No abstract

The structure of the lining cclls at the surface of the synovial membrane facing the joint cavity has been studied by elcctron microscopy. The long cytoplasmic processes of these cells appear to be oriented toward the surface of the membrane, where they overlap and intertwine. The matrix of the lining cells contains dense material but no fibers with thc periodicity of collagen. The lining cells are divided into two cell types or states of activity on the basis of their cytoplasmic contcnts. Type A is more numerous and contains a prominent Golgi apparatus, numerous vacuolcs (0.4 to 1.5 microns in diamctcr) containing varying amounts of a dense granular material, many filopodia, mitochondria, intracellular fibrils, and micropinocytotic-likc vesicles. Type B contains large amounts of ergastoplasm with fewer large vacuoles, micropinocytotic-like vesicles, and mitochondria. The probable functions of these cells are discussed in the light of current knowledge of the metabolism and function of the synovial membrane.

Osteoporosis and atherosclerosis are both widely prevalent in an ageing population, and induce serious morbidities and death. There is growing evidence that in addition to their relationship to ageing, osteoporosis and atherosclerosis are also linked by biological associations. This article reviews their clinical interrelations, discusses the basic biology of bone and the arterial wall, and presents five examples that illustrate their biological linkages. Current therapeutic approaches emerging from these linkages, including statins, bisphosphonates, and the thiazolidinediones, have dual effects on bone and the vasculature. Additional therapies derived from experimental studies that enhance bone density and reduce atherogenesis hold further promise to diminish the morbidity and mortality of osteoporosis and atherosclerosis, with attendant benefits to society.

Sharp and Dohme Research L a b o r a t o r i e s , Rahway, N.J. 07065 -Anastassiades TP, Wood A. Effect of soluble products from lectinstimulated lymphocytes on the growth, adhesiveness, and glycosaminoglycan synthesis of cultured synovial fibroblastic cells.