bluuebunny/crossref_metadata_2025 huggingface dataset:
Retention of ingested porcine reproductive and respiratory syndrome virus in houseflies
Authors: Schurrer Jennifer A. , Dee Scott A. , Moon Roger D. , Murtaugh Michael P. , Finnegan Colleen P. , Deen John , Kleiboeker Steven B. , Pijoan Carlos B. J.
Published: December 2005

Objective—To evaluate retention of porcine reproductive and respiratory syndrome virus (PRRSV) in houseflies for various time frames and temperatures.

Sample Population—Fifteen 2-week-old pigs, two 10-week-old pigs, and laboratory-cultivated houseflies.

Procedure—In an initial experiment, houseflies were exposed to PRRSV; housed at 15°, 20°, 25°, and 30°C; and tested at various time points. In a second experiment to determine dynamics of virus retention, houseflies were exposed to PRRSV and housed under controlled field conditions for 48 hours. Changes in the percentage of PRRSV-positive flies and virus load per fly were assessed over time, and detection of infective virus at 48 hours after exposure was measured. Finally, in a third experiment, virus loads were measured in houseflies allowed to feed on blood, oropharyngeal washings, and nasal washings obtained from experimentally infected pigs.

Results—In experiment 1, PRRSV retention in houseflies was proportional to temperature. In the second experiment, the percentage of PRRSV-positive houseflies and virus load per fly decreased over time; however, infective PRRSV was found in houseflies 48 hours after exposure. In experiment 3, PRRSV was detected in houseflies allowed to feed on all 3 porcine body fluids.

Conclusions and Clinical Relevance—For the conditions of this study, houseflies did not support PRRSV replication. Therefore, retention of PRRSV in houseflies appears to be a function of initial virus load after ingestion and environmental temperature. These factors may impact the risk of insect-borne spread of PRRSV among farms. (Am J Vet Res2005;66:1517–1525)
Assessment of the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique
Authors: Suchodolski Jan S. , Ruaux Craig G. , Steiner Jörg M. , Fetz Kathrin , Williams David A.
Published: December 2005

Objective—To evaluate the qualitative variation in bacterial microflora among compartments of the intestinal tract of dogs by use of a molecular fingerprinting technique.

Animals—14 dogs (similarly housed and fed identical diets).

Procedure—Samples of intestinal contents were collected from the duodenum, jejunum, ileum, colon, and rectum of each dog. Bacterial DNA was extracted from the samples, and the variable V6 to V8 region of 16S ribosomal DNA (gene coding for 16S ribosomal RNA) was amplified by use of universal bacterial primers; polymerase chain reaction amplicons were separated via denaturing gradient gel electrophoresis (DGGE). Similarity indices of DGGE banding patterns were used to assess variation in the bacterial microflora among different compartments of the intestine within and among dogs. Bacterial diversity was assessed by calculating the Simpson diversity index, the Shannon-Weaver diversity index, and evenness.

Results—DGGE profiles indicated marked differences in bacterial composition of intestinal compartments among dogs (range of similarity, 25.6% to 36.6%) and considerable variation among compartments within individual dogs (range of similarity, 36.7% to 57.9%). Similarities between neighboring intestinal compartments were significantly greater than those between non-neighboring compartments. Diversity indices for the colon and rectum were significantly higher than those of the duodenum, jejunum, and ileum.

Conclusions and Clinical Relevance—Results indicated that the different intestinal compartments of individual dogs appear to host different bacterial populations, and these compartmental populations vary among dogs. In dogs, fecal sample analysis may not yield accurate information regarding the composition of bacterial populations in compartments of the gastrointestinal tract. (Am J Vet Res2005;66:1556–1562)
Evaluation of cytokine production by equine alveolar macrophages exposed to lipopolysaccharide, Aspergillus fumigatus, and a suspension of hay dust
Authors: Laan Tamarinde T. J. M. , Bull Sarah , Pirie R. Scott , Fink-Gremmels Johanna
Published: December 2005

Objective—To evaluate cytokine production by
equine alveolar macrophages after exposure to
lipopolysaccharide (LPS), Aspergillus fumigatus, and
hay dust, and determine the effect of clenbuterol on
the cytokine response.

Animals—6 horses.

Procedures—Alveolar macrophages were exposed to
PBS solution (negative control), LPS, hyphae and conidia
of Aspergillus fumigatus (AF), or a suspension of
hay dust (HDS) and incubated for 24 hours at 37°C.
Concentrations of tumor necrosis factor (TNF)-α and
interleukin (IL)-1β were measured in the supernatant.
The procedure was repeated with cells that were concurrently
incubated with 0.5µM clenbuterol.

Results—Exposure to HDS and AF significantly
increased production of TNF-α by equine alveolar
macrophages. The increase in TNF-α produced in
response to HDS and AF was 5 and 7 times as great,
respectively, as the increase measured in response to
LPS. The concentration of IL-1β in the supernatant
was significantly increased after exposure of cells to
AF. Clenbuterol was effective at inhibiting TNF-α production
by cells exposed to LPS, HDS, or AF.

Conclusions and Clinical Relevance—Increased
production of TNF-α and IL-1 indicated that the proinflammatory
cytokines produced by alveolar
macrophages in response to allergens may play a role
in recurrent airway obstruction (RAO) in horses.
Equine alveolar macrophages are not only a primary
pulmonary defense mechanism but may also influence
the pathogenesis of equine RAO. The β2-adrenoceptor
agonist clenbuterol, a drug that is commonly
used for treatment of equine RAO, promotes immediate
bronchodilation and may also contribute to
downward modulation of the inflammatory response.
(Am J Vet Res 2005;66:1584–1589)
Evaluation of well-being, productivity, and longevity of pregnant sows housed in groups in pens with an electronic sow feeder or separately in gestation stalls
Authors: Anil Leena , Anil Sukumarannair S. , Deen John , Baidoo Samuel K. , Wheaton Jonathan E.
Published: December 2005

Objective—To compare well-being, performance,
and longevity of gestating sows housed in stalls or in
pens with an electronic sow feeder (ESF).

Animals—382 pregnant sows of parities 1 through 6.

Procedure—Sows were housed in separate stalls
(n = 176) or group pens (206) with an ESF. Well-being
of sows was assessed at various time points in terms
of injuries, salivary cortisol concentration, and behavior
in a novel arena or to a novel object. Farrowing performance
and longevity of sows were also assessed.

Results—Total injury scores (TIS) of sows in pens
were significantly higher at initial introduction and
mixing. In stall-housed sows, TIS was significantly
higher during late gestation. The TIS and cortisol concentration
were significantly lower in stall-housed
sows, compared with values for sows in pens. As parity
increased, the likelihood of higher median TIS
decreased significantly in pen-housed sows and
increased significantly in stall-housed sows. The TIS
of sows in pens was negatively correlated with body
weight and backfat thickness, whereas these correlations
were positive in stall-housed sows. Farrowing
performance and results for novel arena or objects did
not differ. Proportion of sows removed was significantly
higher for pens than for stalls; lameness was
the major reason for removal for both systems.

Conclusions and Clinical Relevance—Stalls impose
space restrictions for larger sows, resulting in injuries
during late gestation. Interventions are needed to
minimize aggression during initial introduction and
mixing and at the ESF in pens to reduce severe
injuries or lameness of gestating sows. (Am J Vet Res
2005;66:1630–1638)
Life expectancy in a birth cohort of Boxers followed up from weaning to 10 years of age
Authors: Hagen Marjan A. E. van , Ducro Bart J. , Broek Jan van den , Knol Bart W.
Published: December 2005

Objective—To determine mortality rate over time, risk factors for death, and heritability of life expectancy in Boxers.

Animals—1,733 purebred Boxers born in The Netherlands between January 1994 and March 1995.

Procedure—Dogs were followed up from weaning (ie, 49 days of age) to 10 years of age through use of a written questionnaire sent to owners every 6 months. Mortality rate over time, risk factors potentially associated with death, and heritability of life expectancy were examined by use of a proportional hazards model based on the Weibull distribution.

Results—Estimated mortality rate during the 10-year study period for this birth cohort of Boxers was 45%. The probability of surviving to 5 years of age was 88%; the probability of surviving to 10 years of age was 55%. Estimated effective heritability of life expectancy was 0.076, meaning that in this population, an estimated 7.6% of the observed variation in life expectancy could be attributed to genetic differences among dogs that were passed from parents to their offspring.

Conclusions and Clinical Relevance—Results suggest that cumulative incidence of death from weaning to 10 years of age among this birth cohort of Boxers was 45%. The estimated heritability of life expectancy suggested that life expectancy can be improved by use of selective breeding. (Am J Vet Res2005;66:1646–1650)
Rate of change of oxygen concentration for a large animal circle anesthetic system
Authors: Solano Adrian M. , Brosnan Robert J. , Steffey Eugene P.
Published: December 2005

Objective—To describe the effects of changes in circuit
volume and oxygen inflow rate on inspired oxygen
concentration for a large animal circle anesthetic
system.

Study Population—A large animal circle anesthetic
system, a 10 L/min flowmeter, and 20- and 40-L
breathing bags.

Procedure—Circuit volume was determined by a carbon
dioxide dilution technique. Oxygen flow rates of
3, 6, and 10 L/min were delivered to the circuit with
the large breathing bag, and a flow rate of 6 L/min
was used with the small bag. Gas samples were collected
during a 20-minute period. The time constant
(τ) and half-time (T1/2) were calculated and compared
with measured values.

Results—Mean ± SEM volume of the breathing circuit
with a 20- and 40-L breathing bag was 32.97 ±
0.91 L and 49.26 ± 0.58 L, respectively. The from
measurements was 11.97, 6.10, and 3.60 minutes at
oxygen flow rates of 3, 6, and 10 L/min, respectively,
for the large breathing bag and 3.73 minutes at a flow
rate of 6 L/min for the small breathing bag. The T1/2
was 8.29, 4.22, and 2.49 minutes at oxygen flow
rates of 3, 6, and 10 L/min, respectively, for the large
breathing bag and 2.58 minutes for the small breathing
bag.

Conclusions and Clinical Relevance—This study
emphasizes that there are delays in the rate of
increase in the inspired oxygen concentration that
accompany use of conventional large animal circle
anesthetic systems and low rates of inflow for fresh
oxygen. (Am J Vet Res 2005;66:1675–1678)
Pharmacokinetics and tissue distribution of itraconazole after oral and intravenous administration to horses
Authors: Davis Jennifer L. , Salmon Jacklyn H. , Papich Mark G.
Published: December 2005

Objective—To determine the pharmacokinetics of itraconazole after IV or oral administration of a solution or capsules to horses and to examine disposition of itraconazole in the interstitial fluid (ISF), aqueous humor, and polymorphonuclear leukocytes after oral administration of the solution.

Animals—6 healthy horses.

Procedure—Horses were administered itraconazole solution (5 mg/kg) by nasogastric tube, and samples of plasma, ISF, aqueous humor, and leukocytes were obtained. Horses were then administered itraconazole capsules (5 mg/kg), and plasma was obtained. Three horses were administered itraconazole (1.5 mg/kg, IV), and plasma samples were obtained. All samples were analyzed by use of high-performance liquid chromatography. Plasma protein binding was determined. Data were analyzed by compartmental and noncompartmental pharmacokinetic methods.

Results—Itraconazole reached higher mean ± SD plasma concentrations after administration of the solution (0.41 ± 0.13 µg/mL) versus the capsules (0.15 ± 0.12 µg/mL). Bioavailability after administration of capsules relative to solution was 33.83 ± 33.08%. Similar to other species, itraconazole has a high volume of distribution (6.3 ± 0.94 L/kg) and a long half-life (11.3 ± 2.84 hours). Itraconazole was not detected in the ISF, aqueous humor, or leukocytes. Plasma protein binding was 98.81 ± 0.17%.

Conclusions and Clinical Relevance—Itraconazole administered orally as a solution had higher, more consistent absorption than orally administered capsules and attained plasma concentrations that are inhibitory against fungi that infect horses. Administration of itraconazole solution (5 mg/kg, PO, q 24 h) is suggested for use in clinical trials to test the efficacy of itraconazole in horses. (Am J Vet Res2005;66:1694–1701)
Vasopressin, cortisol, and catecholamine concentrations in dogs with dilated cardiomyopathy
Authors: Tidholm Anna , Häggström Jens , Hansson Kerstin
Published: December 2005

Objective—To evaluate plasma concentrations and urinary excretion of vasopressin and cortisol and urinary excretion of catecholamines in dogs with dilated cardiomyopathy (DCM).

Animals—15 dogs with clinical signs of DCM, 15 dogs with preclinical DCM, and 15 control dogs.

Procedure—Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs. Blood and urine samples were collected.

Results—Plasma concentration of vasopressin and the urine cortisol-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM and dogs with preclinical DCM, compared with control dogs. Plasma vasopressin concentration was significantly higher in dogs with clinical signs of DCM, compared with dogs with preclinical DCM. Urine vasopressin-to-urine creatinine ratio was significantly increased in dogs with clinical signs of DCM, compared with dogs with preclinical DCM and control dogs. Urine epinephrine-to-urine creatinine ratio and urine norepinephrine-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM, compared with control dogs. Plasma concentration of cortisol and urine dopamine-to-urine creatinine ratio did not differ significantly among groups.

Conclusions and Clinical Relevance—According to this study, the neuroendocrine pattern is changed in dogs with preclinical DCM. These changes are even more pronounced in dogs with clinical signs of DCM. Analysis of concentrations of vasopressin, cortisol, and catecholamines may aid in identification of the clinical stages of DCM. These findings may also provide a basis for additional studies of the possible beneficial effects of vasopressin antagonists and β-adrenergic receptor antagonists in the treatment of dogs with congestive heart failure and DCM. (Am J Vet Res2005;66:1709–1717)
Serum creatine kinase response to exercise during dexamethasone-induced insulin resistance in Quarter Horses with polysaccharide storage myopathy
Authors: Firshman Anna M. , Valberg Stephanie J. , Karges Tami L. , Benedict Luke E. , Annandale Erin J. , Seaquist Elizabeth R.
Published: December 2005

Objective—To determine effects of dexamethasone on insulin sensitivity, serum creatine kinase (CK) activity 4 hours after exercise, and muscle glycogen concentration in Quarter Horses with polysaccharide storage myopathy (PSSM).

Animals—4 adult Quarter Horses with PSSM.

Procedure—A 2 × 2 crossover design was used with dexamethasone (0.08 mg/kg) or saline (0.9% NaCl) solution administered IV every 48 hours. Horses were exercised on a treadmill daily for 3 wk/treatment with a 2-week washout period between treatments. Serum CK activity was measured daily 4 hours after exercise. At the end of each treatment period, serum cortisol concentrations were measured, a hyperinsulinemic euglycemic clamp (HEC) technique was performed, and muscle glycogen content was determined.

Results—Mean ± SEM serum cortisol concentration was significantly lower after 48 hours for the dexamethasone treatment (0.38 ± 0.08 mg/dL), compared with the saline treatment (4.15 ± 0.40 mg/dL). Dexamethasone significantly decreased the rate of glucose infusion necessary to maintain euglycemia during the HEC technique, compared with the saline treatment. Muscle glycogen concentrations and mean CK activity after exercise were not altered by dexamethasone treatment, compared with the saline treatment.

Conclusions and Clinical Relevance—Dexamethasone significantly reduced whole-body insulin-stimulated glucose uptake in Quarter Horses with PSSM after a 3-week period but did not diminish serum CK response to exercise or muscle glycogen concentrations in these 4 horses. Therefore, a decrease in glucose uptake for 3 weeks did not appear to alleviate exertional rhabdomyolysis in these horses. It is possible that long-term treatment may yield other results. (Am J Vet Res2005;66:1718–1723)
Platelet function and association of bovine viral diarrhea virus with platelets of persistently infected cattle
Authors: Walz Paul H. , Grooms Daniel L. , Bell Thomas G. , Kaiser Lana , Baker John C. , Brock Kenny V.
Published: December 2005

Objective—To determine whether viral involvement with platelets obtained from cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) is associated with altered platelet function or decreased platelet counts.

Sample Population—Platelets obtained from 8 cattle PI with BVDV and 6 age-, sex-, and breed-matched uninfected control cattle.

Procedure—Manual platelet counts were determined, and platelet function was assessed through optical aggregometry by use of the aggregation agonists ADP and platelet-activating factor. Identification of BVDV in serum and preparations of purified platelets was determined by use of virus isolation tests.

Results—No significant difference in platelet counts was detected between cattle PI with BVDV and control cattle. In response to the aggregation agonists, maximum aggregation percentage and slope of the aggregation curve were not significantly different between cattle PI with BVDV and control cattle. We isolated BVDV from serum of all PI cattle and from purified platelets of 6 of 8 PI cattle, but BVDV was not isolated from serum or platelets of control cattle.

Conclusions and Clinical Relevance—Isolation of BVDV from platelets in the peripheral circulation of cattle immunotolerant to BVDV does not result in altered platelet function or decreases in platelet counts. (Am J Vet Res2005;66:1738–1742)
Effects of radial shock waves on membrane permeability and viability of chondrocytes and structure of articular cartilage in equine cartilage explants
Authors: Byron Christopher R. , Benson Britany M. , Stewart Allison A. , Stewart Matthew C.
Published: December 2005

Objective—To investigate in vitro effects of radial
shock waves on membrane permeability, viability, and
structure of chondrocytes and articular cartilage.

Sample Population—Cartilage explants obtained
from the third metacarpal and metatarsal bones of 6
horses.

Procedure—Equine cartilage was subjected to radial
shock waves and then maintained as explants in culture
for 48 hours. Treatment groups consisted of a
negative control group; application of 500, 2,000, and
4,000 impulses by use of a convex handpiece (group
A); and application of 500, 2,000, and 4,000 impulses
by use of a concave handpiece (group B). Effects on
explant structure were evaluated by use of environmental
scanning electron microscopy (ESEM).
Membrane permeability was determined by release
of lactate dehydrogenase (LDH). Chondrocyte viability
was assessed by use of vital cell staining.
Comparisons of LDH activity and nonviable cell percentages
were performed by ANOVA.

Results—Cell membrane permeability increased significantly
after application of 2,000 and 4,000 impulses
in groups A and B. A significant decrease in cell viability
was observed for application of 4,000 impulses
in explants of group A. There was no detectable damage
to integrity of cartilage explants observed in any
treatment group by use of ESEM.

Conclusions and Clinical Relevance—Radial shock
waves do not appear to structurally damage articular
cartilage but do impact chondrocyte viability and
membrane permeability. Caution should be exercised
when extremely high periarticular pulse doses are
used until additional studies can determine the longterm
outcome of these effects and appropriate periarticular
treatment regimens can be validated. (Am J
Vet Res 2005;66:1757–1763)
Evaluation of papillomaviruses associated with cyclosporine-induced hyperplastic verrucous lesions in dogs
Authors: Favrot Claude , Olivry Thierry , Werner Alexander H. , Nespecca Gilles , Utiger Anna , Grest Paula , Ackermann Mathias
Published: December 2005

Objective—To determine whether cyclosporine Ainduced hyperplastic skin lesions of dogs were associated with papillomavirus infections.

Animals—9 dogs that were treated with cyclosporine A and developed hyperplastic skin lesions.

Procedure—History and clinical and histopathologic data were collected. Paraffin-embedded skin biopsy specimens from hyperplastic skin lesions were immunostained for common papillomavirus genusspecific structural antigens by use of a polyclonal rabbit anti-bovine papillomavirus type 1 antiserum. Sections from each tissue block underwent DNA extraction, and polymerase chain reaction (PCR) assays were performed with several sets of primers to amplify a wide range of papillomavirus DNA from humans and other animals.

Results—In 7 of 9 dogs, there were more than 10 hyperplastic skin lesions that microscopically resembled those of psoriasiform lichenoid dermatosis. In those dogs, results of testing for papillomavirus via immunohistochemical analyses and PCR assays were negative. In the other 2 dogs, there were only 1 and 3 verrucous lesions, and in those dogs, histologic evaluation revealed koilocytes and nuclear viral inclusions that were immunoreactive for papillomavirus antigens. Papillomavirus DNA was amplified from both dogs. One of the sequences was characteristic for the canine oral papillomavirus, whereas the other had similarities with the recently described canine papillomavirus 2.

Conclusions and Clinical Relevance—In dogs, hyperplastic skin lesions occasionally develop during treatment with cyclosporine A. Most of the lesions resemble those of psoriasiform lichenoid dermatosis, although papillomavirus can be detected in some instances. (Am J Vet Res2005;66:1764–1769)
Characterization of protection from systemic infection and disease by use of a modified-live noncytopathic bovine viral diarrhea virus type 1 vaccine in experimentally infected calves
Authors: Kelling Clayton L. , Hunsaker Breck D. , Steffen David J. , Topliff Christina L. , Abdelmagid Omar Y. , Eskridge Kent M.
Published: December 2005

Objective—To evaluate protection against systemic infection and clinical disease provided by use of a modified-live noncytopathic bovine viral diarrhea virus (BVDV) type 1 vaccine in calves challenged with NY-1 BVDV.

Animals—10 calves, 5 to 7 months of age.

Procedures—Calves were allocated (n = 5/group) to be nonvaccinated or vaccinated SC on day 0 with BVDV type 1 (WRL strain). Calves in both groups were challenged intranasally with NY-1 BVDV on day 21. Calves' rectal temperatures and clinical signs of disease were recorded daily, total and differential WBC and platelet counts were performed, and serum neutralizing antibody titers against NY-1 BVDV were determined. Histologic examinations and immunohistochemical analyses to detect gross lesions and distribution of viral antigens, respectively, were performed.

Results—After challenge exposure to NY-1 BVDV, nonvaccinated calves developed high rectal temperatures, increased respiratory rates, viremia, leukopenia, lymphopenia, and infection of the thymus. Vaccinated calves did not develop high rectal temperatures or clinical signs of respiratory tract disease. Vaccinated calves appeared to be protected against systemic replication of virus in that they did not develop leukopenia, lymphopenia, viremia, or infection of target organs, and infectious virus was not detected in peripheral blood mononuclear cells or the thymus.

Conclusions and Clinical Relevance—The modifiedlive BVDV vaccine protected calves against systemic infection and disease after experimental challenge exposure with NY-1 BVDV. The vaccine protected calves against infection and viremia and prevented infection of target lymphoid cells. (Am J Vet Res2005;66:1785–1791)
Experimental canine leptospirosis caused by Leptospira interrogans serovars pomona and bratislava
Authors: Greenlee Justin J. , Alt David P. , Bolin Carole A. , Zuerner Richard L. , Andreasen Claire B.
Published: December 2005

Objective—To evaluate gross, histopathologic, and serum biochemical findings caused byLeptospira interrogansserovars pomona and bratislava inoculated in dogs.

Animals—Twenty-seven 8-week-old female Beagles.

Procedure—Dogs were randomly assigned to challenge or control groups. Challenge groups were conjunctivally inoculated on 3 successive days with 5 ×107L interrogansserovar pomona (n = 12) or serovar bratislava (11). Clinical signs were recorded throughout the experiment, and clinical pathology assays, bacteriologic culture, and necropsies (6 or 7 dogs necropsied at each time point) were done on postinoculation day (PID) 7, 10, 14, and 20.

Results—Infection could not be confirmed in any serovar bratislava–inoculated dog, and control dogs remained healthy throughout the experiment. Positive culture and fluorescent antibody test results were confirmed in 11 of 12 serovar pomona–inoculated dogs. Fever and lethargy starting at PID 7 were the most common clinical signs in serovar pomona–infected dogs. On day 10, gross lesions included multifocal renal and pulmonary hemorrhage and perirenal edema. Serovar pomona–inoculated dogs had histopathologic lesions including hepatitis, interstitial nephritis, and pneumonia at PID 7, 10, 14, and 20. Increases in BUN, anion gap, and bilirubin concentration occurred on PID 10, 14, and 20. Platelet counts in dogs with positive results of bacteriologic culture were decreased from baseline values on PID 10, 12, and 14.

Conclusions and Clinical Relevance— Conjunctival inoculation with L interrogans serovar pomona resulted in a high rate of infection with concomitant hemorrhagic and inflammatory lesions of the kidneys, liver, and lungs. (Am J Vet Res2005;66:1816–1822)
Assessment of scintigraphic and thermographic changes after focused extracorporeal shock wave therapy on the origin of the suspensory ligament and the fourth metatarsal bone in horses without lameness
Authors: Ringer Simone K. , Lischer Christoph J. , Ueltschi Gottlieb
Published: December 2005

Objective—To monitor the effect of focused extracorporeal
shock wave therapy (ESWT) on bone and
bone-tendon junction of horses without lameness by
use of nuclear scintigraphy and thermography.

Animals—6 warmblood horses without lameness.

Procedure—The origin of the suspensory ligament at
the metacarpus (OSL-MC) and the fourth metatarsal
bone were treated at 2 time points (days 0 and 16)
with 2,000 shocks applied by a focused ESWT device
at an energy flux density of 0.15 mJ/mm2. One forelimb
and 1 hind limb were treated, and the contralateral
limbs served as controls. To document the effect
of focused ESWT, nuclear scintigraphy was performed
on days -1, 3, 16 (before second ESWT), and
19. Thermography was performed on days -1, 0 (1
hour after first ESWT), 1, 3, 8, 16 (twice; before and 1
hour after second ESWT), and 19. On days 3, 16 (first
scans), and 19, thermography was performed before
scintigraphy.

Results—Scintigraphically, significant variations in
radiopharmaceutical activity at the OSL-MC were
detected in treatment and control limbs. No significant
differences, however, in mean temperature or
radiopharmaceutical activity could be detected by use
of thermography or nuclear scintigraphy, respectively,
between the treatment and control limbs at any time
point in response to ESWT.

Conclusions and Clinical Relevance—After 2 treatments
of focused ESWT, no physiologic effect on the
studied structures could be demonstrated by use of
nuclear scintigraphy or thermography. Results of this
study indicate that at currently used ESWT settings,
no damage to the bone or bone-tendon junction
should occur. (Am J Vet Res 2005;66:1836–1842)
Effects of glucosamine and chondroitin sulfate on mediators of osteoarthritis in cultured equine chondrocytes stimulated by use of recombinant equine interleukin-1β
Authors: Neil Kirsten M. , Orth Michael W. , Coussens Paul M. , Chan Pooi-See , Caron John P.
Published: December 2005

Objective—To determine whether glucosamine and chondroitin sulfate (CS) at concentrations approximating those achieved in plasma by oral administration would influence gene expression of selected mediators of osteoarthritis in cytokine-stimulated equine articular chondrocytes.

Sample Population—Samples of grossly normal articular cartilage obtained from the metacarpophalangeal joint of 13 horses.

Procedure—Equine chondrocytes in pellet culture were stimulated with a subsaturating dose of recombinant equine interleukin (reIL)-1β. Effects of prior incubation with glucosamine (2.5 to 10.0 µg/mL) and CS (5.0 to 50.0 µg/mL) on gene expression of matrix metalloproteinase (MMP)-1, -2, -3, -9, and -13; aggrecanase 1 and 2; inducible nitric oxide synthase (iNOS); cyclooxygenase (COX)-2; nuclear factor κB; and c-Jun- N-terminal kinase (JNK) were assessed by use of a quantitative real-time polymerase chain reaction assay.

Results—Glucosamine at a concentration of 10 µg/mL significantly reduced reIL-1β–induced mRNA expression of MMP-13, aggrecanase 1, and JNK. Reductions in cytokine-induced expression were also observed for iNOS and COX-2. Chondroitin sulfate had no effect on gene expression at the concentrations tested.

Conclusions and Clinical Relevance—Concentrations of glucosamine similar to those achieved in plasma after oral administration in horses exerted pretranslational regulation of some mediators of osteoarthritis, an effect that may contribute to the cartilage- sparing properties of this aminomonosaccharide. Analysis of results of this study indicated that the influence of CS on pretranslational regulation of these selected genes is limited or lacking. (Am J Vet Res2005;66:1861–1869)
Effects of short- and long-term recombinant equine growth hormone and short-term hydrocortisone administration on tissue sensitivity to insulin in horses
Authors: Graaf-Roelfsema Ellen de , Tharasanit Theerawat , Dam Klien G. van , Keizer Hans A. , Breda Erik van , Wijnberg Inge D. , Stout Tom A. E. , Kolk Johannes H. van der
Published: December 2005

Objective—To determine the effects of short-term IV administration of hydrocortisone or equine growth hormone (eGH) or long-term IM administration of eGH to horses on tissue sensitivity to exogenous insulin.

Animals—5 Standardbreds and 4 Dutch Warmblood horses.

Procedure—The euglycemic-hyperinsulinemic clamp technique was used to examine sensitivity of peripheral tissues to exogenous insulin 24 hours after administration of a single dose of hydrocortisone (0.06 mg/kg), eGH (20 µg/kg), or saline (0.9% NaCl) solution and after long-term administration (11 to 15 days) of eGH to horses. The amounts of metabolized glucose (M) and plasma insulin concentration (I) were determined.

Results—Values for M and the M-to-I ratio were significantly higher 24 hours after administration of a single dose of hydrocortisone than after single-dose administration of eGH or saline solution. After long-term administration of eGH, basal I concentration was increased and the mean M-to-I ratio was 22% lower, compared with values for horses treated with saline solution.

Conclusions and Clinical Relevance—Increases in M and the M-to-I ratio after a single dose of hydrocortisone imply that short-term hydrocortisone treatment increases glucose use by, and insulin sensitivity of, peripheral tissues. Assuming a single dose of hydrocortisone improves sensitivity of peripheral tissues to insulin, it may be an interesting candidate for use in reducing insulin resistance in peripheral tissues of horses with several disease states. In contrast, long-term administration of eGH decreased tissue sensitivity to exogenous insulin associated with hyperinsulinemia. Therefore, increased concentrations of growth hormone may contribute to insulin resistance in horses with various disease states. (Am J Vet Res2005;66:1907–1913)
Immunohistochemical analysis of the distribution of desmoglein 1 and 2 in the skin of dogs and cats
Authors: Miragliotta Vincenzo , Coli Alessandra , Ricciardi Maria P. , Podestà Adriano , Abramo Francesca
Published: December 2005

Objective—To compare the distribution of
desmoglein (Dsg) 1 and 2 in skin specimens obtained
from dogs and cats to provide information about the
possible role of the density of Dsg 1 and 2 in the localization
of lesions attributable to pemphigus foliaceus
in these 2 species.

Sample Population—Skin biopsy specimens
obtained from 4 dogs and 4 cats.

Procedure—Biopsy specimens were collected from
the muzzle, bridge of the nose, ear, dorsum,
abdomen, area adjacent to the teats, and footpads of
each animal. Immunohistochemical analysis was performed
on formalin-fixed, paraffin-embedded skin
samples by use of a biotinylated mouse monoclonal
anti-Dsg 1 and 2 antibody raised against bovine muzzle.
Color development was performed by use of the
streptavidin-biotin-peroxidase method with a chromogenic
substrate.

Results—Immunohistochemical staining yielded a
positive reaction in skin samples obtained from all
anatomic sites. The intensity and distribution of staining
were related to the number of layers of the stratum
spinosum. No differences were detected
between samples obtained from dogs and cats.

Conclusions and Clinical Relevance—No differences
in intensity of Dsg 1 and 2 antigen were observed in
the stratum spinosum between skin samples obtained
from dogs and cats. Analysis of this result suggests
that factors other than the distribution of Dsg may be
responsible for the differences in localization of primary
clinical lesions in dogs and cats with pemphigus foliaceus.
(Am J Vet Res 2005;66:1931–1935)
Evaluation of a recombinant human adenovirus-5 vaccine administered via needle-free device and intramuscular injection for vaccination of pigs against swine influenza virus
Authors: Wesley Ronald D. , Lager Kelly M.
Published: December 2005

Objective—To evaluate the safety and efficacy of a
human adenovirus-5 vaccine for protecting weaned
pigs against swine influenza virus subtype H3N2
infection when administered via 2 injection methods.

Animals—76 pigs.

Procedure—6 groups of weaned pigs received a 10-
fold serial dilution of recombinant adenovirus expressing
H3 hemagglutinin and a constant amount of
recombinant adenovirus expressing nucleoprotein,
either via a needle-free injection device or by traditional
IM injection. In each group of 10 pigs, 1 served
as a nonvaccinated contact pig to monitor whether
there was spread of vaccinial virus from pig to pig.
Vaccinated pigs and nonvaccinated controls were
challenged or sham-inoculated 5 weeks later. After
challenge, pigs were observed for clinical signs and
nasal secretions were tested for virus. On day 5 after
challenge, pigs were euthanatized; lungs were examined
for gross lesions, and bronchoalveolar lavage
specimens were tested for virus replication.

Results—A hemagglutination inhibition (HI) antibody
response was elicited in a dose-dependent manner.
Traditional IM administered vaccination induced consistently
higher HI antibody responses than vaccination
via needle-free injection, but the differences were
not significant. Likewise, traditional IM administration
was superior at reducing nasal virus shedding except
at the highest dose, at which both methods blocked
virus replication. The severity of lung lesions was
reduced in a dose-dependent manner by both vaccination
methods. Sentinel pigs did not seroconvert.

Conclusions and Clinical Relevance—The human
adenovirus-5 vaccine at high doses prevented nasal
virus shedding after challenge exposure with both
methods of administration. The replication-defective
vaccine virus was not transmitted to sentinel pigs.
(Am J Vet Res 2005;66:1943–1947)
Evaluation of an osteoconductive resorbable calcium phosphate cement and polymethylmethacrylate for augmentation of orthopedic screws in the pelvis of canine cadavers
Authors: Hutchinson Geoffrey S. , Griffon Dominique J. , Siegel Arthur M. , Pijanowski Gerald J. , Kurath Peter , Eurell Jo Ann C. , Johnson Ann L.
Published: December 2005

Objective—To evaluate the effect of an osteoconductive resorbable calcium phosphate cement (CPC) on the holding power of bone screws in canine pelvises and to compare the effect with that for polymethylmethacrylate (PMMA).

Sample Population—35 pelvises obtained from canine cadavers.

Procedure—Each pelvis was sectioned longitudinally. Within each pair of hemipelvises, one 4.0-mm cancellous screw was placed in the sacroiliac (SI) region and another in the iliac body. Similar regions on the contralateral- matched hemipelvis were assigned 1 of 3 augmentation techniques (CPC-augmented 4.0-mm cancellous screws, PMMA-augmented 4.0-mm cancellous screws, and CPC-augmented 3.5-mm cortical screws). Pullout force was compared between matched screws and between treatment groups prior to examination of cross sections for evaluation of cement filling and noncortical bone-to-cortical bone ratio.

Results—CPC and PMMA augmentation significantly increased pullout force of 4.0-mm screws inserted in the SI region by 19.5% and 33.2%, respectively, and CPC augmentation significantly increased pullout force of 4.0-mm cancellous screws inserted in the iliac body by 21.2%. There was no difference in the mean percentage augmentation between treatment groups at either location. Cement filling was superior in noncortical bone, compared with filling for cortical bone. Noncortical bone-to-cortical bone ratio was significantly greater in the sacrum (6.1:1) than the ilium (1.3:1).

Conclusions and Clinical Relevance—CPC and PMMA improve the ex vivo holding strength of 4.0-mm cancellous screws in the SI and iliac body regions and SI region, respectively. Cement augmentation may be more effective in areas with greater noncortical bone-to-cortical bone ratios. (Am J Vet Res2005;66:1954–1960)
Evaluation of coexpression of microsomal prostaglandin E synthase-1 and cyclooxygenase-2 in interleukin-1– stimulated equine articular chondrocytes
Authors: Farley Judith , Sirois Jean , MacFarlane Patrick-Hubert , Kombé Aimé , Laverty Sheila
Published: December 2005

Objective—To characterize expression of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) and regulation of prostaglandin E2(PGE2) production by equine articular chondrocytes.

Sample Population—Articular cartilage from the metacarpophalangeal joints of 7 adult horses.

Procedure—Equine chondrocyte monolayer cultures were stimulated with different concentrations (2.5, 5, 10, and 20 ng/mL) of recombinant human interleukin- 1β (rhIL-1β) for 24 hours and then with rhIL-1β (5 ng/mL) for 3, 6, 9, 12, and 24 hours. Concentration of PGE2in the media was measured via radioimmunoassay. Total RNA was extracted from harvested chondrocytes, and regulation of COX-2 and mPGES-1 mRNA was studied via reverse transcriptase-polymerase chain reaction assay and Southern blot analysis with equine-specific probes. Western blot analyses were performed on cellular extracts to characterize expression of COX-2 and mPGES-1 protein.

Results—Stimulation with 5, 10, and 20 ng of rhIL- 1β/mL caused a significant increase in PGE2concentrations in the culture media, and incubation of cells with rhIL-1β (5 ng/mL) for 6 to 24 hours increased PGE2production significantly. The increase in prostaglandin production was associated with an induction of COX-2 and mPGES-1 transcripts. There also was an rhIL-1β–dependent induction in COX-2 and mPGES-1 protein expression.

Conclusions and Clinical Relevance—Collectively, results indicated that the rhIL-1β–dependent increase in PGE2production in equine chondrocytes in monolayer culture was associated with coordinated upregulation of COX-2 and mPGES-1 expression. The pathophysiologic consequences of upregulated COX-2 and mPGES-1 expression and of PGE2synthesis in rhIL-1β–stimulated equine chondrocytes remain to be elucidated. (Am J Vet Res2005;66:1985–1991)
Direct and indirect markers of cartilage metabolism in synovial fluid obtained from dogs with hip dysplasia and correlation with clinical and radiographic variables
Authors: Fujita Yukihiro , Hara Yasushi , Nezu Yoshinori , Yamaguchi Shinya , Schulz Kurt S. , Tagawa Masahiro
Published: December 2005

Objective—To compare activities of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and matrix metalloproteinase (MMP)-3 and contents of sulfated glycosaminoglycan (S-GAG) in joint fluid obtained from dogs with hip dysplasia (HD) and clinically normal dogs, evaluate correlations among these markers in joint fluid obtained from dogs with HD, and evaluate correlations between each marker and clinical and radiographic variables.

Animals—26 dogs with HD (clinical group) and 43 clinically normal Beagles (control group).

Procedure—Joint fluid was aseptically collected from the hip joints of all dogs. For each dog in the clinical group, age, duration of lameness, radiographic osteoarthritis (OA) score, and Norberg angle in each affected joint were recorded. Activities of IL-1β, IL-6, TNF-α, and MMP-3 and S-GAG contents were measured. Values were compared between groups by use of Mann-WhitneyUtests, and the Spearman rank correlation test was used to evaluate correlations among markers and between each marker and clinical or radiographic variables.

Results—Values of all markers were significantly higher for the clinical group, compared with values for the control group. There was a moderate positive correlation between lameness duration and IL-6 activity and a strong negative correlation between the Norberg angle and IL-1β activity.

Conclusions and Clinical Relevance—Analysis of our results indicated that there was a significant increase in markers of OA in dogs with HD. Activities of IL-1β and IL-6 in joint fluid of dogs with HD may be influenced by the severity of laxity in the hip joint and lameness duration, respectively. (Am J Vet Res2005;66:2028–2033)
Evaluation of the internal vertebral venous plexus, vertebral canal, dural sac, and vertebral body via nonselective computed tomographic venography in the cervical vertebral column in healthy dogs
Authors: Gómez Marcelo A. , Jones Jeryl C. , Broadstone Richard V. , Inzana Karen D. , Freeman Larry E.
Published: December 2005

Objective—To evaluate nonselective computed tomographic (CT) venography for evaluating the cervical internal vertebral venous plexus (IVVP), define the diameter and area dimensions of the IVVP, and determine the relationship between dimensions of the cervical IVVP and other vertebral components in medium-sized dogs.

Animals—6 healthy dogs that weighed 18 to 27 kg.

Procedure—Helical CT scans were performed from C1 to C7 before and after IV injection of contrast medium (480 mg of iodine/kg) and a continuous infusion (240 mg of iodine/kg). Image data were transferred to a CT workstation, and measurements were performed on displayed transverse images. Diameter and area measurements of the vertebral canal, dural sac, IVVP, and vertebral body were obtained at C3 to C7.

Results—Opacification of vertebral venous structures was achieved in all dogs with no adverse reactions. Sagittal diameters of the IVVP for C3 to C7 ranged from 0.6 to 3.2 mm. Transverse diameters ranged from 2.32 to 5.74 mm. The IVVP area represented 12.4% of the mean vertebral canal transverse area and 30.61% of the mean vertebral epidural space area. Area measurements of the IVVP were significantly correlated with vertebral canal area and dural sac area.

Conclusions and Clinical Relevance—Results indicated that nonselective CT venography is a safe, sensitive method for performing morphometric assessments of the cervical IVVP in dogs. Findings support the theory that there may be a physiologic or developmental relationship between cervical vertebral canal components. (Am J Vet Res2005;66:2039–2045)
Use of gyroscopic sensors for objective evaluation of trimming and shoeing to alter time between heel and toe lift-off at end of the stance phase in horses walking and trotting on a treadmill
Authors: Keegan Kevin G. , Satterley Justin M. , Skubic Marge , Yonezawa Yoshiharu , Cooley Jason M. , Wilson David A. , Kramer Joanne
Published: December 2005

Objective—To determine whether a shoe with an axialcontoured lateral branch would induce greater lateral roll of the forelimb hoof during the time between heel and toe lift-off at end of the stance phase (breakover).

Animals—10 adult horses.

Procedure—A gyroscopic transducer was placed on the hoof of the right forelimb and connected to a transmitter. Data on hoof angular velocity were collected as each horse walked and trotted on a treadmill before (treatment 1, no trim–no shoe) and after 2 treatments by a farrier (treatment 2, trim–standard shoe; and treatment 3, trim–contoured shoe). Data were converted to hoof angles by mathematical integration. Breakover duration was divided into 4 segments, and hoof angles in 3 planes (pitch, roll, and yaw) were calculated at the end of each segment. Multivariable ANOVA was performed to detect differences among treatments and gaits.

Results—Trimming and shoeing with a shoe with contoured lateral branches induced greater mean lateral roll to the hoof of 3.2° and 2.5° during the first half of breakover when trotting, compared with values for no trim–no shoe and trim–standard shoe, respectively. This effect dissipated during the second half of breakover. When horses walked, lateral roll during breakover was not significantly enhanced by use of this shoe.

Conclusions and Clinical Relevance—A shoe with an axial-contoured lateral branch induced greater lateral roll during breakover in trotting horses, but change in orientation of the hoof was small and limited to the first half of breakover. (Am J Vet Res2005;66:2046–2054)
Clinicopathologic findings in dogs seroreactive to Bartonella henselae antigens
Authors: Goodman Robert A. , Breitschwerdt Edward B.
Published: December 2005

Objective—To assess the potential clinical relevance
of seroreactivity to Bartonella henselae antigens in
dogs.

Animals—40 dogs seroreactive to B henselae and 45
dogs that did not seroreact to B henselae.

Procedure—A case-control study was conducted.
Clinical and clinicopathologic findings were extracted
from medical records of each dog.

Results—Statistical differences were not detected
between dogs seroreactive or nonseroreactive to
B henselae when analyzed on the basis of disease
category or results of hematologic, biochemical,
urine, or cytologic analysis. However, seroreactivity
to B henselae antigens was detected in 2 of 4 dogs
with a clinical diagnosis of granulomatous meningoencephalitis,
3 of 4 dogs with immune-mediated
hemolytic anemia, 3 of 4 dogs with infective endocarditis,
2 of 3 dogs with lymphoid neoplasia, and 5
of 10 dogs with polyarthritis. Additionally, seroreactivity
to B henselae antigens was detected in 18 of
34 thrombocytopenic dogs and 14 of 27 dogs with
neutrophilia.

Conclusions and Clinical Relevance—Significant
associations were not detected between seroreactivity
to B henselae and various diseases. Prospective
epidemiologic studies investigating specific diseases,
such as meningoencephalitis or polyarthritis, and specific
hematologic abnormalities, such as immunemediated
hemolytic anemia or thrombocytopenia,
should be conducted to further define the potential
clinical relevance of antibodies against B henselae in
dogs.

Impact for Human Medicine—Bartonella organisms
are increasingly reported as pathogens that induce
are increasingly reported as pathogens that induce
chronic infections in humans and dogs. Dogs may
serve as natural candidates for future study of the disease
in humans. (Am J Vet Res 2005;66:2060–2064)