Acta dermato-venereologica. Supplementum最新文献

The incidence of basal cell carcinoma is increasing. New aspects of diagnosis and treatment are discussed in this thesis. Interferon can be used for the treatment of BCC. In paper I, 15 patients received 13.5 x 10(6) IU of alfa-2b-interferon intralesionally. Four patients healed completely whereas a 75% reduction was seen in 5 cases. Intralesional alfa-2b-interferon can reduce the number of excisions during Mohs Micrographic Surgery. Topical photodynamic therapy involves the application of ALA on the skin. In tumour cells selectively, formation of the photosensitizer Pp IX occurs. After 4 hours of occlusion of ALA the area is irradiated with light at a wavelength of 630 nm. Tumour cells are selectively destroyed during this procedure. 144/157 SBCC healed in this series and 14/18 Mb Bowen (paper II). The method is only suited for thin BCCs as the result on thicker lesions is poor (2/10 healed). The cosmetic result was generally good or excellent. Another way of utilising the tumour selectivity of Pp IX is for diagnostic purposes. Instead of illuminating with 630 nm, 365, 366 and 405 nm are used to induce a specific fluorescence. In the present paper (III), 50% of facial BCCs with ill-defined borders could be completely visualised and another 23% partly outlined. The technique did not seem to work in 27% of the cases. The critical factor using ALA is probably the relatively poor penetrance through the skin. In paper IV, microdialysis is used for pharmacokinetic studies of ALA for the first time. The concentration of ALA increases rapidly in lesional skin whereas there is virtually no penetration in healthy skin. Also, the blood perfusion in BCCs was investigated by means of laser Doppler Perfusion Imager. The perfusion in skin overlying a BCC was 2.5 fold higher compared to normal skin. For BCCs with ill-defined borders Mohs Micrographic Surgery is generally recommended. Regarding Mohs Micrographic Surgery, Sweden is underserved as only 1% of BCCs are treated with Mohs Micrographic Surgery as opposed to 30% in the US. Consequently, the Swedish cases are probably more severe. The long-term results are reported in paper V. Two hundred and twenty-eight tumours were followed for at least 5 years. The rate of recurrence was 8%. This figure is slightly higher than in international materials but surprisingly low considering the type of tumours.

This contribution summarises the results from a number of investigations undertaken in the spirit of the Domain Mosaic Model proposed by Forslind in 1994. Atomic Force Microscopy (AFM) studies on the two-dimensional phase behaviour of some stratum corneum lipids revealed phase separation of the lipids in the typical case and the ability of cholesterol to reduce the line tension between phases. A theoretical model was developed describing the response of an oriented stack of polar lipid bilayers in the presence of a gradient in water chemical potential (water solution to humid air). The gradient gives rise to an inhomogeneous water swelling, and presumably to a liquid crystal-to-gel transition in the lamellar region closest to humid air. Skin penetration enhancers such as Azone and oleic acid cause phase transformations in lipid bilayer systems which may be relevant in the context of skin permeation.

In order to gain some insight into the molecular organization of lipids in the skin barrier we used Fourier transform infrared (FTIR) spectroscopy to investigate models of the stratum corneum (SC) containing deuterated hexadecanoic acid, cholesterol, and ceramide 2 or ceramide 5. In both models there is clear evidence of separate conformationally ordered domains of ceramide and fatty acids. In addition, these chains are packed in orthorhombic subcells at physiological temperatures. The ceramide headgroup behavior indicates distinct hydrogen bonding patterns between the ceramide 2 and ceramide 5 models. In the ceramide 2 model the amide I mode is split into two components suggesting strong transverse intermolecular hydrogen bonding between headgroups. In contrast, no amide splitting is observed for ceramide 5 although the amide frequencies are indicative of strong hydrogen bonding. These observations on the molecular organization of SC lipids are discussed in terms of skin barrier function.

The pathogenesis of venous leg ulcers is multifactorial. In this review article new physiological, molecular and cellular abnormalities in venous ulcers related to the chronic inflammation are presented and discussed. Venous hypertension causes disturbed microcirculation and pathological changes of the capillaries, which eventually locks the condition in a self-amplifying, detrimental cascade with persistent elevated levels and activities of pro-inflammatory cytokines and proteases preventing progress into a healing phase. As a consequence fibroblasts senescence and become less responsive to growth factors the older the ulcers become. Current data imply there is no deficiency but rather an unfavorable distribution of growth factors in venous ulcers. An imbalance in proteolytic enzymes and their endogenous inhibitors is a common finding in chronic venous leg ulcers. Variation in disease severity and concomitant ailments in this heterogeneous patient group may explain the contradictory results in the literature. Thus, to advance the areas of research further, longitudinal studies involving larger number of patients are required to identify the major pathogenic factors.