Kenji Tasaka

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We studied the roles of the phosphatidylinositol 3-kinase (PI-3K)-protein kinase B/Akt-BAD cascade in both cisplatin-resistant Caov-3 and -sensitive A2780 human ovarian cancer cell lines. Treatment of both Caov-3 and A2780 cells with cisplatin but not with the trans-diaminodichloroplatinum (transplatin) isomer stimulated the activation of Akt, and the PI-3K(More)
In a previous study, we speculated that some of the high mercury levels observed in head hair from a total of 14 subjects who resided around Lake Victoria, Tanzania, might be attributable to the habitual use of toilet soap containing considerable amounts of mercury (Harada et al. Sci Total Environ 1999;227:249-256). In August 1998, the current study was(More)
The proliferation of vascular smooth muscle cells (VSMC) is a crucial pathophysiological process in the development of atherosclerosis. Although estrogen is known to inhibit the proliferation of VSMC, the mechanism responsible for this effect remains to be elucidated. In addition, the effect of raloxifene on VSMC remains unknown. We have shown here that(More)
When rat mast cells loaded with fluorescent Ca2+ indicator Quin 2 were exposed to either compound 48/80 (0.1 micrograms/mL) or substance P (2 microM) at 37 degrees C for 30 seconds in a Ca-free medium, a marked increase of Quin 2 fluorescence was noticed, indicating that Ca2+ was released from the intracellular Ca store. The pixel values of the whole cell(More)
To clarify the role of endogenous histamine in learning and memory, the effect of α-fluoromethylhistidine on active avoidance response in rats was studied. α-Fluoromethylhistidine (20–100 mg/kg or 10–50 µg) significantly (P<0.05 orP<0.01) prolonged the response latency in active avoidance response when administered by either intraperitoneal or(More)
Although estrogen is known to activate endothelial nitric oxide synthase (eNOS) in the vascular endothelium, the molecular mechanism responsible for this effect remains to be elucidated. In studies of both human umbilical vein endothelial cells (HUVECs) and simian virus 40-transformed rat lung vascular endothelial cells (TRLECs), 17beta-estradiol (E2), but(More)
The expression of thrombospondin-1 (TSP-1) and its role in gliomas have not been well examined. In the present study TSP-1 expression in a panel of malignant glioma cell lines and the expression of TSP-1 and transforming growth factor (TGF-beta) proteins in low-grade and malignant glioma tissues were investigated. Reverse transcription-polymerase chain(More)
Synaptosome-associated protein of 25 kDa (SNAP-25) has been shown to play an important role in Ca2+-dependent exocytosis in neurons and endocrine cells. During fertilization, sperm-egg fusion induces cytosolic Ca2+ mobilization and subsequently Ca2+-dependent cortical granule (CG) exocytosis in eggs. However, it is not yet clear whether SNAP-25 is involved(More)
Although gonadotropin-releasing hormone agonists (GnRHa) have been used in the therapy of the endocrine-dependent cancers, their biological mechanism remained obscure. We have studied the roles of mitogen-activated protein kinase family in the antiproliferative effect of GnRHa on the Caov-3 human ovarian cancer cell line. Reverse transcription-PCR assays(More)
A 61-year-old woman, who was diagnosed in 1982 as having polycythemia vera, was admitted to our hospital in July 1998 because of a splenic tumor in an enlarged spleen due to myelofibrosis. As it was difficult to identify the etiology of the splenic tumor, partial splenectomy was carried out. The resected tumor proved to be an extremely proliferative lesion(More)