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Chen LC, Chowdhury A, Huffman SL. Anthropometric assessment of energy-protein malnutrition and subsequent risk of mortality among preschool aged children. Am J Clin Nutr 1980; 33:1836-45. [PMID: 6773410 DOI: 10.1093/ajcn/33.8.1836] [Citation(s) in RCA: 208] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
This paper examines the usefulness of various anthropometric classification systems of nutritional status in prognosticating the subsequent risk of mortality among 2019 children aged 13 to 23 months residing in a rural area of Bangladesh. The indices investigated included: weight-for-age; weight-for-height; height-for-age; arm circumference-for-age; arm circumference-for-height; weight quotient; and height quotient. Cross-sectional anthropometry was conducted during October 1975 to January 1976 and the mortality experience of the study children was followed prospectively over 24 months. Results indicated that severely malnourished children, according to all indices, experienced substantially higher mortality risk. Normal, mild, and moderately malnourished children all experienced the same risk. All indices were found to discriminate mortality risk; weight/age and arm circumference/age were strongest and weight/height weakest. For each index, a threshold level was noted below which mortality risk climbed sharply. The discriminating power of anthropometry was enhanced when maternal weight, maternal height, or housing size were included.
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Mukhopadhyay AK, Kersulyte D, Jeong JY, Datta S, Ito Y, Chowdhury A, Chowdhury S, Santra A, Bhattacharya SK, Azuma T, Nair GB, Berg DE. Distinctiveness of genotypes of Helicobacter pylori in Calcutta, India. J Bacteriol 2000; 182:3219-27. [PMID: 10809703 PMCID: PMC94510 DOI: 10.1128/jb.182.11.3219-3227.2000] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The genotypes of 78 strains of Helicobacter pylori from Calcutta, India (55 from ulcer patients and 23 from more-benign infections), were studied, with a focus on putative virulence genes and neutral DNA markers that were likely to be phylogenetically informative. PCR tests indicated that 80 to 90% of Calcutta strains carried the cag pathogenicity island (PAI) and potentially toxigenic vacAs1 alleles of the vacuolating cytotoxin gene (vacA), independent of disease status. This was higher than in the West (where cag PAI(+) vacAs1 genotypes are disease associated) but lower than in east Asia. The iceA2 gene was weakly disease associated in Calcutta, whereas in the West the alternative but unrelated iceA1 gene at the same locus is weakly disease associated. DNA sequence motifs of vacAm1 (middle region) alleles formed a cluster that was distinct from those of east Asia and the West, whereas the cagA sequences of Calcutta and Western strains were closely related. An internal deletion found in 20% of Calcutta iceA1 genes was not seen in any of approximately 200 strains studied from other geographic regions and thus seemed to be unique to this H. pylori population. Two mobile DNAs that were rare in east Asian strains were also common in Calcutta. About 90% of Calcutta strains were metronidazole resistant. These findings support the idea that H. pylori gene pools differ regionally and emphasize the potential importance of studies of Indian and other non-Western H. pylori populations in developing a global understanding of this gastric pathogen and associated disease.
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Kersulyte D, Mukhopadhyay AK, Velapatiño B, Su W, Pan Z, Garcia C, Hernandez V, Valdez Y, Mistry RS, Gilman RH, Yuan Y, Gao H, Alarcón T, López-Brea M, Balakrish Nair G, Chowdhury A, Datta S, Shirai M, Nakazawa T, Ally R, Segal I, Wong BC, Lam SK, Olfat FO, Borén T, Engstrand L, Torres O, Schneider R, Thomas JE, Czinn S, Berg DE. Differences in genotypes of Helicobacter pylori from different human populations. J Bacteriol 2000; 182:3210-8. [PMID: 10809702 PMCID: PMC94509 DOI: 10.1128/jb.182.11.3210-3218.2000] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
DNA motifs at several informative loci in more than 500 strains of Helicobacter pylori from five continents were studied by PCR and sequencing to gain insights into the evolution of this gastric pathogen. Five types of deletion, insertion, and substitution motifs were found at the right end of the H. pylori cag pathogenicity island. Of the three most common motifs, type I predominated in Spaniards, native Peruvians, and Guatemalan Ladinos (mixed Amerindian-European ancestry) and also in native Africans and U.S. residents; type II predominated among Japanese and Chinese; and type III predominated in Indians from Calcutta. Sequences in the cagA gene and in vacAm1 type alleles of the vacuolating cytotoxin gene (vacA) of strains from native Peruvians were also more like those from Spaniards than those from Asians. These indications of relatedness of Latin American and Spanish strains, despite the closer genetic relatedness of Amerindian and Asian people themselves, lead us to suggest that H. pylori may have been brought to the New World by European conquerors and colonists about 500 years ago. This thinking, in turn, suggests that H. pylori infection might have become widespread in people quite recently in human evolution.
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Roy B, Chowdhury A, Kundu S, Santra A, Dey B, Chakraborty M, Majumder PP. Increased risk of antituberculosis drug-induced hepatotoxicity in individuals with glutathione S-transferase M1 'null' mutation. J Gastroenterol Hepatol 2001; 16:1033-7. [PMID: 11595069 DOI: 10.1046/j.1440-1746.2001.02585.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Pathogenesis and genetic factors influencing predisposition to antituberculosis drug (ATD)-induced hepatotoxicity are not clear. Polymorphism at the genetic locus of a drug and xenobiotic compound metabolizing enzyme, N-acetyltransferase type 2 (NAT2), is reported to be associated with the excess generation of toxic reactive metabolites. Polymorphisms at the glutathione S-transferase (GST) loci (GSTM1 and GSTT1) are involved in the detoxification of these toxic metabolites in the human body to a lesser extent. We have examined whether polymorphisms at these loci are associated with the risk of ATD-induced hepatotoxicity. METHODS In this case-control study, 33 pulmonary tuberculosis patients with ATD-induced hepatotoxicity and 33 pulmonary tuberculosis patients receiving ATD drugs without any evidence of hepatotoxicity were considered as cases and controls, respectively. Point mutations at NAT2 and homozygous 'null' mutations at GSTM1 and GSTT1 genes were looked into genomic DNA, isolated from peripheral blood mononuclear cells by using polymerase chain reaction (PCR). RESULTS The frequency of homozygous 'null' mutation at the GSTM1 gene was significantly higher among cases (n = 17, 52%) than controls (n = 8, 24%) (P < 0.05, relative risk 2.13, 95% CI: 1.25-3.10). Frequencies of mutations at GSTT1 and NAT2 genes did not differ significantly between cases and controls. CONCLUSION Homozygous 'null' mutation at the GSTM1 gene might predispose an individual to ATD-induced hepatotoxicity.
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Moga DE, Calhoun ME, Chowdhury A, Worley P, Morrison JH, Shapiro ML. Activity-regulated cytoskeletal-associated protein is localized to recently activated excitatory synapses. Neuroscience 2004; 125:7-11. [PMID: 15051140 DOI: 10.1016/j.neuroscience.2004.02.004] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2004] [Indexed: 11/21/2022]
Abstract
Activity-regulated, cytoskeletal-associated protein (Arc) is an immediate early gene induced in excitatory circuits following behavioral episodes. Arc mRNA is targeted to activated regions of the dendrite after long-term potentiation (LTP) of the dentate gyrus, a process dependent on NMDA receptor activation. We used post-embedding immunogold electron microscopy (EM) to test whether synaptic Arc expression patterns are selectively modified by plasticity. Consistent with previous light microscopic observations, Arc protein was rapidly induced in the dentate gyrus following LTP-producing stimulation of the perforant path and was detectable in granule cell nuclei, somata and dendrites after two hours of high frequency stimulation. Post-embedding EM revealed Arc immunogold labeling in three times as many spines in the middle molecular layer of the stimulated dentate gyrus than in either the ipsilateral outer molecular layer or the contralateral middle and outer molecular layers. This upregulation did not occur with low frequency stimulation of the perforant path. Therefore Arc protein localization may be a powerful tool to isolate recently activated dendritic spines.
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Huffman SL, Chowdhury A, Chakraborty J, Simpson NK. Breast-feeding patterns in rural Bangladesh. Am J Clin Nutr 1980; 33:144-54. [PMID: 7355776 DOI: 10.1093/ajcn/33.1.144] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Nearly 1500 women with live births from February through September 1974 were included in this multiple phase study of breast-feeding patterns in a rural area of Banglandesh. The median duration of breast feeding was observed to be 30 months. Over 75% of the women whose most recently born children were living were breast feeding at 2 1/2 years postpartum. The major reason for discontinuing breast feeding in the 1st year was infant death, and in the 2nd year, pregnancy. Insufficient milk was given as a reason for discontinuing breast feeding by 18% of the women who stopped breast feeding for reasons other than child death; among these women almost 60% were pregnant at the time they stopped. Of the breast-feeding women who became pregnant, over 50% continued to breast feed through the 6th month of pregnancy. A sample of 200 breast-feeding women with children ages 17 to 25 months were followed longitudinally for 1 1/2 years or until the mothers conceived. A seasonal trend in suckling time was observed with women reducing suckling during the harvest season. Total suckling time was inversely associated with socioeconomic factors and with infant nutritional status. No association was found between mean suckling time and maternal nutritional status, maternal morbidity, infant morbidity, or child's sex.
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Case Reports |
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Ansaruzzaman M, Lucas M, Deen JL, Bhuiyan NA, Wang XY, Safa A, Sultana M, Chowdhury A, Nair GB, Sack DA, von Seidlein L, Puri MK, Ali M, Chaignat CL, Clemens JD, Barreto A. Pandemic serovars (O3:K6 and O4:K68) of Vibrio parahaemolyticus associated with diarrhea in Mozambique: spread of the pandemic into the African continent. J Clin Microbiol 2005; 43:2559-62. [PMID: 15956363 PMCID: PMC1151933 DOI: 10.1128/jcm.43.6.2559-2562.2005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Forty-two episodes of Vibrio parahaemolyticus infections were detected in Beira, Mozambique, from January to May 2004. The majority of the isolates (81%) belonged to the pandemic serovars (O3:K6 and O4:K68) of V. parahaemolyticus. The pandemic serovars were positive by group-specific PCR (GS-PCR) and a PCR specific for open reading frame ORF8 (ORF8-PCR), which are molecular markers of the pandemic clone, and were positive for tdh but negative for trh. The remaining 19% of the strains also possessed the tdh gene but were GS-PCR and ORF8-PCR negative and did not belong to the pandemic serovars. Patients with V. parahaemolyticus infection were older (mean age, 27 years) than patients infected by other diarrheal agents (mean age, 21 years). Ten percent of diarrhea patients from whom no V. parahaemolyticus was cultured were severely dehydrated, but none of the V. parahaemolyticus cases were severely dehydrated. This is the first report of the isolation of pandemic strains of V. parahaemolyticus in sub-Saharan Africa and clearly indicates that the pandemic of V. parahaemolyticus has spread into the African continent.
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Research Support, Non-U.S. Gov't |
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Sadiq S, Ghazala Z, Chowdhury A, Büsselberg D. Metal toxicity at the synapse: presynaptic, postsynaptic, and long-term effects. J Toxicol 2012; 2012:132671. [PMID: 22287959 PMCID: PMC3263637 DOI: 10.1155/2012/132671] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 07/05/2011] [Indexed: 12/19/2022] Open
Abstract
Metal neurotoxicity is a global health concern. This paper summarizes the evidence for metal interactions with synaptic transmission and synaptic plasticity. Presynaptically metal ions modulate neurotransmitter release through their interaction with synaptic vesicles, ion channels, and the metabolism of neurotransmitters (NT). Many metals (e.g., Pb(2+), Cd(2+), and Hg(+)) also interact with intracellular signaling pathways. Postsynaptically, processes associated with the binding of NT to their receptors, activation of channels, and degradation of NT are altered by metals. Zn(2+), Pb(2+), Cu(2+), Cd(2+), Ni(2+), Co(2+), Li(3+), Hg(+), and methylmercury modulate NMDA, AMPA/kainate, and/or GABA receptors activity. Al(3+), Pb(2+), Cd(2+), and As(2)O(3) also impair synaptic plasticity by targeting molecules such as CaM, PKC, and NOS as well as the transcription machinery involved in the maintenance of synaptic plasticity. The multiple effects of metals might occur simultaneously and are based on the specific metal species, metal concentrations, and the types of neurons involved.
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review-article |
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Fukuda R, Ishimura N, Ishihara S, Chowdhury A, Morlyama N, Nogami C, Miyake T, Niigaki M, Tokuda A, Satoh S, Sakai S, Akagi S, Watanabe M, Fukumoto S. Intrahepatic expression of pro-inflammatory cytokine mRNAs and interferon efficacy in chronic hepatitis C. LIVER 1996; 16:390-9. [PMID: 9021719 DOI: 10.1111/j.1600-0676.1996.tb00768.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To investigate the relationship between intrahepatic cytokine expression and interferon (IFN) response in chronic hepatitis C [CH(C)], interleukin (IL)-1 beta, -2, -4, -6, -8, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and TNF-beta mRNAs were investigated semiquantitatively by reverse transcription polymerase chain reaction using serial liver biopsies taken before and after IFN-alpha treatment from 24 patients with CH(C), including 12 responders and 12 non-responders. Before IFN treatment, IL-2, TNF-beta, IFN-gamma and IL-8 mRNA were associated with severe hepatitis activity whereas IL-4 mRNA was associated with weak hepatitis activity, regardless of IFN response. IL-2, TNF-beta and IFN-gamma mRNAs were significantly greater in IFN non-responders. After IFN treatment a complete response to IFN was significantly associated with the disappearance of these pro-inflammatory cytokines, whereas non-responders retained the expression of cytokine mRNA as before IFN treatment. Our results indicated that IFN-alpha treatment may modulate the intrahepatic cytokine network, and this may be one mechanism of IFN-alpha that reduces hepatitis activity, aside from an anti-viral effect. A difference in cytokine network may be involved in IFN response in CH(C).
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Das J, Chowdhury A, Hussam R, Banerjee AV. The impact of training informal health care providers in India: A randomized controlled trial. Science 2016; 354:354/6308/aaf7384. [DOI: 10.1126/science.aaf7384] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 08/25/2016] [Indexed: 11/02/2022]
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Sarkar MA, Roy S, Kole RK, Chowdhury A. Persistence and metabolism of imidacloprid in different soils of West Bengal. PEST MANAGEMENT SCIENCE 2001; 57:598-602. [PMID: 11464790 DOI: 10.1002/ps.328] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A laboratory experiment was performed to study the persistence of imidacloprid from two formulations (Confidor 200 g litre-1 SL and Gaucho 700 g kg-1 WS), and its metabolism in three different soils (Gangetic alluvial soil of Kalyani, lateritic soil of Jhargram and coastal alkaline soil of Canning) of West Bengal following application at 0.5 kg and 1.0 kg AIha-1. Dissipation of imidacloprid in soil followed first-order kinetics and DT50 values ranged from 28.7 to 47.8 days. The shortest half-lives (28.7 and 35.8 days) were observed in the lateritic soil of Jhargram for both liquid and powder formulations. The formation of two metabolites of imidacloprid, imidacloprid-urea and imidacloprid-olefin, was first detected on day 30 of degradation at 28 (+/- 1) degrees C in all three soils.
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Vuddhakul V, Chowdhury A, Laohaprertthisan V, Pungrasamee P, Patararungrong N, Thianmontri P, Ishibashi M, Matsumoto C, Nishibuchi M. Isolation of a pandemic O3:K6 clone of a Vibrio parahaemolyticus strain from environmental and clinical sources in Thailand. Appl Environ Microbiol 2000; 66:2685-9. [PMID: 10831459 PMCID: PMC110602 DOI: 10.1128/aem.66.6.2685-2689.2000] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Application of an immunomagnetic enrichment method selective for Vibrio parahaemolyticus serovar K6 allowed isolation of a strain belonging to the pandemic O3:K6 clone of V. parahaemolyticus from fresh shellfish not implicated in a clinical case in southern Thailand. Arbitrarily primed PCR profiles of this strain, clinical O3:K6 strains isolated from sporadic diarrhea cases in the same area, and a standard pandemic O3:K6 strain were indistinguishable.
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Kadakol A, Sappal BS, Ghosh SS, Lowenheim M, Chowdhury A, Chowdhury S, Santra A, Arias IM, Chowdhury JR, Chowdhury NR. Interaction of coding region mutations and the Gilbert-type promoter abnormality of the UGT1A1 gene causes moderate degrees of unconjugated hyperbilirubinaemia and may lead to neonatal kernicterus. J Med Genet 2001; 38:244-9. [PMID: 11370628 PMCID: PMC1734859 DOI: 10.1136/jmg.38.4.244] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Research Support, U.S. Gov't, P.H.S. |
24 |
51 |
14
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Ghosh S, Banerjee P, Deny P, Mondal RK, Nandi M, Roychoudhury A, Das K, Banerjee S, Santra A, Zoulim F, Chowdhury A, Datta S. New HBV subgenotype D9, a novel D/C recombinant, identified in patients with chronic HBeAg-negative infection in Eastern India. J Viral Hepat 2013; 20:209-18. [PMID: 23383660 DOI: 10.1111/j.1365-2893.2012.01655.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 07/02/2012] [Indexed: 02/06/2023]
Abstract
Genome diversity is a hallmark of hepatitis B virus (HBV), which allowed its classification into 10 genotypes (A-J) and numerous subgenotypes. Among them, Genotype D is currently segregated into eight subgenotypes (D1-D8). Here, we report the identification and characterization of a novel subgenotype within genotype D of HBV from chronic hepatitis B e antigen (HBeAg)-negative patients of Eastern India. Phylogenetic tree analysis based on complete genome sequences revealed that six of 39 HBV/D isolates formed a distinct cluster supported by high bootstrap value and had nucleotide divergence >4% relative to the known D subgenotypes (D1-D8), justifying their assignment into a new subgenotype (D9). By comparing the amino acid sequences of the four ORFs of HBV/D9 with D1-D8, 36 specific residues, including a unique one (E(112) in the core region), were identified that could be considered as a signature of D9. Further analysis by Simplot, BootScan and jpHMM demonstrated that D9 resulted from a discrete recombination with genotype C over the precore-core region. This type of recombination has not been described previously as all C/D recombinants reported so far possessed genotype C backbones with mosaic fragments derived from HBV/D. Interestingly, compared to other subgenotypes of HBV/D, D9 isolates had a higher frequency of mutations (A1762T and G1764A) in the basal core promoter region that had been implicated in the development of hepatocellular carcinoma. Further investigations are needed to determine the overall prevalence and clinical significance of these newly characterized D9 strains and to assess the impact of inter-genotypic recombination on viral properties.
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Qadri F, Hasan JA, Hossain J, Chowdhury A, Begum YA, Azim T, Loomis L, Sack RB, Albert MJ. Evaluation of the monoclonal antibody-based kit Bengal SMART for rapid detection of Vibrio cholerae O139 synonym Bengal in stool samples. J Clin Microbiol 1995; 33:732-4. [PMID: 7751386 PMCID: PMC228023 DOI: 10.1128/jcm.33.3.732-734.1995] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A monoclonal antibody-based test, Bengal SMART, was developed for rapid detection of Vibrio cholerae O139 synonym Bengal directly from stool specimens. The test, which takes about 15 min to complete, was used to screen 189 diarrheal stool specimens. The results were compared with those of a monoclonal antibody-based coagglutination test (COAT) and the conventional culture methods used as the "gold standard" for detection of V. cholerae O139. The Bengal SMART test showed a sensitivity of 100% and a specificity of 97% in comparison with the gold standard. It also fared better than COAT, which had a sensitivity of 96% for rapid detection of V. cholerae O139 synonym Bengal. These results show that Bengal SMART is suitable for use in field settings for rapid diagnosis of cholera caused by V. cholerae O139.
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research-article |
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Layek A, Banerjee S, Manna B, Chowdhury A. Synthesis of rare-earth doped ZnO nanorods and their defect–dopant correlated enhanced visible-orange luminescence. RSC Adv 2016. [DOI: 10.1039/c6ra02278b] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Rare-earth doped sub-10 nm diameter ZnO nanorods show defect–dopant assisted enhanced visible-orange luminescence and also display multicolour rare-earth emission.
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Fukuda R, Ishimura N, Kushiyama Y, Moriyama N, Ishihara S, Chowdhury A, Tokuda A, Sakai S, Akagi S, Watanabe M, Fukumoto S. Hepatitis B virus with X gene mutation is associated with the majority of serologically "silent" non-b, non-c chronic hepatitis. Microbiol Immunol 1996; 40:481-8. [PMID: 8865153 DOI: 10.1111/j.1348-0421.1996.tb01098.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Hepatitis B virus (HBV) with X gene mutations has been a putative pathogen of chronic hepatitis without serological markers of known hepatitis viruses. The aim of this study was to reconfirm whether the HBV with the X gene mutation is associated with these serologically "silent" non-B, non-C (NBNC) chronic hepatitis, alcoholic liver disease (ALD) and autoimmune hepatitis (AIH). HBV DNA was amplified from serum and sequenced in 30 patients with NBNC chronic hepatitis in comparison with 20 patients with ALD and 5 patients with AIH. HBV DNA was identified in 21 patients (70%) in NBNC chronic hepatitis by nested polymerase chain reaction while only one patient (5%) in ALD and none in AIH showed HBV DNA. Eighteen (85.7%) of the 21 identified HBV DNAs had an identical 8-nucleotide deletion mutation at the distal part of the X region. This mutation affected the core promoter and the enhancer II sequence of HBV DNA and created a translational stop codon which truncated the X protein by 20 amino acids from the C-terminal end. All the HBV DNAs had a precore mutation at the 83rd nucleotide resulting in disruption of HBe antigen synthesis. These results indicate that HBV mutants are closely associated with the majority of serologically "silent" NBNC chronic hepatitis cases and the population of such mutant HBV DNAs is not uniform.
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Comparative Study |
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Chowdhury A, Ackerson BJ, Clark NA. Laser-induced freezing. PHYSICAL REVIEW LETTERS 1985; 55:833-836. [PMID: 10032459 DOI: 10.1103/physrevlett.55.833] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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Qadri F, Azim T, Chowdhury A, Hossain J, Sack RB, Albert MJ. Production, characterization, and application of monoclonal antibodies to Vibrio cholerae O139 synonym Bengal. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1994; 1:51-4. [PMID: 7496922 PMCID: PMC368195 DOI: 10.1128/cdli.1.1.51-54.1994] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mouse monoclonal antibodies (MAbs) were derived against acetone-treated whole cells of the newly recognized Vibrio cholerae O139 serogroup which is causing epidemics of cholera-like disease in India and Bangladesh. Four MAbs specifically recognized the lipopolysaccharide antigens of V. cholerae O139. MAbs ICL9 and ICL13 were of the immunoglobulin M (IgM) isotype, ICL11 was of the IgG3 isotype, and ICL12 was of the Ig2b isotype. A fifth MAb, ICL10, of the IgG2b isotype cross-reacted with V. cholerae O91. All five MAbs recognized V. cholerae O139 in an enzyme-linked immunosorbent assay, slide agglutination test, motility inhibition test, and indirect immunofluorescence test. During a 1-month evaluation of these MAbs in our clinical laboratory, all 86 cases diagnosed as V. cholerae O139 by a rabbit polyclonal antiserum were also detected by these MAbs, establishing their utility as highly sensitive and specific diagnostic reagents. With these MAbs, it should now be possible to screen for the V. cholerae O139 serogroup in epidemic and endemic diarrhea cases and in environmental and food samples.
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Datta S, Chattopadhyay S, Patra R, De R, Ramamurthy T, Hembram J, Chowdhury A, Bhattacharya SK, Berg DE, Nair GB, Mukhopadhyay AK. Most Helicobacter pylori strains of Kolkata in India are resistant to metronidazole but susceptible to other drugs commonly used for eradication and ulcer therapy. Aliment Pharmacol Ther 2005; 22:51-7. [PMID: 15963080 DOI: 10.1111/j.1365-2036.2005.02533.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Helicobacter pylori infection is very common in India, as in other developing countries, but few data exist on the susceptibility of H. pylori to antimicrobial agents commonly used for eradication here. AIM To determine the antimicrobial susceptibility of H. pylori strains from Kolkata, in eastern India. METHODS A total of 67 H. pylori strains isolated from gastritis and peptic ulcer patients of Kolkata were examined in the study. Minimum inhibitory concentration to the antibiotics was determined by the agar dilution method. RESULTS Most of the strains (85%) were resistant to at least 8 microg/mL of metronidazole and 7.5% strains were resistant to tetracycline, which was high when compared with other reports in India. All Kolkata strains were highly sensitive to clarithromycin, furazolidone and amoxicillin. CONCLUSIONS Our results differed significantly from the few available reports on drug sensitivity profile of H. pylori from other parts of India, namely, Hyderabad, Mumbai and Lucknow. This finding supports the need for rigorous susceptibility testing as a guide to empirical treatment and more generally, to define the resistance patterns of H. pylori in particular geographical areas.
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Chowdhury A, Dyachok O, Tengholm A, Sandler S, Bergsten P. Functional differences between aggregated and dispersed insulin-producing cells. Diabetologia 2013; 56:1557-68. [PMID: 23604550 PMCID: PMC3671110 DOI: 10.1007/s00125-013-2903-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 03/12/2013] [Indexed: 11/27/2022]
Abstract
AIMS/HYPOTHESIS Beta cells situated in the islet of Langerhans respond more vigorously to glucose than do dissociated beta cells. Mechanisms for this discrepancy were studied by comparing insulin-producing MIN6 cells aggregated into pseudoislets with MIN6 monolayer cells and mouse and human islets. METHODS MIN6 monolayers, pseudoislets and mouse and human islets were exposed to glucose, α-ketoisocaproic acid (KIC), pyruvate, KIC plus glutamine and the phosphatidylinositol 3-kinase (PI3K) inhibitors LY294002 or wortmannin. Insulin secretion (ELISA), cytoplasmic Ca(2+) concentration ([Ca(2+)]c; microfluorometry), glucose oxidation (radiolabelling), the expression of genes involved in mitochondrial metabolism (PCR) and the phosphorylation of insulin receptor signalling proteins (western blotting) were measured. RESULTS Insulin secretory responses to glucose, pyruvate, KIC and glutamine were higher in pseudoislets than monolayers and comparable to those of human islets. Glucose oxidation and genes for mitochondrial metabolism were upregulated in pseudoislets compared with single cells and monolayers, respectively. Phosphorylation at the inhibitory S636/639 site of IRS-1 was significantly higher in monolayers and dispersed human and mouse cells than pseudoislets and intact human and mouse islets. PI3K inhibition only slightly attenuated glucose-stimulated insulin secretion from monolayers, but substantially reduced that from pseudoislets and human and mouse islets without suppressing the glucose-induced [Ca(2+)]c response. CONCLUSIONS/INTERPRETATION We propose that islet architecture is critical for proper beta cell mitochondrial metabolism and IRS-1 signalling, and that PI3K regulates insulin secretion at a step distal to the elevation of [Ca(2+)]c.
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Chowdhury A, Fukuda R, Fukumoto S. Growth factor mRNA expression in normal colorectal mucosa and in uninvolved mucosa from ulcerative colitis patients. J Gastroenterol 1996; 31:353-60. [PMID: 8726826 DOI: 10.1007/bf02355024] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study was carried out to investigate the expression of various growth factors (GFs) involved in mucosal healing and thereby to clarify whether there are potential differences in the expression of GFs between normal colonic mucosa and the uninvolved mucosa of ulcerative colitis (UC). GF mRNA was investigated by reverse transcription polymerase chain reaction in colorectal biopsies from 20 normal controls and 15 UC patients. The positive rates (%) for mRNA expression for normal/UC were: epidermal growth factor (EGF) 65/53, transforming growth factor (TGF)-alpha 100/87, TGF-beta 1 60/33, insulin like growth factor-I 45/33, platelet-derived growth factor-A 55/67, basic fibroblast growth factor 0/0, hepatocyte growth factor (HGF) 50/53, EGF receptor 20/27, erb-B2 75/73, and HGF receptor (c-MET) 55/67. Semiquantitation of mRNA showed significantly lower expression of TGF-beta 1 (P < 0.05) in UC. Differences in expression and mRNA levels were not statistically significant for any other GFs. Our results indicate that mucosa in chronic persistent UC has a low basal expression of TGF-beta 1 mRNA, and, since TGF-beta 1 is a multifunctional GF that plays important roles in regulating repair and regeneration following tissue injury, this low expression may be partially responsible for the intractability of the disease.
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Mahalanabis D, Chowdhury A, Jana S, Bhattacharya MK, Chakrabarti MK, Wahed MA, Khaled MA. Zinc supplementation as adjunct therapy in children with measles accompanied by pneumonia: a double-blind, randomized controlled trial. Am J Clin Nutr 2002; 76:604-7. [PMID: 12198006 DOI: 10.1093/ajcn/76.3.604] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Zinc deficiency, common in developing countries, is associated with decreased immunocompetence. Zinc supplementation benefits children with acute and persistent diarrhea and prevents pneumonia. Most deaths from vaccine-preventable diseases are from measles and whooping cough; pneumonia is the most common complication of measles and often the proximate cause of related deaths. OBJECTIVE We evaluated the effect of zinc supplementation on episodes of illness in children with measles accompanied by pneumonia. DESIGN In a double-blind, randomized controlled trial, children aged 9 mo-15 y who were admitted to the Infectious Diseases Hospital in Calcutta with clinically severe measles accompanied by pneumonia and who had been ill for </= 7 d were randomly assigned to receive zinc (20 mg, in elemental form as acetate, twice daily for 6 d) or a placebo. All patients received standard treatment with antibiotics and an initial 100 000-IU dose of vitamin A (as palmitate) by mouth. RESULTS Time-to-event analysis using the Cox proportional hazards model (42 in the zinc group and 43 in the placebo group) showed that the time needed for the resolution of fever and tachypnea, the return of appetite, and the achievement of a "much improved" or "cured" status was not different between the 2 groups. A high proportion of children had low serum retinol and zinc concentrations. Improvement in serum zinc and retinol concentrations after 6 d of treatment was not different between the 2 groups. CONCLUSION Children with severe measles accompanied by pneumonia treated with antibiotics and vitamin A did not show any additional benefit from also receiving a zinc supplement.
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Fukuda R, Ishimura N, Nguyen TX, Chowdhury A, Ishihara S, Kohge N, Akagi S, Watanabe M, Fukumoto S. The expression of IL-2, IL-4 and interferon-gamma (IFN-gamma) mRNA using liver biopsies at different phases of acute exacerbation of chronic hepatitis B. Clin Exp Immunol 1995; 100:446-51. [PMID: 7774054 PMCID: PMC1534464 DOI: 10.1111/j.1365-2249.1995.tb03720.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
To investigate the hypothesis that Th1 phenotype cytokines are associated with the increasing activity of hepatitis and Th2 phenotype cytokines with decreasing activity in the liver of chronic viral hepatitis, expressions of the mRNA of the cytokines IL-2, IFN-gamma and IL-4 in the liver of 23 patients with chronic hepatitis B were investigated by reverse transcription polymerase chain reaction. Patients were divided into three groups according to the phase of acute exacerbation of hepatitis as increasing (n = 9), decreasing (n = 8), and stable phase (n = 6). Both IL-2 and IFN-gamma mRNA were preferentially expressed in increasing phase than in decreasing phase (P < 0.01, P < 0.05, respectively) and associated with the high serum alanine aminotransferase (ALT) level. On the other hand, IL-4 mRNA was detected in decreasing phase with significant frequency compared with increasing phase (P < 0.05). However, expression of IL-4 mRNA was not associated with serum ALT level. Our results suggest that Th1 phenotype cytokines up-regulate and Th2 phenotype cytokines down-regulate the liver inflammation of chronic viral hepatitis.
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Qadri F, Chowdhury A, Hossain J, Chowdhury K, Azim T, Shimada T, Islam KM, Sack RB, Albert MJ. Development and evaluation of rapid monoclonal antibody-based coagglutination test for direct detection of Vibrio cholerae O139 synonym Bengal in stool samples. J Clin Microbiol 1994; 32:1589-90. [PMID: 8077410 PMCID: PMC264045 DOI: 10.1128/jcm.32.6.1589-1590.1994] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A monoclonal antibody-based coagglutination test directly detected Vibrio cholerae O139 synonym Bengal in 83 of 120 watery diarrheal stool specimens; on culture, 90 samples were positive. Thus, with 92% sensitivity, 100% specificity, and 100% positive and 95% negative predictive values, the coagglutination test is a useful rapid test for V. cholerae O139.
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