Reticuloendotheliosis virus (REV) is a retrovirus that causes a neoplastic disease in a wide range of avian hosts including chickens, turkeys, and ducks. In 1993, REV was detected in the endangered Attwater's prairie chicken (Tympanachus cupido attwateri), a subspecies of Tympanachus cupido. Subsequent infections of this prairie chicken have been identified at captive breeding facilities throughout Texas. The implications of these infections have severely hindered repopulation efforts by these facilities. This study focused on investigating REV infection of captive Attwater'€™s prairie chicken in order to better understand the disease affecting these endangered birds. The overall objective was to develop a means of eliminating this threat to the repopulation of the Attwater's prairie chicken. Several aspects of virus infection were investigated. Reagents capable of recognizing prairie chicken IgY and viral gag polypeptides were developed for use in assays for detection of antibody responses and titration of viral concentrations. Sequencing data of genomes collected from isolates of Texas prairie chickens and domestic chickens, as well as three REV prototype viruses, were compared to determine relationships among strains and identify the potential origin of the REV infecting Attwater'€™s prairie chicken. Additionally, a flow cytometry technique of segregating the lymphocyte population from peripheral blood mononuclear cells (PBMC) using a pan leukocyte monoclonal antibody was developed to more accurately measure changes within lymphocyte populations. This technique combined with intracellular labeling was used to deduce the target cells of REV infection. A nested polymerase chain reaction (PCR) test was developed for greater sensitivity in detecting infection in birds than the previous method of single amplification PCR. This greater sensitivity results in earlier identification of the virus in infected birds, which allows for earlier removal of infected birds to minimize transmission of the virus throughout the flock. The sensitivity of the nested PCR diagnostic test was determined in a dose response pathogenesis study, which was conducted on hybrid greater/Attwater's prairie chicken to observe the experimental development of disease in these birds. Finally, a vaccine was developed using plasmid DNA with REV encoded genes and tested on naturally infected prairie chickens to determine its efficacy in reducing viral load. Although no reduction in viral load was detected, the vaccine may be effective in providing prophylactic protection in future studies.

We consider joint chance-constrained programs with random lefthand sides. The motivation of this project is that this class of problem has many important applications, but there are few existing solution methods. For the most part, we deal with the subclass of problems for which the underlying parameter distributions are discrete. This assumption allows the original problem to be formulated as a deterministic equivalent mixed-integer program. We rst approach the problem as a mixed-integer program and derive a class of optimality cuts based on irreducibly infeasible subsets of the constraints of the scenarios of the problem. The IIS cuts can be computed effciently by means of a linear program. We give a method for improving the upper bound of the problem when no IIS cut can be identifi ed. We also give an implementation of an algorithm incorporating these ideas and finish with some computational results. We present a tabu search metaheuristic for fi nding good feasible solutions to the mixed-integer formulation of the problem. Our heuristic works by de ning a sufficient set of scenarios with the characteristic that all other scenarios do not have to be considered when generating upper bounds. We then use tabu search on the one-opt neighborhood of the problem. We give computational results that show our metaheuristic outperforming the state-of-the-art industrial solvers. We then show how to reformulate the problem so that the chance-constraints are monotonic functions. We then derive a convergent global branch-and-bound algorithm using the principles of monotonic optimization. We give a finitely convergent modi cation of the algorithm. Finally, we give a discussion on why this algorithm is computationally ine ffective. The last section of this dissertation details an application of joint chance-constrained stochastic programs to a vaccination allocation problem. We show why it is necessary to formulate the problem with random parameters and also why chance-constraints are a good framework for de fining an optimal policy. We give an example of the problem formulated as a chance constraint and a short numerical example to illustrate the concepts.

Thesis (M.A.)--Northern Kentucky University, 2009. / Made available through ProQuest. Publication number: AAT 1469963. ProQuest document ID: 1913184301. Includes bibliographical references (p. 36-38)

Thesis (Ph. D.)--University of Queensland, 2001. / Privately bound. Includes bibliographical references.

Source: Masters Abstracts International, Volume: 47-06, page: 3554. Adviser: David W. Smith. Includes bibliographical references.

Burkholderia pseudomallei and Burkholderia mallei cause the diseases melioidosis and glanders, respectively. These diseases are endemic mainly in southeastern Asia and northern Australia, but they also pose a bioterrorism threat in the developed world. These diseases have high mortality, partially due to the lack of vaccines and rapid, accurate diagnostic assays. The work discussed here represents a part of a larger project to develop a dependable diagnostic assay for use in both developing endemic areas and the developed world, as well as a subunit vaccine to protect against disease. In this study, several proteins from B. pseudomallei, B. mallei, and the closely related but less virulent B. thailandensis have been cloned, expressed and purified in order to develop highly sensitive and specific diagnostic reagents for the detection of B. pseudomallei and B. mallei in infected patient samples. Protein targets expressed in this study were also used in subunit vaccine development for melioidosis and glanders. / text

Mucosal delivery of recombinant adenovirus serotype 5 (rAd5)-based vaccine preparations are appealing for vaccine development in terms of lowering toxicity induced by high viral loads and substantial liver accumulation following systemic injection of the vaccine. However, this mode of delivery is currently under-developed due to the relatively low T-cell mediated immune responses generated against the encoded transgene. The first study described in this thesis demonstrated that sublingual immunization induces rapid migration of MHCII+, CD11C+ antigen presenting cells to the delivery site and elicit antigen-specific T and B cell-mediated immune responses in naïve mice and those with pre-existing immunity (PEI) to Ad5 at a level higher than that achieved after oral immunization. More importantly, this strategy improved protection of animals with PEI to Ad in contrast to poor protection after IM injection. The second study was designed to establish a method for inducing PEI that most accurately reflects natural infection in rodents and identifies the immunologic parameters elicited by rAd5-based Ebola vaccine necessary for protection against lethal infection. When immunization occurred by the same route in which PEI was induced, the antigen-specific multifunctional CD8+ T cell and antibody responses were significantly reduced. This correlated with poor survival after challenge with a lethal dose of Ebola Zaire in rodents. The data suggests that 1) establishment of PEI by the same route used for immunization is the most stringent test for a novel formulation designed to be effective in those with PEI to Ad5, and 2) for a formulation to be effective in those with PEI, it must be capable of restoring antigen-specific multifunctional CD8+ T cell and antibody responses, compromised by PEI. The third study screened novel formulations for their ability to improve in vitro transduction efficiency and immunogenicity and efficacy in vivo in the presence of anti-Ad5 neutralizing antibodies. Formulations consisting of pharmaceutically acceptable, non-immunogenic excipients that can prime the arms of immune response compromised by PEI improved survival after lethal challenge with Ebola Zaire challenge for rAd5-based Ebola vaccine in rodents with PEI. Taken together, these studies provide insight on how to reconstitute necessary immune responses in vaccine protocols by establishing a reliable PEI model in rodents, testing routes of administration, and formulations of the rAd5-based Ebola vaccine. / text

Adenoviruses, particularly types 4 and 7, are associated with febrile respiratory illness (FRI) outbreaks in US military basic trainees. Vaccines against these two serotypes controlled FRI in basic trainees until production ceased in the mid-1990s. After contracting a new manufacturer, adenovirus vaccination of military basic trainees resumed in 2011. The purpose of this dissertation was to assess the cost-effectiveness of using the new adenovirus type 4 and type 7 vaccines for the prevention of FRI in US military basic trainees from the perspective of each military branch. Two decision tree models comparing adenovirus vaccination to no adenovirus vaccination were used for this dissertation. The first model is similar to previous models used to assess the cost-effectiveness of the adenovirus vaccine in the military, where the outcome is number of FRI hospitalizations prevented. The second model created for this dissertation used information gathered from published literature and conversations with experts on the adenovirus vaccine. The outcome for the second model was number of training days lost (TDL) averted. Results from part I indicated that adenovirus vaccination of basic trainees was cost-effective as measured by FRI hospitalizations prevented in all US military service branches but the Coast Guard. The model showed that reintroducing the adenovirus vaccine to basic trainees saved the Army $5.8 million, the Navy, $1 million, the Marine Corps, $238,000, and the Air Force, $5.2 million, annually. In addition, adenovirus vaccination prevented 1,221, 543, 317, 677 cases of FRI hospitalization annually in the Army, Navy, Marine Corps, and Air Force respectively. In part II of this study, adenovirus vaccination of basic trainees was the dominant strategy as measured by TDL averted in all US military service branches but the Marine Corps and the Coast Guard. Results indicate that it would cost approximately $37.63 and $563.78 per TDL averted for the Marine Corps and Coast Guard respectively. Both models used for this dissertation provide evidence supporting the cost-effectiveness of using the adenovirus vaccine in US basic trainees in all services but the Coast Guard. / text

Background Chronic smokers are at risk of premature death associated with underlying pulmonary or cardiovascular diseases. Dual influenza and pneumococcal vaccination has been shown to prevent death and hospitalization secondary to pulmonary or cardiovascular diseases in elderly persons. Its effect in chronic smokers remained unknown. Methods This is a prospective randomized open-labeled trial conducted from April 2010 to March 2013, comprising adult patients aged less than 50 years who were chronic smokers. Subjects were randomly assigned into 4 groups. Group 1 (study group) patients received both trivalent influenza vaccine (TIV) and the 23-valent polysaccharide pneumococcal vaccine (PPV). There were 3 control groups: Group 2 patients received the TIV only. Group 3 patients received the PPV only and Group 4 patients did not receive any vaccines. The TIV used was the Vaxigrip® (Sanofi Pasteur, France) and the PPV used was the Pneumovax®23 (Merck, USA). All enrolled patients were follow-up for 24 months post vaccination. Patient details, Charlson comorbidity index, medications, subsequent hospitalization, diagnosis and mortality were recorded and analyzed. Results A total of 1006 subjects were enrolled and completed the study (Group PPV+TIV: 250; Group TIV: 254, Group PPV: 250 and Group None: 259). The baseline demographics and Charlson comorbidity index were similar among subjects in the 4 groups. The median age was 48 years and 85.9% were male patients. Significantly fewer subjects who received the dual vaccination (Group PPV+TIV) were hospitalized (p<0.001), with shorter mean length of stay (p<0.001), and less frequent hospitalization (p<0.001) for cardiovascular or respiratory diseases than no vaccination (Group None) or single vaccination (Group TIV and Group PPV). Multivariate analysis demonstrated that dual vaccination with PPV + TIV was the only independent factor associated with reduced risk of hospitalization (p<0.001; relative risk 0.288; 95% CI 0.101-0.154). There was no difference in mortality rate among the groups. Both vaccinations were well tolerated and no serious adverse events were reported. Conclusion Dual influenza and pneumococcal vaccinations prevented chronic smokers against hospitalization secondary to pulmonary or cardiovascular causes. Annual influenza and a single pneumococcal vaccination should be promoted among chronic smokers. / published_or_final_version / Microbiology / Master / Master of Medical Sciences

The Shiga-like toxins have DNA sequence homology to the toxins accountable for the dysentery brought about by the Shigella species. Escherichia coli which encode and produce shiga-like toxins are referred to as shiga toxin-producing E. coli (STEC). Upon infection with STEC, humans may develop a variety of clinical symptoms ranging in severity from bloody diarrhea to life threatening hemolytic uremic syndrome (HUS). Hemolytic uremic syndrome is the most fatal disease manifestation upon STEC infection for humans and has been documented to occur in up to 20% of patients upon STEC infection [29]. The Shiga toxins (Shiga toxin 1 and 2) are regarded as the principal virulence factor of STEC and are responsible for the clinical manifestations during HUS in humans [49]. Cattle are the primary non-human reservoir for STEC and therefore represent an attractive target for pre-slaughter intervention as a means to reduce human infections. To date, vaccination with secreted proteins including Shiga toxin 2 (Stx2), has reduced the numbers of bacteria shed in feces [3]. Even though published data exists supporting vaccination in cattle as a means to reduce STEC, commercially available vaccines are not being used by farms and STEC remain a significant zoonotic pathogen of humans causing disease and death. To further our knowledge about STEC pathogenesis in cattle, we examined the effect of Shiga toxin 2 on bovine immune responses. Bovine lymphocyte function was determined in the presence of Shiga toxin 2 and the magnitude of bovine immunological responses was measure after immunization with Shiga toxin 2. In general, results suggest that Shiga toxin 2 downregulates bovine immune responses suggesting vaccination with effector molecules that exclude Shiga toxin 2 may induce a better immunological response and improve vaccine efficacy. To examine the possibility that Stx2 modulates bovine immune responses, we investigated lymphocyte function in the presence of Stx2. Menge et al [70] have reported that bovine lymphocytes express the Stx receptor and that Shiga toxin 1 inhibits lymphocyte proliferation in vitro. We isolated two populations of lymphocytes, peripheral blood mononuclear cells (PBMCs) and ileal Peyer’s patch lymphocytes (IPPL) and compared lymphocyte function in the presence and absence of Stx2. We found that Stx2 did not affect IPPL viability in vitro but did inhibit IPPL proliferation after 12 hours of incubation in vitro. In contrast, no altered PBMC function could be observed in the presence of Stx2. These results suggest that receptor-bound Stx2 may inhibit IPPL proliferation and that the two populations of lymphocytes isolated are unique and distinct from each other in their response to Stx2. To determine the effect of Stx2 on bovine immune responses during STEC infection, a bovine ileal ligated loop model was employed. Ligated loops were inoculated with either a Stx2+ STEC strain or an isogenic Stx2- STEC strain. After 24 hours, IPPL populations were isolated from each ligated loop and immunophenotyped. The results indicated a significantly reduced CD4+ T cell population in the presence of Stx2. No differences in the levels of IFNá, TNFá, IL12 or IFNã could be detected between groups. These results suggest that Stx2 modulates bovine immune responses but not as a result of increased production of these cytokines. To extend this finding, we determined the effect of Stx2 on bovine immune responses during active immunization by using ELISA to measure serological responses in the presence and absence of Stx2. Serological responses to secreted proteins, as well as a co-administered antigen (hen egg lysozyme), were significantly reduced in the groups of cattle that were immunized with either purified Stx2 or secreted protein preparations isolated from STEC compared to groups vaccinated with antigens which did not contain the toxin. Bovine proliferative responses were also measured and the results indicated significantly reduced proliferation in the groups vaccinated with the formulations containing Stx2. Therefore, based on these results, we conclude that Stx2 downregulates bovine immune responses and thus may contribute to the colonization and persistence of cattle by STEC.