Linked Life Data

15654980

Source:http://linkedlifedata.com/resource/pubmed/id/15654980

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-1-18
pubmed:abstractText
Overexposure to short- and long-wave ultraviolet radiations (UVB, UVA) may contribute to melanoma development through combined genotoxic and mitogenic effects in melanocytes. This study compares the impact of UVA-1 versus UVB, and single versus fractionated exposures on melanocyte proliferation in hairless SKH-2 mice. A single erythemal dose was compared with an equal dose fractionated over 8 d, and dose-dependency was studied. Proliferation (Ki-67 positive-sign) in melanocytes (melanoma antigen recognized by T-cells-1 positive or micropthalmia transcription factor positive) was ascertained in double-labeled skin sections. Single erythemal UVB exposures caused a delayed, dose-dependent increase of melanocyte proliferation. The highest, 17-fold, increase (from 0.05% to 0.8% of melanocytes) occurred 4 d after UVB exposure, without any detectable effect on overall melanocyte numbers. Correspondingly, DNA repair-deficient xeroderma pigmentosum A (Xpa) mice proved exquisitely sensitive to melanocyte proliferation induction by UVB exposure. No discernable effects were measured from fractionated suberythemal UVB exposures, or from any UVA-1 exposure regimen. Hence, melanocyte proliferation appears to be most efficiently induced by a single UVB overexposure. Moreover, the ineffectiveness of UVA-1 radiation and the enhanced sensitivity of Xpa mice point at pyrimidine dimers as causative DNA lesions. Consequently, murine nevi and melanoma are expected to be most effectively induced by intermittent UVB overexposures.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-202X
pubmed:author
pubmed:issnType
Print
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
241-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Single UVB overexposure stimulates melanocyte proliferation in murine skin, in contrast to fractionated or UVA-1 exposure.
pubmed:affiliation
Dermatology Department, University Medical Center Utrecht, Utrecht, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't