http://hdl.handle.net/1957/19531 2013-06-18T05:26:18Z http://hdl.handle.net/1957/37407 Development of an enzyme-linked immunosorbent assay for the serologic diagnosis of bovine adenovirus type 3 Whipple, Margaret Jo An enzyme-linked immunosorbent assay was developed to measure specific antibody response in bovine sera to bovine adenovirus type 3 (BA3), an etiologic agent of respiratory disease causing economic losses annualy to the cattle industry. Observed endpoint titers were determined using the intersection point from optical density values of serially diluted sera with a positive-negative threshold. Regression equations were determined from standards with titers ranging from low to high and used to predict ELISA titers from a single-serum dilution. A near-linear relationship existed between the observed and predicted ELISA titers of 118 bovine sera (r=0.9261). Predicted ELISA titers were determined using the single-dilution method for another 76 bovine sera and the correlation between the ELISA titers and serum-virus neutralization titers for these sera indicated a strong linear trend (r=0.8172). Both the ELISA and serum-virus neutralization titers on the bovine sera tested indicated widespread exposure to several types of bovine adenovirus. Although detection of active infection would still require examination of sera over time for evidence of a rising titer, the single-dilution ELISA devised should provide a rapid and sensitive method for detection of antibody response to bovine adenovirus type 3. Graduation date: 1992 1991-11-26T00:00:00Z http://hdl.handle.net/1957/37348 The effect of 3,4,5,3',4',5'- hexachlorobiphenyl on plasma corticosterone and prolactin concentration in the mouse Youngberg, Jill Annette Meyer It was hypothesized that alterations in plasma concentrations of corticosterone (CS) and prolactin (PRL) may be at least partially responsible for polychlorinated biphenyl (PCB)-induced immunosuppression. A 2 by 2 factorial experiment examined the interactions of PCB and P815, an allogeneic tumor, on plasma concentrations of CS and PRL, and on body, spleen, and thymus weights. The PCB dosage used (10 mg/kg) was previously shown to suppress immune response to the tumor. The four study groups were: Group A (vehicle control), Group B (tumor only), Group C (PCB only), and Group D (tumor plus PCB). Mice received one dose of PCB (Groups C and D) or carrier (Groups A and B) on day -1; tumor (Groups B and D) or carrier (Groups A and C) was injected intraperitoneally on day 0. In Experiment 1, animals were killed on days -1, -0.6, 0 through 10, 21, 42, and 84. Body, spleen, and thymus weights were measured. Plasma samples were obtained for CS and PRL measurements. In Experiment 2, the study was repeated with samples obtained only on days 3 and 10. Group A body weights increased steadily throughout Experiment 1. Relative to Group A, the weight gain in Group B was significantly (p < 0.05) higher. Group C lost weight on days 0 through 6, and gained significantly (p < 0.05) less weight than Group A. Group D gained significantly (p < 0.05) less weight than Groups A, B, and C. As a percent of body weight, spleen weight remained constant over 21 days in Experiment 1 in both Groups A and D. Compared to Group A, Group B showed significantly (p < 0.05) increased spleen percent body weight while Group C showed significantly (p < 0.05) decreased spleen percent body weight. As a percent of body weight, thymus weight remained constant for 21 days in Experiment 1 in Group A. Groups Band C were similar (p > 0.05) and showed a decreased thymus percent body weight compared to Group A. Group D showed significantly (p < 0.05) decreased thymus percent body weight relative to the other three groups. Mean CS concentrations in Experiment 1 in Groups A and B were similar (p < 0.05). Relative to Groups A and B, Group C CS concentrations were elevated, with a peak of 126.1 ng/ml on day 4. Group D CS concentrations were higher than the other three groups, peaking at 294.1 ng/ml on day 10. There was no significant difference in PRL concentrations in Groups A, B, and C in Experiment 1 (p > 0.05). Mean PRL concentration in Group D was significantly (p < 0.05) lower than in the other three groups. The results of Experiment 2 validated those of Experiment 1. Although absolute values differed, the pattern of changes seen in body and organ weights and in CS and PRL concentrations was similar. An acute exposure to PCB and tumor resulted in an increase in circulating CS concentration and a decrease in circulating PRL concentrations. These changes may contribute to PCB-induced immunosuppressioin. Graduation date:1992 1991-08-20T00:00:00Z http://hdl.handle.net/1957/37228 Respiratory pathogenesis of Pasteurella Multocida in turkeys Abrar, Mahdi Pasteurella multocida causes diseases in many animal species including fowl cholera, a septicemic disease of poultry and other birds. Pathogenesis of the disease has been studied by many investigators by the systemic administration of the organism in poultry. However, only a few studies have been done as to the respiratory pathogenesis of the organism. The objective of the study was to investigate the fate of P. multocida after the intratracheal administration in turkeys The fate of four strains of Pasteurella multocida was studied after their intratracheal inoculation in young adult turkeys. Viable bacterial counts were made in respiratory tissues as well as in the liver, spleen and blood at 6 and 9 hrs after the inoculation of approximately 10⁹ viable organisms of each strain. A virulent, encapsulated strain, P-1059, invaded systemically by 6 hrs postinoculation (PI) and multiplied vigorously in all tissues and organs examined. A blue colony mutant of P-1059, T-325, which does not possess a thick layer of capsule, as well as CU vaccine strain, invaded the parenchymal organs, but did not show significant increase in viable counts at 9 hrs PI compared with at 6 hrs PI. Another vaccine strain, M-9, also invaded blood and internal organs by 6 hrs PI, however, its viable counts showed no significant change between 6 and 9 hrs PI, or in some tissues significant decrease at 9 hrs PI. The results indicate that all the four strains possess high capacity to invade respiratory tissues with varying capacity to persist in host tissues. The lesions caused by two strains of Pasteurella multocida (P-1059 and M-9) were observed after their intratracheal inoculation in young adult turkeys. The lesions were observed in the respiratory organs at 0, 0.25, 0.5, 1, 2, 3, and 6 hrs after inoculation of approximately 10⁹ viable organisms of each strain. Both virulent strain, P-1059 and non-virulent vaccine strain, M-9, have capacity to invade and multiply in the tissues examined. Macroscopicly, the lesions in the lung and in the airsac were found as early as 1 hr PI, including the infected lung was foamy and the airsac became cloudy. They became more severe by 2 to 6 hrs PI. Microscopicly, hecerophiles were present, occasionally, in the lung, trachea and airsac by 0 to 1 hr after inoculation. Then they became more severe by 2 to 6 hrs PI. By 6 hrs PI, there were diffuse heterophiles infiltration in the trachea, lung, anc airsac. The lung vascular was edema. The trachea ciliate and mucous gland was cystic or hyperplasia, and the airsac shewed increased in thickness and cloudiness. These results of study indicate that the lesion caused by P-1059 and vaccine strain, M-9, were not significantly different. Graduation date: 1992 1991-11-18T00:00:00Z http://hdl.handle.net/1957/36598 Serologic survey of llamas in Oregon for antibodies to viral diseases of livestock Picton, Rebecca Anne Serums from 270 llamas representing 21 farms throughout Oregon were obtained and assayed for antibody levels against viruses of livestock. These viral diseases included: bovine viral diarrhea (BVD), bovine herpesvirus 1 (BHV-1), parainfluenza-3 (PI-3), bovine respiratory syncytial virus (BRSV), bovine adenovirus species 3 (BA3), equine herpesvirus 1 (EHV-1), equine adenovirus (EA), equine influenza, subtypes 1 and 2 (EI-1, EI-2), equine viral arteritis (EVA), ovine progressive pneumonia (OPP), bluetongue (BT), vesicular stomatitis, New Jersey strain and Indiana strain (VSV-NJ, VSV-IN), and llama adenovirus strain 7649 (LA7649). Antibodies to Ehrlichia risticii (ER), the rickettsia) organism causing Potomac horse fever (PHF), were also assayed. Of the 270 llamas, 252 had antibodies to LA7649. A total of 60 llamas possessed antibodies to various viruses associated with livestock disease. Seven of these llamas had antibodies to more than one virus (excluding LA7649). Forty three exhibited antibodies to EA, 12 to BVD, and 12 to PI-3. Four had antibodies to BTV, 2 to BHV-1, and 2 to EI-1. One had antibodies to EI-2, one to EHV-1, and one to BRSV. All 270 llamas lacked antibodies to EVA, BA3, VSV-NJ, VSV-IN, OPP and ER. Presence and type of livestock were noted on each farm. Whether a llama was born on the farm or purchased and the length of time the llama had been on the farm was also noted. Graduation date: 1993 1993-03-16T00:00:00Z