Search Results - (Author, Cooperation:K. Ichikawa)

2013-02-09

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Catalysis ; *Electrons ; Hydrogen/*chemistry ; Hydrogenase/*chemistry/metabolism ; Iron/*chemistry ; Ligands ; Models, Chemical ; Molecular Mimicry ; Molecular Structure ; Nickel/*chemistry ; Organometallic Compounds/*chemistry ; Oxidation-Reduction

2018-01-09

The Company of Biologists

0950-1991

1477-9129

Biology

Chromatin & epigenetics, Musculoskeletal system

2018-07-03

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1089-7674

AIP Digital Archive

Physics

An experimental study of the rapid step-switching of the frequency of a submillimeter wave gyrotron is described. Modulation of the energy of the electron beam in turn modulates the electron mass and hence the cyclotron resonance frequency fc or its second harmonic 2fc, while the magnetic field B0 remains the same. This opens up the possibility of switching from one cavity mode to another. The first experimental results for frequency switching between two fundamental modes and between a fundamental and a second harmonic mode are demonstrated.

Electronic Resource

1089-7674

AIP Digital Archive

Physics

Experimental results of the amplitude modulation of the output of a submillimeter wave gyrotron are presented. The 100% modulation of the output at frequencies up to several hundred kilohertz has been achieved with anode modulation levels of only a few percent. A good account of the experimental results is given by including a small modulation of the anode voltage in an energy transfer formula and then calculating the power output.

Electronic Resource

1089-7674

AIP Digital Archive

Physics

GYROTRON FU IV, a frequency tunable gyrotron for spectroscopy in the submillimeter wavelength range using a 17 T superconducting magnet, has been designed and constructed. Simulations predict that the gyrotron will emit radiation at high frequencies up to 394 GHz (TE041 cavity mode) at the fundamental of the electron cyclotron frequency, up to 858 GHz (TE091 mode) at the second harmonic and up to 1301 GHz (TE8 11 1 mode) at the third harmonic. Preliminary experimental results have demonstrated operation from 158 to 443 GHz at the fundamental and from 336 to 838 GHz at the second harmonic. Output powers are several hundred watts and efficiencies several percent. © 1995 American Institute of Physics.

Electronic Resource

1089-7674

AIP Digital Archive

Physics

The development of a submillimeter wave, high-harmonic gyrotron using a 12 T superconducting magnet is described. It has achieved frequencies as high as 636 GHz (corresponding to a wavelength of 472 μm) in second harmonic operation. Many resonances could be obtained as a single mode without competing modes. Typical output power is several hundred watts at both the fundamental and the second harmonic. At low beam currents (Ib∼0.5 A), third harmonic operation has been obtained. © 1995 American Institute of Physics.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract— Glial cells isolated from rabbit cerebral cortex contained approximately one-third more phospholipids per unit protein than the neuronal cell bodies. The pattern of individual phospholipids was rather similar in both cell types. The incorporation of intracisternally administered 32P into neuronal and glial phospholipid classes of rabbit brain was studied at intervals ranging from 5 to 60min. In general, for all investigated phospholipids the incorporation of the label was somewhat faster in neurons than in glial cells. Phosphatidylinositol showed the fastest and ethanolamine plasmalogen the slowest incorporation of 32P in both neurons and glial cells. A lag phase of about 10 min could be observed before labelling of the glial phosphatidylcholine, phosphatidylethanolamine, ethanolamine plasmalogen, phosphatidylserine and sphingomyelin had occurred. Among the neuronal phospholipids a lag phase was found only for the labelling of the ethanolamine plasmalogen. Norepinephrine increased the incoropration of 32P into phosphatidylinositol of both glia and neurons but had no effect on the specific radioactivity of ethanolamine plasmalogen and sphingomyelin. Labelling of phosphatidylcholine was slightly inhibited in both cell types by the administration of norepinephrine.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

—1,2-Diacyl-, 1-alk-1′-enyl-2-acyl-and 1-alkyl-2-acyl-sn-glycero-3-phosphorylcholine, specifically labelled with different fatty acids at the 2 position, were prepared enzymically using the acyltransferase system of rabbit sarcoplasmic reticulum. The substrates were submitted to hydrolysis by mitochondrial phospholipase A2 (phosphatide acyl-hydrolase, EC 3.1.1.4) obtained from normal and from rat brain afflicted with EAE. In the acute stage of the disease an increase of approximately 25 per cent in phospholipase A 2 activity could be observed in comparison to that from the control animals for all investigated substrates. Phospholipase A2 obtained from normal rat brains and from those afflicted with EAE had a higher affinity for 1,2-diacyl-sn-glycero-3-phosphorylcholine when compared to the corresponding alkyl acyl- and alkenyl acyl-analogues. Choline plasmalogen was cleaved more slowly than the corresponding alkyl acyl derivative. The enzyme activity returned to the control level in the recovery stage of the demyelinating disease.

Electronic Resource

1399-3038

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

As previously reported, antigen-specific IL-2 responsiveness of lymphocytes from patients with bronchial asthma was induced by stimulation with Dermatophagoides farinae, antigen-specifically, in the context of HLA-DQ antigen. We analysed the antigen-presenting processes in the induction of IL-2 responsiveness. Non-adherent responder cells cultured with Df-pulsed autologous adherent cells acquired IL-2 responsiveness, which decreased after prolonged culture of adherent cells for 72 h before recombination with fresh autologous non-adherent cells. HLA-DQ expression on cultured adherent cells also decreased in parallel with the reduction of their ability to induce IL-2 responsiveness. However, the treatment of adherent cells with IFN-γ restored the expression of these HLA-Class 2 antigens mainly on CD14+ antigen-presenting cells (monocytes.), but not on CD20+ cells (B cells), which overcame the decrease of Df-induced IL-2 responsiveness during prolonged culture. These data suggest that IFN-γ potentiates the up-regulation of Df-specific IL-2 responsiveness, which is likely to depend on the restoration of HLA-DQ expression on monocytes.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background The tumour necrosis factor (TNF) gene family, which includes TNF, LTA, and LTB, is located consecutively on human chromosome 6p21 region, which has been linked to asthma by several genome-wide screens. (LTA, lymphotoxin-α; LTB, lymphotoxin-β).Objective The aim of the present study was to determine whether genes on 6q21 are related to development of atopic asthma.Methods We screened for mutations in the coding and promoter regions of genes in the TNF–LTA region, including BAT1, NFKBIL1, LTA, TNF, LTB, AIF, and BAT2, and conducted a transmission disequilibrium test of 41 polymorphisms in 137 families identified through pro-bands with childhood-onset atopic asthma. (BAT1, HLA-B-associated transcript 1; NFKBIL1, nuclear factor of κ light polypeptide gene enhancer in B cells inhibitor-like 1; AIF, allograft inflammatory factor 1).Results  Haplotypes of the LTA/TNF linkage disequilibrium block were associated significantly with asthma (global P=0.0097). Transmission patterns of the common haplotypes to asthmatic offspring were predicted by a single-nucleotide polymorphism in the LTA promoter region. The G allele of the LTA−753G/A polymorphism was transmitted preferentially to asthma-affected individuals (P=0.001). Luciferase reporter assays with constructs containing the 5′ and 3′ flanking regions of the LTA gene showed 30–50% lower transcriptional activity when the −753A allele was present than that of other haplotypes.Conclusion Our results suggest that LTA is one of the genes that contributes to susceptibility to atopic asthma, and that the association of the TNF/LTA haplotypes to asthma may be defined by the polymorphism in the LTA promoter region in the Japanese population.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background The prevalence of atopic diseases has been increasing in developed countries. This could be explained by the hygiene hypothesis, which states that exposure to specific infections or endotoxins during infancy drives the maturing immune system towards a Th1 phenotype and away from the Th2 phenotype, which is associated with allergic diseases. Toll-like receptors (TLRs) play important roles in the signalling of many pathogen-related molecules and endogenous proteins associated with immune activation.Objective The aim of the present study was to investigate whether polymorphisms in genes encoding TLRs are associated with asthma or total serum IgE levels.Methods We screened the 5′ flanking and coding regions of the TLR2,TLR3, TLR4, and TLR9 genes for polymorphisms by direct sequencing of DNA from 32 asthmatics, and analysed the effect of the polymorphisms on the development of atopic asthma and on total serum IgE levels.Results We identified 16 variants in TLRs. The transmission disequilibrium test of the families revealed that none of the alleles or haplotypes were associated with asthma or total IgE levels (P〉0.05). However, we found an insertion/deletion polymorphism in the 5′ untranslated region of TLR2, and an expression construct containing the deletion allele showed lower luciferase activity than the wild-type alleles, suggesting that the deletion allele has reduced transcriptional activity.Conclusion Our results indicate that polymorphisms in TLRs are not likely to be associated with the development of atopy-related phenotypes in a Japanese population.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Cats are an important source of indoor allergens. However, only two cat allergens, Fel d 1 and albumin, have been cloned and sequenced. IgE antibodies to Fel d 1 and albumin do not fully account for IgE responses to cat and there is good immunochemical evidence that cats produce other allergens.Objective To identify and define the molecular structure of the other potential cat allergens.Methods A cat skin cDNA library was screened using pooled serum obtained from five asthmatic patients which contained high levels of IgE antibody to cat dander. Selected cDNA clones were screened by plaque immunoassay and one cDNA clone, encoding cystatin, was expressed in E. coli. The three dimensional structure of cat cystatin was modelled using the SWISS-MODEL computer program.Results Three positive cDNA clones (A, B and C) were identified, two of which were fully sequenced. Clones A and C encoded the same 98 amino acid residue sequence which showed 79% and 75% homology with bovine and human cystatin A, respectively. The cat cystatin sequence contained the conserved cysteine protease inhibitor signature and two of three lipocalin motifs. By plaque immunoassay, 60–90% of cat allergic sera had IgE ab to the expressed cystatin clones. The cysteine protease inhibitor motif was also partially conserved in dog allergen sequences, Can f 1 and Can f 2, which are lipocalins. The recombinant protein was expressed in E. coli as an 11-kDa protein, corresponding to the predicted MW of cat cystatin. The three-dimensional structure of cat cystatin was modelled on human cystatin structures.Conclusion A newly identified allergen, cystatin (Fel d 3), has been cloned from cat skin and is a member of the cysteine protease inhibitor family.

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0303-7207

(Human) ; Hepatoma cell line ; Isoelectric focusing ; Receptor form ; Thyroid hormone receptor

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0925-4005

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electrical Engineering, Measurement and Control Technology

Electronic Resource