Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 217-228).

The purpose of this investigation was to study the biophysical and biochemical properties of some of the enteroviruses. Previous work in this laboratory on several members o.f this large sub-group of the Picornaviruses had emphasised the importance of a more detailed examination of some of the surface properties of representative strains of enteroviruses, by currently available techniques.

No description available.

Thesis (M.S.P.H.)--University of South Florida, 2003. / Title from PDF of title page. Document formatted into pages; contains 57 pages. Includes bibliographical references.

Enterovirus 71 (EV71) belongs to the Enterovirus genus of the family Picornaviridae and is the major causative agent of hand, foot and mouth disease (HFMD). Although clinical manifestations of HFMD are usually mild and self-limiting, severe HFMD patients suffer from a diverse array of neurological diseases and sometimes these diseases are fatal. HFMD usually occurs in young children and gradually becomes a new threaten in Asia. Unfortunately, effective EV71 vaccine is not available to date and alternative treatments are still in debate. This is partially due to the lack of understanding of EV71 pathogenesis and host immune responses against EV71. Natural killer (NK) cells are key effector cells in host antiviral activities by directly killing viral-infected cells and producing cytokines and chemokines, especially in early phase of viral infection. After enteroviruses infection, NK cells were one of the most abundant cell types in the inflammatory infiltrate, and appeared to limit both enteroviruses replication and virus-induced disease in experimental mice model. However, role of human NK cells during EV71 infection, especially the direct interaction between EV71 and human NK cells, was not studied extensively. Clinical observation manifested that patients with severe EV71 infection have marked diminished NK cells in peripheral blood. Therefore we hypothesized that EV71 might directly target human NK cells as one of its immunoevasion strategies. Here, we demonstrated for the first time that fresh primary human NK cells were susceptible to EV71 infection. By flow cytometry and florescence microscope, EV71 capsid protein VP1 was able to be detected in viral-infected NK cells as soon as 6 hours after infection and peaked at 24 hour after infection. In the same time, EV71 viral RNA was detected by quantitative RT-PCR and the viral copies increased from 6 hour onwards to peak at 12 hours after infection. We further demonstrated the infectious entry of EV71 in human NK cells was depended on clathrin-mediated endocytosis. Next, we illustrated that EV71 infection could trigger NK cells apoptosis as evidenced by increased Annexin V+, PI+, and activated caspase 3+ cells in EV71-treated NK cells. We further proved that the cytotoxicity of NK cells was inhibited by EV71 infection and this inhibition might not be related with down-regulation of NKp46, but may be related to the increased apoptosis. In conclusion, our data suggested that EV71 might directly target and kill NK cells as a strategy to evade human innate immunity, which might facilitate virus replication, transmission and then contribute to viral-related pathogenesis. / published_or_final_version / Paediatrics and Adolescent Medicine / Master / Master of Philosophy

The use of the neutralisation assay in the serotyping of unknown enterovirus isolates has been successfully applied for years since its description by Lim and Benyesh-Melnick1. However, the procedure is labour-intensive and time consuming. In addition, the continuous depletion of the Benyesh-Melnick sera makes it prohibitive for most diagnostic laboratories to continue using the assay. Owing to these factors, a majority of laboratories only type for the polioviruses and report any other enterovirus isolate as “a nonpolio enterovirus”. With this approach, however, important findings such as the isolation of a new enterovirus or association of a known enterovirus with a new clinical syndrome will remain unidentified. In this study, a multiple-serum-pools approach similar to that described by Lim and Benyesh-Melnick1 (LBM) for the neutralisation test, was applied in an immunofluorescence (IMF) test for the rapid serotyping of enteroviruses. This test was able to type any unknown enterovirus isolate belonging to the different enterovirus serotypes tested in this study, in about three hours as compared to the eight days currently taken by the LBM neutralisation test1.

No description available.

No description available.

Thesis (M.S.- Microbiology and Medical Technology)--University of Arizona, 1968. / Includes bibliographical references (leaves 60-64).

Thesis (M.Sc.)--University of Adelaide, Dept. of Microbiology, 1974.