Author/Editor		Kansky, Aleksej
Title		Fotokarcinogeneza
Translated title		Photocarcinogenesis
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 33, št. Suppl 1
Publication year		1999
Volume		str. S69-74
Language		slo
Abstract		Photocarcinogenesis is a complex and still not fully explored process. Epidemiological studies as well as animal experiments show that wave lenghts in the range of 320-280 nm (UV B) are the main pathogenetic factor. Skin complexion and other genetic factors are however also important. The UV B rays are injuring directly the molecules of deoxyribonucleic acidic in the nuclei keratinocytes, fibroblast and Langerhans; cells, but the inducement of various molecules (chromatophores) into an excited stage is a further pathogenetic mechanism. This situation lasts only fraction of a ssecond and the relase of various forms of energy, which follows, is injuring cells and their organel as well as producing noxious products, e.g., pereoxides. In the inducement of carcinogenesis further mechanisms are usually coivolved as an impaired action of repartion enzmes, immunosuppression of T lymphocytes by UV B, expression of oncogenes and antiocogenes and others. A short review of th eabove mentioned processes is given.
Summary		Fotokarcinogeneza je zapleten in kompleksen proces. Epidemiološke študije in poskusi na živalih kažejo, da je najpomembnejši činitelj ultravijolična (UV) svetloba z valovno dolžino med 320 in 280 nm. UV žarki lahko okvarjajo neposredno molekule deoksiribonukleinske kisline (DNK) v jedrih celic, pomembnejša pa je aktivacija različnih molekul, ki prehajajo v ekscitirano stanje ter se nato spojijo z DNK v fotoadukte. Ekscitirano stanje traja le delce sekunde, ko preneha, se sproščajo različne oblike energije, pri čemer prihaja do okvare celic in njihovih organel, kakor tudi do nastanka različnih škodljivih spojin kot so npr. peroksidi. Za nastanek kožnih karcinomov so pomembni še nekateri drugi procesi: moteno delovanje reparacijskih encimov, imunosupresijski učinek UV svetlobe na limfocite T, akkor tudi aktivnost onkogenov in antionkogenov. Pri vseh naštetih procesih sodeluje tudi dednost, saj vpliva med drugim na občutlivost kože za svetlobo, na reparacijske encime, na občutljivost limfocitov na svetlobo ter na delovanje onkogenov.
Descriptors		SKIN NEOPLASMS ULTRAVIOLET RAYS