Intramembranous bone tissue response to biodegradable octacalcium phosphate implant.

Previous studies showed that synthetic octacalcium phosphate (OCP) enhances bone formation coupled with its own osteoclastic biodegradation more than non-biodegradable hydroxyapatite (HA), including sintered HA ceramic, when implanted in animal bone defects. The present study was designed to investigate whether synthetic OCP in granule form has biodegradable characteristics when implanted in the subperiosteal area of mouse calvaria in comparison with non-sintered stoichiometric HA, especially in relatively short periods after implantation. OCP crystals exhibited plate-like morphology, whereas HA crystals had a sphere-like structure.

Comparative study on osteoconductivity by synthetic octacalcium phosphate and sintered hydroxyapatite in rabbit bone marrow.

Octacalcium phosphate (OCP) is thought to be a precursor of the mineral crystals in biological apatite. Synthetic OCP has been shown to be converted into an apatite structure when implanted in murine calvarial bone, to enhance bone regeneration more than synthetic hydroxyapatite (HA), and to degrade faster than biodegradable beta-tricalcium phosphate. This study was designed to investigate whether OCP implantation enhances the formation and resorption of new bone (remodeling) concomitant with OCP degradation when implanted intramedullary in a rabbit femur for 12 weeks, compared to sintered HA ceramic.

Successful treatment for rhabdomyosarcoma by total spondylectomy in a child.

A 7-year-old girl with a retroperitoneal rhabdomyosarcoma having invaded the L3 vertebra was treated by combination therapy consisting of chemotherapy, surgical resection and intraoperative radiation. Surgically, total spondylectomy was performed through a combined anterior and posterior procedures, and the spine was reconstructed with fibula bone grafts using a pedicle screw system made of titanium alloy. Transverse junction plates were not used at operation because of their bulkiness for the patient.

Aromatase in human bone tissue.

Peripheral aromatization of androgens exert estrogenic actions in many tissues. Recently in situ production of estrogens by aromatase was detected in human bone and cultured osteoblasts and has been proposed to participate in the maintenance of bone mass. We examined aromatase expression by immunohistochemistry and mRNA in situ hybridization in 16 cases of tibia (female 2 male, 14 female, 62 +/- 5.

Extradural granulocytic sarcoma of the thoracic spine in acute myelogenous leukemia with 8; 21 chromosome translocation.

We report a case of a 19-year-old male with an extradural granulocytic sarcoma at T5/6 to T7 demonstrated by MRI. He recovered from paraplegia that had progressed rapidly after excision of the tumor as an emergency operation. Histopathological studies disclosed granulocytic sarcoma.