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C Bhattacharyya

Publications and source records attributed to C Bhattacharyya.

7 recordsLinked to original sources
PubMed2003

Integrated analysis of transcript profiling and protein sequence data.

Transcript profiling can be used to elucidate the molecular and cellular mechanisms involved in ageing and cancer. A recent study of human gastrointestinal stromal tumours (GISTs) with mutations in the KIT gene, Cancer Res. 61 (2001) 8624 exemplifies a common type of investigation. cDNA microarrays were used to generate measurements for 1987 clones in two types of tissues: 13 KIT mutation-positive GISTs and 6 spindle cell tumours from locations outside the gastrointestinal tract. Statistical problems associated with such two-class, high-dimensional profiling data include simultaneous classification and relevant feature identification, probabilistic clustering and protein sequence family modelling. Here, the GIST data were reexamined using specific solutions to these problems, namely sparse hyperplanes, nai;ve Bayes models and profile hidden Markov models respectively. The integrated analysis of molecular profiling and sequence data highlighted 6 clones that may be of clinical and experimental interest. The protein encoded by one of these putative biomarkers defined a novel protein family present in diverse eucarya. The family may be involved in chromosome segregation and/or stability. One family member is a potential biomarker identified recently from a retrospective analysis of transcript profiles for sporadic breast cancer samples from patients with poor and good prognosis, Signal Process. (in press).

Amino Acid Sequence↗
PubMed2001

Developmental expression of alcohol dehydrogenase (ADH3) in zebrafish (Danio rerio).

Alcohol dehydrogenase (ADH) is the primary enzyme responsible for metabolism of ethanol to acetaldehyde. One class of ADH has been described in fish, and has been found to be structurally similar to mammalian class III ADH (glutathione-dependent formaldehyde dehydrogenase) but functionally similar to class I ADH (primarily responsible for ethanol metabolism). We have cloned a cDNA by RT-PCR from zebrafish (Danio rerio) liver representing the zebrafish ADH3 gene product, with a coding region of 1131 nucleotides. The deduced amino acid sequences share 90% identity to ADH3 from the marine fish Sparus aurata, and 82 and 81% identity to the mouse and human sequences, respectively. Using a quantitative competitive RT-PCR assay, ADH3 mRNA was detected at all timepoints analyzed and was lowest between 8 and 24 h postfertilization. Thus, differential ADH3 expression may be at least partly responsible for temporal variations in the sensitivity of zebrafish embryos to developmental alcohol exposure.

Alcohol Dehydrogenase↗
PubMed1995

Peptide from a prokaryotic adhesin blocks leukocyte migration in vitro and in vivo.

The integrin CD11b/CD18 promotes leukocyte extravasation during inflammation. Filamentous hemagglutinin (FHA) of Bordetella pertussis binds to CD11b/CD18, raising the possibility that peptides derived from FHA might inhibit leukocyte migration. The Arg-Gly-Asp (RGD) sequence of FHA has been suggested to modulate binding of ligands to CD11b/CD18. Peptides derived from this region inhibited adherence and transendothelial migration of neutrophils in vitro and prevented recruitment of leukocytes into the cerebrospinal fluid in an experimental model of meningitis in rabbits. The mechanism of the antiinflammatory effect may involve modulation of the activity of CD11b/CD18 through peptide interaction with the leukocyte response integrin/integrin-associated protein complex.

Adhesins, Bacterial↗
PubMed1995

Inhibition of leukocyte-endothelial cell interactions and inflammation by peptides from a bacterial adhesin which mimic coagulation factor X.

Factor X (factor ten) of the coagulation cascade binds to the integrin CD11b/CD18 during inflammation, initiating procoagulant activity on the surface of leukocytes (Altieri, D.C., O.R. Etingin, D.S. Fair, T.K. Brunk, J.E. Geltosky, D.P. Hajjar, and T. S. Edgington. 1991. Science [Wash.DC]. 254:1200-1202). Filamentous hemagglutinin (FHA), an adhesin of Bordetella pertussis also binds to the CD11b/CD18 integrin (Relman D., E. Tuomanen, S. Falkow, D.T. Golenbock, K. Saukkonen, and S.D. Wright. 1990. Cell. 61:1375-1382). FHA and the CD11b/CD18 binding loops of Factor X share amino acid sequence similarity. FHA peptides similar to Factor X binding loops inhibited 125I-Factor X binding to human neutrophils and prolonged clotting time. In addition, ETKEVDG and its Factor X analogue prevented transendothelial migration of leukocytes in vitro and reduced leukocytosis and blood brain barrier disruption in vivo. Interference with leukocyte migration by a coagulation-based peptide suggests a novel strategy for antiinflammatory therapy.

Adhesins, Bacterial↗
PubMed1993

The cell wall mediates pneumococcal attachment to and cytopathology in human endothelial cells.

Streptococcus pneumoniae interacts with vascular endothelial cells during the course of bacteremia. In this study, we characterized the initial attachment of pneumococci to human endothelial cells (EC) and the response of the endothelium to this interaction. Pneumococci adhered to EC in a dose-dependent fashion. Attachment was rapid, with the majority of bacteria attached by 30 min. No difference was found between the attachment of unencapsulated (R6) and encapsulated (SIII) strains. Purified pneumococcal cell wall components competitively inhibited attachment of R6 by a maximum of 60% in a dose-dependent manner. Following attachment of pneumococci or exposure of EC to pneumococcal cell wall, pronounced changes in EC morphology ensued, resulting in striking separation of the cells of the monolayer and, eventually, destruction of the cells. The cytopathic effects of the cell wall were inhibited by antibodies to interleukin-1 but not to tumor necrosis factor. Both antibodies were required to neutralize the cytopathology caused by intact pneumococci. We conclude that pneumococci attach rapidly to human EC and that the cell wall is important in this interaction. Intact pneumococci and pneumococcal cell wall induce profound morphologic changes in human EC, leading to loss of barrier integrity. These cytopathic effects are likely to be cytokine mediated.

Actins↗
PubMed1992

Induction of procoagulant activity on human endothelial cells by Streptococcus pneumoniae.

The inflammatory response in infection caused by gram-negative organisms involves induction of procoagulant activity (PCA) on human endothelial cells. Although infections caused by gram-positive organisms are also associated with fibrin formation and thrombosis, the bacterial determinants inducing PCA are unknown. This study shows that intact pneumococci and the pneumococcal cell wall efficiently induce PCA on human endothelial cells. Upon exposure of endothelial cells to pneumococci, PCA was first detectable at 30 min, peaked at 2 h, and disappeared by 6 h. The specific activities of encapsulated and unencapsulated strains for induction of PCA were equivalent. Purified pneumococcal cell walls were as potent as endotoxin in induction of PCA. The ability to induce a procoagulant state on endothelial cells is a new biological activity of gram-positive cell walls which promotes the participation of the coagulation cascade in the inflammatory response to disease caused by gram-positive organisms.

Blood Coagulation Factors↗