Myocarditis in round heart disease of turkeys

Summary Round heart disease in the turkey has been studied by light and electron microscopy. Myocarditis, characterized by focal muscle cell degeneration and mononuclear infiltrates, was present in turkeys from 1 day after hatching through 8 weeks of age. Myocardial injury was most severe from age 5 to 12 days. Virus-like particles, 60–90 mµ in diameter, resembling the avian leukosis viruses, were present in the myocardial cells of all turkeys with myocarditis.Dilatation and hypertrophy, predominantly of the left ventricle developed after the second week of life. Collagen accumulation beneath the endocardium was evident by electron microscopy in 1- and 2-day-old birds. This progressed to marked endocardial fibroelastosis after 1 month and was often associated with involvement of the mitral valve and its papillary muscles and chordae tendineae. Maturing and adult turkeys demonstrated congestive heart failure with congestion of the lungs and liver, pleural effusions and ascites. Because of the similarity of gross and microscopic findings, round heart disease in turkeys may serve as an experimental model for primary endocardial fibroelastosis in humans.Supported by research grants from the Dwan Family Fund; University of Minnesota Graduate School; Minnesota Turkey Growers Association; U.S. Public Health Service, National Heart Institute, HE06314-10, HE05694 and Training Grant HE05570.     

Indications and diagnostic outcome of antineutrophil cytoplasmic antibody testing in hospital medicine: a pattern of over-screening

Clinical Rheumatology - Antineutrophil cytoplasmic antibodies (ANCA) serology can aid in the diagnosis and classification of ANCA-associated vasculitides (AAV). However, it is often ordered in...     

MR imaging of pituitary adenomas after gamma knife stereotactic radiosurgery

OBJECTIVE: The purpose of this study was to evaluate the response of pituitary adenomas to radiosurgery as manifested by changes in size and appearance on serial MR imaging. MATERIALS AND METHODS: Over a mean follow-up period of 36 months, changes in 44 pituitary adenomas were assessed on 147 enhanced MR imaging studies. Prior surgery had been performed in 36 tumors (82%). RESULTS: At the time of radiosurgery, mean tumor volume was 5.9 +/- 0.8 cm(3) (mean diameter, 2.2 cm). The mean reduction in volume at last follow-up was 41% (+/- 5%, p < 0.001), and a decrease in tumor volume of 25-100% was observed in 34 tumors (77%). Mean reduction in tumor volume at 6 months after radiosurgery was 9% (p = 0.095); at 1 year, 24% (p < 0.001); at 2 years, 34% (p < 0.001); at 3 years, 41% (p < 0.001); and at 4 years, 50% (p = 0.008). Six months after radiosurgery a slight and transient increase in size was observed in 21% of tumors. During follow-up, neither decreased contrast enhancement nor cyst development was associated with changes in tumor volume. CONCLUSION: Tumor control was observed for most pituitary adenomas after radiosurgery and occurred gradually over a period of several years. A small increase in tumor size might be observed in the first 6 months after radiosurgery. In most cases, reductions in tumor size were not accompanied by a change in contrast enhancement or cyst formation.     

Alteration by immunosuppression of early mortality in a naturally occurring cardiomyopathy.

Turkeys from a highly inbred flock, which shows a 100 per cent incidence of naturally occurring cardiomyopathy, were treated daily for 3 weeks following hatching with cortisone acetate, or for 4 days following hatching with parenteral cyclophosphamide, or underwent surgical removal of the bursa of Fabricius at hatching. Mortality was significantly reduced during the first 10 days of age when each of the treated groups was compared with its own control group. By 5 weeks of age, the mortality rates in the bursectomized and cyclophosphamide-treated birds were not significantly different than their control groups. Five-week mortality in the cortisone acetate-treated group, however, was significantly lower than in its control group. Long-term morbidity, as reflected by the incidence of cardiac dilatation and hypertrophy in all birds during or killed through one year of age, was lower in the cortisone acetate-treated birds and significantly reduced in the bursectomized birds. These data suggest that the humoral immune system may function in the pathogenesis of this naturally occurring cardiomyopathy in the turkey.     

Paradoxes of the EphB4 receptor in cancer

Recent findings have started to uncover the intriguing roles of the Eph family of receptor tyrosine kinases in normal epithelial cells and during oncogenic transformation. This review focuses on EphB4, an Eph receptor that has both tumor-suppressing and tumor-promoting activities in breast cancer. Understanding the multifaceted role of EphB4 in tumorigenesis may allow the development of new anticancer therapies.     

Development of a competency-based approach to teaching preventive medicine

A collaborative project to develop a competency-based curriculum and associated instructional materials for teaching preventive medicine to medical students has been undertaken by the Association of Teachers of Preventive Medicine in cooperation with the Center for Educational Development in Health at Boston University. A general model of physician responsibilities in the preventive dimension of clinical practice was elaborated and specific performance objectives were delineated. Specifications of physician performance were verified through Delphi and questionnaire surveys among approximately 100 practicing physicians. Three facets of physician performance emerged as warranting special attention: planning a practice-based program of clinical prevention, adapting the program to the needs of individual patients, and assisting patients to modify behavior patterns. Competency-based educational objectives were derived from the physician performance objectives. An instructional system to facilitate attainment of these objectives is under development. It incorporates five modules based on the following themes: the epidemiologic basis of clinical prevention, methods of clinical prevention, management planning for preventive services, clinical health and risk appraisal, and intervention for behavior change. Each module consists of units of instruction which specify expected learning outcomes, provide guidelines for evaluation of student performance, and recommend appropriate learning activities and resources.