bluuebunny/crossref_metadata_2025 huggingface dataset:
Preferential binding of heparin to granulocytes of various species
Authors: Harenberg Job , Malsch Reinhard , Piazolo Lukas , Huhle Günther , Heene Dieter L.
Published: January 2024

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

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

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

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

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

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

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)
Genomic DNA fingerprinting, using pulsed-field gel electrophoresis, of Staphylococcus intermedius isolated from dogs
Authors: Shimizu Akira , Berkhoff Herman A. , Kloos Wesley E. , George Carol G. , Ballard Deborah N.
Published: January 2024

Objectives

To investigate the degree of polymorphism in the pulsed-field gel electrophoresis (PFGE) patterns of Staphylococcus intermedius and to assess the value of this typing method for discriminating strains.

Sample population

52 S intermedius isolates from diseased and healthy dogs.

Procedure

Chromosomal DNA of S intermedius was digested with restriction endonuclease Sma I, and the fragments were separated by PFGE in a 1 % agarose gel.

Results

Sma I cut the chromosomal DNA into 15 to 23 fragments ranging from about < 1 to 679 kb, and most of the detectable fragments were < 155 kb. Nine fragments, 115, 48, 33, 26, 16, 13, 10, 4, and < 1 kb, were shared by all or almost all (> 71 %) of the strains examined. Of the 52 strains, each had a different pattern. S intermedius had a high degree of restriction fragment length polymorphism. The PFGE patterns obtained for S intermedius were stable and reproducible when the strains were tested in the different experiments.

Conclusions

Genomic DNA fingerprinting by PFGE is an effective technique for discriminating S intermedius strains. The PFGE method appears to be a useful molecular marker for epidemiologic or ecologic studies of S intermedius. (Am J Vet Res 1996;57:1458-1462)
Estimation of arcuate artery resistive index as a diagnostic tool for aminoglycoside-induced acute renal failure in dogs
Authors: Rivers Bill J. , Walter Patricia A. , Letourneau Janis G. , Finlay David E. , Ritenour E. Russell , King Vickie L. , O’Brien Timothy D. , Polzin David J.
Published: January 2024

Objective

To determine the potential clinical usefulness of duplex Doppler estimation of arcuate artery resistive index (a measure of intrarenal blood flow impedance) for diagnosis of aminoglycoside-induced nephrotoxicosis.

Animals

30 adult, female, mixed-breed dogs, allotted to 3 groups of 10 dogs each as: toxic dosage of gentamicin, therapeutic dosage of gentamicin, and saline solution sham equivalent in volume to that of the toxic dosage of gentamicin.

Procedure

After baseline screening to establish normalcy (serum biochemical analysis, endogenous creatinine clearance determination, urinalysis, urine protein-to-creatinine ratio, urine culture, gray-scale sonography, and percutaneous ultrasound-guided renal biopsy), results of arcuate artery resistive index determination were compared with serum creatinine and urine specific gravity values on a Monday-Wednesday-Friday data collection schedule for 10 days. Endogenous creatinine clearance determination, ultrasound-guided renal biopsy, and urine culture were repeated at the end of data collection in all 3 groups.

Results

Significant differences in resistive index measurements were not observed, despite clinicopathologic and renal biopsy results compatible with severe acute tubular necrosis in dogs of the toxic dosage group.

Conclusions

Duplex Doppler sonography of arcuate artery blood flow impedance, expressed as the resistive index, appears to have poor clinical usefulness as a diagnostic tool in this disorder.

Clinical Relevance

Normal arcuate artery resistive index values obtained in dogs for which aminoglycoside-induced nephrotoxicosis is suspected do not exclude the disorder. If abnormal arcuate artery resistive index values are obtained for such dogs, further evaluation for nephropathies other than aminoglycoside-induced nephrotoxi-cosis may be considered. (Am J Vet Res 1996;57:1536–1544)
High-speed exercise history and catastrophic racing fracture in Thoroughbreds
Authors: Estberg Leah , Stover Susan M. , Gardner Ian A. , Drake Christiana M. , Johnson Bill , Ardans Alex
Published: January 2024

Objective

To investigate the relation between several racing speed history characteristics and risk of fatal skeletal injury (FSI) in racing Thoroughbreds.

Animals

64 Thoroughbreds euthanatized during a 9-month period in 1991 at a California racemeet because of a catastrophic fracture incurred while racing (cases), identified retrospectively. For each race in which an FSI occurred, 1 control horse was randomly selected from the noncatastrophically injured participants.

Procedure

Racing and officially timed workout histories were obtained for each horse. Several history characteristics were calculated to summarize racing career patterns and high-speed exercise schedules prior to date of injury and included age at first race, proportion of career spent laid up, average duration of laid up periods, average lifetime racing frequency, time from last lay up to date of injury, and total and rate of distance accumulated 1 to 6 months prior to date of injury. History characteristics associated with FSI were screened by paired t-test and studied in detail using conditional logistic regression.

Results

High total and high average daily rates of exercise distance accumulation within a 2-month period were associated with higher risks for FSI during racing, yet career patterns, such as age at first race or total proportion of career spent laid up, were not found to be associated with risk for FSI. A horse that had accumulated a total of 35 furlongs of race and timed-work distance in 2 months, compared with a horse with 25 furlongs accumulated, had an estimated 3.9-fold increase in risk for racing-related FSI (95% confidence interval = 2.1, 7.1). A horse that had accumulated race and timed-work furlongs at an average rate of 0.6 furlong/d within a 2-month period, compared with a horse with an average of 0.5 furlong/d, had an estimated 1.8-fold increase in risk for racing-related FSI (95% confidence interval = 1.4, 2.6).

Conclusions and Clinical Relevance

Thoroughbred racehorses that either accumulate large total highspeed distances or rapidly accumulate high-speed distances within a 2-month period may be at increased risk for FSI during racing. (Am J Vet Res 1996;57:1549–1555)
Effects of intermittent feed deprivation, intermittent feed deprivation with ranitidine administration, and stall confinement with ad libitum access to hay on gastric ulceration in horses
Authors: Murray Michael J. , Eichorn Evelyn S.
Published: January 2024

Objectives

To determine the effect of decreasing gastric acidity in a feed-deprivation protocol on induction of gastric ulcers, and to determine whether stall confinement may be a factor contributing to gastric ulceration in horses.

Animals

8 adult horses, 4 geldings and 4 mares, 3 to 8 years old, and 7 adult horses, 5 geldings and 2 mares, 4 to 11 years old.

Procedure

Gastric ulceration was induced in horses by alternating 24-hour periods of feed deprivation and ad libitum access to hay, for a total of 96 hours' feed deprivation. This protocol was repeated with the horses receiving the histamine type-2 receptor (H2) antagonist ranitidine (6.6 mg/kg of body weight, PO, q 8 h). In another group of horses, severity of gastric lesions was compared after 7 days’ pasture turnout and 7 days’ stall confinement with ad libitum access to hay. Gastroscopy was performed after each feed-deprivation protocol was completed, and total lesion area in the gastric squamous epithelial mucosa was measured. Gastroscopy was performed at the beginning and end of 7 days’ pasture turnout and 7 days’ stall confinement.

Results

Alternating periods of feed deprivation resulted in erosion and ulceration of the gastric squamous epithelial mucosa of each horse. Concurrent treatment with ranitidine resulted in significantly (P < 0.05) less area of ulceration in the gastric squamous epithelial mucosa. After 7 days’ stall confinement, 6 of 7 horses had ulceration in the gastric squamous epithelial mucosa, and 1 horse had a lesion in the glandular mucosa, whereas after 7 days’ pasture turnout, 2 horses had reddening of the gastric squamous mucosa along the lesser curvature (P < 0.05).

Conclusions and Clinical Relevance

Severe ulceration of the gastric squamous epithelial mucosa, caused by excess acidity, can develop rapidly in horses deprived of feed or not consuming feed. Suppression of gastric acidity with the histamine type-2 receptor antagonist ranitidine effectively minimized the area of ulceration caused by feed deprivation. Compared with being turned out to pasture, stall confinement alone appears to be an important factor in the development of gastric ulcers in horses, probably as a result of altered eating behavior. (Am J Vet Res 1996;57:1599–1603)
Effect of metoclopramide on fed-state gastric myoelectric and motor activity in dogs
Authors: Hall Jean A. , Solie Thomas N. , Seim Howard B. , Twedt David C.
Published: January 2024

Objective

To investigate the effects of metoclopramide, a putative gastroprokinetic agent, on dogs that had recovered from gastric dilatation-volvulus (GDV), a disorder characterized by delayed gastric emptying.

Animals

6 healthy dogs and 5 dogs after treatment and recovery from GDV.

Procedure

Baseline recordings of gastric electrical and contractile activities were made 8 or 10 days after circumcostal gastropexy and implantation of serosal electrodes and strain-gauge force transducers. Gastric activities were recorded again the next day after treatment with the clinically recommended oral metoclopramide dose (0.3 mg/kg of body weight) administered a half hour before feeding. Recordings were analyzed to determine gastric slow-wave frequency, presence of slow-wave dysrhythmia, slow-wave propagation velocity, coupling of contractions to slow waves, a motility index based on relative contractile amplitudes, and onset of contractions after a standardized meal.

Results

Significant differences in gastric electrical or contractile activities were not detected after metoclopramide treatment in dogs with GDV. Compared with control dogs after metoclopramide treatment, gastric slow-wave propagation velocity was significantly (P = 0.03) faster for the dogs with GDV at postprandial minute 90.

Conclusion

At a clinically recommended dosage, metoclopramide treatment did not change gastric myoelectric and motor activities in a way that would promote increased gastric emptying in dogs with GDV.

Clinical Relevance

Metoclopramide treatment may not benefit dogs with GDV and delayed gastric emptying. (Am J Vet Res 1996;57:1616–1622)
Effect of omeprazole on sodium and potassium output in pentagastrin-stimulated equine gastric contents
Authors: Merritt A. M. , Burrow J. A. , Horbal M. J. , Madison J. B. , Tran T.
Published: January 2024

Objective

To better characterize the source of the large nonparietal secretory response to pentagastrin (PG) expressed in gastric contents of cannulated horses.

Animals

Adult cross-bred horses: 4 geldings and 1 mare.

Procedure

Horses were prepared by surgical insertion of a silastic gastric cannula from which gastric contents after feed was withheld could be continuously collected by gravity drainage. During experiments, the horses were lightly restrained in stocks, the gastric cannula was opened, and a catheter was inserted into a jugular vein. Over the next 5 hours, gastric contents were collected in 15-minute aliquots for which volume, pH, [Na+], and [K+] were measured. During the first hour, treatment was not administered. At the start of the second hour, either 0.5 mg of omeprazole (OME; dissolved in glycerol formal)/kg of body weight, or 0.9% NaCI (PSS) of comparable volume, was given IV at random as a bolus. At the start of the third hour, IV infusion of PG (6 µg/kg/h) was started and continued for the next 2 hours.

Results

The response to PG in the PSS-treated horses was similar to that previously seen-significant decrease in pH and increase in volume of gastric contents, and no change in [K+] and [Na+], but a modest volume-related increase in their respective outputs. After OME treatment, pH of the contents increased sharply and remained between 5 and 6 throughout PG infusion. Sodium concentration significantly increased after OME and virtually paralleled the pH response throughout the rest of the experiment; volume of gastric contents significantly increased in response to PG infusion and resulted in a significant increase in Na output. There was no change in K output in OME-treated animals.

Conclusions

PG induces a marked, nonparietal, secretory response into the gastric contents of cannulated horses. The volume and [Na+] of this response was maintained after pretreatment with OME, although the pH of the contents became basic, indicating that this nonparietal response is not mediated by an OME-sensitive proton pump. (Am J Vet Res 1996;57:1640–1644)
Experimentally induced Bartonella henselae infections followed by challenge exposure and antimicrobial therapy in cats
Authors: Regnery R. L. , Rooney J. A. , Johnson A. M. , Nesby S. L. , Manzewitsch P. , Beaver K. , Olson J. G.
Published: January 2024

Objectives

To elucidate kinetics of Bartonella henselae bacteremia and IgG response, evaluate antibiotic therapy, and investigate challenge exposure in cats.

Animals

Specific-pathogen-free cats.

Procedure

Cats were inoculated with B henselae or B quintana and monitored. Convalescent cats were challenge exposed with B henselae. Amoxicillin, enrofloxacin, erythromycin, and tetracycline HCI were evaluated for effect on B henselae bacteremia.

Results

Cats developed B henselae bacteremia within 1 week; bacteremia persisted for longer than 2 months before subsiding spontaneously. IgG antibody titer developed shortly after onset of bacteremia; antibody coexisted with bacteremia for several weeks and remained detectable after bacteremia subsided. Cats inoculated with B quintana remained abacteremic. On challenge exposure to B henselae, cats previously infected with B henselae remained abacteremic; cats previously inoculated with B quintana supported B henselae infection. Tetracycline HCI and erythromycin depressed B henselae bacteremia; however, duration of bacteremia remained similar to that in untreated cats. Obvious signs of illness were not observed.

Conclusions

Long-duration, high-titer B henselae infections were highly reproducible in cats. Convalescent cats were immune to reinfection. B quintana-inoculated cats did not have evidence of infection and were susceptible to B henselae challenge exposure. Antibiotic therapy was incompletely efficacious in terminating cat bacteremia.

Clinical Relevance

A cat with an inapparent B henselae infection must provisionally be regarded as a possible reservoir for infection for a minimum of 2 to 3 months. Convalescent cats are resistant to reinfection. Usual antibiotic therapy was not completely efficacious. Measurement of IgG antibody can be used to detect past or current infection. (Am J Vet Res 1996;57:1714–1719)
Feline ocular epithelial response to growth factors in vitro
Authors: Wong Charissa J. , Peiffer Robert L. , Oglesbee Steve , Osborne Catherine
Published: January 2024

Objective

To examine the proliferative abilities of growth factors known to participate in wound healing on feline lens, iris pigment, ciliary, and retinal pigment epithelium cultured in vitro.

Animals

8 clinically normal cats.

Procedure

Iris pigment, lens, ciliary, and retinal pigment epithelia of normal eyes of cats were isolated and cultured. Morphologic characteristics of primary cell cultures were studied by light and electron microscopy. Subcultures of epithelial cells were exposed to media supplemented with 0.5% fetal bovine serum plus various combinations of insulin and/or growth factors, including transforming growth factor-α, epidermal growth factor, acidic fibroblast growth factor, and basic fibroblast growth factor. Growth promoting effects were evaluated by counting with an electronic cell counter.

Results

Cells retained many of the morphologic characteristics of in vivo cells. Cell proliferation assays indicated that transforming growth factor-α stimulated lens and ciliary epithelial cell growth, and epidermal growth factor enhanced lens and iris pigment epithelial cell growth. Acidic fibroblast growth factor had proliferative effects on lens, iris pigment, and ciliary epithelium. Basic fibroblast growth factor was the most potent stimulator of all mitogens used, and caused substantial proliferation in all cell types. Insulin alone stimulated lens and ciliary epithelial proliferation but, combined with other growth factors, had a synergistic effect with those causing cell proliferation, except acidic fibroblast growth factor with iris pigment epithelium.

Conclusion

Morphologic studies support the argument that pigment-producing cells are involved in feline ocular sarcoma. Growth factor studies indicated that ciliary epithelium has the most profound proliferative effect of all growth factors used. These data may help guide future studies in determining the cell of origin for feline ocular sarcoma. (Am J Vet Res 1996;57:1748–1752)
Effects of dietary fumonisin B1-containing culture material, deoxynivalenol-contaminated wheat, or their combination on growing barrows
Authors: Harvey Roger B. , Edrington Thomas S. , Kubena Leon F. , Elissalde Marcel H. , Casper Howard H. , Rottinghaus George E. , Turk James R.
Published: January 2024

Objective

To examine the toxic effects of fumonisin B1 (FB1(-containing culture material and deoxynivalenol (DON)-contaminated wheat diets on barrows.

Animals

24, 7-week-old crossbred barrows allotted to 4 equal groups of 3 replicates of 2 barrows/replicate.

Procedure

Barrows were fed diets for 28 days that were formulated as follows: no additional FCM or DON/kg of feed (control); 100 mg FB1/kg of feed; 5 mg DON/kg of feed; or 100 mg FB1 plus 5 mg DON/kg of feed. Body weight and feed consumption were monitored weekly. On day 28, blood samples were obtained for serum biochemical, hematologic, and immunologic measurements. On day 29, barrows were euthanatized and necropsies were performed.

Results

Analyzed mycotoxin content of diets were: none detected (control); 47 mg of FB1/kg of feed (FB1 diet); 4.5 mg of DON/kg of feed (DON diet); and 56 mg of FB1 and 3.7 mg of DON/kg of feed (FB1 plus DON diet). Differences were detected among groups of barrows for clinical performance, serum biochemical analytes, immunologic response, and histopathologic lesions.

Conclusions

Combining FB1-containing material and DON-contaminated wheat in the diets of growing barrows induces a more toxic response than that induced by either toxin singly. For many variables, the response could be described as additive; however, for some variables, responses were interactive in a greater-than-additive manner.

Clinical Relevance

Caution should be exercised when formulating swine diets that could contain FB1 and DON, because the condition induced by their combination is more severe than that predicted for each mycotoxin's toxicity. (Am J Vet Res 1996;57:1790–1794)
Biochemical and site-specific effects of insulin-like growth factor I on intrinsic tenocyte activity in equine flexor tendons
Authors: Murphy David J. , Nixon Alan J.
Published: January 2024

Objective

To examine the site-specific and dose-dependent effects of insulin-like growth factor I (IGF-I) on normal equine tendon in vitro.

Samples

Superficial digital flexor tendon explants derived from a euthanatized 3-year-old horse.

Procedure

Explants in culture were treated with 0, 100, 250, or 500 ng of IGF-I/ml for 14 days with an end-stage radiolabel of 20 μCi of [3H]proline/ml or 5 μCi of [3H]thymidine/ml. The tendon tissues were then analyzed biochemically for hydroxyproline content by reverse-phase high-performance liquid chromatography, DNA content by fluorometry, and glycosaminoglycan content by the dimethylmethylene blue dye-binding assay. In addition, morphologic analysis of the explants comprised histologic examination, autoradiography, and immunohistochemistry.

Results

Hydroxyproline content was significantly increased in explants treated with 100 and 250 ng of IGF-I/ml. Additionally, the collagen synthetic rate, measured by incorporation of [3H]proline into hydroxyproline, was significantly increased for all treatment groups. On the basis of autoradiograms, fibroblast proliferation and collagen synthesis were predominantly confined to the endcap and adjacent endotenon of the explants. Enhanced immunoreactivity for type-I collagen, compared with type-III collagen, was evident in the treated explants, an observation supported by positive staining for type-I collagen with picrosirius red. Histologically, treated explants contained greater numbers of larger and more metabolically active fibroblasts, compared with untreated controls.

Conclusion

IGF-I enhances collagen synthesis in normal equine flexor tendon in a dose-dependent manner. IGF-I also exerts its primary effect on cell proliferation and collagen synthesis in the epitenon and adjacent endotenon and accompanying perivascular connective tissues, consistent with enhancement of intrinsic tendon metabolism.

Clinical Relevance

IGF-I may have a potential role in the treatment of tendinitis in horses. (Am J Vet Res 1997;58:103–109)
Deficiencies of myocardial troponin-T and creatine kinase MB isoenzyme in dogs with idiopathic dilated cardiomyopathy
Authors: O'Brien Peter James
Published: January 2024

Objective

To test the hypothesis that the derangement of myocardial energy homeostasis characteristic of idiopathic dilated cardiomyopathy (IDCM) of Doberman Pinschers was attributable to deficiency of creatine kinase (CK) isoenzyme MB relative to CK isoenzyme MM and troponin-T (Tn-T).

Animals

9 Doberman Pinschers with advanced congestive heart failure attributable to IDCM and 9 mixed-breed dogs without cardiac disease (controls).

Procedure

Myocardial myofibrillar CK-MM, mitochondrial CK, and cytosolic CK-MB activities were determined in comparison with the concentration of cardiac-specific, myofibrillar protein Tn-T. Myocardial biopsy specimens were obtained after euthanasia and were ultrafrozen. Isoenzymes of CK were separated eloctrophoretically, and their activity was determined, using a coupled-enzyme, kinetic, fluorescent assay and densitometry. Troponin-T content was determined by immunoassay.

Results

Myofibrillar CK-MM and mitochondrial CK activities and Tn-T content were 25% lower in the dogs with IDCM than in controls, whereas cytosolic CK-MB activity was 50% lower.

Conclusion

Deficiency of CK-MB activity is a component of and may have a central role in the energy deficiency characteristic of failing myocardium in IDCM of Doberman Pinschers. A side-product of this study was the observation that, in dogs, CK-MB activity and Tn-T content of myocardium are sufficiently high to be candidate serum markers for active cardiac injury. (Am J Vet Res 1997;58:11–16)
Evaluation of association of blood and bronchoalveolar eosinophil numbers and serum total immunoglobulin E concentration with the expression of nonspecific airway reactivity in dogs
Authors: Collie D. David S. , DeBoer Douglas J. , Muggenburg Bruce A. , Bice David E.
Published: January 2024

Objective

To characterize the relation between bronchoalveolar and blood eosinophil numbers, serum total IgE concentration, and nonspecific airway reactivity in healthy dogs.

Animals

26 healthy Beagles.

Procedure

Prior to measurement of nonspecific airway responsiveness, dogs were anesthetized and bronchoscopy was performed to recover bronchoalveolar lavage (BAL) fluid. Repeated measurements were made in 6 dogs.

Results

The percentage of blood eosinophils varied between 0 and 13 (mean ± SD, 5.6 ± 3.6) %, the percentage of eosinophils in BAL fluid ranged between 0 and 63.5 (8.8 ± 12.9) %, and total serum IgE concentration was 0.1 to 107.5 (23.4 ± 29.1) U/ml. A strong association was evident between numbers of blood eosinophils and total serum IgE concentration (R2 = 0.413, P < 0.001), and a trend toward an association between numbers of blood eosinophils and numbers of eosinophils in BAL fluid was apparent (R2 = 0.110, P = 0.053). Significant associations were not found between any other aspects of the blood and BAL fluid cell profiles and total serum IgE concentration or airway reactivity. Serum total IgE concentration was not associated with airway reactivity. Further, in dogs examined on repeated occasions, variation in BAL fluid eosinophil numbers was not associated with any change in serum total IgE concentration or airway reactivity.

Conclusions

Neither numbers of bronchoalveolar or blood eosinophils nor serum total IgE concentration have a significant role in determining airway reactivity in healthy dogs. (Am J Vet Res 1997;58:34–39)
Plasma von Willebrand factor in Thoroughbreds in response to high-intensity treadmill exercise
Authors: Smith Jennifer M. , Meyers Kenneth M. , Barbee David D. , Schott Harold , Bayly Warwick M.
Published: January 2024

Objective

To determine whether plasma von Willebrand factor (vWf) concentration changes in horses during and after treadmill exercise.

Animals

5 mature, fit Thoroughbreds.

Procedure

A blood sampling catheter was placed in the right jugular vein. A warm-up period was followed by a 3-minute rest period. Horses were galloped at racing pace until fatigued (about 2 minutes). Blood samples were collected prior to warm-up, during the postwarm-up rest period, 1 minute into the run, at cessation of the run, and 5 to 120 minutes after cessation of the run. vWF activity was measured by ELISA and corrected for plasma volume changes (measured by changes in plasma albumin concentration). Platelet-poor plasma from 10 clinically normal, resting horses was pooled, assigned a value of 100 U/dl, and served as a control for all assays.

Results

vWf activity began increasing 1 minute after horses reached full speed. At 5 minutes after cessation of exercise, vWf values had increased by mean of 92% (P < 0.05) from baseline. vWf activity returned to baseline by 15 minutes after exercise, and remained there until 90 minutes after exercise, when it began to increase.

Conclusion and Clinical Relevance

The spontaneous decrease in vWf values after completion of exercise was unexpected because vWf has a long half-life in circulation. This unexpected finding is compatible with increased vWf consumption and suggests that microvascular trauma may occur in horses during strenuous exercise. (Am J Vet Res 1997;58:71–76)
Effects of time and dilution on concentration of xanthine in frozen urine and plasma of dogs
Authors: Bartges Joseph W. , Osborne Carl A. , Felice Lawrence J. , Chen Menglan , Ulrich Lisa K.
Published: January 2024

Objective

To evaluate the effects of dilution on Stability of xanthine in canine urine stored at −20 C, and to evaluate the effects of storage at −20 C on Stability of xanthine in canine plasma.

Animals

6 reproductively intact female Beagles, 3.9 to 4.2 years old and weighing 8.5 to 10.1 kg.

Procedure

Dogs were fed a 31.4% protein (dry weight), meat-based diet for 21 days, and administered allopurinol (15 mg/kg of body weight, q 12 h) during days 14 to 21; urine and plasma samples were obtained on day 22, Urine samples were preserved undiluted or diluted, and divided into 1-ml aliquots for storage at −20 C for 1 to 12 weeks. Plasma samples were divided into 1-ml aliquots for storage at −20 C for 1 to 12 weeks. Urine and plasma xanthine concentrations were measured on day of collection (baseline) and after 1, 2, 4, 6, 9, and 12 weeks.

Results

Dilution of urine samples did not have a significant effect on consistency of xanthine concentration measured for up to 12 weeks of storage. Although xanthine concentration did not differ significantly between undiluted and diluted urine samples, average xanthine concentration measured in diluted samples was consistently higher, compared with that in undiluted samples. Compared with baseline values, plasma xanthine concentration was significantly lower at 6, 9, and 12 weeks of storage.

Conclusions

Measurement of xanthine concentration is reproducible in undiluted or diluted urine samples for up to 12 weeks, although dilution may provide better results. Measurement of plasma xanthine concentration is reproducible in samples stored for up to 4 weeks.

Clinical Relevance

To ensure reproducibility of measurements of xanthine concentration in urine samples collected from dogs that are affected with urate uroliths and receiving allopurinol, urine should be diluted 1:20 with deionized water. These measurements may be useful for monitoring dogs that are receiving allopurinol for dissolution or prevention of urate uroliths. (Am J Vet Res 1997;58:118–120)
Effects of parathyroidectomy on induced renal failure in dogs
Authors: Finco Delmar R. , Brown Scott A. , Crowell Wayne A. , Hoenig Margarethe E. , Ferguson Duncan C. , Brown Cathy A. , Cooper Tanya A.
Published: January 2024

Objective

To determine the effects of parathyroid hormone (PTH) depletion on dogs with induced chronic renal failure.

Animals

2 groups of 26 mixed-breed dogs of both sexes (13 were parathyroidectomized [PTX] and 13 had sham surgery).

Procedure

After surgical reduction of renal mass and PTX, dogs were selected for a 24-month period of study and monitored for clinical, hematologic, blood biochemical, and organ function status. On development of uremia or after 24 months, dogs were euthanatized, and tissues were examined.

Results

Higher survival rate and smaller decrement in renal function (glomerular filtration rate) were observed in PTX dogs, compared with those that had sham surgery, but values did not reach statistical significance. The PTX dogs remained hypocalcemic during the study and had lower serum Ca2+ × P product values. Regardless of parathyroid state, survivors and fatalities could be separated on the basis of serum Ca2+ × P product values. Parathyroidectomy did not prevent renal deposition of calcium, and renal lesions were poorly correlated with renal cortical calcium concentration. Abnormalities reported in dogs with renal failure, which were attributed to PTH (glucose intolerance, pulmonary hypertension), were not observed in PTX dogs or those that had sham surgery.

Conclusions and Clinical Relevance

PTX had beneficial effects, but these were mediated via changes in mineral homeostasis rather than via direct effects of PTH. Results attributable to PTX were similar to those previously obtained by dietary restriction of phosphate intake. (Am J Vet Res 1997;58:188–195)
Attempted immunization of cats with feline infectious peritonitis virus propagated at reduced temperatures
Authors: Baldwin Charles W. , Scott Fredric W.
Published: January 2024

Objective

To protect cats by inoculating them intratracheally with feline infectious peritonitis virus (FIPV), followed by a second inoculation with virus propagated at reduced temperatures.

Animals

Twelve 12-week-old, specific-pathogen-free kittens.

Procedure

Ten to 400,000 plaque-forming units (PFU) of virulent (low passage) FIPV, strain FIPV-1146 were inoculated intratracheally, followed by intranasal inoculation with high-passage FIPV-1146 (104 to 106, TCID50) on day 133. Cats were allotted to 2 groups and challenge exposed on day 188 by aerosolization of either virulent FIPV-1146 or FIPV-UCD1.

Results

Two of the 3 severely affected kittens, given 3 dosages intratracheally, were euthanatized. The third kitten recovered. A serologic response was not detected in cats inoculated with 100 PFU or less and in 1 of 2 cats given 1,000 PFU. Clinical signs of infection were not observed in surviving cats after intranasal inoculation with high-passage FIPV-1146 133 days after the initial dose. All cats seroconverted. Aerosol challenge exposure of all kittens with either virulent FIPV-1146 or FIPV-UCD1 caused no adverse effects except in kittens previously affected after the first inoculation. Residual lesions of FIPV were observed histologically.

Conclusions and Clinical Relevance

There appeared to be a beneficial effect clinically by intratracheal/intranasal inoculation, but not complete protection, as observed histologically. (Am J Vet Res 1997; 58:251–256)