bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic behavior of three preparations of α-tocopherol after oral administration to postpubertal heifers
Authors: Bontempo Valentino , Baldi Antonella , Cheli Federica , Fantuz Francesco , Politis Ioannis , Carli Silvano , Dell'Orto Vittorio
Published: December 2005

Objective—To assess the kinetic behavior of 3 preparations of α-tocopherol (vitamin E) after oral administration to heifers.

Animals—8 postpubertal Friesian heifers.

Procedure—A single oral bolus of 5,000 U of α-tocopherol in oil or encapsulated in liposomes or cyclodextrin was administered to each cow, using a 4 X 4 design with 8 days between treatments. Blood samples for kinetic analyses were obtained at various times for 168 hours after treatment.

Results—Mean (± SEM) maximal plasma concentrations of α-tocopherol were 4.86 ± 0.49 µg/ml, 5.03 ± 0.39 µg/ml, and 5.08 ± 0.56 µg/ml after administration of oil, liposomal, and cyclodextrin preparations, respectively. Plasma concentrations peaked 21 to 34 hours after administration. The disappearance rate constant (Kd) was less after administration of α-tocopherol encapsulated in liposomes, compared with the other 2 preparations. Area under the concentration versus time curve was greater after administration of either encapsulated form of α-tocopherol, compared with α-tocopherol in oil, but these differences were not significant.

Conclusions and Clinical Relevance—The lower Kddetermined for α-tocopherol encapsulated in liposomes suggests that this formulation may result in longer persistance of the vitamin in plasma than the other 2 preparations. Dietary supplementation with α-tocopherol encapsulated in liposomes may enhance plasma availability of this vitamin in cattle and could be useful during periods of increased vitamin E requirements, such as parturition and early stages of life. (Am J Vet Res2000;61:589–593)
Determination of serum insulin concentration during intravenous glucose tolerance testing of healthy bulls
Authors: Anderson David E. , Monke Donald R. , Silveira Fernando , Ayars William , Rings D. Michael
Published: December 2005

Objective—To determine the insulin response curve during IV glucose tolerance testing of mature Holstein bulls.

Animals—8 Holstein bulls between 5 and 8 years old and weighing between 911.5 and 1035.5 kg.

Procedure—A 50% glucose solution was rapidly administered IV so that each bull received a mean dose of 258 mg of glucose/kg of body weight. Serum glucose and insulin concentrations were determined before and 30, 60, 120, and 240 minutes after glucose infusion.

Results—Serum glucose concentrations 30 and 60 minutes after infusion were significantly greater than baseline concentration. Concentrations returned to baseline values 120 minutes after infusion. Serum insulin concentration was significantly greater 30 minutes after glucose administration, compared with baseline and 240-minute concentrations.

Conclusions and Clinical Relevance—Intravenous glucose tolerance testing of mature Holstein bulls resulted in a characteristic insulin response curve. Baseline and peak insulin concentrations were higher in these bulls, compared with values reported for mature Norwegian Red cows. (Am J Vet Res2000; 61:61–63)
Effects of treatment with growth hormone and somatostatin on efficacy of diammine [1,1-cyclobutane dicarboxylato (2-)-0,0']-(SP-4-2) in athymic rats with osteosarcoma
Authors: Conzemius Michael G. , Graham Joanne C. , Haynes Joseph S. , Graham Christine A.
Published: December 2005

Objective—To determine the effect of exogenous growth hormone or somatostatin on chemotherapeutic efficacy in athymic (nude) rats with osteosarcoma. Animals—66 female athymic rats.

Procedure—Osteosarcoma was induced at an intratibial site. Rats were randomly allotted to 6 treatment groups. Rats were treated with saline (0.9% NaCl) solution alone, platinum, diammine [1,1-cyclobutane dicaboxylato (2-)-0,0']-(SP-4-2) (CBDCA; ie, carboplatin) plus saline solution, somatostatin alone, somatostatin plus CBDCA, growth hormone alone, or growth hormone plus CBDCA. Variables measured included estimated WBC count and percentage of neutrophils, plasma concentration of insulin-like growth factor I (IGF-I), body weight, tumor volume, weight of primary tumor, survival time, and distant metastasis at time of death.

Results—Tumors formed at the injection sites in all rats. Treatment with growth hormone increased, and treatment with somatostatin decreased, plasma IGF-I concentration. Treatment with growth hormone or somatostatin altered CBDCA efficacy, as determined by evaluation of mean and median survival times. Metastatic pulmonary disease developed in 63 of 64 rats.

Conclusions and Clinical Relevance—The technique used here reliably induced local osteosarcomas and metastatic pulmonary disease. Treatment with growth hormone and CBDCA or somatostatin may improve chemotherapeutic efficacy without increasing toxic effects.

Implications for Human Medicine—Results reported here may be useful in the study of osteosarcoma in humans. (Am J Vet Res2000;61:646–650)
Effect of hyperbaric oxygen treatment on incorporation of an autogenous cancellous bone graft in a nonunion diaphyseal ulnar defect in cats
Authors: Kerwin Sharon C. , Lewis Daniel D. , Elkins A. Derrell , Oliver Julian L. , Hosgood Giselle , Pechman Robert D. , Dial Sharon L. , Strain George M.
Published: December 2005

Objective—To determine whether hyperbaric oxygen treatment (HBOT) would affect incorporation of an autogenous cancellous bone graft in diaphyseal ulnar defects in cats.

Animals—12 mature cats.

Procedure—Bilateral nonunion diaphyseal ulnar defects were created in each cat. An autogenous cancellous bone graft was implanted in 1 ulnar defect in each cat, with the contralateral ulnar defect serving as a nongrafted specimen. Six cats were treated by use of hyperbaric oxygen at 2 atmospheres absolute for 90 minutes once daily for 14 days, and 6 cats were not treated (control group). Bone labeling was performed, using fluorochrome markers. Cats were euthanatized 5 weeks after implanting, and barium sulfate was infused to evaluate vascularization of grafts. Ulnas were evaluated by use of radiography, microangiography, histologic examination, and histomorphometric examination.

Results—Radiographic scores did not differ between treatment groups. Microangiographic appearance of grafted defects was similar between groups, with all having adequate vascularization. Differences were not observed between treated and nontreated groups in the overall histologic appearance of decalcified samples of tissue in grafted defects. Mean distance between fluorescent labels was significantly greater in cats given HBOT than in nontreated cats. Median percentage of bone formation in grafted defects was significantly greater in cats given HBOT.

Conclusions—Hyperbaric oxygen treatment increased the distance between fluorescent labels and percentage of bone formation when incorporating autogenous cancellous bone grafts in induced nonunion diaphyseal ulnar defects in cats, but HBOT did not affect revascularization, radiographic appearance, or qualitative histologic appearance of the grafts. (Am J Vet Res2000;61:691–698)
Evaluation of the measurement of leukotriene B4 concentrations in exhaled condensate as a noninvasive method for assessing mediators of inflammation in the lungs of calves
Authors: Reinhold Petra , Becher Gunther , Rothe Michael
Published: December 2005

Objective—To determine whether measurement of an inflammatory mediator in exhaled condensate could provide a noninvasive method for evaluating lungs of calves.

Animals—84 calves ≤ 2 months old.

Procedure—Concentration of leukotriene B4(LTB4) was evaluated in the exhaled condensate of healthy calves and calves with experimentally induced respiratory tract infections. For collection of samples of exhaled condensate, the total amount of exhaled air was directed into a cooled double-jacketed tube. Each tube was sealed and stored at –80 C. The LTB4concentration was measured, using an ELISA.

Results—In exhaled condensates of clinically healthy calves, normally distributed and highly reproducible LTB4concentrations (mean ± SD, 116.1 ± 55.4 pg/ml) were measured. After experimentally induced infection withPasteurella multocidaserovarD, LTB4in exhaled condensate increased significantly (mean, 179% increase), compared with basal concentrations before infection; this increase in LTB4was significantly correlated with deterioration in lung function. In 2 of 4 calves experimentally infected with bovine respiratory syncytial virus, the LTB4concentration in exhaled condensate increased (300 to 400% increase), compared with baseline values, which was associated with development of bronchial hyperresponsiveness after infection.

Conclusions and Clinical Relevance—Collection of exhaled condensate is tolerated well by calves and is an acceptable method for obtaining fluid from exhaled air originating from the lungs. This method provides alternatives for diagnosing and evaluating treatment of naturally acquired and experimentally induced diseases of the lungs and airways in calves. (Am J Vet Res2000;61:742–749)
Reference values for activated coagulation time in cats
Authors: Bay Jeff D. , Scott Michael A. , Hans Jerry E.
Published: December 2005

Objective—To establish reference values for activated coagulation time (ACT) in cats by use of jugular venipuncture and direct collection of blood into ACT vacuum tubes.

Animals—100 clinically normal cats that were to have elective surgery performed at a private practice.

Procedure—Collection of 3 blood samples for ACT measurement was attempted for each cat at the time of elective surgery: sample 1, obtained before sedation; sample 2, tube 1 of 2 consecutive samples obtained from a single venipuncture of the contralateral jugular vein after sedation with acepromazine and ketamine hydrochloride; and sample 3, tube 2 collected immediately following collection of sample 2 without removing the needle from the vein. Venipuncture quality was rated subjectively on a 3- point scale.

Results—Median ACT were 95 seconds for each sample group. The middle 95% of values ranged inclusively from 55 to 185 seconds (sample 1), 65 to 135 seconds (sample 2), 45 to 145 seconds (sample 3), and 55 to 165 seconds overall (samples 1, 2, and 3). Significant differences in ACT values were not detected between sample groups. Significant relationships between ACT and venipuncture quality or sex of cat were not detected.

Conclusions and Clinical Relevance—With the ACT protocols used, clinically normal cats had ACT of < 165 seconds. The ACT in cats does not appear to be significantly affected by sex, sedation with acepromazine and ketamine, or by moderately traumatic venipunctures. These results refute widespread statements that ACT should be < 65 seconds in healthy cats. Cats with ACT repeatedly > 165 seconds should be further evaluated for hemostatic disorders. (Am J Vet Res2000;61:750–753)
Evaluation of diet as a cause of gastric ulcers in horses
Authors: Nadeau Jenifer A. , Andrews Frank M. , Mathew Alan G. , Argenzio Robert A. , Blackford James T. , Sohtell Morgan , Saxton Arnold M.
Published: December 2005

Objective—To measure pH, volatile fatty acid (VFA) concentrations, and lactate concentrations in stomach contents and determine number and severity of gastric lesions in horses fed bromegrass hay and alfalfa hay-grain diets.

Animals—Six 7-year-old horses.

Procedure—A gastric cannula was inserted in each horse. Horses were fed each diet, using a randomized crossover design. Stomach contents were collected immediately after feeding and 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after feeding on day 14. The pH and VFA and lactate concentrations were measured in gastric juice. Number and severity of gastric lesions were scored during endoscopic examinations.

Results—The alfalfa hay-grain diet caused significantly higher pH in gastric juice during the first 5 hours after feeding, compared with that for bromegrass hay. Concentrations of acetic, propionic, and isovaleric acid were significantly higher in gastric juice, and number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. Valeric acid, butyric acid, and propionic acid concentrations and pH were useful in predicting severity of nonglandular squamous gastric lesions in horses fed alfalfa hay-grain, whereas valeric acid concentrations and butyric acid were useful in predicting severity of those lesions in horses fed bromegrass hay.

Conclusions and Clinical Relevance—An alfalfa haygrain diet induced significantly higher pH and VFA concentrations in gastric juice than did bromegrass hay. However, number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. An alfalfa hay-grain diet may buffer stomach acid in horses. (Am J Vet Res2000;61: 784–790)
In vitro effects of nonsteroidal anti-inflammatory drugs on cyclooxygenase activity in dogs
Authors: Kay-Mugford Patricia , Benn Sally J. , LaMarre Jonathan , Conlon Peter
Published: December 2005

Objective—To establish an in vitro assay and determine the differential suppressive activity of non steroidal anti-inflammatory drugs (NSAID) on cyclooxygenase (COX)-1 and COX-2 isoenzymes in dogs.

Procedure—COX activity was evaluated in the presence and absence of 4 NSAID (meloxicam, tolfenamic acid, carprofen, and ketoprofen), using a canine monocyte/macrophage cell line that constitutively expresses COX-1, but can be induced to express COX-2 when incubated with lipopolysaccharide. Inhibition of prostaglandin E2(PGE2) synthesis by each NSAID was measured by enzyme immunoassay and attributed to specific COX-1 or COX-2 activity through assessment of COX messenger RNA expression by use of northern blot analysis and reverse transcription- polymerase chain reaction (RT-PCR). The COX selectivity of each drug was evaluated from dose-response curves by calculating a ratio (COX- 1:COX-2) of inhibitory concentration values on the basis of concentrations that reduced PGE2by 50% in each COX model.

Results—Meloxicam and tolfenamic acid preferentially inhibited COX-2, with meloxicam inhibiting COX-2 activity 12 times more effectively than COX-1 activity. Carprofen was only 1.75 times more selective for COX-2 than for COX-1, and ketoprofen was slightly more selective for COX-1.

Conclusions—COX-1 and COX-2 were differentially sensitive to inhibition in vitro by NSAID. Meloxicam and tolfenamic acid were selective for COX-2. Effects of carprofen and ketoprofen approached equipotency against both isoenzymes. Selective COX-2 inhibitors are a new class of drugs with anti-inflammatory effects similar to conventional NSAID but with fewer adverse effects. Development of these agents for veterinary use would be facilitated by the convenience of using a canine cell line as a model system to screen COX- 1 and COX-2 inhibitor activities in vitro. (Am J Vet Res2000;61:802–810)
Pharmacokinetics of penicillin G procaine versus penicillin G potassium and procaine hydrochloride in horses
Authors: Uboh Cornelius E. , Soma Lawrence R. , Luo Yi , McNamara Elizabeth , Fennell Mary A. , May Laura , Teleis Donna C. , Rudy Jeffrey A. , Watson Anthony O.
Published: December 2005

Objective—To compare the pharmacokinetics of penicillin G and procaine in racehorses following IM administration of penicillin G procaine (PGP) with pharmacokinetics following IM administration of penicillin G potassium and procaine hydrochloride (PH).

Animals—6 healthy adult mares.

Procedure—Horses were treated with PGP (22,000 units of penicillin G/kg of body weight, IM) and with penicillin G potassium (22,000 U/kg, IM) and PH (1.55 mg/kg, IM). A minimum of 3 weeks was allowed to elapse between drug treatments. Plasma and urine penicillin G and procaine concentrations were measured by use of high-pressure liquid chromatography.

Results—Median elimination phase half-lives of penicillin G were 24.7 and 12.9 hours, respectively, after administration of PGP and penicillin G potassium. Plasma penicillin G concentration 24 hours after administration of penicillin G potassium and PH was not significantly different from concentration 24 hours after administration of PGP. Median elimination phase halflife of procaine following administration of PGP (15.6 hours) was significantly longer than value obtained after administration of penicillin G potassium and PH (1 hour).

Conclusions and Clinical Relevance—Results suggest that IM administration of penicillin G potassium will result in plasma penicillin G concentrations for 24 hours after drug administration comparable to those obtained with administration of PGP. Clearance of procaine from plasma following administration of penicillin G potassium and PH was rapid, compared with clearance following administration of PGP. (Am J Vet Res2000;61:811–815)
Failure to detect bovine immunodeficiency virus contamination of stud bull spermatozoa, blood leukocytes, or semen leukocytes in samples supplied by artificial insemination centers
Authors: Burger Rebecca A. , Nelson Phillip D. , Kelly-Quagliana Kindra , Coats Karen S.
Published: December 2005

Objective—To determine whether bovine immunodeficiency virus (BIV) infection could be detected in spermatozoa, blood leukocytes, or semen leukocytes from stud bulls in artificial insemination centers.

Animals—30 bulls at 3 artificial insemination centers.

Procedure—Polymerase chain reaction testing that used 3 sets of primer pairs targeting pol and env regions of the BIV proviral genome was performed on DNA extracted from semen leukocytes, spermatozoa, and blood leukocytes from each bull. Southern blot analysis was performed to increase sensitivity of detection. Western blot analysis of plasma samples was used to detect antibodies against BIV.

Results—BIV provirus was not detected in DNA samples obtained from semen leukocytes, spermatozoa, or blood leukocytes, and antibodies against BIV were not detected.

Conclusions and Clinical Relevance—Contrary to our report of high point prevalence of BIV contamination of semen from a single artificial insemination center, bulls of the study reported here did not appear to be infected. Maximum risk of BIV infection in similar bulls was estimated at 10% with a confidence level of 95%. (Am J Vet Res2000;61:816–819)
Comparison of the trotting gaits of Labrador Retrievers and Greyhounds
Authors: Bertram John E. A. , Lee David V. , Case Holly N. , Todhunter Rory J.
Published: December 2005

Objective—To compare the trotting gaits of Labrador Retrievers and Greyhounds to determine whether differences in locomotion are attributable to differences in their manner of moving or to body size and shape differences between these 2 breeds.

Animals—8 healthy 5-month-old Greyhounds and 5 healthy Labrador Retrievers between 6 and 18 months old.

Procedure—A series of 4 force platforms was used to record independent ground reaction forces on the forelimbs and hind limbs during trotting. Values of stride parameters were compared between breeds before and after normalization for size differences. Standard values of absolute and normalized stride period and stride length were determined from linear regressions of these parameters on relative (normalized) velocity. Forces were normalized to body weight and compared at the same relative velocity.

Results—Greyhounds used fewer, longer strides than the Labrador Retrievers to travel at the same absolute speed. After normalization for body size differences, most measurable differences between breeds were eliminated. Subtle differences that did persist related to proportion of the stride that the forefoot was in contact with the ground, timing of initial hind foot contact relative to initial forefoot contact, and distribution of vertical force between the forelimbs and hind limbs.

Conclusions and Clinical Relevance—Results suggest that apparent differences in the trotting gait between Labrador Retrievers and Greyhounds are mainly attributable to differences in size, and that dogs of these 2 breeds move in a dynamically similar manner at the trot. (Am J Vet Res2000;61: 832–838)
Effects of various adjuvants on efficacy of a vaccine against Streptococcus bovis and Lactobacillus spp in cattle
Authors: Shu Quan , Hillard Michael A. , Bindon Bernard M. , Duan Enkui , Xu Yuqing , Bird Simon H. , Rowe James B. , Oddy Victor H. , Gill Harsharnjit S.
Published: December 2005

Objective—To determine efficacy of vaccines incorporating
QuilA, alum, dextran combined with mineral
oil, or Freund adjuvant for immunization of feedlot cattle
against Streptococcus bovis and Lactobacillus spp.

Animals—24 steers housed under feedlot conditions.

Procedure—Steers were randomly assigned to 4
experimental groups and a control group. Animals in
experimental groups were inoculated on days 0 and
26 with vaccines containing Freund adjuvant (FCA),
QuilA, dextran combined with mineral oil (Dex), or
alum as adjuvant. Serum anti-S bovis and anti-
Lactobacillus IgG concentrations were measured,
along with fecal pH, ruminal fluid pH, and number of
S bovis and Lactobacillus spp in ruminal fluid.

Results—Throughout the study, serum anti-S bovis
and anti-Lactobacillus IgG concentrations for animals in
the Dex, QuilA, and alum groups were similar to or significantly
higher than concentrations for animals in the
FCA group. Serum anti-S bovis and anti-Lactobacillus
IgG concentrations were significantly increased on
days 26 through 75 in all 4 experimental groups, and
there was a linear relationship between anti-S bovis
and anti-Lactobacillus IgG concentrations. For animals
in the QuilA and Dex groups, mean pH of feces
throughout the period of experiment were significantly
higher and numbers of S bovis and Lactobacillus spp in
ruminal fluid on day 47 were significantly lower than
values for control cattle.

Conclusions and Clinical Relevance—Results suggest
that immunization of feedlot steers against
S bovis and Lactobacillus spp with vaccines incorporating
Freund adjuvant, QuilA, dextran, or alum as an
adjuvant effectively induced high, long-lasting serum
anti-S bovis and anti-Lactobacillus IgG concentrations.
Of the adjuvants tested, dextran may be the most
effective. (Am J Vet Res 2000;61;839–843)
Flow cytometric analysis of nuclear DNA for sex identification in three psittacine species
Authors: Canon Nicole R. , Tell Lisa A. , Needham Martha L. , Gardner Ian A.
Published: December 2005

Objective—To evaluate flow cytometric analysis for
sex identification in 3 psittacine species, establish reference
values for blood cell DNA content for each
species, and determine effects of sample storage on
DNA content.

Animals—36 orange-winged Amazon parrots, 41
budgerigars, and 39 cockatiels.

Procedure—Blood samples were stained and analyzed
by use of flow cytometry to measure cellular
DNA content. Samples were analyzed immediately
after collection and after being stored at 4 C for 48
and 72 hours.

Results—Mean DNA content (picograms per cell)
was 3.248 for Amazon parrots, 2.702 for budgerigars,
and 2.946 for cockatiels; DNA concentrations in samples
analyzed immediately overlapped in a male and a
female Amazon parrot and among 19 cockatiels. For
budgerigars, DNA overlap between sexes was not
detected in samples analyzed immediately or after
storage for 72 hours. Sex was identified correctly in
94.4% of Amazon parrots, 100% of budgerigars, and
51.3% of cockatiels. For both sexes, DNA content in
samples analyzed immediately was significantly different
from that of stored samples.

Conclusions and Clinical Relevance—Flow cytometric
analysis was accurate for sex identification of
Amazon parrots and budgerigars. Sample storage at 4
C for 48 or 72 hours caused variability in DNA content.
(Am J Vet Res 2000;61:847–850)
Laminar microvascular flow, measured by means of laser Doppler flowmetry, during the prodromal stages of black walnut-induced laminitis in horses
Authors: Adair Henry S. , Goble Dallas O. , Schmidhammer James L. , Shires G. M. H.
Published: December 2005

Objective—To measure changes in laminar microvascular blood flow (LMBF) over time in healthy horses and horses in the prodromal stage of black walnutinduced laminitis and to determine the effects of glyceryl trinitrate application on LMBF in horses with acute laminitis.

Animals—10 healthy adult horses.

Procedure—Laser Doppler flowmetry was used to measure LMBF. Baseline measurements were obtained, horses were given deionized water via a nasogastric tube, and measurements were obtained hourly for 12 hours. Twenty-four hours later, baseline measurements were again obtained, and horses were given black walnut extract. Measurements were obtained hourly for 12 hours or until development of Obel grade-3 laminitis. At this time, 5 horses were treated with phenylbutazone, and the other 5 were treated with phenylbutazone and glyceryl trinitrate, and measurements were obtained hourly for an additional 12 hours.

Results—LMBF was significantly decreased 1 and 2 hours after administration of the black walnut extract but then returned to near-baseline values for the next 6 hours. Eight hours after extract administration, there was a second significant decrease in LMBF that persisted until the end of the study. Glyceryl trinitrate had no effect on LMBF. Clinical signs of laminitis developed 8 to 12 hours after extract administration.

Conclusions and Clinical Relevance—Results suggest that in horses with black walnut-induced laminitis, there is an early decrease in LMBF followed by reperfusion prior to onset of clinical signs. Treatment with glyceryl trinitrate after development of clinical signs of laminitis did not have a significant effect on LMBF. (Am J Vet Res2000;61:862–868)
Effects of dietary antioxidant supplementation on oxidative damage and resistance to oxidative damage during prolonged exercise in sled dogs
Authors: Baskin Carole R. , Hinchcliff Kenneth W. , DiSilvestro Robert A. , Reinhart Gregg A. , Hayek Michael G. , Chew Boon P. , Burr John R. , Swenson Richard A.
Published: December 2005

Objectives—To determine effects of dietary antioxidant supplementation on plasma concentrations of antioxidants, exercise-induced oxidative damage, and resistance to oxidative damage during exercise in Alaskan sled dogs.

Animals—62 Alaskan sled dogs.

Procedure—Dogs were matched for age, sex, and ability and assigned to 1 of 3 groups: sedentary and nonsupplemented (control [C]; n = 21), exercised and supplemented (S; 22), and exercised and nonsupplemented (N; 19). Dogs in group S were given 400 units of α- tocopherol acetate, 3 mg of β-carotene, and 20 mg of lutein orally per day for 1 month, then dogs in groups S and N completed 3 days of exercise. Blood samples were collected before and after 1 and 3 days of exercise and after 3 days of rest. Plasma antioxidant concentrations were determined, and oxidative damage to DNA (plasma 7,8 dihydro-8-oxo-2'deoxyguanosine [8-oxodG] concentration) and membrane lipids (plasma hydroperoxide concentration) and resistance of plasma lipoproteins to oxidation were assessed.

Results—Supplementation increased plasma concentrations of α-tocopherol, β-carotene, and lutein. Plasma concentration of α-tocopherol increased and concentration of lutein decreased in group S with exercise. Concentration of 8-oxodG decreased in group S but increased in group N during and after exercise. Lag time of in vitro oxidation of lipoprotein particles increased with exercise in group S only.

Conclusions and Clinical Relevance—Dietary supplementation with antioxidants resulted in increased plasma concentrations of antioxidants. Moreover, supplementation decreased DNA oxidation and increased resistance of lipoprotein particles to in vitro oxidation. Antioxidant supplementation of sled dogs may attenuate exercise-induced oxidative damage. (Am J Vet Res2000;61:886–891)
Pharmacokinetics of erythromycin estolate and erythromycin phosphate after intragastric administration to healthy foals
Authors: Lakritz Jeffrey , Wilson W. David , Marsh Antoinette E. , Mihalyi Judy E.
Published: December 2005

Objective—To determine pharmacokinetics and plasma concentrations of erythromycin and related compounds after intragastric administration of erythromycin phosphate and erythromycin estolate to healthy foals.

Animals—11 healthy 2- to 6-month-old foals.

Procedure—Food was withheld from foals overnight before intragastric administration of erythromycin estolate (25 mg/kg of body weight; n = 8) and erythromycin phosphate (25 mg/kg; 7). Four foals received both drugs with 2 weeks between treatments. Plasma erythromycin concentrations were determined at various times after drug administration by use of high-performance liquid chromatography. Maximum plasma peak concentrations, time to maximum concentrations, area under plasma concentration versus time curves, half-life of elimination, and mean residence times were determined from concentration versus time curves.

Results—Maximum peak concentration of erythromycin A after administration of erythromycin phosphate was significantly greater than after administration of erythromycin estolate (2.9 ± 1.1 µg/ml vs 1.0 ± 0.82 µg/ml). Time to maximum concentration was shorter after administration of erythromycin phosphate than after erythromycin estolate (0.71 ± 0.29 hours vs 1.7 ± 1.2 hours). Concentrations of anhydroerythromycin A were significantly less 1 and 3 hours after administration of erythromycin estolate than after administration of erythromycin phosphate.

Conclusions and Clinical Relevance—Plasma concentrations of erythromycin A remained > 0.25 µg/ml (reported minimum inhibitory concentration forRhodococcus equi) for at least 4 hours after intragastric administration of erythromycin phosphate or erythromycin estolate, suggesting that the recommended dosage for either formulation (25 mg/kg, q 6 h) should be adequate for treatment ofR equiinfections in foals. (Am J Vet Res2000;61:914–919)
Use of a nonionic detergent (Triton WR 1339) in healthy cats to assess hepatic secretion of triglyceride
Authors: Hall Jean A. , Gradin Joseph L. , Andreasen Claire B. , Wander Rosemary C.
Published: December 2005

Objective—To determine whether a nonionic detergent
(Triton WR 1339) can be used in cats to assess
hepatic secretion of triglyceride.

Animals—28 healthy cats.

Procedure—Triton WR 1339 was administered IV
according to the following schedule: 5, 50, 150, and
250 mg/kg of body weight. Control cats did not
receive an injection or received 0.9% NaCl or PBS
solutions at the same osmolarity and volume as the
250 mg/kg group. Blood samples were collected
throughout the 48-hour period after administration for
determination of triglyceride and cholesterol concentrations
and for RBC morphology and osmotic fragility
studies.

Results—Administration of Triton WR 1339 at 150
and 250 mg/kg caused profound hypertriglyceridemia.
Triglyceride concentrations increased in a
curvilinear fashion for the first 2 hours and remained
increased for approximately 24 hours. Area under the
time-concentration curve for triglyceride at 5 hours
differed significantly among groups. At 12 and 24
hours, cholesterol was significantly higher in cats
receiving 250 mg/kg. The most dramatic changes in
osmotic fragility and RBC morphology were in cats
receiving 250 mg/kg; 1 of these cats developed
severe icterus and died 5 days later. Feeding rice and
casein before administering Triton WR 1339 at 150
mg/kg did not appear to affect the hypertriglyceridemia
response.

Conclusions and Clinical Relevance—Triton WR 1339
can be administered IV to cats at a rate of 150 mg/kg to
assess hepatic triglyceride secretion, although some
cats may have increased RBC osmotic fragility. Higher
dosages caused substantial adverse effects, whereas
lower dosages did not alter plasma triglyceride concentration.
(Am J Vet Res 2000;61:941–950)
Use of an instrument sandwiched between the hoof and shoe to measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter in horses
Authors: Kai Makoto , Aoki Osamu , Hiraga Atsushi , Oki Hironori , Tokuriki Mikihiko
Published: December 2005

Objective—To develop an instrument that could be sandwiched between the hoof and shoe of horses and that would reliably measure vertical ground reaction forces and three-dimensional acceleration at the walk, trot, and canter.

Animals—5 clinically sound Thoroughbreds.

Procedures—The recording instrument (weight, 350 g) consisted of 2 metal plates, 2 bolts, 4 load cells, and 3 accelerometers. It was mounted to the hoof with a glue-on shoe and devised to support as much load exerted by a limb as possible. The load cells and accelerometers were wired to a 16-channel transmitter, and transmitted signals were received and amplified with a telemetry receiver.

Results—The recording instrument could measure in real time the 4 components of the ground reaction force or their resultant force along with acceleration in 3 dimensions as horses walked, trotted, or cantered on a treadmill. Patterns of force-time curves recorded for consecutive strides were similar to each other and to those previously reported, using a force plate.

Conclusions and Clinical Relevance—The recording instrument developed for use in the present study allowed us to record vertical ground reaction force and acceleration in 3 dimensions in horses at the walk, trot, and canter. (Am J Vet Res2000;61:979–985)
Pharmacokinetics and tissue distribution of amoxicillin in healthy and Salmonella Typhimurium-inoculated pigs
Authors: Agersø Dr. Henrik , Friis Christian , Nielsen Jens Peter
Published: December 2005

Objective—To determine pharmacokinetics and tissue distribution of amoxicillin in healthy andSalmonellaTyphimurium-inoculated pigs.

Animals—12 healthy pigs and 12STyphimuriuminoculated pigs.

Procedure—Concentration of amoxicillin in tissue was measured by use of high-performance liquid chromatography 4, 8, 12, and 24 hours after IM administration. Pharmacokinetic values of amoxicillin in plasma were assessed by use of a 1-compartment model with first-order absorption.

Results—Inoculation caused diarrhea and increased rectal temperature and WBC count. Absorption halflife was shorter in inoculated pigs (0.26 hours) than in healthy pigs (0.71 hours), and inoculated pigs had longer elimination half-life. Distribution ratios in healthy pigs ranged from 0.31 to 0.56 and in inoculated pigs ranged from 0.14 to 0.48. Ratios for distribution to intestinal mucosa ranged from 0.34 to 1.16 in healthy pigs and from 0.22 to 0.36 in inoculated pigs.

Conclusions and Clinical Relevance—SalmonellaTyphimurium inoculation altered absorption of amoxicillin from the injection site and prolonged elimination half-life. However, distribution of amoxicillin to intestinal tract tissue was only affected to a minor degree. (Am J Vet Res2000;61:992–996)
Analgesic, hemodynamic, and respiratory effects induced by caudal epidural administration of meperidine hydrochloride in mares
Authors: Skarda Roman T. , Muir III William W.
Published: December 2005

Objective—To determine the analgesic, hemodynamic, and respiratory effects induced by caudal epidural administration of meperidine hydrochloride in mares.

Animals—7 healthy mares.

Procedure—Each mare received meperidine (5%; 0.8 mg/kg of body weight) or saline (0.9% NaCl) solution via caudal epidural injection on 2 occasions. At least 2 weeks elapsed between treatments. Degree of analgesia in response to noxious electrical, thermal, and skin and muscle prick stimuli was determined before and for 5 hours after treatment. In addition, cardiovascular and respiratory variables were measured and degree of sedation (head position) and ataxia (pelvic limb position) evaluated.

Results—Caudal epidural administration of meperidine induced bilateral analgesia extending from the coccygeal to S1 dermatomes in standing mares; degree of sedation and ataxia was minimal. Mean (± SD) onset of analgesia was 12 ± 4 minutes after meperidine administration, and duration of analgesia ranged from 240 minutes to the entire 300-minute testing period. Heart and respiratory rates, rectal temperature, arterial blood pressures, Hct, PaO2, PaCO2, pHa, total solids and bicarbonate concentrations, and base excess were not significantly different from baseline values after caudal epidural administration of either meperidine or saline solution.

Conclusions and Clinical Relevance—Caudal epidural administration of meperidine induced prolonged perineal analgesia in healthy mares. Degree of sedation and ataxia was minimal, and adverse cardiorespiratory effects were not detected. Meperidine may be a useful agent for induction of caudal epidural analgesia in mares undergoing prolonged diagnostic, obstetric, or surgical procedures in the anal and perineal regions. (Am J Vet Res2001;62:1001–1007)
Effects of enalaprilat on cardiorespiratory, hemodynamic, and hematologic variables in exercising horses
Authors: Muir III William W. , Sams Richard A. , Hubbell John A. E. , Hinchcliff Kenneth W. , Gadawski Jennifer
Published: December 2005

Objective—To determine the effects of IV administration of enalaprilat on cardiorespiratory and hematologic variables as well as inhibition of angiotensin converting enzyme (ACE) activity in exercising horses.

Animals—6 adult horses.

Procedure—Horses were trained by running on a treadmill for 5 weeks. Training was continued throughout the study period, and each horse also ran 2 simulated races at 120% of maximum oxygen consumption. Three horses were randomly selected to receive treatment 1 (saline [0.9% NaCl] solution), and the remaining 3 horses received treatment 2 (enalaprilat; 0.5 mg/kg of body weight, IV) before each simulated race. Treatment groups were reversed for the second simulated race. Cardiorespiratory and hematologic data were obtained before, during, and throughout the 1-hour period after each simulated race. Inhibition of ACE activity was determined during and after each race in each horse.

Results—Exercise resulted in significant increases in all hemodynamic variables and respiratory rate. The pH and PO2of arterial blood decreased during simulated races, whereas PCO2remained unchanged. Systemic and pulmonary blood pressure measurements and arterial pH, PO2, and PCO2returned to baseline values by 60 minutes after simulated races. Enalaprilat inhibited ACE activity to < 25% of baseline activity without changing cardiorespiratory or blood gas values, compared with horses administered saline solution.

Conclusions and Clinical Relevance—Enalaprilat administration almost completely inhibited ACE activity in horses without changing the hemodynamic responses to intense exercise and is unlikely to be of value in preventing exercise-induced pulmonary hemorrhage. (Am J Vet Res2001;62:1008–1013)
Use of an antineoepitope antibody for identification of type-II collagen degradation in equine articular cartilage
Authors: Billinghurst R. Clark , Buxton Elizabeth M. , Edwards Michael G. , McGraw Megan S. , McIlwraith C. Wayne
Published: December 2005

Objective—To develop an antibody that specifically
recognizes collagenase-cleaved type-II collagen in
equine articular cartilage.

Sample Population—Cartilage specimens from
horses euthanatized for problems unrelated to the
musculoskeletal system.

Procedure—A peptide was synthesized representing
the carboxy- (C-) terminus (neoepitope) of the equine
type-II collagen fragment created by mammalian collagenases.
This peptide was used to produce a polyclonal
antibody, characterized by western analysis for
reactivity to native and collagenase-cleaved equine
collagens. The antibody was evaluated as an antineoepitope
antibody by ELISA, using peptides ± an
amino acid at the C-terminus of the immunizing peptide.
Collagen cleavage was assayed from equine
articular cartilage cultured with interleukin-1 (IL-1), ± a
synthetic MMP inhibitor, BAY 12-9566. Cartilage
specimens from osteoarthritic and nonarthritic joints
were compared for antibody staining.

Results—An antibody, 234CEQ, recognized only collagenase-
generated 3/4-length fragments of equine
type-II collagen. This was a true antineoepitope antibody,
as altering the C-terminus of the immunizing
peptide significantly decreased competition for binding
in an inhibition ELISA. The IL-1-induced release of
type-II collagen fragments from articular cartilage was
prevented with the MMP inhibitor. Cartilage from an
osteoarthritic joint of a horse had increased staining
with the 234CEQ antibody, compared with normal
articular cartilage.

Conclusions and Clinical Relevance—We generated
an antineoepitope antibody recognizing collagenase-
cleaved type-II collagen of horses. This antibody
detects increases in type-II collagen cleavage in diseased
equine articular cartilage. The 234CEQ antibody
has the potential to aid in the early diagnosis of
arthritis and to monitor treatment responses. (Am J
Vet Res 2001;62:1031–1039)
Barrier pressure at the gastroesophageal junction in anesthetized dogs
Authors: Pratschke Kathryn M. , Bellenger Christopher R. , McAllister Hester , Campion Deirdre
Published: December 2005

Objective—To evaluate the effect of body position on
barrier pressure at the gastroesophageal junction in
anesthetized Greyhounds and to assess alterations in
barrier pressure following gastropexy.

Animals—8 adult Greyhounds.

Procedure—Barrier pressure at the gastroesophageal
junction was measured by fast (1 cm/s)
and slow (1 cm/10 s) withdrawal of a subminiature
strain gauge transducer through the gastroesophageal
junction in 8 anesthetized dogs. The
effect of body position was measured. Each dog then
was placed in right-lateral recumbency, and gastropexy
was performed in the left flank. Additional
measurements were obtained 1, 5, 10, 20, and 30
minutes after gastropexy.

Results—Barrier pressure for dogs positioned in sternal
recumbency (mean ± SEM, 1.1 ± 0.53 mm Hg)
was significantly less than for dogs positioned in right
lateral or left lateral recumbency. Following gastropexy,
there was a steady increase in barrier pressure.
Thirty minutes after gastropexy, barrier pressure
was significantly higher (13.36 ± 3.46 mm Hg), compared
with the value before surgery.

Conclusions and Clinical Relevance—Barrier pressure
in anesthetized dogs is highly variable and influenced
by body position. This is most likely the result
of anatomic interrelationships between the
diaphragm, stomach, and terminal portion of the
esophagus. Gastropexy also increases barrier pressure
in the immediate postoperative period, which
may be clinically relevant in terms of understanding
how resolution of gastroesophageal reflux disease
associated with hiatal hernia may be affected by gastropexy
combined with hernia reduction. (Am J Vet
Res 2001;62:1068–1072)
Relationship between degree of viremia and disease manifestations in calves with experimentally induced bovine viral diarrhea virus infection
Authors: Walz Paul H. , Bell Thomas G. , Wells Jennifer L. , Grooms Daniel L. , Kaiser Lana , Maes Roger K. , Baker John C.
Published: December 2005

Objective—To compare degree of viremia and disease manifestations in calves with type-I and -II bovine viral diarrhea virus (BVDV) infection.

Animals—16 calves.

Procedure—Colostrum-deprived calves obtained immediately after birth were assigned to 1 control and 3 treatment groups (4 calves/group). Calves in treatment groups were inoculated (day 0) by intranasal instillation of 107median tissue culture infective dose BVDV 890 (type II), BVDV 7937 (type II), or BVDV TGAN (type I). Blood cell counts and virus isolation from serum and leukocytes were performed daily, whereas degree of viremia was determined immediately before and 4, 6, 8, and 12 days after inoculation. Calves were euthanatized on day 12, and pathologic, virologic, and immunohistochemical examinations were performed.

Results—Type-II BVDV 890 induced the highest degree of viremia, and type-I BVDV TGAN induced the lowest. Virus was isolated more frequently and for a longer duration in calves inoculated with BVDV 890. A parallel relationship between degree of viremia and rectal temperature and an inverse relationship between degree of viremia and blood cell counts was observed. Pathologic and immunohistochemical examinations revealed more pronounced lesions and more extensive distribution of viral antigen in calves inoculated with type-II BVDV.

Conclusions and Clinical Relevance—Degree of viremia induced during BVDV infection is associated with severity of clinical disease. Isolates of BVDV that induce a high degree of viremia may be more capable of inducing clinical signs of disease. Strategies (eg, vaccination) that reduce viremia may control clinical signs of acute infection with BVDV. (Am J Vet Res2001;62:1095–1103)
Use of an orally administered combined sugar solution to evaluate intestinal absorption and permeability in cats
Authors: Johnston Karen L. , Ballèvre Olivier P. , Batt Roger M.
Published: December 2005

Objective—To evaluate intestinal permeability and absorption in healthy cats in association with diet and normal intestinal microflora.

Animals—6 healthy domestic shorthair cats.

Procedure—A sugar solution containing D-xylose, 3- 0-methyl-D-glucose, L-rhamnose, lactulose, and51Cr- EDTA was administered intragastrically to healthy cats, and urinary excretion of ingested sugars was determined 5 hours after administration. After the same cats had received metronidazole for 1 month, the study was repeated. A final study was performed while cats were maintained on a new diet differing in composition and processing.

Results—Lactulose-to-rhamnose ratios, reflecting intestinal permeability, were higher in cats, compared with values for humans or dogs, and values obtained before and after metronidazole administration (mean ± SEM; before, 0.40 ± 0.08; after, 0.45 ± 0.09) were not significantly different. Intestinal absorption also was unaltered after antibiotic administration, and the xylose-to-glucose ratio was 0.70 ± 0.03 before and 0.71 ± 0.06 after metronidazole administration. Sugar recovery did not differ significantly while cats were maintained on canned or dry food.

Conclusions and Clinical Relevance—Reference ranges were established for the percentage urinary recovery of orally administered D-xylose, 3-0-methyl-Dglucose, L-rhamnose, lactulose, and51Cr-EDTA obtained after 5 hours in healthy cats. The intestines of cats appear to be more permeable than those of other species, although the normal bacterial microflora does not appear to influence the integrity or function of the feline intestine, because values obtained for the measured variables before or after antibiotic administration were not significantly different. In addition, differences were not detected when the diet was completely altered. (Am J Vet Res2001;62:111–118)