Publications by authors named "Ikeuchi M"

Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 σ factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp.

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The photoconversion mechanism of a green/red sensory cyanobacteriochrome AnPixJ was studied. The phycocyanobilin-binding second GAF domain of AnPixJ of Anabaena sp. PCC 7120 was expressed in Escherichia coli cells.

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The light-induced reaction of the BLUF (blue light photoreceptor using flavin adenine dinucleotide) photoreceptor PixD from Synechocystis sp. PCC6803 (Slr1694) was investigated using the time-resolved transient grating method. A conformational change coupled with a volume contraction of 13 mL mol(-1) was observed with a time constant of 45 ms following photoexcitation.

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A thermophilic cyanobacterium, Thermosynechococcus vulcanus RKN, exhibits cell aggregation under low temperature illuminated conditions as a means of physiological acclimation to avoid excess light stress. The cell aggregation was dispersed with cellulase treatment. We developed a method to quantify small amounts of cellulose by partial cellulose purification followed by quantitation of liberated glucose by cellulase.

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Objective: Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain.

Methods: This study was an open-label, nonrandomized, and controlled study.

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Induced pluripotent stem (iPS) cells are expected to provide a source of tissue, a renewable cell source for tissue engineering, and a method for in vitro drug screening for patient-specific or disease-specific treatment. A simple technology by which iPS cells can be differentiated effectively and in large quantities is strongly desired. In this paper, a new device (Tapered Soft Stencil for Cluster Culture: TASCL) is proposed for the easy and efficient formation of EBs which can be used in regenerative medicine.

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Contralateral thalamus, the place of termination of spinothalamic tract, is affected in patients with pain. We employed single photon emission computed tomography (SPECT) to evaluate the thalamic perfusion in patients with spontaneous neuropathic pain. Ten patients with complex regional pain syndrome (CRPS) and eleven radiculopathiy patients were enrolled in this study.

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TePixD, a cyanobacterial sensor of blue light using flavin adenine dinucleotide (FAD) (BLUF) which exists in a decamer form, was found to exhibit photoreaction sensitive to light intensity. While the number of excited molecules increased monotonically as the laser power increased, the number of decamers exhibiting a global conformational change initially increased, and then decreased with the increase of excitation intensity. This unusual power dependence was analyzed based on a Poisson distribution equation, demonstrating that decamers containing more than one excited monomer subunit do not undergo conformational change.

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The cyanobacterial phototaxis regulator protein, TePixJ, is a member of the subfamily of cyanobacteriochromes that binds phycoviolobilin (PVB) as a chromophore and exhibits reversible photoconversion between blue light-absorbing (Pb) and green light-absorbing (Pg) forms. We reconstituted the PVB-binding photoactive holocomplex in vivo and in vitro. Coexpression of the apoprotein and phycocyanobilin (PCB) in Escherichia coli (in vivo reconstitution) produced a mixture of the PCB-bound and PVB-bound holoproteins.

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PsbM and PsbI are two low molecular weight subunits of photosystem II (PSII), with PsbM being located in the center, and PsbI in the periphery, of the PSII dimer. In order to study the functions of these two subunits from a structural point of view, we crystallized and analyzed the crystal structure of PSII dimers from two mutants lacking either PsbM or PsbI. Our results confirmed the location of these two subunits in the current crystal structure, as well as their absence in the respective mutants.

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The supercomplex organization of photosystem complexes was studied in various cyanobacteria, a glaucocystophyte and a primitive rhodophyte by blue-native PAGE with a wide range of detergent concentrations. In contrast to known cyanobacteria that produced the PSI trimer, a filamentous N(2)-fixing cyanobacterium Anabaena sp. PCC 7120 and a glaucocystophyte Cyanophora paradoxa NIES 547 had a PSI tetramer and dimer but no trimer at all.

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To reveal macromolecular crowding effects on a chemical reaction of a BLUF (sensors of blue light using FAD) protein (PixD from a thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 [TePixD, Tll0078]), the photoreaction was studied at various concentrations of the macromolecule Ficoll-70 by UV/Vis absorption spectroscopy and the pulsed laser-induced transient grating (TG) method. The absorption spectrum did not change with varying concentration of Ficoll-70. The crowding did not affect the quantum yield of the spectral red shift reaction, recovery rate of the product, rate constant of the volume change reaction and the magnitude of the volume change.

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Molecular genetics has been successful in identifying leaf- size regulators such as transcription factors, phytohormones, and signal molecules. Among them, a ROTUNDIFOLIA4-LIKE/DEVIL (RTFL/DVL) family of Arabidopsis, genes encoding peptides with no secretion-signal sequence, is unique in that their overexpressors have a reduced number of leaf cells specifically along the proximodistal axis. However, because the RTFL/DVL lack any obvious homology with functionally identified domains, and because of genetic redundancy among RTFL/DVL, their molecular and developmental roles are unclear.

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Pyoderma gangrenosum is a rare ulcerative disorder of the skin of unknown etiology. We present a case of pyoderma gangrenosum that occurred following total knee arthroplasty, which was initially misdiagnosed as severe wound infection. Repeated debridement procedures resulted in a large soft tissue defect around the anterior knee joint.

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Oxygen-evolving photosystem II (PSII) isolated from a marine centric diatom, Chaetoceros gracilis, contains a novel extrinsic protein (Psb31) in addition to four red algal type extrinsic proteins of PsbO, PsbQ', PsbV, and PsbU. In this study, the five extrinsic proteins were purified from alkaline Tris extracts of the diatom PSII by anion and cation exchange chromatographic columns at different pH values. Reconstitution experiments in various combinations with the purified extrinsic proteins showed that PsbO, PsbQ', and Psb31 rebound directly to PSII in the absence of other extrinsic proteins, indicating that these extrinsic proteins have their own binding sites in PSII intrinsic proteins.

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We have previously identified two target genes (slr1667 and slr1668) for transcriptional regulation by a cAMP receptor protein, SYCRP1, in a cAMP-dependent manner. For this study we investigated the localizations of products of slr1667 and slr1668 (designated cccS and cccP, respectively) biochemically and immunocytochemically, and examined the phenotypes of their disruptants. CccS protein was detected in the culture medium and the acid-soluble fraction containing proteins derived from outside the outer membrane.

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Article Synopsis
  • An "electrical storm" is a dangerous heart condition characterized by repeated episodes of erratic heart rhythms like ventricular tachycardia or fibrillation.
  • A case study discusses a patient who experienced these electrical storms unexpectedly after heart surgery (coronary artery bypass grafting).
  • The storms were effectively stopped with nifekalant hydrochloride, suggesting it may be a promising treatment for severe heart rhythm issues that don't respond to the standard medication, amiodarone.
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Responding to green and red light, certain cyanobacteria change the composition of their light-harvesting pigments, phycoerythrin (PE) and phycocyanin (PC). Although this phenomenon-complementary chromatic adaptation-is well known, the green light-sensing mechanism for PE accumulation is unclear. The filamentous cyanobacterium Nostoc punctiforme ATCC 29133 (N.

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The close association of the extrinsic PsbO, PsbP and PsbQ proteins with PSII core subunits in oxygen-evolving PSII complexes from a green alga, Chlamydomonas reinhardtii, was examined by cross-linking experiments with a water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). The green algal PSII complexes treated with EDC were washed with alkaline Tris to remove the non-cross-linked extrinsic proteins, and then applied to Blue-Native-PAGE to prepare PSII core complexes. The extrinsic proteins cross-linked with PSII core complexes were detected by immunoblotting analysis using antibodies against extrinsic proteins and PSII core subunits.

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A filamentous non-N(2)-fixing cyanobacterium, Arthrospira (Spirulina) platensis, is an important organism for industrial applications and as a food supply. Almost the complete genome of A. platensis NIES-39 was determined in this study.

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PsbK is a small membrane protein of the PSII core complex and is highly conserved from cyanobacteria to plants. Here, we studied its role in the thermophilic cyanobacterium, Thermosynechococcus elongatus BP-1, by focusing on a psbK disruptant with hexahistidine-tagged CP47. The psbK disruptant showed photoautotrophic growth comparable with that of the wild type under a wide range of light conditions.

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Tenascin-C (TN-C) is an extracellular matrix glycoprotein with high bioactivity. It is expressed at low levels in normal adult heart, but upregulated under pathological conditions, such as myocardial infarction (MI). Recently, we (Ref.

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Objectives: This study aims to investigate the effects of thromboprophylactic transcutaneous electrical nerve stimulation (TpTENS) of the peroneal nerve on venous blood flow in the limbs of volunteers. TpTENS might be considered for use in preventing venous stasis during surgical treatment.

Methods: In 10 volunteers, peak venous velocity (PV) and flow volume (FV) in the popliteal vein were measured using duplex ultrasonography during calf-muscle stimulation.

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Ycf12 (Psb30) and PsbZ are two low molecular weight subunits of photosystem II (PSII), with one and two trans-membrane helices, respectively. In order to study the functions of these two subunits from a structural point of view, we constructed deletion mutants lacking either Ycf12 or PsbZ from Thermosynechococcus elongatus, and purified, crystallized and analyzed the structure of PSII dimer from the two mutants. Our results showed that Ycf12 is located in the periphery of PSII, close to PsbK, PsbZ and PsbJ, and corresponded to the unassigned helix X1 reported previously, in agreement with the recent structure at 2.

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Photosystem II (PSII) is a large membrane protein complex that uses light to split water into molecular oxygen, protons, and electrons. Here we report the (1)H, (15)N and (13)C backbone chemical shift assignments for the Psb27 protein of Photosystem II from Synechocystis PCC 6803. These assignments will now provide the basis for the structural analysis of the Psb27 protein.

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