bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation into intraerythrocytic and extraerythrocytic acid-base and electrolyte changes after long-term ammonium chloride administration in dogs
Authors: Schober Karsten E. 
Published: January 2024

Abstract

Objectives
To investigate the effect of ammonium chloride-induced urine acidification on acid-base status (ABS) of blood, plasma, and erythrocytes, and to compare the diagnostic value of acid-base analysis for erythrocytes with that for blood and plasma.

Design
Ammonium chloride (100 mg/kg of body weight) was administered orally every 12 hours for 8 consecutive days. The ABS was determined daily in venous blood, plasma, and lysed, packed erythrocytes (erythrolysate) and in urine. In plasma and erythrocytes, concentrations of sodium (Na+) and potassium (K+) were analyzed.

Animals
16 clinically normal (8 treated and 8 control) dogs.

Procedure
The acid-base analysis (standard pH, standard bicarbonate concentration, base excess, and carbon dioxide tension) in blood, plasma, and erythrocytes was determined by use of the CO2, O2 gas equilibration method. Determination of urine ABS (pH, concentrations of acids and bases, net acid-base excretion, and baseacid quotient) was performed by titration methods. Determination of concentrations of Na+ and K+ in erythrocytes was performed by flame photometry, and in plasma, by use of ion-specific electrodes.

Results
Ammonium chloride caused metabolic acidosis in blood and plasma, but no change of ABS in erythrocytes. The concentrations of K+ in plasma and erythrocytes did not change in treated dogs; however, the concentrations of Na+ in plasma and erythrocytes decreased significantly (P <0.05) after ammonium chloride administration. Urinary acid excretion increased significantly (P<0.05) in treated dogs; urine pH was between 4.51 and 5.49 at all times.

Conclusions
Ammonium chloride administration (100 mg/kg, PO, q 12 h) causes substantial blood and urine acidification but does not influence erythrocyte ABS. In this study, determination of erythrocyte ABS did not provide any additional benefit in diagnosing metabolic acidosis, compared with analysis of blood. (Am J Vet Res 1996; 57:743–749)
Effects of various methods of preservation on the stability of uric acid in frozen canine urine
Authors: Bartges Joseph W. , Osborne Carl A. , Felice Lawrence J. , Fletcher Thomas F. , Lulich Jody P. , Chen Menglan 
Published: January 2024

Abstract

Objective
To evaluate the effects of dilution and alkalinization, separately and together, on the stability of uric acid in canine urine stored at −20 C.

Design
Prospective-controlled study.

Animals
5 dogs with confirmed ammonium urate uroliths, 6 Beagles, and 6 mixed-breed dogs.

Procedure
Dogs were fed a 31.4% protein (dry weight), meat-based diet for 21 days, and urine samples were collected on day 22. Urine samples were preserved, using combinations of dilution and alkalinization, and divided into 1-ml aliquots for storage at −20 C for 1 to 12 weeks. Urine uric acid concentrations were measured, using high-performance liquid chromatography, on day of collection (baseline), and after 1, 2, 4, 8, and 12 weeks.

Results
Alkalinization did not have a significant effect on reproducibility of measurements of uric acid concentrations in urine; however, dilution did have a significant effect. Compared with baseline, uric acid concentrations in urine samples collected from dogs with ammonium urate uroliths and Beagles and diluted 1:10 or 1:20 with deionized water were not different after storage for 1 to 12 weeks. Uric acid concentrations in urine samples collected from mixed-breed dogs did not differ from baseline values during the 12-week storage period whether samples were undiluted or were diluted 1:10 or 1:20 with deionized water.

Conclusions
Measurements of uric acid concentration are most reproducible in canine urine samples stored at −20 C for 1 to 12 weeks when samples are diluted 1:20 with deionized water.

Clinical Relevance
To ensure reproducibility of measurements of uric acid concentration in urine samples collected from dogs affected with urate uroliths, urine should be diluted 1:20 with deionized water. Alkalinization is not necessary, and is not recommended because of the additional step in processing and its potential to interfere with measurement of other urinary analytes. (Am J Vet Res 1996;57:787–790)
Comparison among strains of porcine reproductive and respiratory syndrome virus for their ability to cause reproductive failure
Authors: Mengeling William L. , Vorwald Ann C. , Lager Kelly M. , Brockmeier Susan L. 
Published: January 2024

Abstract

Objective
To compare the virulence of selected strains of porcine reproductive and respiratory syndrome virus (PRRSV) relative to reproductive performance of pregnant gilts.

Design
16 pregnant gilts (principals) were exposed oronasally to 4 strains (vaccine strain RespPRRS, field strains VR-2385, VR-2431, and NADC-8, 4 gilts/strain) of PRRSV on or about day 90 of gestation. 4 pregnant gilts (controls) were kept under similar conditions, except for exposure to PRRSV. Samples and specimens obtained from gilts, pigs (before ingestion of colostrum), and fetuses were tested for PRRSV and homologous antibody.

Animals
20 pregnant gilts.

Procedure
The virulence of each strain of PRRSV was evaluated mainly on the clinical status of the corresponding litters at farrowing.

Results
Most gilts remained clinically normal throughout the study and farrowed normally at or near the expected farrowing time. All virus strains crossed the placenta of principal gilts to infect fetuses in utero. The number of late-term dead fetuses (which appeared to be the best measure of relative virulence) ranged from 0 for litters of control gilts and gilts exposed to strain RespPRRS, to 38 for gilts exposed to strain NADC-8. All principal gilts became viremic and developed antibody against PRRSV. All strains persisted in alveolar macrophages of at least some principal gilts for at least 7 weeks after exposure.

Conclusion
Strains of PRRSV vary in virulence.

Clinical Relevance
The effects of PRRSV on reproductive performance are strain dependent and this should be considered in making a tentative diagnosis on the basis of clinical observations. (Am J Vet Res 1996;57:834–839)
Pharmacokinetics of enrofloxacin in adult horses and concentration of the drug in serum, body fluids, and endometrial tissues after repeated intragastrically administered doses
Authors: Giguère Steeve , Sweeney Raymond W. , Bélanger Myriam 
Published: January 2024

Abstract

Objective
To investigate the pharmacokinetics of enrofloxacin in adult horses.

Design
2-dose oral and IV cross-over trial followed by multiple oral doses.

Animals
8 clinically normal adult horses.

Procedure
Enrofloxacin was administered at dosages of 2.5 mg/kg of body weight to 4 horses and 5.0 mg/kg to 4 other horses. Each dose was given by the intragastric and IV routes, using a cross-over design. After the first intragastric dose, 5 additional doses were administered at 12-hour intervals. Enrofloxacin concentrations were measured in serum, synovial fluid, peritoneal fluid, urine, CSF, and endometrial tissues.

Results
Disposition of enrofloxacin after IV administration conformed to a 2-compartment model with an elimination half-life of 5.95 and 6.09 hours for the low and high dose, respectively. After the first intragastric administration, time to peak concentration was 1.0 ± 0.35 and 1.25 ± 0.43 hours, and the bioavailabihty was 57.39 ± 8.45 and 62.52 ± 19.65% for the low and high dose, respectively. After multiple intragastric administration, peak serum concentration (at 72 to 96 hours) was 2.62 ± 0.61 μg/ml for the low dose and 5.97 ± 1.56 μg/ml for the high dose. After multiple intragastric doses, synovial fluid, urine, and endometrial tissue concentrations exceeded serum concentrations. Peritoneal fluid and CSF concentrations were lower than serum concentrations.

Conclusions
Computer modeling of the pharmacokinetic variables suggested that a single daily IV administered dose of 5.5 mg/kg, or orally administered doses of 7.5 mg/kg every 24 hours or 4.0 mg/kg every 12 hours, would be effective in horses. Additional studies are necessary to confirm the efficacy and safety of these dosages in a clinical setting. (Am J Vet Res 1996;57:1025–1030)
Generation of in vitro natural cytotoxicity of horse lymphocytes against sarcoid-derived tumor cells not expressing major histocompatibility complex antigens
Authors: Broström Hans , Troye-Bomberg Marita , Perlmann Peter 
Published: January 2024

Abstract

Objective
To analyze in vitro lymphocyte-mediated immune responses of horses with sarcoids against allogeneic sarcoid cells containing endogenous retrovirus but not expressing major histocompatibility complex antigens.

Design
Lymphocyte-mediated immune reactions were assessed by means of proliferative responses in mixed lymphocyte tumor cell culture (MLTC) assay and lymphocyte-mediated cytotoxicity against various equine target cells.

Animals
12 horses with sarcoid tumors and 15 control horses.

Procedure
Blood lymphocytes were cocultured in MLTC with allogeneic sarcoid cells (Mc-1, BayMc-1), equine testis cells, or normal equine dermal fibroblasts. Lymphocytes were assayed for proliferative responses by [3H]thymidine uptake and for cytotoxicity against the same targets by 51Cr release assay. The lymphocyte populations were analyzed for some common surface markers.

Results
Lymphocytes from horses with sarcoids exerted an anamnestic proliferative response in MLTC against Mc-1 cells, but this procedure never generated cytotoxic lymphocytes. However, lymphocytes from all horses cultured in medium with 10% allogeneic serum only had selective, natural cytotoxicity against Mc-1 that was generated without DNA synthesis. Approximately 80% of the lymphocytes disappeared during culture; however the remaining population of small, viable lymphocytes indicated a decrease of CD4+ and CD8+ T lymphocytes, but numbers of T cells with receptors for Helix pomatia A hemagglutinin were unaffected. Few lymphocytes had Fc-receptors for IgG, were complement-reactive positive cells, or were B cells expressing surface immunoglobulin.

Conclusions
Results may indicate a natural defense system, which preferentially recognizes and lyses tumor cells that are deficient in surface expression of major histocompatibility complex antigens, without intervention of conventional T-cell receptors or antibodies. (Am J Vet Res 1996;57:992–999)
Use of tilmicosin for treatment of pasteurellosis in rabbits
Authors: McKay Sharon G. , Morck Douglas W. , Merrill John K. , Olson Merle E. , Chan Siu C. , Pap Kathleen M. 
Published: January 2024

Abstract

Objectives
To determine tilmicosin concentrations in serum and tissues of rabbits given a single dose of 25 mg of tilmicosin/kg of body weight. To examine the effects of tilmicosin treatment (25 mg/kg, SC) in rabbits with pasteurellosis.

Procedure
After receipt of tilmicosin, healthy New Zealand White female rabbits (n = 3 at each time) were euthanatized at 2, 4, 8, 24, 48, and 72 hours for collection of blood samples and tissue specimens; 4 rabbits served as untreated controls. Rabbits (male and female) with pasteurellosis (n = 42) also were treated. Tilmicosin concentration was determined in serum, lung, and uterine tissues. Rabbits with pasteurellosis were treated with tilmicosin. Response was monitored, using bacteriologic culturing and antibiotic resistance and susceptibility testing, and by scoring clinical signs of disease.

Results
Serum tilmicosin concentration reached 1.91 ±0.18 μg/ml after 2 hours, decreased to 0.77 ± 0.07 μg/ml by 8 hours, and was below minimum inhibitory concentrations for Pasteurella multocida at 24 hours. Terminal half-life in serum was 5.97 hours. Lung and uterus concentrations were 14.43 ± 1.34 and 11.57 ± 0.09 ppm at 2 hours, and were 5.10 ± 1.05 and 8.87 ± 1.66 ppm at 24 hours, respectively. 69% (29/42) of rabbits with pasteurellosis responded favorably in 3 days. Second treatment was required in 31% (13/42), and 5 of these rabbits had clinical signs on day 6; 2 of these 5 had improved. Treatment success rate was 93% (39/42). Of the rabbits that were culture positive on day 0, 35% (6/17) remained positive on day 3. 1 of 6 rabbits was culture positive on day 6.

Conclusion
Tilmicosin (25 mg/kg, SC) was an effective treatment for pasteurellosis in New Zealand White rabbits.

Clinical Relevance
Tilmicosin treatment of pasteurellosis in rabbits is useful in research rabbits and in those destined for meat production. A single dose of antibiotic minimizes stress-associated handling. (Am J Vet Res 1996;57:1180-1184)
Single intravenous and multiple dose pharmacokinetics of gentamicin in healthy llamas
Authors: Lackey Margaret N. , Belknap Ellen B. , Greco Deborah S. , Fettman Martin J. 
Published: January 2024

Objective
To determine the pharmacokinetics of gentamicin sulfate in healthy llamas after IV administration of a single bolus and after repeated parenteral administration.

Design
Prospective clinical trial.

Animals
19 clinically normal, adult male llamas for the single-dose trial and 10 of the 19 llamas for the multiple-dose trial.

Procedure
In the first trial, llamas were given gentamicin (5 mg/kg of body weight, IV) as a single bolus, and serum gentamicin concentration was monitored over the next 48 hours. 2 months later, llamas were given gentamicin (2.5 mg/kg) IV for the first day, then IM every 8 hours for 7 days. Serum gentamicin concentration and indices of renal function and damage were monitored during the 7 days.

Results
There were no significant dose- or time-related differences in clearance of the drug; volume of distribution; apparent coefficients of the distribution and elimination phases, α and β, respectively; mean residence time; or distribution (t½α) and elimination phase (tt/2β) half-lives. The 5 mg/kg IV kinetic study revealed t½β, of 14.5 ± 5.06 minutes and t½β of 166 ± 20.5 minutes. The 2.5 mg/kg IV kinetic study revealed t½α of 17.7 ± 6.59 minutes and t½β of 165 ± 40.3 minutes. Peak serum gentamicin concentration averaged 10.10 μg/ml in the multiple-dose trial, and trough concentration averaged 1.50 μg/ml.

Conclusions
Dose effects were not observed for gentamicin clearance, volume of distribution, or half-lives. Multiple dosing at 2.5 mg/kg every 8 hours does not appear to cause renal impairment in healthy llamas.

Clinical Relevance
Gentamicin pharmacokinetic variables in llamas appear to resemble those in other ruminant species. (Am J Vet Res 1996;57:1193–1199)
Effects of pentoxifylline on hemorheologic alterations induced by incremental treadmill exercise in Thoroughbreds
Authors: Weiss Douglas J. , Geor Raymond J. , Burger Katherina 
Published: January 2024

Abstract

Objectives
To determine whether pentoxifylline treatment altered hematologic, rheologic, electrolyte, or blood gas test results of Thoroughbreds during submaximal treadmill exercise.

Animals
5 healthy Thoroughbreds that had raced within the past year and had no history of exercise-induced pulmonary hemorrhage.

Procedure
Mixed venous blood samples were obtained before exercise, at treadmill speeds of 9 and 13 m/s, and 20 minutes after exercise; hematologic, rheologic, electrolyte, and blood gas test results were determined.

Results
Pentoxifylline treatment resulted in a 45% reduction in RBC filtration pressures for horses at rest. The improved RBC filterability persisted during treadmill exercise. Horses treated with pentoxifylline had a greater decrease in Po2 values and a lesser increase in plasma lactate concentration during treadmill exercise.

Conclusion
Administration of pentoxifylline improved RBC deformability of horses at rest and during treadmill exercise.

Clinical Relevance
Improved RBC deformability resulting from pentoxifylline treatment may reduce exercise-associated shear stress in pulmonary capillaries, thereby attenuating exercise-induced pulmonary hemorrhage. (Am J Vet Res 1996;57:1364-1368)
Effect of pubic symphysiodesis on acetabular rotation and pelvic development in guinea pigs
Authors: Mathews Kyle G. , Stover Susan M. , Kass Philip H. 
Published: January 2024

Abstract

Objective
To evaluate the effect of premature closure of the pubic symphysis on pelvic development.

Animals
18, 21-day-old male guinea pigs.

Procedure
The pubic symphysis was surgically approached in 10 guinea pigs of the symphysiodesis group and in 4 of the sham-operated group; 4 guinea pigs served as unoperated controls. The pubic symphysis was destroyed by use of electrocautery in the 10 guinea pigs of the symphysiodesis group. All guinea pigs were allowed to grow to skeletal maturity and were euthanatized at 33 weeks of age. Body weight was recorded throughout the study and was compared between groups. Histologic examination of the symphyses confirmed premature closure of the pubic symphyseal growth plates in guinea pigs of the symphysiodesis group. Pelvic measurements taken from pretreatment radiographic views and from video images of harvested pelves were compared between groups.

Results
There were no significant differences between groups with regard to pretreatment radiographic variables, rate of weight gain, or body weight at any time. Pubic symphysiodesis resulted in significant narrowing of the caudal aspect of the pelvis, narrowing and shortening of the pubic bones, and outward rotation of the acetabula.

Conclusions
The pubic symphyseal growth plates contribute significantly to development of the pelvis. Premature closure of these growth plates (pubic symphysiodesis) results in outward rotation of the acetabula, which might be beneficial in some cases of canine hip dysplasia; however, this rotation is accompanied by concomitant narrowing pf the caudal aspect of the pelvis. (Am J Vet Res 1996;57:1427-1433)
Effects of mold proteases on the biological activity of allergenic pollen extracts
Authors: Rosenbaum Michele R. , Esch Robert E. , Schwartzman Robert M. 
Published: January 2024

Abstract

Objective
To determine the effect of mold extracts with high protease activity on the biological activity of allergenic tree, grass, and weed extracts, using in vivo and in vitro methods, in atopic dogs.

Animals
15 dogs with history and clinical signs of atopy. All dogs had strong positive reactions (3+ or 4+) to 1 or more preselected allergens and negative reactions (0) to molds.

Procedure
Mold extracts and saline solution were coincubated separately with tree, grass, and weed pollen extracts at 4 C for 30 and 180 days. Skin end-point titration (30-day incubation) and ELISA inhibition (30- and 180- day incubations) tests were performed on all samples. The biological activity of pollen extracts coincubated with mold extracts was compared with that of pollen extracts coincubated with saline solution.

Results
In the skin end-point titration test, weed pollen extracts coincubated with a mixed mold extract lost a statistically significant amount of biological activity, compared with saline coincubated controls. In the ELISA inhibition test, grass and weed pollen extracts incubated with a mixed mold extract lost a significant amount of biological activity, compared with saline coincubated controls. A significant correlation in the measurement of biological activity was found between a loss of end-point dilution in the skin end-point titration test and a decrease in relative potency, as measured by the ELISA inhibition test for allergenic grass and weed extracts.

Conclusion and Clinical Relevance
Mold proteases can decrease the biological activity of certain grass and weed pollen extracts when coincubated in the same vial for 30 days. Separation of mold and pollen extracts, when preparing immunotherapy vaccines, may help prevent loss of pollen extract potency and increase the vaccine’s stability and efficacy. (Am J Vet Res 1996;57:1447-1452)
Antibody responses of cattle to outer membrane proteins of Pasteurella multocida A:3
Authors: Confer A. W. , Nutt S. H. , Dabo S. M. , Panciera R. J. , Murphy G. L. 
Published: January 2024

Abstract

Objective
To quantify the serum antibody responses to Pasteurella multocida A:3 outer membrane proteins (OMP) for cattle vaccinated with the homologous serogroup and to correlate those responses with the extent of experiment tally induced pneumonia.

Animals
29, 5- to 8-month-old beef-type calves.

Procedure
Calves were vaccinated SC or by aerosol exposure on davs 0 and 7 with live or killed P multocida or phosphate-buffered saline solution (control) and subsequently challenge exposed with virulent P multocida. Antibody responses to P multocida A:3 outer membranes were quantified, using an ELISA. Antibody responses to individual OMP were detected by immunoblot analysis (western blot) and were quantified by densitometry. Antibody responses were compared among groups of calves and for various times after vaccination. Regression analyses were used to determine whether significant correlations existed between lesion scores and antibody responses to either whole outer membranes or to individual OMP

Results
By ELISA, antibody responses to outer membranes for calves aerosol vaccinated with live P multocida were significantly (P < 0.05) greater than those for control calves or for killed P multocida vaccinates. There was a significant (P<0.05) correlation between lesion score and antibody responses to outer membranes. By western blotting and densitometry, antibodies to 11 prominent OMP (100, 97, 90, 85, 74, 53, 46 35, 32, 21, and 16 kd) were identified and quantified. In experiment 1, SC vaccination with live P multocida increased antibody binding to all protein bands except 85- 74-, and 35-kd bands. Aerosol vaccination with live P multocida stimulated increases in antibody binding to all bands except 100 and 16 kd. Antibody responses to the 97-, 90-, 74-, and 35- kd bands were significantly (P <0.05) greater for live aerosol vaccinates than for control calves. In experiment 2, antibody responses were not different between the killed P multocida vaccinates or control calves. Antibody responses for live P multocida aerosol vaccinates were significantly (P <0.05) greater than those for control calves for the 100-, 90-, 85-, 74-, 53-, 35-, and 16-kd bands. Regression analyses indicated significant correlations (P <0.05) between lesion score and antibody responses to the 100-, 90-, 53-, 46-, 35-, and 32-kd OMP.

Conclusions
Several OMP of P multocida type A:3 may be important for stimulating immunity to the organism in cattle. (Am J Vet Res 1996;57:1453-1457)