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Absmeier E, Chandrasekaran V, O'Reilly FJ, Stowell JAW, Rappsilber J, Passmore LA. Specific recognition and ubiquitination of translating ribosomes by mammalian CCR4-NOT. Nat Struct Mol Biol 2023; 30:1314-1322. [PMID: 37653243 PMCID: PMC7615087 DOI: 10.1038/s41594-023-01075-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 07/24/2023] [Indexed: 09/02/2023]
Abstract
Translation affects messenger RNA stability and, in yeast, this is mediated by the Ccr4-Not deadenylation complex. The details of this process in mammals remain unclear. Here, we use cryogenic electron microscopy (cryo-EM) and crosslinking mass spectrometry to show that mammalian CCR4-NOT specifically recognizes ribosomes that are stalled during translation elongation in an in vitro reconstituted system with rabbit and human components. Similar to yeast, mammalian CCR4-NOT inserts a helical bundle of its CNOT3 subunit into the empty E site of the ribosome. Our cryo-EM structure shows that CNOT3 also locks the L1 stalk in an open conformation to inhibit further translation. CCR4-NOT is required for stable association of the nonconstitutive subunit CNOT4, which ubiquitinates the ribosome, likely to signal stalled translation elongation. Overall, our work shows that human CCR4-NOT not only detects but also enforces ribosomal stalling to couple translation and mRNA decay.
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Affiliation(s)
- Eva Absmeier
- MRC Laboratory of Molecular Biology (LMB), Cambridge, UK
- Freie University of Berlin, Berlin, Germany
| | | | | | | | - Juri Rappsilber
- Technical University of Berlin, Chair of Bioanalytics, Berlin, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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Chandrasekaran V, Bokarewa MI, Oparina N, Andersson KM, Katona G, Erlandsson M, Jensen M, Damdimopoulos A. POS0032 FUNCTIONAL ROLE OF SURVIVIN IN ORGANIZATION OF BIVALENT CHROMATIN REGIONS AND CONSEQUENCE FOR ARTHRITIS-RELEVANT GENE EXPRESSION. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.4856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundBivalent chromatin (BvCR) is characterized by the presence of simultaneous active and repressive modifications on histone H3 proteins. Influencing expression of the genes, BvCR determine cell fate and direct differentiation and lineage commitment in primary T cells and contribute to autoimmunity. Survivin is highly expressed during cell division and in effector Th1 cells contributing to aggravation of autoimmune inflammation. Survivin can physically bind to DNA, specifically to Threonine-3 of histone H3 (1). Thus, functional, and mechanistic data point to a potential chromatin regulatory role for survivin, potentially acting in combination with histone epigenetic modifications (EMs).ObjectivesThe goal of our study is to establish the colocalization of survivin with BvCRs and to deduce functional effects of this collaboration on chromatin organization and gene expression.MethodsChromatin from CD4+ T cells of 14 female subjects was immunoprecipitated with survivin antibodies and histone H3K27ac, H3K27me3, H3K4me3 antibodies, and coupled with DNA sequencing (ChIPseq, Hiseq2000, Illumina). BvCR were identified as exact overlaps of the three histone EM peaks and the overlapping regions were searched for co-localization with survivin using the ‘ChIPPeakAnno’ Bioconductor package. Tag counts K27me3>K27ac were defined as inactive/poised BvCR, while tag count K27me3<K27ac were identified asactive BvCR. Motif search was done through the MEME tool, and high/moderate complexity motifs with E-value >10e-5 were selected and scanned through the HOCOMOCO database to identify consensus transcription factor (TF) motifs. TFs co-localized with the BvCD were identified through ReMap database. To identify survivin sensitive genes, CD4+ T cells were treated with survivin inhibitor YM155 and a list of reproducible DEG (log2FC>[0.4], >1 experiment) was mapped and analysed for clustering with BvCR.ResultsCo-localization of survivin ChIP peaks with individual H3-peaks was significantly less frequent compared to overlap with all three (a3)-H3 BvCR (7.1 vs 29.8%, p=8.9e-13). Overlap of a3-H3 peaks not containing survivin was less frequent (34%) compared to those which contained survivin (66%). Notably, survivin peak size was 5.5-fold higher when colocalized with a3-H3 peaks, compared to no, or any single H3 (p<2.2e-16). In contrast, no size difference for any of the H3 EM peaks was found.Further analysis of two non-redundant groups of BvCR that contain (survivin-a3H3, n=4085), and not containing survivin (a3H3noSurv, n = 2131) demonstrated that survivin was mostly associated with inactive BvCR (OR1.29, p=6.6e-6), while no such specificity was found for BvCR with no survivin. Additionally, survivin containing BvCR contained abundant binding sites matching known consensus TF motifs. No sequence-specific motifs were identified in BvCR with no survivin. Comparison of results obtained through HOCOMOCO and ReMap databases resulted in a list of 68 unique TFs. Many of those are key regulators of adaptive immune responses, cellular metabolism, and pluripotency. Differentially expressed genes mapped to BvCR demonstrated enrichment for cellular hormone metabolic processes, regeneration and DNA biosynthesis.ConclusionThis study provides experimental evidence that survivin defines binding specificity in bivalent chromatin regions being associated with regulation of cellular metabolism and renewal of CD4+ T cells that are functionally important to resist autoimmunity.References[1]Kelly AE, Ghenoiu C, Xue JZ, Zierhut C, Kimura H, Funabiki H. Survivin reads phosphorylated histone H3 threonine 3 to activate the mitotic kinase Aurora B Science. 2010 Oct 8; 330(6001): 235–239.Disclosure of InterestsNone declared
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Andersson KM, Malmhäll-Bah E, Erlandsson M, Chandrasekaran V, Töyrä Silfverswärd S, Pullerits R, Bokarewa MI. AB0024 PLURIPOTENCY MARKER PBX1 PREDICTS TREATMENT EFFECT IN RHEUMATOID ARTHRITIS. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.1963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundAccelerated immunosenescence with contraction of T cell repertoire, demise of thymic function and expansion of CD28null T cells with poor T cell reconstitution is the hallmark of rheumatoid arthritis (RA)1.ObjectivesIn this study we assessed if PBX1 transcription factor that maintains the pluripotency of hematopoietic stem cells could be used to predict treatment response in RA patients.MethodsCD4+ T cells of 87 RA female patients (age, median 61y (23-76); disease duration, median 9y (0-45)) were isolated from the perpheral blood, activated with aCD3 and subjected to transcriptional analysis by RNAseq (Illumina). External RNAseq of CD4+ T cells of 80 RA patients (f 56, m 24) was used for validation. The genes differentially expressed (DEG, nominal p<0.05) between PBX1hi and PBX1lo groups were identified by R-studio using Benjamini-Hochberg correction (Bioconductor, DESeq2 package). DEGs were clustered by covariance to identify PBX1 associated genes and biological processes. Clinical variates and treatment regimens in PBX1hi and PBX1lo groups were compared.ResultsThe patients of PBX1hi and PBX1lo groups were of similar age and disease duration but differed in anti-rheumatic treatment. PBX1hi group was often treated with conventional DMARDs and monotherapy, while PBX1lo group was mostly treated with biologics and/or JAK-inhibitors in combination with cDMARDs (χ2, p=0.0099). This treatment led to sufficient disease control in both PBX1 groups (median DAS28; 2.6 and 2.7, respectively). In the external RA cohort of the patients resistant to conventional DMARDs, PBX1hi patients had significantly fewer frequency of non-responders to anti-TNF treatment compared to PBX1lo (χ2, p=0.026).Pathway analysis of the DEGs identified strong enrichment for regulation of transcription (cor.p=10-23), RNA metabolic processes (cor.p=10-18) and differentiation (cor.p=10-7) in PBX1hi CD4+ cells, which corresponds to the known biological properties of PBX12. PBX1hiCD4+ cells in both datasets had imprinted features of pluripotency3 and expressed higher levels of KIT and CAT, low proliferation markers Ki67 and BIRC5, and had virtually no cytokine production. In the main cohort, PBX1hiCD4+ cells were recognized by naïve T cell marks CD62L (SELL) and CD45 (PTPRC), and also PECAM1, CR2, and CD28, indicating recent thymic egress. In the validation cohort, PBX1hiCD4+ cells were enriched with stem cell markers CD34, MEG3, and DNMT3B. Lineage specific TFs (TBET, GATA3, FOXP3, RORC) and cytokines (IFNG, TNF, IL10, IL17F, etc.) were accumulated in PBX1loCD4+ cells indicating terminally differentiated effector CD4+ T cells.ConclusionThis study shows that enrichment with PBX1hi CD4+ cells is associated with naïve pluripotent phenotype of CD4 lymphocytes. Patients with high PBX1 expression are less heavily treated and respond better to treatment. This suggests boosting of PBX1-expression to be a way of treating RA.References[1]Keotz K et al, PNAS 2000:97(16) 9203-9208. T cell homeostasis in patients with rheumatoid arthritis.[2]Veiga RN et al, J Mol Med (Berl) 2021:99(12) 1667-1680. PBX1: a key character of the hallmarks of cancer.[3]Bock C et al, Cell 2011:144(3) 439-452. Reference Maps of human ES and iPS cell variation enable high-throughput characterization of pluripotent cell linesDisclosure of InterestsNone declared
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Jomaa A, Gamerdinger M, Hsieh HH, Wallisch A, Chandrasekaran V, Ulusoy Z, Scaiola A, Hegde RS, Shan SO, Ban N, Deuerling E. Mechanism of signal sequence handover from NAC to SRP on ribosomes during ER-protein targeting. Science 2022; 375:839-844. [PMID: 35201867 DOI: 10.1126/science.abl6459] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The nascent polypeptide-associated complex (NAC) interacts with newly synthesized proteins at the ribosomal tunnel exit and competes with the signal recognition particle (SRP) to prevent mistargeting of cytosolic and mitochondrial polypeptides to the endoplasmic reticulum (ER). How NAC antagonizes SRP and how this is overcome by ER targeting signals are unknown. Here, we found that NAC uses two domains with opposing effects to control SRP access. The core globular domain prevented SRP from binding to signal-less ribosomes, whereas a flexibly attached domain transiently captured SRP to permit scanning of nascent chains. The emergence of an ER-targeting signal destabilized NAC's globular domain and facilitated SRP access to the nascent chain. These findings elucidate how NAC hands over the signal sequence to SRP and imparts specificity of protein localization.
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Affiliation(s)
- Ahmad Jomaa
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Martin Gamerdinger
- Department of Biology, Molecular Microbiology, University of Konstanz, 78457 Konstanz, Germany
| | - Hao-Hsuan Hsieh
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Annalena Wallisch
- Department of Biology, Molecular Microbiology, University of Konstanz, 78457 Konstanz, Germany
| | | | - Zeynel Ulusoy
- Department of Biology, Molecular Microbiology, University of Konstanz, 78457 Konstanz, Germany
| | - Alain Scaiola
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | | | - Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Elke Deuerling
- Department of Biology, Molecular Microbiology, University of Konstanz, 78457 Konstanz, Germany
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Chandrasekaran V, Desai N, Burton NO, Yang H, Price J, Miska EA, Ramakrishnan V. Visualizing formation of the active site in the mitochondrial ribosome. eLife 2021; 10:e68806. [PMID: 34609277 PMCID: PMC8492066 DOI: 10.7554/elife.68806] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/18/2021] [Indexed: 02/07/2023] Open
Abstract
Ribosome assembly is an essential and conserved process that is regulated at each step by specific factors. Using cryo-electron microscopy (cryo-EM), we visualize the formation of the conserved peptidyl transferase center (PTC) of the human mitochondrial ribosome. The conserved GTPase GTPBP7 regulates the correct folding of 16S ribosomal RNA (rRNA) helices and ensures 2'-O-methylation of the PTC base U3039. GTPBP7 binds the RNA methyltransferase NSUN4 and MTERF4, which sequester H68-71 of the 16S rRNA and allow biogenesis factors to access the maturing PTC. Mutations that disrupt binding of their Caenorhabditis elegans orthologs to the large subunit potently activate mitochondrial stress and cause viability, development, and sterility defects. Next-generation RNA sequencing reveals widespread gene expression changes in these mutant animals that are indicative of mitochondrial stress response activation. We also answer the long-standing question of why NSUN4, but not its enzymatic activity, is indispensable for mitochondrial protein synthesis.
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Affiliation(s)
| | - Nirupa Desai
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Nicholas O Burton
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
| | - Hanting Yang
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Jon Price
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Eric A Miska
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
- Wellcome Sanger Institute, Wellcome Genome CampusCambridgeUnited Kingdom
| | - V Ramakrishnan
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
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Chandrasekaran V, Katona G, Bokarewa MI, Andersson KM, Erlandsson MC, Jensen M, Oparina N, Damdimopoulos A. POS0397 AGGREGATED SURVIVIN BINDING AROUND HISTONE H3 EPIGENETIC MODIFICATIONS IN RISK LOCI ASSOCIATED WITH RHEUMATOID ARTHRITIS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.3212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Background:Survivin is an integral part of the Chromosomal Passenger Complex (CPC) which plays a vital role in mitosis. Experiments have demonstrated that survivin can physically bind to DNA. Crystallographic studies show that survivin binds to Threonine-3 of histone H3. In patients with autoimmune diseases, increased survivin expression contributes to an aggravated disease phenotype. Thus, functional, and mechanistic data point to a potential chromatin regulatory role for survivin, possibly in combination with the established gene regulatory function carried out by histone epigenetic modifications (EM).Objectives:The objective of the study was to analyse the co-localization of chromatin bound survivin with three histone H3 epigenetic modifications – acetylated lysine 27 (K27ac) and trimethylated lysine 4 (K4me3) and lysine-27 (K27me3). The second objective was to analyse if survivin-bound DNA sequences overlapped with sequences in the vicinity of 106 GWAS SNPs that are associated with a risk of developing rheumatoid arthritis (RA).Methods:Chromatin from CD4 T cells of 14 female subjects was immunoprecipitated with survivin antibodies and each of the histone H3 antibodies, and coupled with sequencing (ChIPseq, Hiseq2000, Illumina). After mapping the annotations of sequenced regions to the human reference genome hg38, enriched peaks were identified through Homer software. The identified survivin ChIP peaks were analysed for colocalization with peaks of the three histone H3 EMs and with RA risk loci, using the Bioconductor package ‘ChIPPeakAnno’ through RStudio.Results:Among the total of ~13,000 individual survivin ChIP-peaks, 33% colocalized with histone H3 EM peaks. The overlapping peaks show a linear increase in average peak size compared with the peaks showing no colocalization with any H3 EM peak. A maximum of 5.5-fold increase in average peak size was observed when survivin bound peaks overlap with peaks of all three H3 EMs. A major proportion (86%) of top RA risk SNPs was associated with either binding of survivin or H3 EMs. In this subset, 63% of RA risk SNPs were found within an area of 100 kilobases from survivin ChIP-peaks, with preferential enrichment of high-scoring peaks when survivin colocalizes with all 3 H3 EMs. Survivin was bound to risk SNPs annotated to, among others, the major immunological genes CD83, IRF4, CD28, ICOS and IL2RAConclusion:This study presents experimental evidence that survivin binding to DNA preferentially occurred in regions with high density of histone EMs. The increased aggregation of survivin around histone H3 EMs point to its potential regulatory function in gene transcription. Since regions around RA risk SNPs overlap with survivin peaks, survivin’s nuclear function could have immunologically important effects in mechanisms of autoimmune diseases.Disclosure of Interests:None declared
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Oparina N, Erlandsson M, Chandrasekaran V, Andersson KM, Damdimopoulos A, Töyrä Silfverswärd S, Katona G, Bokarewa MI. POS0360 COMPLEX LANDSCAPE OF BIRC5/SURVIVIN GENOME BINDING IN HUMAN CD4+ T CELLS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.3708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:Survivin, coded by BIRC5 gene, is a multitasking protein essential for cell renewal and homeostasis. In autoimmune conditions as rheumatoid and psoriasis arthritis, survivin was associated with inflammation severity and joint damage. Importantly, inhibition of survivin alleviated experimental arthritis in mice. We have recently shown survivin to be essential for T cell differentiation and micro-RNA processing. The known anti-apoptotic and proliferation facilitating functions of survivin does not explain the nuclear localization of survivin in interphase.Objectives:We aimed to uncover nuclear functions of BIRC5/survivin in CD4 cell of RA patients and healthy.Methods:CD4 T cells were isolated from the peripheral blood using positive selection on magnetic beads (EasySep) and activated for 48h with ConA+LPS. Chromatin immunoprecipitation (ChIP) with polyclonal anti-survivin antibodies was done in four independent samples of healthy donors (n=5), healthy smokers (n=3), rheumatoid arthritis (n=3) and breast cancer (n=2). Pooled libraries were constructed for each group and ChIPseq was carried out (Illumina). For comparative RNAseq analysis, activated CD4 T cells were incubated with or without survivin inhibitor (YM155) for 24h. State-of-the-art bioinformatics pipelines were applied for NGS data and the survivin-binding peaks were used for comparison with genes, chromatin state annotation and functional gene- and regulatory regions-based functional analysis. Co-localization of peaks in the whole genome and in vicinity of the differentially expressed genes (DEG) was done using ReMap integrated ChIPseq datasets for all human cells and tissues.Results:We identified 13 thousands non-overlapping survivin ChIP-peaks (>3000 peaks were present in at least 3 samples). Survivin-bound regions were enriched near the genes and promoters (p=e-30 and p=e-8), which implied that survivin role in transcription could be mediated by known transcription factors. Thus, we analyzed survivin peaks vs binding regions of 1135 transcription regulators (TR) available in ReMap.Potential partner proteins of survivin were selected based on the enrichment of the overlapping peaks in the whole genome and in CD4-active regulatory areas. Both, strict overlaps and location within 10 and 100kb survivin peak vicinity were analyzed. This approach allowed us to select >150 TRs enriched in all tests. The enriched TRs were involved in immunity and RA-relevant pathways including cytokine response and production, JAK-STAT signaling, etc. Among the TRs co-localized with survivin were CHD8, MAX, EP300, BRD2, CTCF and RAD21, all responsible for chromatin architecture. Several TRs were massively enriched in the vicinity of DEGs after survivin depletion including MAX, AR, CTCF, MYC and IRF1. Search for TR binding motifs in survivin peaks supported over-representation of binding sites for IRFs (p=e-5) and several proteins of the bZIP-family (p=e-5).Conclusion:Analysis of the survivin bound DNA in CD4 cells demonstrated the nonrandom distribution with specific enrichment within the regulatory elements of the genes and co-localizeation with protein partners to regulate their transcription.Disclosure of Interests:None declared
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Desai N, Yang H, Chandrasekaran V, Kazi R, Minczuk M, Ramakrishnan V. Elongational stalling activates mitoribosome-associated quality control. Science 2020; 370:1105-1110. [PMID: 33243891 PMCID: PMC7116630 DOI: 10.1126/science.abc7782] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 09/24/2020] [Indexed: 02/02/2023]
Abstract
The human mitochondrial ribosome (mitoribosome) and associated proteins regulate the synthesis of 13 essential subunits of the oxidative phosphorylation complexes. We report the discovery of a mitoribosome-associated quality control pathway that responds to interruptions during elongation, and we present structures at 3.1- to 3.3-angstrom resolution of mitoribosomal large subunits trapped during ribosome rescue. Release factor homolog C12orf65 (mtRF-R) and RNA binding protein C6orf203 (MTRES1) eject the nascent chain and peptidyl transfer RNA (tRNA), respectively, from stalled ribosomes. Recruitment of mitoribosome biogenesis factors to these quality control intermediates suggests additional roles for these factors during mitoribosome rescue. We also report related cryo-electron microscopy structures (3.7 to 4.4 angstrom resolution) of elongating mitoribosomes bound to tRNAs, nascent polypeptides, the guanosine triphosphatase elongation factors mtEF-Tu and mtEF-G1, and the Oxa1L translocase.
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Affiliation(s)
- Nirupa Desai
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Hanting Yang
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - Razina Kazi
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - V. Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK,Corresponding author.
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Kaba R, Ashry A, Elbadri A, Gukop P, Li A, Sohal M, Bajpay A, Saba M, Sharma R, Gallagher M, Chandrasekaran V, Momin A. 16-month outcomes following hybrid ablation for long-standing persistent atrial fibrillation in patients with dilated atria. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.0629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Introduction
Although catheter ablation therapy is a well-established treatment for cardiac dysrhythmias, the success rates for longstanding, persistent AF with dilated atria remain unsatisfactory. The minimally invasive hybrid technology is a novel form of therapy.
Methods
A prospective, single-center UK study to evaluate the hybrid ablation technique for patients with longstanding (>1 year) persistent AF and dilated atria. Stage 1 was a minimally invasive epicardial approach for ablation of the posterior wall of left atrium (LA) and pulmonary veins (PVs). Stage 2 was a transcatheter approach via the femoral veins to isolate the endocardial aspect of the PVs +/− posterior wall. Occasionally, the sequence of the stages was reversed.
Results
Forty-one patients were enrolled for the study with a mean follow-up for 16±9 months. Mean age was 65±9 years and the mean BMI was 32±7. Males constituted 75% of the study cohort. Mean LA size was 48±7 mm and mean left ventricular ejection fraction (LVEF) was 51.9%, although 51.6% of patients had impaired LVSF (LVEF below 55%). 87.8% CI (0.7–0.9) of patients remained in sinus rhythm (SR) without repeat ablation, whereas only 12.2% CI (0.04–0.02) had redeveloped persistent AF. Although numerically different, there was no statistically significant difference in maintaining SR between patients with severely dilated LA (>50 mm) and those without (70% vs. 90%, respectively; z=−1.39, p=0.165). Major perioperative complications during stage 1 ablation were low, with IVC injury in 1 patient and a mild stroke in 1 patient. Median LOS was 1 day (1–4 days) and there was no 30-day mortality after stage 1.
Conclusions
The hybrid ablation therapy has a conversion rate from longstanding persistent AF to SR of 87.8% at a mean follow-up of 16±9 months, without repeat ablation. LOS was short, with very few complications and no peri-operative mortality. The hybrid approach appears to be very encouraging for a condition with otherwise low success rates by conventional endocardial techniques alone.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- R.A Kaba
- St George's Hospital (London), London, United Kingdom
| | - A Ashry
- St George's Hospital (London), London, United Kingdom
| | - A Elbadri
- St George's Hospital (London), London, United Kingdom
| | - P Gukop
- St George's Hospital (London), London, United Kingdom
| | - A Li
- St George's Hospital (London), London, United Kingdom
| | - M Sohal
- St George's Hospital (London), London, United Kingdom
| | - A Bajpay
- St George's Hospital (London), London, United Kingdom
| | - M Saba
- St George's Hospital (London), London, United Kingdom
| | - R.A Sharma
- St George's Hospital (London), London, United Kingdom
| | - M Gallagher
- St George's Hospital (London), London, United Kingdom
| | | | - A Momin
- St George's Hospital (London), London, United Kingdom
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Rahul KK, Shivakarthik E, Meka JK, Das A, Chandrasekaran V, Rajasekhar BN, Lo JI, Cheng BM, Janardhan P, Bhardwaj A, Mason NJ, Sivaraman B. Residue from vacuum ultraviolet irradiation of benzene ices: Insights into the physical structure of astrophysical dust. Spectrochim Acta A Mol Biomol Spectrosc 2020; 231:117797. [PMID: 31837964 DOI: 10.1016/j.saa.2019.117797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/12/2019] [Accepted: 11/12/2019] [Indexed: 06/10/2023]
Abstract
We have irradiated benzene ices deposited at 4 K on a cold, interstellar dust analog with vacuum ultraviolet (9 eV) irradiation for periods lasting from several hours to nearly a day, after which the irradiated ice was warmed to room temperature. Vacuum ultraviolet photoabsorption spectra of the aromatic residue left at room temperature were recorded and showed the synthesis of benzene derivatives. The residue was also imaged using an electron microscope and revealed crystals of various sizes and shapes. The result of our experiments suggests such geometrically shaped dust particles may be a key component of interstellar dust.
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Affiliation(s)
- K K Rahul
- Physical Research Laboratory, Ahmedabad, India
| | | | - J K Meka
- Physical Research Laboratory, Ahmedabad, India
| | - A Das
- Indian Centre for Space Physics, Kolkata, India
| | | | - B N Rajasekhar
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - J-I Lo
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - B-M Cheng
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - P Janardhan
- Physical Research Laboratory, Ahmedabad, India
| | - A Bhardwaj
- Physical Research Laboratory, Ahmedabad, India
| | - N J Mason
- School of Physical Sciences, University of Kent, Canterbury, Kent CT2, UK
| | - B Sivaraman
- Physical Research Laboratory, Ahmedabad, India.
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Lin Z, Gasic I, Chandrasekaran V, Peters N, Shao S, Mitchison TJ, Hegde RS. TTC5 mediates autoregulation of tubulin via mRNA degradation. Science 2019; 367:100-104. [PMID: 31727855 DOI: 10.1126/science.aaz4352] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022]
Abstract
Tubulins play crucial roles in cell division, intracellular traffic, and cell shape. Tubulin concentration is autoregulated by feedback control of messenger RNA (mRNA) degradation via an unknown mechanism. We identified tetratricopeptide protein 5 (TTC5) as a tubulin-specific ribosome-associating factor that triggers cotranslational degradation of tubulin mRNAs in response to excess soluble tubulin. Structural analysis revealed that TTC5 binds near the ribosome exit tunnel and engages the amino terminus of nascent tubulins. TTC5 mutants incapable of ribosome or nascent tubulin interaction abolished tubulin autoregulation and showed chromosome segregation defects during mitosis. Our findings show how a subset of mRNAs can be targeted for coordinated degradation by a specificity factor that recognizes the nascent polypeptides they encode.
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Affiliation(s)
- Zhewang Lin
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Ivana Gasic
- Department of Systems Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | | | - Niklas Peters
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Sichen Shao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Timothy J Mitchison
- Department of Systems Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
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Abstract
Post-renal transplant fungal infections continue to be a major cause of mortality and morbidity. Universally reported fungi are Candida, especially Candida albicans, Cryptococcus, Aspergillus, Trichophyton rubrum and Pityriasis versicolor. Here, we report a case of infection caused by a rare fungus Diaporthe. It is an endophyte reported as plant pathogens and infrequently in humans and mammals. The patient was a renal transplant recipient on immunosuppressant. He had hypothyroidism and diagnosed with permanent pacemaker due to a complete heart block. The patient was treated with itraconazole (200 mg) successfully.
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Affiliation(s)
- K Vichitra
- Department of Microbiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Lokeshwari Gopal
- Department of Microbiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Balajee Govindarao
- Department of Nephrology, Gleneagles Global Health City, Chennai, Tamil Nadu, India
| | - V Chandrasekaran
- Department of Nephrology, Gleneagles Global Health City, Chennai, Tamil Nadu, India
| | - Anupma Jyoti Kindo
- Department of Microbiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
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Juszkiewicz S, Chandrasekaran V, Lin Z, Kraatz S, Ramakrishnan V, Hegde RS. ZNF598 Is a Quality Control Sensor of Collided Ribosomes. Mol Cell 2018; 72:469-481.e7. [PMID: 30293783 PMCID: PMC6224477 DOI: 10.1016/j.molcel.2018.08.037] [Citation(s) in RCA: 224] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/07/2018] [Accepted: 08/22/2018] [Indexed: 01/30/2023]
Abstract
Aberrantly slow translation elicits quality control pathways initiated by the ubiquitin ligase ZNF598. How ZNF598 discriminates physiologic from pathologic translation complexes and ubiquitinates stalled ribosomes selectively is unclear. Here, we find that the minimal unit engaged by ZNF598 is the collided di-ribosome, a molecular species that arises when a trailing ribosome encounters a slower leading ribosome. The collided di-ribosome structure reveals an extensive 40S-40S interface in which the ubiquitination targets of ZNF598 reside. The paucity of 60S interactions allows for different ribosome rotation states, explaining why ZNF598 recognition is indifferent to how the leading ribosome has stalled. The use of ribosome collisions as a proxy for stalling allows the degree of tolerable slowdown to be tuned by the initiation rate on that mRNA; hence, the threshold for triggering quality control is substrate specific. These findings illustrate how higher-order ribosome architecture can be exploited by cellular factors to monitor translation status. ZNF598 is a direct sensor of ribosome collisions incurred by many unrelated causes The minimal target recognized and ubiquitinated by ZNF598 is a collided di-ribosome Collided di-ribosome structure shows that ZNF598 ubiquitin sites are near the interface Collisions are required to terminally arrest translation in ZNF598-dependent manner
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Affiliation(s)
| | | | - Zhewang Lin
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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Kumar AKH, Chandrasekaran V, Kannan T, Lavanya J, Swaminathan S, Ramachandran G. Intrapatient variability in plasma rifampicin & isoniazid in tuberculosis patients. Indian J Med Res 2018; 147:287-292. [PMID: 29923518 PMCID: PMC6022390 DOI: 10.4103/ijmr.ijmr_1961_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background & objectives: Large variability in anti-tuberculosis (TB) drug concentrations between patients is known to exist. However, limited information is available on intrapatient drug levels during the course of anti-TB treatment (ATT). This study was conducted to evaluate intrapatient variability in plasma rifampicin (RMP) and isoniazid (INH) concentrations during ATT at start of the treatment, at the end of intensive phase (IP) of ATT and at the end of ATT in adult TB patients being treated in the Revised National TB Control Programme (RNTCP). Methods: Adult TB patients (n=485), receiving thrice-weekly ATT in the RNTCP, were studied. Two-hour post-dosing concentrations of RMP and INH were determined at month 1, end of IP and end of ATT, after directly observed drug administration. Drug concentrations were estimated by high-performance liquid chromatography. Results: The median (inter-quartile range) RMP concentrations during the first month, at end of IP and end of ATT were 2.1 (0.4-5.0), 2.4 (0.6-5.5) and 2.2 (0.5-5.3) μg/ml, respectively. The corresponding INH concentrations were 7.1 (4.2-9.9), 7.2 (3.9-10.9) and 6.7 (3.9-9.5) μg/ml. None of the differences in drug concentrations obtained at different time points during ATT were significant. RMP and INH concentrations at different time points were significantly correlated. Age and body mass index caused significant variability in drug concentrations. Interpretation & conclusions: Plasma RMP and INH estimations in adult TB patients at two hours after drug administration remained unaltered during ATT. Clinicians can consider testing drug concentrations at any time point during ATT. These findings may assume significance in the context of therapeutic drug monitoring of anti-TB drug concentrations.
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Affiliation(s)
- A K Hemanth Kumar
- Department of Biochemistry & Clinical Pharmacology; ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India
| | - V Chandrasekaran
- Department of Biochemistry & Clinical Pharmacology; ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India
| | - T Kannan
- Department of Biochemistry & Clinical Pharmacology; ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India
| | - J Lavanya
- District TB Officer, Chennai Corporation, Chennai, India
| | - Soumya Swaminathan
- ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India
| | - Geetha Ramachandran
- Department of Biochemistry & Clinical Pharmacology; ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India
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Saha K, Chandrasekaran V, Heber O, Iron MA, Rappaport ML, Zajfman D. Ultraslow isomerization in photoexcited gas-phase carbon cluster [Formula: see text]. Nat Commun 2018; 9:912. [PMID: 29500438 PMCID: PMC5834543 DOI: 10.1038/s41467-018-03197-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/26/2018] [Indexed: 01/29/2023] Open
Abstract
Isomerization and carbon chemistry in the gas phase are key processes in many scientific studies. Here we report on the isomerization process from linear [Formula: see text] to its monocyclic isomer. [Formula: see text] ions were trapped in an electrostatic ion beam trap and then excited with a laser pulse of precise energy. The neutral products formed upon photoexcitation were measured as a function of time after the laser pulse. It was found using a statistical model that, although the system is excited above its isomerization barrier energy, the actual isomerization from linear to monocyclic conformation takes place on a very long time scale of up to hundreds of microseconds. This finding may indicate a general phenomenon that can affect the interstellar medium chemistry of large molecule formation as well as other gas phase processes.
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Affiliation(s)
- K. Saha
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - V. Chandrasekaran
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 Israel
- Present Address: Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014 India
| | - O. Heber
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - M. A. Iron
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - M. L. Rappaport
- Department of Physics Core Facilities, Weizmann Institute of Science, Rehovot, 7610001 Israel
| | - D. Zajfman
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 Israel
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Hemanth Kumar AK, Kannan T, Chandrasekaran V, Sudha V, Vijayakumar A, Ramesh K, Lavanya J, Swaminathan S, Ramachandran G. Pharmacokinetics of thrice-weekly rifampicin, isoniazid and pyrazinamide in adult tuberculosis patients in India. Int J Tuberc Lung Dis 2018; 20:1236-41. [PMID: 27510252 DOI: 10.5588/ijtld.16.0048] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To study the pharmacokinetics of rifampicin (RMP), isoniazid (INH) and pyrazinamide (PZA) in adult tuberculosis (TB) patients and examine factors that influence drug pharmacokinetics. METHODS Adult TB patients (n = 101) receiving thrice-weekly anti-tuberculosis treatment in the Revised National TB Control Programme (RNTCP) were studied. The study was conducted at steady state after directly observed drug administration. RMP, INH and PZA concentrations were estimated using high-performance liquid chromatography and NAT2 genotyping by real-time polymerase chain reaction. RESULTS RMP peak concentration (Cmax) was sub-therapeutic (<8 μg/ml) in 88% of the patients. The Cmax of RMP, INH and PZA at 2 h was observed in respectively 83.2%, 97.0% and 92.1% of the patients. The Cmax and area under the curve from 0 to 8 h (AUC0-8) of PZA was lower in TB patients with diabetes mellitus than in non-diabetics. Significant associations were observed between the Cmax and the AUC0-8 of RMP, INH and PZA with drug doses; RMP with category of treatment; INH with smoking, body mass index and N-acetyl transferase 2 genotype; and PZA with sex and smoking. CONCLUSIONS Several risk factors for drug concentration variations were identified. Two-hour post-dosing drug concentrations mimicked Cmax. A high proportion of TB patients had RMP Cmax below the expected range, which is a matter of concern.
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Affiliation(s)
| | - T Kannan
- National Institute for Research in Tuberculosis, Chennai, India
| | | | - V Sudha
- National Institute for Research in Tuberculosis, Chennai, India
| | - A Vijayakumar
- National Institute for Research in Tuberculosis, Chennai, India
| | - K Ramesh
- National Institute for Research in Tuberculosis, Chennai
| | | | - S Swaminathan
- National Institute for Research in Tuberculosis, Chennai, India
| | - G Ramachandran
- National Institute for Research in Tuberculosis, Chennai, India
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Desikan P, Chauhan DS, Sharma P, Panwalkar N, Chourey M, Patidar ML, Yadav P, Chandrasekaran V, Ohri BS. Genetic diversity of Mycobacterium tuberculosis isolates from central India. Indian J Med Res 2017; 143:481-6. [PMID: 27377505 PMCID: PMC4928555 DOI: 10.4103/0971-5916.184287] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background & objectives: There is a paucity of data available on genetic biodiversity of Mycobacterium tuberculosis isolates from central India. The present study was carried out on isolates of M. tuberculosis cultured from diagnostic clinical samples of patients from Bhopal, central India, using spoligotyping as a method of molecular typing. Methods: DNA was extracted from 340 isolates of M. tuberculosis from culture, confirmed as M. tuberculosis by molecular and biochemical methods and subjected to spoligotyping. The results were compared with the international SITVIT2 database. Results: Sixty five different spoligo international type (SIT) patterns were observed. A total of 239 (70.3%) isolates could be clustered into 25 SITs. The Central Asian (CAS) and East African Indian (EAI) families were found to be the two major circulating families in this region. SIT26/CAS1_DEL was identified as the most predominant type, followed by SIT11/EAI3_IND and SIT288/CAS2. Forty (11.8%) unique (non-clustered) and 61 (17.9%) orphan isolates were identified in the study. There was no significant association of clustering with clinical and demographic characteristics of patients. Interpretation & conclusions: Well established SITs were found to be predominant in our study. SIT26/CAS1_DEL was the most predominant type. However, the occurrence of a substantial number of orphan isolates may indicate the presence of active spatial and temporal evolutionary dynamics within the isolates of M. tuberculosis.
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Affiliation(s)
- Prabha Desikan
- Bhopal Memorial Hospital & Research Centre (ICMR), Bhopal, Madhya Pradesh, India
| | - D S Chauhan
- National JALMA Institute of Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Pragya Sharma
- National JALMA Institute of Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Nikita Panwalkar
- Bhopal Memorial Hospital & Research Centre (ICMR), Bhopal, Madhya Pradesh, India
| | - Manju Chourey
- Bhopal Memorial Hospital & Research Centre (ICMR), Bhopal, Madhya Pradesh, India
| | - Mohan Lal Patidar
- Bhopal Memorial Hospital & Research Centre (ICMR), Bhopal, Madhya Pradesh, India
| | - Priyanka Yadav
- National JALMA Institute of Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - V Chandrasekaran
- National Institute for Research in Tuberculosis (ICMR), Chennai, India
| | - B S Ohri
- State TB Office, Directorate of Health Services, Bhopal, Madhya Pradesh, India
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Saha K, Prabhakaran A, Chandrasekaran V, Rappaport ML, Heber O, Zajfman D. An experimental setup to study delayed electron emission upon photoexcitation of trapped polyatomic anions. Rev Sci Instrum 2017; 88:053101. [PMID: 28571459 DOI: 10.1063/1.4982034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A Velocity Map Imaging (VMI) spectrometer has been designed and integrated with an electrostatic ion beam trap to study delayed electron emission from trapped polyatomic anions upon photodetachment. The VMI spectrometer is small in size and can record a wide range of photoelectron energies, with variable magnification. Delayed electron emission can be recorded in our experimental setup for any time duration after the photoexcitation of the polyatomic anions. Experiments were carried out with trapped O- and C5- ions to demonstrate the capability of the spectrometer. Delayed electron emissions from C5- as well as prompt photoelectrons from O- were detected by the VMI spectrometer upon photoexcitation. The design and performance of the spectrometer are presented in detail.
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Affiliation(s)
- K Saha
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - A Prabhakaran
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - V Chandrasekaran
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - M L Rappaport
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - O Heber
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
| | - D Zajfman
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel
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Li YL, Chandrasekaran V, Carter SD, Woodward CL, Christensen DE, Dryden KA, Pornillos O, Yeager M, Ganser-Pornillos BK, Jensen GJ, Sundquist WI. Primate TRIM5 proteins form hexagonal nets on HIV-1 capsids. eLife 2016; 5. [PMID: 27253068 PMCID: PMC4936896 DOI: 10.7554/elife.16269] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 05/19/2016] [Indexed: 12/04/2022] Open
Abstract
TRIM5 proteins are restriction factors that block retroviral infections by binding viral capsids and preventing reverse transcription. Capsid recognition is mediated by C-terminal domains on TRIM5α (SPRY) or TRIMCyp (cyclophilin A), which interact weakly with capsids. Efficient capsid recognition also requires the conserved N-terminal tripartite motifs (TRIM), which mediate oligomerization and create avidity effects. To characterize how TRIM5 proteins recognize viral capsids, we developed methods for isolating native recombinant TRIM5 proteins and purifying stable HIV-1 capsids. Biochemical and EM analyses revealed that TRIM5 proteins assembled into hexagonal nets, both alone and on capsid surfaces. These nets comprised open hexameric rings, with the SPRY domains centered on the edges and the B-box and RING domains at the vertices. Thus, the principles of hexagonal TRIM5 assembly and capsid pattern recognition are conserved across primates, allowing TRIM5 assemblies to maintain the conformational plasticity necessary to recognize divergent and pleomorphic retroviral capsids. DOI:http://dx.doi.org/10.7554/eLife.16269.001 After infecting a cell, a virus reproduces by forcing the cell to produce new copies of the virus, which then spread to other cells. However, cells have evolved ways to fight back against these infections. For example, many mammalian cells contain proteins called restriction factors that prevent the virus from multiplying. The TRIM5 proteins form one common set of restriction factors that act against a class of viruses called retroviruses. HIV-1 and related retroviruses have a protein shell known as a capsid that surrounds the genetic material of the virus. The capsid contains several hundred repeating units, each of which consists of a hexagonal ring of six CA proteins. Although this basic pattern is maintained across different retroviruses, the overall shape of the capsids can vary considerably. For instance, HIV-1 capsids are shaped like a cone, but other retroviruses can form cylinders or spheres. Soon after the retrovirus enters a mammalian cell, TRIM5 proteins bind to the capsid. This causes the capsid to be destroyed, which prevents viral replication. Previous research has shown that several TRIM5 proteins must link up with each other via a region of their structure called the B-box 2 domain in order to efficiently recognize capsids. How this assembly process occurs, and why it enables the TRIM5 proteins to recognize different capsids was not fully understood. Now, Li, Chandrasekaran et al. (and independently Wagner et al.) have investigated these questions. Using biochemical analyses and electron microscopy, Li, Chandrasekaran et al. found that TRIM5 proteins can bind directly to the surface of HIV-1 capsids. Several TRIM5 proteins link together to form large hexagonal nets, in which the B-box domains of the proteins are found at the points where three TRIM5 proteins meet. This arrangement mimics the pattern present in the HIV-1 capsid, and just a few TRIM5 rings can cover most of the capsid. Li, Chandrasekaran et al. then analysed TRIM5 proteins from several primates, including rhesus macaques, African green monkeys and chimpanzees. In all cases analyzed, the TRIM5 proteins assembled into hexagonal nets, although the individual units within the net did not have strictly regular shapes. These results suggest that TRIM5 proteins assemble a scaffold that can deform to match the pattern of the proteins in the capsid. Further work is now needed to understand how capsid recognition is linked to the processes that disable the virus. DOI:http://dx.doi.org/10.7554/eLife.16269.002
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Affiliation(s)
- Yen-Li Li
- Department of Biochemistry, University of Utah, Salt Lake City, United States
| | | | - Stephen D Carter
- Division of Biology, California Institute of Technology, Pasadena, United States
| | - Cora L Woodward
- Division of Biology, California Institute of Technology, Pasadena, United States
| | - Devin E Christensen
- Department of Biochemistry, University of Utah, Salt Lake City, United States
| | - Kelly A Dryden
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, United States
| | - Owen Pornillos
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, United States
| | - Mark Yeager
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, United States.,Department of Medicine, Division of Cardiovascular Medicine, University of Virginia Health System, Charlottesville, United States
| | - Barbie K Ganser-Pornillos
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, United States
| | - Grant J Jensen
- Division of Biology, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
| | - Wesley I Sundquist
- Department of Biochemistry, University of Utah, Salt Lake City, United States
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Albeck Y, Lerner G, Kandhasamy DM, Chandrasekaran V, Strasser D. Intense-Field Double Detachment of Electrostatically Bound F–(NF3)n Cluster Anions. J Phys Chem A 2016; 120:3246-52. [DOI: 10.1021/acs.jpca.5b11792] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Y. Albeck
- Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - G. Lerner
- Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - D. M. Kandhasamy
- Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - V. Chandrasekaran
- Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - D. Strasser
- Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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21
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Anamandra SH, Chandrasekaran V. COLOR CHILD: a novel color image local descriptor for texture classification and segmentation. Pattern Anal Appl 2015. [DOI: 10.1007/s10044-015-0528-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kumar R, Chandrasekaran V. Sargassum wightii Extract as a Green Inhibitor for Corrosion of Brass in 0.1 N Phosphoric Acid Solution. ACTA ACUST UNITED AC 2015. [DOI: 10.13005/ojc/310239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Subramani R, Kolappan C, Chandrasekaran V, Selvakumar N, Wares F, Baskaran D, Swaminathan S. Could repeated prevalence surveys lead to decreasing tuberculosis prevalence in a community? Int J Tuberc Lung Dis 2015; 19:635-9. [PMID: 25946351 DOI: 10.5588/ijtld.14.0562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Tiruvallur District, South India, where one baseline tuberculosis (TB) disease prevalence survey followed by three repeat prevalence surveys were conducted every 2.5 years between 1999 and 2008, and where the DOTS strategy was implemented in 1999. OBJECTIVE To rule out the possibility that the observed decline in TB prevalence was influenced by conducting repeat prevalence surveys, we compared the findings from two surveys: the third repeat survey conducted in 2006-2008 and an independent single survey in a neighbouring area conducted in 2008-2009. DESIGN An independent survey was conducted to estimate the prevalence of TB in the same district in 2008-2009 using a different set of villages and employing repeat survey methodology. The independent survey findings were compared with those of the third repeat survey. RESULTS The estimated prevalence rate of culture- and smear-positive TB was respectively 401 per 100,000 and 186 per 100,000 population in the third repeat survey area. The corresponding rates were 340 and 184/100,000 in the independent survey area. The difference in prevalence was not significant (culture P = 0.09; smear P = 0.93). CONCLUSION The estimated prevalence rates in the two different sample survey areas were comparable, indicating that the repeated prevalence surveys in the study area did not influence the observed decline in TB disease prevalence.
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Affiliation(s)
- R Subramani
- National Institute for Research in Tuberculosis, Chennai, India
| | - C Kolappan
- National Institute for Research in Tuberculosis, Chennai, India
| | | | - N Selvakumar
- National Institute for Research in Tuberculosis, Chennai, India
| | - F Wares
- Global Tuberculosis Programme, World Health Organization, Geneva, Switzerland
| | - D Baskaran
- National Institute for Research in Tuberculosis, Chennai, India
| | - S Swaminathan
- National Institute for Research in Tuberculosis, Chennai, India
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Selvakumar N, Kumar V, Balaji S, Prabuseenivasan S, Radhakrishnan R, Sekar G, Chandrasekaran V, Kannan T, Thomas A, Arunagiri S, Dewan P, Swaminathan S. High rates of ofloxacin resistance in Mycobacterium tuberculosis among both new and previously treated patients in Tamil Nadu, South India. PLoS One 2015; 10:e0117421. [PMID: 25738956 PMCID: PMC4349813 DOI: 10.1371/journal.pone.0117421] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/22/2014] [Indexed: 11/18/2022] Open
Abstract
Periodic drug resistance surveillance provides useful information on trends of drug resistance and effectiveness of tuberculosis (TB) control measures. The present study determines the prevalence of drug resistance among new sputum smear positive (NSP) and previously treated (PT) pulmonary TB patients, diagnosed at public sector designated microscopy centers (DMCs) in the state of Tamil Nadu, India. In this single-stage cluster-sampling prevalence survey, 70 of 700 DMCs were randomly selected using a probability-proportional to size method. A cluster size of 24 for NSP and a varying size of 0 to 99 for PT cases were fixed for each selected DMC. Culture and drug susceptibility testing was done on Lowenstein-Jensen medium using the economic variant of proportion sensitivity test for isoniazid (INH), rifampicin (RMP), ofloxacin (OFX) and kanamycin (KAN). Human Immunodeficiency Virus (HIV) status was collected from patient records. From June 2011 to August 2012, 1524 NSP and 901 PT patients were enrolled. Any RMP resistance and any INH resistance were observed in 2.6% and 15.1%, and in 10.4% and 30% respectively in NSP and PT cases. Among PT patients, multi drug resistant TB (MDR-TB) was highest in the treatment failure (35%) group, followed by relapse (13%) and treatment after default (10%) groups. Extensively drug resistant TB (XDRTB) was seen in 4.3% of MDR-TB cases. Any OFX resistance was seen in 10.4% of NSP, 13.9% of PT and 29% of PT MDR-TB patients. The HIV status of the patient had no impact on drug resistance levels. RMP resistance was present in 2.6% of new and 15.1% of previously treated patients in Tamil Nadu. Rates of OFX resistance were high among NSP and PT patients, especially among those with MDR-TB, a matter of concern for development of new treatment regimens for TB.
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Affiliation(s)
- N. Selvakumar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Vanaja Kumar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - S. Balaji
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - S. Prabuseenivasan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - R. Radhakrishnan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Gomathi Sekar
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - V. Chandrasekaran
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - T. Kannan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - Aleyamma Thomas
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
| | - S. Arunagiri
- State TB Cell, Government of Tamil Nadu, Chennai, India
| | | | - Soumya Swaminathan
- National Institute for Research in Tuberculosis (Indian Council of Medical Research), Chennai, India
- * E-mail:
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Thomas BE, Charles N, Watson B, Chandrasekaran V, Senthil Kumar R, Dhanalakshmi A, Wares F, Swaminathan S. Prevalence of chest symptoms amongst brick kiln migrant workers and care seeking behaviour: a study from South India. J Public Health (Oxf) 2014; 37:590-6. [PMID: 25538142 DOI: 10.1093/pubmed/fdu104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Early detection and treatment of tuberculosis (TB) have been key principles of TB control. However, this can be a challenge with 'hard to reach' populations such as migrants. Brick kiln workers are one such group of migrants who are exposed to smoke, heat and dust from brick kilns which are one of the major causes of respiratory illnesses. METHODOLOGY A cross-sectional community based study was carried out in Thiruvallur, Tamil Nadu, South India, from August 2011 to June 2012. A total of 4002 individuals from 55 brick kiln chambers were interviewed to determine the prevalence of chest symptoms and care seeking behaviour patterns. RESULTS Three hundred and seventy-seven (9.4%) chest symptomatics were identified. The most significant variables associated with chest symptoms were illiteracy, alcohol abuse and heavy smoking. Of the chest symptomatics identified, 50.4% took action to get relief from their symptoms. The duration of over 6-month stay in the chamber was significantly associated with taking action (OR, 5.5, 95% CI: 2.3, 13.3). CONCLUSIONS The TB control programme needs to further explore how to extend its services to such 'hard to reach' groups. Active case finding to ensure early diagnosis and treatment initiation amongst such groups needs consideration.
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Affiliation(s)
- Beena E Thomas
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - Niruparani Charles
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - Basilea Watson
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - V Chandrasekaran
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - R Senthil Kumar
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - A Dhanalakshmi
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
| | - Fraser Wares
- Global TB Programme, World Health Organisation, Geneva, Switzerland
| | - Soumya Swaminathan
- National Institute for Research in Tuberculosis, Indian Council of Medical Research (ICMR), Chennai 600 031, India
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Kamath R, Robin S, Chandrasekaran V. Common mental disorders: a challenge among people living with human immunodeficiency virus infection/acquired immunodeficiency syndrome in udupi, India. Ann Med Health Sci Res 2014; 4:242-7. [PMID: 24761246 PMCID: PMC3991948 DOI: 10.4103/2141-9248.129051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Globally, the prevalence of common mental disorders (CMD) is greater among people living with human immunodeficiency virus/acquired immunodeficiency syndrome (PLHA) as opposed to the general population. There is relatively limited research on mental health in PLHA in India and this study seeks to gain insight in this area. AIM The aim of this study is to find the prevalence of CMD among PLHA in Udupi district. SUBJECTS AND METHODS In this cross-sectional study, 227 PLHA were selected using a convenience sampling method and interviewed at a district antiretroviral treatment center. The Kessler Psychological Distress Scale (K10 scale) and the General Health Questionnaire (GHQ-12) were used to measure distress and stress, respectively to assess CMD. Statistical analysis was performed with categorical variables expressed as frequencies and percentages. Continuous variables were measured using mean and standard deviation. Univariate and multivariate analyses using binomial logistic regression was carried out. SPSS version 15 (SPSS Inc., Chicago, IL, USA) was used to analyze the data. RESULTS The K10 Psychological Distress Scale indicated that 78.9% (n = 179/227) of participants suffered from mild to severe mental disorder and it was higher among divorced, separated or widowed PLHA followed by the married participants versus unmarried individuals. The GHQ-12 scale showed 68.3% (n = 155/227) suffering from mild to severe mental stress with the female gender developing stress 2.3 times more often. CONCLUSION High levels of distress were seen among PLHA. They should be periodically screened for CMD and provided early psychological intervention at the point of contact with health professionals. Psychological care needs to be integrated along with the clinical care.
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Affiliation(s)
- R Kamath
- Department of Public Health, Manipal University, Manipal, Karnataka, India
| | - S Robin
- Department of Public Health, Manipal University, Manipal, Karnataka, India
| | - V Chandrasekaran
- Department of Public Health, Manipal University, Manipal, Karnataka, India
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Suresh Jeyakumar RP, Chandrasekaran V. Adsorption of lead(II) ions by activated carbons prepared from marine green algae: Equilibrium and kinetics studies. Int J Ind Chem 2014. [DOI: 10.1186/2228-5547-5-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Rekha B, Jagarajamma K, Chandrasekaran V, Wares F, Sivanandham R, Swaminathan S. Improving screening and chemoprophylaxis among child contacts in India's RNTCP: a pilot study. Int J Tuberc Lung Dis 2013; 17:163-8. [PMID: 23317950 DOI: 10.5588/ijtld.12.0415] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While contact screening and chemoprophylaxis is recommended by India's Revised National Tuberculosis Control Programme for asymptomatic children aged <6 years who are household contacts of smear-positive pulmonary tuberculosis (PTB) patients, implementation is suboptimal. OBJECTIVE To evaluate the effectiveness of an isoniazid preventive therapy (IPT) register and card in improving the adherence of health care workers (HCWs) to programmatic guidelines. METHODOLOGY This prospective study was conducted in two Tuberculosis Units in South India. Child contacts of smear-positive PTB patients initiated on treatment between November 2009 and January 2010 were screened, and IPT was initiated in asymptomatic children. HCWs were trained in the use of the IPT register and card. The process was evaluated using patient and HCW interviews. RESULTS Of 87 children identified aged <6 years, 71 (82%) were traced by HCWs; 53 were screened for TB and initiated on IPT, and 39 completed treatment. HCWs expressed satisfaction with the use of the IPT card and register, saying that it helped them to remember to complete required tasks. CONCLUSION In a programme setting, with HCW training and introduction of specific documentation (IPT card and register), implementation of contact tracing and chemoprophylaxis for child contacts improved from 19% to 61%.
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Affiliation(s)
- B Rekha
- National Institute for Research in Tuberculosis (formerly Tuberculosis Research Centre), Chennai, India
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Aviv O, Kafle B, Chandrasekaran V, Heber O, Rappaport ML, Rubinstein H, Schwalm D, Strasser D, Toker Y, Zajfman D. Absolute photo-destruction and photo-fragmentation cross section measurements using an electrostatic ion beam trap. Rev Sci Instrum 2013; 84:053106. [PMID: 23742531 DOI: 10.1063/1.4804646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We describe a technique to measure absolute photo-induced cross sections for cluster anions stored in an electrostatic ion beam trap (EIBT) with a central deflector. The setup allows determination of total photo-destruction cross sections as well as partial cross sections for fragmentation and electron detachment. The unique properties of this special EIBT setup are investigated and illustrated using small Al(n)(-) clusters.
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Affiliation(s)
- O Aviv
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100, Israel
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Ganser-Pornillos BK, Pornillos O, Chandrasekaran V, Cheng A, Sundquist WI, Yeager M. The HIV-1 Capsid: Assembly and Restriction by TRIM5α. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Kolappan C, Subramani R, Chandrasekaran V, Thomas A. Trend in tuberculosis infection prevalence in a rural area in South India after implementation of the DOTS strategy. Int J Tuberc Lung Dis 2012; 16:1315-9. [PMID: 23107632 DOI: 10.5588/ijtld.12.0098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Three tuberculin surveys were conducted at intervals of 5 years following the implementation of a DOTS-based programme in 1999 in Tiruvallur District, South India. OBJECTIVE To estimate the trend in the prevalence of tuberculosis (TB) infection among children and to evaluate the impact of the DOTS strategy. METHODS Children aged 1-9 years in the sample for each survey were registered and administered 1 tuberculin unit of purified protein derivative RT 23 with Tween 80 by intradermal injection on the volar aspect of the left forearm. The induration diameter of the reaction was measured in mm after 72 h (3 days) and the prevalence of TB infection estimated. RESULTS The induration data of bacille Calmette-Guérin (BCG) vaccinated and non-vaccinated children were analysed using the mixture model. The estimated prevalence of TB infection among non-BCG-vaccinated children in the three tuberculin surveys were respectively 19.4%, 13.8% and 11.4%, with an average annual decline of 5.2% (95%CI 3.6-6.8). The prevalence of TB infection among BCG-vaccinated children decreased, with an average annual decline of 5.4% (95%CI 10.0-18.6). CONCLUSION A significant declining trend in the prevalence of TB infection among children was observed following the implementation of the DOTS strategy in the area.
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Affiliation(s)
- C Kolappan
- National Institute for Research in Tuberculosis, Indian Council of Medical Research, Chetput, Chennai, India
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Mathur R, Singh R, Ray S, Ghosal P, Chandrasekaran V. Effect of Trivalent Additions and Processing on Structural and Magnetic Transitions in Ni-Mn-Ga Ferromagnetic Shape Memory Alloys. DEFENCE SCI J 2012. [DOI: 10.14429/dsj.62.1279] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Suhadev M, Thomas BE, Raja Sakthivel M, Murugesan P, Chandrasekaran V, Charles N, Durga R, Auxilia M, Mathew TA, Wares F. Alcohol use disorders (AUD) among tuberculosis patients: a study from Chennai, South India. PLoS One 2011; 6:e19485. [PMID: 21611189 PMCID: PMC3096635 DOI: 10.1371/journal.pone.0019485] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 04/08/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Alcohol Use Disorders (AUDs) among tuberculosis (TB) patients are associated with nonadherence and poor treatment outcomes. Studies from Tuberculosis Research Centre (TRC), Chennai have reported that alcoholism has been one of the major reasons for default and mortality in under the DOTS programme in South India. Hence, it is planned to conduct a study to estimate prevalence of alcohol use and AUDs among TB patients attending the corporation health centres in Chennai, India. METHODOLOGY This is a cross-sectional cohort study covering 10 corporation zones at Chennai and it included situational assessment followed by screening of TB patients by a WHO developed Alcohol Use Disorders Identification Test AUDIT scale. Four zones were randomly selected and all TB patients treated during July to September 2009 were screened with AUDIT scale for alcohol consumption. RESULTS Out of 490 patients, 66% were males, 66% were 35 years and above, 57% were married, 58% were from the low monthly income group of 8. Age (>35 years), education (less educated), income (CONCLUSIONS AUD among TB patients needs to be addressed urgently and the findings suggest the importance of integrating alcohol treatment into TB care.
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Mathur R, Singh R, Ray S, Raja M, Ghosal P, Chandrasekaran V. Structural and Magnetic Studies in Ni-Mn-Ga based Ferromagnetic Shape Memory Alloys. DEFENCE SCI J 2011. [DOI: 10.14429/dsj.61.645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Saravanan P, Sreedhar B, Mishra D, Perumal A, Chandrasekaran V. Hierarchical assembly of Sm2Co7/Co magnetic nanoparticles into highly stable and uniform nanospheres. J Nanosci Nanotechnol 2011; 11:3706-3710. [PMID: 21776759 DOI: 10.1166/jnn.2011.3819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hierarchical assembly of colloidal Sm2Co7/Co clusters in the form of nanospheres has been processed through a polyol process. The SmCo nanospheres are found to be robust, uniform ( 100 nm) and tend to self-assemble in the form of ordered superstructures. Each nanosphere consists of large number of discrete fine particles ( 6.0 nm), having two-phase structure of both Sm2Co7 and Co-phases. Upon annealing, these phases transform into Sm2Co17 phase with very high magnetization (169 emu/g). A possible mechanism on the formation of nanospheres from the individual Sm2Co2o7 and Co nanoparticles is also discussed.
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Affiliation(s)
- P Saravanan
- Advanced Magnetics Group, Defence Metallurgical Research Laboratory, Hyderabad 500058, India
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Thirunavukkarasu AB, Chandrasekaran V. Efficacy of anti-scorpion venom serum over prazosin in severe scorpion envenomation: Is the current evidence enough? J Postgrad Med 2011; 57:83-4; author reply 84. [DOI: 10.4103/0022-3859.75353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Muruganathan A, Thomas A, Muniyandi M, Chandrasekaran V. Revised National Tuberculosis Control Programme (RNTCP). J Indian Med Assoc 2010; 108:868-870. [PMID: 21661468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The global annual inicidence is estimated to be 1.98 million cases in India. This situation is further threatened by emergence of multidrug-resistant tuberculosis. The Revised National Tuberculosis Control Programme is based on Directly Observed Treatment Short-course (DOTS) strategy. DOTS facilitates relapse-free cure for TB. Diagnostic algorithms for pulmonary tuberculosis have been narrated in this article. Treatment of tuberculosis stands on patients' categorisation in 3 groups and schedule is described. The side-effects and their remedies are also narrated. The IMA has a role to join hands with the government to work closely to bring down the disease burden.
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Safren SA, Thomas BE, Mimiaga MJ, Chandrasekaran V, Menon S, Swaminathan S, Mayer KH. Depressive symptoms and human immunodeficiency virus risk behavior among men who have sex with men in Chennai, India. PSYCHOL HEALTH MED 2010; 14:705-15. [PMID: 20183543 DOI: 10.1080/13548500903334754] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Men who have sex with men (MSM) in India are a hidden population, facing unique environmental stressors and cultural pressures that place them at risk for depression. Depression may affect HIV risk behavior in MSM, and may affect the degree to which MSM may benefit from HIV prevention interventions. Depression in MSM in India, however, has largely been understudied. Two hundred ten MSM in Chennai completed an interviewer-administered behavioral assessment battery, which included the 20-item Center for Epidemiologic Studies Depression Scale (CES-D), demographics, sexual risk and identity, and other psychosocial variables. Over half (55%) of the sample exceeded the cutoff (CES-D >or= 16) to screen in for clinically significant depressive symptoms; this was associated with having had unprotected anal sex (OR = 1.97; 95% CI: 1.01-3.87) and higher number of male partners (OR = 1.04; 95% CI: 1.01-1.07). Statistically significant bivariate predictors of meeting the screen in for depressive symptoms included sexual identity (Kothi > Panthi; OR = 4.90; 95% CI: 2.30-10.54), not being married (OR = 3.40; 95% CI: 1.72-6.81), not having a child (OR = 4.40; 95% CI: 2.07-9.39), family not knowing about one's MSM identity (OR = 2.30; 95% CI: 1.18-4.90), having been paid for sex (OR = 5.10; p 95% CI: 2.87-9.47), and perceiving that one is at risk for acquiring HIV (OR = 1.10; 95% CI: 1.02-1.17; continuous). In a multivariable logistic-regression model, unique predictors of screening in for depressive symptoms included not being married (AOR = 3.10; 95% CI: 1.23-7.65), having been paid for sex (AOR = 3.80; 95% CI: 1.87-7.99) and the perception of increased risk for HIV (AOR = 1.10; 95% CI: 1.03-1.21; continuous); unprotected anal sex in the 3 months prior to study enrollment approached statistical significance (AOR = 2.00; 95% CI: 0.91-4.48). Depression among MSM in Chennai is of concern and should be considered while developing HIV prevention interventions with this population. MSM who are not married, sex workers, and those who perceive they are at risk for acquiring HIV may be of higher risk for symptoms of depression.
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Affiliation(s)
- Steven A Safren
- Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
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Abstract
In this paper, a novel topology constraint free neural network architecture using a generalized fuzzy gated neuron model is presented for pattern recognition task. The main feature is that the network does not require weight adaptation at its input and the weights are initialized directly from the training pattern set. The elimination of the need for iterative weight adaptation schemes facilitates quick network set up times which make the fuzzy gated neural networks very attractive. The performance of the proposed network is found to be functionally equivalent to spatio-temporal feature maps under a mild technical condition. The classification performance of fuzzy gated neural network is demonstrated on a 12-class synthetic three-dimensional (3-D) object data set, real-world eight-class texture data set, and real-world 12-class 3-D object data set. The performance results are compared with the classification accuracies obtained from spatiotemporal feature map, adaptive subspace self-organizing map, multilayer feedforward neural networks, radial basis function neural networks, and linear discriminant analysis. Despite the network's ability to accurately classify seen data and adequately generalize validation data, its performance is found to be sensitive to noise perturbations due to fine fragmentation of the feature space. This paper also provides partial solutions to the above robustness issue by proposing certain improvements to various modules of the proposed fuzzy gated neural network.
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Affiliation(s)
- V Chandrasekaran
- KCS Computer Services Private Ltd., South Melbourne, Vic-3205, Australia
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Banu Rekha VV, Jagarajamma K, Wares F, Chandrasekaran V, Swaminathan S. Contact screening and chemoprophylaxis in India's Revised Tuberculosis Control Programme: a situational analysis. Int J Tuberc Lung Dis 2009; 13:1507-1512. [PMID: 19919768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND India's Revised National Tuberculosis Control Programme (RNTCP) recommends screening of all household contacts of smear-positive pulmonary tuberculosis (PTB) cases for tuberculosis (TB) disease, and 6-month isoniazid preventive therapy (IPT) for asymptomatic children aged <6 years. OBJECTIVE To assess the implementation of child contact screening and IPT administration under the RNTCP. METHODS A cross-sectional study conducted in four randomly selected TB units (TUs), two in an urban (Chennai City) and two in a rural (Vellore District) area of Tamil Nadu, South India, from July to September 2008. The study involved the perusal of TB treatment cards of source cases (new or retreatment smear-positive PTB patients started on treatment), interview of source cases and focus group discussions (FGDs) among health care workers. RESULTS Interviews of 253 PTB patients revealed that of 220 contacts aged <14 years, only 31 (14%) had been screened for TB, and that of 84 household children aged <6 years, only 16 (19%) had been initiated on IPT. The treatment cards of source cases lacked documentation of contact details. FGDs revealed greater TB awareness among urban health care workers, but a lack of detailed knowledge about procedures. CONCLUSION Provision for documentation using a separate IPT card and focused training may help improve the implementation of contact screening and IPT.
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Thomas B, Mimiaga MJ, Mayer KH, Johnson CV, Menon S, Chandrasekaran V, Murugesan P, Swaminathan S, Safren SA. HIV prevention interventions in Chennai, India: are men who have sex with men being reached? AIDS Patient Care STDS 2009; 23:981-6. [PMID: 19821722 DOI: 10.1089/apc.2009.0092] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
India has the greatest number of HIV infections in Asia and the third highest total number of infected persons globally. Men who have sex with men (MSM) are considered by the Government of India's National AIDS Control Organization (NACO) a "core risk group" for HIV in need of HIV prevention efforts. However there is a dearth of information on the frequency of participation in HIV prevention interventions and subsequent HIV risk and other correlates among MSM in India. Recruited through peer outreach workers, word of mouth and snowball sampling techniques, 210 MSM in Chennai completed an interviewer-administered assessment, including questions about participating in any HIV prevention interventions in the past year, sexual risk taking, demographics, MSM identities, and other psychosocial variables. Bivariate and multivariable logistic regression procedures were used to examine behavioral and demographic correlates with HIV prevention intervention participation. More than a quarter (26%) of the sample reported participating in an HIV prevention intervention in the year prior to study participation. Participants who reported engaging in unprotected anal sex (UAS; odds ratio [OR] = 0.28; p = 0.01) in the 3 months prior to study enrollment were less likely to have participated in an HIV prevention program in the past year. MSM who were older (OR = 1.04; p = 0.05), kothis (feminine acting/appearing and predominantly receptive partners in anal sex) compared to panthis (masculine appearing, predominantly insertive partners; OR = 5.52, p = 0.0004), those with higher educational attainment (OR = 1.48, p = 0.01), being "out" about having sex with other men (OR = 4.03, p = 0.0001), and MSM who reported ever having been paid in exchange for sex (OR = 2.92, p = 0.001) were more likely to have reported participation in an HIV prevention intervention in the preceding year. In a multivariable model, MSM reporting UAS in the prior 3 months were less likely to have participated in an HIV prevention intervention (AOR = 0.34, p = 0.04). MSM who were older (AOR = 1.05, p = 0.05), those with higher educational attainment (AOR = 1.92, p = 0.0009), and MSM who were "out" about having sex with other men (AOR = 2.71, p = 0.04) were more likely to have reported participating in an HIV prevention program. Findings suggest that exposure to HIV prevention interventions may be protective against engaging in UAS for some MSM in India. Understanding predictors of participation in an HIV prevention intervention is helpful for identifying Indian MSM who might have had no exposure to HIV prevention information and skills building, hence allowing researchers and prevention workers to focus efforts on individuals at greatest need.
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Affiliation(s)
- Beena Thomas
- Tuberculosis Research Center, Indian Council of Medical Research, Chennai, India
| | - Matthew J. Mimiaga
- Harvard Medical School/Massachusetts General Hospital, Boston, Massachusetts
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Kenneth H. Mayer
- The Fenway Institute, Fenway Health, Boston, Massachusetts
- Brown Medical School/Miriam Hospital, Providence, Rhode Island
| | | | | | - V. Chandrasekaran
- Tuberculosis Research Center, Indian Council of Medical Research, Chennai, India
| | - P. Murugesan
- Tuberculosis Research Center, Indian Council of Medical Research, Chennai, India
| | - Soumya Swaminathan
- Tuberculosis Research Center, Indian Council of Medical Research, Chennai, India
| | - Steven A. Safren
- Harvard Medical School/Massachusetts General Hospital, Boston, Massachusetts
- The Fenway Institute, Fenway Health, Boston, Massachusetts
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43
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Jaggarajamma K, Balambal R, Muniyandi M, Vasantha M, Thomas B, Nirupa C, Sudha G, Chandrasekaran V, Wares F. Perceptions of tuberculosis patients about private providers before and after implementation of Revised National Tuberculosis Control Programme. Indian J Tuberc 2009; 56:185-190. [PMID: 20469729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Most of the persons with chest symptoms in India approach private providers (PPs) for health care. It has been observed that patients who start treatment with PPs for tuberculosis (TB) frequently switch over subsequently to the public sector. The reasons for this discontinuation and their perceptions of the TB care provided by the PPs are unknown. OBJECTIVE To document the perceptions about PPs India's Revised National TB Control Programme (RNTCP) and the reasons for discontinuation of treatment with PPs and subsequent attendance at a public provider. METHODS This was a cross sectional study on patients registered under TB programme during 1997 and 2005 in rural and urban areas. During this period patients who were initially diagnosed and treated for TB in a private clinic and subsequently shifted to public health facility were considered for the study. A semi-structured interview schedule was used to collect the factors related to patient's perceptions on PPs, the factors responsible for initiating treatment with PPs, reasons for discontinuing treatment with PPs, and their willingness to continue treatment from government health facilities were collected. This data was compared with data collected in 1997 before implementation of the RNTCP. RESULTS A total of 1000 and 1311 TB patients were registered during 1997 and 2005 respectively. Among them, 203 (20%) and 104 (8%) patients were identified as having been initially diagnosed and started on TB treatment by PPs and subsequently shifted to government health facilities. There were significant changes in reasons for selecting PPs between the two periods: being convenient (47% vs 10%; p < 0.001), quality care (41% vs 19%; p < 0.001), motivated by others (49% vs 19%; p < 0.001), confidentiality (19% vs 9%; p < 0.05) and known doctor (6% vs 28%; p < 0.001) respectively. Financial problems were the most common reason for discontinuation of treatment in both periods. The use of sputum test for diagnosing TB by PPs was significantly increased after RNTCP implementation. CONCLUSION This study suggests that slowly perceptions of patients have changed towards PPs, and RNTCP has begun to gain acceptance amongst patients in terms of convenience, confidentiality and personal care.
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Affiliation(s)
- K Jaggarajamma
- Tuberculosis Research Centre (ICMR), Mayor Ramanathan Road, Chetput, Chennai 600031.
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44
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Narayanan PR, Gopi PG, Subramani R, Santha T, Chandrasekaran V, Muniyandi M, Radhakrishnan S. DOTS reaches socially marginalized population in the community: a study from a rural area of South India. J Commun Dis 2009; 41:195-200. [PMID: 22010487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.
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Affiliation(s)
- P R Narayanan
- Tuberculosis Research Centre, Mayor V.R. Ramanathan Road, Chetput, Chennai-600 031
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45
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Thomas B, Mimiaga MJ, Menon S, Chandrasekaran V, Murugesan P, Swaminathan S, Mayer KH, Safren SA. Unseen and unheard: predictors of sexual risk behavior and HIV infection among men who have sex with men in Chennai, India. AIDS Educ Prev 2009; 21:372-383. [PMID: 19670971 PMCID: PMC3623672 DOI: 10.1521/aeap.2009.21.4.372] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In India men who have sex with men (MSM) are stigmatized, understudied, and at high risk for HIV. Understanding the impact of psychosocial issues on HIV risk behavior and HIV infection can help shape culturally relevant HIV prevention interventions. Peer outreach workers recruited 210 MSM in Chennai who completed an interviewer-administered psychosocial assessment battery and underwent HIV testing and counseling. More than one fifth (46/210) reported unprotected anal intercourse in the past 3 months, 8% tested positive for HIV, and 26% had previously participated in an HIV prevention intervention. In a multivariable logistic-regression model controlling for age, MSM subpopulation (kothi, panthi, or double-decker), marital status, and religion, significant predictors of any unprotected anal intercourse were being less educated (adjusted odds ratio [AOR] = .54; p = .009), not having previously participated in an HIV prevention program (AOR = 3.75; p = .05), having clinically significant depression symptoms (AOR = 2.8; p = .02), and lower self-efficacy (AOR = .40; p < .0001). Significant predictors of testing positive for HIV infection were: being less educated (AOR = .53; .05) and not currently living with parent(s) (AOR = 3.71; p = .05). Given the prevalence of HIV among MSM, efforts to reach hidden subpopulations of MSM in India are still needed. Such programs for MSM in India may need to address culturally-relevant commonly cooccurring psychosocial problems to maximize chances of reducing risk for infection.
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Affiliation(s)
- Beena Thomas
- Tuberculosis Research Center, Indian Council of Medical Research, Chennai, India
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46
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Rachwalik M, Kourliouros A, Chandrasekaran V. [Quadruple coronary endarterectomy while off-pump coronary artery bypass surgery - a case report]. Kardiol Pol 2009; 67:526-528. [PMID: 19521939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Coronary endarterectomy is a controversial procedure. It has got many supporters and enemies among cardiac surgeons. It is very rare, particularly while performing off pump coronary artery bypass grafting. We present a case of a 50-year-old man who underwent coronary artery stenting and than has been admitted to surgery because of the restenosis in coronary arteries. During the surgery four arteries have been grafted. At the same time we performed four endarteriectomies in these vessels. No major problem was observed. We describe our technique and briefly present current literature regarding this problem.
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Krupp K, Madhivanan P, Karat C, Chandrasekaran V, Sarvode M, Klausner J, Reingold A. Novel recruitment strategies to increase participation of women in reproductive health research in India. Glob Public Health 2009; 2:395-403. [PMID: 19283635 DOI: 10.1080/17441690701238031] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In India, care seeking for reproductive health among women is inadequate. This poses a unique challenge to researchers recruiting cohorts for studies in clinic-based settings. The purpose of this paper is to describe the recruitment process used in a prospective cohort study investigating the relationship between bacterial vaginosis and acquisition of HSV-2 among sexually active women in Mysore, India. Participants were initially recruited from an obstetrics/gynaecology outpatient clinic. Results were compared with a 'community supported' enrolment process, which included community preparation and reproductive health education followed by screening of potential participants. During November 2005, 1,054 women were screened in the clinic. Of the total screened, 246 (23%) were eligible and only 78 (7%) enrolled. Between December 2005 and April 2006, investigators adopted a community supported enrolment process. During that period, 1,077 potential participants were screened, 947 were eligible, and 918 (85%) enrolled. Fifty-six (72%) participants recruited from the clinic returned for their first follow-up visit, compared with 795 (97%) participants recruited using the community supported enrolment process. Since obstetrics/gynaecology departments in India are poor places to recruit non-pregnant women of reproductive age, a community supported process yields more eligible potential participants to screen, and results in significantly better study retention.
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Affiliation(s)
- K Krupp
- Asha Kirana Hospital, Mysore, India
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Ramachandran R, Chandrasekaran V, Muniyandi M, Jaggarajamma K, Bagchi A, Sahu S. Cross-referral between HIV counselling and testing centres and smear microscopy centres in Tamil Nadu. Int J Tuberc Lung Dis 2009; 13:221-225. [PMID: 19146751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND The combined tuberculosis and human immunodeficiency virus (TB-HIV) epidemic demands effective and urgent action. OBJECTIVE To assess the effectiveness of the system of referral of TB suspects from the integrated HIV counselling and testing centres (ICTCs) to the designated microscopy centres (DMCs) in Tamil Nadu, and to identify reasons for dropping out. DESIGN ICTC counsellors identified TB suspects among clients (excluding pregnant women and children) in six districts of Tamil Nadu in 2007 and referred them to DMCs, irrespective of their HIV status. From the records at ICTCs and DMCs, we collected information on the number of referrals to the DMCs, TB suspects attending DMCs and smear-positive TB cases with or without HIV. Clients who did not attend the DMCs were interviewed to elicit reasons for dropping out. RESULTS Of 18329 clients counselled, 1065 (6%) were identified as TB suspects and referred to DMCs. Of these, 888 (83%) attended and 177 (17%) dropped out; 81% of the drop-outs were interviewed. Reasons for dropping out were multiple: 51% were due to the health system, 62% due to the disease and 62% due to personal reasons. Twelve per cent of DMC attendees were smear-positive. CONCLUSION The ICTC-to-DMC referral system makes a significant contribution to the detection of TB cases. Reasons for dropping out were multiple, but are correctable. This study also probes into current policies on programme coordination and recommends strategies for strengthening the collaboration between the TB and HIV programmes.
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Affiliation(s)
- R Ramachandran
- Tuberculosis Research Centre, Indian Council of Medical Research, Chennai, India.
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Indhumathi E, Chandrasekaran V, Jagadeswaran D, Varadarajan M, Abraham G, Soundararajan P. THE RISK FACTORS AND OUTCOME OF FUNGAL PERITONITIS IN CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS. Indian J Med Microbiol 2009. [DOI: 10.1016/s0255-0857(21)01757-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Indhumathi E, Chandrasekaran V, Jagadeswaran D, Varadarajan M, Abraham G, Soundararajan P. The risk factors and outcome of fungal peritonitis in continuous ambulatory peritoneal dialysis patients. Indian J Med Microbiol 2009; 27:59-61. [PMID: 19172063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
AIM To determine the risk factors and outcome of fungal peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients over a 7-year period. PATIENTS AND METHODS This retrospective study was conducted on 30 cases of fungal peritonitis in CAPD patients during a 7-year period (2000-2007). The diagnosis was based on elevated CAPD effluent count and isolation of fungi. Patients were evaluated for previous episode of bacterial peritonitis. RESULTS The incidence of fungal peritonitis was 16.2%. Age varied between 8 and 75 years, with a mean age of 57 years. Twenty-three were males (76.7%) and seven were females (23.3%). Seventeen patients (56.6%) had previous episodes of bacterial peritonitis that was treated with multiple antibiotics. The common fungus was Candida species (50%). CAPD catheter removal and initiation of antifungal therapy was done for all patients. Reinsertion was done for three (10%) patients. Mortality rate was 20%. CONCLUSION Patients with previous bacterial peritonitis and antibiotic usage are at greater risk of developing fungal peritonitis.
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Affiliation(s)
- E Indhumathi
- Department of Nephrology, Sri Ramachandra University, No. 1, Ramachandra Nagar, Porur, Chennai-600 116, Tamil Nadu, India.
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