خيارات البحث
النتائج 241 - 250 من 484
Effect of administration of prostaglandin F2 alpha on embryo recovery from the uterus on day 5 after ovulation in mares
1990
Hinrichs, K. | Riera, F.L.
Ten mares were used to investigate the effect of administration of prostaglandin F2 alpha on uterine tubal motility, as reflected by embryo recovery from the uterus 5 days after ovulation (day 0). Mares were assigned to 3 groups: group A, uterine flush for embryo recovery on day 7; group B, uterine flush for embryo recovery on day 5; and group C, uterine flush for embryo recovery on day 5, after treatment with prostaglandin F2 alpha (10 mg, IM) on day 3. Each mare was assigned to each group once. Embryo recovery rates for the 3 groups were: A, 6 of 10; B, 2 of 8; and C, 0 of 10. The embryo recovery rate for group C was significantly lower (P < 0.01) than that for group A. Embryo recovery rate for group B was not significantly different from group A or group C. Administration of prostaglandin on day 3 did not increase embryo recovery rate from the uterus on day 5. Additionally, the 25% embryo recovery rate (2 of 8) for group B mares suggested an earlier time for entry of the embryo into the uterus than has previously been reported.
اظهر المزيد [+] اقل [-]Reactivation of latent pseudorabies virus infection in vaccinated commercial sows
1990
Cowen, P. | Li, S. | Guy, J.S. | Erickson, G.A. | Blanchard, D.
Pseudorabies virus (PRV) was isolated from 9 of 44 PRV-vaccinated seropositive sows on 5 of 11 farms. Although serum-neutralization antibody titers were 1:16 to 1:256, 28 virus isolates were obtained from tonsil, nasal, or buccal swab samples from 9 sows given 2 ml of dexamethasone/kg of body weight IM for 5 days. Pseudorabies virus was isolated from 6 of 20 sows (3 of 5 farms) given a killed-virus vaccination. Virus was obtained from 3 of 24 sows (2 of 6 farms) given modified-live virus and killed-virus vaccination. Evaluation of the 9 PRV with 5 restriction endonucleases revealed 4 PRV existing genotypes. The 9 isolated types of PRV appeared to be indistinguishable by Kpn I and BamHI restriction endonuclease analysis; however, when analyzed with Sal I, HinfI, and Pst I, isolates 7 (farm D), 8 (farm C), and 9 (farm B) had numerous differences. Isolates 1, 2, 3, and 4 (farm F) and 5 and 6 (farm G) appeared to be the same genotype when further analyzed with Pst I, HinfI, and Sal I.
اظهر المزيد [+] اقل [-]Characterization of a panel of monoclonal antibodies and their use in the study of the antigenic diversity of bovine viral diarrhea virus
1990
Corapi, W.V. | Donis, R.O. | Dubovi, E.J.
A panel of 40 monoclonal antibodies (MAb) specific for bovine viral diarrhea virus (BVDV) was produced, and each MAb was characterized and grouped according to its viral protein specificity, immunoglobulin subclass, virus-neutralizing activity, and immunoreactivity with a large collection of BVDV isolates. The MAb were found to be specific for 1 of 3 sets of related viral-induced proteins found in cells infected with the Singer strain of BVDV. Group-1 MAb were specific for the 80- and 118-kilodalton (kD) proteins of BVDV. Group-2 MAb recognized 3 proteins with molecular sizes of 54, 56, and 58 kD. Group-3 MAb recognized a 43- and a 65-kD protein. The MAb belonged to either the IgG1, IgG2a, IgG2b, IgG3 subclasses or the IgE class of mouse immunoglobulin. All MAb in group 2 were able to neutralize BVDV and had neutralization titers that ranged from 24 to 1,600,000. The reactivity of the MAb with numerous field isolates of BVDV was highly variable. Both cytopathic and noncytopathic biotypes of BVDV were examined and had the same degree of antigenic variation. The greatest degree of variation was detected with group-2 MAb. The data demonstrate that BVDV isolates have a high degree of antigenic variation that is largely confined to the envelope glycoproteins associated with virus neutralization. The results also suggest that antigenic variability of this virus is important in the development and severity of the disease it causes.
اظهر المزيد [+] اقل [-]Determination of macrophage chemotaxis to atherosclerotic plaque extract in domestic turkeys with hypertension
1990
Johnson, P.D. | Klesius, P.H. | Krista, L.M.
The chemotactic activity of turkey peritoneal macrophages in response to an atherosclerotic plaque extract from a hypertensive strain of turkeys was determined. Atherosclerotic plaque extract stimulated macrophage chemotaxis, whereas normal aortic extract did not stimulate macrophage chemotaxis. However, differences were not revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of extracts of atherosclerotic plaque and normal aorta. Chemotactic activity was diminished with pronase treatment, suggesting the chemoattractant is a protein. Seemingly, atherosclerotic plaque of turkeys contains a macrophage chemotaxin.
اظهر المزيد [+] اقل [-]Necrotic oophoritis in heifers vaccinated intravenously with infectious bovine rhinotracheitis virus vaccine during estrus
1990
Smith, P.C. | Nusbaum, K.E. | Kwapien, R.P. | Stringfellow, D.A. | Driggers, K.
Twenty-two Hereford heifers were injected IM with prostaglandin F2 alpha(a), 11 days apart to synchronize estrous cycles. Twelve of 14 heifers that had signs of estrus were inoculated IV with 1 of 3 modified-live infectious bovine rhinotracheitis virus vaccines, and 2 were assigned to a nonvaccinated control group. Also, 6 of the 8 anestrous heifers were inoculated IV with 1 of the 3 vaccines on the fourth day after the last prostaglandin injection and the other 2 were assigned to the nonvaccinated group. Vaccine virus was isolated from the blood and nasal and vaginal secretions from the vaccinated heifers on postvaccination days 4, 7, and 9. On postvaccination day 9, all heifers were ovariectomized and ovarian tissues were processed for virus isolation and histologic examination. Vaccine virus was isolated from ovarian tissues of some heifers in each of the vaccine groups. Necrotic oophoritis characterized by multifocal areas of ovarian tissue necrosis, hemorrhage, and mononuclear lymphocytic infiltration was observed. The corpora lutea and surrounding ovarian tissues taken from vaccinated heifers in each group had varying amounts of necrotic and inflammatory change, but the changes appeared to be more severe in 1 group than in the other 2. Virus also was isolated from 2 of the controls; these heifers apparently became infected with vaccine virus that had been excreted from the vaccinated animals.
اظهر المزيد [+] اقل [-]Acute airsacculitis in turkeys inoculated with phorbol myristate acetate
1990
Ficken, M.D. | Barnes, H.J.
Phorbol myristate acetate (PMA), which induces acute pulmonary injury in mammals, induced acute airsacculitis in turkeys after intra-airsac inoculation of 0.1 mg/kg. Grossly, air sacs contained multifocal to diffuse hemorrhage and edema at postinoculation hours (PIH) 3 and 6. Microscopically, there was multifocal congestion and small thrombocyte aggregates within small blood vessels by PIH 0.5, with a few vessels containing small numbers of marginating heterophils. By PIH 1.5, thrombocyte aggregates were larger and more numerous, and moderate numbers of heterophils were located perivascularly. Erythrocytes and proteinaceous fluid were in air sac interstitium. By PIH 3 and 6, hemorrhage and exudation of proteinaceous fluid had increased, in some instances severely distending the air sac. Ultrastructurally, changes resulting from PMA-induced injury were thrombocyte aggregation and degeneration, air sac epithelial cell vacuolation with separation of interdigitating cell processes, and endothelial cell vacuolar degeneration with loss of vascular integrity. Air sac lavage fluids had mildly increased total cell counts by PIH 1.5, but values returned to baseline by the end of the experiment, indicating lack of cell exudation into the air sac lumen. Circulating leukocyte changes included transient lymphopenia at PIH 3 and marked heterophilia at PIH 6. These results indicate that thrombocytes and/or heterophils are central to the pathogenesis of injury induced in air sacs by PMA and that the air sac responds differently to PMA than to pathogenic bacteria.
اظهر المزيد [+] اقل [-]Clinical and lymphohematologic responses after bone marrow transplantation in sibling and unrelated donor-recipient pairs of cats
1990
Cain, J.L. | Cain, G.R. | Turrel, J.M. | Theilen, G.H.
Conditions necessary for establishment of a graft, posttransplant supportive care and complications, and lymphohematopoietic reconstitution after bone marrow transplantation were evaluated in 7 cats. Donor-recipient pairs were selected on the basis of low mutual reactivity in one-way mixed lymphocyte reactions. Before transplantation, cats were given marrow ablative (7 Gray) total-body gamma irradiation. Cyclosporine A was administered to cat 7, which was given marrow from an unrelated donor. Rapid hematologic recovery was attained in 5 of 5 (cats 1 to 5) sibling bone marrow recipients and 1 (cat 7; cyclosporine A-treated) of 2 recipients from unrelated donors. Lymphocyte recovery was prolonged, requiring up to 100 days to attain reference concentrations. Lymphocyte blastogenic responses were below reference range in 2 of 3 cats (cats 1 and 3) examined approximately 1 to 3 months after transplantation. Serum IgG concentrations determined 1 to 6 months after transplantation were within reference range in cats 1 to 5 which were given sibling bone marrow. Fatal infections did not develop in cats that had established grafts. Antimicrobial-responsive fevers did develop, but were generally detected only when granulocyte counts were low (< 1 X 10(9) cells/L). Clinical signs of disease in the immediate posttransplant period consisted of hepatic lipidosis (fatal) in cat 4, hepatitis (mild graft-vs-host disease) in cat 3, and immune-mediated hemolytic anemia and thrombocytopenia in cat 7. Cats with hepatitis and immune-mediated disease responded to immunosuppressive therapy.
اظهر المزيد [+] اقل [-]Immunodominant proteins of Sarcocystis cruzi bradyzoites isolated from cattle affected or nonaffected with eosinophilic myositis
1990
Granstrom, D.E. | Ridley, R.K. | Baoan, Y. | Gershwin, L.J.
Sarcocystis cruzi sarcocysts were isolated from eosinophilic myositis (Em)-affected and nonaffected bovine hearts. Isolates were ruptured and used to prepare a bradyzoite antigen extract from each heart. The nonaffected heart from one newborn calf contained no apparent sarcocysts when examined histologically and was used to prepare Sarcocystis-negative control antigen. Blood samples were taken from the heart approximately 20 minutes after slaughter. Serum was obtained and evaluated, using a radioimmunoassay to measure Sarcocystis-specific IgG and IgE titers. Sarcocystis cruzi extract from a heart without EM lesions was used for antigen in the radioimmunoassay. Sarcocystis-specific IgG titer ranged between 1:1,280 and 1:2,560 in EM-affected cattle and was 1:640 in nonaffected cattle. Sarcocystis-specific IgE titer ranged between 1:640 and 1:1,280 in Em-affected and nonaffected cattle. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein (western) immunoblot analysis were used to compare antigen extracts and serum samples from EM-affected vs nonaffected cattle. Twenty protein bands, ranging from approximately 22 to 215 kD, were detected consistently on bradyzoite blots probed with anti-bovine IgG after incubation with serum samples. Seven of these bands, 37, 44, 53, 57, 94, 113, and 215 kD, were also detected consistently on bradyzoite blots probed with monoclonal anti-bovine IgE. One additional band, 61 kD, was detected consistently on bradyzoite blots probed for IgE, but was seldom recognized when probed for IgG. Sixteen protein bands were evident in silver-stained gels of S cruzi-negative, newborn calf antigen, but none were recognized by antisera on western blots. Consistent differences were not found among antigen extracts or among serum from EM-affected vs nonaffected cattle on silver-stained gels or western blots.
اظهر المزيد [+] اقل [-]Isolation of Mycobacterium paratuberculosis from washed bovine ova after in vitro exposure
1990
Rohde, R.F. | Shulaw, W.P. | Hueston, W.D. | Bech-Nielsen, S. | Haibel, G.K. | Hoffsis, G.F.
To establish whether Mycobacterium paratuberculosis could be cultured from Dulbecco phosphate-buffered saline solution (DPBSS) and to test 3 sampling methods, DPBSS supplemented with 2% fetal bovine serum was inoculated with M paratuberculosis at concentrations of 10(4), 10(3), 10(2), 10(1), and 10(0) colony-forming units/ml. The inoculated media was sampled after mixing, after centrifugation, and after centrifugation and decontamination with 0.75% hexadecylpyridinium chloride. The samples were inoculated onto 3 slants of Herrolds egg yolk medium supplemented with sodium pyruvate and mycobactin J and 1 slant without mycobactin J. Mycobacterium paratuberculosis was isolated following all 3 sampling methods for all concentrations. Treatment with hexadecylpyridinium chloride decreased the number of colonies isolated. To test the efficacy of a 10-step wash procedure for removing M paratuberculosis from bovine ova, washed zona pellucida intact bovine ova were incubated in DPBSS supplemented with 2% fetal bovine serum containing concentrations of 10(4), 10(3), 10(2), 10(1), and 10(0) colony-forming units of M paratuberculosis/ml for 12 hours at 22 C. Ten zona pellucida intact ova were removed from each concentration and washed by passing through 10 changes of DPBSS supplemented with 15% fetal bovine serum. The media from each wash step was inoculated onto slants of Herrolds egg yolk medium. The ova were included with the tenth wash step. Mycobacterium paratuberculosis was isolated from 1 of 10 tenth-wash steps at the 10(4) concentration and 5 of 10 tenth-wash steps at 10(3).
اظهر المزيد [+] اقل [-]Bovine monoclonal antibodies specific for bovine herpesvirus-1 glycoprotein gIII
1990
Srikumaran, S. | Onisk, D.V. | Zamb, T.J. | Osorio, F.A. | Rice, D.N.
Spleen cells from a calf immunized with bovine herpesvirus-1 (BHV-1) were fused with the nonsecreting murine cell line SP2/0. Several bovine-murine hybridomas secreting bovine immunoglobulins were stabilized. Of these, 9 hybridomas secreted bovine monoclonal antibodies that specifically bound to BHV-1 in a radioimmunoassay. Two of these monoclonal antibodies reacted specifically with BHV-1 in an indirect fluorescent antibody test and immunoprecipitated a BHV-1 glycoprotein with molecular mass of 97 kilodaltons.
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