B Ch. 85,86

Front 1

Mutations in what suppressor gene can lead to melanoma

Back 1

CDKN2A. usually encodes p14 and p16. p16 usually serves as a cell cycle checkpoint regulator at G1

Front 2

Most common XP in Japan?

Back 2

XPA

Front 3

Most common XP in the US?

Back 3

XPc, milder phenotype

Front 4

Max absorption wavelength of DNA? Most common pyrimide dimer?

Back 4

260 nm, most common pyriimidine dimers are Cyclobutane PD's, T-T dimer M/C

Front 5

XP associated with TTD?

Back 5

XPB and XPD

Front 6

Gene for XP variant?

Back 6

mutation in pol-n-gene. Bypas T-T dimers--UV mutator phenotype

Front 7

HLA associated with actinic prurigo

Back 7

HLA-DR4, subtype DRB1*0407. m/c native americans. generally presents in childhood.

Front 8

Pathogenesis of solar urticaria

Back 8

An IgE mediated response to a photo-induced allergen most likely.

Front 9

Four disorders associated with defects in NER proteins.

Back 9

1. XP, 2. Cockayne syndrome, 3. UV-sensitive syndrome, 4. Photosensitive form of TTD, also COFS syndrome but no photosensitivity.

Front 10

defective in XP?

Back 10

global genomic nucleotide repair of UVR-induced damage.

Front 11

Cockayne syndrome appearance?

Back 11

photosensitivity without pigment changes. 'cachectic dwarfism.' calcification of basal ganglia. Mutations in ERCC8, ERCC6

Front 12

TTD (trichothiodystrophy)

Back 12

"PIBID(S)" photosensitivity, icthyosis, brittle hair, intellectual impairment, decreased fertility, short stature. Mutations in XPD, XPB. reduction of cysteine-rich matrix in hair.

Front 13

Bloom syndrome defect?

Back 13

BLM gene (RECQL) resulting in chr. instability.

Front 14

Bloom syndrome assoc. with increased risk of?

Back 14

leukemia, lymphoma, GI adenocarcinoma.

Front 15

Rothmund-Thompson syndrome mutation?

Back 15

RECQL4, protein product is a DNA helicase.

Front 16

Inheritance of NER or chr. instability syndromes in B ch. 86?

Back 16

AR

Front 17

Syndrome with defective coupled transcription TC-NER and inability to recover RNA synthesis after exposure to UVR?

Back 17

Cockayne

Front 18

Phototox with "slate-gray hyperpigmentation" after what meds?

Back 18

amiodarone, tricyclics, diltiazem

Front 19

Histology of solar lentigo?

Back 19

elongated rete, mild increase in number of melanocytes. No elongation of rete with ephelides.

Front 20

UVC wavelength

Back 20

200-280 nm

Front 21

What is a chromophore?

Back 21

A light absorbing molecule

Front 22

Patients with chronic actinic dermatitis show what on testing

Back 22

Lowered MEDB

Front 23

Absorption for conversion of 7-dehdrocholesterol to previtamin D3 is in what range

Back 23

UVB
290-320

Front 24

Phototoxicity and photoallergy are usually associated with absorption in what range?

Back 24

UVA

Front 25

Most fluorescent UV sources are from?

Back 25

Low pressure mercury vapor lamps. Emit at 254nm absorbed by phosphor lining in the bulb lining.

Front 26

Fluoresent UVA bulbs for phototesting have emission at?

Back 26

352 nm

Front 27

Irradiance of a UV source is measured in?

Back 27

Watts

Front 28

Range most effective for cutaneous immunosuppression?

Back 28

UVB

Front 29

A normal MEDB on untanned Caucasion skin?

Back 29

20-70 mJ/cm2

Front 30

RECQL defects seen in what?
Clue: WeBeR 2,3,4

Back 30

RECQL2 - Weber
RECQL3 - Bloom's
RECQL4 - Rothmund-Thompson

Front 31

aminoglycoside with most sun sensitivity?

Back 31

Demeclocycline>doxycycline>tetracycline

Front 32

XP variant has defective .....repair?

Back 32

post-replication repair.
pol-1-n gene

Front 33

Pheomelanin offers less protection and is made of?

Back 33

cysteinyldopa molecules.

eumelanin=dihydroxyindole

Front 34

M/C dimer with Cyclobutane Pyrimidine Dimers?

Back 34

T-T dimer

-T-C dimers seen with 6,4 photoproducts

Front 35

most effective wavelength for inducing photoproducts?

Back 35

300nm

Front 36

Genes assoc. with cockayne

Back 36

ERCC8 (chr. 5)
ERCC6 (chr. 10)

Front 37

Short stature, facial erythema and telangiectasias, high-pithced voice, increase risk for acute leukemia or lymphoma, may have a cafe au lait macule

Back 37

Bloom Syndrome, RecQL3 helicase gene

Front 38

Initial erythema, edema on face replaced by red-brown reticulated patches.
-Alopecia
-skeletal abnormalities
-rare osteosarcoma
-Also known as Poikiloderma congenitale

Back 38

Rothmund-Thompson
RecQL4

Front 39

Cachectic dwarf with large ears and microcephaly.
Salt and pepper retinal pigmentation.
Deafness, photosensitve ruption in "butterfly" distrbution on face
-Large hands, large feet

Back 39

Cockayne syndrome
-ERCC8 (CSA) chr. 5
-ERCC6 (CCB) chr. 10

defcient RNA synthesis and increased cell death after UV irradiation.

Front 40

Photosensitivity
Icthyosis
Brittle hair
Intelectual impairment
Decreased fertility
Short stature

Back 40

Trichothiodystrophy.
ERCC2-same complementation group as XPD.

Front 41

Photosensitivity, cerebellar ataxia, aminoaciduria.

Back 41

Hartnup's syndrome.

gen. defect in transport of neutral aa's across brush border epithelium. with decreases abs of tryptophan and a pellagra like syndrome

Front 42

MOST EFFECTIVE UV IN PRODUCING pyrimidine dimers which may activate oncogenes?

Back 42

UVB

m/c imder is cyclobutane dimers