Yutaka Okumura

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PURPOSE From the role of double strand DNA dependent protein kinase (DNA-PKcs) activity of non-homologous end joining (NHEJ) repair for DNA double strand breaks (DSBs), we aim to define possible associations between thermo-sensitisation and the enzyme activities in X-ray irradiated cells. MATERIALS AND METHODS DNA-PKcs deficient mouse, Chinese hamster and(More)
Fatty-acid esters of dinophysistoxin-1 (DTX1) in scallops Patinopecten yessoensis, mussels Mytilus coruscus, and toxic dinoflagellate Dinophysis species, collected from Japanese seawater, were analyzed by liquid-chromatography mass spectrometry (LC–MS). Precursor ion monitoring, multiple reaction monitoring for 18 fatty-acid esters of DTX1, and full-scan(More)
Ketoprofen has been reported to have such side effects as photosensitive dermatitis in humans (The Ministry of Health, Labour and Welfare, 2001). In the present study, as part of a safety evaluation of Miltax, an application drug containing ketoprofen, phototoxicity of Miltax was examined in guinea pigs. In the present skin phototoxicity study, Miltax was(More)
To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki University (Japan). The data were compared with those of our previous study(More)
Glycosaminoglycans were prepared from the Engelbreth-Holm-Swarm mouse tumor. Enzymatic analysis demonstrated heparan sulfate (95.8%) and chondroitinase ABC-sensitive galactosaminoglycans (4.2%). HPLC analysis of the disaccharide units showed that heparan sulfate chains were undersulfated on average, comprising approximately 30% nonsulfated and 60%(More)
The study was performed to evaluate the percutaneous penetration of ketoprofen after transdermal administration using a microdialysis technique in pigs, in comparison with rats. Ketoprofen release from patches was determined by analysis of the remaining drug content after application to hairless rats and pigs. Skin and knee joint penetration of ketoprofen(More)
The androgen receptor (AR) is the main therapeutic target for treatment of metastatic prostate cancers. The present study demonstrates that the topoisomerase I inhibitor camptothecin selectively inhibits androgen-responsive growth of prostate cancer cells. Camptothecin strikingly inhibited mutated and wild-type AR protein expression in LNCaP and PC-3/AR(More)
Radiotherapy for malignant pelvic disease is often followed by acute radiation colitis (ARC). It has been reported that sucralfate treatment has a protective effect against ARC, though the mechanisms of action are unknown. The effects of sucralfate on X-ray radiation-induced apoptosis was studied at 4 Gy in the colonic crypt cells of rats. Sucralfate enemas(More)
Expression of heat shock protein 70, induced by an antiulcer drug, provides protection against gastric ulcers. However, the mechanisms responsible for this protection are not known. The expression in ulcer-resistant, spontaneously hypertensive rats was 2.8-fold higher than in normotensive rats. One hour after restraint and water immersion stress, strong(More)
Mutation of p53 is the most common genetic alteration observed in human tumours and is reported to lead to variations in cell radiosensitivity. However, the relationship between the mutation point and the degree of radiosensitivity is unclear. Saos-2 cells with different mutations of p53 were prepared and examined for radiosensitivity. Cells with p53(More)