Calcium-binding proteins and calcium function: Edited by R.H. Wasserman,R.A. Corradino,E. Carafoli,R.H. Kretsinger,D.H. MacLennan and F.L. Siegel. Eisevier/ North-Holland,Amsterdam 1977, 528 pp. US $ 45.00

Rat-liver chromatin was kept under several conditions. The maximum binding capacity (B_max) and the apparent association constant (K_a) for triiodothyronine (T₃)-binding were determined. Binding activity (B_max × K_a) was unstable at 0 and ?20°C in the reaction buffer. Maximum binding activity was found upon storage at ?70°C or in liquid nitrogen where about 70% of the original activity remained after 3 weeks. With storage, K_a decreased more rapidly than B_max which showed little change. These temperature-dependent changes in the stored chromatin were specific for the receptor and not observed for other characteristics of the chromatin i.e., template activity and the electrophoretic separation pattern of chromatin proteins. The elution profile of the receptor on a hydroxylapatite column was unchanged during storage of the chromatin, suggesting that the chemical nature of the binding protein(s) may not change during storage.     

The prevalence and distribution of macrophages bearing Fc gamma R I, Fc gamma R II, and Fc gamma R III in synovium.

Fc-receptors for IgG (Fc gamma R) are important triggers of effector function in macrophages. We have investigated the distribution of cells bearing Fc gamma R I, Fc gamma R II, and Fc gamma R III in 14 synovia and 3 nodules from rheumatoid arthritis (RA) patients, using monoclonal antibodies on serial cryostat sections. 8 osteoarthritis (OA), 2 ankylosing spondylitis (AS) patients and one sarcoid patient were also studied. Significant numbers of macrophages bearing Fc gamma R were present in inflamed synovial tissue with no significant difference in relative frequency between RA and OA. There was no correlation with the degree of lymphocytic infiltration. Distinctive staining patterns for the three Fc-receptors suggest differential regulation of these molecules on macrophages in synovium.