Shigeo Iwasaki

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To date, cloned farm animals have been produced by nuclear transfer from embryonic, fetal, and adult cell types. However, mice completely derived from embryonic stem (ES) cells have been produced by aggregation with tetraploid embryos. The objective of the present study was to generate offspring completely derived from bovine ES-like cells. ES-like cells(More)
Mutant ras oncogenes are associated with various human tumors, being found in approximately 25% of all human cancers. Since its identification, the enzyme Ras protein farnesyltransferase (PFTase), which catalyzes the initial step of Ras-processing, has been viewed as a most promising target for cancer therapy. Consequently, a number of synthetic and natural(More)
Rhizoxin, an antibiotic, exhibits potent anti-mitotic activity against most eucaryotic cells including those of higher vertebrates, plants and fungi by binding to β-tubulin. ThebenA gene of three independently isolated rhizoxin-resistant (Rhir) mutants ofAspergillus nidulans was cloned, sequenced and compared with that of the wild-type, rhizoxin-sensitive(More)
OC-108 is a novel sclerosing agent for hemorrhoids, containing aluminum potassium sulfate (alum) and tannic acid as its main ingredients. In clinical studies, OC-108 injection therapy for severe internal hemorrhoids proved to be highly effective, not only on bleeding but also for prolapse, and the effects were comparable to hemorrhoidectomy. The aim of this(More)
Rhizoxin and ansamitocin P-3 (a maytansinoid compound), potent inhibitors of mammalian brain tubulin assembly, inhibit growth of a variety of fungi including Aspergillus nidulans. Mutants of A. nidulans, benA10 which is a benomyl resistant β-tubulin gene mutant and tubAl which is a benomyl supersensitive a-tubulin gene mutant, were both sensitive to(More)
Previous studies by our and other groups have shown that microbial products containing more than one epoxide group, including eponemycin, radicicol, depudecin and AGM-1470, exhibits anti-angio-genic activity in an in vivo assay system involving chorioallantoic membranes (CAMs) of growing chick embryos. Based on these findings, rhizoxin, a microbial(More)
Rhizoxin is an antitumor drug prepared from the fungus Rhizopus Mnensis. It is an inhibitor of microtubule assembly and a potent com petitive inhibitor of the binding of tubulin of ansamitocin P-3, a maytansine analogue. Rhizoxin also weakly inhibits vinblastine binding to tu bulin. We have previously found that maytansine and vinblastine differ strikingly(More)
Non-esterified (non-sulfated and non-glucuronidated) bile acid profile in the serum and bile was assessed using mass fragmentation spectrometry in relation to the decrement rate of the serum total bilirubin after relief of the biliary obstruction by external biliary drainage in fourteen patients. Biliary excretion of the total bile acid was decreased and(More)
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