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1. Dermatology > UV light > Flashcards

Flashcards in UV light Deck (7)
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1
Q

What is the depth of UVB?

A

240-320nm

2
Q

What damage does UVB do?

A

direct DNA damage

- damaging when sun is overhead

3
Q

What is the depth of UVA?

A

320-400nm

4
Q

What damage does UVA do?

A

indirect oxidative damage

- penetrates into the skin deeper

5
Q

What DNA damage does UVB cause?

A

forms DNA lesions - CPD and 6-4PP which are formed by covalent bonds.
These are usually removed by Nucleotide Excision Repair but if not repaired it can lead to DNA base pairing mutations

6
Q

What DNA damage does UVA cause?

A

causes deoxyguanosine to form 8-oxo-deoxyguanosine

which can cause GC -> AT point mutations

7
Q

What does chronic UV exposure cause?

A

Langerhan cells to lose their antigen presenting ability
Keratinocytes and dermal dendrocytes to secrete IL-10
CD4 T cells to dominate which becomes immunosuppresive