bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphocyte reactivity to antigens of Haemonchus contortus in antigen-inoculated and H contortus-naive lambs
Authors: Torgerson P. R. , Lloyd S. 
Published: January 2024

SUMMARY
Lambs were inoculated during either fetal or early neonatal life with antigens of Haemonchus contortus (HcAg) third-stage larvae, or ovalbumin (ova), or were left untreated. By the time lambs were 4 weeks old, blood lymphocytes from all of them responded to HcAg. This was evident in all lambs, regardless of the previous inoculation regimen, although higher response was seen in HcAg-inoculated lambs, compared with naive lambs. Only lambs inoculated with ova had ova-specific lymphocyte activity. In HcAg-naive lambs, the maximal HcAg lymphocyte response was observed between the ages of 5 and 25 weeks, with gradual decrease thereafter. In vitro detection of HcAg-reactive lymphocytes was affected by antigen concentration and presence of plasma. Plasma inhibited HcAg-reactive lymphocytes from all lambs at high in vitro antigen concentration and completely abrogated the response in H contortus antigen-naive lambs.
Effects of ketamine infusion on halothane minimal alveolar concentration in horses
Authors: Muir William W. , Sams Richard 
Published: January 2024

SUMMARY
Eight adult horses were used in a study to determine ketamine's ability to reduce halothane requirement. To obtain steady-state plasma concentrations of 0.5, 1.0, 2.0, 4.0, and 8.0 μg/ml, loading doses and constant infusions for ketamine were calculated for each horse on the basis of data from other studies in which the pharmacokinetic properties of ketamine were investigated. Blood samples for determination of plasma ketamine concentrations were collected periodically during each experiment. Plasma ketamine concentrations were determined by capillary gas chromatography/mass spectrometry under electron-impact ionization conditions, using lidocaine as the internal standard. Halothane minimal alveolar concentration (mac; concentration at which half the horses moved in response to an electrical stimulus) and plasma ketamine concentration were determined after steady-state concentrations of each ketamine infusion had been reached. Plasma ketamine concentrations > 1.0 μg/ml decreased halothane mac. The degree of mac reduction was correlated directly with the square root of the plasma ketamine concentration, reaching a maximum of 37% reduction at a plasma ketamine concentration of 10.8 ± 2.7 μg/ml. Heart rate, mean arterial blood pressure, and the rate of increase of right ventricular pressure did not change with increasing plasma ketamine concentration and halothane mac reduction. Cardiac output increased significantly during ketamine infusions and halothane mac reduction. Our findings suggest that plasma ketamine concentrations > 1.0 μm/ml reduce halothane mac and produce beneficial hemodynamic effects.
Induction of fatty liver in cows by ethionine administration and concomitant decreases of serum apolipoproteins B-100 and A-I concentrations
Authors: Uchida Eiji , Katoh Norio , Takahashi Kiyoshi 
Published: January 2024

Summary
Ethionine, an analogue of methionine, induces fatty liver in rats by inhibiting protein synthesis, including that of apolipoproteins in liver. Ethionine was administered to cows to elucidate the participation in fatty liver development of impaired triglyceride secretion from liver attributable to decreased apolipoprotein synthesis. The administration resulted in a significant increase of liver triglyceride contents. Several apolipoproteins were found to have decreased concentrations. In particular, apolipoprotein B-100 in very low-density (0.95 to 1.006 g/ml) lipoprotein and in low-density (1.006 to 1.063 g/ml) lipoprotein fractions was greatly reduced. The decreases of apolipoprotein B-100 concentrations in the 2 lipoprotein fractions were at least partly correlated to the decreased triglyceride concentrations in the respective fractions. Decreased concentrations of apolipoprotein A-I in high-density (1.063 to 1.210 g/ml) lipoprotein were also observed, although not as distinctly as with apolipoprotein B-100. Total cholesterol and phospholipid concentrations in low- and high-density lipoprotein fractions were decreased. The decrease in cholesterol was attributed to reduced concentrations of cholesteryl esters. It was suggested that the impaired lipid secretion from liver attributable to the decreased apolipoprotein concentrations has a role in ethionine-induced fatty liver of cows.
Functional, radiographic, and histologic assessment of healing of autogenous osteochondral grafts and full-thickness cartilage defects in the talus of dogs
Authors: Dew Terry L. , Martin Robert A. 
Published: January 2024

Summary
A circular (5.5 mm diameter) full-thickness cartilage defect was created on the medial ridge of the talus in 12 skeletally mature dogs. In 6 dogs, the articular surface of the lesion was repaired, using an osteochondral graft obtained from the ipsilateral manus. The graft (digit I, first phalanx, distal articular surface and diaphysis) was contoured to obtain a press fit in the drilled talar recipient site. In 6 dogs, the lesion was not treated and healed by fibrous tissue replacement. Functional assessment (lameness, hock range of motion, joint stability, joint crepitus, and mid-femoral muscle circumference) was completed before surgery and at postoperative weeks 2 through 20. Radiographic assessment (periarticular soft tissue width, joint space width, osteophyte formation, and graft incorporation) was completed before surgery and at postoperative weeks 0, 6, 12, and 20. To facilitate histologic assessment, tissues were stained with toluidine blue and H&E. Histologic assessment of the articular surface on the surgically treated talus, ipsilateral tibia, and contralateral talus was completed, using a modification of the Mankin grading system. Subchondral bone was examined to assess graft viability and incorporation. Analysis of the ordinal data was completed, using a Mann-Whitney rank sum test.
All dogs were fully weight bearing by postoperative week 7. Dogs without grafts had significantly (P = 0.036) better clinical function at postoperative week 6. Significant difference in functional assessment was not evident at postoperative week 20. Immediate postoperative radiographic assessment revealed significant (P = 0.005) difference between nongrafted and grafted groups. Significant difference was not observed at postoperative week 6, 12, or 20. All grafts appeared radiographically incorporated by postoperative week 12. All grafts restored joint surface congruity, whereas 3 of 6 nongrafted lesions had poor articular congruity. Of 6 grafts, 4 partially retained normal hyaline cartilage, resulting in significantly (P = 0.014) lower Mankin grades. Significant histologic differences between groups were not apparent when the apposing tibia and control talus were examined.
Talar reconstruction by use of a phalangeal osteochondral graft is a viable surgical procedure. These data indicate that normal articular and subchondral architecture are more closely approximated by osteochondral reconstruction than by fibrous tissue repair.
Measurement of lymphoblast proliferative capacity of stimulated blood mononuclear cells from cattle with chronic paratuberculosis
Authors: Kreeger John M. , Snider Theron G. 
Published: January 2024

Summary
Concanavalin A (conA) blast proliferation as a quantitative measure of lymphoblast proliferative capacity by blood mononuclear cell supernatants was measured in cattle naturally infected with Mycobacterium paratuberculosis and in healthy control cattle. Blast cell proliferation was significantly reduced in infected animals, compared with control cattle when blood mononuclear cells were stimulated with conA. Proliferation was significantly greater than media control when M bovis purified protein derivative and johnin were used to stimulate cells from the infected group. After sensitizing control and affected cattle with M paratuberculosis bacterin (live M bovis and keyhole limpet hemocyanin in Freund's incomplete adjuvant), infected animals had no difference in blast cell proliferative capacity with the mycobacterial antigens and conA stimulation, whereas healthy animals had significantly increased blast proliferation in response to all the sensitizing antigens. The blast cell proliferative capacity in infected animals with keyhole limpet hemocyanin stimulation was increased significantly after sensitization; however, it remained significantly less than that in the sensitized control group. These data indicate that cattle naturally infected with M paratuberculosis probably produce suboptimal interleukin-2 (il-2) activity in response to a potent il-2 inducer (conA) and fail to optimize il-2 activity when sensitized with a potent immunogen (keyhole limpet hemocyanin).
Blood types in cattle of Iberian ancestry and in Holsteins at various altitudes
Authors: Ramirez German , Miller Wilmer J. , Bittle Polly A. , Hidalgo Alvaro , Santacruz Rafael , Colice Gene 
Published: January 2024

Summary
Gene frequencies of rbc antigens were determined in Holsteins and Colombian (criollas) cattle living at 3,000 m, and in cattle descended from fighting bulls (Vacas de lidia) living at 2,500 m. These frequencies were compared with those of Holsteins, cattle native to Florida (scrub cattle), longhorns, and native cattle from Brazil (caracu cattle) living at sea level. The criollas, Vacas de lidia, scrub cows, longhorns, and caracu are descendants of original Iberian stock introduced to the Americas. We found that despite common ancestry (scrub cattle, longhorns, criollas, and caracu), genetic differences may have been derived through years of demographic isolation. The most remarkable blood-group differences were found in the high prevalence of the B system phenogroup (heritable group of antigenic factors) BQA'G'34 in the Vacas de lidia, and of the S system phenogroup U1H' in these cattle and in caracu. Furthermore, the gene frequencies differed in the Holsteins maintained at moderately high altitude (descended from Holsteins kept at sea level), and may have been reflective of the need to adapt to moderately high altitude and chronic hypoxemic conditions. Blood group polymorphism was found in all groups of cattle, although it was reduced in the Vacas de lidia, possibly because their breeding has been carefully controlled and they appear to be highly inbred.
Evaluation of plasma cortisol and corticosterone responses to synthetic adrenocorticotropic hormone administration in ferrets
Authors: Rosenthal Karen L. , Peterson Mark E. , Quesenberry Kathy E. , Lothrop Clinton D. 
Published: January 2024

SUMMARY
Plasma cortisol and corticosterone responses of 8 clinically normal adult ferrets to synthetic acth (cosyntropin) were evaluated. Cosyntropin was administered iv at 4 dosages (0.5, 1.0, 5.0, and 10 μg/ kg of body weight) at 2- to 4-week intervals, with blood samples collected 60 and 120 minutes after injection. After completion of the studies, an additional acth stimulation test was performed by administering cosyntropin (1.0 μg/kg) im. The baseline plasma cortisol concentrations from all studies ranged from 25.9 to 235 nmol/L (mean ± sem = 73.8 ± 7.0 nmol/L), and plasma corticosterone values ranged from 1.7 to 47 nmol/L (mean ± sem = 8.3 ± 1.1 nmol/L). After iv administration of cosyntropin, plasma concentrations of cortisol and corticosterone increased significantly (P ≤ 0.05) and reached peak values at 60 minutes; however, there were no significant differences between plasma cortisol or corticosterone responses to the 4 dosages of cosyntropin. Intramuscular administration of 1.0 μg of cosyntropin/kg induced increases in plasma cortisol and corticosterone concentrations that were similar to the responses induced by iv administration of cosyntropin. The mean molar ratio of cortisol to corticosterone, calculated from the resting plasma concentrations, was approximately 9:1, whereas the acth-stimulated cortisol to corticosterone ratio was approximately 4:1. Results of this study indicated that administration of cosyntropin to clinically normal ferrets, at dosages ranging from 0.5 to 10 μg/kg, increased plasma concentrations of cortisol and corticosterone. Although cosyntropin stimulates the adrenocortical secretion of cortisol and corticosterone, cortisol appears to be the predominate circulating glucocorticoid in ferrets.
Identification of Pasteurella haemolytica A1 isolates from market-stressed feeder calves by use of enzyme and antimicrobial susceptibility profiles
Authors: Purdy Charles W. , Scanlan Charles M. , Loan Raymond W. , Foster Gene S. 
Published: January 2024

SUMMARY
An epidemiologic study of Pasteurella haemolytica serovar 1 (Ph1) in market-stressed feeder calves from 7 farms in eastern Tennessee was conducted. The nasal mucus of each calf was cultured sequentially at the farm of origin (day 0), at an auction market (day 133), and at a feedyard in Texas (days 141, 148, 155, and 169). Of the 103 calves tested, 77 were culture-positive, including 1 on day 0, 1 on day 133, 20 on day 141, 57 on day 148, 50 on day 155, and 14 on day 169. From the 143 Ph1 isolates, 20 enzyme profiles were determined by use of a commercial enzyme system that detects 19 enzymatic reactions; 4 antimicrobial susceptibility profiles were obtained, using the disk-diffusion method, which evaluated susceptibility to 11 antibacterial drugs. All isolates were positive for acid phosphatase and alkaline phosphatase, but were negative for α-galactosidase, α-mannosidase, β-glucosidase, β-glucuronidase, cystine aminopeptidase, N-acetyl-β-glucosaminidase, and trypsin. Other positive enzyme reactions included: leucine aminopeptidase, 140 Ph1 isolates; phosphohydrolase, 90 isolates; α-fucosidase, 63 isolates; esterase (C4), 59 isolates; valine aminopeptidase, 30 isolates; esterase lipase (C8), 24 isolates; β-galactosidase, 2 isolates; and α-glucosidase, chymotrypsin and lipase (C14), 1 isolate each. Thirty-four Ph1 profiles were identified, using combined enzyme and antimicrobial susceptibility profiles. The data indicate that the strains isolated during the feedyard period may have been determined more by farm of origin (P ≤ 0.001) than by habitation with calves from other farms while in the feedyard. The combined enzyme and antimicrobial susceptibility profile method is a rapid and simple epidemiologic technique for tracking Ph1 strains in market-stressed feeder calves.
Corneal thickness measured by ultrasonic pachymetry in cats
Authors: Gilger Brian C. , Wright James C. , Whitley R. David , McLaughlin Susan A. 
Published: January 2024

SUMMARY
Ultrasonic pachymetry was used to measure central superior peripheral, and temporal peripheral corneal thickness of 35 cats (70 eyes) with normal corneas, anterior chambers, and intraocular pressures. Mean central corneal thickness for both eyes in 3 locations for 35 cats was 578 ± 64 µm. Significant differences did not exist between central and peripheral corneal thickness. Corneal thickness increased significantly (P < 0.0001) with age up to 100 months. There was no significant difference in corneal thickness with regard to sex of the cats when adjusted for age.
Factors influencing fecal shedding of Campylobacter jejuni in dogs without diarrhea
Authors: Torre Elvira , Tello Montserrat 
Published: January 2024

SUMMARY
Rectal swab specimens were collected from 362 apparently healthy dogs of different origin, age, breed, and sex. Specimens were obtained in summer, autumn, and winter. Ninety-five thermophilic Campylobacter spp were isolated: C jejuni biotype I, n = 57, C jejuni biotype II, n = 1, C coli, n = 36, and C laridis, n = 1. Biotypes of C jejuni recovered were the same as those associated with Campylobacter-induced enteritis in human beings.
Prevalence of C jejuni was significantly (P < 0.05) greater: in dogs < 6 months old than in adult dogs; in dogs living under high density and cohabitation housing conditions for long periods; and in autumn.
Effect of hypercapnia on the arrhythmogenic dose of epinephrine in horses anesthetized with guaifenesin, thiamylal sodium, and halothane
Authors: Gaynor James S. , Bednarski Richard M. , Muir William W. 
Published: January 2024

SUMMARY
The effect of hypercapnia on the arrhythmo-genic dose of epinephrine (ADE) was investigated in 14 horses. Anesthesia was induced with guaifenesin and thiamylal sodium and was maintained at an end-tidal halothane concentration between 0.86 and 0.92%. Base-apex ECG, cardiac output, and facial artery blood pressure were measured and recorded. The ADE was determined at normocapnia (arterial partial pressure of carbon dioxide [Paco2 = 35 to 45 mm of Hg), at hypercapnia (Paco2 = 70 to 80 mm of Hg), and after return to normocapnia. Epinephrine was infused at arithmetically spaced increasing rates (initial rate = 0.25 μg/kg of body weight/min) for a maximum of 10 minutes. The ADE was defined as the lowest epinephrine infusion rate, to the nearest 0.25 μg/kg/min, at which 4 premature ventricular complexes occurred in a 15-second period. The ADE (mean ± SD) during hypercapnia (1.04 ± 0.23 μg/kg/min) was significantly (P < 0.05) less than the ADE at normocapnia (1.35 ± 0.38 μg/kg/min), whereas the ADE after return to normocapnia (1.17 ± 0.22 μg/kg/min) was not significantly different from those during normocapnia or hypercapnia. Baseline systolic and diastolic arterial pressures and cardiac output decreased after return to normocapnia. Significant differences were not found in arterial partial pressure of O2 (PaO2) or in base excess during the experiment. Two horses developed ventricular fibrillation and died during normocapnic determinations of ADE. Hypercapnia was associated with an increased risk of developing ventricular arrhythmias in horses anesthetized with guaifenesin, thiamylal sodium, and halothane.
Detection of Toxoplasma gondii antigen-containing immune complexes in the serum of cats
Authors: Lappin Michael R. , Cayatte Suzanne , Powell Cynthia C. , Gigliotti Andrew , Cooper Christi , Roberts Steven M. 
Published: January 2024

SUMMARY
Enzyme-linked immunosorbent assays for the detection of Toxoplasma gondii antigen-containing IgM immune complexes (T gondii-specific IgM-lC) and IgG immune complexes (T gondii-specific IgG-IC) in the serum of cats were developed. Serum from clinically ill, naturally infected cats; healthy, naturally infected cats; and healthy cats experimentally inoculated with T gondii was assayed. All combinations of T gondii-specific IgM, IgG, antigens, IgM-IC and IgG-IC were detected in naturally infected and experimentally infected cats. Clinically ill cats and cats with ocular signs of toxoplasmosis were more likely than healthy cats to have Tgondii-specific IC in serum. It was concluded that T gondii-specific IC form in the serum of cats, may play a role in clinical disease development, and affect the results of Tgondii-specific IgM, IgG, and antigen serologic assays.
Neuromuscular blockade by use of atracurium in anesthetized llamas
Authors: Hildebrand S. V. , Hill T. 
Published: January 2024

SUMMARY
Anesthesia was induced in 8 healthy llamas by administration of guaifenesin and ketamine, and was maintained with halothane in oxygen. On 2 separate experimental days, atracurium was given to induce 95 to 99% reduction of evoked hind limb digital extensor tension (twitch). For the first part of the study, atracurium was given IV as repeat boluses, with muscle twitch strength being allowed to return without intervention to 75% of baseline after each bolus before the subsequent bolus was given. A total of 5 bolus doses of atracurium was given. For the first bolus, 0.15 mg/kg of body weight IV, and for subsequent boluses, 0.08 mg/kg, induced desired relaxation. Onset of relaxation was slightly more rapid for repeat, compared with initial, bolus. Duration of relaxation and recovery time were similar to initial and repeat doses. Maximal twitch reduction was observed in 4 ± 0.2 minutes (mean ± SEM). Duration from maximal twitch reduction to 10% recovery was 6.3 ± 0.4 minutes. Twitch recovery from 10 to 50% of baseline took 11.6 ± 0.6 minutes. Twitch recovery from 10 to 75% recovery took 19.5 ± 1.1 minutes. Recovery from 10% twitch to 50% fade took 12.8 ± 0.5 minutes. Fade at 50% recovery of twitch was 39 ± 0.02%. Significant (P < 0.05) animal-to-animal variation was observed in twitch recovery times.
For the second part of the study, atracurium was initially given IV as a 0.15-mg/kg bolus, followed by infusion for 1 to 2 hours. Infusion rate required some early adjustment to maintain desired relaxation, but the rate that prevailed was 1.07 ± 0.07 ml/kg/h (0.4 mg of atracurium/ml of saline solution). Recovery of muscle twitch was similar to that previously mentioned for repeat bolus administration. At the end of the study, edrophonium (0.5 mg/kg) with atropine (0.01 mg/kg, IV) was effective in antagonizing residual neuromuscular blockade by atracurium. All llamas recovered without injury from anesthesia, although 1 llama had a rough recovery. It was concluded that atracurium can provide neuromuscular blockade by either repeat bolus administration or continuous infusion in llamas.
Effects of long-term administration of clenbuterol in mature female rats
Authors: Re Giovanni , Badino Paola , Dacasto Mauro , Nebbia Carlo , Biolatti Bartolomeo , Di Carlo Francesco , Girardi Carlo 
Published: January 2024

SUMMARY
Female Sprague-Dawley rats were treated IM with 0, 2.5, 25, and 50 μg of clenbuterol HCl/kg of body weight/d for 21 days. In all treated rats, significant increase in body weight gain (P < 0.05) and improvement in feed conversion ratio (P < 0.05) were recorded. Hydrometra was observed in the uterus of treated rats, and histologically, it was possible to see dilatation of luminal glands and ovarian alterations. Clenbuterol treatment induced significant (P < 0.05) increase in uterine estrogen receptor concentration of rats treated with the 2 higher doses. Treatment apparently failed to enhance the rate of oxidative and conjugative biotransformations, except for glucuronidation of p-nitrophenol (P < 0.05). On the basis of the data obtained, we could affirm that high doses of clenbuterol affect the female reproductive system of rats inducing, almost in part, estrogen-like modifications, but probably by a different mechanism of action correlated to intense adrenergic stimulation.