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  1. Article ; Online: Isolation of N-nitrosodimethylamine from drug substances using solid-phase extraction-liquid chromatography-tandem mass spectrometry.

    Yamamoto, Eiichi / Kan-No, Hitomi / Tomita, Naomi / Ando, Daisuke / Miyazaki, Tamaki / Izutsu, Ken-Ichi

    Journal of pharmaceutical and biomedical analysis

    2021  Volume 210, Page(s) 114561

    Abstract: N-Nitrosodimethylamine (NDMA) has been detected in some drug substances and pharmaceutical products ...

    Abstract N-Nitrosodimethylamine (NDMA) has been detected in some drug substances and pharmaceutical products containing sartans, ranitidine and metformin, and a potential risk of NDMA contamination exists in other drug substances and their pharmaceutical products. To quantitate NDMA in various drugs having diverse physicochemical properties, a specific, sensitive, and reliable analytical method is required, in addition to methods that can be applied to a class of nitrosamines. We aimed to develop an off-line isolation method for NDMA in drug substances using SPE for quantification with LC-APCI-MS/MS. Impediments to accurate quantitation of NDMA in drug substances using LC-MS/MS and insufficient durability of the system are attributed to the extremely large amounts of active pharmaceutical ingredients (APIs) in sample solutions in comparison to the trace amount of NDMA. A reduced retention of NDMA and/or decreased separation from other substances in LC, matrix effect in MS detection, and undesirable contamination of instruments with API and other substances may be occasionally encountered, all of which consequently result in deterioration of system performance and generation of unreliable data, even in the cases where a divert valve is configured between the column and ion source of the MS instrument. To address these problems, an off-line NDMA isolation methodology from APIs exhibiting diverse physicochemical properties, namely ranitidine hydrochloride (ranitidine), metformin hydrochloride (metformin), nizatidine, valsartan, and telmisartan, was developed. The applicability of the method was confirmed by batch analysis of metformin and ranitidine. Furthermore, contrary to previous reports, NDMA was found to be stable over a wide pH range. The proposed methodology and data from this study would contribute to the control of NDMA contamination in various drugs to realize the safe delivery of pharmaceuticals to patients.
    MeSH term(s) Chromatography, Liquid ; Dimethylnitrosamine/analysis ; Gas Chromatography-Mass Spectrometry ; Humans ; Pharmaceutical Preparations ; Solid Phase Extraction ; Tandem Mass Spectrometry
    Chemical Substances Pharmaceutical Preparations ; Dimethylnitrosamine (M43H21IO8R)
    Language English
    Publishing date 2021-12-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 604917-5
    ISSN 1873-264X ; 0731-7085
    ISSN (online) 1873-264X
    ISSN 0731-7085
    DOI 10.1016/j.jpba.2021.114561
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Bleb Embolization of Ruptured Cerebral Aneurysms with Coils and n-Butyl Cyanoacrylate Following Proximal Flow Control: Two Case Reports.

    Tone, Osamu / Sato, Yohei / Tamaki, Masashi / Takada, Yoshiaki

    Journal of neuroendovascular therapy

    2021  Volume 16, Issue 6, Page(s) 313–319

    Abstract: ... endovascular procedures. We report two cases of ruptured aneurysms treated using coils and n-butyl cyanoacrylate (NBCA ...

    Abstract Objective: Morphologically challenging cerebral aneurysms cannot be treated through standard endovascular procedures. We report two cases of ruptured aneurysms treated using coils and n-butyl cyanoacrylate (NBCA).
    Case presentations: Case 1 was an 80-year-old woman diagnosed with a subarachnoid hemorrhage (SAH). An angiogram revealed a large and wide-necked basilar artery bifurcation aneurysm. Bilateral superior cerebellar and posterior cerebral arteries (PCAs) originated from the aneurysmal wall. A 3-mm-diameter bleb was detected on the aneurysmal fundus. The bleb enlarged 1 month following coil insertion. During the second treatment, we infused a small volume of 33% NBCA into the coil-framed bleb following proximal flow control of the bilateral vertebral arteries (VAs). The complete bleb obliteration was confirmed by the angiogram at 6 months later. The coil shape was followed up via plane X-ray for 5 years. No rebleeding occurred. Case 2 was a 41-year-old woman diagnosed with SAH. An angiogram revealed a dissecting aneurysm of the left PCA (P1 and P2 segments) accompanying a bleb on the P1 segment. Endovascular treatment was performed, and a coil was inserted into the bleb, infusing 33% NBCA into the coil frame following proximal flow control of bilateral VAs and the right internal carotid artery. Angiograms conducted at 3 months, 1 year, and 9 years and an MRA conducted 12 years later revealed a lack of bleb recanalization.
    Conclusion: We developed a Coil and NBCA technique to obliterate ruptured blebs following proximal flow control. This technique can be considered an effective alternative for treating morphologically challenging cerebral aneurysms.
    Language English
    Publishing date 2021-10-01
    Publishing country Japan
    Document type Case Reports
    ISSN 2186-2494
    ISSN (online) 2186-2494
    DOI 10.5797/jnet.cr.2021-0082
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Modification of N-Terminal Amino Acids of Fungal Benzoate Hydroxylase (CYP53A15) for the Production of

    Tamaki, Shun / Yagi, Mitsuhiko / Nishihata, Yuki / Yamaji, Hideki / Shigeri, Yasushi / Uno, Tomohide / Imaishi, Hiromasa

    Journal of microbiology and biotechnology

    2018  Volume 28, Issue 3, Page(s) 439–447

    Abstract: The aromatic ... ...

    Abstract The aromatic compound
    MeSH term(s) Animals ; Ascomycota/enzymology ; Ascomycota/genetics ; Benzoates/metabolism ; Cloning, Molecular ; Cytochrome P-450 Enzyme System/metabolism ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Gene Expression Regulation, Bacterial ; Genes, Fungal/genetics ; Humans ; NADPH-Ferrihemoprotein Reductase/genetics ; Oxygenases/chemistry ; Oxygenases/genetics ; Parabens/metabolism ; Plasmids ; Rabbits ; Reaction Time ; Recombinant Proteins/genetics ; Recombinant Proteins/metabolism ; Temperature
    Chemical Substances Benzoates ; Parabens ; Recombinant Proteins ; Cytochrome P-450 Enzyme System (9035-51-2) ; Oxygenases (EC 1.13.-) ; benzoate 1,2-dioxygenase (EC 1.14.12.10) ; NADPH-Ferrihemoprotein Reductase (EC 1.6.2.4) ; 4-hydroxybenzoic acid (JG8Z55Y12H)
    Language English
    Publishing date 2018-03-14
    Publishing country Korea (South)
    Document type Journal Article
    ISSN 1738-8872
    ISSN (online) 1738-8872
    DOI 10.4014/jmb.1711.11030
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Automated system measuring triple oxygen and nitrogen isotope ratios in nitrate using the bacterial method and N

    Hattori, Shohei / Savarino, Joel / Kamezaki, Kazuki / Ishino, Sakiko / Dyckmans, Jens / Fujinawa, Tamaki / Caillon, Nicolas / Barbero, Albane / Mukotaka, Arata / Toyoda, Sakae / Well, Reinhard / Yoshida, Naohiro

    Rapid communications in mass spectrometry : RCM

    2017  Volume 31, Issue 4, Page(s) 396

    Language English
    Publishing date 2017-02-28
    Publishing country England
    Document type Journal Article ; Published Erratum
    ZDB-ID 58731-x
    ISSN 1097-0231 ; 0951-4198
    ISSN (online) 1097-0231
    ISSN 0951-4198
    DOI 10.1002/rcm.7800
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Automated system measuring triple oxygen and nitrogen isotope ratios in nitrate using the bacterial method and N

    Hattori, Shohei / Savarino, Joel / Kamezaki, Kazuki / Ishino, Sakiko / Dyckmans, Jens / Fujinawa, Tamaki / Caillon, Nicolas / Barbero, Albane / Mukotaka, Arata / Toyoda, Sakae / Well, Reinhard / Yoshida, Naohiro

    Rapid communications in mass spectrometry : RCM

    2016  Volume 30, Issue 24, Page(s) 2635–2644

    Abstract: ... atmospheric nitrate formation pathways and their contribution to ecosystems. N: Methods: The main ... ii) N: Results: The δ: Conclusions: An automated system was developed to measure triple oxygen ... and nitrogen isotopes in nitrate using N ...

    Abstract Rationale: Triple oxygen and nitrogen isotope ratios in nitrate are powerful tools for assessing atmospheric nitrate formation pathways and their contribution to ecosystems. N
    Methods: The main improvements to a previous system are (i) an automated distribution system of nitrate to the bacterial medium, (ii) N
    Results: The δ
    Conclusions: An automated system was developed to measure triple oxygen and nitrogen isotopes in nitrate using N
    Language English
    Publishing date 2016-12-30
    Publishing country England
    Document type Journal Article
    ZDB-ID 58731-x
    ISSN 1097-0231 ; 0951-4198
    ISSN (online) 1097-0231
    ISSN 0951-4198
    DOI 10.1002/rcm.7747
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Cross sections of (n,x) reactions on cerium isotopes induced by D-T neutrons.

    Wang, Qiang / Han, Yafei / Chen, Bingjun / Huang, Zhenglin / Tamaki, Shingo / Murata, Isao / Wang, Tieshan / Fang, Kaihong

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

    2019  Volume 147, Page(s) 144–151

    Abstract: Neutron induced reaction cross sections of Cerium isotopes ( ...

    Abstract Neutron induced reaction cross sections of Cerium isotopes (
    Language English
    Publishing date 2019-03-09
    Publishing country England
    Document type Journal Article
    ZDB-ID 1142596-9
    ISSN 1872-9800 ; 0883-2889 ; 0969-8043
    ISSN (online) 1872-9800
    ISSN 0883-2889 ; 0969-8043
    DOI 10.1016/j.apradiso.2019.03.012
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: The N-terminal region of RTP1S plays important roles in dimer formation and odorant receptor-trafficking.

    Fukutani, Yosuke / Tamaki, Ryohei / Inoue, Ryosuke / Koshizawa, Tomoyo / Sakashita, Shuto / Ikegami, Kentaro / Ohsawa, Ikuroh / Matsunami, Hiroaki / Yohda, Masafumi

    The Journal of biological chemistry

    2019  Volume 294, Issue 40, Page(s) 14661–14673

    Abstract: ... we attempted to reveal the mode of action and critical residues of RTP1S in OR trafficking. Experiments using N ... terminal truncation and Ala substitution mutants of RTP1S demonstrated that four N-terminal amino acids ...

    Abstract Receptor-transporting protein 1S (RTP1S) is an accessory protein that mediates the transport of mammalian odorant receptors (ORs) into the plasma membrane. Although most ORs fail to localize to the cell surface when expressed alone in nonolfactory cells, functional expression of ORs is achieved with the coexpression of RTP1S. However, the mechanism for RTP1S-mediated OR trafficking remains unclear. In this study, we attempted to reveal the mode of action and critical residues of RTP1S in OR trafficking. Experiments using N-terminal truncation and Ala substitution mutants of RTP1S demonstrated that four N-terminal amino acids have essential roles in OR trafficking. Additionally, using recombinant proteins and split luciferase assays in mammalian cells, we provided evidence for the dimer formation of RTP1S. Furthermore, we determined that the 2nd Cys residue is required for the efficient dimerization of RTP1S. Altogether, these findings provide insights into the mechanism for plasma membrane transport of ORs by RTP1S.
    MeSH term(s) Animals ; Cell Movement/genetics ; Dimerization ; Flow Cytometry ; HEK293 Cells ; Humans ; Membrane Transport Proteins/chemistry ; Membrane Transport Proteins/genetics ; Mice ; Molecular Chaperones/chemistry ; Molecular Chaperones/genetics ; Odorants/analysis ; Protein Transport/genetics ; Receptors, G-Protein-Coupled/chemistry ; Receptors, G-Protein-Coupled/genetics ; Receptors, Odorant/chemistry ; Receptors, Odorant/genetics
    Chemical Substances Membrane Transport Proteins ; Molecular Chaperones ; RTP1 protein, mouse ; Receptors, G-Protein-Coupled ; Receptors, Odorant
    Language English
    Publishing date 2019-08-08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.RA118.007110
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Biological impacts of resveratrol, quercetin, and N-acetylcysteine on oxidative stress in human gingival fibroblasts.

    Orihuela-Campos, Rita Cristina / Tamaki, Naofumi / Mukai, Rie / Fukui, Makoto / Miki, Kaname / Terao, Junji / Ito, Hiro-O

    Journal of clinical biochemistry and nutrition

    2015  Volume 56, Issue 3, Page(s) 220–227

    Abstract: ... quercetin, and N-acetylcysteine (NAC) on human gingival fibroblasts (HGFs) under oxidative stress induced ...

    Abstract In periodontitis, production of reactive oxygen species (ROS) by neutrophils induces oxidative stress and deteriorates surrounding tissues. Antioxidants reduce damage caused by ROS and are used to treat diseases involving oxidative stress. This study summarizes the different effects of resveratrol, quercetin, and N-acetylcysteine (NAC) on human gingival fibroblasts (HGFs) under oxidative stress induced by hydrogen peroxide. Real-time cytotoxicity analyses reveals that resveratrol and quercetin enhanced cell proliferation even under oxidative stress. Of the antioxidants tested, resveratrol is the most effective at inhibiting ROS production. HGFs incubated with resveratrol and quercetin up-regulate the transcription of type I collagen gene after 3 h, but only resveratrol sustained this up-regulation for 24 h. A measurement of the oxygen consumption rate (OCR, mitochondrial respiration) shows that resveratrol generates the highest maximal respiratory capacity, followed by quercetin and NAC. Simultaneous measurement of OCR and the extracellular acidification rate (non-mitochondrial respiration) reveals that resveratrol and quercetin induce an increase in mitochondrial respiration when compared with untreated cells. NAC treatment consumes less oxygen and enhances more non-mitochondrial respiration. In conclusion, resveratrol is the most effective antioxidant in terms of real-time cytotoxicity analysis, reduction of ROS production, and enhancement of type I collagen synthesis and mitochondrial respiration in HGFs.
    Language English
    Publishing date 2015-03-28
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 632945-7
    ISSN 1880-5086 ; 0912-0009
    ISSN (online) 1880-5086
    ISSN 0912-0009
    DOI 10.3164/jcbn.14-129
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Effects of Modifying Thioflavin T at the N 3 -Position on Its G4 Binding and Fluorescence Emission

    Yuka Kataoka / Hiroto Fujita / Tamaki Endoh / Naoki Sugimoto / Masayasu Kuwahara

    Molecules, Vol 25, Iss 4936, p

    2020  Volume 4936

    Abstract: We previously synthesized thioflavin T (ThT) with a hydroxyethyl group introduced at the N 3 ... with an amino group (ThT-AE) was synthesized for the first time. Furthermore, three other N 3 -modified ThT ... derivatives (ThT-OE2, ThT-SP, and ThT-OE11) having different substituent structures were synthesized by the N ...

    Abstract We previously synthesized thioflavin T (ThT) with a hydroxyethyl group introduced at the N 3 -position (ThT-HE), which binds predominantly to the parallel G-quadruplex (G4) structure found in c-Myc and emits strong fluorescence. In this study, to investigate the effects of introduced substituents on G4 binding and fluorescence emission, a ThT derivative in which the hydroxyl group of ThT-HE was replaced with an amino group (ThT-AE) was synthesized for the first time. Furthermore, three other N 3 -modified ThT derivatives (ThT-OE2, ThT-SP, and ThT-OE11) having different substituent structures were synthesized by the N-acylation of the terminal amino group of ThT-AE, and their G4-binding and emission properties were investigated. The results showed that, although ThT-AE shows binding selectivity depending on the type of G4, its emission intensity is significantly decreased as compared to that of ThT-HE. However, ThT-OE11, which features an 11-unit oxyethylene chain attached to the terminal amino group of ThT-AE, regained about one-half of the emission intensity of ThT-HE while retaining selectivity for G4s. Accordingly, ThT-OE11 may be used as a key intermediate for synthesizing the conjugates of G4 binders and probes.
    Keywords G-quadruplex ; G4-binder ; G4-probe ; thioflavin T derivative ; Organic chemistry ; QD241-441
    Subject code 540
    Language English
    Publishing date 2020-10-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: A convenient preparation of N (ε)-methyl-L-lysine derivatives and its application to the synthesis of histone tail peptides.

    Chi, Hongfang / Islam, Md Shahidul / Nsiama, Tienabe K / Kato, Tamaki / Nishino, Norikazu

    Amino acids

    2014  Volume 46, Issue 5, Page(s) 1305–1311

    Abstract: A convenient route is established for the preparation of N (α)-Fmoc-N (ε)-(Boc, methyl)-L-lysine ... and N (α)-Fmoc-N (ε)-dimethyl-L-lysine as building blocks to be used for the synthesis of methylated ... of the synthesis of N (ε)-methyl-L-lysine derivatives. ...

    Abstract A convenient route is established for the preparation of N (α)-Fmoc-N (ε)-(Boc, methyl)-L-lysine and N (α)-Fmoc-N (ε)-dimethyl-L-lysine as building blocks to be used for the synthesis of methylated peptides. This methodology is based on the use of malonate derivatives and dibromobutane to produce key intermediates, L-2-amino-6-bromohexanoic acid derivatives, which could be modified to the required group at the ε-position. Fmoc-protection is accessible, so these compounds can be used in solution as well as in solid-phase peptide synthesis. Also the peptides containing these methylated lysines have been proved to resist the action of trypsin and lysyl endopeptidase. Thus, this new method could be considered as an improvement of the synthesis of N (ε)-methyl-L-lysine derivatives.
    MeSH term(s) Histones/chemical synthesis ; Histones/chemistry ; Lysine/analogs & derivatives ; Lysine/chemistry ; Molecular Structure ; Peptides/chemical synthesis ; Peptides/chemistry ; Solid-Phase Synthesis Techniques/methods
    Chemical Substances Histones ; Peptides ; Lysine (K3Z4F929H6)
    Language English
    Publishing date 2014-05
    Publishing country Austria
    Document type Evaluation Studies ; Journal Article
    ZDB-ID 1121341-3
    ISSN 1438-2199 ; 0939-4451
    ISSN (online) 1438-2199
    ISSN 0939-4451
    DOI 10.1007/s00726-014-1690-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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