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Therefore, heat treatment at 60 degrees C is a useful sterilization method, not only in biological but also mechanical terms.

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Some pituitary adenomas seem to be related to bone loss. It is unknown what kinds of pituitary adenomas affect bone mass. We attempted to determine what kinds of pituitary adenomas caused osteoporosis, and whether hormonal disturbance in pituitary adenoma patients affected bone mass. This study included 53 surgical patients (39 women of premenopausal age and 14 men) aged 21 to 62 years. We measured vertebral bone mineral density (BMD); various bone metabolic parameters, such as serum calcium, phosphorus, alkaline phosphatase, and blood urea nitrogen, parathormone, vitamin D, vitamin K, and hormonal activity in the anterior lobe of the pituitary gland. Comparisons were made of the mean Z scores (the ratio to the mean BMD of age-matched healthy Japanese women and men) among patient groups and controls. Compared with the female controls, the mean Z score was significantly higher in the women with acromegalic adenoma and significantly lower in those with adrenocorticotrophic hormone (ACTH)-secreting adenoma. In male patients, the mean Z scores were significantly decreased in prolactin-secreting adenoma and nonfunctioning adenoma, compared with that in normal controls. Acromegalic adenoma contributes significantly to vertebral bone mass acquisition, although ACTH adenoma may carry a significant risk of osteoporosis in female patients. Male patients with prolactin-secreting and nonfunctioning adenoma have a significant risk of bone decrease.

Human imnmunodeficiency virus (HIV) infection is one of the possible serious complications associated with bone allografts. In order to prevent infection, grafted bone is sterilized by various treatments. Heat treatment has attracted attention as a simple and practical method. We carried out a histological study of the influence of heat treatment on autogenic bone grafts. To eliminate the problem of antigenicity of grafted bone, we used autografts, not allografts. Three types of heat-treated autografts were employed: heat-treated at 60 degrees C for 30 min, at 80 degrees C for 10 min, and at 100 degrees C for 5 min; as a control, fresh autografts were replaced in the rabbits' ilium. One, 2, 4 and 8 weeks after grafting, we performed microangiography and prepared two types of samples: transparent and haematoxylin-eosin (H&E) stained. Then, using an image analyzer, we quantitatively measured revascularization and new bone formation in the grafted bone. The grafts heat-treated at 60 degrees C showed early and good revascularization and new bone formation, from 1 to 8 weeks. The grafts heat-treated at 80 degrees C showed relatively good revascularization and new bone formation. However, the grafts heat-treated at 100 degrees C showed unsatisfactory revascularization and bone formation, less than 40% of control 8 weeks after grafting. Therefore, heat treatment at 60-80 degrees C does not seriously affect revascularization and new bone formation.