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Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

At least 433 records · Page 24Linked to original sources
PubMed1998

Validation of tobacco and alcohol intake questionnaire in relation to food intakes for the Five City Study and a proposed classification for Indians.

Cross-sectional survey was conducted among 1806 subjects (904 men and 902 women) between 25-64 years of age. The survey instruments were questionnaires according to guidelines of WHO and other Indian studies and based on scores of various attributes of tobacco and alcohol consumption. All subjects with tobacco and alcohol consumption were classified separately into mild, moderate and heavy consumption and previous consumptions were also recorded. The overall prevalence of tobacco consumption was significantly higher in men compared to women (27.5 vs 11.6%), while mild tobacco intakes were comparable (2.0 vs 1.6%), moderate (22.2 vs 7.7%) and heavy (3.3 vs 2.2%) tobacco consumptions were significantly higher in men compared to women. The overall prevalence of alcohol consumption was 10.4% in men without any subject among women. The prevalence of moderate (6.6%) alcohol intakes was significantly higher compared to mild (1.2%) and heavy (2.5%) alcohol consumption. Whisky and country liquor were most commonly consumed alcoholic beverages. Smoking (20.7 vs 1.6%) and tobacco chewing (13.3 vs 10.7%) in men and women respectively were common modes of tobacco consumption. Tobacco consumption was significantly associated with lower consumption of vitamin C and beta-carotene and lower body mass index. These findings suggest that tobacco and alcohol consumption assessed by scores constructed on the basis of various attributes appear to be accurate and the questionnaires may be used with precision for classification and assessment in other population groups.

Adult↗
PubMed1998

Absence of detectable measles virus genome sequence in inflammatory bowel disease tissues and peripheral blood lymphocytes.

A highly sensitive measles-specific RT-PCR-nested PCR system was established, which consistently amplified measles virus genome sequence from control samples containing as little as 5.5 x 10(-3) pfu per reaction. This method failed to detect the presence of measles virus in 93 colonoscopic biopsies and 31 peripheral blood lymphocyte preparations, examined and obtained from patients with inflammatory bowel disease (IBD) and noninflammatory controls. All patients had detectable levels of serum neutralization antibody against measles virus. Each biopsy was estimated to have about one million cells, based on the amplification of the beta actin gene. The assay was calibrated by use of a known number of lymphocytes. The method applied was able to amplify measles virus RNA from a nucleic acid mixture equivalent to 18 cells derived from subacute sclerosing panencephalitis (SSPE) brain material. The level of measles RNA present, if any, in the biopsies is therefore at least 50,000-fold less than in SSPE.

Adult↗
PubMed1998

Immune response in rabbits against Rhipicephalus sanguineus.

Rabbits immunised with homogenates of unfed larvae and nymphs of the tick R. sanguineus developed significant level of protective immunity to infestation with all the stages of the species. The acquisition of resistance was based on feeding and developmental performance parameters (rejection, moulting percentages and feeding period) of larvae and nymphs. The acquisition of resistance against adults was also measured by feeding and reproductive performance of female ticks viz., rejection percent, engorged female and egg mass weights, engorgement, preoviposition and oviposition periods and efficiency of female ticks in converting their food reserve to eggs and larvae. Sera from larval extract (RLAg) immunised rabbits were strongly positive for anti-RLAg antibodies after 3 weeks of immunisation while nymphal extract (RNAg) immunised rabbits were positive for anti-RNAg antibodies after 2 weeks of immunisation in enzyme linked immunosorbent assay. The immunised rabbits were also positive for immediate type hypersensitivity (ITH) reaction on Intradermal inoculation of RLAg and RNAg.

Animals↗
PubMed1998

Immunization of rabbits against Hyalomma anatolicum anatolicum using homogenates from unfed immature ticks.

Antigens were prepared from unfed larvae and nymphs of H. a. anatolicum as homogenised antigens (HLAg and HNAg, respectively). Five rabbits each were inoculated, s.c. with 8.56 mg HLAg and 9.34 mg HNAg in 3 divided doses. Following immunisation rabbits developed significant level of protective immunity to infestation with adults of this species. Significant reduction in engorged percentage and weights of engorged females and egg masses were observed in females fed on immunized rabbits, compared to that of female ticks fed on control rabbits. The engorgement period was also increased significantly. However, conversion efficiency indices remained unaffected. Larval antigen immunized rabbits showed significant antibody level from 28-126 days while with HNAg elevated antibody levels were recorded up to 112 days. Further, the rabbits immunized with HLAg had elevated level of antibodies against HLAg, HNAg, and adult antigen in ELISA. But HNAg immunized rabbits had lower levels of antibodies against HLAg and HAAg as compared to values recorded against HNAg. Anti-HLAg and anti-HNAg sera recognised common antigenic bands of 97.4, 85, 66, 47.3, 42 and 31 kDa in homogenates of larvae, nymphs and adults.

Animals↗
PubMed1998

Alteration of preference of food substances in terms of taste & nutritional value following the lesion of two subdistricts of nucleus accumbens.

Adult albino rats of Wistar strain (200 to 250 g) were lesioned at the nucleus accumbens (Acb) either in the shell area (Acbsh) or in the core area (Acbc). The rats were offered a choice of water and 0.2 per cent saccharine or water and 12 per cent sucrose solution. During the prelesion period, the rats preferred water to the sweet tasting fluids. The Acbc lesion shifted the preference to saccharine from water, but rats with the same lesion consumed equal quantities of sucrose and water. On the other hand, lesion of the Acbsh increased the water intake when paired with either sucrose or saccharine. Food intake was also increased in this lesioned group. The results suggest that the Acbc area appears to participate in the mediation of taste of food while the Acbsh area probably regulates feeding behaviour based on the nutritional value of food substances.

Animals↗
PubMed1998

Prevalence and determinants of central obesity and age-specific waist:hip ratio of people in five cities: the Indian Women's Health Study.

OBJECTIVE: To study the prevalence of central obesity and age-specific waist:hip ratio of urban women from five Indian cities. DESIGN AND SETTING: Cross-sectional surveys were conducted in 6-12 urban streets in different parts of India using similar methods of sample selection and criteria of diagnosis. SUBJECTS AND METHODS: We randomly selected 3212 women, aged 25-64 years, from Moradabad (n = 902), Trivandrum (n = 760), Calcutta (n = 365), Nagpur (n = 405), and Bombay (n = 780). Evaluation was by a questionnaire administered by a physician and a dietician, a physical examination, and anthropometric measurements. RESULTS: The overall prevalence of central obesity among the total number of women was 55.0%, with the highest prevalence in Calcutta (62.2%) and the lowest in Bombay (47.4%). Waist:hip ratio was 0.85 +/- 0.13 (mean +/- SD) with the highest ratio for women in Calcutta (0.87 +/- 0.12) and the lowest for women in Moradabad (0.84 +/- 0.16). After pooling of data from all five cities, multivariate logistic regression analysis showed that, regardless of age, body mass index (> 23 kg/m2; odds ratio 1.12), sedentary lifestyle (odds ratio 2.51), and family history of obesity (odds ratio 2.15) were strongly associated with central obesity. Excess intake of fat was weakly associated with central obesity but age was not a risk factor for central obesity, although the prevalence was highest among those aged over 55 years in Moradabad, Calcutta, and Nagpur. CONCLUSIONS: The overall prevalence of central obesity among the urban women of India has increased, more so in Calcutta and Trivandrum. Body mass index, sedentary lifestyle, and family history of excess intake of fat were significant risk factors for central obesity.

Adult↗
PubMed1998

Purification and characterization of avian glycolipid: beta-galactosyltransferases (GalT-4 and GalT-3): cloning and expression of truncated betaGalT-4.

Acidic glycolipid of ganglio-(containing sialic acid) and sialyl-lactofucosyl-type, SA-Lex (containing sialic acid and fucose) are developmentally regulated and appear to be ubiquitous on neuronal and cancer cell surfaces of animals. Two glycolipid: beta-galactosyltransferases, GalT-3 and GalT-4, were characterized in embryonic chicken brain (ECB). Based on substrate competition experiments, these two activities were believed to be due to expression of two gene products. A cDNA fragments (about 600 bp) encoding the catalytic domain of the GalT-4 (UDP-Gal:LcOse3Cer beta1,4galactosyltransferase) from ECB and human Colo-204 were isolated. These cDNAs were expressed as a soluble glutathione-S-transferase fusion protein (48 kDa) in Escherichia coli. Interactions between GlcNAc-, UDP-hexanolamine-, and alpha-lactalbumin were studied with the purified fusion protein (recombinant and truncated). Functionally it was similar to that of native GalT-4 purified (40000-fold) from 11-day-old ECB. GalT-3 (UDP-Gal:GM2beta1,3galactosyltransferase) was purified from 19-day-old ECB, and a polyclonal antibody was produced against the peptide backbone for immunoscreening of a lambdaZAP ECB cDNA expression library. Each of the GalT-3 peptides (62 and 65 kDa was analyzed by protein fingerprinting analysis indicating a similar peptide mapping pattern.

Animals↗
PubMed1998

Alpha-cyano-beta-hydroxy-beta-methyl-N-[4-(trifluoromethoxy)phenyl] propenamide: an inhibitor of the epidermal growth factor receptor tyrosine kinase with potent cytotoxic activity against breast cancer cells.

Epidermal growth factor receptor (EGF-R) tyrosine kinase is known to be overexpressed in several malignancies and is an important target for anticancer drug design. We constructed a homology model to represent the structure of EGF-R and propose that this model can be used to design potent inhibitors of EGF-R. We used our EGF-R model and a docking procedure to rationally design compounds predicted to bind favorably to EGF-R. This approach led to the successful design of a leflunomide metabolite analogue, which was found to have an IC50 value of 1.7 microM in EGF-R inhibition assays and killed >99% of human breast cancer cells in vitro by triggering apoptosis. The reported studies may provide the basis for the development of a new class of potent and clinically useful anti-breast cancer agents.

Aniline Compounds↗
PubMed1998

Cell cycle control protein p34cdc2 homologue and its phase specific accumulation in synchronized onion (Allium cepa L.) root meristem cells.

A key regulator of the cell cycle is a highly conserved protein kinase whose catalytic subunit, p34cdc2, is encoded by cdc2 gene. Immunoblotting with a polyclonal antibody raised against PSTAIRE sequence (found in the N-terminal region of all cdc2 and cdc2 related proteins throughout the phylogenetic scale including higher plants), was used to study the presence of p34cdc2 in onion scale leaves and root tip cells. p34cdc2 homologues are beyond the detection level in scale leaves. PSTAIRE antibody was used to estimate p34cdc2 kinase protein levels during cell cycle in highly synchronous population of Allium cepa L. root meristem cells. p34cdc2 kinase protein showed gradual increase in their levels from S phase to G2 phase boundary. Immunoprecipitation followed by in vitro histone H1 kinase assays also depicted that its kinase activity increased parallel to the increase in p34cdc2 level.

Amino Acid Sequence↗
PubMed1997

The effects of neonatal median nerve injury on the responsiveness of tactile neurones within the cuneate nucleus of the cat.

1. The capacity of cuneate neurones to attain normal functional properties following neonatal median nerve injury was investigated with single neurone recording in anaesthetized cats, 12-24 months subsequent to a controlled crush injury. Effectiveness of the peripheral nerve injury was confirmed by the abolition of the median nerve compound action potential following the crush. 2. Cuneate recording was carried out after denervation of the forearm, apart from the median nerve, to ensure that neurones studied had receptive fields within the distribution zone of the regenerated median nerve. Controlled and reproducible tactile stimuli were used to evaluate the functional capacities of neurones to determine whether they were consistent with those reported earlier for cuneate neurones in cats that had normal peripheral nerve development. 3. Twenty-two cuneate neurones with well-defined tactile receptive fields within the distribution zone of the regenerated median nerve were classified according to their adaptation characteristics and functional properties. Slowly adapting neurones responded throughout static skin indentations and had graded and approximately linear stimulus-response relations over indentation ranges up to 1.5 mm. Rapidly adapting neurones responded to the dynamic phases of skin indentations and could be divided into two broad classes, one most sensitive to vibrotactile stimuli at 200-400 Hz which appeared to receive a predominant input from Pacinian corpuscle receptors, and a non-Pacinian group that included neurones most sensitive to skin vibration at 5-50 Hz which appeared to receive glabrous skin input from the rapidly adapting class of afferent fibres. 4. Based on the stimulus-response relations and on measures of phase locking in the responses to vibrotactile stimuli, it appears that the functional properties of cuneate neurones activated from the field of a regenerated median nerve subsequent to a neonatal nerve crush injury were consistent with those reported previously for 'control' cuneate neurones. The results indicate that cuneate neurones can acquire normal tactile coding capacities despite the disruption caused by prior crush injury to their peripheral nerve source.

Animals↗
PubMed1997

Ca2+/calmodulin-binding peptides block phototransduction in Limulus ventral photoreceptors: evidence for direct inhibition of phospholipase C.

Phototransduction in Limulus photoreceptors involves a G protein-mediated activation of phospholipase C (PLC) and subsequent steps involving InsP3-mediated release of intracellular Ca2+. While exploring the role of calmodulin in this cascade, we found that intracellular injection of Ca2+/calmodulin-binding peptides (CCBPs) strongly inhibited the light response. By chemically exciting the cascade at various stages, we found the primary target of this effect was not in late stages of the cascade but rather at the level of G protein and PLC. That PLCdelta1 contains a calmodulin-like structure raised the possibility that PLC might be directly affected by CCBPs. To test this possibility, in vitro experiments were conducted on purified PLC. The activity of this enzyme was strongly inhibited by CCBPs and also inhibited by calmodulin itself. Our results suggest that the calmodulin-like region of PLC has an important role in regulating this enzyme.

Amino Acid Sequence↗
PubMed1997

Cytoarchitecture of sensorimotor areas in the cat cerebral cortex.

The organization of multiple motor areas in the cerebral cortex has been investigated frequently in primates but rarely in nonprimate species. To compare sensorimotor areas in cats and primates, the cytoarchitecture of frontal and parietal areas of the cat cerebral cortex was described and mapped from coronal sections stained with cresyl violet or thionine. Multiple subdivisions of areas 4 and 6 were recognized; of these, the cytoarchitecture of area 4 gamma is similar to that of area 4 described in other carnivores and in primates and is characterized by giant pyramidal cells in multiple rows or clusters in lamina V. In other subdivisions of area 4 (4 delta, 4sfu, and 4fu), giant pyramidal cells are few or absent in lamina V, and these subdivisions resemble area 6 of primates. Area 6 of the cat cortex is heterogeneous, and differences in laminar appearance and size of pyramidal cells in lamina V distinguish its four subdivisions (6a alpha, 6a beta, 6a gamma, and 6iffu). The adjoining prefrontal areas are distinguishable from area 6 by the presence of a thin internal granular lamina (lamina IV) and the reduced size of pyramidal cells in lamina V. Laminae are poorly differentiated in the cingulate areas, where a rostral and caudal subdivision can be distinguished on the basis of the absence or presence of lamina IV. Area 3a is characterized by a thin lamina IV and is located between frontal agranular and parietal granular (well-defined lamina IV) fields (3b, 1, 2, 2pri, 5, and 7). Insular cortex can be subdivided into granular and agranular fields.

Animals↗
PubMed1997

Comparison of the cortical connections of areas 4 gamma and 4 delta in the cat cerebral cortex.

Area 4 of the cat cerebral cortex has been subdivided into several regions based on cytoarchitectonic studies: areas 4 gamma, 4 delta, 4sfu, and 4fu (Hassler and Muhs-Clement [1964] J. Hirnforsch. 6:377-420). In a previous study, we found separate representations of contralateral limb movements in areas 4 gamma and 4 delta (Ghosh [1997] J. Comp. Neurol. 380:191-214). To investigate the relationship between these representations, the ipsilateral cortical connections of area 4 gamma and 4 delta were compared by the use of the retrograde neural tracers. After intracortical microstimulation of area 4, tracer was injected into one or two of the following regions: the forelimb regions of the rostral and caudal subdivisions of areas 4 gamma and 4 delta (r4 gamma, r4 delta, c4 gamma, c4 delta, separated by the cruciate sulcus) and the hindlimb regions of c4 gamma and c4 delta. Retrogradely labeled neural profiles were counted in every fourth section of the coronal series and located in cytoarchitectonic areas of the ipsilateral cortex. We found topographically organized reciprocal connections between areas 4 gamma and 4 delta; these connections were part of a rich network of interconnections between the cytoarchitectonic subdivisions of area 4. The forelimb regions of c4 gamma and c4 delta, of r4 gamma and c4 delta, and of r4 gamma and r4 delta were interconnected. These findings support the location of a secondary motor area in 4 delta. No interconnections between the forelimb regions of r4 gamma and c4 gamma, and of r4 delta and c4 gamma, could be found. Area 6 (particularly area 6a gamma) was found to project strongly to the forelimb regions of r4 gamma and r4 delta and relatively weakly to the forelimb region of c4 delta. Retrogradely labeled neurons were also detected in areas 3a, 3b, 1, 2pri, 5, 7, and insula after tracer injections in area 4.

Animals↗
PubMed1997

Ipsilateral cortical connections of area 6 in the cat cerebral cortex.

Many motor areas have been identified within cytoarchitectonic area 6 of the cerebral cortex in primates. To provide a better understanding of the motor functions of area 6 in the cat, the ipsilateral cortical connections of the different cytoarchitectonic subdivisions of area 6 (areas 6a alpha, 6a beta, 6a gamma, and 6iffu) were studied by the use of fluorescent retrograde tracers. Tracer injections, made in the forelimb and face regions of areas 6a alpha and 6a gamma, were guided by data from intracortical microstimulation (ICMS). ICMS did not evoke movements from areas 6a beta and 6iffu. Retrogradely labeled neurons were enumerated in cytoarchitectonically identified areas in the frontal and parietal lobes to show that the subdivisions of area 6 are strongly interconnected except for areas 6a gamma and 6a beta. There are considerable differences in the pattern of connections of the area 6 subdivisions with area 4 and with prefrontal, cingulate, and parietal cortices. Area 4 gamma projects strongly to area 6a gamma but not to the other subdivisions. Areas 4 delta, 4fu, and 4sfu project strongly to 6a alpha and 6iffu but relatively weakly to area 6a beta. Prefrontal areas project strongly to area 6a beta and 6iffu, moderately to 6a alpha, but weakly to area 6a gamma. Cingulate areas project strongly to area 6iffu and moderately to areas 6a alpha and 6a beta but do not project to area 6a gamma. Parietal projections from primary and second somatosensory cortex were directed to area 6a gamma, whereas areas 5, 7, and insula were found to project to all the subdivisions of area 6. These findings support earlier suggestions that secondary motor areas may be located in areas 6a alpha and 6a gamma (Ghosh [1997] J. Comp. Neurol. 380:191-214). Features of the pattern of cortical connections of area 6 common to the cat and primates suggest that their motor areas in the frontal lobe are organized in a similar manner.

Animals↗
PubMed1997

The transcriptional activity of NF-kappaB is regulated by the IkappaB-associated PKAc subunit through a cyclic AMP-independent mechanism.

Stimulation of cells with inducers of NF-kappaB such as LPS and IL-1 leads to the degradation of IkappaB-alpha and IkappaB-beta proteins and translocation of NF-kappaB to the nucleus. We now demonstrate that, besides the physical partitioning of inactive NF-kappaB to the cytosol, the transcriptional activity of NF-kappaB is regulated through phosphorylation of NF-kappaB p65 by protein kinase A (PKA). The catalytic subunit of PKA (PKAc) is maintained in an inactive state through association with IkappaB-alpha or IkappaB-beta in an NF-kappaB-IkappaB-PKAc complex. Signals that cause the degradation of IkappaB result in activation of PKAc in a cAMP-independent manner and the subsequent phosphorylation of p65. Therefore, this pathway represents a novel mechanism for the cAMP-independent activation of PKA and the regulation of NF-kappaB activity.

Adenosine Triphosphate↗
PubMed1997

A novel MAP-kinase kinase from Candida albicans.

A putative MAP-kinase kinase-encoding gene, CaSTE7, was isolated from Candida albicans by complementation of ste7 and ste11 mutants of the pheromone signal-transduction pathway of Saccharomyces cerevisiae. The nucleotide (nt) sequence revealed an ORF of 1767 nt encoding a putative protein of 589 amino acids (aa). CaSTE7 has a strong homology with MAP-kinase kinase STE7 of S. cerevisiae, the kinase domain having 45% homology with that of STE7. The deduced aa sequence contained all eleven consensus kinase subdomains found in MAP-kinase kinases. It can suppress the mating defect of ste5, ste11, ste7, and fus3 kss1 double mutants, but it cannot bypass the ste12 mutation. CaSTE7 behaves as a hyperactive allele of STE7, suppressing the mating defects of the pheromone signal-transduction pathway by constitutively stimulating STE12, and hence STE12-dependent processes.

Amino Acid Sequence↗
PubMed1997

Involvement of host factors in transcription from baculovirus very late promoters -- a review.

The baculovirus expression vector system has emerged as the system of choice for the expression of a number of heterologous genes of both prokaryotic and eukaryotic origin. This system utilizes the baculovirus very late, hyperactive polyhedrin and p10 promoters to drive the transcription of foreign genes. Regulation of transcription from these promoters is presently not well understood even though a number of viral gene products that may be important for transcription have been identified. Fresh insight into host-virus interactions during baculovirus pathogenesis is now offered by the identification of insect host factors that interact with transcriptionally essential motifs of these promoters as well as cis-acting enhancer-like elements upstream from the promoter.

Base Sequence↗