Isolation, via activity-directed fractionation, of mercaptobenzothiazole and dibenzothiazyl disulfide as 2 allergens responsible for tennis shoe dermatitis.

Although contact dermatitis from shoes is common, the causative allergen is frequently not known. Reliance cannot be placed on standard screening trays because such testing can be negative when testing to shoe materials is positive. Furthermore, the relevance of positive screening tests is almost never proven by extracting that allergen from the patient's shoes.

Comparative friction of orthodontic wires under dry and wet conditions.

Kinetic coefficients of friction for stainless steel, beta-titanium, nickel-titanium, and cobalt-chromium arch wires were measured on a smooth stainless steel or Teflon surface. A universal materials testing instrument was used to pull 0.017 X 0.

Dentin stresses in post-reconstructed teeth with diminishing bone support.

Dentin stresses from simulated functional loads to post-reinforced tooth models with four levels of periodontal support were calculated using finite element analysis. As bone levels diminished, stresses were found to increase dramatically and to concentrate in the small amount of dentin remaining near the post apex.

Some historical highlights and portents for the future of biomedical research on radium and the actinides.

Radiobiological research on the actinide elements has been a continuum since the first cryptic report by Hamilton at Berkeley, California, in February 1944. Yet certain landmarks in the work, certain people and certain organizations were responsible for the equivalent of quantum jumps in our concepts and understanding. This paper will review very briefly a few of these.

Modifying the setting rate of an addition-type silicone impression material.

Two methods for controlling the working time of an addition-type silicone impression material are presented. The progress of the polymerization reaction of this modified system was studied using viscosity and a new "compression set" technique. The physical properties are presented and compared to those typical of condensation silicones, and a method of clinical use is suggested.