خيارات البحث
النتائج 1 - 4 من 4
Efficacy and safety of a modified-live cyprinid herpesvirus 3 vaccine in koi (Cyprinus carpio koi) for prevention of koi herpesvirus disease
2014
Weber, E. P Scott III | Malm, Kirsten V. | Yun, Susan C. | Campbell, Lori A. | Kass, Philip H. | Marty, Gary D. | Salonius, Kira | Dishon, Arnon
Objective—To investigate safety and efficacy of a cyprinid herpesvirus type 3 (CyHV3) modified-live virus vaccine for the prevention of koi herpesvirus disease (KHVd). Animals—420 healthy koi (Cyprinus carpio koi). Procedures—Fish were vaccinated with a 1× dose or 10× overdose of CyHV3 modified-live virus vaccine or a placebo through bath exposure in tanks at 22°C. Horizontal transmission of vaccine virus was evaluated by commingling unvaccinated and vaccinated fish. Efficacy was evaluated by challenge exposure of vaccinated and naïve fish to a wild-type virus. Fish that died were submitted for quantitative PCR assay for CyHV3 and histologic evaluation. Results—The CyHV3 vaccine was safe and efficacious, even at a 10× overdose. Vaccine-associated mortality rate was inversely associated with body weight, with a cumulative mortality rate of 9.4% (18/192) in fish weighing ≤ 87 g and no deaths in fish weighing > 87 g (0/48). Horizontal transfer of vaccine virus from vaccinates to naïve fish was negligible. For efficacy, the vaccine provided a significant reduction in mortality rate after challenge exposure to a wild-type virus, with a prevented fraction of 0.83 versus the placebo control fish. Conclusions and Clinical Relevance—KHVd is highly contagious and commonly leads to deaths in 80% to 100% of exposed fish, representing a major threat to koi and common carp populations throughout the world. The CyHV3 modified-live virus vaccine had a favorable safety profile and was an effective vaccine for the control of KHVd in koi weighing > 87 g.
اظهر المزيد [+] اقل [-]Safety and early onset of immunity with a novel European porcine reproductive and respiratory syndrome virus vaccine in young piglets
2016
Pinotkowski, Michael | Kroll, Jeremy | Kraft, Christian | Coll, Teresa
Porcine reproductive and respiratory syndrome virus (PRRSV) can be difficult to manage in commercial settings. A novel type I PRRSV vaccinal strain (94881) was evaluated for safety and efficacy/onset of immunity (OOI) in piglets. In 2 experiments, groups of piglets were vaccinated intramuscularly (IM) at approximately 14 d of age with a maximum-range commercial dose, an overdose, or a placebo in experiment 1 and either a minimum-range commercial dose or a placebo in experiment 2. The piglets in experiment 1 were evaluated for local and systemic reactions from days -2 through 14 after vaccination. The piglets in experiment 2 were challenged with a virulent heterologous type I PRRSV isolate 14 d after vaccination and observed once daily for general health from days -1 through 12 after vaccination and once daily for clinical signs associated with challenge from days 13 through 24 after vaccination. The average daily weight gain (ADWG) and the results of serologic and viremia testing were evaluated in experiments 1 and 2. Lung lesion scores and results of testing for PRRSV in lung tissue were evaluated in experiment 2. In experiment 1 the vaccine was shown to be safe, as there were no relevant differences between the vaccinated piglets and the piglets given a placebo. In experiment 2 the vaccine's efficacy, with an OOI of 14 d after vaccination, was established, as the vaccinated and challenged piglets exhibited significantly lower lung lesion scores, viremia, viral load in lung tissue, and total clinical sign scores, along with a significantly greater ADWG, compared with the placebo-vaccinated and challenged piglets.
اظهر المزيد [+] اقل [-]Immunohistochemical expression of insulin, glucagon, and somatostatin in pancreatic islets of horses with and without insulin resistance
2018
Newkirk, Kim M. | Ehrensing, Gordon | Odoi, Agricola | Boston, Ray C. | Frank, Nicholas
OBJECTIVE To assess insulin, glucagon, and somatostatin expression within pancreatic islets of horses with and without insulin resistance. ANIMALS 10 insulin-resistant horses and 13 insulin-sensitive horses. PROCEDURES For each horse, food was withheld for at least 10 hours before a blood sample was collected for determination of serum insulin concentration. Horses with a serum insulin concentration < 20 μU/mL were assigned to the insulin-sensitive group, whereas horses with a serum insulin concentration > 20 μU/mL underwent a frequently sampled IV glucose tolerance test to determine sensitivity to insulin by minimal model analysis. Horses with a sensitivity to insulin < 1.0 × 10(−4) L•min−1•mU−1 were assigned to the insulin-resistant group. All horses were euthanized with a barbiturate overdose, and pancreatic specimens were harvested and immunohistochemically stained for determination of insulin, glucagon, and somatostatin expression in pancreatic islets. Islet hormone expression was compared between insulin-resistant and insulin-sensitive horses. RESULTS Cells expressing insulin, glucagon, and somatostatin made up approximately 62%, 12%, and 7%, respectively, of pancreatic islet cells in insulin-resistant horses and 64%, 18%, and 9%, respectively, of pancreatic islet cells in insulin-sensitive horses. Expression of insulin and somatostatin did not differ between insulin-resistant and insulin-sensitive horses, but the median percentage of glucagon-expressing cells in the islets of insulin-resistant horses was significantly less than that in insulin-sensitive horses. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that, in insulin-resistant horses, insulin secretion was not increased but glucagon production might be downregulated as a compensatory response to hyperinsulinemia.
اظهر المزيد [+] اقل [-]Comparison of penetrating and nonpenetrating captive bolt methods in horned goats
2017
Collins, Samantha L. | Caldwell, Marc | Hecht, Silke | Whitlock, Brian K.
OBJECTIVE To use MRI and CT to compare the amount of tissue damage (soft tissue and bone) to the heads of goats after administration of a nonpenetrating or penetrating captive bolt. ANIMALS Cadavers of twelve 1- to 5-year-old mixed-breed goats that had been euthanized with an overdose of pentobarbital as part of an unrelated study. PROCEDURES Cadavers were randomly assigned to receive a nonpenetrating (n = 6) or penetrating (6) captive bolt. The head of 1 cadaver was imaged via CT and MRI. The muzzle of a device designed to administer either a penetrating or nonpenetrating captive bolt was then placed flush on the dorsal midline of each head at the level of the external occipital protuberance (poll) and aimed downward toward the cranialmost portion of the intermandibular space, and the assigned bolt was administered. Heads were removed, and CT and MRI of each head were performed. After imaging, each skull was transected along the sagittal plane to permit gross evaluation of central nervous tissue and obtain digital photographic images. In addition, 1 head that received a nonpenetrating captive bolt was further evaluated via blunt dissection and removal of adnexa from the external surface of the calvarium. RESULTS MRI, CT, and dissection of skulls revealed severe skeletal and soft tissue damage after impact with the penetrating and nonpenetrating captive bolts. CONCLUSIONS AND CLINICAL RELEVANCE The nonpenetrating captive bolt appeared to cause damage similar to that of the penetrating captive bolt in the cranium and soft tissues of the head in caprine cadavers. This damage suggested that administration of a nonpenetrating captive bolt as described here may be an acceptable method of euthanasia in goats.
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