Papers by Sajalendu Ghosh
Journal of chemical …, 2000
Journal of Chemical Crystallography (JOCC) PP261-344769 September 8, 2001 11:3 Style file version... more Journal of Chemical Crystallography (JOCC) PP261-344769 September 8, 2001 11:3 Style file version Nov. 07, 2000 ... Journal of Chemical Crystallography, Vol. 30, No. 10, October 2000 ( c 2001) ... Regiospecificity of nucleotideamino acid mating vs. water
The Indian Journal of Medical Research
Journal of diarrhoeal diseases research
... Centre for Diarrhoeal 0253-8768/87 $1.00+ 0.10 Disease Research, Bangladesh SHORT COMMUNICATI... more ... Centre for Diarrhoeal 0253-8768/87 $1.00+ 0.10 Disease Research, Bangladesh SHORT COMMUNICATION EFFECT OF HANDWASHING ON THE INCIDENCE OF DIARRHOEA IN A CALCUTTA SLUM BK SIRCAR, PG SENGUPTA, SK MONDAL, DN GUPTA, NC SAHA, S ...
The Indian journal of medical research, 1999
From October to December 1998, single faecal samples from 67 healthy cattle in a semi-urban commu... more From October to December 1998, single faecal samples from 67 healthy cattle in a semi-urban community near Calcutta were examined for Shiga toxin producing Esch. coli (STEC) using a multiplex PCR primary screen followed by plating on sorbitol MacConkey agar. STEC was isolated from the faeces of 7 (10.5%) animals. The eight strains isolated belonged to eight serotypes viz, O146:H1, O149:HNT, ONT:H34, ONT:H19, O88:HN, ONT:H2, O82:H8 and O28ac:H21. Bead enzyme linked immunosorbent assay showed that three strains produced Shiga toxin 1, one produced Shiga toxin 2 and four produced both.
Applied and environmental microbiology, 1997
Acidophilic heterotrophic strain GS19h of the genus Acidocella exhibited extremely high resistanc... more Acidophilic heterotrophic strain GS19h of the genus Acidocella exhibited extremely high resistance to CdSO4 and ZnSO4, with a MIC of 1 M for each. The respective MICs for an Acidocella aminolytica strain were 400 and 600 mM. The MICs of NiSO4 for the above strains were 200 and 175 mM, respectively. These strains were also resistant to CuSO4, the MICs being 20 and 40 mM, respectively. An Acidocella facilis strain showed resistance only to ZnSO4, with a MIC of 150 mM. The metal salts, in general, extended the lag period, log period, and generation time, with decreases in growth rate and optimum growth. A. aminolytica and strain GS19h each contain more than one plasmid, while A. facilis contains none. After transformation by electroporation with the plasmid preparation from strain GS19h, an Acidiphilium multivorum strain became highly resistant to cadmium and zinc, and the plasmid profile of the transformed cells was found to differ from that of the original Acidiphilium multivorum str...
Indian journal of public health
In a cross sectional study of total 14514 tribal Nicobarese people of Car Nicobar Island, an unio... more In a cross sectional study of total 14514 tribal Nicobarese people of Car Nicobar Island, an union territory of India, situated in Bay of Bengal, morbidity, mortality and treatment practices of diarrhoeal diseases of under-five children were surveyed. The incidence of diarrhoea (0.2 episode/ch.year), Crude death rate (3.6/1000) and IMR (31/1000 live births) were exceedingly low as compared to SouthEast Asian Countries including mainland of India. ORS utilisation rate was high (41%) as compared to the National figure (12.0%). This is the first study of it's kind carried out in this island and amongst the Nicobarese tribe in India. A preliminary study carried out among the mothers of the hospitalised children indicated that protective behaviours like breast feeding, hand washing, use of chlorinated water and proper disposal of stool were regularly being practiced by the community traditionally. An in-depth study on risk factors of diarrhoea in this island can yield useful clue for...
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1996
A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between ... more A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between August 1992 and December 1994. A cohort of rural children below 4 years of age was prospectively observed to determine the clinico-epidemiological aspects of mucoid diarrhoea and examine propensity to invasiveness. Overall, the incidence of diarrhoea was 1.7 episodes/child/year, and that of mucoid and bloody dysentery was 08 and 0.2 episodes/child/year, respectively. Children aged 6-l 1 months had a higher incidence of mucoid diarrhoea (1.3 episodes/child/year) and the peak season occurred in June and July. Multivariate analysis using logistic regression showed that mucoid diarrhoea and bloody dysentery were closely similar in both clinical and laboratory findings, including raised faecal leucocyte count (> lo/high power microscope field [hpfl). However, abdominal pain occurred more frequently in bloody dysentery than in mucoid diarrhoea. Faecal leucocyte count (> lO/hpf) can therefore be used as an indicator for invasiveness of mucoid diarrhoea at the community level.
Mammalian Genome, 2010
The adrenomedullary hormone epinephrine transduces environmental stressors into cardiovascular ev... more The adrenomedullary hormone epinephrine transduces environmental stressors into cardiovascular events (tachycardia and hypertension). Although the epinephrine biosynthetic enzyme PNMT genetic locus displays both linkage and association to such traits, genetic variation underlying these quantitative phenotypes is not established. Using an integrated suite of computational and experimental approaches, we elucidate a functional mechanism for common (minor allele frequencies [ 30%) genetic variants at PNMT. Transcription factor binding motif prediction on mammalian PNMT promoter alignments identified two variant regulatory motifs, SP1 and EGR1, disrupted by G-367A (rs3764351), and SOX17 motif created by G-161A (rs876493). Electrophoretic mobility shifts of approximately 30-bp oligonucleotides containing ancestral versus variant alleles validated the computational hypothesis. Queried against chromaffin cell nuclear protein extracts, only the G-367 and -161A alleles shifted. Specific antibodies applied in electrophoretic gel shift experiments confirmed binding of SP1 and EGR1 to G-367 and SOX17 to -161A. The in vitro allele-specific binding was verified in cella through promoter reporter assays: lower activity for -367A haplotypes cotransfected by SP1 (p = 0.002) and EGR1 (p = 0.034); and enhanced inhibition of -161A haplotypes (p = 0.0003) cotransfected with SP1 ? SOX17. Finally, we probed cis/trans regulation with endogenous factors by chromatin immunoprecipitation using SP1/EGR1/SOX17 antibodies. We describe the systematic application of complementary computational and experimental techniques to detect and document functional genetic variation in a trait-associated regulatory region. The results provide insight into cis and trans transcriptional mechanisms whereby common variation at PNMT can give rise to quantitative changes in human physiological and disease traits. Thus, PNMT variants in cis may interact with nuclear factors in trans to govern adrenergic activity.
Journal of the American College of Cardiology, 2010
The purpose of this study is to understand whether naturally occurring genetic variation in the p... more The purpose of this study is to understand whether naturally occurring genetic variation in the promoter of chromogranin B (CHGB), a major constituent of catecholamine storage vesicles, is functional and confers risk for cardiovascular disease.
FEMS Microbiology Letters, 2000
Preservation of the acidophilic heterotroph, Acidocella sp. strain GS19h, at 4³C in stab culture ... more Preservation of the acidophilic heterotroph, Acidocella sp. strain GS19h, at 4³C in stab culture eliminated all indigenous plasmids from this bacterium. Growth at 42³C initially caused changes in the plasmid profile followed by total elimination of plasmids after 10 cycles of growth. Concomitant to this loss of all plasmids, the cured derivatives became sensitive to CdSO 4 and ZnSO 4 , and the MIC value of the salts dropped from 1 M for each in the case of parental strain to 2 mM and 5 mM, respectively, suggesting plasmid-mediated inheritance of metal resistance in this bacterium. The cured derivatives could not utilise lactose, indicating this metabolic activity to be plasmid-associated in this strain. ß
European Journal of Pharmacology, 2011
Biochanin-A, an isoflavone, existing in red clover, cabbage and alfalfa, has an inhibitory and ap... more Biochanin-A, an isoflavone, existing in red clover, cabbage and alfalfa, has an inhibitory and apoptogenic effect on certain cancer cells. However, the actual mechanism by which this compound inhibits proliferation and induces apoptosis in cancer cells and the mechanism of its anti-inflammatory activities have not been well characterized. In this study, we have investigated the anti-inflammatory and anti-proliferative activity of Biochanin-A. The effects of Biochanin-A on RAW 264.7, HT-29 cell lines and mouse peritoneal macrophages have been investigated in vitro. Cell proliferation and anti-inflammatory effects were analyzed by 3-(4-5dimethylthiozol-2-yl)2-5-diphenyl-tetrazolium bromide (MTT) assay, 3 H-thymidine incorporation assay, Western blot, cytokines estimation, Luciferase assay, Electrophoretic mobility shift assay (EMSA) and Kinase assay. Present investigation demonstrated that, Biochanin-A inhibited lipopolysacharide (LPS)-induced nitric oxide(NO) production in macrophage and showed dose dependent inhibition of inducible nitric oxide synthase (iNOS) expression. The induction of NF-κB binding activity by LPS was inhibited markedly by coincubation with different doses of Biochanin-A. Biochanin-A inhibited the LPS-induced IkB kinase (IKK) activity and nuclear factor kappa beta (NF-κB) activation associated with the inhibition of iNOS expression. LPS-induced phosphorylation of IκBα and p38 MAPK was blocked by Biochanin-A and it inhibited IL-6, IL-1β and TNF-α production in RAW264.7 cells indicating its anti-inflammatory activity in association with antiproliferation. Biochanin-A is important for the prevention of phosphorylation and degradation of IκBα, thereby blocking NF-κB activation, which in turn leads to decreased expression of the iNOS, thus preventing proliferation and inflammation.
Current Microbiology, 2002
The acidophilic heterotroph, Acidiphilium symbioticum KM2, is highly resistant to several metals ... more The acidophilic heterotroph, Acidiphilium symbioticum KM2, is highly resistant to several metals and harbors three plasmids of 3.8, 7.1, and 56 kb in size. The bacterium becomes extremely sensitive to metals when it is cured of its plasmids. A mini-plasmid library was constructed by ligating the plasmid DNA fragments generated by MboI partial digestion into the BamHI site of pBluescriptII KS+. The Lac(-)Amp(r) transformants of Escherichia coli DH5alpha, isolated after transformation with the library, were counter-selected on Cu(2+), Cd(2+), Ni(2+), and Zn(2+)-containing plates. Only Cd(2+)- and Zn(2+)-resistant colonies were developed, and, after screening, four types of recombinant plasmids designated as pNM201 (7.2 kb), pNM206 (3.4 kb), pNM208 (4.5 kb), and pNM215 (4.9 kb) were obtained. The DNA insert in pNM206 hybridized strongly with the 3.8-kb plasmid and weakly with the 7.1-kb plasmid of Acidiphilium symbioticum KM2. The DNA insert in pNM215 hybridized only with the 7.1-kb plasmid. These results strongly suggested that resistance to cadmium and zinc in A. symbioticum KM2 is mediated by these plasmids. The smallest insert of 422 bp in pNM206 conferring metal resistance in E. coli has no sequence similarity with the reported metal-resistant genes. All the putative ORFs are significantly rich (up to 37%) in basic amino acids, mainly arginine.
Current Microbiology, 2005
Acidophilic bacteria of mine origin are ideal systems for studying microbial metal resistance bec... more Acidophilic bacteria of mine origin are ideal systems for studying microbial metal resistance because of their ability to grow in the presence of high concentrations of metal salts. We have previously shown that the metal-resistant transformants obtained after transformation of Escherichia coli DH5a with plasmid DNA preparation from Acidocella sp. strain GS19h did not contain any plasmid suggesting chromosomal integration of the plasmid(s) (Appl Environ Microbiol 1997; 63: 4523-4527). The present study provides evidence in support of this suggestion. The pulsed field gel electrophoresis (PFGE) pattern of genomic DNA of the plasmidless metal-resistant transformants differed markedly from that of the untransformed DH5a strain. Moreover, when the recombinant plasmids constructed by cloning plasmid DNA fragments of the Acidocella strain GS19h in the vector pBluescript II KS+ were used to transform E. coli DH5a strain, no plasmid DNA was detected in some of the zinc-and ampicillinresistant (Zn r Amp r ) clones. The PFGE pattern of genomic DNA of such a transformed clone also differed markedly from that of the parent strain, suggesting chromosomal integration of the recombinant plasmid(s) containing both ampicillin-and zinc-resistance determinants. This observation was further supported by hybridization of chromosomal DNA of the plasmidless Zn r Amp r E. coli DH5a clone with the probes made from the plasmid DNA of strain GS19h and the vector DNA. Thus, this study corroborates our previous finding and documents the phenomenon of integration of metal-resistant determinants from the Acidocella GS19h plasmid(s) into the chromosome of E. coli DH5a.
Current Microbiology, 2003
When the highly metal-resistant acidophilic heterotrophic strain, Acidiphilium symbioticum KM2, w... more When the highly metal-resistant acidophilic heterotrophic strain, Acidiphilium symbioticum KM2, was incubated with two Escherichia coli strains, viz. S17-1 (pSUP106) and K12, on a medium that supported growth of these two divergent species of different habitats, E. coli transconjugants were isolated that contained novel plasmids and were resistant to Zn(2+) (48 m M), Cu(2+) (12 m M), Ni(2+) (12 m M), chloramphenicol (50 microg/ml), and tetracycline (25 microg/ml). The transconjugant plasmids did not hybridize with any of the A. symbioticum KM2 plasmids. After curing of the plasmids, the transconjugants became sensitive to 12 m M Zn(2+), 12 m M Cu(2+), and 12 m M Ni(2+), but remained chloramphenicol and tetracycline resistant-the phenotypic markers that were originally present in pSUP106. That a part of pSUP106 was integrated into the chromosome of the transconjugants was evident from the hybridization of pSUP106 with chromosomal DNA of the cured derivatives of the transconjugants. Further, the transconjugant plasmids hybridized only with the chromosomal DNA of E. coli S17-1 and not with the chromosomal DNA of A. symbioticum KM2 or E. coli K12, suggesting their host chromosomal origin. Thus, the present study describes a unique event of genetic rearrangements in the E. coli strain S17-1 (pSUP106), resulting in the formation of novel plasmids conferring metal-resistance phenotypes in the cell.
Cell and Tissue Research, 2011
Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (... more Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) augment the biosynthesis of tyrosine hydroxylase (TH). We tested whether secretin belonging to the glucagon/ PACAP/VIP superfamily would increase transcription of the tyrosine hydroxylase (Th) gene and modulate catecholamine secretion. Secretin activated transcription of the endogenous Th gene and its transfected promoter (EC 50 ∼4.6 nM) in pheochromocytoma (PC12) cells. This was abolished by pre-treatment with a secretin receptor (SCTR) antagonist and by inhibition of protein kinase A (PKA), mitogen-activated protein kinase, or CREB (cAMP response element-binding protein). In agreement, secretin increased PKA activity and induced phosphorylation of CREB and binding to Th CRE, suggesting secretin signaling to transcription via a PKA-CREB pathway. Secretin stimulated catecholamine secretion (EC 50 ∼3.5 μM) from PC12 cells, but this was inhibited by pre-treatment with VIP-preferring receptor (VPAC1)/PACAP-preferring receptor (PAC1) antagonists. Secretin-evoked secretion occurred without extracellular Ca 2+ and was abolished by intracellular Ca 2+ chelation. Secretin augmented phospholipase C (PLC) activity and increased inositol-1,4,5-triphosphate (IP 3 ) levels in PC12 cells; PLC-β inhibition blocked secretin-induced catecholamine secretion, indicating the participation of intracellular Ca 2+ from a phospholipase pathway in secretion. Like PACAP, secretin evoked long-lasting catecholamine secretion, even after only a transient exposure. Thus, transcription is triggered by nanomolar concentrations of the peptide through SCTR, with signaling along the cAMP-PKA and extracellular-signal-regulated kinase 1/2 pathways and through CREB. By contrast, secretion is triggered only by micromolar concentrations of peptide through PAC1/VPAC receptors and by utilizing a PLC/intracellular Ca 2+ pathway.
Aquaculture International, 2014
High consumer preference together with its polyculture potential has undoubtedly driven Rohu (Lab... more High consumer preference together with its polyculture potential has undoubtedly driven Rohu (Labeo rohita) and Catla (Catla catla) to top the list of the most preferred fishes among the Indian major carps. Commonly found in these fishes are hybrids that can be natural or man-made. Increasing emphasis on biodiversity issues has necessitated proper stock management of these through molecular genetics techniques. Also with few morphological differences that can be used to differentiate wild types and hybrids properly, the problem demands a straightforward molecular approach. Here, we report a simple PCR-based technique that can differentiate the hybrid variety from wild types easily using three different microsatellite markers. Three sets of primers were used to amplify three different microsatellite markers from the genomic DNA isolated from pectoral fins. When the PCR products using all three primer sets were analyzed, 'hybrid-Rohu' could be distinguished from wild types. Whereas the hybrid-Rohu DNA yielded specific PCR products with all three primer pairs, only two PCR products were obtained either from wild-type Catla DNA (by primer sets 1 and 2) or from wild-type Rohu DNA (by primer sets 1 and 3). This study clearly demonstrates that a simple PCR-based technique will help the fish breeders and hatcheries to identify and differentiate suspected hybrid-Rohu carp from the wild types within a few hours.
Process Metallurgy, 1999
... Environ. Microbiol., 63 (1997) 2089. 16. S. Ghosh, NR Mahapatra and PC Banerjee. Appl. Enviro... more ... Environ. Microbiol., 63 (1997) 2089. 16. S. Ghosh, NR Mahapatra and PC Banerjee. Appl. Environ. Microbiol., 63 (1997) 4523. 17. PC Banerjee, MK Ray, C. Koch, S. Bhattacharyya, S.Shivaji and E. Stackebrandt, System. Appl. Microbiol., 19 (1996) 78. 18. ...
The American Journal of Human Genetics, 2004
The chromogranin/secretogranin proteins are costored and coreleased with catecholamines from secr... more The chromogranin/secretogranin proteins are costored and coreleased with catecholamines from secretory vesicles in chromaffin cells and noradrenergic neurons. Chromogranin A (CHGA) regulates catecholamine storage and release through intracellular (vesiculogenic) and extracellular (catecholamine release-inhibitory) mechanisms. CHGA is a candidate gene for autonomic dysfunction syndromes, including intermediate phenotypes that contribute to human hypertension. Here, we show a surprising pattern of CHGA variants that alter the expression and function of this gene, both in vivo and in vitro. Functional variants include both common alleles that quantitatively alter gene expression and rare alleles that qualitatively change the encoded product to alter the signaling potency of CHGA-derived catecholamine release-inhibitory catestatin peptides.
Acta Paediatrica, 2010
In a rural community-based prospective study, diarrhoea in relation to the feeding patterns of a ... more In a rural community-based prospective study, diarrhoea in relation to the feeding patterns of a cohort of infants was studied. A total of 148 infants between the ages of 0 and 2 months were enrolled and followed until the completion of 1 year of age. Survival analysis showed that by the fourth month of age exclusive breastfeeding dropped by 75%. The proportion of complementary breastfeeding increased from 18.6 to 52.9% during the same period and to 83.7% by the eighth month. This study clearly highlights the tendency for early switch over from exclusive breastfeeding to complementary breastfeeding. Early weaning was associated with an incidence rate ratio (IRR) of 3.02 (95% CI 1.043-8.802). The IRR of 3.02 and its confidence limits (1.043-8.02) suggest a significant protective effect of exclusive breastfeeding against diarrhoea in infants. The results of this study indicate that promotion of exclusive breastfeeding has a potential role to reduce the incidence of diarrhoea amongst infants. The findings of this study will be useful for Diarrhoeal Disease Control Programme in reducing diarrhoeal morbidity.
Journal of Neurochemistry, 2006
The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remai... more The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remained elusive. Utilizing wild-type and mutant Chgb promoter/luciferase reporter constructs, this study established a crucial role for the cAMP response element (CRE) box at )102/)95 bp in endocrine [rat pheochromocytoma (chromaffin) cell line (PC12) and rat pituitary somatotrope cell line (GC)] and neuronal [rat dorsal root ganglion/mouse neuroblastoma hybrid cell line (F-11), cortical and hippocampal primary neurons] cells. Additionally, G/C-rich domains at )134/)127, )125/)117 and )115/)110 bp played especially important roles for endocrine-specific expression of the Chgb gene. Co-transfection of expression plasmids for CREB, activator protein-2 (transcription factor) (AP-2), early growth response protein (transcription factor) (Egr-1) or specificity protein 1 (transcription factor) (Sp1) with the Chgb promoter constructs trans-activated expression of the Chgb gene. Nuclear extracts from either PC12 or F-11 cells formed specific complexes with the Chgb ()110/)87 bp) (CRE) oligonucleotide, which were either supershifted or disrupted by anti-CREB antibodies. In addition PC12 nuclear extracts also formed a specific complex with a Chgb ()140/)104-bp) oligonucleotide containing three G/C-rich regions, which was dose-dependently disrupted by anti-AP-2, anti-Egr-1 or anti-Sp1 antibodies; indeed, any one of these three antibodies completely abolished the complex, suggesting that all three factors bind the region simultaneously, at least in vitro. Chromatin immunoprecipitation assays documented the binding of the transcription factors CREB, AP-2, Egr-1 and Sp1 to the chromosomal Chgb gene promoter in vivo in PC12 cells within the context of chromatin. We conclude that the neuroendocrine-specific expression of Chgb is mediated by the CRE and G/C boxes in cis and the transcription factors CREB, AP-2, Egr-1 and Sp1 in trans.
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Papers by Sajalendu Ghosh