bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the effects of penicillin G potassium and potassium chloride on the motility of the large intestine in horses
Authors: Roussel Allen J. , Hooper R. Neil , Cohen Noah D. , Bye Alicia D. , Hicks Russell J. , Schulze Joseph L.
Published: January 2006

Objective—To evaluate effects of IV administration of penicillin G potassium (KPEN) or potassium chloride (KCl) on defecation and myoelectric activity of the cecum and pelvic flexure of horses.

Animals—5 healthy horses.

Procedure—Horses with 12 bipolar electrodes on the cecum and pelvic flexure received KPEN or KCl solution by IV bolus 4 hours apart. Each horse received the following: 2 × 107U of KPEN (high-dose KPEN) followed by 34 mEq of KCl (high-dose KCl), 1 × 107U of KPEN (low-dose KPEN) followed by 17 mEq of KCl (low-dose KCl), high-dose KCl followed by high-dose KPEN, and low-dose KCl followed by low-dose KPEN. Number of defecations and myoelectric activity were recorded for 60 minutes. The first three 5-minute segments and first four 15-minute segments of myoelectric activity were analyzed.

Results—Number of defecations during the first 15- minute segment was greater after high-dose KPEN treatment than after high-dose or low-dose KCl treatment. Compared with reference indexes, myoelectric activity was greater in the pelvic flexure for the first 5- minute segment after high-dose KCl treatment, in the cecum and pelvic flexure for the first 5-minute segment and in the pelvic flexure for the first 15-minute segment after low-dose KPEN treatment, and in the pelvic flexure for the first and second 5-minute segments and the first three 15-minute segments after high-dose KPEN treatment.

Conclusions and Clinical Relevance—IV administration of KPEN stimulates defecation and myoelectric activity of the cecum and pelvic flexure in horses. Effects of KPEN may be beneficial during episodes of ileus. (Am J Vet Res2003;64:1360–1363)
Endoscopic evaluation of the gastroduodenal mucosa to determine the safety of short-term concurrent administration of meloxicam and dexamethasone in healthy dogs
Authors: Boston Sarah E. , Moens Noël M. M. , Kruth Stephen A. , Southorn Erin P.
Published: January 2006

Objective—To evaluate the safety, with respect to the development of gastric ulcers and erosions, of concurrent administration of meloxicam and dexamethasone for 3 days to healthy dogs.

Animals—20 conditioned purpose-bred research Beagles.

Procedure—Seven days prior to treatment, dogs were anesthetized for endoscopic evaluation of the upper portion of the gastrointestinal tract (ie, the gastric and duodenal mucosa). Five regions of the gastroduodenal area were scored by 2 investigators. Dogs were randomly assigned to 1 of 4 treatment groups as follows: saline-saline, dexamethasonesaline, saline-meloxicam, and dexamethasone-meloxicam groups. On days 1, 2, and 3, dogs received either dexamethasone or saline (0.9% NaCl) solution injections SC twice daily. On days 2, 3, and 4, dogs received either meloxicam or saline solution injections SC once daily. On day 2, dogs were anesthetized for a sham surgery (ie, electrostimulation). On day 5, the gastroduodenal area of each dog was reevaluated by use of endoscopic evaluation and histologic examination of biopsy specimens.

Results—The total endoscopic score of the dexamethasone- meloxicam group was significantly greater than the scores of the other groups. The dexamethasone- saline group had a mean cumulative score that was significantly greater than the saline-meloxicam or saline-saline groups. Endoscopic scores of the salinemeloxicam group were not significantly different from scores of the saline-saline group. No significant differences in histologic findings were found between groups.

Conclusions and Clinical Relevance—In healthy dogs, meloxicam appears to be safe with regard to adverse effects on the gastrointestinal tract. Concurrent administration of dexamethasone and meloxicam is more likely to cause gastric erosions than meloxicam administration alone. (Am J Vet Res2003;63:1369–1375)
Detection of lameness and determination of the affected forelimb in horses by use of continuous wavelet transformation and neural network classification of kinematic data
Authors: Keegan Kevin G. , Arafat Samer , Skubic Marjorie , Wilson David A. , Kramer Joanne
Published: January 2006

Objective—To investigate continuous wavelet transformation and neural network classification of gait data for detecting forelimb lameness in horses.

Animals—12 adult horses with mild forelimb lameness.

Procedure—Position of the head and right forelimb foot, metacarpophalangeal (ie, fetlock), carpal, and elbow joints was determined by use of kinematic analysis before and after palmar digital nerve blocks. We obtained 8 recordings from horses without lameness, 8 with right forelimb lameness, and 8 with left forelimb lameness. Vertical and horizontal position of the head and vertical position of the foot, fetlock, carpal, and elbow joints were processed by continuous wavelet transformation. Feature vectors were created from the transformed signals and a neural network trained with data from 6 horses, which was then tested on the remaining 2 horses for each category until each horse was used twice for training and testing. Correct classification percentage (CCP) was calculated for each combination of gait signals tested.

Results—Wavelet-transformed vertical position of the head and right forelimb foot had greater CCP (85%) than untransformed data (21%). Adding data from the fetlock, carpal, or elbow joints did not improve CCP over that for the head and foot alone.

Conclusions and Clinical Relevance—Wavelet transformation of gait data extracts information that is important for the detection and differentiation of forelimb lameness of horses. All of the necessary information to detect lameness and differentiate the side of lameness can be obtained by observation of vertical head movement in concert with movement of the foot of 1 forelimb. (Am J Vet Res2003;64:1376–1381)
Use of magnetic motor-evoked potentials in horses with bilateral hind limb ataxia
Authors: Nollet Heidi , Van Ham Luc , Verschooten Francis , Vanderstraeten Guy , Deprez Piet
Published: January 2006

Objective—To determine the usefulness of magnetic motor-evoked potentials (MMEPs) for assessing the integrity of the cervical, thoracic, and thoracolumbar spinal cord in horses with bilateral hind limb ataxia.

Animals—9 horses and 1 donkey with bilateral hind limb ataxia of various degrees.

Procedure—The motor cortex was stimulated magnetically, and MMEPs were recorded bilaterally from the extensor carpi radialis and cranial tibial muscles.

Results—In 5 horses and 1 donkey, MMEPs with normal onset latencies and peak-to-peak amplitude were recorded from the extensor carpi radialis muscles, whereas abnormal onset latencies and peak-topeak amplitudes were recorded from the cranial tibial muscles. In these animals, a spinal cord lesion in the thoracic or thoracolumbar segments was suspected. In 4 horses, onset latencies and peak-topeak amplitude of MMEPs recorded from the extensor carpi radialis and cranial tibial muscles were abnormal. In these horses, a cervical spinal cord lesion was suspected.

Conclusions and Clinical Relevance—Transcranial magnetic stimulation can be considered a valuable diagnostic tool for assessing the integrity of the spinal cord, and MMEPs may be used for differentiating thoracic or thoracolumbar spinal cord lesions from mild cervical spinal cord lesions that cause ataxia in the hind limbs only. (Am J Vet Res2003;64:1382–1386)
Molecular cloning of the canine telomerase reverse transcriptase gene and its expression in neoplastic and non-neoplastic cells
Authors: Yazawa Mitsuhiro , Okuda Masaru , Kanaya Noriko , Hong Sung-Hyeok , Takahashi Tomoko , Ohashi Emi , Nakagawa Takayuki , Nishimura Ryohei , Sasaki Nobuo , Masuda Kenichi , Ohno Koichi , Tsujimoto Hajime
Published: January 2006

Objective—To perform molecular cloning of the canine telomerase reverse transcriptase (TERT) gene and determine its expression in neoplastic and nonneoplastic cells.

Sample Population—9 canine tumor cell lines derived from various neoplasms, 16 primary canine tumors, and tissues from 15 normal canine organs.

Procedure—Tumor cell lines were derived from canine tumors that included osteosarcoma, mammary gland adenocarcinoma, melanoma, acute lymphoblastic leukemia, lymphoma, and mastocytoma and a canine primary fibroblast culture. Canine TERT complementary DNA (cDNA) was amplified by use of polymerase chain reaction (PCR) and sequenced. Expression of TERT mRNA was examined by reverse transcription (RT)-PCR assay. Telomerase activity was measured by use of the telomeric repeat amplification protocol assay.

Results—The canine TERT cDNA clone was 237 base pairs in length and contained a central region encoding the reverse transcriptase motif 2. Expression of TERT mRNA was detected in canine tumor cell lines that had telomerase activity but not in telomerasenegative canine primary fibroblasts. The TERT mRNA was detected in 13 of 16 canine tumor tissues and several normal tissues such as liver, ovary, lymph node, and thymus. A significant correlation between TERT expression level and telomerase activity was noted.

Conclusions and Clinical Relevance—Expression of TERT mRNA was closely associated with telomerase activity in neoplastic cells as well as some non-neoplastic cells from dogs. In addition to telomerase activity, expression of TERT mRNA can be used as a marker of tumor cells. (Am J Vet Res2003;64:1395–1400)
Use of recombinant human thyroid-stimulating hormone for thyrotropin-stimulation testing of euthyroid cats
Authors: Stegeman Julie R. , Graham Peter A. , Hauptman Joe G.
Published: January 2006

Objective—To evaluate response of euthyroid cats to administration of recombinant human thyroid-stimulating hormone (rhTSH).

Animals—7 healthy cats.

Procedure—Each cat received each of 5 doses of rhTSH (0, 0.025, 0.050, 0.100, and 0.200 mg), IV, at 1-week intervals. Serum concentration of total thyroxine (TT4) and free thyroxine (fT4) was measured immediately before each injection (time 0) and 2, 4, 6, and 8 hours after administration of each dose.

Results—Overall TT4response did not differ significantly among cats when administered doses were ≥ 0.025 mg. Serum TT4concentrations peaked 6 to 8 hours after administration for all doses ≥ 0.025 mg. For all doses ≥ 0.025 mg, mean ± SEM TT4concentration at 0, 6, and 8 hours was 33.9 ± 1.7, 101.8 ± 5.9, and 101.5 ± 5.7 nmol/L, respectively. For all doses ≥ 0.025 mg, mean fT4 concentration at 0, 6, and 8 hours was 38.7 ± 2.9, 104.5 ± 7.6, and 100.4 ± 8.0 pmol/L, respectively. At 8 hours, the fT4 response to 0.025 and 0.050 mg was less than the response to 0.100 and 0.200 mg. Adverse reactions after rhTSH administration were not detected.

Conclusions and Clinical Relevance—The TSH stimulation test can be performed in cats by IV administration of 0.025 to 0.200 mg of rhTSH and measurement of serum TT4concentrations at time of injection and 6 or 8 hours later. Clinical validation of the TSH stimulation test would facilitate development of additional tests of thyroid gland function, such as a TSH assay. (Am J Vet Res2003;64:149–152)
Epidemiologic study of results of pulsed-field gel electrophoresis of isolates of Rhodococcus equi obtained from horses and horse farms
Authors: Cohen Noah D. , Smith Karen E. , Ficht Thomas A. , Takai Shinji , Libal Melissa C. , West Brian R. , delRosario Lemuel S. , Becu Teotimu , Leadon Desmond P. , Buckley Thomas , Chaffin M. Keith , Martens Ronald J.
Published: January 2006

Objective—To compare isolates ofRhodococcus equion the basis of geographic source and virulence status by use of pulsed-field gel electrophoresis (PFGE).

Sample Population—290 isolates ofR equi(218 virulent isolates from foals and 72 avirulent isolates from feces, soil, and respiratory tract samples) obtained between 1985 and 2000 from horses and horse farms from 4 countries.

Procedure—DNA from isolates was digested with the restriction enzymeAseIand tested by use of PFGE. Products were analyzed for similarities in banding patterns by use of dendrograms. A similarity matrix was constructed for isolates, and the matrix was tested for nonrandom distributions of similarity values with respect to groupings of interest.

Results—There was little grouping of isolates on the basis of country, virulence status, or region within Texas. Isolates ofR equiwere generally < 80% similar, as determined by use of PFGE. Isolates from the same farm generally were rarely of the same strain.

Conclusions and Clinical Relevance—Considerable chromosomal variability exists among isolates ofR equiobtained from the same farm, sites within Texas, or among countries from various continents. Only rarely will it be possible to link infections to a given site or region on the basis of analysis of isolates by use of PFGE of chromosomal DNA. (Am J Vet Res2003;64:153–161)
Use of an amplified ELISA technique for detection of a house dust mite allergen ( Der f 1) in skin and coat dust samples from dogs
Authors: Glass Emmett V. , Reid Rachel A. , Hillier Andrew , Needham Glen R.
Published: January 2006

Objective—To use an amplified ELISA technique to
document the presence and quantify the concentration
of the house dust mite allergen, Der f 1, in skin
and coat dust samples collected from dogs.

Animals—29 pet dogs of various breeds.

Procedure—Dogs were weighed, and body surface
area in square meters was determined. Skin and coat
dust samples were obtained by vacuuming dogs.
Collected dust was analyzed by use of standard and
amplified ELISA techniques.

Results—By use of the standard ELISA technique,
Der f 1 was detected in skin and coat dust samples
from 6 of 29 (21%) dogs. Mean concentration of Der
f 1 in the 6 samples with positive assay results was
16.16 ng/mL (range, 5.61 to 31.24 ng/mL). Samples
with negative assay results were retested for dust
mite allergen by use of an amplified ELISA technique;
an additional 14 dogs had positive assay results.
Mean concentration of allergen was 0.36 ng/mL
(range, 0.19 to 2.20 ng/mL). Combining both techniques,
20 of 29 (69%) dogs had positive assay
results for Der f 1.

Conclusions and Clinical Relevance—Results of our
study indicate that house dust mite allergens are present
on the skin and in the coat of dogs, and this
source of allergen may act as a reservoir for allergen
exposure in hypersensitive dogs. Use of an amplified
ELISA technique to determine environmental concentrations
of house dust mite allergens in homes and on
dogs will help to identify the relationship between
immunologic findings and environmental exposures
in dogs with atopic dermatitis. (Am J Vet Res 2003;64:162–165)
Effects of oral administration of methazolamide on intraocular pressure and aqueous humor flow rate in clinically normal dogs
Authors: Skorobohach Brian J. , Ward Dan A. , Hendrix Diane V. H.
Published: January 2006

Objective—To determine magnitude and duration of the effect of oral administration of methazolamide at 2 dosages on intraocular pressure (IOP) in dogs in single- dose and multiple-dose trials and to determine aqueous humor flow rate (AHFR) by use of anterior segment fluorophotometry before and during treatment.

Animals—25 healthy adult Beagles.

Procedure—Baseline IOPs and AHFRs were determined on days 0 and 1, respectively. On day 2, the single-dose trial was initiated with oral administration of 25 or 50 mg of methazolamide at 7 AM to 2 groups of 10 dogs each. Five dogs served as controls. In the multiple-dose trial, the same dogs received 25 or 50 mg of methazolamide at 7 AM and at 3 and 11 PM on days 3 through 9.

Results—Intraocular pressures varied diurnally with highest IOPs in the morning. In the single-dose trial, IOP decreased significantly at 3 to 6 hours after treatment and then increased significantly at later time points, compared with baseline values. In the multipledose trial, dogs in both treatment groups had significantly lower IOPs during the treatment period at 10 AM and 1 PM but not at 6 and 9 PM, compared with baseline values. In both treatment groups morning IOPs had returned to baseline values by the first day after treatment. Evening IOPs were significantly increased by 2 to 3 days after treatment, compared with baseline values. The AHFRs in both treatment groups were significantly lower than pretreatment AHFRs.

Conclusions and Clinical Relevance—Oral administration of methazolamide decreases IOPs and AHFRs in clinically normal dogs, with effectiveness diminishing in the evening. (Am J Vet Res2003;64:183–187)
Evaluation of the ability of carprofen and flunixin meglumine to inhibit activation of nuclear factor kappa B
Authors: Bryant Clare E. , Farnfield Belinda A. , Janicke Heidi J.
Published: January 2006

Objective—To determine whether the nonsteroidal anti-inflammatory drugs (NSAIDs) carprofen, flunixin meglumine, and phenylbutazone have cyclooxygenase (COX)-independent effects that specifically inhibit activation of the proinflammatory transcription factor nuclear factor kappa B (NfκB).

Study Population—Purified ovine COX-1 and -2 and cultures of RAW 264.7 murine macrophages.

Procedure—The COX-1 and -2 inhibitory effects of the NSAIDs were tested in assays that used purified ovine COX-1 and -2. Prostaglandin production was analyzed by use of a radioimmunoassay. Inhibitory effects of these drugs on lipopolysaccharide (LPS)- induction of inducible nitric oxide synthase (iNOS) and LPS-stimulated translocation of NfκB were determined by use of RAW 264.7 murine macrophages.

Results—Flunixin meglumine and phenylbutazone were selective inhibitors of COX-1. Carprofen and flunixin meglumine, but not phenylbutazone, inhibited LPS-induction of iNOS. Carprofen and, to a lesser degree, flunixin meglumine had inhibitory effects on NFκB activation.

Conclusions and Clinical Relevance—The ability of drugs such as carprofen and flunixin meglumine to inhibit activation of NfκB-dependent genes such as iNOS, in addition to their effects on COX, suggests an additional mechanism for their anti-inflammatory effects and may explain the ability of flunixin meglumine to be an effective inhibitor of the effects of endotoxin in horses with endotoxemia. (Am J Vet Res2003;64:211–215)
Effects of obesity on lipid profiles in neutered male and female cats
Authors: Hoenig Margarethe , Wilkins Caroline , Holson Jennifer C. , Ferguson Duncan C.
Published: January 2006

Objective—To examine whether obese cats, compared with lean cats, have alterations in lipoprotein metabolism that might lead to a decrease in glucose metabolism and insulin secretion.

Animals—10 lean and 10 obese adults cats (5 neutered males and 5 neutered females each).

Procedure—Intravenous glucose tolerance tests with measurements of serum glucose, insulin, and nonesterified fatty acid (NEFA) concentrations were performed. Lipoprotein fractions were examined in serum by isopycnic density gradient ultracentrifugation.

Results—Obese cats had insulin resistance. Plasma triglyceride and cholesterol concentrations were significantly increased in obese cats, compared with lean cats. Very low density lipoprotein (VLDL) concentrations were increased in obese cats, compared with lean cats; however, the composition of various fractions remained unchanged between obese and lean cats, indicating greater synthesis and catabolism of VLDL in obese cats. Serum high density lipoprotein (HDL) cholesterol concentrations were increased in obese cats, compared with lean cats. Serum NEFA concentrations were only significantly different between obese and lean cats when separated by sex; obese male cats had higher baseline serum NEFA concentrations and greater NEFA suppression in response to insulin, compared with lean male cats.

Conclusions and Clinical Relevance—Lipid metabolism changes in obese cats, compared with lean cats. The increase in VLDL turnover in obese cats might contribute to insulin resistance of glucose metabolism, whereas the increase in serum HDL cholesterol concentration might reflect a protective effect against atherosclerosis in obese cats. (Am J Vet Res2003;64:299–303)
Effect of dietary protein quality and essential fatty acids on fatty acid composition in the liver and adipose tissue after rapid weight loss in overweight cats
Authors: Szabo Joseph , Ibrahim Wissam H. , Sunvold Gregory D. , Bruckner Geza G.
Published: January 2006

Objective—To examine effects of dietary protein quality (casein [CA] vs corn gluten [CG]) and dietary lipids (corn oil [CO] vs oil blend [OB] rich in long-chain polyunsaturated fatty acids [LCPUFAs]) on fatty acid composition in liver and adipose tissue after weight loss in overweight cats.

Animals—24 ovariohysterectomized adult cats.

Procedure—Cats were allowed ad libitum access to a high-quality diet until they weighed 30% more than their ideal body weight. Cats were then randomly assigned to 1 of 4 weight-reduction diets (6 cats/diet) and were fed 25% of maintenance energy requirements per day. Diets consisted of CG–CO, CA–CO, CG–OB, and CA–OB, respectively, and were fed until cats lost weight and returned to their original lean body mass. Liver biopsy specimens and samples of perirenal, subcutaneous, and abdominal fat were obtained and analyzed for fatty acid content.

Results—Following weight loss, fatty acid composition of the liver and adipose tissue was primarily affected by protein quality in that cats fed CA had significantly higher percentages of 20:4(n-6) and 22:6(n-3) fatty acids than those fed CG. Cats fed the CG–CO diet had the lowest concentrations of LCPUFAs, suggesting that dietary lipids and protein quality each influence fatty acid composition in tissues.

Conclusions and Clinical Relevance—These data provide direct evidence that dietary protein quality alters fatty acid composition of tissues during weight loss in cats. The fatty acid patterns observed suggest that protein quality may alter fatty acid composition through modulation of desaturase activity. (Am J Vet Res2003;64:310–315)
Evaluation of a stochastic Markov-chain model for the development of forelimb injuries in Thoroughbred racehorses
Authors: Hill Ashley E. , Carpenter Tim E. , Gardner Ian A. , Stover Susan M.
Published: January 2006

Objective—To evaluate a Markov-chain model for the development of forelimb injuries in Thoroughbreds and to use the model to determine effects of reducing sprint distance on incidence of metacarpal condylar fracture (CDY) and severe suspensory apparatus injury (SSAI).

Sample Population—Weekly exercise and injury data for 122 Thoroughbreds during racing or training.

Procedure—Weekly data were used to construct a Markov-chain model with 5 states (uninjured [UNINJ], palpable suspensory apparatus injury [PSAI], SSAI, CDY, and lost to follow-up [LOST]). Transition probabilities between UNINJ and PSAI were estimated as a function of weekly sprint distance by use of linear regression analysis. The model was used to predict distributions of annual CDY and SSAI incidences in southern California racehorses and was validated by using CDY incidence reported by racetrack practitioners. The model was modified by reducing the number of sprint distances that were > 6 furlongs (> 1.20 km) by 20%, and CDY and SSAI incidences were compared with those generated by the baseline model.

Results—The model accurately fit development of injuries in the sample population but overestimated development of injuries in the southern California racehorse population. Development of and recovery from PSAI were correlated with distance run at high speeds. Reducing by 20% the number of sprints run at distances > 6 furlongs significantly reduced modeled annual CDY and SSAI incidence by 9%.

Conclusions and Clinical Relevance—Reducing the number of sprints at distances > 6 furlongs, particularly among horses with PSAI, reduces risk of CDY and SSAI. (Am J Vet Res2003;64:328–337)
Moment arms about the carpal and metacarpophalangeal joints for flexor and extensor muscles in equine forelimbs
Authors: Brown Nicholas A. T. , Pandy Marcus G. , Buford William L. , Kawcak Christopher E. , McIlwraith C. Wayne
Published: January 2006

Objective—To determine whether muscle moment arms at the carpal and metacarpophalangeal joints can be modeled as fixed-radius pulleys for the range of motion associated with the stance phase of the gait in equine forelimbs.

Sample Population—4 cadaveric forelimbs from 2 healthy Thoroughbreds.

Procedure—Thin wire cables were sutured at the musculotendinous junction of 9 forelimb muscles. The cables passed through eyelets at each muscle's origin, wrapped around single-turn potentiometers, and were loaded. Tendon excursions, measured as the changes in lengths of the cables, were recorded during manual rotation of the carpal (180° to 70°) and metacarpophalangeal (220° to 110°) joints. Extension of the metacarpophalangeal joint (180° and 220°) was forced with an independent loading frame. Joint angle was monitored with a calibrated potentiometer. Moment arms were calculated from the slopes of the muscle length versus joint angle curves.

Results—At the metacarpophalangeal joint, digital flexor muscle moment arms changed in magnitude by ≤ 38% during metacarpophalangeal joint extension. Extensor muscle moment arms at the carpal and metacarpophalangeal joints also varied (≤ 41% at the carpus) over the range of joint motion associated with the stance phase of the gait.

Conclusions and Clinical Relevance—Our findings suggest that, apart from the carpal flexor muscles, muscle moment arms in equine forelimbs cannot be modeled as fixed-radius pulleys. Assuming that muscle moment arms at the carpal and metacarpophalangeal joints have constant magnitudes may lead to erroneous estimates of muscle forces in equine forelimbs. (Am J Vet Res2003;64:351–357)
Evaluation of transcutaneous Doppler ultrasonography for the measurement of blood flow in the femoral artery of pigs
Authors: Palacio Maria Josefa Fernández del , Fuentes Virginia Luis , Bonagura John D. , Schober Karsten E. , Hatfield Daniel G. , Laughlin M. Harold
Published: January 2006

Objective—To compare measurements of blood flow
in the common femoral artery obtained by duplex
Doppler ultrasonography (DDU) and a reference ultrasonic
transit-time flow (TTF) method and to examine
the impact of Doppler spectral waveform measurement
techniques on volumetric estimates.

Animals—5 healthy female pigs.

Procedure—Femoral arterial blood flow was measured
simultaneously in anesthetized pigs by use of a
TTF probe (left femoral artery) and transcutaneous
DDU (right femoral artery). A range of flow states was
induced pharmacologically by using xylazine,
bradykinin, dobutamine, and isoflurane. Volumetric
blood flow was calculated from DDU waveforms,
using the product of the flow velocity integral (FVI),
the cross-sectional vessel area, and heart rate. Three
calculations of FVI were obtained by manually tracing
the Doppler spectral envelopes at the outer envelope,
the modal, and the inner envelope of the spectral dispersion
pattern. Data analysis included calculation of
Pearson correlation coefficients and Bland-Altman
limits of agreement.

Results—Blood flow measured by DDU was more
closely correlated with TTF measurements when the
modal or inner envelope tracing method was used
( r, 0.76 and 0.78; limits of agreement, –100 to 54.2
and –48.5 to 77.0 mL/min, respectively). Limits of
agreement for the outer envelope tracing method
were –238.5 to 64 mL/min.

Conclusion and Clinical Relevance—Transcutaneous
DDU is a reliable noninvasive technique for
measuring blood flow in the femoral artery of pigs
over a range of flow states. Tracing the inner envelope
of the Doppler spectral dispersion pattern provided
the best estimate of blood flow in this study.
(Am J Vet Res 2003;64:43–50)
Measurement of glycated hemoglobin percentages for use in the diagnosis and monitoring of diabetes mellitus in nonhuman primates
Authors: Dutton Christopher J. , Parvin Curtis A. , Gronowski Ann M.
Published: January 2006

Objective—To identify a technique for measurement
of glycated hemoglobin percentage in blood samples
obtained from various species of nonhuman primates
(NHPs), to determine whether these percentages varied
with respect to glycemic control, and to assess
whether this physiologic variable provided a suitable
test for diagnosing diabetes mellitus in NHPs.

Sample Population—166 blood samples collected
from 121 NHPs comprising 22 species from the
Haplorhine and Strepsirhine suborders and including
nondiabetic, treated-diabetic, and diabetic animals in
23 zoologic institutions throughout the United States.

Procedure—Hemoglobin A1c percentage was measured
in 154 samples by use of high-performance liquid
chromatography. Total glycated hemoglobin percentage
was measured in 159 samples by use of a
boronate-affinity chromatographic assay. Glucose
concentration was measured in 157 samples with an
autochemical analyzer by use of a hexose kinase
method.

Results—The boronate-affinity chromatographic technique
for measurement of total glycated hemoglobin
percentage was the most suitable method.
Nondiabetic Haplorhines had percentages higher than
those in nondiabetic Strepsirhines. In Haplorhines,
diabetic animals had percentages higher than those in
treated-diabetic animals, which had percentages higher
than those in nondiabetic animals. In Strepsirhines,
this pattern was less pronounced.

Conclusions and Clinical Relevance—Measurement
of total glycated hemoglobin percentage provides
useful information for diagnosing diabetes mellitus
in Haplorhines and, possibly, in Strepsirhines.
Until reference ranges are established for each
species, it is recommended that results for samples
from NHPs without clinical signs of diabetes mellitus
be compared with results of samples collected concomitantly
from NHPs with clinical signs of this condition.
( Am J Vet Res 2003;64:562–568)
Effect of intranasal exposure to leukotoxindeficient Mannheimia haemolytica at the time of arrival at the feedyard on subsequent isolation of M haemolytica from nasal secretions of calves
Authors: Frank Glynn H. , Briggs Robert E. , Duff Glenn C. , Hurd H. Scott
Published: January 2006

Objective—To determine the effect of intranasal exposure to live leukotoxin (LktA)-deficientMannheimia haemolytica(MH) at the time of feedyard arrival on nasopharyngeal colonization by wildtype MH in calves.

Animals—200 calves.

Procedure—Calves from Arkansas (AR calves; n = 100; mean body weight, 205 kg) were purchased from an order buyer barn. Calves from New Mexico (NM calves; n = 100; mean body weight, 188 kg) were obtained from a single ranch. Calves were transported to a feedyard, where half of each group was exposed intranasally with LktA-deficient MH at the time of arrival. Calves were observed daily for respiratory tract disease (RTD), and nasal swab specimens were collected periodically to determine nasopharyngeal colonization status with MH. Serum samples were assayed for antibodies to MH.

Results—15 AR calves had nasopharyngeal colonization by wild-type MH at the order buyer barn, whereas none of the NM calves had nasopharyngeal colonization. Intranasal exposure to LktA-deficient MH elicited an increase in serum antibody titers against MH in NM calves, but titers were less in NM calves treated for RTD. Exposure of NM calves to LktA-deficient MH offered protection from nasopharyngeal colonization by wild-type MH.

Conclusions and Clinical Relevance—Exposure of calves to LktA-deficient MH elicited an increase in serum antibody titers against MH and decreased colonization of the nasopharynx by wild-type MH. Earlier exposure would likely allow an immune response to develop before transportation and offer protection from nasopharyngeal colonization and pneumonia caused by wild-type MH. (Am J Vet Res2003;64:580–585)
Effects of acepromazine on renal function in anesthetized dogs
Authors: Boström Ingrid , Nyman Görel , Kampa Naurepon , Häggström Jens , Lord Peter
Published: January 2006

Objective—To investigate the effects of IM administration of acepromazine on indices of relative renal blood flow and glomerular filtration rate (GFR) by means of scintigraphy, as well as the effects on physiologic, hematologic, and serum biochemical variables in anesthetized dogs, compared with effects of administration of saline.

Animals—6 healthy Beagles.

Procedure—Acepromazine (0.1 mg/kg) or physiologic saline (0.9 NaCl) solution was administered IM 30 minutes prior to induction of anesthesia with thiopentone; anesthesia was maintained with inspired isoflurane for 2.25 hours. Blood gases and circulatory and ventilatory variables were monitored. Renal function was evaluated by scintigraphic measurements of GFR and relative renal blood flow and analyses of serum and urine. Statistical analyses used ANOVA or Friedman ANOVA.

Results—Values of relative renal blood flow and GFR remained high despite low blood pressures. After administration of acepromazine, mean ± SD arterial blood pressure was 66 ± 8 mm Hg during anesthesia; this value was below the threshold (80 mm Hg) for renal autoregulation of GFR. In comparison, mean arterial blood pressure after administration of saline was significantly higher (87 ± 13 mm Hg). However, between treatments, there were no significant differences in GFR, relative renal blood flow, or other indices of renal function.

Conclusions and Clinical Relevance—Measurements of renal function and blood flow in dogs during anesthesia with thiopentone and isoflurane did not differ significantly between treatments, which suggested that acepromazine protects renal function despite inducing reduction in blood pressure, compared with effects of administration of saline. (Am J Vet Res2003; 64:590–598)
Effects of calcium disodium EDTA and meso-2,3-dimercaptosuccinic acid on tissue concentrations of lead for use in treatment of calves with experimentally induced lead toxicosis
Authors: Meldrum James B. , Ko Kam W.
Published: January 2006

Objective—To compare the efficacy of calcium disodium EDTA (CaNa2EDTA) and meso-2,3-dimercaptosuccinic acid (DMSA) in reducing concentrations of lead in selected tissues for use in treatment of calves with experimentally induced lead toxicosis.

Animals—19 sexually intact male Holstein calves that weighed 35 to 60 kg.

Procedure—Calves were randomly assigned to 1 of 5 treatment groups: group 1, control calves; group 2, lead only; group 3, lead and EDTA; group 4, lead and DMSA; and group 5, lead, EDTA, and DMSA. Calves in groups 2 to 5 were dosed daily with lead (5 mg/kg, PO) for 10 days. Doses of EDTA (100 mg/kg) and DMSA (25 mg/kg) were administered IV once daily for 4 consecutive days beginning on day 11. Effects of the chelators on lead concentrations in the liver, kidneys, testes, muscles, bones, and brain were compared among the various groups.

Results—Compared with the effects of EDTA, DMSA greatly reduced lead concentrations in renal and hepatic tissues. We did not detect significant differences for the effects of EDTA or DMSA on lead concentrations in the testes; there was an adverse interaction of EDTA with DMSA that caused an increase in lead concentrations in the testes.

Conclusions and Clinical Relevance—DMSA is much more effective than EDTA in removing lead from renal and hepatic tissues in calves. Use of DMSA in calves with lead intoxication appears to be a viable treatment option. Combining DMSA and EDTA as a treatment modality in calves did not offer any advantages. (Am J Vet Res2003;64:672–676)
Pharmacokinetics of imipenem in dogs
Authors: Barker Corrie W. , Zhang Weijiang , Sanchez Susan , Budsberg Steven C. , Boudinot F. Douglas , Stevenson M. A. McCrackin
Published: January 2006

Objective—To determine the plasma pharmacokinetics of imipenem (5 mg/kg) after single-dose IV, IM, and SC administrations in dogs and assess the ability of plasma samples to inhibit the growth ofEscherichia coliin vitro.

Animals—6 adult dogs.

Procedure—A 3-way crossover design was used. Plasma concentrations of imipenem were measured after IV, IM, and SC administration by use of high-performance liquid chromatography. An agar well antimicrobial assay was performed with 3E coliisolates that included a reference strain and 2 multidrug-resistant clinical isolates.

Results—Plasma concentrations of imipenem remained above the reported minimum inhibitory concentration for E coli (0.06 to 0.25 µg/mL) for a minimum of 4 hours after IV, IM, and SC injections. Harmonic mean and pseudo-standard deviation halflife of imipenem was 0.80 ± 0.23, 0.92 ± 0.33, and 1.54 ± 1.02 hours after IV, IM, and SC administration, respectively. Maximum plasma concentrations (Cmax) of imipenem after IM and SC administration were 13.2 ± 4.06 and 8.8 ± 1.7 mg/L, respectively. Time elapsed from drug administration until Cmax was 0.50 ± 0.16 hours after IM and 0.83 ± 0.13 hours after SC injection. Growth of all 3 E coli isolates was inhibited in the agar well antimicrobial assay for 2 hours after imipenem administration by all routes.

Conclusions and Clinical Relevance—Imipenem is rapidly and completely absorbed from intramuscular and subcutaneous tissues and effectively inhibits in vitro growth of certain multidrug-resistant clinical isolates of E coli. (Am J Vet Res2003;64:694–699)
Comparison of nociceptive withdrawal reflexes and recruitment curves between the forelimbs and hind limbs in conscious horses
Authors: Spadavecchia Claudia , Arendt-Nielsen Lars , Andersen Ole K. , Spadavecchia Luciano , Doherr Marcus , Schatzmann Urs
Published: January 2006

Objective—To compare nociceptive withdrawal reflexes (NWRs) evoked from the distal aspect of the left forelimb and hind limb in conscious standing horses and to investigate NWR recruitment for graded electrical stimulation intensities.

Animals—20 adult horses.

Procedure—Surface electromyographic (EMG) activity evoked by transcutaneous electrical stimulation of the digital palmar (or plantar) nerve was recorded from the common digital extensor and cranial tibial muscles. Stimuli consisted of 25-millisecond train-of-5 constant current pulses. Current intensity was gradually increased until NWR threshold intensity was reached. The EMG signal was analyzed for quantification of the NWR. Behavioral responses accompanying the reflex were scored (scale, 0 to 5). The NWR recruitment curves were determined at 0.9, 1.1, 1.2, and 1.3 times the NWR threshold intensity.

Results—The NWR threshold was significantly higher for the hind limb (median value, 6.6 mA; range, 3 to 10 mA) than the forelimb (median, 3 mA; range, 1.7 to 5.5 mA). The NWR of the hind limb had a significantly longer latency (median, 122.8 milliseconds; range, 106 to 172 milliseconds), compared with the forelimb (median, 98 milliseconds; range, 86 to 137 milliseconds), and it was associated with significantly stronger behavioral reactions. Gradual increase of NWR amplitude was evident at increasing stimulation intensities and supported by the behavioral observations.

Conclusions and Clinical Relevance—We documented NWRs evoked from the forelimb and hind limb and their recruitment with stimuli of increasing intensity in horses. These results provide a basis for use of NWRs in studies on nociceptive modulation in horses. (Am J Vet Res2003;64:700–707)
Evaluation of β3-adrenoceptor-mediated relaxation in intact and endotoxin-treated equine digital veins
Authors: Mallem Mohamed Y. , Gogny Marc , Gautier Freddy , Bucas Veronique , Desfontis Jean-Claude
Published: January 2006

Objective—To investigate the functional expression of β3-adrenoceptors (β3-ARs) in equine digital veins (EDVs) and to examine whether β3-AR relaxation was altered in EDVs incubated with endotoxin.

Sample Population—Forelimbs obtained from 30 horses.

Procedure—Forelimbs were obtained from horses in an abattoir. Equine digital veins were carefully removed from distal portions of the forelimbs. Rings of dissected EDVs were mounted in 5-mL organ baths to record isometric tension in the presence of various β3-AR agonists (SR 58611A, ZD 2079, and ZM 215001).

Results—In intact EDVs, isoprenaline, SR 58611A, ZD 2079, and ZM 215001 induced concentrationdependent relaxation. Isoprenaline and SR 58611Ainduced relaxations were reduced or unaffected by nadolol, respectively. In intact EDVs, SR 58611Ainduced relaxation was significantly reduced in the presence of 2µM ZM 215001 (used as a β3-AR antagonist). In endothelium-denuded EDVs or intact EDVs in the presence of a nitric oxide synthase inhibitor, isoprenaline and SR 58611A-induced relaxations were significantly decreased. The endothelium-independent relaxation to SR 58611A was significantly inhibited in the presence of ZM 215001. In endotoxin-treated EDV, isoprenaline- and SR 58611A-induced relaxations were significantly reduced. In these conditions, cycloheximide (a protein synthesis inhibitor) and ibuprofen (a cyclooxygenase inhibitor) restored the relaxant response to SR 58611A.

Conclusions and Clinical Relevance—β3-Adrenoceptors are functionally expressed in EDVs. Incubation in the presence of endotoxin, used as an in vitro model of laminitis, induced an alteration of β-ARmediated relaxations in EDVs, which could be the consequence of cyclooxygenase induction and subsequent prostanoid production. (Am J Vet Res2003;64:708–714)
Correlation of ultrasonographic observations with anatomic features and radiography of the elbow joint in dogs
Authors: Knox Van W. , Sehgal Chandra M. , Wood Andrew K. W.
Published: January 2006

Objective—To define the ultrasonographic appearance of the elbow joint of dogs and to develop an ultrasonographic imaging protocol to reliably accomplish complete evaluation of that joint.

Animals—11 clinically normal mixed-breed dogs.

Procedure—Ultrasonographic observations (by use of a 5 to 10 MHz linear array probe) were made of 22 elbow joints in cadaveric forelimbs from clinically normal dogs. Images in standard anatomic planes were recorded with a multi-image camera, on videotape, or onto a computer. The anatomic plane of the ultrasonographic beam and position of the ultrasonographic probe were also recorded. Dissection of each elbow joint was performed, and anatomic features were correlated with ultrasonographic images.

Results—Structures clearly identified ultrasonographically included the lateral and medial humeral epicondyles, the humeroradial and humeroulnar joints, anconeal process, medial coronoid process, hyaline cartilage covering the proximal articular surface of the radius, collateral ligaments, tendons of triceps brachii and supinator muscles, and the supinator tendon and sesamoid in the supinator cartilage. An ultrasonographic imaging protocol for examination of the elbow joint was developed.

Conclusions and Clinical Relevance—Precise correlations were established between the gross anatomic appearance of the elbow joint and the ultrasonographic images of its component structures. The ultrasonographic imaging protocol will enable complete examination of all regions of the joint for detection of pathologic lesions. (Am J Vet Res2003;64:721–726)
Evaluation of ground reaction forces produced by chickens walking on a force plate
Authors: Corr Sandra A. , McCorquodale Caroline C. , McGovern Rod E. , Gentle Mike J. , Bennett David
Published: January 2006

Objective—To evaluate the use of a force plate as a method for objective gait analysis in adult poultry, to characterize ground reaction forces (GRFs) produced in adult chickens during normal walking, and to assess the variability of GRFs.

Animals—18 clinically normal 5-month-old Brown Leghorn hens

Procedure—Vertical, craniocaudal, and mediolateral GRFs were measured as hens walked across a standard force plate embedded in the middle of a runway.

Results—All GRFs were significantly affected by speed, and variability was high. With increasing speed, overall stance time decreased, but the percentage of stance time spent in braking or propulsion remained approximately equal. There was an overall increase in maximum propulsion force, which was produced at a greater rate over a shorter time; thus, propulsion integral decreased. Maximum braking forces and braking integrals were variable, but the rate at which the forces were generated increased. Mediolateral forces were 2 to 3 times greater in hens than values that have been reported for other species.

Conclusion and Clinical Relevance—A standard force plate can be used to objectively measure GRFs in walking adult hens; however, the large variation in the data suggests that the technique in its current form would be of limited clinical use. Overall, vertical and craniocaudal forces had similar characteristics to those of other species, whereas mediolateral forces were found to be much greater in chickens than for other species. (Am J Vet Res2003;64:76–82)
Differentiation of strains of equine arteritis virus of differing virulence to horses by growth in equine endothelial cells
Authors: Moore Brian D. , Balasuriya Udeni B. R. , Nurton Jane P. , McCollum William H. , Timoney Peter J. , Guthrie Alan J. , MacLachlan N. James
Published: January 2006

Objective—To compare growth characteristics of
strains of equine arteritis virus (EAV) of differing virulence
to horses in rabbit kidney (RK)-13 cells and
equine endothelial cells (EECs) cultured from the pulmonary
artery of a foal.

Sample Population—13 strains of EAV, including 11
field isolates of differing virulence to horses; the highly
virulent, horse-adapted Bucyrus strain; and the
modified-live virus (MLV) vaccine derived from it.

Procedure—The growth characteristics of the 13
strains were compared in EECs and RK-13 cells. Viral
nucleoprotein expression, cytopathogenicity, and
plaque size were compared to determine whether
growth characteristics of the 13 strains were predictive
of their virulence to horses.

Results—Cytopathogenicity, viral nucleoprotein
expression, and plaque size induced by all 13 viruses
were similar in RK-13 cells, whereas virulent strains of
EAV caused significantly larger plaques in EECs than
did the avirulent strains of EAV. Paradoxically, the
highly attenuated MLV vaccine and 1 field isolate of
EAV caused plaques in EECs that were larger than
those caused by any of the other viruses, and
sequence analysis confirmed the field isolate of EAV
to be indistinguishable from the MLV vaccine.

Conclusions and Clinical Relevance—With the
notable exception of the MLV vaccine, growth of the
various strains of EAV in EECs was predictive of their
individual virulence to horses. Thus, EECs provide a
relevant and useful model to further characterize
determinants of virulence and attenuation amongst
strains of EAV. (Am J Vet Res 2003;64:779–784)
Effects of pico-tesla electromagnetic field treatment on wound healing in rats
Authors: Trostel C. Todd , McLaughlin Ron M. , Lamberth John G. , Cooper Robert C. , Elder Steven H. , Pool Roy R. , Gao Cheng , Cromiak Joseph A. , Boyle Carolyn R.
Published: January 2006

Objective—To evaluate the effects of a pico-tesla electromagnetic field (PTEF) on healing of sutured and open skin wounds and clinicopathologic variables in rats.

Animals—64 male Fischer-344 rats.

Procedure—An incision made in the dorsal aspect of the neck was sutured (n = 32) or left open to heal (32). In each group, 16 rats were not PTEF-treated (controls). Wound treatment consisted of exposure to a PTEF once daily. Rats in each group were euthanatized at days 2, 4, 7, and 14. Wounds were evaluated via tensiometry (sutured wounds), digital planimetry (open wounds), laser Doppler perfusion imaging, bacteriologic culture, and histologic examination. Blood samples were collected from all rats for analysis.

Results—At day 14, sutured wounds in PTEF-treated rats were stronger (ultimate stress) and tougher (strain energy) than were sutured wounds in control rats. Open wounds in PTEF-treated rats contracted more quickly at days 2 and 4 than did those in control rats. Compared with control wounds, histologic changes (indicative of improved healing) in sutured and open wounds in PTEF-treated rats were detected as early as day 4. Laser Doppler perfusion measurements, results of CBCs, serum biochemical analyses, and bacteriologic cultures were not different between groups.

Conclusions and Clinical Relevance—Exposure to the PTEF caused no adverse effects on clinicopathologic, histologic, or bacteriologic variables tested in this study. It appears that PTEF is a safe form of adjuvant treatment for wounds and improves strength of sutured wounds and speeds contraction of open wounds. (Am J Vet Res2003;64:845–854)