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Atrial and ventricular myocardial blood flows in horses at rest and during exercise.
1994
Manohar M. | Goetz T.E. | Hutchens E. | Coney E.
Right atrial, pulmonary artery, pulmonary capillary, pulmonary artery wedge, and systemic blood pressures of strenuously exercising horses increase markedly. As a consequence, myocardial metabolic O2 demand in exercising horses must be high. Experiments were, therefore, carried out on 9 healthy, exercise-conditioned horses (2.5 to 8 years old; 481 +/- 16 kg) to ascertain the regional distribution of myocardial blood supply in the atria and ventricles at rest and during exercise. Blood flow was measured, using 15-micrometer-diameter radionuclide-labeled microspheres that were injected into the left ventricle while reference blood samples were being withdrawn at a constant rate from the thoracic aorta. Myocardial blood flow was determined at rest and during 2 exercise bouts performed on a high-speed treadmill at 8 and 13 m/s (0% grade). The sequence of exercise bouts was randomized among horses, and a 60-minute rest period was permitted between exercise bouts. There was considerable heterogeneity in the distribution of myocardial perfusion in the atria and the ventricles at rest; the right atrial myocardium received significantly (P < 0.05) less perfusion than did the left atrium, and these values were significantly (P < 0.05) less than those for the respective ventricular myocardium. The right ventricular myocardial blood flow also was significantly less than that in the left ventricle. With exercise, myocardial blood flow in all regions increased progressively with increasing work intensity and marked coronary vasodilation was observed in all cardiac regions. During exercise at 8 or 13 m/s, right and left atrial myocardial blood flows (per unit weight basis) were not different from each other. Although at treadmill speed of 8 m/s, left ventricular myocardial blood flow exceeded that in the right ventricle, this was not the case at 13 m/s, when perfusion values (per unit weight basis) became similar.
显示更多 [+] 显示较少 [-]New insights into the prevalence and phylogenetic diversity of Cysticercus ovis isolates in sheep from Sulaymaniyah, Iraq
2021
Although ovine cysticercosis is not a zoonotic problem, it results in substantial economic losses due to the condemnation of infected tissues or entire carcasses. This study aimed to record preliminary data on the prevalence, and phylogenetic diversity of Cysticercus ovis isolates from slaughtered sheep in the province of Sulaymaniyah, Iraq. From January to September 2020, 6, 411 slaughtered sheep were examined for C. ovis by routine meat inspection. The amplification and sequence analysis of the COX1 gene for up to 35 specimens of C. ovis was performed using conventional PCR. The overall prevalence rate was 1.3%, and the prevalence was significantly higher in older sheep (>1 year) than younger ones (<1 year) (P< 0.05). The cardiac muscle showed a higher tendency to carry C. ovis infection compared to other examined muscles. Sequence analysis of the COX1 gene revealed six haplotypes, and the level of pairwise nucleotide diversity between individual haplotypes was 1–2%. Five out of six of the Taenia ovis haplotypes recovered could have been recorded for the first time globally. Phylogenetic interpretation indicated that all the T. ovis haplotypes clustered in a single clade, and it also indicated an extremely close similarity to Iranian and New Zealand isolates. Globally, this report adds new data on C. ovis genetic diversity, which provide an extremely useful molecular background with regard to future preventive as well as control strategies.
显示更多 [+] 显示较少 [-]Distribution of 2-deoxy-2-fluoro-d-glucose in the coelom of healthy bald eagles (Haliaeetus leucocephalus)
2013
Jones, Michael P. | Morandi, Federica | Wall, Jonathan S. | Long, Misty J. | Stuckey, Alan C. | LeBlanc, Amy K.
Objective: To determine 2-deoxy-2-fluoro (fluorine 18)-d-glucose (18FDG) biodistribution in the coelom of bald eagles (Haliaeetus leucocephalus). Animals: 8 healthy adult bald eagles. Procedures: For each eagle, whole-body transmission noncontrast CT, 60-minute dynamic positron emission tomography (PET) of the celomic cavity (immediately after 18FDG injection), whole-body static PET 60 minutes after 18FDG injection, and whole-body contrast CT with iohexol were performed. After reconstruction, images were analyzed. Regions of interest were drawn over the ventricular myocardium, liver, spleen, proventriculus, cloaca, kidneys, and lungs on dynamic and static PET images. Standardized uptake values were calculated. Results: Kidneys had the most intense 18FDG uptake, followed by cloaca and intestinal tract; liver activity was mild and slightly more intense than that of the spleen; proventricular activity was always present, whereas little to no activity was identified in the wall of the ventriculus. Activity in the myocardium was present in all birds but varied in intensity among birds. The lungs had no visibly discernible activity. Mean ± SD standardized uptake values calculated with representative regions of interest at 60 minutes were as follows: myocardium, 1. 6 ± 0.2 (transverse plane) and 1.3 ± 0.3 (sagittal plane); liver, 1.1 ± 0.1; spleen, 0.9 ± 0.1; proventriculus, 1.0 ± 0.1; cloaca, 4.4 ± 2.7; right kidney, 17.3 ± 1.0; left kidney, 17.6 ± 0.3; and right and left lungs (each), 0.3 ± 0.02. Conclusions and Clinical Relevance: The study established the biodistribution of 18FDG in adult eagles, providing a baseline for clinical investigation and future research.
显示更多 [+] 显示较少 [-]Characterization of canine mitochondrial protein expression in natural and induced forms of idiopathic dilated cardiomyopathy
2006
Lopes, R. | Solter, P.F. | Sisson, D.D. | Oyama, M.A. | Prosek, R.
Objective-To map canine mitochondrial proteins and identify qualitative and quantitative differences in heart mitochondrial protein expression between healthy dogs and dogs with naturally occurring and induced dilated cardiomyopathy (DCM). Sample Population-Left ventricle samples were obtained from 7 healthy dogs, 7 Doberman Pinschers with naturally occurring DCM, and 7 dogs with induced DCM. Procedures-Fresh and frozen mitochondrial fractions were isolated from the left ventricular free wall and analyzed by 2-dimensional electrophoresis. Protein spots that increased or decreased in density by greater than or equal to 2-fold between groups were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or quadrupole selecting, quadrupole collision cell, time-of-flight mass spectrometry. Results-Within narrow pH gradients of control canine heart mitochondrial samples, a total of 1,528 protein spots were revealed. Forty subunits of heart mitochondrial proteins that differ significantly from control tissues were altered in tissue specimens from dogs with naturally occurring and induced forms of DCM. The most affected heart mitochondrial proteins in both groups were those of oxidative phosphorylation (55%). Upregulation of manganese superoxide dismutase was suggestive of heart oxidative injury in tissue specimens from dogs with both forms of DCM. Evidence of apoptosis was associated with overexpression of the heart mitochondrial voltage-dependent anion channel-2 protein and endonuclease G in tissue specimens from dogs with induced DCM. Conclusions and Clinical Relevance-Alterations of heart mitochondrial proteins related to oxidative phosphorylation dysfunction were more prevalent in tissue specimens from dogs with induced or naturally occurring DCM, compared with those of control dogs.
显示更多 [+] 显示较少 [-]Influence of phenytoin on isoproterenol-induced myocardial fibrosis in rats
1990
Besbasi, F.S. | Hamlin, R.L.
A study was designed to determine whether phenytoin (PHE) prevents the myocardial necrosis and subsequent fibrosis produced by isoproterenol (ISO). Seven groups of female rats of the Wistar strain were used. Rats in groups 1 and 5 served as controls. Rats in group 3 were injected SC with 85 mg of ISO/kg of body weight for 2 consecutive days. Rats in groups 2 and 6 received 100 mg of PHE/kg orally. Rats in groups 4 and 7 received both PHE and ISO. There were 6 to 9 rats/group. Effects of ISO and PHE were evaluated gravimetrically, histologically, and electrocardiographically. Heart weight/body weight ratios for each group receiving ISO, with or without PHE, were greater than for groups not receiving ISO (P < 0.05). Light microscopic examination of heart sections of rats given ISO alone or ISO + PHE revealed multiple and diffuse areas of fibrosis. Fibrosis in hearts from rats receiving PHE + ISO was less severe than that in hearts from rats receiving ISO alone, but the difference was not statistically significant. Electrocardiographic changes of statistical significance were not observed in rats receiving any compound (alone or in combination), when compared with the control groups of equal age.
显示更多 [+] 显示较少 [-]Endomyocardial biopsy in cats
1990
Rush, J.E. | Keene, B.W. | Eicker, S.W.
A technique for transvenous endomyocardial biopsy of the right ventricle was developed and evaluated for safety and efficacy in anesthetized healthy cats positioned in left lateral recumbency. At least 6 endomyocardial biopsy specimens were obtained from the right ventricle or interventricular septum of 11 cats. In 4 cats, the right jugular vein was torn during attempts to pass the introducing catheter into the right ventricle; however, in only 1 cat did this preclude catheter passage. This cat's heart was biopsied via the left jugular vein. Except for damage to the jugular vein, complications were infrequent, and the biopsy procedure was well tolerated by all cats.
显示更多 [+] 显示较少 [-]Spectrophotometric method for differentiation of cardiac and hepatic lactate dehydrogenase activities in dogs
1989
Aguilera-Tejero, E. | Mayer-Valor, R. | Gomez-Cardenas, G.
To differentiate the origin of high total lactate dehydrogenase (LD) activity in canine sera, a spectrophotometric method based on the preferential inhibition of cardiac LD isoenzymes by pyruvate was performed. Comparison with the electrophoretic separation of LD isoenzyme activities and determination of the hydroxybutyrate dehydrogenase-to-LD ratio indicated that the method proposed gave a better discrimination between cardiac and hepatic LD activities than did the other tests.
显示更多 [+] 显示较少 [-]First report of Madurella mycetomi isolate that induced systemic pulmonary and myocardium mycosis with verminious enteritis in Dugong dugon, of Mersing, Johore
2018
Hanafi H. | Noordin M. M. | Mazlina M. | Tamimi M. A. A. | Syed Abdullah S. A. K. | Aida M. | Norina L. | Zaidin A. | Sarol K.
The major causes of the decline of the Dugong population along the urban coast of Mersing, Johor includes gill netting, subsistence hunting, habitat loss from extreme weather events that are likely to be exacerbated by climate change, humansettlement, breach of the bots and sea water pollution. In March 2017, a male Dugong dugon, estimated age of 10 to 20 years, wasincidentally found dead near Pulau Tinggi, Mersing, Johor by a fisherman. The entire body was found to have old and new scarsat the anterior part of the abdomen. The right eye was protruded out and bleeding which indicated that the eye was piercedby a sharp object. Necropsy revealed the upper small intestine and the stomach compartments were semi-impacted with a massive helminth burden (more than 1,000 nematodes). Paradujardinia halicoris worms were identified based on morphological characteristics. Zoonotic fungus named Madurella mycetomi were isolated from heart and lung after incubation for 14 days.Histologically, the lung was confirmed to have the presence of big mast cells which formed capsules, indicating presence offungal spores causing systemic mycoses where the macrophages invade and engulf the spores. The shrinkage of myocardium myocyte and myocardium necrosis with mild vasculitis indicates heart failure. Groucott’s stain confirmed Madurella mycetomi infection that induced systemic pulmonary and myocardium mycosis in Dugong dugon.
显示更多 [+] 显示较少 [-]Associations of various physical and blood analysis variables with experimentally induced Mycoplasma bovis pneumonia in calves
2014
Fraser, Brandon C. | Anderson, David E. | White, Brad J. | Miesner, Matt D. | Lakritz, Jeff | Amrine, David | Mosier, Derek A.
Objective-To determine associations of blood analysis variables and orbit and nasal planum surface temperatures with the onset and severity of Mycoplasma bovis pneumonia in calves. Animals-28 healthy calves. Procedures-Calves were challenged with M bovis (n = 24) on day 0 or not challenged (4). Blood samples were obtained for cardiac troponin I, CBC, and serum biochemical analyses on various days. Orbit and nasal planum surface temperatures were determined with infrared thermography on various days. Calves were euthanized, gross necropsies were performed, heart and lung samples were collected for histologic evaluation, and microbial cultures of lung samples were performed on day 14. Pneumonia severity was categorized as mild (< 10% lung consolidation) or moderate (≥ 10% lung consolidation). Associations between measured variables and severity of pneumonia or sample collection day were determined. Results-Plasma cardiac troponin I concentration for the 28 calves was significantly higher on day 14 than it was on day 0 or 7 (least squares mean, 0.02, 0, and 0 ng/mL, respectively). No other variables changed significantly during the study. No substantial gross or histologic abnormalities were identified in cardiac muscle samples. Day 14 plasma fibrinogen concentration was significantly different between calves with mild pneumonia and those with moderate pneumonia (mean, 0.44 and 0.74 g/dL, respectively). Calves with moderate pneumonia had significantly lower least squares mean surface temperature of the dorsal aspect of the nasal planum (18.7°C) versus calves with mild pneumonia (22.9°C). Conclusions and Clinical Relevance-Results indicated the evaluated variables had low value for assessment of bovine respiratory disease complex in calves.
显示更多 [+] 显示较少 [-]Effects of clenbuterol administration on serum biochemical, histologic, and echocardiographic measurements of muscle injury in exercising horses
2012
Thompson, Jessica A. | Eades, Susan C. | Chapman, Ann M. | Paulsen, Daniel B. | Barker, Steven A. | McConnico, Rebecca S.
Objective: To determine the effects of clenbuterol, at a dosage of up to 3.2 μg/kg for 14 days, PO, on skeletal and cardiac muscle in healthy horses undergoing treadmill exercise. Animals: 12 healthy horses from 3 to 10 years old. Procedures: Horses were randomly assigned to a control group (n = 6) or clenbuterol group (6) and received either saline (0.9% NaCl) solution or clenbuterol, PO, every 12 hours for 14 days. Horses were subjected to submaximal treadmill exercise daily during treatment. Muscle biopsy specimens were collected before and after treatment for determination of apoptosis. Echocardiographic measurements, serum clenbuterol and cardiac troponin I concentrations, and serum activities of creatine kinase and aspartate aminotransferase were measured before, during, and after treatment. Jugular venous blood samples were collected every 3 days during treatment. Echocardiography was repeated every 7 days after beginning treatment. Response variables were compared between treatment groups and across time periods. Results: No significant effect of clenbuterol or exercise on response variables was found between treatment and control groups at any time point or within groups over time. Conclusions and Clinical Relevance: Results did not reveal any adverse effects of treatment with an approved dose of clenbuterol on equine cardiac or skeletal muscle in the small number of horses tested.
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