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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
431

[en] ANALYSIS OF THE DEMANDS OF PATIENTS AT THE SERVICE OF APPLIED PSYCHOLOGY AT PUC-RIO / [pt] ANÁLISE DAS DEMANDAS DE PACIENTES DO SERVIÇO DE PSICOLOGIA APLICADA DA PUC-RIO

BRUNA DE MOURA CORTES COUTINHO 25 April 2023 (has links)
[pt] A pandemia do COVID-19 teve impactos sem precedentes em indivíduos e comunidades em todo o mundo. Uma questão de grande preocupação é o impacto da pandemia na saúde mental. O isolamento, o medo e a incerteza causados pelo vírus levaram ao aumento das taxas de ansiedade, depressão e outros problemas de saúde mental. As preocupações com o aumento da prevalência de distúrbios psicológicos já estão levando os países a incluir a saúde mental e o apoio psicossocial em seus planos de resposta à COVID-19, mas, apesar disso, permanecem grandes lacunas e preocupações. Os múltiplos estressores desencadeados pelo vírus, somados às graves interrupções nos serviços públicos, deixaram sérias lacunas no atendimento de quem mais precisa. Além do agravamento e generalização de condições de saúde mental pré-existentes, agora também há a necessidade de acomodar questões recém-desenvolvidas. Nosso objetivo é, portanto, investigar os principais motivos que levaram os pacientes do Serviço de Psicologia Aplicada da PUC-Rio a buscar tratamento psicológico antes (2019) e durante a pandemia (2020 e 2021). Através de uma análise lexical dos formulários de demanda psicológica, pretendemos rastrear as possíveis transições e agravos entre demandas psicológicas de adultos (artigo 1) e famílias (artigo 2) utilizando o software IRaMuTeQ e o método Reinert, que analisa qualitativa e quantitativamente as transcrições relatórios. Por meio desse recurso de análise, é possível começar a mapear e investigar as queixas subjetivas desses pacientes, sua evolução e suas correlações. / [en] The COVID-19 pandemic has had unprecedented impacts on individuals and communities around the world. A matter of great concern is the impact of the pandemic on mental health. The isolation, fear and uncertainty caused by the virus has led to increased rates of anxiety, depression and other mental health issues. Concerns about the increasing prevalence of psychological disorders are already leading countries to include mental health and psychosocial support in their COVID-19 response plans, but despite this, major gaps and concerns remain. The multiple stressors triggered by the virus, in addition to the severe interruptions in public services, have left serious gaps in the care of those who need it most. In addition to the worsening and generalization of pre-existing mental health conditions, there is now also a need to accommodate newly developed issues. Our objective is therefore to investigate the main reasons that led patients from the Service of Applied Psychology at PUC-Rio to seek psychological treatment before (2019) and during the pandemic (2020 and 2021). Through a lexical analysis of the psychological demand forms, we intend to trace the possible transitions and aggravations between psychological demands of adults (article 1) and families (article 2) using the IRaMuTeQ software and the Reinert method, which qualitatively and quantitatively analyzes the transcribed reports. Through this analysis resource, it is possible to start mapping and investigating the subjective complaints of these patients, their development and their correlations.
432

Role of GPR84 in Kidney Injury in a Surrogate COVID-19 Mouse Model

Blais, Amélie 05 January 2023 (has links)
40% of severe acute respiratory syndrome coronavirus two (SARS-CoV-2) severe cases develop acute kidney injury (AKI). Current treatment for renal complications limits financial and material resources available. To explore alternative treatments and accelerate research in case of future coronavirus outbreaks, a mouse model of coronavirus disease 2019-associated AKI (C19-AKI) would represent a critical biomedical research tool. The surrogate model of C19-AKI (SMC) developed consisted of angiotensin-converting enzyme two (ACE2) knockout (KO) mice receiving 400 ng/kg/min of angiotensin (Ang) II by osmotic minipump for eight days with a single injection of lipopolysaccharide (LPS; 10 mg/kg) on the seventh day of Ang II and euthanasia 24 hours after LPS. Similarly, to C19-AKI, the SMC exhibited albuminuria, elevated blood urea nitrogen, electrolyte imbalance, neutrophil infiltration, and upregulation of the G-coupled protein receptor (GPR)84 and pro-inflammatory and injury markers. GPR84 was found in bronchoalveolar lavage fluid neutrophils of coronavirus disease 2019 (COVID-19) patients, suggesting a potential implication of GPR84 in the disease. We hypothesised that GPR84 deletion or antagonism with GLPG-1205 could attenuate SMC’s indices of renal injury and inflammation. GLPG-1205 and GPR84 KO had no effects in the SMC model, as suggested by unchanged albuminuria, electrolytes, and markers expression. Interestingly, neutrophil infiltration was attenuated by GLPG-1205 only. The SMC is an interesting tool for therapeutic development for infections associated with renal injury, such as SARS-CoV-2. GPR84 role in the SMC needs to be further assessed.
433

[en] DIGITAL INNOVATION TO RESPOND TO GENDER-BASED VIOLENCE: EXPERIENCES FROM THE PANDEMIC IN BRAZIL / [pt] INOVAÇÕES DIGITAIS NO COMBATE À VIOLÊNCIA CONTRA A MULHER: INICIATIVAS DURANTE A PANDEMIA DA COVID-19 NO BRASIL

ROBERTA SALOMONE DE PAIVA 04 November 2021 (has links)
[pt] Este estudo pretende analisar e discutir os principais dados sobre violência doméstica durante o primeiro ano de pandemia da Covid-19 e apresentar algumas respostas e iniciativas tecnológicas que foram aprimoradas e/ou criadas para atender as vítimas no Brasil. Com a propagação da Covid-19 em todo mundo no ano de 2020, medidas de isolamento social foram adotadas como importante estratégia para a redução do número de infectados pelo vírus. Ficar em casa, no entanto, virou sinônimo de insegurança para muitas mulheres, já que é no próprio domicílio onde ocorre grande parte dos casos de feminicídio no país. Um mês depois de a Organização Mundial de Saúde decretar a pandemia, o relatório Covid-19 e o Combate à Violência Contra Mulheres e Meninas (ONU Mulheres) já mostrava que o número de casos de violência doméstica tinha aumentado em vários lugares do mundo. Esse texto apresenta os principais aplicativos para celular, serviços de atendimentos online e outras ferramentas digitais, assim como aponta para a necessidade de iniciativas e políticas específicas, investimento e desenvolvimento em novas tecnologias para combater os casos de violência contra as mulheres. / [en] This dissertation aims to analyze and discuss the main data on domestic violence during the first year of coronavirus pandemic and present some answers and technological initiatives that were improved to assist victims in Brazil. With the spread of Covid-19 around the world during 2020, social isolation was adopted as an important strategy to reduce the number of people infected by the virus. However, staying home has become synonymous of insecurity for many women, as most of femicide cases happen at home. A month after the World Health Organization declares Covid-19 a pandemic, the report Covid-19 and Ending Violence Against Women and Girls (UN Women) already showed that the number of cases of domestic violence had increased in many parts of the world. This text presents mobile applications, online assistance services and other digital tools as points the need of specific initiatives and policies, investment, and development in new technologies to combat cases of violence against women.
434

Coronavírus em aves silvestres e domésticas provinientes de diferentes regiões do Brasil. / Coronavirus in wild and domestic birds from different regions of Brazil.

Barbosa, Carla Meneguin 21 September 2015 (has links)
Apesar de ainda não terem sido relatados Coronavírus aviários com potencial zoonótico, espécies de aves silvestres e domésticas podem portar CoVs de grande importância econômica como o vírus da Bronquite Infecciosa (IBV). Além disso, nos últimos anos, diversos novos CoVs geneticamente distintos do IBV vêm sendo identificados em diferentes famílias de aves e mamíferos silvestres e domésticos. O Brasil contem 18% do total da diversidade de espécies de aves no mundo, no entanto, estudos sobre a presença de Coronavírus em aves silvestres ainda são bastante escassos. O presente estudo tem por objetivo realizar análise retrospectiva da presença de Coronavírus em amostras de aves silvestres e domésticas de diferentes regiões brasileiras coletadas entre os anos de 2004 e 2013 através de RT-PCR; realizar a caracterização molecular e a análise filogenética afim de correlacionar sua epidemiologia às rotas de migrações de aves, à proximidade das regiões urbanas e de granjas avícolas, verificando a possibilidade de transmissão. Do total de 746 amostras testadas, 25 apresentaram resultados positivos para os Coronavírus com primers para o gene da RpRd e foram sequenciadas. Obtivemos sucesso no sequenciamento de 7 dessas amostras, sendo 4 positivas para Gammacoronavírus e 3 positivas para Deltacoronavírus. Na tentativa de sequenciamento do gene da proteína S uma galinha (Gallus gallus), da Ilha de Marajó-PA, mostrou sequência que foi identificada como uma cepa de IBV. Este trabalho é inédito no Brasil, pois demonstra a presença de Gamma e Deltacoronavírus aviários circulando em diversas regiões, próximo a áreas urbanas e indústrias avícolas, mostrando evidências de que aves silvestres podem carrear estes Coronavírus entre diferentes sítios migratórios no Brasil. / Regardless it has never been reported any avian Coronavirus with zoonotic potential, species of both wild and domestic birds can carry CoVs of great economic importance as the Infectious Bronchitis Virus (IBV). Furthermore, recently, many new CoVs, genetically distinct from IBV have been identified in different families of wild and domestic birds and mammals. Even though Brazil contains 18% of the bird species diversity in the world studies about the presence of Coronaviruses in wild birds are still quite scarce. This study aims to perform retrospective analysis of the presence of coronavirus in wild birds and domestic samples of different Brazilian regions collected between the years 2004 and 2013 by RT PCR and to perform molecular characterization and phylogenetic analysis in order to correlate its epidemiology to routes of bird migrations , the proximity of urban and poultry industry regions , verifying the possibility of transmission. Of the amount of 746 samples tested, 25 were positive for Coronavirus in PCR and nested PCR tests with primers for RpRd gene and were sequenced. We have succeeded in sequencing 7 of these samples which 4 were positive for Gammacoronavirus and 3 for Deltacoronavirus. In attempt of sequencing the S protein gene, we have succeeded in a chicken sample (Gallus gallus) from Ilha de Marajó-PA. This sample was identified as a strain of IBV. This work is unprecedented in Brazil, as it demonstrates the presence of Gamma and Deltacoronavirus in birds circulating in different regions, close to urban areas and poultry industries, showing evidence that wild birds may carry these Coronavirus between different migratory sites in Brazil.
435

Diversidade molecular dos genes codificadores das proteínas não-estruturais Nsp2 e protease Papaína-like e da proteína estrutural S1 de amostras brasileiras do Coronavírus aviário / Molecular diversity of Nsp2 and Papain-like protease and S1 structural protein coding genes in Brazilian isolates of Avian coronavirus

Rossa, Giselle Ayres Razera 14 November 2014 (has links)
Coronavírus, incluindo-se o Coronavírus aviário (ACoV), possuem o maior genoma composto por RNA conhecido entre os vírus. Aproximadamente dois terços desse genoma codificam proteínas não estruturais (Nsps), cujas funções parecem estar associadas à replicação e patogênese viral. Até o momento, esses alvos têm sido pouco explorados quanto a sua diversidade em diferentes linhagens de ACoV. O presente estudo teve como objetivo investigar a diversidade dos genes codificadores das proteínas não estruturais Nsp2 e protease Papaína-like (Plpro), utilizando-se linhagens brasileiras de ACoV. Para tanto, 10 linhagens de ACoV, isoladas em ovos embrionados, foram submetidas à RT-PCR direcionada aos genes codificadores de Plpro e Nsp2, seguindo-se o sequenciamento de DNA e a análise filogenética, juntamente com sequências homólogas obtidas no GenBank. Além disso, realizou-se a genotipagem por meio do sequenciamento parcial do gene codificador da proteína de espícula (região S1). Três das amostras virais obtidas e investigadas no presente trabalho apresentaram padrão de segregação discordante para os genes estudados. O isolado CRG I22 agrupou-se com linhagens virais pertencentes ao genótipo Massachusetts para S1 e com o grupamento de ACoVs brasileiros os genes da Nsp2 e Plpro. O isolado CRG I33 agrupou-se com linhagens virais pertencentes ao genótipo brasileiro para s1 e plpro e de maneira divergente para o gene da Nsp2. Para o isolado CRG I38, não foi obtida a genotipagem por s1, entretanto, similarmente ao observado para o isolado CRG I33, esse isolado agrupo-se com linhagens virais brasileiras para o gene plro e de maneira independente para o gene nsp2. As demais linhagens estudadas resultaram na formação de um grupamento especificamente brasileiro de ACoV, para os três genes estudados. Esses achados sugerem a ocorrência de recombinação nessas amostras discrepantes. Quanto às identidades médias entre as sequencias nucleotídicas analisadas, a região de s1 analisada apresentou as menores identidades (73,75% ±16,78), seguido pelo gene plpro (88,06% ±5,7) e do gene nsp2 (92,28% ±4,37), em acordo com a literatura. Assim sendo, os alvos investigados podem constituir ferramentas úteis na epidemiologia molecular do ACoV e na investigação de linhagens recombinantes do vírus. O presente estudo é o primeiro a investigar a diversidade genética de genes codificadores de proteínas não-estruturais em linhagens brasileiras de ACoV. Os resultados aqui apresentados reforçam a existência de um genótipo brasileiro de ACoV, para os 3 genes estudados. Entretanto, discrepâncias pontuais encontradas no padrão genotípico para s1, nsp2 e nsp3 permitem inferir uma diversidade genética maior do que a conhecida até o momento, possivelmente resultante de eventos de recombinação entre ACoVs brasileiros, ACoVs vacinais e outros ainda desconhecidos. Os resultados obtidos auxiliam na compreensão dos padrões e evolução dos ACoVs / Coronaviruses, including Avian coronavirus (ACoV), have the largest known RNA genome. Nearly two thirds of its genome codes for non-structural proteins (Nsps), whose functions appear to be linked to viral replication and pathogenesis. Hitherto these targets have been poorly explored regarding the ACoV lineages diversity. The present study aimed to assess the diversity of non-structural protein 2 (nsp2), papain-like protease (plpro) and spike protein (S1 subunit) coding genes, in Brazilian ACoV strains. To this end, 10 ACoV strains, isolated in embryonated eggs, had its 3rd and 5th passages submitted to RT-PCR targeting nsp2, plpro and s1, followed by DNA sequencing and phylogenetic analysis, herewith homologous sequences obtained from GenBank. Three of the ACoV strains sequenced showed a discordant segregation pattern for target genes. CRG I22 strain clustered with Massachusetts genotipe strains for S1, and with Brazilian cluster for nsp3 and plpro genes. CRG I33 strain, clustered with Brazilian strains for S1 and plpro genes, and was divergent for nsp2 gene. For CRG I38 strain, the S1 sequence was not obtained, however, similarly to what was observed for CRG I33, this strain grouped with the Brazilian lineage for plpro gene and was divergent for nsp2 gene. All the other ACoV here sequenced resulted in a specific Brazilian cluster for the three studied genes. Regarding the mean nucleotide identities measured, s1 gene showed the lowest identity (73.75% ±16.78), followed by plpro gene (88.06% ±5.7) and nsp2 gene (92.28% ±4.37), in accordance with previous reported data. Therefore, the targets of the present study are useful tools for ACoV molecular epidemiology studies and for the survey of recombinant ACoV strains. The presented study is the first one investigating the molecular diversity of non-structural proteins coding genes in Brazilian strains of ACoV. Results achieved herein reinforce the data over the circulation of ACoV Brazilian strains in this country, for the three investigated genes. However, divergences found between S1, nsp2 and plpro genetic patters allow inferring a higher molecular diversity than previously known. It is possible that this divergence is due to recombination events between ACoV from vaccines, Brazilian field strains and others still unknown. These results contribute on the comprehension over genetic patters and evolution of ACoV
436

Etude de la régulation de l’expression des ARN non-codants au cours de l’infection par des virus à ARN : Implications de la protéine KSRP dans la réplication du virus de l’Hépatite C et de la souche HCoV-229E des Coronavirus / Non-coding RNA regulation during infection by RNA viruses : Involvment of KSRP for the replication of the Hepatitis C virus and for the Coronoavirus HCoV-229E strain

Baudesson, Camille 15 February 2019 (has links)
Les virus à ARN sont à l’origine de nombreuses épidémies depuis ces dernières décennies. Malgré des avancées thérapeutiques majeures, une majorité d’infection est orpheline de traitement. Le développement d’antiviraux à spectre large est une alternative thérapeutique pour maximiser le nombre de virus ciblés, minimiser les coûts de production et améliorer la prise pour les patients. Afin de trouver de nouvelles cibles cellulaires, la compréhension des mécanismes moléculaires utilisés par les virus pour infecter l’hôte est essentielle.Les virus utilisent des facteurs cellulaires pour survivre et se propager. Parmi ceux-ci, on trouve les microARNs (miARNs) et les longs ARNs non-codants (lncARNs) qui peuvent participer à la réponse antivirale mais peuvent également être détournés par les virus pour favoriser l’infection. Ces d’ARN non-codants peuvent interagir avec des protéines cellulaires (« RNA-binding protein » (RBP)) telles que la protéine KSRP. Cette RBP est impliquée dans le contrôle de l’expression des ARNs en participant à l’épissage de certains pré-ARNm, à la dégradation des ARNs contenant des séquences riches en AU et à la maturation de certains miARNs. Ses fonctions et sa localisation sont dépendantes de la phosphorylation de certains résidus par les kinases cellulaires Akt, ATM et p38/MAPK.Le but de ma thèse a été d’étudier la modulation de l’expression de ces deux classes d’ARN non-codants au cours de l’infection par des virus à ARN tels que le virus de l’Hépatite C (VHC) et la souche HCoV-229E des Coronavirus. Plus particulièrement nous avons cherché à étudier l’implication de KSRP dans la régulation d’ARN non-codants essentiels pour ces infections.Mes recherches ont commencé par l’étude de la maturation du microARN-122 (miR-122), un facteur proviral de l’infection par le VHC. Nous avons montré que KSRP phosphorylée sur le résidu S193 par Akt interagissait avec le complexe nucléaire DROSHA/DGCR8 et ainsi était essentielle à la maturation du pri-miR-122 en miR-122 favorisant la réplication virale. Notre avons ensuite étudié le rôle des phosphorylations de KSRP par ATM et p38/MAPK sur la réplication et sur la maturation du miR-122. La phosphorylation par ATM ne semble pas jouer un rôle majeur sur ces deux paramètres. En revanche, la phosphorylation de KSRP sur le résidu T692 par la kinase p38/MAPK semble jouer un rôle positif sur la réplication VHC.Dans un second temps, par homologie avec les résultats obtenus dans le cas du VHC, nous avons étudié le rôle de KSRP lors de l’infection par la souche HCoV-229E des Coronavirus. En transfectant un siKSRP ou un plasmide exprimant la protéine KSRP, nous avons pu démontrer que KSRP était un facteur proviral pour la réplication virale.Afin d’identifier les ARN non-codants modulés au cours de l’infection HcoV-229E et dont l’expression pouvait être régulée par KSRP, nous avons effectué deux analyses de séquençage à haut débit (« NGS »). L’analyse réalisée sur des cellules infectées vs non-infectées nous a permis d’identifier l’ensemble des miARNs et lncARNs dérégulés par le virus. Nous avons croisé ces résultats avec un second « NGS » fait sur des cellules infectées, inhibées pour KSRP et nous avons trouvé que l’expression du LinC00473 était modulée dans les deux conditions expérimentales. En étudiant ce facteur cellulaire au cours de l’infection nous avons observé une forte induction KSRP-dépendante du LinC00473 à 24 h post-infection, puis une diminution à 48 h post-infection. L’inhibition de ce facteur entraîne une diminution de la réplication virale suggérant que le LinC00473 est un facteur proviral au début de l’infection.Nos résultats ont permis de montrer le rôle proviral de la protéine KSRP lors de deux infections virales (VHC et HCoV-229E des Coronavirus). Son implication dans la régulation de l’expression des ARNs fait de cette protéine un outil efficace pour découvrir de nouvelles cibles thérapeutiques ARN non-codants au cours d’autres infections virales. / Résumé en anglaisRNA viruses have been the cause of many epidemics in recent decades. Despite major therapeutic advances, a majority of infection is currently orphan for treatment. The development of new broad spectrum antivirals is a therapeutic alternative to maximize the number of targeted viruses, minimize production costs and improve access to population. In order to find new cellular targets for this type of therapeutic approach, understanding the molecular mechanisms used by RNA viruses to infect the host is essential.Viruses exploit cellular factors to survive and to disseminate. Among those factors, microRNA (miRNA) and long non-coding RNA (lnCRNA) can participate to cellular antiviral response but can also be hijacked by the virus to improve the infection. These two families of non-coding RNA could interact with cellular RNA-binding protein (RBP) such as KSRP. This ubiquitous protein is involved in RNA expression control via its participation to pre-mRNA splicing, decay of AU-rich element mRNA and maturation of microRNAs. The functions and localization of KSRP are dependent of post- modification by the cellular kinases Akt, ATM and p38/MAPK.The aim of my thesis was to study the modulation of the expression of these two classes of non-coding RNA during infection by RNA viruses such as the hepatitis C virus (HCV) and the HCoV-229E strain of the Coronaviruses. More specifically, we evaluated the involvement of KSRP in the regulation of non-coding RNAs essential for these infections.My research project began with the study of microRNA-122 (miR-122) the maturation. This miRNA is a proviral factor for HCV infection. We have shown that the Akt-dependent phosphorylation of S193-KSRP promoted the interaction of pri-miR-122 with the DROSHA / DGCR8 nuclear complex and thus was essential for the maturation of miR-122, finally promoting viral replication. We then investigated the role of KSRP phosphorylation by ATM and p38 / MAPK on viral replication and on miR-122 maturation. ATM phosphorylation does not seem to play a major role in these two parameters. In contrast, phosphorylation of KSRP on the T692 residue by p38 / MAPK kinase appears to play a positive role on viral replication.In a second step, by homology with the results obtained in the case of the HCV infection, we studied the role of KSRP during the infection with the HCoV-229E strain of Coronaviruses. After siKSRP transfection or exogenous expression of the KSRP protein, we were able to demonstrate that KSRP was a proviral cellular factor for HCoV-229E replication.In order to characterize the modulation of non-coding RNAs expression during HcoV-229E infection and to identify the non-coding RNAs whose expression could be regulated by KSRP, we performed two high-throughput sequencing ("NGS") assays. The analysis performed on infected and non-infected cells allowed us to identify all the miRNAs and lncRNAs whose expression was altered by the virus. We cross-examined these results with a second "NGS" performed on HCoV-229E infected cells inhibited for KSRP. We found that the expression of an InCARN (LinC00473) was modulated under both experimental conditions. We demonstrated a strong KSRP-dependent induction of LinC00473 expression at 24 h post-infection, then a decrease at 48 h post-infection. Inhibition of this factor results in decreased viral replication suggesting that LinC00473 is a proviral cell factor at the onset of infection.Our results have shown the proviral role of the KSRP protein during two viral infections (HCV and HCoV-229E of the coronaviruses). Its involvement in the regulation of RNA expression makes of KSRP an effective tool for discovering new non-coding RNA therapeutic targets for other viral infections
437

T cell responses to S-glutathionylated And heteroclitic viral epitopes and CCl2-mediated immune dysregulation in mice infected with a neurotropic coronavirus

Trujillo, Jonathan Anthony 01 May 2014 (has links)
Mice infected with neurotropic variants of the murine coronavirus, mouse hepatitis virus, (strains JHMV or J2.2–V–1) develop acute and chronic CNS infections, and provide a model system to study the pathogenesis of virus–induced neuroinflammation, mechanisms of virus persistence, and anti–viral immune responses in the CNS. Using the J2.2–V–1 model of CNS infection, we addressed the role of sustained CCL2 production during viral infection using mice in which CCL2 was expressed transgenically in oligodendrocytes. Tonic CCL2 expression in the CNS resulted in delayed kinetics of virus clearance, and converted what is typically a mild, nonlethal disease to acutely lethal encephalitis, with the majority of mice succumbing to the infection. CCL2 induced a rapid and dysregulated inflammatory response that was no longer protective and was unable to efficiently clear virus from the CNS. Infected CCL2 Tg mice had increased numbers of Foxp3–expressing CD4 T cells (Tregs) and of macrophages and microglia expressing elevated levels of YM–1, a marker for alternatively activated macrophages, and nitric oxide. Our results showed that CCL2 has effects beyond serving as a chemoattractant for leukocytes, and has effects on the composition and function of inflammatory cells at sites of infection. In a separate set of experiments, I identified and characterized two additional heteroclitic variants of the JHMV epitope S598 that induced CD8 T cells with greater antigen sensitivity to the native S598 determinant relative to the cells primed by the native epitope. One of these heteroclitic epitopes elicited a T cell response with nearly complete cross–reactivity towards the native peptide. The structural data show that these heteroclitic epitopes induced modest conformational changes in the local environment of the peptide–MHCI complex. I also provide data to support the notion that heteroclitic determinants augment functional avidity by increasing surface epitope density. Collectively, these data will help guide the design of heteroclitic epitopes in the setting of vaccine development. Lastly, I examined the consequences of oxidative stress induced by viral infection on antigen presentation. The brains of JHMV–infected mice were found to have signs of oxidative stress, with significantly decreased ratios of reduced (GSH) to oxidized (GSSG) glutathione, suggesting that there is an environment that is conducive for cysteine modification with oxidized glutathione. We found that virus–induced oxidative stress resulted in the presentation of both native and S–glutathionylated forms of the JHMV epitope S510 by infected cells. A subset of the S510–specific CD8 T cells failed to recognize the modified form of the epitope, suggesting that GSH–modification of a cysteine–containing viral epitope might interfere with T cell recognition. Further, GSH-modified peptides were identified in stressed human cells, including herpes virus–transformed B cells, suggesting that the modification is not limited to mouse cells. Collectively these findings have implications for both anti–viral immunity and anti–tumor immunity, where oxidative stress has been shown to play a role during infection and tumorgenesis.
438

5’-Proximal cis-Acting RNA Signals for Coronavirus Genome Replication

Guan, Bo-Jhih 01 August 2010 (has links)
RNA sequences and higher-order structures in the 5’ and 3’ untranslated regions (UTRs) of positive-strand RNA viruses are known to function as cis-acting elements for translation, replication, and transcription. In coronaviruses, these are best characterized in the group 2a bovine coronavirus (BCoV) and mouse hepatitis virus (MHV), yet their precise mechanistic features are largely undefined. Here, we use a reverse genetics system in MHV to exploit the ~30% nt sequence divergence between BCoV and MHV to establish structure/function relationships of 5’ UTR cis-replication elements. It had been previously shown that a precise replacement of the 391-nt MHV 3’ UTR with the 288-nt BCoV 3’ UTR yields wt-like MHV. Our attempts to replace the 209-nt MHV 5’ UTR with the 210-nt BCoV 5’ UTR, however, yielded a non-viable chimera. Therefore, a systematic analysis of individual 5’-terminal structures was made to identify compatible elements. By placing each of four putative cis-acting domains from the BCoV 5’ UTR into the MHV genome, we learned that (i) stem-loops (SLs) I & II and SLIII are functionally compatible, (ii) SLIV is compatible if it spans parts of the 5’ UTR and the nonstructural protein 1 (nsp1) cistron, thus identifying this part of ORF 1 as a component of the cis-replication signal, (iii) a relatively unstructured 32-nt region mapping between SLIII and SLIV defines a novel virus species-specific cis-replication element, (iv) spontaneous suppressor mutations within MHV SLI and nsp1 cistron compensated for growth defects arising from the BCoV 32-nt element in the MHV genome, (v) cross talk between the 32-nt element, SLI, and the nsp1 cistron appears essential for virus replication, (vi) the BCoV 5’ UTR and nsp1 cistron function together in the MHV genome to generate a wt-like MHV phenotype, and (vii) a functional 5’ UTR-nsp1 domain in group 2a coronaviruses cannot be substituted by the corresponding genomic element from the group 2b SARS-CoV. We postulate that the interaction between the 5’ UTR and nsp1 cistron (or possibly nsp1 protein) functions as a molecular switch between genome translation and ignition of negative-strand RNA synthesis.
439

Des virus entéritiques au nématode parasite Trichinella; aller et retour entre recherche et expertises

Boireau, Pascal 02 October 2003 (has links) (PDF)
Ce mémoire préparé en vue d'obtenir une habilitation à diriger des recherches est présenté en deux grandes parties. La première partie décrit les résultats acquis, les principaux axes de recherche développés au cours de 15 années durant lesquelles cette activité s'est effectuée de façon alternative au LCRV et à l'INRA. Si l'essentielle de mes missions fut d'abord une pratique de la recherche, j'ai progressivement été amené à partir de 1993 à initier des axes stratégiques et à animer la recherche de l'unité. La seconde partie présente mon curriculum vitae de façon synthétique avec un bilan des productions scientifiques. La première partie fait référence aux publications ordonnées dans la seconde partie selon des règles classiques (Publications internationales (Pn), publications techniques (diffusion nationale), participation à des congrès (Cn)....) Etant Inspecteur en Chef de la Santé Publique Vétérinaire (anc. Vétérinaire Inspecteur), j'ai du assurer un certain nombre de missions à caractère administratif. D'abord rapporteur à la commission d'AMM vétérinaire pour les sérums et vaccins, je me suis progressivement impliqué dans des missions d'expertises en cherchant à potentialiser mes axes de recherche avec ces missions parallèles. Aussi ai-je appartenu à des commissions apparemment très différentes, mais qui avaient cependant toutes en commun l'expertise de produits biologiques et plus précisément des produits issus des biotechnologies.
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Detection of human coronavirus infections by reverse transcription PCRin children hospitalized with respiratory disease in Hong Kong

Kwan, See-wai, Grace., 關詩慧. January 2005 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

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