William F. G. Tucker

Generalized histiocytosis X in the elderly: a light and electron microscope and monoclonal antibody study

Two elderly female patients are described with generalized histiocytosis X (Letterer‐Siwe disease). In each case, a definitive diagnosis was not established until ultrastructural and immunoperoxidase investigations had been performed. The histopathological findings in skin biopsies from each patient were similar. Light microscopy demonstrated a bandlike epidermotrophic cellular infiltrate which included large atypical cells (histiocytosis X cells). Electron microscopy showed that these cells contained Birbeck granules. Monoclonal antibody studies demonstrated the presence of T6, T4 and HLA‐DR surface antigens. Lysozyme and alpha‐1‐antitrypsin were absent from the cells. The associated cellular infiltrate included T4 and T8 positive lymphocytes. It is possible that more cases of generalized histiocytosis X in adults will be identified with the increasing use of specialized histopathological techniques and that the disease is more common than currently believed.

Fish oil in psoriasis—a double-blind randomized placebo-controlled trial

Recent uncontrolled work has suggested that dietary supplementation with fish oils high in eicosapentaenoic acid may improve psoriasis.1 We have investigated this in a double‐blind, placebo‐controlled trial.

The calmodulin content of normal and leukaemic lymphocytes

Normal human peripheral blood mononuclear cells (PBMC) and leukaemic cell lines (three of human and one of gibbon origin) were found to contain similar levels of calmodulin (CaM) when expressed relative to the total cell protein. Two of the cell lines examined further were found to contain much higher amounts of CaM per cell (up to 5-fold) than PBMC but this was readily explained by their much greater cell size. Variations in CaM levels were noted during culture of both PBMC and leukaemic cells which were apparently independent of the percentage of cells undergoing active division in these cultures. These results do not support, the contention that transformed cells contain a higher proportion of CaM than normal cells.

Calmodulin levels in psoriasis—the effect of treatment

Calmodulin (CaM) is an intracellular calcium binding protein which appears to have an essential modulatory role in a variety of intracellular processes. Levels of CaM in the epidermis in psoriasis have been shown to be elevated in both lesional and non‐lesional skin (Van de Kerkhof & Van Erp, 1983; Tucker et al., 1984).