The effect of dantrolene sodium in relation to blood levels in spastic patients after prolonged administration.

In 25 patients with spasticity, pharmacokinetics and effects of dantrolene sodium were investigated after prolonged administration. A beneficial effect occurred in seven patients. The results were better on 100 mg daily than on a higher daily dose. An increase of the daily dose from 200 to 400 mg was not associated with higher blood levels. Many side effects were noted such as: anorexia, nausea, drowsiness, depression and muscle weakness. From this study we conclude that dantrolene sodium is a muscle relaxant with a weak to moderate effect in patients with spasticity; the effect at doses higher than 200 mg daily is probably poor.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.