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- Bartosik, Jacek, et al.
(författare)
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Ultrastructural alteration of tape-stripped normal human skin after photodynamic therapy
- 2004
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Ingår i: EJD. European Journal of Dermatology. - 1167-1122. ; 14:2, s. 91-95
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Tidskriftsartikel (refereegranskat)abstract
- The effect of photodynamic therapy on tape-stripped normal human skin was explored ultrastructurally. Back skin areas of 3 healthy Caucasian volunteers, 2 men and 1 woman, were tape-stripped 10 consecutive times followed by topical treatment with 5-aminolevulinic acid (20%, w/w) for 4 hours under occlusion (Tegaderm(R)). Then the areas were irradiated for 30 minutes with Waldman PDT 1200 lamp (570-650 nm) with a total dose of 70 J/cm(2). Full-thickness punch biopsies were taken immediately after irradiation, and at 3 and 24 hours for electron microscopy examination. Photodynamic therapy caused morphological alterations mainly in the epidermis. Keratinocytes became oedematous and tonofilament bundles were split, but desmosomes remained normal. Many keratinocytes contained large intracellular vacuoles and extremely electronlucent cytoplasm implying cell damage. Although the majority of Langerhans cells were unaffected isolated Langerhans cells became apoptotic at 3 hours. The melanocytes preserved their normal morphology. The epidermal alterations recovered 24 hours after the irradiation. Inflammatory cell infiltrates were evident at 3 and 24 hours but no other dermal changes were observed. In conclusion, photodynamic therapy with 5-aminolevulinic acid affects mainly keratinocytes and can trigger apoptosis in Langerhans cells while melanocytes appear refractory, at least morphologically, to photodynamic therapy.
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| 2. |
- Johnson, Louis Banka, et al.
(författare)
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Combination of pre-operative radiotherapy and surgery suppresses local accumulation of collagen and TGF-beta 1 in rats
- 2006
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Ingår i: Journal of Surgical Research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 133:2, s. 136-142
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Tidskriftsartikel (refereegranskat)abstract
- Background. The systemic and local tissue repair responses of radiation in combination with surgery are still unclear. We have studied the effect of fractionated pre-operative radiotherapy with or without subsequent laparotomy on collagen accumulation using a rodent model. Materials and methods. Thirty-two male Sprague-Dawley rats were divided into four groups (eight rats per group): 1) sham radiation and sham laparotomy (control); 2) sham radiation and laparotomy; 3) radiation and sham laparotomy; and 4) radiation followed by laparotomy. Expanded polytetrafluoroethylene (ePTFE) tubes were implanted subcutaneously in the abdominal wall in the radiotherapy field and on the back outside the radiotherapy field day 0. The abdomen (3 cm x 4 cm) was irradiated day 3 (10 Gy) and again day 7 (10 Gy). On day 10, implants were extirpated, laparotomy undertaken in groups 2 and 4 and new ePTFE tubes implanted subcutaneously. The second implants were extirpated on day 20. Implants were analyzed for hydroxyproline, total protein and transforming growth factor-ss 1 (TGF-ss 1) levels. Results. On day 10, hydroxyproline (P < 0.05) and TGF-ss 1 (P < 0.001) were lower in ePTFE tubes in irra-diated compared with non-irradiated rats. On day 20, the abdominal ePTFE hydroxyproline remained low (P < 0.001) in animals subjected to laparotomy and pre-operative irradiation while hydroxyproline levels of rats subjected to irradiation only were similar to controls. The effects of radiation on hydroxyproline were confined to the irradiated abdominal area. There was a positive correlation between hydroxyproline and TGF-ss 1 levels in the abdominal wall implant day 20 (r = 0.53, P < 0.005). Conclusion. A clinically relevant fractionated radiation scheme reduced subcutaneous collagen accumulation pre-operatively and profoundly within the radiation field post-operatively after laparotomy, possibly because of lowered TGF ss 1 levels. (c) 2006 Elsevier Inc. All rights reserved.
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