Inhibition of HLA B8-restricted recognition by unrelated peptides: evidence for allosteric inhibition

A panel of synthetic peptides representing human lymphocyte antigen (HLA) B8, other class I and class II restricted T cell epitopes and two B cell epitopes, were all able to compete with recognition of a HLA B8 restricted epitope by a cytotoxic T cell clone. Competition was obtained when the competitor peptides were added either before or after the target epitope. The target epitope also had a slow off rate, implicating allosteric inhibition. The presence of non-specific, allosteric binding sites may interfere with experiments attempting to define immunologically relevant MHC binding specificities.     

Dermatitis from hexavalent chromate in the accelerator of an epoxy sealant (PR1422) used in the aircraft industry

4 aircraft construction workers developed allergic contact dermatitis of the hands and forearms. The allergen was hexavalent chromate in the accelerating solution of an epoxy-based sealant (PR1422). Although chromate dermatitis from an epoxy resin has been described, epoxy system accelerators are a hitherto unrecognized source of occupational chromate dermatitis.     

Determination of suicide in South Africa: medical practitioner perspectives.

Decisional processes underlying the determination of a suicide in the largest injury surveillance system currently available in South Africa are assessed through face-to-face semi-structured interviews with 32 medical practitioners involved in the system. Focus is placed on their current work circumstances and practices, and views of operational and empirical criteria proposed by US experts. Common themes and discrepancies in opinions emerged regarding the quality of the data currently available for suicide determinations, and regarding the importance and difficulty in assessing the US-developed criteria in South Africa. A truly standard approach is unlikely without considerable changes to the medico-legal system.