Iwao Yanagida

Characterization of cells cultured from human giant-cell tumors of bone. Phenotypic relationship to the monocyte-macrophage and osteoclast.

Cell culture techniques were used to clarify the histogenesis of giant-cell tumor of bone. Even after passage, nearly all of the mononuclear cells possessed tartrate-resistant acid phosphatase and receptors for eel calcitonin, which are both phenotypic markers for osteoclasts. Eel calcitonin produced an increase in the cyclic adenosine monophosphate (cAMP) content of the mononuclear cells. More than 90% of mononuclear tumor cells expressed monocyte markers; flow cytometric C3b receptor, a macrophage marker, was also detected in a few cells. These findings demonstrate that the mononuclear cells expressed phenotypes of both the osteoclast and monocyte-macrophage and that they originate in a monocyte-macrophage-osteoclast lineage. Giant-cell tumor of bone may thus provide a good model for investigating the mechanism of bone resorption in which cells of osteoclast lineage play a central role.

The Problem of Operative Treatment for Femoral Neck Fractures in the Elderly

We investigated the relationship of functional prognosis and preoperative period in 44 patients over the age of 65 with a femoral neck fracture. 23 cases were operated within 5 days from injury, 7 cases between 6-9 days, 10 cases between 10-19 days and 4 cases over 20 days. There was no significant difference in the functional prognosis among each group. But it seemed that, in early operative 23 cases, the periods of admission were shorter than those in other cases. As most of elderly patients have multiple-system complications, life-threatening problems must be recognized and addressed. Furthermore, operative treatment should be done as early as possible.