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Biomedical subjects

U Chowdhury

Publications and source records attributed to U Chowdhury.

9 recordsLinked to original sources
PubMed2001

Gastrin inhibits cholangiocarcinoma growth through increased apoptosis by activation of Ca2+-dependent protein kinase C-alpha.

BACKGROUND/AIMS: We determined the role of gastrin in the regulation of cholangiocarcinoma growth. METHODS: We evaluated for the functional presence of cholecystokinin (CCK)-B/gastrin receptors in the cholangiocarcinoma cell lines, Mz-ChA-1, HuH-28 and TFK-1. We determined the effect of gastrin on the growth of Mz-ChA-1, HuH-28 and TFK-1 cells. We evaluated the effect of gastrin on growth and apoptosis of Mz-ChA-1 in the absence or presence of inhibitors for CCK-A (L-364, 718) and CCK-B/gastrin (L-365, 260) receptors, the intracellular Ca2+ chelator (BAPTA/AM), and the protein kinase C (PKC)-alpha inhibitor, H7. We evaluated if gastrin effects on Mz-ChA-1 growth and apoptosis are associated with membrane translocation of PKC-alpha. RESULTS: Gastrin inhibited DNA synthesis of Mz-ChA-1, HuH-28 and TFK-1 cells in a dose- and time-dependent fashion. The antiproliferative effect of gastrin on Mz-ChA-1 cells was inhibited by L-365, 260, H7 and BAPTA/AM but not L-364, 718. Gastrin induced membrane translocation of PKC-alpha. The inhibition of growth of Mz-ChA-1 cells by gastrin was associated with increased apoptosis through a PKC-dependent mechanism. CONCLUSIONS: Gastrin inhibits the growth of Mz-ChA-1, HuH-28 and TFK-1 cells. Gastrin inhibits growth and induces apoptosis in Mz-ChA-1 cells through the Ca2+-dependent PKC-alpha. The data suggest a therapeutic role for gastrin in the modulation of cholangiocarcinoma growth.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2001

Clinical implications of brain imaging in eating disorders.

Imaging studies have greatly improved the understanding of the pathology and physiology of psychiatric disorders, such as schizophrenia, affective disorders, obsessive-compulsive disorder, and Tourette syndrome. In the past few years, several neuroimaging studies have concentrated on patients with eating disorders. Although the number of studies is small compared with studies of other psychiatric disorders, the results are beginning to highlight potential areas in the brain that may lead to a better understanding of these disorders. Much research still is needed, and replication of results across centers is needed. The brain is an extremely complex organ; that eating disorders are a result of abnormalities in one specific area of the brain is unlikely. More likely is that several components of the brain have a role, including cortex and subcortical regions and involvement of several neurochemical pathways and circuits within the brain. Further studies are needed in this exciting development of research about eating disorders.

Brain↗
PubMed2001

Genetic association studies of schizophrenia using the 8p21-22 genes: prepronociceptin (PNOC), neuronal nicotinic cholinergic receptor alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1).

Schizophrenia is a common, genetically heterogeneous disorder with a lifetime prevalence of approximately 1% in the general population. Linkage studies of affected families have now strongly implicated a susceptibility locus on chromosome 8p21-22. Tests of allelic association with markers on 8p21-22 should be able to localise any quantitative trait nucleotides (QTN's) or susceptibility mutations to within a few hundred kilobases. Three brain expressed candidate susceptibility genes, prepronociceptin (PNOC), neuronal cholinergic receptor, nicotinic, alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1) have been mapped to chromosome 8p21-22. A case-control, allelic association study was performed using a novel highly polymorphic dinucleotide repeat, D8S2611 near the PNOC gene, two previously characterised dinucleotide repeats, D8S131 and D8S131P at the CHRNA2 locus and an RFLP at the 3'UTR of the arylamine N-acetyltransferase 1 (NAT1) gene. No differences were found in allele frequencies between the patient and control groups. DNA variations or mutations at or near the three genes under study are unlikely to increase susceptibility to schizophrenia in our population sample.

3' Untranslated Regions↗
PubMed2000

A microarray enzyme-linked immunosorbent assay for autoimmune diagnostics.

In order to quantify autoantibodies in the sera of patients with autoimmune disease, we have created a microarray-based immunoassay that allows the simultaneous analysis of 18 known autoantigens. The microarrays contain serial dilutions of the various antigens, thereby allowing accurate determination of autoantibody titer using minimal amounts of serum. The assay is very sensitive and highly specific: as little as 40 fg of a known protein standard can be detected with little or no cross-reactivity to nonspecific proteins. The signal intensities observed from serial dilutions of immobilized antigen correlate well with serial dilutions of autoimmune sera. Miniaturized and highly parallelized immunoassays like these will reduce costs by decreasing reagent consumption and improve efficiency by greatly increasing the number of assays that can be performed with a single serum sample. This system will significantly facilitate and accelerate the diagnostics of autoimmune diseases and can be adapted easily to any other kind of immunoassay.

Antibodies, Antinuclear↗
PubMed1999

Chemical and pharmacological evaluation of different ayurvedic preparations of iron.

Ayurvedic preparations of metallic iron commonly categorised as different 'putas' of 'Louha Bhasma' was chemically analysed and pharmacologically investigated in iron deficiency anemia. Atomic absorption spectral (AAS) study of different putas of Louha Bhasma revealed the presence of various proportions of important metals along with varied concentration of iron in it. The effect of a representative puta viz. 50 puta of Louha Bhasma in the management of agar gel diet and phlebotomy induced iron deficiency anemia in animal model was found to be statistically highly significant (P < 0.001) in comparison to the control and standard drug Fefol treated groups.

Anemia, Iron-Deficiency↗
PubMed1990

Valve replacement in the young patient with rheumatic heart disease. Review of a twenty-year experience.

During a 20-year period 303 young subjects between 9 and 20 years of age (mean, 16.2 +/- 2.72 years) with rapid and relentlessly progressive valvular disease from rheumatic fever underwent valve replacements. The Starr-Edwards ball valve prosthesis remains the device of choice, although other valves have been implanted. The overall hospital mortality rate was 9.6% in the mitral valve, 3.5% in the aortic valve, and 4.2% in the double valve replacement groups. Actuarial survival at 10, 15, and 20 years was 78.4% (+/- 3.3%), 70.0% (+/- 5.8%), and 59.3% (+/- 11.1%), respectively, for patients with mitral valve replacement. The rates for aortic valve replacement were 85.9% (+/- 4.6%) at 10 and 15 years and 72.7% (12.8%) at 20 years. In the double valve replacement group the survival rates after 5 and 10 years were 79.9% (+/- 5.1%). The incidence of thromboembolism was 0.41, 0.59, and 1.04 per 100 patient-years for the mitral, aortic, and double-valve prostheses, respectively. The prospect of childbearing seems promising in those young women who were subsequently married. Our favorable and gratifying experience in this review bears testimony to the physiologic advantages of the Starr-Edwards valve as the device of choice in the rehabilitation of patients with advanced and severe valvular disease after rheumatic fever.

Adolescent↗