bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous identification and determination of residual penicillins by use of high-performance liquid chromatography with spectrophotometric or fluorometric detectors
Authors: Hong Chih-Chun , Lin Chin-Lan , Tsai Chin-En , Kondo Fusao 
Published: January 2024

SUMMARY
Using 7 penicillins (amoxicillin, ampicillin, methicillin, penicillin G, oxacillin, cloxadllin, and dicloxadllin), simultaneous and direct determination of residual penicillins in biological samples was carried out by use of bioassay and high-performance liquid chromatography with spectrophotometric or fluorometric detectors.
By use of assay medium seeded with penicillin-sensitive Micrococcus luteus (ATCC No. 9341) as a test organism, we were able to detect penicillins even at low concentrations. All penicillins treated with 10 U of penicillinase/ml did not produce inhibition zones by disk testing even at a concentration of 100 μg of penicillin/ml/assay plate.
Using a mobile phase of acetonitrile:methanol: 0.01M KH2PO4 (19:11:70, v/v/v; pH, 7.1), standard solutions of the penicillins were separated from each other by use of high-performance liquid chromatography analysis, producing symmetric peaks without tailing each of which had a characteristic retention time. Simultaneous detection of residual penicillins in bovine serum, kidneys, and liver, for the 5 penicillins for which analysis was possible by use of the uv method, yielded recovery rates from 71.4 to 102.3%; for the 2 amino-penicillins, amoxicillin and ampicillin, which could only be detected by use of the fluorometric method, recovery rate ranged from 72.9 to 103%.
Enantioselective glucuronidation and subsequent biliary excretion of carprofen in horses
Authors: Soraci Alejandro , Benoit Etienne , Jaussaud Philippe , Lees Peter , Delatour Paul 
Published: January 2024

SUMMARY
Carprofen (cpf) enantiomers and their glucuronide conjugates (gluc) were measured in plasma and bile of horses after iv administration of the racemic compound (0.7 mg/kg of body weight). The cpf was detectable in plasma for up to 72 hours after dosing, whereas gluc appeared early (time for maximal plasma concentration, 1 hour) and was measurable transiently at low concentration (maximal plasma concentration, 0.5 μg/ml). The enantiospecific plasma profiles indicated a clear predominance of R-cpf, whereas the stereoselectivity of the glucuronides favored S-gluc. At 1, 2, and 12 hours after administration of the drug, bile concentrations of gluc were high compared with those in plasma and enantioselectivity favored S-gluc. These data indicate that the higher body clearance observed for S-cpf is a consequence of the enantioselectivity in liver glucuronidation and subsequent biliary excretion of the S enantiomer of the drug.
Specific antibodies in serum and vaginal mucus of heifers inoculated with a vaccine containing Tritrichomonas foetus
Authors: Gault Ruth A. , Kvasnicka William G. , Hanks Donald , Hanks Maynard , Hall Mark R. 
Published: January 2024

SUMMARY
Thirty-five heifers were allotted to 3 groups. Group 1 (control) consisted of 10 heifers that were not vaccinated and were challenge exposed by breeding to infected bulls. Group 2 (natural challenge exposure) consisted of 10 heifers that were vaccinated and challenge exposed by breeding to infected bulls. Group 3 (experimental challenge exposure) consisted of 15 heifers that were vaccinated and challenge exposed by breeding to infected bulls and by intravaginal inoculation with 107 Tritrichomonas foetus. Total immunoglobulin concentrations and specific trichomonal antibodies were determined in serum and vaginal secretions of heifers, using radial immunodiffusion and elisa procedures.
Control heifers remained infected for a mean of 10.6 weeks (range, 0 to 18 weeks), and heifers of the natural and experimental challenge-exposure groups remained infected for 3.2 and 5.0 weeks, respectively (range, 0 to 12 weeks). Total serum and cervicova- ginal mucus concentrations of IgM, IgA, IgG1, and IgG2 did not change significantly after vaccination or challenge exposure. However, elisa titers of total trichomonal antibodies increased up to 1:10,000 (range, 1:400 to 1:10,000) in serum after vaccination, and increased approximately tenfold above background in cervicovaginal mucus. In serum, the predominant trichomonal antibody isotype was IgG1, although trichomonal IgA and IgM antibodies also increased. The predominant trichomonal antibody detected in cervicovaginal mucus was IgA. Antibody titers in serum and cervicovaginal mucus of vaccinated heifers were not increased by infection. However, in control heifers, the total local trichomonal antibody response increased three- to fivefold after infection. In these heifers, specific antibodies in serum were predominantly IgGI and local (cervicovaginal) antibodies were predominantly IgA.
Influence of allopurinol and two diets on 24-hour urinary excretions of uric acid, xanthine, and ammonia by healthy dogs
Authors: Bartges Joseph W. , Osborne Carl A. , Felice Lawrence J. , Unger Lisa K. , Chen Menglan 
Published: January 2024

SUMMARY
Hyperxanthinuria and xanthine uroliths have been recognized with increased frequency in dogs with ammonium urate uroliths that had been given allopurinol. We hypothesized that dietary modification might reduce the magnitude of uric acid and xanthine excretion in urine of dogs given allopurinol. To test this hypothesis, excretion of metabolites, volume, and pH were determined in 24-hour urine samples produced by 6 healthy Beagles during periods of allopurinol administration (15 mg/kg of body weight, PO, q 12 h) and consumption of 2 special purpose diets: a 10.4% protein (dry matter), casein-based diet and a 31.4% protein (dry matter), meat-based diet.
Significantly lower values of uric acid (P = 0.004), xanthine (P = 0.003), ammonia (P = 0.0002), net acid (P = 0.0001), titratable acid (P = 0.0002), and creatinine (P = 0.01) excreted during a 24-hour period were detected when dogs consumed the casein-based diet and were given allopurinol, compared with the 24-hour period when the same dogs consumed the meat-based diet and were given allopurinol. For the same 24-hour period, urine pH values, urine volumes, and urine bicarbonate values were significantly (P = 0.0004, P = 0.04, and P = 0.002, respectively) higher during the period when the dogs were fed the casein-based diet and given allopurinol than when they were fed the meat-based diet and given allopurinol. Endogenous creatinine clearance was significantly (P = 0.006) lower when dogs were fed the casein-based diet and given allopurinol than when they were fed the meat-based diet and given allopurinol. Significantly lower concentrations of plasma uric acid (P = 0.0001), plasma xanthine (P = 0.01), and serum urea nitrogen (P = 0.0001) were detected when dogs consumed the casein-based diet and were given allopurinol than when they consumed the meat-based diet and were given allopurinol. On the basis of these results, use of the casein-based diet and allopurinol in protocols designed for dissolution of urate uroliths may be beneficial in preventing hyperxanthinuria and xanthine urolith formation.
Clinical pharmacologic aspects of cefixime in dogs
Authors: Lavy E. , Ziv G. , Aroch I. , Glickman A. 
Published: January 2024

SUMMARY
The minimal inhibitory concentration (mic) of cefixime, a new third-generation orally administered caphalosporin, was determined for reference and clinical isolates from dogs. The mic of the drug for all but 1 of the 18 Enterobacteriaceae isolates tested, 1 Pasteurella canis, 1 Rhodococcus equi, 1 Streptococcus canis, and 1 Streptococcus group G isolate, was less than 1.0 μg/ml. The mic for 9 Staphylococcus intermedius isolates ranged from 1.56 to 6.25 μg/ml and, for 8 Sta aureus isolates, the mic values ranged from 1.56 to 12.5 μg/ml. Pseudomonas aeruginosa, Actinomyces sp, and a single Bordetella bronchiseptica isolate were considered resistant to cefixime.
Cefixime was administered orally in 2 phases at a standard dosage of 5 mg/kg of body weight to clinically normal adult male and female dogs. In the first phase, the drug was given once as a capsule and once as a suspension. In the second phase, it was administered once per day for 6 consecutive days in capsule form. Serum drug concentration was determined by use of a microbiological assay, and the following kinetic values were estimated for each dog: area under the concentration-time curve, peak serum drug concentration (Cmax), time of Cmax, absorption half-life, and elimination half-life (t1/2el) The kinetic profile of the drug in serum after oral administration of a single dose of cefixime was similar, with mean Cmax values of 3.36 and 4.76 μg/ml after treatment with the capsule and suspension, respectively. Quick oral absorption is characteristic for cefixime in dogs; mean absorption half-life values of 1.3 and 0.58 hours for the capsule and suspension, respectively, were calculated. Drug elimination from serum was biphasic, with an initial mean t1/2el of 8.1 to 8.6 hours and a secondary mean t1/2el of 11.7 to 14.5 hours. In the trial involving once daily treatment for 6 days, serum drug concentration after the sixth dose was significantly (P < 0.05) higher than that after the first dose, indicating drug accumulation. Cefixime is extensively bound to canine serum proteins (82 to 92% at concentration ranging between 7.5 and 1.5 μg/ml). Concentration of cefixime was determined in the uterus, ovaries, and abdominal fat tissues 24 hours after single-dose treatment and 24 hours after the sixth treatment. Tissue drug distribution was limited after administration of the single dose, but improved after the sixth dose. The in vitro antibacterial activity of the drug and its pharmacokinetic properties warrant assessing its clinical and bacteriologic efficacy as a longterm once-daily orally administered treatment for common bacterial infections in dogs.
Assessment of protection from systemic infection or disease afforded by low to intermediate titers of passively acquired neutralizing antibody against bovine viral diarrhea virus in calves
Authors: Bolin Steven R. , Ridpath Julia F. 
Published: January 2024

SUMMARY
Colostrum-deprived calves (n = 24) were fed various amounts of colostrum, colostrum substitute, or milk replacer to establish a range in titer of passively acquired viral neutralizing antibody in serum. The calves were then challenge exposed intranasally with a virulent, noncytopathic bovine viral diarrhea virus (bvdv-890). After viral challenge exposure, calves were monitored for fever, leukopenia, thrombocytopenia, and diarrhea. In addition, viral isolation and viral titration were performed on specimens of nasal secretions, buffy coat cells, and serum obtained from the calves. Fever and systemic spread of virus were detected in calves that had viral neutralizing titer of 256 or lower. Calves that had viral neutralizing titer lower than 16 developed severe clinical disease manifested by fever, leukopenia, thrombocytopenia, and diarrhea. Severity and duration of signs of disease decreased as titers of passively acquired viral neutralizing antibody increased. These results indicate that low to intermediate titers of passively acquired viral neutralizing antibody were not sufficient to fully protect calves from virulent bovine viral diarrhea virus.
Bovine immunodeficiency virus in stud bull semen
Authors: Nash Jerry W. , Hanson Larry A. , Cyr Coats Karen St. 
Published: January 2024

SUMMARY
Bovine immunodeficiency virus (biv), a lentivi- rus, is prevalent in dairy and beef cattle in southeastern United States and may be associated with a lymphoproliferative disease. The mode(s) of biv transmission are undefined. Because artificial insemination is a common practice in dairy production, contaminated stud semen could serve as an important source of infection if the virus is harbored in seminal fluids. To evaluate this possibility, we procured 11 cryopreserved semen specimens from a stud semen repository. Leukocytes were purified from the specimens, and the leukocyte dna was used as template in a polymerase chain reaction procedure that targeted a 235-base pair, highly conserved domain of the biv pol gene. The target sequence was amplified from the seminal leukocyte dna of 9 of the specimens (82%), and nucleotide sequencing confirmed the biv specificity of the fragment. This finding provides evidence that stud bull semen may serve as an important reservoir of biv, suggesting the possibility that artificial insemination of dairy cows may have a major role in transmission and wide-spread dissemination of this bovine lentivirus.
Development of monoclonal antibodies and capture immunoassays for feline immunodeficiency virus
Authors: Dreitz Matthew J. , Dow Steven W. , Fiscus Susan A. , Hoover Edward A. 
Published: January 2024

SUMMARY
We generated monoclonal antibodies (mab) against feline immunodeficiency virus (fiv) and characterized these mab by single competition enzyme immunoassays (eia), immunoblot analysis, and radioimmunoprecipitation. Four mab identified 3 distinct epitopes of the fiv p24/26 gag major core protein. One mab recognized the pl6/17 gag protein; none recognized envelope proteins. We developed an fiv p26 antigen capture eia that proved more sensitive (0.5 ng of p26/ml), less expensive, and less timeconsuming than reverse transcriptase assay. The same mab were used to develop an antibody eia specific for fiv p26. The mab and capture assays reported should prove useful in fiv diagnosis and research.
Subcellular pathologic features of glucocorticoid-induced hepatopathy in dogs
Authors: Rutgers H. Carolien , Batt Roger M. , Vaillant Camille , Riley Jane E. 
Published: January 2024

SUMMARY
Dogs are particularly susceptible to development of glucocorticoid-induced hepatopathy, but the mechanisms are not well understood. We investigated the pathogenesis of glucocorticoid hepatopathy by examining sequential morphologic and biochemical changes in the liver of dogs during steroid administration.
Six adult Beagles were given prednisolone acetate (4 mg/kg of body weight, once daily for 24 days, im). Serum samples and percutaneous liver biopsy specimens were obtained before the start of the study (treatment day [td] 0) and at td 5, 10, 15, and 25. There were significant (P < 0.05) and progressive increases in serum activities of alkaline phosphatase, γ-glutamyltransferase, and alanine transaminase. Light microscopic changes in liver biopsy specimens included progressive hepatocellular swelling and vacuolation. Electron microscopy revealed glycogen accumulation, peripheral displacement of organelles, and prominent dilatation of bile canaliculi, compared with findings at td 0. Liver biopsy specimens taken at td 25 had significantly (P < 0.05) increased activities of the plasma membrane enzymes, alkaline phosphatase and γ-glutamyltransferase, and 5'-nucleotidase was significantly (P < 0.01) decreased. Subcellular fractionation on reorientating sucrose density gradients revealed high-density peaks of alkaline phosphatase and γ-glutamyltransferase, compatible with a specific increase in the biliary canalicular component of the enzyme activities. Neutral α-glucosidase activity was shifted to the denser fractions, indicative of an increase in the proportion of rough to smooth endoplasmic reticulum and consistent with enhanced synthesis of plasma membrane proteins. There also was evidence for progressive increase in fragility of intracellular organelles, particularly lysosomes.
These findings indicate that glucocorticoid hepatopathy in dogs is associated with progressive alterations not only to the plasma membrane, but also to other subcellular organelles.
Enzyme release by bovine neutrophils
Authors: Watson G. L. , Slocombe R. F. , Robinson N. E. , Sleight S. D. 
Published: January 2024

SUMMARY
Release of enzymes from cytoplasmic granules has been postulated to have a major role in neutrophil-mediated tissue injury. Secretion or release of primary granules, specific granules, and cytosolic enzymes by bovine neutrophils was examined by quantifying the release of β-glucuronidase, B12-binding protein, and lactate dehydrogenase, respectively, in response to predetermined amounts of phorbol myristate acetate, calcium ionophore, and opsonized zymosan. These responses were compared with the enzyme release induced by exposure to live or dead, unopsonized or opsonized Pasteurella haemolytica. The greatest release of β-glucuronidase, B12-binding protein, and lactate dehydrogenase was observed in neutrophils exposed to live organisms partially because of neutrophil lysis. Bovine neutrophils respond markedly to particulate agonists, live or dead, pathogenic or nonpathogenic, by a selective release of specific granules, an effect enhanced by opsonization. Particulate agonists induce minimal primary granule release other than that induced by cell death. Because bovine neutrophils contain quantitatively high numbers of specific granules, the high rate of secretion/release in response to P haemolytica organisms could have a major role in the tissue responses that characterize the lesions of pneumonic pasteurellosis.
Noninvasive detection of nonsteroidal anti-inflammatory drug-induced gastropathy in dogs
Authors: Meddings Jon B. , Kirk David , Olson Merle E. 
Published: January 2024

SUMMARY
Nonsteroidal anti-inflammatory drugs (nsaid) are widely used for treatment of people and animals. Their use is limited by frequent side effects commonly involving the gastrointestinal tract, most important of which is development of ulcerating lesions principally in the stomach. Unfortunately, presence of such lesions is often unsuspected because clinical signs may be overlooked until a complication develops. We reported that such damage can be detected by measuring the increase in gastric permeability that is a hallmark of this condition. Sucrose is a novel probe molecule for determination of site-specific gastric permeability. As a disaccharide, it is large enough to be effectively excluded by the intact gastric epithelium, and because it is rapidly digested within the small intestine, absorption of the intact molecule implies damage proximal to this site. Recently, we found that increased sucrose permeability is useful in predicting presence of endoscopically relevant gastric damage in people. We extended these results to the detection of nsaid-induced gastropathy in dogs. Dogs treated with aspirin developed nsaid-induced gastropathy (including gastric ulceration), and the degree of endoscopically detectable damage correlated well with sucrose permeability. Furthermore, healing of these lesions could also be monitored by sequential measurements of sucrose permeability. Sucrose permeability decreased more rapidly than the disappearance of gastric ulcers, suggesting that this technique is more sensitive to generalized mucosal damage than is the presence of discrete, endoscopically visible ulceration. This was confirmed by creating artificial ulcers in the antrum and observing that sucrose permeability was not increased in this setting. We conclude that determination of increased sucrose permeability is a useful, noninvasive means of predicting presence of gastric damage in dogs treated with nsaid.
Pharmacologic interaction of furosemide and phenylbutazone in horses
Authors: Hinchcliff K. W. , McKeever K. H. , Muir W. W. , Sams R. A. 
Published: January 2024

SUMMARY
The effect of premedication with phenylbutazone on systemic hemodynamic and diuretic effects of furosemide was examined in 6 healthy, conscious, mares. Mares were instrumented for measurement of systemic hemodynamics, including cardiac output and pulmonary arterial, systemic arterial, and intracardiac pressures, and urine flow. Each of 3 treatments was administered in a randomized, blinded study; furosemide (1 mg/kg of body weight, iv) only, phenylbutazone (8.8 mg/kg, po, at 24 hours and 4.4 mg/kg, iv, 30 minutes before furosemide) and furosemide, or 0.9% NaCl. Phenylbutazone administration significantly attenuated, but did not abolish, the diuretic effect of furosemide. Phenylbutazone completely inhibited the immediate effect of furosemide on cardiac output, stroke volume, total peripheral resistance, and right ventricular peak pressure. Premedication with phenylbutazone did not inhibit equally the diuretic and hemodynamic effects of furosemide, indicating that some of furosemide's hemodynamic effects are mediated by an extrarenal activity of furosemide.
Effects of short-term cortisol infusion on growth hormone-releasing hormone stimulation of growth hormone release in sheep
Authors: Thompson K. , Coleman E. S. , Hudmon A. , Kemppainen R. J. , Soyoola E. O. , Sartin J. L. 
Published: January 2024

SUMMARY
Excess production or long-term administration of glucocorticoids is detrimental to longitudinal growth in people and rats. A portion of this effect is attributed to cortisol inhibition of growth hormone (gh). Glucocorticoid effects are usually studied in subjects under long-term treatment with synthetic, more potent glucocorticoids, and, to the authors' knowledge, have not been examined in domestic animals. We sought to examine the effects of cortisol infusion on gh release in sheep. Cortisol infusion into castrated, male Suffolk sheep (1 to 1.5 years old) caused a significant (P < 0.0001) increase in cortisol concentretion. Basal gh release was not affected over the 4-hour period of infusion. Growth hormone-releasing hormone administration stimulated gh release in both groups (P < 0.001); however, the control group had a greater response to growth hormone-releasing hormone than did the cortisol infused group (P < 0.0001). These results were duplicated in cultured sheep pituitary cells. Cortisol inhibition of gh release may be mediated via enhanced somatostatin release, owing to a direct inhibition of somatotrope function, or a combination of both mechanisms. Because of effects of stress and disease in increasing cortisol concentration, additional study of the mechanisms for cortisol inhibition of gh release in sheep needs to be performed.
Cardiovascular, hormonal, and metabolic responses to severe prolonged hemorrhage in adult sheep
Authors: Wintour E. Marelyn , Moritz Karen M. , Potocnik Simon J. 
Published: January 2024

SUMMARY
Over a 54-hour period, blood was removed from 8 adult sheep (body weight, 38.1 ± 0.5 kg, mean ± sem ) in 9 episodes, 5 on day 1, 3 on day 2, and 1 on day 3. Cumulative blood loss was 1,630 ± 63, 2,380 ± 71, and 2,693 ± 69 ml on days 1, 2, and 3, respectively. Blood samples (20 ml) were collected from 5 control ewes (33.8 ± 2.8 kg) at equivalent times. Over the first day, mean arterial blood pressure decreased in the hemorrhaged sheep from 101 ± 2 mm of Hg to 76 ± 5 mm of Hg, but returned to control values by the beginning of the second day and, thereafter, was not different from control values. Heart rate was increased after the first hemorrhage episode and remained high throughout the entire protocol. Over the entire period, there were statistically significant decreases in hematocrit, plasma osmolality, sodium, total calcium (P < 0.001 ), potassium, and chloride values (P < 0.05 ). There was no change in plasma phosphate, bicarbonate, creatinine, or magnesium concentrations and an increase in plasma urea nitrogen (P < 0.001 ) concentrations. Plasma arginine vasopressin concentration was increased significantly (P < 0.001 ) over the entire period. Plasma acth concentration was significantly (P < 0.05 ) increased over time, but only some values on day 1 were significantly outside the normal range of the control group data. Because of wide variation between sheep, the group data for aldosterone were not significantly different from control values. Blood volume was restored on day 1 with fluid of osmolality, Na, and Cl composition equivalent to that of plasma. The effects of arginine vasopressin were apparent by day 2, when the major decrease in osmolality and Na and Cl concentrations were observed. The sheep has good capacity to withstand severe, prolonged hemorrhage, most likely because of a large reserve of rbc in the spleen; hematocrit remained at 31% of control values when an estimated 100 % of initial circulating blood volume had been removed.