Kusintha kwa Maselo Kumayambitsa Kuchuluka Kwambiri kwa UV
Kuwala kwa dzuwa kumakhudza kwambiri khungu lomwe lingabweretse msinkhu msinkhu, khansara ya khungu, ndi zina zambiri zokhudzana ndi khungu. Kuonekera kwa ultraviolet (UV) kuwala kumachititsa pafupifupi 90 peresenti ya zizindikiro zonse za khungu kuvulala.
Zoona Zokhudza Uphungu wa UV
Dzuŵa limatulutsa kuwala kwa dzuwa komwe timagawanika m'magulu molingana ndi kutalika kwake kwa thupi (monga kuyeza ndi nanometer, kapena nm):
- Mazira a UVC (100 mpaka 290 nm)
- Mazira a UVB (290 mpaka 320 nm)
- Ma radiation UVA (320 mpaka 400 nm)
Mazira a UVC ali ndi mawonekedwe afupipafupi kwambiri ndipo amapezeka kwambiri ndi ozoni. Choncho, sizimakhudza khungu. Komabe, kuwala kwa UVC kumawoneka kuchokera kuzinthu zoterezi monga mercury arc nyali ndi nyali za germicidal.
Mazira a UVB amakhudza khungu lakunja (epidermis) ndipo ndilo chifukwa chachikulu chowotchera dzuwa. Zimakhala zovuta kwambiri pakati pa maola 10 am ndi 2 koloko masana pamene kuwala kwa dzuwa kumakhala kowala kwambiri. Komanso zimakhala zovuta kwambiri m'miyezi ya chilimwe, zomwe zimapanga pafupifupi 70 peresenti ya chiwonetsero cha UVB chaka chilichonse. Chifukwa cha kutalika kwa dzuwa, UVB sichilowa m'galasi mosavuta.
Ma radiation UVA, mosiyana, nthawiyomwe ankaganiza kuti amakhala ndi zotsatira zochepa chabe pakhungu. Kafukufuku wasonyeza kuti UVA ndiwothandiza kwambiri pakhungu. UVA imalowa mkati mwa khungu ndi mphamvu zomwe sizikusintha kwambiri UVB.
Ndipo, mosiyana ndi UVB, UVA sichidasankhidwa ndi galasi.
Zotsatira Zowononga za UVA ndi UVB
Ma radiation onse a UVA ndi UVB angayambitse zovuta zokhudzana ndi khungu, kuphatikizapo makwinya, matenda okalamba , khansa ya khungu, komanso chitetezo chochepa cha matenda. Ngakhale kuti sitimvetsetse bwino njira za kusintha kumeneku, ena amakhulupirira kuti kugwa kwa collagen ndi kupanga mawonekedwe a ufulu waulere kungasokoneze DNA kukonza pa maselo.
Mazira a dzuwa amadziwika kuti amachulukitsa chiwerengero cha timadontho ta timadzi timene timayambitsa dzuwa. Kuwopsa kwambiri kwa dzuŵa kungayambitsenso chitukuko chodziwika bwino chotchedwa actinic keratoses. Matenda a Actinic amaonedwa kuti ndi otetezeka chifukwa mmodzi pa zana adzayamba kukhala squamous cell carcinoma . Matenda a "Actinic" omwe amachititsa "kuphuka" nthawi zambiri amakhala ophweka kumva kusiyana ndi kuwona ndipo nthawi zambiri amawonekera pamaso, makutu, ndi kumbuyo kwa manja.
Kutuluka kwa UV kungachititse kuti seborrheic keratoses , yomwe imawoneka ngati zilonda zam'mimba "zimamatira" pakhungu. Mosiyana ndi keratoses ya actinic, seborrheic keratoses sakhala ndi khansa.
Otsutsa a Collagen ndi Free Free
Mazira a UV angapangitse collagen kuti iwonongeke kwambiri kuposa kukalamba . Imachita izi polowera pakati pa khungu (dermis), zomwe zimachititsa kuti elastin isamangidwe bwino. Pamene zotupazi zimadziwika, mavitamini amapangidwa omwe amawononga collagen mosazindikira ndipo amapanga "zotentha za dzuwa." Kupitiriza kuwonetsetsa kumangowonjezereka pang'onopang'ono, motsogolerera kukwinya ndi kugwedeza.
Mafuta a dzuwa ndi amodzi mwa omwe amapanga zowonjezera . Zamadzimadzi osakanizidwa ndi makompyuta osakhazikika omwe ali ndi electroni imodzi yokha mmalo mwa awiri.
Chifukwa chakuti ma electron amapezeka awiriawiri, molekyuyo iyenera kumanga makompyuta ake osowa m'mamolekyu ena, n'kupangitsa kuti maselo awonongeke maselo. Zosintha zamagetsi sizingowonjezera chiwerengero cha michere yomwe imathyola collagen, imatha kusintha maselo a selo m'njira yomwe ingayambitse khansa.
Zotsatira za machitidwe a Immune
Thupi liri ndi chitetezo cha chitetezo cha chitetezo choteteza chitetezo cha mthupi. Chitetezo cha chitetezo cha mthupi chimakhala ndi maselo oyera amagazi oyera omwe amatchedwa T lymphocytes ndi maselo a khungu omwe amatchedwa maselo a Langerhans . Khungu likayamba kuwala kwa dzuwa, mankhwala ena amamasulidwa omwe amateteza maselowa mosalekeza, kufooketsa mthupi lonse.
Iyi si njira yokhayo yomwe kuwonetsetsa kwambiri kumachepetsa chitetezo cha munthu. Thupi lomaliza la chitetezo cha thupi limatchedwa apoptosis, "njira yodzipha" yomwe imatanthawuza kupha maselo owonongeka omwe sangathe kukhala odwala khansa. (Ichi ndi chimodzi mwa zifukwa zomwe mumayendera pambuyo pa kutentha kwa dzuwa.) Ngakhale kuti njirayi siimvetsetse bwino, kuyang'ana kwa UV koopsa kumawoneka kuti kumateteza apoptosis, kulola maselo osakanikira mwayi kukhala oipa.
Kusintha kwa Khungu kwa Dzuwa
Kutentha kwa UV kumapangitsa kuti khungu likhale losafunika komanso lopukuta khungu lotchedwa solar elastosis. Zingathe kuchititsanso kuti mitsempha ya mitsempha ikhale yopyapyala, zomwe zimapangitsa kuti zikhale zovuta kuvulaza ndi kangaude (telangiectasias) pamaso.
Mitundu yambiri yomwe imawoneka ndi dzuwa imasintha kwambiri (dzuwa limakhala ndi lentigo). Kuthamanga kumachitika pamene maselo opangira mtundu wa khungu ( melanocytes ) akuwonongeka, zomwe zimapangitsa kuti chilemacho chiwonjezeke. Manyowa akuluakulu, omwe amadziwikanso ngati mawanga , amapezeka kumbuyo kwa manja, chifuwa, mapewa, mikono, ndi kumbuyo. Ngakhale mabala achikulire amawoneka kawirikawiri kwa akulu akulu, iwo sali obadwa nawo monga dzina lawo limasonyeza koma zotsatira za dzuwa kuvulala.
Kuwonekera kwa UV kungachititse kuti maonekedwe a mawanga, manja, ndi manja azioneka ngati ma thoranocyte akuwonongedwa pang'onopang'ono ndi mazira a dzuwa.
Kansa ya Khungu ndi Melanoma
Kukhoza kwa dzuwa kuyambitsa khansara kumadziwika bwino. Mitundu itatu yaikulu ya khansa yapakhungu ndi khansa ya khansa , basal cell carcinoma , ndi squamous cell carcinoma.
Matenda a melanoma ndi omwe amafa kwambiri kuposa atatuwo pamene amafalitsa (metastasizes) mosavuta kuposa enawo. Basal cell carcinoma ndilofala kwambiri ndipo imafala kufalikira kwanuko kusiyana ndi kusokonezeka. Squamous cell carcinoma ndi yachiwiri kwambiri ndipo amadziwika kuti amatha kusokonezeka, ngakhale kuti sali ofala monga melanoma.
Amakhulupirira kuti kuchuluka kwa dzuwa kumene munthu amapatsidwa asanakwanitse zaka 20 ndikutengera chiopsezo cha khansa ya khansa. Mosiyana ndi zimenezi, chiopsezo cha basal cell carcinoma kapena squamous cell carcinoma chikugwirizana ndi mtundu wa khungu la munthu komanso kuchuluka kwa moyo wake wonse ku dzuwa.
> Zosowa
- > Ratushny, V .; Gober, M .; Hick, R .; et al. "Kuchokera ku keratinocyte kupita ku khansa: tizilombo toyambitsa matenda komanso tizilombo toyambitsa matenda a squamous cell carcinoma." Journal of Investigation Clinic. February 1, 2012; 122 (2): 464-472.
- > Narendhirakannan, R. ndi Hannah, A. "Kupanikizika Kwambiri ndi Kansa ya Khungu: Mwachidule." Ind J Clin Biochem. April 2013; 28 (2): 110-115.