Linked Life Data

9077481

Source:http://linkedlifedata.com/resource/pubmed/id/9077481

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1997-4-9
pubmed:abstractText
The goal of this investigation was to establish methodology to determine and prevent phototoxic responses of normal skin to photodynamic therapy (PDT). The drug used was a second-generation photosensitizer, benzoporphyrin derivative monoacid ring A (BPD-MA). The dependence of skin phototoxicity on drug dose (0.5-2.0 mg/kg), fluence (1.2-390 J/cm2), and wavelength (690 nm and 458 nm) was studied in the New Zealand albino rabbit in the first 5 h after injection. Skin responses were recorded for 2 wk after irradiation. Noninvasive measurements of drug fluorescence were made on unexposed skin sites during the first 5 h after drug injection. Immediate responses to PDT included erythema induced by 458 nm light and blanching induced by 690 nm light. Delayed reactions included edema on the day of exposure, purpura at 24 h, eschar by day 2 or 3, and scar by the end of follow-up. The threshold fluence for immediate responses correlated strongly with the threshold fluence for delayed reactions. The induction of threshold purpura on day 1 was a reliable index for skin phototoxicity that led to necrosis. The minimum purpura dose on day 1 after irradiation increased exponentially with the interval between drug injection and irradiation, independent of irradiation wavelength, for all drug doses. The action spectrum for threshold purpura mimics closely the absorption spectrum of BPD-MA. The in vivo drug fluorescence correlated with skin phototoxicity, thus allowing predictive dosimetry. This model system defines the safety limits for skin phototoxicity of PDT with BPD-MA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-202X
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
501-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Predictive dosimetry for threshold phototoxicity in photodynamic therapy on normal skin: red wavelengths produce more extensive damage than blue at equal threshold doses.
pubmed:affiliation
Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, U.S.A.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't