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Amelia R Woolums,
Roy D Berghaus, Londa J Berghaus,
Roger W Ellis,
Mel E Pence,
Jeremiah T Saliki,
Katherine A E Hurley,
Kimberly L Galland,
William W Burdett,
Scott T Nordstrom,
David J Hurley
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ABSTRACT: Objective-To compare immune responses following modified-live virus (MLV) vaccination at weaning after intranasal or SC administration of an MLV vaccine to beef calves at 2 or 70 days of age. Animals-184 calves. Procedures-Calves were allocated to 1 of 5 groups. The IN2 (n = 37) and IN70 (37) groups received an MLV vaccine containing bovine herpesvirus 1 (BHV1), bovine viral diarrhea virus (BVDV) types 1 and 2, bovine respiratory syncytial virus (BRSV), and parainfluenza 3 virus intranasally and a Mannheimia haemolytica and Pasteurella multocida bacterin SC at median ages of 2 and 70 days, respectively. The SC2 (n = 36) and SC70 (37) groups received a 7-way MLV vaccine containing BHV1, BVDV1, BVDV2, BRSV, parainfluenza 3 virus, M haemolytica, and P multocida SC at median ages of 2 and 70 days, respectively; the control group (37) remained unvaccinated until weaning. All calves received the 7-way MLV vaccine SC at median ages of 217 (weaning) and 231 days. Serum neutralizing antibody (SNA) titers against BHV1, BVDV1, and BRSV and intranasal IgA concentrations were determined at median ages of 2, 70, 140, 217, and 262 days. Cell-mediated immunity (CMI) against BHV1, BRSV, BVDV1, and P multocida was determined for 16 calves/group. Results-At median ages of 140 and 217 days, BVDV1 SNA titers were significantly higher for the SC70 group than those for the other groups. Intranasal IgA concentrations and CMI increased over time for all groups. Vaccination at weaning increased SNA titers and CMI in all groups. Conclusions and Clinical Relevance-SC administration of an MLV vaccine to 70-day-old calves significantly increased BVDV1 antibody titers before weaning.
American Journal of Veterinary Research 02/2013; 74(2):343-54. · 1.27 Impact Factor
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ABSTRACT: There are no studies investigating interactions between clarithromycin or azithromycin and rifampin or other commonly used antimicrobial agents against virulent isolates of Rhodococcus equi. In addition, there is no published data on the postantibiotic effects (PAEs) and pharmacodynamics properties of antimicrobial agents against R. equi. The objectives were to assess in vitro interactions, pharmacodynamics, and PAEs of 11 antimicrobial agents belonging to various antimicrobial classes against R. equi. Antimicrobial agents investigated (erythromycin, clarithromycin, azithromycin, rifampin, amikacin, gentamicin, enrofloxacin, vancomycin, imipenem, ceftiofur, and doxycycline) were selected based on in vitro activity against large numbers of isolates of R. equi and frequency of use in foals or humans infected with R. equi. Three virulent strains of R. equi were evaluated by time-kill curves and checkerboard assays, and the postantibiotic effect was measured at 5×MIC. Only amikacin, gentamicin, enrofloxacin, and vancomycin were bactericidal against R. equi. Combinations including a macrolide (erythromycin, clarithromycin, azithromycin) and either rifampin or doxycycline, and the combination doxycycline-rifampin were synergistic. Combinations containing amikacin and erythromycin, clarithromycin, azithromycin, or rifampin and the combination gentamicin-rifampin were antagonistic. The PAEs of rifampin, erythromycin, clarithromycin, vancomycin, and doxycycline were relatively long with median values ranging between 4.5 and 6.5h. Azithromycin, gentamicin, and imipenem had intermediate PAEs ranging between 3.3 and 3.5h. Amikacin, enrofloxacin, and ceftiofur had shorter PAEs ranging between 1.3 and 2.1h. Gentamicin, amikacin, enrofloxacin, and doxycycline exhibited concentration-dependent activity whereas erythromycin, clarithromycin, azithromycin, rifampin, ceftiofur, imipenem, and vancomycin exhibited time-dependent activity against R. equi.
Veterinary Microbiology 05/2012; 160(1-2):207-13. · 3.33 Impact Factor
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ABSTRACT: To assess the in vitro capability of aqueous black walnut extracts (BWEs) to generate reactive oxygen species in water-based media ranging in makeup from a simple buffer solution to a complex solution containing serum.
3 BWEs.
Production of reactive oxygen species by BWEs prepared in water or N-hexane was tested in PBS solution, PBS solution containing 0.5% bovine serum albumin and 5mM glucose (PBG), and RPMI-1640 medium (RPMI) containing 10% fetal bovine serum or 10% donor horse serum. Reactive oxygen species production was measured as conversion of nonfluorescent dihydrorhodamine 123 by reactive oxygen species to its fluorescent product, rhodamine-123. Hydrogen peroxide was used as a standard for reactive oxygen species activity.
BWEs prepared in water generated reactive oxygen species in a dose-dependent manner over a 4-hour period, with peak activity detected when the BWEs were added as 10% (vol/vol) of the RPMI. The BWE prepared in N-hexane generated maximal reactive oxygen species activity after incubation for 3 to 4 hours when added at concentrations ranging from 0.3% to 0.5% (vol/vol) of the RPMI. The BWE prepared in water generated the highest fluorescent signal in PBS solution, whereas the BWE prepared in N-hexane generated the highest fluorescent signal in PBG.
The BWEs prepared in water generated a dose-dependent induction of fluorescence in all the water-based solutions tested. These findings indicated that the BWEs, which are used to induce laminitis in horses, generate reactive oxygen species.
American Journal of Veterinary Research 03/2011; 72(3):308-17. · 1.27 Impact Factor
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ABSTRACT: To evaluate effects of black walnut extract (BWE) on equine mononuclear cells and determine whether BWE has direct proinflammatory effects.
Mononuclear cells separated from blood samples from 8 horses.
Aqueous BWE was prepared and processed to eliminate contamination with particulates and microbes. A Limulus amoebocyte lysate assay was used to detect lipopolysaccharide (LPS) contamination in the BWE. Mononuclear cells were incubated in minimal essential medium with or without the addition of 0.6% to 10% (vol/vol) BWE. These mononuclear cells were assessed for viability, activities of caspases 3 and 7, nitric oxide production, procoagulant activity, and tumor necrosis factor-α production. The effect of LPS on cellular responses induced by BWE was assessed by coincubation with 13 U of polymyxin B/mL; mononuclear cells incubated with LPS were used as a reference.
BWE did not cause loss of cell membrane integrity in mononuclear cells but did induce a dose-dependent increase in activities of caspases 3 and 7. Neither BWE nor LPS significantly induced production of nitric oxide. Both BWE and LPS induced comparable amounts of procoagulant activity and tumor necrosis factor-α production; coincubation with polymyxin B reduced the activity for BWE and LPS by 50% and approximately 100%, respectively.
Addition of BWE induced inflammatory activation of equine mononuclear cells, a portion of which was independent of the effects of LPS. Furthermore, BWE and LPS may work in concert to induce systemic inflammatory responses that contribute to the development of acute laminitis in horses.
American Journal of Veterinary Research 03/2011; 72(3):318-25. · 1.27 Impact Factor
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ABSTRACT: To assess IgE response and cytokine gene expressions in pulmonary lymph collected from bovine respiratory syncytial virus (BRSV)-infected calves after ovalbumin inhalation.
Thirteen 7- to 8-week-old calves.
The efferent lymphatic duct of the caudal mediastinal lymph node of each calf was cannulated 3 or 4 days before experiment commencement. Calves were inoculated (day 0) with BRSV (n = 7) or BRSV-free tissue culture medium (mock exposure; 6) via aerosolization and exposed to aerosolized ovalbumin on days 1 through 6 and day 15. An efferent lymph sample was collected daily from each calf on days -1 through 16; CD4+ and CD8+ T lymphocyte subsets in lymph samples were enumerated with a fluorescence-activated cell scanner. Expressions of several cytokines by efferent lymphocytes and lymph ovalbumin-specific IgE concentration were measured. Each calf was euthanized on day 16 and then necropsied for evaluation of lungs.
Mean fold increase in ovalbumin-specific IgE concentration was greater in BRSV-infected calves than in mock-infected calves. At various time points from days 4 through 10, percentages of T lymphocyte subsets and CD4+:CD8+ T lymphocyte ratios differed between BRSV-infected calves and day -1 values or from values in mock-infected calves. On days 3 through 5, IL-4 and IL-13 gene expressions in BRSV-infected calves were increased, compared with expressions in mock-infected calves. Lung lesions were consistent with antigen exposure.
In response to the inhalation of aerosolized ovalbumin, BRSV infection in calves appeared to facilitate induction of a T helper 2 cell response and ovalbumin-specific IgE production.
American Journal of Veterinary Research 01/2011; 72(1):134-45. · 1.27 Impact Factor
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ABSTRACT: Stimulation of adenosine A(2A) receptors results in anti-inflammatory effects in a variety of cell types. Lipopolysaccharide (LPS) and pro-inflammatory cytokines, such as TNF-alpha and IL-1, have been reported to up-regulate the expression of adenosine A(2A) receptors and thereby enhance the functional activity of adenosine A(2A) receptors in human and murine monocyte/macrophage cell lines and in monocytes/macrophages isolated from those species. In this study, we investigated the effects of LPS and TNF-alpha on the expression and functional activity of adenosine A(2A) receptors in isolated equine peripheral blood monocytes. The results of this study indicate that LPS and TNF-alpha up-regulate the transcription of adenosine A(2A) receptors for up to 24h; the response to LPS was of greater magnitude than the response to TNF-alpha. In this study, incubation with LPS, but not with TNF-alpha, resulted in down-regulation of adenosine A(3) receptor mRNA expression. Furthermore, incubation of these cells with LPS significantly increases the surface density of adenosine A(2A) receptors, and incubation with low concentrations of either LPS or TNF-alpha significantly increases the potency of the adenosine A(2A) receptor agonist, ATL313, to inhibit LPS-induced production of TNF-alpha. These findings suggest that the increased expression of adenosine A(2A) receptors and the enhanced functional potency of adenosine A(2A) receptor agonists after exposure to pro-inflammatory substances such as LPS or TNF-alpha may render adenosine A(2A) receptor agonists particularly important in the treatment of the systemic inflammatory response syndrome that occurs secondary to endotoxemia and bacterial infections in adult horses and neonatal foals.
Veterinary Immunology and Immunopathology 06/2010; 135(3-4):289-95. · 2.08 Impact Factor
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ABSTRACT: Although studies have been performed to characterize responses of macrophages from individual anatomical sites (e.g., alveolar macrophages) or of murine-derived macrophage cell lines to microbial ligands, few studies compare these cell types in terms of phenotype and function. We directly compared the expression of cell surface markers and functional responses of primary cultures of three commonly used cells of monocyte-macrophage lineage (splenic macrophages, bone marrow-derived macrophages, and bone marrow-derived dendritic cells) with those of the murine-leukemic monocyte-macrophage cell line, RAW 264.7. We hypothesized that RAW 264.7 cells and primary bone marrow-derived macrophages would be similar in phenotype and would respond similarly to microbial ligands that bind to either Toll-like receptors 2, 3, and 4. Results indicate that RAW 264.7 cells most closely mimic bone marrow-derived macrophages in terms of cell surface receptors and response to microbial ligands that initiate cellular activation via Toll-like receptors 3 and 4. However, caution must be applied when extrapolating findings obtained with RAW 264.7 cells to those of other primary macrophage-lineage cells, primarily because phenotype and function of the former cells may change with continuous culture.
Comparative immunology, microbiology and infectious diseases 10/2009; 33(5):443-54. · 2.99 Impact Factor
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ABSTRACT: Bovine respiratory syncytial virus (BRSV) and Haemophilus somnus (H. somnus) co-infect to form a polymicrobial respiratory disease in calves. Both BRSV and H. somnus vaccinations have independently been shown to sometimes induce adverse IgE mediated responses. We hypothesized that combining these disease agents in vaccination would induce cytokine shifts resulting in greater IgE production and enhanced disease. Concurrent vaccination with subsequent infection with one or both pathogens in calves was conducted to evaluate the isotypic antibody responses, disease severity and cytokine response. BRSV-specific serum IgE levels were elevated for the most clinically diseased calves, while no difference was detected in the IgE levels to H. somnus among groups. The IFN-gamma message and H. somnus-specific IgG2 antibodies were significantly elevated in calves with the lowest clinical scores. Vaccination preferentially stimulated higher levels of IgG1 antibodies to BRSV, but in contrast higher levels of IgG2 antibodies to H. somnus. Concurrent vaccination induced IgE antibodies to BRSV, which were directly correlated with disease severity whereas vaccine induced IgG2 antibodies to H. somnus were inversely correlated with disease severity.
Vaccine 09/2006; 24(33-34):6018-27. · 3.77 Impact Factor
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ABSTRACT: Specific allergen immunotherapy represents the only curative treatment of allergy. No studies have evaluated its efficacy in feline allergic asthma. We hypothesized that an abbreviated course of immunotherapy (rush immunotherapy, RIT) would blunt eosinophilic airways inflammation in experimental feline asthma induced with Bermuda grass allergen (BGA). The 6-month study included asthmatic-RIT treated cats; asthmatic-no RIT treated cats; and non-asthmatic cats. RIT involved increasing parenteral doses (20-200 microg) of BGA over 2 days. Numbers of eosinophils in bronchoalveolar lavage fluid (BALF), serum and BALF immunoglobulins, lymphocyte blastogenesis assays, and cytokines in blood and BALF were evaluated. BALF eosinophils decreased (P=0.048) only in asthmatic-RIT treated cats (baseline 1.1 x 10(6); Month 6, 2.4 x 10(5)). Serum BGA-specific IgG was higher (P<0.001) at all time points after baseline within the asthmatic-RIT group, and was higher (P<0.001) than asthmatic-no RIT cats at Months 1 and 3. No differences (P=0.133) in BGA-specific IgE levels over time were noted among asthmatic-RIT cats, but this group had lower IgE levels (P<0.001) levels than asthmatic no-RIT cats at Months 3 and 6. Differences in BGA-specific IgA levels over time and between the two groups did not reach the traditional level of significance. The mean BGA stimulation index in the asthmatic-RIT cats was biologically insignificant at 6 months, reflecting BGA-specific lymphocyte hypoproliferation. Preliminary results of cytokine profiles were not significantly different; however, BAL cytokine profiles favoring a Th2 response prior to RIT shifted to increased IFN-g and IL-10 thereafter. RIT dampens eosinophilic airways inflammation in cats with experimental asthma. The mechanism of RIT may involve changes in allergen-specific immunoglobulins, induction of hyporesponsive lymphocytes, or alteration of cytokine profiles.
Veterinary Immunology and Immunopathology 03/2006; 110(1-2):141-53. · 2.08 Impact Factor
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ABSTRACT: Bovine respiratory syncytial virus (BRSV) and Haemophilus somnus are two bovine respiratory pathogens that cause disease singly or as part of a polymicrobial infection. BRSV infection is often associated with a predisposition towards production of a T helper type 2 (Th2) response and IgE production. In contrast, an IgG2 response to H. somnus has been shown to be most important for recovery. An experiment was performed to evaluate the hypothesis that infection with H. somnus on day 6 of experimental BRSV infection would result in disease enhancement and potentially an altered immune response when compared with single infection. Three groups of calves were either dually infected or singly infected with H. somnus or BRSV. Serum and bronchoalveolar lavage fluid (BALF) pathogen specific IgG1, IgG2, IgE, and IgA responses were evaluated by ELISA. TaqMan RT-PCR was used to examine cytokine gene expression by PBMC and BAL cells. Clinical signs were evaluated for 28 days after BRSV infection, followed by necropsy and histological examination of the lungs. In dually infected calves, disease was significantly more severe, H. somnus was isolated from the lungs at necropsy, and high IgE and IgG responses were detected to H. somnus antigens. Cytokine profiles on day 27 were elevated in dually infected calves, but did not reflect a skewed profile. These results contrasted with singly infected calves that were essentially normal by day 10 of infection and lacked both lung pathology and the presence of H. somnus in the lung at necropsy. The increase in IgE antibodies specific for antigens of H. somnus presents a possible mechanism for pathogenesis of the disease enhancement.
Veterinary Immunology and Immunopathology 09/2005; 107(1-2):119-30. · 2.08 Impact Factor
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ABSTRACT: To compare the effects of an orally administered corticosteroid (prednisone), an inhaled corticosteroid (flunisolide), a leukotriene-receptor antagonist (zafirlukast), an antiserotonergic drug (cyproheptadine), and a control substance on the asthmatic phenotype in cats with experimentally induced asthma.
6 cats with asthma experimentally induced by the use of Bermuda grass allergen (BGA).
A randomized, crossover design was used to assess changes in the percentage of eosinophils in bronchoalveolar lavage fluid (BALF); airway hyperresponsiveness; blood lymphocyte phenotype determined by use of flow cytometry; and serum and BALF content of BGA-specific IgE, IgG, and IgA determined by use of ELISAs.
Mean +/- SE eosinophil percentages in BALF when cats were administered prednisone (5.0 +/- 2.3%) and flunisolide (2.5 +/- 1.7%) were significantly lower than for the control treatment (33.7 +/- 11.1%). We did not detect significant differences in airway hyperresponsiveness or lymphocyte surface markers among treatments. Content of BGA-specific IgE in serum was significantly lower when cats were treated with prednisone (25.5 +/- 5.4%), compared with values for the control treatment (63.6 +/- 12.9%); no other significant differences were observed in content of BGA-specific immunoglobulins among treatments.
Orally administered and inhaled corticosteroids decreased eosinophilic inflammation in airways of cats with experimentally induced asthma. Only oral administration of prednisone decreased the content of BGA-specific IgE in serum; no other significant local or systemic immunologic effects were detected among treatments. Inhaled corticosteroids can be considered as an alternate method for decreasing airway inflammation in cats with asthma.
American Journal of Veterinary Research 08/2005; 66(7):1121-7. · 1.27 Impact Factor
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ABSTRACT: To evaluate changes in cysteinyl leukotriene (LT) concentrations in urine and bronchoalveolar lavage fluid (BALF) in cats with experimentally induced asthma.
19 cats with experimentally induced asthma and 5 control cats.
Cats were sensitized to Bermuda grass or house dust mite allergen, and phenotypic features of asthma were confirmed with intradermal skin testing, evaluation of BALF eosinophil percentages, and pulmonary function testing. A competitive ELISA kit for LTC4, LTD4, and LTE4 was used for quantitative analysis of LTs. Urinary creatinine concentrations and BALF total protein (TP) concentrations were measured, and urinary LT-to-creatinine ratios and BALF LT-to-TP ratios were calculated.
Mean urinary LT-to-creatinine ratios did not differ significantly between control cats and allergen-sensitized cats before or after sensitization and challenge exposure with saline (0.9% NaCl) solution or allergen, respectively. In BALF the mean LT-to-TP ratio of control cats did not differ significantly before or after sensitization and challenge exposure with saline. Asthmatic cats had BALF LT-to-TP ratios that were significantly lower than control cats at all time points, whereas ratios for asthmatic cats did not differ significantly among the various time points.
Although LTs were readily detectable in urine, no significant increases in urinary LT concentrations were detected after challenge in allergen-sensitized cats. Spot testing of urinary LT concentrations appears to have no clinical benefit for use in monitoring the inflammatory asthmatic state in cats. The possibility that cysteinyl LTs bind effectively to their target receptors in BALF and, thus, decrease free LT concentrations deserves further study.
American Journal of Veterinary Research 12/2003; 64(11):1449-53. · 1.27 Impact Factor
