The Intercellular Substances of Bone Marrow. I. Preliminary Studies of the Physical and Chemical Character of the Intercellular Bone Marrow Substances in Normal Rabbits

Separation of cellular and noncellular fractions of rabbit bone marrow wasaccomplished by mechanical disruption of the marrow stroma and centrifugation. Viscosity studies performed on the intercellular substances showed a decreasing viscosity with increasing age of the animals. Chemical analyses confirmed the presence of mucopolysaccharide material in the intercellular substance of the marrow, but neither this material nor the fat present in the stromacould account for the viscosity measured or the changes in viscosity observed.

Submitted on January 9, 1961 Accepted on February 23, 1961     

ALOPECIA AREATA HAIRS: A SCANNING ELECTRON MICROSCOPE STUDY

SUMMARY.— The fractured ends of exclamation mark hairs were found to be quite distinct from those of normal hairs broken by traction when examined with the scanning electron microscope. The cuticular scales of exclamation mark hairs, telogen hairs from around lesions, hairs from unaffected parts of the scalp, and hairs from normal subjects were found to possess smooth edges when first produced. More distally, however, the edges of the scales became jagged, although their configuration remained unaltered, in all cases.