bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of α-tocopheryl acetate supplementation on vitamin E concentrations in Greyhounds before and after a race
Authors: Scott Karen C. , Hill Richard C. , Lewis Daniel D. , Boning Alvin J. , Sundstrom Deborah A.
Published: December 2005

Objectives—To determine effect of α-tocopherol
supplementation on serum vitamin E concentrations
in Greyhounds before and after a race.

Animals—8 adult racing Greyhounds.

Procedure—Dogs were given 2 capsules of α-tocopheryl
acetate (total, 680 units [0.5 g]) with food that
contained ≤ 15 mg of vitamin E/kg each morning for 7
days. Dogs were exercised in a 30 × 30-m grass paddock
for 15 minutes twice a day and raced for 500 m
twice a week. Blood samples were collected before
and 5 minutes after a race, before supplementation
was begun, and after 7 days of supplementation.
Blood and diet samples were analyzed for tocopherols
and α-tocopheryl acetate.

Results—Before supplementation, serum α-tocopherol
concentration after racing (mean ± SD,
6.7 ± 2.4 mg/L ) was significantly lower than before
racing (12.2 ± 3.1 mg/L). After supplementation, α-
tocopherol concentrations were significantly higher
overall, although values obtained before (26.6 ± 5.2
mg/L) and after (29.8 ± 3.6 mg/L) racing were not significantly
different.

Conclusions and Clinical Relevance—Supplementation
with α-tocopheryl acetate increased serum
α-tocopherol concentrations and eliminated the
decrease in α-tocopherol concentration that was
detected after a race, which may decrease oxidation
during exercise and improve performance or recovery.
(Am J Vet Res 2001;62:1118–1120)
Results of hyperamplification of centrosomes in naturally developing tumors of dogs
Authors: Setoguchi Asuka , Okuda Masaru , Nishida Etsuko , Yazawa Mitsuhiro , Ishizaka Tomomichi , Hong Sung-Hyeok , Hisasue Masaharu , Nishimura Ryohei , Sasaki Nobuo , Yoshikawa Yasuhiro , Masuda Kenichi , Ohno Koichi , Tsujimoto Hajime
Published: December 2005

Objective—To evaluate results of centrosome hyperamplification in naturally developing tumors of dogs.

Sample Population—Tumor specimens from 9 dogs with tumors (rhabdomyosarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, and mammary gland tumor) and 2 canine osteosarcoma cell lines.

Procedure—3 antibodies for centrosome proteins (ie, anti-γ-tubulin, anti-BRCA1, and anti-pericentrin) were used for immunohistochemical analysis. Double immunostaining for centrosomes was used to confirm the specificity of these antibodies for centrosomes. Mutational analysis of the caninep53gene was carried out by polymerase chain reaction–singlestrand conformation polymorphism analysis, and expression of canine MDM2 protein was evaluated by use of immunohistochemical analysis, using anti- MDM2 antibody.

Results—Immunohistochemical analysis of dog osteosarcoma cell lines with apparent aneuploidy revealed frequent hyperamplification of centrosomes in the osteosarcoma cell lines. Similar hyperamplified centrosomes were detected in the tumor tissues from all of the 9 tumors. The frequency of cells with hyperamplified centrosomes (3 to 20/cell) in each tumor tissue ranged from 9.50 to 48.1%, whereas centrosome hyperamplification was not observed in normal lymph nodes from these dogs. In 8 of the 9 tumors, mutation ofp53gene or overexpression of MDM2, or both, was detected.

Conclusions and Clinical Relevance—Various types of naturally developing tumors in dogs often have hyperamplification of centrosomes associated with chromosome instability. Hyperamplification of centrosomes is a novel tumor marker for use in cytologic and histologic examinations of clinical specimens obtained from dogs. (Am J Vet Res2001;62:1134–1141)
Evaluation of collagenase activity, matrix metalloproteinase-8, and matrix metalloproteinase-13 in horses with chronic obstructive pulmonary disease
Authors: Raulo Saara M. , Sorsa Timo A. , Kiili Markus T. , Maisi Päivi S.
Published: December 2005

Objectives—To determine collagenase activity and evaluate matrix metalloproteinase (MMP)-8 and MMP-13 in horses with chronic obstructive pulmonary disease (COPD).

Animals—12 horses with COPD and 12 healthy control horses.

Procedure—Collagenase activity was determined by use of an assay for degradation of type-I collagen. Western immunoblot analysis was used to identify interstitial collagenases MMP-8 and MMP-13 in tracheal epithelial lining fluid (TELF). Immunocytochemistry and in situ hybridization were used to determine cellular expression of these 2 collagenases in cells in bronchoalveolar lavage fluid (BALF).

Results—Collagenase activity was approximately 7 times higher in samples obtained from horses with COPD, compared with control horses. During stabling, horses with COPD had significantly higher collagenase activity than after being maintained on summer pasture, when activity was similar to that of control horses. Immunoreactivity of MMP-8 and MMP-13 was significantly increased in TELF of horses with COPD, compared with healthy horses. In TELF, a positive correlation was detected between immunoreactivity of MMP-8 and MMP-13 and the amount of degradation of type-I collagen. Macrophages and epithelial cells were the major cellular sources of MMP-8 and MMP-13.

Conclusions and Clinical Relevance—Increased collagenase activity in TELF indicates active ongoing disease and, thus, may reflect lung tissue changes in horses with COPD. Measurements of collagenase activity and MMP immunoreactivity may provide additional diagnostic tools to identify the active phase of chronic lung disease. (Am J Vet Res2001;62:1142–1148)
Effect of maternal immunity on the immune response to oral vaccination against rabies in young foxes
Authors: Müller Thomas F. , Schuster Peter , Vos Ad C. , Selhorst Thomas , Wenzel Ulf D. , Neubert Andreas M.
Published: December 2005

Objective—To determine effect of maternal antibodies
on immune response to oral vaccination against
rabies in young foxes.

Animals—250 cubs from 48 vixens.

Procedure—Sera were obtained from cubs of 36 vaccinated
(maternally vaccinated [MV+]) and 12 nonvaccinated
(MV–) vixens between 23 and 71 days of age
and tested for neutralizing antibodies. Seventy-one
MV+ cubs and 33 MV–- cubs were vaccinated orally
with modified-live virus vaccine SAD B19. Geometric
mean titer (GMT) was determined in these cubs
approximately 21, 39, and 57 days after vaccination.
In a subsequent experiment, 10 vaccinated MV+ cubs,
6 vaccinated MV– cubs, and 6 control cubs were challenge
inoculated with virulent rabies virus approximately
100 days after vaccination.

Results—Serum GMT of nonvaccinated MV– cubs
(0.23 U/ml) was significantly greater than that of nonvaccinated
MV– cubs (0.15 U/ml). The GMT of vaccinated
MV+ cubs 21, 39, and 57 days after vaccination
were 2.85, 2.11, and 0.79 U/ml, respectively, and
were significantly less than those of vaccinated MV–
cubs (12.19, 6.76, and 4.02 U/ml, respectively). All
challenge-inoculated cubs with GMT < 0.5 U/ml succumbed
to rabies.

Conclusion and Clinical Relevance—Partially
impaired immune response in cubs < 8 weeks old
from vaccinated vixens causes insufficient protection
against rabies. Inhibition of the immune response persists
longer than the period during which maternal
antibodies are detectable. Thus, oral vaccination campaigns
for young foxes in areas where vaccination
has been performed need to be reconsidered. (Am J
Vet Res 2001;62:1154–1158)
Efficacy of computerized discrimination between structure-related and non–structure–related echoes in ultrasonographic images for the quantitative evaluation of the structural integrity of superficial digital flexor tendons in horses
Authors: van Schie Hans T.M. , Bakker Erwin M. , Jonker A. Mieke , van Weeren P. Rene
Published: December 2005

Objective—To evaluate effectiveness of computerized discrimination between structure-related and non–structure-related echoes in ultrasonographic images for quantitative evaluation of tendon structural integrity in horses.

Sample Population—4 superficial digital flexor tendons (2 damaged tendons, 2 normal tendons).

Procedure—Transverse ultrasonographic images that precisely matched histologic sections were obtained in fixed steps along the long axis of each tendon. Distribution, intensity, and delineation of structurerelated echoes, quantitatively expressed as the correlation ratio and steadiness ratio , were compared with histologic findings in tissue that was normal or had necrosis, early granulation, late granulation, early fibrosis, or inferior repair.

Results—In normal tendon, the even distribution of structure-related echoes with high intensity and sharp delineation yielded high correlation ratio and steadiness ratio. In areas of necrosis, collapsed endotendon septa yielded solid but blurred structure-related echoes (high correlation ration and low steadiness ratio). In early granulation tissue, complete lack of organization caused zero values for both ratios. In late granulation tissue, reorganization and swollen endotendon septa yielded poorly delineated structurerelated echoes (high correlation ratio, low steadiness ratio). In early fibrosis, rearrangement of bundles resulted in normal correlation ration and slightly low steadiness ratio. In inferior repair, the almost complete lack of structural reorganization resulted in heterogeneous poorly delineated low-intensity echoes (low correlation ratio and steadiness ratio).

Conclusions and Clinical Relevance—The combination of correlation ratio and steadiness ratio accurately reflects histopathologic findings, making computerized correlation of ultrasonographic images an efficient tool for quantitative evaluation of tendon structural integrity. (Am J Vet Res2001;62:1159–1166)
Evaluation of hoof wall surface temperature as an index of digital vascular perfusion during the prodromal and acute phases of carbohydrate-induced laminitis in horses
Authors: Hood David M. , Wagner Ilka P. , Brumbaugh Gordon W.
Published: December 2005

Objective—To evaluate the use of hoof wall surface temperature (HWST) as an indirect indicator of digital perfusion and to describe HWST patterns during the prodromal and acute phases of carbohydrate-induced laminitis in horses.

Animals—30 adult horses without foot abnormalities.

Procedures—Three experiments were performed. In the first, HWST was measured in 2 groups of horses acclimatized to hot (n = 6), or cold (6) environments and exposed to cold (15 C) ambient temperature. In the second experiment, HWST were measured in both forefeet of 6 horses before and after application of a tourniquet to 1 forefoot to induce vascular occlusion. In the third experiment, HWST were recorded in 12 horses before and during the prodromal and acute phases of carbohydrate-induced laminitis.

Results—Mean HWST of hot-acclimatized cold-challenged horses was significantly less than that of cold-acclimatized cold-challenged horses at all times. Transient episodes of high HWST were observed during prolonged cold-induced vasoconstriction. Hoof wall surface temperature significantly decreased during arterial occlusion and increased during reperfusion. Digital hypothermia was observed during the prodromal phase of carbohydrate-induced laminitis.

Conclusions and Clinical Relevance—Determination of HWST is a valid technique to evaluate digital perfusion under appropriate controlled conditions in horses. Digital hypothermia detected during the prodromal phase of laminitis is consistent with decreased digital vascular perfusion or metabolic activity. If administered to horses during the prodromal phase, agents that enhance digital perfusion may prevent development of laminitis. (Am J Vet Res2001; 62:1167–1172)
Treadmill study of the range of back movement at the walk in horses without back pain
Authors: Licka Theresia F. , Peham Christian , Zohmann Elisabeth
Published: December 2005

Objective—To evaluate back movement during walking in horses.

Animals—22 adult horses with no history or signs of back pain.

Procedure—3-dimensional movements of markers on the hooves, head, and back were measured with a motion analysis system while the horses were walking on a treadmill. The positions of markers on the hooves, head, and the skin above the spinous processes of T5, T10, T16, L3, and 2 sacral vertebrae were recorded. From a minimum of 6 walking motion cycles/horse, marker movement and the time of occurrence of minimum and maximum marker positions within the motion cycle were determined. Angles were calculated between the markers on the head, T16, and S4 or S5 and between the markers on T5, T16, and S4 or S5.

Results—Lateral back movement was maximal at L3, where it reached (mean ± SD) 3.5 ± 0.8% of the horses' height at the withers. Maximum dorsoventral back movement was found at the sacrum, where it reached 4.7 ± 1.3% of the height at the withers. In the horizontal plane, the angle between T5, T16, and S4 or S5 was altered by 11 ± 2.5° during the motion cycle. In the sagittal plane, the angle between the head, T16, and S4 or S5 was altered by 7 ± 3°.

Conclusions and Clinical Relevance—Results of this study may be used as basic kinematic reference data for evaluation of back movement in horses. (Am J Vet Res2001;62:1173–1179)
Seasonal changes in serum calcium, phosphorus, and vitamin D concentrations in llamas and alpacas
Authors: Smith Bradford B. , Van Saun Robert J.
Published: December 2005

Objective—To evaluate the interaction of season and age on serum calcium, phosphorus, and vitamin D3concentrations in llamas and alpacas.

Animals—23 clinically normal llamas and 7 alpacas.

Procedures—Animals were assigned to 1 of the 3 following groups on the basis of age at the start of the study: adult (age, ≥ 24 months; n = 8), yearling (> 12 but < 20 months; 5), and neonate (< 6 months; 17). Twelve serum samples were obtained at monthly intervals. Calcium, phosphorus, and vitamin D3concentrations were measured, and the calcium-to-phosphorus concentration (Ca:P) ratio calculated. Effect of season and age on each of these variables was determined.

Results—Vitamin D3concentrations varied significantly as a function of season; the highest and lowest concentrations were detected September through October and February through March, respectively. The seasonal decrease in vitamin D3 concentration was significantly greater in neonates and yearlings, compared with adults. Serum phosphorus concentration decreased as a function of age, with the most significant seasonal change detected in the neonate group. The Ca:P ratio in neonates varied between 1.1 and 1.3 except during winter months when it increased to ≥ 2.0.

Conclusions and Clinical Relevance—Mean vitamin D3 concentration varied by > 6 fold in neonatal and yearling llamas and alpacas and > 3 fold in adult animals as a function of season. These results support the hypothesis that seasonal alterations in vitamin D3 concentrations are a key factor in the development of hypophosphatemic rickets in llamas and alpacas. (Am J Vet Res2001;62:1187–1193)
Rapid infection in market-weight swine following exposure to a Salmonella Typhimurium-contaminated environment
Authors: Hurd H. Scott , Gailey Jared K. , McKean James D. , Rostagno Marcos H.
Published: December 2005

Objective—To evaluate the possibility of swine becoming infected withSalmonellaTyphimurium when housed for 2 to 6 hours in an environment contaminated withSalmonella, similar to a lairage situation prior to slaughter.

Animals—40 crossbred market pigs with an approximate body weight of 92 kg.

Procedure—Five trials were conducted (8 pigs/trial) in simulated lairage conditions. Superficial inguinal, ileocecal, and mandibular lymph nodes, cecal contents, distal portion of the ileum, and fecal samples were obtained from each pig after 2 (n = 10), 3 (10), and 6 (5) hours of exposure to an environment contaminated with feces defecated by 10 pigs intranasally inoculated with nalidixic acid-resistantSalmonellaTyphimurium (χ4232). In addition, 5 control pigs that were not exposed were also evaluated in the same manner.

Results—Feces deposited on the floor by intranasally inoculated swine were mixed with water to form slurry with a resulting load of approximately 103colonyforming units ofSalmonellaTyphimurium/g of material. Eight of 10, 6 of 10, and 6 of 6 pigs exposed to the slurry for 2, 3, or 6 hours, respectively, had positive results for at least 1 sample when tested for the specific strain ofSalmonellaTyphimurium.

Conclusions and Clinical Relevance—Pigs can become infected during routine resting or holding periods during marketing when exposed to relatively low amounts ofSalmonellaorganisms in the preslaughter environment. Intervention at this step of the production process may have a major impact on the safety of pork products. (Am J Vet Res2001;62:1194–1197)
Long-term temporal evaluation of ground reaction forces during development of experimentally induced osteoarthritis in dogs
Authors: Budsberg Steven C.
Published: December 2005

Objective—To describe changes in vertical ground reaction forces (GRF) over 48 months in dogs with osteoarthritis (OA) of the stifle joint induced by transection of a cranial cruciate ligament (CCL).

Animals—12 clinically normal adult dogs.

Procedure—Vertical GRF (eg, peak force and impulse) were determined prior to and 1, 2, 3, 6, 10, and 12 months after transection of the right CCL. In 7 dogs, data were also collected 24, 32, 38, 42, and 48 months after transection.

Results—Vertical peak force and impulse were significantly decreased in the right hind limb at all times after transection, compared with baseline values. From 10 through 48 months after transection, vertical GRF remained essentially static. Ground reaction forces in the unoperated (left) hind limb also changed significantly during the study. Left vertical impulse significantly increased 3 months after transection, whereas at 24, 38, 42, and 48 months after transection, left vertical peak force was significantly decreased, compared with the baseline value .Mean intradog coefficients of variation (CV) for peak vertical force and impulse ranged from 7.38 and 9.32, respectively, 1 month after transection to 1.96 and 2.76, respectively, at 42 months.

Conclusions and Clinical Relevance—Vertical GRF in the affected hind limb equilibrated approximately 10 months after CCL transection. Prior to this, force transmission across the affected stifle joint changed significantly over time. Intradog CV were small, indicating that GRF may be an appropriate outcome measurement for evaluation of OA development induced by CCL transection in dogs. (Am J Vet Res2001;62:1207–1211)
Expression of a transforming gene (E5) of bovine papillomavirus in sarcoids obtained from horses
Authors: Carr Elizabeth A. , Théon Alain P. , Madewell Bruce R. , Hitchcock Margaret E. , Schlegel Richard , Schiller John T.
Published: December 2005

Objective—To determine expression of a transforming
gene (E5) of bovine papillomavirus in sarcoids,
other tumors, and normal skin samples collected
from horses with and without sarcoids.

Sample Population—23 sarcoids and 6 samples of
normal skin obtained from 16 horses with sarcoids, 2
samples of normal skin and 2 papillomas obtained
from horses without sarcoids, and 1 papilloma
obtained from a cow.

Procedure—Protein was extracted from tissue samples
collected from horses and incubated with
agarose beads covalently coupled to Staphylococcus
aureus protein A and an anti-E5 polyclonal antibody.
Following incubation, proteins were eluted from the
beads and electrophoresed on a 14% polyacrylamide
gel and transferred to a polyvinylidene difluoride
membrane. The E5 protein was detected by use of
western blot analysis, using a chemiluminescence
detection system.

Results—All 23 sarcoids had positive results for
expression of E5 protein. Quantity of viral protein
appeared to vary among sarcoids. All other tissues
examined had negative results for E5 protein. Highest
expression for E5 protein was observed in biologically
aggressive fibroblastic variants of sarcoids, compared
with expression in quiescent tumors.

Conclusions and Clinical Relevance—This study
documented that activation and expression of the E5
gene is evident in sarcoids obtained from horses.
These data support the conclusion that infection with
bovine papillomavirus is important in the initiation or
progression of sarcoids in horses. Treatment strategies
designed to increase immune recognition of
virally infected cells are warranted. (Am J Vet Res
2001;62:1212–1217)
Effects of dexamethasone on emesis in cats sedated with xylazine hydrochloride
Authors: Ho Chiu-Ming , Ho Shung-Tai , Wang Jhi-Joung , Lee Tak-Yu , Chai Chok-Yung
Published: December 2005

Objective—To determine antiemetic efficacy of prophylactic administration of dexamethasone and its influence on sedation in cats sedated with xylazine hydrochloride.

Animals—6 healthy adult cats (3 males and 3 females).

Procedure—The prophylactic antiemetic effect of 4 doses of dexamethasone (1, 2, 4, and 8 mg/kg of body weight, IM) or saline (0.9% NaCl) solution (0.066 ml/kg, IM) administered 1 hour before administration of xylazine (0.66 mg/kg, IM) was evaluated. Cats initially were given saline treatment (day 0) and were given sequentially increasing doses of xylazine on days 7, 14, 21, and 28. After xylazine injection, all cats were observed for 30 minutes to allow assessment of frequency of emesis and time until onset of the first emetic episode. The influence of dexamethasone on xylazine-induced sedation in these cats also was evaluated.

Results—Prior treatment with 4 or 8 mg/kg of dexamethasone significantly reduced the frequency of emetic episodes and also significantly prolonged the time until onset of the first emetic episode after xylazine injection. Time until onset of the first emetic episode also was significantly prolonged for dexamethasone at a dose of 2 mg/kg. Time until onset of sedation after administration of xylazine was not altered by administration of dexamethasone.

Conclusions and Clinical Relevance—Dexamethasone (4 or 8 mg/kg, IM) significantly decreased the frequency of emetic episodes induced by xylazine without compromising sedative effects in cats. Dexamethasone may be used prophylactically as an antiemetic in cats treated with xylazine. (Am J Vet Res2001;62:1218–1221)
Evaluation of monoclonal antibodies for identification of subpopulations of myeloid cells in bone marrow obtained from dogs
Authors: Weiss Douglas J.
Published: December 2005

Objective—To evaluate monoclonal antibodies that
may be useful for immunophenotyping myeloid cells
in bone marrow of dogs.

Sample Population—Bone marrow specimens
obtained from 5 dogs.

Design—Specimens were labeled with monoclonal
antibodies that detected CD18, major histocompatability
antigen class-II (MHC class-II), CD14, and Thy-1.
Cells labeled with each of the antibodies were isolated
by use of a fluorescence-activated cell sorter.
Differential cell counts of sorted cells were used to
determine cells that were labeled by each of the various
antibodies.

Results—Myeloid cells labeled with anti-CD18 antibody
included granulocytes, lymphocytes, and monocytes-
macrophages. Immature and mature granulocytes
were labeled. Lymphocytes, monocytesmacrophages,
and eosinophils were labeled with anti-Thy-1 antibody. Cells labeled with anti-MHC-class II
antibody included approximately 9% of bone marrow
cells, which consisted almost exclusively of lymphocytes
and monocytes-macrophages. Approximately
4% of bone marrow cells were labeled with anti-CD14 antibody, with > 90% of sorted cells being
monocytes-macrophages.

Conclusions and Clinical Relevance—Four monoclonal
antibodies for use in detecting subpopulations
of canine bone marrow cells were evaluated. These
antibodies should be useful in differentiating the origin
of leukemic cells in dogs. (Am J Vet Res 2001;62:1229–1233)
Metabolic alterations in dogs with osteosarcoma
Authors: Mazzaferro Elisa M. , Hackett Timothy B. , Stein T. Peter , Ogilvie Gregory K. , Wingfield Wayne E. , Walton Judy , Turner A. Simon , Fettman Martin J.
Published: December 2005

Objective—To evaluate changes in resting energy expenditure (REE) as well as protein and carbohydrate metabolism in dogs with osteosarcoma (OSA).

Animals—15 weight-stable dogs with OSA that did not have other concurrent metabolic or endocrine illness and twelve 1-year-old sexually intact female Beagles (control dogs).

Procedures—Indirect calorimetry was performed on all dogs to determine REE and respiratory quotient (RQ). Stable isotope tracers (15N-glycine, 4.5 mg/kg of body weight, IV; 6,6-deuterium-glucose, 4.5 mg/kg, IV as a bolus, followed by continuous-rate infusion at 1.5 mg/kg/h for 3 hours) were used to determine rate of protein synthesis and glucose flux in all dogs. Dualenergy x-ray absorptiometry (DEXA) scans were performed to determine total body composition.

Results—Accounting for metabolic body size, REE in dogs with OSA was significantly higher before and after surgery, compared with REE of healthy control dogs. The RQ values did not differ significantly between groups. Dogs with OSA also had decreased rates of protein synthesis, increased urinary nitrogen loss, and increased glucose flux during the postoperative period.

Conclusions and Clinical Relevance—Alterations in energy expenditure, protein synthesis, urinary nitrogen loss, and carbohydrate flux were evident in dogs with OSA, similar to results documented in humans with neoplasia. Changes were documented in REE as well as protein and carbohydrate metabolism in dogs with OSA. These changes were evident even in dogs that did not have clinical signs of cachexia. (Am J Vet Res2001;62:1234–1239)
Use of quantitative analysis of sonographic brightness for detection of early healing of tendon injury in horses
Authors: Micklethwaite Lucy , Wood Andrew K.W. , Sehgal Chandra M. , Polansky Marcia , Dowling Bradley A. , Dart Andrew J. , Rose Reuben J. , Hodgson David R.
Published: December 2005

Objectives—To determine whether quantitative analysis of sonographic brightness could be used to detect healing of an induced injury of the superficial digital flexor tendon in horses and whether rate of healing was influenced by equine recombinant growth hormone.

Animals—8 clinically normal Standardbreds.

Procedures—A localized injury was created in the left and right superficial digital flexor tendons of each horse by injection of 2,000 units of collagenase. After injury, 4 horses received equine recombinant growth hormone, a possible promoter of tendon healing. Sonographic images (7.5 MHz) of the flexor tendons and ligaments of the metacarpal region were recorded on videotape prior to injury and weekly for 7 weeks after injury. Images were digitized, and sonographic brightness of tendons and ligaments was calculated.

Results—Collagenase-induced injury was sonographically similar to naturally occurring injury. After injury, sonographic brightness of the tendon decreased; after 3 weeks, brightness progressively increased, although by 7 weeks brightness had not returned to preinjury value. Equine recombinant growth hormone had no significant effect on the rate of tendon healing, as evaluated sonographically or at necropsy.

Conclusions and Clinical Relevance—As healing developed, alterations in sonographic brightness of injured tendons coincided with real changes in tendon structure. Quantitative sonographic brightness could be used to accurately monitor healing of equine tendon and ligament injuries and investigate the efficacy of various treatment regimens. (Am J Vet Res2001;62:1320–1327)
Oral vaccination of sexually mature pigs with Brucella abortus vaccine strain RB51
Authors: Edmonds Matthew D. , Samartino Luis E. , Hoyt Phillip G. , Hagius Sue D. , Walker Joel V. , Enright Fred M. , Schurig Gerhardt G. , Elzer Philip
Published: December 2005

Objective—To develop a novel oral vaccine delivery system for swine, using the rough vaccine strain ofBrucella abortus.

Animals—56 crossbred pigs from a brucellosis-free facility.

Procedure—In 3 separate experiments, pigs were orally vaccinated with doses of 1 × 109to > 1 × 1011CFU of strain RB51 vaccine. The vaccine was placed directly on the normal corn ration, placed inside a whole pecan, or mixed with cracked pecans and corn.

Results—Oral vaccination of pigs with vaccine strain RB51 resulted in a humoral immune response to strain RB51 and short-term colonization of the regional lymph nodes.

Conclusions and Clinical Relevance—A viscous liquid such as Karo corn syrup in association with pecans that scarify the oral mucosa are necessary when placing the live vaccine directly onto corn or other food rations. Doses of > 1 × 1011CFU of RB51 organisms/pig in this mixture ensures 100% colonization of regional lymph nodes via the oral route. This method may allow an efficient and economical means to vaccinate feral swine for brucellosis. (Am J Vet Res2001;62:1328–1331)
Establishment of two vaccine-associated feline sarcoma cell lines and determination of in vitro chemosensitivity to doxorubicin and mitoxantrone
Authors: Williams Laurel E. , Banerji Nilanjana , Klausner Jeffrey S. , Kapur Vivek , Kanjilal Sagarika
Published: December 2005

Objective—To establish 2 vaccine-associated feline sarcoma (VAFS) cell lines and to determine their in vitro sensitivity to the chemotherapeutic agents doxorubicin and mitoxantrone.

Sample Population—Tumor specimens collected from 2 cats undergoing surgery for removal of vaccine- associated sarcomas.

Procedures—Tumor specimens were minced and treated with trypsin under aseptic conditions to obtain single-cell suspensions, which were then cultured in vitro in medium supplemented with 5% heat-inactivated fetal bovine serum. Growth rates and sensitivity after 24 hours of exposure to various concentrations (0.1 to 100 μg/ml) of doxorubicin and mitoxantrone were assessed for each cell line. Survival of cells was estimated 3 days after exposure to the 2 agents, and the concentration of each drug that resulted in a 50% reduction in the number of viable cells (IC50) was calculated.

Results—Two tumor-derived cell lines (FSA and FSB) were successfully established and determined to be sensitive to doxorubicin and mitoxantrone. Under the conditions tested, the IC50of doxorubicin were 0.6 and 1.5 μg/ml for cell lines FSB and FSA, respectively. The IC50of mitoxantrone was 0.4 μg/ml for both cell lines.

Conclusions and Clinical Relevance—The establishment of VAFS cell lines provides a tool for the in vitro screening of antitumor drugs. Doxorubicin and mitoxantrone were effective in decreasing the number of viable cells in the 2 cell lines tested. Both of these anthracycline antibiotics have been used to treat various neoplasias in cats, and their efficacy for adjuvant treatment of vaccine-associated sarcomas should be further evaluated. (Am J Vet Res2001;62:1354–1357).
Morphologic stages of the equine embryo proper on days 17 to 40 after ovulation
Authors: Acker Denise A. , Curran Sandra , Bersu Edward T. , Ginther O. J.
Published: December 2005

Objective—To describe the gross and histologic changes that develop in the equine embryo proper (ie, the portion of the embryo that becomes the fetus) from days 17 to 40 after ovulation and to compare the external features of equine embryos with those of porcine, ovine, and human embryos.

Sample Population—34 embryos collected from mixed-breed pony mares.

Procedure—External features for each embryo proper, including length, number of branchial arches, growth of appendages, face and head features, and body features, were examined, using a dissecting microscope, for embryos collected on days 17 to 40. Internal features were histologically examined by serially sectioning embryos collected on days 20 to 35.

Results—Number of embryos recovered for each day ranged from 1 to 5. The initial detection of features was not related closely to age; typically, the first attainment of a given body length or characteristic varied over a 3-day period among embryos. Similarly, the period during which individual characteristics for a given Carnegie stage were attained ranged from 3 to 6 days. Age at first appearance of a characteristic was greater for equine embryos than ages reported for ovine and porcine embryos but less than for human embryos. Indicators of age included number of pairs of branchial arches, all limb buds present, retinal pigmentation, and prominence of the pontine flexure.

Conclusions—No embryologic structures or changes were found that could be considered unique to equine embryos on days 17 to 40 after ovulation. (Am J Vet Res2001;62:1358–1364)
Effects of Mannheimia haemolytica leukotoxin on apoptosis and oncosis of bovine neutrophils
Authors: Cudd Laura A. , Ownby Charlotte L. , Clarke Cyril R. , Sun Yude , Clinkenbeard Kenneth D.
Published: December 2005

Objective—To investigate the concentration-dependent
effects of Mannheimia haemolytica (formerly
Pasteurella haemolytica) leukotoxin (LKT) on apoptosis
and oncosis in bovine neutrophils and to examine the
role of calcium ions (Ca2+) in LKT-induced apoptosis.

Sample Population—Neutrophils isolated from
blood samples obtained from healthy calves.

Procedure—Neutrophil suspensions were exposed
to lytic or sublytic dilutions of LKT and then examined
by use of transmission electron microscopy (TEM) or
gel electrophoresis. Contribution of extracellular Ca2+
to LKT-induced apoptosis was investigated by incubating
neutrophils with LKT or control solutions in
buffer containing 1 mM CaCl2 or in Ca2+-free buffer
containing 1 mM ethylene glycol-bis (b-aminoethyl
ether)- N,N-tetraacetic acid (EGTA) prior to diphenyl
amine analysis.

Results—Examination by TEM revealed that bovine
neutrophils exposed to lytic dilutions of LKT had
changes consistent with oncosis, whereas neutrophils
exposed to sublytic dilutions of LKT and staurosporin,
an inducer of apoptosis, had changes consistent
with apoptosis. Effects of sublytic dilutions of
LKT on apoptosis were confirmed by gel electrophoresis.
Replacement of extracellular Ca2+ with
EGTA, a Ca2+ chelator, reduced apoptosis attributable
to the calcium ionophore A23187, but it did not have
significant effects on apoptosis induced by LKT or
staurosporin.

Conclusions and Clinical Relevance—The ability of
LKT to cause apoptosis instead of oncosis is concentration-
dependent, suggesting that both processes of
cell death contribute to an ineffective host-defense
response, depending on the LKT concentration in
pneumonic lesions. Furthermore, although Ca2+ promotes
A23187-induced apoptosis, it is apparently not
an essential second messenger for LKT-induced apoptosis.
( Am J Vet Res 2001;62:136–141)
Reactivity of serum samples of dogs and horses tested by use of class-specific recombinant-based enzyme-linked immunosorbent assays for detection of granulocytic ehrlichiosis
Authors: Magnarelli Louis A. , IJdo Jacob W. , Andel Amy E. Van , Wu Caiyun , Oliver James H. , Fikrig Erol
Published: December 2005

Objective—To test serum samples of dogs and horses by use of class-specific recombinant-based ELISA for establishing a diagnosis of granulocytic ehrlichiosis attributable to infection with organisms from theEhrlichia phagocytophilagenogroup.

Sample Population—Serum samples from 43 clientowned dogs and 131 horses (81 with signs of acute illness and 50 without signs of disease).

Procedure—Serum samples were analyzed, using ELISA with a recombinant 44-kd protein antigen for IgM and IgG antibodies to the human granulocytic ehrlichiosis (HGE) agent (NCH-1 strain). Western blot analyses, using infected human promyelocytic leukemia cells, were conducted on 38 serum samples of horses and 11 serum samples of dogs to verify reactivity to the 44-kd peptide.

Results—IgM or IgG antibodies to the HGE agent were detected in 5 to 28% of dog serum samples and 5 to 37% of horse serum samples. Thirty-five of 38 (92%) horse serum samples had corresponding results on both tests (2 positive results for 26 samples and 2 negative results for 9 samples), using an ELISA for IgG antibodies or immunoblotting for total immunoglobulins. All 11 serum samples of dogs had positive results for both methods.

Conclusion and Clinical Relevance—These ELISA with recombinant 44-kd antigen are suitable for detecting IgM or IgG antibodies to the HGE agent in serum samples of dogs and horses. Positive results for serum samples of horses from Connecticut, New York, Virginia, and Georgia indicate that the HGE agent is widely distributed in tick-infested areas of the eastern United States. (Am J Vet Res2001;62:1365–1369)
Characterization of α-adrenoceptor subtypes in smooth muscle of equine ileum
Authors: Re Giovanni , Badino Paola , Odore Rosangela , Galaverna Davide , Girardi Carlo
Published: December 2005

Objective—To determine the concentration and binding characteristics of α-adrenoceptor subtypes in smooth muscle cell membranes of equine ileum.

Sample Population—Segments of longitudinal and circular smooth muscle from the ileum of 8 male and 8 female adult horses.

Procedure—Distribution of α-adrenoceptor subtypes was assessed by use of radioligand binding assays incorporating [3H]-prazosin and [3H]-rauwolscine, highly selective α1- and α2-adrenoceptor antagonists, respectively. Characterization of adrenoceptor subtypes was performed by use of binding inhibition assays.

Results—On the basis of binding affinity for specific radioligands, low- and high-affinity α1- and α2-adrenoceptors were detected. Concentration of low-affinity α2-adrenoceptors was significantly greater in male horses, compared with females. Competition studies confirmed the specificity of the radioligands used in the binding assays. α1-Adrenoceptors of both subtypes in male and female horses had a higher affinity for prazosin than phentolamine, whereas yohimbine did not compete with the radioligand for binding. For α2-adrenoceptors regardless of subtype, potency of inhibition elicited by each drug varied between sexes. In males, yohimbine was a more potent inhibitor than phentolamine, which was more potent than prazosin. In females, yohimbine was more potent than prazosin, which was more potent than phentolamine.

Conclusions and Clinical Relevance—High- and low-affinity α1- and α2-adrenoceptors were detected in smooth muscle of equine ileum. Because α-adrenoceptor subtypes, particularly α2-adrenoceptors, are involved in the regulation of gastrointestinal tract function, characterization of these receptors may represent the basis for development of new therapeutic strategies for the control of gastrointestinal disturbances in horses. (Am J Vet Res2001;62:1370–1374)
Plasma and bronchoalveolar fluid concentrations of nitric oxide and localization of nitric oxide synthesis in the lungs of horses with summer pastureassociated obstructive pulmonary disease
Authors: Costa Lais R. R. , Seahorn Thomas L. , Moore Rustin M. , Oliver Julian L. , Hosgood Giselle L.
Published: December 2005

Objective—To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD).

Animals—7 adult horses with SPAOPD and 6 clinically normal adult horses.

Procedure—Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (ΔPpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF, and epithelial lining fluid (ELF) were determined by use of a chemiluminescent method. Inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) were localized in formalin-fixed lung specimens by use of immunohistochemical staining, and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) activity was localized in cryopreserved specimens by use of histochemical staining.

Results—Plasma concentration of NO in affected horses was slightly but not significantly greater than concentration in nonaffected horses. Nitric oxide concentrations in BALF or ELF did not differ between groups. Immunoreactivity of iNOS in bronchial epithelial cells of 3 of 5 lung lobes was greater in horses with SPAOPD, compared with nonaffected horses. However, staining for NT and NADPHd activity did not differ between groups.

Conclusions and Clinical Relevance—Expression of iNOS was greater in bronchial epithelial cells of horses with SPAOPD, compared with nonaffected horses, suggesting that NO may play a role in amplifying the inflammatory process in the airways of horses with this disease. (Am J Vet Res2001;62:1381–1386)
Pharmacokinetics and toxic effects of lithium chloride after intravenous administration in conscious horses
Authors: Hatfield Cindy L. , McDonell Wayne N. , Lemke Kip A. , Black William D.
Published: December 2005

Objective—To determine the pharmacokinetics and toxic effects associated with IV administration of lithium chloride (LiCl) to conscious healthy horses.

Animals—6 healthy Standardbred horses.

Procedure—Twenty 3-mmol boluses of LiCl (0.15 mmol/L) were injected IV at 3-minute intervals (total dose, 60 mmol) during a 1-hour period. Blood samples for measurement of serum lithium concentrations were collected before injection and up to 24 hours after injection. Behavioral and systemic toxic effects of LiCl were also assessed.

Results—Lithium elimination could best be described by a 3-compartment model for 5 of the 6 horses. Mean peak serum concentration was 0.561 mmol/L (range, 0.529 to 0.613 mmol/L), with actual measured mean serum value of 0.575 mmol/L (range, 0.52 to 0.67 mmol/L) at 2.5 minutes after administration of the last bolus. Half-life was 43.5 hours (range, 32 to 84 hours), and after 24 hours, mean serum lithium concentration was 0.13 ± 0.05 mmol/L (range, 0.07 to 0.21 mmol/L). The 60-mmol dose of LiCl did not produce significant differences in any measured hematologic or biochemical variables, gastrointestinal motility, or ECG variables evaluated during the study period.

Conclusions and Clinical Relevance—Distribution of lithium best fit a 3-compartment model, and clearance of the electrolyte was slow. Healthy horses remained unaffected by LiCl at doses that exceeded those required for determination of cardiac output. Peak serum concentrations were less than steadystate serum concentrations that reportedly cause toxic effects in other species. (Am J Vet Res2001; 62:1387–1392)
In vitro inhibition of Salmonella organisms isolated from reptiles by an inactivated culture of microcin-producing Escherichia coli
Authors: Wooley Richard E. , Ritchie Branson W. , Currin M. F. Pamela , Chitwood Sharon W. , Sanchez Susan , Crane Maria M. , Lamberski Nadine
Published: December 2005

Objective—To determine whether an inactivated culture
of a microcin-producing avian Escherichia coli
was capable of killing Salmonella isolates from reptiles
in an in vitro test system.

Sample Population—57 Salmonella isolate from reptiles.

Procedure—A wild-type avian E coli electrotransformed
with a plasmid coding for the production of
microcin 24 was tested in an in vitro microassay system
for its ability to kill 57 Salmonella spp isolated
from reptiles. The reptile population included snakes,
iguana, frilled lizards, turtles, other lizards, and
unspecified reptiles.

Results—44 of the Salmonella isolates were inhibited
strongly, compared with the in vitro assay controls; 12
had weak inhibition, and 1 was not inhibited by the
microcin-producing E coli. Thirteen of the 57 isolates
had resistance to at least 1 antibiotic, primarily streptomycin.
There were 9 O serogroups identified in the
57 isolates, with serogroup H being the most prevalent
(18 to 57).

Conclusion and Clinical Relevance—Antibiotics are
not recommended to eliminate Salmonella organisms
from reptiles because of the development of antibiotic
resistance. Further studies are necessary to determine
whether the use of microcin-producing bacteria will be
effective in controlling Salmonella infections in companion
reptiles. (Am J Vet Res 2001;62:1399–1401)
Water quality in cattle feedyard playas in winter and summer
Authors: Purdy Charles W. , Straus David C. , Parker David B. , Williams Brock P. , Clark R. Nolan
Published: December 2005

Objective—To determine the impact of feedyards on
endotoxin concentration, fecal coliform count, and
other water quality measurements during winter and
summer in feedyard playas (shallow lakes).

Sample Population—Water samples obtained from
7 feedyard playas and 3 nonfeedyard control playas.

Procedure—Surface water samples were collected
from each playa and at various depths from 3 feedyard
playas. Endotoxin concentrations, 22 water quality
variables, and fecal coliform counts were determined
in samples collected in summer and winter
from various combinations of playas.

Results—Cattle numbers per feedyard ranged from
40,000 to 175,000 head/y. Mean endotoxin concentrations
were significantly lower in control playas than
in feedyard playas in winter and summer. Endotoxin
concentration appeared to be homogenous at various
water depths. Values for 20 of 22 water quality variables
were higher in the feedyard playas than in control
playas in winter and summer. In winter only, mean
total fecal coliform concentration in feedyard playas
was significantly greater than in control playas.

Conclusions and Clinical Relevance—Results indicated
that feedyards have the potential to impact
water quality in playas, and cattle should not be
allowed access to them. Feedyard playa water should
not be used under high pressure to settle dust in pens
with cattle or to cool cattle, because aerosols containing
pathogens and high concentrations of endotoxin
are a health hazard for humans and cattle. (Am J
Vet Res 2001;62:1402–1407)
Evaluation of opioid receptors in synovial membranes of horses
Authors: Sheehy Jenifer G. , Hellyer Peter W. , Sammonds Ginger E. , Mama Khursheed R. , Powers Barbara E. , Hendrickson Dean A. , Magnusson Kathy R.
Published: December 2005

Objective—To evaluate μ-opioid receptors in synovial
membranes of horses and determine whether these
receptors are up-regulated in nerve endings during
inflammation.

Sample Population—Synovial tissue obtained from
39 client-owned horses during arthroscopy and 14
research horses during necropsy; brain and synovial
tissues were obtained during necropsy from 1 horse,
and control tissues were obtained from a mouse.

Procedure—Horses were classified into 7 groups on
the basis of histologically determined degree of
inflammation. Binding of primary rabbit antibody
developed against μ-opioid receptors in equine synovial
tissue was studied, using western blot analysis.
Synovial membranes were tested for μ-opioid receptors
by immunohistochemical staining, using a
diaminobenzidine-cobalt chloride chromogen.
Homogenates of synovial membranes were evaluated
by use of radioligand binding.

Results—Examination of western blots of equine
thalamus revealed that rabbit antibody developed
against μ-opioid receptors yielded a band (molecular
weight, 55 kd) that corresponded with that of other
opioid receptors. Use of immunohistochemical staining
of synovial tissue revealed considerable staining
in the proliferative lining layer and in regions surrounding
vascular structures. Specific radioligand
binding of tissue homogenates was found in all
groups. We did not detect significant differences in
binding between horses with inflammation and horses
without inflammation.

Conclusions and Clinical Relevance—Results of
immunohistochemical analysis and radioligand binding
of tissue homogenates suggest that there are opioid
receptors in synovial membranes of horses. Our
results support the practice of intra-articular administration
of opioids to relieve pain after arthroscopic
surgery in horses. (Am J Vet Res 2001;62:1408–1412).