bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution and numbers of mucous glands in the horse trachea
Authors: WIDDICOMBE J. H. , PECSON I. S. 
Published: April 2007

SummaryHorses commonly suffer from respiratory diseases associated with excess secretions in the airway lumen, some of which are presumably derived from airway mucous glands. However, these structures have been little investigated in the horse. Accordingly, we describe here the number, distribution and size of equine tracheal mucous glands, and compare the data with similar information for other mammalian species. Two types of gland acini were present. In the thick connective tissue, up to 400 μm beneath the epithelium, gland acini were grouped in thin sheets that, in cross‐section, averaged 20 μm thick and were up to 4.0 mm in length. However, it is probable that most sheets had maximal diameters much less than 4.0 mm. Between 400 to 900 μm below the epithelium, the connective tissue was much more diffuse, and glands were larger and more globular. Gland volume in the ventral portion was ˜1.7 μl/cm2 of mucosal surface, and ˜1.1 μl/cm2 in the dorsal portion. Glands were somewhat more abundant between, rather than over, the cartilaginous rings, but the difference between the 2 locations was not marked. Mucous gland openings were small (20 μm diameter) and very unevenly distributed, generally occurring about 100 μm apart in longitudinal rows of about 5. Average frequency of openings in the ventral portions of 3 tracheas was ˜1.0/mm2 of mucosal surface. The volume of individual glands was therefore ˜17 nl. Although the frequency of gland openings in the horse trachea is similar to that for the tracheas of other large mammalian species, horse tracheal gland volume was only about 15% that of the other species. Therefore, the excess ‘mucous’ secretions seen in equine recurrent airway obstruction and other respiratory diseases are unlikely to be caused by comparatively high levels of airway mucous gland secretion. Instead, they may be caused mainly by hyperplasia of the mucus‐producing cells of the surface epithelium or by vascular transudation.
Pharmacokinetics of gentamicin C1, C1aand C2in horses after single intravenous dose
Authors: STEINMAN A. , ISOHERRANEN N. , ASHOACH O. , SOBACK S. 
Published: April 2007

SummaryGentamicin pharmacokinetics has not been studied in horses. Pharmacokinetics of gentamicin C1, C1aand C2components following i.v. administration of total gentamicin at 6.6 mg/kg bwt to 6 healthy mature horses was determined. Significant differences in clearance, half‐life (t1/2), and mean residence time (MRT) between the gentamicin C1aand the 2 other components were found. The total body clearance (CL) of gentamicin C1awas 1.62 ± 0.50 ml/min × kg and similar to the glomerular filtration rate (GFR) reported for horses. The CL of gentamicin C1and C2were 1.03 ± 0.08 ml/min × kg and 1.10 ± 0.15 ml/niin × kg, respectively, and significantly slower than that of gentamicin C1a. The values of apparent volume of distribution at steady state were 0.22 ± 0.05, 0.26 ± 0.12 and 0.23 ± 0.05 l/kg for gentamicin C1, C1aand C2, respectively. The MRT values were mean ± s.d. 3.6 ± 0.5, 2.7 ± 0.3 and 3.5 ± 0.4 h and thet1/2values were 3.1 (2.5–4.0), 2.4 (2.0–3.2) and 3.3 (2.4–4.3) h (harmonic mean and range) forgentamicin C1, C1aand C2, respectively. The MRT andt1/2values for gentamicin C1awere significantly shorter than those of gentamicin C1and C2. It was concluded that the difference in pharmacokinetics between the gentamicin components has potential pharmacological and toxicological implications.
Serum level of cartilage oligomeric matrix protein (COMP) in equine osteoarthritis
Authors: MISUMI K. , VILIM V. , HATAZOE T. , MURATA T. , FUJIKI M. , OKA T. , SAKAMOTO H. , CARTERS S. D. 
Published: April 2007

SummaryThis study was designed to assay and compare cartilage oligomeric matrix protein (COMP) in horse sera, in samples from normal and joint diseased horses, and to investigate the relationships between COMP in sera and synovial Quids (SF) with keratan sulphate (KS) data. Sera from 38 horses free of any joint pathology (controls) and from horses with aseptic joint disease (AJD horses, n = 40) were assayed for COMP and KS concentrations. Of the 78 horses in the study, 53 were also assayed for COMP and KS concentrations in SF. COMP and KS were measured by inhibition ELISA, using monoclonal antibodies 12C4 and 5D4, respectively. The COMP concentration in sera from AJD horses (mean ± s.d. 10.7 ± 7.4 μg/ml) was significantly (P<0.02) lowerthan in control sera (14.8 ± 7.8 μg/ml). The joint disease sera also had significantly lower (P<0.01) KS levels (180.5 ± 61.8 ng/ml) than controls (237.1 ± 116.1 ng/ml). A significant correlation (r= 0.52, n = 53, P<0.001) was seen between serum and SFin COMPlevels; no such relationship was seen in KS levels. It is possible that serum COMPconcentration could be a more specific marker of equine joint disease than any other described to date.
Effect of chronic airway inflammation and exercise on pulmonary and systemic antioxidant status of healthy and heaves‐affected horses
Authors: KIRSCHVINK N. , SMITH N. , FIÉVEZ L. , BOUGNET V. , ART T. , DEGAND G. , MARLIN D. , ROBERTS C. , GÉNICOT B. , LINDSEY P. , LEKEUX P. 
Published: April 2007

SummaryIn heaves‐affected horses the relation between oxidant status, airway inflammation (AI) and pulmonary function (PF) is unknown. The oxidant status of blood and pulmonary epithelial lining fluid (PELF) of healthy (H, n = 6) and heaves‐affected horses in clinical remission (REM, n = 6) and in crisis (CR, n = 7) was assessed at rest, during and afterstandardised exercise test by measurement of reduced and oxidised glutathione, glutathione redox ratio [GRR%]; uric acid and 8‐epi‐PGF2α. Oxidant status was related to PF parameters (mechanics of breathing and arterial blood gas tension) and AI parameters (bronchoalveolar lavage [BAL] neutrophil% and AI score). Haemolysate glutathione was significantly different between groups and was correlated with PF and AI parameters; GRR in PELF was increased during CR and was correlated with PF and AI parameters. Exercise induced an increase of plasma uric acid that was significantly higherboth in REM and CR. PELF 8‐epi‐PGF2αwas significantly increased in CR and correlated with PF and AI parameters. These results suggest that oxidative stress occurring in heaves is correlated with PF and AI and may be locally assessed by PELFglutathione status, uric acid and 8‐epi‐PGF2α. Systemic repercussions are reflected by assay of GSH in resting horses and by uric acid in exercising horses.
A description of the motion of the navicular bone during in vitro vertical loading of the equine forelimb
Authors: van DIXHOORN I. D. E. , MEERSHOEK L. S. , HUISKES R. , SCHAMHARDT H. C. 
Published: April 2007

SummaryMotion of the navicular bone might play a role in the development of navicular disease in horses but is difficult to asses. In the present study, 3‐dimensional motion of this bone was determined using roentgen stereophotogrammetric analysis. Tantalum pellets were inserted, in vitro, in the bones of 6 forelimbs of mature Shetland ponies and kinematics were measured during vertical loading up to 2 kN. The motions of the navicular bone and coffin joint were limited to flexion/extension, there were no substantial out‐of‐plane motions. There was only little flexion between the navicular bone and the coffin bone, which was correlated (r = 0.66) with coffin joint flexion. There was substantial flexion between the navicular bone and the short pastern, which was highly correlated with coffin joint flexion (r = 0.97). We conclude that the navicular bone, generally, follows the coffin bone during coffin joint flexion, although there are small but consistent motions between the navicular bone and the coffin bone. These motions might play a role in the development of navicular disease in horses.
High intensity exercise conditioning increases accumulated oxygen deficit of horses
Authors: HINCHCLIFF K. W. , LAUDERDALE M. A. , DUTSON J. , GEOR R. J. , LACOMBE V. A. , TAYLOR L. E. 
Published: April 2007

SummaryHigh intensity exercise is associated with production of energy by both aerobic and anaerobic metabolism. Conditioning by repeated exercise increases the maximal rate of aerobic metabolism, aerobic capacity, of horses, but whether the maximal amount of energy provided by anaerobic metabolism, anaerobic capacity, can be increased by conditioning of horses is unknown. We, therefore, examined the effects of 10 weeks of regular (4–5 days/week) high intensity (92 ± 3 %V̇O2max) exercise on accumulated oxygen deficit of 8 Standardbred horses that had been confined to box stalls for 12 weeks. Exercise conditioning resulted in increases of 17% in V̇O2max(P<0.001), 11% in the speed at which V̇O2maxwas achieved (P = 0.019) and 9% in the speed at 115% of V̇O2max(P = 0.003). During a high speed exercise test at 115%V̇O2max, sprint duration was 25% longer (P = 0.047), oxygen demand was 36% greater (P<0.001), oxygen consumption was 38% greater (P<0.001) and accumulated oxygen deficit was 27% higher (P = 0.040) than values before conditioning. VLa4was 33% higher (P<0.05) after conditioning. There was no effect of conditioning on blood lactate concentration at the speed producing V̇O2maxor at the end of the high speed exercise test. The rate of increase in muscle lactate concentration was greater (P = 0.006) in horses before conditioning. Muscle glycogen concentrations before exercise were 17% higher (P<0.05) after conditioning. Exercise resulted in nearly identical (P = 0.938) reductions in muscle glycogen concentrations before and after conditioning. There was no detectable effect of conditioning on muscle buffering capacity. These results are consistent with a conditioning‐induced increase in both aerobic and anaerobic capacity of horses demonstrating that anaerobic capacity of horses can be increased by an appropriate conditioning programme that includes regular, high intensity exercise. Furthermore, increases in anaerobic capacity are not reflected in blood lactate concentrations measured during intense, exhaustive exercise or during recovery from such exercise.
Clinical and endoscopic evidence of progression in 152 cases of equine recurrent laryngeal neuropathy (RLN)
Authors: DIXON P. M. , McGORUM B. C. , RAILTON D. I. , HAWE C. , TREMAINE W. H. , PICKLES K. , McCANN J. 
Published: April 2007

SummaryExamination of the long‐term histories and clinical findings was performed in 351 horses suffering from recurrent laryngeal neuropathy (RLN) to examine for possible evidence of progression of this disorder. Fifty‐two out of 351 cases (15%) had evidence of progression of the degree of laryngeal dysfunction over a median period of 12 months (range 1.5–48 months) with the onset of progression occurring at median age 7 years. In 30 cases, there was both endoscopic (median deterioration of 3 endoscopic grades; range 1–5 grades) and clinical evidence, with 29 (97%) of these horses concurrently developing sudden‐onset, abnormal exercise‐related respiratory ‘noises» and 13 (43%) concurrently reporting reduced exercise performance. In the remaining 22 horses there was solely clinical evidence of RLN progression, including the sudden onset of abnormal exercise‐related respiratory sounds in 16 (73%) and the worsening of such sounds in 6 (23%), associated with reduced exercise performance in 13 (59%) of these 22 cases. Endoscopically, 13 (59%) of the latter 22 cases had marked (total or almost total) RLN that did not appear compatible with their previous exercise‐performance histories. This evidence of progression of RLN may be of particular significance in disputes concerning horses that are apparently normal at pre‐purchase examination but are later shown to have RLN and also in the surgical treatment of less severe cases of RLN.
Ultrasonographic investigation of the atlanto‐occipital articulation in the horse
Authors: GOLLOB E. , EDINGER H. , STANEK C. , WURNIG C. 
Published: April 2007

SummaryThe purpose of this study was to evaluate ultrasonographic imaging as a means of easy and noninvasive diagnosis of articular and periarticular structures of the atlanto‐occipital articulation in the horse; and to find a safe approach to the atlanto‐occipital joint. Ultrasonographic investigations were performed on 6 healthy horses and 16 specimens from horses humanely destroyed age 2–17 years (mean 9.56 years). Preliminary examinations included anatomical studies and preparation of cross‐sections. On 4 horse specimens, puncture of the atlanto‐occipital joint under ultrasonographic guidance was performed and a new lateral approach undertaken. For ultrasonographic investigations, the neck was divided into 4 zones according to anatomical and clinical modalities: 1) insertion of the funiculus nuchae; 2) tuberculum dorsale of the atlas; 3) atlanto‐occipital joint and 4) region above the foramen alare. Each zone was examined in transverse and longitudinal planes proceeding from cranial to caudal. Ultrasonography was found to be useful for soft tissue imaging of this region and was performed down to the atlanto‐occipital joint of which the joint surfaces, joint capsule and collateral ligament could be delineated in both planes. We conclude that ultrasonography of the neck is a useful technique, representing an easy to use and safe method. However, further studies are indicated which should be performed on live subjects.
Urea as a measure of dilution of equine synovial fluid
Authors: GOUGH M. R. , MUNROE G. A. , MAYHEW I. G. 
Published: April 2007

SummaryThis paper tests the hypothesis that serum and synovial urea concentrations are similar and that urea concentration can be used as an accurate marker for synovial fluid dilution in normal equine joints. Serum and synovial fluid urea concentrations were compared in 42 horses and were equivalent for individual horses (P<0.0001). Mean ± s.e. serum concentration was 6.1 ± 0.552 mmol/l and synovial concentration 6.0 ± 0.459 mmol/l. The normal range for synovial urea concentration was determined as 2.5–7.7 mmol/l. The synovial urea concentration from different synovial structures in individual horses were compared and were equivalent (P = 0.002). Known dilutions of synovial fluid with saline were made. The actual and expected synovial urea concentrations were compared and were equivalent (P<0.001). An accurate method of calculating synovial fluid dilution has been determined.
Antigen challenge increases adherence of circulating neutrophils in horses with chronic obstructive pulmonary disease
Authors: MARR K. A. , LEES P. , CUNNINGHAM F. M. 
Published: April 2007

SummaryActivation of circulating neutrophils has been observed following challenge of horses with chronic obstructive pulmonary disease (COPD) and may facilitate the accumulation of these cells in the airways. In this study, no significant difference was observed between adherence to protein coated plastic of blood neutrophils from asymptomatic COPD‐susceptible and normal horses stimulated by the mediators PAF, human recombinant (hr)IL‐8 and hrC5a. Twenty‐four hours after the start of a 7 h antigen challenge, adherence of unstimulated neutrophils from COPD‐susceptible horses increased from 2.5 (0.5–4.1)% and 3.4 (0.6–6.6)% to 19.6 (16.9–20.3)% and 21.8 (10.6–23.1)% adherence for cells in medium containing 0.1% or 0.2% BSA, respectively; (median [range]; n = 4). Adherence of cells from normal horses remained unchanged. Addition of an anti‐CD18 monoclonal antibody, H20A, inhibited the increase in adherence at 24 h by 96 (45–100)%, n = 3. The percentage of neutrophils in bronchoalveolar lavage fluid at 24 h increased from 1 (0–2) to 80 (65–94), (median (range), n = 4). These results suggest that antigen challenge results in exposure of circulating equine neutrophils to one or more factors that prime, or activate, these cells, which may enhance their recruitment to the lungs. Inhibition of circulating neutrophil activation may therefore represent a therapeutic target.
Normal ultrasonographic anatomy and injury of the patellar ligaments in the horse
Authors: DYSON S. J. 
Published: April 2007

SummaryThe purposes of this study were to investigate the ultrasonographic appearance of the patellar ligaments in clinically normal horses and to describe the clincical features, diagnosis and outcome of patellar ligament injury. The medial, middle and lateral patellar ligaments of 5 Thoroughbred and 5 Warmblood horses, free from lameness and in full work, were examined ultrasonographically. The ligaments were all of uniform echogenicity and each ligament was fairly consistent in its shape. The size of the ligaments of the Warmblood horses tended to be bigger than the lighter bodyweight Thoroughbred horses. The bone surfaces were smooth at the ligament insertions on the patella and tibia. Nine horses, including 7 showjumpers, were identified with a unilateral hindlimb lameness associated with ultrasonographic evidence of damage to one or more patellar ligaments. Four horses had primary desmitis of the middle patellar ligament, one of which had concurrent intermittent upward fixation of the patella and a second had abnormal movement of the patella. Two additional horses had desmitis of the middle patellar ligament associated with previous medial patellar desmotomy. Two horses had desmitis of both the middle and lateral patellar ligaments, and one horse had desmitis of the lateral patellar ligament alone. None of the 9 horses were able to return consistently to their former level of competition. Careful clinical evaluation and ultrasonographic examination of the patellar ligaments should be considered in horses with hindlimb lameness of otherwise undetermined cause.
Immunological and haematinic consequences of feeding a standardised Echinacea (Echinacea angustifolia) extract to healthy horses
Authors: O'NEILL W. , McKEE S. , CLARKE A. F. 
Published: April 2007

SummaryThis study was undertaken to compile new data on the efficacy of Echinacea in stimulating the immune system of the horse. Use of Echinacea is becoming widespread in horses, despite an absence of controlled laboratory research into its effectiveness or safety. This paper documents results of a double‐blind, placebo‐controlled, cross‐over trial investigating the effect of standardised Echinacea extract on 8 horses. Animals were supplemented with Echinacea or placebo for 42 days, and their response to supplements recorded. Treatment with Echinacea increased phagocytic ability of isolated neutrophils, boosted peripheral lymphocyte counts and appeared to stimulate neutrophil migration from peripheral circulation into the tissues. Echinacea supplement also increased the size and concentration of peripheral red blood cells, and the concentration of haemoglobin and packed cell volume. It was concluded that Echinacea effectively stimulates equine immunocompetence, and the plant extract behaves, in equine subjects, as a haematinic agent, i.e. one which improves the quality of blood by increasing haemoglobin levels and the numberof erythrocytes and which, by virtue of theireffects on oxygen transport cells, are considered to improve parameters of exercise physiology and performance.
Repeatability of back kinematics in horses during treadmill locomotion
Authors: FABER M. , JOHNSTON C. , VAN WEEREN P. R. , BARNEVELD A. 
Published: April 2007

SummaryWe tested the hypothesis that repeatability of a standardised protocol for quantifying back kinematics is sufficiently high not to prevent its use in the clinical evaluation of horses with back problems. We investigated the extent to which differences between laboratories may affect the results when a standardised protocol is used. As a clinical tool, movement analysis techniques are helpful for the objective and quantitative assessment of kinematics. Knowledge about the repeatability of the kinematic data is very important. The present study investigates the repeatability of back kinematics in 10 sound horses over5 successive days and in 2 laboratories (5 horses at each location). Measurements were performed on the treadmill during the walk and the trot. The between‐stride, between‐day and between‐horse repeatability were determined. A high degree of between‐stride and between‐day repeatability was observed in the spatiotemporal parameters and in the time‐angle diagrams of thoracic and lumbar vertebrae, the sacrum and the hindlimb during both the walk and trot. Much more variability was found between horses, with the highest degree of dissimilarity in the lateral bending rotation of the L1 vertebra. For range of motion values, the between‐day coefficient of variability was <14% and the between‐horse coefficient of variability was up to 4 times higher. Small differences were found in range of motion values between the 2 laboratories. It is concluded that an analysis of back kinematics in the horse can provide highly repeatable data, warranting clinical use.
Dietary soyabean oil depresses the apparent digestibility of fibre in trotters when substituted for an iso‐energetic amount of corn starch or glucose
Authors: JANSEN W. L. , GEELEN S. N. J. , KUILEN J. van der , BEYNEN A. C. 
Published: April 2007

SummaryThe aim of the present study was to establish whether the inhibitory effect of fat feeding on fibre digestion has been underestimated due to the substitution of fat for corn starch. A high fat intake has been shown to lower total intestinal tract apparent digestibility of crude fibre in horses but, since fat was substituted for nonstructural carbohydrates, including starch, the specific effect of fat could not be ascertained. The possibility could not be excluded that starch also inhibits fibre digestibility, so that the fat effect observed earlier would have been underestimated. In this study, the intakes of iso‐energetic amounts of soyabean oil, corn starch or glucose were compared as to fibre digestibility. Unlike starch, glucose is fully absorbed by the small intestine and, therefore, is not expected to influence fibre fermentation in the caecum and colon. Six trotters were fed rations high in soyabean oil (158 g/kg dry matter), corn starch (337 g/kg dry matter) or glucose (263 g/kg dry matter) according to a 3 × 3 Latin square design. Apparent crude fibre digestibility was similar for the rations with corn starch (mean ± s.d., 70.7 ± 3.06% of intake, n = 6) or glucose (71.0 ± 1.90%), but was significantly depressed by fat feeding (56.5 ± 7.65%). Similar observations were made for apparent digestibilities of neutral and acid detergent fibre and of cellulose. It was concluded that the addition of fat to the feed ration of horses has a specific inhibitory effect on fibre utilisation and, therefore, reduces the amount of energy provided by dietary fibre.
Chemoattractant properties of conditioned medium from equinecorpora luteacollected at various stages of the oestrous cycle
Authors: LAWLER D. F. , BRAZIL T. J. , DAGLEISH M. P. , WATSON E. D. 
Published: April 2007

SummaryThis study investigated the chemotactic activity of equine CL at different stages of the oestrous cycle. The purpose of this was to ascertain whether luteal tissue itself contributes to the massive influx of leucocytes around the time of natural and induced luteal regression.Corpora luteawere collected at different stages of dioestrus and after treatment with PGF2αCulture medium harvested afterincubation of luteal tissue for 20 h was chemotactic for both polymorphonuclear and mononuclear cells in late dioestrus (before functional regression) as well as after natural and induced luteal regression. By contrast, midluteal tissue showed no chemotactic activity. This is the first report of the ability of equine luteal tissue actively to recruit inflammatory cellsin vitroand supports our earlier findings that this infiltration starts prior to functional luteolysis. We hypothesise that this early influx of inflammatory cells may play an active role in luteal regression. Further research is needed to identify the specific chemotactic factor(s).