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It has been reported that UV radiation leads to local and systemic immunosuppression, due to DNA damage and altered cytokine expression. This has implications in cutaneous tumor surveillance. The Langerhans cells may undergo changes in quantity, morphology, and function due to UV exposure and may eventually become depleted. One proposed ...
Indirect DNA damage: The chromophore absorbs UV-light (* denotes an excited state), and the energy of the excited state is creating singlet oxygen (1 O 2) or a hydroxyl radical (•OH), which then damages DNA through oxidation. [1]
All bands of UV radiation damage collagen fibers and accelerate aging of the skin. Both UVA and UVB destroy vitamin A in skin, which may cause further damage. [61] UVB radiation can cause direct DNA damage. [62] This cancer connection is one reason for concern about ozone depletion and the ozone hole.
The sun is, by far, the greatest source of ultraviolet (UV) radiation, which is the culprit that causes most skin cancers—the most common form of cancer in the U.S. According to the Skin Cancer ...
Ultraviolet radiation is thought to cause up to 95% of basal and squamous cell carcinomas, ... “But what happens if that mutation occurs in a gene that’s really important for DNA repair, for ...
UV light, specifically non-ionizing shorter-wavelength radiation such as UVC and UVB, causes direct DNA damage by initiating a synthesis reaction between two thymine molecules. The resulting dimer is very stable. Although they can be removed through excision repairs, when UV damage is extensive, the entire DNA molecule breaks down and the cell ...
This process of absorption works to reduce the risk of DNA damage and the formation of pyrimidine dimers. UVA light makes up 95% of the UV light that reaches earth, whereas UVB light makes up only about 5%. UVB light is the form of UV light that is responsible for tanning and burning. Sunscreens work to protect from both UVA and UVB rays.
A UV radiation induced thymine-thymine cyclobutane dimer (right) is the type of DNA damage which is repaired by DNA photolyase. Note: The above diagram is incorrectly labelled as thymine as the structures lack 5-methyl groups.