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Antibody response to glycoprotein I in maternally immune pigs exposed to a mildly virulent strain of pseudorabies virus
1991
Oirschot, J.T. van | Daus, F. | Kimman, T.G. | Zaane, D. van
To study the antibody response to glycoprotein I (gI) of pseudorabies virus (PRV) in maternally immune pigs, 3 groups of 6 pigs were given low doses of the mildly virulent Sterksel strain of PRV at 3 and 11 weeks of age. Group A consisted of seronegative pigs; groups B and C consisted of pigs with maternal antibodies deficient of antibodies to gI. At 3 weeks of age, 3 pigs of each group were inoculated intranasally with 10(2.5) plaque-forming units (groups A and B), or with 10(3.5) plaque-forming units (group C) of PRV. The 3 other pigs in each group were contact-exposed to the inoculated pigs. In group A, 4 of 6 pigs shed virus and all developed antibodies to gI of PRV and produced PRV-specific IgM and virus-neutralizing antibodies. In groups B and C, 10 pigs shed virus and all developed low and inconsistent titers of gI antibodies, whereas only 3 pigs produced PRV-IgM antibodies with low titers. Thus, after PRV infection of pigs with high concentrations of maternal antibodies deficient of gI antibodies, the antibody responses to PRV were severely inhibited. The pigs were reinoculated with 10(3) plaque-forming units of the same virus 8 weeks after the first inoculation. The pigs in group A did not respond at all, as they were immune. The pigs in groups B and C shed considerable amounts of virus. Three pigs had a clear secondary antibody response to gI, whereas the others developed an early to normal antibody response to gI. None of the pigs mounted a secondary neutralizing antibody response to PRV. We concluded that inoculation of pigs having high titers of gI-deficient maternal antibodies with low doses of a mildly virulent PRV, induced low to undetectable concentrations of antibodies to gI.
Mostrar más [+] Menos [-]Effect of Pasteurella haemolytica saline capsular extract on bovine pulmonary endothelial cells
1991
Kumar, S. | Breider, M.A. | Corstvet, R.E. | Maddux, J.L.
The purpose of this in vitro study was to determine whether Pasteurella haemolytica capsular extract (CE) damages bovine pulmonary endothelial cells (EC) directly or through neutrophil-mediated mechanisms. Chromium 51-labeled EC were treated with the following variables: CE (1, 10, and 100 ng of protein/ml), CE and bovine neutrophils (10(6) cells/well), and CE and polymyxin B (500 U/ml). Although only minimal damage to EC occurred by 5 hours after treatment, by 22 hours after treatment, the 10-ng and 100-ng CE dose produced severe damage to EC, as indicated by 51Cr release, cellular detachment, and loss of monolayer confluency. The component in the CE that was toxic to the EC was lipopolysaccharide, evidenced by effective neutralization of the toxic effect with polymyxin B. Neutrophils inhibited the CE-mediated EC toxicity and were activated, as indicated by shape change and adhesion to EC monolayers. We concluded that the lipopolysaccharide component of CE causes direct damage to EC, which can be attenuated by neutrophils and polymyxin B.
Mostrar más [+] Menos [-]Use of adult dog serum as a substitute for colostrum in the neonatal dog
1991
Poffenbarger, E.M. | Olson, P.N. | Chandler, M.L. | Seim, H.B. | Varman, M.
Failure to obtain passive transfer of immunity via colostrum can be detrimental to the health and survival of a young pup. It has been stated that pups that do not receive colostrum in the first 2 days after birth, be given adult dog serum as a source of protective immunoglobulins. Twenty-five Beagle pups were obtained by cesarean section from 6 Beagle bitches. The pups were allotted to 3 groups at birth. Group 1 was a control group and was allowed to suckle colostrum. Group-2 pups received 22 ml of pooled adult dog serum/kg of body weight (10 ml/lb) SC at birth. Group-3 pups were given 22 ml of pooled adult dog serum/kg by stomach tube at birth. Pups from groups 2 and 3 were separated from the bitch for 48 hours to prevent colostral antibody absorption and were fed a commercially available milk replacer by stomach tube. After 48 hours, all pups were returned to the bitch until they were weaned at 6 weeks of age. Blood samples were collected from all of the pups at birth and on days 1, 2, 7, 14, 21, 28, and 35. The concentration of IgA, IgG, and IgM in serum was determined by radial immunodiffusion and compared by use of a one-way analysis of variance. The control pups had significantly higher serum concentrations of IgA and IgG, than the pups in groups 2 and 3 on days 1 and 2 and 2 and 7, respectively. Group-2 pups had significantly higher serum IgM concentrations on day 1 than either group 1- or group-3 pups.
Mostrar más [+] Menos [-]Effect of dietary protein on functional, morphologic, and histologic changes of the kidney during compensatory renal growth in dogs
1991
White, J.V. | Finco, D.R. | Crowell, W.A. | Brown, S.A. | Hirakawa, D.A.
Two diets similar in caloric density and mineral content, but markedly different in protein content, were used to study the effects of dietary protein on renal function and morphologic and histopathologic changes in dogs that had functional renal tissue reduced by seven-eighths nephrectomy. The effects of moderate protein intake (MPrI = 15% protein; dry-matter basis) and high-protein intake (HPrI = 31% protein; dry-matter basis) were studied for the initial 7 months (period 1 [P1]) after renal mass reduction. Diets were then switched between groups during the following 7 months (period 2 [P2]) to evaluate the effects of increased or decreased protein intake. The HPrI caused significantly (P < 0.05) greater glomerular filtration rate (GFR) and renal growth than did MPrI during P1. Dogs that maintained HPrI during P1 and MPrI during P2 (group 1) had significant (P < 0.05) reduction in GFR during P2. Dogs that maintained MPrI during P1 and HPrI during P2 (group 2) had significant (P < 0.05) improvement in GFR and renal growth during P2. At the end of the study, renal reserve was evaluated in both groups of dogs before and after group 1 was returned to HPrI for 2 weeks. During this 2-week feeding trial, group-1 dogs had marked improvement in renal reserve, relative to group 2, and GFR increased to the terminal P1 values. Results indicate a possible residual benefit from HPrI during the early phase of compensatory renal growth in the form of functional compensatory memory to HPrI. The severity of renal lesions was indistinguishable between dogs of dietary groups during both study phases. Plasma electrolyte concentrations rapidly returned to normal range after renal ablation, but mild azotemia and proteinuria persisted throughout most of the study. High protein intake was not associated with increased degree or progression of proteinuria.
Mostrar más [+] Menos [-]Cytologic, microbiologic, and biochemical analysis of bronchoalveolar lavage fluid obtained from 24 healthy cats
1991
Padrid, P.A. | Feldman, B.F. | Funk, K. | Samitz, E.M. | Reil, D. | Cross, C.E.
Twenty-four healthy cats underwent bronchoscopy and bronchoalveolar lavage to determine the normal cytologic environment of the lower respiratory tract of cats. Initial screening to ensure the health of the study population included complete histories, physical examinations, thoracic radiography, CBC, serologic tests for feline leukemia virus, feline immunodeficiency virus, and occult heart-worm, and sugar and Baermann fecal flotation. In 18 cats, protected catheter brush samples of airway secretions from the lavaged lung segment were taken for culture of aerobic and anaerobic bacteria and mycoplasma. Bronchial lavage fluid (5 sequential 10-ml aliquots of normal saline solution) was pooled and filtered with cotton gauze. The unspun sample was used for determination of a total nucleated cell count. Lavage fluid was cytocentrifuged and 500 cells/slide were scored for determination of the cellular differential. Activity of lactate dehydrogenase and concentrations of total protein and IgG within the supernatant were measured, and assays were performed to detect the presence of IgA and IgM. Complete histologic evaluation of the lavaged lung of each of 6 random-source cats was performed after differential cell counting revealed 18% eosinophils within bronchoalveolar lavage fluid recovered from this group. Alveolar macrophages were the predominant cells encountered; however, a quarter of all cells recovered were eosinophils. A significant relationship was not found between the abundance of eosinophils in the lavage fluid, and either isolation of aerobic bacteria, high total nucleated cell counts, total protein concentrations, or activity of lactate dehydrogenase. Histologic evaluation of the lungs of 5 of 6 random-source cats revealed normal lungs in 2 cats, and minimal abnormal change in 3 others. Evaluation of the lungs from 1 random source cat revealed acute, mild eosinophilic bronchiolitis. We conclude that large numbers of eosinophils may be retrieved from the bronchoalveolar lavage fluid of healthy cats.
Mostrar más [+] Menos [-]Comparison of methods to determine glucose kinetics and measurement of recycling and lactose formation in lactating cows
1991
Biedebach, M.C. | Anand, R.S. | Black, Al | Jevning, R.
Several investigators have suggested that the conventional multicompartmental exponential analysis of in vivo glucose metabolism is arbitrary and possibly not the most accurate description of glucose kinetics, especially in the large animal. In support of that hypothesis, we found that in a systematic comparison of 3 methods, blood-specific radioactivity data in single-injection studies of glucose metabolism in lactating cows was better described graphically, or by a hybrid polynomial-biexponential curve fit, than by an exclusively exponential curve fit. We hypothesized that this finding was attributable to partial failure of linearity and steady-state assumptions that underlie the exponential model. Second, using both an irreversible tracer (3H-labeled glucose) and reversible tracer (14C-labeled glucose), we found that glucose carbon recycling had no effect during the first 2 hours, but became significant in lactating cows 7 hours after injection. Finally, we determined that approximately 52 to 55% of the glucose replacement rate was being used to generate lactose.
Mostrar más [+] Menos [-]Comparison of flunixin meglumine and flurbiprofen for control of ocular irritative response in dogs
1991
Millichamp, N.J. | Dziezyc, J.
Dogs were treated with the cyclo-oxygenase inhibitors flunixin meglumine IV or flurbiprofen topically. Acute inflammation was induced in the eyes by disruption of the anterior lens capsule, using a neodymium:yttrium aluminum garnet laser. Pupil diameter and intraocular pressure were measured before and after inducing ocular inflammation. Both drugs maintained mydriasis and increased intraocular pressure in the inflamed eyes, compared with untreated controls.
Mostrar más [+] Menos [-]Use of orthopedic markers for quantitative determination of proximal radial and ulnar growth in foals
1991
Smith, B.L. | Auer, J.A. | Taylor, S. | Hulse, D.S. | Longnecker, M.T.
Cortical bone screws were implanted into the proximal portion of the right and left radius and ulna of 6 newborn Quarter Horse foals as radiographic markers for measurement of growth. Distance between markers on a lateral radiographic view was measured. Radiographs were taken at 2-week intervals until the horses were 8 weeks old, at 4-week intervals until they were 48 weeks old, and at 12-week intervals until they were 72 weeks old. The proximal radius and ulna grew at similar rates during the 72-week period of evaluation, and growth continued throughout 72 weeks. The proximal radius grew 3.5 cm, and the ulna grew 3.4 cm. Although the rates of growth were similar, growth from the ulnar physis contributed only to the length of the olecranon; growth was not transmitted to the ulnar diaphysis distal to the cubital joint. The proximal radius slid distally in relation to the ulna as growth occurred at the proximal radial physis. These findings suggest that transfixing the ulna to the radius while growth is occurring at the proximal radial physis impedes the natural shifting process, and subluxation of the elbow can result. Severity of subluxation would be inversely related to the age of the horse at the time of transfixation.
Mostrar más [+] Menos [-]Changes in serum immunoglobulin values in kittens after ingestion of colostrum
1991
Yamada, T. | Nagai, Y. | Matsuda, M.
Immunoglobulin values were determined in fetal and kitten sera. In the fetal and precolostral kitten sera, only IgG was detected, except in 1 case in which IgM was detected. The IgG, IgA, and IgM were transferred to the kittens through colostrum ingestion with some selectivity. Concentration of the transferred IgG, IgA, and IgM decreased significantly with half-lives of 4.15 +/- 1.29 days, 2.03 +/- 0.33 days, and 2.2 +/- 1.2 days, respectively. As a result of this decrease and increase of de novo immunoglobulin synthesis, IgG, IgA, and IgM were at their lowest values when kittens were 20 to 25 days, 14 to 20 days, and 8 to 10 days old, respectively. After their nadir was reached, IgG values increased gradually, IgA slowly, and IgM rapidly, as a result of de novo immunoglobulin synthesis. When the kittens were 90 days old, their immunoglobulin values were 80% (IgG), 7% (IgA), and 100% (IgM), compared with those of adult cats. These findings suggest that kittens that receive inadequate colostrum from their mothers will be particularly susceptible to infection after they are 5 weeks old.
Mostrar más [+] Menos [-]Characterization of eugonic fermenters group EF-4 by polyacrylamide gel electrophoresis and protein immunoblot analysis
1991
Hanner, T.L. | Allen, J.W. | Robertson-Byers, A. | Hurley, S.L.
Whole-cell lysates and proteinase K-extracted lipopolysaccharide (LPS) of 19 strains of the group eugonic fermenter-4 (EF-4) were analyzed by electrophoresis and protein immunoblotting. These strains were isolated from dog- and cat-bite abscesses in human beings, ferret and human gastric lesions, and cat-lung infections. These strains represent 2 biovar groupings; EF-4a biovars ferment glucose and possess arginine dihydrolase activity, whereas EF-4b biovars do not. Electrophoresis of whole-cell lysates could distinguish between these biovars groups. Electrophoresis of LPS extracts revealed that all strains of EF-4 possess smooth chemotypes. Two strains of EF-4a reacted weakly in protein immunoblots and revealed distinct LPS profiles. These studies suggests that subgroups of EF-4 biovars may exist.
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