bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete primary sequence of equine cartilage link protein deduced from complementary DNA
Authors: Dudhia Jayesh , Platt David 
Published: January 2024

SUMMARY
Investigation of the structure of equine articular cartilage link protein (lp) from individuals ranging in age from 1 to 15 years identified 3 distinct isoforms having molecular weights of 46,000, 43,000, and 41,000. The relative amounts of each of the 3 isoforms altered with age. The largest form did not change with age; however, amounts of the Mr 43,000 and 41,000 forms increased with increasing age. The results suggested that an accumulation, in the extracellular matrix of cartilage, of these 2 smaller products may have arisen from proteolytic cleavage. The complete amino acid sequence of the protein core was determined from complementary dna products prepared by polymerase chain reaction amplification of cartilage lp mRNA. The sequence had 96% similarity with human lp and with that of other species for which the primary structure has been determined. This high degree of sequence conservation and the isoform data indicate that extracellular processing of lp occurs by similar mechanisms in various species. At the transcription level, equine chondrocytes were found to express lp as 2 abundant mRNA of 5.0 and 3.0 kb, and a smaller mRNA of 1.5 kb. Processing of the lp mRNA in horses, thus, appears to be similar to that found in other species investigated, and although multiple transcripts are present, the coding region remains unaltered and only 1 protein product is made.
Effect of bethanechol, neostigmine, metoclopramide, and propranolol on myoelectric activity of the ileocecocolic area in cows
Authors: Steiner Adrian , Roussel Allen J. , Martig Johannes 
Published: January 2024

SUMMARY
The effect of bethanechol, neostigmine, metoclopramide, and propranolol on myoelectric activity of the ileum, cecum, and proximal loop of the ascending colon was determined in 6 healthy Jersey cows implanted with 8 pairs of bipolar electrodes. Assigned at random, each cow received each of 5 treatments in 3-day intervals. The treatments included bethanechol (0.07 mg/kg of body weight, sc), neostigmine (0.02 mg/kg, sc), metoclopramide (0.15 mg/kg, im), dl-propranolol (0.2 mg/kg, im), and 0.9% sodium chloride (NaCl) solution (20 ml, sc). All drugs were administered during early phase I of the migrating myoelectric complex in the ileum. Myoelectric activity was recorded for 4 hours after treatment, and data were analyzed for each hour separately.
Bethanechol and neostigmine significantly (P < 0.05) increased the number of cecocolic spikes per minute per electrode, duration of cecocolic spike activity (%), and number of cecocolic propagated spike sequences per 10 minutes, relative to NaCl, during 1 or more hours of the recording period. The effect of bethanechol was more pronounced on duration of spike activity and number of propagated spike sequences, whereas neostigmine mainly increased the number of (uncoordinated) spikes. Metoclopramide and propranolol had no significant effect on cecocolic myoelectric activity, relative to NaCl.
It was concluded that bethanechol and, less likely, neostigmine at the dosage used in this study may be suitable for medical treatment of cecal dilatation in cattle in which hypomotility of the cecum and proximal loop of the ascending colon has to be reversed. The potential advantage of bethanechol vs neostigmine for medical treatment of cecal dilatation is worth further evaluation.
Ultrasonography as a method to determine tendon cross-sectional area
Authors: Gillis Carol , Sharkey Neil , Stover Susan M. , Pool Roy R. , Meagher Dennis M. , Willits Neil 
Published: January 2024

SUMMARY
Ultrasonographic cross-sectional area (csa) measurements of equine superficial digital flexor (sdf) tendon were obtained to determine the feasibility of ultrasonography for csa measurement of tendon in vivo and in vitro. Ultrasonographic measurements were compared with a more traditional csa measurement method, ink-blot analysis. In addition, values for ultrasonographic sdf tendon mean echogenicity were obtained in vivo and in vitro. The left forelimb sdf tendons of 23 horses were evaluated ultrasonographically. Cross-sectional images were acquired at 4-cm intervals distal to the base of the accessory carpal bone (dacb) to the level of the proximal sesamoid bones while horses were standing squarely. After euthanasia, the left forelimbs were mounted in a materials testing system (mts) and loaded under tension to standing load. Ultrasonographic images were again acquired at the same locations. The ultrasonographic images were digitized, and values for ultrasonographic csa and mean echogenicity were obtained for each level.
Immediately after mechanical testing, a 1-cm-thick transverse section of sdf tendon at 12 cm dacb was removed. Three ink blots were prepared from each end of the removed tendon section and digitized. The 6 csa values were averaged to generate a value for morphologic csa for each sdf tendon at 12 cm dacb.
Standing ultrasonographic tendon csa at 12 cm dacb was consistently smallest (mean ± sd csa = 86 ± 11 mm2), followed by mts ultrasonographic csa (mean, 95 ± 12 mm2), ink-blot morphologic csa being largest (mean, 99 ± 15 mm2). Comparison of standing and mts ultrasonographic csa values at 12 cm dacb revealed a strong positive linear correlation between methods (R2 = 0.74, P = 0.001). Comparison of ink-blot csa at 12 cm dacb with standing and mts ultrasonographic csa revealed strong positive linear correlations (R2 = 0.64, P = 0.001 and R2 = 0.72, P = 0.001, respectively).
For ultrasonographic mean echogenicity, standing values insignificantly exceeded mts values at each level. The authors conclude that ultrasonography is a useful technique for the noninvasive assessment of sdf tendon csa that can be applied in vivo and in vitro.
Intracranial pressure and cerebral perfusion pressure in clinically normal equine neonates
Authors: Kortz Gregg D. , Madigan John E. , Goetzman Boyd W. , Durando Mary 
Published: January 2024

SUMMARY
Intracranial pressure (icp) and cerebral perfusion pressure (cpp) were determined in 8 clinically normal neonatal foals. After the foals oriented themselves and nursed the mares, they were sedated as necessary, and local anesthesia was provided for making the skin incisions. Using a technique similar to that used in human beings, an indwelling subdural catheter was placed to measure icp. Carotid artery catheterization was used to measure arterial blood pressure. Cerebral perfusion pressure was calculated as the difference between mean arterial blood pressure and icp.
Intracranial pressure and cpp readings were taken twice during each 24-hour period, starting at 6 hours of age and continuing through 72 hours of age. Mean (± sd) icp were 5.83 ± 1.82, 8.81 ± 2.06, and 9.55 ± 1.55 mm of Hg (range, 2 to 15 mm of Hg), and mean cpp were 80.19 ± 10.34, 75.30 ± 10.86, and 76.80 ± 12.59 mm of Hg (range, 50 to 109 mm of Hg) for each of the first three 24-hour periods after birth, respectively. All 8 foals had physical and neurologic examinations, csf analysis, and computerized axial tomography evaluations. The foals manifested normal behavior during the interval of measurements, and adverse effects of the procedure were not detected during the monitoring period. Establishment of normal values for icp and cpp are important to clinicians who have the opportunity to apply this technique for monitoring and evaluating neonatal foals with signs of cns dysfunction.
Thyroid, renal, and splanchnic circulation in horses at rest and during short-term exercise
Authors: Manohar Murli , Goetz Thomas E. , Saupe Beth , Hutchens Elizabeth , Coney Elizabeth 
Published: January 2024

SUMMARY
Using radionuclide-labeled 15-μm-diameter microspheres injected into the left ventricle, we examined blood flow to the thyroid gland, adrenal glands, kidneys, and various gastrointestinal tract tissues in 9 healthy horses while they were standing quietly (rest) and during exercise at 2 work intensities (8 and 13 m/s). Hemodynamic measurements were made during steady-state conditions, as judged by the stability of heart rate as well as aortic, pulmonary, and right atrial pressures. The similarity of blood flow values for the left and the right kidneys during each of the 3 conditions indicated adequate mixing of microspheres with blood. In standing horses, of all tissues examined, the thyroid gland had the highest blood flow (1,655.2 ± 338.5 ml/min/100 g)—being about threefold that in the kidneys. Adrenal blood flow, by contrast, was only 25% of that in the kidneys (589.5 ± 50.4 ml/min/100 g). Among the gastrointestinal tract tissues, glandular stomach and pancreas had the highest blood flows (214.3 ± 21.6 and 197.6 ± 23.4 ml/min/100 g, respectively). Small intestinal perfusion was not different from that in the ventral colon and cecum, but their values exceeded those for the dorsal and small colons. Exercise at 8 and 13 m/s caused significant increase in adrenal blood flow as vascular resistance decreased significantly. In the kidneys, blood flow was only insignificantly affected during exercise at 8 m/s, but at 13 m/s there was a profound reduction in renal blood flow as intense renal vasoconstriction occurred. Vasoconstriction also caused thyroid and pancreatic blood flow to decrease significantly at both levels of exertion. Significant vasoconstriction occurring in all gastrointestional tract tissues at 8 and 13 m/s caused blood flow to be diverted away from these vascular beds. Thus, our data indicated that renal, adrenal, and splanchnic organ/tissue blood flow responses of strenuously exercising horses closely resemble those described for exercising ponies.
Effects of tumor necrosis factor blockade on interleukin 6, lactate, thromboxane, and prostacyclin responses in Miniature Horses given endotoxin
Authors: Cargile Jana L. , MacKay Robert J. , Dankert John R. , Skelley Leslie 
Published: January 2024

SUMMARY
A monoclonal antibody (mab) against equine tumor necrosis factor-α (Eq tnf) was used to investigate the role of tnf in cytokine, eicosanoid, and metabolic responses of Miniature Horses given endotoxin. Plasma concentrations of interleukin 6 (il-6), lactate, thromboxane A2 metabolite, and prostacyclin metabolite (6-keto-pgf1α) were measured in 10 Miniature Horses given 0.25 µg of lipopolysaccharide (lps; Escherichia coli O55:B5)/kg of body weight. Five horses were given Eq tnf mab and 5 were given isotype-matched mab as control. All horses were given 1.86 mg of antibody/kg by iv infusion, 5 minutes before lps was given iv. Blood samples were taken 20 minutes before and at multiple intervals for 24 hours after lps was given. Interleukin 6 bioactivity in plasma was measured, using il-6-dependent cell line (B9). Eicosanoid activities were assessed by enzyme immunoassay, and plasma lactate concentration was determined enzymatically. Data were analyzed by anova and Tuke's honest significant difference test for significant (P < 0.05) effect of treatment. Horses given Eq tn mab had significantly (P < 0.050) lower peak mean ± sem il-6 (59 ± 29 U/ml), lactate (16 ± 2.00 mg/dl), and 6-keto-pgf1α (254 ± 79 pg/ml) values then did horses given control mab (880 ± 375 U/ml for il-6; 26 ± 0.04 mg/dl for lactate; and 985 ± 290 pg/ml for 6-keto-pgf1α). There was no effect of anti-tnf treatment on lps-induced thromboxane A2 metabolite production. Tumor necrosis factor mediated il-6, lactate, and prostacyclin responses, without affecting thromboxane production in horses given lps.
Pathologic effects in brain after intracranial pressure monitoring in clinically normal dogs, using a fiberoptic monitoring system
Authors: Bagley Rodney S. , Keegan Robert D. , Greene Stephen A. , Harrington Michael L. , Moore Michael P. 
Published: January 2024

SUMMARY
During 2 separate studies, intracranial pressure (icp) was measured in 13 healthy dogs (group A, n = 7; group B, n = 6), using a fiberoptic monitoring system implanted surgically in the right superficial cerebral cortex. Average icp was measured for 15 minutes after a 15-minute post-implantation period of equilibration. Intracranial pressure was measured in group-A dogs at 2.0 and 1.3% end-tidal isoflurane concentrations. Mean ± 1 sd icp in group-A dogs at 2.0 and 1.3% end-tidal isoflurane concentrations was 11 ± 2 and 11 ± 3 mm of Hg, respectively. Dogs of group A were euthanatized immediately after measurements were obtained. Mean icp ± 1 sd in group-B dogs was 11 ± 3 mm of Hg. After monitoring, but prior to euthanasia, group-B dogs underwent callosotomy, and were maintained for 30 days after surgery. The brain was removed from all dogs, formalin fixed, and examined grossly and microscopically for lesions associated with fiberoptic cable implantation. Variable degrees of hemorrhage and mechanical brain damage were seen focally around the catheter site in all brains from group-A dogs, especially when the cable entered through a sulcus. In 1 dog, local vacuolation was seen in the brain immediately adjacent to the tract associated with implantation of the fiberoptic catheter. In all other dogs, the additional cortex was histologically normal. Histologic lesions associated with cable implantation were not observed in group-B dogs.
Pharmacokinetics of bacampicillin in equids
Authors: Sarasola Patxi , McKellar Quintin A. 
Published: January 2024

SUMMARY
Bacampicillin hydrochloride is an ester prodrug that is hydrolyzed to ampicillin after its absorption from the gastrointestinal tract. It was administered intragastrically at a dose rate of 13.5 mg/kg of body weight to ponies and horses, and was highly bioavailable (F = 41.0%), compared with other penicillins in adult horses. The high peak ampicillin plasma concentration of 6,1 ± 0,5 µg/ml achieved and persistence of the antibiotic at concentration of 0.3 ± 0.1 µg/ml 6 hours after its intragastric administration, suggest that bacampicillin hydrochloride may reach suitable bactericidal concentrations for treatment of infections caused by susceptible microorganisms.
In a separate experiment, dichlorvos, an organo-phosphate compound that inhibits some of the esterase activity in plasma, was administered orally to the same animals at a dose rate of 40 mg/kg, followed by intragastric administration of bacampicillin hydrochloride at a dose of 13.5 mg/kg. Plasma pseudocholines-terase and erythrocyte acetylcholinesterase activities were reduced to < 5% of reference (predichlorvos) values after dichlorvos administration. However, rate of hydrolysis of bacampicillin into ampicillin was not affected. Consequently, the disposition and fate of bacampicillin when administered intragastrically 1 day after dichlorvos administration were similar to the values obtained after administration of bacampicillin alone.
Intragastric coadministration of probenecid at a dose rate of 75 mg/kg and bacampicillin at 13.5 mg/ kg limited absorption of the antibiotic from the gastrointestinal tract. This suggests existence of a common transport mechanism for bacampicillin and probenecid in the gastrointestinal wall, and precludes use of this combination for treatment. The bioavailable fraction of ampicillin after combination treatment indicated prolonged residence time in the plasma, presumably as a consequence of reduced renal tubular secretion.
Kinematic differences between the distal portions of the forelimbs and hind limbs of horses at the trot
Authors: Back Willem , Schamhardt Henk C. , Hartman Wrister , Barneveld Albert 
Published: January 2024

SUMMARY
In literature, it has been hypothesized that the concussion at impact in the equine forelimb is larger than that in the hind limb, and therefore, eventually more clinical lameness may develop in the distal portion of the forelimbs. As the functional anatomy of the distal forelimb and hind limb segments is similar, a study was undertaken to compare the kinematics of hoof and fetlock in the forelimbs and hind limbs. For this purpose, the trot of 24 clinically normal (sound) horses on a treadmill (4 m/s) was recorded, using modern gait analysis equipment.
It appeared that vertical hoof velocity at impact and the resulting vertical hoof acceleration were higher in the forelimb than in the hind limb. In contrast, horizontal hoof velocity at impact and the resulting horizontal acceleration were higher in the hind limb. Just after impact, the fetlock was more rapidly extended in the forelimb than the hind limb. The peak maximal and minimal accelerations of that joint also were significantly (P < 0.05) higher in the forelimb than in the hind limb.
Results of this study indicate that, at the beginning of the stance phase, the distal portion of the forelimb is subjected to more kinematic stress than the distal portion of the hind limb. The higher angular velocity of the fetlock can be interpreted as more rapid loading of this joint, whereas the higher peak accelerations represent the higher oscillatory changes in fetlock movement. It is known from literature that repetitive impulsive joint loading and rapid oscillations in joint movement, even within physiologic limits, contribute to development of osteoarthrosis. Therefore, the differences between distal forelimb and hind limb kinematics found in this study may be related to the generally known higher incidence of chronic lameness in the forelimbs.
Thoracic lymphatic cannulation for the study of pulmonary immune responses in lung lymph of calves
Authors: Gershwin Laurel J. , Gunther Robert A. , Smith Steven G. , Boyle Gabrielle A. , Friebertshauser Kathleen E. 
Published: January 2024

Abstract

Objective
To develop a system for analysis of immune response variables in the lymph draining the lung and to establish baseline data for clinically normal calves.

Design
Surgery was performed on 6 calves to insert a cannula into the efferent lymphatic duct of the caudal mediastinal lymph node to create a long-term thoracic lymph fistula draining to the exterior. Lymph was collected daily, and on the fifth postoperative day, calves were exposed to an aerosol of cell culture medium (mock infection). For the next 10 days, lymph was collected for analysis and, on the tenth day, necropsy was performed.

Animals
Six 6- to 8-week-old Holstein bull calves.

Procedures
Daily lymph samples were evaluated for: flow rate; total and differential cell counts; and IgG, IgM, IgA, IgE, and protein concentrations. On days −4, −1, 1, 4, 7, and 10, cells were stained and quantitated by fluorescence-activated cell sorter analysis for T, B, CD4+, and CD8+ cells. Blood lymphocytes were evaluated on days -1 and 10 for comparison.

Results
Flow was established for up to 25 days, with a mean rate between 11 and 22 ml/h. Protein concentrations in lymph and plasma did not indicate a protein drain. Although mean lymphocyte counts reflected a slight gradual decrease in lymph lymphocytes, this effect was not apparent in every calf, nor was the effect seen in blood lymphocytes. There were no significant changes in IgG, IgM, IgA, or IgE concentration, with the exception of IgA concentration in 1 calf that developed an abscess at the cannulation site. The T-cell subset absolute numbers of CD4+ and CD8+ cells decreased slightly over time, but the CD4+-to-CD8+ cell ratio remained almost constant at near 2.

Conclusions
Creation of a thoracic lymphatic fistula appears to be a useful technique for studying effects of lung infection on immunologic variables, with potential application to bacterial and viral respiratory tract diseases.

Clinical Relevance
Thoracic lymphatic cannulation can be used in studies to determine pathogenic mechanisms in respiratory tract disease and to develop more effective vaccines against respiratory tract pathogens.
Absorption of diazepam after its rectal administration in dogs
Authors: Papich Mark G. , Alcorn Jane 
Published: January 2024

SUMMARY
A cross-over study was performed in 6 healthy mixed-breed dogs and 4 healthy Beagles. Diazepam was administered per rectum to Beagles (0.5 mg/kg of body weight) and mixed-breed dogs (2 mg/kg), and iv (0.5 mg/kg) to both groups of dogs. Each dog received the drug by both routes, with a 1-week washout period between dosages. After diazepam administration, blood samples were collected to measure plasma concentration of diazepam and its active metabolites, desmethyldiazepam and oxazepam, by use of reverse-phase high-performance liquid chromatography (hplc). Systemic availability was assessed by comparing the area under the curve for diazepam metabolites for each route of administration. Mean (± sd) diazepam concentrations in plasma after rectal administration were low in comparison with those obtained after iv administration, with systemic availability of only 7.4 (± 5.9) and 2.7 (± 3.2)% for the high and low dose, respectively. However, diazepam was converted to its metabolites within minutes after administration. Accounting for the total concentration of benzodiazepines (diazepam plus desmethyldiazepam and oxazepam) in plasma, systemic availability was 79.9 (± 20.7) and 66.0 (± 23.8)% for the high and low dosage, respectively. After iv administration, diazepam concentration decreased, with a half-life of only 14 to 16 minutes, but desmethyldiazepam and oxazepam concentrations decreased more slowly, with a half-life of 2.2 to 2.8 hours and 3.5 to 5.1 hours, respectively.
Each of the metabolites is reported to have anticonvulsant activity. After rectal administration of the high dose, mean total benzodiazepine concentration was above 1.0 μg/ml within 10 minutes and was maintained above this concentration for at least 6 hours. We conclude that diazepam is absorbed after rectal administration in dogs, and that the pharmacologic effects are probably caused by the active metabolites, not the parent drug. Samples also were analyzed by use of a nonspecific commercial benzodiazepine fluorescence polarization immunoassay (fpia). Correlation between the fpia and hplc assay was strongest for diazepam (R2 = 0.84), weak for desmethyldiazepam (R2 = 0.09), and nonexistent for oxazepam. We conclude from a comparison of assays that hplc is preferred over the fpia method for measuring benzodiazepines in dogs.
Evidence for endothelium-derived relaxing factor/nitric oxide in equine digital arteries
Authors: Cogswell Andria M. , Johnson Philip J. , Adams H. Richard 
Published: January 2024

Abstract

Objective
To test the hypothesis that endothelium-derived nitric oxide modulates vasomotor reactivity in equine digital arteries.

Design
Digital arteries were isolated from adult horses, and their vasodilator properties were examined in an in vitro controlled environment.

Animals
Five adult horses (1 gelding, 4 mares) without evidence of hoof or vascular disease were studied.

Procedure
Arterial rings with or without endothelium were exposed to endothelium-dependent vasodilator drugs in the presence or absence of a pharmacologic inhibitor of the enzyme nitric oxide synthase.

Results
Vasodilator effects of 3 endothelium-dependent vasorelaxant agents were significantly greater in endothelium-intact vessels than in endothelium-denuded vessels. Moreover, a nitric oxide synthase inhibitor reduced vasodilator responses to endothelium-dependent vasodilators in endothelium-intact arteries, but had no discernable effects in endothelium-denuded arteries.

Conclusions
These findings indicate the presence of endothelium-derived relaxing factor/nitric oxide in blood vessels of horses, and identify vascular endothelium as an endogenous modulator of vasomotor tone in the digital arteries of this species.