bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid spread of a unique strain of Pasteurella haemolytica serotype 1 among transported calves
Authors: Briggs Robert E. , Frank Glynn H. , Purdy Charles W. , Zehr Emilie S. , Loan Raymond W.
Published: January 2024

Objective

To determine the rate and mode of infectious spread of Pasteurella haemolytica among calves maintained under typical conditions during collection, transport, and the first month of feeding.

Animals

101 two- to five-month-old Angus-crossbred calves.

Procedure

Samples obtained from cattle prior to and after they were transported to a feedlot were used for isolation and characterization of P haemolytica. Samples were also obtained from additional calves, some of which were sick, and these calves were then commingled with the transported calves for 3 days. A strain of P haemolytica that contains a rare deletion of the 4.2-kilobase streptomycin- and sulfonamide-resistance plasmid was inoculated into both palatine tonsils of 12 calves. Nasal secretions were aspirated from the ventral nasal meatus. Tonsillar wash specimens were procured. Pasteurella haemolytica organisms were quantitatively cultured and identified on the basis of colony morphology and response to specific antisera. Plasmids were isolated by an alkaline lysis procedure and identified by agarose gel electrophoresis.

Results

A single plasmid profile was observed from P haemolytica isolated from samples obtained prior to shipment. Commingled calves were shedding P haemolytica containing each known plasmid profile. After shipment, samples contained P haemolytica isolates with each known plasmid profile. The plasmid profile of the unique P haemolytica isolate was recovered from all 12 inoculated calves and 10 other calves. Some calves simultaneously shed P haemolytica isolates with differing plasmid profiles.

Conclusions and Clinical Relevance

Pasteurella haemolytica serotype 1 was horizontally transmitted among calves within days of commingling, which continued after calves were transported to a feedlot. (Am J Vet Res 1998;59:401–405)
Signaling pathways for tissue factor expression in lipopolysaccharide-stimulated bovine alveolar macrophages
Authors: Dean David F. , Bochsler Philip N. , Carroll Roger C. , Olchowy Timothy W. J. , Neilsen Nancy R. , Slauson David O.
Published: January 2024

Objective

To investigate receptor-mediated intracellular events in bovine alveolar macrophages (AM) stimulated by bacterial lipopolysaccharide (LPS), using tissue factor (TF) expression as the measurable functional endpoint.

Sample Population

Pulmonary AM harvested from 1- to 4-month-old male Holstein calves.

Procedure

Alveolar macrophages, acquired by use of volume-controlled bronchopulmonary lavage, were treated with CD14 monoclonal antibody (20 μg/ml), pertussis toxin (300 ng/ml), or 1 of 3 known protein kinase C (PKC) inhibitors (10 μM chelerythrin, 100 μM H-7, or 50 nM staurosporin), then were stimulated with LPS alone (0.01, 0.10, 1.0, 10.0 μg/ml) or LPS (0.25, 0.5, 1.0 ng/ml) in combination with concentrated bovine serum fraction 2 (500 ng/ml). Tissue factor expression was quantified by use of a colorimetric assay. Changes in intracellular Ca2+ concentration and pH were monitored, using Ca2+- and pH-sensitive fluorescent dyes, with changes in fluorescent intensity after incubation with LPS measured by spectrophotometry.

Results

Treatment of AM with a CD14 monoclonal antibody caused profound inhibition of TF expression (P < 0.0001) after stimulation by LPS combined with bovine serum fraction 2. Pertussis toxin had a significant (P < 0.0319) inhibitory effect on TF expression when cells were stimulated by LPS alone. Treatment with all 3 PKC inhibitors caused marked reduction in TF expression of cells stimulated with LPS alone or with phorbol myristate acetate. Stimulation of cells by LPS failed to mobilize intracellular Ca2+ stores or to alter cytosolic pH.

Conclusion

LPS combined with serum factors binds to CD14 on the surface of AM, and PKC is an important signaling kinase in the pathway utilized by LPS, resulting in enhanced TF expression; a pertussis toxin-sensitive G protein is involved in the signaling pathway utilized by LPS alone; and mobilization of Ca2+ does not have a role in the signal transduction pathway utilized by LPS nor does LPS affect cytosolic pH of AM. (Am J Vet Res 1998;59:445–451)
Comparison of isoflurane with sevoflurane for anesthesia induction and recovery in adult dogs
Authors: Johnson Rebecca A. , Striler Elaine , Sawyer Donald C. , Brunson David B.
Published: January 2024

Objective

To compare mask anesthesia induction and recovery characteristics between 2 inhalant anesthetic agents: isoflurane and sevoflurane.

Animals

16 clinically normal, young adult Beagles.

Procedure

Using a cross-over design, dogs were randomly selected to receive sevoflurane or isoflurane via a face mask and a circle anesthetic system. Vaporizer setting concentrations were increased in step-wise, equal minimum alveolar concentrations (MAC) for each anesthetic until the vaporizer setting of 2.6% for isoflurane or 4.8% for sevoflurane (2 MAC) was reached. Concentration was kept constant until the dog had a negative tail clamp response and was intubated. End-tidal concentration was maintained at 1.8 to 2.0% or 3.3 to 3.8% for isoflurane or sevoflurane, respectively (1.4 to 1.6 MAC) for 30 minutes. Dogs were allowed to recover with only tail clamp stimulation until a positive response was obtained. Extubation was performed when a spontaneous swallow reflex was observed. Dogs were allowed to achieve sternal recumbency and stand unassisted without further stimulation.

Results

Sevoflurane induction resulted in shorter time to loss of palpebral reflex, negative tail clamp response, and time to tracheal intubation, and was of better quality than isoflurane induction. Both anesthetics were associated with rapid and smooth recovery.

Conclusions

Sevoflurane mask induction is faster and of better quality, compared with isoflurane, in adult dogs. Recovery time and quality are comparable.

Clinical Relevance

On the basis of these results, sevoflurane is a suitable inhalant anesthetic for mask induction and recovery in adult dogs and appears to have some advantages over isoflurane, including faster and smoother mask induction. (Am J Vet Res 1998;59:478–481)
Identification and purification of apolipoprotein C-III from the serum of cows
Authors: Yamamoto Midori , Katoh Norio , Adachi Yoshikazu , Oikawa Shin
Published: January 2024

Objective

To identify, purify, and analyze distribution of apolipoprotein C-III in lipoprotein fractions and to evaluate its concentration in serum from calves, heifers, and cows during various stages of lactation.

Sample Population

Sera from 3 female calves, 3 heifers, and 12 cows during early, middle, late, and nonlactation stages.

Procedure

Apolipoprotein C-III was identified by use of amino-terminal amino acid sequence analysis of bands separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purification was performed by extraction with acetone, delipidation with 2-propanol, and 2 chromatographic steps. The apolipoprotein C-III concentration in the total lipoprotein fraction was evaluated by densitometric scanning of the bands for apolipoprotein C-III separated by electrophoresis, using purified apolipoprotein C-III as an internal standard.

Results

Apolipoprotein C-III was identified as 8.2- and 7.3-kd proteins with identical amino acid sequences. The 2 proteins were mainly found in the high-density lipoprotein fraction, then were purified separately. Serum apolipoprotein C-III concentration was significantly (P< 0.05) higher in cows during lactation than in nonlactating cows and was negatively correlated with serum triglyceride concentration (r = −0.620, P < 0.01).

Conclusions

The role of apolipoprotein C-III in cows may involve a function related to lactation. (Am J Vet Res 1998;59:667-672)
Cloning of equine interleukin 1 receptor antagonist and determination of its full-length cDNA sequence
Authors: Howard Rick D. , McIlwraith C.Wayne , Trotter Gayle W. , Nyborg Jennifer K.
Published: January 2024

Objectives

To clone equine interleukin 1 receptor antagonist (IL-1 ra) and determine its full-length cDNA sequence.

Procedure

A cDNA library derived from lipopolysaccharide-stimulated equine monocytes was screened by means of plaque hybridization to radiolabeled equine IL-1ra DNA probes generated by means of the polymerase chain reaction. The cDNA nucleotide sequence for equine IL-1ra was determined by use of the dideoxy chain termination technique, analyzed by use of computer software for sequence characteristics, and compared with sequences reported for IL-1ra of other species.

Results

The cDNA for equine IL-1ra was 1,614 base pairs in length with an ORF encoding a peptide of 177 amino acids with a predicted molecular mass of 20.427 kd. Similarity between the amino acid sequence of equine IL-1ra and sequences for human, murine, rat, and lapine IL-1ra was 76%. Similarity between sequence for equine IL-1ra and sequences for equine interleukin-1α and equine interleukin-1ß were 22.6 and 24.6%, respectively.

Conclusion

Comparison of the sequence for equine IL-1ra with sequences for IL-1ra of other species indicated a high degree of conservation.

Clinical Relevance

Results establish a basis for studying the roles of interleukin-1 in healthy and diseased joints in horses. (Am J Vet Res 1998;59:712-716)
Induction of temporary otitis media in specific-pathogen-free pigs by intratympanic inoculation of Mycoplasma hyorhinis
Authors: Morita Takehito , Sasaki Aya , Kaji Noriyuki , Shimada Akinori , Kazama Satoshi , Yagihashi Takeshi , Umemura Takashi
Published: January 2024

Objective

To examine whether Mycoplasma hyorhinis inoculated into the tympanic cavity can cause otitis media in pigs.

Animals

17- or 22-day-old specific-pathogen-free pigs.

Procedure

Histologic and bacteriologic examinations were performed on specimens from the tympanic cavity and auditory tube at 0, 7, 14, and 25 days after intratympanic inoculation of M hyorhinis (auditory tube cloning strain 14).

Results

In M hyorhinis-inoculated pigs, mild to moderate inflammation of the auditory tube and tympanic cavity first appeared at postinoculation day (PID) 7. In pigs euthanatized at PID 14, the degree of inflammation was aggravated. Immunohistochemical analysis revealed M hyorhinis antigens on the luminal surface of the auditory tube and tympanic cavity. By PID 25, lesions had lessened. By use of transmission and scanning electron microscopic examinations, mycoplasmal organisms were identified among the cilia in the auditory tubes at PID 14 but not at PID 25. Results of bacteriologic examination indicated that 104 to 106 color-changing units of M hyorhinis were isolated from the tympanic cavity at PID 0. Variable numbers of M hyorhinis were isolated at PID 7 and 14, and numbers were decreased at PID 25.

Conclusions

M hyorhinis inoculated into the tympanic cavity can cause a self-limiting otitis media in SPF pigs. (Am J Vet Res 1998;59:869–873)
Epidemiologic herd-level assessment of causative agents and risk factors for winter dysentery in dairy cattle
Authors: Smith David R. , Fedorka-Cray Paula J. , Mohan Ram , Brock Kenny V. , Wittum Thomas E. , Morley Paul S. , Hoblet Kent H. , Saif Linda J.
Published: January 2024

Objective

To test the association between exposure to bovine coronavirus (BCV) and outbreaks of winter dysentery (WD) in dairy herds and to examine other risk factors for outbreaks of WD in dairy herds.

Animals

12 dairy herds in Ohio affected with WD (case herds). For each case herd, 2 unaffected herds from the same area were concurrently used as control herds.

Procedure

A case-control study was conducted, using herds as the unit of investigation. Multivariate logistic regression modeling was used to identify risk factors for contracting disease.

Results

4 factors appeared to increase a herd's risk for WD: increase in herd prevalence of adult cows that had a fourfold or more increase in BCV serum IgG antibody titer; increase in herd prevalence of adult cows that had a fourfold or more increase in bovine viral diarrhea virus (BVDV) titer; housing cattle in tie-stall or stanchion barns rather than free-stall facilities; and use of equipment to handle manure and subsequently handle feed. The adjusted population-attributable risk for these variables was 71, 43, 53, and 31%, respectively, and 99% overall, indicating that these variables had considerable impact on WD outbreaks for the study population.

Conclusions and Clinical Relevance

In dairies in Ohio, recent herd exposure to BCV appeared to increase the risk for WD outbreaks. Some WD outbreaks might have been associated with acute BVDV infection. Certain housing and management practices may have increased the risk of an outbreak of WD. (Am J Vet Res 1998;59:994–1001)
Evaluation of serum apolipoprotein C-III concentration by enzyme-linked immunosorbent assay and its higher concentration in cows during midlactation than during the nonlactating stage
Authors: Yamamoto Midori , Katoh Norio , Oikawa Shin
Published: January 2024

Objective

To determine serum apolipoprotein C-III (apoC-III) concentration in cows in various stages of lactation by use of an ELISA.

Sample Population

Sera obtained from 29 Holstein cows during early lactation, 65 cows during midlactation, 42 cows during late lactation, and 23 cows during the nonlactating stage.

Procedure

A 7.3-kd bovine apoC-III antiserum raised in rabbits was purified by affinity chromatography, and an ELISA was developed.

Results

In the immunoblot analysis, the antiserum reacted with the 7.3-kd apoC-III and moreover with another 8.2-kd apoC-III isoform. The 2 isoforms of apoC-III were also indistinguishable in the developed ELISA, the 2 proteins being measured as total apoC-III. In the ELISA for serum apoC-III concentration, addition of 2-mercaptoethanol to the coating buffer (50 mM sodium carbonate buffer, pH 9.6) was required. Mean ± SEM bovine serum apoC-III concentration (μg/ml of serum) was 71.6 ± 12.1 for the early lactating stage, 115 ± 14.0 for the midlactating stage, 104 ± 18.8 for the late lactating stage, and 55.3 ± 8.4 for the nonlactating stage. Concentration of apoC-III was significantly (P < 0.05) higher in cows during midlactation than in cows during the nonlactating stage and was correlated negatively with serum triglyceride concentration (r = −0.479; P< 0.01) and positively with total cholesterol (r = 0.421; P < 0.05) and phospholipids (r = 0.415; P < 0.05) concentrations.

Conclusions

Changes of apoC-III concentration in various stages of lactation suggest that this apolipoprotein is involved in a function related to lactation. (Am J Vet Res 1998;59:1358–1363)
Evidence for a compensatory increase in synthesis of brush border enzymes in the jejunum of Irish Setters with gluten-sensitive enteropathy
Authors: Manners H. K. , Sørensen S. H. , Embaye H. , Odedra R. M. , Batt R. M.
Published: January 2024

Objective

To determine whether biosynthesis of aminopeptidase N (ApN), alkaline phosphatase (AP), and total microvillus membrane protein is altered in Irish Setters with gluten-sensitive enteropathy (GSE).

Animals

A litter of 6 Irish Setters with GSE and 3 healthy Greyhounds.

Procedures

Explants obtained from affected dogs at 4 and 12 months were maintained in vitro and were compared with material from healthy control dogs. Biosynthesis of ApN and AP was monitored by incorporation of [35S]methionine and immunoprecipitation of these enzymes.

Results

Jejunal explants from affected Irish Setters had significantly higher rates of biosynthesis of total protein, microvillus membrane protein, AP, and ApN, compared with control tissue. Two forms of ApN with apparent molecular mass of 155 and 135 kd and 4 forms of AP with apparent molecular mass of 210 to 260, 150, 130, and 105 kd were identified in total membrane fractions from control and affected dogs.

Conclusions

Reduced activities of ApN and AP in dogs with GSE are not attributable to decreased synthesis of these proteins and document enhanced synthesis of microvillar membrane proteins, which may be a compensatory response to enterocyte damage. The 150-kd form of AP was most prominent in tissue from the most affected dogs, probably representing an early form of this enzyme. In contrast, the 105-kd form was most intense in tissue from controls and less intense in tissue of affected dogs. (Am J Vet Res 1998;59:1392–1397)
Evaluation of an assay for detecting telomerase activity in neoplastic tissues of dogs
Authors: Biller Barbara J. , Kitchell Barbara E. , Cadile Casey D.
Published: January 2024

Objective

To determine feasibility of using the telomere repeat amplification protocol (TRAP) assay to detect telomerase activity in tumors of dogs.

Sample Population

Samples of tumor or normal tissue were obtained from client-owned dogs that underwent surgical biopsy during the period of January 1996 through December 1997.

Procedure

The TRAP assay was used to detect telomerase activity in malignant or benign tumors of dogs. Telomerase status (positive or negative) was compared with results of histologic examination for each sample to estimate specificity and sensitivity of this assay for the diagnosis of malignancy.

Results

Of 26 malignant tumors, 24 were telomerase positive on TRAP assay, whereas 3 of 4 benign tumors and 3 of 3 normal tissues were telomerase negative. Analysis of these results indicated an estimated sensitivity of 92% and specificity of 86% for tumor analysis, using the TRAP assay.

Conclusion

The TRAP assay can be used to measure telomerase activity in malignant tumors of dogs.

Clinical Relevance

Because telomerase activation may be required for indefinite longevity of cells, it may also serve as a tumor marker and therapeutic target. The TRAP assay can be used to detect telomerase in samples of fluid as well as tissues obtained from solid tumors. Therefore, it may have considerable clinical value in rapid and noninvasive diagnosis of neoplasia in dogs. Additional studies must be completed to more accurately determine sensitivity and specificity of the assay. (Am J Vet Res 1998;59:1526-1529)
Correlation between longitudinal bone growth, growth hormone, and insulin-like growth factor-I in prepubertal dogs
Authors: Conzemius Michael G. , Brown Dorothy Cimino , Brabec Marek , Smith Gail K. , Washabau Robert , LaFond Elizabeth , Chakraborty Prabir K.
Published: January 2024

Objective

To determine the association between longitudinal bone growth and concentrations of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in serum from prepubertal dogs.

Animals

6 male 14-week-old German Shepherd Dogs.

Procedure

Blood was obtained every 30 minutes for 14 consecutive days. Concentrations of GH and IGF-I in serum were determined, using a canine-specific radioimmunoassay and conventional radioimmunoassay after acid-ethanol extraction, respectively. Simultaneous biplanar radiography was performed daily to measure bone growth. Spectral analysis was used to estimate specific features of GH secretion during an extended period. Multiple linear regression with different lag times between independent and dependent variables was used to determine the strongest predictors of bone growth.

Results

The power spectra of GH concentrations in serum had a primary peak at a frequency of 0.02 cycles/h or a periodicity of 50 h/cycle. A significant determinant of longitudinal bone growth was a lag time of 1 day in concentration of GH in serum. The relationship between IGF-I concentration in serum and bone growth was not significant.

Conclusions

The primary frequency of GH secretion is outside the time frame of a single day and the concentration of GH in serum is a primary determinant of bone growth.

Clinical Relevance

A better understanding of the components of bone growth provide discernment to improved diagnosis and treatment of abnormal bone growth. (Am J Vet Res 1998;59:1608-1612)
Humoral and cell-mediated immune responses of beef and dairy cattle experimentally infested with Psoroptes ovis
Authors: Lonneux Jean-François , Nguyen Thu Queen , Hollanders Wim , Denis Martine , Thiry Etienne , Pastoret Pierre Paul , Losson Bertrand
Published: January 2024

Objective

To compare cellular and humoral immune responses of beef (Belgian White and Blue [BWB]) and dairy (Friesian-Holstein [FH]) cattle to Psoroptes ovis infestation and to determine whether P ovis infestation impaired immune responses to infectious bovine rhinotracheitis virus (IBR) vaccine or an immunogenic protein (keyhole-limpet hemocyanin [KLH]).

Animals

19 BWB and 6 FH 1-year-old calves.

Procedure

2 trials were performed. In each trial, 7 (trial 1) or 6 (trial 2) BWB calves and 3 FH calves were experimentally infested with P ovis and 3 BWB calves were maintained as uninfested controls. Animals were inoculated with KLH and IBR virus vaccine twice; 3 BWB calves in each trial were treated with ivermectin. Serum antibody responses to KLH, IBR virus, and P ovis were measured by use of ELISA. A lymphocyte transformation assay was used to determine nonspecific responses to 3 mitogens and specific lymphocyte reactivity to P ovis antigen.

Results

In each trial, 3 BWB and 3 FH calves developed clinical signs of psoroptic mange and mites could be recovered. Infested and control animals developed similar antibody titers to KLH and IBR virus. Antibodies to P ovis were detected early in some infested calves, and this was correlated with a marked cell-mediated immune response. Lymphocyte responsiveness to the 3 mitogens was not significantly different among groups.

Conclusions

In these calves, infestation with P ovis induced a marked humoral and cell-mediated immune response. Immunosuppression was not evident. (Am J Vet Res 1998;59:583–587)
Cardiorespiratory effects of low-flow and closed circuit inhalation anesthesia, using sevoflurane delivered with an in-circuit vaporizer and concentrations of compound A
Authors: Muir William W. , Gadawski Jennifer
Published: January 2024

Objectives

To determine the concentrations of sevoflurane and compound A (a degradation product of sevoflurane) in the anesthetic circuit when sevoflurane was delivered with an in-circuit vaporizer, and to determine the cardiorespiratory effects of sevoflurane in dogs.

Animals

6 mixed-breed dogs.

Procedure

In-circuit vaporizers were connected to the inspiratory limb of a circle rebreathing system connected to a ventilator. A reservoir bag was attached to the Y-piece connector to act as an artificial lung, and sevoflurane concentrations in the anesthetic circuit were measured at vaporizer settings of 1, 3, 5, 7, and 10 and oxygen flow rates of 250 and 500 ml/min. Cardiorespiratory effects of sevoflurane were determined in dogs while they were breathing spontaneously, during controlled ventilation, and during closed circuit anesthesia. Concentrations of compound A were determined by means of gas chromatography with flame ionization.

Results

The concentration of sevoflurane in the anesthetic circuit increased with vaporizer setting and time. For oxygen flow rates of 250 and 500 ml/min, vaporizer settings between 5 and 7 and between 7 and 10, respectively, produced sevoflurane concentrations closest to values reported to produce surgical anesthesia in dogs. Significant differences were not observed in cardiorespiratory variables with time or among anesthetic conditions. Concentrations of compound A in the anesthetic circuit were less than values reported to produce renal toxicoses and death in rats.

Conclusion

Results suggested that sevoflurane can be administered to nonsurgically stimulated dogs, using an in-circuit vaporizer and low (< 15 ml/kg/min) oxygen flow rates, without causing significant cardiorespiratory depression or clinically important concentrations of compound A. (Am J Vet Res 1998;59:603–608)
Permanent implantation of a reinforced polytetrafluoroethylene vascular graft for treatment of artificial defects of the teat cistern mucosa in cows
Authors: Metzger Lorenz , Hirsbrunner Gaby , Waldvogel Andreas , Eicher Richard , Schällibaum Melchior , Steiner Adrian
Published: January 2024

Objective

To evaluate use of a reinforced polytetrafluoroethylene vascular graft for treatment of an artificial defect of mucosa of the teat cistern in lactating cows.

Design

Prospective study.

Animals

9 clinically normal lactating dairy cows.

Procedure

A 20-mm wide circumferential area of mucosa was sharply excised from the cistern of 1 teat on each cow 10 days after spontaneous calving, and the lesion was covered by a graft. After 14 days of passive milk drainage, routine milking was resumed. Follow-up examinations were performed during the next 2 lactation periods and included evaluation of wound healing, location and sonographic appearance of the implant, milk flow and yield, and somatic cell counts. Cows were slaughtered, and teats and mammary glands were examined microscopically.

Results

Implants had partially to totally collapsed within 30 to 90 days. Milk flow was significantly increased by day 15 of the first lactation, but decreased significantly by day 300 of lactation 1. At the end of lactation 1, milk flow had ceased in 3 out of 7 quarters. Only 3 of 9 quarters drained through grafted teats were milkable at the end of the study. Somatic cell counts of these quarters were significantly increased in the first lactation period. At necropsy, 2 grafts were in the teat cistern, but only 1 was incorporated into the mucosa by connective tissue. The mucosa was thickened in all teats with grafts, and there was epithelial metaplasia and granulation tissue proliferation.

Clinical Relevance

Use of a polytetrafluoroethylene graft can preserve patency in the first lactation period. However, the graft may not be sufficiently incorporated into the mucosa if routine machine milking is resumed 2 weeks after implantation. (Am J Vet Res 1999;60:56–62)
Protective role of maternal antibodies against Haemophilus parasuis infection
Authors: Solano-Aguilar G. I. , Pijoan C. , Rapp-Gabrielson V. , Collins J. , Carvalho L. F. , Winkelman N.
Published: January 2024

Objective

To evaluate the impact of maternal antibodies after challenge exposure of baby pigs with a homologous serovar of Haemophilus parasuis.

Animals

7 gilts and their litters from a high health status farm.

Procedure

Gilts were vaccinated twice with a commercial bacterin that contained H parasuis serovar 4 and 5 or, as a control, adjuvant only. A group of pigs was also vaccinated similarly before challenge exposure. After early and late challenge exposure at 3 and 4 weeks, respectively, all pigs from vaccinated gilts were evaluated for clinical signs of infection, lesions, and antibody titer.

Results

All pigs coming from control gilts had severe signs of H parasuis infection. Macroscopic lesions included polyserositis and pneumonia, and bacteriologic examination confirmed H parasuis as the etiologic agent. Vaccinated pigs born to vaccinated gilts did not have clinical signs of disease. However, some vaccinated pigs born to control gilts had signs of nervous system dysfunction and lameness. There was no difference in lesion scores between early or late challenge exposure, but lesions scores for pigs from vaccinated and control gilts were different (P < 0.01).

Conclusions

Under these experimental conditions, immune-naive and vaccinated pigs from vaccinated gilts were protected against systemic lesions when challenge exposed with a virulent strain of H parasuis.

Clinical Relevance

Vaccination of the gilt and pigs protects the latter from polyserositis, but results are not different from those for nonvaccinated pigs from vaccinated gilts. Maternal antibodies did not seem to interfere with vaccination of pigs at 1 and 3 weeks of age. (Am J Vet Res 1999;60:81–87)
Enhancement of phagocytic and chemokinetic activities of rainbow trout head kidney cells by C-reactive protein
Authors: Kodama Hiroshi , Arimitsu Hideyuki , Mukamoto Masafumi , Sugimoto Chihiro
Published: January 2024

Objective

To investigate immunostimulating activity of purified rainbow trout (Oncorhynchus mykiss) C-reactive protein (CRP) on trout phagocytic cells.

Animals

20 rainbow trout and 2 rabbits.

Procedure

The effect of CRP on phagocytic activity of head kidney (HK) cells was examined by use of a phagocytosis assay with plastic particles. The enhancing effect of CRP on migration activity of HK cells was examined by use of the blind well assay.

Results

Glass-adherent cells from clinically normal trout had increased dose-dependent phagocytic activity against plastic particles when cells were incubated in the presence of CRP. Pretreatment of particles with CRP also enhanced phagocytic activity of the cells, indicating an opsonic effect of CRP. Rabbit anti-trout CRP serum suppressed the enhancing activity of CRP. The HK cells had significant dose-dependent chemokinetic activity against CRP that was not inhibited by anti-CRP serum, indicating that a CRP-antibody complex also could be chemokinetic.

Conclusions

Rainbow trout CRP has immunostimulating activity for HK cells, resulting in enhanced phagocytic and chemokinetic activities. (Am J Vet Res 1999;60:240–244)
Systemic and tissue chamber fluid platinum concentrations released from cis-diamminedichloroplatinum II-impregnated polymethylmethacrylate in healthy dogs
Authors: Buss Michael S. , Henry Carolyn J. , Tyler Jeff W. , Tobias Karen S. , Daoud Sayed , Hoopes Jack , Moore Michael P.
Published: January 2024

Objectives

To determine systemic and local platinum concentrations released from subcutaneously implanted cis-diamminedichloroplatinum (cisplatin)-impregnated polymethylmethacrylate (PMMA) and to evaluate systemic or local adverse reactions.

Animals

6 healthy dogs.

Procedure

Cisplatin (20 mg) was inserted into PMMA that was fashioned into cylinders and placed into subcutaneous tissue chambers overlying the thorax (treated site). An empty tissue chamber was placed over the opposite side (control site). Plasma samples were obtained for platinum determination before implantation, at 3, 6, and 12 hours after implantation on day 0, and once daily on days 1, 2, 3, 7, 14, 21, and 29. At similar times on similar days, tissue chamber fluid samples also were obtained for platinum determination. Complete blood count, serum urea nitrogen and creatinine concentration determinations, and urinalyses were performed on days 1, 2, 3, 7, 14, 21, and 29. Complete necropsy was performed at conclusion of the study.

Results

Tissue chamber platinum concentrations at the treated site were significantly greater than plasma and control site tissue chamber concentrations on days 2, 3, 7, 10. Mean plasma platinum concentration at 3 (0.735 µg/ml), 6 (0.691 µg/ml), 12 (0.534 µg/ml), 24 (0.131 µg/ml), 48 (0.2 µg/ml), 72 (0.1 µg/ml), and 158 (0.014 µg/ml) hours was significantly greater than pretreatment values (0.0 µg/ml). Plasma platinum concentration 10 days after treatment (0.011 µg/ml) did not significantly differ from pretreatment values. Local or systemic adverse reactions were not apparent.

Conclusions

The route of cisplatin administration was safe. Greater concentration of platinum was released locally relative to plasma concentration for an extended period. (Am J Vet Res 1999;60:280–283)
Effects of dietary cysteine on blood sulfur amino acid, glutathione, and malondialdehyde concentrations in cats
Authors: Fettman Martin J. , Valerius Karina D. , Ogilvie Gregory K. , Bedwell Cathy L. , Richardson Kristi L. , Walton Judy A. , Hamar Dwayne W.
Published: January 2024

Objective

To determine effects of dietary cysteine on blood sulfur amino acids (SAA), reduced glutathione (GSH), oxidized glutathione (GSSG), and malondialdehyde (MDA) concentrations in cats.

Animals

12 healthy adult cats.

Procedure

Cats were fed diets with a nominal (0.50 g/100 g dry matter [DM]), moderate (1.00 g/100 g DM), or high (1.50 g/100 g DM) cysteine content in a 3 × 3 Latin square design with blocks of 8 weeks’ duration. Venous blood samples were collected after each diet had been fed for 4 and 8 weeks, and a CBC and serum biochemical analyses were performed; poikilocyte, reticulocyte, and Heinz body counts were determined; and MDA, GSH, GSSG, and SAA concentrations were measured.

Results

Blood cysteine and MDA concentrations were not significantly affected by dietary cysteine content. Blood methionine, homocysteine, and GSSG concentrations were significantly increased when cats consumed the high cysteine content diet but not when they consumed the moderate cysteine content diet, compared with concentrations obtained when cats consumed the nominal cysteine content diet. Blood GSH concentrations were significantly increased when cats consumed the moderate or high cysteine content diet.

Conclusions

Increased dietary cysteine content promotes higher blood methionine, homocysteine, GSH, and GSSG concentrations in healthy cats.

Clinical Relevance

Supplemental dietary cysteine may be indicated to promote glutathione synthesis and ameliorate adverse effects of oxidative damage induced by disease or drugs. (Am J Vet Res 1999;60:328–333)
Synergistic effects of concurrent challenge with bovine respiratory syncytial virus and 3-methylindole in calves
Authors: Bingham Howard R. , Morley Paul S. , Wittum Thomas E. , Bray Tammy M. , West Keith H. , Slemons Richard D. , Ellis John A. , Haines Deborah M. , Levy Mark A. , Sarver Craig F. , Saville William J. A. , Cortese Victor S.
Published: January 2024

Objective

To evaluate the potential synergy between bovine respiratory syncytial virus (BRSV) and 3-methylindole (3MI) in inducing respiratory disease in cattle.

Animals

20 mixed-breed beef calves.

Procedure

A 2 × 2 factorial design was used, with random assignment to the following 4 treatment groups: unchallenged control, BRSV challenge exposure (5 × 104 TCID50 by aerosolization and 5.5 × 105 TCID50 by intratracheal inoculation), 3MI challenge exposure (0.1 g/kg of body weight, PO), and combined BRSV-3MI challenge exposure. Clinical examinations were performed daily. Serum 3MI concentrations, WBC counts, PCV, total plasma protein, and fibrinogen concentrations were determined throughout the experiment. Surviving cattle were euthanatized 7 days after challenge exposure. Pulmonary lesions were evaluated at postmortem examination.

Results

Clinical respiratory disease was more acute and severe in cattle in the BRSV-3MI challenge-exposure group than in cattle in the other groups. All 5 cattle in this group and 3 of 5 cattle treated with 3MI alone died or were euthanatized prior to termination of the experiment. Mean lung displacement volume was greatest in the BRSV-3MI challenge-exposure group. Gross and histologic examination revealed that pulmonary lesions were also most severe for cattle in this group.

Conclusions and Clinical Relevance

Feedlot cattle are commonly infected with BRSV, and 3MI is produced by microflora in the rumen of all cattle. Our results suggest that there is a synergy between BRSV and 3MI. Thus, controlling combined exposure may be important in preventing respiratory disease in feedlot cattle. (Am J Vet Res 1999;60:563–570)
In vitro dose-dependent effects of enrofloxacin on equine articular cartilage
Authors: Beluche Lisa A. , Bertone Alicia L. , Anderson David E. , Kohn Catherine W. , Weisbrode Steven E.
Published: January 2024

Objective

To determine whether enrofloxacin has detrimental, dose-dependent effects on equine articular cartilage in vitro.

Animals

Cartilage explants were developed from 6 healthy horses between 0 and 96 months old.

Procedure

Patellar cartilage explants were incubated in 5 concentrations of enrofloxacin (2 μg/ml, 10 μg/ml, 1,000 μg/ml, 10,000 μg/ml, and 50,000 μg/ml) for 72 hours. Proteoglycan synthesis (Na35SO4 incorporation for 24 hours), proteoglycan degradation (Na35SO4 release for 72 hours), endogenous proteoglycan content (dimethylmethlene blue assay), and total protein content were determined. Cartilage explants were evaluated by use of histomorphologic and histomorphometric techniques (toluidine blue stain) for cytologic and matrix characteristics. Quantitative data were analyzed with a one-way ANOVA to compare results among various enrofloxacin concentration groups and the control group. A general linear model was used to determine whether age had an effect.

Result

Proteoglycan synthesis was excellent in control specimens and in specimens incubated in low concentrations of enrofloxacin (2 μg/ml and 10 μg/ml). High concentrations of enrofloxacin (> 1,000 μg/ml) effectively eliminated proteoglycan synthesis regardless of horse age. Proteoglycan degradation at low concentrations (2 μg/ml and 10 μg/ml) was not different than control. High concentrations of enrofloxacin (> 1,000 μg/ml) caused significant degradation. Different concentrations of enrofloxacin did not affect endogenous proteoglycan. High concentrations of enrofloxacin were associated with a significant increase in number of pyknotic nuclei.

Conclusion

Concentrations of enrofloxacin that might be achieved following systemic administration did not suppress chondrocyte metabolism in vitro. High concentrations of enrofloxacin (> 1,000 μg/ml) were toxic to chondrocytes. (Am J Vet Res 1999;60:577–582)
Nitric oxide synthase activity in healthy and interleukin 1β-exposed equine synovial membrane
Authors: Simmons Emily J. , Bertone Alicia L. , Hardy Joanne , Weisbrode Steven E.
Published: January 2024

Objective

To quantitate nitric oxide synthase (NOS) activity in healthy and interleukin 1β (IL-1β)-exposed equine synovial membrane.

Animals

6 healthy horses, 2 to 8 years old.

Procedure

Recombinant human IL-1β (0.35 ng/kg of body weight) was injected intra-articularly into 1 metacarpophalangeal joint of each horse. The contralateral joint served as an unexposed control. All horses were euthanatized 6 hours after injection of IL-1β, and synovial membrane specimens were assayed for NOS activity by measuring conversion of arginine to citrulline. Severity of inflammation was semiquantitated by analysis of synovial fluids and histologic examination of synovial membrane.

Results

Equine synovial membrane had minimal NOS activity. A significant difference was not detected in NOS activity between control and IL-1β-exposed specimens. Histologic examination revealed a neutrophilic infiltrate in synovial membrane exposed to IL-1β. Synovial fluid from IL-1β-exposed joints had a moderate inflammatory response and significantly greater concentrations of IL-1β and interleukin-6 than fluid from healthy joints.

Conclusion

Healthy equine synovial membrane had low NOS activity that was not affected by exposure to IL-1β. (Am J Vet Res 1999;60:714-716)
Effects of glutamine supplementation of an amino acid-based purified diet on intestinal mucosal integrity in cats with methotrexate-induced enteritis
Authors: Marks Stanley L. , Cook Audrey K. , Reader Rachel , Kass Philip H. , Théon Alain P. , Greve Carl , Rogers Quinton R.
Published: January 2024

Objective

To determine effects of glutamine-supplemented and glutamine-free amino acid-based purified diets, compared with a dry expanded diet, on intestinal structure and function in a model that used cats with methotrexate-induced enteritis.

Animals

18 adult specific-pathogen-free cats.

Procedure

12 cats were given intragastric feedings of an amino acid-based purified diet supplemented with glutamine (7% [wt:wt]) or an isonitrogenous amount of glycine and alanine; 6 cats consumed a dry expanded diet. After 21 days, cats received methotrexate (MTX; 11 mg/kg of body weight, IV). Intestinal permeability testing was performed immediately before and 66 hours after MTX administration. Celiotomy was performed 72 hours after MTX administration for aseptic removal of mesenteric lymph nodes, collection of full-thickness intestinal biopsy specimens, determination of intestinal cellular proliferation, and collection of aortic and portal venous blood samples for determination of arteriovenous amino acid concentrations across the intestine.

Results

Administration of MTX was associated with severe enterotoxicosis manifested as diarrhea (8/12 cats), vomiting (12/12), and positive results for bacterial culture of mesenteric lymph nodes (12/12) in cats receiving the purified diets, independent of glutamine supplementation. Diet did not affect villus tip length and villus surface area in the small intestine or cellular proliferation. Administration of MTX was associated with significantly increased intestinal permeability, which was not attenuated by glutamine supplementation.

Conclusions

Feeding of a glutamine-supplemented amino acid-based purified diet was unable to preserve intestinal function in cats with MTX-induced enteritis.

Clinical Relevance

Intestinal morphologic alterations correlate poorly with intestinal function as measured by means of bacterial translocation and intestinal permeability. (Am J Vet Res 1999;60:755-763)
Cardiorespiratory effects of a tiletamine/zolazepam-ketamine-detomidine combination in horses
Authors: Muir William W. , Gadawski Jennifer E. , Grosenbaugh Deborah A.
Published: January 2024

Objective

To determine cardiorespiratory effects of a tiletamine/zolazepam-ketamine-detomidine (TZKD) combination in horses.

Animals

8 healthy adult horses.

Procedure

Horses were instrumented for measurement of cardiorespiratory, acid-base, and electrolyte values. Each horse was given xylazine (0.44 mg/kg of body weight, IV) 10 to 15 minutes prior to induction of recumbency by administration of the TZKD combination. Cardiorespiratory, acid-base, and electrolyte values were measured at 5-minute intervals for ≥ 30 minutes.

Results

All horses became recumbent within 1 minute after IV administration of TZKD. Mean ± SD duration of recumbency was 40 ± 8 minutes. All horses regained standing position after ≤ 2 attempts. Quality of anesthesia and analgesia was determined to be satisfactory in all horses. Xylazine induced decreases in respiratory rate, heart rate, cardiac output, maximum rate of increase of right ventricular pressure, and rate pressure product. The PaCO2, right atrial pressure, and peripheral vascular resistance increased, whereas blood temperature, PO2, pHa, HCO3−, PCV, total solids, Na, and K values remained unchanged. Subsequent administration of TZKD caused right atrial pressure and PaCO2 to increase and PaO2 to decrease, compared with values obtained after xylazine administration. Remaining cardiorespiratory, acid-base, hematologic, and electrolyte values did not differ from those obtained after xylazine administration.

Conclusion

IV administration of TZKD induces short-term anesthesia in horses. Potential advantages of this drug combination are the small volume of drug administered; minimal cardiorespiratory depression; quality of induction and maintenance of, and recovery from, anesthesia; and duration of drug effects. (Am J Vet Fles 1999;60:770–774)
Diurnal variation in concentrations of various markers of bone metabolism in dogs
Authors: Liesegang Annette , Reutter Regula , Sassi Mirja-Liisa , Risteli Juha , Kraenzlin Marius , Riond J-L. , Wanner Marcel
Published: January 2024

Objective

To evaluate diurnal variation in concentrations of selected markers of bone metabolism in dogs.

Animals

Ten 3-to 4-year-old ovariectomized Beagles.

Procedure

Blood and urine samples were obtained in the morning before dogs were fed (8 am) and then at 2-hour intervals for 24 hours. This procedure was repeated 2 weeks later. Concentrations of osteocalcin OC and carboxy terminal telopeptide of type-I collagen (ICTP) were measured in serum, using a radioimmunoassay; concentrations of hydroxyproline (HYP), pyridinoline (PYD), and deoxypyridinoline (DPD) were analyzed in urine. Hydroxyproline concentration was measured by means of a colorimetric test, whereas PYD and DPD concentrations were quantified by use of high-performance liquid chromatography.

Results

In both parts of the study, hyp concentrations increased significantly, compared with values before feeding, until 8 hours after feeding; hyp concentrations then returned to prefeeding values. Concentrations of DPD and PYD decreased from before feeding until 2 pm and then increased until 8 pm. The ICTP concentrations slowly decreased until 4 pm but returned to prefeeding values thereafter. In both parts of the study, concentrations of oc decreased during the day and then increased to reach values similar to those obtained before feeding.

Conclusions

Changes in the concentrations of bone markers were detected throughout the day in the dogs of this study. Increase in hyp concentration most likely was related to feeding. As documented for bone resorption and formation in other species, circadian rhythms were evident for concentrations of DPD, PYD, and oc. Investigators should consider the time of sample collection when measuring these markers. (Am J Vet Res 1999;60:949-953)
Comparison of insulin-like growth factor-I concentration in mammary secretions and serum of small- and giant-breed dogs
Authors: White Michael E. , Hathaway Marcia R. , Dayton William R. , Henderson T. , Lepine A. J.
Published: January 2024

Objective

To determine insulin-like growth factor-I (IGF-I) concentrations in canine mammary secretions and serum during lactation and to compare them between small and giant breeds of dogs.

Animals

7 gestating Beagles and 4 gestating Great Danes.

Procedure

Dogs were fed a common nutritionally complete and adequate gestation and lactation diet. Milk samples were collected at postpartum hour 12 and postpartum days 3, 7, 14, 21, and 28 after IV oxytocin administration. Two puppies/litter were identified at whelping for collection of blood samples corresponding to the days of milk sample collection plus days 35 and 42. Maternal blood samples were obtained on days 1, 7, and 42 from Beagles and days 1, 7, and 28 from Great Danes and were acid/ethanol extracted and analyzed by use of a radioimmunoassay.

Results

Maternal serum IGF-I concentration was greater in Great Danes at all sample collection times. Similarly, colostrum from Great Danes contained more IGF-I, compared with that of Beagles (70 ng/ml vs 40 ng/ml, respectively). These values decreased to approximately 10 ng/ml by day 3 in both breeds and remained between 10 and 20 ng/ml for the duration of lactation. Growth rate and serum IGF-I concentration were greater in Great Dane puppies at birth to day 42.

Conclusions and Clinical Relevance

High IGF-I concentration in colostrum may be biologically important for newborn puppies. Body mass and serum IGF-I concentration are directly correlated in growing Beagle and Great Dane puppies. Serum IGF-I concentration may be an indicator of growth potential in dogs. (Am J Vet Res 1999;60:1088-1091)