[Thrombotic thrombocytopenic purpura and ankylosing spondylarthritis. Apropos of a case].

The authors report a case of thrombotic thrombocytopenic purpura (TTP) which revealed a hitherto unrecognized ankylosing spondylitis. After a 4-year follow-up, the spondylitis is still progressing in its axial and/or peripheral form, and TTP has not relapsed. TTP is usually primary, but numerous forms consecutive to various diseases, and notably autoimmune diseases, have been reported.

[Bone histomorphometric study in involuted fractured osteoporosis treated with 1-ethane-1-hydroxybiphosphonate (etidronate) during one year].

The efficacy of the biphosphonate etidronate has recently been demonstrated versus the vertebral fracture rate in fractured involuted osteoporosis in the literature. However, it would appear that the increase in bone mass (measured from the calcium density) may alone account for these results. The authors undertook a histomorphometrie study in 20 patients with a group mean age of 55 years presenting recent vertebral fracture in the context of osteoporosis, in order to assess the cell changes which may affect bone quality.

Cortical osteoclasts are less sensitive to etidronate than trabecular osteoclasts.

Acute osteoporosis after spinal cord injury is related to an early increase in osteoclastic resorption. Healthy subjects subjected to bed rest similarly increase their osteoclast number in trabecular bone. Bisphosphonates possess a highly antiosteoclastic activity.

Alcoholic cirrhosis and osteoporosis in men: a light and scanning electron microscopy study.

Subjects with chronic alcoholism are associated with a higher prevalence of bone fractures, compared with age-matched controls. However, the pathogenesis of alcoholic osteopathy remains poorly understood. In this study, the bone cells activities and the bone matrix were studied using different techniques such as bone morphometry, scanning electron microscopy and computer reconstruction.