Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 86-100). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leave 173-189) Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 194-237) Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 139-160). Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 139-160). Also available online.

Thesis (M.S.)--The University of North Carolina at Greensboro, 2010. / Directed by Amy Adamson; submitted to the Dept. of Biology. Title from PDF t.p. (viewed Jul. 12, 2010). Includes bibliographical references (p. 42-48).

Thesis (M.S.)--Brigham Young University. Dept of Physiology and Developmental Biology, 2006. / Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Influenza A virus (IAV) replication and transcription occur in the host cell nucleus; a feature which means both the viral genome (vRNA) and mRNA must be exported from the nucleus to the cytoplasm. The mechanism by which vRNA nuclear export is achieved has been well characterised, but how viral mRNAs are exported is poorly understood. The cellular NXF1-dependent mRNA export pathway has been shown to be involved in the export of some viral mRNAs, but how they are recruited to this pathway is unknown. Prior work from our laboratory showed that segment 7 mRNA was inefficiently exported to the cytoplasm in a sub-viral ‘minireplicon’ system, providing the first indication that there were viral requirements for IAV mRNA nuclear export. Further addition of individual viral polypeptides was tested and the effect on segment 7 mRNA export was analysed by fluorescent in situ hybridization (FISH) and confocal microscopy. This identified the NS1 protein as the viral factor required for efficient segment 7 nuclear export. Mutational studies on NS1 were carried out to unveil the mechanistic role of this protein in viral mRNA nuclear export, by plasmid transfection as well as in the context of recombinant viruses. These approaches indicated that both functional domains of NS1 were necessary to preserve the mRNA export function. Furthermore, these mutant proteins were used to examine the association between NS1 and the NXF1-dependent pathway in the context of mRNA nuclear export. Protein-protein and protein-RNA binding assays indicated that interactions between NXF1 and NS1, and NXF1 and segment 7 mRNA were necessary, but not sufficient to promote segment 7 viral mRNA export. Lastly, the role of NS1 protein in the nuclear export of viral mRNAs from other genome segments was studied. The intracellular localisation of most viral mRNAs was not affected by the absence of NS1 or the presence of an export-incompetent NS1 mutant protein. However, segment 4 mRNA exhibited a similar phenotype to segment 7 mRNA in showing a dependence on NS1 for efficient nuclear export. Overall, the results presented in this dissertation suggest that NS1 acts as an adaptor protein between the viral RNA synthesis machinery and cellular export pathway. This provides deeper insights for the characterization of a recently identified function of the IAV NS1 protein, of being required for the efficient nuclear export of mRNA from “late” kinetic class viral genes.

INTRODUÃÃO - A gripe à uma doenÃa infecciosa aguda de origem viral, de distribuiÃÃo universal, que acomete o trato respiratÃrio. Segundo estatÃsticas da OrganizaÃÃo Mundial da SaÃde (OMS), cerca de 5 a 15% da populaÃÃo mundial se infecta com o vÃrus da influenza anualmente. Em marÃo de 2009, com mudanÃa no padrÃo da ocorrÃncia da influenza no MÃxico, o vÃrus da influenza A (H1N1), um quÃdruplo recombinante nunca antes visto, foi identificado atravÃs da anÃlise de amostras de secreÃÃo de nasofaringe de crianÃas americanas sintomÃticas, confirmando o vÃnculo epidemiolÃgico com os casos no MÃxico (CDC/Atlanta, 2009) e em meses seguintes, com a transmissÃo sustentada de pessoa para pessoa e acometimento de vÃrios paÃses e naÃÃes, foi deflagrada uma nova pandemia. OBJETIVOS - Os objetivos deste estudo foram descrever a evoluÃÃo temporal, caracterizar os padrÃes de morbi-mortalidade e identificar os fatores associados à ocorrÃncia de gravidade e Ãbitos nas diferentes fases da pandemia de Influenza A (H1N1) 2009 no CearÃ. MÃTODOS - Trata-se de estudo descritivo, retrospectivo, dos casos notificados e confirmados de influenza pandÃmica (H1N1) 2009, no Estado do CearÃ, nos anos de 2009 e 2010. RESULTADOS E DISCUSSÃO - A pandemia deu-se em trÃs pequenas ondas, uma na fase de contenÃÃo, caracterizada por casos leves, com resoluÃÃo rÃpida. As duas segundas ondas, na fase de mitigaÃÃo, com casos com maior gravidade, maior taxa de hospitalizaÃÃo, a totalidade de pacientes que necessitaram de cuidados intensivos (UTI) e todos os pacientes que evoluÃram para Ãbito. Foram notificados 615 casos, destes 144 foram confirmados. 55,5% eram do sexo feminino, 30% eram pardos, 72,5% dos casos graves possuÃam alguma comorbidade e 40 pacientes necessitaram de hospitalizaÃÃo. A letalidade hospitalar foi de 20% e a letalidade em UTI foi de 66%. Foram significantes para evoluÃÃo para cura ou Ãbito aspectos relacionados à procura por assistÃncia mÃdica, atraso no inÃcio da terapia antiviral, obesidade, ter baixa escolaridade, uso de ventilaÃÃo mecÃnica e ser hospitalizado em hospitais com atendimento especializado. CONCLUSÃO - A anÃlise dos dados do presente estudo permitiu conhecimento aprofundado acerca do padrÃo de morbi-mortalidade causado pela pandemia de influenza A (H1N1) 2009 no Estado do CearÃ. O estudo sugere que a pandemia de influenza A (H1N1) 2009 nesta regiÃo do Brasil teve magnitude menor se comparado a outros estados de outras regiÃes do paÃs, com baixa incidÃncia, porÃm altas taxas de letalidade em pacientes internados em UTI. / NTRODUCTION - Influenza is an acute infectious disease of viral origin, universal distribution, which affects the respiratory tract. According to statistics from the World Health Organization (WHO), about 5-15% of the world population is infected with influenza virus annually. In March 2009, with change in the pattern of occurrence of influenza in Mexico, influenza virus A (H1N1), a quadruple recombinant never seen before, was identified by analyzing samples of nasopharyngeal secretions from symptomatic American children, confirming the epidemiological link with the cases in Mexico (CDC / Atlanta, 2009) and months, with sustained transmission from person to person and involvement of various countries and nations, was sparked a new pandemic. OBJECTIVES - The objectives of this study were to describe the temporal evolution, characterize the patterns of morbidity and mortality in different periods and to identify factors associated with the occurrence and severity of deaths in different phases of pandemic Influenza A (H1N1) 2009 in CearÃ. METHODS - This study is a descriptive, retrospective study of cases reported and confirmed pandemic influenza (H1N1) 2009 in the state of CearÃ, in the years 2009 and 2010. RESULTS AND DISCUSSION - The pandemic occurred in three small waves, one at retention phase, characterized by mild, with rapid resolution. The second two waves, the mitigation phase, with more severe cases, higher rates of hospitalization, all patients who required intensive care (ICU) and all patients who died. 615 cases were reported, 144 of these were confirmed. 55.5% were female, 30% were mixed race, 72.5% of the cases had some serious comorbidity and 40 patients required hospitalization. Hospital mortality was 20%, and mortality in the ICU was 66%. Were significant for evolution to cure or death issues related to the demand for medical care, delay in initiation of antiviral therapy, obesity, low education, use of mechanical ventilation and be hospitalized in hospitals with specialized care. CONCLUSION - The data analysis of this study allowed in-depth knowledge about the pattern of morbidity and mortality caused by pandemic influenza A (H1N1) 2009 in the state of CearÃ. The study suggests that pandemic influenza A (H1N1) 2009 in this region of Brazil was magnitude lower compared to other states in other regions of the country with low incidence but high mortality rates in ICU patients.