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S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 73 records · Page 4Linked to original sources
PubMed2001

Study of influenza-associated encephalitis/encephalopathy in children during the 1997 to 2001 influenza seasons.

The 1997 to 2001 influenza A epidemics in Japan were markedly neurovirulent, and many children died of influenza-associated encephalitis/encephalopathy. We studied 20 patients with influenza-associated encephalitis/encephalopathy during the last four influenza seasons. No patients had been previously inoculated with influenza vaccine. Antipyretics were used in 16 patients before the onset of encephalopathy. Although all patients were treated intensively, 5 patients died and 8 had neurologic sequelae. Patients with coagulopathy, hepatic dysfunction, and computed tomographic abnormalities had a poor prognosis. The plasma concentrations of inflammatory cytokines were variable. The neuroradiologic findings could be divided into four categories. These findings indicated that the pathogenesis of the brain damage induced by influenza infection was variable. Further investigation is necessary to determine whether insufficient influenza vaccination or the use of antipyretics is one of the reasons for these epidemics of encephalopathy in Japanese children.

Analgesics, Non-Narcotic↗
PubMed2001

Secretion of TNF-alpha, IL-8 and nitric oxide by macrophages activated with Agaricus blazei Murill fractions in vitro.

Water extracts of the mycelial culture and fruiting bodies of Agaricus blazei Murill were fractionated by ethanol precipitation using various ethanol concentrations. Original water extracts from mycelia (Fraction A-0) and fruiting bodies (Fraction B-0) induced TNF-alpha secretion by macrophages derived from rat bone marrow. Fractions B-4 and B-5 obtained from ethanol precipitation of fruiting bodies using 44% and 50% ethanol, respectively, and Fraction B-6 obtained from the supernatant at 50% ethanol markedly induced TNF-alpha secretion. Similar effects were observed in IL-8 secretion by macrophages. Regarding nitric oxide (NO), Fraction B-5 induced a significant increase in NO secretion and Fractions B-4 and B-6 induced slightly NO secretion. Northern blot analysis showed that the increases in cytokine- and NO secretion were due to an increase in cytokine mRNAs or NO synthase mRNA. Therefore, it is concluded that Agaricus blazei Murill components which activate macrophages result in the induction of cytokine- and NO secretion in vitro.

Agaricus↗
PubMed2001

Salt-stress-responsive membrane proteins in Rhodobacter sphaeroides f. sp. denitrificans IL 106.

The salt-mediated-stress response in Rhodobacter sphaeroides f. sp. denitrificans IL 106 was investigated by culturing cells in the presence and in the absence of NaCl in growth media. Fractionation of cells followed by SDS-PAGE and 2D-PAGE revealed an increase in the levels of membrane proteins of 39 and 50 kDa and a decrease in the level of a membrane protein of 52 kDa with increasing levels of external NaCl. The proteins were isolated and sequenced. The polypeptide of 50 kDa in the inner membrane was assigned to an ATP synthase beta chain and that of 52 kDa in the outer membrane to a flagellar filament protein. As the N terminal of the 39 kDa protein in the outer membrane was blocked, partial proteolysis was carried out and four peptides were sequenced. Each sequence exhibited no significant homology with those available in databases, suggesting that the polypeptide of 39 kDa (named SspA) is a novel salt-stress-induced protein.

Journal Article↗
PubMed2001

Inhibition by Agaricus blazei Murill fractions of cytopathic effect induced by western equine encephalitis (WEE) virus on VERO cells in vitro.

Anti-viral activities of Agaricus blazei Murill were investigated. The water extracts of the cultured mycelia and fruiting bodies were fractionated with different concentrations of ethanol. To several viruses which have cytopathic effects (CPE) on VERO cells, inhibition of these effects by the ethanol fractions was tested. Strong inhibition of CPE induced by western equine encephalitis (WEE) virus was observed in the mycelial fractions but not those of fruiting bodies.

Agaricus↗
PubMed2001

Measurement of free choline in plant leaves by capillary electrophoresis.

A low pH capillary electrophoresis (CE) was used for the measurement of free choline in plant leaves. Choline in the leaf extract was first converted to the benzoyl ester and put into CE. A well-resolved peak in the electropherogram was easily obtained. Involvement of enzymes in a two-step oxidation of choline to glycine betaine was evaluated in different plant species with the same method developed for glycine betaine and betaine aldehyde.

Choline↗
PubMed2001

Application of capillary electrophoresis to the simultaneous determination of betaines in plants.

The simultaneous determination of betaines, the key compounds for osmotic regulation in plants, was established by capillary electrophoresis (CE). After four betaines, glycine betaine (GB), beta-alanine betaine (AB), proline betaine (PB), and 2-hydroxyproline betaine (HPB), were esterified with p-bromophenacyl bromide, the esters were electrophoresed in 100 mM sodium phosphate at pH 3.0. A low-pH condition in CE and esterification gave an advantage of resolving each of the ester peaks as well as those of the unreacted reagent and other components. Furthermore, the addition of 4% polyethylene glycol (PEG) gave a better resolution of 4 peaks, resulting in the separation of the overlapped peaks of PB and AB. It was found from the standard addition method being applied to barley leaves that the GB content in plants could be evaluated by using a calibration curve of the GB standard solution. The extraction of GB from plant leaves was also improved by adopting water as the extraction solvent instead of a mixture of organic solvents. The present method was suitably applied to actual plant specimens collected from a saline area of China.

Acetonitriles↗
PubMed2001

[A case of lung cancer underwent carinal resection with right upper lobectomy and carinal reconstruction with double-barreled anastomosis].

A 70-year-old male complaining cough was admitted to our hospital. Bronchoscopic examination revealed a tumor mass which occluded the orifice of the right upper lobe. Chest computed tomographic (CT) scans gave the image of tumor invasion at the carina. The pathological diagnosis of the tumor was squamous cell carcinoma. Operation was accomplished by right posterolateral thoracotomy approach through the fifth rib bed. The carinal resection with right upper lobectomy was followed by a double-barreled anastomosis of the right intermediate trunk and left main-stem bronchus into the carina. The operation was successfully performed and was considered curative. The length of resected airway measured 4.0 cm from tracheal line of resection to the divided the right intermediate trunk. Reinforcement of the anastomosis was not performed in this case. No postoperative complication occurred but mild ischemia of the anastomosis. The patient died of recurrent tumor in a year and 2 months after operation.

Aged↗
PubMed2001

Sarcoidosis with giant parotomegaly.

We report the case of a 63-year-old man with bilateral parotid gland sarcoidosis. Giant, elastic, hard, subcutaneous tumors had been present on the right parotic and submaxillary regions for 11 years and on the left for 1 year. The patient had had diabetes mellitus for 8 years. Noncaseating epithelioid cell granulomata were revealed histopathologically in the periductal area of the parotid gland. Bilateral hilar lymphadenopathy was noted on chest x-ray studies. Serum levels of lysozyme were increased. Levels of serum angiotensin-converting enzyme were within normal limits. Tuberculin skin reaction was positive. The tumors gradually improved after treatment with oral minocycline. Giant parotomegaly, as it occurred in this case, is very rare.

Humans↗
PubMed2001

[Is the bronchoscopic criteria of early lung cancer valid?].

We studied the validity of the bronchoscopic criteria of the early lung cancer using the surgical specimen excised between 1980 and 1999. Twenty-four cases with squamous cell carcinoma of the lung of clinical stage I were located subsegmental or more proximal bronchi and trachea, and the size less than 20 mm in greatest dimension. We histopathologically investigated the endoscopic features in relation to the width of superficial extent, the depth of cancer invasion, and lymph node metastasis. Tumors of the thickened type lesions less than 20 mm in greatest dimension showed no invasion into the cartilaginous layer and no lymph node metastasis. On the other hand, in the nodular and polypoid types, invasion beyond the cartilaginous layer was observed more or less, and lymph node metastasis was observed in 1 case. These cases would not be suitable for bronchoscopic (photodynamic) therapy. In conclusion, the bronchoscopic criteria of early lung cancer is valid in the thickened type, but not in the nodular type or polypoid type.

Aged↗
PubMed2000

Proteoliposomes colocalized with endogenous mitochondria in mouse fertilized egg.

Colocalization of mitochondria is the first step of intermitochondrial interaction or fusion in a cell. Here, we showed colocalization between exogenous mitochondria and endogenous ones or between exogenous proteoliposomes and endogenous mitochondria in mouse fertilized eggs by confocal laser microscopy. Isolated mitochondria from mouse liver and proteoliposomes containing mitochondrial membrane were directly labeled with red fluorescent aliphatic marker, PKH26, which is incorporated into lipid membrane, and then were microinjected into fertilized mouse eggs. Exogenous mitochondria appeared to be almost colocalized with endogenous mitochondria at the 4- and 8-cell stages, when mitochondria were stained with Rhodamine 123 (green fluorescent marker). On the contrary, when liposomes consisted of soy bean phospholipid were microinjected into the eggs as a control, their localization was different from that of endogenous mitochondria. Next, the submitochondrial particles and proteoliposomes were microinjected. Both the proteoliposomes and the submitochondrial particles appeared to colocalize with endogenous mitochondria at the 4-cell stage. These results suggest the existence of a factor that makes liposomes colocalize with mitochondria. Such a proteoliposome would be useful for the development of mitochondrial gene transfer techniques.

Animals↗
PubMed2000

Identification of a novel gene with RING-H2 finger motif induced after chronic antidepressant treatment in rat brain.

Previously, we have identified 200 cDNA fragments as antidepressant related genes/ESTs. In this study, using these cDNAs, we developed our original cDNA microarray for rapid secondary screening of candidate genes as the novel therapeutic targets. With this microarray, we found that the expression of a novel gene, ADRG34, was significantly increased in rat hippocampus which had been chronically treated with a selective serotonin reuptake inhibitor antidepressant, sertraline. RT-PCR analysis also demonstrated the induction of ADRG34 at mRNA levels in rat hippocampus and the frontal cortex. This cDNA encoded 685 amino acid residues containing a RING-H2 finger motif at the carboxy-terminal. Sequence analysis of ADRG34 with the EMBL/GenBank database showed significant homology to mouse and human kf-1 gene. Our data suggest that ADRG34, a possible rat homologue of kf-1, may be one of the common functional molecules induced after chronic antidepressant treatment.

Amino Acid Sequence↗
PubMed2000

Immunologic self-tolerance maintained by CD25(+)CD4(+) regulatory T cells constitutively expressing cytotoxic T lymphocyte-associated antigen 4.

This report shows that cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) plays a key role in T cell-mediated dominant immunologic self-tolerance. In vivo blockade of CTLA-4 for a limited period in normal mice leads to spontaneous development of chronic organ-specific autoimmune diseases, which are immunopathologically similar to human counterparts. In normal naive mice, CTLA-4 is constitutively expressed on CD25(+)CD4(+) T cells, which constitute 5-10% of peripheral CD4(+) T cells. When the CD25(+)CD4(+) T cells are stimulated via the T cell receptor in vitro, they potently suppress antigen-specific and polyclonal activation and proliferation of other T cells, including CTLA-4-deficient T cells, and blockade of CTLA-4 abrogates the suppression. CD28-deficient CD25(+)CD4(+) T cells can also suppress normal T cells, indicating that CD28 is dispensable for activation of the regulatory T cells. Thus, the CD25(+)CD4(+) regulatory T cell population engaged in dominant self-tolerance may require CTLA-4 but not CD28 as a costimulatory molecule for its functional activation. Furthermore, interference with this role of CTLA-4 suffices to elicit autoimmune disease in otherwise normal animals, presumably through affecting CD25(+)CD4(+) T cell-mediated control of self-reactive T cells. This unique function of CTLA-4 could be exploited to potentiate T cell-mediated immunoregulation, and thereby to induce immunologic tolerance or to control autoimmunity.

Abatacept↗
PubMed2000

Functional characterization of the Candida albicans MNT1 mannosyltransferase expressed heterologously in Pichia pastoris.

The alpha1,2-mannosyltransferase gene MNT1 of the human fungal pathogen Candida albicans has been shown to be important for its adherence to various human surfaces and for virulence (Buurman, E. T. , Westwater, C., Hube, B., Brown, A. P. J., Odds, F. C., and Gow, N. A. R. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 7670-7675). The CaMnt1p is a type II membrane protein, which is part of a family of proteins that are important for both O- and N-linked mannosylation in fungi and which represent a distinct subclass of glycosyltransferase enzymes. Here we use heterologous expression of CaMNT1 in the methylotrophic yeast Pichia pastoris to characterize the properties of the CaMnt1p enzyme as an example of this family of enzymes and to identify key amino acid residues required for coordination of the metal co-factor and for the retaining nucleophilic mechanism of the transferase reaction. We show that the enzyme can use both Mn(2+) and Zn(2+) as metal ion co-factors and that the reaction catalyzed is specific for alpha-methyl mannoside and alpha1,2-mannobiose acceptors. The N-terminal cytoplasmic tail, transmembrane domains, and stem regions were shown to be dispensable for activity, whereas truncations to the C-terminal catalytic domain destroyed activity without markedly affecting transcription of the truncated gene.

Amino Acid Sequence↗
PubMed2000

Resetting central and peripheral circadian oscillators in transgenic rats.

In multicellular organisms, circadian oscillators are organized into multitissue systems which function as biological clocks that regulate the activities of the organism in relation to environmental cycles and provide an internal temporal framework. To investigate the organization of a mammalian circadian system, we constructed a transgenic rat line in which luciferase is rhythmically expressed under the control of the mouse Per1 promoter. Light emission from cultured suprachiasmatic nuclei (SCN) of these rats was invariably and robustly rhythmic and persisted for up to 32 days in vitro. Liver, lung, and skeletal muscle also expressed circadian rhythms, which damped after two to seven cycles in vitro. In response to advances and delays of the environmental light cycle, the circadian rhythm of light emission from the SCN shifted more rapidly than did the rhythm of locomotor behavior or the rhythms in peripheral tissues. We hypothesize that a self-sustained circadian pacemaker in the SCN entrains circadian oscillators in the periphery to maintain adaptive phase control, which is temporarily lost following large, abrupt shifts in the environmental light cycle.

Animals↗
PubMed2000

Positional syntenic cloning and functional characterization of the mammalian circadian mutation tau.

The tau mutation is a semidominant autosomal allele that dramatically shortens period length of circadian rhythms in Syrian hamsters. We report the molecular identification of the tau locus using genetically directed representational difference analysis to define a region of conserved synteny in hamsters with both the mouse and human genomes. The tau locus is encoded by casein kinase I epsilon (CKIepsilon), a homolog of the Drosophila circadian gene double-time. In vitro expression and functional studies of wild-type and tau mutant CKIepsilon enzyme reveal that the mutant enzyme has a markedly reduced maximal velocity and autophosphorylation state. In addition, in vitro CKIepsilon can interact with mammalian PERIOD proteins, and the mutant enzyme is deficient in its ability to phosphorylate PERIOD. We conclude that tau is an allele of hamster CKIepsilon and propose a mechanism by which the mutation leads to the observed aberrant circadian phenotype in mutant animals.

Alleles↗
PubMed2000

Recombinant bacillus Calmette-Guérin as a potential vector for preventive HIV type 1 vaccines.

In August 1997, the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) convened an expert working group to discuss current strategies for the development of HIV type 1 vaccines. Based on the recent findings of investigators from Japan's National Institute of Infectious Diseases (NIID) in Tokyo using recombinant bacillus Calmette-Guérin (rBCG) as a potential vectored vaccine for HIV, a recommendation was made that further work in this area is a priority. As a result, the working group reconvened in September 1998 to discuss the progress to date with this vaccine approach, as well as areas of related research to assess the feasibility of a BCG-vectored HIV vaccine. This report summarizes the discussions addressing the available scientific data on the potential use of rBCG as a vector for preventive HIV vaccines, the work necessary to move such candidate vaccines into Phase 1 clinical trials, and recommendations targeted at facilitating the long-term development of rBCG-vectored HIV vaccines.

AIDS Vaccines↗