Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 112-126).

Made available in DSpace on 2016-08-10T10:54:12Z (GMT). No. of bitstreams: 1 RONALDO PORTELA.pdf: 1248321 bytes, checksum: 32236d6c47873061a20e4e8cd5b4e4b3 (MD5) Previous issue date: 2014-03-28 / Background: Syphilis is an infectious disease that in Brazilian prison systems has optimal conditions to increase the risk of transmission among inmates. Objectives: Determine prevalence and assess risk situations associated with transmission of syphilis among inmates of Prison Complex Aparecida de Goiânia/GO in the period from February to September 2011. Methods: cross-sectional study exploratory of quantitative approach. Study participants were 1.173 inmates that answered a questionnaire containing variables on behaviors risk for T. pallidum infection. The seroprevalence was found using serological tests screening VDRL and ELISA as confirmatory. Data were tabulated and the variables were analyzed using the EPI INFO and SPSS (Statistical Package for Social Sciences).Were calculated rates of seroprevalence by age and educational level, and relative risks (odds ratios) associated with risk behaviors. Results: The seroprevalence of syphilis found in this population was 2.22% (IC95%). Of the study participant s total, 83.4% were aged between 18 and 39 years. This age group contributes with 85% of cases found positive for serological screening. The seroprevalence among those with low education contributed 58.2% of the population seroprevalence. For the variables of risk situations the homosexual relationship had an odds ratio of 3.44 (IC 0,77 - 15,29 and p=0,084), use of tattoo 3.05 (IC 1,14 - 8,14 and p=0,019), condom use 1.84 (IC 0,40 - 8,43 and p=0,356)and use of injecting drugs 3.71 (IC 1,35 - 10,13 and p=0,006).Conclusions: The seroprevalence rate was lower than those found in studies performed in other prisons in the country. Of the variables evaluated in the study the use of tattoos and the use of injectable drugs were statistically significant risk factors associated with seropositivity to syphilis. The combination of risk situations evaluated in this study can contribute to the transmission of syphilis on the Brazilian prisons. / Introdução: A sífilis é uma doença infectocontagiosa que encontra no ambiente prisional brasileiro condições que podem aumentar o risco da sua transmissão entre a população carcerária. Objetivos: Determinar a soroprevalência e avaliar as situações de risco associadas à transmissão da sífilis entre os presidiários do Complexo Prisional de Aparecida de Goiânia/GO no período de fevereiro a setembro de 2011. Metodologia: Estudo de base exploratória transversal com abordagem quantitativa. Um total de 1.173 participantes do estudo responderam a um questionário contendo variáveis sobre comportamentos e situações de risco para infecção pelo T. pallidum. A soroprevalência foi encontrada após a triagem sorológica utilizando o teste VDRL e ELISA como confirmatório. Os dados obtidos foram tabulados e as variáveis foram analisadas através dos programas EPI INFO e SPSS (Statistical Package for Social Sciences). Foram calculadas as taxas de soroprevalência por faixa etária e nível de escolaridade, e os riscos relativos (odds ratio) associados a comportamentos de risco. Resultados: A soroprevalência encontrada para sífilis na população estudada foi de 2,22% (IC95%). Do total de participantes do estudo, 83,4% tinham idade entre 18 e 39 anos. Esta faixa etária contribui com 85% dos casos positivos encontrados na triagem sorológica. A soroprevalência entre àqueles que possuem escolaridade abaixo do nível médio contribuiu com 58,2% da soroprevalência encontrada na população. Para as variáveis de situações de risco a relação homossexual teve uma razão de chances de 3,44 (IC 0,77 - 15,29 e p= 0,084), uso de tatuagem 3,05 (IC 1,14 - 8,14 e p= 0,019), uso de preservativos 1,84 (IC 0,40 - 8,43 e p =0,356) e uso de drogas injetáveis 3,71 (IC 1,35 - 10,13 e p= 0,006). Conclusões: A taxa de soroprevalência encontrada foi menor do que as encontradas em estudos realizados em outros presídios do País. Das variáveis avaliadas no estudo o uso de Tatuagens e o uso de Drogas Injetáveis foram os fatores de risco estatisticamente significantes associados à soropositividade para a sífilis. A combinação das situações de risco avaliadas pode contribuir para a transmissão da sífilis nos presídios brasileiros.

The major goal of this study was to achieve sustained cultivation of virulent T. pallidum in vitro. The putatuive binding of host proteins to the outer membrane (OM) of intact, virulent T. pallidum subsp. pallidum has been investigated. A major breakthrough was the development of a filtration assay, usinglow protein-binding membrane filters, for the measurement of substances bound to or incorporated into th eOM of T. pallidum. This avoided the conventional manipulations which can damage the fragile OM of T. pallidum. Using this filtration assay, studies on the binding of host serum proteins demonstrated that intact treponemes did not bind host proteins as previously reported. It also indicated that previous studies were probably performed with damaged by this research. The studies on the binding of polyclonal and monoclonal antibodies to intact and detergent treated treponemes provided evidence of the low level binding of antibody to intact treponemes which was greatly enhanced but the removal of the outer membrane with 0.1% Triton X. This research research corroborated that of others which suggests that the outer membrane of T. pallidum contains very little protein or surface exposed antigen.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-01T15:54:13Z No. of bitstreams: 2 Dissertação - Rafael Alves Guimarães - 2016.pdf: 4476558 bytes, checksum: 46bc5281f5c2ee7c26f5e3c06af53750 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-01T15:54:40Z (GMT) No. of bitstreams: 2 Dissertação - Rafael Alves Guimarães - 2016.pdf: 4476558 bytes, checksum: 46bc5281f5c2ee7c26f5e3c06af53750 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-01T15:54:40Z (GMT). No. of bitstreams: 2 Dissertação - Rafael Alves Guimarães - 2016.pdf: 4476558 bytes, checksum: 46bc5281f5c2ee7c26f5e3c06af53750 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-04-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Crack users are at high risk for syphilis, due to multiple risk behaviors, such as inconsistent condom use, exchanging sex for money and/or drugs and multiple sexual partners. The aim of this study was to investigate the epidemiology of syphilis in institutionalized crack users in Goiânia, Goiás. Between 2012 and 2013, a cross-sectional study was conducted with 600 users of a reference unit for chemical dependency treatment of Goiás. All participants were interviewed regarding socio-demographic characteristics and risk factors for syphilis. Blood samples were then collected for the detection of anti-Treponema pallidum antibodies using enzyme-linked immunosorbent assay (ELISA). Positive samples were retested by the Venereal Disease Research Laboratory (VDRL). Active syphilis was considered when there was a positive ELISA result and VDRL titers ≥ 1:8. Of the 600 samples tested by ELISA, 13.8% (95% CI: 11.3 to 16.8%) were positive and 4.5% (95% CI: 3.1 to 6.5%) had titles VDRL ≥ 1:8. The prevalence of exposure to Treponema pallidum and active syphilis was three times greater in women than in men (p < .001). In multiple regression analysis, female sex (adjusted prevalence ratio [APR]: 3.73; p < .001), exchange sex for money and/or drugs (APR: 3.22; p = .040) and a history of genital ulcers (APR: 4.12; p = .010) were associated with active syphilis. Furthermore, it was observed that the prevalence of infection decreased by 12% for each year of formal study (APR: 0.88; p = .030). The results of this research show high prevalence of syphilis in the investigated crack users and indicate the need to implement strategies for prevention and control of this infection in these individuals, including health education activities, diagnosis of infection in clinical treatment for chemical dependency and treatment of positive cases. / Usuários de crack apresentam elevado risco para sífilis, devido aos múltiplos comportamentos de risco, como uso inconsistente do preservativo, troca de sexo por dinheiro e/ou drogas e múltiplas parcerias sexuais. O objetivo desse estudo foi investigar a epidemiologia da sífilis em usuários de crack institucionalizados em Goiânia, Goiás. Entre 2012 e 2013, um estudo de corte transversal foi conduzido em 600 usuários de uma unidade de referência em tratamento de dependência química de Goiás. Todos os participantes foram entrevistados sobre características sociodemograficas e comportamentos de risco para sífilis. A seguir, foram coletadas amostras sanguíneas para detecção de anticorpos anti-Treponema pallidum pelo ensaio imunoenzimático (ELISA). As amostras positivas foram retestadas pelo Venereal Disease Research Laboratory/Laboratório de Pesquisa de Doenças Venéreas (VDRL). Considerou-se sífilis ativa positividade no ELISA e títulos de VDRL ≥ 1:8. Das 600 amostras testadas pelo ELISA, 13,8% (IC 95%: 11,3-16,8%) foram positivas e 4,5% (IC 95%: 3,1- 6,5%) apresentaram títulos de VDRL ≥ 1:8. A prevalência de exposição ao Treponema pallidum e de sífilis ativa foi três vezes maior em mulheres do que em homens (p < 0,001). Em análise de regressão múltipla, sexo feminino (Razão de Prevalência Ajustada [RPaj]: 3,73; p < 0,001), troca de sexo por dinheiro e/ou drogas (RPaj: 3,22; p = 0,040) e antecedentes de úlceras genitais (RPaj: 4,12; p = 0,010) foram associados à sífilis ativa. Além disso, observou-se que a prevalência da infecção diminuiu 12% a cada ano de estudo formal (RPaj: 0,88; p = 0,030). Os resultados dessa investigação evidenciam elevada prevalência de sífilis nos usuários de crack investigados e indicam a necessidade de implementação de estratégias de prevenção e controle dessa infecção nesses indivíduos, incluindo ações de educação em saúde, diagnóstico da infecção em clínicas de tratamento para dependência química e tratamento dos casos positivos.

Cette thèse aborde la contribution des noyaux gris centraux (NGCs) au contrôle de trois activités motrices importantes que sont la locomotion non obstruée, le contrôle visuoguidé des modifications de la locomotion et celui des mouvements d’atteinte. Ce travail s’inscrit dans le cadre des études antérieures entreprises par notre laboratoire. Celles-ci ont détaillé l’activité de plusieurs aires corticales que nous supposons impliquées dans la planification des modifications locomotrices. De nombreuses cellules enregistrées dans ces études montrent des décharges similaires, quel que soit le membre qui franchit l’obstacle en premier (limb-independent). Ce signal pouvant être transformé en signal dépendant du membre, ou « limb-dependent », pour déterminer, entre autres, quel membre franchira l’obstacle en premier. Nous proposons que les NGCs soient impliqués dans cette transformation et qu’ils puissent contribuer à la fois à la sélection du membre qui enjambera l’obstacle en premier, et à l’initiation des modifications nécessaires à l’enjambement. Pour tester cette hypothèse, nous avons enregistré l’activité pallidale (i.e. noyau entopédonculaire et globus pallidus) de cinq chats lors de la marche sur tapis roulant et lors de l’enjambement des obstacles attachés à celui-ci. Nos résultats ont tout d’abord montré qu’une large population de cellules modulait son activité en accord avec le rythme locomoteur. Un grand nombre d’entre elles présentaient des modifications de leur activité de décharge avant l’initiation de l’enjambement, mais uniquement par rapport au membre controlatéral au site de l’enregistrement. Nous suggérons que ceci serait compatible avec une participation à la sélection du membre. De plus, d’autres cellules déchargeaient avec de brèves bouffées d’activité avant et pendant le franchissement et pourraient fournir les caractéristiques temporelles de celui-ci. La majorité des cellules ont montré des changements reliés à la phase de balancement du membre controlatéral, cependant quelques cellules déchargeaient en rapport avec l’activité de plusieurs membres menant à la suggestion de leur possible contribution à la régulation de la séquence d’activité dans les quatre membres. Pour déterminer si les mêmes cellules contribuaient au mouvement d’atteinte, leur activité a également été enregistrée, après le transfert du chat, sur un appareillage adjacent. La plupart des cellules déchargeaient lors de l’atteinte et pendant la locomotion. Dans certains cas, les modifications étaient très similaires, avec des cellules qui déchargeaient pendant la phase de balancement à la locomotion et pendant la phase de transport pendant l’atteinte. L’activité des autres était plus contrastée, suggérant un contrôle dépendant du contexte et possiblement l’existence de circuits séparés, dans le contrôle de différents mouvements. La tâche d’atteinte nous a aussi permis de corréler les décharges pallidales, avec les ajustements posturaux anticipateurs (APAs) qui précèdent le mouvement, ou avec le mouvement lui-même. Seules quelques cellules ont montré une meilleure corrélation avec les APAs, suggérant un rôle préférentiel du pallidum dans le mouvement spécifiquement, plutôt que dans les activités posturales qui le précèdent. En conclusion, nos résultats suggèrent que l’activité pallidale est étroitement corrélée à différents aspects des activités motrices et suggèrent que le pallidum est bien placé pour, en fonction du contexte, intégrer et transformer le signal cortical et participer au contrôle précis du déplacement et du positionnement du membre. Notons que puisque les plus importants changements d’activité prenaient la forme d’augmentations plutôt que des diminutions, nous discutons la possibilité que ces augmentations puissent sculpter l’activité thalamo-corticale plutôt que relâcher le thalamus de son inhibition. / This thesis addresses the issue of how the basal ganglia contribute to the control of three important motor activities: i) the control of non-obstructed locomotion, ii) the control of visually-guided gait modifications and iii) the control of visually-guided reaching movements. A major impetus for this work comes from previous studies from this laboratory that have detailed the activity of several cortical areas that we postulate are involved in the planning of gait modification. Many of the cells recorded in these studies show similar discharges regardless of which limb is the first to step over the obstacle (limb-independent). This signal therefore has to be transformed into a limb-dependent signal to determine, amongst other issues, which limb will be the first to step over the obstacle. We propose that the basal ganglia are involved in this transformation and that it might make a contribution both in selecting which limb will be the first to step over the obstacle as well as determining temporal aspects of the resulting step. To test this hypothesis, we recorded activity from the pallidum (i.e. globus pallidus and entopedoncular nucleus) of five cats trained to walk on a treadmill and to step over a moving obstacle attached to that treadmill. We showed that a large proportion of pallidal neurons modulated their discharge according to the locomotor rhythm. Many of these neurons discharged before the onset of the step over the obstacle, but only for the contralateral limb to the recording site, compatible with a bias toward selecting that limb. In addition, other cells discharged with brief bursts of activity before and during the step and might contribute to providing temporal information about the upcoming step. The majority of cells showed changes related to the swing phase of the contralateral limb but some cells discharged with respect to the activity in several limbs leading us to suggest a possible contribution to the regulation of the sequence of activity in the four limbs. To determine whether the same cells contributed to discrete reaches, neuronal activity was recorded from the same cells after the transfer of the cat from the treadmill to an adjacent apparatus. Most cells discharged during both behaviours and in some cases the discharges during gait modification and reaching were very similar. In particular, cells discharging during the swing phase of locomotion also discharged during the transport phase of the reach. In other cases, the activity was more disparate, suggesting a context-dependent control over the activity and perhaps the existence of separate circuits for the control of different movements. The reaching task allowed us to correlate the discharge with preparatory postural adjustments that precede movements. Only a few cells showed a better correlation with APAs in comparison with the movement, suggesting a preferential role of the pallidum in focal movements rather than in the preceding postural activities. In conclusion, our results suggest that the activity in the pallidum is tightly correlated with different aspects of motor activity, suggesting that the pallidum is well placed to integrate and transform cortical signals and participate in the precise control of limb displacement. It was noteworthy that the strongest and most frequent changes in activity were increases rather than decreases. We discuss the possibility that these increases in activity might sculpt thalamocortical activity rather than releasing the thalamus from inhibition.

T. pallidum can survive a primary immune response and continue growing in the host for an extended period of time. T. pallidum is thought to bind serum fibronectin (FN) through Tp0483 on the surface to obscure antigens. A Tp0483 fragment (rTp0483) was adsorbed onto functionalized self-assembled monolayers (SAMs) with FN. FN capture by adsorbed rTp0483 depended greatly on surface chemistry with COO- groups being best for FN binding. Hemocompatibility was determined by analysis of plasma protein adsorption, intrinsic pathway activation, and platelet activation. rTp0483+FN bound an equal or lesser amount of fibrinogen (Fg), human serum albumin (HSA), and factor XII (FXII) compared to rTp0483 or FN alone and adsorption of rTp0483 prior to FN greatly decreased platelet activation. Inhibition of protein binding and platelet activation suggested an attenuated hematological response. Biocompatibility of rTp0483 and FN coated surfaces was characterized by macrophage uptake of protein coated polystyrene microspheres (PSMs), macrophage adsorption onto protein coated surfaces, cytotoxic effects of adsorbed rTp0483 and FN, and TNF-α and NO2- release in macrophages stimulated with rTp0483 and FN adsorbed and in solution. Addition of FN to rTp0483 on plain and COO- PSMs reduced phagocytosis compared to rTp0483 alone and on plain PSMs compared to FN alone. On plain PSMs addition of FN to adsorbed rTp0483 decreased TNF-α generation. Adsorption of rTp0483 before FN on large, flat COO- surfaces decreased macrophage adsorption and TNF-α and NO2- generation. High concentrations of rTp0483 were mildly cytotoxic to macrophages. FN binding by Tp0483 on T. pallidum likely plays a role in antigenic disguise and rTp0483+FN coatings may potentially inhibit FN and rTp0483 specific interactions with macrophages. Molecularly imprinted polymer coatings were also examined for biomaterial development. Fouling resistant 2-methacryloyloxyethyl phosphorylcholine (MPC) was imprinted with bovine serum albumin (BSA) protein templates to facilitate BSA specific binding. The BSA template was constructed and verified and BSA specific binding quantified using quartz crystal microbalance (QCM) and enzyme linked immunosorbent assay (ELISA). BSA imprinted coatings were determined to bind significantly more BSA than nonfouling MPC controls demonstrating the feasibility of targeted protein capture.

Treponema pallidum ssp. pallidum is the causative agent of syphilis, a sexually transmitted infection characterized by multi-stage disease and diverse clinical manifestations. Treponema pallidum undergoes rapid vascular dissemination to penetrate tissue, placental, and blood-brain barriers and gain access to distant tissue and organ sites. The rapidity and extent of T. pallidum dissemination is well documented, but the molecular mechanisms that underlie this process have yet to be fully elucidated. Tp0751 is a T. pallidum adhesin that interacts with vascular factors and mediates adherence to endothelial cells under shear flow. This dissertation explores the molecular interactions and functional outcomes of Tp0751-mediated vascular endothelium adhesion. The findings presented herein demonstrate that recombinant Tp0751 adheres to human macrovascular and microvascular endothelial cells, including cerebral brain endothelial cells. This interaction is confirmed using live T. pallidum, where spirochete- endothelial cells interactions are disrupted with Tp0751-specific antiserum. Further, the 67 kDa laminin receptor (LamR) is identified as an endothelial receptor using affinity chromatography coupled with mass spectrometry to isolate and identify Tp0751-interacting proteins from endothelial cells membrane extracts. Notably, LamR is a brain endothelial cell receptor for other neurotropic invasive pathogens. Evaluation of endothelial intercellular junctions reveals that recombinant Tp0751 and live T. pallidum disrupt junctional architecture. However, transwell solute flux assays reveal that Tp0751 and T. pallidum do not alter endothelial barrier integrity. The transendothelial migration of T. pallidum can be partially abrogated with an endocytosis inhibitor, implying a transcellular route for barrier traversal. However, a subpopulation of T. pallidum localizes to intercellular junctions, indicating paracellular traversal may also be employed. These findings enhance our understanding of the mechanics of T. pallidum attachment to endothelial cells and suggest that T. pallidum may use both paracellular and transcellular mechanisms to traverse the vascular endothelium without altering barrier permeability. A more complete understanding of this process will facilitate vaccine development for syphilis. / Graduate / 2020-06-18

<div>The eradication of yaws a neglected tropical disease caused by Treponema pallidum subsp. pertenue, which affects children living in very deprived hard to reach rural communities is constrained by the lack of rapid, accurate diagnosis. I sought to develop a molecular point-of-care test for the diagnosis of yaws. A Loop-mediated isothermal amplification (LAMP) assay with primers targeting the conserved gene, tp0967, with visual detection by lateral flow test strip was developed and optimized. The limit of detection was evaluated while 63 samples from clinical cases of yaws and 5 samples with PCR-confirmed syphilis were used to determine the sensitivity and specificity of the assay compared to the current molecular testing protocol. Reagents were dried in tubes and tested up to 14 days. The developed LAMP assay was found to be optimal when run at 65oC in a water bath for 30 minutes. The limit of detection was 2.7*104 DNA copies/ml. The sensitivity of the LAMP assay using unextracted and DNA extracted samples were 0.67 and 1.00 respectively. None of the syphilis samples tested positive in any of the assays. We show the development of a fast and sensitive LAMP assay for yaws detected by lateral flow test strip. Using extracted DNA, the assay sensitivity is at par with gold standard detection. The assay can be adapted to minimal sample processing required for in-field detection without DNA extraction.</div><div><br></div>

mormaeche@dge.gob.pe / Objective: To assess the seroprevalence of hepatitis B virus (HBV), syphilis, and HIV and associated risk factors in pregnant women and their male partners from six indigenous populations of the Peruvian Amazon Basin. Methods: A cross-sectional study was performed in six indigenous populations from the Peruvian Amazon Basin. Blood samples were obtained and tested for HBV (antibodies to the hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg)), for syphilis (rapid plasma reagin and microhemagglutination assay for Treponema pallidum antibodies), and for HIV (ELISA and indirect immunofluorescence test). A survey was also performed to identify associated risk factors. Results: One thousand two hundred and fifty-one pregnant women and 778 male partners were enrolled in the study. The seroprevalence of anti-HBc in pregnant women was 42.06% (95% confidence interval (CI) 39.28–44.85%) and in their male partners was 54.09% (95% CI 50.32–57.86%). The seroprevalence of HBsAg in pregnant women was 2.11% (95% CI 0.78–3.44%) and in their male partners was 3.98% (95% CI 1.87–6.08%). The seroprevalence of syphilis in pregnant women was 1.60% (95% CI 0.86–2.33%) and in their male partners was 2.44% (95% CI 1.22–3.66%). HIV seroprevalence in pregnant women was 0.16% (95% CI 0.02–0.58%) and in their male partners was 0.29% (95% CI 0.04–1.03%). Sexual risk factors were strongly related to blood markers of syphilis and HBV. Conclusions: Hepatitis B was found to be hyperendemic and strongly related to sexual factors, suggesting an important sexual component in the transmission of the disease in the populations studied. Syphilis was found to have an endemicity in pregnant women above the national level and this may be indicative of high mother-to-child transmission. HIV has started to show its presence in indigenous populations of the Amazon Basin and the results suggest the epidemic is concentrated. / Revisión por pares

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 89-111).