Yasuhiro Kohmura

Hamamatsu Rosai Hospital, Hamamatu, Shizuoka, Japan

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Publications (3)4.26 Total impact

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    ABSTRACT: Introduction: Zinc coproporphyrin I (ZnCP-I) is a photosensitive molecule and a major component of meconium. Here, we examined the effects of ZnCP-I as a potential photosensitizer in photodynamic therapy for tumors. Materials and Methods: (1) Aqueous ZnCP-I was irradiated with a pulsed YAG-SHG laser (wavelength: 532 nm)/YAG-SHG dye laser (wavelength: 566 nm). (2) HeLa cells were incubated in 200 mM ZnCP-I, and accumulation of ZnCP-I in HeLa cells was evaluated with ZnCP-I-specific fluorescence over 500 nm. (3) Aqueous ZnCP-I was administered intravenously to HeLa tumor-bearing mice at a dose of 10.2 mg/kg body weight. The tumors were irradiated with a filtered halogen lamp (wavelength: 580 nm) at 100 J/cm(2) 20 min after administration. Results: (1) An intense near-infrared emission spectrum was observed at around 1,270 nm after irradiation. The emission intensity was proportional to the laser power between 10 and 80 mW and was completely inhibited by addition of NaN(3), a singlet oxygen scavenger. (2) ZnCP-I-specific fluorescence was detected in the HeLa cell cytoplasm. (3) Irradiated tumors treated with ZnCP-I were mostly necrotized. Conclusion: ZnCP-I accumulated in tumor cells, produced singlet oxygen upon irradiation, and necrotized the tumor cells. These results suggest that ZnCP-I may be an effective photosensitizer.
    Fetal Diagnosis and Therapy 01/2013; · 1.90 Impact Factor
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    ABSTRACT: Cases of cancer presenting with microscopically confirmed metastatic malignancies for which no primary site can be detected are a challenge to stage clinically. Adenocarcinoma of unknown primary site is a subtype with high frequency that has no standard treatment and a poor prognosis. A 32-year-old female was found to have a tumor in the abdominal wall. Tumorectomy was conducted. A pathological examination indicated serous papillary adenocarcinoma, and peritoneal or ovarian cancer was suspected. Exploratory laparotomy and partial resection of the ovaries were carried out, but there were no malignant findings in the peritoneum, ovarian tissue or ascitic fluid. This is an extremely rare case of serous papillary adenocarcinoma with a cystic tumor that was categorized as extraovarian peritoneal serous papillary carcinoma (EPSPC) without other clinical findings.
    Journal of Obstetrics and Gynaecology Research 12/2009; 35(6):1142-7. · 0.84 Impact Factor
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    ABSTRACT: Photodynamic therapy (PDT) is a non-invasive cancer therapy that has a strong antitumor effect with intravenous administration of Photofrin. However, Photofrin causes light hypersensitivity that impairs the quality of life (QOL) of patients, and thus an improved method of administration is needed. Here, we report the antitumor effect of local administration of Photofrin in combination with a vasodilator, lidocaine hydrochloride. The antitumor effect was investigated in nude mice transplanted with HeLa cells. An incision was made near the tumor and Photofrin dissolved in lidocaine jelly was applied directly to the tumor. The tumor was irradiated at 100 J/cm(2) with a yttrium aluminum garnet (YAG)-dye laser (630 nm) at 2 h after the direct application and the tumor volume was measured for 30 days after PDT to investigate the antitumor effect. In some mice, the tumor was excised 24 h after PDT and the depth of necrosis was measured in the excised specimen. The tumor was mostly necrotized by PDT following direct application of 10 mg/ml Photofrin dissolved in lidocaine jelly and the effect was greater than with direct application of Photofrin alone. The increase in tumor volume observed in control mice was significantly inhibited in mice that received PDT after direct application of Photofrin in lidocaine jelly. PDT using direct application of Photofrin in lidocaine jelly has a strong antitumor effect in mice and this approach may avoid the adverse effects of systemic Photofrin administration.
    Photodermatology Photoimmunology and Photomedicine 10/2009; 25(5):259-63. · 1.52 Impact Factor