bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of topical application of diclofenac liposomal suspension on experimentally induced subcutaneous inflammation in horses
Authors: Caldwell Fred J. , Mueller P. O. Eric , Lynn Randy C. , Budsberg Steven C.
Published: December 2005

Objective—To determine whether 1% diclofenac
liposomal suspension (DLS) ointment would be
absorbed transdermally and attenuate experimentally
induced subcutaneous inflammation in horses.

Animals—7 healthy adult horses

Procedure—Inflammation was produced by injecting
1% sterile carrageenan into subcutaneously implanted
tissue cages 8 hours before (time –8) and at the
time of application of test ointment. A crossover
design was used. Horses received 1 of 2 treatments
(topically administered control or DLS ointments) during
48 hours of carrageenan-induced subcutaneous
inflammation. A single application of test ointment
(7.2 g) was applied over each tissue cage (time 0).
Samples of transudate and blood were collected at
–8, 0, 6, 12, 18, 24, 30, 36, and 48 hours. Plasma and
transudate diclofenac concentrations were determined
by use of high-performance liquid chromatography.
Transudate concentrations of prostaglandin E2
(PGE2) were determined with a competitive enzyme
immunoassay.

Results—DLS was absorbed transdermally. The highest
concentration (mean ± SEM, 76.2 ± 29 ng/mL)
was detectable in tissue-cage fluid within 18 hours
after application. Minimal concentrations of diclofenac
were detectable in plasma. Application of DLS significantly
decreased transudate concentrations of PGE2
at 6 and 30 hours. Decreases in PGE2 concentration
were observed in the DLS group at all collection
times.

Conclusions and Clinical Relevance—A single topical
application of DLS resulted in concentrations of
diclofenac in transudate within 6 hours and significantly
attenuated carrageenan-induced local production
of PGE2. Results of this study suggest that DLS
is readily absorbed transdermally and may be efficacious
for reducing subcutaneous inflammation in
horses. ( Am J Vet Res 2004;65:271–276)
Effects of dermal application of 10.0% imidacloprid-0.08% ivermectin in ivermectin-sensitive Collies
Authors: Paul Allan J. , Hutchens Douglas E. , Firkins Lawrence D. , Keehan Coleen M.
Published: December 2005

Objective—To evaluate the safety of dermal application of 10.0% imidacloprid-0.08% ivermectin in ivermectin- sensitive Collies at dose rates of 3 to 5 times the proposed maximum therapeutic dose.

Animals—15 Collies (5 males and 10 females) that were confirmed as ivermectin-sensitive dogs.

Procedure—Dogs were assigned to 3 treatment groups (control, 3×, or 5× group) in a randomized block design on the basis of the maximal ivermectinsensitivity score obtained during preliminary screening. Dogs in groups 3× and 5× were treated at 3 and 5 times the maximum label dose, respectively. Control dogs received an application of an equal volume of a nonmedicated solution. Observation and scoring on all days were conducted to specifically include neurologic signs typical of ivermectin toxicosis, including lethargy, ataxia, abnormal mydriasis, and abnormal salivation.

Results—None of the dogs had clinical abnormalities during the study period.

Conclusions and Clinical Relevance—Analysis of results of this study indicates that dermal application of 10.0% imidacloprid-0.08% ivermectin is safe for use in ivermectin-sensitive Collies at dose rates of 3 or 5 times the proposed maximum therapeutic dose. (Am J Vet Res2004;65:277–278)
Quantitative effect of tenorrhaphy on intrinsic vasculature of the equine superficial digital flexor tendon
Authors: Crowson Chris L. , Jann Henry W. , Stein Larry E. , Claypool L. P. , Moll H. David , Blaik Margret A.
Published: December 2005

Objective—To compare effects of the locking-loop suture pattern (LLP) and 3-loop pulley (3LP) suture pattern for tenorrhaphy on the intrinsic vasculature of the superficial digital flexor tendon (SDFT) of horses in vitro after surgery.

Sample Population—16 forelimbs obtained from 8 mature horses.

Procedure—Tenotomy and subsequent tenorrhaphy was performed in anesthetized horses. Following systemic administration of heparin, horses were euthanatized and the limbs were removed and placed under tension to load the flexor tendons. The intrinsic vasculature was then perfused with a mixture of barium sulfate and water. Four-millimeter sections of the SDFT were prepared for microangiographic analysis. Mean vessel density was calculated for each section by use of a grid consisting of 1.5-mm2vascular assessment squares (VAS). Comparisons were made among the control, LLP, and 3LP groups.

Results—Mean ± SD vessel density was 3.11 ± 0.38, 1.47 ± 0.47, and 2.01 ± 0.63 perfused vessels/1.5 mm2for control, LLP, and 3LP groups, respectively. Significant differences in vascular density were detected between the control and 3LP groups, control and LLP groups, and LLP and 3LP groups.

Conclusions and Clinical Relevance—Use of the LLP and 3LP pattern has deleterious effects in vitro on the intrinsic vasculature of the SDFT. However, the 3LP pattern was less disruptive to the intrinsic vasculature, compared with the effects for the LLP. Use of the 3LP tenorrhaphy suture pattern in clinical situations may result in less damage to the intrinsic vasculature of the SDFT of horses during convalescence. (Am J Vet Res2004;65:279–282)
Assessment of the effects of age and joint disease on hydroxyproline and glycosaminoglycan concentrations in synovial fluid from the metacarpophalangeal joint of horses
Authors: van den Boom Robin , Brama Pieter A. J. , Kiers Geesje H. , de Groot Jeroen , van Weeren P. René
Published: December 2005

Objective—To assess the effects of age and joint disease on hydroxyproline and glycosaminoglycan (GAG) concentrations in synovial fluid from the metacarpophalangeal joint of horses and evaluate the association of those concentrations with severity of osteoarthritis and general matrix metalloproteinase (MMP) activity.

Sample Population—Synovial fluid was collected from the metacarpophalangeal joints of foals at birth (n = 10), 5-month-old foals (10), 11-month-old foals (5), and adult horses (73).

Procedure—Hydroxyproline and GAG concentrations were determined in synovial fluid samples. The severity of osteoarthritis in adult joints was quantified by use of a cartilage degeneration index (CDI) and assessment of general MMP-activity via a fluorogenic assay.

Results—Hydroxyproline and GAG concentrations in synovial fluid were highest in neonates and decreased with age. Concentrations reached a plateau in adults by 4 years and remained constant in healthy joints. In synovial fluid from osteoarthritic joints, hydroxyproline and GAG concentrations were not increased, compared with unaffected joints, but hydroxyproline were significantly correlated with the CDI and general MMP activity. There was no significant correlation between GAG concentration and CDI value or MMP activity.

Conclusions and Clinical Relevance—Changes in hydroxyproline concentration in synovial fluid appeared to indicate damage to collagen of the articular cartilage. In joints with osteoarthritis, the lack of high GAG concentration in synovial fluid and the absence of a significant correlation between GAG concentration and CDI values or MMP activity may severely limit the usefulness of this marker for monitoring equine joint disease (J Am Vet Med Assoc2004;65:296–302)
Effect of nasogastric administration of sodium bicarbonate on carbon 13 isotopic enrichment of carbon dioxide in serum of horses
Authors: Hinchcliff Kenneth. W. , Sams Richard. A.
Published: December 2005

Objective—To determine the effect of administration of commercially available sodium bicarbonate (NaHCO3) on carbon 13 (13C) isotopic enrichment of carbon dioxide (CO2) in serum of horses.

Animals—7 healthy Thoroughbreds.

Procedure—Sodium bicarbonate (450 g) was administered via nasogastric intubation to horses. Horses had been fed a diet obtained from the same source and had access to water from the same source for 3 months before the study. Blood samples were collected immediately before and at 2, 4, 6, and 24 hours after administration of NaHCO3. The concentration of total CO2in serum was measured by use of a commercial analyzer. The13C enrichment of bicarbonate in serum was estimated by measurement of13C enrichment of CO2released by acidification of the serum. The13C enrichment of commercially available NaHCO3was also determined and compared with that of CO2in serum of horses before administration of NaHCO3.

Results—Commercially available NaHCO3had a13C enrichment significantly different from that of carbon dioxide in serum of horses before treatment. Administration of NaHCO3increased the concentration of total CO2from pretreatment values. The13C enrichment of CO2in serum was only transiently and minimally affected after administration of NaHCO3.

Conclusions and Clinical Relevance—Administration of NaHCO3was not detected by measuring13C enrichment of CO2in serum of horses. (Am J Vet Res2004;65:307–310)
Evaluation of urine sucrose concentration for detection of gastric ulcers in horses
Authors: O'Conner Michael S. , Steiner Jörg M. , Roussel Allen J. , Williams David A. , Meddings Jon B. , Pipers Frank , Cohen Noah D.
Published: December 2005

Objective—To evaluate the use of sucrose permeability testing to detect ulcers in the gastric squamous mucosa of horses.

Animals—13 adult horses ranging from 5 to 19 years of age.

Procedure—Following induction of gastric ulcers by intermittent feed deprivation, horses underwent sucrose permeability testing (administration of sucrose by nasogastric intubation followed by collection of urine at 2 and 4 hours after intubation) and gastric endoscopy. Squamous ulcers were assigned a severity score (range, 0 to 3) by use of an established scoring system. Horses were subsequently administered omeprazole for 21 days, and sucrose testing and endoscopy were repeated. Pair-wise comparisons of urine sucrose concentration were made between horses with induced ulcers before and after omeprazole treatment. Urine sucrose concentrations also were compared on the basis of ulcer severity score.

Results—Urine sucrose concentrations and ulcer severity scores were significantly higher in horses with induced ulcers before omeprazole treatment than after treatment. Urine sucrose concentrations were significantly higher for horses with ulcer severity scores > 1. Use of a cut-point value of 0.7 mg/mL revealed that the apparent sensitivity and specificity of sucrose permeability testing to detect ulcers with severity scores > 1 was 83% and 90%, respectively. Results were similar after adjusting sucrose concentrations for urine osmolality.

Conclusions and Clinical Relevance—Urine sucrose concentration appears to be a reliable but imperfect indicator of gastric squamous ulcers in horses. Sucrose permeability testing may provide a simple, noninvasive test to detect and monitor gastric ulcers in horses. (Am J Vet Res2004;65:31–39)
Evaluation of antiplatelet effects of ticlopidine in cats
Authors: Hogan Daniel F. , Andrews Dina A. , Talbott Kristen K. , Green Henry W. , Ward Michael P. , Calloway Betsy M.
Published: December 2005

Objective—To determine whether ticlopidine exerts an antiplatelet effect, estimate the pharmacodynamics of ticlopidine, and evaluate any acute adverse effects associated with administration of ticlopidine in cats.

Animals—8 domestic purpose-bred sexually intact male cats.

Procedure—Ticlopidine was administered orally (50 mg, q 24 h; 100 mg, q 24 h; 200 mg, q 24 h; and 250 mg, q 12 h). Each treatment period consisted of 10 days of drug administration. Platelet aggregation studies with adenosine diphosphate (ADP) and collagen and evaluation of oral mucosal bleeding times (OMBTs) were performed on days 3, 7, and 10 during each drug administration. Serotonin was measured to evaluate secretion at baseline and on day 10 for cats that received the 250-mg dosage.

Results—A significant reduction in platelet aggregation was detected in response to ADP on days 7 and 10 at 100 mg, on day 3 at 200 mg, and on days 3, 7, and 10 at 250 mg. A significant increase in the OMBT and decrease in serotonin release on day 10 at 250 mg was also detected; however, the cats had anorexia and vomiting at the 250-mg dosage.

Conclusions and Clinical Relevance—Although there was a consistent antiplatelet effect at the 250-mg dosage, there was dose-dependent anorexia and vomiting that we conclude precludes the clinical usefulness of this drug in cats. (Am J Vet Res2004;65:327–332)
Effects of probiotic Lactobacillus acidophilus strain DSM13241 in healthy adult dogs
Authors: Baillon Marie-Louise A. , Marshall-Jones Zoe V. , Butterwick Richard F.
Published: December 2005

Objective—To evaluate viability of a probiotic strain of
Lactobacillus acidophilusin a dry dog food, determine
its ability to survive transit through the gastrointestinal
tract and populate the colon, and assess its
effects on intestinal and systemic parameters.

Animals—15 adult dogs.

Procedure—Dogs were sequentially fed a dry control
food for 2 weeks, the same food supplemented with
> 109
L acidophilus for 4 weeks, and the control food
again for 2 weeks. Fecal score was assessed daily,
and fecal and blood samples were collected for enumeration
of bacterial populations and measurement
of hematologic variables.

Results—Recovery of L acidophilus from the supplemented
food was 71% and 63% at the start and end
of the study, respectively, indicating that the bacteria
were able to survive manufacture and storage. The probiotic
bacterium was detected in feces via ribotyping
and RNA gene sequencing during the probiotic administration
phase but not 2 weeks after cessation of
administration. Administration of the probiotic-supplemented
food was associated with increased numbers
of fecal lactobacilli and decreased numbers of clostridial
organisms. There were significant increases in
RBCs, Hct, hemoglobin concentration, neutrophils,
monocytes, and serum immunoglobin G concentration
and reductions in RBC fragility and serum NO
concentration.

Conclusions and Clinical Relevance—These data
indicate that L acidophilus can be successfully incorporated
into a dry dog food, survive transit through the
canine gastrointestinal tract, and populate the colon
and are associated with local and systemic changes.
This probiotic bacterium may have the potential to
enhance intestinal health and improve immune function
in dogs. ( Am J Vet Res 2004;65:338–343)
Assessment of the relationship of bispectral index values, hemodynamic changes, and recovery times associated with sevoflurane or propofol anesthesia in pigs
Authors: Martín-Cancho María F. , Carrasco-Jiménez María S. , Lima Juan R. , Ezquerra Luis J. , Crisóstomo Verónica , Usón-Gargallo Jesús
Published: December 2005

Objective—To evaluate bispectral index (BIS) values in pigs during anesthesia maintained with sevoflurane- fentanyl or propofol-fentanyl as a predictor of changes in hemodynamic parameters and duration of recovery from anesthesia.

Animals—12 pigs.

Procedure—Pigs were randomly allocated to undergo 1 of 2 anesthetic regimens. Anesthesia was induced with propofol (2 mg/kg, IV); 6 pigs were administered sevoflurane via inhalation (1 minimum alveolar concentration [MAC] at a fresh gas flow rate of 3 L/min; group I), and 6 were administered propofol (11 mg/kg/h, IV; group II). All pigs received fentanyl (2.5 mg/kg, IV, q 30 min). After abdominal surgery, pigs were allowed to recover from anesthesia. Cardiovascular variables and BIS values were recorded at intervals throughout the procedure; duration of recovery from anesthesia was noted.

Results—No correlation was established between arterial blood pressure and BIS and between heart rate and BIS. Mean BIS at discontinuation of administration of the anesthetic agent was greater in group-II pigs (65.2 ± 10.6 minutes) than in group-I pigs (55.8 ± 2.9 minutes). However, recovery from anesthesia was significantly longer in group II (59.80 ± 2.52 minutes) than in group I (9.80 ± 2.35 minutes).

Conclusions and Clinical Relevance—In swine anesthetized with sevoflurane or propofol and undergoing abdominal surgery, the BIS value derived from an electroencephalogram at the end of anesthesia was not useful for predicting the speed of recovery from anesthesia. Moreover, BIS was not useful as a predictor of clinically important changes in arterial blood pressure and heart rate in those anesthetized pigs. (Am J Vet Res2004;65:409–416)
Evaluation of efficacy of an inactivated vaccine against bovine respiratory syncytial virus in calves with maternal antibodies
Authors: Patel Jay R. , Didlick Susan A.
Published: December 2005

Objective—To assess short- and long-term efficacy of an inactivated bovine respiratory syncytial virus (BRSV) vaccine administered IM to calves with maternally derived antibodies.

Animals—28 two-week-old calves with neutralizing, maternally derived antibodies against BRSV.

Procedure—For evaluation of short-term efficacy, 6 calves were vaccinated IM at 2 and 6 weeks of age and challenged intranasally and intratracheally along with a matched group of 4 unvaccinated control calves at 10 weeks of age. For evaluation of long-term efficacy, 2 groups of 6 calves each were vaccinated IM at 2, 6, and 18 weeks of age or 14 and 18 weeks of age; these calves were challenged intranasally and intratracheally along with 6 matched unvaccinated control calves at 43 weeks of age. Serum virus neutralizing antibody titer, clinical reactions, and virus shedding in nasal mucus and lung washings were assessed.

Results—None of the vaccination regimens resulted in a significant increase in serum virus neutralizing antibody titer. As judged by virus shedding in nasal mucus and lung washings, vaccinated calves were protected against challenge, compared with unvaccinated control groups. Clinical signs attributable to challenge were coughing (short-term efficacy study) and tachypnea and dyspnea (long-term efficacy study). The severity and incidence of disease were significantly lower in the vaccinated groups, compared with that in the unvaccinated groups.

Conclusions and Clinical Relevance—Through vaccination, it is possible to protect vulnerable calves with maternal antibodies against BRSV infection and reduce respiratory tract disease. (Am J Vet Res2004;65:417–421)
Evaluation of three-dimensional kinematics of the distal portion of the forelimb in horses walking in a straight line
Authors: Chateau Henry , Degueurce Christophe , Denoix Jean-Marie
Published: December 2005

Objective—To develop a method that allows quantification of the 3 anatomic rotations in the digital joints of moving horses and measure these rotations when horses are walking in a straight line on a hard track.

Animals—4 healthy French Trotter horses.

Procedure—Triads of ultrasonic kinematic markers were surgically linked to the 4 distal segments of the digits of the left forelimb of each horse. Three-dimensional (3-D) coordinates of these markers were recorded in horses walking in a straight line. The three angles of rotation of each digital joint were calculated by use of a joint coordinate system as well as the 3-D orientation of the hoof and third metacarpal bone. A calibration procedure was developed to convert data from measurements within a technical coordinate system to data in relation to an anatomically relevant coordinate system.

Results—Precision of the method was 0.5o, and repeatability of the calibrations resulted in variations of 1.4o. Extrasagittal movements of the proximal and distal interphalangeal joints were obvious during landing because the impact of the hoof was on the lateral side. Mean ± SD extension of the proximal interphalangeal joint was 10.0 ± 2.5o.

Conclusions and Clinical Relevance—This study provides a description of the technical background, error analysis, and procedures used to measure the 3-D rotations of the 4 distal segments of the forelimb in walking horses. As a major result substantial involvement of the proximal interphalangeal joint in the sagittal and extrasagittal planes,should incline investigators and clinicians to consider the functional importance of this joint. (Am J Vet Res2004;65:447–455)
Effects of a muscarinic type-2 antagonist on cardiorespiratory function and intestinal transit in horses anesthetized with halothane and xylazine
Authors: Neto Francisco J. Teixeira , McDonell Wayne N. , Black William D. , Moraes Aury N. , Duronghphongtorn Sumit
Published: December 2005

Objective—To evaluate the cardiorespiratory and intestinal effects of the muscarinic type-2 (M2) antagonist, methoctramine, in anesthetized horses.

Animals—6 horses.

Procedure—Horses were allocated to 2 treatments in a randomized complete block design. Anesthesia was maintained with halothane (1% end-tidal concentration) combined with a constant-rate infusion of xylazine hydrochloride (1 mg/kg/h, IV) and mechanical ventilation. Hemodynamic variables were monitored after induction of anesthesia and for 120 minutes after administration of methoctramine or saline (0.9% NaCl) solution (control treatment). Methoctramine was given at 10-minute intervals (10 µg/kg, IV) until heart rate (HR) increased at least 30% above baseline values or until a maximum cumulative dose of 30 µg/kg had been administered. Recovery characteristics, intestinal auscultation scores, and intestinal transit determined by use of chromium oxide were assessed during the postanesthetic period.

Results—Methoctramine was given at a total cumulative dose of 30 µg/kg to 4 horses, whereas 2 horses received 10 µg/kg. Administration of methoctramine resulted in increases in HR, cardiac output, arterial blood pressure, and tissue oxygen delivery. Intestinal auscultation scores and intestinal transit time (interval to first and last detection of chromium oxide in the feces) did not differ between treatment groups.

Conclusions and Clinical Relevance—Methoctramine improved hemodynamic function in horses anesthetized by use of halothane and xylazine without causing a clinically detectable delay in the return to normal intestinal motility during the postanesthetic period. Because of their selective positive chronotropic effects, M2antagonists may represent a safe alternative for treatment of horses with intraoperative bradycardia. (Am J Vet Res2004;65:464–472)
Biochemical evaluation of mitochondrial respiratory chain enzymes in canine skeletal muscle
Authors: Wakshlag Joseph J. , Cooper Barry J. , Wakshlag Robin R. , Kallfelz Francis. A. , Barr Stephen C. , Nydam Daryl V. , Dimauro S.
Published: December 2005

Objective—To perform respiratory chain enzymatic activity assays on canine skeletal muscle biopsy specimens and establish reference range values of skeletal muscle enzyme activities for dogs.

Sample Population—Biopsy specimens from the vastus lateralis muscle were obtained from 24 dogs (8 sexually intact males and 14 sexually intact females) ranging from 15 months to 6 years of age.

Procedure—Mean values of citrate synthase, cytochrome-coxidase, succinate dehydrogenase, succinate dehydrogenase-cytochrome-creductase, nicotinamide adenine dinucleotide (NADH) dehydrogenase, and NADH dehydrogenase-cytochrome-creductase activities were established by use of 6 standard spectrophotometric assays for respiratory chain enzyme analysis.

Results—Compared with published data for skeletal muscle enzyme activities in humans, skeletal muscle enzyme activities in dogs were 2- to 4-fold higher. Additionally, citrate synthase activity, a marker for mitochondrial volume, was positively correlated with age in dogs, suggesting that mitochondrial volume increases with age, although no apparent change in respiratory chain enzymatic activity with an increase in age was found.

Conclusions and Clinical Relevance—Reference range values for skeletal muscle enzyme activities of dogs are needed to accurately interpret results of respiratory chain enzymatic activity assays. During investigation of metabolic myopathies, if skeletal muscle biopsy specimens are evaluated for respiratory chain enzyme kinetics, they should be performed and evaluated in concert with skeletal muscle biopsy specimens from clinically normal animals of the same species. (Am J Vet Res2004;65:480–484)
In vivo investigation of the efficacy of a customized solution to attenuate injury following low-flow ischemia and reperfusion injury in the jejunum of horses
Authors: Hoogmoed Linda M. Van , Nieto Jorge E. , Spier Sharon J. , Snyder Jack R.
Published: December 2005

Objective—To evaluate the efficacy of a customized solution to attenuate intestinal injury following 20% low-flow ischemia and reperfusion in the jejunum of horses.

Animals—10 healthy adult horses.

Procedure—Two 30.5-cm-long segments of jejunum were exteriorized through a ventral midline incision and the mesenteric artery and vein supplying that portion of the intestine were instrumented with flow probes. Blood flow was decreased to 20% of baseline for 90 minutes followed by 90 minutes of reperfusion. In 5 horses, 60 mL of the customized solution was placed in the lumen of each segment (treatment-group horses), and 60 mL of lactated Ringer's solution was placed in the lumen of 5 additional horses (control-group horses). Biopsy specimens were obtained from 1 segment in both groups for histologic evaluation. Aliquots of luminal fluid were obtained from the other segment in both groups for determination of albumin concentrations as an index of mucosal permeability.

Results—Compared with control-group horses, treatment-group horses had a significant decrease in luminal albumin concentration following reperfusion. Although differences in mucosal grades were not significantly different between control- and treatment-group horses, treatment-group horses had significantly greater jejunal villous length and area, compared with that of control-group horses.

Conclusions and Clinical Relevance—Intraluminal administration of the customized solution in the jejunum, compared with lactated Ringer's solution, results in an improvement in histologic findings and mucosal translocation of albumin in horses with mild intestinal injury. (Am J Vet Res2004;65:485–490)
Influence of morphine sulfate on the halothane sparing effect of xylazine hydrochloride in horses
Authors: Bennett Rachel C. , Kollias-Baker Cynthia , Steffey Eugene P. , Sams Richard
Published: December 2005

Objective—To quantitate the dose and time-related effects of morphine sulfate on the anesthetic sparing effect of xylazine hydrochloride in halothane-anesthetized horses and determine the associated plasma xylazine and morphine concentration-time profiles.

Animals—6 healthy adult horses.

Procedure—Horses were anesthetized 3 times to determine the minimum alveolar concentration (MAC) of halothane in O2and characterize the anesthetic sparing effect (ie, decrease in MAC of halothane) by xylazine (0.5 mg/kg, IV) administration followed immediately by IV administration of saline (0.9% NaCl) solution, low-dose morphine (0.1 mg/kg), or high-dose morphine (0.2 mg/kg). Selected parameters of cardiopulmonary function were also determined over time to verify consistency of conditions.

Results—Mean (± SEM) MAC of halothane was 1.05 ± 0.02% and was decreased by 20.1 ± 6.6% at 49 ± 2 minutes following xylazine administration. The amount of MAC reduction in response to xylazine was time dependent. Addition of morphine to xylazine administration did not contribute further to the xylazine-induced decrease in MAC (reductions of 21.9 ± 1.2 and 20.7 ± 1.5% at 43 ± 4 and 40 ± 4 minutes following xylazine-morphine treatments for low-and high-dose morphine, respectively). Overall, cardiovascular and respiratory values varied little among treatments. Kinetic parameters describing plasma concentration-time curves for xylazine were not altered by the concurrent administration of morphine.

Conclusions and Clinical Relevance—Administration of xylazine decreases the anesthetic requirement for halothane in horses. Concurrent morphine administration to anesthetized horses does not alter the anesthetic sparing effect of xylazine or its plasma concentration-time profile. (Am J Vet Res2004; 65:519–526)
Comparison of methods for differentiation of Salmonella enterica serovar Enteritidis phage type 4 isolates
Authors: Lopes Vanessa C. , Velayudhan Binu T. , Halvorson David A. , Lauer Dale C. , Gast Richard K. , Nagaraja Kakambi V.
Published: December 2005

Objective—To compare molecular typing methods
for the differentiation of Salmonella enterica serovar
Enteritidis phage type (PT) 4 isolates that allowed for
the determination of their genetic relatedness.

Sample Population—27 Salmonella Enteritidis PT 4
strains isolated in the United States and Europe.

Procedure—Several molecular typing methods were
performed to assess their ability to genetically differentiate
among Salmonella Enteritidis PT 4 isolates.
Results of pulse-field gel electrophoresis (PFGE),
repetitive polymerase chain reaction (PCR) assay, 16S
rRNA gene sequencing, random amplification of polymorphic
DNA (RAPD), PCR-restriction fragment
length polymorphism of 16S rRNA, and antimicrobial
susceptibility were evaluated.

Results—Compared with results for other techniques,
results for the RAPD typing method with the
RAPD1 primer reveal that it was the most discriminatory
fingerprinting technique, and it allowed us to
cluster Salmonella Enteritidis PT 4 isolates on the
basis of their genetic similarity.

Conclusions and Clinical Relevance—This study
revealed the value of RAPD with the RAPD1 primer as
a tool for epidemiologic investigations of Salmonella
Enteritidis PT 4. It can be used in conjunction with PFGE
and phage typing to determine the genetic relatedness
of Salmonella Enteritidis isolates involved in outbreaks
of disease. A reliable and highly discriminatory method
for epidemiologic investigations is critical to allow investigators
to identify the source of infections and consequently
prevent the spread of Salmonella Enteritidis
PT 4. ( Am J Vet Res 2004;65:538–543)
Evaluation of protective immunity in pigs following oral administration of an avirulent live vaccine of Lawsonia intracellularis
Authors: Kroll Jeremy J. , Roof Michael B. , McOrist Steven
Published: December 2005

Objective—To evaluate the efficacy of an orally administered avirulent live vaccine to protect pigs against challenge exposure with virulentLawsonia intracellularis.

Animals—108 weaned 3-week-old pigs (35 in experiment 1 and 73 in experiment 2).

Procedure—2 experiments were conducted. On day 0, vaccinates were orally administered vaccine via drench or in drinking water, whereas challenge-control pigs were administered cultured medium. On day 21, pigs were challenge exposed with a virulent heterologous isolate ofL intracellularis. Clinical observations, weights, seroconversion, and fecal excretion ofL intracellulariswere measured until day 42. At study termination, pigs were euthanatized and examined forL intracellularis-specific lesion development of the ileum and colon.

Results—Pigs receiving a single dose of vaccine were protected when challenge exposed with virulentL intracellularis(at least 107.7TCID50/dose). In experiment 1, vaccinates had significantly less fecal excretion (47% and 40% for days 35 and 42, respectively), compared with challenge-control pigs. In experiment 2, vaccinates had significantly less fecal excretion (50% and 58% for days 35 and 42, respectively), compared with challenge-control pigs. Significant reductions in lesion development were evident in the ileum of vaccinated pigs (70% and 56% at day 42 for experiments 1 and 2, respectively), compared with challenge- control pigs.

Conclusions and Clinical Relevance—Oral administration by drench or via drinking water of an avirulent live vaccine againstL intracellularisresulted in substantial protection against proliferative enteropathy among vaccinates and offers a better way to reduce stress of pigs during vaccine administration. (Am J Vet Res2004;65:559–565)
Assessment of cellular, biochemical, and histologic effects of bipolar radiofrequency treatment of canine articular cartilage
Authors: Cook James L. , Marberry Kevin M. , Kuroki Keiichi , Kenter Keith
Published: December 2005

Objective—To assess the cellular, biochemical, and histologic effects of bipolar radiofrequency-generated heat on canine articular cartilage.

Sample Population—Articular cartilage explants (n = 72) from 6 canine cadavers and cultured articular chondrocytes from 5 canine cadavers.

Procedure—Cartilage explants were randomly assigned to receive no treatment or treatment with focal (3 seconds) or diffuse bipolar radiofrequency. Following treatment, methylene blue permeability assay was performed (n = 12) and remaining samples (60) were cultured. Immediately and 5, 10, and 20 days after treatment, cultured explants were assessed for glycosaminoglycan (GAG) and collagen contents, type II collagen and matrix metalloproteinase (MMP)-13 immunoreactivity, and modified Mankin histologic scores. Liquid culture media were collected every 4 days and GAG content measured. Additionally, cultured chondrocytes were exposed for 3 seconds to media preheated to 37°, 45°, or 55°C. Cell viability was determined via 2 different assays immediately and 24 hours after treatment.

Results—Radiofrequency-treated cartilage had reduced permeability and considerable histologic damage, compared with control samples; most treated samples had reduced collagen II staining and increased MMP-13 immunostaining. Compared with other treatments, less GAGs were released from cartilage after diffuse radiofrequency treatment throughout the study period. Cell viability was significantly different between controls and cells treated at 55°C immediately and 24 hours after heat treatment.

Conclusions and Clinical Relevance—In this study, bipolar radiofrequency treatment had detrimental effects on normal articular cartilage cells and extracellular matrix with probable long-term clinical consequences. The usefulness of radiofrequency for treatment of osteoarthritic articular cartilage requires further investigation. (Am J Vet Res2004;65:604–609)
Effect of danofloxacin and tilmicosin on body temperatures of beef calves with pneumonia experimentally induced by inoculation with Mannheimia haemolytica
Authors: Fajt Virginia R. , Apley Michael D. , Brogden Kim A. , Skogerboe Terry L. , Shostrom Valerie K. , Chin Ya-Lin
Published: December 2005

Objective—To examine effects of danofloxacin and tilmicosin on continuously recorded body temperature in beef calves with pneumonia experimentally induced by inoculation ofMannheimia haemolytica.

Animals—41 Angus-cross heifers (body weight, 160 to 220 kg) without a recent history of respiratory tract disease or antimicrobial treatment, all from a single ranch.

Procedure—Radiotransmitters were implanted intravaginally in each calf. Pneumonia was induced intrabronchially by use of logarithmic-phase cultures ofM haemolytica. At 21 hours after inoculation, calves were treated with saline (0.9% NaCl) solution, danofloxacin, or tilmicosin. Body temperature was monitored from 66 hours before inoculation until 72 hours after treatment. Area under the curve (AUC) of the temperature-time plot and mean temperature were calculated for 3-hour intervals and compared among treatment groups.

Results—The AUCs for 3-hour intervals did not differ significantly among treatment groups for any of the time periods. Analysis of the mean temperature for 3-hour intervals revealed significantly higher temperatures at most time periods for saline-treated calves, compared with temperatures for antimicrobial-treated calves; however, we did not detect significant differences between the danofloxacin- and tilmicosin-treated calves. The circadian rhythm of temperatures before exposure was detected again approximately 48 hours after bacterial inoculation.

Conclusions and Clinical Relevance—Danofloxacin and tilmicosin did not differ in their effect on mean body temperature for 3-hour intervals but significantly decreased body temperature, compared with body temperature in saline-treated calves. Normal daily variation in body temperature must be considered in the face of respiratory tract disease during clinical evaluation of feedlot cattle. (Am J Vet Res2004;65: 610–615)
Assessment of the neurologic effects of dietary deficiencies of phenylalanine and tyrosine in cats
Authors: Dickinson Peter J. , Anderson Peter J. B. , Williams Diane C. , Powell Henry C. , Shelton G. Diane , Morris James G. , LeCouteur Richard A.
Published: December 2005

Objective—To determine the neurologic effects of reduced intake of phenylalanine and tyrosine in black-haired cats.

Animals—53 specific pathogen-free black domestic shorthair cats.

Procedure—Cats were fed purified diets containing various concentrations of phenylalanine and tyrosine for ≤ 9 months. Blood samples were obtained every 2 months for evaluation of serum aromatic amino acid concentrations. Cats were monitored for changes in hair color and neurologic or behavioral abnormalities. Three cats with neurologic deficits underwent clinical and electrophysiologic investigation; muscle and nerve biopsy specimens were also obtained from these cats.

Results—After 6 months, neurologic and behavioral abnormalities including vocalization and abnormal posture and gait were observed in cats that had received diets containing < 16 g of total aromatic amino acid/kg of diet. Electrophysiologic data and results of microscopic examination of muscle and nerve biopsy specimens from 3 cats with neurologic signs were consistent with sensory neuropathy with primary axonal degeneration. Changes in hair color were detected in cats from all groups receiving < 16 g of phenylalanine plus tyrosine/kg of diet.

Conclusions and Clinical Relevance—Findings suggested that chronic dietary restriction of phenylalanine and tyrosine in cats may result in a predominantly sensory neuropathy. In cats, the long-term nutritional requirement for phenylalanine and tyrosine appears to be greater for normal neurologic function than that required in short-term growth experiments. Official present-day recommendations for dietary phenylalanine and tyrosine in cats may be insufficient to support normal long-term neurologic function. (Am J Vet Res2004;65:671–680)
Comparison of two laparoscopic treatments for experimentally induced abdominal adhesions in pony foals
Authors: Lansdowne Jennifer L. , Bouré Ludovic P. , Pearce Simon G. , Kerr Carolyn L. , Caswell Jeff L.
Published: December 2005

Objective—To compare laparoscopic dissection withlaparoscopic dissection combined with abdominal instillation of ferric hyaluronate gel for the treatment of experimentally induced adhesions in pony foals.

Animals—12 healthy pony foals.

Procedure—A serosal abrasion method was used to create adhesions at 4 sites on the jejunum (day 0). At day 7, laparoscopy was performed and the adhesions observed in each foal were recorded. In group-1 foals (n = 6), the adhesions were separated laparoscopically (treatment 1). In group-2 foals (n = 6), 300 mL of 0.5% ferric hyaluronate gel was infused into the abdomen after the adhesions were separated laparoscopically (treatment 2). At day 24, terminal laparoscopy was performed and the adhesions observed were recorded. Total number of adhesions within each group was compared between day 7 and 24. Data were analyzed to determine whether an association existed between the number of adhesions on day 24 and treatment type.

Results—At day 24, the number of adhesions was significantly decreased within each group, compared with the number of adhesions at day 7 (group-1 foals, 10 vs 22 adhesions; group-2 foals, 3 vs 20 adhesions). Treatment 1 was associated with a significantly higher number of adhesions at day 24, compared with treatment 2 (odds ratio, 4.54; 95% confidence interval, 1.03 to 23.02).

Conclusions and Clinical Relevance—Abdominal instillation of 0.5% ferric hyaluronate gel after laparoscopic dissection was a more effective technique than laparoscopic dissection alone to treat experimentally induced adhesions in pony foals. Laparoscopic adhesiolysis following abdominal surgery in foals is a safe and effective technique. (Am J Vet Res2004;65:681–686)
Relationship of bispectral index to minimum alveolar concentration multiples of sevoflurane in cats
Authors: Lamont Leigh A. , Greene Stephen A , Grimm Kurt A. , Tranquilli William J.
Published: December 2005

Objective—To determine the relationship between bispectral index (BIS) and minimum alveolar concentration (MAC) multiples of sevoflurane in cats.

Animals—8 domestic cats.

Procedure—Each cat was anesthetized twice with sevoflurane. First, the MAC of sevoflurane for each cat was determined by use of the tail clamp method. Second, cats were anesthetized with sevoflurane at each of 5 MAC multiples administered in random order. Ventilation was controlled, and after a 15- minute equilibration period at each MAC multiple of sevoflurane, BIS data were collected for 5 minutes and the median value of BIS calculated.

Results—The mean (± SD) MAC of sevoflurane was 3.3 ± 0.2%. The BIS values at 0.5 MAC could not be recorded as a result of spontaneous movement in all 8 cats. The BIS values at 2.0 MAC were confounded by burst suppression in all 8 cats. Over the range of 0.8 to 1.5 MAC, BIS values decreased significantly with increasing end-tidal sevoflurane concentrations. Mean (± SD) BIS measurements were 30 ± 3, 21 ± 3, and 5 ± 2 at 0.8, 1.0, and 1.5 MAC, respectively.

Conclusions and Clinical Relevance—Values of BIS are inversely and linearly related to end-tidal sevoflurane concentrations in anesthetized cats, and BIS may be a useful predictor of CNS depression in this species. The consistently low BIS values recorded in this study suggest that clinical BIS end points used to titrate anesthetic agents in humans may not be applicable to cats. (Am J Vet Res2004;65:93–98)
Evaluation of xylazine and ketamine for total intravenous anesthesia in horses
Authors: Mama Khursheed R. , Wagner Ann E. , Steffey Eugene P. , Kollias-Baker Cynthia , Hellyer Peter W. , Golden Anne E. , Brevard Lucien F.
Published: December 2005

Objective—To evaluate the use of xylazine and ketamine for total IV anesthesia in horses.

Animals—8 horses.

Procedure—Anesthetic induction was performed on 4 occasions in each horse with xylazine (0.75 mg/kg, IV), guaifenesin (75 mg/kg, IV), and ketamine (2 mg/kg, IV). Intravenous infusions of xylazine and ketamine were then started by use of 1 of 6 treatments as follows for which 35, 90, 120, and 150 represent infusion dosages (µg/kg/min) and X and K represent xylazine and ketamine, respectively: X35+K90 with 100% inspired oxygen (O2), X35+K120-O2, X35+K150-O2, X70+K90-O2, K150-O2, and X35+K120 with a 21% fraction of inspired oxygen (ie, air). Cardiopulmonary measurements were performed. Response to a noxious electrical stimulus was observed at 20, 40, and 60 minutes after induction. Times to achieve sternal recumbency and standing were recorded. Quality of sedation, induction, and recovery to sternal recumbency and standing were subjectively evaluated.

Results—Heart rate and cardiac index were higher and total peripheral resistance lower in K150-O2and X35+K120-air groups. The mean arterial pressure was highest in the X35+K120-air group and lowest in the K150-O2group (125 ± 6 vs 85 ± 8 at 20 minutes, respectively). Mean PaO2was lowest in the X35+K120-air group. Times to sternal recumbency and standing were shortest for horses receiving K150-O2(23 ± 6 minutes and 33 ± 8 minutes, respectively) and longest for those receiving X70+K90-O2(58 ± 28 minutes and 69 ± 27 minutes, respectively).

Conclusions and Clinical Relevance—Infusions of xylazine and ketamine may be used with oxygen supplementation to maintain 60 minutes of anesthesia in healthy adult horses. (Am J Vet Res2005;66:1002–1007)
Evaluation of glucose tolerance and insulin sensitivity in llama crias
Authors: Cebra Christopher K. , Tornquist Susan J.
Published: December 2005

Objective—To investigate glucose tolerance and insulin sensitivity in llama crias.

Animals—7 llamas (age range, 14 to 30 days).

Procedure—On each of 2 sequential days, crias were administered glucose (0.5 g/kg) via rapid IV injection. On 1 day (randomly determined for each cria), regular insulin (0.2 U/kg) or 0.9% NaCl solution (0.002 mL/kg) was administered IV 15 minutes after glucose administration. Blood samples were collected before (baseline) and at 5, 15, 30, 45, 60, 90, 120, 180, and 240 minutes after glucose administration for determination of plasma glucose and insulin concentrations; fractional turnover rates and plasma half-life of glucose were calculated. The data were compared over time and between days (ie, between glucose treatments with and without insulin administration).

Results—A peak plasma glucose concentration of 342 ± 47 mg/dL was detected at 5 minutes after glucose administration and llamas cleared glucose from plasma within 60 minutes; at 15 minutes, plasma insulin concentration attained a peak value of 33 ± 13 µU/mL (ie, triple the baseline value). During the 15- to 45-minute interval, fractional turnover rate of glucose was 1.10 ± 0.24%/min and plasma half-life was 65.7 ± 13.4 minutes. Insulin significantly increased glucose turnover and resulted in hypoglycemia within 75 minutes of administration.

Conclusions and Clinical Relevance—Healthy immature llamas have glucose tolerance and insulin sensitivity superior to that of adults. However, whether sick crias retain the pancreatic sufficiency and tissue responsiveness that are likely responsible for the rapid glucose clearance in healthy individuals is not known. (Am J Vet Res2005;66:1013–1017)
Effect of transforming growth factor-β1 on bone regeneration in critical-sized bone defects after irradiation of host tissues
Authors: Ehrhart Nicole P. , Hong Liu , Morgan Abby L. , Eurell JoAnn A. , Jamison Russell D.
Published: December 2005

Objective—To determine whether sustained release
of transforming growth factor (TGF)-β1 from a gelatin
hydrogel would enhance bone regeneration in critical-sized
long-bone defects and overcome inhibitory
effects of preoperative irradiation.

Animals—24 adult New Zealand White rabbits.

Procedure—Rabbits were allocated to 2 groups.
Twelve rabbits received localized megavoltage radiation
to the right ulna by use of a cobalt 60 teletherapy
unit, and 12 rabbits received no irradiation. Then, a
1.5-cm defect was aseptically created in the right ulna
of each rabbit. Gelatin hydrogel that contained 5 µg of
adsorbed recombinant-human (rh) TGF-β1 was placed
in the defect of 12 rabbits (6 irradiated and 6 nonirradiated),
and the other 12 rabbits received hydrogel
without rhTGF-β1. Rabbits were euthanatized 10
weeks after surgery. New bone formation within the
defect was analyzed by use of nondecalcified histomorphometric
methods. A 1-way ANOVA was used to
compare differences among groups.

Results—New bone formation within the defect was
significantly greater in TGF-β1–treated rabbits than in rabbits
treated with hydrogel carrier alone. Local delivery of
rhTGF-β1 via a hydrogel carrier in irradiated defects
resulted in amounts of bone formation similar to those
for nonirradiated defects treated by use of rhTGF-β1.

Conclusions and Clinical Relevance—Local delivery
of TGF-β1 by use of a hydrogel carrier appears to have
therapeutic potential for enhancing bone formation in
animals after radiation treatments.

Impact for Human Medicine—This technique may
be of value for treating human patients at risk for
delayed bone healing because of prior radiation therapy.
(Am J Vet Res 2005;66:1039–1045)