bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of glycosaminoglycan metabolism by bone morphogenetic protein-2 in equine cartilage explant cultures
Authors: Loredo Grace A. , MacDonald Melinda H. , Benton Hilary P. 
Published: January 2024

Abstract

Objective
To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) regulates glycosaminoglycan (GAG) synthesis and release from equine articular cartilage explant cultures.

Design
Equine articular cartilage explants were maintained in vitro for 7 days in the presence of 0 (control), 1, 10, or 100 ng of rhBMP-2/ml. Synthesis and release of GAG were assessed as measures of production and degradation of the extracellular matrix, respectively.

Animals
6 horses (age range, 2 to 25 years old) without clinically detectable musculoskeletal abnormalities.

Procedure
Rate of synthesis of GAG was assessed by incorporation of [35S]sulfate during the final 24 hours of the 7-day incubation period. Release of GAG was assessed on days 3, 6, and 7, using 1,9-dimethylmethylene blue

Results
Explants from all 6 horses had a significant (P = 0.05) increase in release of GAG in response to incubation with 100 ng of rhBMP-2/ml. There was a significant (P = 0.05) decrease in GAG synthesis in explants from only 2 of the 6 horses at the same concentration of rhBMP-2. There was no significant age correlation between responsive and nonresponsive horses.

Conclusions
A concentration of 100 ng of rhBMP-2/ml stimulates GAG release from explant cultures of equine articular cartilage. The data suggest that bone morphogenetic proteins may be potential regulators of equine cartilage degradation and repair.

Clinical Relevance
Surgical procedures that damage subchondral bone may stimulate generation of improved cartilage-like tissue. It is, therefore, crucial to understand how bone-derived factors may influence cartilage metabolism in horses. (Am J Vet Res 1996;57:554–559)
Viral status and antibody response in cattle inoculated with recombinant bovine leukemia virus-vaccinia virus vaccines after challenge exposure with bovine leukemia virus-infected lymphocytes
Authors: Cherney T. M. , Schultz R. D. 
Published: January 2024

Abstract

Objective
To determine the bovine leukemia virus (BLV) antibody response and infectivity status in BLV-vaccinated cattle after challenge exposure with BLV-infected lymphocytes.

Design
Steers were inoculated with vaccinia virus constructs expressing the gag, pol, and env genes of the BLV or the env gene only of the BLV genome, then challenge exposed with BLV-infected lymphocytes. The steers' BLV antibody and infectivity status was monitored.

Animals
Fifteen 8- to 9-month-old Holstein steers previously determined to be BLV antibody and BLV negative.

Procedure
1 month after second after inoculation, steers were challenge exposed with 106 BLV-infected lymphocytes from a highly infective BLV-positive cow. Serum and blood lymphocytes were obtained regularly for 6 months. The agar gel immunodiffusion assay, ELISA, and serum neutralization assay were used to detect BLV antibody in serum of steers. The sheep infectivity and syncytium-forming assays were used to determine the viral status of the steers.

Results
Differences were seen in antibody responses between the BLV-vaccinated and non-BLV-vaccinated control groups. All cattle were susceptible to infection when challenge exposed with BLV-infected lymphocytes.

Conclusion
Despite the enhanced immune response in the BLV-vaccinated cattle after challenge exposure, none of the BLV-vaccinated cattle was protected from BLV infection.

Clinical Relevance
Vaccination is not an effective way to protect cattle from BLV infection. (Am J Vet Res 1996;57:812–818)
Effects of dietary n-3 fatty acid supplementation versus thromboxane synthetase inhibition on gentamicin-induced nephrotoxicosis in healthy male dogs
Authors: Grauer Gregory F. , Greco Deborah S. , Behrend Ellen N. , Fettman Martin J. , Mani Indu , Getzy David M. , Reinhart Gregory A. 
Published: January 2024

Abstract

Objective
To evaluate the protective effects of dietary n-3 fatty acid supplementation versus treatment with a thromboxane synthetase inhibitor (TXSI) in dogs given high-dose gentamicin.

Design
Clinicopathologic and renal histopathologic changes induced by gentamicin (10 mg/kg of body weight, IM, q 8 h, for 8 days) were compared in dogs fed an n-3 fatty acid-supplemented diet containing a fatty acid ratio of 5.7:1 (n-6:n-3), dogs treated with CGS 12970 (a specific TXSI given at 30 mg/kg, PO, q 8 h, beginning 2 days prior to gentamicin administration), and control dogs. The TXSI-treated and control dogs were fed a diet with a fatty acid ratio of 51.5:1 (n-6:n-3). Both diets were fed beginning 42 days prior to and during the 8-day course of gentamicin administration.

Animals
Eighteen 6-month-old male Beagles, 6 in each group.

Results
After 8 days of gentamicin administration, differences existed among groups. Compared with n-3-supplemented and control dogs, TXSI-treated dogs had higher creatinine clearance. Both TXSI-treated and n-3-supplemented dogs had higher urinary prostaglandin E2 and E3 (PGE2/3) and 6-keto prostaglandin F1α (PGF1α) excretion, compared with control dogs. Urinary thromboxane B2 (TXB2) excretion was higher in n-3-supplemented and control dogs, compared with TXSI-treated dogs. Urine PGE2/3-to-TXB2 and PGF1α-to-TXB2 ratios were increased in TXSI-treated dogs, compared with n-3-supplemented and control dogs, and these ratios were increased in n-3-supplemented dogs, compared with control dogs. In addition, TXSI-treated and n-3-supplemented dogs had lower urinary protein excretion, compared with control dogs. Proximal tubular necrosis was less severe in TXSI-treated dogs, compared with control dogs.

Conclusion
Treatment with CGS 12970 prior to and during gentamicin administration prevented increases in urinary TXB2 excretion and reduced nephrotoxicosis.

Clinical Relevance
Increased renal production/excretion of thromboxane is important in the pathogenesis of gentamicin-induced nephrotoxicosis. (Am J Vet Res 1996;57:948–956)
Histomorphometric and angiographic analysis of bone healing in the humerus of pigeons
Authors: West P. G. , Rowland G. R. , Budsberg S. C. , Aron D. N. 
Published: January 2024

Abstract

Objective
To evaluate the vascular supply and quantitatively compare the periosteal and endosteal callus formed during fracture healing.

Design
36 pigeons were allotted to 2 groups. In each bird, 1 humerus was surgically osteotomized. The wing with the fractured humerus in birds of the first group was infused with a microparticle barium solution, and the humerus was harvested for angiography. Pigeons of the second group were injected with the labels oxytetracycline and calcein. The fractured humerus in each of these birds was harvested for histomorphometry.

Animals
36 nine-month-old pigeons, consisting of 19 male and 17 female birds.

Procedure
1 humerus from each of the 36 pigeons was osteotomized in the center of the bone by use of an obstetrical wire. All fractured wings were placed in a figure-of-8 bandage after surgery. The specimens harvested for angiography were decalcified, radiographed, and sectioned for H&E-stamed tissue slides. Humeruses harvested for histomorphometry were cross-sectioned for tissue slides, which were measured, using a morphometric analyzing system for original and new bone areas.

Results
A continuous intramedullary circulation was not present at any point in the healing process, although 2 of the 42-day-old fractures had a bridging callus. Quantitatively, the periosteal surface formed the largest amount of callus, though the endosteal surface was also active.

Conclusions
Reformation of the intramedullary circulation may not be imperative for osseous union of the pigeon humerus. Fluorochrome labels cannot be accurately measured at the fracture site. However, subjective evaluation of the endosteal surface indicates it is active during the fracture-healing process even though the periosteal surface provides the largest amount of callus formation.

Clinical Relevance
Figure-of-8 coaptation is contraindicated for humeral fractures. The endosteal surface's contribution to the healing process should be considered when avian humeral fractures are stabilized. (Am J Vet Res 1996;57:1010–1015)
Preferential binding of heparin to granulocytes of various species
Authors: Harenberg Job , Malsch Reinhard , Piazolo Lukas , Huhle Günther , Heene Dieter L. 
Published: January 2024

Abstract

Objectives
To address the problem of heparin binding to leukocytes of various animal species.

Design
Leukocytes of the various species were incubated with fluorescent-labeled, low molecular mass heparin (LMMH). Fluorescence intensity on granulocytes, lymphocytes, and monocytes was analyzed by flow cytometry analysis.

Sample Population
Leukocytes were prepared from EDTA-anticoagulated blood of human subjects, rats, rabbits, dogs, pigs, and sheep 3 times.

Procedure
The leukocyte populations were identified by their light scatter properties. In addition, phycoerythrin-labeled CD4, CD13, and CD14 antibodies were used to identify human lymphocytes, granulocytes, and monocytes; CD4, GR-1, and CD11b antibodies were used for mouse, and CD45, RP 3, and ED 9 antibodies were used for identification of rat leukocyte subpopulations.

Results
Granulocytes, monocytes, and lymphocytes of all species bound LMMH in dose-dependent manner. Binding of LMMH-tyramine (tyr)-fluorescein-5-isothiocyanate (FITC) to granulocytes was higher in human subjects, rats, rabbits, dogs, and pigs, compared with binding to monocytes and lymphocytes. Mouse and sheep granulocytes did not bind more heparin than monocytes or lymphocytes. Binding of LMMH-tyr-FITC was reversible in the presence of unlabeled heparin or LMMH. More than 99% of human, rat, rabbit, dog, and sheep granulocyte populations were distinguished from monocytes and lymphocytes by means of their fluorescence intensity owing to LMMH-tyr-FITC. This separation was not obtained for mouse and pig granulocytes.

Conclusion
Evidence of specific heparin binding to granulocytes of many species indicates the relevance of fluorescent-labeled LMMH for biological investigations.

Clinical Relevance
Binding of heparin and LMMH to granulocytes, lymphocytes, and monocytes may have a substantial role in atherosclerosis, inflammation, malignancy, and immunologic diseases. (Am J Vet Res 1996;57:1016–1020)
Induction and maintenance of anesthesia in dogs by intravenous administration of methohexital
Authors: Gentry W. Brooks , Krejcie Tom C. , Henthorn Thomas K. , Avram Michael J. 
Published: January 2024

Abstract

Objective
To devise and test an IV methohexital infusion regimen for induction and maintenance of surgical anesthesia in dogs from which they would rapidly recover.

Design
Dose-response and plasma concentration-effect study.

Animals
11 clinically normal dogs.

Procedure
Bolus methohexital pharmacokinetic variables were determined in ketamine- and pentobarbital-anesthetized dogs. Plasma methohexital concentrations required to inhibit purposeful movement in response to painful stimuli were determined during a stepped methohexital infusion in the same dogs on a second occasion. These pharmacokinetic/pharmacodynamic data were next used to design a bolus and two-stage infusion regimen that would result in stable plasma methohexital concentrations with prolonged infusion. This regimen was tested in a second group of dogs.

Results
Mean steady-state volume of distribution of methohexital in the anesthetized dogs was 1.50 L/kg of body weight and mean elimination clearance was 10.2 ml/kg/min. Mean plasma concentrations required to prevent movement response to a noxious stimulus and at which the dogs could be extubated were 11.8 and 6.9 μg/ml, respectively. After a 6-hour infusion, recovery of airway reflexes sufficient to allow extubation required 67 minutes.

Conclusions
An easily implemented IV methohexital infusion regimen for induction and maintenance anesthesia in dogs was developed. During a 6-hour infusion, hemodynamic variables did not change. Use of this regimen resulted in anesthesia of sufficient depth to prevent withdrawal in response to noxious stimuli and in reliable and acceptable emergence times for use in canine survival studies in a cost-effective manner. (Am J Vet Res 1996;57:1044–1049)
Postmortem evaluation of homotypic variation in shoe characteristics of 201 Thoroughbred racehorses
Authors: Kane Albert J. , Stover Susan M. , Gardner Ian A. , Case James T. , Johnson Bill J. , O'Brien Michael J. , Read Deryck H. , Ardans Alex A. 
Published: January 2024

Abstract

Objectives
To develop a standard technique for evaluation of racehorse shoes, to assess homotypic variation (interlimb variation) in shoe characteristics, and to determine whether shoe characteristics varied with age and sex.

Design
Cross-sectional study.

Animals
Thoroughbred racehorses (n = 201) that died or were euthanatized at California racetracks between August 1992 and July 1994.

Procedure
Shoe characteristics were measured on horses examined after death. Percentage of agreement was used to compare shoe characteristics between limbs (homotypic variation). Using χ2analysis, shoe characteristics were compared between horses grouped by age and sex.

Results
Toe grabs were present on 90.5% of horses, and rim shoes were present on 15.9% of horses. Heel traction devices were less frequent on front (2.5%) than rear (6%) hooves. Pads were present on 24.9% of horses, with bonded rim pads most common. Special types of shoes were present on 5% of horses. Percentage of agreement between left and right front hooves and between left and right rear hooves was high (20/25 variables; % agreement ≥ 99). In contrast, percentage of agreement between left front and left rear hooves and between right front and right rear hooves was low (2/25 variables; % agreement ≥ 99). Presence of a pad was significantly (P < 0.05) associated with age, and several shoe variables (size, presence of a special shoe, overall wear matched) were significantly (P < 0.05) associated with sex.

Clinical Relevance
Except for variables related to special shoes, wear, and weight, 1 shoe for the respective fore- or hind limbs could be used as an indicator for the contralateral shoe worn by Thoroughbred racehorses without substantial loss of information. However, 1 shoe could not be used as an indicator for shoe characteristics of all 4 limbs. Some shoe characteristics are associated with age and sex, and these variables should be considered possible confounders in studies of shoe characteristics. (Am J Vet Res 1996;57:1141-1146)
Evaluation of ivermectin and milbemycin oxime efficacy against Dirofilaria immitis infections of three and four months' duration in dogs
Authors: McCall John W. , McTier Tom L. , Ryan William G. , Gross Sheila J. , Soll Mark D. 
Published: January 2024

Abstract

Objectives
To determine the efficacy of ivermectin (IVM) and milbemycin oxime (MBO) against induced heartworm infection, where monthly treatment is started 3 or 4 months after infection, and to monitor microfilaremia and antigenemia.

Animals
21 heartworm-naive Beagles.

Procedures
Each of 21 dogs was given 50 infective larvae of Dirofilaria immitis by SC inoculation. One group of 5 dogs served as nonmedicated controls, 2 groups of 5 dogs received IVM at 6 μg/kg of body weight or MBO at 500 μg/kg for 12 months beginning at postinfection (PI) month 4, and 2 groups of 3 dogs received IVM or MBO for 13 months beginning at PI month 3. Blood collected at intervals not >1 month beginning at PI month 4 was examined for microfilariae and antigen. Dogs were euthanatized at PI month 16.

Results
Adult worm counts, relative to controls, were reduced in the 4-month treatment groups by 95.1 (P < 0.01) and 41.4% for IVM and MBO, respectively. The difference between the IVM and MBO groups was significant (P < 0.01). Live worms were found in all MBO-treated (range, 8 to 27) and control dogs (range, 12 to 39) and in 3 of 5 IVM-treated dogs (range, 2 to 4). In the 3-month treatment groups, worm counts were reduced by 97.7 (P < 0.01) and 96.8% (P < 0.01) for IVM and MBO, respectively. Microfilariae were seen in all control dogs and in only 2 of the 16 treated dogs. The antigen response of MBO-treated dogs in the 4-month treatment group was only slightly weaker than that for control dogs. In all other treated dogs, this response was delayed and weaker.

Conclusion
Ivermectin is highly (≥ 95%) and significantly more effective than MBO against induced heartworm infection when 1 year of monthly prophylactic dosing is started 4 months after infection.

Clinical Relevance
In some cases of owner compliance failure, monthly administration of IVM gives a high level of protection against young adult heartworms. (Am J Vet Res1996;57:1189-1192)
Maintenance of equine articular cartilage explants in serum-free and serum-supplemented media, compared with that in a commercial supplemented medium
Authors: Kawcak Christopher E. , Trotter Gayle W. , Frisbie David D. , McIlwraith C. Wayne 
Published: January 2024

Abstract

Objective
To evaluate the effects of a commercially defined, serum-free medium additive on equine articular cartilage explants, compared with effects of serum-free and serum-supplemented media.

Animals
Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis.

Procedure
Media were changed every 48 hours, and the glycosaminoglycan (GAG) content was determined in media collected at each time point. Glycosaminoglycan synthesis by explant chondrocytes, and residual GAG content of articular cartilage (as a measure of explant GAG loss) were determined at the end of the study (day 8).

Results
Articular cartilage explants in serum-free medium and the commercial supplemented medium had significantly lower GAG synthesis and GAG content than did those incubated in serum-supplemented medium. There were no significant differences in GAG synthesis and content between serum-free and commercial supplemented medium groups. When comparing medium GAG content for all treatment groups, the GAG content in serum-free medium on day 8 was significantly greater than that in commercial supplemented medium, but significant differences were not evident in percentage of release of GAG (as an indicator of GAG degradation) among all 3 treatment groups.

Conclusions
Commercial supplemented medium had effects on articular cartilage matrix GAG loss into medium equal to those of serum-supplemented medium (eg, both lost articular cartilage explant GAG to a similar degree). However, residual articular cartilage GAG content was higher in serum-supplemented medium, as was GAG synthesis. Commercial supplemented medium appears to either lack the proper ingredients to maintain steadystate GAG synthesis, or lacks proper concentrations of these ingredients. (Am J Vet Res 1996;57:1261–1265)
Effect of anesthesia and surgery on energy expenditure determined by indirect calorimetry in dogs with malignant and nonmalignant conditions
Authors: Ogilvie Gregory K. , Salman Mowafak D. , Kesel M. Lynne , Fettman Martin J. 
Published: January 2024

Abstract

Objective
To determine energy expenditure (EE) of apparently resting, client-owned dogs with malignant or nonmalignant diseases that were recovering from anesthesia and surgery, and compare those values with values from clinically normal, apparently resting, client-owned dogs.

Animals
40 apparently resting, client-owned dogs that had been given general anesthesia for various elective and nonelective surgical procedures, and 30 apparently resting, clinically normal client-owned dogs used as controls.

Procedure
EE was determined, using an open-flow indirect calorimetry system. Each dog was evaluated before and after surgery (0, 1, 2, and 3 days after surgery, then at suture removal > 14 days later) and compared with apparently resting, clinically normal, client-owned dogs (n = 30). Parameters evaluated were rate of oxygen consumption (Vo2/kg of body weight: ml/min/kg; Vo2/kg0.75: ml/min/kg0.75), EE (EE/kg: kcal/kg/d; EE/kg0.75: kcal/kg0.75/d), and respiratory quotient.

Results
Surgery and anesthesia did not significantly alter any of these parameters at any time assessed in any group. The pretreatment Vo. and EE were significantly lower in the dogs with cancer, compared with dogs of other groups.

Conclusions
These data suggest that the EE of a re-stricted group of dogs that undergo anesthesia and surgery for malignant and nonmalignant conditions does not increase from baseline values or when compared with values in clinically normal, client-owned dogs.

Clinical Relevance
This information may be of value when planning nutritional treatment for dogs recovering from anesthesia and surgery. (Am J Vet Res 1996;57:1321-1326)
Comparison of antinociceptive, cardiovascular, and respiratory effects, head ptosis, and position of pelvic limbs in mares after caudal epidural administration of xylazine and detomidine hydrochloride solution
Authors: Skarda Roman T. , Muir William W. 
Published: January 2024

Abstract

Objective
To examine and compare effects of 2α2- adrenergic receptor agonists, xylazine and detomidine, administered into the sacrococcygeal epidural space to induce safe and effective perineal analgesia on cardio-vascular and respiratory functions, head ptosis, and po-sition of pelvic limbs in healthy mares.

Animals
8 healthy mares.

Procedure
Blood samples were drawn and systemic hemodynamics were determined, including cardiac output and pulmonary arterial, systemic arterial, and right atrial pressures. Two-way ANOVA with repeated measures was used to detect significant (P < 0.05) differences between mean scores of perineal analgesia, cardiorespiratory variables, head ptosis, and position of pelvic limbs in mares before and during a 3-hour testing period. Analgesia was determined by lack of sensory perception to electrical stimulation at the perineal dermatome and no response to needle prick stimulation in dermatomes extending from the coccyx to T15. Avoidance responses to electrical current and needle prick stimulation and behavioral changes (head ptosis, position of pelvic limbs) were quantitatively assessed by use of a scoring system.

Results
Epidurally administered xylazine induced perineal analgesia and variable bilateral caudal analgesia extending from the coccyx to S3 dermatome, with minimal cardiovascular and respiratory depression, head ptosis, changes in position of pelvic limbs, and no urination in standing mares. Epidurally administered detomidine in-duced perineal analgesia, variable bilateral analgesia with dermatomal spread ranging from coccyx to S3 and coccyx to T15, with cardiovascular depression, marked head ptosis, changes in position of pelvic limbs, and diuresis in standing mares. Onset of perineal analgesia after xylazine and detomidine administrations was 13.1 ± 3.7 and 12.5 ± 2.7 minutes (mean ± SD), respectively. The period of perineal analgesia was significantly (P < 0.05) longer in mares after epidural xylazine administration than after epidural detomidine administration (165 to > 180 minutes vs 160 ± 8 minutes).

Conclusions
Caudal epidurally administered xylazine (0.25 mg/kg of body weight in 8 ml of 0.9% NaCI) offers the most desirable conditions in mares: long-term perineal analgesia (> 2.5 hours), with minimal cardiopulmonary depression, head ptosis, changes in pelvic limb position, and no urination in standing mares during a 3- hour test period. (Am J Vet Res 1996;57:1338-1345)