T cells play an important role in adaptive immune system against viral infections, while premature aging and dysfunction of T cells induced by unrepaired DNA damages are always non-negligible snags during the long-term of fighting with chronic viral infections, such as Hepatitis B virus (HBV), Hepatitis C virus (HCV) or Human Immunodeficiency Virus (HIV) infection. In this dissertation, we investigated the role of topological DNA damage in reprogramming telomeric DNA damage responses (DDR), mitochondrial metabolisms, and T cell functions using CD4+ T cells derived from individuals with chronic viral infections or healthy subjects treated with topoisomerase inhibitors. The healthy human T cells were treated with camptothecin (CPT) for mitochondrial topoisomerases I (Top1mt) or ICRF-193 or etoposide (ETP) for topoisomerases IIα (Top2α) as models. We found a significant suppression of Top2α and Top1mt protein levels and enzymatic activity in CD4+ T cells in chronically HCV/HIV-infected patients compared to age and gender-matched healthy subjects, along with an accumulation of the topoisomerase cleavage complex (Topcc) in genomic DNA as well as mitochondrial DNA (mtDNA). Mechanistically, topoisomerase inhibition in healthy CD4+ T cells caused topological DNA damage, telomere attrition, mitochondrial metabolic disorder and T cell apoptosis or dysfunction via inducing Topcc accumulation, PARP1 cleavage and failure in DNA repair, thus recapitulating T cell dysregulation in the setting of chronic viral infections. In addition, T cells from virally infected subjects with lower topoisomerase levels were vulnerable to the inhibitor-induced cell apoptosis, indicating an important role for Top2α and Top1mt in preventing DNA topological disruption and cell death. These results demonstrate that accumulation of Topcc and topoisomerase deficiency lead to unrepaired DNA damage and render virally infected patients’ T cells prone to senescence and apoptosis, thus contributing to mitochondrial metabolic disturbance or dysfunction in CD4+ T cell during chronic HCV or HIV infection. This study reveals a novel mechanism by which topoisomerase deficiency promotes telomeric DNA or mtDNA damage and premature T cell aging, and provides a new therapeutic target for restoring the DNA topologic machinery protecting T cells from unwanted DNA damage and to maintain immune competence.

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No description available.

INTRODUÇÃO: Infecções pelo HIV, HBV, HCV e Treponema pallidum encontram no sistema prisional um ambiente favorável para suas propagações e representam grave problema de saúde pública. Neste estudo buscamos conhecer o perfil epidemiológico dos reeducandos de uma unidade prisional e a dinâmica do seu comportamento associado às infecções estudadas. Foram medidas as prevalências dessas infecções e suas coinfecções, investigados os potenciais fatores de risco, assim como medido o padrão de uso de drogas no presídio com ênfase no crack. MÉTODOS: Estudo epidemiológico transversal realizado de fevereiro a dezembro de 2007, na Penitenciária I de São Vicente. Realizada uma análise descritiva utilizando medidas de frequência, médias e desvio padrão. Foram considerados apenas os diagnósticos sorológicos para definição das infecções. Utilizado o OR (odds ratio) como medida de associação com nível de significância de 5% (?). Utilizada a regressão logística para estimar OR ajustado por algumas variáveis. RESULTADOS: Participaram das entrevistas 546 (84,1%) reeducandos e 514 (94,1%) realizaram as sorologias. Apresentaram um perfil jovem com idade média de 29,8 anos. 52,0% (283) referiram relacionamento conjugal com média de dois filhos. Declararam ser de cor parda 51,5% (280). O tempo médio de prisão foi de 10,5 anos. As prevalências identificadas foram: HIV 1,8% [IC95% = 0,1- 3,3], HBV 21,0% [IC95% = 17,8-25,1], HCV 5,3% [IC95% = 3,5-7,6], e 5,3% [IC95% =3,5-7,6] para a infecção pelo Treponema pallidum. Os fatores de risco associados com a infecção pelo HIV foram: uso de droga injetável (OR=15,38), > 30 anos (OR=13,3), uso de cocaína na vida (OR= 5,36) e uso de crack na vida (OR= 5,21). Nas análises multivariadas as variáveis que se mantiveram associadas com o HBV foram: uso de droga injetável (OR=3,36), ter referido DST (OR= 2,28), > de 30 anos (OR=1,86) e mais de cinco anos de prisão (OR= 2,17); com o HCV foram: uso de droga injetável (OR=9,65), uso de maconha na prisão (OR=2,91) e idade >30 anos (OR=8,41); com o Treponema pallidum foram: relação homossexual (OR=11,92) e ter referido sífilis (OR=10,88). As prevalências das coinfecções foram: 0,8% [IC95%= 0,2-2,0] para HIV/HBV, 1,4% [IC95%=0,5-2,8], para HBV/Treponema pallidum, 1,8% [IC95%= 0,8-3,3] para HBV/HCV, e para a tripla infecção 0,4% [IC95%= 0,5-1,4]. Confirmaram o uso de crack na vida 25,0% (136) dos entrevistados. Idade média de início de uso de drogas ilícitas foi de 15,4 anos. Na prisão, o uso de álcool foi relatado por 8,4% (45), tabaco por 62,0% (318), maconha por 36,5 % (194), cocaína por 9,0% (48), e crack por 11,7% (15), sendo seu uso diário referido por 2,3% (3). Uso de drogas injetáveis na vida foi referido por 5,9% (32) e nenhum uso nos últimos seis meses. As situações de violência relacionadas com drogas para 14,3% (28) foram de ameaças de morte, 16,7% (57) agressões físicas e 27,3% (3) sofreram agressão sexual. Para 15,8% (30) o crack esteve relacionado com estas situações. O seu uso com outras drogas foi referido por 41,5% (54). CONCLUSÃO: As prevalências encontradas na população confinada continuam maiores que as observadas na população geral. O consumo de drogas e praticas sexuais desprotegidas foram mantidas no período de confinamento. O tempo de confinamento mostrou-se fator importante na análise de risco. Os fatores de riscos identificados aparecem como importantes indicadores para a estruturação de estratégias de controle dessas infecções junto à população confinada. / INTRODUCTION: Infection by HIV, HBV, HCV and Treponema pallidum are common in the prison system due to an environment favorable to their propagation and represent a serious public health problem. This study aims to understand the epidemiological profile of the inmates in a prison unit and the behaviors associated with the infectious diseases studied. We estimated the prevalence of these infections and their co-infections, investigated potential risk factors, as well as identified the pattern of drug use in prison, especially crack use. METHODS: A cross-sectional epidemiological study conducted from February to December 2007 at the São Vicente Penitentiary . A descriptive analysis using frequency measures, means and standard deviations was conducted. We considered only the setting for serological diagnosis of infections. Odds ratio (OR) with a significance level of 5% (?) was used as a measure of association and a logistic regression was applied to estimate adjusted OR for some variables. RESULTS: A total of 546 prisoners were interviewed (84.1%). Of these, 514 (94.1%) underwent serological analysis. Results showed a profile of young men with an average age of 29.8 years. Fifty-two percent (283) reported marital relationship with an average of two children, and 51.5% (280) reported being of mixed ethnicity. The average time of arrest was 10.5 years. The prevalences were identified: HIV 1.8% [95% CI = 0.1 - 3.3], HBV 21.0% [95% CI 17.8 to 25.1], HCV 5.3% [95% CI = 3.5 to 7.6] and 5.3% [95% CI = 3.5 to 7.6] for infection with Treponema pallidum. The risk factors associated with HIV infection were injected-drug use (OR = 15.38), > 30 years (OR = 13.3), cocaine use (OR = 5.36) and use of crack during lifetime (OR = 5.21). According to multivariate analyzes, variables associated with HBV were: injected-drug use (OR = 3.36), reported any STD (OR = 2.28), > 30 years (OR = 1.86) and more than five years in prison (OR = 2.17); the variables associated with HCV were: injected-drug use (OR = 9.65), marijuana use in prison (OR = 2.91) and age> 30 years (OR = 8.41); the variables associated with Treponema pallidum were: homosexual intercourse (OR = 11.92) and have referred syphilis (OR = 10.88). The prevalence of co-infections were 0.8% [95% CI = 0.2 to 2.0] for HIV / HBV, 1.4% [95% CI = 0.5 to 2.8] for HBV / Treponema pallidum, 1.8% [95% CI = 0.8 to 3.3] for HBV / HCV infection and for the triple infection 0.4% [95% CI = 0.5 to 1.4]. Average age of onset of illicit drug use was 15.4 years. The use of crack during lifetime was reported by 25.0% (136) of respondents. In prison, alcohol use was reported by 8.4% (45), tobacco by 62.0% (318), marijuana by 36.5% (194), 9.0% for cocaine (48), and crack by 11.7% (15), with the daily use of crack reported by 2.3% (3). Injected-drug use during lifetime was reported by 5.9% (32), but no use in the last six months was reported. Drug-related violence episodes reported were death threats 14.3% (28), 16.7% (57) assaults and 27.3% (3) suffered sexual assault. To 15.8% (30) of the respondents, crack use was associated with violence episodes. The use of crack-cocaine in association with other drugs was reported by 41.5% (54). CONCLUSION: The prevalence found in the confined population is still larger than those observed in the general population. Drug use and unprotected sexual practices were maintained during the period of confinement. The confinement time proved to be an important factor in the analysis of risk of infection. The identified risk factors appear to be important indicators for developing strategies to control these infections in the prison environment.

Die vorliegende Arbeit 'Abflu&szlig;entwicklung in Teileinzugsgebieten des Rheins - Simulationen f&uuml;r den Ist-Zustand und f&uuml;r Klimaszenarien' untersucht Auswirkungen m&ouml;glicher zuk&uuml;nftiger Klima&auml;nderungen auf das Abflu&szlig;geschehen in ausgew&auml;hlten, durch Mittelgebirge gepr&auml;gten Teileinzugsgebieten des Rheins: Mosel (bis Pegel Cochem); Sieg (bis Pegel Menden 1) und Main (bis Pegel Kemmern).<br><br>In einem ersten Schritt werden unter Verwendung des hydrologischen Modells HBV-D wichtige Modellprozesse entsprechend der Einzugsgebietscharakteristik parametrisiert und ein Abbild der Gebietshydrologie erzeugt, das mit Zeitreihen gemessener Tageswerte (Temperatur, Niederschlag) eine Zeitreihe der Pegeldurchfl&uuml;sse simulieren kann. Die G&uuml;te der Simulation des Ist-Zustandes (Standard-Me&szlig;zeitraum 1.1.1961-31.12.1999) ist f&uuml;r die Kalibrierungs- und Validierungszeitr&auml;ume in allen Untersuchungsgebieten gut bis sehr gut.<br>Zur Erleichterung der umfangreichen, zeitaufwendigen einzugsgebietsbezogenen Datenaufbereitung f&uuml;r das hydrologische Modell HBV-D wurde eine Arbeitsumgebung auf Basis von Programmerweiterungen des Geoinformationssystems ArcView und zus&auml;tzlichen Hilfsprogrammen entwickelt. Die Arbeitsumgebung HBV-Params enth&auml;lt eine graphische Benutzeroberfl&auml;che und r&auml;umt sowohl erfahrenen Hydrologen als auch hydrologisch geschulten Anwendern, z.B. Studenten der Vertiefungsrichtung Hydrologie, Flexibilit&auml;t und vollst&auml;ndige Kontrolle bei der Ableitung von Parameterwerten und der Editierung von Parameter- und Steuerdateien ein. Somit ist HBV-D im Gegensatz zu Vorl&auml;uferversionen mit rudiment&auml;ren Arbeitsumgebungen auch au&szlig;erhalb der Forschung f&uuml;r Lehr- und &Uuml;bungszwecke einsetzbar.<br><br>In einem zweiten Schritt werden Gebietsniederschlagssummen, Gebietstemperaturen und simulierte Mittelwerte des Durchflusses (MQ) des Ist-Zustandes mit den Zust&auml;nden zweier Klimaszenarien f&uuml;r den Szenarienzeitraum 100 Jahre sp&auml;ter (2061-2099) verglichen. Die Klimaszenarien beruhen auf simulierten Zirkulationsmustern je eines Modellaufes zweier Globaler Zirkulationsmodelle (GCM), die mit einem statistischen Regionalisierungsverfahren in Tageswertszenarien (Temperatur, Niederschlag) an Me&szlig;stationen in den Untersuchungsgebieten &uuml;berf&uuml;hrt wurden und als Eingangsdaten des hydrologischen Modells verwendet werden.<br>F&uuml;r die zweite H&auml;lfte des 21. Jahrhunderts weisen beide regionalisierten Klimaszenarien eine Zunahme der Jahresmittel der Gebietstemperatur sowie eine Zunahme der Jahressummen der Gebietsniederschl&auml;ge auf, die mit einer hohen Variabilit&auml;t einhergeht. Eine Betrachtung der saisonalen (monatlichen) &Auml;nderungsbetr&auml;ge von Temperatur, Niederschlag und mittlerem Durchflu&szlig; zwischen Szenarienzeitraum (2061-2099) und Ist-Zustand ergibt in allen Untersuchungsgebieten eine Temperaturzunahme (h&ouml;her im Sommer als im Winter) und eine generelle Zunahme der Niederschlagssummen (mit starken Schwankungen zwischen den Einzelmonaten), die bei der hydrologischen Simulation zu deutlich h&ouml;heren mittleren Durchfl&uuml;ssen von November bis M&auml;rz und leicht erh&ouml;hten mittleren Durchfl&uuml;ssen in den restlichen Monaten f&uuml;hren. Die St&auml;rke der Durchflu&szlig;erh&ouml;hung ist nach den individuellen Klimaszenarien unterschiedlich und im Sommer- bzw. Winterhalbjahr gegenl&auml;ufig ausgepr&auml;gt. Hauptursache f&uuml;r die simulierte starke Zunahme der mittleren Durchfl&uuml;sse im Winterhalbjahr ist die trotz Temperaturerh&ouml;hung der Klimaszenarien winterlich niedrige Evapotranspiration, so da&szlig; erh&ouml;hte Niederschl&auml;ge direkt in erh&ouml;hten Durchflu&szlig; transformiert werden k&ouml;nnen.<br>Der Vergleich der Untersuchungsgebiete zeigt in Einzelmonaten von West nach Ost abnehmende &Auml;nderungsbetr&auml;ge der Niederschlagssummen, die als Hinweis auf die Bedeutung der Kontinentalit&auml;tseinfl&uuml;sse auch unter ge&auml;nderten klimatischen Bedingungen in S&uuml;dwestdeutschland aufgefa&szlig;t werden k&ouml;nnten.<br>Aus den regionalisierten Klimaszenarien werden &Auml;nderungsbetr&auml;ge f&uuml;r die Modulation gemessener Zeitreihen mittels synthetischer Szenarien abgeleitet, die mit einem geringen Rechenaufwand in hydrologische Modellantworten &uuml;berf&uuml;hrt werden k&ouml;nnen. Die direkte Ableitung synthetischer Szenarien aus GCM-Ergebniswerten (bodennahe Temperatur und Gesamtniederschlag) an einzelnen GCM-Gitterpunkten erbrachte unbefriedigende Ergebnisse.<br>Ob, in welcher H&ouml;he und zeitlichen Verteilung die in den (synthetischen) Szenarien verwendeten Niederschlags- und Temperatur&auml;nderungen eintreten werden, kann nur die Zukunft zeigen. Eine Absch&auml;tzung, wie sich die Abflu&szlig;verh&auml;ltnisse und insbesondere die mittleren Durchfl&uuml;sse der Untersuchungsgebiete bei m&ouml;glichen &Auml;nderungen entwickeln w&uuml;rden, kann jedoch heute schon vorgenommen werden. <br><br>Simulationen auf Szenariogrundlagen sind ein Weg, unbekannte zuk&uuml;nftige Randbedingungen sowie regionale Auswirkungen m&ouml;glicher &Auml;nderungen des Klimasystems ausschnittsweise abzusch&auml;tzen und entsprechende Risikominderungsstrategien zu entwickeln. Jegliche Modellierung und Simulation nat&uuml;rlicher Systeme ist jedoch mit betr&auml;chtlichen Unsicherheiten verkn&uuml;pft. Vergleichsweise gro&szlig;e Unsicherheiten sind mit der zuk&uuml;nftigen Entwicklung des sozio&ouml;konomischen Systems und der Komplexit&auml;t des Klimasystems verbunden. Weiterhin haben Unsicherheiten der einzelnen Modellbausteine der Modellkette Emissionsszenarien/Gaszyklusmodelle - Globale Zirkulationsmodelle/Regionalisierung - hydrologisches Modell, die eine Kaskade der Unsicherheiten ergeben, neben Datenunsicherheiten bei der Erfassung hydrometeorologischer Me&szlig;gr&ouml;&szlig;en einen erheblichen Einflu&szlig; auf die Vertrauensw&uuml;rdigkeit der Simulationsergebnisse, die als ein dargestellter Wert eines Ergebnisbandes zu interpretieren sind.<br><br>Der Einsatz <br>(1) robuster hydrologischer Modelle, die insbesondere temperaturbeeinflu&szlig;te Prozesse ad&auml;quat beschreiben,<br>(2) die Verwendung langer Zeitreihen (wenigsten 30 Jahre) von Me&szlig;werten und<br>(3) die gleichzeitige vergleichende Betrachtung von Klimaszenarien, die auf unterschiedlichen GCMs beruhen (und wenn m&ouml;glich, verschiedene Emissionsszenarien ber&uuml;cksichtigen),<br>sollte aus Gr&uuml;nden der wissenschaftlichen Sorgfalt, aber auch der besseren Vergleichbarkeit der Ergebnisse von Regionalstudien im noch jungen Forschungsfeld der Klimafolgenforschung beachtet werden. / This thesis 'Development of runoff in subcatchments of the River Rhine - simulations of the current state and for climate change scenarios' investigates the impacts of possible future climate changes on runoff and runoff regime in selected subcatchments of the River Rhine. The regional climate in the selected subcatchments Mosel (up to gauge Cochem), Sieg (gauge Menden 1) and Main (gauge Kemmern) is affected by the middle mountain ranges.<br><br>In a first step, important model processes are parameterized according to catchment characteristics. A representation of the regional hydrology is then produced by using the hydrological model HBV-D. Based on time series of daily measurements (temperature, precipitation) at stations within the catchment, this representation can be used to realistically simulate time series of runoff and discharge. <br>In all examined areas, the quality of simulations of the calibration and validation periods for the current state (standard period of measurements 01/01/1961-12/31/1999) can be regarded as good to excellent. <br>To aid the catchment-specific, extensive and time-consuming data processing, a working environment for the hydrological model HBV-D has been developed. It is based on program extensions of the geographical information system ArcView and further programs. The working environment HBV-Params contains a graphical interface that gives both experienced hydrologists and students full control and enables them to flexibly derive parameter values and edit parameter and control files. In contrast to previous versions with only rudimentary working environments, HBV-D can therefore be utilized for research as well as for educational purposes. <br><br>In a second step, the current states of areal precipitation, areal temperature and simulated mean discharge (MQ) are compared to the corresponding states for two scenarios of future climate changes (100 years later, 2061-2099). These scenarios are based on simulated global circulations of one model run for each of two global circulation models (GCM). These global circulations are regionalized (downscaled) using a statistical approach into scenario time series of daily values (temperature, precipitation - input for the hydrological model) at control stations within the individual catchments. <br>For the second half of the 21st century, both regionalized climate change scenarios indicate increases in the mean annual areal temperature and mean annual sum of precipitation, along with a high variability of the latter. The seasonal (monthly) changes in temperature, precipitation and mean discharge between scenario state (2061-2099) and current state indicate increases in temperature (higher in summer than in winter) as well as a general increase in precipitation sums (strong fluctuations between individual months). In the hydrological simulations for all investigated catchments, this results in considerably higher mean discharges from November to March and small increases in mean discharge for the other months. The magnitude of the increases in discharge depends on the individual climate change scenario, one showing higher increases than the other during the summer half-year and vice versa for the winter half-year. The main reason for the simulated strong increase in mean discharge during winter half-year is, in spite of higher temperatures, the still relatively low evapotranspiration which allows higher precipitation to be directly transformed into higher discharges. <br>The comparison of the investigated catchments shows decreasing amounts of changes in the sum of precipitation from West to East in individual months. This indicates the importance of continentality under changed climatic conditions in Southwest Germany. <br>For the modification of measured time series (temperature, precipitation), which can be easily converted as synthetic scenarios into simulated hydrological results, amounts of change are derived from regionalized (downscaled) climate change scenarios. The derivation of synthetic scenarios directly from GCM output at individual GCM gridpoints yielded unsatisfactory results. <br>Only the future itself can show whether the timing and amount of changes in temperature and precipitation used in (synthetic) climate change scenarios come close to reality. An assessment of possible developments in runoff regime and specifically mean discharge under possible changed climatic conditions in the investigated catchments is already feasible today. <br><br>Simulations based on scenarios are one way to establish unknown future boundary conditions for the estimation of regional impacts of possible changes of the climate system. Nevertheless, all types of modeling and simulation of natural systems are linked with uncertainties. Rather large uncertainties persist regarding the future development of the socio-economic system and the complexity of the climate system and earth system. Furthermore, besides data uncertainties associated with the measurement of hydro-meteorological values, uncertainties associated with individual components of the model chain emission scenarios/gas cycle model - GCM/regionalization - hydrological model, which form a cascade of uncertainty, have a great influence on the trustworthiness of the simulation results (which are understood as one shown value within a range of results). <br><br>In the young field of climate impact research the use of <br>(1) robust hydrological models that adequately describe temperature-dependent processes,<br>(2) long time series (at least 30 years long) of measurements, <br>(3) concurrent comparisons of climate change scenarios, based on different GCMs (and, if possible, different emission scenarios)<br>should be considered for reasons of scientific thoroughness and to improve comparability of regional impact studies.

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The anthropogenic impact on earth’s systems has rapidly increased since the middle of the last century and today it is hard to find a stream that is not influenced by human activities. The understanding of causes to changes is an important knowledge for future water management and planning and of that reason climatic and anthropogenic impact on streamflow changes in Sweden were explored and quantified. In the first step trends and abrupt changes in annual streamflow were detected and verified with the non- parametric Mann-Kendall’s and Pettitt’s test, all performed as moving window tests. In the second step HBV, a climatic driven rainfall-runoff model, was used to attribute the causes of the detected changes. Detection and attribution of changes were performed on several catchments in order to investigate regional patterns. On one hand using smaller window sizes, period higher number of detected positive and negative trends were found. On the other hand bigger window sizes resulted in positive trends in more than half of the catchments and almost no negative trends. The detected changes were highly dependent on the investigated time frame, due to periodicity, e.g. natural variability in streamflow. In general the anthropogenic impact on streamflow changes was smaller than changes due to temperature and streamflow. In median anthropogenic impact could explain 7% of the total change. No regional differences were found which indicated that anthropogenic impact varies more between individual catchments than following a regional pattern. / Sedan mitten av förra århundradet har den antropogena påverkan på jordens system ökat kraftigt. Idag är det svårt att hitta ett vattendrag som inte är påverkat av mänsklig aktivitet. Att förstå orsakerna bakom förändringarna är en viktig kunskap för framtida vattenplanering och av denna anledning undersöktes och kvantiferades den antropogen och klimatpåverkan på flödesförändringar i svenska vattendrag. I arbetets första steg användes de Mann-Kendalls och Pettitts test för att lokalisera och verifiera förändringar i årligt vattenflöde. Alla test var icke parametriska och utfördes som ett glidande fönster. I nästa steg undersöktes orsakerna till förändringar med hjälp av HBV, en klimatdriven avrinningsmodell. Ett större antal avrinningsområden undersöktes för att upptäcka regionala mönster och skillnader. Perioder med omväxlande positiva och negativa trender upptäcktes med mindre fönsterstorlekar, medan större fönster hittade positiva trender i mer än hälften av områdena och knappt några negativa trender hittades. De detekterade förändringarna var på grund av periodicitet i årligt vattenflöde till stor grad beroende på det undersöka tidsintervallet. Generellt var den antropogena påverkan större påverkan från nederbörd och temperatur, med ett medianvärde där 7 % av den totala förändringen kunde förklaras med antropogen påverkan. Inga regionala skillnader i antropogen påverkan kunde identifieras vilket indikerar att den varierar mer mellan individuella områden än följer ett regionalt mönster.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-13T11:03:19Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Alline Torquato Vasconcelos - 2014.pdf: 3499445 bytes, checksum: 93905607504e61e452d7ce82396c17a9 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-13T11:04:23Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Alline Torquato Vasconcelos - 2014.pdf: 3499445 bytes, checksum: 93905607504e61e452d7ce82396c17a9 (MD5) / Made available in DSpace on 2015-01-13T11:04:23Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Alline Torquato Vasconcelos - 2014.pdf: 3499445 bytes, checksum: 93905607504e61e452d7ce82396c17a9 (MD5) Previous issue date: 2014-06-06 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Lamivudine (β-L-2',3'-dideoxy-3'-thiacytidine, 3TC) is a nucleoside-based anti-HIV/HBV drug that has provided insights into the nucleic acid double-stranded helix assembly. Two crystal structures thereof assembled with nucleobase pairing and helical stacking as mimicries of DNA, but without the phosphodiester linkages in the fiber periphery, have recently demonstrated that nucleosides bring themselves the chemical information to assemble DNA duplexes even if the covalent backbone is absent. Here, we report the third structural example in which nucleosides are base-paired and helically base-stacked. A DNA-like double stranded helix was prepared cocrystallizing lamivudine with fumaric acid. We have named it as lamivudine duplex III. When substituting maleic acid present in the first example of lamivudine duplex for its trans-stereoisomer, the formation of a DNA-mimicry is still observed but with changes in the crystal stoichiometry, nucleobase pairing pattern and duplex backbone. Lamivudine duplex III exhibits both base pairing motifs present in the antecedent duplexes. In this structure, there are four protonated lamivudine molecules paired in-plane with four neutral ones. These crystallographically independent base pairs are held together through three hydrogen bonds as occurs in lamivudine duplex I made up of cytosine-cytosine+ base pairing only. But, contrarily to the duplex I with pairing between neutral and cationic drug units only, the duplex III has one neutral 3TC=3TC pair in its asymmetric unit. These molecules are kept in contact through only two peripheral N―H•••O hydrogen bonds as in two of the three neutral lamivudine pairs of the second example of lamivudine duplex. In both structures, each neutral pair is face-to-face stacked on top of one another and face-to-tail stacked on bottom of another one. Even in agreement with its higher structural complexity, the duplex III is present with very puckering conformations besides the three different orientations of the OH moiety at C5’. Five-membered oxathiolane ring adopts three envelop puckering modes and two twist conformations. This is the first report of a twist pucker for lamivudine despite of the large number of reported crystal structures thereof. Another remarkable characteristic of the duplex III is in its fiber periphery. There are hydrogen bonds between the 5’-OH moieties of neighbor pairs pointing in the direction of the missing phosphodiester linkages that would covalently bond two adjacent monomers in the strand. Furthermore, the geometry of these interactions reveals the antiparallel orientation of each strand relative to one another into the nucleoside duplex backbone. Noteworthy similarities between the duplexes crystallizing together with either hydrogen maleate or hydrogen fumarate are their left handedness and the outline of surface grooves of similar depth. But, while all hydrogen maleate counterions are lodged on the grooves of the duplex I, some hydrogen fumarate units are also interacting with themselves into one-dimensional chain of counterions. The third example of unusual double-stranded helices of lamivudine strengthens the fact that nucleosides can self-aggregate into DNA-like duplexes even without the covalent phosphodiester linkages in fiber periphery. Besides that, the structure described here adds knowledge on lamivudine versatility to assemble DNA-mimicry in crystals. / A lamivudina (β-L-2',3'-dideoxy-3'-thiacytidine, 3TC) é um fármaco a base de nucleosídeos utilizado para o tratamento de SIDA e Hepatite B. A obtenção de estruturas do tipo dupla hélice de ácidos nucleicos com esse fármaco tem sido alvo de estudo. Recentemente foram reportadas duas estruturas cristalinas mimetizando DNA, formadas por pares de nucleosídeos empacotados em uma dupla hélice, mas sem ligações fosfodiéster na periferia da cadeia. Estas estruturas demonstraram que os nucleosídeos possuem informação química suficiente para a formação de estruturas dessa natureza mesmo com a ausência das ligações covalentes fosfodiéster. Neste trabalho um terceiro exemplo de uma estrutura contendo bases de nuclosídeos pareadas e sobrepostas helicoidalmente, mimetizando DNA, é reportado. Essa modificação cristalina foi preparada através da cocristalização da lamivudina com o ácido fumárico e a estrutura obtida foi denominada duplex III. Com a substituição do ácido maleico, presente no primeiro exemplo de dupla hélice de lamivudina, pelo seu estéreoisômero trans, o ácido fumárico, a formação de uma estrutura mimetizando o DNA também foi observada, porém, com diferenças na estequiometria do cristal, nos padrões de interação do pareamento das bases, assim como no esqueleto da dupla hélice. O pareamento das bases na duplex III de lamivudina possui padrões de interação semelhante a ambas estruturas precedentes. Na duplex III existem quatro pares parcialmente protonados, onde uma lamivudina protonada está pareada com outra neutra. Esse tipo de pareamento se dá através de três ligações de hidrogênio e é semelhante ao pareamento presente na estrutura da duplex I de lamivudina composto apenas por pares do tipo 3TC+≡3TC. Diferentemente da duplex I que possui exclusivamente pares parcialmente protonados, a duplex III possui também um par neutro do tipo 3TC=3TC na sua unidade assimétrica. O pareamento dessas bases é formado apenas por duas ligações de hidrogênio do tipo N―H•••O, semelhante a dois dos três pares neutros que constituem a duplex II de lamivudina. O empacotamento dos pares neutros na duplex III é semelhante ao da duplex II, cada par neutro empacota com uma padrão face a face com o par que o antecede e face a cauda com o par subsequente. Devido à grande complexidade estrutural da duplex III, temos uma maior variação nas conformações assumidas tanto pelo anel oxatiolano quanto pelo fragmento citosinico, assim como nas três orientações adotadas pelo grupo hidroxílico ligado ao carbono C5’. O anel oxatiolano de cinco membros, adota três diferentes conformações do tipo envelope e duas conformações do tipo cambaleante. Apesar de essas serem as primeiras estruturas reportadas com conformações do tipo cambaleante para a lamivudina, esse tipo de conformação é comum para várias outras estruturas cristalinas. Outra característica que merece destaque na estrutura obtida da duplex III está nos padrões de interação presentes na periferia da dupla hélice. Nota-se a presença de ligações de hidrogênio entre os grupos 5’-OH de pares vizinhos, que ocorrem na direção onde as ligações fosfodiéster deveriam existir entre dois monômeros adjacentes. Além disso, a geometria dessas ligações de hidrogênio revelam uma orientação antiparalela de uma fita em relação a outra no esqueleto da duplex. Existem algumas semelhanças notáveis entre as duplexes I e III, cristalizadas com hidrogenomaleato e hidrogenofumarato, como a espiralização a esquerda e o fato de ambas não possuírem diferença entre sulcos principais e secundários, uma vez que todos os sulcos ao longo da cadeia possuem dimensões semelhantes. Porém, todos os contraíons estão acomodados nos sulcos da duplex I, enquanto que na duplex III alguns contraíons interagem entre si formando uma cadeia unidimensional de contraíons. Esse terceiro exemplo de uma estrutura atípica de dupla hélice de lamivudina reforça o fato de que nucleosídeos podem se agregar em estruturas semelhantes a dupla hélice do DNA, mesmo com a ausência das ligações covalentes fosfodiéster. Além disso a estrutura da duplex III adiciona conhecimento quanto a versatilidade da lamivudina em formar estruturas mimetizando DNA em cristais.

INTRODUÇÃO: Infecções pelo HIV, HBV, HCV e Treponema pallidum encontram no sistema prisional um ambiente favorável para suas propagações e representam grave problema de saúde pública. Neste estudo buscamos conhecer o perfil epidemiológico dos reeducandos de uma unidade prisional e a dinâmica do seu comportamento associado às infecções estudadas. Foram medidas as prevalências dessas infecções e suas coinfecções, investigados os potenciais fatores de risco, assim como medido o padrão de uso de drogas no presídio com ênfase no crack. MÉTODOS: Estudo epidemiológico transversal realizado de fevereiro a dezembro de 2007, na Penitenciária I de São Vicente. Realizada uma análise descritiva utilizando medidas de frequência, médias e desvio padrão. Foram considerados apenas os diagnósticos sorológicos para definição das infecções. Utilizado o OR (odds ratio) como medida de associação com nível de significância de 5% (?). Utilizada a regressão logística para estimar OR ajustado por algumas variáveis. RESULTADOS: Participaram das entrevistas 546 (84,1%) reeducandos e 514 (94,1%) realizaram as sorologias. Apresentaram um perfil jovem com idade média de 29,8 anos. 52,0% (283) referiram relacionamento conjugal com média de dois filhos. Declararam ser de cor parda 51,5% (280). O tempo médio de prisão foi de 10,5 anos. As prevalências identificadas foram: HIV 1,8% [IC95% = 0,1- 3,3], HBV 21,0% [IC95% = 17,8-25,1], HCV 5,3% [IC95% = 3,5-7,6], e 5,3% [IC95% =3,5-7,6] para a infecção pelo Treponema pallidum. Os fatores de risco associados com a infecção pelo HIV foram: uso de droga injetável (OR=15,38), > 30 anos (OR=13,3), uso de cocaína na vida (OR= 5,36) e uso de crack na vida (OR= 5,21). Nas análises multivariadas as variáveis que se mantiveram associadas com o HBV foram: uso de droga injetável (OR=3,36), ter referido DST (OR= 2,28), > de 30 anos (OR=1,86) e mais de cinco anos de prisão (OR= 2,17); com o HCV foram: uso de droga injetável (OR=9,65), uso de maconha na prisão (OR=2,91) e idade >30 anos (OR=8,41); com o Treponema pallidum foram: relação homossexual (OR=11,92) e ter referido sífilis (OR=10,88). As prevalências das coinfecções foram: 0,8% [IC95%= 0,2-2,0] para HIV/HBV, 1,4% [IC95%=0,5-2,8], para HBV/Treponema pallidum, 1,8% [IC95%= 0,8-3,3] para HBV/HCV, e para a tripla infecção 0,4% [IC95%= 0,5-1,4]. Confirmaram o uso de crack na vida 25,0% (136) dos entrevistados. Idade média de início de uso de drogas ilícitas foi de 15,4 anos. Na prisão, o uso de álcool foi relatado por 8,4% (45), tabaco por 62,0% (318), maconha por 36,5 % (194), cocaína por 9,0% (48), e crack por 11,7% (15), sendo seu uso diário referido por 2,3% (3). Uso de drogas injetáveis na vida foi referido por 5,9% (32) e nenhum uso nos últimos seis meses. As situações de violência relacionadas com drogas para 14,3% (28) foram de ameaças de morte, 16,7% (57) agressões físicas e 27,3% (3) sofreram agressão sexual. Para 15,8% (30) o crack esteve relacionado com estas situações. O seu uso com outras drogas foi referido por 41,5% (54). CONCLUSÃO: As prevalências encontradas na população confinada continuam maiores que as observadas na população geral. O consumo de drogas e praticas sexuais desprotegidas foram mantidas no período de confinamento. O tempo de confinamento mostrou-se fator importante na análise de risco. Os fatores de riscos identificados aparecem como importantes indicadores para a estruturação de estratégias de controle dessas infecções junto à população confinada. / INTRODUCTION: Infection by HIV, HBV, HCV and Treponema pallidum are common in the prison system due to an environment favorable to their propagation and represent a serious public health problem. This study aims to understand the epidemiological profile of the inmates in a prison unit and the behaviors associated with the infectious diseases studied. We estimated the prevalence of these infections and their co-infections, investigated potential risk factors, as well as identified the pattern of drug use in prison, especially crack use. METHODS: A cross-sectional epidemiological study conducted from February to December 2007 at the São Vicente Penitentiary . A descriptive analysis using frequency measures, means and standard deviations was conducted. We considered only the setting for serological diagnosis of infections. Odds ratio (OR) with a significance level of 5% (?) was used as a measure of association and a logistic regression was applied to estimate adjusted OR for some variables. RESULTS: A total of 546 prisoners were interviewed (84.1%). Of these, 514 (94.1%) underwent serological analysis. Results showed a profile of young men with an average age of 29.8 years. Fifty-two percent (283) reported marital relationship with an average of two children, and 51.5% (280) reported being of mixed ethnicity. The average time of arrest was 10.5 years. The prevalences were identified: HIV 1.8% [95% CI = 0.1 - 3.3], HBV 21.0% [95% CI 17.8 to 25.1], HCV 5.3% [95% CI = 3.5 to 7.6] and 5.3% [95% CI = 3.5 to 7.6] for infection with Treponema pallidum. The risk factors associated with HIV infection were injected-drug use (OR = 15.38), > 30 years (OR = 13.3), cocaine use (OR = 5.36) and use of crack during lifetime (OR = 5.21). According to multivariate analyzes, variables associated with HBV were: injected-drug use (OR = 3.36), reported any STD (OR = 2.28), > 30 years (OR = 1.86) and more than five years in prison (OR = 2.17); the variables associated with HCV were: injected-drug use (OR = 9.65), marijuana use in prison (OR = 2.91) and age> 30 years (OR = 8.41); the variables associated with Treponema pallidum were: homosexual intercourse (OR = 11.92) and have referred syphilis (OR = 10.88). The prevalence of co-infections were 0.8% [95% CI = 0.2 to 2.0] for HIV / HBV, 1.4% [95% CI = 0.5 to 2.8] for HBV / Treponema pallidum, 1.8% [95% CI = 0.8 to 3.3] for HBV / HCV infection and for the triple infection 0.4% [95% CI = 0.5 to 1.4]. Average age of onset of illicit drug use was 15.4 years. The use of crack during lifetime was reported by 25.0% (136) of respondents. In prison, alcohol use was reported by 8.4% (45), tobacco by 62.0% (318), marijuana by 36.5% (194), 9.0% for cocaine (48), and crack by 11.7% (15), with the daily use of crack reported by 2.3% (3). Injected-drug use during lifetime was reported by 5.9% (32), but no use in the last six months was reported. Drug-related violence episodes reported were death threats 14.3% (28), 16.7% (57) assaults and 27.3% (3) suffered sexual assault. To 15.8% (30) of the respondents, crack use was associated with violence episodes. The use of crack-cocaine in association with other drugs was reported by 41.5% (54). CONCLUSION: The prevalence found in the confined population is still larger than those observed in the general population. Drug use and unprotected sexual practices were maintained during the period of confinement. The confinement time proved to be an important factor in the analysis of risk of infection. The identified risk factors appear to be important indicators for developing strategies to control these infections in the prison environment.