Nobuo Origuchi

Expression and localization of bone morphogenetic proteins (BMPs) and BMP receptors in ossification of the ligamentum flavum

To clarify the pathogenesis of ossification of the ligamentum flavum (OLF), we examined the expression and localization of bone morphogenetic proteins (BMPs) and their receptors (BMPRs) in the ligamentum flavum of the patients with OLF by immunohistochemical staining and compared them with staining patterns in control patients. The BMPRs appeared extensively in mature and immature chondrocytes around the calcified zone and in spindle-shaped cells and round cells in the remote part from ossified foci in examined tissue of OLF. The ligands for BMPRs, BMP-2/-4 and osteogenic protein-1 (OP-1)/BMP-7, colocalized in OLF patients. In the control cases, expression of BMPs and BMPRs was observed around the calcified zone at the insertion of the ligamentum flavum to the bone, and limited expression was found in the smaller range. Thus, the expression profile of BMPs and BMPRs in OLF patients was entirely different from the control patients, suggesting that BMPs may be involved in promoting endochondral ossification at ectopic ossification sites in OLF, and that ossification activity is continuous in these patients.

Immunolocalization of bone morphogenetic protein and its receptors in degeneration of intervertebral disc

STUDY DESIGN Immunohistochemical study of expression and localization of bone morphogenetic protein (BMP)-2/4 and type I and II receptors on intervertebral disc. OBJECTIVES To determine the biologic functions of BMPs and their receptors in the process of degeneration of the intervertebral disc. SUMMARY OF BACKGROUND DATA Biologic and pathologic processes in the cell during the degeneration of the intervertebral disc are as yet poorly understood. METHODS The cervical spines of 15 male senescence-accelerated mice aged 8, 24, or 50 weeks were used for histologic and immunohistochemical examination of BMP-2/4 and BMP receptors IA, IB, and II. Immunostaining was performed with the avidin-biotin-peroxidase complex method. RESULTS Degenerative change was recognized within intervertebral discs of senescence-accelerated mice aged 50 weeks. BMP-2/4 and its receptors were abundant in hyaline cartilaginous cells within the endplate of the vertebrae at 8 and 24 weeks of age. However, the expression of BMP-2/4 and its receptors moved from the hyaline cartilage of the endplate of the vertebrae to fibrous cells within the anulus and to the calcified cartilage at the site of enthesis of mice aged 50 weeks. CONCLUSIONS BMP-2/4 and its receptors may play roles in degenerative change of intervertebral disc.

Return to Sports Activity after Meniscal Repair

We reviewed 31 patients treated by meniscal suture from 1994 to 1998. They consisted 19 males and 12 females with a mean age of 19.1 years (range: 10-34 years). The average follow-up period was 9.6 months (range; 1 to 36 months). We evaluated factors about the return to sports activity after meniscal repair. The important factors are sex (female), age (after 30 years), ligament insuf-ficiency, and type of sports (requiring jumping). The rehabilitation method shoud be considered to shorten the return period to sports activity.