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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Immune modulation in pigs through editing of the RELA locus

Ballantyne, Maeve Kellett January 2017 (has links)
Livestock animals are an ancient, vital renewable natural resource. Many livestock species have the ability to convert inedible crops and waste food into food fit for human consumption, in the form of meat, eggs and dairy products. As the global demand for high value animal protein is ever increasing, the livestock market continues to play a major role in worldwide economics. Animal disease has the potential to be a huge burden on the livestock industry, impacting both welfare and production. Major outbreaks of transboundary diseases, such as foot and mouth disease, rinderpest and classical swine disease, have resulted in devastating global economic losses. As a result, scientific research is engaged in lowering this impact by generating effective preventative measures and treatments. One way to reduce livestock disease is to select animals that are genetically resistant, traditionally carried out through selective animal breeding programs; however, this is a time-consuming process and requires that appropriate genetic variation exists within the population. Advances in genome engineering technologies offer us an alternative approach, with the capability to make genetic improvements in livestock within a single generation. It is hypothesised that resilience to a disease, known as African swine fever (ASF), could be genetically engineered into the domestic pig. ASF is a highly contagious disease of domestic pigs and is a re-emerging global threat to the swine industry. It is a lethal haemorrhagic disease caused by a virus, known as the African swine fever virus (ASFV). At present, there is no vaccine or treatment for ASF, and disease control relies on rapid diagnosis, quarantine and the mass slaughter of animals. Unlike the domestic pig, swine indigenous to Sub-Saharan Africa, such as the warthog, show no clinical signs of disease following infection with ASFV. A comparative study was carried out to identify host genetic variation that could underlie the difference in response to ASFV, with candidate genes selected based on their potential involvement with the viral protein A238L, involved in immune evasion. Functional polymorphisms where identified in the porcine RELA gene, encoding RelA, a subunit of the NF-κB transcription factor family. This evolutionary conserved protein family plays a vital role in mediating inflammatory and immune responses. The specific RELA polymorphisms identified alter potential phosphorylation sites within the C-terminal transactivation domain of RelA which have been found to modulate NF-κB transcriptional activity in vitro. We set out to investigate whether genome editing tools could be employed to engineer the RELA sequence of domestic pigs. Initial attempts targeted the final exon of RELA, producing animals with a truncated RelA protein; modified animals lack the final 60 amino acids of the C-terminal transactivation domain. The aim of this thesis was to genotype and characterise the effects of this RELA modification at a molecular, cellular, morphological and whole organism level. The ultimate goal of this project was to investigate whether this RELA modification altered the domestic pig’s response to ASFV in vitro and in vivo. Unlike rela-/- mice which have an embryonic lethal phenotype, these RELA-edited pigs were born healthy and were fully viable when housed in a typical farm environment. Phenotypic analysis of lymphoid tissues from the RELA-edited pigs demonstrated no significant anatomical or histological changes compared to unmodified counterparts. Pigs homozygous for the RELA mutation had a significantly lower body weight compared to wild-type pigs. Molecular studies of samples from these pigs have shown that the modified RelA has an altered activity; however, the RELA modified pigs do develop the characteristic disease phenotype when challenged with ASFV. Finally, genome editors have been developed to introduce a specific warthog allele into the domestic pig RELA locus, these editors are currently being taken forward to produce a novel pig line.
12

Epitope mapping of African swine fever virus p72 capsid protein using polyclonal swine sera and monoclonal antibodies

Phillips, Mallory Elizabeth January 1900 (has links)
Master of Science / Department of Diagnostic Medicine/Pathobiology / Raymond R. R. Rowland / African swine fever is a hemorrhagic disease of domestic pigs caused by African swine fever virus (ASFV), a double-stranded DNA virus and the only member of the family Asfarviridae. The structure of this multilayer virion contains more than 34 proteins including the protein p72 which is the major capsid protein. A single conformational neutralizing epitope has been identified on p72, but information on the other antigenic regions (epitopes) is lacking. The objective of this study was to identify p72 epitopes using polyclonal swine sera and a panel of monoclonal antibodies with the ultimate goal being the development of a blocking ELISA assay for the detection of anti-ASFV antibodies. The segment of the p72 protein from amino acids 1 to 345 was divided into five overlapping fragments which were then commercially synthesized. These fragments were cloned into the pHUE expression vector and transformed into Escherichia coli competent cells. The recombinant proteins were expressed in vitro, purified, and used as antigens in indirect ELISAs and western blots to test monoclonal antibodies and polyclonal swine sera. The monoclonal antibodies were produced against the p72 protein based on the ASFV Georgia/07 strain. The polyclonal sera were obtained from pigs immunized with a defective alphavirus replicon particle, RP-sHA-p72, expressing a recombinant protein composed of the extracellular domain of the ASFV HA protein together with the whole p72 protein. The polyclonal sera reacted to p72 in two distinct regions: between amino acids 1 and 83 and between amino acids 250 and 280. The anti-p72 reactive monoclonal antibodies reacted with p72 in three regions: between amino acids 100 and 171, amino acids 180 and 250, and amino acids 280 and 345. Fine mapping with oligopeptides allowed for the identification of six different linear epitopes. Among the monoclonal antibodies selected for blocking assay development, two have been shown to be promising candidates for further evaluation using sera from ASFV-infected pigs.
13

Dynamics of protection against virulent challenge in swine vaccinated with attenuated African swine fever viruses

Carlson, Jolene Christine January 1900 (has links)
Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Manuel Borca / Stephen Higgs / African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus. ASFV is endemic in Sardinia and Saharan Africa and has been recently expanded from the Caucasus to Eastern Europe. There is no vaccine to prevent the disease and current control measures are limited to culling and restricted animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pret4 virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4 Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 dpi showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response and protection against the challenge. Anti-ASFV antibodies and cytokines in serum, as well as ASFV-specific IFN-γ production in PBMCs, were assessed in each group. Interestingly, with the exception of ASFV-specific antibodies in the surviving swine challenged at 21 and 28 dpi, no solid association between any of the parameters assessed and the extent of protection could be established. These results were corroborated using a similar model based on the use of a rationally attenuated derivative of the highly virulent strain Georgia 2007. These results, encompassing data from 114 immunized swine, underscore the complexity of the system under study where it is very plausible that protection against disease or infection relies heavily on the concurrence and or interaction of different host immune mechanisms.
14

Právní úprava veterinární péče / Legislation of Veterinary Care

Chaloupecká, Denisa January 2020 (has links)
My diploma thesis deals with the legislation of veterinary care. In doing so, I tried to provide a clear and comprehensive overview of all the institutes and essentials that relate to it. Many uninformed people could mistakenly assume that this topic covers solely animal healthcare. Although it is also an integral part of the topic we do not find so much material here; the concept of veterinary work goes beyond that. Within 5 chapters we will learn not only historical contexts of development, but also international conventions or organizations. We will compare the Czech Leagl norms against the Slovak ones. An integral part of the thesis is a brief overview of sources of EU law, both primary and secondary, as well as their historical development. "Welfare", or ensuring animal welfare, is a rather new concept, but a highly important one. Thanks to animal welfare, we have begun to pay attention to animal health both physically and mentally. It was therefore obvious that this topic was briefly addressed, especially its development and implementation. The concept of "an animal" related to this topic has not been not neglected, especially in how the view of the animal has changed in recent years by amending the Civil Code. Since the topic of the diploma thesis is to concern mainly legal regulations, I...
15

Error-prone DNA repair in the African swine fever virus: characterization of six abasic site processing activities and evidence for a mutagenic function

Lamarche, Brandon James 04 August 2005 (has links)
No description available.
16

Détection et caractérisation moléculaires rapides du virus de la peste porcine africaine (ADNdb) et utilisation des reconstructions phylogénétiques pour reconstituer son histoire évolutive / Rapid molecular detection and characterization of African swine fever virus (dsDNA) and use of phylogenetic reconstructions for evolutionary history inference

Michaud, Vincent 29 November 2012 (has links)
La Peste porcine africaine (PPA) est une maladie contagieuse spécifique du porc domestique due au seul arbovirus à ADN identifié à ce jour. Décrite pour la première fois en 1921 au Kenya, la maladie a ensuite diffusé dans de nombreuses régions du monde. Malgré l'isolement de nombreuses souches virales au cours du temps, peu d'études phylogénétiques ont été menées jusqu'ici pour comprendre les relations unissant ces isolats entre eux. Or, la caractérisation est essentielle à la traçabilité des souches et donc à la compréhension de l'épidémiologie de la maladie. De plus, les conditions climatiques et environnementales des principaux pays atteints rendent difficile l'accès, le transport et la conservation de nouvelles souches. Dans cette thèse, un protocole de prélèvement et de conservation du sang a été développé, pour la détection et la caractérisation rapides des souches. Une étude phylogénétique approfondie a été réalisée en utilisant des données de séquences publiques et inédites de virus isolés depuis 1950. Les analyses ont porté sur les gènes B646L, CP204L et E183L. Les analyses phylogénétiques ont utilisé les méthodes de maximum de vraisemblance et d'inférence bayésienne, qui ont permis de proposer une nouvelle nomenclature virale en 35 clusters différents. De plus, une datation des origines du virus a été menée, après avoir éliminé les biais d'analyse dus à une pression de sélection positive et/ou aux recombinaisons. L'horloge moléculaire a permis de déterminer que l'ancêtre commun le plus proche des souches contemporaines (TMRCA) se situait au début du 18ème siècle. / African swine fever (ASF) is a highly lethal disease of domestic pigs caused by the only known DNA arbovirus. It was first described in Kenya in 1921 and since then a substantial number of isolates have been collected worldwide. However, only few phylogenetic studies have been carried out to better understand the relationships between isolates, which is essential for virus traceability and epidemiological understanding of the disease. Access, transport and virus conservation are also complicated by climatic and environmental conditions in affected developing countries. In this thesis, a simple method of blood sampling was developed allowing rapid virus detection and characterization. Comprehensive phylogenetic reconstructions were made using publicly and newly generated sequences of hundreds ASFV isolates of the last 60 years. Analyses focused on B646L, CP204L and E183L genes. Phylogenetic analyses were achieved using maximum likelihood and Bayesian coalescence methods and a new lineage based nomenclature is proposed to designate 35 different clusters. In addition, dating of ASFV origin was carried out from the molecular data sets. To avoid biased diversity, positive selection or recombination events were neutralized. The molecular clock analyses revealed that ASFV strains currently circulating have evolved over 300 years, with a time to the most recent common ancestor (TMRCA) going back to the early 18th century.
17

Evaluation of cross protection by an attenuated African swine fever virus isolate against heterologous challenge

Souto, Ricardo Gomes January 2012 (has links)
African Swine Fever Virus (ASFV) is an Asfivirus and is the only member of the family Asfarviridae. It manifests as a disease that varies from acute to sub-acute or chronic forms. A true carrier state in domestic pigs is unknown but chronically affected individuals may carry and spread the virus for extended periods. African Swine Fever (ASF) is a socio-economically important disease characterized by high morbidity and mortality affecting the livelihood of many small to big scale farmers and seriously compromising international trade. Strategic measures to control this disease are by physical containment and culling in outbreak situations. There is no vaccine available. Nevertheless, every pork producer should ideally be actively involved in having biosecurity measures in place to avoid contamination and contacting their veterinary services in case of suspicion of ASF to have appropriate samples analysed. Official veterinary services must be equipped with proper diagnostic tools in order to provide a quick response. The sensitivity of currently available diagnostic tests at the Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute was analysed in order to report the best technique available. Sensitivity to ASF virus infection and therefore diagnostic potential of cell primary cultures as bone marrow macrophages, blood macrophages and alveolar macrophages was done via comparison of titre results from inoculations of ASFV SPEC 257 as control, and ASFV MOZ 1/98. In addition, molecular detection of specific DNA fragments within the viral genome were compared using five different PCRs. Bone marrow macrophage cultures and blood macrophage cultures were the most reliable cells whereas alveolar macrophages more often showed contamination. Results show that PPA PCR and real time PCR detected the highest diluted samples, thus the lowest concentration of virus, in both trials done with ASFV MOZ 1/98 and ASFV SPEC 257. In addition, animal trials were performed by inoculating domestic pigs with four different ASFV isolates of varying pathogenicity. These viruses were all from distinct geographic origins. Non-virulent ASFV OURT 3/88 and high virulent ASFV BENIN 1/97 were previously described and used as reference viruses. ASFV MOZ 1/98, suspected of having high virulence and ASFV MKUZE, which was thought to be of low virulence were included in this study to provide further information on the pathological and clinical outcome of the disease as well as measuring viral replication in various organs and blood. The study showed that ASFV MKUZE was of intermediate virulence, whilst ASFV MOZ 1/98 was highly virulent with a high mortality rate. Results confirmed the inadequacy of ASFV MKUZE to act as vaccine opposed to ASFV OURT 3/88. Following this, a potential vaccine by use of attenuated Portuguese ASFV OURT 3/88 tested against virulent heterologous challenge with a strain now known with certainty to cause acute ASF, the isolate ASFV MOZ 1/98 collected from a diseased pig in Mozambique. Domestic commercial pigs where submitted to either one or two vaccinations before challenge. Viral load in blood and tissue samples was higher in unvaccinated animals and higher in single vaccinated than in pigs vaccinated twice. However, acute ASF afflicted all groups with severe clinical signs and post-mortem lesions. Although it did not confer total immunity it was determined that pigs vaccinated with European attenuated ASFV OURT 3/88 acquired partial protection against challenge with virulent southern Africa ASFV MOZ 1/98. / Dissertation (MSc)--University of Pretoria, 2012. / gm2014 / ab2015 / Veterinary Tropical Diseases / unrestricted
18

Efficacy of Liming Forest Soil in the Context of African Swine Fever Virus

Tanneberger, Franziska, Abd El Wahed, Ahmed, Fischer, Melina, Deutschmann, Paul, Roszyk, Hanna, Carrau, Tessa, Blome, Sandra, Truyen, Uwe 13 June 2023 (has links)
Since September 2020, Germany has experienced the first ever outbreak of African swine fever (ASF). The first known cases occurred exclusively in wild boar in forest areas in Brandenburg and Saxony; in July 2021, infected domestic pigs were also confirmed for the first time. As wild boar are considered the main reservoir for the virus in the European region, an effective interruption of this infection chain is essential. In particular, the removal and safe disposal of infected carcasses and the direct disinfection of contaminated, unpaved ground are priorities in this regard. For the disinfection, highly potent as well as environmentally compatible disinfectants must be used, which are neither influenced in their effectiveness by the soil condition nor by increased organic contamination. Thus, in this study, slaked lime, milk of lime and quicklime (1% to 10% solutions) were selected for efficacy testing against the test virus recommended by the German Veterinary Society (DVG), Modified Vaccinia Ankara virus (MVAV), and ASF virus (ASFV) in conjunction with six different forest soils from Saxony in two different soil layers (top soil and mineral soil) each. In summary, 10% of any tested lime type is able to inactivate both MVAV and ASFV under conditions of high organic load and independent of the water content of the soil. At least a 4 log reduction of the virus titer in all tested forest soil types and layers and by all applied lime types was observed. In conclusion, the high efficacy and suitability of all tested lime products against both viruses and in the presence of high organic load in forest soil can be confirmed and will help to control ASF spread.
19

Tinzaparin vs. Nadroparin Safety and Efficacy in Neurosurgery

Wilhelmy, Florian, Hantsche, Annika, Gaier, Michael, Kasper, Johannes, Fehrenbach, Michael Karl, Oesemann, Rene, Meixensberger, Jürgen, Lindner, Dirk 01 February 2024 (has links)
Background: An outbreak of African swine fever (ASF) in China in 2020 has led to an unprecedented shortage of nadroparin. Most patients, especially those kept in hospital for surgery, are currently treated with prophylactic anticoagulation (AC). In search of alternatives for nadroparin (fraxiparine), we found no sufficient data on alternatives for neurosurgical patients, such as tinzaparin of European origin. We compared nadroparin and tinzaparin concerning adverse events (bleeding versus thromboembolic events) in neurosurgical patients. Methods: Between 2012 and 2018, 517 neurosurgical patients with benign and malignant brain tumors as well as 297 patients with subarachnoid hemorrhage (SAH) were treated in the Department of Neurosurgery, University Hospital Leipzig, receiving prophylactic anticoagulation within 48 h. In 2015, prophylactic anticoagulation was switched from nadroparin to tinzaparin throughout the university hospital. In a retrospective manner, the frequency and occurrence of adverse events (rebleeding and thromboembolic events) in connection with the substance used were analyzed. Statistical analysis was performed using Fisher’s exact test and the chi-squared test. Results: Rebleeding rates were similar in both nadroparin and tinzaparin cohorts in patients being treated for meningioma, glioma, and SAH combined (8.8% vs. 10.3%). Accordingly, the rates of overall thromboembolic events were not significantly different (5.5% vs. 4.3%). The severity of rebleeding did not vary. There was no significant difference among subgroups when compared for deep vein thrombosis (DVT) or pulmonary embolism (PE). Conclusion: In this retrospective study, tinzaparin seems to be a safe alternative to nadroparin for AC in patients undergoing brain tumor surgery or suffering from SAH.
20

Privata skogsägares upplevelser av afrikansk svinpest i Västmanland : En kvalitativ studie / Private forest owners experiences of African swine fever in Västmanland : A qualitative study

Gustafsson, Frida, Edfast Fluch, Linn January 2024 (has links)
I den svenska skogen förekommer ett stort antal djurarter som påverkar skogen och människan. I Västmanland, som studien behandlade, förekommer bland annat älg, rådjur, varg och vildsvin. Dessa viltarter påverkar markägare i olika uträckning. Västmanland drabbades hösten 2023 av det första fallet av afrikansk svinpest i Sverige. En sjukdom som är väldigt smittsam och med hög dödlighet för vildsvin. Syftet med studien var att beskriva upplevelsen av afrikansk svinpest och dess påverkan på skogsbruket, samt generell attityd till vilt hos privata skogsägare i Västmanland. Denna studie var av kvalitativ karaktär och baserades på semistrukturerade intervjuer. Sex respondenter medverkade i studien. Det transkriberade materialet bearbetades i en innehållsanalys, där fyra teman identifierades. Slutsatserna för studien är att afrikanska svinpesten har haft stor påverkan på skogsägare inom smittområdet, främst genom begränsningar i vardagslivet och skogsbruket. Hjortdjur ses som en fördel och tillgång. Vargen däremot är ett infekterat ämne. Vildsvin väckte inga större känslor, trots utbrottet.

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