDa major intracellular antigen.

The in vivo incorporation of radiolabeled amino acids into antigens of Entamoeba histolytica, HM-1:IMSS, is reported. Immunoprecipitation with sera from patients with invasive amebiasis revealed a 28-kDa antigen present in whole cell lysates of E. histolytica. This antigen was of cytoplasmic origin, as indicated by cell fractionation and Triton X-114 detergent-phase separation. Immunoprecipitation, using sera from patients with invasive amebiasis and symptomless cyst passers, revealed the 28-kDa antigen as the major antigen recognized by the sera tested. Immunoprecipitation analysis using radiolabeled-released proteins instead of whole cell lysates showed a number of bands, including the 28-kDa antigen. The data suggest that the 28-kDa antigen is of cytoplasmic origin or is released from the cytoplasmic compartment.

Amebiasis↗
PubMed1990

Abnormalities of carbohydrate metabolism and of OCT gene function in the Rett syndrome.

The pathogenetic basis of the Rett syndrome (RS) is unknown: an X-linked dominant, male-lethal gene defect is thought likely. We present a girl with RS who has defects both of the urea cycle and of carbohydrate metabolism resulting in fasting hypoglycaemia, post-prandial hyperlactataemia and excess urinary orotic acid excretion after alanine load. Her sister has a similar clinical picture, but less marked metabolic anomalies. The mother of these sisters has abnormal urinary orotic acid excretion; she transmitted opposite ornithine carbomoyltransferase (OCT) alleles to the two girls. Another girl with RS has similar metabolic responses to fasting and to carbohydrate load. We conclude that RS may be an aetiologically homogeneous condition, but that it includes a variable pattern of metabolic anomalies, and that the gene defect is distinct from the OCT locus.

Adolescent↗
PubMed1990

Localizing multiple X chromosome-linked retinitis pigmentosa loci using multilocus homogeneity tests.

Multilocus linkage analysis of 62 family pedigrees with X chromosome-linked retinitis pigmentosa (XLRP) was undertaken to determine the presence of possible multiple disease loci and to reliably estimate their map location. Multilocus homogeneity tests furnished convincing evidence for the presence of two XLRP loci, the likelihood ratio being 6.4 x 10(9):1 in favor of two versus a single XLRP locus and gave accurate estimates for their map location. In 60-75% of the families, location of an XLRP gene was estimated at 1 centimorgan distal to OTC, and in 25-40% of the families, an XLRP locus was located halfway between DXS14 (p58-1) and DXZ1 (Xcen), with an estimated recombination fraction of 25% between the two XLRP loci. There is also good evidence for a third XLRP locus, midway between DXS28 (C7) and DXS164 (pERT87), supported by a likelihood ratio of 293:1 for three versus two XLRP loci.

Chromosome Mapping↗