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النتائج 131 - 140 من 469
Aerosol vaccination of pigs against Mycoplasma hyopneumoniae infection
1993
Murphy, D.A. | Van Alstine, W.G. | Clark, L.K. | Albregts, S. | Knox, K.
Aerosol vaccination is used effectively to immunize poultry against Newcastle disease, but to the authors' knowledge, this vaccination procedure is not well studied in other species. The efficacy of IM and aerosol vaccination of pigs against Mycoplasma hyopneumoniae infection was evaluated. Twenty-one pigs from a Mycoplasma-free herd were randomly allotted by litter and body weight into 3 groups. One group was given aerosolized phosphate-buffered saline solution (PBSS) by inhalation. The second group (AERO) was given aerosolized M hyopneumoniae vaccine by inhalation. The third group (IM) was given the same vaccine by IM injection. Vaccination by IM administration was repeated once, and aerosol vaccination was repeated twice at 2-week intervals. Two weeks after the last vaccination, all pigs were intratracheally challenge-exposed with 3 ml of broth culture containing 10(7) color-changing units (CCU) of a low-passage strain of virulent M hyopneumoniae. Pigs were observed daily for coughing. Four weeks after challenge exposure, all pigs were necropsied. Percentage of lung affected by gross pneumonia was measured, bronchioalveolar lavage fluid (BALF) cells were counted, and quantitative culture for mycoplasmas was performed on lung sections. Additionally, M hyopneumoniae-specific antibodies were measured in prevaccination, postvaccination, and postchallenge-exposure serum and BALF by use of indirect ELISA. Mean prevalence of persistent coughing in pigs of the AERO group (4.6 d/pig) was not different from that in pigs of the PBSS group (3.7 d/pig). Prevalence of coughing in IM vaccinated pigs (1.0 d/ pig) was lower (P < 0.05) than that in pigs of the PBSS group. Mean gross lung lesion scores and BALF cell counts were not different between the AERO (15% pneumonia, 5,233 cells/microliter) and PBSS (11% pneumonia, 3,022 cells/microliter) groups, but were lower (P < 0.05) in the IM group (1.5% pneumonia, 400 cells/microliter) than in the PBSS group. Mean lung mycoplasmal counts were not significantly (P < 0.05) different among the PBSS (10(5.6) CCU/g), AERO (10(5.3) CCU/g), and IM (10(3.3) CCU/g) groups. Postvaccination M hyopneumoniae-specific IgG or IgA was not detectable in BALF after either vaccination procedure. Postvaccination M hyopneumoniae-specific serum IgG concentration was not different among the 3 groups. Postchallenge exposure M hyopneumoniae-specific IgG and IgA were detectable in BALF of all pigs, but were not different among the 3 treatment groups. Postchallenge exposure-specific serum IgG concentration was not different between the PBSS (mean OD, 0.739) and AERO (mean OD, 0.672) groups, but was higher (P < 0.05) in the IM group (mean OD, 1.185) than in the PBSS group. Aerosol vaccination failed to induce local and systemic antibody responses detectable by ELISA, and failed to protect pigs against mycoplasmal pneumonia. Intramuscular vaccination failed to induce local and systemic antibody responses detectable by ELISA, but substantially reduced the clinical signs and lesions caused by challenge exposure to virulent M hyopneumoniae.
اظهر المزيد [+] اقل [-]Comparison of the properties and concentrations of the isoforms of retinol-binding protein in animals and human beings
1993
Burri, B.J. | Neidlinger, T.R. | Zwick, H.
We used size-exclusion high-performance liquid chromatography (HPLC) to investigate the properties of the 2 isoforms of vitamin A-containing (holo) retinol-binding protein (RBP) in animals: the form that is bound to transthyretin (holo-TTR-RBP), and the form that does not bind to TTR (holo-free RBP). We also used radial immunodiffusion to measure immunologically active RBP (apo+ holo RBP). We compared the isoforms of RBP in animals with those of human beings to determine which animal is the best model of human RBP. Size-exclusion HPLC detected holo-free and holo-TTR-RBP in every animal species studied. Apparent concentration of holo-TTR-RBP varied among species: that of rabbits and dogs much greater than that of apes, sheep, goats, monkeys, rhinoceroses, felids, rats, human beings, and deer greater than that of pigs, zebra, and bison greater than that of penguins. Dogs have unusual RBP chromatograms; they have high concentration of RBP, but also appear to transport much of their vitamin A on proteins other than RBP, Human RBP antibody preparations could detect apo + holo RBP immunologic activity only in apes, monkeys, and felids. Apes and monkeys appeared to have complete cross-reactivity to human RBP antibodies. Felids may have substantial, but partial, cross-reactivity. Apes and monkeys appear to be the most relevant animal models for study of human RBP transport. However, there is a need for less-expensive models. Further research is needed, but in the interim, rats or sheep may be satisfactory for some purposes.
اظهر المزيد [+] اقل [-]Isolation and characterization of porcine milk lactoferrin
1993
Chu, R.M. | Wang, S.R. | Weng, C.N. | Pursel, V.G.
We purified porcine whey lactoferrin by affinity chromatography on a heparin-sepharose column, followed by high-performance liquid chromatography. Molecular mass of purified lactoferrin (PLF) is 78,000 daltons. The iron-binding activity of PLF had a UV/ visible-light absorption spectrum indistinguishable from that of human and bovine lactoferrins (absorbance ratio [465 nm/280 nm] approx 0.046). The growth ratio of WIL-2 cells in PLF-supplemented medium is 70% of that in serum-containing medium. The aforementioned characteristics are similar to those of human and bovine lactoferrins. Immunoblot analysis, using polyclonal antibody raised in rabbits against porcine whey lactoferrin, revealed high specificity for PLF, and low cross-reactivity with commercial human and bovine lactoferrins.
اظهر المزيد [+] اقل [-]Comparison of 0.9, 3.6, and 7.2% NaCl for correction of experimentally induced hypochloremic, hypokalemic metabolic alkalosis in sheep
1993
Ward, J.L. | Smith, D.F. | Fubini, S.L. | Grohn, Y.T.
Nine adult female sheep were each surgically fitted with an Ivan and Johnston reentrant cannula in the cranial part of the duodenum just distal to the pylorus. By diversion (loss) of abomasal outflow, this model has been shown to consistently induce hypochloremic, hypokalemic metabolic alkalosis, accompanied by hyponatremia and dehydration. Each sheep was subjected to 3 treatment trials, each preceded by a 24-hour prediversion period, and a diversion period during which a syndrome of hypochloremia (68 +/- 2 mEq/L), hypokalemia, hyponatremia, and metabolic alkalosis was induced. Development of this syndrome was attributable to losses of large amounts of acid and electrolytes in the abomasal effluent. Mean total electrolyte contents of the effluent were: Cl-, 650 +/- 27 mEq; Na+, 388 +/- 23 mEq; and K+, 123 +/- 12 mEq, with total volume loss ranging from 3.6 to 10.0 L of gastric contents and pH ranging from 3 to 5. Decreases in plasma electrolyte concentrations also can be attributed to decreased intake, because anorexia developed shortly after the onset of diversion. Electrolyte losses in urine during diversion were minimal for Cl-(mean +/- SEM, 12.0 +/- 5.1 mEq), but were greater for Na+ (124.2 +/- 14.5 mEq) and K+ (185.1 +/- 31.2 mEq). Treatments consisted of 0.9% NaCl (300 mosm/ L), 3.6% NaCl (1,200 mosm/L, and 7.2% NaCl (2,400 mosm/L) administered over a 2-hour period, with the administered volume determined by the estimated total extracellular fluid Cl- deficit. Significant difference was not found among treatments, with all solutions resulting in return of clinicopathologic and physical variables to prediversion values within 12 hours of treatment. We concluded that rapid iv replacement of Cl-, with small volumes of hypertonic saline solution, is safe and effective for correction of experimentally induced hypochloremic, hypokalemic, metabolic alkalosis in sheep.
اظهر المزيد [+] اقل [-]Development to blastocysts of one- to two-cell equine embryos after coculture with uterine tubal epithelial cells
1993
Ball, B.A. | Brinsko, S.P. | Thomas, P.G.A. | Miller, P.G. | Ellington, J.E.
Development of 1- to 2-cell in vivo fertilized equine embryos cultured with or without uterine tubal epithelial cells (UTEC) was studied. One- to 2-cell embryos (n = 26) were collected surgically from the uterine tubes of pony mares 1 day after ovulation. Four- to 8-cell embryos (n = 9) were collected 2 days after ovulation. Presumptive zygotes and 2-cell embryos were cultured with (n = 17) or without (n = 9) UTEC, and all 4- to 8-cell embryos were cocultured with UTEC as positive controls. Uterine tubal epithelial cells were used as cell suspensions within 2 weeks after initiation of cultures. Embryos were cultured to blastocysts or until the embryo had morphologic degeneration. Six presumptive zygotes failed to cleave in vitro. Development to blastocysts of 1-cell (4 of 11) and 2-cell (2 of 6) embryos cocultured with UTEC was similar. Coculture of 1- to 2-cell embryos with UTEC significantly (P = 0.05) improved development to blastocysts, compared with culture in medium alone (35 vs 0%, respectively); however, development to blastocysts of 1- to 2-cell embryos cocultured with UTEC was less (P < 0.025) than that of 4- to 8-cell embryos cocultured with UTEC (35 vs 89%, respectively).
اظهر المزيد [+] اقل [-]Effects of abdominal insufflation with nitrous oxide on cardiorespiratory measurements in spontaneously breathing isoflurane-anesthetized dogs
1993
Gross, M.E. | Jones, B.D. | Bergstresser, D.R. | Rosenhauer, R.R.
Cardiorespiratory effects of abdominal insufflation were evaluated in 8 dogs during isoflurane anesthesia. Each dog was studied 3 times, in 1 of the following orders of insufflation pressures: 10-20-30, 20-30-10, 30-20-10, 10-30-20, 20-10-30, and 30-10-20 mm of Hg. Anesthesia was induced by use of a mask, dogs were intubated, and anesthesia was maintained by isoflurane in 100% oxygen. After instrumentation, baseline values were recorded (time 0), and the abdomen was insufflated with nitrous oxide. Data were recorded at 5, 10, 15, 20, 25, and 30 minutes after insufflation. The abdomen was then desufflated, with recording of data continuing at 35 and 40 minutes. Mean arterial pressure increased at 5 minutes during 20 mm of Hg insufflation pressure, and from 20 to 30 minutes during 30 mm of Hg pressure. Tidal volume decreased from 5 to 30 minutes during 10 and 20 mm of Hg pressures, and from 5 to 40 minutes during 30 mm of Hg pressure. Minute ventilation decreased at 10 and 20 minutes during 20 mm of Hg pressure. End-tidal CO2 concentration increased from 5 to 30 minutes during 20 and 30 mm of Hg pressure. The PaCO2 decreased at 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Values for pH decreased from 10 to 30 minutes during 20 and 30 mm of Hg pressures. The PaO2 decreased from 20 to 40 minutes during 10 mm of Hg pressure, at 30 minutes during 20 mm of Hg pressure, and from 10 to 40 minutes during 30 mm of Hg pressure. Percentage decrease in tidal volume was greater at 5 and 15 minutes with 30 mm of Hg pressure. Differences in percentage increase in end tidal CO2 concentration were observed among the 3 pressures from 5 to 30 minutes. Although significant, these changes do not preclude use of laparoscopy if insufflation pressure > 20 mm of Hg is avoided.
اظهر المزيد [+] اقل [-]Pharmacokinetics of digoxin administered to horses with congestive heart failure
1993
Sweeney, R.W. | Reef, V.B. | Reimer, J.M.
Nine horses with naturally acquired) congestive heart failure were treated with 2.2 Kg of digoxin/kg of body weight by the IV route, followed by 11 microgram/kg administered orally every 12 hours thereafter. Furosemide was administered IV concurrently with IV administered digoxin every 12 hours. Serum concentration of digoxin was measured after the first (IV) and seventh (orally administered) dose. After IV administration, digoxin disposition was described by a 2-compartment model, with a rapid distribution phase t1/2 alpha = 0.17 hour), followed by a slower elimination phase (beta = 0.096 +/- 0.055 h-1, t1/2 beta = 7.2 hours, where beta is the exponential term from the elimination phase of the concentration vs time curve). Bioavailability after oral administration was 21.2 10.8%. After the seventh orally administered dose, serum concentration of digoxin peaked 1 to 2 hours later, and was 1.9 +/- 0.7 ng/ml (mean +/- SD). In 4 horses, a second increase in serum digoxin concentration was observed 4 to 8 hours after the initial peak which possibly was evidence of enterohepatic recycling of the drug. Response to treatment included reduction in heart rate, peripheral edema, and pulmonary edema, but these could not be attributed to the digoxin alone because the horses were treated concurrently with furosemide.
اظهر المزيد [+] اقل [-]Use of indirect enzyme-linked immunosorbent assay with hot saline solution extracts of a variant (M-) strain of Brucella canis for diagnosis of brucellosis in dogs
1993
Mateu-de-Antonio, E.M. | Martin, M. | Soler, M.
An ELISA, using hot saline solution extracts (HSS) of a less-mucoid variant (M -) strain of Brucella canis as antigen, was developed for detection of antibodies against B canis in dogs. The test was applied to 177 field serum samples previously tested by use of the 2-mercaptoethanol rapid slide agglutination test, 2- mercaptoethanol-tube agglutination test, and agar gel -immunodiffusion containing HSS and cytoplasmic antigens of B canis. Results indicated that this ELISA seems to be highly specific (95.6%) and slightly less sensitive (93.8%). The HSS obtained from B canis wild-type RM 6/66 also have been used, but in our study, it seemed to be unsuitable for use in ELISA because of the high background values observed for sera with negative test results.
اظهر المزيد [+] اقل [-]Prevalence of bluetongue virus expression in leukocytes from experimentally infected ruminants
1993
Ellis, J.A. | Coen, M.L. | Maclachlan, N.J. | Wilson, W.C. | Williams, E.S. | Leudke, A.J.
Replication of bluetongue virus (BTV) in leukocytes from the blood of sheep, cattle, elk, and mule deer inoculated with BTV serotype 10 or 17 was assessed by immunocytochemical staining and dot blot northern hybridization to determine if differences in the prevalence of infection in this blood fraction might account for the differences in clinical disease among these species. Viremia was confirmed by virus isolation in all inoculated animals. Analysis of leukocytes with monoclonal antibodies specific for BTV proteins revealed low numbers of infected leukocytes in only 2 sheep 8 days after inoculation with BTV serotype 10. Most of the cells expressing BTV were identified morphologically as monocytes; approximately 10% of infected cells were lymphocytes. Bluetongue virus was not detected by use of dot-blot hybridization on samples of blood. Our results suggest that differential infection of leukocytes does not account for the pronounced differences in clinical signs and pathologic changes among ruminants.
اظهر المزيد [+] اقل [-]Purification of surface-exposed integral outer membrane proteins of Actinobacillus pleuropneumoniae and their role in opsonophagocytosis
1993
Thwaits, R.N. | Kadis, S.
Previously identified 39-, 50-, and 76-kd integral outer membrane proteins (IOMP) of Actinobacillus pleuropneumoniae, a respiratory tract pathogen, were separated by electroelution of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-obtained fragments and their role in opsonophagocytosis by porcine leukocytes was investigated by flow cytometry of fluorescein-labeled A pleuropneumoniae. Using specific antisera, immunoblot analysis indicated that the 3 proteins were antigenically distinct. Antibodies against each IOMP have an important role as opsonins for phagocytosis by porcine leukocytes. The effect of using a combination of an 3 of the specific antisera was minimal. Antiserum absorbed against intact A pleuropneumoniae and Escherichia coli organisms indicated that the antibodies to the 39-, 50-, and 76-kd IOMP were specific for A pleuropneumoniae antigens. Nonheat-treated antiserum did not increase phagocytosis, compared with heat-inactivated antiserum, indicating that complement may not have a major role in opsonization of A pleuropneumoniae.
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