bluuebunny/crossref_metadata_2025 huggingface dataset:
Diversity of Salmonella serovars in feedyard and nonfeedyard playas of the Southern High Plains in the summer and winter
Authors: Purdy Charles W. , Straus David C. , Clark R. Nolan
Published: December 2005

Objective—To compareSalmonellaisolates cultured from feedyard and nonfeedyard (control) playas (ie, temporary shallow lakes) of the Southern High Plains.

Sample Population—Water and muck (sediment) samples were obtained from 7 feedyard playas and 3 nonfeedyard playas in the winter and summer.

Procedure—Each water and muck sample was enriched with sulfur-brilliant-green broth and incubated in a shaker at 37°C for 24 hours. A sample (100 mL) of the incubated bacterial-enriched broth was then mixed with 100 mL of fresh sulfur-brilliant-green enrichment broth and incubated in a shaker at 37°C for 24 hours. After the second incubation, a swab sample was streaked on differential media. SuspectSalmonellaisolates were further identified by use of biochemical tests, and Salmonella isolates were confirmed and serovar determinations made.

Results—Salmonellaisolates were not recovered from the 3 control playas. SevenSalmonellaenterica serovars were isolated from 5 of 7 feedyard playas in the summer, and 13 S enterica serovars were isolated from 7 of 7 feedyard playas in the winter. In the summer, 296 isolates were cultured, and 47 wereSalmonellaorganisms. In the winter, 288 isolates were cultured, and 171 wereSalmonellaorganisms.

Conclusions and Clinical Relevance—Results indicated that feedyard playas are frequently contaminated with manySalmonellaserovars. These pathogens should be considered whenever feedyard managers contemplate the use of water from these playas. Water from feedyard playas should not be used to cool cattle in the summer or for dust abatement. (Am J Vet Res2004;65:40–44)
Vasopressin secretion in response to osmotic stimulation and effects of desmopressin on urinary concentrating capacity in dogs with pyometra
Authors: Heiene Reidun , Vonderen Ilse K. van , Moe Lars , Mølmen Guro S. , Larsen Nina H. , Kooistra Hans S.
Published: December 2005

Objective—To determine vasopressin (VP) secretory
capacity during osmotic stimulation and the response
to desmopressin treatment in dogs with pyometra
and control dogs.

Animals—6 dogs with pyometra before and after
ovariohysterectomy and 6 control dogs.

Procedure—Urine osmolality (Uosm) was measured
during 12 hours. Values measured on the first day
defined the basal Uosm pattern. On the second day,
dogs were given desmopressin to induce a desmopressin-stimulated Uosm pattern. On day 3, the VP
response to osmotic stimulation was examined.

Results—Median Uosm on day 1 was 340 mOsm/kg
(range, 104 to 1,273 mOsm/kg) and 807 mOsm/kg
(range, 362 to 1,688 mOsm/kg) in dogs with pyometra
before and after surgery, respectively, and 1,511
mOsm/kg (range, 830 to 1,674 mOsm/kg) in control
dogs. Median Uosm during desmopressin treatment
was 431 mOsm/kg (range, 168 to 1,491 mOsm/kg)
and 1,051 mOsm/kg (range, 489 to 1,051 mOsm/kg) in
dogs with pyometra before and after surgery, respectively,
and 1,563 mOsm/kg (range, 1,390 to 2,351) in
control dogs. In dogs with pyometra, threshold for VP
secretion was lower before surgery (median, 340
mOsm/kg; range, 331 to 366 mOsm/kg) than after
surgery (median, 358 mOsm/kg; range, 343 to 439
mOsm/kg) or in control dogs (median, 347 mOsm/kg;
range, 334 to 360 mOsm/kg). Highest maximum plasma
VP values were found in dogs with pyometra.

Conclusions and Clinical Relevance—Dogs with
pyometra had increased urine concentration in
response to desmopressin but not to the degree of
control dogs, whereas VP secretory ability was not
reduced. (Am J Vet Res 2004;65:404–408)
Validation of diagnostic tests for determination of magnesium status in horses with reduced magnesium intake
Authors: Stewart Allison J. , Hardy Joanne , Kohn Catherine W. , Toribio Ramiro E. , Hinchcliff Kenneth W. , Silver Burton
Published: December 2005

Objective—To evaluate the diagnostic value of serum concentrations of total magnesium (tMg) and ionized magnesium (iMg), concentrations of magnesium (Mg) in muscle, intracellular Mg (icMg) concentrations, urinary Mg excretion (EMg), Mg clearance (CMg), and fractional clearance of Mg (FCMg) in horses fed diets with Mg content above and below National Research Council recommendations.

Animals—9 young female horses.

Procedures—6 horses were fed a reduced-Mg diet for 29 days followed by an Mg-supplemented diet for 24 days. Control horses (n = 3) were fed grass hay exclusively. Blood, urine, and tissue samples were collected, and an Mg retention test was performed before and after restriction and supplementation of Mg intake. Serum tMg, serum iMg, muscle Mg, icMg, and urine Mg concentrations were measured, and 24-hour EMg, CMg, and FCMgwere calculated.

Results—Reductions in urinary 24-hour EMg, CMg, and FCMgwere evident after 13 days of feeding a reduced-Mg diet. Serum tMg and iMg concentrations, muscle Mg content, and results of the Mg retention test were not affected by feeding the Mg-deficient diet. Spot urine sample FCMgaccurately reflected FCMgcalculated from 6- and 24-hour pooled urine samples. Mean ± SD FCtMgof horses eating grass hay was 29 ± 8%, whereas mean FCtMgfor horses fed a reduced-Mg diet for 29 days was 6 ± 3%.

Conclusions and Clinical Relevance—The 24-hour EMgwas the most sensitive indicator of reduced Mg intake in horses. Spot sample FCMgcan be conveniently used to identify horses consuming a diet deficient in Mg. (Am J Vet Res2004;65:422–430)
Antiretroviral efficacy of a 98% solution of glycerol or ethylene oxide for inactivation of feline leukemia virus in bone
Authors: Coronado George S. , Swenson Cheryl L.
Published: December 2005

Objective—To determine whether infectious retrovirus was inactivated in bones from FeLV-infected cats after ethylene oxide (ETO) sterilization or preservation in a 98% solution of glycerol in an in vitro cell culture system.

Sample Population—Metatarsal bones obtained from 5 FeLV-infected cats and cultured with feline fibroblast cells.

Procedure—Metatarsal bones were treated with 100% ETO, a 98% solution of glycerol, or left untreated. Twenty-five flasks of feline fibroblast cells were assigned to 5 groups: negative control, positive control, ETO-treated bone, glycerol-treated bone, and untreated bone with 5 replicates/group for 4 passages. Media and cell samples were harvested from every flask at each passage to measure FeLV p27 antigen and the number of copies of provirus per 100 ng of DNA, respectively.

Results—All negative control and ETO-treated group replicates were negative for FeLV p27 antigen and provirus throughout the study. All positive control group replicates were positive for FeLV p27 antigen and provirus at passages 1 to 4. Untreated bone group replicates were positive for FeLV p27 antigen at passages 3 and 4 and provirus beginning at passage 2. Glycerol-treated group replicates had delayed cell replication and were negative for FeLV p27 antigen and provirus at passages 1 to 4 and 2 to 4, respectively.

Conclusions and Clinical Relevance—Ethylene oxide sterilization of bone from FeLV-infected cats appeared to abrogate transmission of infectious retrovirus and effectively sterilized bone allografts.

Impact for Human Medicine—Additional studies to confirm effectiveness of ETO treatment of allograft tissues for prevention of pathogen transmission via transplantation are warranted. (Am J Vet Res2004;65:436–439)
Assessment of erythrocyte morphologic abnormalities in mallards with experimentally induced zinc toxicosis
Authors: Christopher Mary M. , Shooshtari Mahrokh P. , Levengood Jeffrey M.
Published: December 2005

Objective—To describe and quantify morphologic abnormalities in RBCs of mallards (Anas platyrhynchos) with experimentally induced zinc toxicosis.

Animals—120 female mallards.

Procedure—Farm-raised mallards (6 to 8 months old) were used in the study. On day 0, 60 ducks received shot pellets orally by gavage (mean dose of zinc, 0.97 g); another 60 ducks underwent the same procedure without administration of pellets. On day 15, Romanowsky-stained blood smears were prepared from 53 control and 45 zinc-treated ducks (smears were examined retrospectively). In each smear, 200 RBCs were examined and numbers of erythrocytes with abnormal size, shape, or color were expressed as a percentage. Results were compared with PCV values and zinc dose.

Results—Mean PCV value was lower in all zinc-treated ducks, compared with control ducks, and was lower in zinc-treated ducks that died or were euthanatized before day 30 because of severe clinical disease, compared with those that survived. Zinc-treated ducks that survived had a high percentage of polychromatophilic RBCs, and those that that died before day 30 had high percentages of hypochromic RBCs, fusiform RBCs, and RBC nuclear abnormalities. There was no correlation between PCV value or RBC morphologic abnormalities and dose of zinc.

Conclusions and Clinical Relevance—In ducks with severe zinc-induced hemolysis, findings indicated that functional iron deficiency may impair the effectiveness of the erythroid regenerative response and contribute to death. Erythrocyte nuclear abnormalities were consistent with mild dyserythropoiesis. These findings may be applicable to effects of other metal toxicoses and regenerative anemias in birds. (Am J Vet Res2004;65:440–446)
Comparison of the type and number of microorganisms and concentration of endotoxin in the air of feedyards in the Southern High Plains
Authors: Purdy Charles W. , Straus David C. , Parker David B. , Wilson Stephen C. , Clark R. Nolan
Published: December 2005

Objective—To determine the bacterial, fungal, and
endotoxin concentrations in aerosolized ambient air
during the winter and summer in feedyards located in
the Southern High Plains, identify aerosolized microbial
pathogens, and determine the size of microbial
and dust components.

Sample Population—Aerosol samples were
obtained from 7 feedyards.

Procedure—Aerosol samples were collected upwind,
on-site, and downwind from each feedyard at a point
1 m above the ground by use of biological 2- and 6-
stage cascade impactors.

Results—Significantly more microbes were cultured
from on-site and downwind samples than upwind
samples. There were significantly more microbes during
the summer than during the winter. However,
mean endotoxin concentration was significantly higher
during the winter (8.37 ng/m3) than the summer
(2.63 ng/m3). Among 7 feedyards, mean ± SE number
of mesophilic bacteria (1,441 ± 195 colony-forming
units [CFUs]/m3) was significantly higher than mean
number of anaerobic bacteria (751 ± 133 CFUs/m3) or
thermophilic bacteria (54 ± 10 CFUs/m3) in feedyard
air. Feedyard aerosol samples contained more
mesophilic fungi (78 ± 7 CFUs/m3) than thermophilic
fungi (2 ± 0.2 CFUs/m3). Eighteen genera of bacteria
were identified by use of an automated identification
system.

Conclusions and Clinical Relevance—It appeared
that gram-negative enteric pathogens offered little
risk to remote calves or humans via ambient aerosols
and that gram-positive pathogens of the Bacillus,
Corynebacterium, and Staphylococcus spp can be
spread by aerosols in and around feedyards. It was
common to detect concentrations of endotoxin in the
ambient air of 7 feedyards. ( Am J Vet Res 2004;
65:45–52)
Effects of glycopyrrolate on cardiorespiratory function in horses anesthetized with halothane and xylazine
Authors: Neto Francisco J. Teixeira , McDonell Wayne N. , Black William D. , Duronghphongtorn Sumit
Published: December 2005

Objective—To evaluate cardiopulmonary effects of glycopyrrolate in horses anesthetized with halothane and xylazine.

Animals—6 horses.

Procedure—Horses were allocated to 2 treatment groups in a randomized complete block design. Anesthesia was maintained in mechanically ventilated horses by administration of halothane (1% end-tidal concentration) combined with a constant-rate infusion of xylazine hydrochloride (1 mg/kg/h, IV). Hemodynamic variables were monitored after induction of anesthesia and for 120 minutes after administration of glycopyrrolate or saline (0.9% NaCl) solution. Glycopyrrolate (2.5 µg/kg, IV) was administered at 10-minute intervals until heart rate (HR) increased at least 30% above baseline or a maximum cumulative dose of 7.5 µg/kg had been injected. Recovery characteristics and intestinal auscultation scores were evaluated for 24 hours after the end of anesthesia.

Results—Cumulative dose of glycopyrrolate administered to 5 horses was 5 µg/kg, whereas 1 horse received 7.5 µg/kg. The positive chronotropic effects of glycopyrrolate were accompanied by an increase in cardiac output, arterial blood pressure, and tissue oxygen delivery. Whereas HR increased by 53% above baseline values at 20 minutes after the last glycopyrrolate injection, cardiac output and mean arterial pressure increased by 38% and 31%, respectively. Glycopyrrolate administration was associated with impaction of the large colon in 1 horse and low intestinal auscultation scores lasting 24 hours in 3 horses.

Conclusions and Clinical Relevance—The positive chronotropic effects of glycopyrrolate resulted in improvement of hemodynamic function in horses anesthetized with halothane and xylazine. However, prolonged intestinal stasis and colic may limit its use during anesthesia. (Am J Vet Res2004;65:456–463)
Pharmacokinetics of a high dose of amikacin administered at extended intervals to neonatal foals
Authors: Magdesian K. Gary , Wilson W. David , Mihalyi Judy
Published: December 2005

Objective—To determine disposition kinetics of amikacin in neonatal foals administered high doses at extended intervals.

Animals—7 neonatal foals.

Procedure—Amikacin was administered (21 mg/kg, IV, q 24 h) for 10 days. On days 1, 5, and 10, serial plasma samples were obtained for measurement of amikacin concentrations and determination of pharmacokinetics.

Results—Mean ± SD peak plasma concentrations of amikacin extrapolated to time 0 were 103.1 ± 23.4, 102.9 ± 9.8, and 120.7 ± 17.9 µg/mL on days 1, 5, and 10, respectively. Plasma concentrations at 1 hour were 37.5 ± 6.7, 32.9 ± 2.6, and 30.6 ± 3.5 µg/mL; area under the curve (AUC) was 293.0 ± 61.0, 202.3 ± 40.4, and 180.9 ± 31.2 (µg · h)/mL; elimination half-life (t1/2β) was 5.33, 4.08, and 3.85 hours; and clearance was 1.3 ± 0.3, 1.8 ± 0.4, and 2.0 ± 0.3 mL/(min · kg), respectively. There were significant increases in clearance and decreases in t1/2β, AUC, mean residence time, and plasma concentrations of amikacin at 1, 4, 8, 12, and 24 hours as foals matured.

Conclusions and Clinical Relevance—Once-daily administration of high doses of amikacin to foals resulted in high peak plasma amikacin concentrations, high 1-hour peak concentrations, and large values for AUC, consistent with potentially enhanced bactericidal activity. Age-related findings suggested maturation of renal function during the first 10 days after birth, reflected in enhanced clearance of amikacin. High-dose, extended-interval dosing regimens of amikacin in neonatal foals appear rational, although clinical use remains to be confirmed. (Am J Vet Res2004;65:473–479)
In vitro effects of oxytetracycline on matrix metalloproteinase-1 mRNA expression and on collagen gel contraction by cultured myofibroblasts obtained from the accessory ligament of foals
Authors: Arnoczky Steven P. , Lavagnino Michael , Gardner Keri L. , Tian Tao , Vaupel Zachary M. , Stick John A.
Published: December 2005

Objective—To determine the effects of oxytetracycline on matrix metalloproteinase-1 (MMP-1) mRNA expression and collagen gel contraction by equine myofibroblasts in an effort to explain the mechanistic basis for the pharmacologic treatment of flexural deformities in foals.

Sample Population—Cultured myofibroblasts from the accessory ligament (distal check ligament) of 6 foals.

Procedure—Collagen gel scaffolds seeded with equine myofibroblasts were cultured in individual culture dishes containing complete media (Dulbecco's modified Eagle medium with 10% fetal bovine serum) and oxytetracycline (0, 12.5, 25, or 75 µg/mL) for 48 hours. After 24 hours, the gels were released from the bottom of the culture plate and allowed to contract. Photographs were taken at 0, 1, 2, 4, 6, 8, and 24 hours after release to assess the degree of collagen gel contraction. Additional gels were harvested at 2 hours after release for RNA isolation and reverse transcriptase-polymerase chain reaction assessment of the degree of MMP-1 mRNA expression.

Results—Oxytetracycline induced a dose-dependent inhibition of collagen gel contraction by equine myofibroblasts. Oxytetracycline also induced a dose-dependent decrease in MMP-1 mRNA expression by equine myofibroblasts.

Conclusions and Clinical Relevance—Results of this study indicate that oxytetracycline inhibits tractional structuring of collagen fibrils by equine myofibroblasts through an MMP-1 mediated mechanism. In young foals, oxytetracycline administration may make the developing ligaments and tendons more susceptible to elongation during normal weight-bearing. Inhibition of normal collagen organization may provide the mechanistic explanation for the results seen following the pharmacologic treatment of flexural deformities in foals by oxytetracycline administration. (Am J Vet Res2004;65:491–496)
Assessment of a caudal external thoracic artery axial pattern flap for treatment of sternal cutaneous wounds in birds
Authors: Ferrell Shannon T. , Cock Hilde E.V. De , Graham Jennifer E. , Kass Philip H. , Tell Lisa A.
Published: December 2005

Objective—To assess the use of a caudal external thoracic artery axial pattern flap to treat sternal cutaneous wounds in birds.

Animals—16 adult Japanese quail.

Procedure—A cutaneous defect in the region of the mid-sternum was surgically created in all quail. In 6 quail (group I), an axial pattern flap was created from the skin of the lateral aspect of the thorax and advanced over the sternal defect. In 8 quail (group II), a flap was similarly created and advanced but the flap vasculature was ligated. All quail were euthanatized at 14 days after surgery and had necropsies performed. Sections of the flap and the surrounding tissue were examined histologically to assess flap viability.

Results—All axial pattern flaps in group-I quail had 100% survival. In group II, mean percentage area of flap survival was 62.5%; mean area of necrosis and dermal fibrosis of flaps were significantly greater than that detected in group I. In flaps of group-II quail, neovascularization in the deep dermis and profound necrosis of the vascular plexus in the superficial dermis were observed.

Conclusions and Clinical Relevance—Results indicated that the caudal external thoracic artery axial pattern flap could be used successfully in the treatment of surgically created sternal cutaneous defects in quail with no signs of tissue necrosis or adverse effects overall. Use of this technique to treat selfmutilation syndromes or application after surgical debulking of tumors or other masses might be beneficial in many avian species. (Am J Vet Res2004;65:497–502)
In vitro effects and in vivo efficacy of a novel cyclooxygenase-2 inhibitor in dogs with experimentally induced synovitis
Authors: McCann Margaret E. , Andersen Donald R. , Zhang Donghui , Brideau Christine , Black W. Cameron , Hanson Peter D. , Hickey Gerard J.
Published: December 2005

Objective—To determine cyclooxygenase-2 (COX-2) selectivity, pharmacokinetic properties, and in vivo efficacy of ML-1,785,713 in dogs.

Animals—21 healthy male and female mixed-breed dogs and 24 healthy male Beagles.

Procedure—Selectivity of ML-1,785,713 for inhibiting COX-2 was determined by comparing the potency for inhibiting cyclooxygenase-1 (COX-1) with that of COX-2 in canine blood. Pharmacokinetic properties were determined after IV (2 mg/kg) and oral (8 mg/kg) administration in female mixed-breed dogs. In vivo efficacy was evaluated in male mixed-breed dogs with urate crystal-induced synovitis. Prophylactic efficacy was evaluated by administering ML-1,785,713 two hours before induction of synovitis whereas therapeutic efficacy was determined by administering ML-1,785,713 one hour after induction of synovitis.

Results—Blood concentrations that resulted in 50% inhibition of COX-1 and COX-2 activity in vitro were 119.1µM and 0.31µM, respectively, and selectivity ratio for inhibiting COX-2 relative to COX-1 was 384. ML-1,785,713 had high oral bioavailability (101%), low systemic clearance (7.7 mL/min/kg), and an elimination half-life of 5.9 hours. ML-1,785,713 was efficacious when administered prophylactically and therapeutically to dogs with urate crystal-induced synovitis.

Conclusions and Clinical Relevance—ML-1,785,713 is a novel, potent COX-2 inhibitor that is the most selective COX-2 inhibitor described for use in dogs to date. ML-1,785,713 has oral bioavailability and low systemic clearance that is comparable to other nonsteroidal anti-inflammatory drugs. It is effective after prophylactic and therapeutic administration in attenuating lameness in dogs with urate crystal-induced synovitis. Drugs that specifically inhibit COX-2 and not COX-1 at therapeutic doses may have an improved tolerability profile, compared with nonselective nonsteroidal anti-inflammatory drugs. (Am J Vet Res2004;65:503–512)
Cloning and sequencing of the canine and feline cardiac troponin I genes
Authors: Rishniw Mark , Barr Stephen C. , Simpson Kenny W. , Winand Nena J. , Wootton Joyce A.M.
Published: December 2005

Objective—To determine the gene sequences of
canine and feline cardiac troponin I (cTnI), express the
protein from the cloned gene in vitro, and validate the
use of a commercial cTnI serum analyzer in these
species via detection of the expressed protein or
comparison of sequence homology.

Sample Population—Samples of ventricular
myocardium from 5 healthy adult mixed-breed dogs
and 5 healthy adult domestic shorthair cats.

Procedure—The RNA was extracted from myocardial
samples, and cDNA was synthesized via reverse transcriptase
polymerase chain reaction and sequenced.
The canine cDNA for the coding region was
expressed in cell culture and analyzed by western blot
and sandwich enzyme-linked immunosorbent assays.

Results—Canine and feline cTnI genes were cloned
and sequenced. Homology of the nucleotide and
amino acid sequences of the canine and feline cTnI
genes with human and rodent cTnI genes were high;
the greatest homology was detected between canine
and feline genes (95% and 96%, respectively).
Recombinant canine cTnI protein was detected by a
commercial serum cTnI analyzer and by western blot
analysis.

Conclusions and Clinical Relevance—Results indicated
that commercial cTnI analyzers can be used to
measure serum cTnI concentration from dogs and
cats. Additionally, our preliminary characterization of
the feline cTnI gene may facilitate further investigation
of cTnI and its role in familial hypertrophic cardiomyopathy
in cats. ( Am J Vet Res 2004;65:53–58)
Three-dimensional motion pattern of the caudal lumbar and lumbosacral portions of the vertebral column of dogs
Authors: Benninger Monika I. , Seiler Gabriela S. , Robinson Leanne E. , Ferguson Stephen J. , Bonél Harald M. , Busato André R. , Lang Johann
Published: December 2005

Objective—To evaluate the 3-dimensional motion pattern including main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column of dogs.

Animals—Vertebral columns of 9 German Shepherd Dogs (GSDs) and 16 dogs of other breeds with similar body weights and body conditions .

Procedure—Main and coupled motions of the caudal lumbar and lumbosacral portions of the vertebral column (L4 to S1) were determined by use of a testing apparatus that permitted precise application of known pure moments to the vertebral column. Motion was compared between GSDs and dogs of other breeds.

Results—All specimens had a similar motion pattern consisting of main motion and a certain amount of coupled motion including translation. Vertebral columns of GSDs had significantly less main motion in all directions than that of dogs of other breeds. Translation was similar in GSDs and dogs of other breeds and was smallest at the lumbosacral motion segment.

Conclusions and Clinical Relevance—Results indicated that motion in the caudal lumbar and lumbosacral portions of the vertebral column of dogs is complex and provided a basis for further studies evaluating abnormal vertebral columns. (Am J Vet Res2004;65:544–552)
Histomorphologic and morphometric evaluation of the uterine horns in nulliparous and multiparous Beagles
Authors: Augsburger Heinz R. , Kürzi Marcel
Published: December 2005

Objective—To macroscopically, histomorphologically,
and morphometrically compare uterine tissues
obtained from nulliparous and multiparous dogs.

Animals—12 dogs constituting 2 homogenous
groups (7 nulliparous Beagles and 5 multiparous
Beagles, each of which had at least 7 pregnancies).

Procedure—Serum concentrations of progesterone
and estradiol-17β were determined. Samples of uterine
tissues were fixed, embedded in paraffin, and cut
into serial cross sections. Morphometric analysis was
performed on systematically selected trichromestained
sections.

Results—Mean absolute volume of the uterine wall
did not differ between groups. Volume of blood vessels
was significantly higher and relative mean value
for myometrial connective tissue was significantly
lower in the multiparous dogs. Arteries in the
myometrium of multiparous dogs had pronounced
thickening of the intima (ie, pregnancy sclerosis) and
a concomitant thinning of the smooth muscle layer
(tunica media). Furthermore, the elastica interna of
these arteries appeared to be disintegrating and was
highly and irregularly folded. Adventitia of the myometrial
veins in multiparous dogs contained numerous
layers of elastic fibers; however, only a few layers
were observed in the adventitia of corresponding
veins in nulliparous dogs.

Conclusions and Clinical Relevance—In this study,
we documented that in contrast to other species, the
uterus of nonpregnant dogs does not increase in size
and volume even after at least 7 pregnancies.
Furthermore, sclerotic alterations of uterine arteries
are proof of at least 1 pregnancy. Results of this study
may be useful in the evaluation of uterine diseases.
( Am J Vet Res 2004;65:552–558)
Quantification, repeatability, and reproducibility of feline radial and longitudinal left ventricular velocities by tissue Doppler imaging
Authors: Chetboul Valérie , Athanassiadis Nicolas , Carlos Carolina , Nicolle Audrey P. , Tissier Renaud , Pouchelon Jean-Louis , Concordet Didier , Lefebvre Hervé P.
Published: December 2005

Objective—To measure the radial and longitudinal velocities of several myocardial segments of the left ventricular wall by use of tissue Doppler imaging (TDI) in healthy cats and determine the repeatability and reproducibility of the technique.

Animals—6 healthy cats.

Procedure—72 TDI examinations were performed on 4 days by the same trained observer. Radial parameters included left endocardial and epicardial myocardial velocities. Longitudinal parameters included left basal, middle, and apical myocardial velocities.

Results—All velocity profiles had 1 positive systolic wave (S) and 2 negative diastolic waves (E and A). Myocardial velocities were higher in the endocardial than epicardial segments during the entire cardiac cycle (systolic wave S, 4.4 ± 0.82 and 1.9 ± 0.55; diastolic wave E, 9.7 ± 1.70 and 2.2 ± 0.74; and diastolic wave A, 5.1 ± 1.56 and 1.4 ± 0.76, respectively). Velocities were also higher in the basal than in the apical segments (systolic wave S, 4.7 ± 0.76 and 0.2 ± 0.11; diastolic wave E, 9.7 ± 1.36 and 0.5 ± 0.17; and diastolic wave A, 3.7 ± 1.51 and 0.2 ± 0.13, respectively). The lowest within-day and between-day coefficients of variation were observed in endocardial segments (8.2% and 6.5% for systolic wave S and diastolic wave E, respectively) and in the basal segment in protodiastole (5.5%).

Conclusions and Clinical Relevance—Repeatability and reproducibility of TDI were adequate for measurement of longitudinal and radial left ventricular motion in healthy awake cats. Validation of TDI is a prerequisite before this new technique can be recommended for clinical use. (Am J Vet Res2004; 65:566–572)
Assessment of apoptosis in epidermal lamellar cells in clinically normal horses and those with laminitis
Authors: Faleiros Rafael R. , Stokes Ashley M. , Eades Susan C. , Kim Dae Young , Paulsen Daniel B. , Moore Rustin M.
Published: December 2005

Objective—To determine and compare the number, type, location, and distribution of apoptotic epidermal cells in the laminae of clinically normal horses and horses with laminitis.

Sample Population—Formalin-fixed samples of digital lamellar tissue from 47 horses (including clinically normal horses [controls; n = 7], horses with acute [4] and chronic [7] naturally acquired laminitis, and horses with black walnut extract-induced [11] or carbohydrate overload-induced [18] laminitis).

Procedure—Blocks of paraffin-embedded lamellar tissues were stained for DNA fragmentation with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. Differential immunohistochemical staining for caspases 3 and 14 were used to confirm apoptosis.

Results—The number of TUNEL-positive epidermal cells per 0.1 mm of primary laminae was significantly greater in the acute laminitis group than in the other groups. In the acute laminitis group, there were 17 and 1,025 times as many TUNEL-positive basal layer cells and keratinocytes, respectively, compared with the control group. Apoptosis of TUNEL-positive basal layer cells was confirmed by results of caspase 3 immunohistochemical staining. The TUNEL-positive keratinocytes did not stain for caspases 3 or 14.

Conclusions and Clinical Relevance—The large number of apoptotic basal layer cells detected in the lamellar tissue of horses with acute naturally acquired laminitis suggests that apoptosis may be important in the development of acute laminitis. The role of the large number of TUNEL-positive keratinocytes detected in the interface of primary and secondary epidermal laminae of horses with acute laminitis remains to be elucidated. (Am J Vet Res2004;65:578–585)
Effect of dietary soy on serum thyroid hormone concentrations in healthy adult cats
Authors: White Heidi L. , Freeman Lisa M. , Mahony Orla , Graham, Peter A. , Hao Qin , Court Michael H.
Published: December 2005

Objective—To compare effects of short-term administration of a soy diet with those of a soy-free diet on serum thyroid hormone concentrations in healthy adult cats.

Animals—18 healthy adult cats.

Procedure—Cats were randomly assigned to receive either a soy or soy-free diet for 3 months each in a crossover design. Assays included CBC, serum biochemical profile, thyroid hormone analysis, and measurement of urinary isoflavone concentrations.

Results—Genistein, a major soy isoflavone, was identified in the urine of 10 of 18 cats prior to dietary intervention. Compared with the soy-free diet, cats that received the soy diet had significantly higher total thyroxine (T4) and free T4(fT4) concentrations, but unchanged total triiodothyronine (T3) concentrations. The T3/fT4ratio was also significantly lower in cats that received the soy diet. Although the magnitudes of the increases were small (8% for T4and 14% for fT4), these changes resulted in an increased proportion of cats (from 1/18 to 4/18) that had fT4values greater than the upper limit of the laboratory reference range. There was no significant effect of diet on any other measured parameter.

Conclusions and Clinical Relevance—Short-term administration of dietary soy has a measurable although modest effect on thyroid hormone homeostasis in cats. Increase in T4concentration relative to T3concentration may result from inhibition of 5'-iodothyronine deiodinase or enhanced T3clearance. Soy is a common dietary component that increases serum T4concentration in cats. (Am J Vet Res2004; 65:586–591)
Evaluation of leukocyte cell surface markers in dogs with septic and nonseptic inflammatory diseases
Authors: Weiss Douglas J. , Welle Molly , Mortiz Andreas , Walcheck Bruce
Published: December 2005

Objective—To determine whether functional alterations in neutrophils and mononuclear leukocytes are a consistent finding in dogs with inflammatory disease.

Animals—40 healthy dogs, 30 dogs with nonseptic inflammatory diseases, 25 dogs with septic inflammation, and 8 dogs with multiple organ dysfunction syndrome (MODS) secondary to sepsis.

Procedure—Neutrophil size and granularity; expression of cell surface molecules including CD18, CD11b, and mature neutrophil antigen on neutrophils; and major histocompatability antigen class II (MHC class II) expression on monocytes and lymphocytes were evaluated by use of flow cytometry. Neutrophil size and granularity were evaluated by use of forwardangle versus side-angle light scatterplots. Leukocytes were labeled with monoclonal antibodies to quantify surface expression of leukocyte antigens.

Results—Dogs with septic and nonseptic inflammatory diseases and MODS had an increase in percentage of neutrophils with increased size; dogs with septic inflammation and MODS had a greater percentage of neutrophils with decreased granularity. Dogs with septic and nonseptic inflammation and MODS had a low expression of CD18 and mature neutrophil antigen. Dogs with septic and nonseptic inflammation had an increase in CD11b expression. Monocytes from dogs with septic and nonseptic inflammation and MODS had a low expression of CD18. Monocytes and lymphocytes from dogs with septic and nonseptic inflammation and MODS had a low expression of MHC class II.

Conclusions and Clinical Relevance—Neutrophils from dogs with septic and nonseptic inflammation circulate in an activated state, and some dogs have decreased MHC class II expression. Many dogs with MODS have a compensatory anti-inflammatory response that may compromise their responses to antimicrobials. (Am J Vet Res2004;65:59–63)
Identification and concentration of soy phytoestrogens in commercial dog foods
Authors: Cerundolo Rosario , Court Michael H. , Hao Qin , Michel Kathryn E.
Published: December 2005

Objective—To identify and determine the concentrations
of phytoestrogens in commercial dog foods.

Sample Population—24 commercial dog foods,
including 12 moist or dry extruded commercial dog
foods that contained soybeans or soybean fractions
and 12 foods without any soybean–related ingredients
listed on the label.

Procedure—Foods were analyzed for phytoestrogen
content, including 4 isoflavones (genistein, glycitein,
daidzein, and biochanin A), 1 coumestan (coumestrol),
and 2 lignans (secoisolariciresinol and matairesinol) by
use of acid-methanol hydrolysis and high-pressure liquid
chromatography with UV-absorbance detection.
Phytoestrogens were identified and quantified by reference
to authentic standards.

Results—Isoflavones, coumestans, and lignans were
undetectable in diets that did not list soybean–related
ingredients on the label. Only 1 of the 12 diets that
included soybean or soybean fractions had undetectable
concentrations of phytoestrogens and that
product contained soy fiber. The major phytoestrogens
were the isoflavones daidzein (24 to 615 µg/g of
dry matter) and genistein (4 to 238 µg/g of dry matter).

Conclusions and Clinical Relevance—Soybean and
soybean fractions are commonly used ingredients in
commercial dog foods. Dietary intake of phytoestrogens
may have both beneficial and deleterious health
effects. Our results indicated that certain commercial
dog foods contain phytoestrogens in amounts that
could have biological effects when ingested longterm.
( Am J Vet Res 2004;65:592–596)
Comparison of abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with left displaced abomasum or abomasal volvulus
Authors: Wittek Thomas , Constable Peter D. , Fürll Manfred
Published: December 2005

Objective—To compare abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with a left displaced abomasum (LDA) or abomasal volvulus (AV).

Animals—40 lactating dairy cows (25 with an LDA and 15 with an AV).

Procedure—Abomasal luminal gas pressure and volume and pulse oximetry values for the caudal portion of the dorsal ruminal sac and abomasal wall were measured during laparotomy. Abomasal perfusion was assessed on the basis of abomasal O2saturation (pulse oximetry) before correction of the LDA or AV. Abomasal perfusion was also assessed after correction of the LDA or AV by measuring venous O2saturation in the right gastroepiploic vein and calculating the abomasal oxygen-extraction ratio.

Results—Abomasal luminal gas pressure and volume were higher in cattle with an AV than in cattle with an LDA. Abomasal O2saturation was lower and abomasal oxygen-extraction ratio higher in cattle with an AV, compared with values in cattle with an LDA. In cows with an AV, lactate concentration in the gastroepiploic vein was greater than that in a jugular vein, whereas no difference in lactate concentrations was detected in cows with an LDA. Abomasal luminal gas pressure was positively correlated (r, 0.51) with plasma lactate concentration in the gastroepiploic vein and negatively correlated (r, –0.32) with abomasal O2saturation determined by use of pulse oximetry.

Conclusions and Clinical Relevance—Abomasal perfusion decreases as luminal pressure increases in cattle with an AV or LDA. (Am J Vet Res2004; 65:597–603)
Effects of dietary sodium chloride intake on renal function and blood pressure in cats with normal and reduced renal function
Authors: Buranakarl Chollada , Mathur Sheerin , Brown Scott A.
Published: December 2005

Objective—To determine effects of variations in dietary intake of sodium chloride (NaCl) on systemic arterial blood pressure (ABP) in cats with normal and reduced renal function.

Animals—21 adult cats (7 with intact kidneys [control cats; group C], 7 with unilateral renal infarction with contralateral nephrectomy [remnant-kidney model; group RK], and 7 with unilateral renal infarction and contralateral renal wrapping and concurrent oral administration of amlodipine [remnant-wrap model; group WA]).

Procedure—All cats were sequentially fed 3 diets that differed only in NaCl content (50, 100, or 200 mg of Na/kg); each diet was fed for 7 days. The ABP was recorded continuously by radiotelemetry, and renal function (glomerular filtration rate [GFR]) was determined on the sixth day of each feeding period.

Results—Dietary supplementation with NaCl did not affect ABP, but it increased GFR in groups C and WA. The renin-angiotensin-aldosterone axis was activated in groups RK and WA at the lowest NaCl intake, but supplementation with NaCl suppressed this activation in group WA. The lowest NaCl intake was associated with hypokalemia and a high fractional excretion of potassium that decreased in response to supplementation with NaCl. Arterial baroreceptor resetting was evident after chronic hypertension but was not modified by dietary supplementation with NaCl.

Conclusions and Clinical Relevance—Low NaCl intake was associated with inappropriate kaliuresis, reduced GFR, and activation of the renin-angiotensinaldosterone axis without evidence of a beneficial effect on ABP. Therefore, this common dietary maneuver could contribute to hypokalemic nephropathy and progressive renal injury in cats. (Am J Vet Res2004;65:620–627)
Determination of specific receptor sites for platelet activating factor in bovine neutrophils
Authors: Burgos Rafael A. , Hidalgo María A. , Matthei Sabine M. , Hermosilla Ricardo , Folch Hugo , Hancke Juan L.
Published: December 2005

Objective—To identify and characterize a platelet activating factor (PAF) receptor in bovine neutrophils by use of radioligand binding, reverse transcription-polymerase chain reaction (RT-PCR) assay, and western blot analysis.

Animals—4 healthy adult cows.

Procedure—Bovine neutrophil membranes were isolated for association, dissociation, and saturation binding experiments with PAF labeled with hydrogen 3 (3H-PAF). The RT-PCR assay was performed with appropriate human primers, and western blot analysis was developed with a polyclonal antibody obtained from a peptide of bovine PAF receptor.

Results—Analysis of kinetic binding data supported a single class of PAF receptor. Binding of3H-PAF to membrane preparations was selectively displaced by PAF and a nonhydrolyzable analogue of guanine triphosphate (Gpp[NH]p) and by lyso-PAF (a biologically inactive analogue of PAF) to a lesser extent. Among other PAF receptor antagonists, 14-deoxyandrographolide and WEB 2086 were the most effective in inhibiting3H-PAF binding sites in neutrophil membranes; 2 lignans, schisandrin-A and γ-schisandrin were also effective, but 2 gingkolides (BN52020 and BN52021) only mildly inhibited3H-PAF binding. Results of RT-PCR assay and western blot analysis of neutrophil crude membranes confirmed the presence of a PAF receptor.

Conclusions and Clinical Relevance—Results indicated that bovine neutrophils express only 1 type of PAF receptor, and it is likely that this receptor is involved in inflammatory responses. The most effective PAF antagonists were 14-deoxyandrographolide and WEB 2086; these PAF antagonists may be potentially useful in the treatment of inflammatory processes in cattle. (Am J Vet Res2004;65:628–636)
Effect of carboxymethylcellulose and hyaluronate solutions on jejunal healing in horses
Authors: Eggleston Randy B. , Mueller P. O. Eric , Parviainen Anna K. , Groover Erin S.
Published: December 2005

Objective—To compare a double-layer inverting anastomosis with a single-layer appositional anastomosis, coated with either 1% sodium carboxymethylcellulose (SCMC) or 0.4% sodium hyaluronate (HA) solutions, in the small intestine of horses with respect to anastomotic healing and adhesion formation.

Animals—18 adult horses.

Procedure—Midline celiotomy and end-to-end jejunal anastomoses were performed. In control group horses (n = 6), a double-layer inverting anastomosis coated with sterile lactated Ringer's solution was performed. In treatment group horses, a single-layer appositional anastomosis was performed that was coated with 1% carboxymethylcellulose solution (SAA + SCMC group horses, 6) or 0.4% hyaluronate solution (SAA + HA group horses, 6). An additional 500 mL of the respective treatment solution was applied to the jejunal serosal surface, and 2 jejunal serosal abrasion sites were created. Horses were euthanatized 10 days after surgery. Anastomoses and abdominal adhesions were evaluated grossly. Anastomotic healing was evaluated on the basis of bursting wall tension.

Results—Bursting wall tension was significantly greater in SAA + SCMC group horses, compared with control group horses. All intestinal segments failed at a point distant to the anastomosis. Significantly fewer adhesions were found at the abrasion sites of SAA + HA group horses, compared with control group horses. No differences were found in adhesion formation at the anastomotic sites among groups.

Conclusions and Clinical Relevance—Coating a single- layer appositional jejunal anastomosis with SCMC or HA solutions does not adversely affect anastomotic healing. Application of 0.4% HA solution to the serosal surface of the jejunum significantly decreases the incidence of experimentally induced intra-abdominal adhesion formation in horses. (Am J Vet Res2004;65:637–643)
Effects of two anti-inflammatory drugs on physiologic variables and milk production in cows with endotoxin-induced mastitis
Authors: Wagner Sarah A. , Apley Michael D.
Published: December 2005

Objective—To determine the effects of 2 anti-inflammatory drugs in lactating Holstein cows with endotoxin- induced mastitis.

Animals—30 multiparous Holstein cows that had been lactating for 30 to 60 days.

Procedure—Bacterial culture of milk samples and physical examinations established that study cows were in good health and free of mastitis. Mastitis was induced in 1 front mammary gland by intramammary administration of purified bacterial endotoxin. Cows were allocated into 1 of 3 treatment groups: untreated endotoxic mastitis (n = 9), endotoxic mastitis plus flunixin meglumine (9), and endotoxic mastitis plus isoflupredone acetate (10). Heart rate, rectal temperature, mammary surface area, and rumen motility were recorded hourly for 14 hours following endotoxin administration. Flunixin meglumine or isoflupredone acetate was administered after mammary swelling and rectal temperature ≥ 40°C had developed. Milk production was evaluated from 5 days before to 10 days after induction of mastitis.

Results—Neither drug ameliorated loss of milk production or swelling of the affected mammary gland. Both drugs reduced mean heart rate during the 14 hours following endotoxin administration, compared with untreated control cows. Cows treated with flunixin meglumine had increased rumen motility and decreased rectal temperature during the same period, compared with all other cows.

Conclusions and Clinical Relevance—Neither drug enhanced recovery of milk production following endotoxin- induced mastitis. Flunixin meglumine decreased rectal temperature, whereas isoflupredone did not; however, it has not been established that reduction of fever is beneficial to cows with naturally occurring mastitis. (Am J Vet Res2004;65:64–68)
Pathologic changes associated with brucellosis experimentally induced by aerosol exposure in rhesus macaques ( Macaca mulatta )
Authors: Mense Mark G. , Borschel Richard H. , Wilhelmsen Catherine L. , Pitt M. Louise , Hoover David L.
Published: December 2005

Objective—To develop an aerosol exposure method for induction of brucellosis in rhesus macaques (Macaca mulatta).

Animals—10 adult rhesus macaques.

Procedure—8 rhesus macaques were challenge exposed with 102to 105colony-forming units ofBrucella melitensis16M by use of an aerosol-exposure technique, and 2 served as control animals. All macaques were euthanatized 63 days after challenge exposure. Gross and microscopic lesions, bacterial burden in target organs, and histologic changes in tissues were evaluated.

Results—Grossly, spleen weights were increased in exposed macaques, compared with spleen weights in control macaques. Histologically, there was inflammation in the liver, kidneys, spleen, testes, and epididymides in exposed macaques. The spleen and lymph nodes had increased numbers of lymphohistiocytic cells. Morphometrically, the spleen also had an increased ratio of white pulp to red pulp. Areas of hepatitis and amount of splenic white pulp increased with increasing exposure dose.

Conclusions and Clinical Relevance—Pathologic findings in rhesus macaques after aerosol exposure to Bmelitensisare similar to those observed in humans with brucellosis.

Impact for Human Medicine—These results may aid in the development of a vaccine against brucellosis that can be used in humans. (Am J Vet Res2004;65: 644–652)