Search PubMed⌕ Search

Biomedical subjects

T Kaneko

Publications and source records attributed to T Kaneko.

At least 325 records · Page 18Linked to original sources
PubMed1998

Mechanistic study on the roles of a bifidogenetic growth stimulator based on physicochemical characterization.

2-Amino-3-carboxy-1,4-naphthoquinone, discovered as a novel bifidogenetic growth stimulator (BGS), has been characterized by determination of redox and acid-base equilibria, partition properties, and UV-vis and electron spin resonance spectral properties. BGS is proposed to function as an electron transfer mediator from NADH to O2. BGS is reduced by NADH-reduced diaphorase (or related enzymes) and the reduced BGS is reoxidized by autoxidation and a peroxidase-catalyzed reaction. The proposed reaction would spare pyruvate as an important metabolic intermediate, and minimize the cytotoxic effects of H2O2 generated by the autoxidation. Kinetic studies were performed in model enzymatic systems using 2-methyl-1,4-naphthoquinone (VK3) as a reference compound with a very weak growth-stimulating effect. The results support our proposal and reveal the superiority of BGS to VK3 as an electron transfer mediator in the proposed reactions.

Bifidobacterium↗
PubMed1998

Structural analysis of Arabidopsis thaliana chromosome 5. VII. Sequence features of the regions of 1,013,767 bp covered by sixteen physically assigned P1 and TAC clones.

Sixteen P1 and TAC clones assigned to Arabidopsis thaliana chromosome 5 were sequenced, and their sequence features were analyzed using various computer programs. The total length of the sequences determined was 1,013,767 bp. Together with the nucleotide sequences of 109 clones previously reported, the regions of chromosome 5 sequenced so far now total 9,072,622 bp, which presumably covers approximately one-third of the chromosome. A similarity search against the reported gene sequences predicted the presence of a total of 225 protein-coding genes and/or gene segments in the newly sequenced regions, indicating an average gene density of one gene per 4.5 kb. Introns were identified in 72.4% of the potential protein genes for which the entire gene structure was predicted, and the average number per gene and the average length of the introns were 3.3 and 163 bp, respectively. These sequence features are essentially identical to those in the previously reported sequences. The sequence data and gene information are available on the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.

Animals↗
PubMed1998

Projections from the caudal spinal trigeminal nucleus to commissural interneurons in the supratrigeminal region: an electron microscope study in the rat.

Electron microscopic double-labeling study in the rat indicated that projection fibers from the caudal spinal trigeminal nucleus (Vc) were distributed ipsilaterally within the supratrigeminal region (STR) capping the trigeminal motor nucleus (Tm) and made synaptic contact with neurons projecting to the contralateral Tm. Nociceptive inputs to the Vc may reflexly control, via interneurons in the STR, the activities of Tm neurons innervating the masticatory, tensor tympani, and/or tensor veli palatine muscles.

Animals↗
PubMed1998

A monoclonal antibody that recognizes a common carbohydrate epitope shared by various glycoproteins in human secretions.

A monoclonal antibody (mAb; a mouse IgM referred to as 1CF11) recognizing various human glycoproteins was obtained. While the immunoreaction of glycoproteins from human secretions including milk, saliva, and bronchus was demonstrated as a typical dose-responded S-shaped reaction curve on ELISA, no reaction was detected with milks and sera of animal origin as well as human serum. In the constituting polypeptides of the human milk secretory IgA molecule, only the secretory component was recognized by this mAb. Among various chemical treatments of the purified human milk lactoferrin (Lf), only either periodate or mild alkaline treatment abolished the immunoreactivity of the glycoprotein. A recombinant human Lf was not immunoreactive. Finally, the immunoreactive fragments were isolated from human milk Lf, which remained reactive with PAS reagent while lacking the previously reported N-glycans. These results strongly suggest that the mAb 1CF11 recognizes a new glycan O-glycosidically linked to glycoproteins in human secretions.

Animals↗
PubMed1998

Inhibition of linoleic acid hydroperoxide-induced toxicity in cultured human umbilical vein endothelial cells by catechins.

The protective effect of catechins, major components of green tea, was studied in cultured human umbilical vein endothelial cells exposed to toxicity induced by linoleic acid hydroperoxide (LOOH). In the case where cells were incubated in medium containing both LOOH and catechins, (+)-catechin (C) was effective in suppressing of LOOH-induced cytotoxicity, but (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) had no effect. EGCG monoglucoside (EGCG-G1) and EGCG diglucoside (EGCG-G2), apophilic derivatives of EGCG, show a protective effect on LOOH-induced cytotoxicity when present at the time of treatment with LOOH. On the other hand, when cells were incubated with catechins for 24 h before treatment with LOOH there was no protection against the oxidative damage by LOOH. Furthermore, the interaction between catechins and alpha-tocopherol was examined under these culture conditions. C showed a synergistic effect with alpha-tocopherol in protecting against LOOH-induced damage. These results suggest that catechins interact with LOOH present in the medium or near the surface of membranes, but not with LOOH incorporated into cellular membranes and that catechins are able to interact with alpha-tocopherol to provide synergistic protection against the cytotoxicity of LOOH.

Catechin↗
PubMed1998

Structural analysis of Arabidopsis thaliana chromosome 5. VI. Sequence features of the regions of 1,367,185 bp covered by 19 physically assigned P1 and TAC clones.

Nineteen P1 and TAC clones, which have been mapped on the fine physical map of the Arabidopsis thaliana chromosome 5, were sequenced according to the shotgun-based strategy, and their structural features were analysed. The total length of the regions sequenced in this study was 1,367,185 bp. Combining this with the regions covered by 90 P1 and TAC clones previously reported, the total length of chromosome 5 sequenced to date becomes 8,058,855 bp. On the basis of similarity search against protein and EST databases and gene modeling with computer programs, a total of 330 potential protein-coding regions were identified, bringing an average density of the genes to approximately one gene per 4.1 kb. Introns were identified in 81.0% of the potential protein genes for which the entire gene structure was predicted, with an average number per gene of 4.2 and an average length of the introns of 180 bp. The RNA-coding genes identified were 9 tRNA genes corresponding to 8 amino acid species and 2 genes for U2 nuclear RNA. These sequence features are essentially identical to those in the previously reported sequences. The sequence data and gene information are available on the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.

Arabidopsis↗
PubMed1998

Comparison of the structural characteristics of chromosome VI in Saccharomyces sensu stricto: the divergence, species-dependent features and uniqueness of saké yeasts.

Previous studies have revealed that chromosome VI of saké yeasts is much larger than that of the other strains of Saccharomyces cerevisiae. Southern analysis using segments of chromosome VI of a laboratory strain as probes suggested that the nucleotide sequence of a major portion of this chromosome is conserved, but considerable diversity was found in the distal parts in the other strains. Physical maps also indicated that differences in length of chromosome VI were mainly due to differences in its ends. NotI was found to generate 9 kb and/or 16 kb fragments from the left telomere of chromosome VI in most saké yeasts, but no fragment in the case of AB972. SfiI produced one or two 30-50 kb fragments from the right end of this chromosome in all saké yeasts tested, but produced a 20 kb fragment in the case of AB972. All S. cerevisiae strains not employed in saké brewing were the same as AB972 in these respects. S. paradoxus had one NotI site in chromosome VI, while S. bayanus had two, one of which is possibly common to both species. The SfiI site mentioned above was present in chromosome VI of all species, while that of S. bayanus and S. paradoxus each had a second site distinct from the other. Chromosome VI of S. pastorianus was not distinguishable from that of S. bayanus.

Blotting, Southern↗
PubMed1998

Immunocytochemical localization of mu-opioid receptor in primary afferent neurons containing substance P or calcitonin gene-related peptide. A light and electron microscope study in the rat.

Co-expression of mu-opioid receptor-like immunoreactivity (MOR-LI) with substance P (SP)- or calcitonin gene-related (CGRP)-LI was observed in rat trigeminal and dorsal root ganglion neurons. In particular, MOR-LI was found in axon terminals with SP- or CGRP-LI in laminae I and II of the medullary and spinal dorsal horns. MOR may be implicated in modulation of release of SP and CGRP from primary sensory afferents.

Animals↗
PubMed1998

Structural analysis of Arabidopsis thaliana chromosome 5. V. Sequence features of the regions of 1,381,565 bp covered by twenty one physically assigned P1 and TAC clones.

The nucleotide sequences of 21 P1 and TAC clones which have been precisely localized to the fine physical map of the Arabidopsis thaliana chromosome 5, were determined, and their sequence features were analyzed. The total length of the regions sequenced in this study were 1,381,565 bp, bringing the total length of the chromosome 5 sequences determined so far to 6,691,670 bp together with the regions of the 69 clones previously reported. By computer-aided analyses including similarity search against protein and EST databases and gene modeling with computer programs, a total of 337 potential protein-coding genes and/or gene segments were identified on the basis of similarity to the reported gene sequences. An average density of the genes and/or gene segments thus assigned was 1 gene/4,100 bp. Introns were identified in 76.7% of the potential protein genes for which the entire gene structure were predicted, and the average number per gene and the average length of the introns were 3.9 and 176 bp, respectively. These sequence features are essentially identical to those in the previously reported sequences. The numbers of the Arabidopsis ESTs matched to each of the predicted genes have been counted to monitor the transcription level. The sequence data and gene information are available on the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http:@www.kazusa.or.jp@arabi

Arabidopsis↗
PubMed1998

Phosphate group requirement for mitogenic activation of lymphocytes by an extracellular phosphopolysaccharide from Lactobacillus delbrueckii ssp. bulgaricus.

The mitogenic activity of extracellular polysaccharides produced by Lactobacillus delbrueckii ssp. bulgaricus OLL 1073R-1 and NCFB2483 was examined in murine lymphocytes. The extracellular polysaccharide from Lactobacillus delbrueckii ssp. bulgaricus OLL 1073R-1 was fractionated into neutral and acidic polysaccharides by anion-exchange chromatography, while that of Lactobacillus delbrueckii ssp. bulgaricus NCFB2483 were all fractionated into neutral polysaccharide(s). The acidic polysaccharide stimulated mitogenic responses of murine splenocytes and Peyer's patches but not of thymocytes. The optimal concentration of the acidic polysaccharide at the highest stimulation was 160 microg/ml. A significant increase of mitogenic activity was initiated at 24 h, and the highest response was obtained after stimulation for 48 h. The acidic polysaccharide purified by high performance liquid chromatography also had substantial mitogenic activity, and the molecular weight was estimated to be 1.2 x 10(6). The acidic polysaccharide was a phosphopolysaccharide consisting of glucose, galactose and phosphorus. Dephosphorylation by hydrofluoric acid degradation reduced the mitogenic activity in lymphocytes. The phosphopolysaccharide produced by Lactobacillus delbrueckii ssp. bulgaricus 1073R-1 is a potent B-cell-dependent mitogen in which the phosphate group acts as a trigger of the mitogenic induction.

Animals↗
PubMed1998

Redox properties of an H-subunit-depleted photosynthetic reaction center from Rhodopseudomonas viridis.

Recently, we reported that a H-subunit-depleted photosynthetic reaction center (RC-H) was purified from purple nonsulfer photosynthetic bacterium Rhodopseudomonas viridis (Rps. viridis) using a strong detergent sodium alkyl ether sulfate. We compared the redox properties of a native photosynthetic reaction center (RC) and RC-H of Rps. viridis. In RC-H prepared by our method, secondary quinone (QB) was removed while primary quinone (QA) was retained. Absorption spectrum of RC-H was similar to that of RC. After reconstitution of ubiquinone 10 into QB sites, RC-H showed electron transfer activity that was the same as that for native RC. This is the first report about the redox properties of RC-H of Rps. viridis.

Electron Transport↗
PubMed1998

Inhibition of inducible nitric oxide synthase prevents LPS-induced acute lung injury in dogs.

Nitric oxide (NO) is produced by inducible NO synthase (iNOS) after LPS stimulation, and reacts with superoxide to form peroxynitrite. We hypothesize that in LPS-induced lung injury, NO generated by iNOS plays a key role through the formation of peroxynitrite. We developed an acute lung injury dog model by injecting LPS, and examined the effects of selective iNOS inhibitors, aminoguanidine (AG) and S-methylisothiourea sulfate (SMT), on the LPS-induced lung injury. At 24 h after LPS injection, arterial oxygen tension and mean arterial pressure decreased, and shunt ratio and lung wet-to-dry weight ratio increased. On histology, the LPS group had marked neutrophil infiltration and widening of the alveolar septa. On immunohistochemistry, iNOS and nitrotyrosine, a major product of nitration of protein by peroxynitrite, were observed in the interstitium, capillary wall, and neutrophils in the airspaces of the LPS group. Treatments with AG and SMT prevented worsening of gas exchange, hemodynamics, and wet-to-dry weight ratio. On histology, AG and SMT treatments markedly suppressed lung injury, iNOS protein, and nitrotyrosine production. We conclude that NO released by iNOS may play a critical role in the pathogenesis of LPS-induced acute lung injury. This study suggests that iNOS inhibitors may have potential in the treatment of LPS-induced acute respiratory distress syndrome.

Animals↗
PubMed1998

Structural analysis of Arabidopsis thaliana chromosome 5. IV. Sequence features of the regions of 1,456,315 bp covered by nineteen physically assigned P1 and TAC clones.

Nineteen P1 and TAC clones, which have been precisely localized to the fine physical map of Arabidopsis thaliana chromosome 5, were newly sequenced, and their sequence features were analysed. The total length of the clones sequenced was 1,456,315 bp. Together with the previously reported sequences, the regions of chromosome 5 that have been sequenced to date is now 5,310,105 bp. When the sequences determined in this study were subjected to similarity search against protein and expressed sequence tag (EST) databases and analysis with computer programs for gene modeling, a total of 354 potential protein-coding genes and/or gene segments were identified. The average density of the assigned genes and/or gene segments was one gene per 4,114 bp. Introns were identified in 75% of the potential protein genes, and the average number per gene and the average length of the introns were 3.7 and 194 bp, respectively. These sequence features are essentially identical to those in the previously reported sequences. The numbers of the Arabidopsis ESTs matched to each of the predicted genes have been counted to monitor the transcription level. The sequence data and gene information are available on the World Wide Web database KAOS (the Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.

Arabidopsis↗
PubMed1998

CyanoBase, a www database containing the complete nucleotide sequence of the genome of Synechocystis sp. strain PCC6803.

CyanoBase (http://www.kazusa.or.jp/cyano/) is a database containing genomic information on the cyanobacterium Synechocystis sp. strain PCC6803. It furnishes an annotation to each of the 3168 protein genes deduced from the entire nucleotide sequence of this genome. Information on the genome can be directly accessed through three different menus: a clickable physical map of the genome, a gene classification list, and a keyword search menu, all of which are accessible from the main page of the database. The entry page for a gene annotation contains the following information: the location of the gene on the genome, the nucleotide and deduced amino acid sequence of the gene, the result of a similarity search, and the classification of the deduced gene product according to its function. This page has reverse-links to the local physical map and gene classification list so that relevant genes can be searched in terms of their location on the genome and their function. In addition, the main page of CyanoBase provides engines for similarity searches between a query sequence and the entire genome sequence and for keyword searches, in addition to numerous links to pages containing related information.

Bacterial Proteins↗
PubMed1998

Intraoperative pancreatoscopy with the ultrathin pancreatoscope for mucin-producing tumors of the pancreas.

OBJECTIVE: To evaluate the diagnostic accuracy of intraoperative pancreatoscopy with the ultrathin pancreatoscope for the main pancreatic lesions of mucin-producing tumors of the pancreas (MPT). DESIGN: Prospective diagnostic test study with a criterion standard of pathologic examination and masked comparison. SETTING: A university hospital. PATIENTS: Twenty-four consecutive patients with MPT referred for surgery in whom endoscopic retrograde pancreatography, endoscopic ultrasonography, and computed tomography had been performed as a diagnostic examination. All patients underwent surgery and the diagnosis was confirmed by pathologic examination. INTERVENTION: Intraoperative pancreatoscopy was performed with the ultrathin pancreatoscope. MAIN OUTCOME MEASURES: Findings of intraoperative pancreatoscopy, endoscopic retrograde pancreatography, and endoscopic ultrasonography were confirmed by pathologic examination of resected specimens. The diagnostic accuracy of these 3 modalities in detection of MPT lesions in the main pancreatic duct was compared. RESULTS: The diagnostic criterion of MPT lesions in the main pancreatic duct by intraoperative pancreatoscopy was a granular and papillary mural nodule. An MPT lesion in the main pancreatic duct was found in 17 of 24 cases. Intraoperative pancreatoscopy detected 10 cases of intraductal MPT lesions that could not be detected by endoscopic ultrasonography or endoscopic retrograde pancreatography. Five of 10 cases were intraductal multicentric lesions. In 3 of these 5, additional pancreatic resection was performed. For diagnosis of MPT lesions, the sensitivity, specificity, and overall accuracy of intraoperative pancreatoscopy were all 100%; respective values were 43.8%, 100%, and 60.9% for endoscopic retrograde pancreatography and 47%, 100%, and 62.5% for endoscopic ultrasonography. CONCLUSIONS: Intraoperative pancreatoscopy is safe and effective in diagnosing the intrapancreatic duct extension and multicentric lesions of MPT. It provides important information for operative strategy and contributes to successful pancreatic surgery.

Adult↗