Light transmission of composite luting resins.

The final color of all-ceramic restorations is dependent on the surrounding structures and on the ceramic itself. The degree that the layer of the composite luting agent contributes to this final color formation can only be estimated. Based on general optical physics, this paper reports on transmissivity of some commercially available composite luting resins and discusses how these theoretical results apply to clinical situations.

Binding of oxytocin to uterine cells in vitro. Occurrence of several binding site populations and reidentification of oxytocin receptors.

Myometrial and endometrial cells of sheep, rat, and calf in monolayer cell culture display at least three populations of binding sites for oxytocin, with dissociation constants (Kd) of approximately 5 X 10(-9), 4 X 10(-7), and greater than 10(-5) mol/liter, respectively. Binding of the tritium-labeled oxytocin (concentration range, 10(-11) to 5 X 10(-4) M) to the first two sites is displaceable by cold oxytocin. The ratio of binding capacities of the high to medium affinity site appears to average 1:18.