bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytologic responses of Staphylococcus aureus-infected mammary glands of heifers to interferon gamma and interleukin-2 treatment
Authors: Quiroga German H. , Sordillo Lorraine M. , Adkinson R. Wayne , Nickerson Stephen C. 
Published: January 2024

Summary
Cytologic and bacteriologic responses, and changes in cytokine activity were evaluated in secretions of Staphylococcus aureus-infected mammary glands after treatment of heifers with recombinant bovine interferon gamma (rbIFNγ) or interleukin 2 (rbIL-2). Two groups of 4 heifers each, experimentally infected with 107 colony-forming units (cfu) of S aureus, were injected in 2 quarters via the teat canal, with 105 U of rbIFNγ (trial 1) or 7.5 × 105 U of rbIL-2 (trial 2) 2 weeks after experimentally induced infection; control quarters received phosphate-buffered saline solution. Mammary secretion samples were taken on days 0, 1, 2, 3, 4, 7, and 14 after cytokine infusion. Secretions were diluted 1:10 and used to perform somatic cell counts (scc), differential cell counts, and cfu enumerations, and to determine the number of leukocytes expressing major histocompatibility complex class-II (mhc II) antigens. In addition, mammary secretion samples taken on days 0, 1, and 2 were processed to obtain skimmed milk for evaluation of rbIFNγ- and rbIL-2-like activities. Treatment with rbIFNγ did not influence scc, or differential or bacteria counts, or the number of leukocytes expressing mhc II antigens. However, rbIL-2 stimulated leukocytosis, which may have reduced bacteria counts early in the trial; treatment with this cytokine also increased the neutrophil, macrophage, lymphocyte, and eosinophil counts in secretions. Similarly, numbers of mhc II-positive leukocytes were greater in rbIL-2-treated quarters vs controls. Compared with day 0, IFNγ-like activity was increased on only day 1 in both trials. Interleukin-2-like activity was not influenced in the rbIFNγ trial, but was increased on days 1 and 2 in the rbIL-2 trials. Results indicated that neither cytokine may have had a major influence on the course of established S aureus infections. However, the increased scc in rbIL-2-treated quarters may have accounted for the reduction in cfu throughout the trial after treatment with this cytokine. Greatest cytokine-like activity was observed on day 1; however, the consequences of cytokine activity, such as the sustained eosinophilia after rbIL-2 treatment, were detected over the 14-day trial period, indicating possible prolonged action.
Effects of ephedrine on cardiovascular function and oxygen delivery in isoflurane-anesthetized dogs
Authors: Wagner Ann E. , Dunlop Colin I. , Chapman Phillip L. 
Published: January 2024

Summary
The hemodynamic effects of 2 dosages of ephedrine were studied in 6 dogs anesthetized with isoflurane only (end-tidal concentration equivalent to 1.5 times minimum alveolar concentration). Following instrumentation, baseline (time 0) measurements included heart rate (hr), respiratory rate, mean arterial blood pressure (map), cardiac output, and blood gas tensions. Cardiac index (ci), stroke volume (sv), systemic vascular resistance (svr), arterial oxygen content (Cao2), and oxygen delivery and consumption (Do2 and Vo2, respectively) were calculated. Three dogs were given ephedrine iv at a dosage of 0.1 mg/kg of body weight, and 3 dogs were given ephedrine iv at a dosage of 0.25 mg/kg. Measurements were recorded at 5, 10, 15, 30, and 60 minutes. Each dog then received the alternate dosage of ephedrine, and measurements were again recorded at the same intervals. Effects of ephedrine varied with dosage. Neither dosage was associated with significant changes in pH, Pao2, Paco2, Vo2, or respiratory rate. Ephedrine at a dosage of 0.1 mg/kg caused transient significant increases in map, ci, sv, Cao2, and Do2, significant decreases in hr and svr, and a late, slight decrease in Cao2. Ephedrine at a dosage of 0.25 mg/kg caused a greater and more prolonged increase in map, as well as increases in ci, sv, and svr, and a decrease in hr. The higher dosage of ephedrine also caused a pronounced increase in hemoglobin concentration and CaO2, resulting in a 20 to 35% increase in Do2 throughout the 60-minute experiment.
Lymphocyte proliferative responses in neonatal pigs with high or low plasma cortisol concentration after stress induced by restraint
Authors: Brown-Borg H. M. , Klemcke H. G. , Blecha F. 
Published: January 2024

Summary
High plasma cortisol concentration is associated with perception of stress and reduced immune function in pigs. Neonatal pigs (12, 19, or 26 days old) were tested to determine maximal cortisol response to a mild restraint stressor. Pigs were fitted with indwelling jugular cannulas 4 days prior to restraint. One day before restraint, 10 ml of blood was removed for lymphocyte isolation and subsequent in vitro lymphocyte proliferation and interleukin 2 (il-2) assays. On the day of restraint, blood samples were drawn 10 minutes before and 3, 10, and 20 minutes after holding each pig in a supine position for 1 minute. Plasma cortisol concentration was determined by use of radioimmunoassay. Pigs with maximal cortisol response greater than the mean value for that age group were classified in the high-responder (hires) group. Conversely, those with values lower than the mean maximal response were assigned to the low-responder (lores) group. The HIRES pigs had larger relative adrenal gland weights and higher baseline and maximal cortisol responses, compared with lores pigs (P = 0.0170, P = 0.0002, P = 0.0001, respectively). Mitogen-induced lymphocyte proliferative responses (to phytohemagglutinin, concanavalin A, and pokeweed mitogen) were 60% lower (P = 0.0037, P = 0.0432, P = 0.0103, respectively) in hires vs lores pigs. In vitro il-2 production did not differ between hires and lores pigs. Lymphocyte proliferation induced by the B-cell mitogen, pokeweed mitogen, decreased 56% with age (P = 0.0151). Production of il-2 was numerically decreased (P = 0.06) by 50% in 26-day-old pigs, compared with earlier ages. These results indicate that neonatal pigs with low cortisol response to stress may have an advantage, from an immunologic standpoint, over pigs prone to stress.
Pharmacokinetics of L-thyroxine after its oral administration in dogs
Authors: Nachreiner R. F. , Refsal K. R. , Ravis W. R. , Hauptman J. , Rosser E. J. , Pedersoli W. M. 
Published: January 2024

Summary
Twelve mature (5 sexually intact males, 4 castrated males, and 3 females) mixed-breed dogs were surgically thyroidectomized and used in a Latin-square design pharmacokinetic study of orally administered l-thyroxine. The dogs were treated with 44, 22, and 11 μg of l-thyroxine/kg as a single morning dose or in divided doses, morning and evening. Serum concentration of thyroxine (T4) was evaluated to determine a number of pharmacokinetic variables for comparison. Mean steady-state concentrations (Css) were determined from the area under the curve. Variables were analyzed for comparisons between dosages by use of anova.
Concentration at steady state was highest for dogs of the 44-μg/kg of body weight once-daily group and was lowest for dogs of the group given 11 μg/kg in 2 daily doses. Single daily administration resulted in higher Css, except at the 22-μg/kg/d dosage. Clearance was faster for the 22- and 44-μg/kg/d dosages than for the 11-μg/kg/d dosage. The half-life (t1/2) and mean residence time (mrt) also were shorter for the 44-μg/kg/d dosage, possibly indicating more rapid elimination of the drug at higher doses and dose-dependent kinetics. Perhaps, as the dogs’ metabolism increased with higher iodothyronine concentrations, hormone degradation was accelerated. Interval (divided vs single dose) caused some expected changes: maximal concentration was higher and minimal concentration was lower when single administration was used. These undulations resulted in iodothyronine concentrations above the physiologic range for a number of hours, whereas concentration closer to physiologic ranges was achieved by use of divided doses. Delayed absorption (lag time) was seen in 37 of the 72 data sets, but was generally short, about 0.25 hour. Mean time to maximal concentration was 3 to 4 hours. At the higher dosages, serum total T4 concentration was high normal or above normal during most of the time after l-thyroxine administration, but serum concentration of total 3,5,3′-triiodothyronine did not remain within the normal range until the 44-μg/kg/d dosage was used. The customary dosage of 22 μg/kg/d (0.1 mg/10 lb/d) may not be adequate for most dogs. Pharmacokinetic variables appear to be highly dependent on the individual dog. Those with rapid absorption and higher concentration tended to have these characteristics at each dosage in this study. The pharmacokinetic variables, therefore, appear to be highly individualized, and dosages recommended for treatment of hypothyroidism should be considered to be only a starting point for the average dog. To avoid underdosing or overdosing, monitoring of treatment to adjust dose for individual dog kinetic variables seems to be imperative.
Effects of the 21-aminosteroid U-74389G on ischemia and reperfusion injury of the ascending colon in horses
Authors: Vatistas Nicholas J. , Snyder Jack R. , Hildebrand Susan V. , Harmon Faye A. , Woliner Michael J. , Henry Pegeen , Enos L. Reed , Magliano David , Brown Scott Anthony , Drake Christiana 
Published: January 2024

Summary
Sixteen horses were allotted at random to 3 groups: vehicle only; low dosage (vehicle and 3 mg of U-74389G/kg of body weight); high dosage (vehicle and 10 mg of U-74389G/kg). These solutions were given prior to reperfusion. The ascending colon was subjected to 2 hours of ischemia followed by 2 hours of reperfusion. Before, during, and after ischemia, full-thickness colonic tissue biopsy specimens were obtained for measurement of malondealdehyde (mda) concentration and myeloperoxidase activity and for morphologic evaluation.
Although increases were not significant, mda concentration and myeloperoxidase activity increased during ischemia and reperfusion. Administration of U-74389G did not have significant effects on mda concentration and myeloperoxidase activity. However, the lower dosage tended (P = 0.08) to reduce myeloperoxidase activity at 30 and 60 minutes of reperfusion.
In horses of the vehicle-only group, ischemia induced a decrease in mucosal surface area that was continued into the reperfusion period (P ≤ 0.05). Administration of U-74389G at both dosages (3 and 10 mg/kg) prevented the reperfusion-induced reduction in mucosal surface area, which was significant at 60 minutes (high dosage; P = 0.05) and 90 minutes (low and high dosages; P = 0.02). After initial reduction in horses of all groups, mucosal volume increased for the initial 60 minutes of reperfusion.
Our results indicate that lipid peroxidation may be partially involved in continued cellular death after ischemia of the ascending colon of horses. The 21-aminosteroid, U-74389G, prevented further loss of mucosa and partially attenuated the induced increase in myeloperoxidase activity during reperfusion of the ascending colon.
Effect of cryoprecipitate and plasma on plasma von Willebrand factor multimeters and bleeding time in Doberman Pinschers with type-I von Willebrand's disease
Authors: Ching Yvonne N. L. H. , Meyers Kenneth M. , Brassard Jaqueline A. , Wardrop K. Jane 
Published: January 2024

Summary
We determined whether administration of cry-oprecipitate or fresh-frozen plasma (ffp) would enhance glass bead platelet retention and shorten the bleeding time in von Willebrand factor (vWf)-deficient Doberman Pinschers. Plasma concentration of vWf was <15% of the reference value in these dogs and, on the basis of multimeric analysis of vWf, these dogs had type-I von Willebrand's disease (vWd). Concentration of vWf in cryoprecipitate (prepared from ffp of clinically normal dogs) was enriched almost 20 times, and the preparation was a concentrate of the largest and most physiologically active multimers. Administration of a dose of cryoprecipitate calculated to increase plasma vWf concentration of recipient dogs to 50 U/dl increased plasma vWf concentration in recipient dogs to about 40 U/dl. Mean buccal mucosal bleeding time (bmbt) shortened from 6.7 minutes before treatment to 3.8 minutes at 2 hours after treatment. Cryoprecipitate from donor dogs treated with deamino-8-d-arginine vasopressin (1 μg/ kg of body weight) effectively shortened mean bmbt from 6.4 minutes to 3.1 minutes. Administration of cryoprecipitate from vWf-deficient dogs prolonged, rather than shortened, the bmbt. After ffp (450 ml) infusion, plasma vWf concentration increased in recipient dogs, but the bmbt did not shorten. Glass bead platelet retention did not change after administration of cryoprecipitate or ffp. Thus, cryoprecipitate, especially from deamino-8-d-arginine vasopressin-treated donor dogs, is a concentrate of the most hemostatically active multimers of vWf and decreases the bmbt in dogs with vWd.
Secretagogue-induced [14C]aminopyrine uptake in isolated equine parietal cells
Authors: Campbell-Thompson Martha 
Published: January 2024

Summary
Equine oxyntic mucosal cells were obtained by sequential exposure to pronase and collagenase. Acid production by parietal cells was assessed by uptake of [14C]aminopyrine (ap), a weak base that accumulates in intracellular acidic spaces. Incubation for various times revealed a maximal ap uptake at 10 minutes for histamine and carbachol. Similar secretagogue responses were observed for parietal cells from the mucosal cell preparation or after enrichment by elutriation. Histamine and isobutyl-methylxanthine (ibmx) stimulated AP uptake with a dose-dependent response and maximal effective concentration of 100 μM. Carbachol, 1 to 100 μM, and pentagastrin (pg), 1 to 1,000 μM, were ineffective stimulants of ap uptake. The ap uptake values for 100 μM ibmx, 1 μM carbachol, or 100 nM pg were 77 ± 6%, 50 ± 3-2%, and 40 ± 4.5%, respectively, of that observed with maximal stimulation by 100 μM histamine (mean ± sem, n = 4 to 14). Uptake of ap by nonstimulated control cells was 36 ± 3.6% of maximal histamine stimulation. The ap accumulations during control conditions and after stimulation with 100 μM histamine and IBMX, 1 μM carbachol, or 100 nM pg were 1.18 ± 0.39, 2.81 ± 0.85, 1.93 ± 0.48, 1.44 ± 0.36, and 1.23 ± 0.33 pmol of ap/105 parietal cells, respectively. Individual histamine dose-response curves were shifted to the right by increasing ranitidine and cimetidine concentrations (0.1 to 50 μM). These results indicate that isolated equine parietal cells are maximally stimulated by histamine and minimally stimulated by carbachol and pg.
Effect of interleukin 1 on articular cartilage from young and aged horses and comparison with metabolism of osteoarthritic cartilage
Authors: Morris Elisabeth A. , Treadwell Benjamin V. 
Published: January 2024

Summary
The effect of interleukin 1 (il-1) on equine articular cartilage was investigated, using a cartilage explant culture system. Measurement of [35S]O4 incorporation revealed synthesis of matrix proteoglycan by cartilage to be decreased 45, 59.7, and 37.5% after 1, 3, and 5 days, respectively, in culture in the presence of 5 U of il-1/ml. There was no change in proteoglycan degradation as determined by measurement of [35S]O4 release into the culture medium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cartilage-conditioned medium indicated that exposure of cartilage to il-1 caused a decrease in total protein synthesis by 45, 68, and 87% after 1, 3, and 5 days, respectively, in culture while selectively inducing synthesis of the 57-kd neutral metalloproteinase stromelysin (matrix metallo-proteinase-3) in young and adult horses. Identification of stromelysin was confirmed by functional characterization and immunoprecipitation. Baseline total protein synthesis, as well as specific synthesis of stromelysin in cartilage from adult and aged horses, was markedly less than that of young horses. The il-1- induced reduction in total protein synthesis may not be a characteristic of equine articular cartilage from affected joints of horses with naturally acquired osteoarthritis as indicated by an overall increase in protein synthesis by osteoarthritic explants.
Introduction of il-1 into an equine articular cartilage explant culture system resulted in decrease of matrix component synthesis and increase in specific degradative enzyme synthesis and activity. Articular cartilage from aged horses had markedly less overall metabolic activity, compared with cartilage from young horses. Articular cartilage from affected joints of horses with naturally acquired osteoarthritis did not have metabolic alterations identical to those of il-1-stimulated normal articular cartilage from the same individual, necessitating reevaluation of the validity of the il-1-induced model of osteoarthritis. Osteoar thritis is a common, naturally acquired disease of horses, and tissue from animals of all ages and stages of osteoarthritis is available. The equine model of osteoarthritis may afford an important means of studying the alterations in articular cartilage metabolism as a function of age and disease severity.
Responses of the skin over the dorsum to sunlight in hairless descendants of Mexican hairless dogs
Authors: Kimura Tohru , Doi Kunio 
Published: January 2024

Summary
Responses of the skin over the dorsum to solar uv irradiation (2 hours/d for 6 consecutive days) were investigated in hairless descendants of Mexican hairless dogs. Assessment of skin color changes, using a spectrophotometer, indicated that luminance values began to decrease from the third day of uv irradiation, reached the minimal value at 3 weeks, and almost recovered 12 weeks after completion of uv irradiation. The number of the dihydroxyphenylalanine-positive melanocytes increased significantly (P < 0.01) from the third day of uv irradiation, reached its maximal value at 2 weeks, and recovered to normal at 12 weeks after completion of uv irradiation. On the second day of uv irradiation, the epidermis became focally thick, with disarrangement of component cells that had degenerative changes. In addition, a few so-called sunburn cells with pyknotic nuclei were seen in the epidermis. On the third day of uv irradiation, apparent suntan reaction developed, and a large number of epithelial cells in the epidermis were heavily pigmented with melanin granules. At 12 weeks after completion of uv irradiation, the epidermis appeared almost normal. On the other hand, significant changes were not detected in the dermis throughout the study.
Efficacy of injectable abamectin against gastrointestinal tract nematodes and lungworms of cattle
Authors: Kaplan R. M. , Courtney C. H. , Kunkle W. E. , Zeng Q. Y. , Jernigan A. D. , Eagleson J. S. 
Published: January 2024

Summary
Efficacy of abamectin against gastrointestinal tract nematodes and lungworms of cattle was determined in 4 experiments. The first 2 experiments were controlled trials in which efficacy was determined at necropsy in calves with either experimentally induced (n = 14) or naturally acquired (n = 16) infections. Half the calves in each experiment were treated with abamectin (200 μg/kg of body weight, sc), and half were left untreated as controls. Efficacy was > 99% against adult stages of Dictyocaulus viviparus, Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, Cooperia punctata, Trichuris discolor, and C oncophora, and was 92.4% against Nematodirus helvetianus. The second 2 experiments were clinical trials in which efficacy was determined by fecal egg count reduction in naturally infected yearling heifers (n = 75) or 2-year-old heifers (n = 75). Within replicates of 5, 4 heifers were assigned at random to treatment with 200 μg of abamectin/kg and 1 was left untreated as a control. Abamectin was 100% effective in eliminating strongylate nematode eggs from the feces of these heifers. In all experiments, adverse reactions were limited to small, clinically unimportant injection site swellings in 29% of abamectin treated calves. Abamectin was judged to be safe and effective in these trials.
Effects of zeranol implanted during a postweaning weight gain test on testicular, semen, and endocrine characteristics of bulls
Authors: Floyd James G. , Ott Randall S. , Hixon James E. , Veeramachaneni D. N. Rao , Willms Clifton L. , Parrett Douglas F. 
Published: January 2024

Summary
At initiation of a 140-day postweaning weight gain test, Angus bulls were assigned in equal numbers (n = 5) to 1 of 3 treatment groups to determine effects of implantation with zeranol, an estrogenic growth promotant, on selected reproductive characteristics. The bulls, whose age (mean ± sd) was 233 ± 20 days at initiation of the test (day 0), were implanted with 36 mg of zeranol on day 0, on days 0 and 60, or were not implanted. At day 140, scrotal circumference and testicular consistency were unaffected by zeranol implantation. Zeranol implantation did not affect the morphologic characteristics of semen samples collected by electroejaculation on day 159. There was no effect of zeranol treatment on paired weights of testes, epididymides, or vesicular glands from bulls at slaughter 47 to 68 days after day 140. Microscopic lesions associated with estrogenic exposure were not observed in accessory sex glands or epididymides of any bull. Histopathologic changes in the seminiferous epithelium were not induced by zeranol treatment. Implantation with zeranol did not affect body weight or hip weight at day 140 or carcass weight at slaughter. Plasma concentration of luteinizing hormone was increased (P = 0.04), whereas testosterone concentration tended to be less (P = 0.08) in both groups of zeranol-implanted bulls after administration of gonadotropin-releasing hormone on day 140.
Predicting the number of herds infected with pseudorabies virus in the United States
Authors: Miller G. Y. , Forster D. L. , Tsai J. , Bech-Nielsen S. 
Published: January 2024

Summary
Epidemiologic modeling of the likely herd-to-herd transmission of pseudorabies virus (prv) was developed to assess the progress and potential for the prv-eradication program in the United States. The herd-to-herd transmission of prv over a 20-year period (1993 to 2012) in the United States was simulated under various scenarios, which included variable program-funding levels and variable prevalences. A transition model (Markov process model) was used to predict yearly changes in herd prevalence of prv infection. Five mutually exclusive states of nature for herds were assumed: uninfected and not vaccinated; uninfected and vaccinated; known to be infected and not vaccinated; known to be infected and vaccinated; and infected, but not known to be infected. Three prevalences for states in the United States were assumed: higher prevalence, moderate prevalence, and lower prevalence. Three funding levels were assumed: no eradication program, continued funding at the current level, and increased funding of 25%. Estimates made by an expert panel for determining probabilities in the state-transition matrices were used. A model also was developed, and was considered to be the most optimistic scenario likely under increased funding of 25%. The most optimistic estimates of the probabilities that still lay within the range of estimates made by the expert panel were used for this model. Only the optimistic transmission matrices allowed for total eradication of prv. Using the optimistic matrices, all states in the United States of America had moved into the moderate- or low-level risk status by the year 2000. The longest time taken to achieve eradication was for the state of Iowa, where eradication was not achieved until 2012.