bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterotransplantation of equine carcinoma cells in athymic (nude) mice
Authors: Pardini Lani L. , Aaronson Laura M. , Hering Pamela L. , Pardini Ronald S. 
Published: February 2025

SUMMARY
Nondifferentiated equine carcinoma cells from a primary lesion were implanted subcutaneously in athymic (nude) mice. The cells were implanted at 2 sites each in 3 mice. At 1 of the 6 inoculation sites, a tumor developed, which invaded surrounding tissues, as shown by histopathologic examination. Karyotype analysis verified that the tumor was of equine origin. Cells from this tumor were serially heterotransplanted 20 times without change in growth rate. Once established in nude mice, this equine carcinoma cell line was stored cryogenically and then was successfully reimplanted into nude mice. All of the implants developed into tumors, over 20 generations. Preliminary screening of antineoplastic drugs indicated that this tumor line is sensitive to cyclophosphamide. Because of its ease of handling and high reimplantation efficiency, this tumor line should prove useful in equine cancer research.
3-Acetyl-4″-isovaleryl tylosin for prevention of swine dysentery
Authors: Jacks Thomas M. , Judith Frederick R. , Feighner Scott D. , Likoff Robert O. 
Published: February 2025

SUMMARY
The 21 field isolates of Treponema hyodysenteriae which were tested were sensitive to 3-acetyl-4″-isovaleryl tylosin (aiv); the minimal inhibitory concentration was 0.25 to 16 μg/ml.
3-Acetyl-4″-isovaleryl tylosin administered prophylactically to pigs at concentrations of 5 to 100 mg/kg of feed and tylosin at 110 mg/kg of feed for 28 or 31 days prevented swine dysentery induced by tylosin-sensitive T hyodysenteriae strain SQ2; 15 nonmedicated, inoculated control pigs had bloody diarrhea, and 9 pigs died.
In 2 additional trials, aiv administered prophylactically for 28 days at 55 or 110 mg/kg of feed prevented swine dysentery induced by tylosin-insensitive T hyodysenteriae strain B204. All of the inoculated principal pigs medicated with aiv at 55 or 110 mg/kg of feed or carbadox at 55 mg/kg of feed and the noninoculated sentinel pigs for each group had solid feces throughout the 56-day trial. In the nonmedicated, inoculated control groups, bloody diarrhea began at 4 to 5 days after inoculation was done, and 9 of 10 principal pigs and 6 of 9 sentinel pigs had dysentery; 2 pigs died. In the groups medicated with aiv at 27.5 or 5.5 mg/kg of feed, all 5 principal pigs and 3 or 4 sentinel pigs in each group had dysentery; 3 or 4 pigs in each group died. In the group medicated with tylosin at 110 mg/kg of feed, 7 of 10 principal pigs and all 9 sentinel pigs had dysentery; 1 pig died. Treponema hyodysenteriae was not isolated from the inoculated groups medicated with aiv at 55 or 110 mg/kg of feed or with carbadox at 55 mg/kg of feed, but was repeatedly isolated from all other inoculated groups.
Identification of bovine carriers of Moraxella bovis by comparative cultural examinations of ocular and nasal secretions
Authors: Pugh G. W. , McDonald T. J. 
Published: February 2025

SUMMARY
The carrier state of Moraxella bovis was investigated, using bacteriologic examinations of ocular and nasal secretions from cattle under experimental and natural conditions of exposure and management. Moraxella bovis was isolated throughout the year from the ocular and nasal secretions of cattle naturally affected with infectious bovine keratoconjunctivitis. There was also 1 case of nasal transmission of M bovis without isolation of M bovis from ocular secretions and 1 case of M bovis isolation from the vagina of a calf contracted by contact with a calf affected with infectious bovine keratoconjunctivitis. The frequency of isolations and duration of infections, as determined by examination of ocular and nasal secretions, indicated that these secretions were comparable in the identification of M bovis carriers. The increased cultural isolations of M bovis from nasal secretions after shipment relative to the number of isolations before shipment indicated that shipment may serve as a stress factor causing an increase in the number of carriers.
Antibiotic susceptibilities of swine Salmonella isolants from 1979 to 1983
Authors: Mills Kenneth W. , Kelly Barbara L. 
Published: February 2025

SUMMARY
Two hundred seventy-seven Salmonella (27 serotypes) were isolated from Kansas swine over a 5-year period (1979 to 1983). Salmonella cholerae-suis was the predominant isolant from all tissues and made up 94.4% of the Salmonella isolants from the lungs. The percentage of Salmonella isolants susceptible to various antimicrobial agents was determined. The percentage of Salmonella susceptible to carbadox decreased from 1980 to 1983.
Cardiopulmonary effects of continuous intravenous infusion of guaifenesin, ketamine, and xylazine in ponies
Authors: Greene S. A. , Thurmon J. C. , Tranquilli W. J. , Benson G. J. 
Published: February 2025

SUMMARY
Eight ponies were anesthetized with a solution containing 50 mg of guaifenesin, 1 mg of ketamine, and 0.5 mg of xylazine·ml−1 of 5% dextrose in water. Anesthesia was induced by iv injection (1.1 ml · kg−1), followed by continuous iv infusion at 2.75 ml · kg−1 · hr−1. Heart rate, rate-pressure product, mean pulmonary artery pressure, and standard bicarbonate were not significantly changed throughout the study. Systolic, diastolic, and mean arterial pressures and left ventricular stroke work index were significantly decreased at 5 and 15 minutes after a bolus of the anesthetic solution was injected. Systolic blood pressure returned to within the base-line range at 30 minutes, but diastolic and mean arterial pressures were significantly decreased throughout the study. Cardiac index and arterial pH were decreased at 5 minutes only. Systemic vascular resistance was significantly decreased 60 minutes after bolus injection was given. Hypoventilation, as indicated by increased PaCO2, occurred 5 minutes after bolus injection was given.
Effects of dose and duration of therapy on gentamicin tissue residues in sheep
Authors: Brown Scott Anthony , Coppoc Gordon L. , Riviere J. Edmond 
Published: February 2025

SUMMARY
The effects of different doses and dosage regimens on gentamicin pharmacokinetics and tissue residues were determined. Five groups of 12 sheep each were given gentamicin im: group I, 2 mg of gentamicin sulfate/kg once; group II, 6 mg/kg once; group III, 18 mg/kg once; group IV, 6 mg/kg every 24 hours for 3 doses; and group V, 2 mg/kg every 8 hours for 9 doses. Serum concentrations were determined serially until sheep were killed and necropsied. Three sheep from each group were killed at 1, 4, 8, and 12 days after the last dose was administered. Renal cortex, renal medulla, liver, spleen, lung, skeletal muscle, and skeletal muscle at the injection site were assayed for gentamicin. An exponential equation was fitted to the serum concentrations, and various pharmacokinetic variables were determined. Serum clearance tended to increase as the single dose increased (P = 0.0588). Steadystate volume of distribution increased as the single dose was increased (P < 0.05). Renal cortex contained the highest concentration of gentamicin which decreased in a biexponential manner. Concentrations in all tissues, except the injection site, were dependent upon the amount of the total dose, not the size of the injected dose (P < 0.05). Concentrations at the injection site were up to 29 μg/g of tissue at 1 day after the last dose was given and were dependent upon the amount of total dose from multiple injections, not on the amount of each injected dose (P < 0.05). These results indicated that tissue residues increased as the total dose of gentamicin was increased or as the duration of gentamicin therapy was increased. Furthermore, the injection site contained substantial amounts of gentamicin at 1 day after the last dose was given.
Effect of the injection site on the pharmacokinetics of procaine penicillin G in horses
Authors: Firth E. C. , Nouws J. F. M. , Driessens F. , Schmaetz P. , Peperkamp K. , Klein W. R. 
Published: February 2025

SUMMARY
The plasma penicillin concentrations were determined in 5 horses given an iv injection of sodium penicillin G; plasma penicillin concentrations were also determined in a crossover experiment, where animals were given procaine penicillin G subcutaneously at 1 site and im at 4 sites. The mean penicillin plasma peak concentration and bioavailability were highest after the drug was injected in the neck and biceps musculature. Injections in the gluteal muscle and in the subcutaneous sites resulted in similar, but lower, more persistent penicillin plasma concentrations and a lower bioavailability than were obtained with injection in the neck and biceps musculature. The pharmacokinetic data obtained after penicillin was administered via the pectoral muscle route exhibited an intermediate position. Therapeutic implications of the routes of administration with respect to hemolytic streptococcal infections are discussed.
Attempted transmission of Ehrlichia risticii by field-captured Dermacentor variabilis (Acari: Ixodidae)
Authors: Schmidtmann E. T. , Robl M. G. , Carroll J. F. 
Published: February 2025

SUMMARY
The capability of field-collected American dog ticks, Dermacentor variabilis, to infect horses with Ehrlichia risticii, causative agent of Potomac horse fever (phf), was examined by allowing adult ticks collected from horse farms with a history of phf to feed on susceptible horses. More than 500 male and female ticks attached and fed on 3 test horses; however, no clinical or serologic evidence of phf was observed in treated or control horses. All horses were challenge exposed with E risticii-infective blood by inoculation at 60 to 65 days after ticks fed, and all developed clinical phf with subsequent seroconversion. The data, therefore, indicated that adult D variabilis, a common parasite of horses on Maryland premises where phf is enzootic, may not serve as a vector of E risticii.
Eructation of gas through the gastroesophageal sphincter before and after truncal vagotomy in dogs
Authors: Strombeck Donald R. , Harrold Doris , Ferrier William 
Published: February 2025

SUMMARY
The function of the gastroesophageal sphincter (ges) to eructate gas before and after vagotomy was investigated in conscious, fed dogs. Gastric and ges pressures were measured in 5 dogs, using a perfused 4-lumen catheter with a Dent sleeve. To induce eructation, nitrogen gas was insufflated (440 ml/min) into the stomach through 1 channel of the catheter. After base-line studies were completed on each dog, bilateral truncal vagotomy was performed 5 cm cranial to the diaphragm. Mean (± se) ges pressure was 51.5 ± 1 mm of Hg before vagotomy and 28 ± 1.7 mm of Hg after vagotomy (P < 0.001). Mean gastric contraction rates were the same, 4.91 ± 0.11/min and 4.78 ± 0.06/min in dogs before and after vagotomy, respectively.
During insufflation, gastric pressures increased to 11.8 ± 0.7 mm of Hg before eructation in dogs before vagotomy and to 18.4 ± 0.8 mm of Hg in dogs after vagotomy (P < 0.001). Eructation occurred at intervals of 1.79 ± 0.09 minutes before vagotomy and 5.71 ± 0.41 minutes after vagotomy (P < 0.001). Atropine resulted in an interval of 1.98 ± 0.18 minutes before vagotomy. Eructation was not seen in 2 dogs after vagotomy and was sometimes not seen in the 3 others. Gastroesophageal sphincter pressure in dogs before vagotomy began to decrease 4.5 ± 0.2 s before the ges-pressure gradient disappeared, and ges pressure remained there for 5.3 ± 0.3 s before the gradient began to return. Vagotomy resulted in the appearance of phasic contractions (at a rate the same as gastric contractions) of the ges and the terminal few centimeters of esophagus during insufflation. Seemingly, vagal denervation of the ges may result in its motor activity being influenced by the gastric pacemaker.
Ultrastructural changes in inherited cardiac calcinosis of DBA/2 mice
Authors: Van Vleet John F. , Ferrans Victor J. 
Published: February 2025

SUMMARY
Cardiac dystrophic calcinosis, an inherited condition in DBA/2 mice, produced extensive calcific lesions in the right ventricular myoepicardium of affected mice. The morphogenesis of the cardiac alterations was evaluated by microscopic and ultrastructural studies. The initial event was necrosis and mineralization of subepicardial myocytes. Mineral deposits were seen as dense granular and spicular deposits in (i) mitochondria only, (ii) mitochondria and adjacent sarcoplasm, or (iii) the entire sarcoplasm in necrotic myocytes. In mature myoepicardial calcific lesions, the remnants of necrotic myocytes were seen as scattered dense masses of mineralized debris with surrounding fibroplasia and occasional macrophages and giant cells. Male weanling DBA/2 mice (n = 135) were fed either a commercial diet adequate in selenium-vitamin E (Se-E) content, or a basal semipurified Se-E-deficient diet with or without silver acetate for 15, 20 or 25 weeks. Cardiac calcinosis severity seemed to increase in mice which developed concurrent Se-E deficiency. Cardiac calcinosis in the DBA/2 mouse is a useful model of cardiac calcification.
Investigation into the use of narcotic antagonists in the treatment of a stereotypic behavior pattern (crib-biting) in the horse
Authors: Dodman Nicholas H. , Shuster Louis , Court Michael H. , Dixon Ross 
Published: February 2025

SUMMARY
Crib-biting in horses is a repetitive behavior pattern which may involve the activation of both narcotic receptors and dopamine receptors in the cns. Crib-biting frequency, determined in 7 nontreated horses under controlled conditions, was usually linear for many hours and ranged from 0.3 to 14.9 bites/min. Intravenous or im injections of narcotic antagonists decreased these rates to almost zero by about 20 minutes after the injection was given. The duration of the response to a single injection ranged from 20 minutes for naloxone to 4 hours or more for nalmefene and diprenorphine. Effective doses were 0.02 to 0.04 mg of naloxone/kg, 0.04 mg of naltrexone/kg, 0.08 mg of nalmefene/kg, and 0.02 to 0.03 mg of diprenorphine/kg. Crib-biting could be prevented completely for up to a week by continuous infusion of 5 to 10 mg of nalmefene/hr. Crib-biting resumed when the infusion was discontinued, and plasma nalmefene concentrations decreased to below 5 ng/ml. Doses of nalmefene as large as 0.4 mg/kg, iv, produced only minor side effects. These side effects included some passage of semifluid fecal material, intermittent penile relaxation, and mild sedation. Treated horses responded normally to external stimuli, retained their appetites, and performed appropriately when ridden. Sedation wore off during the course of prolonged infusions. Narcotic antagonists may provide a novel and effective treatment of stereotypic behavior disorders.
Distribution and implications of β-endorphin and ACTH-immunoreactive cells in the intermediate lobe of the hypophysis in healthy equids
Authors: Amann John F. , Smith Robin M. , Ganjam V. K. , Paull Willis K. , McClure Robert C. , Green Eleanor M. , Garner Harold E. 
Published: February 2025

SUMMARY
The distribution of cells that stain positive for β-endorphin and ACTH immunoreactivity was studied in the pars intermedia (pi) of the hypophysis in 3 healthy horses and 2 healthy ponies. Serial sections treated with commercial antibodies generated against β-endorphin or ACTH(l-39) were processed for immunocytochemical studies, using the avidin biotin immunoperoxidase-complex method. Distribution patterns of cells reacting with antibodies were similar in cells from all equids. Cells immunostained for ACTH were numerous and widely distributed in the pi. Cells immunopositive for ACTH probably contain corticotrophin-like intermediate lobe peptide that cross-reacts with antisera to ACTH. Cells immunopositive for β-endorphin were fewer in number and had a more limited distribution in the pi. Most β-endorphin-positive cells were located along the border of the pi adjacent to the lobus nervosus and had abundant eosinophilic cytoplasm when stained with hematoxylin and eosin. Cells with prominent eosinophilic cytoplasm were not common in other areas of the pi. When serial sections were examined, cells that stained positive for β-endorphin immunoreactivity also appeared positive for ACTH.
Chemoprophylaxis of cryptosporidiosis in chickens, using halofuginone, salinomycin, lasalocid, or monensin
Authors: Lindsay David S. , Blagburn Byron L. , Sundermann Christine A. , Ernest James A. 
Published: February 2025

SUMMARY
Chemoprophylaxis of Cryptosporidium baileyi infections was attempted by feeding 4 groups of chicks diets containing 3 mg of halofuginone/kg of feed, 60 mg of salinomycin/kg, 75 mg of lasalocid/kg, or 110 mg of monensin/kg. Rations were fed 5 days before oral or intratracheal inoculation with oocysts and were continued for 20 days. None of the drugs prevented C baileyi infections. Clinical signs of respiratory tract disease and gross lesions of air-sacculitis were observed in intratracheally inoculated birds in all treatment groups and nonmedicated controls. Orally inoculated birds did not develop clinical signs of infection. Pathogenic bacteria were not isolated from the respiratory tract systems of any chicks. Halofuginone delayed the establishment of infections of the bursa of Fabricius and cloaca, but not of the trachea.
Effects of loperamide hydrochloride on experimental diarrhea and gastrointestinal myoelectrical activity in calves
Authors: Fioramonti Jean , Buéno Lionel 
Published: February 2025

SUMMARY
The antidiarrheal action of loperamide hydrochloride was tested against diarrhea experimentally induced in calves by intraduodenal infusion of castor oil or hypertonic solution of mannitol. The motility of 4 levels of the digestive tract (abomasum, jejunum, and proximal and spiral loops of the colon) was concomitantly recorded, using an electromyographic technique. Loperamide hydrochloride given per os at 0.4 mg/kg or intraduodenally or subcutaneously at 0.1 mg/kg 1 hour before mannitol or castor oil was given delayed diarrhea. Loperamide hydrochloride given alone orally at a dosage of 0.4 mg/kg did not modify the motility pattern of the digestive tract. Intraduodenally administered loperamide hydrochloride (0.1 mg/kg) increased the frequency of the cyclic activity of the jejunum, whereas subcutaneously administered loperamide hydrochloride at the same dose selectively inhibited the motility of the jejunum. Intraduodenal infusion of mannitol was followed by a disruption of the cyclic activity of the jejunum, and this effect was not antagonized by loperamide hydrochloride, whatever the route of administration. Castor oil infusion was not accompanied with changes in gastrointestinal motility. These results indicate that loperamide hydrochloride is active against an experimentally induced diarrhea in calves and that this action is not mediated through an effect on the digestive motility, at least monitored by this electromyographic technique.
Effect of nonadrenal illness on adrenal function in the cat
Authors: Zerbe C. A. , Refsal K. R. , Peterson M. E. , Armstrong P. J. , Nachreiner R. F. , Schall W. D. 
Published: February 2025

SUMMARY
Adrenal function was assessed by a combined dexamethasone suppression-ACTH stimulation test in 18 healthy cats, 17 diabetic cats, and 19 sick nondiabetic cats. In all groups, plasma Cortisol concentrations decreased after dexamethasone was administered and increased after ACTH was administered. There were no significant (P > 0.05) differences among groups in time trend changes in Cortisol concentration. There was considerable variation in adrenal response between cats in each group. Diabetic cats had more variation in base-line and postdexamethasone plasma Cortisol concentrations (P < 0.05) than did other groups. In sick, nondiabetic cats, Cortisol concentrations tended to be higher in cats with hyperthyroidism (P = 0.06) than in cats with other diseases.
Isoprinosine and levamisole immunomodulation in artificially reared neonatal pigs
Authors: Hennessy K. J. , Blecha F. , Pollmann D. S. , Kluber E. F. 
Published: February 2025

SUMMARY
An experiment was conducted to determine the capability of isoprinosine (iso) and levamisole (lev) to augment delayed-type hypersensitivity and lymphocyte blastogenic reactions in artificially reared pigs. Sow-reared pigs (n = 15) were kept with their dams; artificially reared pigs (n = 15) were removed from sows within 2 days after parturition and reared artificially for 21 days. Isoprinosine was administered orally (75 mg/kg/day) from days 0 to 10. Levamisole (2 mg) was injected subcutaneously on days 5 and 10. Control pigs were given distilled water orally from days 0 to 10 and injected subcutaneously with 0.15M NaCl on days 5 and 10. Lymphocyte proliferative responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen were evaluated at week 2. The phytohemagglutinin skin-test responses were evaluated in all pigs at weeks 1 and 3 of the trial. Hematologic values, body weight, and mortality were evaluated each week.
The skin-test responses and mitogen-induced lymphocyte proliferative responses were lower (P < 0.05) in artificially reared controls when compared with responses in sow-reared pigs. However, iso and lev enhanced (P < 0.05) the responses in the artificially reared pigs to values comparable with those of the sow-reared controls. Body weight was greater (P < 0.01) in sow-reared pigs than in artificially reared pigs; drug treatment did not influence weight gain. These data indicate that immunopotentiation of the cellular immune responsiveness of artificially reared pigs may be possible with iso or lev.
Virulence of wild and mutant strains of Salmonella typhimurium in ligated intestinal segments of calves, pigs, and rabbits
Authors: Clarke R. C. , Gyles C. L. 
Published: February 2025

SUMMARY
A ligated intestine model in calves, pigs, and rabbits was tested for its value as an indicator of virulence of potential vaccine strains of Salmonella typhimurium. A wild virulent strain (3860C), a laboratory strain LT2, and mutants of these 2 strains were evaluated. Inoculation of calf intestinal segments with strain 3860C revealed that fluid responses were greatest in the proximal portion of the small intestine and that doses > 107 organisms were required to produce fluid responses and mucosal damage. Immunoperoxidase-stained sections of intestine revealed that a large dose of Salmonella organisms was required before mucosal invasion could be detected. Aromatic (aroA), galactose epimerase (galE), and diaminopimelic acid (dap) mutants of strain 3860C all resulted in much less fluid response, mucosal invasion, and mucosal damage compared with those by the parent organism. Strain LT2 induced such weak responses that it was not possible to evaluate reductions in virulence of its mutants. In 6-week-old pigs, there was no fluid response to any strains; however, in 1-week-old pigs, there was fluid response to the wild strain and some of its mutants. In adult rabbits, fluid responses were not observed, except when the wild strain was inoculated in the proximal portion of the small intestine. The calf and 1-week-old pig models appeared to be best suited for assessment of virulence of mutant strains of S typhimurium.
Effect of acepromazine, diazepam, fentanyl-droperidol, and oxymorphone on gastroesophageal sphincter pressure in healthy dogs
Authors: Hall J. A. , Magne M. L. , Twedt D. C. 
Published: February 2025

SUMMARY
Treatment of healthy dogs with 4 commonly used psychotropic or analgesic agents significantly decreased resting gastroesophageal sphincter pressure (gesp). Acepromazine decreased gesp by 35% (P = 0.02); oxymorphone decreased gesp by 38% (P < 0.005); diazepam decreased gesp by 42% (P = 0.005); and fentanyl-droperidol decreased gesp by 40% (P = 0.03). Therefore, esophageal manometric evaluation of gastroesophageal sphincter function should not be preceded by administration of these drugs.