Research in veterinary science.
Publisher:
British Veterinary Association. London : British Veterinary Association
Frequency: Bimonthly
Country: England
Language: English
Author(s):
British Veterinary Association.
Start Year:1960 -
ISSN:
0034-5288 (Print)
1532-2661 (Electronic)
0034-5288 (Linking)
1532-2661 (Electronic)
0034-5288 (Linking)
Impact Factor
2.4
2022
| NLM ID: | 0401300 |
| (DNLM): | R25920000(s) |
| (OCoLC): | 01644503 |
| Coden: | RVTSA9 |
| Classification: | W1 RE231 |
Detection of antibodies to Borrelia burgdorferi in naturally infected horses in the USA by enzyme-linked immunosorbent assay using whole-cell and recombinant antigens. Blood samples were collected from 98 horses suspected of having borreliosis or granulocytic ehrlichiosis in Connecticut and New York State, USA during 1985, 1995, and 1996. Serum antibodies to Borrelia burgdorferi were detected by an enzyme-linked immunosorbent assay (ELISA), based on whole-cell and recombinant antigens, in 82 (84%) horses. Of the 181 sera tested, 59% were positive, using whole-cell antigens, compared to 48% with protein (p)37 and 35% with VlsE antigens. An ELISA containing either of these fusion proteins can be used as an adjunct to general screening by an ELISA or immunoblot...
Current practice relating to equine castration in the UK. This study aimed to characterise current practice relating to equine castration in the UK. A questionnaire was posted to all 655 veterinary practices specified to provide veterinary care for horses, or classified as specialist equine practices. Respondents were asked to cite the number of equine castrations performed annually by the practice, describe techniques used for castration, outline anaesthetic/sedative/analgesic drug protocols used and provide details of post-operative medication. There was a 43% response rate to the questionnaire. Considerable variation in techniques and analgesia pr...
cDNA AFLP-based techniques for studying transcript profiles in horses. The identification of differentially expressed genes is a fundamental prerequisite for understanding the molecular regulation of most physiological and pathological processes. Among the procedures employed to compare mRNA populations, those that are gel-based appear to hold great promise and are considered excellent tools for studying gene expression in species, such as the equine one, for which little genomic information is available. In the present study, we evaluated two techniques for studying mRNA profiles in horse tissue, one referred to the cDNA-amplified fragment length polymorphism (A...
Rat, caprine, equine and bovine erythrocyte ghosts exposed to t-butyl hydroperoxide as a model to study lipid peroxidation using a chemiluminescence assay. The aim of the present study was to analyze the time-course of t-butyl hydroperoxide-induced changes in lipid peroxidation, fatty acid composition and chemiluminescence intensity in rat, caprine, equine and bovine erythrocyte ghosts. A relatively high content of arachidonic acid (C20:4 n6) and docosahexaenoic acid (C22:6 n3) was characteristic of the rat erythrocyte ghosts. The fatty acid composition of native erythrocyte ghosts obtained from caprine, equine and bovine was characterized by a high content of oleic acid (C18:1 n9) and a low content of the peroxidable polyunsaturated fatty acids ...
Effect of submaximal exercise on horse homocysteinaemia: possible implications for immune cells. Physical exercise induces a reduction of immune defences and an imbalance of red-ox status. In this study plasma levels of cysteine and homocysteine (Hcy) were determined in horses before and after submaximal treadmill exercise as well as the effect on horse lymphocyte proliferation. The exercise induced a significant increase in plasma Hcy levels, which remained high both after the 20 min recovery period and after 2 h of rest. Moreover, a reduction of lymphocyte responsiveness to the proliferative stimulus induced by Concanavalin A was observed. The effects of different Hcy concentrations on ...
Preferential and non-selective cyclooxygenase inhibitors reduce inflammation during lipopolysaccharide-induced synovitis. Synovitis in horses is frequently treated by administration of non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit cyclooxygenase isoforms (COX-1 and COX-2). Constitutively expressed COX-1 is involved in physiologic functions such as maintenance of gastric mucosal integrity, whereas COX-2 is up-regulated at sites of inflammation. Thus, COX-2 inhibitors reduce inflammation with reduced gastrointestinal side effects as compared to non-selective COX inhibitors. The objective of the present study was to compare the anti-inflammatory effects of the preferential COX-2 inhibitor etodolac wi...
Cytokine responses to Cyathostominae larvae in the equine large intestinal wall. To investigate cytokine responses in cyathostomin infection, we quantified mucosal interleukin-4 (IL-4), interleukin-10 (IL-10), tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma by reverse transcriptase-competitive polymerase chain reaction. The analysis was performed on large intestinal wall samples obtained from six anatomical sites spanning the caecum and colon of 17 naturally exposed horses. The numbers of developing larvae (DL) and early third stage larvae (EL3) were ascertained using transmural illumination and pepsin digestion techniques, respectively. Levels of each cytoki...
Pulmonary artery wedge pressure measurement in healthy warmblood horses and in warmblood horses with mitral valve insufficiencies of various degrees during standardised treadmill exercise. In 12 healthy warmblood horses and 10 horses with mitral valve insufficiencies (MVI) of various degrees heart rate and pulmonary artery wedge pressure (PWP) was measured at rest and during standardised exercise on a high speed treadmill. There was a significant increase in PWP with each change in speed of the treadmill (p < 0.01). The PWP of horses with mild mitral valve regurgitation under working conditions was not significantly different compared to the healthy horses. The horses with moderate mitral valve regurgitation showed a significant higher pulmonary artery wedge pressure at rest and...
Detection of bacterial DNA in synovial fluid from horses with infectious synovitis. Standard culturing techniques are often unrewarding in confirming diagnosis of synovial infection in the equine patient. Several human studies report the use of sensitive polymerase chain reaction (PCR) techniques for the detection of bacterial involvement in acute synovitis. However, successful extraction of bacterial DNA directly from clinical samples from horses without prior culture has not been reported yet. The goal of this study was to develop a sensitive and reliable method for molecular detection and identification of bacterial species in synovial fluid from horses with infectious syn...
Effect of matrix depleting agents on the expression of chondrocyte metabolism by equine chondrocytes. This study was carried out to investigate the effect of two enzymes (collagenase and chondroitinase) and two cytokines/metabolites (interleukin-1beta and retinoic acid) of known catabolic activity on the expression of cartilage metabolism/phenotype in equine articular cartilage. Articular cartilage explants from 11 horses (5-13 years old) were treated for 48 h and assayed for total sulphated glycosaminoglycan (GAG), the incorporation of 35S-sulphate, collagen degradation and mRNA expression of the proteoglycans collagen II, collagen IIA, collagen III, collagen IX, collagen X, collagen XI and g...
Enzyme activities in some types of peripheral leukocytes of thoroughbred race horses before and after the races. Glucose, free fatty acid (FFA), triglyceride (TG) and immunoreactive insulin (IRI) concentrations in plasma and activities of enzymes related to energy metabolism in some types of peripheral leukocytes were measured in thoroughbred race horses before and after racing. Glucose, FFA, TG and IRI concentrations and enzyme activities did not change significantly in plasma. However, the activities of cytosolic hexokinase, malate dehydrogenase (MDH), mitochondrial MDH and aspartate aminotransferase decreased significantly in leukocytes of the horses after the races. The cytosolic ratio of MDH/LDH act...
Detection of enrofloxacin and its metabolite ciprofloxacin in equine hair. Hair analysis to detect drug administration has not been studied extensively in horses. This study aimed to (a) develop an analytical method for enrofloxacin and its metabolite ciprofloxacin in mane and tail hair, (b) relate measured values to doses, routes of administration, hair colour, and (c) demonstrate long-term detectability. Samples were extracted in trifluoroacetic acid at 70 degrees C. Extracts were cleaned-up by solid-phase extraction and analysed by high-performance liquid chromatography with UV-diode array detection. Analyte recoveries were > 87%. Horses were sampled after therape...
Physiological and pathological expression of intermediate filaments in the equine endometrium. The aim of this study was to investigate the expression of the intermediate filaments cytokeratin, vimentin and desmin in the equine endometrium by immunohistological techniques. For this purpose, endometrial biopsies of 151 mares were examined to determine physiological cycle patterns and changes resulting from endometriosis. During the physiological cycle epithelial cells and mesenchymal cells express cytokeratin and vimentin, respectively, whilst desmin and vimentin were coexpressed by the smooth muscle cells. Epithelial coexpression of cytokeratin and vimentin was seen in numerous fibrotic...
Microbiological and serological study of leptospirosis in horses at slaughter: first isolations. A bacteriological survey of kidneys from 145 abattoir horses was performed, which resulted in the isolation of two Leptospira strains. The isolates were serologically typed as belonging to serogroups Australis and Pomona, and REA identified them as L. interrogans serovar Bratislava and L. kirschneri serovar Tsaratsovo, respectively. These are the first Leptospira isolates obtained from horses in Portugal and the Bratislava strain is the first serogroup Australis strain to be isolated in this country. The 145 horses were also serologically tested for leptospiral antibodies, and 37% had MAT titr...
Validation of a method for collection and assay of pentane in the exhaled breath of the horse. Oxidative stress refers to an imbalance between the production of oxidising free radicals and the antioxidant defenses of the cell, and is associated with many pathogenic processes. Oxidative damage to cellular lipids results in the evolution of pentane and ethane gas, and detection of these hydrocarbons in the exhaled breath can be used to monitor in vivo oxidative stress. The aim of this study was to validate a gas chromatography (GC) method for measurement of breath pentane in the horse. The GC-system developed showed good specificity for discrimination of pentane from other breath hydrocar...
Lower gastric ulcerogenic effect of suxibuzone compared to phenylbutazone when administered orally to horses. The objective was to compare the gastrointestinal and general toxicity of suxibuzone (SBZ) to that of phenylbutazone (PBZ) when administered orally in horses. Fifteen healthy horses were allocated to three treatment groups. One group received a high dose of PBZ for two weeks; the second group was given an equimolecular dosage of SBZ; and a third group received placebo. Horses were daily monitored, and blood samples were collected before and during the study. On day 18, complete post-mortem examinations were performed. One horse treated with PBZ showed clinical signs of NSAID toxicosis. Small o...
Effect of high intensity training on anaerobic capacity of middle gluteal muscle in Thoroughbred horses. We hypothesize that high intensity training for Thoroughbred horses that have been subjected to conventional training could further improve the metabolic properties of the middle gluteal muscle. Nine well-trained horses were subjected to high intensity (80-100% Vdot;O(2)max, 5 minx2) training for 12 weeks. Biopsy samples were obtained from the muscle before and after 4 and 12 weeks of training. Three of the 9 horses did not complete the training programme. In the remaining 6 horses, activities of succinic dehydrogenase (SDH), phosphofructokinase (PFK) and 3-hydroxy acyl CoA dehydrogenase (HAD)...
Platelets enhance endotoxin-induced monocyte tissue factor (TF) activity in the horse. Endotoxaemia is the leading cause of death in horses. Disseminated intravascular coagulation (DIG), stimulated by induced monocyte proteins, is a prominent feature. Monocyte-platelet cellular interactions are central to the vascular dysfunction produced by circulating endotoxin and are implicated in many thrombotic diseases in the horse. This study reports that endotoxin (0.01-10 microg ml(-1)) and blood platelets (2.5 x 10(7) - 1 x 10(8) ml(-1)) are potent inducers of expression and activity of monocyte tissue factor (TF), the primary activator of the blood coagulation protease cascade. The c...
Purification and analyses of the specificity of two putative diagnostic antigens for larval cyathostomin infection in horses. Cyathostomins are important equine gastrointestinal parasites. Mass emergence of mucosal stage larvae causes a potentially fatal colitis. Mucosal stages are undetectable non-invasively. An assay that would estimate mucosal larval stage infection would greatly assist in treatment, control and prognosis. Previously, we identified two putative diagnostic antigens (20 and 25 kDa) in somatic larval preparations. Here, we describe their purification and antigen-specific IgG(T) responses to them. Western blots confirmed the purity of the antigens and showed that epitopes in the 20 kDa complex were sp...
Lipopolysaccharide and interferon gamma activate nuclear factor kappa B and induce cyclo-oxygenase-2 in equine vascular smooth muscle cells. Equine endotoxaemia is an important cause of morbidity and mortality in horses caused by the interaction of bacterial lipopolysaccharide (LPS) with cells such as macrophages and vascular smooth muscle. In this study we isolated equine vascular smooth muscle from a variety of vessels and stimulated it with LPS and human interferon (hIFN)-gamma. Using reverse transcriptase polymerase chain reaction (rt-PCR) and Western blot analysis we show that cyclooxygenase-2 (COX-2) is readily expressed in equine vascular smooth muscle. Vascular smooth muscle cells produced prostaglandin E2 in response to LP...
Biochemical characterisation of navicular hyaline cartilage, navicular fibrocartilage and the deep digital flexor tendon in horses with navicular disease. The study hypothesis was that navicular disease is a process analogous to degenerative joint disease, which leads to changes in navicular fibrocartilage and in deep digital flexor tendon (DDFT) matrix composition and that the process extends to the adjacent distal interphalangeal joint. The objectives were to compare the biochemical composition of the navicular articular and palmar cartilages from 18 horses with navicular disease with 49 horses with no history of front limb lameness, and to compare navicular fibrocartilage with medial meniscus of the stifle and collateral cartilage of the hoof...
Activities of enzymes in the malate-aspartate shuttle and the isoenzyme pattern of lactate dehydrogenase in plasma and peripheral leukocytes of lactating Holstein cows and riding horses. The activities of the enzymes involved in the malate-aspartate shuttle and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in plasma and peripheral leukocytes of lactating Holstein cows and thoroughbred riding horses as representative herbivorous animals. In the horse plasma, LDH activities were significantly lower and AST activities were significantly higher than those in the cow plasma. The specific activities of cytosolic malate dehydrogenase (MDH), LDH and AST in the horse leukocytes were higher than those in the cows. The cytosolic ratio of MDH/LDH act...
Cell-specific activation of aflatoxin B1 correlates with presence of some cytochrome P450 enzymes in olfactory and respiratory tissues in horse. Horses may be exposed to aflatoxin B(1) (AFB(1)) via inhalation of mouldy dust, leading to high exposure of olfactory and respiratory tissues. In the present study the metabolic activation of AFB(1) was examined in olfactory and respiratory tissues in horse. The results showed covalent binding of AFB(1)-metabolites in sustentacular cells and cells of Bowman's glands in the olfactory mucosa, in some cells of the surface epithelium of nasal respiratory, tracheal, bronchial and bronchiolar mucosa and in some glands in these areas. Immunohistochemistry revealed that cells expressing proteins react...
Free amino-acid concentrations in the equine placenta: relationship to maternal and fetal plasma concentrations. Free amino-acid concentrations were measured in maternal venous and fetal umbilical vein plasma, and in the allantochorion, of Thoroughbred mares at term. Concentrations in maternal and fetal plasma were similar to those reported previously in equids. The concentrations of free amino-acids in the allantochorion were higher than those in the maternal and fetal plasmas and were characterised by high levels of the nonessential amino-acids as observed in other species. Fourteen of the 20 amino-acids measured had similar allantochorion/umbilical vein concentration ratios suggesting that simple grad...
Identification and quantification of amines in the equine caecum. Acute laminitis has been associated with the release of compounds, as yet unidentified, produced by hindgut fermentation which affect blood flow to the digit. The objectives of this study were to identify amine compounds in equine caecal and colonic contents, some of which are known to have vasoactive properties. In addition, the concentrations of amines in caecal contents of horses fed either grass or hay diets were compared. Fifteen amines were identified in equine hindgut contents in concentrations greater than 1 microM. The caecal concentrations of phenylethylamine, isoamylamine, cadaverin...
Clinical pharmacokinetics of norfloxacin-glycine acetate after intravenous and intramuscular administration to horses. The pharmacokinetic properties of norfloxacin-glycine acetate (NFLXGA) were determined in six horses following a single intravenous (i.v.) and intramuscular (i.m.) dose of 4 mgkg(-1) body weight. Following i.v. and i.m. administration, the plasma drug concentrations were best fitted by an open two-compartment model with a rapid distribution phase. After i.v. NFLXGA administration, the distribution (t(1/2alpha)) and elimination half-life (t(1/2beta)) were 0.42 (0.05) and 5.44 (1.36)h. The volume of distribution of NFLXGA at steady state (Vd(ss)) was 2.19 (0.53) Lkg(-1). After NFLXGA i.m. admini...
Effects of a P2Y(12) receptor antagonist on the response of equine platelets to ADP. Comparison with human platelets. Horses show susceptibility to platelet-related disorders. Equine platelets differ from human platelets in some of their responses, so information available about human platelets must be validated in the horse. Aggregation of platelets by ADP involves both P2Y(1) and P2Y(12) receptors on the platelet surface. We have compared the effect of the P2Y(12) antagonist, AR-C67085, on equine and human platelets in vitro using turbidimetric aggregometry to measure the rate and final extent of aggregation. Aggregation profiles, concentration-response curves and pA(2) values show that the rate of aggregat...
Complete coding sequence of equine inducible nitric oxide synthase. THE gene encoding equine inducible nitric oxide synthase (iNOS) was cloned and sequenced. The strategy consisted of the amplification by PCR of message isolated from primary cultures of equine articular chondrocytes (Frean et al 1997) treated with 100 mg mlÿ1 LPS (Escherichia coli serotype O127:B8). PCR primer pairs were generated by comparison of cross-species published iNOS nucleotide sequences. The sequences of the 30 and 50 termini were derived by the generation of PCR products spanning those regions. The assembly of sequenced PCR fragments revealed a 3930 complete nucleotide sequence wit...
Cytokine mRNA expression pattern in horses with large intestinal disease. The aim of this study was to investigate cytokine expression patterns in the large intestinal mucosa of horses, particularly in diseases associated with inflammation. Many cases of equine colitis remain without a definitive diagnosis and survival rates are poor. In humans, colitis is associated with increased expression of pro-inflammatory cytokines. To examine if similar responses occur in horses, we investigated il -2, il -4, il -5, il -10, tnfalpha, ifngamma and tgfbeta messenger rna expression in large intestinal mucosa. Samples were obtained from animals with large intestinal disease (n=1...