John Martin Wood (1938-2008)--pioneering biochemist, educator and communicator.

John Martin Wood, Emeritus Professor of Medical Biochemistry at the University of Bradford died in Wieck by Greifswald, Germany after a short illness on February 5, 2008 - just short of his 70(th) year. John worked as a pioneering biochemist and educator in the US and in Britain across two research careers. He devoted the first twenty-five years to the role of transition metals in biology, and his last twenty-years to cutaneous enzymology and melanogenesis. Working together with his wife Professor Karin U. Schallreuter, his research on oxidative stress handling in skin and on the expression of a cutaneous catecholaminergic system will help direct research in these fields for many years to come. John impressed on his fellow cutaneous researchers and students the critical importance of appreciating the true role of enzymes in skin health and disease. This obituary aims to contextualize the significant contributions made by this remarkable man to experimental dermatology.

Essaying the mechanical hypothesis: Descartes, La Forge, and Malebranche on the formation of birthmarks.

This essay examines the determination by Cartesians to explain the maternal imagination's alleged role in the formation of birthmarks and the changing notion of monstrosity. Cartesians saw the formation of birthmarks as a challenge through which to demonstrate the heuristic capacity of mechanism. Descartes claimed to be able to explain the transmission of a perception from the mother's imagination to the fetus' skin without having recourse to the little pictures postulated by his contemporaries. La Forge offered a detailed account stating that the failure to explain the maternal imagination's impressions would cast doubt on mechanism. Whereas both characterized the birthmark as a deformation or monstrosity in miniature, Malebranche attributed a role to the maternal imagination in fashioning family likenesses. However, he also charged the mother's imagination with the transmission of original sin.

The discovery of the human melanocyte.

Around 2200 bc the first written description of a human pigmentation disorder, most likely vitiligo, was recorded, and from that moment the history of research into human pigmentation can be traced. For the following 4000 yr, the origins of human skin colour remained an enigma that was to generate a multitude of misconceptions. Even after European physicians began to dissect and compare dark and light coloured skin to reveal its underlying anatomy, the origins of skin and hair pigmentation were a matter of frequently erroneous speculation. The true source of human pigmentation was only finally revealed with the discovery of the melanocyte in the 19th century. Once tyrosinase was identified to be the key enzyme in pigment formation, attention focused on elucidating the chemical structure of melanin, an enterprise that remains incomplete. The developmental origins of the melanocyte were described from 1940 to 1960, and the concept of the epidermal melanin unit was introduced together with a description of the ultrastructure of the melanosome and melanosome transfer. With these advances came the realization that different skin types exhibit distinct differences at the histological level that relate to varying amounts of eumelanin and pheomelanin produced by the melanocytes. The foundation established over the past 4000 yr is the basis for all current research into this fascinating cell type.

Osler and the skin.

William Osler was the greatest physician of his time. Specialists reading his textbooks agreed that in their own specialities he was accurate and illuminating. His grasp of dermatology was particularly striking and skin changes are prominent in five of the syndromes named after him and in at least 100 of his papers. This paper describes how his early training in dermatology under Tilbury Fox in London and Hebra in Vienna combined with his unusual personal qualities to enable him to make massive contributions to a wide variety of dermatological topics. These include smallpox, cutaneous tuberculosis, nail growth, leprosy, scleroderma, pigmentation and purpuric eruptions as well as the more obvious hereditary haemorrhagic telangiectasia, angio-neurotic oedema and Osler's nodes.

Rapid whitening of the hair first reported in the Talmud. Possible mechanisms of this intriguing phenomenon.

The first reported episode of rapid whitening of the hair is recorded in the Talmud. This intriguing phenomenon is explained on the basis of a two-step process. The first step involves the actual abrupt development of white hair due to vitiligo or alopecia areata. The second step involves the apparent sudden whitening of the scalp hair due to either simultaneous lengthening of the white hair or selective loss of the dark hair. In fact, the hair that is perceived as suddenly whitening was already white.

[Vive la berloque. Etymological observations on berloque dermatitis]. / Vive la berloque. Etymologische Betrachtungen zur Berlocke-Dermatitis.

Berloque is no more used in the French language, the term of now-a-days is breloque. Therefore the expression berloque-dermatitis is either an anachronism or a mix-up of two letters.