bluuebunny/crossref_metadata_2025 huggingface dataset:
Migrants' Resources: Multilingualism and Transnational Mobility. A Study on Learning Paths and School to Job Transition of Young Portuguese Migrants
Authors: Fürstenau Sara
Published: December 2005

In this contribution, the results of an empirical study on young immigrants' learning paths and school to job transition are presented. The study focused on the strategies of successful students from the Portuguese immigrant minority in Hamburg. One aim was to find out whether the young people could profit by their migration experiences and multilingual skills. Increasing the multilingualism of individuals is an official goal of the European Union, and it is predicted that the labour market will give increasing importance to the ability to communicate and work in contexts of linguistic and cultural diversity. The question was, though, whether students from an immigrant minority, whose parents had come to Germany in the course of the labour recruitment, could benefit from this development. Interestingly, the young people of the sample turned out to be highly flexible during their future orientations, considering options in Germany as well as in their country of origin. Their strategies and orientations during school to work transition were analysed on the basis of Pierre Bourdieu's model of the linguistic market and from the perspective of the sociological concept of transnational migration.
Effect of transforming growth factor β1 on chondrogenic differentiation of cultured equine mesenchymal stem cells
Authors: Worster Allison A. , Nixon Alan J. , Brower-Toland Brent D. , Williams Janice
Published: December 2005

Objective—To determine the morphologic and phenotypic effects of transforming growth factor β1 (TGF-β1) on cultured equine mesenchymal stem cells (MSC) and articular chondrocytes.

Sample Population—Bone marrow aspirates and articular cartilage samples from a 2-year-old and two 8- month-old horses.

Procedure—After initial isolation and culture, MSC and chondrocytes were cultured in Ham's F-12 medium supplemented with TGF-β1 at a concentration of 0, 1, 5, or 10 ng/ml. Medium was exchanged on day 2, and cells were harvested on day 4. Medium was assayed for proteoglycan (PG) content. Total RNA was isolated from cell cultures, and expression of aggrecan, decrin, collagen type-I, and collagen type-II mRNA was assessed by means of Northern blot analyses. Cell cultures were stained with H&E or toluidine blue and examined histologically. Additional cultures were examined after immunohistochemical staining for type-I and -II collagen.

Results—MSC cultures exposed to TGF-β1 had an increased cellular density with cell layering and nodule formation that was most pronounced in cultures treated with 5 ng of TGF-β1/ml. Expression of collagen type-II mRNA in MSC cultures exposed to 5 ng of TGF- β1/ml was 1.7 times expression in control cultures, and expression of collagen type-I mRNA was 2.8 times expression in control cultures. Treatment of MSC with TGF-β1 led to dose-related increases in area and intensity of type-II collagen immunoreaction.

Conclusion—Results suggest that TGF-β1 enhances chondrogenic differentiation of bone marrow-derived MSC in a dose-dependent manner. (Am J Vet Res2000;61:1003–1010)
Effects of prior feeding on pharmacokinetics and estimated bioavailability after oral administration of a single dose of microencapsulated erythromycin base in healthy foals
Authors: Lakritz Jeffrey , Wilson W. David , Marsh Antoinette E. , Mihalyi Judy E.
Published: December 2005

Objective—To determine effects of prior feeding on pharmacokinetics and estimated bioavailability of orally administered microencapsulated erythromycin base (MEB) in healthy foals.

Animals—6 healthy foals, 3 to 5 months old.

Procedure—Foals were given 2 doses of MEB (25 mg/kg of body weight, PO). One dose was administered after food was withheld overnight, and the other was administered after foals had consumed hay. The study used a crossover design with a 2-week period between doses. Blood was collected via a jugular vein prior to and at specific times after drug administration. Concentrations of erythromycin A and anhydroerythromycin A in plasma were determined, using highperformance liquid chromatography. Results pharmacokinetic analysis of plasma concentration-time data for food-withheld and fed conditions were compared.

Results—Plasma concentrations of erythromycin A for foals were lower after feeding than concentrations when food was withheld. Area under the plasma concentration- time curve, maximum plasma concentration, and estimated bioavailability were greater in foals when food was withheld than when foals were fed. Anhydroerythromycin A was detected in plasma after administration of MEB in all foals.

Conclusions and Clinical Relevance—Foals should be given MEB before they are fed hay. Administration of MEB to foals from which food was withheld overnight apparently provides plasma concentrations of erythromycin A that exceed the minimum inhibitory concentration ofRhodococcus equifor approximately 5 hours. The dosage of 25 mg/kg every 8 hours, PO, appears appropriate. (Am J Vet Res2000;61:1011–1015)
Antibody titers against bovine coronavirus and shedding of the virus via the respiratory tract in feedlot cattle
Authors: Lathrop Sarah L. , Wittum Thomas E. , Loerch Steven C. , Perino Louis J. , Saif Linda J.
Published: December 2005

Objective—To describe patterns of seroconversion to bovine coronavirus (BCV) and shedding of BCV from the respiratory tract in feedlot cattle.

Animals—1,074 calves in feedlots in Ohio, Texas, and Nebraska.

Procedure—Nasal swab specimens were obtained at time of arrival (day 0) and at various times during the initial 28 days after arrival at feedlots. Specimens were tested for BCV, using an antigen-capture ELISA. Serum samples were obtained at time of arrival and again 28 days after arrival; sera were analyzed for antibodies to BCV, using an antibody-detection ELISA.

Results—Samples from 12 groups of cattle entering 7 feedlots during a 3-year period revealed that 78 of 1,074 (7.3%) cattle were shedding BCV (range, 0 to 35.9% within specific groups). At time of arrival, 508 of 814 (62.4%) cattle had low (< 50) or undetectable BCV antibody titers. Seroconversion to BCV during the initial 28 days after arrival was detected in 473 of 814 (58%) cattle tested (range, 20.3 to 84.1% within specific groups). In cattle shedding BCV from the nasal passages, 49 of 68 (72.1%) seroconverted, and 472 of 746 (63.3%) cattle that were not shedding the virus seroconverted.

Conclusions and Clinical Relevance—Bovine coronavirus can be detected in populations of feedlot cattle in the form of viral shedding as well as seroconversion to the virus. Although only a few cattle were shedding the virus at the time of arrival at a feedlot, most of the cattle seroconverted to BCV by 28 days after arrival. (Am J Vet Res2000;61:1057–1061)
DNA ploidy and nuclear morphometric variables for the evaluation of melanocytic tumors in dogs and cats
Authors: Roels Stefan L. M. F. , Van Daele André J. , Van Marck Erik A. , Ducatelle Richard V. A.
Published: December 2005

Objective—To determine the prognostic importance of the DNA content and nuclear morphometric variables in melanocytic tumors of cats and dogs.

Sample Population—27 melanocytic tumors of dogs and cats.

Procedures—Biopsy specimens were investigated by quantitative image analysis after the Feulgen staining method. The DNA content (index), nuclear diameter, ploidy balance, proliferation index, hyperploidy, and growth fraction (Ki67) were measured. Using 1- way ANOVA and a Pearson correlation test, the relationships between the different variables were tested. Their role in the prognosis in affected dogs and cats was estimated using the Cox regression test with respect to 6 months postoperative survival rate.

Results—Significant correlations were found between DNA index and ploidy balance and proliferation index. A significant correlation was also found between hyperploidy and DNA index, and between ploidy balance and proliferation index. Significant differences were found between histologically malignant and benign melanocytic tumors but not between primary malignant tumors and metastatic malignant tumors for DNA index and ploidy balance. No correlation was found between DNA variables and survival time.

Conclusion and Clinical Relevance—In melanocytic tumors of cats and dogs, DNA index and ploidy balance can be used to differentiate histologically benign from malignant tumors. However, DNA content and nuclear morphometric variables have little value in predicting survival time. The DNA index and ploidy balance provide an additional tool to evaluate melanocytic tumors of cats and dogs. Survival in dogs and cats with melanocytic tumors, however, is not determined by modifications of DNA content or changes in nuclear morphometry of tumor cells. (Am J Vet Res2000;61:1074–1079)
Expression of α-smooth muscle actin and fibronectin in tubulointerstitial lesions of cats with chronic renal failure
Authors: Sawashima Ko , Mizuno Shinya , Mizuno-Horikawa Yoko , Shimada Akinori , Kudo Tadaaki , Kurosawa Tsutomu
Published: December 2005

Objective—To examine renal expression of α-smooth muscle actin (α-SMA) and fibronectin in cats with tubulointerstitial nephritis (TIN) for use in predicting progression to renal fibrosis.

Animals—19 cats with TIN and 9 cats without nephritis.

Procedure—Serum creatinine and BUN concentrations were measured. Indices for glomerular extra-cellular matrix (ECM), tubular injury (TI), and fibronectin were determined in renal specimens to quantify the extent of injury and fibrotic lesions. Expression of α-SMA in renal tissue was immunohistochemically detected, and correlations were evaluated between the α-SMA index and other histologic and clinical variables.

Results—The α-SMA index in tubulointerstitial areas (1.63 ± 0.78) was significantly higher in cats with TIN, especially in the periglomerular and peritubular areas, than in cats without nephritis (0.20 ± 0.14). The α-SMA index was significantly associated with the TI index (r2= 0.70), fibronectin index (r2= 0.95), BUN concentration (r2= 0.64), and serum creatinine concentration (r2= 0.66). Of special interest was that interstitial α-SMA expression appeared evident in the kidneys at an early stage of TIN, prior to the onset of ECM deposition.

Conclusion and Clinical Relevance—Analysis of results of histologic and clinical examinations revealed that interstitial α-SMA expression may have clinical importance and may be a useful early histologic marker for development of chronic renal failure in cats. An immunohistochemical examination for fibrogenic molecules (such as α-SMA expression) may provide fundamental information on the pathogenesis of early-stage renal disease and aid clinical management of cats with chronic renal failure, including TIN. (Am J Vet Res2000;61:1080–1086)
Evaluation of short-term increased intraocular pressure on flash- and pattern-generated electroretinograms of dogs
Authors: Hamor Ralph E. , Gerding Paul A. , Ramsey David T. , Whiteley Herbert E. , Benson Gordon J. , Schaeffer David J.
Published: December 2005

Objective—To determine the electrodiagnostic and histologic response of short-term increases of intraocular pressure (IOP) on transient pattern electroretinograms (PERG) and flash electroretinograms (FERG) in the eyes of dogs.

Animals—8 healthy mixed-breed dogs.

Procedure—Transient PERG and FERG waveforms were recorded from dogs (while anesthetized) as IOP was increased from baseline (7 to 19 mm Hg) to 90 mm Hg. One hundred mean PERG responses and a single FERG response were recorded at each step during 3 recording sessions. Globes of each dog were enucleated after euthanasia on posttreatment day 7 and evaluated by a pathologist.

Results—Increases in spatial frequency resulted in decreased amplitudes of N2 (second negative PERG peak). Increases in IOP resulted in decreases in all 3 PERG waveforms and the FERG waveform. All values began to return to baseline after short-term increases in IOP on day 0, and waveforms were not significantly different on posttreatment days 3 and 7.

Conclusions—Data suggest that short-term increases in IOP affect PERG and FERG waveforms, and PERG waveforms are more sensitive to increases in IOP. Differences were not detected between treated and control eyes on histologic examination. Further studies are necessary to determine at what IOP permanent damage to ganglion and photoreceptor cells will develop and whether PERG is a reliable clinical diagnostic technique for use in dogs to reveal retinal damage that is secondary to increased IOP prior to changes in waveforms generated by FERG in dogs. (Am J Vet Res2000;61:1087–1091)
Identification of matrix metalloproteinases in canine neoplastic tissue
Authors: Lana Susan E. , Ogilvie Gregory K. , Hansen Rodney A. , Powers Barbara E. , Dernell William S. , Withrow Stephen J.
Published: December 2005

Objective—To identify matrix metalloproteinases (MMP) 2 and 9 in canine tumor tissue and to compare the amount of activity to that in unaffected stromal tissue.

Animals—30 dogs with spontaneously developing, high-grade osteosarcoma.

Procedure—Tumor and nearby stromal tissue (muscle) were obtained at the time of surgery. Specimens were homogenized, and supernatants were assayed, using gelatin zymography. Human derived standards were run concurrently. Densitometry was done to obtain a semiquantitative arbitrary unit value for each specimen. The amount of activity in tumor tissue was compared with the amount in stromal tissue.

Results—Gelatinolytic bands were observed from the analysis of all tumor tissues and in most stromal tissues. These bands migrated in the same molecular weight area as the human MMP 2 and 9 standards. Gelatinolytic activity could be quenched by the addition of 50 mMEDTA and 1 µg of synthetic tissue inhibitor of metalloproteinase (TIMP) 2 per 100 ml. There was significantly more gelatinolytic activity in tumor tissue than in stromal tissue.

Conclusions and Clinical Relevance—MMP 2 and 9 are detectable in canine neoplastic tissue. matrix metalloproteinases activity in tumor tissue is higher than in unaffected stromal tissue, indicating that canine MMP may be involved in the pathogenesis of tumor growth and metastasis. (Am J Vet Res2000;61:111–114)
Concentrations of gentamicin in serum and bronchial lavage fluid after intravenous and aerosol administration of gentamicin to horses
Authors: McKenzie III Harold C. , Murray Michael J.
Published: December 2005

Objective—To compare concentrations of gentamicin in serum and bronchial lavage fluid after IV and aerosol administration of gentamicin to horses.

Animals—9 healthy adult horses.

Procedure—Gentamicin was administered by aerosolization (20 ml of gentamicin solution [50 mg/ml]) and IV injection (6.6 mg of gentamicin/kg of body weight) to each horse, with a minimum of 2 weeks between treatments. Samples of pulmonary epithelial lining fluid were collected by small volume (30 ml) bronchial lavage 0.5, 4, 8, and 24 hours after gentamicin administration. Serum samples were obtained at the same times. All samples were analyzed for gentamicin concentration, and cytologic examinations were performed on aliquots of bronchial lavage fluid collected at 0.5, 8, and 24 hours.

Results—Gentamicin concentrations in bronchial lavage fluid were significantly greater 0.5, 4, and 8 hours after aerosol administration, whereas serum concentrations were significantly less at all times after aerosol administration, compared with IV administration. Neutrophil counts in bronchial lavage fluid increased from 0.5 to 24 hours, regardless of route of gentamicin administration.

Conclusions and Clinical Relevance—Aerosol administration of gentamicin to healthy horses resulted in gentamicin concentrations in bronchial fluid that were significantly greater than those obtained after IV administration. A mild inflammatory cell response was associated with aerosol delivery of gentamicin and repeated bronchial lavage. Aerosol administration of gentamicin may have clinical use in the treatment of bacterial bronchopneumonia in horses. (Am J Vet Res2000;61:1185–1190)
Evaluation of the ability of orally administered aspirin to mitigate effects of 3-methylindole in feedlot cattle
Authors: Bingham Howard R. , Wittum Thomas E. , Morley Paul S. , Bray Tammy M. , Sarver Craig F. , Queen W. Greg , Shulaw William P.
Published: December 2005

Objective—To evaluate the ability of orally administered aspirin to mitigate 3-methylindole (3MI)-induced respiratory tract disease and reduced rate of gain in feedlot cattle.

Animals—244 beef cattle.

Procedure—In a masked, randomized, controlled field trial, calves were untreated (controls) or received a single orally administered dose of aspirin (31.2 g) on entry into a feedlot. Serum 3MI concentrations were measured on days 0, 3, and 6. Rumen 3MI concentration was measured on day 3. Cattle were observed daily for clinical signs of respiratory tract disease. Lungs were evaluated at slaughter for gross pulmonary lesions.

Results—Mean daily gain (MDG) in cattle treated with aspirin, compared with control cattle, was 0.06 kg greater in the backgrounding unit and 0.03 kg greater for the overall feeding period. Neither serum nor rumen 3MI concentrations appeared to modify this effect. Cattle treated with aspirin were more likely to be treated for respiratory tract disease. Mortality rate, gross pulmonary lesions, and serum and rumen 3MI concentrations were similar between groups. Increased rumen 3MI concentration was associated with a small difference in risk of lung fibrosis.

Conclusions and Clinical Relevance—Cattle given a single orally administered dose of aspirin on feedlot entry had higher MDG in the backgrounding unit and for the overall feeding period, but this finding could not be attributed to mitigation of effects of 3MI. This may have been influenced by low peak 3MI production and slow rates of gain. (Am J Vet Res2000;61:1209–1213)
Clinical effects of exercise on subchondral bone of carpal and metacarpophalangeal joints in horses
Authors: Kawcak Christopher E. , McIlwraith C. Wayne , Norrdin Robert W. , Park Richard D. , Steyn Phillip S.
Published: December 2005

Objective—To determine effects of treadmill exercise on subchondral bone of carpal and metacarpophalangeal joints of 2-year-old horses.

Animals—12 healthy 2-year-old horses.

Procedure—Horses were randomly assigned to the control (n = 6) or exercised (6) groups. Horses in the exercised group ran on a high-speed treadmill 5 d/wk for 6 months. Horses in the control group were hand walked for the same amount of time. Results of clinical, radiographic, nuclear scintigraphic, and computed tomographic examinations, and serum and synovial concentrations of biochemical markers of bone metabolism were compared between groups.

Results—Exercised horses were significantly lamer at the end of the study than control horses. Radionuclide uptake in the metacarpal condyles, but not in the carpal joints, was greater in exercised horses, compared with control horses. Exercised horses also had a higher subchondral bone density in the metacarpal condyles than control horses, but such differences were not detected in the carpal bones.

Conclusions and Clinical Relevance—None of the diagnostic techniques evaluated was sufficiently sensitive to detect all osteochondral damage. Computed tomography and computed tomographic osteoabsorptiometry were superior to conventional radiography for detecting small osteochondral fragments. Nuclear scintigraphy was a sensitive indicator of subchondral bone change but lacked specificity for describing lesions and discerning normal bone remodeling from damage. Newer techniques such as computed tomography may help clinicians better diagnose early and subtle joint lesions in horses prior to development of gross joint damage. (Am J Vet Res2000;61:1252–1258)
In vitro comparison of the use of two large-animal, centrally threaded, positive-profile transfixation pin designs in the equine third metacarpal bone
Authors: Morisset Sophie , McClure Scott R. , Hillberry Ben M. , Fisher Kate E.
Published: December 2005

Objective—To compare the in vitro holding power and associated microstructural damage of 2 large-animal centrally threaded positive-profile transfixation pins in the diaphysis of the equine third metacarpal bone.

Sample Population—25 pairs of adult equine cadaver metacarpal bones.

Procedure—Centrally threaded positive-profile transfixation pins of 2 different designs (ie, self-drilling, self-tapping [SDST] vs nonself-drilling, nonself-tapping [NDNT] transfixation pins) were inserted into the middiaphysis of adult equine metacarpal bones. Temperature of the hardware was measured during each step of insertion with a surface thermocouple. Bone and cortical width, transfixation pin placement, and cortical damage were assessed radiographically. Resistance to axial extraction before and after cyclic loading was measured using a material testing system. Microstructural damage caused by transfixation pin insertion was evaluated by scanning electron microscopy.

Results—The temperature following pin insertion was significantly higher for SDST transfixation pins. Periosteal surface cortical fractures were found in 50% of the bones with SDST transfixation pins and in none with NDNT transfixation pins. The NDNT transfixation pins were significantly more resistant to axial extraction than SDST transfixation pins. Grossly and microscopically, NDNT transfixation pins created less damage to the bone and a more consistent thread pattern.

Conclusions and Clinical Relevance—In vitro analysis revealed that insertion of NDNT transfixation pins cause less macroscopic and microscopic damage to the bone than SDST transfixation pins. The NDNT transfixation pins have a greater pull out strength, reflecting better initial bone transfixation pin stability. (Am J Vet Res2000;61:1298–1303)
Maturation of the auditory system in clinically normal puppies as reflected by the brain stem auditory-evoked potential wave V latency-intensity curve and rarefaction-condensation differential potentials
Authors: Poncelet Luc C. , Coppens Angélique G. , Meuris Sylvain I. , Deltenre Paul F.
Published: December 2005

Objective—To evaluate auditory maturation in puppies.

Animals—Ten clinically normal Beagle puppies.

Procedure—Puppies were examined repeatedly from days 11 to 36 after birth (8 measurements). Clickevoked brain stem auditory-evoked potentials (BAEP) were obtained in response to rarefaction and condensation click stimuli from 90 dB normal hearing level to wave V threshold, using steps of 10 dB. Responses were added, providing an equivalent to alternate polarity clicks, and subtracted, providing the rarefaction-condensation differential potential (RCDP). Steps of 5 dB were used to determine thresholds of RCDP and wave V. Slope of the low-intensity segment of the wave V latency-intensity curve was calculated. The intensity range at which RCDP could not be recorded (ie, pre-RCDP range) was calculated by subtracting the threshold of wave V from threshold of RCDP.

Results—Slope of the wave V latency-intensity curve low-intensity segment evolved with age, changing from (mean ± SD) –90.8 ± 41.6 to –27.8 ± 4.1 μs/dB. Similar results were obtained from days 23 through 36. The pre-RCDP range diminished as puppies became older, decreasing from 40.0 ± 7.5 to 20.5 ± 6.4 dB.

Conclusion and Clinical Relevance—Changes in slope of the latency-intensity curve with age suggest enlargement of the audible range of frequencies toward high frequencies up to the third week after birth. Decrease in the pre-RCDP range may indicate an increase of the audible range of frequencies toward low frequencies. Age-related reference values will assist clinicians in detecting hearing loss in puppies. (Am J Vet Res2000;61:1343–1348)
Measurement of peptidase activity and evaluation of effectiveness of administration of minocycline for treatment of dogs with periodontitis
Authors: Hirasawa Masatomo , Hayashi Kazuhiko , Takada Kazuko
Published: December 2005

Objective—To determine clinical, enzymatic, and microbiologic effects of controlled-release localized administration of minocycline on dogs with periodontitis.

Animals—Five adult Beagles with periodontitis.

Procedure—After tooth scaling and root planing, 2 treatment, 1 placebo, and 1 control site were selected for each dog. Treatment sites (n = 10) received a periodontal formulation of minocycline hydrochloride, placebo sites (5) received ointment without minocycline, and control sites (5) did not receive ointment. Treatments were administered 4 times at weekly intervals. Peptidase activity and clinical and microbiologic effects were evaluated and compared among sites for 17 weeks.

Results—Bleeding of the gums on probing (BOP) and pocket depth (PD) improved at the treatment site and were maintained for 13 weeks after treatment. However, BOP and PD in placebo and control sites increased from weeks 9 to 17. Peptidase activity in the periodontal pocket decreased noticeably from week 1 to 17, compared with baseline values for the treatment site. However, peptidase activity for placebo and control sites increased and were above baseline values on week 9 and week 13, respectively. Total bacterial counts decreased by 90% for treatment sites and remained at that value for 13 weeks. However, for placebo and control sites, bacterial counts increased and reached the baseline value on week 17.

Conclusions and Clinical Relevance—Increased peptidase activity is correlated with the progression of periodontitis in dogs. Treatment with minocycline, using a localized delivery system, was effective in dogs for at least 13 weeks after cessation of drug administration. (Am J Vet Res2000;61:1349–1352)
Results of a longitudinal study of the prevalence of Escherichia coli O157:H7 on cow-calf farms
Authors: Sargeant Jan M. , Gillespie Jerry R. , Oberst Richard D. , Phebus Randall K. , Hyatt Doreene R. , Bohra Lalit K. , Galland John C.
Published: December 2005

Objective—To describe the frequency and distribution ofEscherichia coliO157:H7 in the feces and environment of cow-calf herds housed on pasture.

Sample Population—Fecal and water samples for 10 cow-calf farms in Kansas.

Procedure—Fecal and water samples were obtained monthly throughout a 1-year period (3,152 fecal samples from 2,058 cattle; 199 water samples).Escherichia coliO157:H7 in fecal and water samples was determined, using microbial culture.

Results—Escherichia coliO157:H7 was detected in 40 of 3,152 (1.3%) fecal samples, and 40 of 2,058 (1.9%) cattle had ≥ 1 sample withE coli. Fecal shedding by specific cattle was transient; none of the cattle hadE coliin more than 1 sample. Significant differences were not detected in overall prevalence among farms. However, significant differences were detected in prevalence among sample collection dates.Escherichia coliO157:H7 was detected in 3 of 199 (1.5%) water samples.

Conclusions and Clinical Relevance—Implementing control strategies forE coliO157:H7 at all levels of the cattle industry will decrease the risk of this organism entering the human food chain. Devising effective on-farm strategies to controlE coliO157:H7 in cow-calf herds will require an understanding of the epidemiologic characteristics of this pathogen. (Am J Vet Res2000;61:1375–1379)
Effect of ration and exercise on plasma creatine kinase activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis
Authors: MacLeay Jennifer M. , Valberg Stephanie J. , Pagan Joseph D. , Xue Jinliang L. , De La Corte Flavio D. , Roberts Jennifer
Published: December 2005

Objective—To determine the effects of 3 rations (low grain, fat, high grain) on plasma creatine kinase (CK) activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis (RER).

Animals—5 Thoroughbreds with RER and 3 healthy Thoroughbreds (control horses).

Procedures—Rations were formulated to meet (lowgrain and fat rations) or exceed (high-grain ration) daily energy requirements. Each ration was fed to horses in a crossover design for 3 weeks. Horses were exercised on a treadmill Monday through Friday; maximum speed on Monday and Friday was 11 m/s (6% slope), on Tuesday and Thursday was 9 m/s, and on Wednesday was 4.5 m/s. Plasma CK activity and lactate concentration were determined before and after exercise.

Results—Horses with RER fed the high-grain ration had significantly greater CK activity and change in CK activity 4 hours after exercise, compared with those fed the low-grain ration. Horses with RER exercised at the trot or canter had significantly greater increases in CK activity, compared with those exercised at the gallop. Plasma lactate concentrations after exercise were similar in control and affected horses. Lactate concentration and CK activity were not correlated in horses with RER.

Conclusions and Clinical Relevance—Rations high in grain and formulated to exceed daily energy requirements may increase episodes of rhabdomyolysis in Thoroughbred horses susceptible to RER. (Am J Vet Res2000;61:1390–1395)
Intracellular magnesium concentrations in dogs with gastric dilatation-volvulus
Authors: Bebchuk Trevor N. , Hauptman Joe G. , Braselton W. Emmett , Walshaw Richard
Published: December 2005

Objective—To quantify and compare intracellular magnesium concentrations (Mgi) in clinically normal dogs (control dogs) and dogs that have gastric dilatation- volvulus (GDV dogs) and to determine whether there is a difference in Mgiand serum magnesium concentrations (Mgs) between GDV dogs with and without cardiac arrhythmias.

Animals—41 control dogs and 21 GDV dogs.

Procedure—Rectus abdominis muscle specimens were obtained from control and GDV dogs for determination of Mgi. Blood samples were obtained from GDV dogs for determination of Mgs, and dogs were monitored for 48 hours for cardiac arrhythmias. Muscle specimens were frozen at –40 C, oven dried at 95 C, and digested with concentrated nitric acid. Multielemental analyses were performed by simultaneous/ sequential inductively coupled plasma-atomic emission spectroscopy with fixed-cross flow nebulization. The Mgiwas standardized to sulfur content to correct for the amount of fat and fascia in the muscle specimen. Mean (± SEM) values were recorded in parts per million (ppm).

Results—There were no significant differences in Mgibetween control (627 ± 11.1 ppm) and GDV (597 ± 20.5 ppm) dogs, in Mgibetween GDV dogs with (590 ± 34 ppm) and without (584 ± 29 ppm) cardiac arrhythmias, and in Mgsbetween GDV dogs with (1.77 ± 0.26 ppm) and without (1.51 ± 0.09 ppm) cardiac arrhythmias. There was no correlation between Mgsand Mgi(R2=0.0001).

Conclusions and Clinical Relevance—Results indicate that Mg depletion is not pathophysiologically important in dogs with GDV and does not play a role in the cardiac arrhythmias detected in these patients. (Am J Vet Res2000;61:1415–1417)
Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extract to dogs
Authors: Lee Keun-Woo , Yamato Osamu , Tajima Motoshi , Kuraoka Minako , Omae Shogo , Maede Yoshimitsu
Published: December 2005

Objective—To determine whether dogs given garlic extract developed hemolytic anemia and to establish the hematologic characteristics induced experimentally by intragastric administration of garlic extract.

Animals—8 healthy adult mixed-breed dogs.

Procedure—4 dogs were given 1.25 ml of garlic extract/kg of body weight (5 g of whole garlic/kg) intragastrically once a day for 7 days. The remaining 4 contol dogs received water instead of garlic extract. Complete blood counts were performed, and methemoglobin and erythrocyte-reduced glutathione concentrations, percentage of erythrocytes with Heinz bodies, and percentage of eccentrocytes were determined before and for 30 days after administration of the first dose of garlic extract. Ultrastructural analysis of eccentrocytes was performed.

Results—Compared with initial values, erythrocyte count, Hct, and hemoglobin concentration decreased to a minimum value on days 9 to 11 in dogs given garlic extract. Heinz body formation, an increase in erythrocyte- reduced glutathione concentration, and eccentrocytes were also detected in these dogs. However, no dog developed hemolytic anemia.

Conclusions and Clinical Relevance—The constituents of garlic have the potential to oxidize erythrocyte membranes and hemoglobin, inducing hemolysis associated with the appearance of eccentrocytes in dogs. Thus, foods containing garlic should not be fed to dogs. Eccentrocytosis appears to be a major diagnostic feature of garlic-induced hemolysis in dogs. (Am J Vet Res2000;61:1446–1450)
Prevalence and relevance of antibodies to type-I and -II collagen in synovial fluid of dogs with cranial cruciate ligament damage
Authors: de Rooster Hilde , Cox Eric , Bree Henri van
Published: December 2005

Objective—To measure and compare synovial fluid antibody titers to type-I and -II collagen in stifle joints with instability caused by complete or partial cranial cruciate ligament (CCL) rupture and joints with osteoarthrosis secondary to other pathologic changes in dogs.

Animals—82 dogs with diseased stifle joints.

Procedure—Synovial fluid samples were collected from 7 dogs with clinically normal stifles (control group) and 82 dogs with diseased joints (50 stifle joints with complete rupture of the CCL, 20 with partial damage of the CCL, and 12 joints with radiographic signs of osteoarthritis secondary to other arthropathies). Synovial fluid samples were tested for autoantibodies to type-I and -II collagen by an ELISA.

Results—In dogs with complete and partial CCL rupture, synovial fluid antibody titers to type-I and -II collagen were significantly increased, compared with control dogs. Forty-eight percent (24/50) of samples from dogs with complete CCL rupture and 35% (7/20) of samples from dogs with partial CCL rupture had antibody titers to type-I collagen that were greater than the mean plus 2 standard deviations of the control group titers. Synovial fluid antibody titers to type- II collagen were high in 40% of the dogs with partial or (8/20) complete (20/50) CCL rupture. Dogs with osteoarthrosis secondary to other pathologic changes had significantly increased synovial fluid antibodies to type-I and -II collagen, compared with control dogs.

Conclusion—Increases in autoantibodies to collagen in synovial fluid are not specific for the type of joint disorder. It is unlikely that the anticollagen antibodies play an active role in the initiation of weakening of the CCL. (Am J Vet Res2000;61:1456–1461)
Quantification of measurement of femoral head coverage and Norberg angle within and among four breeds of dogs
Authors: Tomlinson James L. , Johnson Jane C.
Published: December 2005

Objective—To report values for percentage coverage of the femoral head (PC) and Norberg angle (NA) in 4 common breeds of dogs and to determine values for each that distinguish between normal and dysplastic hip status on the basis of Orthopedic Foundation for Animals (OFA) hip evaluation.

Animals—1,841 dogs 24 to 48 months of age that were Labrador Retrievers (455), Golden Retrievers (423), Rottweilers (545), or German Shepherd Dogs (418).

Procedure—Retrospective analysis of NA and PC measured from standard OFA ventrodorsal pelvic radiographs from 4 breeds of dog.

Results—Norberg angle ranged from 67.4 to 124.4° for Labrador Retrievers, 59.7 to 128.6° for Rottweilers, 70.2 to 119.4° for Golden Retrievers, and 55.3 to 121.3° for German Shepherd Dogs. The PC ranged from 6.5 to 79.9% for Labrador Retrievers, 5.7 to 79.5% for Rottweilers, 8.3 to 79.3% for Golden Retrievers, and 5.4 to 83.7% for German Shepherd Dogs. On the basis of logistic regression modeling for determining normal versus abnormal hip status for all 4 breeds, cutoff points for NA were < 105° and PC were < 50%.

Conclusions and Clinical Relevance—Results of our study indicate that cutoff points of NA of 105° and PC of 50% do not differentiate normal versus dysplastic hip status. Each of the 4 breeds had different values for NA and PC that distinguished normal from dysplastic hip status. (Am J Vet Res2000;61:1492–1500)
Hepatic and pulmonary enzyme activities in horses
Authors: Lakritz Jeffrey , Winder Bruce S. , Noorouz-Zadeh Jaffar , Huang Tien L. , Buckpitt Alan R. , Hammock Bruce D. , Plopper Charles G.
Published: December 2005

Objective—To determine hepatic and pulmonary phase-I and phase-II enzyme activities in horses.

Sample population—Pulmonary and hepatic tissues from 22 horses that were 4 months to 32 years old.

Procedure—Pulmonary and hepatic tissues from horses were used to prepare cytosolic (glutathione S-transferase and soluble epoxide hydrolase) and microsomal (cytochrome P450 monooxygenases) enzymes. Rates of microsomal metabolism of ethoxyresorufin, pentoxyresorufin, and naphthalene were determined by high-performance liquid chromatography. Activities of glutathione S-transferase and soluble epoxide hydrolase were determined spectrophotometrically. Cytochrome P450 content was determined by carbon monoxide bound-difference spectrum of dithionite-reduced microsomes. Activity was expressed relative to total protein concentration.

Results—Microsomal protein and cytochromeP450 contents were detectable in all horses and did not vary with age. Hepatic ethoxyresorufin metabolism was detected in all horses; by comparison, pulmonary metabolism of ethoxyresorufin and hepatic and pulmonary metabolism of pentoxyresorufin were detected at lower rates. Rate of hepatic naphthalene metabolism remained constant with increasing age, whereas rate of pulmonary naphthalene metabolism was significantly lower in weanlings (ie, horses 4 to 6 months old), compared with adult horses. Hepatic glutathione S-transferase activity (cytosol) increased with age; however, these changes were not significant. Pulmonary glutathione S-transferase activity (cytosol) was significantly lower in weanlings than adult horses. Hepatic and pulmonary soluble epoxide hydrolase did not vary with age of horses.

Conclusions and Clinical Relevance—Activity of cytochrome P450 isoforms that metabolize naphthalene and glutathione S-transferases in lungs are significantly lower in weanlings than adult horses, which suggests reduced ability of young horses to metabolize xenobiotics by this organ. (Am J Vet Res2000;61:152–157)
Pathogenesis of Streptococcus zooepidemicus infection after intratracheal inoculation in llamas
Authors: Cebra Christopher K. , Heidel Jerry R. , Cebra Margaret L. , Tornquist Susan J. , Smith Bradford B.
Published: December 2005

Objectives—To test whether generalizedStreptococcus zooepidemicusinfection could be induced by intratracheal inoculation in llamas and to characterize this infection.

Animals—6 test and 3 control llamas.

Procedure—Test llamas received 1 of 3 dosages ofS zooepidemicusby intratracheal injection, whereas control llamas received sterile culture medium. Physical examination variables and results of clinicopathologic analyses of blood, peritoneal fluid, and tracheal wash fluid were compared in test llamas between, before, and during the development of bacteremia and with control llamas. Bacteriologic culture was performed on all collected body fluids and tissue specimens that were collected at necropsy. Tissue specimens that were collected at necropsy were examined histologically.

Results—Infection induced fever, anorexia, and signs of depression. Five of 6 infected llamas developed specific signs of inflammation in the thorax or abdomen, bacteremia, neutrophilic leukocytosis with toxic changes and high band neutrophil cell counts, hyperfibrinogenemia, and high peritoneal fluid WBC counts and protein concentrations. On development of bacteremia, llamas had significant decreases in serum iron (from 118 ± 25 to 6 ± 4 µg/ml) and increases in serum glucose (from 131 ± 5 to 253 ± 48 mg/dl) concentrations.

Conclusions and Clinical Relevance—Streptococcus zooepidemicusspreads rapidly to other body compartments after intratracheal inoculation in llamas. Fever, anorexia, and signs of depression are the most consistent clinical signs, although other signs are possible. Clinicopathologic analysis of body fluids yields evidence of inflammation. Infection byS zooepidemicuscan be proven by bacteriologic culture of body fluids before death or of tissue specimens after death.(Am J Vet Res2000:61;1525–1529)
Effects of dexamethasone on development of immunoglobulin G subclass responses following vaccination of horses
Authors: Slack JoAnn , Risdahl Jack M. , Valberg Stephanie J. , Murphy Michael J. , Schram Brian R. , Lunn D. Paul
Published: December 2005

Objective—To determine the effects of dexamethasone on development of IgG subclass responses following vaccination of healthy horses.

Animals—11 mature Thoroughbreds.

Procedure—Horses received 2 IM injections at 2- week intervals of a vaccine containing inactivated infectious bovine rhinotracheitis, bovine viral diarrhea, and parainfluenza-3 viral antigens and were then randomly assigned to 2 groups. Six horses received dexamethasone (0.2 mg/kg of body weight, IM) twice weekly for 8 weeks starting the day of the first vaccination. Five control horses received an equivalent volume of saline (0.9% NaCl) solution. Antigen-specific serum IgG subclass titers were determined weekly after vaccination by use of an ELISA.

Results—Vaccination resulted in similar antigen-specific serum IgG(T) titers in dexamethasone-treated and control horses. In contrast, although control horses developed IgGa and IgGb responses after vaccination, corticosteroid administration completely inhibited these responses in treated horses.

Conclusions and Clinical Relevance—Cortico steroids can have profound effects on primary immune responses in horses and can significantly affect IgG responses to inactivated vaccines. Corticosteroid treatment regimens commonly used to treat diseases in horses may result induction of a nonprotective IgG subclass response, leaving treated horses susceptible to disease. Additionally, mechanisms regulating IgGa and IgGb responses appear to differ from those regulating IgG(T) responses. Further defining these mechanisms is a critical step in designing effective vaccines, and corticosteroid-induced immunomodulation may be a valuable tool for studying immune responses in horses. (Am J Vet Res2000;61:1530–1533)
Anesthetic, cardiorespiratory, and metabolic effects of four intravenous anesthetic regimens induced in horses immediately after maximal exercise
Authors: Hubbell John A. E. , Hinchcliff Kenneth W. , Schmall L. Michael , Muir William W. , Robertson James T. , Sams Richard A.
Published: December 2005

Objective—To determine the anesthetic, cardiorespiratory, and metabolic effects of 4 IV anesthetic regimens in Thoroughbred horses recuperating from a brief period of maximal exercise.

Animals—6 adult Thoroughbreds.

Procedure—Horses were preconditioned by exercising them on a treadmill. Each horse ran 4 simulated races, with a minimum of 14 days between races. Races were run at a treadmill speed that caused horses to exercise at 120% of their maximal oxygen consumption. Horses ran until fatigued or for a maximum of 2 minutes. Two minutes after exercise, horses received a combination of xylazine hydrochloride (2.2 mg/kg of body weight) and acepromazine maleate (0.04 mg/kg) IV. Five minutes after exercise, horses received 1 of the following 4 IV anesthetic regimens: ketamine hydrochloride (2.2 mg/kg); ketamine (2.2 mg/kg) and diazepam (0.1 mg/kg); tiletamine hydrochloride-zolazepam hydrochloride (1 mg/kg); and guaifenesin (50 mg/kg) and thiopental sodium (5 mg/kg). Treatments were randomized. Cardiopulmonary indices were measured, and samples of blood were collected before and at specific times for 90 minutes after each race.

Results—Each regimen induced lateral recumbency. The quality of induction and anesthesia after ketamine administration was significantly worse than after other regimens, and the duration of anesthesia was significantly shorter. Time to lateral recumbency was significantly longer after ketamine or guaifenesinthiopental administration than after ketaminediazepam or tiletamine-zolazepam administration. Arterial blood pressures after guaifenesin-thiopental administration were significantly lower than after the other regimens.

Conclusions and Clinical Relevance—Anesthesia can be safely induced in sedated horses immediately after maximal exercise. Ketamine-diazepam and tiletamine- zolazepam induced good quality anesthesia with acceptable perturbations in cardiopulmonary and metabolic indices. Ketamine alone and guaifenesinthiopental regimens are not recommended. (Am J Vet Res2000;61:1545–1552)
Changes in cardiac dimensions and indices of cardiac function during deconditioning in horses
Authors: Kriz Nikolaus G. , Hodgson David R. , Rose Reuben J.
Published: December 2005

Objective—To investigate the effects of deconditioning on cardiac dimensions and indices of cardiac function in horses.

Animals—Thirteen 3-to 4-year-old Standardbred geldings.

Procedure—All horses had echocardiographic measurements performed at the conclusion of 9 months of intense training and at weeks 1.5, 4, 8, and 12 of deconditioning. Direct echocardiographic measurements included interventricular septal thickness, left ventricular internal dimensions, left ventricular freewall thickness, left atrial dimension, aortic diameter, diameter of the pulmonary artery, slopes of the mitral valve, heart rate, preejection period, and ejection time. Derived indices of cardiac function included fractional shortening, fractional area change, and cardiac output.

Results—Cardiac dimensions did not change significantly for the first 4 weeks of deconditioning but decreased significantly by week 8 and continued to decrease until week 12. Indices of cardiac function increased significantly during the first 10 days of deconditioning, remaining stable until week 4 of deconditioning. After week 4, indices of cardiac function decreased significantly until week 12.

Conclusions and Clinical Relevance—Deconditioning resulted in a general reduction in cardiac dimensions and indices of cardiac function over 12 weeks. However, results of the study reported here indicate that following an intense period of training, cardiac function may be maintained during the first 4 weeks of deconditioning. Results indicate that trained horses may rest for up to 4 weeks without a substantial reduction in cardiac capacity as reflected by echocardiographic indices. (Am J Vet Res2000;61: 1553–1560)
Effects of a hydrolyzed collagen dressing on the healing of open wounds in dogs
Authors: Swaim Steven F. , Gillette Robert L. , Sartin Eva A. , Hinkle Sherri H. , Coolman Shindok L.
Published: December 2005

Objective—To determine the effects of a hydrolyzed bovine collagen dressing (HBCD) on healing of open wounds in healthy dogs.

Animals—9 female Beagles.

Procedures—2 full-thickness skin wounds were made bilaterally on the trunk of each dog. Wounds on 1 side were treated with powdered HBCD covered with a semiocclusive nonadherent bandage. Wounds on the other side (control wounds) were covered with a semiocclusive nonadherent bandage only. Wound healing was subjectively assessed, and percentage increase in tissue perfusion was assessed by use of laser Doppler perfusion imaging (LDPI). Planimetry was performed to determine the percentages of contraction, epithelialization, and total wound healing. Biopsy specimens were examined microscopically to evaluate histologic changes.

Results—The HBCD did not induce a strong inflammatory reaction, as reflected by results of LDPI and histologic examination. Moreover, HBCD appeared hydrophilic and provided an environment to keep wounds clean and enhance early epithelialization. After treatment for 7 days, treated wounds had a significantly greater percentage of epithelialization than control wounds (12.13 vs 7.03%).

Conclusion and Clinical Relevance—The hydrophilic property of HBCD may cleanse contaminated wounds with the body's homeostatic fluids and enhance early wound epithelialization. (Am J Vet Res2000;61:1574–1578)