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1
Yassin, Khaled. "Unravelling the mystery of liver diseases in Egypt : the burden of disease /." Lage : Jacobs, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009222709&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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com, khalesi20022002@yahoo, and Bahman Khalesi. "Studies of beak and feather disease virus infection." Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071119.90905.
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The circovirus Beak and feather disease virus (BFDV) causes psittacine beak and feather disease (PBFD) that is characterised by a chronic disease process associated with feather abnormalities, beak deformities and eventual death in various species of birds in the order Psittaciformes. This disease is seen in captive and wild psittacine species in Australia and several other countries and is a significant threat to the survival of some endangered psittacine species.
This thesis reports on genetic studies that have furthered the understanding of the diversity of BFDV present within Australia. These studies have optimised methods of detecting BFDV. They have also resulted in the production of an immunogenic and antigenic recombinant BFDV Capsid protein that could lead to alternate methods of producing viral antigen for serological tests and the development of a BFDV vaccine.
To assess the optimal method of the detection of BFDV infection, feather and blood samples were submitted by referring veterinarians throughout Australia from psittacine birds tentatively diagnosed with PBFD or with a history of being in contact with PBFD-affected birds. These samples were examined by 3 procedures commonly used to detect BFDV infection: a polymerase chain reaction (PCR) assay and haemagglutination (HA) for the detection of virus, and haemagglutination inhibition (HI) tests for the detection of virus antibody in response to infection. Of the samples examined from 623 psittacine birds, the prevalence of BFDV DNA in feather samples detected by PCR was 18.85%. There was a strong correlation between PCR and HA testing of feather samples, although possible false-positive and false-negative PCR and HA results were obtained in some samples. Of the 143 birds that were PCR feather-positive only 2 had detectable HI antibody and these birds were also HA feather-negative, which suggests that they were developing immunity to recent infection. All birds with HI antibody were feather HA negative.
Despite the rare occurrence of PBFD in cockatiels (Nymphicus hollandicus), 2 of the 13 samples collected from this species were PCR and HA positive indicating that this species can be infected with BFDV.
Three studies were undertaken to further our understanding of the genetics of BFDV in Australian avifauna: sequence analysis of the BFDV detected in a grey cockatiel (Nymphicus hollandicus), a species normally considered resistant to infection with BFDV; analysis of the genome of BFDV present in lorikeets (Trichoglossus sp.) in Australia; and analysis of the genome of BFDV detected in endangered swift parrots (Lathamus discolor). Sequence analysis of the entire genome of the cockatiel BFDV isolate revealed that it clustered phylogenetically with 2 other viruses, one from a sulphur crested cockatoo (SCC1-AUS) and one from a Major Mitchell cockatoo (MMC-AUS), which suggests that this isolate from the grey cockatiel was not a cockatiel-specific biotype. Phylogenetic analysis of the ORF V1 of BFDV detected in 7 lorikeets demonstrated these 7 isolates clustered phylogenetically with other BFDV isolates obtained from Loriidae species elsewhere in the world and confirmed the presence of a loriid-specific genotype. Phylogenetic analysis of the sequence data generated from ORF V1 of virus detected in 2 endangered swift parrots provided evidence they were also infected with BFDV genotypes derived from other species of birds, one isolate clustering with viruses from a Loriidae genotype and the other with isolates derived from species of Cacatuidae and Psittacidae.
As part of this research, a baculovirus expression system was successfully developed for the production of recombinant BFDV Capsid protein. Inoculation of this protein into chickens resulted in the development of HI antibody, which demonstrated its immunogenicity. When used as an antigen in HI tests it detected antibody in virus-infected birds, which demonstrated its antigenicity. This protein offers potential application as an antigen for the development of serological tests and as an immunogen for incorporation into vaccines for control of PBFD.
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Nelson, M. R., A. Nadeem, W. Ahmed, and T. V. Orum. "Cotton Virus Diseases." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210398.
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Virus diseases of cotton have historically been of only sporadic importance to global cotton production. Recent devastating epidemics in Pakistan and other areas have brought new awareness to the potential for disaster of a pathogen once considered to be of a minor importance. Under changing conditions this pathogen (cotton leaf curl virus) has emerged as a serious problem in Pakistan and India. Cotton leaf curl virus does not occur in the United States or the rest of the western hemisphere but recent experience worldwide is a reminder that pathogens, such as this geminivirus, can be moved easily from one part of the world to another and therefor we need to be aware of the potential impact of such pathogens on local crops.
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Tsang, Chiu-shun Peter. "Oral biology of human immunodeficiency virus-infected individuals in Hong Kong /." [Hong Kong : Faculty of Dentistry, University of Hong Kong], 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19900661.
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Engel, Marie. "Eradication of Aujeszky's disease (pseudorabies) virus from pig herds : alternatives to depopulation /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5437-9.pdf.
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Zaid, Ali, and n/a. "IMMUNE EVASION AND DISEASE MECHANISMS IN ROSS RIVER VIRUS INFECTION." University of Canberra. Biomedical Sciences, 2008. http://erl.canberra.edu.au./public/adt-AUC20091216.122508.
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Ross River virus (RRV) is an Alphavirus distributed throughout Australia. It is transmitted by
mosquitoes and is known to cause moderate to severe disease symptoms in humans. Along with
other alphaviruses such as Sindbis virus and Chikungunya virus, RRV is known to cause arthritic
symptoms, characterised by muscle and joint inflammation. Several investigations have established
the role of macrophage cells and pro-inflammatory host factors in the development of RRV-induced
disease.
In this study, we attempted to determine differences between RRV passaged in mammalian and
mosquito cells. There is strong evidence that arthropod-borne viruses are able to display enhanced
infectivity when passaged into arthropod cell line. We showed that mosquito cell-derived RRV
(mos-RRV) was able to replicate to higher titres than mammalian cell-derived RRV. We also
showed that mos-RRV failed to induce Type I IFN-associated antiviral responses.
The second aim of this study was to investigate the role of TNF-ᬠa pro-inflammatory cytokine
implicated in arthritic diseases, in the development of RRV disease. We treated RRV-infected
C57BL/6J mice with a commercially available TNF-ᠩnhibitor drug and monitored disease signs.
We found that the TNF-ᠩnhibitor does not ameliorate RRV disease (RRVD) symptoms, and that it
does not prevent muscle and joint inflammation. We analysed histological sections of muscle and
joint tissue of Enbrel-treated and untreated, RRV-infected cells. We also determined and compared
host cytokine expression profiles.
Finally, we sought to determine the requirement for natural killer (NK) cells in RRV disease. NK
cells have been detected in the synovium of RRV-infected patients since early studies, but their role
in disease pathogenesis remains unclear. Using a NK-dysfunctional mouse (C57BL/6J-Lystbg), we
showed that mice lacking a functional NK system are more susceptible to RRV disease than wildtype,
C57BL/6J mice. We monitored disease symptoms following RRV infection and assessed
muscle and joint inflammation in Lystbg and C57BL/6J mice.
This thesis examines mechanisms of viral infection and immune evasion employed by RRV, as well
as into the role of host cells and cytokines in RRVD pathogenesis disease mechanisms. We showed
that a functional NK cell system is required for the regulation of RRV-induced muscle and joint
inflammation. Our characterisation of the use of a commercial TNF-ᠩnhibitor in RRV-induced
disease in mice may provide information on the role of TNF-ᠩn viral arthritis, and may help
towards developing safe and effective treatment.
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Schmidt, Madelyn R. "Virus-Lymphocyte Interactions: Virus Expression Is Differentially Modulated by B Cell Activation Signals: A Dissertation." eScholarship@UMMS, 1991. https://escholarship.umassmed.edu/gsbs_diss/51.
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It is shown here that the ability of B lymphocytes to act as supportive host cells for virus infections requires they be activated from the resting Gostage of the cell cycle. I have used a series of activation regimens, which allow B cells to progress to different stages in their activation/differentiation pathway toward antibody secretion, in order to evaluate the extent of activation required to support vesicular stomatitis or Newcastle disease virus infections.
At least three distinct phases during B cell activation which affected VSV infection were defined. Freshly isolated resting murine splenic B cells in the Go phase of the cell cycle do not support VSV, assessed by protein synthesis, infectious center formation, and PFU production. Small B cells cultured for 48 hours without stimulation still do not support VSV. B cells stimulated with the lymphokines found in Con A activated supernatants from splenic T cells or cloned T cell lines transited into the G1 phase of the cell cycle but remain refractory to VSV. These VSV non-supportive B cell populations do take up virus particles and transcribe viral mRNAs which can be translated in vitro, suggesting a translational block to VSV. B cells stimulated into the S phase of the cell cycle with anti-immunoglobulin synthesize VSV proteins and increased numbers of infectious centers, but only low level PFU synthesis (center) is observed. Co-stimulation with anti-Ig and lymphokines, which supports differentiation to antibody secretion, enhanced PFU synthesis without further increasing the number of infected B cells. LPS, which activates B cells directly to antibody secretion by a pathway different from anti-Ig, induced infectious centers, and PFUs at levels comparable to those seen when stably transformed permissive cell lines are infected. Co-stimulation of LPS activated B cells with the same lymphokine populations that enhance PFU production when anti-Ig is used as a stimulator suppresses PFU production completely, suggesting that anti-Ig and LPS activated B cells are differentially responsive to lymphokines.
NDV infection of murine B cells differed markedly from VSV infection, as all B cell populations examined gave a similar response pattern. NDV viral proteins were synthesized by B cells in each of the activation states previously described, even freshly isolated B cells. Infectious center formation increased up to 5-fold over the levels observed with unstimulated B cells after anti-Ig or LPS activation. However, PFU synthesis was low (center) for all B cell populations.
These results suggest that these two similar viruses may be dependent on different host cell factors and that these factors are induced for VSV but not NDV by the B cell activators employed here or that the process of infection of B cell by these two viruses induces different cellular responses.
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Choi, Wai-yee Junet. "Serum neopterin for early assessment of severity of severe acute respiratory syndrome and Dengue virus infection." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B32031579.
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Oladele, Oluwafemi. "Characterization of feline borna disease virus /." Uppsala : Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/10454915.pdf.
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Tsang, Chiu-shun Peter, and 曾昭舜. "Oral biology of human immunodeficiency virus-infected individuals in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1997. http://hub.hku.hk/bib/B31237770.
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Murray, Paul G. "Epstein-Barr virus gene expression in the pathogenesis of Hodgkin's disease and other EBV associated diseases." Thesis, University of Wolverhampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360511.
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Rudd, Matthew Francis, and mikewood@deakin edu au. "Virulence determinants of infectious bursal disease virus." Deakin University. School of Biological and Chemical Sciences, 2003. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050825.103742.
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The very virulent (vv) pathotype of infectious bursal disease virus (IBDV) has spread rapidly throughout Europe, Asia, and the Middle East. Although Australia is currently unaffected, there remains the potential for incursion of an exotic isolate. The aim of this study was to identify putative virulence determinants of IBDV to facilitate the development of improved diagnostic assays for detection and characterisation of vvIBDV isolates.
Sequencing of Indonesian vvIBDV Tasik94 revealed a unique substitution
[ A¨S222] in the hypervariable region (HVR) of viral protein (VP) VP2, which did not appear to impinge on virulence or antigenicity. Phylogenetic analyses indicated that Tasik94 was closely related to Asian and European vvIBDV strains. Extensive alignment of deduced protein sequences across the HVR of VP2 identified residuesI242 I256 and I294 as putative markers of the vv phcnotype.
Comparison of the pathology induced by mildly-virulent Australian IBDV 002/73 and Indonesian vvIBDV Tasik94, revealed that histological lesions in the spleen, thymus and bone marrow were restricted to Tasik94-infected birds, suggesting the enhanced pathogenicity of vvIBDV might be attributed to replication in non-bursal lymphoid organs.
The biological significance of the VP2 HVR in virulence was assessed using recombinant viruses generated by reverse genetics. Both genomic segments of Australian IBDV 002/73, and recombinant segment A constructs in which the HVR of 002/73 was replaced with the corresponding region of either tissue culture-adapted virus or vvIBDV (Tasik94), were cloned behind T7 RNA polymerase promoter sequences. In vitro transcription/translation of each construct resulted in expression of viral proteins. Co-transfection of synthetic RNA transcripts initiated replication of both tissue culture-adapted parental and recombinant viruses, however attempts to rescue non-adapted viruses in specific-pathogen-free (SPF) chickens were unsuccessful.
Nucleotide sequence variation in the HVR of VP2 was exploited for the development of a new diagnostic assay to rapidly detect exotic IBDV isolates, including vvIBDV, using reverse transcription polymerase chain reaction (RT-PCR) amplification and Bmrl restriction enzyme digestion. The assay was capable of differentiating between endemic and exotic IBDV in 96% of 105 isolates sequenced to date.
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Shaw, Lucas Ray. "A computational framework for modeling the spread of pathogens and generating effective containment strategies in weakly connected island models." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1404354811&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Hägglund, Sara. "Epidemiology, detection and prevention of respiratory virus infections in Swedish cattle : with special reference to bovine respiratory syncytial virus /." Uppsala : Dept. of Clinical Sciences, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005121.pdf.
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Jones, Curry, Chris Garner, and Amanda Stoltz. "Improving Knowledge of Hepatitis C Screening Guidelines Among a Population of Family Medicine Residents." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/183.
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Hepatitis C is the most common chronic bloodbourne infection in the United States, with an estimated prevalence of 2.7 million. The total cost of care for this patient population was estimated to be $6.5 billion in 2013. Since 1998, the Centers for Disease Control (CDC) have recommended hepatitis C screening for specific high risk populations, but until recently there was no recommendation for age-based screening. The recent advent of new, more efficacious therapies for hepatitis C have made early identification significantly more important. Consequently, the CDC updated its recommendations in 2012 based on recent evidence to include one-time screening for all individuals born between 1945 and 1965. In 2013, the US Preventive Services Task Force (USPSTF) also incorporated this recommendation into their hepatitis C screening guidelines. In spite of this, there is some debate in the medical community regarding cohort screening for hepatitis C, and some data indicates widespread misunderstanding of current screening recommendations among primary care providers. The purpose of this project was to evaluate current knowledge and understanding of hepatitis C screening guidelines among a group of family medicine residents at East Tennessee State University, and to improve their knowledge in order to promote more appropriate screening practices in their patient population. To accomplish this, 13 question surveys were administered to residents to assess their current knowledge. Following these surveys, residents attended an education session covering current recommendations from the CDC and USPSTF. The 13 question survey was administered again in the post-intervention period. A t-test revealed that post-intervention survey scores increased significantly on 8 out of 13 questions. The intervention was successful at improving knowledge of current hepatitis C screening recommendations in the target population. Future research should be directed at broadening the intervention to include a variety of other providers, and at assessing the impact on execution of screening in the patient population, particularly regarding application to people born in the specified birth cohort.
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Dungu-Kimbenga, B. "Study on the effects of a natural Maedi visna virus infection on sheep productivity." Diss., University of Pretoria, 2000. http://hdl.handle.net/2263/25380.
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A cohort study was conducted in order to measure the effect of the chronic indurative lymphocytic mastitis caused by the South African strain ofMaedi visna virus (SA-OMVV) on the pre-weaning growth of lambs born of naturally infected and uninfected ewes kept under similar conditions. 50 naturally infected ewes and 40 controls from an MVV-free source were purchased and kept separately. All ewes were of the same breed - the Dorper¬and 3 to 4 years old. From the adaptation period, through mating, pregnancy and lactation periods they were monitored for MVV antibodies and managed under similar conditions. The lambs were weighed at birth and thereafter every two weeks until the age of 90 days, when they were weaned. The ewes were slaughtered, their udders examined histologically and the lesions were assessed by counting typical lymphocytic follicles. Although the observed values indicated a correlation between the number of follicles in the udder and the reduction in the growth rate of the lambs, this was not statistically significant. Similarly, despite higher counts of lymphoid follicles in the udder of sero-positive ewes as compared to sero-negatives and the observed lower ewe productivity indexes (EPI) in infected ewes, no statistically significant differences were found in the EPI of ewes in different follicle categories. The present study was a first attempt to evaluate the effect of the SA-OMVV infection on sheep productivity in South Africa.Dissertation (MSc)--University of Pretoria, 2000.
Production Animal Studies
Unrestricted
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Cook, Scott C. "Human immunodeficiency virus : determining predictors of unsafe sexual behavior /." free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9962514.
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Hui, Kin-hi Raymond. "Molecular epidemiology of and vaccine development against foot-and-mouth disease virus in Hong Kong." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B31548544.
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Peacey, Matthew, and n/a. "Creation and investigation of a versatile Rabbit haemorrhagic disease virus-like particle vaccine." University of Otago. Department of Microbiology & Immunology, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080215.155033.
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There is a need to develop a range different VLP for use as nanoscale templates and vaccines. The aim of this research was to develop RHDV VLP as a versatile vaccine delivery system easily modified for use against a wide range of different diseases.
Production of Rabbit haemorrhagic disease virus (RHDV) capsid protein in a baculovirus system led to the self-assembly of Virus-like Particles (VLP) that could be purified to greater than 99% purity using simple methods. The capsid gene, vp60, can be manipulated genetically to incorporate immunogenic peptide sequences or a functional DNA-binding site. Fusion of these small epitopes to VP60 was well tolerated, forming VLP and greatly enhanced the presentation of peptide to, and activation of CD4+ T helper cell hybridoma. To avoid constraints imposed on chimeric VLP and dramatically increase the versatility of RHDV VLP, rapid conjugation of antigen was carried out, employing the hetero-bifunctional chemical linker, sulpho-SMCC. Incorporation of sulfhydral groups by design or treatment with SATA allowed for great versatility, in turn enabling many diverse peptides and proteins to be conjugated to VLP.
RHDV VLP and consequently the conjugated GFP antigen were efficiently taken up by DC with more than 85% of DC positive for GFP by flow cytometry. This was also visualised by confocal microscopy and electron microscopy of both gold- labelled VLP and conjugated antigen. RHDV VLP conjugate was shown to induce the significant up regulation of the activation markers CD40, CD80, CD86 and MHC class II on the surface of dendritic cells (DC). As well, DC pulsed with RHDV VLP/OVA effectively presented OVA to both CD4+ and CD8+ T cells transgenic for respective peptide-specific T cell receptors, eliciting a greater proliferative response in both T cell subsets than antigen delivered alone.
The surface accessibility of peptides on VLP was demonstrated, while administration of VLP/Ovalbumin (OVA) conjugate in mice was shown to evoke very high titre antibody responses specific for conjugated antigen. VLP/OVA conjugates were also shown to induce IFN-γ production and OVA-specific cytotoxic killing in vivo, of up to 80% of fluorescently labelled, adoptively transferred target cells. No distinguishable cytotoxicity was detected in unimmunised control mice. This assay was also used to demonstrate the necessity for antigen to be conjugated to VLP, as antigen mixed with VLP induced only sub-optimal killing.
To investigate the anti-tumour effects, mice vaccinated with VLP conjugated to OVA protein, CD4+ or CD8+ T cell OVA epitopes were inoculated with B16- OVA tumour cells and monitored for tumour growth. Untreated control mice had to be sacrificed by day 19, while mice immunised with either VLP/OVA or VLP conjugated with both CD4+ and CD8+ OVA epitopes, showed a significant delay in tumour growth (P = 0.0002), with one mouse remaining free of palpable tumour until day 92.
These results show that RHDV VLP can be easily produced and purified and demonstrate the versatility of this RHDV capsid. Rapid conjugation techniques allowed the modification of VLP with both peptide and protein rendered these antigens highly immunogenic, stimulating both humoral and cell-mediated immunity targeted against conjugated antigens of choice. The versatility and immune stimulating properties of RHDV VLP provides a molecular tool with almost limitless applications within the fields of nanotechnology and immunology.
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Freeborough, Michael-John 1971. "A pathogen-derived resistance strategy for the broad-spectrum control of grapevine leafroll-associated virus infection." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53285.
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Thesis (PhD)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: Grapevine leafroll-associated virus-3 is one of ten members of the C/osteroviridae that are known to infect grapevine. Nine of these viruses are associated with grapevine leafroll disease, of which GLRaV-1 and GLRaV-3 are the most important and widespread. Members of the C/osteroviridae are unique amongst the viruses, as it is the only known family whose members encode a heat shock protein 70 kOa homolog (Hsp70h). The Hsp70h is a movement protein (MP) that is required for the active translocation of the virion structure through the plasmodesmata into adjacent cells. Broad-spectrum resistance to unrelated viruses can be obtained by a pathogen-derived resistance (POR) strategy that is based on the expression of a dysfunctional MP in plants. The Hsp70h has two distinct domains. The N-terminal two thirds of the protein is an ATPase domain and shares high homology with the ATPase domains of all Hsp70h proteins from the C/osteroviridae and Hsp70 proteins from the prokaryote and eukaryote kingdoms. Conserved amino acids are found in the ATPase domain and are required for the positioning of the ATP at the catalytic site for ATP hydrolysis. The C-terminal domain is variable and the function of this domain in the Closteroviridae is not known. In prokaryote and eukaryote Hsp70 proteins, the C-terminal domain is required for protein-protein interactions. The American NY-1 isolate of GLRaV-3 has been sequenced and POR strategies have been attempted with the coat protein, divergent coat protein and replicase genes, but not with a dysfunctional form of the hsp70h gene. In this study, double-stranded RNA was isolated from a commercial vineyard with unknown virus status, but with distinct grapevine leafroll symptoms, and from two grapevine sources of known virus status, one with mild and one with severe symptoms. The GLRaV-3 hsp70h gene was amplified by RT-PCR from the dsRNA and the gene sequence was analysed. The hsp70h gene from the three virus sources contained more than 94% nucleotide sequence homology to the NY-1 isolate and the conserved amino acids required for ATPase activity were present. The hsp70h gene isolated from GLRaV-3 from a commercial Stellenbosch vineyard showing clear leafroll symptoms was selected for further work and was subjected to site-directed mutagenesis to engineer four point mutations in the gene. These four mutations resulted in the substitution of Asn for Asp", Gly for Thr1O, Lys for Glu 174 and Asn for Asp 197. The wild type (WT) and mutated (Mut) forms of the hsp 70h genes were cloned into a bacterial expression vector. Expression of both the WT- and Mut-Hsp proteins was achieved, and the protein was expressed in the insoluble inclusion bodies. All attempts to refold and isolate active proteins from the inclusion bodies were unsuccessful. Attempts to increase the concentration of soluble protein within the expressing bacteria were unsuccessful. Due to the lack of active protein, biochemical tests on the ATPase activity of the WT- and Mut-Hsp proteins could not be conducted. The wt- and mut-hsp genes were cloned into a plant expression vector for transformation into tobacco plants. These transformations were successful and gave rise to 22 Km' and 18 Km' plants from the WT- and Mut-Hsp constructs respectively. Two plant lines, M5 and M10, transformed with the mut-hsp transgene construct, appeared to have a high level of resistance to the challenging potato X potexvirus, whereas all the other tested plants were susceptible to the challenging virus. It was thus shown that a dysfunctional form of the GLRaV-3 Hsp70h could provide resistance to an unrelated virus in tobacco.
AFRIKAANSE OPSOMMING: Wingerdrolblaar-geassosieerde virus 3 (GLRaV-3) is een van 10 lede van die Closteroviridae wat wingerd kan infekteer. Nege van die virusse is met wingerdrolblaar geassosieer. Die GLRaV-1 en GLRaV-3 is die belangrikste en mees wyd verspreide lede van die rolblaar-geassosieerde Closteroviridae. Lede van die Closteroviridae is uniek in die opsig dat die virusse vir 'n 70 kDa-homoloë hitteresponsproteïen (Hsp70h) kodeer. Die Hsp70 is 'n bewegingsproteïen (MP) wat belangrik is vir die translokasie van die virus deur die plasmodesmata na die naasliggende sel. Breë-spektrum weerstand teen onverwante virusse kan behaal word deur 'n patogeen-afgeleide weerstandstrategie (POR), wat op die uitdrukking van 'n disfunksionele MP wat in plante uitgedruk word, gebaseer is. Die Hsp70hproteïen het twee gebiede. Die N-terminale gebied is In ATPase-gebied en toon hoë homologie met ander ATPase-gebiede van Hsp70h-proteïene van die Closteroviridae, asook die prokariotiese en eukariotiese koninkryke. Gekonserveerde aminosure wat belangrik is vir die posisionering van ATP in die katalitiese domein vir ATP-hidrolise is in die ATPase-gebied gevind. Die C-terminale gebied is variërend en die funksie van die gebied in die Closteroviridae is onbekend. In prokariotiese en eukariotiese Hsp70h-proteïene is die C-terminale gebied belangrik vir proteïenproteïen interaksies. Die nukleotiedvolgorde van die Amerikaanse NY-1-isolaat van GLRaV-3 is al bepaal en POR-strategieë is ook op die kapsiedproteïen, uiteenlopende kapsiedproteïen en die replikasie-proteïen uitgevoer, maar nog nie op 'n disfunksionele vorm van die Hsp70h-geen nie. In hierdie studie is dubbelstring-RNA (dsRNA) van 'n kommersiële wingerd met onbekende virusstatus wat rolblaarsimptome toon, geïsoleer, asook van twee wingerde met 'n bekende virusstatus, een met ligte en een met strawwe simptome. Die GLRaV-3 hsp70h-geen is met hulp van die polimerasekettingreaksie-metode (PKR) vanaf die dsRNA geamplifiseer en die geen se nukleotiedvolgorde is bepaal. Die hsp 70-gene van drie verskillende wingerde het meer as 94% homologie met die NY-1-isolaat getoon. Die gekonserveerde aminosure wat vir ATPase-aktiwiteit belangrik is, was teenwoordig. Die hsp70h-geen van GLRaV-3, wat uit 'n kommersiële wingerd met duidelike rolblaarsimptome in die Stellenbosch-gebied geïsoleer is, is vir verdere navorsing gekies en dit is aan setel-gerigte mutagenese blootgestelom vier mutasies van die geen te bewerkstellig. Die gevolg van hierdie vier mutasies was die verandering van Asn na Asp", Gly na Thr1o, Lys na Glu174 en Asn na Asp197. Die wilde (WT) en veranderde (Mut) vorms van die hsp-gene is in 'n bakteriese uitdrukkingsvektor gekloneer. Uitdrukking van beide die WT- en die Mut-Hspproteïene is behaal, maar die proteïene was in die onoplosbare fraksie geleë. Pogings om die onoplosbare proteïene te isoleer en in 'n aktiewe oplosbare vorm te verkry, was onsuksesvol. Verdere pogings om die proteïene in die oplosbare fraksie van die bakteriese ekspressiesisteem uit te druk, was ook onsuksesvol. As gevolg van die gebrek aan aktiewe proteïen kon biochemiese toetse nie op die ATPaseaktiwiteit van die WT- en Mut-Hsp proteïne gedoen word nie. Die wt- en mut-hsp-gene is ook in In plantekspressievektor gekloneer vir transformasie in tabakplante. Hierdie transformasies was suksesvol en het aanleiding gegee tot 22 kanamisienbestande (Km') en 18 Km' plante vanaf die WT- en Mut-Hspkonstrukte onderskeidelik. Twee plantlyne, M5 en M10, wat met die mut-hsptransgene getransformeer is, het 'n hoë vlak van weerstand teen die infekterende aartappelvirus X getoon in vergelyking met ander plante wat met die virus geïnfekteer is. Daar is dus bewys gelewer dat 'n disfunksionele vorm van die GLRaV-3 Hsp70h weerstand kan bied teen 'n onverwante virus in tabak.
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Sahle, Mesfin. "An epidemiological study on the genetic relationships of foot-and-mouth disease viruses in East Africa." Thesis, University of Pretoria, 2004. http://hdl.handle.net/2263/27222.
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Within East African countries many of the known infectious diseases of animals occur commonly and are poorly controlled. Foot-and-mouth disease (FMD) is one of the contagious viral diseases that has great impact on economic development both in terms of direct and indirect losses. The epidemiology of the disease is complex due to the presence of six of the seven serotypes and the presence of large numbers of both wild and domestic susceptible animals in the region. Decision-making to determine the importance of FMD control relative to the economic consequences and what FMD control strategies should be applied based on the epidemiological information is required. In this regard the first step is to investigate the genetic relationships/variability of East African isolates and their phylogeographic distribution. These can provide base-line information for designing control strategies by vaccination as well as the determination of the sources of infection. Sufficient genetic information on the FMO serotypes O, SAT-1 and SAT-2 are lacking and therefore the number of viral Iineages and genotypes or topotypes from East African countries could not be determined. Published studies on the relative occurrence and genotype distribution of FMO are largely confined to the southern and western part of the continent. In this study, the genetic profile of the 3 most prevalent serotypes (0, SAT-2 and SAT-1) recovered from outbreaks in East Africa between 1957 and 2003 was addressed. Phylogenetic analysis of partial and complete sequences of the 10 gene revealed the presence of distinct lineages and genotypes for East Africa as well as historical relationships of some of the genotypes with isolates from other regions. A great variation in the occurrence and distribution of these serotypes were found. All the African and the Middle East/South East Asian isolates of serotype O included in this study clustered into one lineage having 8 distinct topotypes. These results indicated that between countries as well as inter-regional (east and west Africa) spread of viruses occurred in the past. Inter-regional spread of the virus between eastern Africa and western Africa was also confirmed for SAT-1 viruses. The fact that phylogenetic links are found with both serotypes implies that the spread of viruses was possibly associated with unrestricted animal movement due to nomadic movement in Africa. The phylogenetic relationships of SAT-1 viruses are more diversified in Africa. Eight lineages and 11 genotypes were identified when the optimal nucleotide sequence differences of ≥ 23% for lineages and ≥ 6% for genotypes were used as a cut-off values. It was observed that viruses from Uganda are evolving independently from viruses elsewhere on the continent and clustered into 3 discrete lineages. In contrast, viruses from countries neighbouring Uganda, Kenya and Tanzania, clustered into one lineage. Uganda also harboured 3 topotypes of SAT-2 virus isolates, one is distinct for Uganda and the other are shared with Kenya and Zaire (DRC). This study highlighted distinct lineages found in Uganda and needs further investigation. Within SAT-2, 67 isolates from 22 African countries and Saudi Arabia clustered into 5 lineages which consisted of 15 genotypes. Clustering of viruses into distinct genotypes (topotypes) according to year of isolation and geographical origin was observed showing countries with common boundaries shared common epizootics in the past. These results also showed a link between eastern and southern African countries. Attempts were also made to investigate the incidence of FMD in Ethiopia using sera collected from cattle, small ruminants and wildlife. The results obtained from the liquid phase blocking ELISA and the 3ABC ELISA indicated the presence of SAT-1 and SAT-2 in buffalo populations in the southern part of Ethiopia while results from small ruminants and other wildlife were not indicative of any significant role in the epidemiology of FMD. Serological results also indicated that SAT-1 is present in cattle, although this serotype has not been previously identified. The cumulative molecular epidemiological results from this and previous studies indicated that genetic variability of FMD viruses can be independently maintained within country/countries or regions as well as inter-regions of Africa. The serological results from buffaloes in East Africa are also suggestive of a possible reservoir of the SAT types FMD in the region which has a great impact on the control of the disease. Furthermore, the numerous lineages and genotypes of FMD virus isolates in Africa having distinct or overlapping distributions as well as the genetic linkage between regions will complicate the epidemiology of the disease. Therefore, it is strategically important to consider a regional approach and the use of a vaccine which contains a cocktails of antigens of FMD virus strains.Thesis (PhD)--University of Pretoria, 2004.
Veterinary Tropical Diseases
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Lin, Shuhai. "Mass spectrometry-based metabolomics delineates biochemical changes in 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity, high-fructose diet effect, Alzheimer's disease and viral infection." HKBU Institutional Repository, 2011. http://repository.hkbu.edu.hk/etd_ra/1248.
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Dassanayake, E. M. "Studies on virus diseases of Passiflora." Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327860.
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Chen, Pengyin. "Genetics of reactions to soybean mosaic virus in soybean." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54781.
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The genetic interactions among 9 soybean [Glycine max (L.) Merr.] cultivars and 6 strains of soybean mosaic virus (SMV) were investigated. The objectives were to identify genes and/or alleles conditioning resistant and necrotic reactions to SMV and to determine the genetic relationships among resistance genes from cultivars exhibiting differential responses to the SMV strains.
Seven SMV-resistant (R) cultivars (‘PI 486355’, ‘Suweon 97’, ‘PI 96983’, ‘Ogden’, ‘York’, ‘Marshall’, and ‘Kwanggyo’) were crossed in all combinations among each other and with susceptible (S) cultivars ‘Essex’ and ‘Lee 68’. F₂ populations and F₂-derived F₃ lines were inoculated in field with the SMV type strain Gl and in the greenhouse with the virulent strains G4, G5, G6, G7, and G7A.
All F₂ populations from R x S and necrotic (N) x S crosses having PI 96983, Ogden, York, Marshall, and Kwanggyo as either resistant or necrotic parents segregated 3R:1S and 3N:1S, respectively. F₂-derived F₃ progenies from R x S crosses exhibited an F₂ genotypic ratio of 1 homogeneous R : 2 segregating (3R:1S) : l homogeneous S. The results indicate that each of these five resistant parents has a single, dominant or partially dominant gene conditioning the resistant and necrotic reactions to SMV. No segregation for SMV reaction was evident in F₂ and F₃ generations from R x R, N x N, and S x S crosses among the five differential cultivars, indicating that the resistance genes in the five cultivars are alleles at a common locus. The alleles in PI 96983 and Ogden were previously labeled Rsy and rsyt, respectively. Gene symbols, Rsyy, Rsym, and Rsyk are proposed for the resistance genes in York, Marshall, and Kwanggyo, respectively. It is also proposed that the gene symbol rsyt be changed to Rsyt to more accurately reflect its genetic relationship to the susceptible allele.
The R x S crosses with PI 486355 and Suweon 97 as resistant parents segregated 15R:1S in the F₂ and 7 (all R) : 4 (3R:1S) : 4 (15R:1S) : 1 (all S) in the F₃, indicating that each has two independent genes for resistance to SMV. The F₂ plants of PI 486355 x Suweon 97 showed no segregation for SMV reaction, suggesting that they have at least one gene in common. The crosses among all 7 resistant parents produced no susceptible segregates when inoculated with strain G1. It is concluded that the 7 resistant cultivars each have a gene or allele at the Rsy locus.
Data from the experiments furnished conclusive evidence that the necrotic reaction in segregating populations is highly associated with plants that are heterozygous for the resistance gene.Ph. D.
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Osuagwuh, Uchebuchi I. "Semen quality and the excretion of lumpy skin disease virus in semen following vaccination and experimental challenge of vaccinated bulls." Diss., University of Pretoria, 2006. http://hdl.handle.net/2263/23607.
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The aim of this study was to determine the efficacy of vaccination in preventing LSDV excretion in semen and negative effects on semen quality. Lumpy skin disease (LSD) is caused by a virus in the genus Capripoxvirus of the family Poxviridae. The virus has been reported to be excreted in the semen of experimental infected nonvaccinated bulls. Nevertheless, vaccination has been the most widely used method to reduce and prevent the spread of the disease. This work was done to determine the efficacy of lumpy skin disease vaccination in preventing the excretion of lumpy skin disease virus (LSDV) in semen of experimentally infected vaccinated bulls. It also determined further the effect of vaccination and experimental infection on semen quality. Six serologically negative bulls 11-16 months of age were vaccinated with an attenuated Neethling strain of LSD vaccine, and a repeated dose of vaccine was given twenty one days later. These bulls were then experimentally infected by intravenous injection with a virulent field strain of LSDV (V248/93). Six unvaccinated bulls were similarly infected to act as controls. All animals were observed for clinical signs, blood and semen was collected and evaluated twice a week until day 40 post vaccination and every two days until day 28 post-infection when the trial was terminated. Serology was done using the serum neutralization test and viraemia was determined by virus isolation. Semen was examined by polymerase chain reaction (PCR) for the presence of virus. Semen evaluation was done visually and microscopically. Two of the unvaccinated controls developed severe LSD, two showed mild symptoms and two were asymptomatic. No clinical abnormalities were detected following vaccination, and clinical signs were limited to mild lymph node enlargement in four bulls following challenge of the vaccinated bulls. There was a significant difference (P<0.05) in semen quality after experimental infection of the unvaccinated bulls. In the vaccinated bulls, semen quality showed no significant difference (P>0.05) following vaccination and challenge. Three of the vaccinated bulls were serologically positive at the time of experimental infection and four at the end of the trial. Five unvaccinated bulls were found to be viraemic during the course of the trial. No vaccinated bulls were found to be viraemic at any stage. Four unvaccinated bulls excreted the virus in their semen during the course of the trial. Viral nucleic acid was not detected in any semen samples following vaccination or challenge in vaccinated bulls. This study provides evidence that vaccination against LSD prevented the excretion of viral particles in semen. It also illustrated that LSD vaccination prevented any effect on semen quality after experimental infection with virulent virus.Dissertation (MSc (Production Animal Studies))--University of Pretoria, 2006.
Production Animal Studies
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Wilson, Christine, University of Western Sydney, of Arts Education and Social Sciences College, and School of Humanities. "Kuru in contexts." THESIS_CAESS_HUM_Wilson_C.xml, 2001. http://handle.uws.edu.au:8081/1959.7/269.
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It has been a widely accepted belief in scientific and public discourse at the end of the twentieth century that cannibalism was the principal means of transmission of the disease call 'Kuru'.The study argues that other explanations might have been excluded from consideration, in particular, iatrogenic transmission.Circumstantial evidence in support of this proposition is examined.The work begins with an examination of the relationship between a number of diseases including, X disease, poliomyelitis, louping ill, scrapie and kuru through the first half of the twentieth century. Major themes of the work revolve around the boundary between research on animal and human disease, the complexities of research in this area, and the different messages that exist simultaneously in three domains: scientific research and publications, government and institutional archives, and the public domain. The thesis argues that the circumstantial evidence presented needs to be considered seriously and that further research in the area is required before we can come to a reliable understanding of the factors involved in the transmission of kuruDoctor of Philosophy (PhD)
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Smailhodzic, Armin. "Adapting the Standard SIR Disease Model in Order to Track and Predict the Spreading of the EBOLA Virus Using Twitter Data." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1465.
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A method has been developed to track infectious diseases by using data mining of active Twitter accounts and its efficacy was demonstrated during the West African Ebola outbreak of 2014. Using a meme based n-gram semantic usage model to search the Twitter database for indications of illness, flight and death from the spread of Ebola in Africa, principally from Guinea, Sierra Leone and Liberia. Memes of interest relate disease to location and severity and are coupled to the density of Tweets and re-Tweets. The meme spreads through the community of social users in a fashion similar to nonlinear wave propagation- like a shock wave, visualized as a spike in Tweet activity. The spreading was modeled as a system isomorphic to a modified SIR (Susceptible, Infected, Removed disease model) system of three coupled nonlinear differential equations using Twitter variables. The nonlinear terms in this model lead to feedback mechanisms that result in unusual behavior that does not always reduce the spread of the disease. The resulting geographic Tweet densities are coupled to geographic maps of the region. These maps have specific threat levels that are ported to a mobile application (app) and can be used by travelers to assess the relative safety of the region they will be in.
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Choi, Wai-yee Junet, and 蔡偉儀. "Serum neopterin for early assessment of severity of severe acute respiratory syndrome and Dengue virus infection." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B32031579.
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Magalo, Simone Issaca. "Evaluation of immunity and protection induced in pullets by the V4 oral vaccine against a pneumotropic velogenic Newcastle disease virus (NDV) strain." Diss., University of Pretoria, 2002. http://upetd.up.ac.za/thesis/available/etd-11042005-140706/.
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Walsh, Helen Ann. "Rapid Detection of Grapevine Leafroll-associated virus Type 3 using the reverse transcription loop-mediated amplification method." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/41018.
Full textAbstract:
Grapevine Leafroll disease (GLD), one of the most destructive diseases of
grapevines, has been found in every country where grapevines are grown.
Grapevine Leafroll associated virus type 3 (GLRaV-3), one of several viruses
associated with GLD globally, is the most prevalent virus in South African grapevines
and therefore control of GLRaV-3 takes high priority in any strategy aimed at control
of GLD. GLD can be controlled through the use of an integrated strategy which
includes using certified plant material, controlling insect vectors through use of
systemic insecticides and the removal of infected vines by roguing. Infected
individuals are identified each autumn, using either symptom display (in red cultivars,
where infected individuals display interveinal reddening and downward rolling of
leaves) or ELISA (in symptomless white cultivars). ELISA is laborious, time
consuming and relatively insensitivity compared to molecular techniques and a
simpler, more rapid and more sensitive means of indentifying GLRaV-3 infected
vines is required.
A simple RNA extraction procedure combined with a single-tube reverse
transcriptase loop-mediated amplification (RT-LAMP) has been developed which
allows for the rapid, simple detection of GLRaV-3. Using RT-LAMP, a viral target can
be amplified in 2 hours under isothermal conditions. This GLRaV-3 specific RTLAMP
uses hydroxy napthol blue (HNB), a colourimetric indicator that changes from
violet to sky blue only where a positive RT-LAMP reaction has occurred, making
results quick and easy to interpret. The sensitivity of this technique was compared to
ELISA and nested PCR by pooling samples at varying ratios of healthy to infected
plants. Using nested PCR and RT-LAMP 1 infected sample could be detected
amongst 50 healthy individuals while ELISA could only detect 1 amongst 30 infected
making RT-LAMP more sensitive than ELISA. Further RT-LAMP could be performed
in 2 hours compared to nested PCR and ELISA’s 8 and 48 hours respectively. Based
on these results, RT-LAMP is viable alternative for ELISA for the detection of
GLRaV-3 in the field.
RT-LAMP was also tested for its ability to detect GLRaV-3 in grapevine rootstocks
where, due to low viral titres and erratic distribution, it is notoriously difficult to detect. The rootstocks which were used for testing of GLRaV-3 had been tested in a
previous study and it was found that only 28% of samples tested positive after 33
months (post inoculation). Using RT-LAMP, 78% of samples tested positive for
GLRaV-3. Although further testing must be done, RT-LAMP may also be a viable
alternative for testing grapevine rootstocks for GLRaV-3 infection.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Microbiology and Plant Pathology
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Ahmed, Elshafa Hassan. "Identifying Risk Profiles and Generating Protective Vaccine for Epstein-Barr Virus-Associated Lymphoproliferative Diseases." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534540468409883.
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Foster, Rosalinda Gram. "Virus-Host Interactions in the Development of Avian Leukosis Virus-Induced Osteopetrosis: a Dissertation." eScholarship@UMMS, 1993. https://escholarship.umassmed.edu/gsbs_diss/180.
Full textAbstract:
Avian leukosis virus (ALV)-induced osteopetrosis is a proliferative disorder of the bone affecting the growth and differentiation of osteoblasts. Osteopetrosis is a polyclonal disease in which cells of the bone contain, on average, multiple viral DNA copies. Osteopetrotic bone is also characterized by the accumulation of unintegrated viral DNA, suggesting an atypical life cycle of the virus in the infected osteoblasts. To better understand virus-host interactions in the induction of osteopetrosis by ALVs, infected chick osteoblast cultures and osteopetrotic bone were examined for aspects of the virus life cycle and effects of infection on osteoblast function.
Levels of infection and virus expression were compared in cultured osteoblasts and osteopetrotic bone. Osteopetrotic bone contained higher levels of viral DNA and correspondingly higher levels of viral proteins than infected osteoblast cultures, suggesting a higher viral load in the diseased bone. A significant level of mature Gag protein was present in the bone, suggesting the accumulation of mature virus particles in the diseased bone. It is possible that the accumulation of virus could facilitate the high levels of infection observed in the diseased bone.
The mechanism by which unintegrated viral DNA persisted in osteopetrotic bone was investigated by examining the susceptibility of infected osteoblasts to superinfection. The results indicated that, in culture, infected osteoblasts were able to establish interference to superinfection. This suggests that the persistence of unintegrated viral DNA in osteopetrotic bone may not result from the continuing infection of productively infected osteoblasts.
The effect of virus infection on osteoblast function was examined in the diseased bone and in osteoblast cultures. In infected chickens, osteoblast activity, as evidenced by the expression of osteoblast phenotypic markers, was increased only in chickens developing severe osteopetrosis. In culture, virus infection had no apparent effect on either the proliferation or differentiation of osteoblasts. This indicates that infection was itself not sufficient to perturb osteoblast function. Furthermore, it suggested that additional components of the bone may be required for ALV infection to induce the abnormal activity of osteoblasts observed in osteopetrosis.
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Akiew, E. B. "Potato diseases in South Australia : studies in leafroll, early blight and bacterial wilt /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09pha315.pdf.
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Heskett, Eric A. "Efficacy of a recombinant Herpes Virus of Turkeys vector vaccine, expressing genes to Newcastle disease virus and Marek's disease virus in chickens and turkeys, against exotic Newcastle disease virus challenge." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000700.
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羅文新 and Man-sun Law. "DNA vaccine against chicken infectious bursal disease virus." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31221221.
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Martin, Pierre. "Genetic studies on resistance to alfalfa mosaic virus (AMV) and tolerance to white clover mosaic virus (WCMV) in red clover (Trifolium pratense L.)." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61820.
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Nettleton, Peter Francis. "Studies on the relationship between bovine virus diarrhoea virus and border disease virus." Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/30569.
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Reitter, Julie N. "A Mutational Analysis of Structural Determinants Within the Newcastle Disease Virus Fusion Protein: a Dissertation." eScholarship@UMMS, 1994. https://escholarship.umassmed.edu/gsbs_diss/78.
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The fusion protein of the Newcastle Disease Virus (NDV) contains three hydrophobic domains. To explore the topogenic signals of these domains, mutants were constructed in which each of the hydrophobic domains was deleted. The membrane insertion and topology of these proteins was characterized in a wheat germ cell-free translation system supplemented with canine microsomal membranes. The results indicated that the first 13 amino acids of the fusion protein are necessary to confer translation inhibition by SRP. Translocation of the nascent chains containing all or part of the first hydrophobic sequence resulted in the appearance of a species of higher molecular weight consistent with glycosylation of at least four of the five potential N-linked glycosylation sites. When glycosylation was inhibited with a glycosylation competitor peptide, signal sequence cleavage was detected. Protease digestion of mutants missing the C-terminal hydrophobic domain indicated that the C-terminus has stop transfer activity. A comparison of membrane insertion of the wild-type fusion protein to that of a mutant missing the second hydrophobic domain, the fusion sequence, indicated that the fusion domain has stop-transfer activity when synthesized in vitro. Furthermore, the fusion domain shows little signal sequence activity when positioned near the amino terminus of the fusion protein.
The fusion protein has a highly conserved leucine zipper motif immediately upstream from the transmembrane domain of the F1 subunit. In order to determine the role that the conserved leucines have for the oligomeric structure and biological activity of the NDV fusion protein, the heptadic leucines at positions 481,488, and 495 were changed individually and in combination to an alanine residue. Whereas single amino acid changes had little effect on fusion, substitution of two or three leucine residues abolished the fusogenic activity of the protein although cell surface expression of the mutants and sedimentation in sucrose gradients was similar to that of the wild type. Furthermore, deletion of the C-terminal 91 amino acids, including the leucine zipper motif and transmembrane domain resulted in secretion of an oligomeric structure. These results indicate that the conserved leucines do not play a role in oligomer formation but are required for the fusogenic ability of the protein. When the polar face of the potential alpha helix was altered by nonconservative substitutions of a serine-to-alanine (position 473), glutamic acid-to-lysine (position 482) or an asparagine-to-lysine (position 485), the fusogenic ability of the protein was not significantly disrupted.
A phenylalanine residue is at the amino terminus of the F1 protein of all paramyxovirus fusion proteins with the exception of the avirulent strains which have a leucine residue in this position. To explore the role of this phenylalanine in the fusion activity of the protein, this residue was changed to leucine (F117L) or to glycine (F117G) by site-specific mutagenesis while maintaining the cleavage site sequence of virulent strains of NDV. Whereas both the wild-type and the F117G proteins were proteolytically cleaved and F1 was detected, the leucine subsitution abolished cleavage. When co-expressed with the HN protein, the fusion protein with either a phenylalanine and glycine residue at position 117, but not a leucine, was shown to stimulate membrane fusion. However, incubation in trypsin activated the fusion activity of the F117L protein. Thus the presence of a leucine at position 117 of the precursor sequence blocks cleavage, but not fusion acitivity, and indicated that the phenylalanine at the amino terminus of the F1 subunit is not conserved for the fusion activity of the protein.
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Ashraf, Shamaila. "Studies on infectious bursal disease virus." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124124381.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xvi, 216 p.; also includes graphics (some col.). Includes bibliographical references (p. 180-216). Available online via OhioLINK's ETD Center
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Nelson, Merritt, Larry J. Stowell, and Tom Orum. "Analyses of Virus Disease Management Programs." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/214494.
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Chimpolo, Maria M. "Borna disease virus: a UK perspective." Thesis, Northumbria University, 2006. http://nrl.northumbria.ac.uk/373/.
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Borna Disease Virus (BDV) is a single stranded, negative sense, RNA virus and the pathogenic agent of Borna Disease (BD). BD was first described as a disease of horses and sheep, however, it has now has been recognised to cause a persistent infection that leads to neurological and behavioural disturbances in a wide range of hosts, including humans. BDV has been reported in most countries, including most of central Europe, North America, East Africa, East Asia and Australia. However, reports of the incidence and prevalence in both animals and humans in the UK are limited.This study investigated the prevalence of BDV in both human and horse populations in the UK using a range of serological and molecular methods. 528 human samples (95 patients with mood disorders, 32 healthy individuals in close contact with psychiatric patients and 401 blood donors) and 274 horse samples were screened. The results show that BDV is present in both horses with a seroprevalence of 13 %. For humans in the UK a significantly higher proportion of mood disorder patients (29 %) and healthy individuals in close contact with psychiatric patients (28 %) were seropositive for BDV as compared to normal blood donors (17 %), x2 = 8.418 p= 0.015, in this study.From a public point of view, this data is important as it suggests that BDV may be transmitted from psychiatric patients to healthy individuals who are in close contact with them, although it must be stressed that this study only investigated a small number of individuals. Thus a detailed sero-epidemiological study of BDV prevalence in the UK is needed to determine the distribution of this important human virus.
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Bryden, Helen. "Host-virus interactions in Hodgkin's disease." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363166.
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Thevasagayam, Jayne Alison. "Epizootic haemorrhagic disease virus : improved diagnosis." Thesis, University of Hertfordshire, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245401.
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Carbone, Ilaria <1984>. "Human herpes virus and Alzheimer’s disease." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5255/.
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Alzheimer’s disease (AD) is a chronic and progressive neurodegenerative disorder and according to the WHO it is estimated that 36 millions of people worldwide currently suffer from AD. Genetic and environmental factors interact in a complex interplay that might affect pathogenic mechanisms leading to age-related neurodegeneration. The hypothesis is that the presence of allelic polymorphisms in selected genes affecting individual brain susceptibility to infection by the herpes virus family during aging, may contribute to neuronal loss, inflammation and amyloid deposition. Herpes virus family show features relevant to AD, since they infect a large proportion of human population, develop a latent form persisting for several years, are difficult to eliminate by immune responses especially when latency has been established and are able to infect neurons. The association between AD and herpes viruses infection has been investigated. In particular the investigation focused on CMV, EBV and HHV-6 in DNA samples from peripheral blood of a large cohort of patients with clinical diagnosis of AD and age matched CTR, from a longitudinal population study, and DNA samples from brain tissue of patients with neuropathological diagnosis of definitive AD. An association between the presence of EBV and HHV-6 DNA from PBL positivity with the cognitive deterioration and progression to AD has been focused. Moreover, IgG plasma levels in CTR and AD to these viruses were tested. CMV and EBV IgG plasma levels were higher in elderly subjects that developed clinical AD at the end of the five year follow up. Our findings support the notion that persistent cycles of latency and reactivation of herpes viruses may contribute to impair systemic immune response and induce altered inflammatory process that in turn affect cognitive decline during aging.
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Rector, Trent. "Genomic Organization of Infectious Salmon Anemia Virus." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/RectorT2001.pdf.
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Johnson, Raymond Camille Joseph. "Detection of nepoviruses by ELISA in tissue-cultured and field-grown grapevines." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27968.
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The detection by serology of nematode-transmitted polyhedral viruses (nepoviruses) in grapevines is often unreliable. Nepoviruses were detected by enzyme-linked immunosorbent assay (ELISA) in tissue-cultured and field-grown grapevines. Nepovirus detection in in vitro plants (plantlets) was affected by virus distribution and growth room temperature. The reliability of virus detection in field-grown grapevines was improved when modified grinding buffers were used.
Arabis mosaic virus (AMV) was detected by ELISA, for the first time, in in vitro grapevines initiated from field-and screenhouse-grown plants throughout the summer. The virus was not reliably and repeatedly detected in in vitro plantlets grown at 25°C.
AMV and grapevine fanleaf virus (GFLV) distribution was not uniform throughout the plantlets. This distribution was affected by the culture room temperature. The best plant parts to sample for virus detection came from the zones of rapidly proliferating shoots. The viruses were sometimes not detected in samples taken from other tissues.
Growth room temperature had an important effect on virus detection in plantlets. The highest virus titres were found in plants growing at 15°C. Temperature increases in 5°C steps to 30°C reduced virus titre. AMV became undetectable in nearly all plantlets growing at 30°C for as little as 30 days. Growth at 30°C reduced ELISA absorbance values by 76% after 8 days and after 21 days the values were at 4% of pre-treatment levels. The virus titre dropped below detectable levels in most plantlets. AMV could not be detected in plantlets or rooted explants after being placed in a 30°C treatment for 2 months.
Tomato ringspot virus was detected by ELISA, for the first time, in in vitro grapevine plants. The virus was repeatedly detected in in vitro plants growing at 20°C.
Under the typical summer conditions experienced at Sidney, B.C., modifying the standard ELISA grinding buffer (0.01 M phosphate buffered saline, pH 7.4, 0.05% Tween-20, 0.2% ovalbumin, 2% polyvinylpyrrolidone) was essential for reliable detection of AMV or GFLV. AMV was reliably detected by ELISA in foliar samples from field or screenhouse plants throughout the summer when the grinding buffer was modified by increasing the pH to at least 8.2 and adding 1% nicotine or 0.15 M phosphate buffered saline. The most reliable results with GFLV were obtained with the nicotine enhanced buffers.
In comparison, because of the increased workload associated with growing plants in vitro and the unreliable detection of viruses in these plants, it remained preferable to detect nepoviruses in field plants by ELISA.Land and Food Systems, Faculty of
Graduate
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Linher, Katja. "Association of markers in genes of the growth hormone axis with the viral load in lymphoid tissues of chickens infected with Marek's disease virus." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33420.
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Vaccination against Marek's disease (MD) is greatly enhanced by host genetic resistance. Genes of the growth hormone (GH) axis have been reported to affect the ontogeny and effector functions of cells of the immune system. Two strains of White Leghorn chickens bred for contrasting homozygous markers in the GH and GH receptor (GHR) genes were challenged with MDV. Contrasts for the significant interaction between marker genotype and tissue indicated that the GH/GHR marker genotype caused a shift in the distribution of the viral load in lymphoid tissues in the two strains. The analysis suggests that genetic variations in genes of the GH axis may differentially affect the host response to MDV replication in lymphoid tissues. Regarding the early time course of infection, at day 6 the viral load was highest in the thymus, while at day 10, it was highest in the spleen, indicating that the virus may have accumulated in the spleen or was continuing to replicate in this tissue. (Abstract shortened by UMI.)
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Suidgeest, Faira. "Evaluation of two pathogen-derived resistance strategies for Grapevine leafroll-associated virus 3." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96776.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Grapevine leafroll disease (GLD), caused by the members of the family Closteroviridae, is one of the most economic important viral diseases affecting grapevine. Grapevine leafroll associated virus 3 (GLRaV-3), of the genus Ampelovirus, is the most widespread member of the leafroll associated virus family. To prevent the spread of GLD, management strategies such as rogueing and insect vector control are required to limit crop losses. Alternative control strategies based on genetic modification of the grapevine genome, such as pathogen-derived resistance (PDR), is proven to be effective in conferring resistance to several viruses. Therefore, the focus of this study was to evaluate pathogen-derived resistance strategies for GLRaV-3 using the following two approaches; 1) evaluation of transgenic plants expressing a dysfunctional GLRaV-3 heat shock protein 70 homolog (HSP70h) in order to confer resistance against GLRaV-3, and 2) the construction of artificial microRNAs (amiRNAs) to use as a tool for silencing specific sequences of GLRaV-3 in the grapevine host and the development of an amiRNA-mediated silencing validation system. In the first part of this study, six transgenic plant lines (plant lines #1, #3, #9, #14, #15 and #17) as well as a non-modified plant line, were inoculated with GLRaV-3 by grafting buds of each onto GLRaV-3 infected plant material. After approximately five months, GLRaV-3 virus titres of all grafted plants were quantified relative to two reference genes using RT-qPCR. Results were evaluated by comparing the relative virus titre of each transgenic plant line to that of the non-modified control plant line. Results showed that resistance levels of plant line #3 was significantly enhanced (>99%) and remarkably, plant line #14, showed to be more susceptible to the virus. The second part of the study was the construction and validation of amiRNAs targeting GLRaV-3 sequences. Two 21 nt regions of GLRaV-3 were successfully incorporated into miRNA backbone vvi167b of grapevine. Moreover, target constructs were developed by incorporating corresponding GLRaV-3 target sequences into the 3’ UTR of a green fluorescence protein (GFP) gene. Subsequently, the target constructs were co-infiltrated with the constructed amiRNA in Nicotiana benthamiana and GFP expression levels were quantified to determine the silencing efficiency of the amiRNAs. Results showed that the amiRNAs were successful in silencing the GFP target construct, however, they were not specific in silencing exclusively their corresponding target. These amiRNA constructs are ideal for further viral studies to determine the efficiency of silencing GLRaV-3 in GLD infected grapevines.
AFRIKAANSE OPSOMMING: Wingerd rolblaar siekte (GLD), wat veroorsaak word deur die lede van die familie Closteroviridae, is een van die ekonomies mees belangrike virus siektes van wingerd. Grapevine leafroll-associated virus 3 (GLRaV-3), van die genus Ampelovirus, is die mees wydverspreide lid van die rolblaar geassosieerde virus familie. Om die verspreiding van GLD te voorkom, is bestuur strategieë, soos die verwydering van geïnfekteerde plante en insekvektor beheer, ’n vereiste om oes verliese te beperk. Alternatiewe beheer strategieë gebaseer op genetiese modifikasie van die wingerdgenoom, soos patogeen-afgeleide weerstand (PDR), is bewys om effektief te wees in die verlening van weerstand teen verskeie virusse. Daarom was die fokus van hierdie studie om patogeen-afgeleide weerstand strategieë vir GLRaV-3 te evalueer met behulp van die volgende twee benaderings; 1) die evaluering van transgeniese plante wat 'n disfunksionele GLRaV-3 hitte-skok proteïen 70 homoloog (HSP70h) uitdruk, ten einde weerstand te verleen teen GLRaV-3, en 2) die konstruksie van kunsmatige mikroRNAs (amiRNAs) om te gebruik as 'n instrument vir die ondrukking van spesifieke genoomvolgordes van GLRaV-3 in die wingerd gasheer en die ontwikkeling van ’n stelsel om amiRNA-bemiddelde onderdrukking te bevestig. In die eerste deel van hierdie studie, is ses transgeniese plant lyne (plant lyne # 1, # 3, # 9, # 14, # 15 en # 17) sowel as 'n nie-gemodifiseerde gesonde plant lyn, geïnokuleer met GLRaV- 3 deur enting van ogies van elk op GLRaV-3 besmette plantmateriaal. Na ongeveer vyf maande, is GLRaV-3 virus konsentrasies van alle ingeënte plante gekwantifiseer relatief tot twee verwysing gene deur gebruik te maak van tru-transkripsie kwantitatiewe PCR (RTqPCR). Resultate is geëvalueer deur die relatiewe virus konsentrasie van elke transgeniese plant lyn te vergelyk met dié van die nie-gemodifiseerde kontrole lyn. Resultate het getoon dat weerstand vlakke van plant lyn # 3 beduidend verbeter is (> 99%) en merkwaardig is plant lyn # 14 bewys om meer vatbaar vir die virus te wees. Die tweede deel van die studie was die konstruksie en bevestiging van kunsmatige mikroRNAs (amiRNAs) wat GLRaV-3 genoomvolgordes teiken. Twee 21 nt streke van GLRaV-3 is suksesvol geïnkorporeer in die ruggraat van wingerd mikroRNA vvi167b. Verder is teiken konstrukte ontwikkel deur die inkorporering van ooreenstemmende GLRaV-3 teiken genoomvolgordes in die 3'UTR (3’ ongetransleerde area) van 'n groen fluoressensie proteïen (GFP) geen. Daarna is die teiken konstrukte gesamentlik geïnfiltreer met die gekonstrueerde amiRNA in Nicotiana benthamiana en GFP uitdrukkingsvlakke is gekwantifiseer deur die onderdrukkingsdoeltreffendheid van die amiRNAs te bepaal. Resultate het getoon dat die amiRNAs suksesvol was in die onderdrukking van die GFP teiken konstruk, maar hulle was egter nie-spesifiek in die eksklusiewe onderdrukking van die ooreenstemmende teiken. Hierdie amiRNA konstrukte is ideaal vir verdere virus studies om die doeltreffendheid van GLRaV-3 onderdrukking in GLD besmette wingerdstokke te bepaal.
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Pejavar, Sunanda. "Prevalence and Predictors of Chronic Liver Disease in an Urban HIV Population." Yale University, 2006. http://ymtdl.med.yale.edu/theses/available/etd-06282006-135229/.
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Chronic liver disease (CLD) is a leading cause of morbidity and mortality in HIV-infected individuals. The purposes of this study were to determine the prevalence and etiologies of CLD in an urban HIV-infected population and to identify CLD risk factors. We conducted a retrospective chart review of 799 HIV-infected patients seen at four New Haven health centers from 2002 to 2003. We applied the New Haven County Liver Study definition to identify patients with CLD. 65% were male, 44% were African American, and 23% were of Hispanic ethnicity. The mean age was 45 years. 30% had a history of alcohol abuse. 35% reported injection drug use as their HIV risk factor. Heterosexual contact and men having sex with men (MSM) were reported in 31% and 16% of cases. 50% of patients had a diagnosis of AIDS. 60% percent of patients had CLD. Over 50% of cases of CLD were attributed to chronic hepatitis C (HCV), either alone or with coexisting alcoholic liver disease. Alcoholic liver disease alone, hepatitis B virus (HBV), HAART-induced liver disease, and non-alcoholic liver disease (NAFLD) accounted for smaller percentages. 84% of patients were on HAART, but only 3.6% of patients with positive HCV or HBV serologies were on treatment for CLD. 75% of patients received pneumococcal and influenza vaccines, but only half of eligible patients received hepatitis A and B vaccines. In multivariate analysis, alcohol abuse and positive HCV status were associated with CLD. CLD is prevalent in our population. Preventive care and treatment for CLD are being overlooked in many. Vaccines, treatment for viral hepatitis, and strategies for reducing drug and alcohol abuse are priorities.
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Zaver, Himesh, Momani Laith Al, Kalpit Devani, and Chakradhar M. Reddy. "Ledipasvir/sofosbuvir induced nephrotic syndrome: A challenging case of Hepatitis C management." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/80.
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ABSTRACT:
Hepatitis C virus (HCV) is associated with various glomerulopathies and nephrotic syndrome. However nephrotic syndrome following treatment is rare. Ledipasvir/sofosbuvir (L/S) has recently come into favor in treating HCV due to its relatively mild side effects compared to the more traditional interferon therapy. To the best of our knowledge, there are no reported cases of nephrotic syndrome following treatment with L/S. We present a case of nephrotic syndrome suspected secondary to L/S in a patient with chronic kidney disease. Increased vigilance when assessing therapeutic options in HCV patients with renal comorbidities can improve patient outcomes. A 63 year-old male patient presented to the hospital with shortness of breath, and a two-week history of bilateral lower extremity edema. Past medical history was significant for liver cirrhosis secondary to Hepatitis C genotype Ia, hepatocellular carcinoma status post liver transplantation 6 months prior to admission and Stage 3b chronic kidney disease with baseline creatinine (Cr) approximately 1.5 mg/dl. Medications included L/S for HCV and tacrolimus and prednisone for post-transplant treatment. Patient’s vitals were stable and physical exam was remarkable for facial swelling, mainly on the eyelids, decreased breath sounds bilaterally, distended abdomen with a fluid wave, and 2-3+ pitting edema up to the knees on lower extremities bilaterally. Laboratory work-up was remarkable for low albumin of 3.0 g/dl, and total protein of 5.6 g/ dl. Creatinine of 1.8 mg/dl was elevated from patient’s baseline. HCV viral load was undetectable and electrolytes, transaminases and the complete blood count were within normal limits. Subsequently, urine protein to creatinine ratio was measured because of generalized swelling and hypoproteinemia, which was found to be significantly high at 8.80, compared to 0.04 one year prior. 24-hour total urine protein was found to be 2065 mg/day. Renal ultrasonography showed no hydronephrosis and was otherwise unremarkable. Renal biopsy however, revealed changes suggestive of membranoproliferative glomerulonephritis (MPGN] most likely secondary to HCV. No immune complexes, lambda/kappa light chains, or cryogloblin were appreciated. Nephrotoxic agents such as diuretics and corticosteroids were held. Tacrolimus trough was appropriate to dose level and was continued along with L/S. As admission progressed the patient’s creatinine continued to get worse and rose up to 4.3 mg/dl with persistent proteinuria. With tacrolimus trough levels within normal limits and given L/S was the most recently initiated drug, L/S was thought to be the culprit and was thus held. The renal function began to improve gradually, and the patient was discharged in stable condition with close follow up. Follow up one month later found creatinine and renal function return to baseline and proteinuria resolved. Our case shows that Ledipasvir/sofosbuvir may possibly be related to nephrotic syndrome in HCV patients. Although further studies are needed to prove the causality our case seeks to raise clinical suspicion and increase vigilance when assessing therapeutic options in HCV patients with renal comorbidities such as chronic kidney disease.