Small Animal ECGs: An Introduction - by M Martin     

BJ Gavaghan 《Australian veterinary journal》2008,86(7):271-271

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Long‐Term Outcome in Dogs After Circumcostal Gastropexy or Gastrocolopexy for Gastric Dilatation With or Without Volvulus     

ANNA V. EGGERTSDÓTTIR DVM  PhD  MARIANNE LANGELAND DVM  PhD  BJØRN FUGLEM DVM  ANE MOHN DVM  ØYVIND STIGEN DVM  PhD 《Veterinary surgery : VS》2008,37(8):809-810

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Comparison of Fick and thermodilution cardiac output determinations in standing horses     

Lépiz ML  Keegan RD  Bayly WM  Greene SA  McEwen MM 《Research in veterinary science》2008,85(2):307-314

The Fick and thermodilution (TD) methods are two currently popular techniques for determination of cardiac output (CO) in adult horses. To our knowledge, a comparison of these two techniques has not been reported. Six healthy, resting, fit, adult horses of either sex and weighing 516.5+/-33.2 kg (mean+/-SD) were instrumented to enable measurement of cardiac output. Resting CO was determined by the Fick method and by thermodilution while the horses stood quietly in the stocks. Fick and thermodilution CO measurements were repeated under conditions of increased cardiac output achieved with the use of a dobutamine infusion (5 microg kg(-1) min(-1), IV), and again under conditions of decreased CO induced by administration of xylazine (0.5 mg/kg, IV). Fick and thermodilution cardiac outputs were compared using Bland-Altman analysis for repeated measures. The mean of the differences+/-1.96SD (bias and precision) between the two techniques was 1.88+/-24.17 L/min. Variability between measurements with the two techniques was decreased to 3.41+/-46.78 mL kg(-1) min(-1) when CO was normalized for body size by calculation of cardiac index.  相似文献   

Naturally occurring Mycoplasma bovis-associated pneumonia and polyarthritis in feedlot beef calves.   总被引：1，自引：0，他引：1  

Mihai I Gagea  Kenneth G Bateman  Rachel A Shanahan  Tony van Dreumel  Beverly J McEwen  Susy Carman  Marie Archambault  Jeff L Caswell 《Journal of veterinary diagnostic investigation》2006,18(1):29-40

Mycoplasma bovis is perceived as an emerging cause of mortality in feedlot beef cattle. This study examined the lesions and infectious agents in naturally occurring M. bovis-associated bronchopneumonia and arthritis and the relationship of this condition with bovine viral diarrhea virus (BVDV) infection. Standardized pathologic, immunohistochemical, and microbiologic investigations were conducted on 99 calves that died or were euthanized within 60 days after arrival in 72 feedlots. Cranioventral bronchopneumonia with multiple foci of caseous necrosis was identified in 54 of 99 calves, including 30 with concurrent fibrinosuppurative bronchopneumonia typical of pneumonic pasteurellosis. Mycoplasma bovis was consistently identified in these lesions by culture and immunohistochemistry, but also commonly in healthy lungs and those with pneumonia of other causes. Focal lesions of coagulation necrosis, typical of pneumonic pasteurellosis, were often infected with both Mannheimia haemolytica and M. bovis. Arthritis was present in 25 of 54 (46%) calves with M. bovis pneumonia, and all calves with arthritis had pneumonia. BVDV infection was more common in calves with lesions of bacterial pneumonia than in those dying of other causes, but BVDV infection was not more common in calves with caseonecrotic bronchopneumonia than those with fibrinosuppurative bronchopneumonia. Retrospective analysis identified cases of M. bovis pneumonia in the early 1980s that had milder lesions than the current cases. The findings suggest that, in at least some calves, M. bovis induces caseonecrotic bronchopneumonia within the lesions of pneumonic pasteurellosis.  相似文献   

Corticosterone regulation of tryptophan hydroxylase in midbrain of the rat   总被引：5，自引：0，他引：5  

E C Azmitia  B S McEwen 《Science (New York, N.Y.)》1969,166(910):1274-1276

The tryptophan hydroxylase activity in the rat midbrain decreases after adrenalectomy and is restored by treatment with corticosterone. Cycloheximide, adminiistered intracisternally, prevents the restoration of the enzyme activity by corticosterone. Cycloheximide administration to adrenalectomized rats resutlts in a further decrease in the enzyme activity. an indication that the enzyme has a rapid turnover even in the absence of corticosterone.  相似文献   

Coxiella burnetii infection is associated with placentitis in cases of bovine abortion.     

R J Bildfell  G W Thomson  D M Haines  B J McEwen  N Smart 《Journal of veterinary diagnostic investigation》2000,12(5):419-425

A positive score on a modified acid-fast (MAF)-stained smear test of fresh placenta was used to identify a group of bovine abortion submissions believed to be infected with Coxiella burnetii. Immunohistochemical (IHC) testing for Coxiella and Chlamydia antigens was performed on 14 MAF smear-positive cases as well as 29 MAF smear-negative cases received during the study period. Nine MAF smear-positive cases as well as 1 MAF smear-negative case were Coxiella-positive via the IHC test. No placentas were positive for Chlamydia antigen. Various histopathologic features were categorized for all placentas and the presence or absence of selected risk categories was also graded for each case. The results between Coxiella IHC-positive cases and Coxiella IHC-negative/MAF-negative cases were compared using Fisher's exact test (P value at 95% confidence). Significant associations were found between Coxiella IHC-positive cases and the presence of placental inflammation (P = 0.0027), placental necrosis (P = 0.012), fetal pneumonia (P = 0.0152), and the visibility of Coxiella-like organisms within trophoblasts on hematoxylin and eosin-stained sections (P < 0.0001). Histopathologic features of Coxiella IHC-positive placentas included infiltration of the chorionic stroma by mononuclear cells, necrosis of chorionic trophoblasts, and focal exudation of fibrin and neutrophils. The results indicate that MAF smears are a good screening tool for the presence of Coxiella in placentas from bovine abortion cases and that the detection of this pathogen in aborted placentas via traditional staining or IHC methods is usually associated with placentitis.  相似文献   

The application of knowledge synthesis methods in agri-food public health: Recent advancements,challenges and opportunities     

Ian Young  Lisa Waddell  Javier Sanchez  Barbara Wilhelm  Scott A. McEwen  Andrijana Rajić 《Preventive veterinary medicine》2014

Knowledge synthesis refers to the integration of findings from individual research studies on a given topic or question into the global knowledge base. The application of knowledge synthesis methods, particularly systematic reviews and meta-analysis, has increased considerably in the agri-food public health sector over the past decade and this trend is expected to continue. The objectives of our review were: (1) to describe the most promising knowledge synthesis methods and their applicability in agri-food public health, and (2) to summarize the recent advancements, challenges, and opportunities in the use of systematic review and meta-analysis methods in this sector. We performed a structured review of knowledge synthesis literature from various disciplines to address the first objective, and used comprehensive insights and experiences in applying these methods in the agri-food public health sector to inform the second objective. We describe five knowledge synthesis methods that can be used to address various agri-food public health questions or topics under different conditions and contexts. Scoping reviews describe the main characteristics and knowledge gaps in a broad research field and can be used to evaluate opportunities for prioritizing focused questions for related systematic reviews. Structured rapid reviews are streamlined systematic reviews conducted within a short timeframe to inform urgent decision-making. Mixed-method and qualitative reviews synthesize diverse sources of contextual knowledge (e.g. socio-cognitive, economic, and feasibility considerations). Systematic reviews are a structured and transparent method used to summarize and synthesize literature on a clearly-defined question, and meta-analysis is the statistical combination of data from multiple individual studies. We briefly describe and discuss key advancements in the use of systematic reviews and meta-analysis, including: risk-of-bias assessments; an overall quality-of-evidence approach; engagement of stakeholders; Bayesian, multivariate, and network meta-analysis; and synthesis of diagnostic test accuracy studies. We also highlight several challenges and opportunities in the conduct of systematic reviews (e.g. inclusion of grey literature, minimizing language bias, and optimizing search strategies) and meta-analysis (e.g. inclusion of observational studies and approaches to address the insufficient reporting of data and significant heterogeneity). Many of these developments have yet to be comprehensively applied and evaluated in an agri-food public health context, and more research is needed in this area. There is a need to strengthen knowledge synthesis capacity and infrastructure at the regional, national, and international levels in this sector to ensure that the best available knowledge is used to inform future decision-making about agri-food public health issues.  相似文献   

Calcium oxalate crystals in the aragonite-producing green alga penicillus and related genera     

Friedmann EI  Roth WC  Turner JB  McEwen RS 《Science (New York, N.Y.)》1972,177(4052):891-893

Calcium oxalate crystals occur in the marine green algae Penicillus, Rhipocephalus, and Udotea, known as producers of sedimentary aragonite needles. In contrast to the externally deposited aragonite crystals which are generally < 15 micrometers long, the oxalate crystals are larger (up to 150 micrometers) and are located in the vacuolar system of the plant. No calcium oxalate was found in the related but noncalcifying genera Avrainvillea and Cladocephalus.  相似文献   

Pituitary-adrenal influences on fear responding   总被引：1，自引：0，他引：1  

J M Weiss  B S McEwen  M T Silva  M F Kalkut 《Science (New York, N.Y.)》1969,163(863):197-199

In a passive avoidance situation, hypophysectomized male rats show less fear than normal rats, whereas adrenalectomized rats show greater fear than normals. These results probably occur because hypophysectomized rats lack adrenocorticotrophic hormone, which increases arousal or emotionality, whereas adrenalectomized animals lack certain adrenal steroids, which inhibit excitatory effects. The results indicate that adrenocorticotrophic hormone and certain adrenal steroids have opposite effects in regulating fear-motivated behavior.  相似文献   

Lunar impact basins and crustal heterogeneity: new Western limb and far side data from galileo     

Belton MJ  Head JW  Pieters CM  Greeley R  McEwen AS  Neukum G  Klaasen KP  Anger CD  Carr MH  Chapman CR  Davies ME  Fanale FP  Gierasch PJ  Greenberg R  Ingersoll AP  Johnson T  Paczkowski B  Pilcher CB  Veverka J 《Science (New York, N.Y.)》1992,255(5044):570-576

Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (>2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.  相似文献