Dental team''s role in tobacco cessation

In rat experiments new imidazoline derivatives caused a pain-relieving effect and inhibited a rise in arterial pressure in pain. Fluoride derivatives of imidazoline in doses of 1, 2, and 4 mg/kg induced long-term analgesia, had no effect on the background arterial blood pressure (AP), and significantly reduced its nociceptive pressor responses. The bromide derivatives of imidazoline showed no noticeable pain-relieving activity but reduced the nociceptive AP shifts. The background AP parameters did not change in this case. The prospects of directed chemical modification of imidazoline derivatives to obtain new analgesics capable of reducing the undesirable hemodynamic manifestations of pain are discussed.     

In situ levels of intracellular Ca2+ and pH in avian growth plate cartilage

Interactions with the extracellular matrix, accumulation of Ca2+, formation of matrix vesicles, and regulation of tissue pH by growth plate chondrocytes all appear to be vital to endochondral calcification. Thus, the activities of Ca2+ and H+ ions in these cells, while still embedded in their organic matrix, are of great interest. Using laser confocal imaging and sensitive Ca2+ (Indo 1) and pH (BCECF) probes, cellular Ca2+ and pH were analyzed in thin sections of freshly isolated cartilage. Mean values of cytosolic Ca2+ in cells from the various zones of the growth plate were quite similar, but levels in individual cells and subcellular compartments varied significantly. Ca2+ was elevated intensely near the periphery of cells in the zones of maturation and hypertrophy, and many Ca2+ rich particles were seen in the matrix near these cells. Levels of Ca2+ within the cells varied with time. In the proliferative region, cyclical increases and decreases in Ca2+ were seen, but there was little shedding of Ca2+ rich particles. However, after repeated Ca2+ cycling, in the zones of maturation and hypertrophy, Ca2+ rich particles were shed from the cell surface, forming what appeared to be matrix vesicles. Intracellular pH levels also varied significantly within the chondrocytes and between the cells and zones. Numerous focal elevations in pH (> 8.0) were seen in central regions of the maturing and early hypertrophic cells, with lower pH (6.5-7.2) near the cell periphery of the late hypertrophic and calcifying cells. This pattern of cytoplasmic alkalinization and subsequent acidification appears to contribute to loading of Ca2+ and Pi into matrix vesicles during their formation by the chondrocytes.