The Review of Laser Engineering
Online ISSN : 1349-6603
Print ISSN : 0387-0200
ISSN-L : 0387-0200
Volume 35, Issue 8
Displaying 1-9 of 9 articles from this issue
  • Katsuo AIZAWA, Atsushi NAKAMURA
    2007 Volume 35 Issue 8 Pages 481-485
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Talaporfin is a photosensitizer of the molecular weight 799.73. We can check the lesion by observing fluorescence using the endoscopes image and fluorescence spectrum equipment. We introduce angioscope fluorescent image analysis equipment into an abdominal aorta with a hyperlipidemia rabbit, and are accumulated Talaporfin on the inner arteriosclerosis was observed. The arteriosclerosis part of the coronary arteries and its tip arteriole excited Talaporfin by 405 nm, and has observed it as a fluorescent image from the surface outside the heart. By the infrared spectrum, we observed the process to which arteriosclerosis is expanded. As a result, absorption peaks of arteriosclerosis at the ester and fatty acid increased and the ratio of the peak was 0.30. The (C=O) absorption peak of the cholesterol ester of arteriosclerosis was decreasing by the photodynamic therapy. The photodynamic therapy of the arteriosclerosis enabled target to observe spectra of ester. It seems that this observation can advance one big step towards the 21st century
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  • Toru HIRANO
    2007 Volume 35 Issue 8 Pages 486-492
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    PDT is based on the generation of singlet oxygen (1O2) in a photochemical reaction among a tumor-accumulated photosensitizer, irradiation light, and oxygen in a tumor, and the detection of 1O2 is very important for understanding the mechanism of PDT. We used a near-infrared detection system to detect a 1270nm emission that was derived from the 1O2. Utilizing this system, we detected the generation of 1O2 from Photofrin dissolved in water or injected in a HeLa tumor-bearing mouse. We showed the irradiation power dependence of the generation of 1O2 in 5-ALA-mediated PDT with 9L cells and 9L tumor-bearing rats. High-power irradiation reduced the generation of 1O2 more than that with low power, and an MTT assay revealed that more 9L cells were killed by low-powered irradiation. In tumors, low-powered irradiation resulted in efficient tumor necrosis. Generations of 1O2 in ICG and TiO2 irradiation are also described.
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  • Akira KANEDA, Jiro MINEHISA
    2007 Volume 35 Issue 8 Pages 493-497
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Photodynamic therapy (PDT) is a treatment applied by a laser system in combination with a photosensitive drug (photosensitizer) that is excited by laser light. Accumulation of the photosensitizer at the disease site and local excitation by laser irradiation make it possible to selectively treat the diseased region, preserving the functionality and appearance of the treated area. Photodynamic Diagnosis (PDD) enables the identification of a specific disease site through the capturing of fluorescence generated by the photosensitizer. It is expected PDD will prove useful in identifying the disease site for Glioblastoma, amalignant brain tumor for which clear boundaries cannot be easily detected.
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  • Reaction Dynamics and Intracellular Kinetics of Photosensitizer
    Satoko KAWAUCHI, Shunichi SATO, Makoto KIKUCHI
    2007 Volume 35 Issue 8 Pages 498-502
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Photodynamic therapy with pulsed light excitation has interesting characteristics; however, its photosensitization mechanism has not been fully elucidated. We investigated the correlation between oxygen consumption and photobleaching during photodynamic treatment with nanosecond pulsed light excitation and a secondgeneration, lysosomal sensitizer in vitro, and obtained “fluorescence-oxygen diagram” at different pulse frequencies. The diagrams showed that initial oxygen-dependent photobleaching was switched to an oxygenindependent photobleaching, which was re-switched to an oxygen-dependent reaction at the higher frequencies of 10 and 30 Hz; such changes were not observed at 5 Hz. The complex behaviors revealed by the diagrams at 10 and 30 Hz were shown to be associated with the intracellular kinetics of the sensitizer, i.e., initial localization in lysosomes and redistributionto the cytosol during the treatment. The pulse frequencydependent intracellular kinetics of the sensitizer also explained the higher cytotoxicity at 5 Hz than at 10 and 30 Hz.
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  • Osamu SAWADA, Masato OJI
    2007 Volume 35 Issue 8 Pages 503-508
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Age-related macular degeneration (AMD) is the leading cause of legal blindness in developed countries. No effective treatments had existed until Photodynamic therapy using Verteporfin was approved following clinical trials. Treatment of Age-related Macular Degeneration With Photodynamic therapy investigation (TAP investigation) was carried out in United States and Europe and the Japanese Age-related Macular Degeneration Trial (JAT) was in Japan. TAP investigation showed a reduction of moderate and severe vision loss compared with placebo treatment although mean visual acuity decreased even in the PDT group. On the other hands, mean visual acuity was maintained or slightly improved in JAT study. More recently, anti-VEGF drugs, including antibody or aptamer have been shown to be effective for AMD and achieved improvement of mean visual acuity. A combination therapy of PDT and anti-VEGF drugs might achieve further improvement of vision and could become the first choice for AMD treatments
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  • Jitsuo USUDA, Shuji ICHINOSE, Taichiro ISHIZUMI, Takeshi HIRATA, Tatsu ...
    2007 Volume 35 Issue 8 Pages 509-513
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Photodynamic therapy (PDT), one of the treatment modalities for cancer, uses a photosensitizer and laser irradiation to induce the production of reactive oxygen species in cancers cells. In Japan, the United States, and many other countries, PDT is widely used as a treatment option for solid cancers. In the therapeutic guidelines for lung cancer established in 2002 by the Japanese Ministry of Health, Labor and Welfare based on the principle of evidence-based medicine, PDT is the recommended treatment modality for centrally located early stage lung cancer. It has been reported that PDT rapidly induce apoptosis, inflammatory reaction, tumor specific and/or nonspecific immune reaction and damages the microvasculature of the tumor bed. The mechanism of action of PDT is unique and is not well known. In this paper, we discuss the mechanism of the induction of apoptosis or necrosis following PDT.
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  • Naoya HASHIMOTO, Amami KATO, Shuichi IZUMOTO, Toshiki YOSHIMINE
    2007 Volume 35 Issue 8 Pages 514-518
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    The authors described the recent advancement of photodynamic diagnosis (PDD) and therapy (PDT) in neurosurgical field. Intra-operative PDD using 5-aminolevlulinic acid (5-ALA) and violet blue excitation light is now recognized as one of the multidisciplinary treatment modalities for malignant gliomas. The results of PDD in a series of 38 patients who treated in Osaka University Hospital between 2004 and 2006 were presented thoroughly, as well as the review of clinical trial studies in the world.Although the methodology of photodynamic therapy (PDT) for malignant brain tumors is not establishedyet, various PDT clinical trials showed promising results of PDT, as well as the needs for some improvements on photosensitizers and development of simpler and more efficient light delivery systems for neurosurgery.
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  • Takashi SAKAMOTO, Katsunori ISHII, Toshihiro KUSHIBIKI, Kunio AWAZU
    2007 Volume 35 Issue 8 Pages 519-522
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    Photodynamic Diagnoses (PDD) are commonly applied in clinical and basic research areas. A conventional PDD with the maximal absorption wavelength of a photo sensitizer accumulated in the tumor tissue reveals its location. In this study, we evaluated the tissue transmittance of the lasers of two different wavelengths, 405 and 664 nm. These are the maximal absorption wavelengths of Talaporfin Sodium and appeared at different penetration depths in the tumor tissue. When these two wavelength lasers were irradiated to the tissue, different fluorescent intensities were obtained. From these different intensities and the different penetration depths of the lasers, the depth of the tumor's location is clarified.
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  • Kiminori ITO, Katsushi ODA, Michihiro KAWADA, Masahiro KIMURA
    2007 Volume 35 Issue 8 Pages 523-526
    Published: August 15, 2007
    Released on J-STAGE: March 26, 2014
    JOURNAL FREE ACCESS
    We have developed a compact inexpensive system for observing lymphatic vessels through the skin tissue. This method utilizes the high transmittance of near-infrared light through skin tissue and water; it is free from the dangers of radiation. Indocyanine green is used as the contrast dye, and it absorbs and emits near-infrared radiation. A few hours after injecting the dye solution subcutaneously, the lymphatic vessels are clearly observed using an infrared camera.
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