Publications by authors named "Kazuo Hamada"

Our aim in this study was to verify the usefulness of the standardized uptake value (SUV) normalized by individual CT-based lean body mass (LBMCT) in application of PET response criteria in solid tumors (PERCIST).We retrospectively investigated 14 patients (4 male and 10 female) with malignant lymphoma who were undergoing chemotherapy. (18)F-FDG PET/CT examinations were performed before and after chemotherapy.

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The peroxisome is an organelle found in most eukaryotes that is crucial for lipid metabolism. The ability of peroxisomes to divide themselves and transport post-translational proteins suggests that the peroxisome may have had an endosymbiotic origin. However, the localization of peroxisomal proteins to the endoplasmic reticulum (ER) and the similarity of some peroxisomal proteins to those localized in the ER suggest an alternative hypothesis: that the peroxisome was developed from the ER.

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Here, we constructed a phylogenetic tree of 17 bacterial phyla covering eubacteria and archaea by using a new method and 102 carefully selected orthologs from their genomes. One of the serious disturbing factors in phylogeny construction is the existence of out-paralogs that cannot easily be found out and discarded. In our method, out-paralogs are detected and removed by constructing a phylogenetic tree of the genes in question and examining the clustered genes in the tree.

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There is currently no consensus on the evolutionary origin of eukaryotes. In the search of the ancestors of eukaryotes, we analyzed the phylogeny of 46 genomes, including those of 2 eukaryotes, 8 archaea, and 36 eubacteria. To avoid the effects of gene duplications, we used inparalog pairs of genes with orthologous relationships.

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This paper reports the biochemical properties of two types of recombinant flap endonuclease-1 (FEN-1) proteins obtained from the thermophilic crenarchaeon, Sulfolobus tokodaii strain 7. One of the two FEN-1 proteins is a product of the gene with AUG as the translational start codon (StoS-FEN-1), which is originally assigned in the database. The other is a product of the gene with a new AUG start codon (StoL-FEN-1), which is inserted at 153 bases upstream of the original AUG codon.

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The construction of accurate prokaryotic phylogeny is important not only in the field of evolutionary biology, but also in microbiology and pathology. However, in constructing a phylogenetic tree to trace prokaryotic evolution, the phylogenetic relationship is often changed by the choice of species. For the estimation of the accurate lineage of prokaryotes, a new method, named the "random extraction method", was developed.

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Purpose: In this study, we created a whole body fusion image of PET and MRI using automated software for fusion imaging, and assessed the accuracy of the software.

Materials And Methods: Twenty patients with abnormal FDG-PET findings underwent whole body MRI. Images from both modalities were automatically fused in two ways using software (Fusion Viewer, Nihon Medi-Physics Co.

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Attempts were made to define the relationship among the three domains (eukaryotes, archaea, and eubacteria) using phylogenetic tree analyses of 16S rRNA sequences as well as of other protein sequences. Since the results are inconsistent, it is implied that the eukaryotic genome has a chimeric structure. In our previous studies, the origin of eukaryotes to be the symbiosis of archaea into eubacteria using the whole open reading frames (ORF) of many genomes was suggested.

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Vertebrate genomes are mosaics of isochores. On the assumption that marked differences exist in the isochore structure between warm-blooded and cold-blooded animals, variations among vertebrates were previously attributed to adaptation to homeothermy. However, based on the data of coding regions from representatives of extant vertebrates, including a turtle, a crocodile (Archosauromorpha) and a few kinds of snakes (Lepidosauromorpha), it was recently hypothesized that the common ancestors of mammals, birds and extant reptiles already had the "warm-blooded" isochore structure.

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In the previous report, we demonstrated the origin of eukaryotic cell nuclei as the symbiosis of Archaea in Bacteria by the newly developed "Homology-Hit Analysis". In that case, we counted yeast Open Reading Frames (ORFs) showing the highest similarity to a bacterial ORF as orthologous ORFs (Orthologous ORFs were produced by speciation from a common ancestor, and have the highest similarity to each other.) by comparing whole ORFs of yeast with those of individual bacteria.

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Codon usages are known to vary among vertebrates chiefly due to variations in isochore structure. Under the assumption that marked differences exist in isochore structure between warm-blooded and cold-blooded animals, the variations among vertebrates were previously attributed to an adaptation to homeothermy. However, based on data from a turtle species and a crocodile (Archosauromorpha), it was recently proposed that the common ancestors of mammals, birds and extent reptiles already had the "warm-blooded" isochore structure.

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