Masamichi Yamashita

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We have shown previously that chromosome VI of Saccharomyces cerevisiae contains nine origins of DNA replication that differ in initiation frequency and replicate sequentially during the S phase of the cell cycle. Here we show that there are links between activation of these multiple origins and regulation of S-phase progression. We study the effects of a(More)
Large cell neuroendocrine carcinoma (LCNEC) is a neuroendocrine tumor comprising a subgroup of large cell carcinoma and is a type of lung cancer showing a neuroendocrine characteristic similar to that of small cell lung carcinoma In our institution, we started to diagnose LCNEC by immunostaining in 2002, and we herein report 9 patients diagnosed with LCNEC(More)
The association between human T cell lymphotropic virus (HTLV) type I tax variation and disease outcome was studied. The tax gene was sequenced in 61 patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), 55 patients with adult T cell leukemia, and 62 healthy carriers (HCs). Phylogenetic analysis revealed 2 tax gene subgroups(More)
Translational activation of dormant cyclin B1 mRNA stored in oocytes is a prerequisite for the initiation or promotion of oocyte maturation in many vertebrates. Using a monoclonal antibody against the domain highly homologous to that of Drosophila Pumilio, we have shown for the first time in any vertebrate that a homolog of Pumilio is expressed in Xenopus(More)
p34cdc2 protein kinase is a universal regulator of M-phase in eukaryotic cell cycle. To investigate the regulation of meiotic and mitotic cell cycle in mammals, we examined the changes in phosphorylation states of p34cdc2 and its histone H1 kinase activity in mouse oocytes and embryos. We showed that p34cdc2 has three different migrating bands (referred to(More)
Extracellular recordings were obtained from 163 visual tracking neurons in area 7a or PG (24) of alert monkeys. The firing patterns were observed during movements of the chair in which the monkey was seated with its head fixed and of a visual target that the monkey was trained to fixate continuously. Horizontal visual tracking neurons were classified into(More)
Caspase-3 was cloned from zebrafish embryos and its properties were characterized to identify the biological implications of caspase in embryogenesis and apoptosis in zebrafish, which is a model organism in vertebrate developmental biology and genetics. The predicted amino acid sequence, totalling 282 amino acid residues, consisted of the prodomain and(More)
Deterioration in the quality of mammalian oocytes during the metaphase-II arrest period is well known as "oocyte aging." Oocytes in which aging has occurred are called aged oocytes, and these oocytes show enhanced activation and higher fragmentation rates after parthenogenetic activation. Previously we showed that porcine aged oocytes had low(More)
BACKGROUND No method for the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease (sCJD) has been established except for pathologic examination. OBJECTIVE To identify a reliable marker for the clinical diagnosis of MM2-type sCJD. METHODS CSF, EEG, and neuroimaging studies were performed in eight patients with MM2-type sCJD confirmed by(More)
BACKGROUND A complete set of nine ARSs was identified (the tenth ARS in this paper), mapped on chromosome VI of Saccharomyces cerevisiae, and characterized for functional elements. RESULTS The level of activity of all ARSs as chromosomal replication origins was determined by neutral/neutral 2D gel-electrophoresis. These origins were classified into three(More)