bluuebunny/crossref_metadata_2025 huggingface dataset:
Bluetongue virus isolations from vectors and ruminants in Central America and the Caribbean
Authors: Mo Claudette L. , Thompson Lee H. , Homan E. Jane , Oviedo Marco T. , Greiner Ellis C. , González Johnny , Sáenz Maria R. , _ _
Published: January 2024

A regional prospective study of the epidemiology of bluetongue virus (btv) serotypes covering 11 countries in Central America and the Caribbean took place between 1987 and 1992. Active surveillance revealed btv infection to be endemic in the absence of confirmed indigenous cases of bluetongue. During the 6-year span of the study, over 300 btv isolations were obtained from cattle and sheep. Results of the earlier years of the study were summarized, and surveillance activities in the concluding months of the study from November 1990 to February 1992 were evaluated. Forty-five btv isolations were made during this time, 44 from sentinel cattle and 1 from a ram with clinical signs compatible with contagious ecthyma. Virus isolation from potential vectors also was attempted, yielding a further 9 btv isolates from parous Culicoides insignis and C pusillus, 2 btv isolates from blood engorged C filarifer, and 1 epizootic hemorrhagic disease virus type-2 isolate from parous C pusillus. Our extensive network of sentinel herds in the region detected btv-1 as the predominant serotype in Central America in 1991, after an apparent absence of 1 year in the sentinel animals. Other serotypes in Central America at that time included btv-3 and btv-6 in Puerto Rico and the Dominican Republic, btv-4 became the predominant serotype, without detection of btv-8 and btv-17, which were common in recent years of the study. The serotypes found in the Caribbean Basin continued to have marked differences from those in North America. The importance of viewing bluetongue as an infection, the distribution of which is determined principally by ecologic factors, is emphasized.
Biological and biochemical characterization of Fusobacterium necrophorum leukotoxin
Authors: Tan Z. L. , Nagaraja T. G. , Chengappa M. M. , Smith J. S.
Published: January 2024

Biological and biochemical characteristics of the leukotoxin of Fusobacterium necrophorum were determined. Culture supernatant of F necrophorum was toxic to polymorphonuclear neutrophilic, leukocytes from cattle and sheep, but not to those from pigs and rabbits. Culture supernatant and sonicated bacterial cell fractions had low hemolytic activity and did not cause dermonecrosis in a guinea pig. Supernatant derived leukotoxin was inactivated at 56 C for 5 minutes and became unstable at pH > 7.8 or < 6.6. Chemical treatment with 0.1% sodium dodecyl sulfate, 0.25% sodium deoxycholate, 5.2% sodium sulfide, or 0.25 mM titanium (III) citrate markedly decreased leukotoxicity. Enzymatic treatment with protease, trypsin, and chymotrypsin inactivated the toxin completely, whereas amylase had no effect. Use of protease inhibitors failed to prevent loss of leukotoxin activity. Using membrane partition chromatography and gel filtration, the estimated molecular weight of the toxin was > 300,000. On reduction and denaturation, the toxin dissociated into several components by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Application of interspecies scaling to the bispyridinium oxime HI-6
Authors: Baggot J. Desmond
Published: January 2024

Disposition kinetic variables of HI-6, a bispyridinium oxime, have been determined in mice, rats, rabbits, Rhesus monkeys, Beagles, sheep, and human beings. The drug has a short half-life, small apparent volume of distribution and high body clearance in these species, and is eliminated mainly by renal excretion. Using regression analysis and double logarithmic plots of the pharmacokinetic variables vs body weight of the various species, it was observed that body (systemic) clearance is the pharmacokinetic variable to use for interspecies comparison of elimination of the drug. The allometric exponent denoting the proportionality of body clearance of HI-6 to body weight of the 7 species studied was 0.76, which may be related to the renal excretion process for the drug. The apparent volume of distribution was similar (260 to 304 ml/kg of body weight) in the various species. The results indicate that volume of distribution, body clearance, and with less confidence, half-life might be used for interspecies scaling and for predicting these variables in other mammalian species. On the basis of the pharmacokinetic variables in selected species (rats and mice excluded), iv administration of HI-6 at a dosing rate of 20 to 25 mg/kg at 4-hour intervals should provide an average steady-state plasma concentration of 16 to 20 µg/ml in domestic animals. The short half-life of HI-6 precludes increasing the dosage interval.
Airway occlusion pressure and diaphragm global electromyogram analysis for evaluation of inspiratory muscle drive and neuromechanical coupling in cattle
Authors: Desmecht Daniel J-M. , Linden Annick S. , Rollin Frederic A. , Lekeux Pierre M.
Published: January 2024

Although healthy and diseased bovine respiratory tracts have been intensively studied during the last years, to the authors’ knowledge, there have been no attempts to objectively examine the inspiratory drive from the brain to the nerves and muscles and its transformation in pressure. Such technique would be useful in assessing the possibility of altered ventilatory drive or inspiratory muscle fatigue in the context of an animal with ventilatory failure.

The relation among ventilation, airway opening occlusion pressure generated 100 milliseconds after onset of inspiration (Pawo100ms) and 6 indexes describing diaphragmatic electromyographic activity (emgdi) recorded via implanted fishhooks was evaluated during free and impeded CO2 rebreathing in 6 young bulls. The best significant linear correlations (r > 0.8) with inspiratory center afferent stimulation, as judged by end-tidal CO2 concentration in expired air, were found for Pawo100ms, peak moving time average or variance emgdi, and mean integrated emgdi, whatever had been the respiratory impedance. However, with an inspiratory load, Pawo100ms responses systematically had greater increase for a given change in the driving emgdi, implying dependence of the former not only on neural input, but also on configurational factors that determine inspiratory muscle excitation-pressure generation couplings. The reproducibility of emgdi absolute values and changes was satisfactory up to 10 hours, but could not be repeated from one day to the other.

It was concluded that, provided the constancy of the electrical coupling of the recording system to the tissue being studied is ensured, specific emgdi and Pawo100ms values correlate reliably with amount of CO2 during free and loaded breathing. Simultaneous collection of both values during experimentally induced pulmonary disease in calves could, therefore, produce information to help answer questions about the role of cns and inspiratory muscle dysfunction in case of ventilatory failure. Careful interpretation, however, requires additional measurements, such as end-expiratory lung volume, and some familiarity with the underlying physiologic processes that link phrenic nerve discharge to generation of negative pressure at the airway opening.
Concentrations of amino acids in plasma and whole blood in response to food deprivation and refeeding in healthy two-day-old foals
Authors: Zicker Steven C. , Rogers Quinton R.
Published: January 2024

Concentrations of amino acids in plasma and whole blood in response to 10 hours of food deprivation were determined in healthy 2-day-old foals (n = 8) and were compared with control values in foals of the same age (n = 8) allowed free access to suckle. In addition, response of concentrations of amino acids in plasma to 15 minutes of free-access suckling was determined at the end of the 10-hour period in both groups. Response of 13 amino acids in plasma of food-deprived foals was significantly (P < 0.05) different, compared with that in control foals. Concentrations of 3 amino acids (alanine, glycine, and phenylalanine) in plasma increased significantly (P < 0.05), whereas concentrations of 7 amino acids (asparagine, citrulline, histidine, ornithine, proline, tryptophan, and tyrosine) in plasma decreased significantly (P < 0.05) during food deprivation. Response of concentrations of 2 amino acids (glycine and histidine) in whole blood was significantly (P < 0.05) different from that in plasma of food-deprived vs control foals. Refeeding of food-deprived foals resulted in significantly (P < 0.05) different responses for concentrations of all but 2 amino acids (cystine and taurine) in plasma, compared with responses in controls. Changes in concentrations of amino acids in plasma and whole blood of foals in response to food deprivation are similar to those in foals with septicemia and in children with grade 1 or 2 kwashiorkor. The significantly different response of food-deprived foals to refeeding may be attributable to increased protein intake or altered physiologic state.
Association between neutrophil functions and periparturient disorders in cows
Authors: Cai Tian-Quan , Weston Patricia G. , Lund Lisa A. , Brodie Bruce , McKenna Donald J. , Wagner William C.
Published: January 2024

Neutrophil functions were examined in healthy periparturient dairy cows (n = 46) and in cows with retained placenta and metritis complex (n = 20); metritis (n = 18); or mastitis (n = 13). Blood samples (50 ml) were collected from each cow via jugular vein twice weekly from 1.5 weeks before to 4 weeks after parturition. Neutrophil function was evaluated, using 6 tests: random migration, chemotaxis, ingestion, myeloperoxidase activity (iodination), superoxide production (cytochrome C reduction), and antibodydependent cell-mediated cytotoxicity. Ability to ingest bacteria and random migration activity of neutrophils from clinically normal cows were high around parturition and increased immeidately after parturition, whereas myeloperoxidase activity and antibody-dependent cell-mediated cytotoxicity ability of neutrophils from these cows decreased after parturition. Measurement of neutrophil function in 4 over-iectomized cows revealed significant (P < 0.0005) seasonal changes in results of all 6 functional assays. We observed various defects of neutrophil function in all cows with abnormal conditions after parturition. Before parturition, superoxide production activity by neutrophils from cows with metritis and chemotaxis by neutrophils from cows with mastitis were significantly (P < 0.001 and P < 0.05, respectively) lower, indicating that a defect of neutrophil function may be a predisposing factor in the development of these disorders. In conclusion, the host defense role of neutrophils in periparturient cows was impaired, principally because of a defect in killing capacity, which may increase susceptibility to infections. We also investigated the in vitro effects of arachidonic acid metabolites and recombinant human colonystimulating factors (rhcsf) on functions of neutrophils from clinically normal and postparturient cows with abnormalities, including retained placenta, metritis, or mastitis (n = 5/group). Each abnormal cow was matched for postpartum period with a clinically normal cow. Neutrophils from individual cows were preincubated with arachidonic acid metabolites (prostaglandin F2a, 10−7M; prostaglandin E2, 10−6M; leukotriene B4, 10−8M; and lipoxin B, 10−8M) and rhcsf (rh-granulocyte-csf, 1,000 or 6,000 U/ml; rh-granulocyte-macrophage-csf, 5 or 15 ng/ml) in a 37 C water bath for 30 minutes before submitting them to function assays. There was no response by neutrophils from either clinically normal or abnormal postparturient cows to treatment with either arachidonic acid metabolites or rhcsf in any of the 6 functional assays. However, preincubation of neutrophils alone in a 37 C water bath for 30 minutes resulted in some alteration of neutrophil function. This may indicate translocation of receptors between an intracellular pool and the cell surface, as well as differences in receptor numbers or signal transduction mechanisms in these abnormal cows.
Quantification of serum total IgE concentration in dogs by use of an enzyme-linked immunosorbent assay containing monoclonal murine anti-canine IgE
Authors: Hill Peter B. , DeBoer Douglas J.
Published: January 2024

A method for quantification of serum total IgE concentration in dogs by use of an elisa containing monoclonal mouse anti-canine IgE was developed. Microtitration plates were coated with monoclonal mouse anti-canine IgE. Test sera and reference serum dilutions were added, followed by biotinylated monoclonal mouse anti-canine IgE. Avidin-alkaline phosphatase conjugate was added, and color development was measured spectrophotometrically, using a microtitration plate reader. Quantitative results were obtained by assigning to a reference serum a value of 100 IgE units/ml. Asorbance values of unknown samples were converted into IgE units by comparison with a standard curve generated by measurement of reference serum dilutions. Intra- and interassay coefficients of variation were 5 and 7%, respectively, and assay sensitivity was 1 U/ml. The assay was used to establish a normal range for total IgE concentrations in 30 healthy dogs. Total IgE concentration in healthy dogs followed a skewed distribution and ranged from < 1 to 91.2 U/ml, with a geometric mean value of 7.1 U/ml. The IgE concentration was remarkably stable in serum samples subjected to 25 freeze/thaw cycles or incubation at approximately 25 C (room temperature) for up to 10 days. Comparison of total IgE concentrations in 23 serum samples assayed by use of double-overlay radial immunodiffusion and elisa yielded correlation coefficient of 0.94. Comparison of the reference serum standard curve with serial dilutions of a purified IgE solution of known concentration yielded a range of values for the IgE unit of 0.7 to 2.0 μg.
Serotype-specific inhibition of colonization of the tonsils and nasopharynx of calves after Pasteurella haemolytica serotype A1 after vaccination with the organism
Authors: Frank G. H. , Briggs R. E. , Loan R. W. , Purdy C. W. , Zehr E. S.
Published: January 2024

Vaccination of cattle with a tissue culture-derived Pasteurella haemolytica serotype 1 vaccine elicited a serotype-specific inhibition of nasal and tonsillar colonization by the homologous serotype under field conditions.

Calves (n = 101) originated from a single farm, where half the calves were vaccinated. The calves were delivered to an order-buyer barn 105 days later, and given a second dose of vaccine. At the order-buyer barn, calves were mixed with 27 calves, some of which had clinical signs consistent with respiratory tract disease. Also 12 of the original calves were infected with P haemolytica serotype 1 by tonsillar instillation. After 6 days at the order-buyer barn, calves were shipped 1,600 km by truck to a feedyard, and arrived the next day. Tonsillar wash and nasal secretion aspiration specimens were collected for culture of P haemolytica on days 1, 8, and 29 at the feedyard. Inhibition of colonization was evidenced by lower frequency of isolations from the vaccinates than from the nonvaccinates after transport to the feedyard. Selectively lowering the frequency of colonization by P haemolytica serotype 1 could reduce losses attributable to pneumonic pasteurellosis.
Comparison of cellular and extracellular proteins expressed by various isolates of Mycobacterium paratuberculosis and other mycobacterial species
Authors: White W. Bruce , Whipple Diana L. , Stabel Judith R. , Bolin Carole A.
Published: January 2024

Protein expression profiles of 10 isolates of Mycobacterium paratuberculosis, M avium 18 (formerly M paratuberculosis 18), and 1 isolate each of M avium serotype 2, M avium serotype 8, and M bovis BCG were examined. Protein expression profiles of M paratuberculosis and M avium were similar. However, two-dimensional gel analysis of [35S]methionine-labeled cellular proteins resolved 4 proteins, with molecular mass of 28,000, 32,000, 32,000, and 42,000 daltons, which were expressed in greater amounts in M paratuberculosis than in M avium. Two proteins, with molecular mass of 43,000 and 60,000 daltons, were identified, which were expressed in greater amounts in M avium than in M paratuberculosis. Immuno (western)-blot analysis, using antiserum from 2 cows clinically infected with M paratuberculosis as the primary antibodies, suggested that the 42,000- dalton protein may be specific for M paratuberculosis.

Comparison of protein expression profiles may be useful as a tool for differentiating isolates of < M > paratuberculosis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of [35S]methionine-labeled extracellular proteins revealed variability among the isolates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of [35S]methionine-labeled cellular proteins divided the M paratuberculosis isolates into 2 groups on the basis of a difference in the amount of expression of a 28,000-dalton protein. This information may be useful in epidemiologic studies.
Antigenic analysis of Dictyocaulus viviparus by use of test-positive bovine sera
Authors: Hale Gina Lynn , Green Theodore James
Published: January 2024

An antigen extract of Dictyocaulus viviparus was analyzed by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the antigen-recognition patterns of serum antibody from cattle not infected, cattle infected with D viviparus, and cattle with unknown history of D viviparus were analyzed by the use of ELISA and western blotting techniques. Cross-reactive antibody-recognition patterns were determined by comparing western blots of D viviparus-positive sera with blots of D viviparus-negative sera obtained from cattle singly infected with Bunostomum phlebotomum, Cooperia oncophora, C punctata, Nematodirus helvetianus, Oesophagostomum radiatum, or Ostertagia ostertagi. Five antigen bands unique to D viviparus were identified, and their frequency of appearance in western blots of sera from verified D viviparus-positive and -negative cattle, and sera from cattle exposed to the parasite, but with unknown D viviparus immune status, were determined. Of the 5 antigens unique to D viviparus, 29- and 19-kd bands had the highest frequencies of reaction (45.9 and 59.0%, respectively) with the test sera. These bands had strong reactivity with sera containing antibodies to D viviparus and did not react with the heterologous sera. We conclude that the 29- and 19-kd antigens may be useful for developing an improved serodiagnostic test for D viviparus infections in cattle.
Effects of subject stance time and velocity on ground reaction forces in clinically normal Greyhounds at the walk
Authors: Roush James K. , McLaughlin Ronald M.
Published: January 2024

Force plate gait analysis was used to study the effects of subject stance time and velocity on ground reaction forces in 5 adult Greyhounds at the walk. Data from 146 valid trials were obtained. Stance time and velocity were linearly related, and stance time had a strong, negative correlation with velocity (r = −0.72 for the forelimbs, r = −0.56 for the hind limbs). Stance time correlated more closely with changes in peak vertical force and impulse than did velocity. Stance time and velocity correlated less strongly with braking and propulsion forces and impulses. The trials were divided into 2 distinct velocity ranges (V1 = 0.92 to 1.03 m/s, V2 = 1.06 to 1.17 m/s), 2 distinct forelimb stance time ranges (fst1 = 0.43 to 0.48 second, fst2 = 0.50 to 0.55 second), and 2 distinct hind limb stance time ranges (hst1 = 0.40 to 0.45 second, hst2 = 0.46 to 0.51 second). Five trials from each dog were included in each range, and the mean values were used to evaluate changes in ground reaction forces between groups. Peak vertical force in the forelimbs decreased significantly (P = 0.048) as fst increased; however, difference was not detected in vertical force between velocity groups. Peak vertical force in the hind limbs decreased significantly (P = 0.001) as hst increased and increased significantly (P = 0.000) as velocity increased. Differences were not observed between groups in forelimb or hind limb braking and propulsive forces. Vertical impulse in the forelimbs and hind limbs decreased as velocity increased and increased as stance time increased. Braking impulse in the forelimbs decreased as velocity increased and increased as fst increased. Braking force in the hind limbs did not change between velocity or stance time groups. Propulsive impulse in the hind limbs decreased as velocity increased and increased as hst increased. Stance time was a sensitive and accurate indicator of subject velocity in clinically normal dogs at the walk and correlated more closely with changes in some ground reaction forces than did velocity measurements. Stance time measurements could be used to normalize trial data within a sampling period and document consistency in velocity during force plate analysis of clinically normal dogs at the walk.
Changes in the intestinal mucosal cell populations of German Shepherd Dogs fed diets containing different protein sources
Authors: Edwards J. F. , Fossum T. W. , Willard M. D. , Cohen N. D. , Patterson William B. , Carey D. P.
Published: January 2024

Sixteen German Shepherd Dogs from 4 litters were IgA-deficient on the basis of at least 1 of 2 serum IgA determinations, and all had small intestinal bacterial overgrowth, as documented by quantitated small intestinal bacterial culture in another study. These dogs were fed 2 diets that differed principally in their protein source (chicken vs beef, milk, and wheat). All dogs were fed each diet for 2 weeks before the study began. Next, all dogs were fed the chicken-based diet for 2 months. Then, half the dogs (group 1) were randomly assigned to continue eating the chicken-based diet, while the other half (group 2) ate a diet containing beef, milk, and wheat proteins. The small intestine was biopsied at the beginning of the study and after dogs had eaten the assigned diet for 2 and 4 months. At 2 months, group-2 dogs had more colonic mucosal mast cells, but this difference did not persist at 4 months. At the end of the study (ie, 4 months), although all dogs were clinically normal, group-2 dogs had significantly (P = 0.010) decreased numbers of jejunal villus plasma cells. However, these histologic changes were not considered clinically important. There were no significant differences in blood eosinophil counts, serum trypsin-like immunoreactivity, or cobalamin, folate, or IgA concentration. Clinical differences were not detected between the 2 groups, before or after the study. Changes were seen in serum IgM and IgG concentrations. Although results of this study suggest that dietary protein may influence intestinal mucosal cell populations, there was no evidence that the protein sources in these 2 diets caused intestinal disease in these dogs under the conditions of this study.
Bioequivalency comparison between two gonadotropin-releasing hormone products
Authors: Stevens R. D. , Seguin B. E. , Hegstad R. L. , Keefe T. J. , Schultz R. H. , Kennedy T. J.
Published: January 2024

The bioequivalency of 2 gondatropin-releasing hormone (GnRH) preparations, gonadorelin diacetate tetrahydrate and gonadorelin semicarbonate, was compared on the basis of luteinizing hormone (lh)-releasing ability of the 2 products in diestrous dairy cows. Twenty-four cycling, nonlactating Holstein cows were subjected to a double prostaglandin estrus synchronization treatment to simultaneously control stage of the estrous cycle and time factors as potential variables effecting lh responses to the treatments being studied. Circulating progesterone concentration was determined to verify stage of cycle at strategic times throughout the study. Twelve days after the second prostaglandin treatment, all cows were randomly assigned to 1 of 2 groups (n = 12). Each group of 12 cows received single doses (100 μg) of either GnRH preparation at the start of each test period in a 2-period crossover design. Serum samples were obtained prior to and at 12 times (10, 20, 30, 45, 60, 90, 120, 180, 240, 360, 480, and 1,440 minutes) after treatment and were assayed to determine circulating lh concentration. Significant difference between the 2 GnRH products was not found with respect to: mean concentration of lh in the blood during the 24 hours after treatment; maximal lh concentration; time from treatment to maximal lh concentration; and area under the lh concentration curve from time 0 through each of 7 times after treatment (0.5, 1, 1.5, 2, 4, 8, and 24 hours). These data confirm the bioequivalency of the 2 GnRH products.
Effects of three occlusive dressing materials on healing of full-thickness skin wounds in dogs
Authors: Ramsey David T. , Pope Eric R. , Wagner-Mann Colette , Berg John N. , Swaim Steven F.
Published: January 2024

The effects of 3 occlusive dressing materials and a standard, nonadherent dressing material on healing of full-thickness skin defects were evaluated in dogs. Two wounds measuring 2 × 2 cm were created bilaterally (4 wounds/dog) on the dorsolateral aspect of the trunk of 12 Beagles. Wound treatments were evenly distributed between 4 sites, using a Latin square design. Treatments evaluated were: equine amnion (group A), biosynthetic hydrogel dressing (group B), transparent polyethylene sheeting (group T), and a semiocclusive rayon/polyethylene, nonadherent dressing (group C). Rates of contraction and epithelialization of group-A wounds were significantly greater than those of wounds of groups C, B, and T. On days 14, 21, and 28, mean percentage of wound contraction and mean percentage of total wound healed in group A exceeded those wounds in groups C, B, and T. On day 28, wounds in group A were significantly smaller than wounds in groups B and T, but were not significantly smaller than wounds in group C. All wounds in group A achieved 100% healing during the 28-day study period. Mean time for complete healing of group-A wounds was 21 days. The percentages of wounds completely healed by day 28 for groups B, C, and T were 25, 67, and 25%, respectively. Results indicate that use of equine amnion as an occlusive biological dressing on full-thickness wounds in dogs increases rate of healing.
Comparison of estrogen and progesterone receptor expression in normal and tumor mammary tissues from dogs
Authors: Donnay Isabelle , Rauïs Jacques , Devleeschouwer Nicole , Wouters-Ballman Patricia , Leclercq Guy , Verstegen John
Published: January 2024

Concentrations of estrogen (er) and progesterone (pr) receptors were measured by radioreceptor assay in tumor (n = 319) and normal (n = 166) mammary tissue from 248 bitches. Correlations between er and pr and between receptor expression in tumor and normal mammary tissue from the same bitches were evaluated. The influence of tumor, clinical, or hormonal variables on receptor expression also was studied. Approximately 80% of tumor and 95% of normal mammary tissue expressed detectable concentrations of er, pr, or both. Direct correlation was found between er and pr concentrations in normal and tumor tissues. Median er concentrations were significantly higher (46 ± 47 fmol/mg of cytosolic protein vs 27 ± 24 fmol/mg of cytosolic protein; P = 0.0002) in normal than in tumor tissue. On the other hand, pr concentrations were significantly higher (57 ± 52 fmol/mg vs 77 ± 99 fmol/mg; P = 0.03) in tumors (especially benign tumors) than in normal tissue. Poorly differentiated malignant tumors expressed lower concentrations of receptors than did benign or well differentiated malignant tumors. The er and pr concentrations decreased with increasing size of the lesion. Hormonal status of the bitch significantly (P < 0.05) influenced receptor expression in normal tissue: bitches in the luteal phase of the estrous cycle had higher concentrations of er (69 ± 62 fmol/mg) than did ovariectomized bitches (24 ± 19 fmol/mg) or bitches in anestrus (38 ± 45 fmol/mg) or the follicular phase (13 ± 7 fmol/mg). For pr, higher concentrations were observed in normal tissue during anestrus than during pseudopregnancy or in bitches treated with medroxyprogesterone acetate. Similar, but nonsignificant, variations were seen in tumor tissue except in medroxyprogesterone acetate-treated bitches in which pr concentrations were high in tumors and low in normal tissue from the same bitches. Significant relation between age, hormonal history, number or location of lesions, and receptor expression was not observed. However, significantly (P < 0.05) lower receptor concentrations were found in the normal tissue from the 3 cranial pairs of mammary glands (er, 37 ± 45; pr, 43 ± 30 fmol/mg) than from the 2 caudal pairs (er, 51 ± 50; pr, 62 ± 53 fmol/mg). A direct correlation was found for both receptor concentrations between normal tissue adjacent to and distant from the lesions and between normal tissue adjacent to the lesion and the corresponding tumor. In comparison with that in normal tissue, the general mechanism of modulation of receptor expression seems not to be modified in benign lesions and well differentiated malignant tumors. However, hormonal sensitivity is lost in dedifferentiated tumors.
Ultrasonographic cross-sectional area and mean echogenicity of the superficial and deep digital flexor tendons in 50 trained Thoroughbred racehorses
Authors: Gillis Carol , Meagher Dennis M. , Cloninger Ashton , Locatelli Lynn , Willits Neil
Published: January 2024

Fifty Thoroughbred horses were examined. All horses had been in race training for a minimum of 4 months before examination and had worked at racing speed; 24 horses had raced. All horses were clinically sound at the time of examination. Ultrasonography was performed, using a 7.5-MHz transducer with built-in fluid offset. Videotaped images of the palmar soft tissue structures were obtained at 4, 8, 12, 16, 20, and 24 cm distal to the base of the accessory carpal bone (dacb). Images were digitized, and each image was calibrated. Values for cross-sectional area (csa) and mean echogenicity (me) were then determined from the cross-sectional images of the superficial digital flexor (sdf) and the deep digital flexor (ddf) tendons, using an image-analysis program.

The sdf tendons were compared between right and left forelimbs at each level, and from proximad to distad on each limb, as were the ddf tendons. The relation between the sdf and ddf tendons for the same forelimb was determined at each level. There were no significant differences in csa or me at equivalent levels of the left and right sdf tendons. Mean (± sd) csa was 1.01 (± 0.12) cm2 at 4 cm dacb, 0.95 (± 0.14) cm2 at 12 cm dacb, and 1.12 (± 0.15) cm2 at 24 cm dacb. Adjusted me was 2.34 (± 0.34) at 4 cm dacb, 2.03 (± 0.38) at 12 cm dacb, and 2.04 (± 0.35) at 24 cm dacb.

The left and right ddf tendons did not have significant differences in csa or me at any level. Cross-sectional area was 1.13 (± 0.18) cm2 at 4 cm dacb, 1.01 (± 0.12) cm2 at 12 cm dacb, and 1.75 (± 0.29) cm2 at 24 cm dacb. Adjusted me was 2.60 (± 0.46) at 4 cm dacb, 2.49 (± 0.49) at 12 cm dacb, and 2.50 (± 0.44) at 24 cm dacb.

At all levels, the left and right sdf tendons were smaller and less echoic than the ddf tendons of the same limb. The sdf and ddf tendons had an hourglass shape, with smallest csa at 12 cm dacb. Mean echogenicity generally decreased for the sdf and ddf tendons from proximad to distad on the limb.

These results indicate that for clinically normal trained Thoroughbred racehorses, there should be no significant difference in csa or echogenicity between the left and right sdf tendons at equivalent distances dacb. There should be no significant differences in the left and right ddf tendons at equivalent levels dacb. The sdf tendon is usually smaller and less echoic than the corresponding ddf tendon at each level.
Passive protection of calves with Pasteurella haemolytica antiserum
Authors: Mosier Derek A. , Simons K. René , Vestweber Jerome G.
Published: January 2024

Four colostrum-deprived calves each were immunized passively with antisera to whole Pasteurella haemolytica, leukotoxin-containing supernatants of P haemolytica, P haemolytica lipopolysaccharide, or newborn calf serum. Calves were challenge exposed intrabronchially with 5 × 109 P haemolytica, and 24 hours later, the resulting lesions were evaluated. The greatest protection against challenge exposure was provided by the antiserum to whole P haemolytica (lesion score = 6.3), whereas newborn calf serum provided the least protection (lesion score = 28.3). Calves that received antiserum to P haemolytica supernatants were moderately protected (lesion score = 16.3), and the antiserum to lipopolysaccharide provided minimal protection (lesion score = 21.8). Antibodies that were unique to whole P haemolytica antiserum and produced dense bands on immunoblots were detected to antigens at 66, 50, and 30 kd. Antibodies in the supernatant preparation that produced prominent bands reacted to antigens between 100 and 90 kd. Collectively, antibodies to these antigens may be responsible for enhancing resistance to experimentally induced pneumonic pasteurellosis. Antibodies to antigens in P haemolytica lipopolysaccharide provided little to no protection.
Effect of maturation and aging on material and ultrasonographic properties of equine superficial digital flexor tendon
Authors: Gillis Carol , Sharkey Neil , Stover Susan M. , Pool Roy R. , Meagher Dennis M. , Willits Neil
Published: January 2024

Results of studies in human beings and other species have indicated that aging significantly influences the strength, modulus of elasticity, and energy storage ability of tendon. We wanted to determine the effects of aging on the material and ultrasonographic properties of equine superficial digital flexor (sdf) tendon. Ultrasonographic measurements of left forelimb sdf tendon cross-sectional area and mean echogenicity were made in 23 standing horses ranging in age from 2 to 23 years. All horses had not been in work for a minimum of 6 months prior to the study. After euthanasia, left forelimb bone-muscle-tendon-bone specimens were mounted in a materials testing system. The sdf tendon was cyclically loaded sinusoidally 100 times at 0.5 Hz from 1.5 to 5.0% strain, then was submitted to 10-minute creep-and-stress relaxation tests. Modulus of elasticity, load at 3% strain, and creep-and-stress relaxation were determined for each specimen. A significant positive correlation was found between elastic modulus and age. Correlation was not found between age and sdf tendon cross-sectional area or mean echogenicity. When 2-year-old horses were compared with older horses, the latter had tendons with a significantly (P = 0.007) greater modulus of elasticity. The authors conclude that increasing age through maturity is associated with a corresponding increase in equine sdf tendon elastic modulus.
Identity and interactions of rumen microbes associated with dietary sulfate-induced polioencephalomalacia in cattle
Authors: Cummings B. A. , Caldwell D. R. , Gould D. H. , Hamar D. W.
Published: January 2024

To study their role in sulfate reduction, anaerobic bacteria were cultured from rumen fluid samples of cattle fed high-carbohydrate, short-fiber diets with and without added sulfate. The steers fed the diet with added sulfate developed polioencephalomalacia. Microbiological methods included colony-type profiles, molybdate sensitivity, presence of desulfoviridin, sulfate reduction rates of pure and mixed cultures, and incubation time effects on sulfate reduction. Colony-type profiles indicated decreased diversity, but no relative change in numbers of sulfate-reducing bacteria in rumen fluid from cattle fed diets with and without added sulfate. Thirteen bacterial isolates were selected for further study on the basis of colony type, sulfate-reducing activity, and growth in lactate, sulfate, and yeast extract media. Seven of the isolates had Desulfovibrio-like characteristics (ie, they were gram-negative, motile rods that reduced sulfate, were inhibited by molybdate, and contained the pigment desulfoviridin). The remaining 6 isolates were gram-negative, nonmotile rods. Four of these released sulfide from cysteine, and 2 generated only limited amounts of sulfide from sulfate or cysteine. The 7 sulfate-reducing isolates generated sulfide in rumen fluid broth medium at greater rates than those observed in fresh rumen fluid. Sulfate reduction could be sustained in cultures for prolonged incubation times if the gas phase containing hydrogen sulfide was replaced at frequent intervals. Variations in the amount of sulfate reduced by the pure cultures were most pronounced at short incubation times. Sulfate reduction was not inhibited in mixed cultures of sulfate-reducing and nonsulfate-reducing bacteria.
Ultrastructure of selected struvite-containing urinary calculi from cats
Authors: Neumann Rebecca D. , Ruby Annette L. , Ling Gerald V. , Schiffman Peter S. , Johnson Deedra L.
Published: January 2024

Objective

To elucidate the ultrastructural details of struvite-containing urinary calculi from cats.

Design

Specimens studied were inclusive of the range of textures visible during preliminary analysis by use of a stereoscopic dissecting microscope. Textural types, which were used to infer crystal growth conditions, were differentiated with regard to crystal habit, crystal size, growth orientation, and primary porosity.

Sample Population

Thirty specimens were selected from a collection of approximately 1,600 feline urinary calculi: 20 of these were composed entirely of struvite, and 10 consisted of struvite and calcium phosphate (apatite).

Procedure

Qualitative and quantitative analyses of specimens included use of plain and polarized light microscopy, x-ray diffractometry, scanning electron microscopy with backscattered electron imagery, x-ray fluorescence scans, and electron probe microanalysis.

Results

Four textural types were recognized among struvite calculi, whereas 2 textural types of struvite-apatite calculi were described.

Conclusions

The presence of minute, well interconnected primary pores in struvite-containing urinary calculi from cats is an important feature, which may promote possible interaction of calculi with changes in urine composition.

Clinical Relevance

Primary porosity, which can facilitate interaction between the calculus and changing urine composition, may explain the efficacy of dietary or medicinal manipulations to promote the dissolution of struvite-containing uroliths from this species. (Am J Vet Res 1996;57:12–24)
Clinical field trials with tilmicosin phosphate in feed for the control of naturally acquired pneumonia caused by Actinobacillus pleuropneumoniae and Pasteurella multocida in swine
Authors: Moore Gregory M. , Basson Rodney P. , Tonkinson Lealon V.
Published: January 2024

Objective

To determine and evaluate the efficacy of the dose range of tilmicosin phosphate fed to pigs for control of pneumonia attributable to Actinobacillus pleuropneumoniae during episodes of clinical disease in commercial herds.

Design

12 trials were run in 9 geographic locations in herds with a history of pneumonia caused by A pleuropneumoniae.

Animals

Clinically normal male and female pigs of various body weights.

Procedure

Two doses of tilmicosin phosphate (200 and 400 µg/g) and a 0 dose were administered in the feed for 21 days. Variables for determining efficacy were daily independent composite clinical impression score, individual pig weight, mortality, percentage of pneumonic involvement, and frequency of isolation of bacterial pathogens.

Results

Medicated pigs had significantly lower mortality attributed to pneumonia than did nonmedicated pigs. In trials with confirmed pneumonia caused by A pleuropneumoniae or Pasteurella multocida, weight gain, feed conversion, and clinical impression scores were significantly improved in the pigs receiving 200 or 400 µg/g of tilmicosin, compared with nonmedicated pigs.

Conclusions

The clinical field trials reported here confirm that tilmicosin in the feed at 200 µg/g is effective for control of swine pneumonia attributable to A pleuropneumoniae or P multocida.

Clinical Relevance

Under the moderate natural challenge conditions encountered, tilmicosin at 400 µg/g was not different from tilmicosin at 200 µg/g.
Serum neutralizing antibody response and protection against experimentally induced liver abscesses in steers vaccinated with Fusobacterium necrophorum
Authors: Saginala S. , Nagaraja T. G. , Tan Z. L. , Lechtenberg K. F. , Chengappa M. M. , Kemp K. E. , Hine P. M.
Published: January 2024

Objective

To determine the efficacy of leukotoxin-based Fusobacterium necrophorum vaccines and dietary tylosin in providing protection against experimentally induced hepatic abscesses in steers.

Design

30 steers assigned randomly to 6 treatment groups of 5 steers each: 1, phosphate-buffered saline solution (PBSS; control); 2, PBSS control, fed tylosin (100 mg/steer) daily; 3, inactivated whole-cell culture with oil emulsion adjuvant; 4, culture supernatant (crude toxoid) with oil emulsion adjuvant; 5, semipurified leukotoxoid with oil emulsion adjuvant; and 6, semipurified leukotoxoid with saponin adjuvant.

Procedure

Steers were inoculated SC with emulsified antigen or PBSS on days 0 and 21. Blood samples were collected at weekly intervals to monitor serum antileukotoxin antibody titer. On day 42, all steers were challenge exposed intraportally with F necrophorum culture. Three weeks later (day 63), steers were euthanatized and necropsied to examine liver and assess protection.

Results

Antileukotoxin antibody titers of all vaccinated groups markedly increased from baseline values, and mean titers of vaccinated groups were higher than those of the control and tylosin-treated groups. Steers vaccinated with culture supernatant with oil emulsion adjuvant or semipurified leukotoxoid with saponin adjuvant had the highest mean antibody titers. All 5 steers in the control group developed liver abscesses. Tylosin feeding did not protect steers challenge exposed with F necrophorum intraportally.

Conclusions

Culture supernatant was more protective than whole-cell culture or semipurified leukotoxin against experimentally induced hepatic abscesses. Partial purification of leukotoxin appeared to reduce its protective immunity. (Am J Vet Res 1996;57:483–488)
Effect of vaccination of ponies with A4 anti-idiotypic antibody on serum idiotype (1C9) and antilipid A concentration
Authors: BonenClark Greg D. , MacKay Robert J. , Ward Ronald E. , Sheerin Barbara
Published: January 2024

Objective

To evaluate the humoral response of horses to vaccination, using a murine monoclonal anti-idiotypic antibody (A4) that shares an epitope with lipid A.

Design

Serum concentrations of antilipid A antibody and 1C9 (epitope on murine monoclonal antihpid A antibody) were measured serially during the period of vaccination with A4.

Animals

6 clinically normal adult ponies.

Procedure

Ponies were inoculated IM 3 times at monthly intervals with A4. Two weeks after each inoculation, serum was obtained and was assayed by ELISA for antilipid A and 1C9 concentrations. Additional vaccinations were given to 2 of the ponies after a several-month rest period.

Results

There was significant increase in 1C9 concentration (P<0.0001) during the period of vaccination and a trend toward increased antilipid A concentration. The latter effect was not significant (P= 0.055). Additional vaccinations produced further increase in serum 1C9 concentration; antihpid A concentration increased in one of these ponies but not the other. Maximal antihpid A concentration recorded in these ponies was approximately 6 times preimmune concentration and was comparable to that found in a commercial antiendotoxin antiserum. 1C9 also was detected in the commercial antiserum.

Conclusions

A4 anti-idiotype vaccination of horses is safe and may be effective in eliciting an antibody response against endotoxin. The finding of 1C9 in a commercial antiendotoxin antiserum indicates that this idiotype may be part of the normal polyclonal antibody response of horses to endotoxin.

Clinical Relevance

It may be possible to use anti-idiotypic antibody vaccination in horses to induce protection against the effects of endotoxin. (Am J Vet Res 1996; 57:655–658)
Apparent viscosity of the synovial fluid from mid-carpal, tibiotarsal, and distal interphalangeal joints of horses
Authors: Lumsden Jonathan M. , Caron John P. , Steffe James F. , Briggs Jenni L. , Arnoczky Stephen P.
Published: January 2024

Objective

To compare the apparent viscosity of normal synovial fluid of the mid-carpal, tibiotarsal, and interphalangeal joints of horses.

Design

Viscosity evaluation over a range of shear rates was used to characterize the apparent viscosity of synovial fluids from the 3 joints.

Animals

60 clinically normal adult horses.

Procedure

Viscosity data for synovial fluid samples were obtained over a shear rate range of 10 to 250/s and apparent viscosity was calculated at 50, 100, 150, 200, and 250/s. Effect of shear rate on apparent viscosity was determined, using a two-way ANOVA, with significant differences tested, using a Tukey's test at a significance level of P < 0.05.

Results

Synovial fluid from all these joints indicated shear thinning behavior: decreased apparent viscosity with increased shear rate. Apparent viscosity of synovial fluid from the 3 joints was not significantly different over the shear rate range of 50 to 250/s.

Conclusion

Results of this study indicate that the apparent viscosity of the distal interphalangeal joint is not less than that of other joints, as has been reported.

Clinical Relevance

The observation of decreased synovial fluid viscosity of distal interphalangeal joint fluid should be considered as suggestive of joint disease. (Am J Vet Res 1996;57:879–883)
Metabolic and histologic effects of recombinant canine somatotropin on bone healing in dogs, using an unstable ostectomy gap model
Authors: Wilkens Brent E. , Millis Darryl L. , Daniel Gregory B. , Munson Linda , Patel Kanaiyala R. , Buonomo Frances C.
Published: January 2024

Objective

To investigate the effect of recombinant canine somatotropin (STH) on the metabolic and histologic aspects of bone healing in dogs, using an unstable os-tectomy gap model.

Animals

8 mature dogs.

Procedure

A 3-mm ostectomy of the mid portion of the radius was performed in all dogs. Implants designed to release STH at a rate of 4 mg/d were placed SC in 4 dogs (treated group [STHG]), and another 4 dogs received no implants (control group ICG]). Serum concentrations of STH, insulin-like growth factor I, and osteocalcin were de-termined before surgery, and weekly for 8 weeks. Scinti-graphic evaluation of the ostectomy sites was performed before surgery, and at weeks 2, 4, 6, and 8 after surgery. Histologic evaluation of the ostectomy sites was performed at the conclusion of the study at week 8.

Results

Significant (P < 0.05) increases in serum STH, insulin-like growth factor I, and osteocalcin concentrations were observed in dogs of the STHG during the 8-week study period. Scintigraphic activity of the ostectomy sites was increased in dogs of both groups, but dogs of the STHG had significantly (P < 0.05) greater activity, compared with dogs of the CG. Coalescence of nuclear activity across the ostectomy site was observed in dogs of the STHG, whereas dogs of the CG maintained 2 distinct areas of metabolic activity. Histologically, dogs of the STHG had bridging calluses with areas of endochondral ossification and ongoing osteogenic activity, whereas dogs of the CG had nonossified fibrocartilage typical of nonunion fractures.

Conclusion

Using the ostectomy gap model, recombinant canine STH enhanced the metabolic and histologic aspects of bone healing in dogs. (Am J Vet Res 1996;57:1395–1401)