80 results on '"Ryo Nakamura"'
Search Results
2. Serum Cystatin C Level as a Biomarker of Aortic Plaque in Patients with an Aortic Arch Aneurysm
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Mitsuru Yuzaki, Ryo Nakamura, Kentaro Honda, Kouji Tajima, Mitsugi Nagashima, Kouta Agematsu, Masahiro Kaneko, Yasuka Nakanishi, and Yoshiharu Nishimura
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,030204 cardiovascular system & hematology ,Coronary artery disease ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine.artery ,Internal medicine ,Internal Medicine ,medicine ,Humans ,Cystatin C ,Renal Insufficiency, Chronic ,Aortic plaque ,Aged ,Retrospective Studies ,Aged, 80 and over ,Creatinine ,Aortic Aneurysm, Thoracic ,biology ,Aortic arch aneurysm ,business.industry ,Biochemistry (medical) ,Stent ,Biomarker ,Descending aorta ,medicine.disease ,Plaque, Atherosclerotic ,Embolism ,chemistry ,cardiovascular system ,Cardiology ,biology.protein ,Biomarker (medicine) ,Original Article ,Female ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers ,030217 neurology & neurosurgery ,Kidney disease - Abstract
Aim: During surgery for an aortic arch aneurysm, aortic plaque in the descending aorta should be evaluated, but there are currently no suitable biomarkers for it. Surgeons should be especially aware of cerebral embolism from femoral perfusion and of peripheral embolism from stent graft deployment. Cystatin C is a known useful marker of renal dysfunction with a role as a biomarker for severity of coronary artery disease. In the absence of a suitable biomarker for aortic plaque in the descending aorta, we examine cystatin C as a candidate. Methods: In all, 75 patients who underwent surgery for an aortic arch aneurysm were enrolled. They were divided into two groups, depending on whether they had chronic kidney disease or not. The serum cystatin C value and creatinine value were evaluated preoperatively. The aortic plaque volume ratio and components in the descending aorta were calculated from preoperative enhanced computed tomography. Results: The soft plaque volume ratio was higher in patients with chronic kidney disease than in patients without it. Cystatin C positively correlated with the total aortic plaque volume ratio in all cases, and it positively correlated with the soft plaque volume ratio in both groups. Creatinine had no correlation with any type of plaque volume ratio in either group. In patients without chronic kidney disease, the soft plaque volume ratio was higher in patients with higher cystatin C levels than in patients with normal levels. Conclusion: The preoperative serum cystatin C level could be a biomarker of aortic plaque in the descending aorta in patients with an aortic arch aneurysm.
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- 2021
3. Adventitial cystic disease of the femoral vein accompanied by deep vein thrombosis
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Ryo Nakamura, Hideki Kunimoto, Yoshiharu Nishimura, and Kentaro Honda
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Male ,Pulmonary and Respiratory Medicine ,Adventitia ,medicine.medical_specialty ,Deep vein ,Femoral vein ,Case Reports ,030204 cardiovascular system & hematology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Edoxaban ,medicine ,Humans ,Vascular Diseases ,Aged ,Cystic disease ,Venous Thrombosis ,medicine.diagnostic_test ,Cysts ,business.industry ,Ultrasound ,Magnetic resonance imaging ,Femoral Vein ,medicine.disease ,Thrombosis ,medicine.anatomical_structure ,030228 respiratory system ,chemistry ,cardiovascular system ,Surgery ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Venous return curve - Abstract
Adventitial cystic disease of the femoral vein is an extremely rare condition; therefore, diagnosis, treatments, surgical approaches and long-term prognosis are not well defined. We report the case of a 67-year-old man with femoral vein adventitial cystic disease complicated with deep vein thrombosis. He presented with right leg oedema. Ultrasound, computed tomography and magnetic resonance imaging revealed a mass in the femoral vein, and deep vein thrombosis was not detected at the time. However, venous return disorder worsened due to the mass causing a deep vein thrombosis in the femoral vein, and anticoagulation therapy with edoxaban was administered. Subsequently, deep vein thrombosis in the femoral vein disappeared, but remained in the lower calf. The mass and femoral vein were completely resected and reconstructed with an expanded polytetrafluoroethylene graft. No recurrence was observed over 3 years and 3 months.
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- 2021
4. Thermodynamic Simulation for Continuous Formation of Ozone Hydrate
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Hironori D. Nagashima, Ryo Ohmura, Ryo Nakamura, and Kosuke Watanabe
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Ozone ,Materials science ,General Chemical Engineering ,Clathrate hydrate ,Thermodynamics ,Fraction (chemistry) ,02 engineering and technology ,Thermodynamic simulation ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Natural gas ,Environmental Chemistry ,Physics::Chemical Physics ,Physics::Biological Physics ,Renewable Energy, Sustainability and the Environment ,business.industry ,General Chemistry ,021001 nanoscience & nanotechnology ,Decomposition ,0104 chemical sciences ,chemistry ,Scientific method ,0210 nano-technology ,Hydrate ,business - Abstract
O3 concentration in O3-containing clathrate hydrate formed by a continuous process is predicted using the thermodynamic simulation in which the hydrate-forming process is assumed to be a series of numerous equilibrium states each slightly deviating from the preceding state. The thermodynamic simulation was originally developed for natural gas hydrate. In this study, the simulation was modified to take account of O3 self-decomposition. The O3 decomposition rate was experimentally measured in the (O3 + O2 + CO2) system to be used for the material balance calculation model. The phase-equilibrium calculation model used in this study was validated by comparison of the experimental O3 concentration in hydrate to that calculated. The thermodynamic simulation indicated that the O3 concentration in hydrate increased with an increase in the fraction of the gas discharged from the reactor. The higher rate of hydrate formation increased the O3 concentration in hydrate asymptotically. This study revealed that the O3 m...
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- 2018
5. Factors influencing trough and 90-minute plasma dabigatran etexilate concentrations among patients with non-valvular atrial fibrillation
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Shinichiro Ueda, Ryo Nakamura, Shin-ichi Ando, Yoshihiro Imamura, Tomoya Hashimoto, Takuya Araki, Akiko Uematsu, Daisuke Nagano, Hideharu Tomita, Kazuya Hosokawa, Toshiaki Kadokami, Koujirou Yamamoto, Takaya Fukuyama, and Satoshi Yamada
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Male ,medicine.medical_specialty ,medicine.drug_class ,Non valvular atrial fibrillation ,Renal function ,Proton-pump inhibitor ,Single-nucleotide polymorphism ,macromolecular substances ,030204 cardiovascular system & hematology ,Gastroenterology ,Antithrombins ,Dabigatran ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Risk Factors ,Internal medicine ,Atrial Fibrillation ,D-dimer ,medicine ,Humans ,030212 general & internal medicine ,Creatinine ,business.industry ,hemic and immune systems ,Atrial fibrillation ,Hematology ,medicine.disease ,chemistry ,Female ,business ,medicine.drug - Abstract
Dabigatran etexilate, a direct oral anti-coagulation agent, is used in the prevention of thromboembolism in patients with non-valvular atrial fibrillation (NVAF). However, for reasons that are not fully understood, plasma dabigatran etexilate concentrations (PDC) vary significantly among patients.We measured trough and 90min PDC in 98 patients with NVAF. To elucidate the cause of variations in PDC, we determined correlations between PDC and various factors including renal function, co-administration of a P-glycoprotein inhibitor, and the effects of three single nucleotide polymorphisms (SNPs) of the P-glycoprotein intestinal efflux transporter. To further determine the cause of PDC variations, we examined the relationship between PDC, activated partial prothrombin time (APTT), and D-dimer (DD) levels, which are surrogate markers for thrombotic risk.Multivariate analysis showed significant relations among creatinine, creatinine clearance, and CHA2D2-VaSc scores (p=0.04, p=0.01, and p=0.04, respectively). In addition, creatinine and creatinine clearance were significantly correlated with trough and 90min PDC (p0.01), respectively. There was a clear linear relation between PDC and APTT, but not DD levels. However, higher DD levels (0.5μg/mL) were associated with lower trough and 90min PDCs.Renal function and CHA2D2-VaSc scores affect PDC, suggesting these may be primary factors influencing the wide variation observed in PDCs under these conditions. Variations in APTT can primarily be explained by variations in PDC; patients with lower PDCs may have a higher risk of thromboembolism events.
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- 2016
6. Increasing molecular O3 storage capacity in a clathrate hydrate
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Kazutoshi Shishido, Satoshi Takeya, Ryo Nakamura, Ryo Ohmura, and Sanehiro Muromachi
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Ozone ,Phase equilibrium ,Clathrate hydrate ,Analytical chemistry ,Mineralogy ,Fraction (chemistry) ,General Chemistry ,Atmospheric temperature range ,Mole fraction ,Catalysis ,Crystal ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Hydrate - Abstract
This paper reports an experimental study to further increase the ozone storage capacity in a clathrate hydrate and to better understand the relationship between the gas phase O3 concentration and the O3 storage capacity in the hydrate. We performed experiments with the O3 + O2 + CO2 feed gas with an increased O3 fraction in the gas phase exceeding that covered by a preceding study. To accurately specify the thermodynamic conditions to form the hydrate, we first measured the three-phase (gas + liquid + hydrate) equilibrium conditions for the (O3 + O2 + CO2 + H2O) and (O2 + CO2 + H2O) systems. The phase equilibrium data cover the temperature range from 272 to 277 K, corresponding to pressures from 1.6 to 3.1 MPa, for each of the two different (O3 + O2)-to-CO2 or O2-to-CO2 molar ratios in the feed gas, which are approximately 4 : 6 and 5 : 5, respectively. The O3 fraction in the gas phase was ∼0.025. Based on the equilibrium data, we prepared crystal samples of the O3 + O2 + CO2 hydrates at a system pressure of 3.0 MPa and a temperature of 272 K. The highest O3 storage capacity in the hydrates was measured to be 2.15 mass% which is 2.36 times higher than the highest past record of 0.91 mass%. The results also show that the dominant factor to control the O3 storage capacity in the hydrates is the O3 mole fraction in the gas phase in contact with the hydrates.
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- 2014
7. Development of System for Continuously Forming Ozone Containing Hydrates and application to environmental purification
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Shikou Nakamura, Ryo Akiyoshi, Miei Sakurai, Ryo Nakamura, Satoshi Takeya, Tomomi Hatsugai, Shirou Nishitsuka, and Ryo Ohmura
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chemistry.chemical_compound ,Ozone ,chemistry ,Environmental chemistry ,Environmental science - Published
- 2019
8. Improvement of Physicochemical and Enzymatic Properties of Bovine Trypsin by Non-enzymatic Glycation
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Tsukasa Matsuda, Yasuko Kato, and Ryo Nakamura
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chemistry.chemical_classification ,Chromatography ,Chemistry ,Organic Chemistry ,Kinetics ,General Medicine ,Buffer solution ,Trypsin ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Maillard reaction ,symbols.namesake ,Differential scanning calorimetry ,Enzyme ,Glycation ,medicine ,symbols ,Molecular Biology ,Incubation ,Biotechnology ,medicine.drug - Abstract
Bovine trypsin was modified with glucose through the Maillard reaction at 50°C and 65% RH for various periods (1 to 8 days). Tryptic activity against both benzoyl-L-arginine-p-nitroanilide and two protein substrates was enhanced with increases in the reaction period, and reached the maximum after a 4-day reaction. Although there were no big differences in pH dependency of trypsin activity between native and modified trypsins, the Km of the modified trypsin decreased to about half the native one. The modified trypsin retained its original activity almost completely after incubation in a buffer solution of pH 8.0 at 37°C for 72 h, while native trypsin was greatly inactivated. Furthermore, tryptic acitivity at high temperature, residueal activity after heating, and differential scanning calorimetric analysis showed that the modified trypsin was more heat-stable than native trypsin.
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- 2016
9. Biological properties of androgen receptor pure antagonist for treatment of castration-resistant prostate cancer: Optimization from lead compound to CH5137291
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Takuya Shiraishi, Ayako Nishimoto, Hitoshi Yoshino, Hiromitsu Kawata, Shinichi Arai, Haruhiko Sato, Kazutaka Tachibana, Toshito Nakagawa, Nobuyuki Ishikura, and Ryo Nakamura
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Agonist ,Bicalutamide ,medicine.drug_class ,Urology ,Metabolite ,Antagonist ,Pharmacology ,urologic and male genital diseases ,Androgen receptor ,Transactivation ,chemistry.chemical_compound ,Oncology ,chemistry ,In vivo ,LNCaP ,medicine ,medicine.drug - Abstract
BACKGROUND Castration-resistant prostate cancer (CRPC) is still dependent on androgen receptor (AR) signaling. We previously reported that a novel nonsteroidal AR pure antagonist, CH4933468, which is a thiohydantoin derivative with a sulfonamide side chain, provided in vitro proof of concept but did not in vivo. METHODS We developed other derivatives, CH5137291, CH5138514, and CH5166623, and their pharmacological properties were compared with CH4933468 and bicalutamide. Agonist/antagonist activities in AR-mediated transactivation, cell proliferation against LNCaP and LNCaP-BC2, and AR translocation were evaluated. Agonist metabolite was monitored in liver microsomes and in pharmacokinetics experiments. Antitumor activities in CRPC xenograft models were examined using LNCaP-BC2 and VCaP-CRPC. RESULTS All CH compounds completely inhibited AR-mediated transactivation and proliferation of LNCaP and LNCaP-BC2. In contrast bicalutamide showed a partial inhibition of AR-mediated transactivation and a proliferation of LNCaP-BC2. AR translocation to nucleus was inhibited by CH compounds, but stimulated by bicalutamide. In the LNCaP-BC2 xenograft model, however, only CH5137291 showed significant inhibition of plasma PSA level and antitumor activity. The other three CH compounds were metabolized to their core structure which had agonist activity. CH5137291 also exhibited antitumor activity in a VCaP-CRPC xenograft model, but bicalutamide did not. CONCLUSIONS The molecular mechanism of the CH compounds, inhibition of AR translocation, was different from bicalutamide and this action could contribute to AR pure antagonist activity. Agonist metabolite diminished the antitumor activity of AR pure antagonist. CH5137291 exhibited antitumor activity in LNCaP-BC2 and VCaP-CRPC xenograft models, suggesting that the compound has potential for the treatment of CRPC. Prostate 71:1344–1356, 2011. © 2011 Wiley-Liss, Inc.
- Published
- 2011
10. Design and synthesis of an androgen receptor pure antagonist (CH5137291) for the treatment of castration-resistant prostate cancer
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Takuya Shiraishi, Ayako Nishimoto, Toshito Nakagawa, Akie Honma, Masateru Ohta, Hitoshi Yoshino, Kazutaka Tachibana, Nobuyuki Ishikura, Toshiaki Tsunenari, Kentaro Furumoto, Ryo Nakamura, Kazuya Kimura, Hiromitsu Kawata, Haruhiko Sato, Miho Watanabe, Noriyuki Takata, and Takashi Emura
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Male ,Agonist ,medicine.medical_specialty ,medicine.drug_class ,Metabolite ,Transplantation, Heterologous ,Clinical Biochemistry ,hERG ,Mice, Nude ,Pharmaceutical Science ,Antineoplastic Agents ,Pharmacology ,Biochemistry ,Mice ,Structure-Activity Relationship ,chemistry.chemical_compound ,Prostate cancer ,Dogs ,In vivo ,Internal medicine ,Drug Discovery ,medicine ,Animals ,Humans ,Castration ,Molecular Biology ,Sulfonamides ,biology ,Organic Chemistry ,Antagonist ,Prostatic Neoplasms ,Cancer ,Androgen Antagonists ,Haplorhini ,medicine.disease ,Ether-A-Go-Go Potassium Channels ,Rats ,Androgen receptor ,Endocrinology ,Thiohydantoins ,chemistry ,Receptors, Androgen ,Drug Design ,Phenytoin ,Microsomes, Liver ,biology.protein ,Molecular Medicine - Abstract
A series of 5,5-dimethylthiohydantoin derivatives were synthesized and evaluated for androgen receptor pure antagonistic activities for the treatment of castration-resistant prostate cancer. Since CH4933468, which we reported previously, had a problem with agonist metabolites, novel thiohydantoin derivatives were identified by applying two strategies. One was the replacement of the alkylsulfonamide moiety by a phenylsulfonamide to avoid the production of agonist metabolites. The other was the replacement of the phenyl ring with a pyridine ring to improve in vivo potency and reduce hERG affinity. Pharmacological assays indicated that CH5137291 (17b) was a potent AR pure antagonist which did not produce the agonist metabolite. Moreover, CH5137291 completely inhibited in vivo tumor growth of LNCaP-BC2, a castration-resistant prostate cancer model.
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- 2010
11. Purification and characterization of glycerolipid acyl-hydrolase from the red alga Gracilaria vermiculophylla
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Yutaka Itabashi, Ryo Nakamura, Akihiko Hara, Nobuhiro Fusetani, Muhammad Ikbal Illijas, Noriaki Iijima, and Masaru Terasaki
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Gel electrophoresis ,chemistry.chemical_compound ,Biochemistry ,Molecular mass ,chemistry ,Phosphatidylcholine ,Hydrolase ,Size-exclusion chromatography ,Substrate (chemistry) ,Fast protein liquid chromatography ,Aquatic Science ,Biology ,Ammonium sulfate precipitation - Abstract
A glycerolipid acyl-hydrolase was purified 19-fold with a yield of 11% from the prostaglandin-producing red alga Gracilaria vermiculophylla by ammonium sulfate precipitation, anion-exchange chromatoraphy and gel filtration chromatography. Sodium dodecylsulfate-polyacrylamide gel electrophoresis of the final preparation showed a single band corresponding to a molecular mass of 20 kDa, but Superdex 200 fast protein liquid chromatography exhibited a molecular mass of 40 kDa. Accordingly, it was suggested that the purified enzyme was a homodimer of a 20 kDa subunit. The optimal temperature and pH were 37°C and 7–8, respectively. The purified enzyme catalyzed hydrolysis of the acyl groups of both glycoglycerolipids and phospholipids, especially monogalacto-syldiacylglycerol and phosphatidylcholine. These results suggest that the enzyme hydrolyze the membrane lipids of the alga to release various saturated and unsaturated fatty acids, including arachidonic acid as substrate for prostaglandin synthesis.
- Published
- 2008
12. The esterification of glycerine with lauric acid catalyzed by multi-valent metal salts. Selective formation of mono- and dilaurins
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Ryo Nakamura, Yoshihiro Sugi, and Kenichi Komura
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chemistry.chemical_classification ,Zirconium ,Process Chemistry and Technology ,chemistry.chemical_element ,Salt (chemistry) ,General Chemistry ,Lauric acid ,Catalysis ,Monolaurin ,Solvent ,chemistry.chemical_compound ,chemistry ,medicine ,Organic chemistry ,Ferric ,Diglyceride ,medicine.drug ,Nuclear chemistry - Abstract
Multi-valent metal salts, such as zirconium, ferric, and aluminum salt hydrates gave high catalytic activity for the esterification of glycerine (GL) with lauric acid (LA) without the solvent. Among them, ZrOCl 2 · 8H 2 O and AlCl 3 · 6H 2 O gave lauric acid monoglyceride (Monolaurin; ML) in high selectivity. Fe 2 (SO 4 ) 3 · n H 2 O and Zr(SO 4 ) 2 · 4H 2 O gave lauric acid diglyceride (Dilaurin; DL) even in the excess of GL.
- Published
- 2008
13. Dependence of Sheet Resistance of CoSi2with Gate Length of 30 nm on Thickness of Titanium Nitride Capping Layer in Co-Salicide Process
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Satoshi Inagaki, Ryo Nakamura, Yuji Kataoka, Takashi Saiki, Masataka Kase, and Kazuo Kawamura
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Materials science ,Physics and Astronomy (miscellaneous) ,General Engineering ,General Physics and Astronomy ,chemistry.chemical_element ,Nanotechnology ,Salicide ,Titanium nitride ,chemistry.chemical_compound ,chemistry ,Etching (microfabrication) ,Silicide ,Composite material ,Tin ,Layer (electronics) ,Sheet resistance ,Titanium - Abstract
Since the distribution of gate resistance using cobalt silicide (CoSi2) increases markedly for gate lengths of 30 nm or less, CoSi2 is now being replaced by NiSi. However, CoSi2 still has the advantages of a high thermal stability and a low degree of roughness at the interface between the silicide and silicon layers owing to the low degree of mismatch (1.2%) of between their lattice constants. We have achieved excellent sheet resistance (Rs) with a gate length Lg=30 nm by optimizing the thickness of a cobalt capping layer of titanium nitride. The results shows an abnormal Rs behavior, in which one σ of Rs increases with capping layer thickness in the range of 10–50 nm, while it decreases with increasing capping layer thickness in the range of 0–10 nm. Unlike the results of a previous report [K. Goto et al.: IEDM Tech. Dig., 1995, p. 449], the variation in the Rs with a gate length Lg=30 nm is small, even without a TiN capping layer thickness down to 5–10 nm. We suggest that the uniformity of Rs is determined by the thickness of the CoSi layer after selective etching and the titanium concentration in the CoSi layer for capping TiN thicknesses of 10–50 nm, while the uniformity is determined by the titanium concentration and the damage sustained during selective etching for TiN thickness of 0–10 nm. For this optimization, CoSi2 is applicable to the 65 nm node technology node or beyond.
- Published
- 2007
14. Esterification of glycerol by lauric acid over aluminium and zirconium containing mesoporous molecular sieves in supercritical carbon dioxide medium
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Ayyamperumal Sakthivel, Ryo Nakamura, Kenichi Komura, and Yoshihiro Sugi
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Supercritical carbon dioxide ,General Chemical Engineering ,Inorganic chemistry ,Condensed Matter Physics ,Molecular sieve ,Lauric acid ,Supercritical fluid ,Catalysis ,Monolaurin ,chemistry.chemical_compound ,chemistry ,Physical and Theoretical Chemistry ,Mesoporous material ,Mesitylene ,Nuclear chemistry - Abstract
Aluminium and zirconium containing mesoporous MMS-H materials were synthesized and characterized using XRD and N2 adsorption/desorption analysis. The mesoporous materials were applied for the esterification of glycerol (GL) with lauric acid (LA) in supercritical CO2 (SCC) medium. The catalyst shows high conversion up to 93% with the formation of equal amount of lauric acid monoglyceride (Monolaurin; ML) and diglyceride (Dilaurin; DL). The catalytic activity in SCC medium was higher than those in mesitylene and without solvent under N2 atmosphere. The coke formation was less in SCC medium compared to those in the other reaction medium.
- Published
- 2007
15. DmGEN shows a flap endonuclease activity, cleaving the blocked-flap structure and model replication fork
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Tetsuyuki Ohashi, Kengo Sakaguchi, Ryo Takeuchi, Seisuke Kimura, Kei Ichi Takata, Ryo Nakamura, Ayumi Ihara, Yoshihiro Kanai, Tatsushi Ruike, and Gen Ishikawa
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Exonuclease ,Nuclease ,DNA replication ,Flap structure-specific endonuclease 1 ,Cell Biology ,Biology ,Biochemistry ,Molecular biology ,Endonuclease ,chemistry.chemical_compound ,chemistry ,Mutant protein ,biology.protein ,Molecular Biology ,Flap endonuclease activity ,DNA - Abstract
Drosophila melanogaster XPG-like endonuclease (DmGEN) is a new category of nuclease belonging to the RAD2/XPG family. The DmGEN protein has two nuclease domains (N and I domains) similar to XPG/class I nucleases; however, unlike class I nucleases, in DmGEN these two nuclease domains are positioned close to each other as in FEN-1/class II and EXO-1/class III nucleases. To confirm the properties of DmGEN, we characterized the active-site mutant protein (E143A E145A) and found that DmGEN had flap endonuclease activity. DmGEN possessed weak nick-dependent 5'-3' exonuclease activity. Unlike XPG, DmGEN could not incise the bubble structure. Interestingly, based on characterization of flap endonuclease activity, DmGEN preferred the blocked-flap structure as a substrate. This feature is distinctly different from FEN-1. Furthermore, DmGEN cleaved the lagging strand of the model replication fork. Immunostaining revealed that DmGEN was present in the nucleus of actively proliferating Drosophila embryos. Thus, our studies revealed that DmGEN belongs to a new class (class IV) of the RAD2/XPG nuclease family. The biochemical properties of DmGEN and its possible role are also discussed.
- Published
- 2007
16. Multi-Valent Metal Salt Hydrates as Catalysts for the Esterification of Fatty Acids and Alcohols
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Ryo Nakamura, Yasuyuki Miyata, Kenichi Komura, Yoshihiro Sugi, and Kshudiram Mantri
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inorganic chemicals ,chemistry.chemical_classification ,Mechanical Engineering ,Salt (chemistry) ,Fatty acid ,Alcohol ,Mesoporous silica ,Condensed Matter Physics ,Chloride ,Catalysis ,Metal ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Yield (chemistry) ,visual_art ,visual_art.visual_art_medium ,medicine ,Organic chemistry ,General Materials Science ,medicine.drug - Abstract
Some typical multi-valent metal salt hydrates, such as chloride, nitrate, sulfate, and acetate of Fe3+, Al3+, Ga3+, In3+, ZrO2+, HfO2+, Zn2+, Co2+, Ni2+, Mn3+, Cr3+, and Cu2+ have catalytic activities for the esterification of saturated and unsaturated fatty acids and alcohols. Supporting these metal salt hydrates on ordered mesoporous silica such as MCM-41 enhanced the catalytic activity of the esterification. The esters of C10-C18 normal acid and alcohol were obtained in high yield by some of supported metal salt hydrates on MCM-41; however, the yield of the esters decreased with their chain length of acids and alcohols although the activities depended on type of metal salt hydrates. The catalyst is recyclable although some loss of activity was observed.
- Published
- 2007
17. Isolation of a spontaneous cerulenin-resistant sake yeast with both high ethyl caproate-producing ability and normal checkpoint integrity
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Hiroki Okada, Takayuki Koyano, Hitoshi Shimoi, Dai Hirata, Tetsuya Goshima, Kazunori Kume, Ryo Nakamura, Hiroyasu Tamura, Masaki Mizunuma, Takeshi Akao, and Yoshikazu Ohya
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Saccharomyces cerevisiae Proteins ,Mutant ,Saccharomyces cerevisiae ,Cell Cycle Proteins ,Protein Serine-Threonine Kinases ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Drug Resistance, Fungal ,Molecular Biology ,Checkpoint Kinase 2 ,Caproates ,biology ,business.industry ,Alcoholic Beverages ,Organic Chemistry ,General Medicine ,biology.organism_classification ,Yeast ,Cerulenin ,Spindle checkpoint ,chemistry ,Fermentation ,Mutation ,Food Microbiology ,Brewing ,Benomyl ,Fatty Acid Synthases ,business ,Biotechnology - Abstract
In the brewing of high-quality sake such as Daiginjo-shu, the cerulenin-resistant sake yeast strains with high producing ability to the flavor component ethyl caproate have been used widely. Genetic stability of sake yeast would be important for the maintenance of both fermentation properties of yeast and quality of sake. In eukaryotes, checkpoint mechanisms ensure genetic stability. However, the integrity of these mechanisms in sake yeast has not been examined yet. Here, we investigated the checkpoint integrity of sake yeasts, and the results suggested that a currently used cerulenin-resistant sake yeast had a defect in spindle assembly checkpoint (SAC). We also isolated a spontaneous cerulenin-resistant sake yeast FAS2-G1250S mutant, G9CR, which showed both high ethyl caproate-producing ability and integrity/intactness of the checkpoint mechanisms. Further, morphological phenotypic robustness analysis by use of CalMorph supported the genetic stability of G9CR. Finally, we confirmed the high quality of sake from G9CR in an industrial sake brewing setting.
- Published
- 2015
18. Heat Gelling Properties of Hen's Egg Yolk Low Density Lipoprotein (LDL) in the Presence of Other Protein
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Ryo Nakamura and Eiji Kojima
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food.ingredient ,Chromatography ,biology ,Scanning electron microscope ,chemistry.chemical_compound ,Ovalbumin ,food ,Gel strength ,chemistry ,Yolk ,Low-density lipoprotein ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Bovine serum albumin ,Lysozyme ,Food Science - Abstract
Ovalbumin (OV), bovine serum albumin (BSA) and lysozyme (Lys) were added to egg yolk low density lipoprotein (LDL) and the heat-induced gel formation of LDL-protein mixture was studied. The gel formation of LDL-protein mixture was different between the acidic and alkaline pH region; fine stable gels were formed in the alkaline pH region, but weak paste-like gels were formed in the acidic pH region. The effect of added BSA or OV on the gel strength of LDL was much larger than that of Lys. Scanning electron micrographic observation showed that the microstructures of both LDL-BSA and LDL-OV gels were more uniform than that of LDL-Lys gel.
- Published
- 2006
19. Effect of Hydroxamic Acid-Based Matrix Metalloproteinase Inhibitors on Human Gingival Cells andPorphyromonas gingivalis
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Daisuke Hinode, Denis Mayrand, Nozomi Yokoyama, Daniel Grenier, Tomoaki Honna, Masami Yoshioka, Ryo Nakamura, Kaname Masuda, and Mahmoud Rouabhia
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Keratinocytes ,Matrix metalloproteinase inhibitor ,Gingiva ,Matrix Metalloproteinase Inhibitors ,Matrix metalloproteinase ,Hydroxamic Acids ,Statistics, Nonparametric ,chemistry.chemical_compound ,Cell Movement ,Humans ,RNA, Messenger ,Viability assay ,Keratinocyte migration ,Cytotoxicity ,Porphyromonas gingivalis ,Cells, Cultured ,Hydroxamic acid ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Chemistry ,Cell growth ,Phenyl Ethers ,Epithelial Cells ,Tissue Inhibitor of Metalloproteinases ,Fibroblasts ,biology.organism_classification ,Molecular biology ,Biochemistry ,Periodontics - Abstract
Matrix metalloproteinases (MMPs) are considered to play key roles in tissue destruction during periodontitis. In this study, we evaluated the cytotoxicity of hydroxamic acid-based MMP inhibitors (ONO-4817, ONO-MI1-514, and ONO-MI1-570), and their inhibitory effects on MMP-2 and -9 activities and growth of Porphyromonas gingivalis.Human gingival fibroblasts (HGF) and human gingival epithelial cells (HGE) were incubated with test inhibitors prior to investigating cell viability, cell proliferation, and mRNA expression for MMP-2 and -9. Gelatin zymography and a colorimetric MMP assay were performed to study the inhibitory effects on MMP-2 and -9 activities derived from HGF and HGE, respectively. The effect of MMP inhibitors on keratinocyte migration and P. gingivalis growth was also tested.Cell viability was not affected by any of the inhibitors at a final concentration of 50 microM, nor was cell proliferation at 20 microM. All inhibitors clearly inhibited MMP-2 produced by HGF and MMP-9 produced by HGE in a dose-dependent manner. No change was found in mRNA expression of MMPs by gingival cells treated with the inhibitors. ONO-4817 and ONO-MI1-514 inhibited keratinocyte migration. ONO-4817 showed a slightly inhibitory effect on the growth of P. gingivalis.Data obtained in this study support the potential use of the three MMP inhibitors for the prevention and treatment of periodontal disease.
- Published
- 2003
20. Increased inactivation of nitric oxide is involved in impaired coronary flow reserve in heart failure
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Kensuke Egashira, Akira Takeshita, Ken-ichi Arimura, Hiroaki Shimokawa, Ryo Nakamura, Hiroyuki Tsutsui, Tomomi Ide, and Youji Machida
- Subjects
Nitroprusside ,Pacemaker, Artificial ,medicine.medical_specialty ,Adenosine ,genetic structures ,Endothelium ,Physiology ,Vasodilator Agents ,Hyperemia ,Vasodilation ,Nitric Oxide ,Nitric oxide ,chemistry.chemical_compound ,Dogs ,Coronary Circulation ,Tachycardia ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Enzyme Inhibitors ,Endothelial dysfunction ,Heart Failure ,Tiron ,omega-N-Methylarginine ,Lipid peroxide ,business.industry ,Myocardium ,Coronary flow reserve ,medicine.disease ,Immunohistochemistry ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Echocardiography ,1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt ,Indicators and Reagents ,Endothelium, Vascular ,Lipid Peroxidation ,Sodium nitroprusside ,Reactive Oxygen Species ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Recent evidence suggests that increased inactivation of endothelium-derived nitric oxide (NO) by oxygen free radical (OFR) formation is involved in the pathogenesis of endothelial dysfunction in heart failure (HF). However, it is unclear whether increased OFR limits coronary flow reserve in HF. To test this hypothesis, we examined the effects of antioxidant therapy on coronary flow reserve in a canine model of tachycardia-induced HF. The flow reserve (percent increase in coronary blood flow) to adenosine or to 20-s ischemia was less and OFR formation (electron-spin resonance spectroscopy) in myocardial tissues was greater in HF dogs than in controls. Immunohistochemical staining of 4-hydroxy-2-nonenal, an OFR-induced lipid peroxide, was detected in coronary microvessels of HF dogs. Intracoronary infusion of a cell-permeable OFR scavenger, tiron, suppressed OFR formation and improved the vasodilating capacity to adenosine or brief ischemia in HF dogs but not in controls. A NO synthesis inhibitor, N G-monomethyl-l-arginine (l-NMMA), diminished the beneficial effects of tiron in HF dogs. Vasodilation to sodium nitroprusside was similar between control and HF dogs, and no change in its response was noted with tiron or tiron + l-NMMA in either group. In summary, antioxidant treatment with tiron improved coronary flow reserve by increasing NO bioactivity in HF dogs. Thus increased OFR formation may impair coronary flow reserve in HF by reducing NO bioactivity.
- Published
- 2001
21. High-Efficiency GaN/AlxGa1?xN Multi-Quantum-Well Light Emitter Grown on Low-Dislocation Density AlxGa1?xN
- Author
-
T. Ukai, Satoshi Kamiyama, Hiroshi Amano, Tomoaki Sano, Motoaki Iwaya, Ryo Nakamura, S. Terao, Isamu Akasaki, and S. Takanami
- Subjects
Materials science ,Aluminium nitride ,business.industry ,Gallium nitride ,Condensed Matter Physics ,Epitaxy ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,Wavelength ,Full width at half maximum ,chemistry ,law ,Optoelectronics ,Dislocation ,business ,Quantum well ,Light-emitting diode - Abstract
Crack-free and low-dislocation-density Al x Ga 1-x N was achieved by low-temperature-deposited interlayer technique in combination with a lateral seeding epitaxy. We found that there was a strong correlation between the threading dislocation density and the PL intensity in the GaN/AIGaN MQWs. This new UV light emitting diode exhibits strong UV light output, having peak wavelength of 352 nm, a full width at half maximum as narrow as 6 nm and output power of 0.6 mW at 50 mA dc current injection.
- Published
- 2001
22. Consumption of Peptide-derived Arginine by a Periodontopathogenic Bacterium, Porphyromonas gingivalis
- Author
-
Daisuke Hinode, Masami Yoshioka, Kaname Masuda, Hiroyuki Hayashi, Ryo Nakamura, and Koji Tomita
- Subjects
chemistry.chemical_classification ,Arginine ,Lysine ,Ornithine ,Biology ,biology.organism_classification ,Microbiology ,Amino acid ,chemistry.chemical_compound ,Infectious Diseases ,chemistry ,Biochemistry ,Citrulline ,Energy source ,Arginine deiminase pathway ,Porphyromonas gingivalis - Abstract
The specificity of amino acid consumption by Porphyromonas gingivalis , well known as an important pathogen of adult periodontitis, is described. P. gingivalis is an asaccharolytic, black-pigmented and gram-negative anaerobe and produces several types of proteases including cysteine proteases such as arg-gingipain and trypsin-like enzyme. This suggests that arginine is a possible energy source for its growth. When P. gingivalis was grown anaerobically in brain–heart infusion broth, several free amino acids such as lysine, glycine and glutamic acid increased in the culture supernatant with the bacterial growth; but free arginine increased first and then started to decrease after the early log phase. Citrulline and ornithine increased to late log phase in contrast to the decrease of arginine. The total arginine in the medium decreased steadily with the growth of P. gingivalis . In relation to the arginine consumption, cell extracts of P. gingivalis clearly demonstrated enzyme activities for the arginine deiminase pathway and adenosine triphosphate production. The arginine deiminase pathway was also presumed from the presence of putative homologue corresponding to the other bacterial arginine deiminase pathway relating enzymes in the unfinished P. gingivalis W83 genome. These results suggest that P. gingivalis catabolizes arginine which is released from proteins and/or peptides by several types of proteases, and obtains energy through the arginine deiminase pathway.
- Published
- 2001
23. Increased inactivation of nitric oxide is involved in coronary endothelial dysfunction in heart failure
- Author
-
Akira Takeshita, Kensuke Egashira, Hiroaki Shimokawa, Hiroyuki Tsutsui, Tomomi Ide, Ken-ichi Arimura, and Ryo Nakamura
- Subjects
medicine.medical_specialty ,Free Radicals ,Nitric Oxide Synthase Type III ,genetic structures ,Heart disease ,Physiology ,Nitric Oxide ,Nitric oxide ,chemistry.chemical_compound ,Dogs ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Enzyme Inhibitors ,Endothelial dysfunction ,Heart Failure ,omega-N-Methylarginine ,biology ,business.industry ,Hemodynamics ,medicine.disease ,Coronary Vessels ,Immunohistochemistry ,Acetylcholine ,Electric Stimulation ,Nitric oxide synthase ,Endothelial stem cell ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Echocardiography ,Heart failure ,Circulatory system ,1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt ,cardiovascular system ,biology.protein ,Indicators and Reagents ,Endothelium, Vascular ,Lipid Peroxidation ,Nitric Oxide Synthase ,Cardiology and Cardiovascular Medicine ,business ,Blood vessel - Abstract
Recent evidence suggests the possibility that enhanced inactivation of endothelium-derived nitric oxide (NO) by oxygen free radical (OFR) may cause endothelial dysfunction in heart failure (HF). To test this hypothesis, we examined the effect of antioxidant therapy on endothelium-dependent vasodilation of the coronary circulation in a canine model of tachycardia-induced HF. Endothelium-dependent vasodilation was less than that in controls, and OFR formation in coronary arterial and myocardial tissues was greater in HF dogs than those in controls. The immunohistochemical staining of 4-hydroxy-2-nonenal, OFR-induced lipid peroxides was detected in coronary microvessels of HF dogs. Intracoronary infusion of the cell-permeable OFR scavenger Tiron inhibited OFR formation and improved endothelium-dependent vasodilation in HF dogs but not in controls. The NO synthesis inhibitor N G-monomethyl-l-arginine (l-NMMA) diminished the beneficial effect of Tiron in HF dogs. Endothelium-independent vasodilation was similar between control and HF dogs, and no change in its response was noted by Tiron or Tiron plus l-NMMA in either group. In summary, antioxidant treatment with Tiron improved coronary vascular endothelium-dependent vasodilation by increasing NO activity in tachycardia-induced HF. Thus coronary endothelial dysfunction in HF may be, at least in part, due to increased inactivation of NO by OFR.
- Published
- 2001
24. Modification of Ovalbumin with Glucose 6-Phosphate by Amino-Carbonyl Reaction. Improvement of Protein Heat Stability and Emulsifying Activity
- Author
-
Yasuko Kato, Tsukasa Matsuda, Takayoshi Aoki, Natsuki Kato, and Ryo Nakamura
- Subjects
Chromatography ,biology ,Protein polymerization ,Chemical modification ,General Chemistry ,Maillard reaction ,symbols.namesake ,chemistry.chemical_compound ,Ovalbumin ,Glucose 6-phosphate ,chemistry ,Glycation ,symbols ,biology.protein ,Organic chemistry ,Phosphorylation ,Thermal stability ,General Agricultural and Biological Sciences - Abstract
Ovalbumin (OVA) was modified with glucose (Glu) and glucose 6-phosphate (G6P) through the amino-carbonyl reaction (Maillard reaction), and heat-induced aggregation and emulsifying activity of the modified proteins were investigated. G6P reacted with the free amino groups in a similar manner to Glu; about 70-80% of the total amino groups were blocked by the reaction at 50 o C, and 65% relative humidity for 3 days. However, the reaction with G6P induced protein polymerization and brown-color development more strongly than that of Glu. OVA modified with G6P was much more acidic than either native OVA or the Glu-modified OVA, and it was highly soluble and quite resistant to heat-induced aggregation, i.e., its high-concentration solution (5%) was still completely soluble and transparent even after being heated at 100 o C for 10 min. Furthermore, OVA emulsifying activity was increased about 5-fold by the modification with G6P
- Published
- 1995
25. Isolation of Psychrotrophic Lactic Acid Bacteria, and its Application for Fermented Meat Products
- Author
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Yukiko Yoneyama, Ryo Nakamura, Masayuki Sugimoto, Umeyuki Doi, and Takeo Kato
- Subjects
chemistry.chemical_compound ,chemistry ,Fermentation ,Biology ,Isolation (microbiology) ,biology.organism_classification ,Bacteria ,Microbiology ,Lactic acid - Abstract
発酵ソーセージなどの発酵肉製品を安全に製造するために,食肉及び食品加工品から低温発酵能を有する乳酸菌を分離し,スターターとしての適性と有害微生物の生育阻止について検討した.1) 市販牛肉より低温発酵能を有する乳酸菌Lactobacillus sp. SK-1001を分離した.2) Lactobacillus sp. SK-1001は発酵肉製品用スターターとしての基本的適性を有した.実験用のビーカーソーセージを用いて検討した結果, Lactobacillus sp. SK-1001は5℃及び10℃でソーセージを発酵できることが認められた.3) 低温発酵によって,ビーカーソーセージ中のS.aureus, E. coli, P. fluorescensは減少した.また, Lac-tobacillus sp. SK-1001の抗菌活性はその生産する乳酸と微量の酢酸によると推定された.4) 試作試験を行った結果, Lacbacillus sp. SK-1001は発酵ソーセージ及び発酵ハムの低温スターターとして使用できることが認められた.
- Published
- 1994
26. Aggregation of Human Gingival Fibroblasts by Porphyromonas gingivalis
- Author
-
Daisuke Hinode, Masami Morioka, Kanako Yamato, Atsushi Nagata, Mika Ueda, Ryo Nakamura, and Hiroyuki Hayashi
- Subjects
chemistry.chemical_classification ,Protease ,biology ,medicine.medical_treatment ,Vesicle ,Cell ,Leupeptin ,biology.organism_classification ,Microbiology ,chemistry.chemical_compound ,Enzyme ,medicine.anatomical_structure ,chemistry ,medicine ,Bacterial outer membrane ,Porphyromonas gingivalis ,Bacteria - Abstract
The early step in bacterial infections is to adhere the pathogenic bacteria to the host tissue. The cell-aggregating activity of the specific bacteria is considered to be correlated with this mechanism. In this study, the cell aggregating activity of the bacterial surface components from Porphyromonas gingivalis was determined using human gingival fibroblasts (HGF). Among the components tested, only the outer membrane vesicles aggregated the HGF actively. The aggregating activity disappeared by the heat treatment, suggesting that the cell aggregating factor is a proteinous substance. The activity was also inhibited by some protease inhibitors such as TLCK and leupeptin, but it was activated by dithiothreitol proportionally with the increase of the concentration. From these effects which resemble those of the thiol dependent trypsin like protease of P. gingivalis, we suggest that the cell aggregating factor of the outer membrane vesicles is associated with this enzyme.
- Published
- 1994
27. A structural study of the asparagine-linked oligosaccharide moiety of duck ovomucoid
- Author
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Ryo Nakamura, Tsukasa Matsuda, Yoji Arata, Ichio Shimada, Noriko Takahashi, and Kazuno Shikami
- Subjects
Magnetic Resonance Spectroscopy ,Molecular Sequence Data ,Oligosaccharides ,Chemical Fractionation ,Ovomucin ,Quail ,Biochemistry ,High-performance liquid chromatography ,chemistry.chemical_compound ,Species Specificity ,Exoglycosidase ,Amide ,Carbohydrate Conformation ,Animals ,Moiety ,Organic chemistry ,Asparagine ,Sugar ,Molecular Biology ,chemistry.chemical_classification ,Chromatography ,Molecular Structure ,Cell Biology ,Oligosaccharide ,Ducks ,Carbohydrate Sequence ,chemistry ,Proton NMR ,Chickens - Abstract
Asparagine-linked oligosaccharides of duck ovomucoid were released quantitatively from the protein by digestion with glycoamidase A (from almond), the reducing ends of the oligosaccharide chains thus obtained were aminated with a fluorescent reagent, 2-aminopyridine, and the mixture of pyridylamino derivatives of the oligosaccharides was separated using two different types of high performance liquid chromatography (HPLC) on a reversed phase column and an amide adsorption column. More than sixteen different oligosaccharides were separated and the structures were characterized by a combination of the 2-dimensional sugar mapping technique using HPLC, exoglycosidase digestion, and proton nuclear magnetic resonance measurements (1- and 2-dimensional). Furthermore, the HPLC profile of duck ovomucoid oligosaccharides was compared with previously reported profiles obtained from quail and chicken ovomucoids.
- Published
- 1993
28. Isolation ofEnterococcus faeciumwith Antibacterial Activity and Characterization of Its Bacteriocin
- Author
-
Ryo Nakamura, Yukiko Yoneyama, Hiroshi Kato, Takeo Kato, and Tsukasa Matsuda
- Subjects
biology ,Organic Chemistry ,food and beverages ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,Lactic acid ,Microbiology ,chemistry.chemical_compound ,Enterococcus ,chemistry ,Bacteriocin ,Food science ,Antibacterial activity ,Mode of action ,Molecular Biology ,Bacteria ,Biotechnology ,Antibacterial agent ,Enterococcus faecium - Abstract
Enterococcus faecium-100, screened from 120 strains of lactic acid bacteria, produced an antibacterial substance. From the narrow inhibitory spectrum, proteineous nature, and bactericidal mode of action, this antibacterial substance was concluded to be a bacteriocin and designated enterocin-100. E. faecium-100 produced bacteriocin during its log phase and in a narrow pH range of the culture broth around pH 6.3. Enterocin-100 was most active at neutral pH between 6 and 8, and was stable below pH 5.0. From the scanning electron microscopic observation, enterocin-100 caused morphorogical changes especially in highly sensitive bacteria at log and stationary phase.
- Published
- 1993
29. Cytotoxicity of Porphyromonas gingivalis Toward Cultured Human Gingival Fibroblasts
- Author
-
Daisuke Hinode, S. Ichimiya, Makoto Sato, Reiko Kido, Masami Morioka, Ryo Nakamura, and Atsushi Nagata
- Subjects
Protease ,biology ,Lipopolysaccharide ,medicine.medical_treatment ,biology.organism_classification ,In vitro ,Microbiology ,chemistry.chemical_compound ,chemistry ,medicine ,Cytotoxic T cell ,Bacteroides ,Cytotoxicity ,Bacterial outer membrane ,Porphyromonas gingivalis - Abstract
Direct cytotoxicity of black-pigmented Bacteroides was studied in the confluent monolayer of human gingival fibroblasts (HGF) in vitro. Only strains from Porphyromonas gingivalis caused morphological alteration (cell-rounding) and notable depression of viability of fibroblasts. This cytotoxicities were remarkably reduced by treating bacterial cells with acidic buffer (pH 3.5) at 37°C for 30 min. To determine the location of the cytotoxicity, bacterial surface components, i. e., outer membrane (OM), lipopolysaccharide (LPS) and outer membrane vesicles (OM-V) from P. gingivalis 381 were prepared and their cytotoxicity was assessed. The cytotoxicity of OM-V was found to be much stronger than that of the other two components, and this cytotoxic factor seemed to consist largely of protein and to be associated with the enzyme activity of OM-V. The effects of some protease inhibitors and L-cysteine on the cytotoxicity of OM-V suggest that the mechanism of cell-rounding is different from that of cell death.
- Published
- 1992
30. Purification and characterization of three types of proteases from culture supernatants of Porphyromonas gingivalis
- Author
-
Ryo Nakamura, H Hayashi, and Daisuke Hinode
- Subjects
Proteases ,medicine.medical_treatment ,Proteolysis ,Molecular Sequence Data ,Immunology ,Microbiology ,Chromatography, Affinity ,chemistry.chemical_compound ,Affinity chromatography ,Endopeptidases ,Enzyme Stability ,medicine ,Bacteroides ,Protease Inhibitors ,Amino Acid Sequence ,Chromatography, High Pressure Liquid ,Serine protease ,Protease ,biology ,medicine.diagnostic_test ,Leupeptin ,Trypsin ,Culture Media ,Infectious Diseases ,Biochemistry ,chemistry ,biology.protein ,Diisopropyl fluorophosphate ,Electrophoresis, Polyacrylamide Gel ,Parasitology ,Research Article ,medicine.drug - Abstract
Three types of caseinolytic proteases (Pase-A, Pase-B, and Pase-C) were isolated and purified from culture supernatants of Porphyromonas gingivalis 381 by the combined procedures of acetone precipitation, gel filtration, solubilization with octylthioglucoside followed by affinity chromatography on arginine-Sepharose 4B, high-performance liquid chromatography (HPLC) on Biofine IEC-DEAE, and HPLC on TSK-G4000SW. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Pase-A and -B showed diffuse protein bands of 105 to 110 and 72 to 80 kDa, respectively, and Pase-C showed a clear band of about 44 kDa. Pase-B and -C hydrolyzed some synthetic substrates for trypsin, but Pase-B did not act on the carboxyl side of lysine in insulin chain B or on a synthetic substrate which trypsin and Pase-C acted on. Pase-A did not act on the synthetic substrates but cleaved the peptide bonds Glu-Ala and Ala-Leu of insulin. Leupeptin inhibition of the caseinolytic activity of both Pase-A and -B was similar to its inhibition of Pase-C. Phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate strongly inhibited Pase-A, but no significant effect on the other enzymes was observed, suggesting that only Pase-A is a serine protease. The inhibitory characteristics of Pase-B and -C were very similar. Pase-A was not thiol dependent for enzyme activity, but Pase-B was strongly dependent, i.e., even more so than Pase-C. Pase-A inactivated the inhibitory activity of plasma alpha-1-antitrypsin, but the other two did not. These results show that P. gingivalis produces different types of proteases other than the trypsinlike protease generally reported.
- Published
- 1991
31. Enhancing Effect of Malondialdehyde Modification on the Mouse IgE Response to Protein Antigens
- Author
-
Tsukasa Matsuda, Ryo Nakamura, and Hisanori Tani
- Subjects
Antigenicity ,Ovalbumin ,Serum albumin ,Lactoglobulins ,Immunoglobulin E ,Antibodies ,General Biochemistry, Genetics and Molecular Biology ,Mice ,chemistry.chemical_compound ,Lipid oxidation ,Antigen ,Malondialdehyde ,Animals ,Antigens ,Bovine serum albumin ,skin and connective tissue diseases ,Mice, Inbred BALB C ,biology ,Circular Dichroism ,Proteins ,Serum Albumin, Bovine ,chemistry ,Biochemistry ,biology.protein ,Female ,Immunization ,Antibody ,General Agricultural and Biological Sciences - Abstract
To investigate the immunochemical properties of proteins reacted with malondialdehyde (MDA), which is a major degradation product of lipid oxidation, the antibody responses of mice immunized with MDA-modified bovine serum albumin (BSA) were examined. The specific IgE response to MDA-BSA was 4 to 8 times higher than that to native BSA, suggesting that the specific IgE antibody response to MDA-modified protein was enhanced by MDA bound to the surface of the protein. The antibodies to MDA-BSA did not distinguish the modified protein from the native one, and the antibodies raised against the modified proteins were not specific for the MDA portion but were for the carrier proteins.
- Published
- 1990
32. Analysis of Lactose-Protein Maillard Complexes in Commercial Milk Products by Using Specific Monoclonal Antibodies
- Author
-
Yasuko Kato, Tsukasa Matsuda, Ryo Nakamura, and N. Kato
- Subjects
food.ingredient ,medicine.drug_class ,food and beverages ,Pasteurization ,Free amino ,Monoclonal antibody ,law.invention ,Maillard reaction ,symbols.namesake ,chemistry.chemical_compound ,fluids and secretions ,food ,Milk products ,chemistry ,law ,Skimmed milk ,symbols ,medicine ,Food science ,Lactose - Abstract
Summary Lactose-protein Maillard complexes were immunochemically analyzed in various commercial milk products by ELISA and Immunoblotting using a specific monoclonal antibody. The Maillard complexes were detected in all samples analyzed, i.e., modified milk powder, skim milk powder, market pasteurized milk, milk beverages and concentrated milk. The apparent contents of Maillard complexes did not necessarily correlate to the loss of free amino groups, and the contents were generally higher in powdered milk products and milk beverages than in the market pasteurized milk. There appeared to be some relationship between the content of Maillard complexes and the time and temperature for pasteurization. Caseins were the major proteins detected by the antibody as lactose-protein Maillard complexes in various commercial milk products, though several whey proteins and unidentified polymerized proteins were also detected in some of the milk products. Thus, the monoclonal antibody was useful for in situ detection of lactose-protein Maillard adducts in milk and milk products.
- Published
- 2005
33. Synthesis of Aromatic Esters Catalyzed by Palladium on Charcoal: An Efficient Heterogeneous Catalyst for Alkoxycarbonylation of Aryl Iodides
- Author
-
Yoshihiro Sugi, Yoshihiro Kubota, Ryo Nakamura, Minoru Miwa, and Chinnasamy Ramesh
- Subjects
Chemistry ,Aryl ,Organic Chemistry ,chemistry.chemical_element ,General Medicine ,Heterogeneous catalysis ,Catalysis ,chemistry.chemical_compound ,visual_art ,Yield (chemistry) ,visual_art.visual_art_medium ,Organic chemistry ,Phenols ,Charcoal ,Carbonylation ,Carbon monoxide ,Palladium - Abstract
Palladium on charcoal was found to catalyze the carbon-ylation of aryl iodides with various aliphatic alcohols as well as less reactive phenols to give the corresponding esters in high yield at 140 °C and in the presence of carbon monoxide (1.0 MPa). The carbonylation-polycondensation of 2,7-diiodo-9,10-dihydrophenanthrene with bisphenol-A afforded high molecular weight polyarylate, poly [oxy-1,4-phenylene (1-methylethylidene)-1,4-phenyleneoxycarbonyl(9,10-dihydro-2,7-phenanthrenediyl)carbonyl].
- Published
- 2003
34. Diels-Alder reaction catalyzed by ordered micro and mesoporous silicates
- Author
-
Hiroyuki Ishida, Yoshihiro Sugi, Ryo Nakamura, and Yoshihiro Kubota
- Subjects
chemistry.chemical_compound ,Mesoporous organosilica ,Cyclopentadiene ,Chemistry ,Polymer chemistry ,Organic chemistry ,Reactivity (chemistry) ,Mesoporous material ,Zeolite ,Mordenite ,Catalysis ,Diels–Alder reaction - Abstract
Ordered microand mesoporous silicates such as mordenite, Y-zeolite, zeolite beta, and MCM-41 in their proton forms effectively enhance the reactivity and stereoselectivity in the Diels-Alder reaction of cyclopentadiene with 3-buten-2-one (MVK). All-silica periodic mesoporous materials such as [Si]-MCM-41 and FSM-16 also significantly promoted the reaction.
- Published
- 2003
35. Effects of Meat-conditioning and Lactic Fermentation on Pork Muscle Protein Degradation
- Author
-
Takeo Kato, Yasushi Sato, Masayuki Sugimoto, Toyoyuki Tahara, Ryo Nakamura, and Tsukasa Matsuda
- Subjects
Proteases ,medicine.diagnostic_test ,Proteolysis ,Organic Chemistry ,food and beverages ,General Medicine ,Protein degradation ,Biology ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Biochemistry ,Analytical Chemistry ,Lactic acid ,chemistry.chemical_compound ,chemistry ,medicine ,Fermentation ,Food science ,Molecular Biology ,Incubation ,Lactic acid fermentation ,Bacteria ,Biotechnology - Abstract
Fresh and conditioed pork were incubated with and without lactic acid bacteria, and the meat protein degradation during incubation was investigatd. The combination of meat-conditioning and addition of lactic acid bacteria considerably accelerated the protein degradation of meat mixtures. It was considered that the protein degradation in the lactic fermented pork was caused by proteases originated in meats, and both meat-conditioning and lactic acid fermentation acted as enhancing effectors.
- Published
- 1994
36. Generation of plasma kinin by three types of protease isolated from Porphyromonas gingivalis 381
- Author
-
Masami Morioka, S. Ichimiya, Hiroyuki Hayashi, Atsushi Nagata, Ryo Nakamura, and Daisuke Hinode
- Subjects
medicine.medical_treatment ,Bradykinin ,Kinins ,Dithiothreitol ,chemistry.chemical_compound ,Endopeptidases ,medicine ,General Dentistry ,Porphyromonas gingivalis ,Periodontal Diseases ,chemistry.chemical_classification ,Kininogen ,Protease ,biology ,Prekallikrein ,Cell Biology ,General Medicine ,Kinin ,biology.organism_classification ,Enzyme ,Otorhinolaryngology ,chemistry ,Biochemistry ,Kallikreins ,circulatory and respiratory physiology - Abstract
Three types of protease (A, B and C) isolated from the culture supernatant of Porphyromonas gingivalis 381 had peculiar activities on kinin generation from high molecular-weight kininogen in vitro. Protease C released bradykinin from the kininogen in a reaction mixture containing 2 mM dithiothreitol, but A and B did not. However, the activity of degrading bradykinin was much stronger in protease A and B than in C. These findings suggest that only protease C shows plasma kallikrein activity.
- Published
- 1992
37. Greater susceptibility of failing cardiac myocytes to oxygen free radical-mediated injury
- Author
-
Kensuke Egashira, Ryo Nakamura, Hiroyuki Tsutsui, Akira Takeshita, Tomomi Ide, Hideo Utsumi, Nobuhiro Suematsu, and Shunji Hayashidani
- Subjects
medicine.medical_specialty ,Free Radicals ,Physiology ,Radical ,Cell Culture Techniques ,Oxidative phosphorylation ,medicine.disease_cause ,Antioxidants ,Superoxide dismutase ,chemistry.chemical_compound ,Dogs ,Physiology (medical) ,Internal medicine ,medicine ,Myocyte ,Animals ,Cell Size ,chemistry.chemical_classification ,Heart Failure ,Reactive oxygen species ,Glutathione Peroxidase ,biology ,Superoxide Dismutase ,Glutathione peroxidase ,Myocardium ,Electron Spin Resonance Spectroscopy ,Catalase ,Myocardial Contraction ,Oxidative Stress ,Endocrinology ,chemistry ,biology.protein ,Hydroxyl radical ,Cardiology and Cardiovascular Medicine ,Oxidative stress - Abstract
Objective: Oxygen-derived free radicals can produce myocardial cellular damage, which might contribute to the ischemia-reperfusion injury and to heart failure (HF). However, the effects of oxygen radicals on myocyte structure have not been examined in the failing heart. Methods: We examined the susceptibility of intact cardiac myocytes isolated from control ( n = 16) and rapid pacing (240 bpm, 4 wks)-induced HF ( n = 8) dog hearts to an exogenous hydroxyl radical (·OH), generated from H2O2 and Fe3+-nitrilotriacetate. The production of ·OH was monitored by electron spin resonance with 5,5′-dimethyl-1-pyroline- N -oxide (DMPO) as a spin trap. Results: The magnitude of DMPO-OH signals was not attenuated in the presence of either control or HF myocytes. ·OH induced a time-dependent decrease in myocyte length (i.e. hypercontracture). The time to the onset of hypercontracture and that to the submaximal hypercontracture after exposure was significantly shortened in HF. Activities of superoxide dismutase, catalase, and glutathione peroxidase was not decreased in HF. Conclusions: HF myocytes were more susceptible to oxidative stress-induced cellular injury, which was not due to decreased antioxidant defense, but to the intrinsic properties of cells.
- Published
- 2000
38. Remarkable Improvement of Catalytic Performance in Dimethyl Ether to Olefin Reaction over CeO2-modified Calcium-containing MFI Type Zeolite
- Author
-
Kenichi Komura, Akira Iida, Yoshihiro Sugi, and Ryo Nakamura
- Subjects
Propene ,chemistry.chemical_compound ,Olefin fiber ,chemistry ,chemistry.chemical_element ,Organic chemistry ,Dimethyl ether ,General Chemistry ,Calcium ,Zeolite ,Catalysis - Abstract
Dimethyl ether to olefin (DTO) reaction was examined over CeO2-modified Ca-MFI as a catalyst. The CeO2-modified Ca-MFI (Ce/Ca-MFI) showed excellent catalytic performance to give propene as a main p...
- Published
- 2008
39. Esterification of Long Chain Aliphatic Acids with Long Chain Alcohols Catalyzed by Multi-valent Metal Salts
- Author
-
Yoshihiro Sugi, Ryo Nakamura, Kshudiram Mantri, and Kenichi Komura
- Subjects
Metal salts ,General Medicine ,General Chemistry ,Medicinal chemistry ,Chloride ,Catalysis ,chemistry.chemical_compound ,Nitrate ,chemistry ,medicine ,Organic chemistry ,Sulfate ,Long chain ,Nuclear chemistry ,medicine.drug - Abstract
Some typical multi-valent metal salts, such as chloride, nitrate, sulfate, and acetate of Fe(III), Al(III), Ga(III), In(III), Zr(IV), Hf(IV), Zn(II), Co(II), Ni(II), Mn(III), Cr(III), and Cu(II) ha...
- Published
- 2005
40. Participation of an arginyl residue of insulin chain B in the inhibition of hemagglutination by Porphyromonas gingivalis
- Author
-
Hiroyuki Hayashi, K. Yamato, Daisuke Hinode, Ryo Nakamura, Atsushi Nagata, Masami Morioka, and S. Ichimiya
- Subjects
Microbiology (medical) ,Arginine ,Hemagglutination ,medicine.medical_treatment ,Immunology ,Molecular Sequence Data ,Peptide ,Biology ,Microbiology ,chemistry.chemical_compound ,Residue (chemistry) ,Aminohydrolases ,Citrulline ,medicine ,Animals ,Humans ,Insulin ,Amino Acid Sequence ,General Dentistry ,Porphyromonas gingivalis ,chemistry.chemical_classification ,Protease ,Hemagglutinin ,biology.organism_classification ,Peptide Fragments ,Hemagglutinins ,chemistry ,Biochemistry ,Cattle - Abstract
Insulin chain B, containing each one arginyl and lysyl residue in its peptide chain, inhibited hemagglutination by Porphyromonas gingivalis. To determine the further inhibitory profile, chain B was digested into 4 fragments by protease, which was contained in the preparation of hemagglutinin from P. gingivalis. Identification of each fragment by the amino acid analysis revealed that the chain was cleaved at the carboxyl site of arginyl and/or lysyl residues, but one fragment contained citrulline instead of arginine at its carboxyl terminal. This citrulline might have originated from arginine by an arginine deaminase-like enzyme of P. gingivalis. Only one fragment that contained the arginyl residue exhibited inhibitory activity on hemagglutination, but it was considerably weakened compared with that of the intact chain B. The difference in the inhibitory activity seemed to depend on the position of an arginyl residue in the peptide; this was also confirmed using several derivatives of bradykinin. The present result suggests that the internal arginyl residue in a peptide chain may be critical for the inhibition of the hemagglutination by P. gingivalis.
- Published
- 1993
41. Cytotoxicity of Porphyromonas gingivalis toward cultured human gingival fibroblasts
- Author
-
M. Ueda, Atsushi Nagata, Masami Morioka, Ryo Nakamura, Hiroyuki Hayashi, Daisuke Hinode, Reiko Kido, and S. Ichimiya
- Subjects
Microbiology (medical) ,Lipopolysaccharide ,Adolescent ,Immunology ,Fimbria ,Gingiva ,Microbiology ,chemistry.chemical_compound ,medicine ,Humans ,Cytotoxicity ,Fibroblast ,General Dentistry ,Porphyromonas gingivalis ,Cells, Cultured ,biology ,Vesicle ,Cell Membrane ,Fibroblasts ,biology.organism_classification ,Molecular biology ,In vitro ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Bacterial outer membrane ,Bacterial Outer Membrane Proteins - Abstract
Direct cytotoxicity of black-pigmented anaerobic rods was studied on the confluent monolayer of human gingival fibroblasts in vitro. Only strains of Porphyromonas gingivalis caused morphological alteration (cell-rounding) and notable depression of viability of fibroblasts. To determine the location of the cytotoxicity, bacterial surface components, i.e., outer membrane, lipopolysaccharide, fimbriae and outer membrane vesicles were prepared from P. gingivalis and their cytotoxicity was assessed. Among these preparations, only outer membrane vesicles are supposed to have high affinity to human gingival fibroblasts, and the cytotoxicity of outer membrane vesicles was found to be much stronger than that of the other constituents. This cytotoxic factor seemed to consist largely of protein and to be associated with the enzyme activity of outer membrane vesicles. The effects of some protease inhibitors and L-cysteine on the cytotoxicity of outer membrane vesicles suggest that the mechanism of cell-rounding is different from that of cell death.
- Published
- 1993
42. An oxygen free radical scavenger tiron improves coronary endothelial dysfunction in a canine model of tachycardia-induced heart failure
- Author
-
Ken-ichi Arimura, Ryo Nakamura, Akira Takeshita, Kensuke Egashira, and Yoji Machida
- Subjects
Tachycardia ,Tiron ,medicine.medical_specialty ,business.industry ,Radical ,medicine.disease ,Scavenger (chemistry) ,chemistry.chemical_compound ,chemistry ,Internal medicine ,Heart failure ,medicine ,Cardiology ,medicine.symptom ,Endothelial dysfunction ,Cardiology and Cardiovascular Medicine ,business ,Canine model - Published
- 1999
43. Antioxidant therapy with tiron improves coronary vasodilating capacity to ischemia and adenosine by increasing nitric oxide bioactivity in a tachycardiainduced heart failure
- Author
-
Kensuke Egashira, Ryo Nakamura, and Akira Takeshita
- Subjects
medicine.medical_specialty ,Tiron ,Antioxidant ,business.industry ,medicine.medical_treatment ,Ischemia ,Vasodilation ,medicine.disease ,Adenosine ,Nitric oxide ,chemistry.chemical_compound ,chemistry ,Internal medicine ,Heart failure ,medicine ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Published
- 1999
44. Effect of Heat Treatment on Preparation of Colorless Globin from Bovine Hemoglobin Using Soluble Carboxymethyl Cellulose
- Author
-
Ryo Nakamura, Y. Matsuura, Y. Sat, and Shigeru Hayakawa
- Subjects
chemistry.chemical_compound ,Chromatography ,chemistry ,Bovine hemoglobin ,Heating temperature ,medicine ,Urea ,Globin ,Hemoglobin ,Heme ,Food Science ,Carboxymethyl cellulose ,medicine.drug - Abstract
Optimum conditions for the preparation of colorless globin using soluble carboxymethyl cellulose (CMC) were established by mapping super-sim plex optimization. Response for minimization was calculated using two parameters of heme content and protein recovery. When three factors (initial pH, CMC concentration, and final pH) were used, the minimum response of 15.4 was obtained. However, much lower minimum response (8.6 or 6.2) was obtained by adding urea or by heating in addition to the above three factors. By determining the effects of heating temperature (20–80°C) at different final pH (2.25–3.06), the heme content of globin obtained from heated hemoglobin was remarkably lower (2.65.8%) than from unheated hemoglobin (29.2–70.7%).
- Published
- 1986
45. Maillard reaction of disaccharides with protein: suppressive effect of nonreducing end pyranoside groups on browning and protein polymerization
- Author
-
Yasuko Kato, Tsukasa Matsuda, Ryo Nakamura, and Natsuki Kato
- Subjects
Protein polymerization ,Chemistry ,General Chemistry ,Cellobiose ,Maltose ,Isomaltose ,Maillard reaction ,symbols.namesake ,chemistry.chemical_compound ,Amadori rearrangement ,Browning ,symbols ,Organic chemistry ,General Agricultural and Biological Sciences ,Melibiose - Abstract
The Maillard reaction of ovalbumin and several disaccharides (maltose, cellobiose, isomaltose, lactose, melibiose) having glucose at the reducing end was investigated by measuring several properties of the sugar-protein Maillard adducts after each sugar was kept with ovalbumin at 50 OC and 65% RH for 0-20 days. Isomaltose and melibiose mixed with the protein strongly induced brown colorization, production of fluorescent compounds, and protein polymerization, whereas maltose, cellobiose, and lactose did so very weakly. All five of the sugars decreased free amino groups of the protein to less than 20% within 1 week. The weaker production of advanced Maillard reaction products such as brown color and/or fluorescent compounds in the maltose, lactose, and cellobiose systems indicated that the terminal pyranoside groups bonded at the C-4 OH of glucose retarded further degradation to aldehyde components of their Amadori rearrangement products. Earlier studies on the reaction between various reducing sugars and amino acids showed that the rates of the coupling reaction between amino and carbonyl groups and the browning reaction observed at advanced stages of the reaction were affected by the chemical structure of sugars and amino acids (e.g., Lewis and Lea, 1950; Pomeranz et al., 1962; Burton and McWeeney, 1963).
- Published
- 1989
46. Effect of heating on the functional properties of ovotransferrin
- Author
-
Ryo Nakamura, Osamu Umemura, and Hidehiro Takemoto
- Subjects
chemistry.chemical_classification ,Cation binding ,biology ,Inorganic chemistry ,Salt (chemistry) ,Ovotransferrin ,Phosphate ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Inorganic salts ,chemistry ,Ionic strength ,biology.protein ,Solubility ,General Agricultural and Biological Sciences ,Anion binding - Abstract
The effect of heating on the functional properties of ovotransferrin greatly varied with both the pH and ionic strength of the solution. When small amounts of inorganic salts (μ
- Published
- 1979
47. Constituent Proteins of Globulin Fraction Obtained from Egg White
- Author
-
Masahiko Takayama, Ryo Nakamura, Keisuke Nakamura, and Osamu Umemura
- Subjects
Ammonium sulfate ,Chromatography ,Molecular mass ,Globulin ,biology ,Fraction (chemistry) ,General Biochemistry, Genetics and Molecular Biology ,Macroglobulin ,chemistry.chemical_compound ,chemistry ,Biochemistry ,embryonic structures ,biology.protein ,Egg White Proteins ,Dialysis (biochemistry) ,General Agricultural and Biological Sciences ,Egg white - Abstract
A globulin fraction which was salted out from egg white by ammonium sulfate was constituted of five kinds of proteins. One of them was macroglobulin and two were G2 and G3 of Longsworth et al. [J. Am. Chem. Soc., 62, 2580 (1940)]. Remaining two proteins were assumed to be ovoinhibitors. G2 and G3 were separated from each other by CM-cellulose chromatography. The molecular weights of G2 and G3 were almost the same, being about 49, 000. An euglobulin-like protein which was precipitated during the dialysis of the globulin fraction consisted mainly of macroglobulin and aggregates of some other egg white proteins.
- Published
- 1980
48. Effect of Coenzyme Q on Serum Levels of Creatine Phosphokinase in Preclinical Muscular Dystrophy
- Author
-
Hans Zellweger, Gian Paolo Littarru, Coyle W. Williams, Ryo Nakamura, John H. Langston, John B. Brunkhorst, and Karl Folkers
- Subjects
Male ,medicine.medical_specialty ,Ubiquinone ,Biology ,Creatine ,Muscular Dystrophies ,Phosphocreatine ,chemistry.chemical_compound ,Oral administration ,Internal medicine ,medicine ,Humans ,Muscular dystrophy ,Creatine Kinase ,Biological Sciences: Medical Sciences ,Multidisciplinary ,fungi ,Infant ,food and beverages ,Dystrophy ,Skeletal muscle ,medicine.disease ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Child, Preschool ,Coenzyme Q – cytochrome c reductase ,biology.protein ,Creatine kinase - Abstract
Coenzyme Q 10 (CoQ 10 ) exists in human tissue, and is indispensable to mitochondrial enzymes of respiration. CoQ was administered to children with preclinical muscular dystrophy, CoQ enzymology was emphasized, and serum creatine phosphokinase, CPK, (ATP:creatine N -phosphotransferase, EC 2.7.3.2) was repeatedly monitored. A 40-week treatment of an infant, 1-2 years of age, reduced serum CPK ( P < 0.001; total CPK assays, 76). A 40-week treatment of a boy, 3-5 years of age, reduced serum CPK ( P < 0.01); treatment through 80 weeks reduced CPK ( P < 0.001; total CPK assays, 118). This response of preclinical dystrophy to CoQ implies a deficiency of CoQ in skeletal muscle that was actually found previously by assay of the activity of the succinate dehydrogenase:coenzyme Q 10 reductase of the rectus abdominis. The relationships among a CoQ deficiency in muscle, serum CPK, and use of CPK in muscle are uncertain; however, restoration of CoQ enzyme activity in muscle by oral administration of CoQ could lead to increased use of CPK in muscle to form phosphocreatine from creatine and ATP, with a corresponding decrease in serum levels of CPK. The great excess of CPK in serum comes from deteriorating muscle in which CPK is below normal.
- Published
- 1974
49. Some Properties of Uridine 5'-Diphosphogalactose: N-Acetylglucosamine Galactosyltransferase in Human Parotid Saliva
- Author
-
Ryo Nakamura, Akira Tsunemitsu, and Tatsuo Watanabe
- Subjects
Adult ,Male ,0301 basic medicine ,Saliva ,03 medical and health sciences ,chemistry.chemical_compound ,Enzyme activator ,0302 clinical medicine ,stomatognathic system ,N-Acetyllactosamine Synthase ,Humans ,Parotid Gland ,Magnesium ,General Dentistry ,Magnesium ion ,Galactosyltransferase ,chemistry.chemical_classification ,Manganese ,Binding Sites ,biology ,Lactose synthase ,030206 dentistry ,Hydrogen-Ion Concentration ,Uridine ,Enzyme Activation ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Lactose Synthase ,biology.protein ,N-acetyllactosamine synthase - Abstract
Uridine 5'-diphospho (UDP)-galactose: N-acetylglucosamine galactosyltransferase was separated from human parotid saliva and partially purified. The optimum pH of the enzyme was 7.5. The enzyme required a specific acceptor, and its activity was activated by manganese and magnesium ions.
- Published
- 1975
50. Purification of β-N-Acetylhexosaminidase from Egg White and the Microsomal and Lysosomal Fractions of Hen Oviduct
- Author
-
Yuji Ogawa, Yasushi Sato, and Ryo Nakamura
- Subjects
chemistry.chemical_classification ,Chromatography ,General Biochemistry, Genetics and Molecular Biology ,Sepharose ,chemistry.chemical_compound ,Isoelectric point ,Enzyme ,chemistry ,Affinity chromatography ,Biochemistry ,Oviduct ,Sodium dodecyl sulfate ,General Agricultural and Biological Sciences ,Polyacrylamide gel electrophoresis ,Egg white - Abstract
β-N-Acetylhexosaminidase (NAHase) was purified from egg white and the lysosomal and microsomal fractions of hen oviduct. The purification procedure included affinity chromatography using Sepharose 4B coupled with IgG specific for NAHase of hen oviduct. The isoelectric points of the three enzymes were different, but their antigen determinants were identical. In sodium dodecyl sulfate polyacrylamide gel electrophoresis, both the egg white and lysosomal enzyme gave only one protein band each, corresponding to a MW of 68000 and 53000, respectively, but the microsomal enzyme gave two protein bands, corresponding to those of the lysosomal and egg white enzymes.
- Published
- 1983
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