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Prevalence and mutation analysis of the spike protein in feline enteric coronavirus and feline infectious peritonitis detected in household and shelter cats in western Canada
2020
McKay, L. A. | Meachem, M. | Snead, E. | Brannen, T. | Mutlow, N. | Ruelle, L. | Davies, J. L. | Van der Meer, F.
Feline infectious peritonitis (FIP) is a fatal disease for which no simple antemortem diagnostic assay is available. A new polymerase chain reaction (PCR) test has recently been developed that targets the spike protein region of the FIP virus (FIPV) and can identify specific mutations (M1030L or S1032A), the presence of which indicates a shift from feline enteric coronavirus (FeCV) to FIPV. This test will only be useful in the geographical region of interest, however, if the FIP viruses contain these mutations. The primary objective of this study was to determine the presence of the M1030L or S1032A mutations in FeCV derived from stool samples from a selected group of healthy cats from households and shelters and determine how many of these cats excrete FeCV. The secondary objective was to evaluate how often these specific FIPV mutations were present in tissue samples derived from cats diagnosed with FIP at postmortem examination. Feline enteric coronavirus (FeCV) was detected in 46% of fecal samples (86/185), all were FeCV type 1, with no difference between household or shelter cats. Only 45% of the FIPV analyzed contained the previously reported M1030L or S1032A mutations. It should be noted that, as the pathological tissue samples were opportunistically obtained and not specifically obtained for PCR testing, caution is warranted in interpreting these data.
اظهر المزيد [+] اقل [-]Biomechanical evaluation of an absorbable fixation strap for use in total laparoscopic gastropexy in dogs
2020
Fracassi, Laura | Crovace, Alberto Maria | Staffieri, Francesco | Lactignola, Luca
OBJECTIVE To compare load-to-failure results for laparoscopic absorbable fixation straps (AFSs) deployed at various angles and for AFSs versus absorbable knotless (barbed) suture when used in simulated total laparoscopic gastropexy (TLG) in specimens from cadaveric dogs. SAMPLE 30 stomach and abdominal body wall specimens. PROCEDURES Specimens were assigned to 1 of 3 groups for use in simulated TLG constructs for comparisons of load-to-failure results for single AFSs deployed at 30°, 60°, or 90° (AFS-angle group; n = 10) or for a gastropexy span of 4 to 5 cm achieved with 3-0 absorbable knotless (barbed) monofilament suture applied in a simple continuous pattern (TLG-1; 10) versus 8 AFSs applied with a deployment angle > 30° (TLG-2; 10). A 1-way ANOVA was used to compare results among AFS deployment angles (30°, 60°, or 90°) and between TLG-1 and TLG-2. RESULTS Mean ± SD load to failure for the AFS-angle group was significantly higher for the AFS deployment angles of 60° (8.00 ± 3.90 N) and 90° (12.71 ± 8.00 N), compared with 30° (5.17 ± 1.90 N). However, no substantial difference was detected in the mean ± SD load to failure for TLG-1 (39.18 ± 7.1 N) versus TLG-2 (31.43 ± 10.86 N). CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study supported the potential use of AFSs in gastropexy in dogs; however, prospective clinical research with adequate long-term follow-up is warranted before recommendations can be made.
اظهر المزيد [+] اقل [-]Effect of Achyranthes japonica Nakai extract on immunity and anti-inflammation in dogs
2020
Lee, Gun-Hwi | Hwang, Kyung-A | Kang, Ji-Houn | Choi, Kyung-Chul
Achyranthes japonica Nakai (A. japonica) is a medicinal herb found widely distributed throughout Korea. The biological activities of A. japonica are well-documented and include anti-fungal, anti-inflammatory, and immunity enhancement. The objective of the present study was to investigate the immune-related activities of A. japonica extract in dogs. The extract was acquired by ethanol extraction and purified by filtration. To examine the effect of A. japonica extract on immune cell viability, human lymphocytes, such as Jurkat T-cells and Ramos B-cells, were exposed to the extract. After treatment with the extract, the number of Ramos B-cells was increased, whereas Jurkat T-cells remained unaffected. Griess assay revealed decreased nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated mouse macrophage Raw 264.7 cells after exposure to A. japonica extract. To evaluate the in-vivo effect in dogs, feed containing A. japonica extract was provided to 8 dogs for 2 months. Blood samples were collected before, during, and after consumption of the feed. Peripheral blood mononuclear cells (PBMCs) were isolated from the blood samples and the number of T-cells and B-cells were assessed using flow cytometry with anti-dog fluorescein isothiocyanate (FITC)-conjugated CD3 and anti-dog phycoerythrin (PE)-conjugated CD21 antibodies, respectively. We observed a significant increase in the average number of B-cells in the PBMCs during ingestion of the feed containing A. japonica. In addition, enzyme-linked immunosorbent assay (ELISA) revealed a decrease in the levels of tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, in 3 out of 8 dogs and increased levels of interleukin-10 (IL-10), an anti-inflammatory cytokine, in 4 out of 8 dogs. Taken together, we believe that these changes indicate that A. japonica extract is beneficial in improving the immunity of dogs by stimulating B-cells and inducing production of anti-inflammatory responses.
اظهر المزيد [+] اقل [-]β-glucan from Saccharomyces cerevisiae is involved in immunostimulation of ovine ruminal explants
2020
Zhang, Man | Jin, Xin | Cao, Gui-Fang | Yang, Yin-Feng
In this study, we investigated whether β-glucan from Saccharomyces cerevisiae exerts beneficial effects on mucosal immunity in an ovine ruminal explant (ORE) model. Once the ORE model was established, viability was assessed through histological change, E-cadherin expression, CK-18 and Ki-67 distribution. Then, the OREs were co-cultured with β-glucan, following which, gene and protein expression levels of sheep β-defensin-1 (SBD-1), pro-inflammatory interleukin (IL)-6, and anti-inflammatory IL-10 were detected using quantitative real-time polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Hematoxylin & eosin staining, qPCR, and immunohistochemistry showed that the overall ORE structure was intact after 96 hours in culture, but explants cultured for more than 24 hours showed epithelial degradation. Therefore, we performed the follow-up test within 24 hours. qPCR and ELISA revealed that the gene and protein expression levels of SBD-1, IL-6, and IL-10 in the OREs significantly increased (P < 0.05) after treatment with β-glucan compared with controls. This study identified the feasibility and optimal conditions of ORE culture and demonstrated that β-glucan activates SBD-1, IL-6, and IL-10 secretion in OREs to promote mucosal immunity.
اظهر المزيد [+] اقل [-]Expression of microRNAs in plasma and in extracellular vesicles derived from plasma for dogs with glioma and dogs with other brain diseases
2020
Narita, Momoko | Nishida, Hidetaka | Asahina, Ryota | Nakata, Kohei | Yano, Hirohito | Dickinson, Peter J. | Tanaka, Toshiyuki | Akiyoshi, Hideo | Maeda, Sadatoshi | Kamishina, Hiroaki
OBJECTIVE To measure expression of microRNAs (miRNAs) in plasma and in extracellular vesicles (EVs) derived from plasma for dogs with glioma and dogs with other brain diseases. SAMPLE Plasma samples from 11 dogs with glioma and 19 control dogs with various other brain diseases. PROCEDURES EVs were isolated from plasma samples by means of ultracentrifugation. Expression of 4 candidate reference miRNAs (let-7a, miR-16, miR-26a, and miR-103) and 4 candidate target miRNAs (miR-15b, miR-21, miR-155, and miR-342-3p) was quantified with reverse transcription PCR assays. Three software programs were used to select the most suitable reference miRNAs from among the 4 candidate reference miRNAs. Expression of the 4 target miRNAs was then calculated relative to expression of the reference genes in plasma and EVs, and relative expression was compared between dogs with glioma and control dogs with other brain diseases. RESULTS The most suitable reference miRNAs were miR-16 for plasma and let-7a for EVs. Relative expression of miR-15b in plasma and in EVs was significantly higher in dogs with glioma than in control dogs. Relative expression of miR-342-3p in EVs was significantly higher in dogs with glioma than in control dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that miR-15b and miR-342-3p have potential as noninvasive biomarkers for differentiating glioma from other intracranial diseases in dogs. However, more extensive analysis of expression in specific glioma subtypes and grades, compared with expression in more defined control populations, will be necessary to assess their clinical relevance.
اظهر المزيد [+] اقل [-]Computed tomographic evaluation of pancreatic perfusion in healthy dogs
2020
Kloer, Timothy B. | Rao, Sangeeta | Twedt, David C. | Marolf, Angela J.
OBJECTIVE To evaluate the feasibility of contrast-enhanced CT for assessment of pancreatic perfusion in healthy dogs. ANIMALS 6 healthy purpose-bred female Treeing Walker Coonhounds. PROCEDURES Contrast-enhanced CT of the cranial part of the abdomen was performed with 3-mm slice thickness. Postprocessing computer software designed for evaluation of human patients was used to calculate perfusion data for the pancreas and liver by use of 3-mm and reformatted 6-mm slices. Differences in perfusion variables between the pancreas and liver and differences in liver-specific data of interest were evaluated with the Friedman test. RESULTS Multiple pancreatic perfusion variables were determined, including perfusion, peak enhancement index, time to peak enhancement, and blood volume. The same variables as well as arterial, portal, and total perfusion and hepatic perfusion index were determined for the liver. Values for 6-mm slices appeared similar to those for 3-mm slices. The liver had significantly greater median perfusion and peak enhancement index, compared with the pancreas. CONCLUSIONS AND CLINICAL RELEVANCE Measurement of pancreatic perfusion with contrast-enhanced CT was feasible in this group of dogs. Hepatic arterial and pancreatic perfusion values were similar to previously published findings for dogs, but hepatic portal and hepatic total perfusion measurements were not. These discrepancies might have been attributable to physiologic differences between dogs and people and related limitations of the CT software intended for evaluation of human patients. Further research is warranted to assess reliability of perfusion variables and applicability of the method for assessment of canine patients with pancreatic abnormalities.
اظهر المزيد [+] اقل [-]Duration of immunity after rabies vaccination in dogs: The Rabies Challenge Fund research study
2020
Dodds, W Jean | Larson, Laurie J. | Christine, Kris L. | Schultz, Ronald D.
A prospective study of 65 research beagles kept in a rabies-free environment was undertaken to determine the duration of immunity after they received licensed rabies vaccines. The eventual goal was to extend mandated rabies booster intervals to 5 or 7 years and help reduce the risk of vaccine-associated adverse events. Three groups of dogs were vaccinated with 1 of 2 commercial rabies vaccines or saline at 12 and 15 weeks of age. Beginning 5 years 5 months later, vaccinated and unvaccinated dogs were challenged with virulent rabies virus and observed for 90 days over a series of 3 trials. Humoral and cellular immune responses were examined by serology and flow cytometry. Brain tissue from all challenged dogs was tested for rabies virus. Challenge trial 1 was confounded due to insufficiently virulent virus. In trials 2 and 3 virulent challenge provided 100% mortality in controls. Vaccinate survival was 80% (4/5) after 6 years 7 months, 50% (6/12) after 7 years 1 month, and 20% (1/5) after 8years 0 months. Antibody responses 12 days post-challenge correlated strongly with survival. In a separate non-challenge trial, administration of either a recombinant or a killed rabies vaccine demonstrated memory antibody responses 6 years 1 month after initial vaccination compared with unvaccinated controls. Our data demonstrated that i) duration of immunity to rabies in vaccinated dogs extends beyond 3 years; ii) immunologic memory exists even in vaccinated dogs with serum antibody titer < 0.1 IU/mL; and iii) non-adjuvanted recombinant rabies vaccine induces excellent antibody responses in previously vaccinated dogs 14 days after administration.
اظهر المزيد [+] اقل [-]The effect of inspired oxygen concentration on oxidative stress biomarkers in dogs under inhalation anesthesia
2020
Chongphaibulpatana, Patarakit | Kumagai, Yuu | Fukui, Daisuke | Katayama, Masaaki | Uzuka, Yuji
This study investigated oxidative stress biomarkers at 3 different oxygen concentrations in dogs under general anesthesia to determine whether high-concentration oxygen increases oxidative stress. Six healthy beagles were randomly assigned to receive 3 anesthesia protocols (inhalation of 40%, 60%, and 100% oxygen) during 3 hours of general anesthesia with sevoflurane, with at least one week in between each protocol. For each experiment, blood samples were collected at 0, 3, 6, and 24 hours after inhalation of oxygen. Derivatives of reactive oxygen metabolites, biochemical antioxidant potential, superoxide dismutase, and 8-hydroxydeoxyguanosine in the blood did not significantly differ among the 3 groups at any time point. This study is the first comparing high concentrations of oxygen with low concentrations of oxygen for anesthesia in dogs. According to our findings, 100% oxygen may not alter the oxidative stress level in dogs during general anesthesia with sevoflurane for 3 hours.
اظهر المزيد [+] اقل [-]Infection of calves with in-vivo passaged bovine parainfluenza-3 virus, alone or in combination with bovine respiratory syncytial virus and bovine coronavirus
2020
Ellis, John | Erickson, Nathan | Gow, Sheryl | West, Keith | Lacoste, Stacey | Godson, Dale
Bovine respiratory disease complex is etiologically complex and usually involves co-infection by several agents, including bovine parainfluenza virus-3 (BPIV-3), bovine respiratory syncytial virus (BRSV), and bovine coronavirus (BCoV). Traditionally, vaccines have been tested in seronegative calves infected with a single in vitro-passaged agent, often with little disease, resulting in unvaccinated subjects. To overcome the potential problem of attenuation coincident with in vitro culture of the viruses, cocktails of field isolates of BPIV-3s and BCoVs were passaged in the lungs of neonatal colostrum-deprived calves. Lung lavage fluids were used as inocula, alone and in combination with in-vivo passaged BRSV, and aerosolized into a trailer containing conventionally reared 9-week-old weaned Holstein calves with decayed, but still measurable, maternal antibodies. Calves developed acute respiratory disease of variable severity. Upon necropsy, there were characteristic gross and histologic lesions in the respiratory tract, associated immunohistochemically with BPIV-3, BRSV, and BCoV. In-vivo passage of viruses is an alternative to in vitro culture to produce inocula to better study the pathogenesis of infection and more rigorously and relevantly assess vaccine efficacy.
اظهر المزيد [+] اقل [-]Effect of presurgical storage conditions on leakage pressures of enterotomy sites closed with unidirectional barbed suture material in fresh, chilled, and frozen-thawed cadaveric canine jejunal specimens
2020
Duffy, Daniel J. | Chang, Yi-Jen | Balko, Julie A. | Moore, George E.
OBJECTIVE To evaluate the effect of presurgical storage conditions on leakage pressures of enterotomy sites closed with unidirectional barbed suture material in fresh, chilled, and frozen-thawed cadaveric canine jejunal specimens. SAMPLE 36 grossly normal jejunal segments obtained from 4 dog cadavers. PROCEDURES 9 jejunal segments were harvested immediately from each euthanized dog and randomly assigned to be tested within 4 hours after collection (fresh segments), stored at 4°C for 24 hours before testing (chilled segments), or stored at −20°C for 7 days and thawed at 21°C for 6 hours before testing (frozen-thawed segments). For leakage pressure testing, a 3-cm-long antimesenteric enterotomy was performed and repaired with 3-0 unidirectional barbed suture material in a simple continuous pattern in each segment. Time to complete the enterotomy, initial leakage pressure, maximum intraluminal pressure, and leakage location were recorded for each segment. RESULTS Mean ± SD initial leakage pressure for fresh, chilled, and frozen-thawed segments was 52.8 ± 14.9 mm Hg, 51.8 ± 11.9 mm Hg, and 33.3 ± 7.7 mm Hg, respectively. Frozen-thawed segments had significantly lower mean initial leakage pressure, compared with findings for fresh or chilled segments. Time to complete the enterotomy, maximum intraluminal pressure, and leakage location did not differ among groups. CONCLUSIONS AND CLINICAL RELEVANCE Leak pressure testing of cadaveric jejunal segments that are fresh or chilled at 4°C for 24 hours is recommended for enterotomy studies involving barbed suture material in dogs. Freezing and thawing of cadaveric jejunal tissues prior to investigative use is not recommended because leak pressure data may be falsely low.
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