bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebral, renal, adrenal, intestinal, and pancreatic circulation in conscious ponies and during 1.0, 1.5, and 2,0 minimal alveolar concentrations of halothane-02 anesthesia
Authors: Manohar Murli , Goetz Thomas E. 
Published: February 2025

SUMMARY
Blood flow to the brain, kidneys, adrenal glands, pancreas, and small intestine was studied in 8 healthy ponies while awake (control) and during 1.0, 1.5, and 2.0 minimal alveolar concentrations (mac) of anesthesia produced, using halothane vaporized in oxygen. During the anesthesia steps, intermittent positive-pressure ventilation was used to ensure isocapnia. Organ blood flow was determined with 15-μm (diameter) radionuclide-labeled microspheres, after allowing 30 minutes of equilibration at each of the 3 preestablished end-tidal halothane concentrations. The sequence of 1.0, 1.5, and 2.0 mac levels of anesthesia (0.90, 1.35, and 1.80% end-tidal halothane) was randomized for every animal.
In the awake ponies, cerebral blood flow in the cortical (106 ± 15 ml/min/100 g) and deep gray (103 ± 12 ml/min/100 g) matter was approximately 5-fold of that in the white matter (22 ± 3 ml/min/100 g). In the brain stem, there was a decreasing gradient of blood flow from the cranial (thalamohypothalamus; 65 ± 8 ml/min/100 g) to caudal regions (medulla: 34 ± 5 ml/min/100 g).
Vasodilatation occurred in all regions of the brain with halothane-02 anesthesia; the decrease in vascular resistance reached its nadir at 1.5 mac. In the medulla and pons, blood flow increased above control values, with each of the 3 concentrations of halothane, but in the midbrain and thalamohypothalamus, it remained similar to the control value. In the cerebral white matter and cerebellum, blood flow increased with 1.0 and 1.5 mac of halothane anesthesia, whereas mean aortic pressure decreased to 91% and 74% of the control value. Blood flow in the cerebral cortex was not different from the control value, even at 2.0 mac of halothane, despite a 49% reduction in perfusion pressure.
Renal blood flow decreased from its control value (483 ± 79 ml/min/100 g) with each concentration of halothane; at 2.0 mac, renal vascular resistance increased markedly. Marked dilatation occurred in the adrenal gland vasculature during halothane anesthesia, and at 1.0 and 1.5 mac, adrenal blood flow was significantly increased. The pancreatic and small intestinal vasculature exhibited intense vasoconstriction during each level of halothane-O2 anesthesia.
It is concluded that in ponies anesthetized with halothane-O2, vasodilation occurred in the cerebrum, cerebellum, brain stem, and adrenal glands, whereas intense vasoconstriction occurred in the pancreatic and small intestinal vasculature. Renal blood flow decreased in halothane-anesthetized ponies.
Theophylline and dyphylline pharmacokinetics in the horse
Authors: Ayres James W. , Pearson Erwin G. , Riebold Thomas W. , Chang Shyi-Feu 
Published: February 2025

SUMMARY
The pharmacokinetics of theophylline and dyphylline were determined after iv administration in horses. In a preliminary experiment, the usual human dosage (milligram per kilogram) of each drug was given to 1 horse. Results were used to calculate dosages for a cross-over study, using 6 horses for each drug.
Theophylline plasma concentrations decreased triex-ponentially in 5 of 6 healthy horses after iv infusion of 10 mg of aminophylline/kg of body weight for 16 to 32 minutes. In the 6 horses, total body elimination rate constants were variable, and the half-life of theophylline was 9.7 to 19.3 hours. Clearance was 42.3 to 69.2 ml/hr/kg. The initial distribution phase was rapid (t½ approx 3.5 to 4 minutes); a 2nd distribution phase was slower (t½ approx 1.5 to 2 hours). Plasma concentrations of theophylline were in the assumed effective range (10 to 20 (μg/ml) from 15 minutes until 40 minutes after time zero. The mean apparent volume of distribution was 1.02 L/kg.
After bolus iv injection of dyphylline (20 mg/kg), pharmacokinetics were best described by a 2-compartment open model in 2 horses and by a 3-compartment open model in 4 horses, In the 6 horses, elimination half-life of dyphylline was 1.9 to 2.9 hours, and clearance was 200 to 320 ml/hr/kg. Plasma concentrations (approx 50 μg/ml) were observed at 10 minutes after injection without adverse effects. Concentrations > 10 μg/ml were observed from time zero to about 1.5 hours after injection.
Theophylline induced significant increases in heart rate, but dyphylline did not affect heart rate significantly. Systolic, diastolic, and mean arterial blood pressures were decreased by theophylline and by dyphylline, with theophylline generally inducing greater decreases than did dyphylline. Neither drug had a significant effect on arterial oxygen tension, carbon dioxide tension, or bicarbonate in the horses evaluated.
Use of oxibendazole for control of cambendazole-resistant small strongyles in a band of ponies: A six-year study
Authors: Drudge J. H. , Lyons E. T. , Tolliver S. C. , Swerczek T. W. 
Published: February 2025

SUMMARY
Oxibendazole (obz; 10 mg/kg of body weight) was administered to ponies at 8-week intervals to control strongylosis in a breeding band of Shetland-type ponies (n = 29 to 50) from October 1978 through September 1984. A similar use of cambendazole (cbz; 20 mg/kg of body weight) in this band of ponies during the preceding 4-year period resulted in the survival of a cbz-resistant population (S) of small strongyles. Effectiveness of obz treatments was monitored by pre- and posttreatment counts of the number of strongyle eggs per gram of feces (epg) and of the number of strongyle larvae per gram of feces (lpg). For the First 4 years of the 6-year period, epg and lpg counts were determined for 3 to 5 of the obz treatments; during the last 2 years, counts were determined for each treatment. For the 1st year, the mean reduction in epg was 96%. During the 2nd and 3rd years, mean reductions in epg were 80% and 81%, respectively. For the 4th and 5th years, mean reductions in epg were 69% and 43%, respectively. For the 6th year, the mean reduction in epg was 37%. Statistical analyses of the epg data, using the linear plateau method, indicated a significant increase in residual (surviving) strongyle infections after the periodic obz treatments, with a mean annual increase in survival of 10.3% for the 6 years. Changes in lpg were variable, but an overall loss of effectiveness of the obz treatments was evident. Only infective larvae of small strongyles were observed in the cultures; larvae of 2 species of large strongyles, Strongylus vulgaris and Strongylus edentatus, were conspicuously absent. Dynamics of the process of resistance selection by obz was gradual and in a stair-step fashion. A mean appreciable activity of 40% was retained for the 5th and 6th years; in the previous 4-year period in which cbz was used, strongyle activity of cbz rapidly decreased during the 2nd year and was nearly inactive during the 3rd and 4th years. This ineffectiveness of cbz persisted after a hiatus of nearly 3 years of obz use, when cbz was evaluated once again in the present, study.
Foaling rates in the brood mares were 32% to 58% during the 5 seasons evaluated. Four abnormal foals were born, 1 each in 1980, 1982, 1983, and 1984. These deformities were categorized as genetic in origin, in contrast with the teratologic-type deformities previously associated with the use of cbz in this band.
Experimental infection of pregnant and lactating goats with Leptospira interrogans serovars hardjo and szwajizak
Authors: Tripathy D. N. , Hanson L. E. , Bedoya M. , Mansfield M. E. 
Published: February 2025

SUMMARY
Pathogenesis of 2 Leptospira serovars, hardjo and szwajizak, was studied in pregnant and lactating goats. Although clinical signs of leptospiral infection were minimal, cultural isolations were made from the mammary gland of 2 goats and the kidney of 1 goat inoculated with serovar hardjo (C846). The isolations were made only on solid bovine albumin polysorbate-80 medium supplemented either with rabbit serum or sodium pyruvate.
Cultural isolations of serovar szwajizak were made from kidney, liver, brain, urine, and mammary gland samples of 1 goat and the liver and kidney samples of its kids. These isolations were made in only the solid bovine albumin polysorbate-80 medium which had been supplemented with normal goat serum.
Pharmacokinetics of gentamicin in channel catfish (Ictalurus punctatus)
Authors: Setser Mark D. 
Published: February 2025

SUMMARY
The pharmacokinetics of gentamicin were determined in male and female Ictalurus punctatus weighing between 0.3 kg and 1.7 kg. Plasma gentamicin concentrations were measured by radioimmunoassay technique.
In the 1st experiment, an intracardiac bolus dosage of gentamicin (1 mg/kg) was given to 10 channel catfish. Samples of blood were obtained (by cardiac puncture) immediately before gentamicin was given and at various times over a 24-hour period. The gentamicin half-life was 770 minutes (β = 0.0009 ± 0.0003 minute−1). The maintenance therapeutic IV dosage of gentamicin was calculated to be 1.6 mg/kg given at 33.2-hour intervals.
In the 2nd experiment, an im dosage of the drug (1 mg/kg) was given to 9 channel catfish, and samples of blood were obtained at various times over a 24-hour period. The gentamicin half-life was 770 minutes (β = 0.0009 ± 0.0002 minutes−1). The maintenance therapeutic IM dosage of gentamicin was calculated to be 3.5 mg/kg given at 33.2-hour intervals. The IM bioavailability of gentamicin in channel catfish was estimated to be 60%. Other pharmacokinetic values were also determined.
It was concluded that the therapeutic regimen of choice for gentamicin in channel catfish was 3.5 mg/kg given im with 33-hour intervals between doses.
Glucose intolerance in cats given short-term therapies of prednisolone and megestrol acetate
Authors: Middleton Deborah J. , Watson A. D. J. 
Published: February 2025

SUMMARY
Six cats were each given prednisolone (2 mg/kg of body weight/day) and megestrol acetate (5 mg/cat/day) on separate occasions for 8 days. The drugs induced similar increases in fasting blood glucose concentrations and decreases in glucose excretion rates in the cats. Usually, each cat developed reduced tolerance of an iv glucose load; concomitant fasting hyperglycemia occurred in 3 cats after prednisolone therapy, and in 1 of these 3 cats after megestrol acetate.
Identification of feline monocytes and neutrophils as effector cells in antibody-dependent cellular cytotoxicity: Sequential analysis, using light microscopy, histochemistry, and scanning electron microscopy
Authors: Kooistra L. , Splitter G. A. , Albrecht R. M. 
Published: February 2025

SUMMARY
Feline monocytes and neutrophils functioned as effector cells in antibody-dependent cellular cytotoxicity (adcc) against antibody-coated chicken erythrocytes. Using light microscopy, effector cell populations were identified in effector-target cell interactions, with further characterization of these identical individual effector cells by histochemical evaluations and scanning electron microscopy. Monocytes and neutrophils, but not lymphocytes, were observed attacking target cells. Carbonyl iron depletion of monocytes and neutrophils from peripheral blood leukocytes caused a marked reduction from a mean of 62% to 3.6% lysis in adcc as measured by a 4-hour 51Cr release assay. Effector cells functioning in the adcc reaction were visualized, using sequential analysis and light microscopy, histochemistry, and scanning electron microscopy.
Pasteurella haemolytica leukotoxin: Comparison of 51chromium-release, trypan blue dye exclusion, and luminol-dependent chemiluminescence-inhibition assays for sensitivity in detecting leukotoxin activity
Authors: Chang Yung-Fu , Renshaw Harland W. 
Published: February 2025

SUMMARY
Dilutions of concentrated, dialyzed Pasteurella haemolytica culture supernatant were caused to react with bovine neutrophil (pmn) suspensions, and then the trypan blue dye exclusion (tbde), 51chromium (51Cr)-release, and luminol-dependent chemiluminescence-inhibition (ldcll) assays were done to compare their relative sensitivities in detecting biological activity of Ρ haemolytica leukotoxin (cytotoxin). The culture supernatant was concentrated approximately 200:1, and when caused to react as an undiluted preparation with bovine pmn, it was cytotoxic for 38.6% and 80.4% of pmn as determined by tbde and 51Cr-release assays, respectively. This undiluted leukotoxin preparation caused 100% inhibition of the luminol-dependent chemiluminescence responses of bovine pmn. The LDCLl assay was the most sensitive of the 3 in vitro assays for Ρ haemolytica leukotoxin activity—being approximately 17 times and 2,480 times more sensitive than the 51Cr-release and tbde assays, respectively.
The relative advantages and disadvantages of the 3 assays as in vitro systems for detecting and titrating leukotoxin activity and investigating the role of leukotoxin in disease pathogenesis and immunity are discussed. Because of its sensitivity, specificity, economy, technical ease, and potential for adaptation to automation, the LDCLl assay would seem to be the in vitro assay of choice for quantitating Ρ haemolytica leukotoxin activity. To aid standardization of studies of leukotoxin between different laboratories, it is suggested that Ρ haemolytica leukotoxin activity be quantitated and expressed as chemiluminescence inhibitory units. It is proposed that 1 chemiluminescence inhibitory unit be defined as that amount of Ρ haemolytica leukotoxin activity capable of totally abrogating, in a 20-minute incubation period, the luminol-dependent chemiluminescence response of 1 × 106 bovine pmn incubated with heat-killed Ρ haemolytica in the presence of heat-inactivated bovine fetal serum saturated with luminol. The methods for conducting the LDCLl assay are described.
Effects of thyrotropin-releasing hormone on serum concentrations of thyroxine and triiodothyronine in healthy, thyroidectomized, thyroxine-treated, and propylthiouracil-treated dogs
Authors: Li W. I. , Chen C. L. , Tiller A. A. , Kunkle G. A. 
Published: February 2025

SUMMARY
Effects of thyrotropin-releasing hormone (trh) on serum concentrations of thyroid hormones were studied in 36 mixed-bred dogs. Dogs were randomly assigned to 7 groups. Significant increases (P < 0.05) of serum thyroxine (T4) values occurred as early as 2 hours and reached a peak at 6 to 8 hours after iv injection of 300 to 1,100 μg of trh. Thyroxine concentrations in response to a trh dose > 500 μg were similar to those observed with the 300-μg dose. Transient coughing, vomiting, salivation, and defecation after large doses (900 and 1,100 μg) were observed.
Mean serum T4 concentration decreased from 2.1 μg/dl to 0.9 μg/dl within 1 day of thyroidectomy. Clinical signs of hypothyroidism, including lethargy, dry coats, and diffuse alopecia, were present in 2 dogs at a month after surgical operation. Thyroxine concentrations were detectable for > 2 months. Injection (iv) of 700 μg of trh 6 weeks after surgical operation had no effect on serum concentration of T4 in thyroidectomized dogs.
In 5 T4-treated dogs, trh (700 μg, iv) significantly increased the serum T4 value, indicating that pituitary thyrotropes were responsive to trh, in spite of daily medication of 0.8 mg of T4.
Four dogs were treated orally with 200 mg of propylthiouracil/day for 5 weeks. Intravenous injection of 700 μg of trh in propylthiouracil-treated dogs had no effect on the serum T4 concentration, indicating that trh had no effect on serum T4 values in these dogs during the experimental period.
These results indicate that trh can replace bovine thyrotropin for the canine thyroid function test. The recommended dosage is 300 to 500 μg. The best time to obtain blood samples is 6 to 8 hours after iv injection. Thyroxine should be used as the indicator of thyroid function, since there is lack of adequate release of triiodothyronine in response to the recommended trh dosage used.
Evaluation of the myoelectrical activity of the equine ileum infected with Strongylus vulgaris larvae
Authors: Berry C. R. , Merritt A. M. , Burrows Colin F. , Campbell Martha , Drudge J. H. 
Published: February 2025

SUMMARY
Five weanling ponies were subjected to an intensive 6-Week deworming program after which 4 Ag-AgCl bipolar electrodes were implanted surgically on the distal ileum. For 3 hours each day for 5 consecutive days, ileal myoelectrical activity was recorded from fed ponies under 3 sequential conditions: preinoculation, after oral administration of 1,000 killed Strongylus vulgaris infective larvae (3 ponies), and after oral administration of 1,000 live S vulgaris infective larvae. Recordings were analyzed for slow wave frequency, percentage duration of phases I, II, and III of the migrating myoelectrical complex (mmc), and the frequency of distinct, rapidly migrating action-potential complexes within phase 2 of the mmc.
After administration of live and killed infected 3rd-stage larvae, there was a marked increase in the number of disrupted phase ΙΠ complexes, and a significant (P < 0.001) increase in the number of migrating action-potential complexes. In addition, after inoculation of live 3rd-stage larvae, there was a significant increase (P < 0.001) in the percentage of time that the mmc was occupied by prolonged periods devoid of spike activity (phase I).
The results indicate that S vulgaris larval mucosal penetration and submucosal migration can cause changes in ileal myoelectrical activity that could cause colic, and that larval antigen alone within the lumen may disrupt ileal motility.
Fimbriae and enterotoxins associated with Escherichia coli serogroups isolated from pigs with colibacillosis
Authors: Wilson R. A. , Francis D. H. 
Published: February 2025

SUMMARY
A comprehensive study of 223 Escherichia coli isolates from pigs with colibacillosis included determination of O serogroups, detection of heat-labile enterotoxin, heat-stable enterotoxin (STa and STb), and identification of K88, K99, 987-P, F-41, and type 1 fimbriae.
The incidence of the various E coli types among isolates of pigs of different ages was also determined. Escherichia coli bearing K88 fimbriae accounted for 48% of all isolates studied, were most often of serogroup 0157, 0149, or 08, and usually produced labile toxin alone or in combination with STa or STb. These E coli were commonly isolated from pigs in each age group studied (0 to 5 days, 6 to 10 days, 11 to 24 days, and > 24 days). Escherichia coli bearing 987-P accounted for 30% of the isolates, were most often of serogroup 0141 or 020, and usually produced STa. Escherichia coli bearing K99 accounted for 13% of the isolates, usually were of serogroup 0101 or 08, and almost always produced STa. Escherichia coli bearing 987-P or K99 were most often isolated from pigs < 6 days of age. Fimbriae F-41, when identified, were usually on E coli of serotype 0101:K99. Although infrequently found, type 1 fimbriae were on E coli of most of the serogroups identified in this study.
Experimentally induced infectious bovine rhinotracheitis virus infection during early pregnancy: Effect on the bovine corpus luteum and conceptus
Authors: Miller J. M. , Van Der Maaten M. J. 
Published: February 2025

SUMMARY
Pairs of heifers were inoculated iv with infectious bovine rhinotracheitis virus on postbreeding days (pbd) 7, 14, 21, or 28, and were euthanatized 13 to 15 days after inoculation. Reproductive tracts were examined for cytopathologic changes (light microscopy), virus (cell culture), and viral antigen (immunohistochemical evaluation).
Heifers inoculated on pbd 7 or 14 had mild oophoritis characterized by foci of necrosis and mononuclear cell accumulations in the corpus luteum. Most of these heifers also had a few necrotic follicles in at least one ovary. Heifers inoculated on pbd 21 or 28 did not have corpus luteum lesions, but necrotic follicles were numerous in both ovaries. Viral antigen was observed in all ovarian lesions, and infectious virus was isolated from a few of the affected tissues.
The uteri of all heifers inoculated on pbd 21 or 28 and 1 heifer inoculated on pbd 7 contained normal-appearing concepti. The uterus of the other pbd 7 heifer contained a degenerating conceptus that was infected with infectious bovine rhinotracheitis virus, as determined by viral isolation, immunohistochemical evaluation, and electron microscopy. Heifers inoculated on pbd 14 were not pregnant at necropsy, but histologic evidence was found that the postbreeding estrous cycle had been longer than normal, indicating that early embryonic death had occurred.
Campylobacter-like organisms isolated from gastric mucosa of ferrets
Authors: Fox J. G. , Edrise B. M. , Cabot E. B. , Beaucage C. , Murphy J. C. , Prostak K. S. 
Published: February 2025

SUMMARY
Campylobacter-like organisms (clo) were isolated from gastric lesions in 1 ferret and gastric mucosa of 2 healthy ferrets. The organism was not isolated from biopsies of gastric mucosa of 14 other healthy ferrets, 1 of which had small gastric lesions located at the pylorus. Lesions from which clo were isolated were located in the antrum of 1 ferret and were classified as inflammation with repair. Affected gastric tissue was highly vascularized with fibrous connective tissue surrounding irregularly shaped glands. Necrosis and ulceration of adjacent mucosa also were observed. Using Warthin-Starry stain, Campylobacter-like organisms were seen on and in the glandular epithelium of the ferret with gastric lesions from which clo were isolated.
Canine atrioventricular node: Scanning electron microscopy and enzyme histochemistry
Authors: Sandusky George E. , White Sandy L. , Wightman Karen A. 
Published: February 2025

SUMMARY
Morphologic features of the canine atrioventricular (av) node were evaluated, using histochemical cholinesterase reactions and scanning electron microscopy. Three distinct regions of the av node were observed: the transitional zone, superficial av node, and deep av node. The transitional zone lacked distinct cellular arrangement, and the cells were large and round with extensive branching on the ends. Superficial av nodal cells were elongated, tightly packed, and smaller than were transitional cells. The superficial av node was the densest zone of the av node. Cell-to-cell contact was end-to-end. Deep av nodal cells were long, formed laminated fascicles, were larger than the superficial av nodal cells, and were continuous with the av bundle.
Cross-sectional area of the aditus laryngis and rima glottidis before and after transection of the left recurrent laryngeal nerve in the horse
Authors: Martin G. S. , Beadle R. E. , Haynes P. F. , Watters J. W. 
Published: February 2025

SUMMARY
The ventral-to-dorsal height of the rima glottidis was measured from lateral pharyngeal radiographs after correction for magnification. The rima glottidis height was used to enlarge accurately endoscopic photographs of 5 horses taken before and after transection of the left recurrent laryngeal nerve. Areas of the rima glottidis and aditus laryngis were measured, using a computerized digitizer. Mean area of the aditus laryngis was 1,908 mm2 before neurectomy and 1,346 mm2 after neurectomy (P = 0.025). Mean area of the rima glottidis was 1,198 mm2 before neurectomy and 805 mm2 after neurectomy (P = 0.025). Mean width of the rima glottidis was 31 mm before neurectomy and 20 mm after neurectomy (P = 0.001). Significant differences were not found between the pre- and postneurectomy heights of the rima glottidis.