RESUMO
In humans, alterations in bone metabolism have been associated with myopathies. We postulate the hypothesis that perhaps similar pathologies can also be associated in modern chickens. Hence, this study aimed to assess the fat infiltration in bone marrow and its repercussion on broiler chicken affected by Wooden Breast (WB) myopathy. Ten Cobb 500 live birds with extreme rigidity of the Pectoralis major (PM) muscle were selected as WB affected chickens by physical examination of the muscle at 49 days of age, whereas ten chickens healthy with no physical signs of hardness in the breast muscle were considered to be unaffected. Macroscopic lesions in affected chickens included areas of firm and inflamed muscle with pale appearance, hemorrhaging, and viscous exudate on the surface. Bone marrow and sections of the PM muscle were collected and analyzed for light microscopy. Additionally, transmission electron microscopy was conducted in affected or unaffected muscle. Chickens affected with WB showed significant reductions (P < 0.05) in femur diameter, calcium, and phosphorous percentage but increased breast weight, compression force and filet thickness when compared with non-affected chickens. Interestingly, bone marrow from WB chicken had subjectively, more abundant infiltration of adipose tissue, when compared with non-affected chickens. Histology of the Pectoralis major of birds with WB showed abundant infiltration of adipose tissue, muscle fibers degeneration with necrosis and infiltration of heterophils and mononuclear cells, connective tissue proliferation, and vasculitis. Ultrastructural changes of WB muscle revealed lack definition of bands in muscle tissue, or any normal ultrastructural anatomy such as myofibrils. The endomysium components were necrotic, and in some areas, the endomysium was notable only as a string of necrotic tissue between degraded myofibrils. The fascia appeared hypertrophied, with large areas of necrosis and myofiber without structural identity with degraded mitochondria adjacent to the disrupted muscle tissue. As far as we know, this is the first study that describes a subjective increase in adipose tissue in the bone marrow of chickens affected with WB when compared with non-affected chickens, and reduced bone mineralization.
RESUMO
PURPOSE: Recurrence is the most common complication after an initial episode of primary spontaneous pneumothorax (PSP). However, preventive surgery in children remains a controversial issue. The purpose of this study was to determine predictive factors of recurrence to better inform early surgical referrals. METHODS: We retrospectively reviewed all consecutive patients under 18 years of age who conservatively treated for an initial episode of PSP between March 2005 and September 2011. RESULTS: One hundred fourteen patients were included in this study. The mean follow-up period was 43.1 months. Ipsilateral and contralateral recurrence developed in 47.3% and 14.0% of patients. The risk of ipsilateral recurrence for patients with or without air-containing lesions according to high-resolution computed tomography (HRCT) was 60.3% and 31.4%. In the multivariate analysis, the presence of air-containing lesions on HRCT scans and bullae on chest X-rays were independent risk factors for ipsilateral recurrence. CONCLUSION: The presence of bleb or bullae on HRCT scans or chest X-rays after an initial episode of PSP was significantly related to the ipsilateral recurrence in children. If the risk factors are clarified in further studies, hospital stays and the recurrence of PSP after the first episode could be reduced with early video-assisted thoracoscopic surgery.