著者

Shun Kobayashi Daisuke Hira Keitaro Yoshida Masanori Toyofuku Yosuke Shida Wataru Ogasawara Takashi Yamaguchi Nobuo Araki Mamoru Oshiki

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

pp.ME18058, (Released:2018-10-12)

被引用文献数

35

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Aerobic ammonia-oxidizing archaea (AOA) play a crucial role in the global nitrogen cycle by oxidizing ammonia to nitrite, and nitric oxide (NO) is a key intermediate in AOA for sustaining aerobic ammonia oxidation activity. We herein heterologously expressed the NO-forming, copper-containing, dissimilatory nitrite reductase (NirK) from Nitrososphaera viennensis and investigated its enzymatic properties. The recombinant protein catalyzed the reduction of 15NO2– to 15NO, the oxidation of hydroxylamine (15NH2OH) to 15NO, and the production of 14-15N2O from 15NH2OH and 14NO2–. To the best of our knowledge, the present study is the first to document the enzymatic properties of AOA NirK.

著者

Yuga Hirakata Mamoru Oshiki Kyohei Kuroda Masashi Hatamoto Kengo Kubota Takashi Yamaguchi Hideki Harada Nobuo Araki

出版者

日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

pp.ME16067, (Released:2016-07-12)

被引用文献数

22

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Predation by protists is top-down pressure that regulates prokaryotic abundance, community function, structure, and diversity in natural and artificial ecosystems. Although the effects of predation by protists have been studied in aerobic ecosystems, they are poorly understood in anoxic environments. We herein studied the influence of predation by Metopus and Caenomorpha ciliates—ciliates frequently found in anoxic ecosystems—on prokaryotic community function, structure, and diversity. Metopus and Caenomorpha ciliates were cocultivated with prokaryotic assemblages (i.e., anaerobic granular sludge) in an up-flow anaerobic sludge blanket (UASB) reactor for 171 d. Predation by these ciliates increased the methanogenic activities of granular sludge, which constituted 155% of those found in a UASB reactor without the ciliates (i.e., control reactor). Sequencing of 16S rRNA gene amplicons using Illumina MiSeq revealed that the prokaryotic community in the UASB reactor with the ciliates was more diverse than that in the control reactor; 2,885–3,190 and 2,387–2,426 operational taxonomic units (>97% sequence similarities), respectively. The effects of predation by protists in anaerobic engineered systems have mostly been overlooked, and our results show that the influence of predation by protists needs to be examined and considered in the future for a better understanding of prokaryotic community structure and function.

著者

Kazumasa Oura Takashi Yamaguchi Taro Suzuki Mao Yamaguchi Oura Ryo Itabashi Tetsuya Maeda

出版者

The Japanese Society of Internal Medicine

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

pp.9316-22, (Released:2022-08-10)

参考文献数

15

被引用文献数

1

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Several case reports of patients with both moyamoya syndrome (MMS) and antiphospholipid syndrome (APS) have been published. However, the relationship between MMS and APS has not been clarified. We herein report a patient with MMS who had an ischemic stroke with rapid worsening of stenosis of the middle cerebral artery associated with APS. The patient was triple-positive for antiphospholipid antibodies. Patients with MMS complicated by APS should be closely followed up with vascular imaging.

著者

Haruki Imamura Takashi Yamaguchi Daiji Nagayama Atsuhito Saiki Kohji Shirai Ichiro Tatsuno

出版者

International Heart Journal Association

雑誌

International Heart Journal (ISSN:13492365)

巻号頁・発行日

vol.58, no.4, pp.577-583, 2017 (Released:2017-08-03)

参考文献数

38

被引用文献数

71

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Resveratrol has been reported to have potent anti-atherosclerotic effects in animal studies. However, there are few interventional studies in human patients with atherosclerogenic diseases. The cardio-ankle vascular index (CAVI) reflects arterial stiffness and is a clinical surrogate marker of atherosclerosis. The aim of the present study was to investigate the effect of resveratrol on arterial stiffness assessed by CAVI in patients with type 2 diabetes mellitus (T2DM).In this double-blind, randomized, placebo-controlled study, 50 patients with T2DM received supplement of a 100mg resveratrol tablet (total resveratrol: oligo-stilbene 27.97 mg/100 mg/day) or placebo daily for 12 weeks. CAVI was assessed at baseline and the end of study. Body weight (BW), blood pressure (BP), glucose and lipid metabolic parameters, and diacron-reactive oxygen metabolites (d-ROMs; an oxidative stress marker) were also measured.Resveratrol supplementation decreased systolic BP (-5.5 ± 13.0 mmHg), d-ROMs (-25.6 ± 41.8 U.CARR), and CAVI (-0.4 ± 0.7) significantly (P < 0.05) and decreased BW (-0.8 ± 2.1 kg, P = 0.083) and body mass index (-0.5 ± 0.8 kg/m2, P = 0.092) slightly compared to baseline, while there were no significant changes in the placebo group. Decreases in CAVI and d-ROMs were significantly greater in the resveratrol group than in the placebo group. Multivariate logistic regression analysis identified resveratrol supplementation as an independent predictor for a CAVI decrease of more than 0.5.In conclusion, 12-week resveratrol supplementation may improve arterial stiffness and reduce oxidative stress in patients with T2DM. Resveratrol may be beneficial in preventing the development of atherosclerosis induced by diabetes. However, a large-scale cohort study is required to validate the present findings.

著者

Shoichi YASUNO Takeomi MURATA Kazuko KOKUBO Takashi YAMAGUCHI Masugu KAMEI

出版者

(社)日本農芸化学会

雑誌

Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)

巻号頁・発行日

vol.61, no.11, pp.1944-1946, 1997-11-23 (Released:2008-02-08)

参考文献数

8

被引用文献数

34 78

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ρ-Aminobenzoic ethyl ester (ABEE)-derivatized monosaccharides were separated by HPLC with a trifluoroacetic acid (TFA) solution or borate buffer as the eluent. In the case of the TFA solution, ABEE-derivatized monosaccharides of the neutral and amino sugars found in animal glycoproteins were separated in a simultaneous analysis. In the case of the borate buffer, ABEE-derivatized monosaccharides of identical molecular weights such as ABEE-Gal, -Glc, and -Man were separated as stereoisomers. Glucuronic acid and galacturonic acid were detected and separated within 8 min. The relationship between the peak areas and the amounts of ABEE-derivatized monosaccharides was linear in the range of 1 to 1000 pmol.

著者

Mamoru Oshiki Yuka Toyama Toshikazu Suenaga Akihiko Terada Yasuhiro Kasahara Takashi Yamaguchi Nobuo Araki

出版者

Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.37, no.2, pp.ME21090, 2022 (Released:2022-04-12)

参考文献数

61

被引用文献数

14

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Agricultural soil is the primary N2O sink limiting the emission of N2O gas into the atmosphere. Although Gemmatimonadetes bacteria are abundant in agricultural soils, limited information is currently available on N2O reduction by Gemmatimonadetes bacteria. Therefore, the effects of pH and temperature on N2O reduction activities and affinity constants for N2O reduction were examined by performing batch experiments using an isolate of Gemmatimonadetes bacteria, Gemmatimonas aurantiaca (NBRC100505T). G. aurantiaca reduced N2O at pH 5–9 and 4–50°C, with the highest activity being observed at pH 7 and 30°C. The affinity constant of G. aurantiaca cells for N2O was 4.4‍ ‍μM. The abundance and diversity of the Gemmatimonadetes 16S rRNA gene and nosZ encoding nitrous oxide reductase in agricultural soil samples were also investigated by quantitative PCR (qPCR) and amplicon sequencing ana­lyses. Four N2O-reducing agricultural soil samples were assessed, and the copy numbers of the Gemmatimonadetes 16S rRNA gene (clades G1 and G3), nosZ DNA, and nosZ mRNA were 8.62–9.65×108, 5.35–7.15×108, and 2.23–4.31×109 copies (g dry soil)–1, respectively. The abundance of the nosZ mRNA of Gemmatimonadetes bacteria and OTU91, OUT332, and OTU122 correlated with the N2O reduction rates of the soil samples tested, suggesting N2O reduction by Gemmatimonadetes bacteria. Gemmatimonadetes 16S rRNA gene reads affiliated with OTU4572 and OTU3759 were predominant among the soil samples examined, and these Gemmatimonadetes OTUs have been identified in various types of soil samples.

著者

Deepchandi Lekamge Tomoki Sasahara Shin-ichi Yamamoto Masashi Hatamoto Takashi Yamaguchi Shinya Maki

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.38, no.4, pp.401-408, 2021-12-25 (Released:2021-12-25)

参考文献数

37

被引用文献数

2

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Potato (Solanum tuberosum L.) is a major global food crop. Contemporary potato production largely utilizes micropropagation to produce healthy seed potatoes. The micropropagation of potatoes is widely achieved through nodal explants using the conventional Murashige and Skoog (MS) medium. Currently, effective culture media that can facilitate rapid propagation are increasingly required for new cultivars that have been developed to possess improved traits. In this study, we evaluated the effect of enhanced meso nutrients (CaCl2.2H2O, MgSO4, and KH2PO4) in MS medium on the growth of S. tuberosum. The cultivars used in this study were representative of Japanese, European, and Peruvian lines. Enhanced meso nutrients improved the overall quality of all cultivars, as indicated by longer shoots and larger leaves with dark color, compared with MS medium only. Shoots grown on enhanced mesos were approximately 1.5 times longer than on MS medium. Quantitative ion analysis revealed that plantlets with improved shoot length and leaf quality in most cultivars had increased calcium, magnesium, potassium, and phosphorus uptake than plantlets on MS medium. The results suggest that the reduced iron uptake on 3.0×MS, compared with 2.0× or 2.5×MS mesos, reduced plant growth. This study revealed for the first time that mesos concentrations higher than MS medium concentrations, complemented by enhanced calcium, magnesium, potassium, phosphorus, and iron uptake, play a significant role in improving the in vitro growth of potato.

著者

Takahiro Kumagai Hirotaka Sakurai Taisuke Shioi Hirotaka Kato Jun-ichi Itoh Keisuke Kusaka Takashi Yamaguchi Masayuki Nakagawa Daisuke Sato

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.11, no.1, pp.117-127, 2022-01-01 (Released:2022-01-01)

参考文献数

42

被引用文献数

2

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This study reveals the characteristics of switched reluctance motors (SRMs) made by blanking (a) 20HX1300 of high grade low-iron-loss silicon steel (0.20mm thickness) and (b) 2605SA1 of amorphous alloy (0.025mm thickness). The blanking of the amorphous alloy is an innovative technology for the mass production of the high efficiency amorphous-alloy-motor. The impact of the processing methods on the magnetic properties are evaluated using the ring cores processed by the following methods: the wire cutting and the blanking. On the other hand, the experiment with the SRMs processed by the blanking evaluates the characteristics depending on the material. As first prototype, 70W-SRM (40mm thickness) is manufactured by blanking 1600 sheets of the amorphous alloy and adhesively laminating them. In the experiment, the motor efficiency of the amorphous-alloy-SRM is improved by 6.9p. t. compared with that of silicon-steel-SRM. In addition, the iron loss of amorphous-alloy-SRM is reduced by 78.7% compared with that of silicon-steel-SRM.

著者

Atsuhito Saiki Yasuhiro Watanabe Takashi Yamaguchi Masahiro Ohira Daiji Nagayama Naoko Sato Mizuho Kanayama Mao Takahashi Kazuhiro Shimizu Masao Moroi Yoh Miyashita Kohji Shirai Ichiro Tatsuno

出版者

Japan Atherosclerosis Society

雑誌

Journal of Atherosclerosis and Thrombosis (ISSN:13403478)

巻号頁・発行日

vol.28, no.10, pp.1083-1094, 2021-10-01 (Released:2021-10-01)

参考文献数

32

被引用文献数

8

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Aim: In the TOHO Lipid Intervention Trial Using Pitavastatin (TOHO-LIP), a multicenter randomized controlled trial, pitavastatin significantly reduced cardiovascular (CV) events compared to atorvastatin in patients with hypercholesterolemia. To investigate the mechanism by which pitavastatin preferentially prevents CV events, we investigated the relationship between CV events and cardio-ankle vascular index (CAVI) using the TOHO-LIP database. Methods: For the subgroup analysis, we selected patients from a single center, Toho University Sakura Medical Center. After excluding those who had CV events at baseline or during the first year, 254 patients were enrolled. The primary end point was the same as that of TOHO-LIP, and three-point major cardiac adverse events (3P-MACE) was added as secondary end point. Results: The cumulative 5-year incidence of 3P-MACE (pitavastatin 1.6%, atorvastatin 6.1%, P=0.038) was significantly lower in pitavastatin group (2 mg/day) than in atorvastatin group (10 mg/day). CAVI significantly decreased only in pitavastatin group during the first year (9.50–9.34, P=0.042), while the change in low-density lipoprotein cholesterol (LDL-C) did not differ between the two groups. The change in CAVI during the first year positively correlated with 3P-MACE and tended to be an independent predictor of 3P-MACE in Cox proportional hazards model (hazard ratio, 1.736; P=0.079). The annual change in CAVI throughout the observation period was significantly higher in subjects with CV events compared to those without. Conclusions: In this subgroup analysis, the reduction in CV events tended to be associated with the CAVI-lowering effect of pitavastatin, which was independent of the LDL-C-lowering effect.

著者

Masayuki Kuroda Hideaki Bujo Koutaro Yokote Takeyoshi Murano Takashi Yamaguchi Masatsune Ogura Katsunori Ikewaki Masahiro Koseki Yasuo Takeuchi Atsuko Nakatsuka Mika Hori Kota Matsuki Takashi Miida Shinji Yokoyama Jun Wada Mariko Harada-Shiba on behalf of the Committee on Primary Dyslipidemia under the Research Program on Rare and Intractable Disease of the Ministry of Health Labour and Welfare of Japan

出版者

Japan Atherosclerosis Society

雑誌

Journal of Atherosclerosis and Thrombosis (ISSN:13403478)

巻号頁・発行日

pp.RV17051, (Released:2021-04-18)

参考文献数

68

被引用文献数

7

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Lecithin cholesterol acyltransferase (LCAT) is a lipid-modification enzyme that catalyzes the transfer of the acyl chain from the second position of lecithin to the hydroxyl group of cholesterol (FC) on plasma lipoproteins to form cholesteryl acylester and lysolecithin. Familial LCAT deficiency is an intractable autosomal recessive disorder caused by inherited dysfunction of the LCAT enzyme. The disease appears in two different phenotypes depending on the position of the gene mutation: familial LCAT deficiency (FLD, OMIM 245900) that lacks esterification activity on both HDL and ApoB-containing lipoproteins, and fish-eye disease (FED, OMIM 136120) that lacks activity only on HDL. Impaired metabolism of cholesterol and phospholipids due to LCAT dysfunction results in abnormal concentrations, composition and morphology of plasma lipoproteins and further causes ectopic lipid accumulation and/or abnormal lipid composition in certain tissues/cells, and serious dysfunction and complications in certain organs. Marked reduction of plasma HDL-cholesterol (HDL-C) and corneal opacity are common clinical manifestations of FLD and FED. FLD is also accompanied by anemia, proteinuria and progressive renal failure that eventually requires hemodialysis. Replacement therapy with the LCAT enzyme should prevent progression of serious complications, particularly renal dysfunction and corneal opacity. A clinical research project aiming at gene/cell therapy is currently underway.

著者

山口 崇 Takashi Yamaguchi

出版者

東京理科大学

巻号頁・発行日

2015-03-20

---

2014

著者

Shun Kobayashi Daisuke Hira Keitaro Yoshida Masanori Toyofuku Yosuke Shida Wataru Ogasawara Takashi Yamaguchi Nobuo Araki Mamoru Oshiki

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.33, no.4, pp.428-434, 2018 (Released:2018-12-28)

参考文献数

47

被引用文献数

1 35

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Aerobic ammonia-oxidizing archaea (AOA) play a crucial role in the global nitrogen cycle by oxidizing ammonia to nitrite, and nitric oxide (NO) is a key intermediate in AOA for sustaining aerobic ammonia oxidation activity. We herein heterologously expressed the NO-forming, copper-containing, dissimilatory nitrite reductase (NirK) from Nitrososphaera viennensis and investigated its enzymatic properties. The recombinant protein catalyzed the reduction of 15NO2− to 15NO, the oxidation of hydroxylamine (15NH2OH) to 15NO, and the production of 14–15N2O from 15NH2OH and 14NO2−. To the best of our knowledge, the present study is the first to document the enzymatic properties of AOA NirK.

著者

Yuta Sato Daiji Nagayama Atsuhito Saiki Rena Watanabe Yasuhiro Watanabe Haruki Imamura Takashi Yamaguchi Noriko Ban Hidetoshi Kawana Ayako Nagumo Masahiro Ohira Kei Endo Takumi Kurosu Takanobu Tomaru Kohji Shirai Ichiro Tatsuno

出版者

Japan Atherosclerosis Society

雑誌

Journal of Atherosclerosis and Thrombosis (ISSN:13403478)

巻号頁・発行日

pp.31385, (Released:2015-12-02)

参考文献数

41

被引用文献数

34 82

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Aim: We investigated whether cardio-ankle vascular index (CAVI), an arterial stiffness marker, independently predicts future cardiovascular events in subjects with metabolic disorders.Methods: 1562 outpatients underwent CAVI between April 2004 and March 2006 at Toho University, Sakura Medical Center in Chiba, Japan. Patients who already had cardiovascular events at baseline, patients with low ankle brachial index (<0.9), and patients with atrial fibrillation were excluded. After exclusion, 1080 subjects with metabolic disorders including diabetes mellitus, hypertension and dyslipidemia were screened and followed prospectively.Results: Eventually, 1003 subjects (92.9% of 1,080 subjects) followed until March 2012 (follow-up duration 6.7±1.6 years) were analyzed. During the observation period, 90 subjects had new-onset myocardial infarction or angina pectoris confirmed by angiography. All subjects were stratified into quartiles by baseline CAVI (Q1: CAVI ≤8.27, Q2: CAVI 8.28-9.19, Q3: CAVI 9.20-10.08, Q4: CAVI ≥10.09). Age, male ratio and future cardiovascular events increased as CAVI quartile became higher. In Cox proportional hazards regression analysis, the factors independently associated with higher risk of future cardiovascular events were every 1.0 increment of CAVI [hazard ratio (HR) 1.126, p= 0.039], male gender (HR 2.276, p=0.001), smoking (HR 1.846, p=0.007), diabetes mellitus (HR 1.702,p=0.020), and hypertension (HR 1.682, p=0.023).Conclusion: In individuals with metabolic disorders, CAVI was a predictor of future cardiovascular events, independent of traditional coronary risk factors. CAVI is a potentially valuable tool to identify persons likely to benefit from more intensive therapeutic approaches.

著者

Yuga Hirakata Mamoru Oshiki Kyohei Kuroda Masashi Hatamoto Kengo Kubota Takashi Yamaguchi Hideki Harada Nobuo Araki

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

vol.30, no.4, pp.335-338, 2015 (Released:2015-12-22)

参考文献数

22

被引用文献数

11 23

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The aim of the present study was to investigate the prokaryotic community structure of the anaerobic ciliate, Metopus sp. using rRNA sequencing, fluorescence in situ hybridization (FISH), and transmission electron microscopy (TEM). Metopus sp. was physically separated from anaerobic granular sludge in a domestic wastewater treatment plant and anoxically cultivated for 7 d. 16S rRNA gene sequences from the prokaryotes Methanoregula boonei and Clostridium aminobutyricum were abundantly detected in Metopus ciliates. The FISH analysis using the oligonucleotide probes Mg1200b and Cla568 demonstrated that these prokaryotes were localized within Metopus cells. These results identify M. boonei- and C. aminobutyricum-like prokaryotes as novel endosymbionts of Metopus ciliates.

著者

Kiyonori Kai Takashi Yamaguchi Yu Yoshimatsu Junzo Kinoshita Munehiro Teranishi Wataru Takasaki

出版者

日本毒性学会

雑誌

The Journal of Toxicological Sciences (ISSN:03881350)

巻号頁・発行日

vol.38, no.2, pp.269-277, 2013-04-01 (Released:2013-03-28)

参考文献数

21

被引用文献数

20 41

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A sensitive urinary biomarker for acute kidney injury (AKI) was investigated in beagle dogs with nephrotoxicity induced by gentamicin. Gentamicin sulphate at 25 or 50 mg/kg was injected (s.c.) for 9 days, and conventional urinalysis, ELISA assay of neutrophil gelatinase-associated lipocal (NGAL) in urine, blood chemistry, and pathological examinations were performed. The dog given gentamicin at 25 mg/kg only showed slight deposition of lysosomal granules in the proximal tubular epithelium of the kidneys without any other significant changes even though urinary NGAL was elevated on Day 10 (day of necropsy). In the dog receiving gentamicin at 50 mg/kg, increases in urinary NGAL were observed on Days 3 and 5, and absence of urination, marked increases in serum urea nitrogen and creatinine, enlargement and discoloration of the kidneys with marked necrosis, and swelling of proximal epithelium were observed. In conclusion, urinary NGAL is considered to be a candidate as a sensitive predictable biomarker of AKI in the gentamicin-induced nephrotoxicity model in dogs.