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| Identifier |
uch.med.phd//2001stefanidou |
| Title |
In vitro και in vivo μελέτη του φωτοδυναμικού φαινομένου στο δέρμα. Φωτοδυναμική θεραπεία και πειραματική προσέγγιση σε κακοήθη και φυσιολογικά κερατινοκύτταρα υπό ειδικές συνθήκες |
| Creator |
Stefanidou - Antonakaki, Maria P
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| Abstract |
Photodynamic therapy is based on the property of particular porphyrin-derived or related compounds to accumulate preferentially in the tumor than in the normal surrounding tissue. Activation of the compound by light results in tumor destruction, presumably through the intermediate formation of singlet oxygen or other cytotoxic agents. In the present study the efficacy of hematoporphyrin-mediated photodynamic treatment is compared for keratinocytes grown on Petri dishes versus collagen gel. Malignant cells were found to be constantly more sensitive to photodynamic therapy than normal keratinocytes. It is found that independently of the light dose and of the drug concentration, keratinocytes on collagen exhibited increased resistance to photodynamic treatment in comparison with those on Petri dish. The relative degree of resistance is essentially the same for both malignant and normal cells. Interestingly, no protection is afforded by the collagen gel to the cells in the corresponding control (light only and hematoporphyrin only) experiments. Thirty seven malignancies, 20 solar keratoses(SK) and 17 basal cell carcinomas(BCC) were submitted to photodynamic therapy with aminolevulinic acid(ALA-PDT). The overall cure response rate for SK was 85% and 70,6% for BCC. Specific histological findings in sequential histology were indicative of the destructive mechanisms in SK and BCC. Most of the lesions developed peak fluorescence 1,5-4 hours after ALA application. The photosensitizer accumulation efficiency was found high in BCC and low in SK. It was worth noticing that the peak fluorescence differed among tumors, even of the same type and this was an indication to start the irradiation more objectively. Time course erythema elicitation was found to differ between SK and BCC in accordance with recorded histological differences relative to PDT- destruction mechanisms. Erythema development was shown to correlate significantly with the phototoxic effect and might be considered a reliable predictor of PDT efficacy.
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| Issue date |
2001-01-01 |
| Date available |
2001-02-07 |
| Collection
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School/Department--School of Medicine--Department of Medicine--Doctoral theses
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Type of Work--Doctoral theses
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| Views |
240 |
In vitro και in vivo μελέτη του φωτοδυναμικού φαινομένου στο δέρμα. Φωτοδυναμική θεραπεία και πειραματική προσέγγιση σε κακοήθη και φυσιολογικά κερατινοκύτταρα υπό ειδικές συνθήκες
