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Résultats 101-110 de 555
Effect of calf age and Salmonella bacterin type on ability to produce immunoglobulins directed against Salmonella whole cells or lipopolysaccharide
1992
Roden, L.D. | Smith, B.P. | Spier, S.J. | Dilling, G.W.
A commercially available Salmonella bacterin was administered to Holstein calves starting at 1 to 19 weeks of age. Serum samples were obtained before administering bacterin and at 2-week intervals thereafter. An ELISA with Salmonella dublin lipopolysaccharide (LPS) or S dublin whole cells as antigen, was used to measure specific IgG and IgM responses. Antibody responses to LPS were not detected from calves < 12 weeks old inoculated with killed bacterin. Immunoglobulin responses to whole-cell antigen were detected from all age groups of calves inoculated with the same killed Salmonella bacterin. Calves < 11 weeks old are able to produce immunoglobulins to some whole-cell antigens, but are unable to produce anti-LPS immunoglobulins when inoculated with killed Salmonella bacterin. This age-related response to killed Salmonella antigens may account, in part, for increased susceptibility to salmonellosis in calves < 12 weeks old. In comparison to the response for killed antigen, 8 calves given modified-live aromatic-dependent S dublin bacterin at 1 to 3 weeks of age had detectable anti-LPS immunoglobulin after immunization, although the response was not as rapid and was of a lesser magnitude than that of older calves given killed Salmonella bacterin.
Afficher plus [+] Moins [-]Systemic and pulmonary antibody response of calves to Pasteurella haemolytica after intrapulmonary inoculation
1992
McBride, J.W. | Corstvet, R.E. | Paulsen, D.B. | McClure, J.R. | Enright, F.M.
Systemic and pulmonary antibody responses of calves to Pasteurella haemolytica were evaluated by measuring immunoglobulin production in blood for 9 days and in pulmonary lavage fluid for 7 days after intrapulmonary inoculation. Clinical signs, pulmonary lesions, pulmonary and systemic inflammatory response, and amount of antigen in lavage fluid were used to evaluate the response of calves to challenge with P haemolytica. The pulmonary response consisted of production of IgG, IgE, and IgM antibodies to P haemolytica antigens and a 17- to 68-fold increase of cells in lavage fluid 8 hours after inoculation, with a gradual decrease toward normal. Antibodies of the IgM isotype to P haemolytica were demonstrated as early as 8 hours through 7 days after inoculation in 3 of 3 calves. Of the anti-P haemolytica isotypes, IgM was found in the highest concentration. In all of the inoculated calves, IgE was found 1 to 2 days after inoculation, and IgG was found in 2 of 3 inoculated calves from day 1 through 7 after inoculation. Detection of IgG correlated with smaller pulmonary lesions. Immunoglobulin A was not detected in lavage fluid. Serum was evaluated for IgG and IgM antibody response to P haemolytica. Specific IgM was detectable 5 days after inoculation, and IgG was detectable 7 days after inoculation. Pasteurella haemolytica antigens were not detected in serum or plasma. A transient increase in neutrophil count was found 8 hours after inoculation, with return to baseline values by 24 hours after inoculation. Antigen was detected in lavage fluid by use of monoclonal antibodies against selected P haemolytica capsular antigen, outer membrane antigens, and leukotoxin in all inoculated calves 8 hours after inoculation. The monoclonal antibody specific for P haemolytica capsule provided the best detection of antigen. The other monoclonal antibodies detected antigen, but were less consistent.
Afficher plus [+] Moins [-]Comparison of intranasal and intratracheal oxygen administration in healthy awake dogs
1992
Mann, F.A. | Wagner-Mann, C. | Allert, J.A. | Smith, J.
Intranasal (IN) and intratracheal (IT) oxygen administration techniques were compared by measuring inspired oxygen concentrations (FI(O2)) and partial pressures of arterial oxygen (Pa(O2)) in 5 healthy dogs at various IN (50, 100, 150, and 200 ml/kg of body weight/min) and IT (10, 25, 50, 100, 150, 200, and 250 ml/kg/min) oxygen flow rates. Intratracheal administration of oxygen permitted lower oxygen flow rates than IN administration. Each IT oxygen flow rate produced significantly higher FI(O2) and Pa(O2), than the corresponding IN flow rate. An IT oxygen flow-rate of 25 ml/kg/min produced FI(O2) and Pa(O2) Values equivalent to those produced by an IN oxygen flow rate of 50 ml/kg/min. An IT oxygen flow rate of 50 ml/kg/min produced FI(O2) and Pa(O2) values equivalent to those produced by IN oxygen flow rates of 100 and 150 ml/kg/min. All IT oxygen flow rates greater than or equal to 100 ml/kg/min produced FI(O2) and Pa(O2) values that were greater than FI(O2) and Pa(O2) values produced by IN oxygen flow rates of 200 ml/kg/min. The lowest flow rates studied (50 ml/kg/min, IN, and 10 ml/kg/min, IT) produced Pa(O2), capable of maintaining 97% hemoglobin saturation, which should be adequate for most clinical situations. Arterial blood gas analysis and FI(O2) measurements are necessary to accurately guide oxygen flow adjustments to achieve the desired Pa(O2) and to prevent oxygen toxicity produced by excessive FI(O2).
Afficher plus [+] Moins [-]Splenectomy in cattle via transthoracic approach
1992
Thompson, J.R. | Kersting, K.W. | Wass, W.M. | Davis, I.A. | Plumlee, K.H.
Sixty-eight cattle under general anesthesia were splenectomized. The transthoracic approach was used to provide better access to the spleen and to facilitate ligature of the major splenic vessels. The procedure was easier and less time-consuming, compared with other surgical approaches, and is considered to be less stressful to the animals. Postoperative recovery was complete in 67 of 68 cattle. After surgery, 1 animal developed respiratory tract disease that was thought to have been unrelated to the surgery.
Afficher plus [+] Moins [-]Antigen expresssion in canine tissue, recognized by a monoclonal antibody generated against canine melanoma cells
1992
Oliver, J.L. | Wolfe, L.G.
A murine hybridoma monoclonal antibody (MAB), IBF9, was generated by fusing myeloma cells (P3X63Ag8.653) with spleen cells from a BALB/c mouse immunized with the canine melanoma cell line CML-10c7. Initial screening of hybridoma antibodies was performed by use of an indirect immunoperomidase assay on formalin-fixed CML-10c7 cells. The isotype of MAB IBF9 was IgG1 as determined by radial gel immunodiffusion. The antibody was tested for reactivity against a panel of formalin-fixed, paraffin-embedded normal and neoplastic canine tissues, using immunoperoxidase staining. Immunostaining was observed in melanomas (24 of 38), a few carcinomas, basal cell tumors, and cutaneous lymphosarcomas. Immunostaining was not observed in fibrosarcomas, hemangiosarcomas, hemangiopericytomas, or histiocytomas. Staining of normal adult canine tissues was limited to a few epithehal tissues and a small percentage of lymphocytes. Fetal tissues were not reactive with MAB IBF9. There were statistically significant differences in frequency of reactivity among melanomas with regard to oral vs non-oral, malignant vs benign, and mitotic indices greater than or equal to 1 vs mitotic indices < 1. Differences were not significant when tumors were compared for degree of pigmentation or histologic type. On the basis of these findings, we suggest that MAB IBF9 may be of assistance in diagnosis of nonpigmented melanomas and in assessing the malignant potential of melanomas.
Afficher plus [+] Moins [-]Hematologic alterations in adult cats fed 6 or 12% propylene glycol
1992
Bauer, M.C. | Weiss, D.J. | Perman, V.
Cat foods containing propylene glycol (PG) induce Heinz body formation in feline erythrocytes. To further study the hematologic importance of dietary PG, 21 adult cats were allotted to 3 groups of 7 each and fed diets containing 0, 6, or 12% PG on a dry-weight basis. Cats fed PG had a dose-related increase in Heinz bodies within 2 weeks, and the increase persisted throughout the study. Although only slight changes occurred in PCV, hemoglobin concentration, and RBC count, punctate reticulocytes were significantly increased in the group fed 12% PG. Mean RBC survival was decreased in the groups fed 6 or 12% PG by 30 and 55%, respectively, compared with the control group. These data indicate that PG-containing diets cause a dose-dependent erythrocyte destruction, even when fed at concentrations as low as 6%.
Afficher plus [+] Moins [-]Potential use of simple manganese salts as antioxidant drugs in horses
1992
Singh, R.K. | Kooreman, K.M. | Babbs, C.F. | Fessler, J.F. | Salaris, S.C. | Pharm, J.
The scavenging of superoxide radicals by endogenous and therapeutically administered superoxide dismutases may prevent superoxide-mediated oxidative stress leading to lipid peroxidation, membrane lysis, and cell death in a wide variety of normal and pathologic states. Simple inorganic manganous salts such as MnCl2 also have superoxide dismutase-like activity and are extremely inexpensive, compared with enzymatic superoxide dismutase preparations. In this study, we explored the use of Mn salts as antioxidant drugs. We used the percentage of inhibition of nitroblue tetrazolium reduction by superoxide as a measure of the amount of superoxide dismutase-like activity. We found concentration-related increases in superoxide scavenging activity in simple buffer solutions upon addition of 1.25, 2.5, and 5.0 microM MnSO4. To determine whether Mn salts can inhibit oxidative damage in tissues, we used an in vitro model of lipid peroxidation in ischemic and reoxygenated rat liver slices. Concentrations of 10, 100, and 1000 micromoles MnCl2/L of buffer significantly decreased indicators of lipid peroxidation believed to be initiated by intracellular superoxide. We then determined the effectiveness of MnCl2 as a superoxide scavenger in conscious horses by measuring the superoxide scavenging ability of equine plasma before and during intravenous infusions of 1.0 L volumes of 0.9% saline solution containing 0, 12.5, or 25 mM MnCl2. Plasma Mn concentrations, which were determined by atomic absorption spectrophotometry, increased as a function of time and dose. Intravenously administered MnCl2 concomitantly produced dose-related increases in superoxide scavenging ability of equine plasma at 15, 30, 45, and 60 minutes after the onset of infusion, compared with preinfusion control values. Heart rate and blood pressure of the treated horses, which were monitored to measure toxicity of MnCl2, gradually increased in both treatment groups. Clinical adverse effects of MnCl2 administration included defecation, pawing, hyperexcitability, flank watching, and sweating. The results of this study indicate that simple Mn salts may scavenge superoxide radicals in vivo with minimal adverse reactions and at a trivial cost.
Afficher plus [+] Moins [-]Effects of clinically apparent and subclinical Ostertagia ostertagi infections on nitrogen and water metabolism in calves
1992
Xiao, L. | Gibbs, H.C.
Four balance trials were conducted in 3 groups of 5 calves each at 0, 4, 8, and 14 weeks after initial inoculation with Ostertagia ostertagi. Group-1 calves were inoculated with 100,000 third-stage larvae (L3) of O. ostertagi/wk for 14 weeks. Group-2 calves were inoculated with 10,000 L3/wk for 14 weeks, and group-3 calves were not inoculated. Effects of infection on apparent digestibilities of dry matter and nitrogen, and balances of nitrogen and water were evaluated. Neither clinically apparent (group 1) nor subclinical (group 2) O. ostertagi infections had observable effects on the apparent digestibility of dry matter. Subclinical infection also had no significant effects on nitrogen digestibility or nitrogen and water balance. Clinically apparent infection, however, decreased the apparent digestibilities of nitrogen significantly (P < 0.05) at 4, 8, and 14 weeks after inoculation, and decreased nitrogen balance at 4 and 8 weeks after inoculation. Group-1 calves also had lower water intake, fecal-water excretion, and apparent water balance, but higher urinary water output at 4, 8, and 14 weeks after inoculation.
Afficher plus [+] Moins [-]Effect of titanium endoprostheses on bone mineral density measurements, using quantitative computed tomography
1992
Markel, M.D. | Morin, R.L. | Roy, R.G. | Gottsauner-Wolf, F. | Chao, E.Y.S.
Quantitative computed tomography has been used extensively to measure bone mineral density; particularly in the vertebral column and in the proximal portion of the femur in human beings with osteoporosis. Other potential applications of this technique include evaluation of bone adjacent to metallic endoprostheses and evaluation of fractures as they heal. Unfortunately, metal causes severe image degradation, principally seen as starburst streaking. One method used to decrease these artifacts is by imaging less-attenuating materials, such as titanium alloy. Titanium decreases image degradation sufficiently to allow accurate determination of the geometric properties of cadaveric bone. In our study, the effect of a titanium segmental endoprosthesis on bone mineral density measurement was determined by use of bone specimens from dogs and calibration standards. Titanium decreased the bone mineral density of calibration solutions from 6.8 (500 mg/cm3) to 17.7% (250 mg/cm3), and increased bone mineral density of cortical bone by 5.3%. Titanium did not affect the repeatability of these scans, indicating that the error caused by titanium was systematic and can be corrected. Our data were suggestive that quantitative computed tomography can be used to measure bone mineral density of cortical bone adjacent to titanium endoprostheses, with a predictable increase in density measurement.
Afficher plus [+] Moins [-]Composition and analysis of cerebrospinal fluid in clinically normal adult cattle
1992
Welles, E.G. | Tyler, J.W. | Sorjonen, D.C. | Whatley, E.M.
Cerebrospinal fluid and serum were obtained from 16 clinically normal adult cows (11 dairy, 5 beef). Sodium, potassium, magnesium, total protein, and albumin concentrations, osmolality, and lactate dehydrogenase and creatine kinase activities, were quantified in CSF and serum. Total and differential cell counting, protein electrophoresis, and IgG quantification were performed on CSF. Statistical analyses of these variables, including mean, SEM, range, and 95% confidence intervals, were performed. Effects of blood contamination were evaluated, and were found to be negligible for all measured constituents. Correction factors for CSF creatine kinase and lactate dehydrogenase activities accounting for cellular contamination were developed. Total nucleated cell count was similar to counts in CSF of other species, but higher than values in healthy people. Differential leukocyte count in CSF was similar to that reported in CSF of other domestic animals: mostly lymphocytes, fewer monocytoid cells, and scant neutrophils. Cerebrospinal fluid protein concentration was higher than concentration reported for dogs, goats, and people, but was similar to values reported for horses. Beef cows had higher CSF total protein concentration than did dairy cows; also, beef cows had higher CSF gamma-globulin concentration. The concentration of sodium in CSF was slightly higher than the value in serum, and potassium concentration was lower than the value in serum. In contrast to studies of human beings, CSF osmolality was generally less than serum osmolality in the cows studied. Reference values for CSF electrolyte concentrations and osmolality are useful for diagnosis of salt poisoning and for assessment of the effects of fluid therapy. Magnesium concentration was lower in CSF, compared with serum. Reference values may be useful for diagnosis of grass tetany. Glucose concentration in CSF was variable, compared with serum concentration; sometimes, it was similar, lower, or even higher than serum glucose concentration. This variation reflects a more complete equilibration of glucose between CSF and blood, owing to the lower and more stable blood glucose concentration in cows. Creatine kinase activity in CSF was markedly less than, and was not correlated with, serum creatine kinase activity. Cerebrospinal fluid lactate dehydrogenase activity was markedly lower than serum lactate dehydrogenase activity. Compared with lactate dehydrogenase, creatine kinase activity had a wider range in these healthy cows; therefore, the former enzyme has higher specificity and sensitivity for diagnosis of diseases affecting the CNS.
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