Cell-to-Cell adhesion via intercellular adhesion molecule-1 and leukocyte function-associated antigen-1 pathway is involved in 1alpha,25(OH)2D3, PTH and IL-1alpha-induced osteoclast differentiation and bone resorption.

Cell-to-cell interaction is required for the differentiation of osteoclast precursors as well as for osteoclast function. The present study was undertaken to determine whether 1,25 dihydroxyvitamin D3 (1,25D), PTH, IL-1alpha and PGE2 depend on cell-to-cell interactions through the intercellular adhesion molecule (ICAM)-1/leukocyte function-associated antigen (LFA)-1 pathway in osteoclast formation and bone resorption. We found that mouse osteoblasts expressed ICAM-1 and that the expression was increased by treatment with PTH, IL-1alpha or 1,25D, but not by PGE2.

Hepatic sarcoidosis associated with chronic hepatitis C.

A 57-year-old woman with sarcoidosis was referred because of the appearance of multiple small low-attenuation areas in the liver on computed tomography (CT). A liver biopsy specimen showed chronic active hepatitis accompanied by sarcoid granulomas. The patient received prednisolone and, later, interferon-alpha.

The mutual regulation of arginine-vasopressin and PTHrP secretion in dissociated supraoptic neurons.

PTHrP is detected in the supraoptic nucleus (SON) and paraventricular nucleus. We have recently demonstrated that PTHrP(1-34) is involved in AVP release and synthesis in the SON in vivo and in vitro. PTHrP and AVP, which act on blood vessels, may interact by autocrine and paracrine mechanisms in the central nervous system.