bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of collagenase-induced mitral valve regurgitation in dogs
Authors: Fujiki Makoto , Misumi Kazuhiro , Sakamoto Hiroshi 
Published: December 2005

AbstractObjective—To investigate the hemodynamic changes induced by injecting collagenase into the mitral valve to induce mitral valve regurgitation (MVR) in dogs.Animals—9 healthy Beagles.Procedure—Dogs were randomly assigned to 3 groups: control (saline [0.9% NaCl] solution; n = 3), single collagenase injection (C1; 3), and 2 collagenase injections (C2; 3). Open-heart surgery was performed, and saline or collagenase solutions were injected into the mitral valve. Before and weekly for 11 weeks after surgery, radiography, echocardiography, and phonocardiography were performed. Mean pulmonary arterial pressure and mean pulmonary arterial wedge pressure (mPAWP) were measured before and 11 weeks after surgery. Postmortem examinations were performed after dogs were euthanatized.Results—No changes were detected in the control group during the 11-week follow-up period. A systolic murmur and MVR developed 1 week after surgery in groups C1 and C2. The murmur changed from a protosystolic to a pansystolic murmur, and left atrial diameter and the left atrial-to-aortic root diameter ratio increased with time. Mean pulmonary arterial pressure and mPAWP were greater 11 weeks after surgery in groups C1 and C2, compared with presurgery values. During necropsy, tissue loss was detected in the mitral valve at the site of collagenase injection. Degree of regurgitation corresponded to lesion size.Conclusions and Clinical Relevance—Injection of collagenase into the mitral valve of healthy dogs induced MVR, and dogs with MVR developed progressive hemodynamic changes without acute overload. Collagenase-induced MVR may be an appropriate model for evaluation of prognostic markers of idiopathic MVR in dogs. (Am J Vet Res2000;61:1593–1598)
Characterization of cultured smooth muscle cells obtained from the palmar digital arteries of horses
Authors: Rodgerson Dwayne H. , Belknap James K. , Fontaine Genevieve L. , Kroll Dan L. 
Published: December 2005

AbstractObjective—To develop methods to isolate, culture, and characterize smooth muscle cells (SMC) from equine palmar digital arteries.Sample Population—Segments of the medial or lateral palmar digital arteries from the forelimbs of 6 horses.Procedure—To obtain smooth muscle explants, arterial segments were incised longitudinally. The tunica intima was gently scraped from the underlying tunica media, and explants were obtained from the tunica media. Approximately 18 to 24 explants were obtained from each palmar digital arterial segment. A substrate-attached technique was used to initiate primary culture of SMCCultured cells were identified as SMC, using light microscopy, electron microscopy, reverse transcriptase-polymerase chain reaction (RTPCR), and northern blot analysis. The replication index and serum dependence of equine SMC in culture was characterized by use of bromodeoxyuridine.Results—The SMC of equine palmar digital arteries were successfully cultured, as confirmed by RT-PCR and northern blot analysis techniques for smooth muscle α-actin and detection of SMC-specific organelles during electron microscopy. When characterized by light and electron microscopy, SMC were found to have undergone phenotypic modulation to a more synthetic phenotype in culture while retaining characteristics of SMC.Conclusions and Clinical Relevance—Culture of SMC from equine palmar digital arteries via an explant protocol is a viable technique for studying vascular biological mechanisms in horses. In vitro studies of SMC may aid investigators in determining cellular mechanisms involved in disease processes such as laminitis. (Am J Vet Res2000;61:1602–1608)
Comparison of the phenotypes of Streptococcus zooepidemicus isolated from tonsils of healthy horses and specimens obtained from foals and donkeys with pneumonia
Authors: Anzai Tohru , Walker John A. , Blair Matthew B. , Chambers Thomas M. , Timoney John F. 
Published: December 2005

AbstractObjective—To determine whether streptococcal pneumonia is caused by strains ofStreptococcus zooepidemicussimilar to those obtained from the tonsils of healthy horses.Sample Population—5 tonsils from healthy horses, 8 tracheal washes and 6 lung specimens from foals with pneumonia, and 5 nasopharyngeal swab specimens from donkeys with acute bronchopneumonia.Procedure—Variable M-like protectively immunogenic SzP proteins of 5 isolates ofS zooepidemicusfrom each tonsil and clinical specimen were compared, using immunoblots. TheSzPgene of 13 isolates representative of various SzP immunoblot phenotypes from 1 healthy horse and 9 horses and donkeys with pneumonia were sequenced and compared. Cell-associated hyaluronic acid concentration and resistance to phagocytosis of some isolates were measured.Results—Tonsils of each healthy horse were colonized by several SzP phenotypes similar to those of foals or donkeys with pneumonia. In contrast, multiple isolates from animals with pneumonia had the same SzP phenotype, indicating infection by a single strain or clone. Analysis of the SzP sequence confirmed that differences in immunoblot phenotype were associated with sequence differences and that several SzP genotypes were in healthy horses and animals with pneumonia. Isolates with high concentrations of cell-associated hyaluronic acid were more resistant to phagocytosis.Conclusions and Clinical Relevance—An SzP-specific immunoblot is a useful, sensitive measure of diversity among strains ofS zooepidemicus. Single strains with SzP phenotypes similar to those found in tonsils of healthy horses cause pneumonia. Because of the diversity of SzP phenotype and genotype among isolates from animals with pneumonia, SzP phenotype is not an important determinant of invasiveness or epizootic capabilities. (Am J Vet Res2000;61:162–166)
Purification and characterization of a feline hepatic insulin receptor
Authors: Paxton R. , Ye L. X. 
Published: December 2005

AbstractObjective—To elucidate the functional characteristics of a highly purified soluble liver insulin receptor in cats.Sample population—Frozen livers from domestic cats were obtained commercially.Procedures—The feline hepatic insulin receptor was purified from Triton X-100 solubilized plasma membranes by the use of several chromatography matrices, including affinity chromatography on an insulin-Sepharose matrix.Results—The receptor, although not homogeneous, was purified 3,000-fold. Two silver-stained protein bands were identified following sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) with molecular weight of 134,000 and 97,000, which are similar to insulin receptors isolated from other animals. This isolated receptor had steady-state insulin binding by 40 minutes at 24 C. Optimal insulin binding occurred at pH 7.8 and with 150 mMNaCl. Under these conditions, a curvilinear Scatchard plot was obtained with the isolated receptor. Using a 2 bindingsite model, the feline insulin receptor had a high-affinity low-capacity site with a dissociation constant (KD; nM) of 3 and a low-affinity high-capacity site with a KDof 1,180. The receptor also had tyrosine kinase activity toward an exogenous substrate that was stimulated by insulin and protamine.Conclusions and Clinical Relevance—Many of the reported characteristics of the liver insulin receptor in cats are similar to those for the receptor isolated from other animals and tissues, although some differences exist. These similarities suggest that characterization of the feline insulin receptor is important to understanding insulin resistance in cats with diabetes as well as in humans with diabetes. (Am J Vet Res2000;61:1625–1632)
Correlation of clinical score, intrapleural pressure, cytologic findings of bronchoalveolar fluid, and histopathologic lesions of pulmonary tissue in horses with summer pasture-associated obstructive pulmonary disease
Authors: Costa Lais R. Rodrigues , Seahorn Thomas L. , Moore Rustin M. , Taylor Henry W. , Gaunt Stephen D. , Beadle Ralph E. 
Published: December 2005

AbstractObjective—To correlate clinical score, intrapleural pressure, cytologic findings of bronchoalveolar lavage fluid (BALF), and histologic lesions of pulmonary tissue in horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD).Animals—8 adult horses affected with SPAOPD and 6 adult horses without evidence of respiratory tract disease.Procedure—Clinical score, change in intrapleural pressure (ΔPpl) during tidal breathing, results of cytologic examination and bacteriologic culture of BALF, and results of histologic examination of pulmonary parenchyma were evaluated.Results—Clinical scores for SPAOPD-affected horses (median, 5.75; range, 4.0 to 7.5) were significantly greater, compared with clinically normal horses (median, 2.0; range, 2.0 to 3.0). Cytologic examination of BALF from SPAOPD-affected horses revealed predominantly nondegenerate neutrophils. Histologic lesions were identified throughout pulmonary tissue and included severe accumulation of mucus and neutrophils within the small airways, metaplasia of bronchiolar goblet cells, and mild peribronchial infiltrate. Histologic examination of specimens collected via percutaneous biopsy was predictive of disease and corresponded to findings at postmortem examination. Clinical score and δPpl were highly correlated with mucus accumulation in the airways of affected horses. Peribronchial inflammatory infiltrate correlated with percentage of neutrophils in BALF of affected horses.Conclusions and Clinical Relevance—Clinical scoring and ΔPpl provided valid estimates of disease severity. Findings from cytologic examination of BALF of SPAOPD-affected horses varied, although, in most instances, it was diagnostically useful. Severe mucus accumulation in the airways was the most remarkable histopathologic finding in SPAOPDaffected horses. Examination of biopsy specimens collected from pulmonary parenchyma was consistently useful in diagnosing SPAOPD. (Am J Vet Res2000;61:167–173)
Net joint moments and joint powers in horses with superficial digital flexor tendinitis
Authors: Clayton Hilary M. , Schamhardt Henk C. , Willemen Maarten A. , Lanovaz Joel L. , Colborne G. Robert 
Published: December 2005

AbstractObjective—To determine whether analysis of net joint moments and joint powers is a suitable technique for evaluation of mechanics and energetics of lameness in horses and to measure effects of superficial digital flexor tendinitis.Animals—6 sound horses.Procedure—Horses were evaluated before (sound evaluation) and after (lame evaluation) induction of superficial digital flexor tendinitis in 1 forelimb by injection of collagenase. Recordings were made with an optoelectronic system and a force plate as horses trotted. Net joint moments and joint powers in the sagittal plane at each joint in the forelimbs during the stance phase were determined. Peak values were determined, and mechanical energy absorbed and generated at each joint was calculated. Comparisons were made between contralateral limbs during sound and lame evaluations.Results—Lame limbs had significant reductions in peak values for net joint moments on the palmar aspect of metacarpophalangeal (fetlock), carpal, and humeroulnar joints. Total energy absorbed was significantly lower at every joint in lame limbs, compared with compensating limbs.Conclusions and Clinical Relevance—Horses with superficial digital flexor tendinitis had significant differences between lame and compensating limbs for net joint moments and joint powers at all joints, indicating that the gait of horses with superficial digital flexor tendinitis is energetically inefficient. Assessment of net joint moments and joint powers is a useful tool in evaluating equine lameness. (Am J Vet Res2000;61:197–201)
Role of platelet-activating factor in alveolar septal injury associated with experimentally induced pneumonic pasteurellosis in calves
Authors: McClenahan David J. , Fagliari Jose J. , Evanson Oral A. , Weiss Douglas J. 
Published: December 2005

AbstractObjective—To determine whether platelet-activating factor (PAF) is involved in acute lung microvascular injury associated with pneumonic pasteurellosis in calves.Animals—15 healthy 2- to 4-week-old male Holstein calves.Procedure—Calves were anesthetized and inoculated intrabronchially with saline (0.9% NaCl) solution (n = 5) or 1 × 109Pasteurella haemolyticaorganisms (n = 10). Of the 10 calves inoculated withP haemolytica, 5 also were treated with WEB 2086, a potent inhibitor of PAF, and 5 were treated with vehicle. Blood and bronchoalveolar lavage samples were collected before and 1, 2, 4, and 6 hours after inoculation ofP haemolytica. Blood samples were analyzed to evaluate total number and differential counts of leukocytes, dilute whole-blood leukocyte deformability, size of neutrophils, and neutrophil CD11b expression. Bronchoalveolar lavage samples were analyzed for total number and differential counts of nucleated cells, total protein concentration, and hemoglobin concentration. Size and gross and histologic appearance of lung lesions also was determined.Results—Treatment of calves with WEB 2086 reduced size of lung lesions, attenuated the increase in microvascular permeability, and reduced neutrophil infiltration in the first 4 hours after inoculation. Treatment with WEB 2086 also attenuated a decrease in leukocyte deformability, increase in size of neutrophils, and CD11b expression by circulating neutrophils.Conclusions and Clinical Relevance—It appears that PAF is a major mediator for altered lung microvascular permeability and activation of circulating neutrophils in the first 4 hours after onset of pneumonic pasteurellosis in calves. (Am J Vet Res2000;61: 248–254)
Digital angiography of the feet of horses
Authors: Rosenstein Diana S. , Bowker Robert M. , Bartlett Paul C. 
Published: December 2005

AbstractObjective—To describe the vascular anatomy of the palmar digital artery and its major branches in the equine foot and to quantify the diameter of these vessels by use of digital angiograms.Sample Population—6 thoracic limbs obtained from 6 horses.Procedure—Distal portions of each limb were perfused with aerated Krebs-Henseleit solution. Digital angiograms were acquired in standing and lateral recumbent positions, following an intra-arterial injection of iopamidol. Select vessels were measured on radiographic views, and values were corrected for magnification.Results—The palmar digital artery tapered from 2.28 mm at the coronary region to 1.61 mm at the entrance to the solar canal, and the major arterial branches ranged in diameter from 0.71 to 1.42 mm in the standing position.Conclusions and Clinical Relevance—Digital angiography is useful for imaging small vessels, but penumbra limits the image resolution of the macrovasculature of the foot. The palmarodorsal projection is more useful for evaluation of the terminal arch and solar branches, but 2 projections are necessary for a thorough examination of the foot. Image magnification, position of horse, and vascular response to contrast medium must be considered in the quantitative assessment of vessel diameter. Digital angiography may be performed in clinical cases and research models for examination of vascular perfusion of the distal portion of the limb. (Am J Vet Res2000;61:255–259)
Doppler ultrasonography and single-fiber laser Doppler flowmetry for measurement of hind limb blood flow in anesthetized horses
Authors: Raisis Anthea L. , Young Lesley E. , Taylor Polly M. , Walsh Karen P. , Lekeux Pierre 
Published: December 2005

AbstractObjective—To use Doppler ultrasonography and singlefiber laser Doppler flowmetry (LDF) to evaluate blood flow in the dependent and nondependent hind limbs of anesthetized horses and to evaluate changes in femoral arterial blood flow and microvascular skeletal muscle perfusion in response to administration of phenylephrine hydrochloride or dobutamine hydrochloride.Animals—6 healthy adult horses.Procedure—Horses were anesthetized and positioned in left lateral recumbency. Doppler ultrasonography was used to measure velocity and volumetric flow in the femoral vessels. Single-fiber LDF was used to measure relative microvascular perfusion at a single site in the semimembranosus muscles. Phenylephrine or dobutamine was then administered to decrease or increase femoral arterial blood flow, and changes in blood flow and microvascular perfusion were recorded.Results—Administration of phenylephrine resulted in significant decreases in femoral arterial and venous blood flows and cardiac output and significant increases in mean aortic blood pressure, systemic vascular resistance, and PCV. Administration of dobutamine resulted in significant increases in femoral arterial blood flow, mean aortic blood pressure, and PCV. Significant changes in microvascular perfusion were not detected.Conclusion and Clinical Relevance—Results suggest that Doppler ultrasonography and single-fiber LDF can be used to study blood flows in the hind limbs of anesthetized horses. However, further studies are required to determine why changes in femoral arterial blood flows were not associated with changes in microvascular perfusion. (Am J Vet Res2000;61:286–290)
Cell-surface lactoferrin as a marker for degranulation of specific granules in bovine neutrophils
Authors: Swain Steve D. , Jutila Kathryn L. , Quinn Mark T. 
Published: December 2005

AbstractObjective—To develop a rapid and accurate flow cytometric method for measuring degranulation of specific granules in bovine neutrophils.Sample Population—Blood samples obtained from four 6- to 18-month-old Holstein cattle.Procedure—A monoclonal antibody (BL97) was generated against bovine lactoferrin and tested for applicability in ELISA, immunoprecipitation tests, immunofluorescence microscopy, and flow cytometric analyses. Using this antibody, cell-surface lactoferrin was measured concurrent with amount of secreted lactoferrin from bovine neutrophils activated with phorbol myristate acetate (PMA). Cell-surface lactoferrin also was measured on neutrophils in bovine whole blood stimulated with PMA, platelet-activating factor (PAF), N-formyl-methionyl-leucyl-phenylalanine (fMLF), and interleukin 8 (IL-8).Results—Antibody BL97 recognized bovine lactoferrin in ELISA and western immunoblots and was useful for immunoprecipitation testing, immunofluorescence microscopy, and flow cytometric analyses of bovine leukocytes. Neutrophils activated with PMA had parallel increases in content of secreted lactoferrin (measured by ELISA) and cell-surface lactoferrin (measured by flow cytometry) with increasing PMA concentrations. In addition, fluorescein-conjugated BL97 antibody detected increases in cell-surface lactoferrin on neutrophils in bovine whole blood after activation with PMA, PAF, and IL-8. In contrast, increases in cell-surface lactoferrin were not detected on bovine neutrophils treated withfMLF.Conclusion and Clinical Relevance—Measurement of cell-surface lactoferrin on bovine neutrophils by flow cytometry is a valid and rapid method for assessment of release of lactoferrin from specific granules in these cells and represents a means to rapidly measure neutrophil activation. This technique allows for investigation of mechanisms of neutrophil modification in isolated cells as well as in whole blood. (Am J Vet Res2000;61:29–37)
Bovine respiratory syncytial virus-specific IgE is associated with interleukin-2 and -4, and interferon-γ expression in pulmonary lymph of experimentally infected calves
Authors: Gershwin Laurel J. , Gunther Robert A. , Anderson Mark L. , Woolums Amelia R. , McArthur-Vaughan Kerrie , Randel K. Erin , Boyle Gabrielle A. , Friebertshauser Kathleen E. , McInturff Pat S. 
Published: December 2005

AbstractObjective—To study the local immune response of calves to bovine respiratory syncytial virus (BRSV) infection with emphasis on IgE production and cytokine gene expression in pulmonary lymph.Animals—Twelve 6- to 8-week-old Holstein bull calves. Six similar control calves were mock infected to obtain control data.Procedure—Lymphatic cannulation surgery was performed on 12 calves to create a long-term thoracic lymph fistula draining to the exterior. Cannulated calves were exposed to virulent BRSV by aerosol. Lymph fluid collected daily was assayed for BRSV and isotype-specific IgE antibody, total IgG, IgA, IgM, and protein concentrations. Interleukin-4 (IL-4), interleukin- 2 (IL-2), and interferon-γ were semi-quantitated by reverse transcription-polymerase chain reaction (RT-PCR). Cell counts and fluorescence-activated cell scanner (FACSCAN) analysis of T-cell subsets were performed on lymph cells.Results—Calves had clinical signs of respiratory tract disease during days 5 to 10 after infection and shed virus. Bovine respiratory syncytial virus-specific IgE in infected calves was significantly increased over baseline on day 9 after infection. Mean virus-specific IgE concentrations strongly correlated with increases in severity of clinical disease (r = 0.903). Expression of IL-2, IL-4, and interferon-γ was variably present in infected and control calves, with IL-4 expression most consistent during early infection.Conclusions and Clinical Relevance—Infection with BRSV was associated with production of BRSV-specific IgE, and IL-4 message was commonly found in lymph cells of infected calves. This finding supports the concept that BRSV-induced pathophysiology involves a T helper cell type-2 response. Effective therapeutic and prophylactic strategies could, therefore, be developed using immunomodulation to shift the immune response more toward a T helper cell type-1 response. (Am J Vet Res2000;61:291–298)
Blood oxygen binding in double-muscled calves and dairy calves with conventional muscle conformation
Authors: Cambier Carole , Clerbaux Thierry , Detry Bruno , Beerens Dominique , Frans Albert , Gustin Pascal 
Published: December 2005

AbstractObjective—To assess in vivo blood oxygen binding in double-muscled calves and dairy calves with conventional muscle conformation.Animals—58 dairy and 48 double-muscled calves.Procedure—Calves were classified as neonatal (24 hours old) or older calves (2 to 26 days old). Venous and arterial blood samples were collected, and hemoglobin concentration, pH, Pco2, and Po2were determined. Blood oxygen equilibrium curves (OEC) under standard conditions were constructed, and the oxygen exchange fraction (OEF) and the amount of oxygen released at the tissue level by 100 ml of blood (OEF Vol%) were calculated.Results—In each breed, partial pressure of oxygen at 50% saturation of hemoglobin (P50) under standard conditions was significantly higher in older than in neonatal calves, indicating a right shift in OEC with age. Venous P50was significantly lower in neonatal double-muscled calves than in neonatal dairy calves, but arterial and venous P50were significantly higher in older double-muscled calves than in older dairy calves. In double-muscled, but not in dairy, calves, OEF was significantly higher in older than in neonatal calves. In neonatal calves, OEF Vol% was not significantly different between breeds, but OEF Vol% was significantly higher in older double-muscled calves than in older dairy calves.Conclusions and Clinical Relevance—The lower OEF in neonatal double-muscled calves, compared with dairy calves, could contribute to the higher sensitivity of double-muscled calves to hypoxia. Blood oxygen affinity decreased with age, but OEF and OEF Vol% were unchanged with age in dairy calves, whereas they increased with age in double-muscled calves. (Am J Vet Res2000;61:299–304)