PubMed Health⌕ Search

Biomedical subjects

E A Carr

Publications and source records attributed to E A Carr.

At least 19 recordsLinked to original sources
PubMed2001

Expression of a transforming gene (E5) of bovine papillomavirus in sarcoids obtained from horses.

OBJECTIVE: To determine expression of a transforming gene (E5) of bovine papillomavirus in sarcoids, other tumors, and normal skin samples collected from horses with and without sarcoids. SAMPLE POPULATION: 23 sarcoids and 6 samples of normal skin obtained from 16 horses with sarcoids, 2 samples of normal skin and 2 papillomas obtained from horses without sarcoids, and 1 papilloma obtained from a cow. PROCEDURE: Protein was extracted from tissue samples collected from horses and incubated with agarose beads covalently coupled to Staphylococcus aureus protein A and an anti-E5 polyclonal antibody. Following incubation, proteins were eluted from the beads and electrophoresed on a 14% polyacrylamide gel and transferred to a polyvinylidene difluoride membrane. The E5 protein was detected by use of western blot analysis, using a chemiluminescence detection system. RESULTS: All 23 sarcoids had positive results for expression of E5 protein. Quantity of viral protein appeared to vary among sarcoids. All other tissues examined had negative results for E5 protein. Highest expression for E5 protein was observed in biologically aggressive fibroblastic variants of sarcoids, compared with expression in quiescent tumors. CONCLUSIONS AND CLINICAL RELEVANCE: This study documented that activation and expression of the E5 gene is evident in sarcoids obtained from horses. These data support the conclusion that infection with bovine papillomavirus is important in the initiation or progression of sarcoids in horses. Treatment strategies designed to increase immune recognition of virally infected cells are warranted.

Animals↗
PubMed2001

Bovine papillomavirus DNA in neoplastic and nonneoplastic tissues obtained from horses with and without sarcoids in the western United States.

OBJECTIVE: To determine the incidence of bovine papillomavirus (BPV) type 1 or 2 in sarcoids and other samples of cutaneous tissues collected from horses in the western United States. ANIMALS: 55 horses with sarcoids and 12 horses without sarcoids. PROCEDURE: Tissue samples (tumor and normal skin from horses with sarcoids and normal skin, papillomas, and nonsarcoid cutaneous neoplasms from horses without sarcoids) were collected. Tissue samples were analyzed for BPV-1 or -2 DNA, using a polymerase chain reaction (PCR) and restriction fragment length polymorphism. The PCR products from 7 sarcoid-affected horses were sequenced to evaluate percentage homology with expected sequences for BPV-1 or-2. RESULTS: Most (94/96, 98%) sarcoids contained BPV DNA. Sixty-two percent of the tumors examined had restriction enzyme patterns consistent with BPV-2. Thirty-one of 49 (63%) samples of normal skin obtained from horses with sarcoids contained BPV DNA. All samples subsequently sequenced had 100% homology with the expected sequences for the specific viral type. All tissues from healthy horses, nonsarcoid neoplasms, and papillomas were negative for BPV DNA. CONCLUSIONS AND CLINICAL RELEVANCE: Bovine papillomaviral DNA was detected in essentially all sarcoids examined. There appears to be regional variation in the prevalence of viral types in these tumors. The fact that we detected viral DNA in normal skin samples from horses with sarcoids suggests the possibility of a latent viral phase. Viral latency may be 1 explanation for the high rate of recurrence following surgical excision of sarcoids.

Animals↗
PubMed2000

Influence of tumor cell proliferation and sex-hormone receptors on effectiveness of radiation therapy for dogs with incompletely resected meningiomas.

OBJECTIVE: To assess the influence of tumor cell proliferation and sex-hormone receptors on the efficacy of megavoltage irradiation for dogs with incompletely resected meningiomas. DESIGN: Longitudinal clinical trial. ANIMALS: 20 dogs with incompletely resected intracranial meningiomas. PROCEDURE: Dogs were treated with 48 Gy of radiation administered 3 times per week on an alternate-day schedule of 4 Gy/fraction for 4 weeks, using bilateral parallel-opposed fields. RESULTS: Tumor proliferative fraction measured by immunohistochemical detection of proliferating cell nuclear antigen (PFPCNA index) ranged from 10 to 42% (median, 24%). Progesterone receptor immunoreactivity was detected in 70% of tumors. Estrogen receptor immunoreactivity was not detected. An inverse correlation was found between detection of progesterone receptors and the PFPCNA index. The overall 2-year progression-free survival (PFS) rate was 68%. The only prognostic factor that significantly affected PFS rate was the PFPCNA index. The 2-year PFS was 42% for tumors with a high PFPCNA index (value > or = 24%) and 91% for tumors with a low PFPCNA index (value < 24%). Tumors with a high PFPCNA index were 9.1 times as likely to recur as were tumors with a low PFPCNA index. CONCLUSIONS AND CLINICAL RELEVANCE: This study confirms the value of irradiation for dogs with incompletely resected meningiomas. Prognostic value of the PFPCNA index suggests-that duration of treatment and interval from surgery to start of irradiation may affect outcome. Loss of progesterone receptors in some tumors may be responsible for an increase in PFPCNA index and may indirectly affect prognosis after radiation therapy.

Animals↗
PubMed1999

Changes in left ventricular dynamics during graded exercise.

Three mature Thoroughbred horses were prepared surgically with ultrasonic sonomicrometer crystals affixed to their ventricular pericardia. Signals from crystals recorded dimensions of axes across the left ventricle. Cubic algorithms were fitted to dimensional data to generate volume estimates that matched stroke volumes simultaneously measured using the Fick principle. As horses stood at rest or exercised at various intensities (approx 7, 12, 24, 47 and 100% maximal rate of O2 consumption VO2max[), left ventricular dimensions were recorded and 20 consecutive diastolic and systolic volumes calculated. Although Fick estimates detected no difference in stroke volume at different exercise intensities, sonomicrometer measurements of stroke volume were significantly lower at rest and higher at VO2max. These differences mirrored changes in end-diastolic volume, although end-systolic volume did not change. At all exercise intensities, stroke volume was most variable and end-diastolic volume the least. The pattern conforms to the Frank-Starling mechanism, and indicates that at high exercise intensities ventricular myocytes generate high pressures with higher myocardial wall stress due to the increased size of the chamber.

Animals↗
PubMed1997

Acute hemorrhagic pulmonary infarction and necrotizing pneumonia in horses: 21 cases (1967-1993).

OBJECTIVE: To characterize history, clinical signs, and pathologic findings in horses with histologically confirmed acute hemorrhagic pulmonary infarction and necrotizing pneumonia. DESIGN: Retrospective study. ANIMALS: 21 horses. RESULTS: 19 of the 21 horses were Thoroughbred racehorses in training. Eighteen horses had had strenuous exercise immediately prior to onset of illness. Fifteen horses had a serosanguineous nasal discharge during hospitalization. Seventeen horses had radiographic evidence of pulmonary consolidation and pleural effusion. Nine of 14 horses had ultrasonographic evidence of large pulmonary parenchymal defects consistent with consolidation. Pleurocentesis yielded a suppurative, serosanguineous effusion in the 14 horses in which it was performed. Bacteria were isolated from all transtracheal aspirates (14) and from 6 of 12 pleural fluid samples. Actinobacillus suis-like organisms and Streptococcus equi subsp zooepidemicus were most commonly isolated. Nineteen horses were hospitalized and treated. Mean duration of treatment was 5 days, and most horses were euthanatized because of secondary complications, continued costs of medical treatment, or poor prognosis for future performance. Pathologic lesions included well-demarcated regions of hemorrhagic pulmonary infarction with necrosis and a serosanguineous pleural effusion. Thrombosis of pulmonary vessels was found in 11 horses. CLINICAL IMPLICATIONS: An acute or peracute onset of severe respiratory distress, with serosanguineous nasal discharge, ultrasonographic and radiographic evidence of severe pulmonary consolidation, and serosanguineous suppurative pleural effusion, is strongly suggestive of pulmonary infarction in horses. Horses with pulmonary infarction responded poorly to conventional treatment for pleuropneumonia and had a poor prognosis for recovery.

Actinobacillus↗
PubMed1996

Laryngeal and pharyngeal dysfunction in horses homozygous for hyperkalemic periodic paralysis.

OBJECTIVE: Evaluate histories, clinical signs, and laboratory data of 69 horses homozygous by DNA testing for hyperkalemic periodic paralysis (HPP). DESIGN: Cohort study. SAMPLE POPULATION: 69 of 189 horses testing homozygous for HPP between October 1992 and November 1994. PROCEDURE: Questionnaires addressing signalment, training regimes, medical history, and current status of affected horses were sent to owners, trainers, or attending veterinarians. Data from completed questionnaires were tabulated and evaluated, using descriptive statistics. RESULTS: Sixty-nine (37%) of 189 questionnaires were completed and returned. Clinical episodes of muscle weakness or paralysis varied in severity and frequency from mild muscle fasciculations to recumbency and death. Sixty-three of 68 HPP-affected horses were reported to have had stridor associated with exercise, excitement, stress, or episodes of muscle paralysis. Common endoscopic findings in affected horses included pharyngeal collapse, pharyngeal edema, laryngopalatal dislocation, and laryngeal paralysis. Twelve of 27 horses receiving acetazolamide had decreases in stridor while receiving medication. CLINICAL IMPLICATIONS: Most horses testing homozygous for HPP had clinical signs associated with pharyngeal and laryngeal dysfunction. Hyperkalemic periodic paralysis should be included on a differential list for horses examined for signs of laryngeal or pharyngeal dysfunction or stridor. Treatment with acetazolamide may help to control respiratory tract signs associated with this disease.

Animals↗
PubMed1995

Uptake and translocation of microparticles in small intestine. Morphology and quantification of particle distribution.

The intestinal transit of large (micro-) particles to other sites of the body remains a controversial issue of relevance in various fields of study. In this report fluorescent polystyrene latex microparticles in the size range of 2 microns were used as models for nonspecifically absorbed nonbiodegradable particulates. They were administered to young adult rats as a single oral dose of 1.65 x 10(9) particles; Peyer's patches and surrounding normal absorptive small intestinal tissue were collected at various time points. Quantification of solubilized tissue samples and fluorescence (epi- and confocal) qualitative and quantitative microscopy showed uptake of latex microparticles in all parts of the intestine sampled, but with the proximal segment the preferential site of absorption. The maximum uptake of particles occurred 0.5 hr after dosing in all three segments of the small intestine; there were progressively smaller numbers with distance from the pylorus and with time. Translocation of small numbers of particles to the mesenteric lymph nodes was also detected at 0.5 hr. Transmucosal passage of particles occurred primarily in the villous tissues adjacent to the Peyer's patch regions. These studies give confirmatory evidence for the uptake and translocation of microparticulates across the mucosal barrier and provide new information regarding site- and time-related effects on particle uptake and the involvement of the villous epithelium in particle translocation.

Animals↗
PubMed1995

A commentary on morphological and quantitative aspects of microparticle translocation across the gastrointestinal mucosa.

It is now generally accepted that particulates in the nano-range (< 1 micron) can and do cross the intestinal mucosa. However, the issue is less well resolved for particles in the micro-range (> 1 micron) and this is discussed in relation to the variety of experimental designs present in the literature. Emphasis is placed on the relative contributions of quantitative bulk tissue analysis with respect to qualitative and quantitative morphological analysis. The discussion is extended to observations on factors influencing the particle translocation process including variation in particle uptake in relation to intestinal region and time post-dose administration based on data for uptake of -2 microns latex particles by rat Peyer's patch tissue. Although a significant body of data now identifies the intestinal processus of particle translocation it is underlined that discrepancies may arise as a consequence of different analytical approaches and that this is an issue to be addressed for valid comparisons of data.

Animals↗
PubMed1993

Ruptured urinary bladder after dystocia in a cow.

Rupture of the urinary bladder of a cow occurred secondary to prolonged dystocia. Primary surgical closure of the tear was performed after drainage of the uroperitoneum, and the cow recovered without complications.

Animals↗
PubMed1989

Sulfinpyrazone prolongs survival and decreases platelet uptake of heart allografts.

The purpose of this study was to evaluate the potential benefit of the platelet active drug sulfinpyrazone (SPZ) on uptake of indium-III-oxine (111In)-labeled platelets and survival of rat heart allografts. Lewis rats bearing ACI heterotopic heart transplants were treated with SPZ in high, intermediate, or low doses. In 111-labeled platelet uptake was measured 5 days postoperatively and calculated as a ratio between the transplanted and native hearts. Left and right ventricles were measured separately. SPZ given in doses of 400 and 200 mg/kg daily significantly decreased platelet uptake in the graft and reduced the ratio of uptake between transplanted and native hearts (P less than 0.05). In animals treated with SPZ 100 mg/kg/day platelet uptake was not significantly less than that of the nontreated control animals. Survival of allografts was determined by daily palpation and compared to vehicle-treated controls. Mean graft survival was prolonged for animals treated with 100 mg/kg and 200 mg/kg daily, i.e., 19.0 +/- 3.02 and 11.42 +/- 1.97 days, respectively. Animals administered 400 mg/kg did not have longer graft survival than controls (6.63 +/- 0.66 versus 6.31 +/- 0.18 days). Most animals in the 400 mg/kg group died as a result of adverse side effects of the drug. We conclude that SPZ in low to intermediate doses prolongs allografted heart survival. The enhanced survival in the lower dose group may in part be due to mechanisms other than platelet adhesiveness.

Animals↗
PubMed1989

Uptake of perfusion imaging agents by transplanted hearts: an experimental study in rats.

There is a need for a reliable noninvasive marker of rejection in transplanted hearts. Endomyocardial biopsy is now the universally accepted diagnostic method of choice, but the invasiveness of the procedure and the limited size of the sample obtained makes this method far from ideal. As coronary blood flow may be expected to decrease during acute rejection, there has been interest in thallium-201 chloride (T1), a perfusion marker, as an imaging agent for diagnosing cardiac rejection. Hexakis(t-butylisonitrile)-technetium (Tc-TBI) is a representative of a new class of radiopharmaceuticals proposed as perfusion markers. We have compared the uptake of these imaging agents in a rat model of cardiac transplantation. Uptake of Tc-TBI as well as of T1 was significantly lower in rejecting than in nonrejecting hearts. This change was found in both left (LV) and right (RV) ventricles. Allografts in animals treated with cyclosporine (CyA) showed less severe rejection and higher uptakes of both imaging agents as compared to unmodified rejection. Our results suggest that perfusion imaging with these radionuclides is a potentially useful approach to the problem of detecting allograft rejection.

Animals↗
PubMed1989

Uptake of myocardial imaging agents by rejecting and nonrejecting cardiac transplants. A comparative clinical study of thallium-201, technetium-99m, and gallium-67.

To study the scintigraphic detectability of cardiac rejection, we performed 135 planar myocardial scans ([99mTc]pyrophosphate, 85; 201Tl, 36; 67Ga, 14) together with endomyocardial biopsies in ten patients for a (mean) 17-mo postoperative period. Specificity of each agent exceeded 89%. Technetium-99m pyrophosphate showed results that significantly correlated with the severity of rejection (p = 0.03), as shown by biopsy, but neither 201Tl nor 67Ga did so (p = 0.63 and 0.81, respectively). Technetium-99m pyrophosphate showed better diagnostic accuracy (85%) than 201Tl (69%) and 67Ga (64%). Technetium-99m pyrophosphate also showed higher negative predictive value (91%) than thallium (76%) and gallium (69%). Thus, a normal 99mTc pyrophosphate scan was usually associated with absence of cardiac rejection. However, all three agents showed unacceptably poor sensitivity (0% to 30%) and thus were not useful as a screening test for cardiac rejection, even when the same agent was used serially in imaging a given patient.

Adult↗
PubMed1987

Probenecid inhibition of the renal excretion of dyphylline in chicken, rat and man.

The effect of probenecid on the renal excretion of dyphylline was studied in chicken, rat and man. Dyphylline was found to be actively excreted when measured by the Sperber preparation in hens, the isolated perfused kidney of the rat and clearance studies in man. In each study probenecid significantly decreased dyphylline excretion demonstrating that dyphylline occupied the renal organic anion transport system. This same drug interaction, at the level of the renal excretory system, in these three species occurred at comparable concentrations of dyphylline and probenecid.

Adult↗
PubMed1985

Effect of vitamin D3 on imaging of experimental myocardial infarcts with technetium-99m pyrophosphate: further studies of the role of calcium.

We previously found that a pulse dose of vitamin D3 increased [99mTc]PPi uptake by rat myocardial necrosis. Vitamin D3 raised serum and lesion [Ca] but not, we now report, lesion [Fe]. We now also report that D3 increased [99Tc]PPi uptake by myocardial infarcts (L) in dogs from 0.345 +/- 0.007% administered (kg) dose/g in controls to 0.703 +/- 0.089 in treated (p less than 0.025). Vitamin D3 decreased uptake by dog bone (B) as measured in rib and sternum, increasing L/B from 1.10 +/- 0.23 to 2.30 +/- 0.52 (p = 0.06) X (L) was positively, (p less than 0.005) and uptake by sternum was negatively (p less than 0.05) correlated with serum [Ca] and [P], respectively. Scintigrams graded by a "blinded" observer, showed 4+, 4+, and 3+ infarcts, respectively, in three D3-treated dogs, and 2+, 2+, and 1+, respectively, in three untreated. One untreated and one treated dog were negative; the latter showed the least response to D3 in serum [Ca] and [99mTc] in tissue samples. Vitamin D3 can increase L/B in dogs, enhancing scintigraphic images.

Animals↗
PubMed1985

Uptake of technetium-99m methylene diphosphonate by fractured and osteoporotic bone after a pulse dose of vitamin D3.

The effect of a pulse dose of Vitamin D3 on uptake of [99mTc]MDP by fractured and osteoporotic bone, respectively, was compared with D3's effect on uptake by normal bone in rats. At 4, 7, and 14 days, respectively, after femoral fracture, basal uptake was significantly (p less than 0.005) increased at the fracture site by 336.8, 276.1, and 183.5%, respectively, over the contralateral control site. D3-treated rats had lower uptakes than untreated controls at all three fracture sites and at 12 of 15 normal bone sites but analysis of variance showed the uptake differences were not significant. Cortisone-induced osteoporosis caused a significant (p less than 0.05) decrease in basal uptake. The decrease occurred in all nine bone areas studied. D3 caused a significant (p less than 0.05) increase (mean 16.2%) in uptake by these osteoporotic bones, but a significant (0.1 greater than p greater than 0.05) decrease (mean 13.0%) in uptake by the same bones in normal controls. Thus, D3 had an effect on uptake by the bone lesion, osteoporosis, that differed from D3's effect on uptake by fracture or normal bone.

Animals↗