bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetics and tissue residues of Gentamicin in lactating cows after multiple intramuscular doses are administered
Authors: Haddad Nadim S. , Ravis W. R. , Pedersoli W. M. , Carson R. L. 
Published: February 2025

SUMMARY
Gentamicin was administered im to 6 healthy, mature, lactating cows at a dosage of 3.5 or 5 mg/kg of body weight every 8 hours for 10 consecutive days (total, 30 doses). Endometrial biopsies were done at 72, 136 or 144, and 216 hours after the first dose was administered. On the 10th day, just before the last dose of gentamicin was administered, blood samples (designated 10th-day base-line samples) were obtained, and serial blood samples were obtained for 144 hours after the last injection was given. The cows were catheterized on the 10th day, and urine was obtained for 10 to 18 consecutive hours. Milk samples were also obtained. The cows were slaughtered at different times after the last dose was given, and samples were taken from 22 tissues and organs. Serum, milk, urine, and tissue gentamicin concentrations were determined by radioimmunoassay.
Serum gentamicin concentrations were best fitted to a 2-compartment open model. The mean half-lives for absorption, distribution, and elimination were 0.16 ± 0.14, 2.59 ± 0.53, and 44.91 ± 9.38 hours, respectively. Total body clearance and renal clearance were 1.65 ± 0.69 and 1.32 ± 0.25 ml/min/kg, respectively. The percentage of the dose excreted unchanged in the urine at 8 hours after the last dose was given was 98 ± 15. As expected, of the tissues examined, the gentamicin concentrations in the kidney cortex and medulla were 1,500 times greater than those in serum. Renal function remained within the baseline range during the 10 days of gentamicin treatment. In order to achieve average serum gentamicin concentrations of 5.95 μg/ml, maximal steady-state concentrations of 12.34 μg/ml, and minimal steady-state concentrations of 2.19 μg/ml, a dosage regimen of 5 mg/kg of body weight every 8 hours is recommended.
Myometrial activity during natural and dexamethasone-induced parturition in the cow
Authors: Burton M. J. , Dziuk H. E. , Fahning M. L. , Zemjanis R. 
Published: February 2025

SUMMARY
Myometrial activity was monitored during natural and dexamethasone-induced parturition in 8 Holstein dairy cattle, using strain gauge transducers. Four gauges were attached to the serosal surface of the gravid uterine horn, dividing it into thirds. Parturition was induced in 2 of 4 heifers and 2 of 4 cows (group 1); the remaining animals were allowed to calve spontaneously (group 2). Chains of low-amplitude contractions (repeated small deviations from base line) were detected before parturition was induced, and these were more common at distended parts of the uterus. Uncharacteristically sharp peaks followed by small rhythmic contractions, during preinduction recording, indicated that the myometrium was responsive to fetal movement even several days before parturition. By 18 hours before parturition, discrete single contractions appeared independently of contraction chains, and the first tubocervical peristaltic contraction waves were detected. The mean area under recorded contraction curves (uterine work) increased quadratically and the frequency of contractions decreased linearly from 12 hours before parturition to 2 hours after parturition. There was also an increase in the proportion of tubocervical waves over this period, and contraction chains were no longer present. During the second stage of labor, distended and undistended parts of the uterus were equally active, and forceful maternal straining was associated with larger sustained contractions. Fetal membrane rupture was accompanied by a doubling in the rate of passage of contraction waves along the length of the uterus. After the calf was expelled, contractions became extremely regular, and the majority progressed in a tubocervical direction. Although contraction waves were propagated more slowly after calving was completed, the area under recorded contraction curves continued to increase. Therefore, at 2 hours after parturition, uterine work was approximately 150% of that at calf expulsion. From 12 hours before to 2 hours after parturition, there were no significant differences in uterine activity between heifers and cows. Although all animals in group 1 retained their placenta, this was not the result of abnormal uterine activity during the immediate peri-partum period, because differences were not detected between the animals in groups 1 and 2.
Heparin-induced agglutination of erythrocytes in horses
Authors: Moore James N. , Mahaffey Edward A. , Zboran Michael 
Published: February 2025

SUMMARY
Heparin was administered subcutaneously 2 times a day for 4 days to 5 horses. An additional group of 5 horses was used as time-matched controls. Significant decreases in pcv, erythrocyte count, and hemoglobin concentration were observed during heparin therapy. The mean corpuscular volume (mcv) of the heparin-treated horses increased to a peak value of 66.1 fl on the last day of treatment. Erythrocyte creatine concentration and glucose 6-phosphate dehydrogenase activity increased moderately during the treatment. These data indicated that the rapid, profound increase in mcv during heparin therapy was not primarily a result of release of large immature erythrocytes from the bone marrow.
A second experiment was subsequently performed, using 3 horses. These horses were given heparin 2 times a day, as was done in the first experiment. Saline wet mounts of erythrocyte suspensions were examined once a day for the presence of agglutination. Cell suspensions were examined with or without exposure to a dilute trypsin solution, and erythrocyte counts were done on each suspension, using an electronic cell counter. Agglutination of erythrocytes was evident on the first day of treatment and became more pronounced as treatment progressed. Exposure to trypsin solution reversed the agglutination. The apparent erythrocyte count decreased and mcv increased sharply in the samples processed normally, but there was little change in those suspensions exposed to trypsin. These data indicate that heparin treatment induces erythrocyte agglutination in horses, that this agglutinating factor(s) is proteinic, that alterations in erythrocyte count and mcv are largely artifac-tual, and that evidence indicating that heparin induces augmentation of reticuloendothelial system function may require reconsideration.
Effects of feline leukemia virus infection on neutrophil chemotaxis in vitro
Authors: Kiehl A. R. , Fettman M. J. , Quackenbush S. L. , Hoover E. A. 
Published: February 2025

SUMMARY
A procedure for measuring in vitro feline neutrophil chemotaxis was developd, using a modified Boyden chamber apparatus and 3-μm-pore polycarbonate filters. A pooled feline serum sample was used as the chemoattractant. Chemotaxis was evaluated in 5 groups of cats: group 1—specific-pathogen-free cats that had not been exposed to feline leukemia virus (FeLV); group 2—previremic, FeLV-infected, specific-pathogen-free cats; group 3—FeLV-viremic, subclinically affected cats; group 4— FeLV-viremic, clinically affected cats; and group 5—sick cats that were not infected with FeLV.
Neutrophils from the viremic, clinically affected cats had significantly lower (P < 0.025) chemotactic responses than did those from subclinically affected, viremic cats. Conversely, neutrophils from cats that were ill due to causes other than FeLV had the highest mean chemotactic values. Among the viremic, subclinically affected cats, a linear relationship was found between age and chemotaxis, indicating that impairment of neutrophil function may be greater in younger viremic cats. However, FeLV-infected cats can not be identified on the basis of neutrophil chemotaxis.
Immunologie response to Pasteurella haemolytica and resistance against experimental bovine pneumonic pasteurellosis, induced by bacterins in oil adjuvants
Authors: Confer A. W. , Panciera R. J. , Gentry M. J. , Fulton R. W. 
Published: February 2025

SUMMARY
Immunogenicity of and protection afforded by Pasteurella haemolytica bacterins were studied in calves. Bacterins contained an aluminum hydroxide in gel (alh) adjuvant or one of the following oil-in-water adjuvants: Freund's complete adjuvant (fca), Freund's incomplete adjuvant (fia), and trehalose dimycolate (tdm). On days 0 and 7, calves were vaccinated with phosphate-buffered saline solution (pbss), a bacterin, or live P haemolytica. Transthoracic intrapulmonic challenge exposure was done on day 21. In 3 experiments, there were no significant (P > 0.05) differences between lung lesions induced in pbss-or alh bacterin-vaccinated calves. Both fca and fia bacterins significantly (P < 0.05) enhanced resistance against challenge exposure. Resistance induced by fca and fia bacterins was comparable with that induced by vaccination with live P haemolytica. Calves vaccinated with fia bacterin and challenge-exposed to P haemolytica at a concentration of 4.5 × 109 colony-forming units (4.5 times greater than used in the first 3 experiments) resisted challenge exposure similar to calves given live organisms. The tdm bacterin failed to enhance resistance.
All bacterins caused a significant increase (P < 0.05) in serum antibody to P haemolytica somatic antigens, as measured by a quantitative fluorometric immunoassay.
Pasteurella haemolytica leukotoxin neutralizing antibody titers did not increase significantly (P > 0.05) in sera after vaccination with any bacterin. Vaccination with fca and fia bacterins resulted in a significant increase (P < 0.001) in serum antibody to a carbohydrate-protein sub-unit of P haemolytica, as measured by an enzyme-linked immunosorbent assay. The tdm-bacterin vaccinates had antibody responses similar to those of the alh bacterin-or pbss-vaccinated calves. High antibody responses to the glycoprotein subunit correlated significantly (P < 0.05) with resistance to challenge exposure.
Seemingly, P haemolytica bacterins adjuvanted with fca or fia enhance resistance to induced pneumonic pasteurellosis, whereas alh-adjuvanted bacterins do not. The mechanism of induced resistance was not associated with leukotoxin neutralizing antibody, but may have been caused by antibody to antigens in a carbohydrate-protein subunit of P haemolytica.
Absolute and relative concentrations of immunoglobulins G, M, and A, and albumin in the lacteal secretion of sows of different lactation numbers
Authors: Klobasa F. , Butler J. E. 
Published: February 2025

SUMMARY
The concentrations of immunoglobulin (Ig)G, IgM, IgA, and albumin in the lacteal secretion of 80 sows were measured not more than 14 times during lactation to determine whether the age of the sow, the anatomic location of the mammae, or the farrowing barn housing of the sow influenced Ig concentrations. The combined data indicated that there were lactation stage-dependent changes in the total Ig concentration, as well as changes in the relative importance of the 3 classes of Ig studied. Mean values of any one time point showed enormous variation in absolute values, with coefficients of variation ranging up to 70%. The largest variations were observed between colostral samples obtained on the first day. The IgM showed the least variation on day 1. Such variations hindered attempts to statistically identify their source. Normalization of Ig concentrations in relation to albumin concentrations decreased some of the apparent variation. Normalized data accentuated the changeover from colostrum to milk which occurred after the first 3 days. There was also a 3-fold increase in IgA concentrations which occurred during the last 4 weeks of lactation. Data showed that older sows tended to have higher concentrations of all Ig. Lactation number-dependent increases in IgM and IgG were restricted to colostrum in lactation numbers higher than 4. Immunoglobulin A increased in a similar pattern and, in addition, increased in mature milk in sows with more than 2 lactations. The enormous variations observed seemed to be individual animal variations. This allowed only trends, rather than statistically significant differences, to be recognized. Several such trends were apparent. First, variations among individual mammae were not greater than overall variations, supporting the view that variations were individual animal variations. Secondly, caudally located glands showed a tendency to have higher Ig concentrations and lower albumin concentrations than other mammae. Thirdly, IgG, IgM, and albumin concentrations seemed to be highest in sows of 1 to 2 lactations, whereas IgA concentrations were higher in older sows. Finally, sows housed in different farrowing barns had different relative concentrations of IgG:IgA:IgM in colostrum, which was maintained into early lactation. It was concluded that variation in the amount of lacteal Ig in sows, other than those which are associated with differences in the stage of lactation, cannot be ascribed to a single physiologic factor. Individual animal variation seems to have the largest influence.
Cross-reactivity between human and feline la antigens, using a monoclonal antibody HLA-D.m1
Authors: Kuramochi T. , Takeishi M. , Ishida T. , Kato K. , Ishida M. 
Published: February 2025

SUMMARY
A murine monoclonal antibody HLA-D.m1 produced against human la antigens which react with 10% to 30% of human peripheral-blood mononuclear cells was found to react with > 90% of feline mononuclear cells. The antigen was not expressed on granulocytes. By direct immunofluorescence, 7% to 41% of feline lymphocytes expressed surface immunoglobulins. In mixed-lymphocyte reaction, the addition of antibody HLA-D.ml to cultures abolished proliferation. These studies indicate that most feline peripheral-blood mononuclear cells express la-like antigens.
Arterial hypotention and the development of postanesthetic myopathy in halothane-anesthetized horses
Authors: Grandy J. L. , Steffey E. P. , Hodgson D. S. , Woliner M. J. 
Published: February 2025

SUMMARY
The effect of halothane-induced hypotension on the development of postanesthetic myopathy was studied, using 6 healthy adult horses. Horses were anesthetized with halothane in oxygen for 3.5 hours on each of 2 occasions. Intermittent positive-pressure ventilation was used to maintain Paco2 of 45 to 55 mm of Hg throughout both anesthetic exposures. By regulating the inspired halothane concentration, a mean arterial blood pressure of 85 to 95 mm of Hg (normotension) was maintained throughout the 1st anesthetic exposure, and a mean arterial blood pressure of 55 to 65 mm of Hg (hypotension) was maintained during the 2nd anesthetic exposure. All horses recovered uneventfully from normotensive anesthesia, but all had some muscle dysfunction after prolonged hypotensive anesthesia. Because of apparent animal discomfort and lameness involving more than 1 limb, 3 horses were euthanatized soon after they recovered from hypotensive anesthesia. The 3 other horses showed a degree of lameness. In addition, 1 horse had raised, swollen plaques over the hip, rib, and facial areas which were in contact with the surgical table, and another had evidence of facial nerve paralysis. One hour after the 6 horses stood after hypotensive anesthesia was completed, values obtained for aspartate transaminase and creatinine were significantly (P < 0.05) greater than those obtained after normotensive anesthesia was completed. Aspartate transaminase, total bilirubin, and creatinine values were significantly (P < 0.05) increased when compared with those obtained before horses were anesthetized. A large increase was measured in creatine kinase. Twenty-four hours after hypotensive anesthesia was completed, creatine kinase and lactate dehydrogenase in the 3 surviving horses were significantly (P < 0.05) greater than those values after normotensive anesthesia was completed.
Anesthetic interaction in cardiovascular research models: Effects of xylazine and pentobarbital in cats
Authors: Fosse Richard T. , Grong Ketil , Stangeland Lodve , Lekven Jon 
Published: February 2025

SUMMARY
The effects of xylazine given to cats before anesthetization was induced with pentobarbital were determined. Cardiac hemodynamic variables and regional blood flow rates in the heart and other organs were measured, using radiolabeled microspheres. Two groups, each of 10 cats, were included in the study: one group (group 1) was anesthetized with pentobarbital given intraperitoneally and subsequently given xylazine; the other group (group 2) was first given 1 mg of xylazine/kg, im, and then anesthetized with pentobarbital given iv. Anesthesia was maintained in both groups with nitrous oxide.
The preanesthetic administration of xylazine decreased the amount of pentobarbital used for surgical anesthesia by approximately 50%. It also resulted in decreased heart rate, cardiac contractility, and cardiac output and increased left ventricular end-diastolic pressure, compared with those values in cats given pentobarbital (group 1). After the latter cats (anesthetized with pentobarbital) were given xylazine, heart rate, cardiac contractility, and cardiac output decreased and left ventricular end-diastolic pressure increased to values similar to those found in group 2 (given xylazine before anesthetization). Myocardial tissue blood flow rates in the left and right ventricles were lower in the cats of group 2. In group 1 cats, myocardial blood flow rates decreased when xylazine was subsequently added. Blood flow rates in the kidneys and gastrointestinal tract were generally decreased by xylazine.
Xylazine profoundly changed cardiac hemodynamic function and perfusion in the heart, as well as several other organ systems, because of marked cardiodepression.
Canine distemper virus: In vivo virulence of in vitro-passaged persistent virus strains
Authors: Axthelm Michael K. , Krakowka Steven , Gorham John R. 
Published: February 2025

SUMMARY
Groups of ferrets were inoculated intraperitoneally with cell lysates or equivalent doses of whole cells from 9 different cell lines persistently infected with canine distemper virus. Viral persistence in these cell lines was characterized by noncytolytic infection and restricted release of cell-free infectious virus. In vivo replication competency of the various viruses in ferrets ranged from nil to virulent and did not correlate with in vitro titers of inocula. Ferret virulence (cell lysates only) for one cell line (CCL64-RCDV) was associated with morphologic absence of virion assembly, failure to interfere with lytic virus replication after superinfection, and in vitro infectivity restricted to canine macrophage-like tumor cells. Virion protein production in the CCL64-RCDV virulent inoculum and in the CCL64-Ly avirulent inoculum was evaluated by use of the immunoblot technique. All major virion proteins were produced by infected cells. Virulence was not associated with obvious changes in electrophoretic mobility of virion proteins when profiles of ferret-virulent CCL64-RCDV were compared with those of avirulent CCL64-Ly.
Changes in basal lamina of seminiferous tubules associated with deranged spermatogenesis in the bull
Authors: Veeramachaneni D. N. Rao , Heath E. H. , Ott R. S. , McEntee K. , Hixon J. E. 
Published: February 2025

SUMMARY
The basal lamina of seminiferous tubules of 16 beef bulls, with scrotal circumferences (sc) from 40.5 to 28 cm, was characterized. The mean thickness of basal laminae was from 0.55 to 0.94 μm in normospermic bulls with sc > 30 cm. Of 3 bulls that had a sc < 30 cm, 1 had hypoplastic testes and was azoospermic, whereas 2 bulls had atrophic changes in their testes and were Oligospermie. The latter 2 bulls had thick basal laminae, with a mean of 1.35 μm and 1.68 μm, respectively, whereas basal laminae of the bull with hypoplastic testes had a mean thickness of 0.96 μm, comparable with that of bulls with normal testes (sc, > 30 cm). Thickness of the basal lamina of seminiferous tubules might be a useful criterion in differentiating atrophy from hypoplasia.
Total protein, albumin quota, and electrophoretic patterns in cerebrospinal fluid of dogs with central nervous system disorders
Authors: Sorjonen D. C. 
Published: February 2025

SUMMARY
Cerebrospinal fluid was analyzed for total protein, albumin quota, and electrophoretic patterns of albumin and α-, β-, and γ-globulins in 10 healthy dogs and 35 dogs with cns disorders. Values obtained in healthy dogs were used to establish control data. Samples also were collected from dogs with neurologic diseases that were classified according to clinical and pathologic diagnosis as inflammation, neoplasm, and spinal cord compression. The albumin quota and total csf albumin values were used as indicators of blood-brain barrier disturbance. Four patterns were observed on agarose electrophoresis that included intrathecal immunoglobulin production, intrathecal immunoglobulin production combined with blood-brain barrier disturbance, blood-brain barrier disturbance, and unaltered csf. These patterns correlated with the observed clinical and pathologic conditions. Seemingly, agarose electrophoresis of csf is a simple and reliable technique that aids in the diagnosis of cns disorders of dogs.
Blood antioxidant status and plasma pyruvate kinase activity of halothane-reacting pigs
Authors: Duthie Garry G. , Arthur John R. 
Published: February 2025

SUMMARY
Samples of blood were collected (by jugular venipuncture) from 10 homozygote halothane-reacting pigs and 7 homozygote nonreactors. Antioxidant status was assessed by measurement of blood glutathione peroxidase, glucose-6-phosphate dehydrogenase, and superoxide dismutase activities and plasma concentrations of vitamin E. Significant differences in these values were not apparent between halothane-reacting pigs and nonreactors. Halothane-reacting pigs had tissue damage as indicated by significantly increased plasma activities of the enzymes creatine kinase and pyruvate kinase. The latter showed better discrimination between the 2 populations than did creatine kinase and could prove to be a more effective marker for identification of stress-susceptible pigs.
Effect of topical phenylephrine on the equine pupil
Authors: Hacker Dennis V. , Buyukmihci Nedim C. , Franti Charles E. , Bellhorn Roy W. 
Published: February 2025

SUMMARY
The mydriatic effect of 10% phenylephrine was evaluated in 9 horses. Base-line pupillary size in mesopic conditions and during light stimulation was ascertained before application of pharmacologic agents. In study 1, 10% phenylephrine was applied to each eye (n = 5 horses). After 15 minutes, the pupillary size was determined in both lighting conditions. Phenylephrine was again applied to each eye, and after an additional 15 minutes, the pupillary size was determined. In study 2, 1% tropicamide was applied to each eye (n = 4 horses), and after 30 minutes, the pupillary size was determined in both lighting conditions. Tropicamide and phenylephrine were applied to each eye immediately after determination of pupillary size, and after an additional 30 minutes, the pupillary size was determined. There was no significant change (P > 0.9) in pupillary size when phenylephrine was used alone or when phenylephrine was used in an eye that had been dilated with tropicamide.
Antibody activity to Babesia canis in dogs in North Carolina
Authors: Levy M. G. , Breitschwerdt E. B. , Moncol D. J. 
Published: February 2025

SUMMARY
Sera from 600 dogs from 6 geographic regions of North Carolina were analyzed for antibody activity to Babesia canis, using an indirect fluorescent antibody test. Overall, 3.8% of the dogs had an antibody titer ≥ 1:80, which was considered to be indicative of infection. Dogs were more likely to be seropositive if they were housed at humane facilities and were located within areas of the state with a milder climate than were pet animals living within colder regions of North Carolina.