bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidative capacity of skeletal muscle fibres in racehorses: histochemical versus biochemical analysis
Authors: VALBERG STEPHANIE , GUSTAVSSON BIRGITTA ESSÉN , WALLBERG HELENA SKOGLUND 
Published: April 2010

SummaryThe oxidative capacity of skeletal muscle fibre types was evaluated histochemically using the nicotinamide dinucleotide diaphorase (NADH‐D) staining, and biochemically by measuring the activity of citrate synthase (CS) in both whole muscle samples and in pools of fibres of identified type. Duplicate determinations of the NADH‐D staining pattern resulted in standard deviations (sd) between duplicates of 6 and 11 per cent for two observers. The NADH‐D pattern was found to differ between observers. Duplicate determinations of CS activity in the same fibre pools resulted in an sd value of 2.9 μ mol/g/min. Measurements of whole muscle CS activity did not provide information about the distribution of oxidative capacity among fibre types. The NADH‐D stain and CS activity in fibre pools both showed that, in general, type I and IIA fibres had a higher oxidative capacity than type IIB fibres. Biochemical techniques also showed, however, that the CS activity in type I and IIA fibres of different horses could vary as much as twofold, whereas the NADH‐D rating showed a high intensity staining for most type I and IIA fibres in all horses. Furthermore, type IIB fibres received a lower NADH‐D rating than the other fibre types even when the CS activities were quite similar. For purposes of research, biochemical measurement of oxidative capacity in individual muscle fibre types provides valuable quantitative and comparative information. The ease of histochemical NADH‐D staining in comparison to fibre dissections makes this technique more practical for routine estimates of the distribution of oxidative capacity among muscle fibres. Since racehorses have a high muscle oxidative capacity, NADH‐D stains should be carefully interpreted and comparative evaluations are best made if quantitative biochemical measurements of whole muscle oxidative capacity are added to histochemical evaluations.
The effect of detomidine (Domosedan) on the maintenance of equine pregnancy and foetal development: ten cases
Authors: KATILA TERTTU , OIJALA MARI 
Published: April 2010

SummaryDetomidine was administered throughout 10 pregnancies in eight mares. An intravenous injection of 20 pg/kg bodyweight was given weekly from Day 14 to Day 60 of gestation and thereafter every four weeks until parturition. One mare suffered torsion of the large colon and was destroyed on Day 86; the foetus was normally developed. A further mare aborted at 167 days. The remaining eight pregnancies continued to full term. One foal was delivered by caesarean section because of torticollis and, of the seven foals born spontaneously, one had bilateral upward patellar fixation at one month old. Therefore, although only six of the 10 foals developed normally, the other four cases showed no pathological similarities to suggest a common cause. Although these data were based on a small number of mares, they did not suggest that the repeated administration of detomidine had specific adverse effects on the pregnancies.
Cardiorespiratory and sedative effects of a combination of acepromazine, xylazine and methadone in the horse
Authors: NILSFORS L. , KVART C. , KALLINGS P. , CARLSTEN J. , BONDESSON U. 
Published: April 2010

SummaryCardiorespiratory and sedative effects of a combination of acepromazine, xylazine and methadone were studied in the horse. Acepromazine and xylazine produced cardiovascular effects whereas methadone mainly affected respiratory rate. Decreases in heart rate, arterial blood pressure and respiratory rate were seen. Sedation was superior to that of acepromazine, xylazine or a combination of these. No serious side effects were seen.
Effect of ovarian steroids on migration of uterine lumenal neutrophils and on chemokinetic factors in uterine secretions from mares
Authors: WATSON E. D. 
Published: April 2010

SummaryIncubation of blood neutrophils with uterine flushings collected from ovariectomised mares treated with oestradiol, stimulated migration under agarose, whereas flushings from mares treated with progesterone or oily vehicle, inhibited migration. After intra‐uterine infusion of bacteria, however, flushings from oestradiol‐treated and vehicle‐treated mares inhibited migration, whereas progesterone treatment stimulated migration. Migration of uterine‐derived neutrophils under agarose was less than that of blood neutrophils and was not influenced by treatment with ovarian steroids. Uterine susceptibility to infection in progesterone‐treated mares was not, therefore, correlated with the migratory activities of uterine neutrophils or the chemokinetic properties of uterine secretionsin vitro.
A comparison of enterotomies through the antimesenteric band and the sacculation of the small (descending) colon of ponies
Authors: ARCHER R. M. , PARSONS J. C. , LINDSAY W. A. , WILSON J. W. , SMITH D. F. 
Published: April 2010

SummaryThree pairs of longitudinal enterotomies were performed in the small colon of 10 ponies. Each pair consisted of one enterotomy through the antimesenteric band and one through the sacculation. The ponies were destroyed 96 h after surgery. The enterotomies in the two sites were compared for: speed of surgery, adhesions, bursting wall tension, neovascularisation by micro‐angiography, and histological reaction. Enterotomies made through the antimesenteric band were superior because they were quicker to perform, stronger, more accurately apposed, and had less inflammation than those made through the sacculation.
A method for reproducing fatal idiopathic colitis (colitis X) in ponies and isolation of a Clostridium as a possible agent
Authors: PRESCOTT J. F. , STAEMPFLI H. R. , BARKER I. K. , BETTONI R. , DELANEY K. 
Published: April 2010

SummarySevere colitis was induced in two ponies after oral pre‐treatment with clindamycin and lincomycin, followed by intestinal content from two horses which had died from naturally‐occuring idiopathic colitis. Two ponies treated with antibiotic alone, and two ponies treated with intestinal content alone, were unaffected. In a further study, three ponies treated on separate occasions with lincomycin, administered orally, died or were destroyed 67 to 72 h after initial treatment. No established salmonella, yersinia or Campylobacter pathogens were isolated from these ponies, but a Clostridium closely resemblingClostridium cadaveriswas isolated as the predominant Clostridium from them all and from the colonic content of one of six horses which died from naturally‐occuring idiopathic colitis. It was not isolated from six horses with non‐fatal diarrhoea. This Clostridium is a candidate as an agent of some cases of fatal colitis in horses.
Macrophage clearance of125I‐labelled polyvinyl pyrrolidone in the horse: Effect of ovarian steroids and persistent endometritis
Authors: WATSON ELAINE D. , STOKES C. R. 
Published: April 2010

SummaryThe rate of clearance of125I‐labelled polyvinyl pyrrolidone (PVP) from blood was measured in mares as an indicator of macrophage function. In three out of four cycling mares, PVP clearance was slower during oestrus than dioestrus. Similarly, administration of oestrogen to four ovariectomised mares tended to depress PVP clearance compared with clearance from the same mares before they received oestrogen. However, the effect of oestrogen was not statistically significant. Mares susceptible to persistent endometritis had rates of PVP clearance which were similar to those of genitally normal mares.
BCG emulsion immunotherapy of equine sarcoid
Authors: VANSELOW B. A. , ABETZ I. , JACKSON A. R. B. 
Published: April 2010

SummaryOf 61 horses with sarcoids treated with intralesional injection of a double emulsion incorporating inactivated bacillus Calmette Guérin organisms, 36 (59 per cent) showed complete regression and 11 (18 per cent) showed partial regression. The majority of cases required only one treatment. Not all sarcoids were responsive to this therapy; those not responding were usually large or on horses with multiple sarcoids.
Attempts to prevent equine post neurectomy neuroma formation through retrograde transport of two neurotoxins, doxorubicin and ricin
Authors: CUMMINGS J. F. , FUBINI S. L. , TODHUNTER R. J. 
Published: April 2010

SummaryDigital neurectomies, performed to relieve pain and lameness, are often complicated postoperatively by formation of painful neuromas. In this study attempts were made to deliver lethal doses of neurotoxin to the cell bodies of the transected digital nerve fibres via long‐distance retrograde axon transport and, thereby, prevent the regenerative changes that lead to neuroma formation. After applying doxorubicin in various ways to the digital nerve stumps of ponies, degenerating or necrotic neurones appeared only sporadically in the spinal ganglia. Although doxorubicin was largely ineffective in retrograde destruction of cell bodies, when absorbed in pledgets on the stumps it exerted a sustained action which prevented Schwann cell proliferation and axon sprouting. Ricin, in contrast to doxorubicin, was effective in retrograde destruction of sensory neurons. Many affected neurons were devoid of polysomes but packed with mitochondria; others had advanced to various stages in cytolysis. Despite its effectiveness, ricin cannot be recommended because of its extreme toxicity. The clinical use of retrograde transport in equine neurectomy will probably depend on future development of hybrid toxins with high neural specificity and low systemic toxicity.
Ectopic ureter managed by unilateral nephrectomy in two female horses
Authors: SULLINS K. E. , McILWRAITH C. W. , YOVICH J. V. , MacHARG MARGARET A. , FESSLER J. 
Published: April 2010

SummaryUnilateral ureteral ectopia was diagnosed in three‐year‐old and 10‐month‐old fillies exhibiting urinary incontinence since birth. In one case reimplantation of the ureter onto the bladder was planned but considered to be impractical intraoperatively. Unilateral nephrectomy was performed successfully in both cases which alleviated the urinary incontinence. Both horses had normal urinary function postoperatively and became healthy, serviceable animals.
Narcotic analgesics, their detection and pain measurement in the horse: A review
Authors: KAMERLING S. , WOOD T. , DeQUICK D. , WECKMAN T. J. , TAI C. , BLAKE J. W. , TOBIN T. 
Published: April 2010

SummaryNarcotic analgesics produce pharmacological effects by interacting with specific opiate receptors. At least five major types of opiate receptors have been recognised. These include μ (morphine) and kappa (ethylketazocine) receptor types. Narcotic analgesics which interact with μ receptors produce locomotor and autonomic stimulation at doses that produce little or no analgesia. Therefore, use of these drugs as analgesics in equine medicine has not been very satisfactory. Theoretical considerations suggested that the role of kappa agonists in equine analgesia be investigated. Using a pure kappa agonist, U‐50. 488H, good analgesia was produced in the horse with little or no locomotor stimulation or autonomic effects. These data suggest that kappa agonists may be superior analgesics for clinical use in the horse. On the other hand, the locomotor stimulant effects of μ agonist analgesics enable their use as illegal medications. Specifically, these agents produce a good running response, signs of central nervous stimulation and analgesia, all potentially useful effects in a racehorse. Regulatory control of most narcotic analgesics can be obtained by high performance thin layer chromatographic screening. However, effective screening for the fentanyls and small doses of etorphine can only be achieved by use of immunoassay.
Comparison of transtracheal aspirate and bronchoalveolar lavage cytology in 50 horses with chronic lung disease
Authors: DERKSEN F. J. , BROWN C. M. , SONEA I. , DARIEN B. J. , ROBINSON N. E. 
Published: April 2010

SummaryComparisons were made between transtracheal aspirate (TTA) and bronchoalveolar lavage (BAL) cytology obtained from 50 horses with chronic lung disease and from 10 control horses. There was no significant correlation between the TTA cytology and the BAL cytology, suggesting that the cell population in the trachea is not representative of the cell population in the lower airways. In control horses the range of differential cell counts obtained from TTA fluid was remarkably large, whereas the variability in cell populations observed in BAL fluid was smaller. In the principal horses the total and differential cell counts of the TTA and BAL fluids were within the 95 per cent confidence interval in 38 and 24 per cent of cases, respectively; and an increase in percentage neutrophils was most common. It was concluded that BAL may be a useful diagnostic aid when evaluating horses with chronic lung disease, but that the clinical usefulness of cytological evaluations of TTA fluid may be limited in these cases.
Muscular adaptation of horses during intensive training and detraining
Authors: ESSÉN‐GUSTAVSSON BIRGITTA , McMIKEN D. , KARLSTRÖM K. , LINDHOLM A. , PERSSON S. , THORNTON J. 
Published: April 2010

SummaryFive horses were studied during a five‐week regime of controlled intensive daily training on a high‐speed treadmill followed by five weeks of detraining. Muscle biopsies were taken weekly from both the right and left gluteus muscle and from the sternocephalicus muscle before, and at the end of, the training and detraining periods. Histochemical and biochemical analyses of the sternocephalicus muscle showed no metabolic adaptation with either training or detraining. No significant differences were observed in any of the analysed parameters in the gluteus muscle between contralateral sites. Glycogen levels decreased by 10 to 15 per cent after one to two weeks of training, remained low during the training period and increased to pretraining levels after one week's cessation of training. Citrate synthase activity increased rapidly and was 27 per cent higher after one week and 42 per cent higher after five weeks of training. Lactate dehydrogenase activity decreased by 15 per cent during this period. The changes seen in these enzyme levels persisted during the detraining period. No alterations were seen in fibre type composition but type IIA fibre areas decreased by 19 per cent after five weeks training and capillary density increased by 17 per cent. It is concluded that a period of intensive training will rapidly increase the oxidative capacity and the capillary density in an actively working muscle, and that these metabolic adaptations are well maintained during a subsequent period of detraining.
Interactions between chloramphenicol, acepromazine, phenylbutazone, rifampin and thiamylal in the horse
Authors: BURROWS G. E. , MacALLISTER C. G. , TRIPP P. , BLACK J. 
Published: April 2010

SummaryThe potential for interactions between chloramphenicol, phenylbutazone, acepromazine and thiamylal and chloramphenicol, rifampin, and phenylbutazone were evaluated in two groups of experiments. In the first, five horses were given thiamylal intravenously (iv) (6.6 mg/kg) after pretreatment with acepromazine, and the time of recumbency was determined. Administration of chloramphenicol iv (25 mg/kg) 1 h prior to anaesthesia significantly lengthened the recumbency time from 21.8 ± 4.8 mins to 36.0 ± 8.3 mins. There was an apparent but not statistically significant decrease in recumbency time when phenylbutazone (4.4 mg/kg) was administered iv daily for 4 days prior to anaesthesia. In the second series of experiments, phenylbutazone (4.4 mg/kg), chloramphenicol (25 mg/kg) and rifampin (10 mg/kg) were administered in various sequences to five different horses. Chloramphenicol pretreatment produced a significant decrease in the elimination rate and rifampin a significant increase in the elimination rate of phenylbutazone. The half‐life of elimination of phenylbutazone alone was about 4 h. Following four days pretreatment with rifampin it was approximately 2.7 h, it was approximately 5.6 h and 9.5 h, respectively, when chloramphenicol was administered in one dose 1 h before or two doses 12 h and 1 h before phenylbutazone.
Effects of season and lower ambient temperature on the structure of the sweat glands in anhidrotic horses
Authors: JENKINSON D. McEWAN , LONEY C. , ELDER H. Y. , MONTGOMERY I. , MASON D. K. 
Published: April 2010

SummaryHistological studies of the sweat glands of anhidrotic horses in the Hong Kong summer and under conditions of reduced thermal stress, both natural and controlled, were undertaken to determine if glandular regeneration occurs. Clinical data were collected for comparison with the histological results in each instance. Horses were assigned to one of three categories on the basis of the resulting change in the number of thin glandular profiles in a cooler environment. Group 1, which was classed as normal, had a low initial value, which was maintained. Group 2, typical of mild and moderately affected animals, had a high initial value, which fell markedly after as little as six weeks in the cool environment. Animals in Group 3, classed as severely affected, had a high initial value which remained high even after prolonged exposure to the cool environment. Light microscopical examination of the sweat glands in the heat, and after six weeks in a cool environment, provided a means of predicting the degree of anhidrotic severity and the potential for recovery in a cool climate. This was superior to clinical observation, although a diagnostic test based on glandular function is still required.
Development of an equine nuclear medicine facility for gamma camera imaging
Authors: ATTENBURROW D. P. , PORTERGILL M. J. , VENNART W. 
Published: April 2010

SummaryA nuclear medicine facility constructed specifically for the application of a gamma camera system to the radioisotope imaging of bone, pulmonary circulation and ventilation in the horse is described. The gamma camera was previously used for human nuclear medicine, and a support for the gamma camera head was specifically designed for this work. Imaging protocols are suggested and the necessary materials for bone and lung studies are described. Images of bone and lung are shown and computer analysis of the data indicated. Imaging times are approximately 1 to 2 mins and typical bone and lung studies can be completed in 20 to 30 mins.
Blood chemistry and skeletal muscle metabolic responses during and after different speeds and durations of trotting
Authors: VALBERG STEPHANIE , GUSTAVSSON BIRGITTA ESSEN , LINDHOLM A. , PERSSON S. G. B. 
Published: April 2010

SummaryEight standardbred horses trotted on a treadmill for 55 mins at a sub‐maximal speed of 5m/sec and subsequently performed an exercise test consisting of 2 min intervals at increasing speed. Heart (HR) and respiratory (Rf) rates and venous blood samples were obtained before, during and for 5 mins after exercise. Gluteus medius muscle biopsies and rectal temperatures were taken before and after exercise. The mean HR was 132/min and the mean Rf was 156/min during the 5m/sec trotting. With 5m/sec exercise, plasma free fatty acids (FFA), glucose, creatinine and Cortisol concentrations increased markedly. Blood lactate increased slightly and plasma potassium increased initially and then decreased with a lengthened duration of trotting. Within 5 mins post exercise plasma FFA, glucose and Cortisol concentrations continued to rise, whereas creatinine and lactate levels declined slightly and potassium concentrations declined rapidly to below resting values. The mean intramuscular (im) glycogen utilisation was 86 mmol/kg, no significant changes occurred in creatine phosphate (CP), adenosine triphosphate (ATP) and glucose‐6‐phosphate (G‐6‐P) concentrations and muscle lactate decreased significantly. During the second exercise test mean HR was 215/min and Rf 126/min at top speed. No significant change was seen in plasma glucose whereas Cortisol levels rose to a lesser extent, and creatinine lactate, ammonia and potassium concentrations to a greater extent, compared to 5 m/sec trotting. Post exercise, these parameters continued to increase except for creatinine which declined slightly and potassium which decreased rapidly. The mean im glycogen utilisation was 144 mmol/kg, ATP concentrations were unaltered, CP declined, lactate and G‐6‐P increased during exercise. The rapid changes in concentrations of blood chemistry parameters post exercise emphasise the importance of obtaining blood samples during exercise when studying metabolic response.
Thyroid hormone periodicity in healthy adult geldings
Authors: DUCKETT WENDY M. , MANNING J. P. , WESTON PATRICIA G. 
Published: April 2010

SummarySerum samples were collected from 10 healthy geldings every 4 h for three consecutive days and the triiodothyronine (T3) and thyroxine (T4) concentrations determined by radioimmunoassay. There were significant differences in the hormone concentrations related to time. The mean (± sd) T3concentration peaked around 08.00 h at a level (54.06 ± 14.02 ng/dl) significantly (P<.001) higher than the lowest concentration (38.71 ± 10.81 ng/dl) around midnight. Although the highest mean T3level was 08.00 h, this value was not significantly different from the noon and 16.00 h levels. Likewise, the mean T3level at midnight was not significantly different from the 20.00 h and 04.00 h levels, resulting in a plateau from 08.00 h to 16.00 h and a trough from 20.00 h to 04.00 h. The mean (± sd) T4concentration peaked around 16.00 h at a level (2.43 ± .81 μg/dl) significantly (P<.01) higher than the lowest concentration (1.79 ± .63 μg/dl) around 04.00 h.
Twin embryos in mares I: from ovulation to fixation
Authors: GINTHER O. J. 
Published: April 2010

SummaryRecent findings on the origin and development of twins from ovulation (Day 0) to fixation (mean: Day 16) are reviewed. Available data show that almost all twins originate from multiple ovulations. Results of recent ultrasound studies indicate that the number of days between double ovulations does not affect the conception rate per ovum or embryo survival during the first 16 days after each ovulation. Embryo reduction is the natural elimination of excess embryos so that only one embryo enters the foetal stage. In two studies, embryo reduction before or on the day of fixation was not considered an important aspect of the natural correction of twins. Diameters and growth rates on Days 11 to 16 were similar between singletons and twins and the presence of two vesicles did not have a direct effect on their diameter other than that attributable to their age. Twin and singleton embryonic vesicles were mobile within the uterine lumen from the first day of detection (Days 9 to 11) to the day of fixation (mean: Day 16). In one study, the embryonic vesicles were in the uterine body for over 50 per cent of the time during Days 9 to 12 and thereafter were most often in the uterine horns. For twins of dissimilar size, the preference for uterine body versus horns appeared to be an independent function of each vesicle based on its age or size. After Day 12, the number of entries from the uterine body into the horns increased and the vesicles began a maximum mobility phase which continued until fixation. Both members of twin sets were in a given uterine segment more often than would be expected by chance. Results of ultrasound studies indicated that uterine contractions are the propulsive force for conceptus mobility, apparently in response to the production of a stimulant by the conceptuses. Greatest uterine contractility coincided with the period of maximum conceptus mobility. The increase in contractility began four days earlier in pregnant than in nonpregnant mares. Fixation probably occurs when an embryonic vesicle becomes so large and uterine tone so great that the vesicle can no longer move despite the continuation of uterine contractions. Combined data showed that fixation of twins occurred unilaterally more often than would be expected by chance. The incidence of unilateral fixation increased greatly when vesicles were dissimilar in diameter or originated from asynchronous ovulations.