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Wang J, Xing D, He Y, Hu X: Experimental study on photodynamic diagnosis of cancer mediated by chemiluminescence probe. J Radiat Res. 1996 Mar;37(1):29-37.
A novel method of photodynamic diagnosis of cancer mediated by chemiluminescence probe is presented. The mechanism for photodynamic therapy involves singlet oxygen ((1) O (2)) generated by energy transfer from photosensitizers. (1) O (2) can react with 3,7-dihydro-6-[4-[2-(N'-(5-fluoresceinyl) thioureido) ethoxy] phenyl]-2-methy limidazo [1,2-a] pyrazin-3-one sodium salt (FCLA), which is a Cypridina luciferin analog and a specific chemiluminescence probe for detecting (1) O (2) and superoxide (O (2)(-)). The reaction of FCLA and (1) O (2) can give emission with peak wavelength at about 532 nm. In the present study, FCLA was chosen as an optical reporter of (1) O (2) produced from the photosensitization reaction of hematoporphyrin derivative in model solution and in nude mice with transplanted mammary cancer. Photosensitized chemiluminescence from the reaction of FCLA with (1) O (2) was detected by a highly sensitive Intensified Charge-Coupled Device detector. The chemiluminescence was markedly inhibited by the addition of 10 mmol/l sodium azide (NaN (3)) to the model solution and minor effects were observed at the addition of 10 micromol/l superoxide dismutase, 20 mmol/l mannitol and 100 microg/ml catalase, respectively, thus indicating that (1) O (2) generation from photosensitization reaction mainly results in light emission. Experiments in vivo with tumor-bearing mice showed a clear chemiluminescence image of tumor. The study suggests that this novel method may be applicable to the diagnosis of superficial tumors. |
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