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Spatial and temporal distribution of foot-and-mouth disease virus in the lake zone of Tanzania Full text
2014
Joseph M. Genchwere | Christopher J. Kasanga
This study was conducted to determine the spatiotemporal distribution of foot-and-mouth disease (FMD) virus (FMDV) serotypes and evaluate the awareness of livestock keepers about FMD in Tanzania. An observational prospective study involving serological analysis, FMDV antigen detection and questionnaire survey was carried out in the lake zone of Tanzania. Seroprevalence of antibodies to the nonstructural protein 3ABC of FMDV and serotype-specific antigen detection were investigated by using SVANOVIR® FMDV 3ABC-Ab ELISA and indirect-sandwich ELISA (sELISA), respectively, whilst a structured questionnaire was used to evaluate the awareness of livestock keepers about FMD. During the period of 2010–2011, both serum and tissue (foot-and-mouth epithelia) samples were collected from cattle suspected of FMD in 13 districts of the four regions of the lake zone. A total of 107 (80.5%) out of 133 tested serum samples were seropositive to nonstructural protein 3ABC, with at least one sample being positive from all 10 districts screened. Fifteen (53.6%) out of 28 tissue epithelial samples collected from FMD cases in eight districts during the course of this study were positive to serotype O FMDV antigen. Of these eight districts, serotype O FMDV antigens were detected from seven districts and no other serotypes were recovered from animal samples screened. Questionnaire surveys in six districts indicated that livestock keepers in the lake zone were aware of the clinical manifestations (26/29 = 90.0%) and economic impact (23/29 = 79.0%) of FMD in the region. The questionnaire data showed that FMD outbreaks often occurred after rainy seasons (22/29 = 75.9%), with the highest peaks predominantly occurring just after the long rains in May and June, and at the end of the short rains in November and December of each year. The spatial distribution of the FMD cases suggested that serotype O virus exposure was the only widespread cause of the 2010–2011 outbreaks in the lake zone.
Show more [+] Less [-]Influence of prior determination of baseline minimum alveolar concentration (MAC) of isoflurane on the effect of ketamine on MAC in dogs Full text
2014
Gianotti, Giacomo | Valverde, Alex | Johnson, Ron | Sinclair, Melissa | Gibson, Thomas | Dyson, Doris H.
The objective of this study was to determine if prior measurement of the minimum alveolar concentration (MAC) of isoflurane influences the effect of ketamine on the MAC of isoflurane in dogs. Eight mixed-breed dogs were studied on 2 occasions. Anesthesia was induced and maintained using isoflurane. In group 1 the effect of ketamine on isoflurane MAC was determined after initially finding the baseline isoflurane MAC. In group 2, the effect of ketamine on isoflurane MAC was determined without previous measure of the baseline isoflurane MAC. In both groups, MAC was determined again 30 min after stopping the CRI of ketamine. Plasma ketamine concentrations were measured during MAC determinations. In group 1, baseline MAC (mean ± SD: 1.18 ± 0.14%) was decreased by ketamine (0.88 ± 0.14%; P < 0.05). The MAC after stopping ketamine was similar (1.09 ± 0.16%) to baseline MAC and higher than with ketamine (P < 0.05). In group 2, the MAC with ketamine (0.79 ± 0.11%) was also increased after stopping ketamine (1.10 ± 0.17%; P < 0.05). The MAC values with ketamine were different between groups (P < 0.05). Ketamine plasma concentrations were similar between groups during the events of MAC determination. The MAC of isoflurane during the CRI of ketamine yielded different results when methods of same day (group-1) versus separate days (group-2) are used, despite similar plasma ketamine concentrations with both methods. However, because the magnitude of this difference was less than 10%, either method of determining MAC is deemed acceptable for research purposes.
Show more [+] Less [-]In-vitro immunosuppression of canine T-lymphocyte-specific proliferation with dexamethasone, cyclosporine, and the active metabolites of azathioprine and leflunomide in a flow-cytometric assay Full text
2014
Nafe, Laura A. | Dodam, John R. | Reinero, Carol R.
A high rate of mortality, expense, and complications of immunosuppressive therapy in dogs underscores the need for optimization of drug dosing. The purpose of this study was to determine, using a flow-cytometric assay, the 50% T-cell inhibitory concentration (IC50) of dexamethasone, cyclosporine, and the active metabolites of azathioprine (6-mercaptopurine) and leflunomide (A77 1726) in canine lymphocytes stimulated with concanavalin A (Con A). Whole blood was collected from 5 privately owned, healthy dogs of various ages, genders, and breeds. Peripheral blood mononuclear cells, obtained by density-gradient separation, were cultured for 72 h with Con A, a fluorochrome-tagged cell proliferation dye, and various concentrations of dexamethasone (0.1, 1, 10, 100, 1000, and 10 000 μM), cyclosporine (0.2, 2, 10, 20, 30, 40, 80, and 200 ng/mL), 6-mercaptopurine (0.5, 2.5, 50, 100, 250, and 500 μM), and A77 1726 (1, 5, 10, 25, 50, and 200 μM). After incubation, the lymphocytes were labeled with propidium iodide and an antibody against canine CD5, a pan T-cell surface marker. Flow cytometry determined the percentage of live, proliferating T-lymphocytes incubated with or without immunosuppressants. The mean (± standard error) IC50 was 3460 ± 1900 μM for dexamethasone, 15.8 ± 2.3 ng/mL for cyclosporine, 1.3 ± 0.4 μM for 6-mercaptopurine, and 55.6 ± 22.0 μM for A77 1722. Inhibition of T-cell proliferation by the 4 immunosuppressants was demonstrated in a concentration-dependent manner, with variability between the dogs. These results represent the initial steps to tailor this assay for individual immunosuppressant protocols for dogs with immune-mediated disease.
Show more [+] Less [-]Use of a novel one-nostril mask-spacer device to evaluate airway hyperresponsiveness (AHR) in horses after chronic administration of albuterol Full text
2014
Mazan, Melissa R. | Lascola, Kara | Burns, Susan J. | Hoffman, Andrew M.
Inflammatory airway disease (IAD) is very common in stabled horses. Short-acting beta agonist (SABA) drugs are often used to relieve clinical signs, although long-term exposure to these drugs may result in rebound bronchoconstriction. The purpose of this study was twofold: i) to describe the deposition of radiolabeled drugs using a novel one-nostril design mask-spacer combination with a breath-activated inhaler (BAI), and ii) to determine whether treatment for 10 d with inhaled albuterol using this device would impair the ability of albuterol to prevent bronchospasm during a histamine challenge test. The percentage of radio-aerosol deposited in the total lung was 12.39% ± 5.05%. All study horses demonstrated airway hyperresponsiveness (AHR) before enrollment in the study [mean provocative concentration eliciting 35% increase in delta flow (PC35) < 6 mg/mL histamine]. There was no significant difference in airway hyperresponsiveness to post-albuterol histamine challenge before or after treatment with albuterol. A 10-d treatment with placebo, however, caused a significant increase in airway hyperresponsiveness in all horses (P < 0.001). The results of this study show that the novel mask-spacer device was effective in delivering radiolabeled aerosolized drug to the lung and that delivery of a SABA for 10 d using this device did not result in increased airway hyperresponsiveness.
Show more [+] Less [-]Efficacy of a flexible schedule for administration of a Leptospira borgpetersenii serovar Hardjo bacterin to beef calves Full text
2014
Cortese, Victor S. | Gallo, Guillermo F. | Cleary, Diane L. | Galvin, Jeffrey E. | Leyh, Randy D.
Objective- To determine whether a flexible vaccination regimen provides protection against challenge exposure with a virulent Leptospira borgpetersenii serovar Hardjo isolate. Animals- Fifty-five 4-week-old calves seronegative for antibodies against L borgpetersenii serovar Hardjo. Procedures- Calves were assigned to 3 groups and administered 2 doses of adjuvant (control calves; n = 11), 1 dose of serovar Hardjo bacterin and 1 dose of adjuvant (22), or 2 doses of the serovar Hardjo bacterin (22); there was a 16-week interval between dose administrations. Three weeks after the second dose, all calves were challenge exposed by use of conjunctival instillation of a heterologous strain of L borgpetersenii serovar Hardjo for 3 consecutive days. Urine samples for leptospiral culture were collected for 5 weeks after challenge exposure; at that time, all calves were euthanized and kidney samples collected for leptospiral culture. Results- Antibody titers increased in both leptospiral-vaccinated groups of calves. A significant increase in antibody titers against L borgpetersenii serovar Hardjo was detected after administration of the second dose of L borgpetersenii serovar Hardjo bacterin and challenge exposure. In 10 of 11 adjuvant-treated control calves, serovar Hardjo was isolated from both urine and kidney samples. Leptospira borgpetersenii serovar Hardjo was not isolated from the urine or kidney samples obtained from any of the 21 remaining calves that received 1 dose of bacterin or the 20 remaining calves that received 2 doses of bacterin. Conclusions and Clinical Relevance- Protection in young calves was induced by vaccination with 1 or 2 doses of a serovar Hardjo bacterin.
Show more [+] Less [-]Effect of intramammary administration of prednisolone on the blood-milk barrier during the immune response of the mammary gland to lipopolysaccharide Full text
2014
Wellnitz, Olga | Wall, Samantha K. | Saudenova, Makhabbat | Bruckmaier, Rupert M.
Objective-To investigate effects of intramammary administration of prednisolone on the immune response of mammary glands in cows. Animals- 5 lactating Red Holsteins. Procedures- Cows received a different intramammary infusion in each mammary gland (10 mg of prednisolone, 100 μg of lipopolysaccharide [LPS], 100 μg of LPS and 10 mg of prednisolone, or saline [0.9% NaCl] solution). Milk samples were collected before (time 0) and 3, 6, 9, 12, 24, and 36 hours after treatment. Somatic cell count (SCC), lactate dehydrogenase (LDH) activity, and concentrations of serum albumin (SA) and tumor necrosis factor (TNF)-α in milk and mRNA expression of TNF-α, interleukin (IL)-8, and IL-1β in milk somatic cells were analyzed. Results-Saline solution or prednisolone did not change SCC, LDH activity, and SA and TNF-α concentrations in milk and mRNA expression of TNF-α, IL-1β, and IL-8 in milk somatic cells. The SCC and TNF-α concentration in milk increased similarly in glands infused with LPS, independent of prednisolone administration. However, the increase of LDH activity and SA concentration in milk after LPS infusion was diminished by prednisolone administration. The mRNA expression of TNF-α, IL-8, and IL-1β in milk somatic cells increased after LPS infusion and was unaffected by prednisolone. Conclusions and Clinical Relevance- Intramammary administration of prednisolone did not induce an immune response and did not change mRNA expression of TNF-α, IL-8, and L-1β during the response to intramammary administration of LPS. However, prednisolone reduced disruption of the blood-milk barrier. This could influence the severity and cure rate of mastitis.
Show more [+] Less [-]Use of an inverse dynamics method to describe the motion of the canine pelvic limb in three dimensions Full text
2014
Headrick, Jason F. | Zhang, Songning | Millard, Ralph P. | Rohrbach, Barton W. | Weigel, Joseph P. | Millis, Darryl L.
Objective- To use an inverse dynamics method to describe the motion of the canine pelvic limb in 3 dimensions. Animals-6 healthy adult dogs. Procedures- For each dog, 16 anatomic and tracking markers were used to define the center of rotation for the pelvic limb joints and a kinematic model was created to describe the motion of the pelvic limb. Kinetic, kinematic, and morphometric data were combined so that an inverse dynamics method could be used to define angular displacement, joint moment, and power of the hip, stifle, and tibiotarsal (hock) joints in the sagittal, frontal, and transverse planes. Results-Movement and energy patterns were described for the hip, stifle, and hock joints in the sagittal, frontal, and transverse planes. Results- Movement and energy patterns were described for the hip, stifle, and hock joints in the sagittal, frontal, and transverse planes. Conclusions and Clinical Relevance- Knowledge of the 3-D movement of the pelvic limb can be used to better understand its motion, moment, and energy patterns in healthy dogs and provide a referent with which gaits of dogs with pelvic limb injuries before and after surgical repair or rehabilitation can be compared and characterized. This information can then be used to guide decisions regarding treatment options for dogs with pelvic limb injuries.
Show more [+] Less [-]Pharmacokinetics of meloxicam administered orally to rabbits (Oryctolagus cuniculus) for 29 days Full text
2014
Delk, Katie W. | Carpenter, James W. | KuKanich, Butch | Nietfeld, Jerome C. | Kholes, Micah
Objective-To determine the pharmacokinetics and safety of meloxicam in rabbits when administered orally for 29 days. Animals-6 healthy rabbits. Procedures-Meloxicam (1.0 mg/kg, PO, q 24 h) was administered to rabbits for 29 days. Blood was collected immediately before (time 0) and 2, 4, 6, 8, and 24 hours after drug administration on days 1, 8, 15, 22, and 29 to evaluate the pharmacokinetics of meloxicam. On day 30, an additional sample was collected 36 hours after treatment. Plasma meloxicam concentrations were quantified with liquid chromatography–mass spectrometry, and noncompartmental pharmacokinetic analysis was performed. Weekly plasma biochemical analyses were performed to evaluate any adverse physiologic effects. Rabbits were euthanatized for necropsy on day 31. Results-Mean +/- SD peak plasma concentrations of meloxicam after administration of doses 1, 8, 15, 22, and 29 were 0.67 +/- 0.19 μg/mL, 0.81 +/- 0.21 μg/mL, 1.00 +/- 0.31 μg/mL, 1.00 +/- 0.29 μg/mL, and 1.07 +/- 0.19 μg/mL, respectively; these concentrations did not differ significantly among doses 8 through 29. Results of plasma biochemical analyses were within reference ranges at all time points evaluated. Gross necropsy and histologic examination of tissues revealed no clinically relevant findings. Conclusions and Clinical Relevance-Plasma concentrations of meloxicam for rabbits in the present study were similar to those previously reported in rabbits that received 1. 0 mg of meloxicam/kg, PO every 24 hours, for 5 days. Results suggested that a dosage of 1. 0 mg/kg, PO, every 24 hours for up to 29 days may be safe for use in healthy rabbits.
Show more [+] Less [-]Effects of experimental mechanical manipulations on local inflammation in the jejunum of horses Full text
2014
Hopster-Iversen, Charlotte C. S. | Hopster, Klaus | Staszyk, Carsten | Rohn, Karl | Freeman, David E. | Rötting, Anna K.
Objective—To determine characteristics of the inflammatory reaction in the jejunum of horses in response to various mechanical manipulations. Animals—12 adult warmblood horses without gastrointestinal tract disorders. Procedures—The proximal aspect of the jejunum in each horse was divided into 5 segments, and the following manipulations were performed: manual emptying, placement of Doyen forceps, enterotomy alone, enterotomy with mucosal abrasion, and serosal abrasion. Jejunum samples were collected before (control), immediately after, and 30 minutes after the end of manipulations and histologically evaluated to determine distribution of neutrophils and eosinophils. Results—Macroscopically, all manipulations resulted in jejunal hemorrhage and edema. Compared with control samples, neutrophil numbers were significantly higher after manipulations in the serosa (after all manipulation types), circular muscle layer (after manual emptying), submucosa (after placement of Doyen forceps), and mucosa (after all manipulations except enterotomy alone). Eosinophil numbers were significantly higher in the submucosa after mechanical abrasion of the serosa and manual emptying versus control samples. Conclusions and Clinical Relevance—Results indicated mechanical manipulation of the jejunum resulted in local inflammatory reactions characterized predominantly by infiltration of neutrophils. This could contribute to the development of postoperative ileus or adhesions in horses without macroscopically detectable injury of the jejunum during surgery.
Show more [+] Less [-]Effects of interleukin-6 and interleukin-1β on expression of growth differentiation factor-5 and Wnt signaling pathway genes in equine chondrocytes Full text
2014
Svala, Emilia | Thorfv, Anna I. | Ley, Cecilia | Henriksson, Helena K Barreto | Synnergren, Jane M. | Lindahl, Anders H. | Ekman, Stina | Skiöldebrand, Eva S.R.
Objective-To determine the effects of interleukin (IL)-6 and IL-1β stimulation on expression of growth differentiation factor (GDF)-5 and Wnt signaling pathway genes in equine chondrocytes. Sample-Macroscopically normal articular cartilage samples from 6 horses and osteochondral fragments (OCFs) from 3 horses. Procedures-Chondrocyte pellets were prepared and cultured without stimulation or following stimulation with IL-6 or IL-1β for 1, 2, 12, and 48 hours; expression of GDF-5 was determined with a quantitative real-time PCR assay. Expression of genes in various signaling pathways was determined with microarrays for pellets stimulated for 1 and 2 hours. Immunohistochemical analysis was used to detect GDF-5, glycogen synthase kinase 3β (GSK-3β), and β-catenin proteins in macroscopically normal cartilage samples and OCFs. Results-Chondrocytes stimulated with IL-6 had significantly higher GDF-5 expression within 2 hours versus unstimulated chondrocytes. Microarray analysis of Wnt signaling pathway genes indicated expression of GSK-3β and coiled-coil domain containing 88C increased after 1 hour and expression of β-catenin decreased after 2 hours of IL-6 stimulation. Results of immunohistochemical detection of proteins were similar to microarray analysis results. Chondrocytes in macroscopically normal articular cartilage and OCFs had immunostaining for GDF-5. Conclusion and Clinical Relevance-Results indicated IL-6 stimulation decreased chondrocyte expression of the canonical Wnt signaling pathway transactivator β-catenin, induced expression of inhibitors of the Wnt pathway, and increased expression of GDF-5. This suggested IL-6 may inhibit the Wnt signaling pathway with subsequent upregulation of GDF-5 expression. Anabolic extracellular matrix metabolism in OCFs may be attributable to GDF-5 expression. This information could be useful for development of cartilage repair methods.
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