PHOTOBIOLOGY AND PHOTODERMATOLOGY

Question 1

95% of this UV radiation reaches the earths surface?

Answer 1

UVA

Question 2

this UV is present consistently from dawn to dusk?

Answer 2

UVA

Question 3

this UV peaks around noon?

Answer 3

UVB

Question 4

this UV is not filtered by window glass, but this one is?

Answer 4

UVA, UVB

Question 5

these UVs are filtered by windshields?

Answer 5

both UVA and UVB

Question 6

portion of the EM spectrum that is absorbed

Answer 6

Absorption spectrum

Question 7

portion of EM spectrum that produces a certain effect

Answer 7

Action spectrum

Question 8

this UV (longer wavelength) reaches the dermis?

Answer 8

UVA

Question 9

this UV is nearly entirely absorbed by epidermis

Answer 9

UVB

Question 10

tanning booths use what UV?

Answer 10

UVA and so vitamin D isn’t provided

Question 11

UV short term effects?

Answer 11

visible: sunburn and tanning
functional: immunosuppression, hardening in photodermatoses

Question 12

tanning is dependent on what two phases?

what about darker skin?

Answer 12

immediate pigment darkening (UVA) and delayed tanning (UVB)

type III and ip tans with UVB and fair skin burns with supra erythematogenic doses of UVB

Question 13

UVR immunosuppression involves even non-irradiated skin, T/F?

Answer 13

true

Question 14

those who use tanning beds are at increased risk of?

Answer 14

melanoma

Question 15

lentigo maligna melanoma ia correlated with?

Answer 15

chronic frequent sun exposure while other types are correlated with intermittent exposure

Question 16

these cancer types are associated with high cumulative exposure to UV radiation (face, hands and forearms)

Answer 16

SCC,BCC,LMM

Question 17

what is the chromophore for UVB?

so damage can be direct or indirect?

Answer 17

DNA

both (direct, UVB and indirect, UVA)

Question 18

UVA has a signature mutation which is?

Answer 18

guanine oxidation (7,8 dihydro-8-oxoguanosine) aka 8-oxoG

Question 19

the repair of UV damaged DNA is done through?

Answer 19

nucleotide excision repair pathway (NER)

base excision repair but for non bulky mutations

Question 20

what are the protective proteins?

Answer 20

p53 and PTCH