Characterization and comparison of the responses of equine digital arteries and veins to endothelin-1     

Katz LM  Marr CM  Elliott J 《American journal of veterinary research》2003,64(11):1438-1443

OBJECTIVE: To compare the responses of equine digital arteries (EDAs) and equine digital veins (EDVs) to endothelin-1 (ET-1) and determine the role of the endothelium and type of receptors involved in the modulation and mediation of those responses, respectively. SAMPLE POPULATION: 5 to 9 palmar digital vessels/experiment from 28 healthy horses. PROCEDURE: Rings of dissected vessels were mounted under tension between force transducer wires in organ baths containing Krebs-Henseleit solution at 30 degrees C. Responses of EDAs and EDVs (with intact [+e] or denuded [-e] endothelium) to cumulative concentrations of ET-1 (10(-10) to 3 X 10(-7) M) were compared. For (+e)EDAs and (+e)EDVs precontracted with a thromboxane-mimetic (U44069; 10(-8) M) and (-e)EDAs and (-e)EDVs, responses to an ETB receptor agonist (S6c; 10(-10) to 3 X 10(-7) M) were evaluated. Responses to ET-1 (10(-7) M) in (-e)EDAs and (-e)EDVs were evaluated after incubation with an ETA receptor antagonist (BQ-123; 3 X 10(-7) M), an ETB receptor antagonist (BQ-788; 3 X 10(-7) M), or vehicle solution. RESULTS: Endothelin-1 induced a concentration-dependent contraction of endothelium-intact and -denuded EDAs and EDVs; EDVs were more sensitive. Neither vessel type relaxed in response to S6c, although 2 of the (-e)EDAs contracted mildly. Whereas BQ-123 inhibited the (-e)EDA and (-e)EDV responses to ET-1, BQ-788 had no effect. CONCLUSIONS AND CLINICAL RELEVANCE: Endothelin-1 induced digital vasoconstriction (marked constriction in veins). This action was unaffected by endothelium and mediated predominantly by ETA receptors. These findings suggest ET-1 can induce selective digital venoconstriction.  相似文献   

Cardiac emergencies and problems of the critical care patient.     

Celia M Marr 《Veterinary Clinics of North America: Equine Practice》2004,20(1):217-230

Cardiac disease and dysfunction can occur as a primary disorder(ie, with pathology situated in one or more of the cardiac structures) or can be classified as a secondary problem when it occurs in patients with another primary problem that has affected the heart either directly or indirectly. Primary cardiac problems are encountered in horses presented to emergency clinics; however,this occurs much less frequently in equine critical patients than cardiac problems arising secondary to other conditions. Nevertheless,if primary or secondary cardiac problems are not identified and addressed, they certainly contribute to the morbidity and mortality of critical care patients.  相似文献   

Sonographic features of drug-induced splenic congestion     

Robert T. O''Brien  DVM  MS    Kenneth R. Waller III  BS  Teresa L. Osgood  DVM 《Veterinary radiology & ultrasound》2004,45(3):225-227

Drug-induced splenic congestion has been reported in dogs secondary to barbiturate administration. This research attempted to verify and quantify size changes associated with drug-induced splenic congestion in dogs. Transverse plane ultrasound images of the spleen in normal dogs were collected to determine the maximum diameter in the minimum dimension prior to, and 15 min after, administration of acepromazine, thiopental, or propofol. Significant splenic enlargement was seen after administration of acepromazine (P<0.01) and thiopental (P=0.02), but no enlargement was seen after administration of propofol. Significantly increased attenuation (P<0.01) and a trend of increased backscatter (P=0.09) were measured after administration of acepromazine. These results indicate that measurable splenomegaly occurs after acepromazine and thiopental administration. This represents the first report of a condition causing measurable diffuse increased attenuation in the spleen. Propofol does not cause measurable splenic enlargement under the conditions of this research.  相似文献   

CONTRAST HARMONIC ULTRASOUND OF SPONTANEOUS LIVER NODULES IN 32 DOGS     

R.T. O''Brien  DVM  MS    M. Iani  DVM    J. Matheson  DVM    F. Delaney  BS    K. Young  VMD  PhD 《Veterinary radiology & ultrasound》2004,45(6):547-553

Thirty-two dogs with spontaneous hepatic nodules were given intravenous ultrasound contrast medium (Definity or Sonovue) and imaged with contrast harmonic software on a conventional ultrasound machine system. Digital video images were initially reviewed to describe the perfusion pattern of malignant nodules. The images were reviewed again to test this pattern against all individual nodules. Subjectively, there was improved conspicuity of malignant nodules after contrast enhancement compared with conventional imaging and increased numbers of malignant nodules were often noted. There was decreased conspicuity of benign nodules and no additional nodules were seen after contrast enhancement. There was a highly significant (P < 0.0001) association of malignancy with a hypoechoic nodule at surrounding normal liver peak contrast enhancement. Benign nodules were isoechoic to the surrounding normal liver at peak contrast enhancement. Only one benign nodule (hepatoma) had regions of hypoechogenicity compared with the surrounding normal liver at peak liver contrast enhancement. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were highly significant (P < 0.0001) (100%, 94.1%, 93.8%, 100%, and 96.9%, respectively). No complications or morbidity was noted throughout the course of the study. Contrast harmonic ultrasound appears to be accurate at discriminating between naturally occurring benign and malignant nodules in the liver of dogs.  相似文献   

Effect of a trivalent vaccine against Staphylococcus aureus mastitis lymphocyte subpopulations, antibody production, and neutrophil phagocytosis   总被引：2，自引：0，他引：2       下载免费PDF全文

Jai-Wei Lee  Celia N. O’Brien  Albert J. Guidry  Max J. Paape  Kimberley A. Shafer-Weaver    X. Zhao 《Canadian journal of veterinary research》2005,69(1):11-18

The effect of a novel bovine mastitis trivalent vaccine, containing Staphylococcus aureus capsular polysaccharide type 5 (T5), 8 (T8), and 336 (T336), on lymphocyte subpopulations, antibody production, and neutrophil phagocytosis was evaluated. Twenty pregnant heifers were immunized with either the trivalent alone, trivalent emulsified in Freund's incomplete adjuvant (FICA), trivalent in aluminum hydroxide, or adjuvant only (FICA). Immunization was done 30 d before the expected calving date followed by 2 boosts in a 2-week interval. Compared to FICA, serum antigen-specific immunoglobulin (Ig)G1 and IgG2 were significantly increased in all the vaccinated groups before parturition and sustained until 3 wk postpartum. In comparison with the trivalent alone, formulation with either adjuvant enhanced production of IgG2, but not IgG1. Immune sera, which contained the highest amount of antibodies, slightly increased neutrophil phagocytosis to the 3 serotypes of killed S. aureus, but most of the differences were not significant due to large variation between the cows. The percentage of CD4+ lymphocyte was significantly higher in vaccinated groups than that of FICA 4 wk after the primary immunization. In comparison with FICA, cows inoculated with trivalent vaccine and adjuvants had an increased percentage of CD8+ lymphocytes at 2 time points, 2 wk before and after calving. Our results indicated that the whole cell trivalent vaccine, with or without adjuvants, is able to elicit antibody responses specific to the 3 capsular polysaccharide antigens. The increase of T8-specific IgG2 was more noticeable when the vaccine was emulsified with adjuvants.  相似文献   

Successful Low Dose Insemination of Flow Cytometrically Sorted Ram Spermatozoa in Sheep     

SP de Graaf  G Evans  WMC Maxwell  JA Downing  JK O''Brien 《Reproduction in domestic animals》2007,42(6):648-653

The fertility of ram spermatozoa that had undergone flow cytometric sorting (MoFlo SX) and cryopreservation was assessed after low-dose insemination of synchronized Merino ewes. Oestrus was synchronized with progestagen-impregnated pessaries, PMSG and GnRH treatment. Ewes (n = 360) were inseminated with 1 x 10(6), 5 x 10(6) or 15 x 10(6) motile sorted frozen-thawed (S(1), S(5), or S(15) respectively) or non-sorted frozen-thawed (C(1), C(5) or C(15) respectively) spermatozoa from three rams. An additional group of ewes were inseminated with 50 x 10(6) motile non-sorted frozen-thawed spermatozoa (C(50)) to provide a commercial dose control. The percentage of ewes lambing after insemination was similar for C(50) (24/38, 63.2%), C(15) (37/54, 68.5%), S(15) (38/57, 66.7%), S(5) (37/56, 66.1%) and S(1) (32/52, 61.5%) groups (p > 0.05), but lower for C(5) (19/48, 39.6%) and C(1) (19/55, 34.5%) treatments (p < 0.05). This study demonstrates sorted ram spermatozoa are equally fertile to non-sorted spermatozoa even when inseminated at 2% of the dose. Furthermore, at very low artificial insemination doses (1 or 5 million motile) the fertility of sorted ram spermatozoa is superior to non-sorted spermatozoa inseminated in equal numbers. These results have significance for the future commercialization of sex-preselection technology in sheep as a reduction in the minimum effective sperm number will allow a corresponding decrease in the associated cost per dose.  相似文献   

Peter D Rossdale,OBE, MA,PhD, Dr (h.c.) Berne,Dr (h.c.) Edinburgh,DVSc (h.c.) Sydney,DESM, FACVSc,FRCVS. 1927-2021     

Celia M. Marr  Tim Mair 《Equine veterinary journal》2022,54(2):192-196

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Erratum to: A social–ecological approach to landscape epidemiology: geographic variation and avian influenza     

Graeme S. Cumming  Celia Abolnik  Alexandre Caron  Nicolas Gaidet  John Grewar  Eléonore Hellard  Dominic A. W. Henry  Chevonne Reynolds 《Landscape Ecology》2015,30(6):987-987

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Genetic variation and gene flow among Prunus cerasoides D. Don populations in northern Thailand: analysis of a rehabilitated site and adjacent intact forest     

Greuk Pakkad  Suad Al Mazrooei  David Blakesley  Celia James  Stephen Elliott  Tapio Luoma-Aho  Jarkko Koskela 《New Forests》2008,35(1):33-43

This study describes the level of genetic variation and gene flow within and among populations of Prunus cerasoides in rehabilitated sites and adjacent intact forest. The seven microsatellite loci employed detected a total of 75 alleles (n = 401). Polymorphic information content (PIC) varied from 0.34 to 0.83. Between the adult populations there was moderate genetic differentiation with an F _ST value of 0.0575, which suggests that the restoration plots had a similar genetic composition to that of the natural population. The gene flow assessment provides some interesting insights into the genetic diversity of P. cerasoides. In the 16 naturally occurring trees over 83% of the genotyped seed were fathered by unidentified trees whereas in restoration plot A only about 32% of the pollen came from an unidentified father. This proportion was even less in Plot C where 25% of the pollen parents were unidentified. The naturally occurring trees within Doi Suthep were surrounded by planted trees, which were contributing to the paternity of the seed crop. This result demonstrates that ‘‘fill in’’ planting should consist of locally sourced material if it is considered important to conserve the genetic integrity of the local populations.  相似文献   

Quantification of vitellin/vitellogenin-like proteins in the oyster Crassostrea corteziensis (Hertlein 1951) as a tool to predict the degree of gonad maturity     

Fabiola G. Arcos  Ana María Ibarra  María del Carmen Rodríguez-Jaramillo  Ethel Awilda García-Latorre  & Celia Vazquez-Boucard 《Aquaculture Research》2009,40(6):644-655

The oyster's reproductive process is poorly documented, especially in terms of a quantitative approach. In recent years, investigations with this species have been directed at determining important reproductive factors. Within this scope, techniques that allow standardized and accurate quantitative estimations of gonad development have become of primary importance. In this study, the histological characteristics and the levels of vitellin/vitellogenin-like proteins (Vn/Vtg) from ovaries of the Mexican Pacific 'pleasure' oyster Crassostrea corteziensis (Hertlein 1951) were analysed during different stages of gonad maturation using quantitative histological techniques and an enzyme-linked immunosorbent assay. This was performed in order to evaluate a possible quantitative tool to predict the degrees of gonad maturity and to analyse the biological implications of the findings relative not only to broodstock conditioning but also to natural populations. Using this information, we expect to be able to undertake further research on different reproductive aspects of this oyster species, including, among others, evaluation of the response in Vn/Vtg concentrations to different diets and environmental conditions during laboratory conditioning.  相似文献