bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pilot study on the treatment with thioproline of 24 small animals with tumors
Authors: Grier Ronald L. , Merkley David F. , Roth James A. 
Published: February 2025

SUMMARY
Thioproline (thiazolidine-4-carboxylic acid) was administered in a 16-week trial by either im or subcutaneous routes to 23 dogs and 1 cat with solid tumors (12 animals) and incompletely excised malignant tumors (12 animals). Acute partial responses were observed in 3 of the 12 animals with solid tumors. In a mammary gland carcinoma and oral fibrosarcoma, there was tumor enlargement by the 4th day of drug therapy followed by partial regression. Drug activity appeared to be directed against tumor blood supply. Tumor progression occurred in 11 of the 12 other animals (incompletely excised tumors). Although 4 of 5 dogs with intranasal tumors were alive and relatively free of tumorous signs at 9 months or more after surgical operation was done, there was no microscopic evidence of reverse transformation or cytostatic activity in the 2 intranasal tumors that were reoperated upon. There was no hematologic or biochemical toxicosis noted. Apparent pain from injection and abscess formation were the most frequent complications from parenteral administration and would preclude using this method on a long-term basis.
Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: Effect of oral treatment with intestinal microflora
Authors: Naqi S. A. , Cook Jeanne , Sahin Nigar 
Published: February 2025

SUMMARY
One-day-old turkeys (Meleagris gallopavo) were orally inoculated with the intestinal contents of an adult turkey, and the intestinal tissues were studied by immunofluorescence for immunoglobulin (Ig)-bearing cells at 3, 7, 14, and 21 days of age. Microflora inoculation increased numbers of Ig-bearing cells in the gut-associated lymphoid tissues; the most uniform effects were observed at 3 days of age. As the birds grew older, this uniformity in response to the microflora inoculation was not evident in all the tissues. In the bursa of Fabricius and the large intestine of the inoculated birds, IgM-bearing cells were more numerous throughout the study period. Compared with noninoculated control turkeys, IgA-bearing cells in the cecal tonsils, and IgG- and IgA-bearing cells in the small intestine were increased at all age intervals.
Changes in the microscopic anatomy of the bovine teat canal during mammary involution
Authors: Comalli M. P. , Eberhart R. J. , Griel L. C. , Rothenbacher H. 
Published: February 2025

SUMMARY
Changes in the microscopic anatomy of the bovine teat canal were examined during mammary involution. Morphometric analyses revealed a significant (P < 0.05), temporary dilatation of the teat canal lumen on day 7 of the nonlactating period. Additionally, the teat canal epithelium physiologically atrophied as evidenced by decreased cross-sectional area and thickness during the first 30 days of the nonlactating period, significantly so (P < 0.05) between days 0 and 7. This physiologic atrophy was due mainly to a reduction in area and thickness of the stratum granulosum and may have resulted from continuing keratinization, a process that led to increased thickness of the keratin layer and formation of a functional plug during later stages of involution.
Changes in cells of the stratum granulosum indicated a decrease in the rate of epithelial cell maturation during involution. The mitotic index (percentage of basal cells in mitosis) of the teat canal epithelium decreased significantly (P < 0.05) between days 0 and 7 of the nonlactating period. Bacteria, observed in histologic sections, appeared to colonize only certain regions of the keratin layer. Seemingly, changes in the teat canal during mammary involution may be important factors in changing susceptibility to new intramammary infection during the early and mid-nonlactating periods.
Aspects of bacteriology and endocrinology of cows with pyometra and retained fetal membranes
Authors: Olson Jerry D. , Ball Leslie , Mortimer Robert G. , Farin Peter W. , Adney William S. , Huffman E. Michael 
Published: February 2025

SUMMARY
In an effort clarify the pathogenesis of pyometra, 20 cows with retained fetal membranes and 20 without, but with contemporary calving dates were studied. They were palpated and their uteri were subjected to sample collections for bacteriologic cultural examinations twice weekly for 4 weeks. Blood samples were obtained each day and evaluated for serum progesterone concentration.
Three cows without and 3 with retained fetal membranes developed pyometra during the study, resulting in 3 groups designated control (con), cows with retained fetal membranes (rfm), and cows with pyometra (pyo).
Bacterial isolations occurred less frequently the con group than in the pyo and rfm groups. Growth patterns of bacteria also varied between groups. Coliform and incidental bacteria disappeared from the uterus of the pyo group by the end of the 3rd week. In contrast, heavy growth of Corynebacterium pyogenes and gram-negative anaerobic bacteria developed during this same period the pyo group.
In cows with pyometra, the significant persistent pathogenic bacteria recovered were C pyogenes and gram-negative anaerobic bacteria, especially Fusobacterium necrophorum and Bacteroides melaninogenicus. Anaerobic bacteria were isolated simultaneously with C pyogenes in most cows of the pyo group, but less often in con and rfm groups, and highest growth levels were present near the time of ovulation. Clinically, pyometra usually developed about 10 days after observation of concurrent ovulation and high growth levels of C pyogenes and gram-negative anaerobic bacteria.
A hypothesis is presented for development of pyometra in the cow.
Pharmacokinetic disposition of theophylline in horses after intravenous administration
Authors: Kowalczyk D. F. , Beech J. , Littlejohn D. 
Published: February 2025

SUMMARY
The pharmacokinetics of theophylline were determined in 6 healthy horses after a single iv administration of 12 mg of aminophylline/kg of body weight (equivalent to 9.44 mg of theophylline/kg). Serum theophylline was measured after the iv dose at 0.25, 0.5, 1, 2, 4, 6, 8, 12, and 15 hours. Serum concentration plotted against time on semilogarithmic coordinates, indicated that theophylline in 5 horses was best described by a 2-compartment open model and in 1 horse by a 1-compartment open model. The following mean pharmacokinetic values were determined; elimination half-life = 11.9 hours, distribution half-life = 0.495 hours, apparent specific volume of distribution = 0.885 ± 0.075 L/kg, apparent specific volume of central compartment = 0.080 L/kg, and clearance = 51.7 ± 11.2 ml/kg/hr.
Three horses with reversible chronic obstructive pulmonary disease were serially given 1, 3, 6, 9, 12, and 15 mg of aminophylline/kg in single iv doses (equivalent to 0.8, 2.4, 4.7, 7.1, 9.44, and 11.8 mg of theophylline/kg, respectively). The horses were exposed to a dusty barn until they developed clinical signs of respiratory distress and were then given the aminophylline. Effects of increasing doses on different days were correlated with clinical signs, blood pH, and blood gases. The 3 horses had a decrease in the severity of clinical signs after the 9, 12, or 15 mg doses of aminophylline/kg. The horses at 0.5 hour after dosing had a significant decrease in (43.6 ± 5.5 to 39.4 ± 6.7 mm of Hg, P < 0.001) and a significant increase in blood pH (7.38 ± 0.017 to 7.41 ± 0.023, P < 0.001). There were no significant changes in (75.6 ± 11.1 to 70.5 ± 8.4 mm of Hg), heart rate (45.7 ± 6.1 to 47.0 ± 7.0/min) and respiratory rate (19.7 ± 5.4 to 20.7 ± 3.0/min) at 0.5 hour.
Hemodynamics in the guinea pig after anesthetization with ketamine/xylazine
Authors: Hart Mark V. , Rowles John R. , Hohimer A. Roger , Morton Mark J. , Hosenpud Jeffrey D. 
Published: February 2025

SUMMARY
The resting hemodynamics were determined in 8 guinea pigs after they were anesthetized with ketamine/xylazine. Measurements were made of blood pressure, heart rate, cardiac output, arterial blood gases, and pH. These measurements were obtained initially at 4 to 5 hours after an injection (im) of ketamine HC1 (25 mg) and xylazine (0.15 mg) was given to anesthetize the animals for catheterization (period 1), again 5 days after the operation (period 2), and finally 4 to 5 hours after a 2nd injection of ketamine/xylazine (period 3). There were no differences in heart rates, respiratory rates, or cardiac outputs among the 3 study periods. However, arterial blood pressure was slightly, but significantly, lowered after, and presumably due to, instrumentation (62 ± 4 mm of Hg, P < 0.05) when compared with the 5-day postoperative period (67 ± 7 mm of Hg) or after the readministration of anesthetics (66 ± 7 mm of Hg). The partial pressure of carbon dioxide in the arterial blood was slightly lower (4 mm of Hg, P < 0.05) in both acutely postanesthetic periods (period 1 and period 3) than in the same animals at postoperative day 5 (period 2). This study has demonstrated that resting hemodynamics measured shortly after this anesthesia with ketamine/xylazine are not largely different from those in chronically instrumented animals.
Colonization and persistence of Escherichia coli in axenic and monoxenic turkeys
Authors: Dominick M. A. , Jensen A. E. 
Published: February 2025

SUMMARY
Sites of colonization and persistence of virulent (O78) and avirulent (O2) Escherichia coli were determined in 3-week-old axenic turkeys. Colonization of O78 in turkeys infected with Streptococcus faecalis was also determined. Colonization and persistence of E coli in the intestinal tract and lung were not correlated with virulence. Both serotypes persisted in high titer in crop, ileum, ceca, colon, and lung. Persistence of E coli in the liver was positively correlated with virulence, although both serotypes were recovered from the liver in the absence of bacteremia, indicating possible intestinal translocation of E coli to the liver. A reduction in intestinal colonization and translocation of O78 was determined in monoxenic turkeys infected with S faecalis. In contrast, S faecalis had no effect on lung titers of O78. Air sacculitis, pericarditis, and pneumonia were observed in axenic and monoxenic turkeys infected with O78. Bacteremia was detected in a turkey exposed to O78.
Serum immunoreactive gastrin concentrations in the dog: Basal and postprandial values measured by radioimmunoassay
Authors: Gabbert N. H. , Nachreiner R. F. , Holmes-Wood Phyllis , Kivela Joanne Hazard 
Published: February 2025

SUMMARY
A commercially available radioimmunoassay designed for quantitating human gastrin was evaluated for use in quantitating dog gastrin Because of the similarities in molecular structures of the two, the assay appears to be useful for dogs. Serum gastrin concentration in 12 fasting dogs averaged 64.8 pg/ml. After dogs were fed, the concentration increased to 117.8 pg/ml within 30 minutes and returned to base line by 90 minutes A standard feeding procedure may be useful in evaluating dogs with gastrinoma.
Kinetics of phagocytosis in the normal canine iridocorneal angle
Authors: Samuelson Don A. , Gelatt Kirk N. , Gum Glenwood G. 
Published: February 2025

SUMMARY
Microspheres of 3 different sizes were infused separately into the eyes of dogs with normotensive and hypertensive intraocular pressures. Latex spheres (0.5 or 1.0 μm) or 3.0 μm plastic spheres were added to Ringer's solution with 6% gelatin. Initially, this mixture was injected into the anterior chamber of dogs with intraocular pressures of 20, 50, or 75 mm of Hg. After 10, 20, 30, 60, or 90 minutes had elapsed, the dogs were euthanatized and the gelatin was hardened. Tissues were subsequently studied by light and transmission electron microscopies. Phagocytosis of the 0.5 and 1.0 μm spheres by trabecular cells was first detected within 10 minutes and within 20 minutes for the 3.0 μm spheres. Migration of cells in the corneoscleral trabecular meshwork was observed after 30 minutes. Phagocytosis was less active at hypertensive pressures and had larger sphere sizes. Microspheres in the uveal trabecular meshwork were ingested mostly by macrophages and polymorphonuclear leukocytes.
Age-related changes in the cat testis and epididymis
Authors: Elcock Laura Hart , Schoning Polly 
Published: February 2025

SUMMARY
Forty-two pairs of testes and epididymides were obtained from clinically healthy cats and were examined histologically for age-related changes. All of the following testicular features increased with age: thickness of the testicular tunica adventitia, the amount of lipofuscin in the interstitial cell, hyperplasia of interstitial cells, vacuolation of Sertoli cell cytoplasm, degeneration of seminiferous tubules and thickness of the seminiferous tubular basement membrane. Two spermatoceles were found in the oldest cat. Age-related changes in the cat epididymis included increased thickness of the epididymal tunica adventitia, occasional intraepithelial cysts and hyperplasia of the epithelium, and one spermatocele in the head of the epididymal duct. Lymphocytic foci were common in testicular and epididymal connective tissue of cats of all ages and were reactive in the 2 oldest cats. Several changes were most frequent in 3- to 6.9-year-old cats: eosinophilic to amphophilic round cytoplasmic bodies in interstitial cells, proteinaceous tubular luminal debris, and spermatozoa in the epididymal duct. Cats < 1 year old had significant (P < 0.05) amounts of seminiferous tubular degeneration and a high percentage of epididymal intraepithelial cysts and hyperplasia.
Effect of ivermectin on performance of beef cattle on Georgia pastures
Authors: Ciordia H. , McCampbell H. C. , Calvert G. V. , Plue R. E. 
Published: February 2025

SUMMARY
A total of 469 cows and calves from 2 herds, each on 6 pastures, was used to evaluate the anthelmintic efficacy and animal-performance benefits of ivermectin given subcutaneously at a dosage of 200 μg/kg to nursing beef calves and their dams during a grazing season. Pastures were paired across the 2 herds. Three pasture groups from 1 herd were randomly assigned to either a nonmedicated control or to a medicated group. Treatment assignments were reversed in the other herd. The control groups comprised 110 cows and 108 calves, whereas 127 cows and 124 calves were treated with ivermectin (200 μg/kg).
The cows were treated once, in late spring, and the calves were treated twice, once in late spring and again in midsummer. Cattle from one herd were weighed on days −12, 21, 49, 77 (day of 2nd treatment for calves), and 105, and the other herd was weighed on days −6, 23, 57, 86 (day of 2nd treatment for calves), and 113. Rectal fecal samples for nematode egg counts were obtained from approximately 25% of the cattle in each pasture on weighing days; usually, the same cattle were sampled each time.
Calves treated with ivermectin gained (P < 0.05) more weight than control calves up to the 2nd treatment date and up to the termination of the study. There was no significant difference between treated and control cows, with regard to weight gain over either interval. Treated calves had fewer positive fecal egg counts (P < 0.01) and passed fewer eggs (P < 0.05) after both treatments than did control calves. There were no differences in either number of eggs or number of negative cows between treatment groups. Adverse reactions attributable to treatment were not seen.
Calcium in the turkey yolk sac during late development and postembryonic involution
Authors: Cheville Norman , Coignoul Freddy 
Published: February 2025

SUMMARY
Yolk sacs (ys) were examined by gross, histochemical, and electron microscopic techniques from incubation day 12 to 10 days of age. Weights were maximal at 22 days of incubation and declined markedly thereafter; by 7 days of age, the yolk was completely absorbed. Endodermal cells of ys epithelium were highly polar with nuclei, mitochondria, and glycogen in basal areas and lipid globules and intralysosomal yolk granules near luminal surfaces. Yolk laminar spherules were first seen at day 16 of incubation. They increased progressively with incubation and disappeared rapidly after hatching. Spherules stained for calcium, glycosaminoglycans, and alkaline phosphatase in late incubation and were considered calcium storage structures. Histochemical evidence of intracellular calcium loading of yolk matrix (from 18 days of incubation until 5 days of age) suggested a specific calcium transport function of ys epithelium.
Bacterial growth in whey from mastitic and nonmastitic quarters
Authors: Mattila T. , Syväjärvi J. , Sandholm M. 
Published: February 2025

SUMMARY
Growth of Escherichia coli and Staphylococcus aureus was analyzed by turbidometry in 456 selected whey samples. The samples had been graded mastitic or nonmastitic as determined by antitrypsin assay and bacteriologic examination. Whey samples from inflamed quarters (antitrypsin increased) and infected quarters significantly promoted bacterial growth as compared with whey samples from control quarters. The growth-stimulatory effect was limited to the diseased quarters, since control quarters from the same animals did not support enhanced bacterial growth. The observations indicate that in chronic mastitis, the inflammatory process leads to changes in the whey that promote bacterial growth in vitro.
Pathogenesis of Staphylococcus aureus mastitis: Bacteriologic, histologic, and ultrastructural pathologic findings
Authors: Gudding Roar , McDonald John S. , Cheville Norman F. 
Published: February 2025

SUMMARY
Three lactating cows were experimentally infected with Staphylococcus aureus ATCC 29740 (Newbould 305 strain). Cows were euthanatized 2 to 216 hours after inoculation. Bacteriologic and microscopic examinations showed that S aureus attached to epithelial cells of the mammary gland in vivo. The histopathologic changes observed were progressive swelling, vacuolar degeneration of epithelial layers, and multiple foci of epithelial erosions and ulcers throughout the ductal system. The cellular response of the infected glands was demonstrated by a rapid increase in the number of somatic cells in the secretion and by accumulation of neutrophils below, within, and on the epithelium of the teat and lactiferous sinuses. The inflammatory response did not prevent infection nor subsequent pathologic changes in the inoculated glands.
Pharmacokinetics of 4-aminopyridine in cattle
Authors: Kitzman Joseph V. , Wilson Robert C. , Booth Nicholas H. , Zahner Joanne M. , Hendricks H. Lamar , Bush Parshall B. 
Published: February 2025

SUMMARY
Concentrations of 4-aminopyridine hydrochloride in plasma of cattle were measured over an 8-hour period following a bolus IV injection (0.3 mg/kg). The drug was assayed by a gas-liquid chromatographic method using a nitrogen-phosphorus detector. Plasma 4-aminopyridine hydrochloride vs time data best fit a 2-compartment pharmacokinetic model. Distribution half-life was 12.08 minutes; elimination half-life, 128.96 minutes; volume of the central compartment, 1.48 L/kg; volume of distribution based on total area, 3.07 L/kg; volume of distribution at steady state, 2.75 L/kg; and body clearance, 16.57 ml/min/kg.
Effects of whole blood clots, time, and implant size on vascularization and collagen deposition along Teflonensheathed carbon fibers implanted in ewes
Authors: Stein Larry E. , Pijanowski Gerald J. 
Published: February 2025

SUMMARY
Seventy-two subcutaneous implants were examined to evaluate connective tissue response to Teflonensheathed carbon fibers and whole blood clots.
Carbon fibers significantly (P ≤ 0.001) increased vascularization and collagen formation within the Teflon sheath. Carbon fibers provide a potentially strong scaffold that would physically support cell migration during wound healing, However, obvious foreign body reactions occurred, which indicate that further studies on the biologic features of carbon fiber are needed before carbon fibers become entirely acceptable for long-term implantation.
Compared with no-clot controls, Teflon tubes containing only whole blood clots stimulated a significant (P ≤ 0.001) wound-healing response, including organized collagen fiber formation. Other variables tested in this study such as length and diameter of the Teflon tubes did not significantly influence connective tissue responses.
Meperidine-acepromazine-pentobarbital anesthesia in cats: Reversal by 4-aminopyridine and yohimbine
Authors: Hatch Roger C. , Zahner Joanne M. , Booth Nicholas H. 
Published: February 2025

SUMMARY AND CONCLUSIONS
Groups of atropinized cats (6/group) were given im meperidine (5.5 mg/ kg of body weight) plus acepromazine (0.25 mg/kg). Forty minutes later, the cats were anesthetized to disappearance of pedal reflexes with 1% pentobarbital iv. Volume of anesthetic was recorded. Five minutes later, the cats were given iv saline solution (2 ml; control group), the antagonists 4-aminopyridine (4-AP; 0.5 mg/kg), yohimbine (0.4 mg/kg), or a combination of 0.5 mg of 4-AP/ kg plus 0.4 mg of yohimbine/kg. Mean arousal time (mat), walk time (mwt), respiratory rate, and heart rate were measured. Emergence phenomena also were recorded.
Meperidine plus acepromazine caused mydriasis and mild sedation without ataxia or marked protrusion of the 3rd eyelid. The cats did not resist restraint for venipuncture. The pooled mean dosage level of pentobarbital required for anesthesia was 12.3 mg/kg. Control group mat and mwt were 66.2 minutes and 126 minutes, respectively. Marked residual sedation lasted several hours. In cats given 4-AP plus yohimbine, mat and mwt were decreased to 4.4 minutes and 36.5 minutes, respectively. These values were not significantly shorter than those same values in cats given 4-AP or yohimbine alone (P > 0.05), but the combination of 4-AP plus yohimbine produced a qualitatively better reversal of anesthesia than did 4-AP or yohimbine alone. Emergence was smooth in all 4 groups; mild-to-moderate residual sedation lasted 2 to 4 hours in the principals. Relapses, drug side effects, and behavioral aberrations were not observed. Mean respiratory rates and heart rates decreased during anesthesia but these values were not excessively depressed or stimulated at any time. Cardiac irregularities were not detected by palpation or auscultation. Meperidine-acepromazine-pentobarbital anesthesia may prove suitable for short surgical procedures in healthy cats. The anesthetic state can be smoothly and permanently reversed within minutes with 4-AP plus yohimbine without producing undesirable effects.
Immunity to toxoplasmosis in hamsters
Authors: Elwell Michael R. , Frenkel J. K. 
Published: February 2025

SUMMARY
Protective immunity to Toxoplasma was studied in hamsters. Immunity developed in 2 to 3 weeks after vaccinations were performed. Vaccination with live RH, T-45, and ts-4 strains afforded the best protection against challenge exposure with the most pathogenic RH strain used, Even a killed-toxoplasma vaccine protected all hamsters against the slightly less pathogenic T-1 strain through 24 weeks, but it did not protect hamsters against challenge exposure with the RH strain. Both ts-4, a nonpersistent strain, and killed-toxoplasma vaccine provided protective immunity in hamsters that was not dependent upon premunition, Toxoplasma antibody titers in hamsters given the 2 vaccines were similar. However, there was a difference in the quality of immunity: fever and body weight loss were seen in hamsters vaccinated with the killed-toxoplasma vaccine after they were challenge exposed with T-1 strain, whereas these changes were rarely seen in hamsters given the live-toxoplasma vaccine and then challenge exposed with RH strain. Delayed-type hypersensitivity to Toxoplasma antigen always appeared before protective immunity and was detected in all hamsters by 4 days after vaccination with live-toxoplasma strains. Although the development of delayed-type hypersensitivity preceded protective immunity, it was not indicative that protective immunity was present or would develop.