bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bronchial circulation during prolonged exercise in ponies
Authors: Manohar Murli , Duren Stephen E. , Sikkes Bridget P. , Day Jennifer , Baker John P. 
Published: January 2024

Summary
Tracheal, bronchial, and renal blood flow were studied in 8 healthy ponies at rest and during exercise performed on a treadmill at a speed setting of 20.8 km/h and 7% grade (incline) for 30 minutes. Blood flow was determined with 15-μm-diameter radionuclide-labeled microspheres that were injected into the left ventricle when the ponies were at rest, and at 5, 15, and 26 minutes of exertion. Heart rate and mean aortic pressure increased from resting values (40 ± 2 beats/min and 124 ± 3 mm of Hg, respectively) to 152 ± 8 beats/min and 133 ± 4 mm of Hg at 5 minutes of exercise, to 169 ± 6 beats/min and 143 ± 5 mm of Hg at 15 minutes of exercise, and to 186 ± 8 beats/min, and 150 ± 5 mm of Hg at 26 minutes of exercise. Tracheal blood flow at rest and during exercise remained significantly (P < 0.05) less than bronchial blood flow. Tracheal blood flow increased only slightly with exercise. Vasodilation caused bronchial blood flow to increase throughout exercise. Pulmonary arterial blood temperature of ponies also increased significantly (P < 0.05) with exercise and a significant (P < 0.005) correlation was found between bronchial blood flow and pulmonary arterial blood temperature during exertion. At 5 minutes of exercise, renal blood flow was unchanged from the resting value; however, renal vasoconstriction was observed at 15 and 26 minutes of exercise. We concluded that bronchial circulation of ponies increased with exercise in close association with a rise in pulmonary arterial blood temperature. Also, increased thermal burden necessitated redistribution of blood flow away from kidneys late in exercise.
Influence of cyclooxygenase inhibitors on furosemide- induced hemodynamic effects during exercise in horses
Authors: Olsen S. C. , Coyne C. P. , Lowe B. S. , Pelletier N. , Raub E. M. , Erickson H. H. 
Published: January 2024

SUMMARY
Furosemide, which commonly is used as a prophylactic treatment for exercise-induced pulmonary hemorrhage in horses, may mediate hemodynamic changes during exercise by altering prostaglandin metabolism. To determine if furosemide's hemodynamic effects during exercise in horses could be reversed, cyclooxygenase inhibitors were administered with furosemide. Four treatments were administered 4 hours prior to treadmill exercise at 9 and 13 m/s. They included a control treatment (10 ml of 0.9% NaCl solution, iv), furosemide (1 mg/kg of body weight, iv) administered alone, and furosemide in combination with phenylbutazone (4 mg/kg, iv, q 12 h for 2 days) or with flunixin meglumine (1.1 mg/kg, iv, on the day of experiment). Five horses were randomly assigned to complete all treatments. Physiologic variables at rest prior to exercise were not influenced by treatments. Furosemide, administered alone, reduced mean right atrial pressure and mean pulmonary artery pressure during exercise. The combinations of furosemide and flunixin meglumine or furosemide and phenylbutazone, at both levels of exercise intensity, returned mean right atrial pressure and mean pulmonary artery pressure to the value of the control treatment. During rest and exercise, plasma lactate concentration, pcv, heart rate, mean carotid artery pressure, oxygen consumption, carbon dioxide elimination, and cardiac output were not altered by any of the treatments. At 5 minutes after exercise, the administration of furosemide, alone or with phenylbutazone, reduced mean right atrial pressure. Other measured variables were not significantly influenced by treatments during recovery from exercise. These results suggested that cyclooxygenase inhibition partially reverses the decrease in mean right atrial pressure or pulmonary artery pressure induced by furosemide during exercise. Furosemide may mediate some of its physiologic activities in exercising horses through the cyclooxygenase pathway.
Effects of low-dose aspirin and specific thromboxane synthetase inhibition on whole blood platelet aggregation and adenosine triphosphate secretion in healthy dogs
Authors: Grauer Gregory F. , Rose Barbara J. , Toolan LeeAnn , Thrall Mary Anna Hull , Colgan Sean P. 
Published: January 2024

SUMMARY
Platelet aggregation and adenosine triphosphate (atp) secretion in response to arachidonic acid (10 μM) or collagen (5 μg/ml) were compared in healthy, adult female Beagles treated with low-dosage aspirin (3.5 mg/kg of body weight, po, q 12 h for 7 treatments) or with CGS 12970, a specific thromboxane synthetase inhibitor (10 mg/kg, po, q 8 h for 10 treatments). Platelet aggregation was assessed in whole blood by use of an electrical impedance method. Baseline values obtained prior to treatment served as controls. Addition of arachidonic acid to blood from nontreated dogs resulted in significantly (P < 0.001) increased impedance, but had no effect in blood from dogs treated with either aspirin or CGS 12970. Treatment with CGS 12970 or aspirin significantly (P < 0.001) decreased platelet atp secretion in response to arachidonic acid, compared with baseline values; however atp secretion in aspirin-treated dogs was significantly (P < 0.01) less than atp secretion in CGS 12970-treated dogs. Differences in platelet aggregation were not observed between control dogs and aspirin- or CGS 12970-treated dogs in response to collagen as an aggregant, however, collagen-induced platelet atp secretion was significantly (P < 0.001) decreased in dogs treated with aspirin, compared with control values and values from dogs treated with CGS 12970. In dogs treated orally with 0.1, 0.2, 1.0, or 10 mg of CGS 12970/kg, dose-dependent inhibition of arachidonic acid-induced platelet aggregation was observed, with impedance changes not observed at the 10-mg/kg dosage and normal platelet aggregation associated with the 0.1-mg/kg dosage. After a single orally administered dosage of 10 mg of CGS 12970/kg, platelet aggregation was maximally inhibited at 1 hour, remained negligible through 12 hours, and returned to normal by 96 hours. Platelet numbers were not affected by treatment with CGS 12970. These results indicate that similar to low-dose aspirin administration, treatment with CGS 12970 decreases arachidonic acid-induced, but not collagen-induced, whole blood platelet aggregation in dogs. Low-dose aspirin administration, however, was more effective than CGS 12970 treatment in reducing arachidonic acid- and collagen-induced platelet atp secretion.
Effect of head and neck position on respiratory mechanics in horses sedated with xylazine
Authors: Lavoie J. P. , Pascoe J. R. , Kurpershoek C. J. 
Published: January 2024

SUMMARY
We studied the temporal changes in respiratory mechanics associated with xylazine administration (1.1 mg/kg of body weight, iv) in standing horses (experiment 1), and determined the effects of head and neck position (experiment 2) and atropine administration (experiment 3) on the observed changes.
Thoroughbred geldings, 3 to 5 years old (5 in experiment 1, 4 in experiments 2 and 3) were used. Flow rates were obtained from a pneumotachograph and a differential transducer attached to a tight-fitting mask. Electronic integration of the flow signal gave tidal volume. Total pulmonary pressure (PL) was defined as the difference between esophageal pressure, measured with a balloon sealed to the end of a polyethylene catheter, and mask pressure. In experiment 3, a blunt cannula positioned in the dorsal third of the eighth or tenth intercostal space was used to estimate transpulmonary pressure. Lateral tracheal pressure was measured, using a polypropylene catheter inserted percutaneously in the mid-extrathoracic tracheal lumen. Upper and lower airway pressures were defined as the difference between mask pressure or transpulmonary pressure and lateral tracheal pressure, respectively.
Five observations were made: (1) There was a significant (P < 0.05) increase in PL from 10 to 40 minutes after administration of xylazine. (2) Although an overall agreement between head and neck position and PL was detected, the maximal PL value was not always obtained with lowest head and neck position. (3) Lower and upper airway resistance increased with low head carriage, with a greater increase in upper airway resistance resulting in a decrease in lower to total airway resistance ratio. (4) Increased airway resistance was reversed by elevating the head and neck. (5) Atropine did not prevent the increase in airway resistance during sedation with xylazine and had no effect on resistance with changes in head position.
Effect of repeated doses of albendazole on enantiomerism of its sulfoxide metabolite in goats
Authors: Benoit Etienne , Besse Stçphane , Delatour Paul 
Published: January 2024

SUMMARY
Five adult Saanen goats were dosed orally 3 times with albendazole (2.5 mg/kg of body weight) at 24-hour intervals, and blood samples were taken by jugular venapuncture at standardized intervals. Plasma was analyzed to determine concentrations of S-oxidation metabolites, and a chiral column was used for enantiomeric discrimination of the sulfoxide metabolite of albendazole. Marked changes were evident between the first and subsequent plasma profiles concerning, on one hand, the proportions of sulfoxide and sulfone metabolites concentrations and, on the other hand, the enantiomeric balance of the sulfoxide metabolite. These correlated phenomena may be explained by the following arguments: the enzyme responsible for sulfoxidation is mainly a flavine-containing monooxygenase, whereas the enzyme responsible for sulfonation is a cytochrome-dependent monooxygenase; the latter, but not the former, is induced by albendazole; the enantioselectivities of both enzymic systems are opposite, the flavine produces the (+) sulfoxide, whereas the cytochromes can use as a substrate, specifically, the (-) sulfoxide.
Cytogenetic characterization of the Madin-Darby bovine kidney cell line
Authors: Kopp Ewald , Nowotny Norbert , Mayr Burkhard , Schleger Walter 
Published: January 2024

SUMMARY
The permanent bovine cell line, Madin-Darby bovine kidney, was cytogenetically analyzed. Chromosomal staining indicated 52 metaphase chromosomes with variations from 49 to 54. The isochromosomes 5, 12, and 13, and centric fusions between chromosomes 1 and 26, 9 and 11, 9 and 24, 17 and 25, 18 and 23, 20 and 24, and 24 and 27 were considered marker chromosomes.
Inhibition of interleukin 1-mediated proteoglycan degradation in bovine articular cartilage explants by addition of sodium hyaluronate
Authors: Morris Elisabeth A. , Wilcon Sandra , Treadwell Benjamin V. 
Published: January 2024

Summary
The effect of exogenous hyaluronate on normal cartilage metabolism and interleukin-1 (il-1)-induced cartilage matrix degradation was investigated in a bovine cartilage explant culture system. Addition of hyaluronate at a concentration of 1.5 mg/ml to cartilage culture explants consistently decreased normal proteoglycan release from the matrix to a value less than that found in control cultures. Addition of 1.5 mg of hyaluronate/ml to il-1 stimulated cartilage culture systems reduced proteoglycan release from the matrix by 83 to 113%. The reduction in control and il-1-stimulated proteoglycan degradation by hyaluronate had a concentration-dependent trend.
Evaluation of alterations in protein (enzyme) release by il-1-stimulated chondrocytes after introduction of hyaluronate was evaluated by use of sodium dodecyl sulfate agar gel electrophoresis of cartilage-conditioned media. The quantity or the molecular weight profile of il-1-induced proteins did not differ after introduction of hyaluronate into the culture system.
Results indicate that introduction of high molecular weight hyaluronate into cartilage culture systems results in a decrease in proteoglycan release from the matrix in control systems, as well as in cultures incubated with il-1. Because il-1-stimulated protein synthesis by chondrocytes remains unchanged after addition of exogenous hyaluronate, the mechanism of inhibition of matrix degradation does not appear to be interference with binding of il-1 to chondrocytes or to be inhibition of the production of neutral metalloproteases, including stromelysin.
Evaluation of intestinal villus height in rats after ischemia and reperfusion by administration of superoxide dismutase, polyethylene glycol-conjugated superoxide dismutase, and two 21-aminosteroids
Authors: Stone William C. , Bjorling Dale E. , Southard James H. , Galbreath Elizabeth J. , Lindsay William A. 
Published: January 2024

Summary
Intestinal ischemia was induced and maintained for 60 minutes in male Sprague-Dawley rats weighing 175 to 225 g. Prior to reperfusion, the following drugs were administered via the caudal vena cava: 0.9% NaCl (0.5 ml), superoxide dismutase (sod; 1,000 IU/kg of body weight), polyethylene glycol-conjugated sod (peg-sod; 1,000 IU/kg), or the 21-aminosteroids, U74006F (3 mg/kg) or U78715G (3 mg/kg). A sham-operated control group was included. Animals from each group were euthanatized at 5 periods of reperfusion: 5 minutes, 30 minutes, 18 hours, 3 days, and 7 days after reperfusion. Fixed tissues were embedded in paraffin, sectioned at 5 μm, and stained with H&E. Villi profiled in cross section were measured from the crypt villus junction to the tip of the villus. The mean villus height for each rat was calculated and compared by two-way anova to determine the effects of time and treatment.
Villus height was maintained after 30 minutes of reperfusion in rats of the sham- and U74006F-treated groups; U78715G and sod treatment attentuated the loss in villus height, and villus height was not maintained in the peg-sod- and 0.9% NaCl-treated rats. In all rats, villus height was comparable to, or was greater than villus height in sham-operated controls by 18 hours after reperfusion in all animals and remained constant through 7 days.
Administration of the 21-aminosteroids maintained villus height after ischemia and reperfusion. Treatment with peg-sod did not maintain villus height to the degree observed in rats treated with sod.
Effect of age on activation of porcine intestinal guanylate cyclase and binding of Escherichia coli heat-stable enterotoxin (STa) to porcine intestinal cells and brush border membranes
Authors: Jaso-Friedmann Liliana , Dreyfus Lawrence A. , Whipp Shannon C. , Robertson Donald C. 
Published: January 2024

Summary
Development of age-dependent resistance to enterotoxigenic Escherichia coli was studied, using isolated enterocytes and brush border membranes (bbm) from 7-day-old and 7-week-old pigs. Binding of 125I-labeled heat-stable (125I-STa) enterotoxin to enterocytes and bbm was specific, temperature- and time-dependent, saturable, and partially reversible. Scatchard analysis revealed a single class of receptors. Mean ± sd avidity of binding (apparent affinity constant, Ka) of 125I-STa to enterocytes from 7-day-old and 7-week-old pigs was 2.14 ± 0.29 × 108 and 2.72 ± 0.25 × 108 L/mol, respectively. Numbers of STa receptors were calcuated to be 64,903 ± 2,900/enterocyte for 7-day-old pigs and 53,029 ± 3,117/enterocyte for 7-week-old pigs. Numbers of STa receptors expressed per milligram of bbm protein from 7-day-old pigs were 2.66 × 1011, compared with 2.29 × 1011 for bbm from 7-week-old pigs. By 5 minutes after addition of STa to reaction mixtures, intracellular cyclic guanosine monophosphate concentration increased 13.9-fold in enterocytes from 7-day-old pigs and 8.7-fold in enterocytes from 7-week-old pigs. The particulate guanylate cyclase activity associated with bbm from 7-week-old pigs was slightly more sensitive to low amounts of STa, compared with bbm from 7-day-old pigs; however, differences were not observed at intermediate and high amounts. These data indicate that lack of a secretory response to STa by older pigs is not attributable either to decreased numbers of STa receptors or to decreased signal response between the STa receptor and membrane-bound guanylate cyclase. Development of age-dependent resistance by porcine small intestine to STa appears to be attributable to steps in the secretory pathway that respond to increased concentration of cyclic guanosine monophosphate.
Effect of treatment with oxytetracycline during the acute stages of experimentally induced equine ehrlichial colitis in ponies
Authors: Palmer J. E. , Benson C. E. , Whitlock R. H. 
Published: January 2024

Summary
Eighteen ponies were inoculated iv with Ehrlichia risticii-infected P388D1 mouse monocyte cells. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 9 ponies were treated with oxytetracycline (6.6 mg/kg of body weight, iv, q 24 h) for 5 days. The remaining 9 ponies served as infected nontreated controls. Mean scores of the following variables were not significantly different between groups on the day treatment was begun: rectal temperature, diarrhea, borborygmal sounds, feed intake, mental attitude, and evidence of a hyperresonant area in the abdomen. All ponies were observed for progression of clinical signs typical of ehrlichial colitis. Within 12 hours of initiation of treatment, only 1 treated pony had a rectal temperature > 38.8 C and most rectal temperatures were < 38.3 C. In contrast, only 2 control ponies had rectal temperatures < 38.8 C (mean rectal temperature values were significantly, P = 0.01, different between groups). In the treatment group, 4 ponies had no signs of depression after the first day of treatment, and only 1 had signs of depression after the second day of treatment (mean scores between groups were significantly different, P = 0.01). Feed intake remained normal in 4 treated ponies and improved in 4 of the remaining 5 after treatment began. Most of the control ponies had a progressive decrease in their feed intake during the observation period (mean scores between groups were significantly, P = 0.01, different). Three ponies in the control group and 2 ponies in the treatment group developed diarrhea before the treatment observation period began. Of the remaining 6 control ponies, 4 developed diarrhea after the treatment observation period began. None of the ponies in the treatment group developed diarrhea after treatment began. A profound decrease in borborygmal sounds, with silent periods lasting longer than 3 minutes, developed in 7 control ponies. Only 2 treatment ponies had borborygmi decreased to this level (mean scores between groups were significantly, P = 0.01, different). Three of 9 control group ponies developed severe disease and were euthanatized. All treatment-group ponies survived. In surviving ponies, clinical signs lasted 8 to 16 days (mean, 11.5) in the control group, but lasted only 1 to 7 days (mean, 4.5) in the treatment group (P = 0.01). Ponies from the treatment group did not develop clinical signs when reinoculated with Ehrlichia risticii at 4 and 8 months after original inoculation.
Effect of xylazine on the arrhythmogenic dose of epinephrine in thiamylal/halothane-anesthetized horses
Authors: Gaynor James S. , Bednarski Richard M. , Muir William W. 
Published: January 2024

Summary
The effect of xylazine on the arrhythmogenic dose of epinephrine (ade) was studied in 9 horses. Anesthesia was induced by administration of guaifenesin (50 mg/kg of body weight, iv) followed by thiamylal (4 to 6 mg/kg, iv) and was maintained at 1 minimal alveolar concentration (mac) of halothane (0.89%). Base apex ecg and facial artery pressure were recorded. Epinephrine was infused in a sequence of arithmetically spaced increasing rates (initial rate 0.25 µg/kg/min) for a maximum of 10 minutes. The ade was defined as the lowest epinephrine infusion rate to the nearest 0.25 µg/kg/min at which at least 4 premature ventricular depolarizations occurred in a 15- second period. Xylazine (1.1 mg/kg, iv) was administered after the control ade was determined. Xylazine did not significantly alter the ade (control, 1.12 ± 0.38 µg/kg/ min; xylazine, 1.21 ± 0.46 µg/kg/min). Blood pressure increased transiently for 8 minutes after xylazine administration. Baseline systolic and diastolic arterial pressures and heart rate were not significantly different from control baseline pressures and heart rate 15 minutes after xylazine administration. Blood pressure and heart rate increased significantly during control and xylazine ade determinations. Significant differences in pH, Pao2, Paco2, or base excess were not observed between baseline and ade in the control or xylazine groups. One horse developed atrial fibrillation, and 2 horses developed ventricular fibrillation during ade determinations.
Changes in erythrocyte deformability in NaCl-induced right-sided cardiac failure in broiler chickens
Authors: Mirsalimi S. M. , O’Brien P. J. , Julian R.J. 
Published: January 2024

Summary
In this study, we tested the hypothesis that erythrocyte deformability is decreased in the development of cardiac failure induced by NaCl toxicosis. Deformability of erythrocytes and routine hematologic and biochemical variables were measured in 6 of 50 chickens that were given 5 g of NaCl/L in their drinking water from day 7 to day 42, and were compared with values in 6 of 50 healthy chickens given free access to tap water. Deformability was assessed by passing a 10% suspension of erythrocytes through a polycarbonate membrane with 5-µm pores. Chickens were euthanatized and heart and body weights were determined.
Treatment with NaCl induced right-sided cardiac failure up to day 28. The ratios of heart weight to body weight were greater, for right ventricle by 20 to 64% and for left ventricle by 15 to 27%, attributable to NaCl treatment. Deformability of erythrocytes of NaCl-treated chickens was markedly decreased, in association with increased erythrocyte size and plasma Na+ concentration. However, only part of the decreased deformability could be explained by swelling of erythrocytes. Decreased deformability could not be explained by increased cell viscosity because mean corpuscular hemoglobin concentration, the primary determinant of erythrocyte viscosity, was decreased. Because decreased deformability of erythrocytes has been demonstrated previously to be associated with increased vascular resistance, decreased deformability may have contributed to the development of right-sided cardiac failure in these chickens.
Effect of sodium hyaluronate in collagenase-induced superficial digital flexor tendinitis in horses
Authors: Foland J. W. , Trotter G. W. , Powers B. E. , Wrigley R. H. , Smith F. W. 
Published: January 2024

Summary
Superficial digital flexor tendinitis was induced in each forelimb of 8 horses by injecting 4,000 U of collagenase into the midmetacarpal region of the tendon. In each horse, each tendon was treated 24 and 96 hours after the collagenase injection with sc injections of sodium hyaluronate (treated limbs) or an equal volume of 0.9% NaCl solution (control limbs). Exercise was restricted for the first 3 weeks of the study, and a controlled exercise program was instituted for the remainder of the study. Horses were evaluated clinically for lameness, tendon swelling, and midmetacarpal limb circumference. Ultrasonographic examinations were performed regularly (11 examinations/horse) throughout the study, and all horses were euthanatized 12 weeks after collagenase injections. Tendons from 4 horses were harvested for biomechanical testing, and samples were obtained from tendons from the remaining 4 horses for biochemical analysis of collagen. Samples were obtained from all tendons for microscopic evaluation. Significant differences between treated and control tendons were not noticed in any of the variables examined in live horses, although trends toward less lameness in treated limbs and toward better healing on ultrasonographic examination in control limbs were recorded. Significant differences were not noticed in biomechanical or biochemical evaluations, and the only significant (P < 0.05) microscopic finding was more severe inflammation in tendons from treated limbs. This study did not reveal significant benefits of treatment with sodium hyaluronate outside a synovial sheath on tendon repair in collagenase-induced tendinitis.