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Y Goto

Publications and source records attributed to Y Goto.

At least 73 records · Page 4Linked to original sources
PubMed2002

Transverse-mass dependence of two-pion correlations in Au+Au collisions at square root[s(NN)] = 130 GeV.

Two-pion correlations in square root[s(NN)] = 130 GeV Au+Au collisions at RHIC have been measured over a broad range of pair transverse momentum k(T) by the PHENIX experiment at RHIC. The k(T) dependent transverse radii are similar to results from heavy-ion collisions at square root[s(NN)] = 4.1, 4.9, and 17.3 GeV, whereas the longitudinal radius increases monotonically with beam energy. The ratio of the outwards to sidewards transverse radii (R(out)/R(side)) is consistent with unity and independent of k(T).

Journal Article↗
PubMed2002

Measurement of single electrons and implications for charm production in Au+Au collisions at square root[s(NN)] = 130 GeV.

Transverse momentum spectra of electrons from Au+Au collisions at square root[s(NN)] = 130 GeV have been measured at midrapidity by the PHENIX experiment at the Relativistic Heavy Ion Collider. The spectra show an excess above the background from photon conversions and light hadron decays. The electron signal is consistent with that expected from semileptonic decays of charm. The yield of the electron signal dN(e)/dy for p(T) > 0.8 GeV/c is 0.025+/-0.004(stat)+/-0.010(syst) in central collisions, and the corresponding charm cross section is 380+/-60(stat)+/-200(syst) microb per binary nucleon-nucleon collision.

Journal Article↗
PubMed2002

Retarded gastric acid secretion in rats infected with larval Taenia taeniaeformis.

The influence of hepatic larval Taenia taeniaeformis infection on gastric acid secretory activity and gastric mucosal integrity was investigated. After 12 weeks of infection with 2,000 T. taeniaeformis eggs, the gastric pH values of control and infected rats were 4.1+/-0.6 (mean +/- SD) and 8.4+/-0.2, respectively. There was no difference in the basal acid secretion between control (1.7+/-0.7 micro Eq.H(+)/15 min) and infected (1.9+/-0.3) rats. However, infected rats failed to respond to histamine stimulation, the maximum acid output level being 2.8+/-0.4 in the infected rats, compared to 12.9+/-3.3 in control rats. Larval T. taeniaeformis infection resulted in the suppression of gastric acid secretion leading to hypergastrinemia.

Animals↗
PubMed2002

Protective and curative effects of topically applied CX-659S, a novel diaminouracil derivative, on chronic picryl chloride-induced contact hypersensitivity responses.

BACKGROUND: CX-659S, a newly discovered anti-inflammatory compound, exerts inhibitory effects against acute contact hypersensitivity responses (CHRs) induced by picryl chloride (PC), oxazolone and dinitrochlorobenzene. The murine model of chronic CHR induced by repeated application of PC is known to mimic many, if not all, events occurring within the lesional skin of patients with atopic dermatitis (AD). OBJECTIVES: To investigate the ability of CX-659S to inhibit PC-induced chronic CHR in mice. METHODS: The protective and curative effects of CX-659S were tested on PC-treated ears of BALB/c mice, and were compared with those of prednisolone. Effects were quantified by measurements of ear thickness, serum IgE and cytokine mRNA expression. RESULTS: Both protectively applied and curatively applied CX-659S significantly inhibited increases in ear thickness and total serum IgE. Inhibition was dose-dependent. Although protectively applied prednisolone showed similar activities to CX-659S against chronic CHR, curatively applied prednisolone did not affect the serum IgE level despite inhibiting increases in ear thickness and inflammatory cell infiltration. Consistent with these results, CX-659S reduced mRNA expression of interleukin (IL)-4 and IL-10 but not of interferon (IFN)-gamma, whereas prednisolone inhibited not only mRNA expression of IL-4 and IL-10 but also that of IFN-gamma in the ear lesion. In contrast to prednisolone, CX-659S did not show any side-effect such as atrophy, alopecia or telangiectasia. CONCLUSIONS: CX-659S is the first promising compound having inhibitory activities against chronic CHR accompanied by a diminishing effect on elevated serum IgE, without any other side-effect. Therefore, CX-659S may be a promising candidate for management of patients with recurring AD who require long-term therapy.

Administration, Topical↗
PubMed2002

Substitution of Dmo1 with normal alleles results in decreased manifestation of diabetes in OLETF rats.

AIM: Dmo1 (Diabetes Mellitus OLETF type I) is a major quantitative trait locus for dyslipidaemia, obesity and diabetes phenotypes in the Otsuka Long Evans Tokushima Fatty (OLETF) rat strain. To evaluate possible metabolic and pathological improvements generated by correction of the Dmo1 genetic pathway, we produced congenic lines, in which both OLETF Dmo1 alleles are replaced by the F344-derived genome. METHODS: Congenic animals were produced by introgressing F344-derived Dmo1 alleles into the OLETF rat. Congenic animals of the fourth generation (BC4) were intercrossed to obtain F1 animals (BC4:F1). Animals of the next generation, BC4:F2, were used for this study. We used 23 BC4:F2 males harbouring homozygous replacement of the OLETF Dmo1 region with the F344-derived genome. Seven animals with OLETF-derived Dmo1 alleles were used as controls. RESULTS: Dmo1-F344/F344 congenic rats showed significant decreases in body weight, abdominal fat weight, serum triacylglycerols, total cholesterol, food consumption and blood glucose after glucose loading (13%, 39%, 45%, 27%, 18% and 27% respectively; p < 0.05) compared with Dmo1-OLETF/OLETF animals. Furthermore, histopathological analysis of the kidney showed that mesangial sclerosis, hyalin deposits and deposition of PAS-positive substance were significantly lower in Dmo1-F344/F344 animals (p < 0.05). CONCLUSION: Improvements in metabolic parameters and histopathological scores show that correction of the Dmo1 genetic pathway in the diabetic and mildly obese OLETF rat strain produces wide-ranging therapeutic effects. Thus, this pathway might represent a new drug target also applicable to humans.

Animals↗
PubMed2002

Age related expression of Werner's syndrome protein in selected tissues and coexpression of transcription factors.

AIMS: Werner's syndrome (WS) is an uncommon autosomal recessive disease resulting from mutational inactivation of human WRN helicase, Werner's syndrome protein (WRNp). Patients with WS progressively develop a variety of aging characteristics after puberty. The aim of this study was to determine the distribution of WRNp and the expression of the transcription factors regulating WRN gene expression in a variety of human organs in an attempt to understand the WS phenotype. METHODS: Tissue specimens were obtained from 16 controls aged from 27 gestational weeks to 70 years of age and a 56 year old female patient with WS. The distribution of WRNp and the expression of the transcription factors regulating WRN gene expression-SP1, AP2, and retinoblastoma protein (Rb)- were studied in the various human organs by immunohistochemical and immunoblot analyses. RESULTS: In the healthy controls after puberty, high expression of WRNp was detected in seminiferous epithelial cells and Leydig cells in the testis, glandular acini in the pancreas, and the zona fasciculata and zona reticularis in the adrenal cortex. In addition, the SP1 and AP2 transcription factors, which regulate WRNp gene expression, appeared in an age dependent manner in those regions where WRNp was expressed. In controls after puberty, SP1 was expressed in the testis and adrenal gland, whereas AP2 was expressed in the pancreas. CONCLUSIONS: These findings suggest that the age specific onset of WS may be related to age dependent expression of WRNp in specific organs.

Adolescent↗
PubMed2002

Differential patterns of histone methylation and acetylation distinguish active and repressed alleles at X-linked genes.

In female mammals, one of the two X chromosomes is inactivated to compensate for the difference in dosage of X-linked genes between males and females. X inactivation involves sequential alterations to the chromatin that ultimately lead to the transcriptional repression of genes on the X chromosome. Here, histone methylation and acetylation along X-linked genes are investigated by chromatin immunoprecipitation (ChIP) of adult fibroblast cell lines. At PGK1 and HPRT, chromatin on the active X chromosome reveals H3 lysine 4 methylation and acetylation of histones H3 and H4. These modifications are absent on the repressed allele, which is marked by H3 lysine 9 methylation. On the expressed allele of XIST (on the inactive X chromosome), we found that H3 acetylation is confined to the promoter, whereas H3 lysine 4 methylation and H4 acetylation are present along the entire gene. On the repressed XIST allele, in contrast, the promoter and gene exhibit H3 lysine 9 methylation. At only 1.5 kb upstream of the XIST gene, chromatin on the inactive X chromosome has strongly reduced levels of H4 acetylation and is marked by both H3 lysine 9 and H3 lysine 4 methylation. These data demonstrate that patterns of histone methylation and acetylation are distinct along and upstream of XIST and suggest that the inactive X chromatin configuration occurs at a region close to the 5' end of the gene.

Acetylation↗
PubMed2002

The proportion of cells with functional X disomy is associated with the severity of mental retardation in mosaic ring X Turner syndrome females.

Turner syndrome females (45,X) do not have mental retardation (MR), whereas some mosaic ring X Turner syndrome females, with 45,X/46,X,r(X), have severe MR. The MR is believed to be caused by a failure of X chromosome inactivation (XCI) of the small ring X chromosome, which leads to functional X disomy (FXD), To explore this hypothesis, we examined the proportion of FXD cells in the peripheral blood of four ring X Turner syndrome females with various levels of MR, using two newly developed XCI assays based on DNA methylation of X-linked genes. As a result, the two patients with extremely severe MR showed complete FXD patterns, whereas the remaining two patients with relatively milder MR showed partial FXD patterns. These results indicate that the proportion of FXD cells may be associated with the severity of MR in mosaic ring X Turner syndrome females, although this association should be confirmed by examining brain cells during development. One of the cases with severe MR and a complete FXD pattern neither lacked the XIST gene nor had uniparental X isodisomy, and we discuss the mechanism of the failure of XCI in this case.

Child↗
PubMed2002

Change in cytoskeletal phenotype and extracellular matrix production of muscularis mucosae during early invasive colorectal adenocarcinoma.

Bundles of eosinophilic spindle cells are often found in histological preparations of the stroma of invasive colorectal adenocarcinomas. To clarify their significance, especially during the early invasive phase, we histologically and immunohistochemically studied 33 submucosally invasive colorectal adenocarcinomas in terms of their relationship with the muscularis mucosa, their cytoskeletal phenotype, and their production of extracellular matrix (ECM). Histological continuity between bundles of eosinophilic spindle cells and the muscularis mucosa was identified in 19 out of 33 adenocarcinomas (57.6%). With respect to their cytoskeletal phenotypes, the expression of alpha-smooth muscle actin (alpha-SMA) did not differ between the muscularis mucosa and the eosinophilic spindle cells, whereas the expression of desmin and high molecular weight caldesmon (h-CD) of the eosinophilic spindle cells was decreased compared with that of the muscularis mucosa (p<0.05). Definitive type I procollagen (procollagen I) expression was identified, at least in part, in 16 out of 20 (80%) areas of the eosinophilic spindle cells that were continuous with the muscularis mucosa, and in 26 out of 29 (89.7%) areas of the eosinophilic spindle cells that were not. These findings suggest that the muscularis mucosa is the origin of the eosinophilic spindle cells, that they undergo phenotypic changes separately from the smooth muscle, that is, myofibroblastic changes, and that they contribute to carcinomatous stroma formation through production of an ECM component. These findings should be taken into consideration when determining the level of submucosal invasion by colorectal adenocarcinomas.

Actins↗
PubMed2002

Behavior of nuisance mussel, Limnoperna fortunei, in water supply facilities.

Limnoperna fortunei, a species of bivalve of foreign origin, was confirmed to exist in Japan for the first time in 1992. It was found in some facilities of Hanshin Water Supply Authority in 1994. Later, it was found to cause various problems such as clogging of sampling pipes. Following this finding, research was initiated to investigate the possibility of its causing major incidents of bio-fouling such as total blockage of water passage by adhering to the raw water transmission pipe wall in massive numbers. As a result, it was found that Limnoperna fortunei was spawned in summer and grew up to 20 mm in size by the end of a one-year period when it began to die out and became detached immediately. Therefore, it was concluded that no deliberate efforts to remove them are required to avoid major problems.

Animals↗
PubMed2001

Suppression of hadrons with large transverse momentum in central Au+Au collisions at root square[s(NN)] = 130 GeV.

Transverse momentum spectra for charged hadrons and for neutral pions in the range 1 GeV/c<p(T)<5 GeV/c have been measured by the PHENIX experiment at RHIC in Au+Au collisions at root square[s(NN)] = 130 GeV. At high p(T) the spectra from peripheral nuclear collisions are consistent with scaling the spectra from p+p collisions by the average number of binary nucleon-nucleon collisions. The spectra from central collisions are significantly suppressed when compared to the binary-scaled p+p expectation, and also when compared to similarly binary-scaled peripheral collisions, indicating a novel nuclear-medium effect in central nuclear collisions at RHIC energies.

Journal Article↗
PubMed2001

Correlation of functional and ultrastructural abnormalities of mitochondria in mouse heart carrying a pathogenic mutant mtDNA with a 4696-bp deletion.

We examined the correlation of functional and structural abnormalities of cardiac mitochondria created by pathogenic mutant mtDNAs using mito-mice with hearts carrying 88% mutant DeltamtDNA4696 with a 4696 deletion. COX histochemistry, quantitative PCR analysis, and electronmicrographs showed that accumulation of 91.6% DeltamtDNA4696 in single cardiac muscle fibers induced progressive reduction of COX activity to form COX-negative fibers. Moreover, hearts carrying 88% DeltamtDNA4696 consisted of three types of cardiac muscle fibers with different functional properties, COX-positive, -negative, and -intermediate fibers, which corresponded respectively to three types of fibers with different structural properties; type A fibers containing mitochondria with only lamellar cristae, type B containing mitochondria with only tubular cristae, and type C possessing mitochondria with both lamellar and tubular cristae. These observations suggest that lamellar cristae with COX activity transform into tubular cristae without COX activity along with the accumulation of DeltamtDNA4696, which would be responsible for insufficient supply of mtDNA products required to keep the normal structure and function of mitochondrial cristae. The correlation of these structural and functional abnormalities of cristae should provide important insight into diagnosis of cardiomyopathies caused by accumulation of pathogenic mutant mtDNAs.

Animals↗
PubMed2001

Differentiation of Fusobacterium necrophorum subspecies from bovine pathological lesions by RAPD-PCR.

Nineteen strains from bovine abscesses identified as Fusobacterium necrophorum by the VPI method were examined by other methods. The API 20A test kit characterized all 19 strains as F. necrophorum. Seven of the strains had haemagglutinating activity and were classified as F. necrophorum subspecies necrophorum, and the remaining, 12 nonhaemagglutinating strains, were classified as F. necrophorum subspecies funduliforme. We used RAPD-PCR with a 10-mer oligonucleotide primer, W1L-2, to confirm this differentiation of the two subspecies. These results suggest that random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) with a suitable primer can be used as a new tool for the differentiation of F. necrophorum subspecies isolated from bovine pathological lesions.

Animals↗
PubMed2001

TNF-alpha-induced cell death in feline immunodeficiency virus-infected cells is mediated by the caspase cascade.

TNF-alpha induced apoptosis in a feline fibroblastic cell line (CRFK) infected with FIV but not in its uninfected control. In this study, to understand the molecular basis of the different susceptibilities to TNF-alpha between FIV-infected and uninfected cells, we examined the expression of TNF receptors and the activation of the caspase and NF-kappaB pathways. Expression levels of TNFR I and TNFR II mRNAs were similar between uninfected and FIV-infected CRFK cells. To understand the role of caspases in TNF-alpha-induced apoptosis, we examined the effect of three different classes of caspase inhibitors, Z-VAD-FMK, Ac-YVAD-CMK, and Z-DEVD-FMK, on the TNF-alpha-induced apoptosis in FIV-infected cells. Pretreatment with each of these caspase inhibitors protected FIV-infected CRFK cells from TNF-alpha-induced cell death. Moreover, one of the caspase substrates, poly(ADP-ribose) polymerase, was shown to be cleaved after TNF-alpha treatment in FIV-infected CRFK cells but not in uninfected CRFK cells. Electrophoretic mobility shift assay using an NF-kappaB motif oligonucleotide and promoter assay using an NF-kappaB luciferase reporter construct indicated that TNF-alpha treatment had induced activation of NF-kappaB in both FIV-infected and uninfected CRFK cells. The present study indicates that TNF-alpha-induced apoptosis in FIV-infected CRFK cells is mediated by the activation of the caspase cascade, but not by either upregulation of TNF receptor or inhibition of NF-kappaB.

Amino Acid Chloromethyl Ketones↗
PubMed2001

Cancer prevention with green tea and monitoring by a new biomarker, hnRNP B1.

The study of green tea polyphenols as a cancer preventative is approaching a new era, with significant results accumulating rapidly. This paper briefly reviews four topics related to mechanisms of action of tea polyphenols: (I) identification of the genes commonly affected by EGCG, as demonstrated by Clontech's Atlas cDNA Expression Array; (II) the significance of heterogeneous nuclear ribonucleoprotein B1 (hnRNP B1) as a new biomarker for early detection of lung cancer, and inhibition of its expression by EGCG; (III) the synergistic or additive effects of EGCG with the cancer preventive agents, sulindac and tamoxifen, on induction of apoptosis in PC-9 cells and on inhibition of intestinal tumor development in multiple intestinal neoplasia (Min) mice; (IV) the results of a 10 year prospective cohort study demonstrating the effectiveness of daily consumption of green tea in preventing cancer, and a prototype study for developing green tea beverage as cancer preventive.

Animals↗
PubMed2001

A two-process model describes the hydrogen exchange behavior of cytochrome c in the molten globule state with various extents of acetylation.

Acetylation of Lys residues of horse cytochrome c steadily stabilizes the molten globule state in 18 mM HCl as more Lys residues are acetylated [Goto and Nishikiori (1991) J. Mol. Biol. 222, 679-686]. The dynamic features of the molten globule state were characterized by hydrogen/deuterium exchange of amide protons, monitored by mass spectrometry as each deuteration increased the protein mass by 1 Da. Electrospray mass spectrometry enabled us to monitor simultaneously the exchange kinetics of more than seven species with a different number of acetyl groups. One to four Lys residue-acetylated cytochrome c showed almost no protection of the amide protons from rapid exchange. The transition from the unprotected to the protected state occurred between five and eight Lys residue-acetylated species. For species with more than nine acetylated Lys residues, the exchange kinetics were independent of the extent of acetylation, and 26 amide protons were protected at 60 min of exchange, indicating the formation of a rigid hydrophobic core with hydrogen-bonded secondary structures. The apparent transition to the protected state required a higher degree of acetylation than the conformational transition measured by circular dichroism, which had a midpoint at about four acetylated residues. This difference in the transitions suggested a two-process model in which the exchange occurs either from the protected folded state or from the unprotected unfolded state through global unfolding. On the basis of a two-process model and with the reported values of the exchange and stability parameters, we simulated the exchange kinetics of a series of acetylated cytochrome c species. The simulated kinetics reproduced the observed kinetics well, indicating validity of this model for hydrogen exchange of the molten globule state.

Acetylation↗
PubMed2001

Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC.

The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that / remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).

Journal Article↗