bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of age, body weight, and heart rate on transmitral and pulmonary venous flow in clinically normal dogs
Authors: Schober Karsten E. , Fuentes Virginia Luis
Published: December 2005

Objective—To determine the influence of age, body
weight (BW), heart rate (HR), sex, and left ventricular
shortening fraction (LVSF) on transmitral and pulmonary
venous flow in clinically normal dogs.

Animals—92 client-owned dogs 3 months to 19
years old.

Procedure—Transthoracic Doppler echocardiography
recordings of transmitral flow and pulmonary venous
flow were obtained in conscious unsedated dogs.
Influence of age, BW, HR, sex, and LVSF on diastolic
variables was assessed, using statistical methods
such as ANOVA on ranks and univariate and multivariate
forward stepwise linear regression analyses.

Results—Age significantly influenced isovolumic
relaxation time (IVRT; r = 0.56), ratio between peak
velocity of the early diastolic mitral flow wave-to-peak
velocity of late diastolic mitral flow wave (E:A;
r = –0.44), deceleration time of early diastolic mitral
flow (DTE; r = 0.26), and peak velocity of atrial reversal
pulmonary venous flow wave (AR-wave; r= 0.37).
Significant changes of mitral inflow and pulmonary
venous flow variables were evident only in dogs > 6
and > 10 years old, respectively. Body weight significantly
influenced DTE ( r = 0.63), late diastolic flow
duration ( r= 0.60), and AR duration ( r= 0.47), whereas
HR significantly affected DTE ( r = –0.34), IVRT
( r= –0.33), and peak velocity of AR ( r= 0.24). Sex or
LVSF (range 22 to 48%) did not influence any echocardiographic
variables.

Conclusions and Clinical Relevance—Age, BW, and
HR are important factors that affect filling of the left
atrium and left ventricle in clinically normal dogs. (Am
J Vet Res 2001;62:1447–1454)
Relationship of the degree of goniodysgenesis and other ocular measurements to glaucoma in Great Danes
Authors: Wood James L. N. , Lakhani Ken H. , Mason Ian K. , Barnett Keith C.
Published: December 2005

Objectives—To assess the association between
goniodysgenesis, ocular measurements, and glaucoma
in Great Danes.

Animals—180 Great Danes.

Procedure—Eye examination and measurements
were obtained from 180 Great Danes; for 30 of these
dogs, depth of the anterior chamber, vitreal body
length, and total depth of the globe were also measured.
These data were merged with electronic pedigree
information on 43,371 kennel club registered
Great Danes. Relationships among goniodysgenesis,
ocular measurements, and glaucoma and the heritability
of goniodysgenesis were estimated.

Results—The degree of goniodysgenesis was significantly
and positively associated with the likelihood of
glaucoma. There was a significant association
between the degree of goniodysgenesis in offspring
and parents. The estimated heritability of the degree
of goniodysgenesis was 0.52. The depth of the anterior
chamber of the eye was also a good predictor of
goniodysgenesis (ie, the dog was almost certain to
have glaucoma if the depth was < 3.7 mm). If both
parents had goniodysgenesis < 70%, then with 95%
confidence, the occurrence of glaucoma in the ensuing
offspring would be < 4/1000. This strategy translates
to ensuring that the depth of the anterior chamber
of the eye is > 3.7 mm for both parents.

Conclusions and Clinical Relevance—The strong
and significant correlation among goniodysgenesis,
other eye measurements, and glaucoma and the significant
heritability of goniodysgenesis suggests that
glaucoma may be heritable in Great Danes. If so, glaucoma
can be controlled by breeding only from sires
and dams with a minimum degree of goniodysgenesis.
(Am J Vet Res 2001;62:1493–1499)
In vitro evaluation of a customized solution for use in attenuating effects of ischemia and reperfusion in the equine small intestine
Authors: Van Hoogmoed Linda M. , Snyder Jack R. , Nieto Jorge , Harmon Faye A.
Published: December 2005

Objective—To determine whether a customized solution could attenuate the effects of low-flow ischemia and reperfusion injury of the equine jejunum.

Sample Population—A segment of jejunum obtained from 21 healthy adult horses.

Procedure—A segment of jejunum was maintained in an isolated extracorporeal circuit, and arterial flow was reduced to 20% of baseline for 40 minutes (ischemia) followed by 60 minutes of reperfusion. In 1 group, a customized solution was infused at a rate of 1 ml/min during low-flow ischemia and 3 ml/min during reperfusion. In a second group, the solution was infused at the same rate during low-flow ischemia, but it was infused at a rate of 7 ml/min during reperfusion. Control groups received lactated Ringer's solution administered at the same rates as for the customized solution. Various metabolic, hemodynamic, histologic, and permeability variables were recorded.

Results—A lower flow rate during reperfusion (3 ml/min) had a beneficial effect, compared with lactated Ringer's solution or the higher flow rate (7 ml/min). Use of the solution at this rate resulted in less histomorphologic injury and reduced mucosal permeability to albumin.

Conclusions and Clinical Relevance—Use of a customized solution at a lower flow rate during repurfusion appeared to have a protective effect on equine jejunum when administered IV during low-flow ischemia and reperfusion. (Am J Vet Res2001; 62:1679–1686)
Cardiopulmonary evaluation of the use of medetomidine hydrochloride in cats
Authors: Lamont Leigh A. , Bulmer Barret J. , Grimm Kurt A. , Tranquilli William J. , Sisson David D.
Published: December 2005

Objective—To evaluate the cardiovascular effects of the α2-adrenergic receptor agonist medetomidine hydrochloride in clinically normal cats.

Animals—7 clinically normal cats.

Procedure—Cats were anesthetized with isoflurane, and thermodilution catheters were placed for measurement of central venous, pulmonary, and pulmonary capillary wedge pressures and for determination of cardiac output. The dorsal pedal artery was catheterized for measurement of arterial blood pressures and blood gas tensions. Baseline variables were recorded, and medetomidine (20 µg/kg of body weight, IM) was administered. Hemodynamic measurements were repeated 15 and 30 minutes after medetomidine administration.

Results—Heart rate, cardiac index, stroke index, ratepressure product, and right and left ventricular stroke work index significantly decreased from baseline after medetomidine administration, whereas systemic vascular resistance and central venous pressure increased. However, systolic, mean, and diastolic arterial pressures as well as arterial pH, and oxygen and carbon dioxide tensions were not significantly different from baseline values.

Conclusions and Clinical Relevance—When administered alone to clinically normal cats, medetomidine (20 µg/kg, IM) induced a significant decrease in cardiac output, stroke volume, and heart rate. Arterial blood pressures did not increase, which may reflect a predominant central α2-adrenergic effect over peripheral vascular effects. (Am J Vet Res2001;62:1745–1762)
Evaluation of accuracy and reliability of indirect calorimetry for the measurement of resting energy expenditure in healthy dogs
Authors: O'Toole Elizabeth , McDonell Wayne N. , Wilson Brian A. , Mathews Karol A. , Miller Craig W. , Sears William C.
Published: December 2005

Objective—To assess accuracy and reliability of open-flow indirect calorimetry in dogs.

Animals—13 clinically normal dogs.

Procedure—In phase 1, oxygen consumption per kilogram of body weight (VO2kg) was determined in 6 anesthetized dogs by use of open-flow indirect calorimetry before and after determination of VO2/kg by use of closed-circuit spirometry. In phase 2, four serial measurements of VO2and carbon dioxide production (VCO2) were obtained in 7 awake dogs by use of indirect calorimetry on 2 consecutive days. Resting energy expenditure (REE) was calculated.

Results—Level of clinical agreement was acceptable between results of indirect calorimetry and spirometry. Mean VO2/kg determined by use of calorimetry before spirometry was significantly greater than that obtained after spirometry. In phase 2, intraclass correlation coefficients (ICC) for REE and VO2were 0.779 and 0.786, respectively, when data from all 4 series were combined. When the first series was discounted, ICC increased to 0.904 and 0.894 for REE and VO2, respectively. The most reliable and least variable measures of REE and VO2were obtained when the first 2 series were discounted.

Conclusions and Clinical Relevance—Open-flow indirect calorimetry may be used clinically to obtain a measure of VO2and an estimate of REE in dogs. Serial measurements of REE and VO2in clinically normal dogs are reliable, but a 10-minute adaption period should be allowed, the first series of observations should be discounted, multiple serial measurements should be obtained, and REE. (Am J Vet Res2001;62:1761–1767).
Detailed ultrasonographic mapping of the pelvis in clinically normal horses and ponies
Authors: Tomlinson Julia E. , Sage Abby M. , Turner Tracy A. , Feeney Daniel A.
Published: December 2005

Objective—To map the equine pelvis using ultrasonography, validated by use of computed tomography (CT), magnetic resonance imaging (MRI), and measurements of frozen cadaver slices.

Animals—6 ponies and 6 horses.

Procedure—Ultrasonographic examination of the pelvis was performed on 6 clinically normal ponies. Measurements were obtained for imaged structures. Computed tomography, MRI, and measurements of frozen sections were performed after death and used to verify measurements. Linear regression determined the degree of correlation between measurements obtained ultrasonographically and the other modalities. Six clinically normal horses were then examined by use of ultrasonography. For each structure measured mean, SD, and range were calculated.

Results—Data obtained from ponies revealed high correlations between ultrasonographic findings and those of CT, MRI, and frozen section measurements (r2= 0.97,r2= 0.99, andr2= 0.99, respectively). Differences between structures measured on each side of the pelvis were not significant. Variation in size of structures was not associated with weight of horses. A correlation was not found between weight of horses and ponies and size of structure.

Conclusions and Clinical Relevance—Ultrasonography can be used to accurately measure and evaluate the musculoskeletal structures of the pelvis of horses. The use of CT, MRI, and measurements of frozen sections provided a means of validating the ultrasonographic measurements. Reference range values determined in our study can be used to evaluate horses with suspected pelvic disease. (Am J Vet Res2001;62:1768–1775)
Comparison of urine composition of healthy Labrador Retrievers and Miniature Schnauzers
Authors: Stevenson Abigail E. , Markwell Peter J.
Published: December 2005

Objective—To compare urine composition in Labrador Retrievers (LR) and Miniature Schnauzers (MS) fed the same dog food.

Animals—8 healthy LR (mean [± SD] age, 3.1 ± 1.7 years) and 8 healthy MS (mean age, 3.7 ± 1.3 years).

Procedure—A nutritionally complete dry dog food was fed to the dogs for 24 days. Urinary pH, volume, specific gravity, frequency of urination, and urinary concentrations of 12 analytes were measured for each dog; urinary relative supersaturation (RSS) with calcium oxalate and brushite (calcium hydrogen phosphate dihydrate) were calculated from these values.

Results—MS urinated significantly less often and had a lower urine volume (ml/kg of body weight per d) and a significantly higher urine pH, compared with LR. Urinary calcium concentration and brushite RSS were significantly higher in the urine of MS. As a result of a high calorie requirement, primarily as a result of high surface area to volume ratio, MS had significantly higher intake (per kg body weight) of dietary minerals, compared with LR.

Conclusions and Clinical Relevance—Differences in urine composition exist between breeds fed the same diet, some of which, including lower urine volume, higher calcium concentration, and higher brushite RSS, may contribute to the high prevalence of calcium oxalate uroliths observed in MS. Differences between breeds should be considered when evaluating strategies for controlling calcium oxalate stone formation. (Am J Vet Res2001;62:1782–1786)
Effect of age and body weight on neurohumoral variables in healthy Cavalier King Charles Spaniels
Authors: Eriksson Anders S. , Järvinen Anna-Kaisa , Eklund Kari K. , Vuolteenaho Olli J. , Toivari Mervi H. , Nieminen Markku S.
Published: December 2005

Objective—To evaluate the effect of age and body weight on several neurohumoral variables that are commonly altered in heart failure in Cavalier King Charles Spaniels.

Animals—17 healthy privately owned Cavalier King Charles Spaniels, 10 males and 7 females, ranging in age from 0.4 to 9.7 years, and ranging in body weight from 6.6 to 12.2 kg.

Procedure—The clinical condition of the dogs was evaluated by physical examination, thoracic radiography, and echocardiography. Plasma nitrate and nitrite (P-NN), N-terminal atrial natriuretic and brain natriuretic peptides (NT-ANP and BNP, respectively), endothelin (ET-1), urine cyclic guanosine monophosphate (UcGMP), and urine nitrate and nitrite (U-NN) concentrations were analyzed.

Results—Plasma concentrations of NT-ANP and P-NN increased significantly with age, but plasma NT-ANP and P-NN also correlated significantly, irrespective of age. A modest increase of left atrial size did not explain the increase of NT-ANP and P-NN with age. Concentration of ET-1 correlated positively with heart rate; heart rate did not change with age. Weight had a negative impact on NT-ANP, P-NN, and U-cGMP concentrations and left atrial relative size.

Conclusions and Clinical Relevance—Age-matched controls are essential for evaluation of NT-ANP and PNN concentrations and left atrial size. Weight may alter reference values of plasma NT-ANP, P-NN, and urine cGMP concentrations. Natriuretic peptides can be used as further evidence that heart failure exists. The increased plasma concentrations of NT-ANP (but not BNP) and P-NN with aging reflect neurohumoral physiologic changes that must be distinguished from pathologic changes in patients with heart failure. (Am J Vet Res2001;62:1818–1824)
Expression of CD3 and CD11b antigens on blood and mammary gland leukocytes and bacterial survival in milk of cows with experimentally induced Staphylococcus aureus mastitis
Authors: Rivas Ariel L. , Quimby Fred W. , Coksaygan Ozden , Alba Argia , Arina Ainhoa , Arrobas M. Juncal , González Rubén N. , Mohammed Hussni O. , Lein Donald H.
Published: December 2005

Objectives—To differentiate early (1 to 8 days) from late (9 to 14 days) inflammatory phases and assess relationships between leukocyte phenotype and bacterial recovery in cows withStaphylococcus aureus-induced mastitis.

Animals—10 first-lactation Holstein cows.

Procedure—Blood and milk samples were collected from 4 or 6 cows before and after intramammary infusion of sterile broth orS aureus, respectively. Flow cytometric expression of CD3 and CD11b antigens on blood and milk leukocytes, leukocyte differential counts, bacterial counts in milk, and somatic cell counts were determined longitudinally.

Results—Density of CD3 molecules decreased on blood lymphocytes and increased on milk lymphocytes after infusion of bacteria. Density of CD11b molecules on lymphocytes and phagocytes and percentage of CD11b+lymphocytes in milk increased significantly after infusion; maximum values were achieved during the early inflammatory phase. Density of CD3 and CD11b molecules on milk lymphocytes and macrophages, respectively, 1 day after inoculation were negatively correlated with bacterial recovery on day 1 and days 9 to 14, respectively. Density of CD11b molecules on milk macrophages and the ratios of phagocyte to lymphocyte percentages and polymorphonuclear cell to macrophage percentages in milk differentiated the early from the late inflammatory phase.

Conclusions and Clinical Relevance—Activation of bovine mammary gland macrophages and T cells in response to intramammary infusion ofS aureuswas associated with an inability to culture this bacterium from milk. Identification of specific inflammatory phases ofS aureus-induced mastitis in cows may allow for the design of more efficacious treatment and control programs. (Am J Vet Res2001;62:1840–1851)
Pharmacokinetics of azithromycin and concentration in body fluids and bronchoalveolar cells in foals
Authors: Jacks Stephanie , Giguère Steeve , Gronwall Ronald R. , Brown Murray P. , Merritt Kelly A.
Published: December 2005

Objective—To determine the pharmacokinetics of azithromycin and its concentration in body fluids and bronchoalveolar lavage cells in foals.

Animals—6 healthy 6- to 10-week-old foals.

Procedure—Azithromycin (10 mg/kg of body weight) was administered to each foal via IV and intragastric (IG) routes in a crossover design. After the first IG dose, 4 additional IG doses were administered at 24-hour intervals. A microbiologic assay was used to measure azithromycin concentrations in serum, peritoneal fluid, synovial fluid, pulmonary epithelial lining fluid (PELF), and bronchoalveolar (BAL) cells.

Results—Azithromycin elimination half-life was 20.3 hours, body clearance was 10.4 ml/min·kg, and apparent volume of distribution at steady state was 18.6 L/kg. After IG administration, time to peak serum concentration was 1.8 hours and bioavailability was 56%. After repeated IG administration, peak serum concentration was 0.63 ± 0.10 µg/ml. Peritoneal and synovial fluid concentrations were similar to serum concentrations. Bronchoalveolar cell and PELF concentrations were 15- to 170-fold and 1- to 16-fold higher than concurrent serum concentrations, respectively. No adverse reactions were detected after repeated IG administration.

Conclusions and Clinical Relevance—On the basis of pharmacokinetic values, minimum inhibitory concentrations ofRhodococcus equiisolates, and drug concentrations in PELF and bronchoalveolar cells, a single daily oral dose of 10 mg/kg may be appropriate for treatment ofR equiinfections in foals. Persistence of high azithromycin concentrations in PELF and bronchoalveolar cells 48 hours after discontinuation of administration suggests that after 5 daily doses, oral administration at 48-hour intervals may be adequate. (Am J Vet Res2001;62:1870–1875)
Shedding of porcine reproductive and respiratory syndrome virus in mammary gland secretions of sows
Authors: Wagstrom Elizabeth Allen , Chang Chih-Cheng , Yoon Kyoung-Jin , Zimmerman Jeffrey J.
Published: December 2005

Objective—To document shedding of porcine reproductive and respiratory syndrome (PRRS) virus in mammary gland secretions of experimentally inoculated sows, to evaluate effects of vaccination during gestation on virus shedding during the subsequent lactation, and to evaluate shedding of PRRS virus in milk of sows in commercial herds.

Animals—6 sows seronegative for PRRS virus were used for experiment 1, and 2 sows were retained for experiment 2. For experiment 3, 202 sows in commercial herds were used.

Procedure—In experiment 1, 2 sows were inoculated with PRRS virus, 2 sows were vaccinated with modified- live PRRS virus vaccine, and 2 sows served as control pigs. Mammary gland secretions were assayed for PRRS virus. In experiment 2, pregnant vaccinated sows from experiment 1 were vaccinated with another modified-live PRRS virus vaccine. Mammary gland secretions were assayed in the same manner as for experiment 1. For experiment 3, milk collected from 202 sows in commercial herds was assayed for PRRS virus.

Results—In experiment 1, PRRS virus was detected in mammary gland secretions of both vaccinated and 1 of 2 virus-inoculated sows. In experiment 2, virus was not detected in samples from either vaccinated sow. In experiment 3, all samples yielded negative results.

Conclusions and Clinical Relevance—Naïve sows inoculated late in gestation shed PRRS virus in mammary secretions. Previous vaccination appeared to prevent shedding during the subsequent lactation. Results for samples obtained from sows in commercial herds suggested that virus shedding in mammary gland secretions of such sows is uncommon. (Am J Vet Res2001;62:1876–1880)
Comparison of deposition images obtained by use of an ultrafine 99m-technetium-labeled carbon dry aerosol with ventilation images obtained by use of 81m-krypton gas for evaluation of pulmonary dysfunction in calves
Authors: Votion Dominique M. , Coghe Joost D. , Lekeux Pierre M.
Published: December 2005

Objective—To characterize the accuracy of an ultrafine 99m-technetium-labeled carbon dry aerosol for use in assessment of regional ventilation in calves with pulmonary dysfunction.

Animals—7 Belgian White and Blue calves.

Procedure—The ultrafine aerosol was assessed by comparing deposition (D) images with ventilation (V) images obtained by use of 81m-krypton (81mKr) gas viaD-to-Vratio (D:V) image analysis in calves during spontaneous breathing (SB) and during experimentally induced pulmonary dysfunction (ePD).

Results—Mismatching index (LrTot) calculated on theD:Vimages revealed a good match (LrTot, 0.96 ± 0.01) betweenDandVdistribution patterns in calves during SB. Calculation of the ultrafine aerosol penetration index relative to81mKr (PIRel) revealed preferential distribution of the ultrafine aerosol in lung parenchyma (PIRel,1.13 ± 0.11). In ePD, heterogeneity in the D:V distribution was observed (LrTot, 0.78 ± 0.10) as a result of ultrafine aerosol particles impaction in airways as indicated by PIRel(0.66 ± 0.16) and a proportion of pixels more radioactive inDimages, compared withVimages, that was located in the central part of the lung (47.5 ± 7.7% in ePD vs 32.8 ± 5.7% in SB). However, this central deposition did not prevent visual examination of the entire ventilated lung.

Conclusions and Clinical Relevance—The ultrafine aerosol appears suitable for use in examination of ventilated parts of lungs of cattle, even those with impaired pulmonary function. However, airway impaction of ultrafine aerosol particles impedes the quantification of regional ventilation in cattle with abnormal lung function. (Am J Vet Res2001;62: 1881–1886)
Use of an intravitreal sustained-release cyclosporine delivery device for treatment of equine recurrent uveitis
Authors: Gilger Brian C. , Wilkie David A. , Davidson Michael G. , Allen Janice B.
Published: December 2005

Objective—To evaluate the use of an intravitreal sustained-release cyclosporine (CsA) delivery device for treatment of horses with naturally occurring recurrent uveitis.

Animals—16 horses with recurrent uveitis.

Procedures—Horses with frequent recurrent episodes of uveitis or with disease that was progressing despite appropriate medication were selected for this study. Additional inclusion criteria included adequate retinal function as determined by use of electroretinography, lack of severe cataract formation, and no vision-threatening ocular complications (eg, retinal detachment, severe retinal degeneration, and posterior synechia). Sustained-release CsA delivery devices (4 µg of CsA/d) were implanted into the vitreous through a sclerotomy at the pars plana. Reexaminations were performed 1, 3, 6, and 12 months after implantation, then continued annually. Ophthalmic changes, number of recurrent episodes of uveitis, and vision were recorded.

Results—The rate of recurrent episodes after device implantation (0.36 episodes/y) was less than prior to surgery (7.5 episodes/y). In addition, only 3 horses developed episodes of recurrent uveitis after surgery. Vision was detected in 14 of 16 affected eyes at a mean follow-up time of 13.8 months (range, 6 to 24 months).

Conclusions and Clinical Relevance—This intravitreal sustained-release CsA delivery device may be a safe and important tool for long-term treatment of horses with chronic recurrent uveitis. (Am J Vet Res2001;62:1892–1896)
Computed tomography of the tarsal joint in clinically normal dogs
Authors: Gielen Ingrid M. , De Rycke Lieve M. , van Bree Henri J. , Simoens Paul J.
Published: December 2005

Objective—To use computed tomography to provide a detailed description of tarsal joint structures in clinically normal dogs.

Animals—6 clinically normal adult mixed-breed dogs weighing 25 to 35 kg and one 12-month-old Bullmastiff weighing 65 kg.

Procedure—To perform computed tomography (CT) of both tarsal regions, dogs were anesthetized and placed in ventral recumbency. One- and 2-mm contiguous slices were obtained, using a third generation CT scanner. Individual images were reviewed, using bone (window width = 3,500 Hounsfield units; window level = 500 Hounsfield units) and soft-tissue (window width = 400 Hounsfield units; window level = 66 Hounsfield units) settings. After euthanasia, the hind limbs from the Bullmastiff were removed and frozen at –18 C. Tarsal joints were sectioned into approximately 1-mmthick slab sections, using a cryomicrotome. Anatomic sections were photographed and compared with the corresponding CT images. Computed tomographic reconstructions of the tarsocrural joint were created in sagittal and dorsal planes.

Results—Structures on the CT images were matched with structures in the corresponding anatomic sections. The entire tarsocrural joint surface could be evaluated on the reconstructed images in the sagittal and dorsal planes.

Conclusions and Clinical Relevance—CT images provide full anatomic detail of the bony structures of the tarsal joint in dogs. Tendons and large blood vessels can also be evaluated. These results could be used as a basis for evaluation of CT images of the hind limbs of dogs with tarsal joint injuries. (Am J Vet Res2001;62:1911–1915)
Serum lipid peroxide and α-tocopherol concentrations and superoxide dismutase activity in captive bottle-nosed dolphins
Authors: Kasamatsu Masahiko , Tsunokawa Masatoshi , Taki Michihiro , Higuchi Hidetoshi , Nagahata Hajime
Published: December 2005

Objective—To evaluate serum lipid peroxide (LPO) and α-tocopherol concentrations and superoxide dismutase (SOD) activity in captive bottle-nosed dolphins and to evaluate effects of storage on production of LPO in various marine fish.

Animals—16 bottle-nosed dolphins.

Procedure—8 dolphins (group A) were fed chub mackerel and herring (high fat) and arabesque greenling and banded blue-sprat (low fat); the other 8 dolphins (group B) were fed chub mackerel and Pacific saury (high fat) and shishamo smelt and Japanese horse mackerel (low fat). Each group had been on these respective diets for 3 years. Serum LPO and α-tocopherol concentrations, serum SOD activity, and superoxide production by neutrophils were measured. All types of marine fish were frozen at –20 C for 6 months, and concentrations of LPO were measured at various time points.

Results—Serum LPO concentrations in group-A dolphins were significantly higher than those in group B. Serum α-tocopherol concentrations and SOD activity in group A were significantly lower than those in group B. A significant negative correlation was found between serum LPO and α-tocopherol concentrations in all 16 dolphins. The LPO concentrations in mackerel and herring fed to group-A dolphins were higher than those of other fish. Concentrations of LPO in herring stored for 3 and 6 months at –20 C were higher than those in herring before freezing and in herring stored for 1 month.

Conclusions and Clinical Relevance—Serum LPO and α-tocopherol concentrations in captive bottlenosed dolphins may be strongly influenced by high amounts of polyunsaturated fatty acid and LPO found in marine fatty fishes. High concentrations of serum LPO, as found in group-A dolphins, were associated with decreased antioxidative states. Monitoring of serum LPO and α-tocopherol concentrations and serum SOD activity may be useful for the management of captive marine mammals. (Am J Vet Res2001;62:1952–1956)
Investigation of mRNA expression of tumor necrosis factor-α, interleukin-1β, and cyclooxygenase-2 in cultured equine digital artery smooth muscle cells after exposure to endotoxin
Authors: Rodgerson Dwayne H. , Belknap James K. , Moore James N. , Fontaine Genevieve L.
Published: December 2005

Objective—To determine messenger RNA expression of cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and interleukin- (IL)-1β from cultured equine smooth muscle cells (SMC).

Sample Population—Segments of palmar digital artery harvested from 6 clinically normal adult horses.

Procedure—Explants were collected from the tunica media of arteries for primary culture of SMC. Equine mononuclear cells were used as control cells. Subcultured vascular SMC and control cells were exposed to lipopolysaccharide (20 µg/ml and 100 ng/ml, respectively). Northern blot analysis with equine-specific probes for COX-2, TNF-α, and IL-1β was performed, using isolated total cellular RNA.

Results—Although no message was detected for IL-1β or TNF-α in control or endotoxin-exposed equine vascular SMC from all horses, COX-2 underwent a distinct substantial up-regulation after endotoxin exposure. Endotoxin-exposed equine mononuclear cells had up-regulation of IL-1β and TNF-α mRNA.

Conclusions and Clinical Relevance—Increased expression of COX-2 mRNA by equine vascular SMC may be an important early pathophysiologic event in the onset of endotoxemia in horses. Potentiated local vascular production of various prostanoids after increased expression of mRNA for COX-2 may result in vasoactive events observed with laminitis. (Am J Vet Res2001;62:1957–1963)
Evaluation of a short interspersed nucleotide element in the 3' untranslated region of the defective dystrophin gene of dogs with muscular dystrophy
Authors: Fletcher Sue , Carville Kylie S. , Howell John M. , Mann Christopher J. , Wilton Steve D.
Published: December 2005

Objectives—To determine the distribution of a 231- base pair (bp) element in the dystrophin gene 3' untranslated region (UTR) in a colony of Golden Retrievers with muscular dystrophy and other unrelated dogs and to estimate the frequency of recombination for the canine dystrophin gene.

Animals—77 dogs from the Golden Retriever Muscular Dystrophy (GRMD) colony at the Murdoch Veterinary School and 30 unrelated dogs from the Murdoch University Veterinary Clinic.

Procedure—Samples of blood or hair from dogs were used for amplification of DNA, using primers to the canine dystrophin 3' UTR.

Results—The DNA from affected dogs generated a larger PCR product than that obtained from clinically normal dogs. Products were cloned and sequenced, and the difference in size was found to be attributable to a 231-bp short interspersed nucleotide element (SINE). The SINE was found in all affected dogs in the colony but not in most unaffected puppies in the colony. Eighteen of 19 dogs in the colony were heterozygous for the GRMD mutation, and 7 of 30 unrelated dogs also were heterozygous for the SINE.

Conclusion and Clinical Relevance—Evidence of recombination between the GRMD mutation and the SINE was observed in only 4 dogs (2 sets of littermates) in the GRMD colony. Incidence of this SINE in a few unrelated dogs suggests that this particular insertion into the dystrophin gene may have been a recent event. The SINE in the dystrophin 3' UTR did not have an apparent influence on dystrophin mRNA concentrations. (Am J Vet Res2001;62:1964–1968)
Cytotoxic effects of peroxynitrite, polymorphonuclear neutrophils, free-radical scavengers, inhibitors of myeloperoxidase, and inhibitors of nitric oxide synthase on bovine mammary secretory epithelial cells
Authors: Ledbetter Tonya K. , Paape Max J. , Douglass Larry W.
Published: December 2005

Objective—To determine cytotoxic effects of activated polymorphonuclear neutrophils (PMN) and peroxynitrite on bovine mammary secretory epithelial cells before and after addition of nitric oxide synthase inhibitors, myeloperoxidase (MPO) inhibitors, and free-radical scavengers.

Sample Population—Polymorphonuclear neutrophils from 3 lactating cows.

Procedure—Cells from the bovine mammary epithelial cell line MAC-T were cultured. Monolayers were treated with activated bovine PMN, lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA), 3-morpholino- sydnonimine (SIN-1), 4-amino-benzoic acid hydrazide (ABAH), NG-monomethyl-L-arginine, histidine, and superoxide dismutase (SOD). At 24 hours, activity of lactate dehydrogenase in culture medium was used as a relative index of cell death. Tyrosine nitration of proteins in MAC-T cell lysates was determined by visual examination of immunoblots.

Results—Lipopolysaccharide, PMA, and ≤ 0.1 mMSIN-1 were not toxic to MAC-T cells. Activated PMN, ≥ 6 mg of histidine/ml, and 0.5 mMSIN-1 were toxic. Together, histidine and 500,000 activated PMN/ml also were toxic. NG-monomethyl-L-arginine did not have an effect, but ABAH decreased PMN-mediated cytotoxicity. Ten and 50 U of SOD/ml protected MACT cells from cytotoxic effects of 0.5 mMSIN-1. Compared with control samples, nitration of MAC-T tyrosine residues decreased after addition of 500,000 PMN/ml or ≥ 6 mg of histidine/ml. Superoxide dismutase increased and SIN-1 decreased tyrosine nitration of MAC-T cell proteins in a dose-responsive manner.

Conclusions and Clinical Relevance—Peroxynitrite, MPO, and histidine are toxic to mammary secretory epithelial cells. Superoxide dismutase and inhibition of MPO activity mitigate these effects. Nitration of MAC-T cell tyrosine residues may be positively associated with viability. (Am J Vet Res2001;62:286–293)
Comparison of four methods for determination of total protein concentrations in pleural and peritoneal fluid from dogs
Authors: Braun Jean-Pierre , Guelfi Jean-François , Pagès Jean-Pierre
Published: December 2005

Objective—To compare 4 techniques for determination
of total protein concentrations in peritoneal and
pleural effusions from dogs.

Sample Population—23 peritoneal and 12 pleural
fluid samples from 35 dogs with various abnormalities.

Procedure—Samples were collected into tubes containing
EDTA, centrifuged, and stored at −20 C until
total protein concentrations were assessed. Protein
concentration in each sample was determined by use
of urine test strips, refractometry, and Bradford and
biuret techniques. Accuracy of each method was
determined, using dilutions of human control sera.

Results—There was good correlation among results
of all quantitative procedures. Results of the biuret
technique were more accurate than results of the
Bradford assay. Refractometry underestimated protein
concentration in samples with < 20 g of protein/L. Results of urine test strips correctly classified
effusion samples into 2 groups on the basis of total
protein concentrations less than or greater than 20 g/L.

Conclusions and Clinical Relevance—Results of
any of these 4 techniques can be used to rapidly and
efficiently differentiate peritoneal and pleural fluid
from dogs into transudates and exudates on the basis
of total protein concentration less than or greater than
20 g/L, respectively. (Am J Vet Res 2001;62:294-296)
Reduction of diameter of the left ventricle of dogs by plication of the left ventricular free wall
Authors: de Andrade James Newton Bizetto Meira , Wouk Antonio Felipe , Camacho Aparecido Antonio , Germiniani Clotilde de Lourdes Branco , Gavazzoni Lilian
Published: December 2005

Objective—To determine effects of reducing the diameter of the left ventricle of dogs by plication of the left ventricular free wall.

Animals—8 healthy adult mixed-breed dogs.

Procedure—Left lateral thoracotomy and a T-shaped pericardiotomy were performed. The free wall of the left ventricle was imbricated with 3 interrupted transfixing sutures applied in a horizontal mattress pattern, using 3-0 polypropylene suture assembled on a straight cutting needle. Surgeons were careful to avoid the coronary vessels. Echocardiography was performed 24 hours before and 48 hours after surgery. Electrocardiography was performed before and 1, 2, 7, 15, 21, 30, and 60 days after surgery.

Results—Echocardiographic measurements revealed that the diameter of the left ventricle was reduced by a mean of 23.5%. Electrocardiography revealed ventricular premature complexes 24 hours after surgery that regressed without treatment during the first week after surgery.

Conclusions and Clinical Relevance—Plication of the left ventricular free wall of dogs can reduce enddiastolic and end-systolic dimensions of the left ventricle. The technique is simple and does not require cardiopulmonary bypass. According to Laplace's law, the reduction of cardiac diameter leads to reduction on free-wall tension and may improve left ventricular function in dilatated hearts. Thus, additional studies involving dogs with dilated cardiomyopathy should be conducted. (Am J Vet Res2001;62:297–300)
Respiratory reflexes in spontaneously breathing anesthetized dogs in response to nasal administration of sevoflurane, isoflurane, or halothane
Authors: Mutoh Tatsushi , Kanamaru Arata , Suzuki Hodaka , Tsubone Hirokazu , Nishimura Ryohei , Sasaki Nobuo
Published: December 2005

Objective—To characterize respiratory reflexes elicited by nasal administration of sevoflurane (Sevo), isoflurane (Iso), or halothane (Hal) in anesthetized dogs.

Animals—8 healthy Beagles.

Procedure—A permanent tracheostomy was created in each dog. Two to 3 weeks later, dogs were anesthetized by IV administration of thiopental and α-chloralose. Nasal passages were isolated such that inhalant anesthetics could be administered to the nasal passages while the dogs were breathing 100% O2via the tracheostomy. Respiratory reflexes in response to administration of each anesthetic at 1.2 and 2.4 times the minimum alveolar concentration (MAC) and the full vaporizer setting (5%) were recorded. Reflexes in response to administration of 5% of each anesthetic also were recorded following administration of lidocaine to the nasal passages.

Results—Nasal administration of Sevo, Iso, and Hal induced an immediate ventilatory response characterized by a dose-dependent increase in expiratory time and a resulting decrease in expired volume per unit of time. All anesthetics had a significant effect, but for Sevo, the changes were smaller in magnitude. Responses to administration of each anesthetic were attenuated by administration of lidocaine to the nasal passages.

Conclusions and Clinical Relevance—Nasal administration of Sevo at concentrations generally used for mask induction of anesthesia induced milder reflex inhibition of breathing, presumably via afferent neurons in the nasal passages, than that of Iso or Hal. Respiratory reflexes attributable to stimulation of the nasal passages may contribute to speed of onset and could promote a smoother induction with Sevo, compared with Iso or Hal. (Am J Vet Res2001;62:311–319)
Influence of age and sex on plasma lipid and lipoprotein concentrations and associated enzyme activities in cats
Authors: Butterwick Richard F. , McConnell Michael , Markwell Peter J. , Watson Tim D. G.
Published: December 2005

Objective—To determine effects of age and sex on plasma lipid and lipoprotein metabolism in cats.

Animals—33 kittens and 16 adolescent, 23 adult, and 10 senior cats.

Procedure—Plasma concentrations of cholesterol, triglyceride, and lipoprotein-cholesterol and activities of lipoprotein lipase, hepatic lipase, and lecithin:cholesterol acyl transferase (LCAT) were measured and compared within and among groups.

Results—Plasma cholesterol and triglyceride concentrations were significantly higher in 5- and 7-week-old kittens, compared with the same kittens after weaning and cats in the other age groups. Cholesterol concentration was significantly less in 20-week-old kittens, compared with adolescent and adult cats. Lipid and lipoprotein-cholesterol concentrations were not significantly different among the adolescent, adult, and senior groups, nor did sex influence lipid and lipoprotein-cholesterol concentrations in these groups. Activities of lipoprotein and hepatic lipases were significantly less in senior cats, compared with the other groups. Activity of LCAT was highest in 20-week-old kittens and was greater in sexually intact adult and adolescent females, compared with their male counterparts. After castration, activities of hepatic lipase and LCAT significantly decreased in adolescent male cats.

Conclusions and Clinical Relevance—The upper limits of reference ranges for plasma cholesterol and triglyceride concentrations should be increased for kittens < 8 weeks of age. Low cholesterol concentrations in adolescent cats likely reflect high tissue demands for growth and steroidogenesis. Decrease in lipoprotein and hepatic lipase activity in senior cats could predispose this age group to hypertriglyceridemia, particularly in insulin-resistant cats or those fed a high fat diet. (Am J Vet Res2001;62:331–336)
Petrographic and geochemic evaluation of equine enteroliths
Authors: Hassel Diana M. , Schiffman Peter S. , Snyder Jack R.
Published: December 2005

Objective—To characterize the texture, mineralogic features, and chemical features of enteroliths obtained from horses.

Sample Population—Enteroliths from 13 horses with colic.

Procedure—Enteroliths were harvested from 13 horses that underwent ventral midline celiotomy for treatment of colic or necropsy because of colonic obstruction and rupture caused by enteroliths. Dietary and environmental history were determined via questionnaires or evaluation of medical records. In 7 horses that underwent surgical treatment for enterolithiasis, samples of colonic contents were obtained via an enterotomy in the pelvic flexure. Colonic concentrations of magnesium (Mg), phosphorus (P), sulfur (S), sodium (Na), calcium (Ca), and potassium (K) were determined. Enteroliths were analyzed via electron microprobe analysis and X-ray diffraction.

Results—Enteroliths varied widely regarding degree of porosity, presence and distribution of radiating texture, and composition and size of the central nidus. A distinct concentric banding was identifiable in all enteroliths. Struvite was the predominant component of all enteroliths, although Mg vivianite was identified in 5 enteroliths, and there were variable quantities of Na, S, K, and Ca in the struvite within enteroliths. Despite an abundance of Ca in colonic fluids, Mgphosphate minerals were preferentially formed, compared with Ca-phosphates (apatite), in equine enteroliths.

Conclusions and Clinical Relevance—Enteroliths comprise 2 major Mg phosphates: struvite and Mg vivianite. There is wide variability in macrotexture and ionic concentrations between and within enteroliths. (Am J Vet Res2001;62:350–358)
Bacteriologic and histologic features in mice after intranasal inoculation of Brucella melitensis
Authors: Mense Mark G. , Verg Lillian L. Van De , Bhattacharjee Apurba K. , Garrett Jennifer L. , Hart James A. , Lindler Luther E. , Hadfield Ted L. , Hoover David L.
Published: December 2005

Objective—To characterize effects of intranasal inoculation of virulentBrucella melitensisstrain 16M in mice.

Animals—Female Balb/c mice, 6 to 8 weeks old.

Procedure—Studies were designed to elucidate gross morphologic lesions, bacterial burden in target organs, and histologic changes in tissues following experimental intranasal inoculation of mice withB melitensis16M, which could be used to characterize a model for testing vaccine efficacy.

Results—Measurable splenomegaly was evident at 3 and 7 weeks after inoculation. A demonstrable increase in splenic colony-forming units (CFU) from infected mice increased over time with increasing dose when comparing inocula of 103, 104, and 105CFU. Recovery of brucellae from the lungs was possible early in infection with 101, 103, and 105CFU, but only the group inoculated with 105CFU consistently yielded quantifiable bacteria. At a dose of 101CFU, few organisms were located in the spleen. Bacteria were recovered up to 140 days after inoculation in mice given 103CFU. At an inoculum of 105CFU, bacterial counts were highest early in infection. Histologic examination of tissues revealed an increase in white pulp and marginal zone in the spleen and lymphohistiocytic hepatitis.

Conclusion and Clinical Relevance—Changes in the spleen and liver increased with increases in dose and with increased time following intranasal inoculation withB melitensis16M. Surprisingly, histologic changes were not observed in the lungs of inoculated mice. (Am J Vet Res2001;62:398–405)
Effect of contact stress in bones of the distal interphalangeal joint on microscopic changes in articular cartilage and ligaments
Authors: Bowker Robert M. , Atkinson Patrick J. , Atkinson Theresa S. , Haut Roger C.
Published: December 2005

Objective—To examine articular cartilage of the distal interphalangeal (DIP) joint and distal sesamoidean impar ligament (DSIL) as well as the deep digital flexor tendon (DDFT) for adaptive responses to contact stress.

Sample Population—Specimens from 21 horses.

Procedure—Pressure-sensitive film was inserted between articular surfaces of the DIP joint. The digit was subjected to a load. Finite element models (FEM) were developed from the data. The navicular bone, distal phalanx, and distal attachments of the DSIL and DDFT were examined histologically.

Results—Analysis of pressure-sensitive film revealed significant increases in contact area and contact load at dorsiflexion in the joints between the distal phalanx and navicular bone and between the middle phalanx and navicular bone. The FEM results revealed compressive and shear stresses. Histologic evaluation revealed loss of proteoglycans in articular cartilage from older horses (7 to 27 years old). Tidemark advancement (up to 14 tidemarks) was observed in articular cartilage between the distal phalanx and navicular bone in older clinically normal horses. In 2 horses with navicular syndrome, more tidemarks were evident. Clinically normal horses had a progressive increase in proteoglycans in the DSIL and DDFT.

Conclusions and Clinical Relevance—Load on the navicular bone and associated joints was highest during dorsiflexion. This increased load may be responsible for microscopic changes of tidemark advancement and proteoglycan depletion in the articular cartilage and of proteoglycan production in the DSIL and DDFT. Such microscopic changes may represent adaptive responses to stresses that may progress and contribute to lameness. (Am J Vet Res2001;62:414–424)
Use of intraosseous blood for repeated hematologic and biochemical analyses in healthy pigs
Authors: Greco Suellen C. , Talcott Michael R , LaRegina Marie C , Eisenbeis Paul E.
Published: December 2005

Objective—To evaluate the clinical and histologic effects of repeated intraosseous (IO) needle placement in domestic pigs and determine whether blood and serum obtained intraosseously could be used for CBC and biochemical analyses.

Animals—5 healthy 10-week-old pigs.

Procedure—An IO needle was placed in the proximomedial region of the tibia of anesthetized pigs every other week for 2 months, and IO blood was obtained for CBC and serum biochemical analyses. Results were compared with those obtained for blood collected at the same time from the auricular vein. Two weeks after the final samples were obtained, pigs were euthanatized and tibias were processed for histologic examination.

Results—Clinical abnormalities, including lameness, were not detected following IO needle placement. Histologic examination revealed only mild multifocal periosteal fibrosis and slight thickening of the periosteum without evidence of osteomyelitis. Chloride, creatinine, glucose, total protein, sodium, and BUN concentrations, alanine transaminase and gamma glutamyl transpeptidase activities, RBC count, mean corpuscular volume, and Hct did not significantly differ between IO and venous samples. However, aspartate transaminase activity, potassium, hemoglobin, and mean corpuscular hemoglobin concentrations, mean corpuscular hemoglobin, and platelet and WBC counts were significantly different.

Conclusion and Clinical Relevance—Repeated placement of IO needles may be a safe and clinically useful method to obtain serial blood samples from domestic pigs, particularly when other vascular sites are not accessible. Intraosseous blood can be used for many of the tests comprising CBC and serum biochemical analyses. (Am J Vet Res2001;62:43–47)