新生豚にみられた先天性過骨症

先天性過骨症は，前肢の硬化・腫脹を特徴とする新生豚の稀な疾患である。本疾患は常染色体の劣性遺伝によるものと考えられているが，原因や発生機序は明らかにされていない。病変部は四肢に限局し，橈骨・尺骨で顕著である。我々は分娩直後に死亡した雌の子豚に前肢の硬化・腫脹を認め，病理学的に先天性過骨症と診断した。組織学的に腫脹していた橈骨・尺骨では線維性骨梁が皮質骨表面から放射状に伸長し，周囲骨格筋は変性・萎縮し，線維化していた。後肢やその他臓器には著変はみられなかった。鑑別診断として，先天性筋症と肺性肥大性骨症が挙げられるが，前者は本例の病変が骨に主座し筋原線維の一次性構造異常がないことから，また後者は造骨形態や胸腔内に腫瘤病変がないことから否定された。Congenital hyperostosis is a rare disease of newborn pigs, characterized by thickening and sclerosis of the forelimbs. It has been suspected that it is inherited as an autosomal recessive trait, but the pathogenesis of the bone abnormalities has not been clarified. The lesions are characteristically localized in the limbs, and the radius and ulna are the most severely affected. We examined a female piglet who died right after delivery; the piglet showed thickening and sclerosis of the forelimbs, and the bone lesions were diagnosed as congenital hyperostosis. Histologically, fibrous trabecular bone proliferated radially and extended out from the surface of cortical bone of the swollen radius and ulna. The skeletal muscles around the bones showed degeneration and atrophy with fibrosis. No lesions were found in other bones and organs. For the differential diagnosis, congenital myopathy and pulmonary hypertrophic osteopathy were considered, but myopathy was excluded because of the lesion distribution and the absence of a primary structural abnormality of myofibrils, while pulmonary hypertrophic osteopathy was also excluded because of the different form of osteogenesis and the absence of a tumor in the thoracic cavity

Inappropriate implantable cardioverter defibrillator shocks—incidence, effect, and implications for driver licensing

PurposePatients with implantable cardioverter defibrillators (ICDs) have an ongoing risk of sudden incapacitation that may cause traffic accidents. However, there are limited data on the magnitude of this risk after inappropriate ICD therapies. We studied the rate of syncope associated with inappropriate ICD therapies to provide a scientific basis for formulating driving restrictions.MethodsInappropriate ICD therapy event data between 1997 and 2014 from 50 Japanese institutions were analyzed retrospectively. The annual risk of harm (RH) to others posed by a driver with an ICD was calculated for private driving habits. We used a commonly employed annual RH to others of 5 in 100,000 (0.005%) as an acceptable risk threshold.ResultsOf the 4089 patients, 772 inappropriate ICD therapies occurred in 417 patients (age 61 ± 15 years, 74% male, and 65% secondary prevention). Patients experiencing inappropriate therapies had a mean number of 1.8 ± 1.5 therapy episodes during a median follow-up period of 3.9 years. No significant differences were found in the age, sex, or number of inappropriate therapies between patients receiving ICDs for primary or secondary prevention. Only three patients (0.7%) experienced syncope associated with inappropriate therapies. The maximum annual RH to others after the first therapy in primary and secondary prevention patients was calculated to be 0.11 in 100,000 and 0.12 in 100,000, respectively.ConclusionsWe found that the annual RH from driving was far below the commonly cited acceptable risk threshold. Our data provide useful information to supplement current recommendations on driving restrictions in ICD patients with private driving habits