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Öğe Associations between human leukocyte antigens and leprosy in the Turkish population(Blackwell Publishing Ltd, 2002) Koçak, M.; Balci, M.; Pence, B.; Kundakci, N.Leprosy is a chronic infection caused by an intracellular microorganism. Genetic predisposition to both disease susceptibility and to host immunological response has been postulated for many years. The aim of this study was to determine whether there is HLA-linked susceptibility to leprosy and its different types. HLA-class I (A, B, C) and II (DR, DQ) antigen frequencies in 80 patients with leprosy (35 borderline lepromatous, 25 lepromatous, 15 borderline tuberculoid, five tuberculoid) were compared with those in 120 healthy individuals. HLA-class I antigens A9, A10, A32, B5, B21, Bw4, Bw6, Cw1, Cw2 and HLA-class II antigens DR9, DR10, DRw52, DQ1, DQ3 were found to be significantly more frequent in patients with leprosy, whereas HLA-class I antigens A3, B44, B49 and HLA-class II antigen DQ5 were so in controls. However, there was no significant difference in HLA-class I and II antigen frequencies between subtypes of leprosy. HLA-A null antigen was found to have weak expression in patients with leprosy. In conclusion, factors other than HLA-class I and class II antigens may have a more critical role in the pathophysiology of leprosy infection in man.Öğe Bcl-2-related proteins, (alpha)-smooth muscle actin and amyloid deposits in aggressive and non-aggressive basal cell carcinomas(Taylor & Francis As, 2002) Bozdoğan, Ö.; Erkek, E.; Atasoy, P.; Koçak, M.; Birol, A.; Caydere, M.Aberrant expression of bcl-gene products has been implicated in the development of non-melanoma skin cancers. Recently, altered expression of alpha-smooth muscle actin has been proposed as predictive of tumour behaviour in basal cell carcinomas. The purpose of this study was to compare the aggressive and non-aggressive basal cell carcinomas in terms of bcl-gene products and alpha-smooth muscle actin expression. Fifty excisional biopsy samples were studied by immunohistochemical technique for the differential expressions of bcl-2, bax, bcl-x and alpha-smooth muscle actin. Bcl-2, bcl-x and bax were expressed in 34 (68%), 38 (76%) and 41 (82%) specimens, respectively. Immunoreactivity for alpha-smooth muscle actin was noted both in tumour nests (64%) and within the stroma (54%). There was a significant difference between aggressive and non-aggressive basal cell carcinomas in terms of bcl-2 and stromal alpha-smooth muscle actin immunoreactivity. Non-aggressive basal cell carcinomas display a concordant expression of bcl-family proteins, whereas aggressive tumours reveal a discordant pattern. An increased expression of stromal alpha-smooth muscle actin with a concomitant decrease or loss of bcl-2 expression may be highly suggestive of aggressiveness in basal cell carcinoma.Öğe Examination of Bcl-2, Bcl-X and bax protein expression in psoriasis(Blackwell Publishing Ltd, 2003) Koçak, M.; Bozdogan, O.; Erkek, E.; Atasoy, P.; Birol, A.Background Psoriasis is an inflammatory skin disease characterized by epidermal hyperplasia and greatly accelerated epidermal turnover. The blockage of normal apoptotic process in the epidermis is one of the factors implicated in the pathogenesis of psoriasis. Objective The purpose of the present study was to elucidate whether bcl-family proteins are significantly involved in the hypothetical antiapoptotic cascade in lesional psoriatic epidermis. Methods Twenty-six lesional biopsy samples of 26 patients with psoriasis and five control specimens from normal skin were studied by immunohistochemical method for the differential expression of pro-apoptotic bax and antiapoptotic bcl-2 and bcl-x proteins. Results Compared with the normal epidermis, bcl-2 expression was significantly reduced, whereas bax and bcl-x were significantly overexpressed in the psoriatic epidermis. The localization of bcl-2/bax/bcl-x proteins in the psoriatic epidermis did not show a significant deviation from that in the normal epidermis. Conclusion These findings indicate a discordant expression of bcl-2 and bax/bcl-x in psoriatic epidermis. Increased bcl-x expression might contribute to the antiapoptotic response in psoriatic keratinocytes. The presence of strong bax expression with a concomitant decrease in bcl-2 expression suggests either a functional defect in bax protein or an inherent/acquired resistance to bax-mediated apoptosis in psoriatic keratinocytes.Öğe Keloid secondary to therapeutic cupping: an unusual complication(Wiley, 2005) Birol, A.; Erkek, E.; Kurtipek, G. S.; Koçak, M.…
