The aim of this thesis was to gain more insight in the involvement of inflammatory processes in vessel wall remodeling seen after PTA or bypass surgery and put these processes in the perspective of... Show moreThe aim of this thesis was to gain more insight in the involvement of inflammatory processes in vessel wall remodeling seen after PTA or bypass surgery and put these processes in the perspective of restenosis, vein graft failure and potential therapeutic preventive strategies. Therefore, we firstly focused on inflammation in general, using the anti-inflammatory agent Dexamethasone, assessing the effects of such a broad approach on restenosis and vein graft remodeling. Then, we further focused on some specific parts of the immune system, namely Interleukin 10 (IL10), chemokines and the complement cascade. Il10 was chosen because it is one of the most studied anti-inflammatory cytokines and this property makes it a potential candidate for ant-restenosis therapy. Furthermore, it was hypothesized that chemokines are involved in vascular remodeling, since they are generally known for their regulatory properties regarding influx of inflammatory cells to tissues and this is one of the first phenomena seen in vascular remodeling. The complement cascade was studied in this context since it contains pro-inflammatory activity and some end-products of the cascade, like chemokines, are potent chemotactic agents. Show less
Polymorphic light eruption (PLE) is a common sun-induced dermatosis presenting with itchy papules, plaques or vesicles on sun-exposed skin sites. In this thesis, epidemiological as well as... Show morePolymorphic light eruption (PLE) is a common sun-induced dermatosis presenting with itchy papules, plaques or vesicles on sun-exposed skin sites. In this thesis, epidemiological as well as pathogenetic mechanisms are desribed. By interviewing almost 7000 indoor working Europeans we found a lifetime prevalence of PLE of 18%. There is no evidence of increasing prevalence toward higher latitudes, as was formerly suggested. PLE is regarded an immunological disorder caused by a delayed type hypersensitivity reaction to a de novo photo-induced antigen in the skin. Upon UVB irradiation of the skin, more epidermal Langerhans cells persist in the epidermis of PLE patients and less neutrophilic granulocytes migrate into the epidermis, in contrast to healthy individuals. We show that UV-hardening therapy restores the epidermal cell migration to a normal situation. The reason for the aberrant cell responses in PLE skin remain for as yet unexplained. The presence of higher IL-1a en Il-1b levels in the skin of PLE patients was indicative of a pro-inflammatory situation after UVB irradiation when compared to healthy controls, but does not explain the aberrant cell responses. Our study further shows that the results of artificial UVA nor UVB provocation have any predictive value for the clinical severity of PLE Show less
