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Hiroshi Hayashi

Publications and source records attributed to Hiroshi Hayashi.

At least 19 recordsLinked to original sources
PubMed2006

High-resolution mapping of DNA methylation in human genome using oligonucleotide tiling array.

DNA methylation is an epigenetic mark crucial in regulation of gene expression. Aberrant DNA methylation causes silencing of tumor suppressor genes and promotes chromosomal instability in human cancers. Most of previous studies for DNA methylation have focused on limited genomic regions, such as selected genes or promoter CpG islands (CGIs) containing recognition sites of methylation-sensitive restriction enzymes. Here, we describe a method for high-resolution analysis of DNA methylation using oligonucleotide tiling arrays. The input material is methylated DNA immunoprecipitated with anti-methylcytosine antibodies. We examined the ENCODE region ( approximately 1% of human genome) in three human colorectal cancer cell lines and identified over 700 candidate methylated sites (CMS), where 24 of 25 CMS selected randomly were subsequently verified by bisulfite sequencing. CMS were enriched in the 5' regulatory regions and the 3' regions of genes. We also compared DNA methylation patterns with histone H3 and H4 acetylation patterns in the HOXA cluster region. Our analysis revealed no acetylated histones in the hypermethylated region, demonstrating reciprocal relationship between DNA methylation and histone H3 and H4 acetylation. Our method recognizes DNA methylation with little bias by genomic location and, therefore, is useful for comprehensive high-resolution analysis of DNA methylation providing new findings in the epigenomics.

Acetylation↗
PubMed2006

Nepalensinols D-G, new resveratrol oligomers from Kobresia nepalensis (Cyperaceae) as potent inhibitors of DNA topoisomerase II.

Four new resveratrol oligomers, nepalensinols D-G, were isolated from the stem of Kobresia nepalensis (Cyperaceae). The structures were determined by detailed NMR spectral analysis. The compounds were assessed for their inhibitory activity against human topoisomerase II, a potential target of anti-tumor agents. These stilbenoids showed potent inhibitory activity against human topoisomerase II with IC50 values of 5-15 microM.

Cyperaceae↗
PubMed2006

Acute inhibition of lymphatic cholesterol transport in rat intestine by SCH 58053.

To clarify the pharmacological mechanism of ezetimibe, SCH 58053, an analog of ezetimibe, was intraduodenally administered to lymph-fistula rats, and its effect on lymphatic lipid transport in the intestine was monitored. SCH 58053, 5.0 mg/kg body weight, was administered one hour before a 5-hour infusion of a lipid emulsion containing 40 micromol/h of triolein and 2.74 micromol/h of cholesterol (Experiment 1) or co-administered at 5.0 mg/kg body weight/h with the lipid emulsion for 4 hours to rats that had been infused with the lipid emulsion alone for 3 hours (Experiment 2). SCH 58053 administration significantly inhibited lymphatic cholesterol transport, but not triglyceride transport, in both groups compared to control rats that did not receive SCH 58053. The ratio of free cholesterol to total cholesterol in the lymph of the treated rats was unchanged compared to the control rats. Thus, the results showed that SCH 58053 is a potent, rapid, and selective inhibitor of lymphatic cholesterol transport in the intestine.

Animals↗
PubMed2005

Malignant catatonia with severe bronchorrhea and its response to electroconvulsive therapy.

A 21-year-old female presented excitement, auditory hallucination, monologue, and insomnia. After 1 week of risperidone administration, she showed hyperthermia, salivation, and muscle rigidity. Risperidone was discontinued, but stupor, convulsions, and respiratory distress developed. In the intensive care unit where she was transferred, catatonic symptoms such as stupor or excitement, catalepsy, and negativism were prominent. In addition, severe bronchorrhea causing respiratory failure was observed. Her catatonic symptoms, hyperthermia, and bronchorrhea resolved by ECT. After recovery, affective flattening, alogia, and avolition remained. The final diagnosis was MC associated with schizophrenia. This report suggests that MC may be complicated by severe bronchorrhea, but this condition responds to ECT.

Adult↗
PubMed2005

Stilbenoids of Kobresia nepalensis (Cyperaceae) exhibiting DNA topoisomerase II inhibition.

Resveratrol oligomers, nepalensinol A, B and C, were isolated from the stem of Kobresia nepalensis (Cyperaceae). The structures were established on the basis of chemical properties and spectroscopic evidence including 2D NMR spectroscopic analysis. Nepalensinol A, B and C showed a potent inhibitory effect on topoisomerase II -- stronger than etoposide (VP-16), a topoisomerase II inhibitor used as an anti-cancer drug. Nepalensinol B, in particular, exhibited the most potent activity with an IC(50) of 0.02 microg/ml.

Animals↗
PubMed2005

Severe cell fragmentation in the endothelial cell apoptosis induced by snake apoptosis toxin VAP1 is an apoptotic characteristic controlled by caspases.

Hemorrhagic snake venom induces apoptosis in vascular endothelial cells (VEC). Vascular apoptosis-inducing protein 1 (VAP1), which is identified as an apoptosis toxin against vascular endothelial cells, induces apoptosis accompanied by severe cell fragmentation compared with that of apoptosis due to other inducers. The mechanism of this morphologic feature is not known. In this report, we examine the roles of the caspases in the apoptosis induced by VAP1. Measurement of the caspase activities shows that activation of caspases occurred in this type of cell death. In the presence of certain caspase inhibitors, the severe cell fragmentation was strongly inhibited. The other hand, cell death induced by VAP1 was not affected by caspase inhibitors. These data suggest that the severe cell fragmentation induced by the snake toxin is a special characteristic of this apoptosis. Apoptosis with severe cell fragmentation may be regarded as a new category of endothelial cell apoptosis.

Animals↗
PubMed2005

Preoperative luteinizing hormone levels predict the ovulatory response to laparoscopic ovarian drilling in patients with clomiphene citrate-resistant polycystic ovary syndrome.

OBJECTIVE: Laparoscopic ovarian drilling (LOD) is a treatment option for women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS), but appropriate indications for this procedure are lacking. The aim of this study was to analyze preoperative factors affecting the efficacy of LOD in producing ovulation in CC-resistant PCOS patients. DESIGN: Retrospective cohort study. PATIENTS AND METHODS: We studied 40 infertile Japanese women with CC-resistant PCOS who received LOD using argon-beam electrocoagulation. These patients satisfied the diagnostic criteria of the revised European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine PCOS consensus. RESULTS: After LOD, ovulation occurred in 33 (83%) patients; pregnancy occurred in 22 patients (55%). Preoperative serum luteinizing hormone (LH) levels were significantly higher in women who ovulated after LOD than in those who did not ovulate. The area under the receiver operator characteristic curve for ovulation using preoperative LH levels was 0.81 (95% confidence interval: 0.67-0.96). After LOD, follicle-stimulating hormone levels increased significantly in the non-ovulating group but were unchanged in the ovulating group. CONCLUSIONS: Preoperative serum LH levels may be a good predictor of LOD efficacy in patients with PCOS. Therefore, eligibility criteria for LOD should be strictly applied, since LOD for patients with inadequate LH levels is not only ineffective, but also may impair ovarian reserve.

Adult↗
PubMed2005

Carboxylester lipase gene polymorphism as a risk of alcohol-induced pancreatitis.

OBJECTIVES: Alcohol abuse causes pancreatic damage in humans. However, only 5% of alcoholic patients have a clinical manifestation of pancreatitis, and the genetic predisposition of alcohol-associated pancreatitis remains elusive. Nonoxidative metabolites of ethanol, fatty acid ethyl esters (FAEEs), might play an important role in pancreatic damage. Carboxylester lipase (CEL) has been known to catalyze FAEE synthesis from fatty acids and ethanol. METHODS: The variable number of tandem repeat (VNTR) polymorphism in the coding region of the CEL gene was studied in patients with alcoholic pancreatitis (n = 100), in alcoholics without pancreatitis (n = 52), in patients with nonalcoholic pancreatitis (n = 50), in hyperlipidemia patients (n = 96), and control subjects (n = 435). RESULTS: The frequency of the NN-type (wild-type) gene was significantly decreased in patients with alcoholic pancreatitis than in other groups. The frequency of subjects who had the L allele in patients with alcoholic pancreatitis was significantly higher than in other groups. The distribution of the CEL gene polymorphism was not different among the control subjects, alcoholics without pancreatitis, patients with nonalcoholic pancreatitis, and patients with hyperlipidemia. CONCLUSIONS: The CEL gene polymorphism, especially an increase in the frequency of the L allele, was found to be associated with alcohol-induced pancreatitis.

Aged↗
PubMed2005

The GTP binding protein Obg homolog ObgE is involved in ribosome maturation.

Obg proteins belong to a subfamily of GTP binding proteins, which are highly conserved from bacteria to human. Mutations of obgE genes cause pleiotropic defects in various species but the function remained unclear. Here we examine the function of ObgE, the Obg homolog in Escherichia coli. The growth rate correlates with the amount of ObgE in cells. Co-fractionation experiments further suggest that ObgE binds to 30S and 50S ribosomal subunits, but not to 70S ribosome. Pull-down assays suggest that ObgE associates with several specific ribosomal proteins of 30S and 50S subunits, as well as RNA helicase CsdA. Purified ObgE cosediments with 16S and 23S ribosomal RNAs in vitro in the presence of GTP. Finally, mutation of ObgE affects pre-16Sr-RNA processing, ribosomal protein levels, and ribosomal protein modification, thereby significantly reducing 70S ribosome levels. This evidence implicates that ObgE functions in ribosomal biogenesis, presumably through the binding to rRNAs and/or rRNA-ribosomal protein complexes, perhaps as an rRNA/ribosomal protein folding chaperone or scaffold protein.

Cytosol↗
PubMed2004

Significance of cell electrokinetic properties determined by soft-particle analysis in bacterial adhesion onto a solid surface.

The influence of extracellular polymeric substances (EPSs) on bacterial cell electrokinetic properties and on cell adhesion onto glass beads in connection with bacterial cell electrokinetic properties was investigated using 12 heterotrophic bacterial strains. Bacterial cell surface properties such as the softness 1/lambda and charge density ZN were determined by Ohshima's soft-particle analysis using the measured electrophoretic mobility as a function of ionic strength. In 10 of 12 strains, when EPSs covering the cell surface were removed, the softness of the cell decreased, indicating that EPS adsorption enhanced the ease of liquid fluid in the ion-penetrable layer on the cell surface. On the other hand, the negative charge density of the cell surface increased for 9 of 12 strains, suggesting that EPSs covering the cell surface decreased the negative charge density of the cell surface layer. In addition, the characteristics of bacterial cell adhesion onto glass beads were evaluated by the packed-bed method and the data were interpreted to indicate cell adhesiveness. As a result, the efficiency of cell adhesion onto glass beads increased as negative cell surface potential psi0 decreased, whereas there seemed to be no correlation between zeta potential and cell adhesiveness. Cell surface potential psi0, which was derived by taking the bacterial polymer layer with EPSs into consideration, provided a more detailed understanding of the electrokinetic properties of bacterial cells.

Bacteria↗
PubMed2004

Regulation of cytokine production in carcinoembryonic antigen stimulated Kupffer cells by beta-2 adrenergic receptors: implications for hepatic metastasis.

Elevated Carcinoembryonic antigen (CEA) levels in the serum indicate a poor prognosis for colorectal cancer patients. Induction of proinflammatory cytokines by CEA interaction with Kupffer cells has been proposed as a mechanism for hepatic metastasis formation. Studies show that the cytokine response in circulating and peritoneal macrophages is regulated by beta-adrenergic receptor signals, though little information is available regarding Kupffer cells. We investigated the relationship between beta-adrenergic receptor stimulation and the response of Kupffer cells to CEA. Comparisons between unstimulated and CEA stimulated rat Kupffer cells, using cDNA arrays, showed up-regulation (>4 fold) of the beta2-adrenergic receptor mRNA. Peak up-regulation occurred after 30 min with a decline at 1 h. We examined the effects of the specific beta2-adrenergic receptor agonist terbutaline on cytokine production by CEA stimulated rat Kupffer cells. Pre-treatment of Kupffer cells with terbutaline followed by CEA caused a significant increase in IL-6 and IL-10 production, but a significant reduction in TNF-alpha production (>3 fold). mRNA levels reflected those of the ELISA assays for IL-6 and IL-10 but not for TNF-alpha. For IL-6 and TNF-alpha, these changes were serum independent, while IL-10 was serum dependent. This response is different from LPS treated Kupffer cells where all three cytokines showed serum dependency. Overall, these data suggest that Kupffer cell stimulation by CEA is under beta-adrenergic receptor control and induction of the beta-receptor is an early event following CEA binding to its receptor. Control of TNF-alpha production is negatively affected by terbutaline, while that of IL-6 and IL-10 is positively controlled suggesting that very different beta-adrenergic receptor signaling pathways are involved.

Adrenergic beta-Agonists↗
PubMed2004

Long-term exposure to low levels of formaldehyde increases the number of tyrosine hydroxylase-immunopositive periglomerular cells in mouse main olfactory bulb.

Multiple chemical sensitivity (MCS) in response to a long-term low-level chemical exposure is as yet an unclarified disorder. To determine the role of olfactory function in the induction of MCS, immunocytochemical analysis of the main olfactory bulb (MOB) was performed after exposure of mice to low levels of formaldehyde. A long-term exposure resulted in an increase in the number of tyrosine hydroxylase-immunopositive periglomerular cells and may affect the neuronal function of the MOB.

Animals↗
PubMed2004

Inhibitory role of endophilin 3 in receptor-mediated endocytosis.

Endophilin 1 (Endo1) participates in synaptic vesicle biogenesis through interactions of its Src homology 3 domain with the polyphosphoinositide phosphatase Synaptojanin and the GTPase Dynamin. Endo1 has also been reported to affect endocytosis by converting membrane curvature via its lysophosphatidic acid acyltransferase activity. Here we report that a closely related isoform of Endo1, Endo3, inhibits clathrin-mediated endocytosis. Mutational analyses showed that the variable region of Endo3 is important in regulating transferrin endocytosis. In the brain, Endo3 is co-localized with dopamine D2 receptor in olfactory nerve terminals and inhibits its clathrin-mediated endocytosis in COS-7 cells. Furthermore, overexpression of Endo3 in an olfactory epithelium-derived cell line suppressed dopamine D2 receptor-mediated endocytosis and therefore accelerated its dopamine-induced differentiation. These results indicate that Endo3 may act as a negative regulator of clathrin-mediated endocytosis in brain neurons.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Paroxetine treatment of delusional disorder, somatic type.

A 77-year-old female showed delusion of infestation in the oral cavity. She was treated by paroxetine 20 mg/day, and the hypochondriacal delusion disappeared after 8 weeks. Hypoperfusion in the left temporal and parietal lobes which was observed when she had the delusion was normalized after resolution of the delusion. This report suggests that paroxetine may be effective for delusional disorder, somatic type. It also supports the previous views that this disorder is associated with serotonergic dysfunction and hypoperfusion in the temporal and parietal lobes.

Aged↗
PubMed2004

Sulpiride treatment of Cotard's syndrome in schizophrenia.

A 33-year-old male suffering from schizophrenia developed the typical symptoms of Cotard's syndrome, i.e., various delusions of negation and severe depressive symptoms. Atypical symptoms such as delusions of persecution and control related to body parts were also observed. These symptoms gradually improved by the treatment with sulpiride 300 mg/day. In the course of improvement of Cotard's syndrome, the patient developed Capgras syndrome. This report suggests that sulpiride is effective for Cotard's syndrome in schizophrenia. It also suggests that the symptoms of Cotard's syndrome are modified according to basic disorders, and this syndrome has a close connection with Capgras syndrome.

Adult↗
PubMed2004

Distinct aggregation and cell death patterns among different types of primary neurons induced by mutant huntingtin protein.

Aggregation of disease proteins is believed to be a central event in the pathology of polyglutamine diseases, whereas the relationship between aggregation and neuronal death remains controversial. We investigated this question by expressing mutant huntingtin (htt) with a defective adenovirus in different types of neurons prepared from rat cerebral cortex, striatum or cerebellum. The distribution pattern of inclusions is not identical among different types of primary neurons. On day 2 after infection, cytoplasmic inclusions are dominant in cortical and striatal neurons, whereas at day 4 the ratio of nuclear inclusions overtakes that of cytoplasmic inclusions. Meanwhile, nuclear inclusions are always predominantly present in cerebellar neurons. The percentage of inclusion-positive cells is highest in cerebellar neurons, whereas mutant htt induces cell death most remarkably in cortical neurons. As our system uses htt exon 1 protein and thus aggregation occurs independently from cleavage of the full-length htt, our observations indicate that the aggregation process is distinct among different neurons. Most of the neurons containing intracellular (either nuclear or cytoplasmic) aggregates are viable. Our findings suggest that the process of mutant htt aggregation rather than the resulting inclusion body is critical for neuronal cell death.

Adenoviridae↗
PubMed2004

Composite metastatic carcinoma in lymph nodes of patients with concurrent medullary and papillary thyroid carcinoma: a report of two cases.

Synchronous occurrence of medullary and papillary carcinoma of the thyroid gland is very rare. We describe two cases of synchronous medullary and papillary carcinoma of the thyroid. In both cases, medullary carcinoma and papillary carcinoma were separate in the thyroid but mixed in some of the lymph node metastases. A review of the literature and our own cases revealed that composite medullary and papillary carcinoma metastases in the lymph nodes is a common feature of patients with synchronous medullary and papillary carcinoma of the thyroid gland.

Adult↗