M.H. Samitz

Nickel-epidermal interactions: Diffusion and binding☆

To elucidate some of the variables associated with nickel contact allergy, the diffusion of nickel through the epidermis and the binding of nickel to the epidermis were investigated. Diffusion of 63Ni through the epidermis from solutions of surfactants was found to be slight. Considerable amounts of nickel, however, were bound to the epidermis. An epidermis powder was prepared, and selected functional groups were inactivated by chemical means. The nickel uptake of these modified epidermis powders as compared to the untreated material indicates that carboxyl groups are involved in the binding of nickel to a greater extent than are amino groups.

Ascorbic acid in the prevention of chrome dermatitis. Mechanism of inactivation of chromium.

The mechanism for the inactivation of hexavalent chromium by ascorbic acid involves reduction to trivalent chromium and subsequent complex formation of the trivalent species. Ascorbic acid and hexavalent chromium react in a ratio of 5:2. This is slightly less than could be expected for oxidation of all the ascorbic acid to dehydroascorbic acid. The chromium-ascorbic acid complex exhibits a strong absorption near 390mμ. The 7:3 ratio may indicate a polymeric species in which the chromium is bound to more than one ascorbic acid molecule.

The binding of mercury to bovine serum albumin

Abstract Additional studies on the binding of mercury by serum albumin is presented. Data were obtained by radiotracer methods and the technique of equilibrium dialysis. The results showed that mercury is bound at other sites in addition to the carboxyl and sulfydryl groups reported previously.

Nickel levels in hair and nickel ingestion in guinea pigs.

Abstract Hair samples from control guinea pigs and from animals receiving 2.5 μg Ni/ml in drinking water for 4 months were analyzed for nickel by atomic absorption spectrometry. No significant differences in nickel contents were observed. These findings are interpreted as an indication that hair is not a tissue for valid biopsy in the assessment of nickel ingestion.

The Effect of Ascorbic Acid on Chrome Ulcers in Guinea Pigs

A new antichrome agent was used on skin ulcers in guinea pigs produced by potassium dichromate. Aqueous ascorbic acid solution (10%) definitely shortens the time required for healing, even when applied as long as thirty minutes after exposure to the ulcerogenic agent. The mode of action and possible significance are discussed.

Chromium complexes with proteins and mucopolysaccharides and their relationship to chromium allergy in sensitized guinea pigs

Abstract Theoretical considerations and equilibrium dialysis are utilized to refute previous reports on the amounts of chromium that can be complexed to proteins and mucopolysaccharides. Purified chromium complexes containing no free chromium were then used to test chromium-sensitized guinea pigs. The chromium-albumin complex is the only one of those studied found to reproducibly elicit.

Techniques of sensitization of guinea pigs with chromium salts. A comparative study

Abstract Three methods of sensitizing guinea pigs to chromium salts are compared. The protocols differed in regard to the concentration of antigen, the route of injection, the methods of reinforcement, the volume injected and simultaneous injection versus splitting of the adjuvant. The split adjuvant method of Maguire, in which the chemical allergen is injected first, resulted in good levels of sensitization in 100% of the animals. This method involved intradermal injections of small amounts of a dilute chromium solution, followed shortly by injection of Freunds complete adjuvant. Though slightly more intense reactions were achieved by the method of Gross et al. , the Gross protocol requires three weekly subcutaneous doses of a larger volume, delivered as an emulsion containing Freunds complete adjuvant. A third method involved intramuscular injection, a larger total volume of chromium, and reinforcement doses containing rather concentrated aqueous solutions. It did not achieve comparable success.