bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteolytic enzymes in equine joints with infectious arthritis
Authors: SPIERS SUE , MAY S. A. , HARRISON LUISE J. , BENNETT D. , EDWARDS G. B. 
Published: April 2010

SummarySignificant amounts of collagenase and caseinase activity were detected in infected synovial fluid samples. Partial characterisation of the enzymes by gel filtration suggested that synovial fluid from cases of infectious arthritis may contain enzymes from both the synovial cells and neutrophils. This finding was also supported by analysis of sequential synovial fluid samples from 4 infected joints. In 3 joints the concentration of caseinase and in 1 joint collagenase paralleled the decline in total nucleated cell count. However, in 3 joints the concentration of collagenase remained high after the total nucleated cell count had returned to normal, suggesting that this enzyme originated from resident articular cells.
Frusemide attenuates the exercise‐induced rise in pulmonary capillary blood pressure in horses
Authors: MANOHAR M. , HUTCHENS E. , CONEY E. 
Published: April 2010

SummaryCatheter mounted micro‐tip‐manometers (the signals from which were matched with fluid‐filled pressure signals from same cardiovascular sites and zeroed at the point of the shoulder), were used to study pulmonary haemodynamics in 8 healthy sound horses at rest and during exercise performed at 8, 10, 12 and 14 m/s on a treadmill. Measurements were made without frusemide (control) and 4 h after iv administration of 250 mg frusemide. Post‐frusemide data were also obtained on a separate day, and these observations were not significantly different from those made on the same day as controls. Pre‐frusemide values of heart rate, mean right atrial pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure and mean pulmonary capillary pressure at 14 m/s were 214 ± 5 beats/min, 54 ± 4, 92 ± 4, 65 ± 6 and 79 ± 5 mmHg, respectively. Exercise at 14 m/s after frusemide resulted in a similar heart rate (216 ± 4 beats/min), but the mean right atrial, pulmonary arterial, pulmonary artery wedge and pulmonary capillary pressures were all significantly lower, i.e. 34 ± 5, 79 ± 4, 45 ± 4, and 62 ± 3 mmHg, respectively. Attenuation, by frusemide, of the exercise‐induced rise in pulmonary capillary pressure would lower the magnitude of the transmural force exerted on the pulmonary capillaries. If, therefore, exercise‐induced pulmonary haemorrhage (EIPH) is caused by stress failure of pulmonary capillaries, frusemide pretreatment has the potential for reducing/limiting the extent of EIPH.
Measurements of urethral pressure profiles in the male horse
Authors: RONEN N. 
Published: April 2010

SummaryUrinary tract pressure profiles were evaluated in 6 clinically normal geldings over 3 consecutive days. This was performed by introducing a 1.3 m‐long cuffed catheter into the urinary tract, under xylazine sedation (0.8 mg/kg, iv). The method was reproducible. The mean (±sd) intra‐vesicular pressure (IVP) and maximal urethral closure pressures (MUCP) were 10.3 (±1.7) and 129.8 (±19.6) cmH2O, respectively, and the ratio between MUCP and IVP was 13.2 (±2.5). A gelding with urinary incontinence showed a significantly lower MUCP (73.4 cmH20), and an MUCP to IVP ratio of 8.0. It was concluded that the day‐to‐day variation was non‐significant, and that the technique may be useful in the differential diagnosis of urinary incontinence in male horses.
Fracture of the wing of the ilium, adjacent to the sacroiliac joint, in Thoroughbred racehorses
Authors: PILSWORTH R. C. , SHEPHERD M. C. , HERINCKX B. M. B. , HOLMES M. A. 
Published: April 2010

SummaryDuring a two year period, sagittal fractures of the wing of the ilium were diagnosed in 10 Thoroughbred horses. All were spontaneous fractures sustained during normal exercise in training and racing, with no history of inciting trauma.When ultrasound scans of the surface of the pelvis were performed, the fracture was clearly visible as a discontinuity of the sacral wing of the ilium. In 3 horses, an irregular contour suggestive of periosteal callus was seen in the vicinity of the acute fracture. All horses examined by gamma scintigraphy had a focal increase in uptake of isotope just lateral to the tuber sacrale.Nine of the horses were treated conservatively by rest. The other horse had bilateral fractures and was subjected to euthanasia at the time of the injury. Six horses returned to full training, and 2 subsequently won, without recurrence of lameness.
Scintigraphic measurement of uterine clearance in normal mares and mares with recurrent endometritis
Authors: LeBLANC M. M. , NEUWIRTH L. , ASBURY A. C. , TRAN T. , MAURAGIS D. , KLAPSTEIN E. 
Published: April 2010

SummaryThe percentage of Technetium 99m‐albumin colloid (99mTc‐μAA), a radiocolloid, cleared from the uterine lumen within 4 h of intrauterine infusion, was measured in 15 mares during 2 consecutive cycles, on Day 3 of oestrus and 48 h after ovulation. Four nulliparous (Group 1) and 4 multiparous (Group 2) mares were classified as resistant and the remaining 7 multiparous mares were classified as susceptible (Group 3) to endometritis. Mares in Groups 1 and 2 cleared more99mTc‐μAA from their uteri than did mares in Group 3 during oestrus (P<0.01) and 48 h after ovulation (P<0.001). In the Group 1 + 2 mares, >50% of the colloid was cleared in 7 and none in the remaining mare, apparently related to lack of cervical relaxation. Mean percentage of99mTc‐μAA cleared by Group 3 mares was negligible (<5%), but some99mTc‐μAA was cleared by 3 of the 7 mares during 4 of the 6 studies conducted. Clearance of radiocolloid infused into the uterus of 3 reproductively normal mares during dioestrus was negligible.99mTc‐μAA infused into the uterus did not adversely affect endometrial integrity as determined by endometrial biopsy. Mares tolerated the procedures well. We conclude that scintigraphy can be used to detect impaired mechanical clearance of the uterus: reproductively normal mares clear >50%99mTc‐μAA within 2 h of infusion whereas those susceptible to endometritis or mares with poor cervical dilatation may exhibit delayed uterine clearance.
Studies on the transportin vitroof lysine, histidine, arginine and ammonia across the mucosa of the equine colon
Authors: BOCHRÖDER BRITTA , SCHUBERT R. , BÖDEKER D. 
Published: April 2010

SummaryDiscs of stripped mucosa from the proximal ventral colon were prepared immediately after slaughter of 8 Shetland cross‐breed ponies. The mucosae were fixed in incubation chambers and used in incubation experiments to study the transmucosal fluxes of the amino acids lysine, histidine and arginine (150 min) and of ammonia (90 min). When the amino acid concentrations in the mucosal solution were in the physiological range (2.8–3.0 mmol/l) no transport to the serosal side of the tissue was found. When the concentrations were raised 10‐fold, less than 2% of the mucosal amino acid pool was recovered in the serosal solution. Ammonia was transported across the mucosa at significant rates although only 63% of the ammonia that disappeared from the mucosal solution was found in the serosal solution. The findings show that the equine proximal colon is virtually impermeable to luminal free amino acids whereas ammonia is transported at rates equal to, or higher than those observed with rumen mucosa from sheep.
Identification of 2 stallion sperm‐specific proteins and their autoantibody response
Authors: TEUSCHER CORY , KENNEY R. M. , CUMMINGS MARGARET R. , CATTEN M. 
Published: April 2010

SummaryIn this study, 2 stallions were immunised with their own spermatozoa to ascertain whether an antisperm autoantibody response could be mounted. The results demonstrated that the stallion can recognise and respond to sperm autoantigens by producing circulating antisperm antibodies, primarily of the IgG class. Such autoantibodies appeared 2–4 weeks after inoculation and persisted for 6–20 weeks. Immunochemical characterisation by western blot identified two major sperm autoantigens, with molecular weights of 70 kD and 62 kD. Control pony stallions immunised with adjuvants alone failed to exhibit such antibodies. IgA antisperm antibodies were measurable in seminal plasma of both stallions. We suggest that, as in other species, autoimmunity to spermatozoa may play a role in idiopathic subfertility in stallions.
Comparison of the stride kinematics of the collected, working, medium and extended trot in horses
Authors: CLAYTON HILARY M. 
Published: April 2010

SummaryHighly‐trained dressage horses were studied to test the hypothesis that stride length is altered independently of stride duration in the transitions between the collected, working, medium and extended trot. Six well‐trained dressage horses were filmed at a frame rate of 150 frames/s performing the collected, working, medium and extended trots in a sand arena. Temporal, linear and angular data were extracted from the films, with 4 strides being analysed for each horse and gait type. There were no significant asymmetries between the left and rights limbs or diagonals when data from the whole group were pooled, but 3 horses showed asymmetries in one or more variables (P<0.01). Analysis of variance and post‐hoc tests indicated that the speed increased significantly (P<0.01) from the collected (3.20 m/s) to the working (3.61 m/s) to the medium (4.47 m/s) to the extended (4.93 m/s) trot. The increases in speed were associated with a significant increase in stride length from 250 cm in the collected trot, to 273 cm in the working trot, 326 cm in the medium trot and 355 cm in the extended trot (P<0.01). The lengthening of the stride was a result of increases between each gait type in the over‐reach distance, whereas the diagonal distance was significantly longer in the extended than the collected trot only (P<0.01). The stride duration tended to decrease as speed increased, and the difference became significant between the collected and extended trots (P<0.01).
Oxytocin enhances clearance of radiocolloid from the uterine lumen of reproductively normal mares and mares susceptible to endometritis
Authors: LeBLANC MICHELLE , NEUWIRTH L. , MAURAGIS D. , KLAPSTEIN E. , TRAN T. 
Published: April 2010

SummaryThe effects of oxytocin on the percentage of technetium99malbumin colloid (99mTc‐μAA), cleared from the uterine lumen was measured in 13 mares. Scintigraphy was performed during 4 consecutive oestrous cycles, on Day 3 of oestrus during Cycles one and 3 and 48 h after ovulation during Cycles 2 and 4. Oxytocin (20 iu) was given i.v. after the initial scintigraphy image during Cycles 3 and 4. Seven multiparous mares(Group 1)were classified as ‘susceptible’ and 6 mares (2 nulliparous and 4 multiparous;Group 2) were classified as ‘resistant’ to endometritis. All mares cleared >90% of99mTc‐μAA within 30 min of oxytocin injection. When no drug was given,Group 1mares cleared negligible amounts of radiocolloid (<5%) andGroup 2mares cleared 50–80%. No mares showed signs of colic after oxytocin administration. It is concluded that oxytocin enhances uterine clearance of radiocolloid and may be useful for treating mares exhibiting impaired uterine clearance.
An investigation of the proteoglycan metabolism of mature equine articular cartilage and its regulation by interleukin‐1
Authors: PLATT D. , BAYLISS M. T. 
Published: April 2010

SummaryThe effect of human recombinant interleukin‐1ß (rhIL‐1ß) on proteoglycan metabolism was investigated in cultures of full thickness explants of articular cartilage from horses 3–21 years of age. Proteoglycan synthesis was inhibited at all ages but no alteration in the hydrodynamic size or electrophoretic heterogeneity was observed in proteoglycan isolated from rhIL‐1ß stimulated cartilage. The sulphation pattern of the newly synthesised proteoglycan molecules was, however, significantly affected by the presence of the peptide regulatory factor. Interleukin‐1 had no effect on the rate of turnover of newly synthesised or endogenous proteoglycans in mature equine articular cartilage and did not influence the structure of proteoglycan fragments released into the culture medium. These observations suggest that IL‐1, released into synovial fluid during inflammation, may modify the proteoglycan composition of normal equine cartilage not by stimulating catabolic enzymes capable of degrading the resident proteoglycans but by promoting the deposition of a reduced number of newly synthesised proteoglycan molecules of abnormal composition.
The structure, innervation and location of arteriovenous anastomoses in the equine foot
Authors: MOLYNEUX G. S. , HALLER C. J. , MOGG K. , POLLITT C. C. 
Published: April 2010

SummaryIn the foot of the horse, arteriovenous anastomoses (AVAs) of epithelioid type occurred in the dermis of the coronary band, in the coronary and terminal papillae, in neurovascular bundles and at the entrance to and along the length of the dermal laminae. A particular feature of the epithelioid segment of AVAs in the horse, compared with that of other species, was the height and surface complexity of many of the endothelial cells. They extended into the lumen, forming undercut and tunnel‐like areas which correlated with the characteristic surface marking of AVAs observed in vascular casts. The number of cell organelles, including the concentration of vesicles in the luminal cytoplasm, suggested cells with a high metabolic activity. The luminal surface possessed numerous microvilli and long cytoplasmic cell processes which appeared to surround material in the lumen.The innervation of AVAs was more dense than that of the arteries and consisted of adrenergic and peptidergic nerves. Noradrenaline‐ and neuropeptide Y‐containing nerves were identified as the vasoconstrictor components of the nerve supply and occurred along arteries and formed dense plexuses around AVAs. Calcitonin gene‐related peptide, substance P and vasoactive intestinal polypeptide are vasodilators and were present in single nerve fibres which accompanied arteries and AVAs along the length of the dermal laminae. In this study the distribution, density and innervation of AVAs in the equine foot are correlated with their proposed role in the development of acute laminitis. The release of vasoactive peptides from diseased organs remote from the foot may induce inappropriate prolonged dilatation of AVAs and thus contribute to the laminar ischaemia of acute laminitis.
Causes of death in racehorses over a 2 year period
Authors: JOHNSON B. J. , STOVER SUSAN M. , DAFT BARBARA M. , KINDE H. , READ D. H. , BARR B. C. , ANDERSON M. , MOORE JANET , WOODS L. , STOLTZ J. , BLANCHARD P. 
Published: April 2010

SummaryNecropsies were performed on 496 horses that had a fatal injury or illness at a California racetrack during the period February 20th 1990 to March 1st 1992. The primary cause of death was categorised by breed, activity at time of injury or illness and organ system affected. Most of the submissions were Thoroughbred horses (432) and Quarter Horses (46). Most of the injuries occurred while racing (42%) and in training sessions (39%); with fewer non‐exercise (12%) and accident (7%) related injuries or illnesses. Musculoskeletal injuries accounted for 83% of the Thoroughbred and 80% of the Quarter Horse submissions. The Thoroughbred horses incurred 306 fractures with 263 in the limbs and 90% of those in the forelimbs. The proximal sesamoid bone(s), third metacarpal bone and humerus were the most common bones fractured in Thoroughbred horses and Quarter Horses. Other major causes of death included respiratory, digestive and multi‐organ system disorders.
Clinical efficacy and safety of clenbuterol HCl when administered to effect in horses with chronic obstructive pulmonary disease (COPD)
Authors: ERICHSEN DEBORAH F. , AVIAD ANITA D. , SCHULTZ R. H. , KENNEDY T. J. 
Published: April 2010

SummaryA field study of 239 horses was conducted to determine the efficacy and safety of clenbuterol HCl, a ß2‐adrenergic bronchodilator, when administered incrementally to effect in the treatment of chronic obstructive pulmonary disease (COPD). The severity of COPD (heaves) and response to treatment was determined by clinical evaluation; an overall ‘heaveiness rating’ (OHR) was assigned at each observation. The horses were treated orally b.i.d. with clenbuterol (as Ventipulmin Syrup), beginning with the lowest dosage of 0.8 μg/kg. On Day 10 of treatment at the effective dose (0.8, 1.6, 2.4 or 3.2 μg/kg), treatment was either withdrawn(Schedule A)or continued for an additional 20 days(Schedule B).Horses onSchedule Ademonstrated a significant improvement in the mean OHR on treatment Day 10 compared to the baseline overall heaveiness rating (BOHR) and a significant increase in the mean OHR (relapse) after the drug was withdrawn.Schedule Bhorses showed significant improvement (compared to BOHR) on treatment Days 10, 20 and 30.Incremental dosing with clenbuterol provided clinical improvement in 75% of the horses with a lower 95% confidence limit of 71%. Twenty‐five percent were nonresponders. A greater percentage of the more severely affected horses required the 3.2 μg/kg dosage or were nonresponders compared to horses with a lower BOHR.Side effects of sweating, muscle tremor, and nervousness were of low intensity (mild to moderate) and frequency (<7% of all observations) due to the regimen of incremental dosing to effect.
Evaluation of the thoraco‐laryngeal reflex (‘slap test’) as an indicator of laryngeal adductor myopathy in the horse
Authors: NEWTON‐CLARKE M. J. , DIVERS T. J. , VALENTINE B. A. 
Published: April 2010

SummaryA study was conducted over a 12 month period to assess the accuracy of the ‘slap test’ in the diagnosis of laryngeal adductor myopathy. The thoraco‐laryngeal reflexes of 15 horses with no clinical signs of idiopathic laryngeal hemiplegia (ILH) were recorded using a video‐endoscope. These ‘slap test’ responses were examined independently by 3 assessors. The horses were subsequently subjected to euthanasia and samples taken from the cricoarytenoideus lateralis (CAL) muscles for histopathological examination and assessment of denervation atrophy. Despite normal adductory responses, moderate to severe atrophy of the left CAL muscles was seen in 5 horses. The remaining horses had varying degrees of adductor myopathy, invariably worse in the left side of the larynx. The ‘slap test’ as performed in this study was therefore unable to differentiate between horses with moderate to severe muscle changes and those without, making it useless as a diagnostic test for adductor myopathy. The reason for the preservation in adductor function despite advanced histological atrophy of the muscle may lie in the degree of reinnervation found in the muscles.
ß‐glucuronidase and trypsin inhibitor capacity of tracheal lavage fluid as indicators of seasonal airway irritation in the horse
Authors: MAISI P. , KOIVUNEN A.‐L. , RANTALA A.‐R. , TURGUT K. 
Published: April 2010

SummaryThe health of the respiratory tracts of 19 horses was studied for 11 months. The horses were placed into 3 groups (healthy, periodically diseased and continuously diseased) based on the measurements of blood gases, intrapleural pressure and on neutrophil content of tracheal mucus. Lysosomal enzymes (N‐acetyl‐ß‐D‐glucosaminidase and ß‐glucuronidase) and reflectors of the proteolytic system (plasmin, plasminogen, trypsin inhibitor capacity) were determined.ß‐glucuronidase appeared to be a good indicator of the presence of disease of the respiratory system. High ß‐glucuronidase values were seen in horses with elevated numbers of neutrophils, elevated arterial alveolar and intrapleural differences as well as in diseased horses during the stabling period. Trypsin inhibitor capacity seemed to be lower in the diseased respiratory system, probably due to the increased consumption of trypsin inhibitors.
The basement membrane at the equine hoof dermal epidermal junction
Authors: POLLITT C. C. 
Published: April 2010

SummaryIn the equine hoof, the basement membrane connects the heavily keratinised hoof wall to the dense connective tissue of the distal phalanx, a region able to withstand considerable mechanical stress. This study investigated the properties of this important anatomical and physiological structure. In contrast to haematoxylin and eosin, the connective tissue stains, periodic acid Schiff, periodic acid silver methenamine and Azan showed good resolution of lamellar basement membrane. The lamellar basement membrane cross‐reacted with mouse monoclonal antibodies raised against human laminin, thereby providing evidence that laminin is a component of the equine basement membrane. The ultrastructure of the equine hoof basement membrane was essentially the same as in other animals but appeared to have many anchoring fibrils and extensions of the lamina densa into the adjoining connective tissue, an arrangement interpreted to convey extra strength to the region. Large areas of the surface of the hoof wall basement membrane could be exposed to examination with the scanning electron microscope by treating tissue blocks with detergent/enzyme or sodium bromide. When epidermal lamellae were separated from their dermal counterparts the basement membrane stayed with the dermis and the dermal lamellae retained their natural shape despite the absence of an adjacent epidermis. The exposed surface of the lamellar basement membrane was generally smooth and unbroken, marked with small indentations and fine wrinkles. At the cut edges of the lamellae, a mesh of fine connective tissue fibres were attached to the inner surface of the basement membrane. The basement membrane of both the coronary and terminal papillae was folded into numerous longitudinal ridges, all parallel to the long axis of the papillae. Like the folds in the basement membrane of the lamellae (the so‐called secondary lamellae) the longitudinal ridges of the papillae are probably an adaptation to increase the surface area of attachment of the dermis to the inner hoof wall. The architecture of the equine basement membrane and the tissues adjacent to it is severely disrupted as the pathology of laminitis develops. A study of the basement membrane using the techniques described in this study may add to our understanding of the pathophysiology of equine laminitis.