| 1. |
- Heyerdahl, H, et al.
(författare)
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Pharmacokinetic studies on 5-aminolevulinic acid-induced protoporphyrin IX accumulation in tumours and normal tissues
- 1997
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Ingår i: Cancer Letters. - 1872-7980. ; 112:2, s. 225-231
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Tidskriftsartikel (refereegranskat)abstract
- Laser-induced fluorescence (LIF) for in vivo point monitoring and fluorescence microscopy incorporating a CCD camera were used to study the fluorescence distribution of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in tumours. Fluorescence in a chemically induced adenocarcinoma in the liver of rats and in an aggressive basal cell carcinoma in a patient were studied after intravenous injection of ALA at a dose of 30 mg/kg body weight. The LIF technique demonstrated slightly more ALA-induced PpIX fluorescence in the tumour than in the surrounding normal liver and abdominal muscle of rats. The visible parts of the human basal cell carcinoma exhibited strong ALA-induced fluorescence, while this fluorescence was much weaker in the necrotic areas of the tumour and in the surrounding normal skin. (C) 1997 Elsevier Science ireland Ltd.
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| 2. |
- Liu, D. L, et al.
(författare)
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Tumour vessel damage resulting from laser-induced hyperthermia alone and in combination with photodynamic therapy
- 1997
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Ingår i: Cancer Letters. - 1872-7980. ; 111:1-2, s. 157-165
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Tidskriftsartikel (refereegranskat)abstract
- This study examined tumour vessel injury resulting from laser-induced hyperthermia alone and in combination with photodynamic therapy (PDT) in the treatment of rat liver tumours by means of scanning electron microscopy. A total of 18 Wistar rats were divided into three groups, Group I (six animals) underwent hyperthermia for 15 min (15-min hyperthermia). Group II (six animals) underwent hyperthermia for 30 min (30-min hyperthermia). Group III (six animals) received the combined treatment of PDT and 30-min hyperthermia. For PDT, delta-amino laevulinic acid at a dose of 60 mg/kg of body weight was intravenously administered 60 min before irradiation at 635 nm. The morphological results indicated that 15-min hyperthermia gave rise to an increase in permeability of the vessels in the treated tumour. Thirty-min hyperthermia caused extreme oedema of vascular endothelial cells and restrictive openings of tumour branch vessels. The combined therapy of PDT and hyperthermia destroyed tumour vasculature. Large breaks of the inner wall of the treated tumour vessels were deeply involved in the basement membrane of the vessel. The results indicate that there may be a close link between inhibition of tumour growth and degree of damage to tumour vessels. (C) 1997 Elsevier Science Ireland Ltd.
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| 3. |
- Wang, I, et al.
(författare)
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Fluorescence diagnostics and kinetic studies in the head and neck region utilizing low-dose delta-aminolevulinic acid sensitization
- 1999
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Ingår i: Cancer Letters. - 1872-7980. ; 135:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- Diagnostic measurements and pharmacokinetic studies were performed in 17 patients with various kinds of malignant, premalignant and benign lesions in the head and neck region by means of point monitoring laser-induced fluorescence. For marking different types of tissue, delta-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was used. The ALA-induced PpIX synthesis was monitored at different time intervals after oral administration of ALA in low doses, 5 and 15 mg/kg b.w. Besides the porphyrin-related signal the tissue endogenous fluorescence was also recorded. The fluorescence spectra were evaluated at two different wavelengths corresponding to the specific drug-related fluorescence peak and the endogenous tissue fluorescence emission at 635 and 490 nm, respectively. The evaluated fluorescence data were correlated to the histopathological tissue investigation. A fall-off in the overall fluorescence intensity at 490 nm was obtained for an the malignant and premalignant areas, as well as an increased red fluorescence. A ratio between the red and the blue/green fluorescence intensity was formed for each time interval after the ALA administration. The lower drug dose seems to be sufficient to obtain a useful demarcation ratio between normal and diseased tissue with a very low PpIX fluorescence intensity in the normal tissue. A PpIX fluorescence maximum seems to occur between 3 and 4 h in normal tissues, whereas malignant tumour tissue shows a higher level for a longer period of time. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.
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