81 results on '"Nozaki T"'
Search Results
2. Stress corrosion cracking of magnesium alloy with the slow strain rate technique
- Author
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Uchida, H., primary, Yamashita, M., additional, Hanaki, S., additional, and Nozaki, T., additional
- Published
- 2008
- Full Text
- View/download PDF
3. Structure and Content of the Entamoeba histolytica Genome
- Author
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Clark, C.G., primary, Alsmark, U.C.M., additional, Tazreiter, M., additional, Saito‐Nakano, Y., additional, Ali, V., additional, Marion, S., additional, Weber, C., additional, Mukherjee, C., additional, Bruchhaus, I., additional, Tannich, E., additional, Leippe, M., additional, Sicheritz‐Ponten, T., additional, Foster, P.G., additional, Samuelson, J., additional, Noël, C.J., additional, Hirt, R.P., additional, Embley, T.M., additional, Gilchrist, C.A., additional, Mann, B.J., additional, Singh, U., additional, Ackers, J.P., additional, Bhattacharya, S., additional, Bhattacharya, A., additional, Lohia, A., additional, Guillén, N., additional, Duchêne, M., additional, Nozaki, T., additional, and Hall, N., additional
- Published
- 2007
- Full Text
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4. High performance methane conversion into valuable products with spark discharge at room temperature
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Kado, S., primary, Sekine, Y., additional, Urasaki, K., additional, Okazaki, K., additional, and Nozaki, T., additional
- Published
- 2004
- Full Text
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5. Selective oxidative coupling of methane with membrane reactor
- Author
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Nozaki, T., primary, Yamazaki, O., additional, Omata, K., additional, and Fujimoto, K., additional
- Published
- 1994
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6. Synthesis of C2+ Hydrocarbons and Syngas by Gas Phase Methane Oxidation Under Pressure
- Author
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Omata, K., primary, Asami, K., additional, Nozaki, T., additional, and Fujimoto, K., additional
- Published
- 1994
- Full Text
- View/download PDF
7. Utilization of oxide ion transfer for oxidative coupling of methane with membrane reactors
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Nozaki, T., primary, Omata, K., additional, and Fujimoto, K., additional
- Published
- 1993
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8. Chapter 3 Device Fabrication Process Technology
- Author
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Nozaki, T., primary and Higashisaka, A., additional
- Published
- 1990
- Full Text
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9. Chapter 1 Active Layer Formation by Ion Implantation
- Author
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Kuzuhara, M., primary and Nozaki, T., additional
- Published
- 1990
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10. New quinolone alkaloids from Euodia Fruit, and their pancreatic lipase inhibitory and PPAR-γ ligand-binding activities.
- Author
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Matsuo Y, Nozaki T, Kamewada Y, Nakagawa M, Nakamura Y, Inaba N, and Mimaki Y
- Subjects
- Animals, Mice, Molecular Structure, Quinolones pharmacology, Quinolones isolation & purification, Male, Phytochemicals pharmacology, Phytochemicals isolation & purification, Indole Alkaloids pharmacology, Indole Alkaloids isolation & purification, China, Quinazolines pharmacology, Quinazolines isolation & purification, Ligands, Plant Extracts pharmacology, Plant Extracts chemistry, Quinazolinones, Evodia chemistry, Lipase antagonists & inhibitors, Fruit chemistry, Alkaloids pharmacology, Alkaloids isolation & purification, PPAR gamma metabolism, Pancreas
- Abstract
Euodia Fruit is a crude drug used to treat migraine and headaches and is well-known to contain indole alkaloids, which may contribute to the observed pharmacological activities. A methanolic extract of Euodia Fruit exhibited pancreatic lipase inhibitory activity (IC
50 13.9 mg/mL). Bioassay-guided fractionation of the extract led to the isolation of 14 quinolone alkaloids (1-14), three indole alkaloids: rutaecarpine (15), evodiamine (16), and dehydroevodiamine (17), and a limonoid: rutaevine acetate (18), among which three quinolone alkaloids (12-14) have been previously undescribed. The structures of 12-14 were determined by extensive spectroscopic analyses, including two-dimensional (2D) NMR. Compounds 2, 3, 6-9, 13, and 14 exhibited pancreatic lipase inhibitory activity, with IC50 values ranging from 1.40 to 7.37 mM. The results revealed that the length of the aliphatic side chain and the presence of an olefinic bond at the C-2 side chain of the quinolone alkaloids could impact lipase inhibitory activity. In soybean oil-loaded mice, orally administered evocarpine (8) reduced serum triglyceride levels in a dose-dependent manner. Furthermore, 8-14 at 5.0 and 50 μM exhibited peroxisome proliferator-activated receptor (PPAR)-γ ligand-binding activity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
- Full Text
- View/download PDF
11. NSC-3852 synergistically enhances the cytotoxicity of olaparib in oral squamous cell carcinoma.
- Author
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Sasaki Y, Inouchi T, Kise C, Nakatsuka R, Inoue A, Masutani M, and Nozaki T
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- Humans, Cell Line, Tumor, Antineoplastic Agents pharmacology, Cell Survival drug effects, Histone Deacetylase Inhibitors pharmacology, DNA Damage drug effects, Phthalazines pharmacology, Piperazines pharmacology, Mouth Neoplasms drug therapy, Mouth Neoplasms pathology, Mouth Neoplasms genetics, Mouth Neoplasms metabolism, Drug Synergism, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell pathology, Carcinoma, Squamous Cell genetics, Poly(ADP-ribose) Polymerase Inhibitors pharmacology, Apoptosis drug effects
- Abstract
The PARP inhibitor olaparib is an anti-cancer agent based on synthetic lethality that targets poly (ADP-ribose) polymerases. It is used as a therapeutic agent for breast, ovarian, pancreatic, and prostate cancers carrying BRCA1/2 mutations that cause deficiency in homologous recombination. In recent years, acquired resistance to PARP inhibitors has become a clinical problem in PARP inhibitor-treated patients. Meanwhile, the development of molecular targeted drugs for highly malignant oral cancers has not progressed, and effective treatment strategies are needed. In this study, we identified the histone deacetylase inhibitor NSC-3852 as a compound that synergistically enhances the effects of olaparib in oral squamous cell carcinoma cell lines. N-Acetyl-l-cysteine treatment partially recovered cell survival after co-treatment with olaparib and NSC-3852. Moreover, the combination of olaparib and NSC-3852 rapidly upregulated γH2AX at 2 h after treatment, and induced S-phase arrest and apoptosis at 24 h after treatment, suggesting that this combination induced apoptosis through accumulation of massive DNA damage. Taken together, these findings demonstrate that NSC-3852 is a sensitizer of olaparib and suggest that the combination of NSC-3852 and olaparib may be a useful therapeutic strategy for homologous recombination-proficient cancers, including cancers with acquired resistance to olaparib and high-grade oral squamous cell carcinoma., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2025
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12. Evidence of γ-secretase complex involved in the regulation of intramembrane proteolysis in Entamoeba histolytica.
- Author
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Makiuchi T, Saito-Nakano Y, and Nozaki T
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- Cell Membrane metabolism, Phylogeny, Humans, Entamoeba histolytica genetics, Entamoeba histolytica enzymology, Entamoeba histolytica metabolism, Amyloid Precursor Protein Secretases metabolism, Amyloid Precursor Protein Secretases genetics, Proteolysis, Protozoan Proteins metabolism, Protozoan Proteins genetics
- Abstract
Presenilins (PSNs) are multifunctional membrane proteins involved in signal transduction, lysosomal acidification, and certain physiological processes related to mitochondria. The aspartic protease activity of PSN and the formation of a γ-secretase complex with other subunits such as nicastrin (NCT) are required for the biological functions. Although PSN is widely conserved in eukaryotes, most studies on PSN were conducted in metazoans. Homologous genes for PSN and NCT (EhPSN and EhNCT, respectively) are encoded in the genome of Entamoeba histolytica, however, their functions remain unknown. In this study, we showed that EhPSN and EhNCT form a complex on the cell membrane, demonstrating that the parasite possesses γ-secretase. The predicted structure of EhPSN was similar to the human homolog, demonstrated by the crystal structure, and phylogenetic analysis indicated good conservation between EhPSN and human PSN, supporting the premise that EhPSN functions as a subunit of γ-secretase. By contrast, EhNCT appears to have undergone remarkable structural changes during its evolution. Blue native-polyacrylamide gel electrophoresis combined with western blotting indicated that a 150-kDa single band contains both EhPSN (estimated molecular size: 47-kDa) and EhNCT (64-kDa), suggesting that the complex also contains other unknown components or post-translational modifications. Coimmunoprecipitation from amebic lysates also confirmed that EhPSN and EhNCT formed a complex. Indirect immunofluorescence analysis revealed that the complex localized to the plasma membrane. Moreover, EhPSN exhibited protease activity, which was suppressed by a γ-secretase inhibitor. This is the first report of a γ-secretase complex in protozoan parasites., Competing Interests: Declaration of competing interest The authors have no conflict of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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13. Multi-locus sequence analysis reveals phylogenetically segregated Entamoeba histolytica population.
- Author
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Upadhyay S, Das K, Ghosal A, Manna S, Saito-Nakano Y, Dutta S, Nozaki T, and Ganguly S
- Subjects
- Animals, Sequence Analysis, Entamoeba histolytica genetics, Entamoebiasis epidemiology, Entamoebiasis parasitology, Liver Abscess, Amebic parasitology, Amebiasis, Dysentery, Amebic parasitology, Entamoeba genetics
- Abstract
Amoebiasis, caused by the enteric parasite, Entamoeba histolytica, is one of the major food- and water-borne parasitic diseases in developing countries with improper sanitation and poor hygiene. Infection with E. histolytica has diverse disease outcomes, which are determined by the genetic diversity of the infecting strains. Comparative genetic analysis of infecting E. histolytica strains associated with differential disease outcomes from different geographical regions of the world is important to identify the specific genetic patterns of the pathogen that trigger certain disease outcomes of Amoebiasis. The strategy is able to elucidate the genealogical relation and population structure of infecting E. histolytica strains from different geographical regions. In the present study, we have performed a comparative genetic analysis of circulating E. histolytica strains identified from different parts of the world, including our study region, based on five tRNA-linked short tandem repeat (STR) loci (i.e., D-A, NK2, R-R, S
TGA -D and A-L) and evaluated their potential associations with differential disease outcomes of Amoebiasis. A number of regional-specific, emerging haplotypes of E. histolytica, significantly associated with specific disease outcomes have been identified. Haplotypes, which have a significant positive association with asymptomatic and amoebic liver abscess outcomes, showed a significant negative association with diarrheal outcome, or vice versa. Comparative multi-locus analysis revealed that E. histolytica isolates from our study region are phylogenetically segregated from the isolates of other geographical regions. This study provides a crucial overview of the population structure and emerging pattern of the enteric parasite, E. histolytica., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest regarding scientific or financial matters., (Copyright © 2023. Published by Elsevier B.V.)- Published
- 2024
- Full Text
- View/download PDF
14. Fast abdominal magnetic resonance elastography with simultaneous encoding of three-dimensional displacements.
- Author
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Ito D, Numano T, Habe T, Okuda S, Nozaki T, and Jinzaki M
- Subjects
- Humans, Liver diagnostic imaging, Abdomen diagnostic imaging, Motion, Movement, Magnetic Resonance Imaging methods, Elasticity Imaging Techniques methods
- Abstract
Three-dimensional (3D) magnetic resonance elastography (MRE) is more accurate than two-dimensional (2D) MRE; however, it requires long-term acquisition. This study aimed to reduce the acquisition time of abdominal 3D MRE using a new sample interval modulation (short-SLIM) approach that can acquire all three motions faster while reducing the prolongation of echo time and flow compensation. To this end, two types of phantom studies and an in vivo test of the liver in three healthy volunteers were performed to compare the performances of conventional spin-echo echo-planar (SE-EPI) MRE, conventional SLIM and short-SLIM. One phantom study measured the mean amplitude and shear modulus within the overall region of a homogeneous phantom by changing the mechanical vibration power to assess the robustness to the lowered phase-to-noise ratio in short-SLIM. The other measured the mean shear modulus in the stiff and background materials of a phantom with an embedded stiffer rod to assess the performance of short-SLIM for complex wave patterns with wave interference. The Spearman's rank correlation coefficient was used to assess similarity of elastograms in the rod-embedded phantom and liver between methods. The results of the phantom study changing the vibration power indicated that there was little difference between conventional MRE and short-SLIM. Moreover, the elastogram pattern and the mean shear modulus in the rod-embedded phantom in conventional SLIM and short-SLIM did not change for conventional MRE; the liver test also showed a small difference between the acquisition techniques. This study demonstrates that short-SLIM can provide MRE results comparable to those of conventional MRE. Short-SLIM can reduce the total acquisition time by a factor of 2.25 compared to conventional 3D MRE time, leading to an improvement in the accuracy of shear modulus estimation by suppressing the patient movements., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
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15. Short tandem repeat (STR) based sequence typing of Entamoeba histolytica identifies S TGA -D locus as a genetic marker, associated with disease outcomes.
- Author
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Upadhyay S, Das K, Ghosal A, Saito-Nakano Y, Dutta S, Nozaki T, and Ganguly S
- Subjects
- Animals, Genetic Markers, Phylogeny, Microsatellite Repeats, RNA, Transfer genetics, Entamoeba histolytica genetics, Entamoebiasis epidemiology, Entamoebiasis parasitology, Entamoeba genetics
- Abstract
Amoebiasis, caused by the enteric parasite Entamoeba histolytica has differential disease outcomes. The association of parasite genotypes with outcomes of amoebic infection is still a paradox and requires to be explored. The genetic information of infecting strains from endemic settings of different geographical regions is essential to evaluate the relation. Comparative genetics of E. histolytica clinical isolates from different disease outcomes have been explored based on two tRNA-linked STR loci (S
TGA -D and A-L). All of the repeat patterns in the A-L locus were newly identified and unique to Indian isolates. The majority of newly identified repeat patterns in STGA -D locus have outcome-specific distributions, predicting the emergence of disease-specific mutations in this target locus. Statistical analysis further reinforces this observation, as identified repeat patterns only from STGA -D but not A-L locus were significantly associated with disease outcomes. Phylogenetic analysis indicates independent segregation and divergence of tRNA-linked STR arrays for each STR locus., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
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16. Mechanistic Modeling of Amyloid Oligomer and Protofibril Formation in Bovine Insulin.
- Author
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Yuzu K, Imamura H, Nozaki T, Fujii Y, Badawy SMM, Morishima K, Okuda A, Inoue R, Sugiyama M, and Chatani E
- Subjects
- Animals, Cattle, Humans, Kinetics, Spectroscopy, Fourier Transform Infrared, Amyloid chemistry, Insulins chemistry
- Abstract
Early phase of amyloid formation, where prefibrillar aggregates such as oligomers and protofibrils are often observed, is crucial for understanding pathogenesis. However, the detailed mechanisms of their formation have been difficult to elucidate because they tend to form transiently and heterogeneously. Here, we found that bovine insulin protofibril formation proceeds in a monodisperse manner, which allowed us to characterize the detailed early aggregation process by light scattering in combination with thioflavin T fluorescence and Fourier transform infrared spectroscopy. The protofibril formation was specific to bovine insulin, whereas no significant aggregation was observed in human insulin. The kinetic analysis combining static and dynamic light scattering data revealed that the protofibril formation process in bovine insulin can be divided into two steps based on fractal dimension. When modeling the experimental data based on Smoluchowski aggregation kinetics, an aggregation scheme consisting of initial fractal aggregation forming spherical oligomers and their subsequent end-to-end association forming protofibrils was clarified. Furthermore, the analysis of temperature and salt concentration dependencies showed that the end-to-end association is the rate-limiting step, involving dehydration. The established model for protofibril formation, wherein oligomers are incorporated as a precursor, provides insight into the molecular mechanism by which protein molecules assemble during the early stage of amyloid formation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
17. Dysfunction of poly (ADP-ribose) glycohydrolase suppresses osteoclast differentiation in RANKL-stimulated RAW264 cells.
- Author
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Sasaki Y, Nakatsuka R, Inoue A, Inouchi T, Masutani M, and Nozaki T
- Subjects
- Glycoside Hydrolases metabolism, Poly (ADP-Ribose) Polymerase-1, Poly Adenosine Diphosphate Ribose metabolism, Poly(ADP-ribose) Polymerases metabolism, Animals, Mice, Osteoclasts metabolism, Ribose
- Abstract
Poly (ADP-ribose) glycohydrolase (PARG) is an enzyme that mainly degrades poly (ADP-ribose) (PAR) synthesized by poly (ADP-ribose) polymerase (PARP) family proteins. Although PARG is involved in many biological phenomena, including DNA repair, cell differentiation, and cell death, little is known about the relationship between osteoclast differentiation and PARG. It has also not been clarified whether PARG is a valuable target for therapeutic agents in the excessive activity of osteoclast-related bone diseases such as osteoporosis. In the present study, we examined the effects of PARG inhibitor PDD00017273 on osteoclast differentiation in RANKL-induced RAW264 cells. PDD00017273 induced the accumulation of intracellular PAR and suppressed the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. PDD00017273 also downregulated osteoclast differentiation marker genes such as Trap, cathepsin K (Ctsk), and dendrocyte expressed seven transmembrane protein (Dcstamp) and protein expression of nuclear factor of activated T cells 1 (NFATc1), a master regulator of osteoclast differentiation. Taken together, our findings suggest that dysfunction of PARG suppresses osteoclast differentiation via the PAR accumulation and partial inactivation of the NFATc1., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2024
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18. Effect of geranylated dihydrochalcone from Artocarpus altilis leaves extract on Plasmodium falciparum ultrastructural changes and mitochondrial malate: Quinone oxidoreductase.
- Author
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Hidayati AR, Melinda, Ilmi H, Sakura T, Sakaguchi M, Ohmori J, Hartuti ED, Tumewu L, Inaoka DK, Tanjung M, Yoshida E, Tokumasu F, Kita K, Mori M, Dobashi K, Nozaki T, Syafruddin D, Hafid AF, Waluyo D, and Widyawaruyanti A
- Subjects
- Humans, Plasmodium falciparum, Malates metabolism, Malates pharmacology, Malates therapeutic use, Plant Extracts pharmacology, Plant Extracts chemistry, Mitochondria metabolism, Quinones pharmacology, Chalcones pharmacology, Chalcones therapeutic use, Antimalarials pharmacology, Antimalarials therapeutic use, Artocarpus chemistry, Artocarpus metabolism, Malaria, Falciparum drug therapy
- Abstract
Nearly half of the world's population is at risk of being infected by Plasmodium falciparum, the pathogen of malaria. Increasing resistance to common antimalarial drugs has encouraged investigations to find compounds with different scaffolds. Extracts of Artocarpus altilis leaves have previously been reported to exhibit in vitro antimalarial activity against P. falciparum and in vivo activity against P. berghei. Despite these initial promising results, the active compound from A. altilis is yet to be identified. Here, we have identified 2-geranyl-2', 4', 3, 4-tetrahydroxy-dihydrochalcone (1) from A. altilis leaves as the active constituent of its antimalarial activity. Since natural chalcones have been reported to inhibit food vacuole and mitochondrial electron transport chain (ETC), the morphological changes in food vacuole and biochemical inhibition of ETC enzymes of (1) were investigated. In the presence of (1), intraerythrocytic asexual development was impaired, and according to the TEM analysis, this clearly affected the ultrastructure of food vacuoles. Amongst the ETC enzymes, (1) inhibited the mitochondrial malate: quinone oxidoreductase (PfMQO), and no inhibition could be observed on dihydroorotate dehydrogenase (DHODH) as well as bc
1 complex activities. Our study suggests that (1) has a dual mechanism of action affecting the food vacuole and inhibition of PfMQO-related pathways in mitochondria., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest in this study., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2023
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19. Syndromic vascular malformations related to the PIK3CA and RAS pathways: A clinical and imaging review.
- Author
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Tsujioka Y, Nozaki T, Niimi Y, Starkey J, Hasegawa D, Kondo M, Enokizono M, Makidono A, Kono T, and Jinzaki M
- Subjects
- Class I Phosphatidylinositol 3-Kinases genetics, Diagnostic Imaging, Humans, Mutation, Proto-Oncogene Proteins c-akt genetics, Proto-Oncogene Proteins c-akt metabolism, Quality of Life, Signal Transduction, Syndrome, ras Proteins genetics, ras Proteins metabolism, Phosphatidylinositol 3-Kinases genetics, Phosphatidylinositol 3-Kinases metabolism, Vascular Malformations diagnostic imaging, Vascular Malformations genetics
- Abstract
Vascular malformations are a complex and diverse group of disorders. They may enlarge with time, impair quality of life, and even be fatal. While many are sporadic, others are part of inherited syndromes; several gene mutations responsible for vascular anomalies have been identified. The PI3K/AKT/mTOR and RAS/MEK/ERK cascades have been extensively studied, and new molecular agents targeting these cascades are being developed. Diagnostic imaging findings are increasingly used to guide genetic testing, and in some cases, pathognomonic imaging characteristics can lead to a specific diagnosis. We review each of the representative syndromes associated with PIK3CA and RAS cascades, with updates of the latest in clinical and imaging information., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
20. Exploring natural microbial resources for the discovery of anti-malarial compounds.
- Author
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Waluyo D, Prabandari EE, Pramisandi A, Hidayati DN, Chrisnayanti E, Puspitasari DJ, Dewi D, Suryani, Kristiningrum, Oktaviani AN, Afrianti KR, Nonaka K, Matsumoto A, Tokiwa T, Adipratiwi N, Ariyani T, Hartuti ED, Putri TZ, Rahmawati Y, Inaoka DK, Miyazaki Y, Sakura T, Nurlaila, Siska E, Kurnia K, Bernawati P, Melinda, Mahsunah AH, Nugroho NB, Mori M, Dobashi K, Yamashita M, Nurkanto A, Watanabe A, Shiomi K, Wibowo AE, and Nozaki T
- Subjects
- Indonesia, Antimalarials isolation & purification, Antimalarials pharmacology, Drug Discovery, Plasmodium falciparum drug effects
- Abstract
Microorganisms in nature are highly diverse biological resources, which can be explored for drug discovery. Some countries including Brazil, Columbia, Indonesia, China, and Mexico, which are blessed with geographical uniqueness with diverse climates and display remarkable megabiodiversity, potentially provide microorganismal resources for such exploitation. In this review, as an example of drug discovery campaigns against tropical parasitic diseases utilizing microorganisms from such a megabiodiversity country, we summarize our past and on-going activities toward discovery of new antimalarials. The program was held in a bilateral collaboration between multiple Indonesian and Japanese research groups. In order to develop a new platform of drug discovery utilizing Indonesian bioresources under an international collaborative scheme, we aimed at: 1) establishment of an Indonesian microbial depository, 2) development of robust enzyme-based and cell-based screening systems, and 3) technology transfer necessary for screening, purification, and identification of antimalarial compounds from microbial culture broths. We collected, characterized, and deposited Indonesian microbes. We morphologically and genetically characterized fungi and actinomycetes strains isolated from 5 different locations representing 3 Indonesian geographical areas, and validated genetic diversity of microbes. Enzyme-based screening was developed against two validated mitochondrial enzymes from Plasmodium falciparum, dihydroorotate dehydrogenase and malate:quinone oxidoreductase, while cell-based proliferation assay was developed using the erythrocytic stage parasite of 3D7 strain. More than 17 thousands microbial culture extracts were subjected to the enzyme- and cell-based screening. Representative anti-malarial compounds discovered in this campaign are discussed, including a few isolated compounds that have been identified for the first time as anti-malarial compounds. Our antimalarial discovery campaign validated the Indonesian microbial library as a powerful resource for drug discovery. We also discuss critical needs for selection criteria for hits at each stage of screening and hit deconvolution such as preliminary extraction test for the initial profiling of the active compounds and dereplication techniques to minimize repetitive discovery of known compounds., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
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21. Multilocus sequence typing (MLST) of Entamoeba histolytica identifies kerp2 as a genetic marker associated with disease outcomes.
- Author
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Das K, Sardar SK, Ghosal A, Saito-Nakano Y, Dutta S, Nozaki T, and Ganguly S
- Subjects
- Genetic Markers, Humans, Entamoeba histolytica genetics, Liver Abscess, Amebic parasitology, Multilocus Sequence Typing, Polymorphism, Genetic, Protozoan Proteins genetics
- Abstract
Amoebiasis caused by protozoan parasite Entamoeba histolytica has diverse infection outcomes. The relationship between parasite genotypes and outcome of amoebic infection is still a paradox and needs to be explored. Genome information of infecting strains from endemic areas throughout the world is essential to explore this relation. Comparative genetics between E. histolytica populations from different disease outcomes have been studied to identify potential genetic markers having single nucleotide polymorphisms (SNPs) significantly associated with specific clinical outcome. Coding and non-coding regions have significantly different rates of polymorphism. Non-synonymous base substitutions were significantly more frequent than synonymous within coding loci. Both synonymous and non-synonymous SNPs within lysine- and glutamic acid rich protein 2 (kerp2) locus were significantly associated with disease outcomes. An incomplete linkage disequilibrium (LD) value with potential recombination events and significant population differentiation (F
ST ) value have also been identified at kerp2 locus within the study population. Presence of disease specific SNPs, potential recombination events, and significant FST value at kerp2 locus indicate that kerp2 gene and its gene product are under constant selection pressure exerted by host on parasite and could also be a potential determinant of disease outcome of E. histolytica infection. Furthermore, E. histolytica isolated from asymptomatic carriers are phylogenetically closer to those causing liver abscess in human and exhibit potential inter-population recombination among them. Individuals with persistent asymptomatic E. histolytica infection may be under high risk of developing amoebic liver abscess formation in future and detailed investigation of asymptomatic individuals from endemic areas should be always required., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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22. Diversity of phosphoinositide binding proteins in Entamoeba histolytica.
- Author
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Watanabe N, Nakada-Tsukui K, and Nozaki T
- Subjects
- Entamoeba histolytica metabolism, Protein Binding, Carrier Proteins metabolism, Entamoeba histolytica genetics, Phosphatidylinositols metabolism, Protozoan Proteins metabolism
- Abstract
Phosphatidylinositol phosphates (PIPs, phosphoinositides) are localized to the membranes of all cellular compartments, and play pivotal roles in multiple cellular events. To fulfill their functions, PIPs that are located to specific organelles or membrane domains bind to and recruit various proteins in spatiotemporal specific manner via protein domains that selectively bind to either a single or an array of PIPs. In Entamoeba histolytica, the human intestinal protozoan parasite, PIPs and PIP-binding proteins have been shown to be involved in their virulence-associated mechanisms such as cell motility, vesicular traffic, trogo- and phagocytosis. In silico search of the domains and the signatures implicated in PIP binding in the E. histolytica proteome allows identification of dozens of potential PIP-binding proteins. However, such analysis is often misleading unless the protein domain used as query is cautiously selected and the binding specificity of the proteins are experimentally validated. This is because all the domains initially presumed to bind PIPs in other systems are not always capable of PIP binding, but rather involved in other biological roles. In this review, we carried out in silico survey of proteins which have PIP-binding domains in the E. histolytica genome by utilizing only validated PIP-binding domains that had been experimentally proven to be faithful PIP-binding bioprobes. Our survey has identified that FYVE (Fab1, YOTB1, Vac1, EEA1) and PH (pleckstrin homology) domain containing proteins are the most expanded families in E. histolytica. A few FYVE domain-containing proteins (EhFP4 and 10) and phox homology (PX) domain containing proteins (EhSNX1 and 2) were previously studied in depth in E. histolytica. Furthermore, most of the identified PH domain-containing proteins are annotated as protein kinases and possess protein kinase domains. Overall, PIP-binding domain-containing proteins that can be identified by in silico survey of the genome using the domains from well characterized bioprobes are limited in E. histolytica. However, their domain architectures are often unique, suggesting unique evolution of PIP-binding domain-containing proteins in this organism., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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23. Interorganellar communication and membrane contact sites in protozoan parasites.
- Author
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Santos HJ and Nozaki T
- Subjects
- Cell Membrane physiology, Organelles physiology, Entamoeba histolytica physiology, Giardia lamblia physiology, Plasmodium physiology, Signal Transduction physiology, Toxoplasma physiology, Trypanosoma brucei brucei physiology
- Abstract
A key characteristic of eukaryotic cells is the presence of organelles with discrete boundaries and functions. Such subcellular compartmentalization into organelles necessitates platforms for communication and material exchange between each other which often involves vesicular trafficking and associated processes. Another way is via the close apposition between organellar membranes, called membrane contact sites (MCSs). Apart from lipid transfer, MCSs have been implicated to mediate in various cellular processes including ion transport, apoptosis, and organelle dynamics. In mammalian and yeast cells, contact sites have been reported between the membranes of the following: the endoplasmic reticulum (ER) and the plasma membrane (PM), ER and the Golgi apparatus, ER and endosomes (i.e., vacuoles, lysosomes), ER and lipid droplets (LD), the mitochondria and vacuoles, the nucleus and vacuoles, and the mitochondria and lipid droplets, whereas knowledge of MCSs in non-model organisms such as protozoan parasites is extremely limited. Growing evidence suggests that MCSs play more general and conserved roles in cell physiology. In this mini review, we summarize and discuss representative MCSs in divergent parasitic protozoa, and highlight the universality, diversity, and the contribution of MCSs to parasitism., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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24. Oocyte resorption in termite queens: Seasonal dynamics and controlling factors.
- Author
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Nozaki T and Matsuura K
- Subjects
- Animals, Female, Ovary physiology, Seasons, Isoptera physiology, Oocytes
- Abstract
Female insects can resorb their oocytes that could not be oviposited. Oocyte resorption is proposed to be an adaptive mechanism to optimize fitness in hostile environments, recouping resources that might otherwise be lost. Social insects have developed reproductive division of labor, wherein a small number of queens are devoted to egg production. Matured queens are highly specialized in reproduction and are largely dependent on nestmate workers for their nourishment. Therefore, oocyte resorption in the queens should be influenced by social factors such as the amount of available workforce, as well as external and abiotic factors. In this study, we investigated the seasonal dynamics and regulation factors of oocyte resorption in actively reproducing termite queens. We continuously collected the field-nests of the subterranean termite Reticulitermes speratus and demonstrated that queens frequently resorbed their oocytes in late summer, even though it is one of the most productive seasons in this species. On the other hand, our laboratory experiment showed that oocyte resorption itself was strongly induced regardless of the season. We also found that the rate of oocyte resorption was influenced by colony size (the number of attending workers). These results suggest that termite queens seasonally resorb their oocytes, yet oocyte resorption itself is regulated by social factors rather than by seasonal factors. Our study provides a unique insight into the regulation of reproduction in social insects., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2021
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25. Mechanism on the plasma-catalytic oxidation of graphitic carbon over Au/γ-Al 2 O 3 by in situ plasma DRIFTS-mass spectrometer.
- Author
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Lu H, Yao X, Li J, Yao S, Wu Z, Zhang H, Lin H, and Nozaki T
- Abstract
Plasma-catalytic oxidation of particulate matter (PM) has potential applications for diesel exhaust cleaning. There is a grand requirement to explore the mechanism of carbonaceous PM oxidation for the development of plasma catalysts. Herein, Au/γ-Al
2 O3 was used to catalyze the gasification of the graphitic carbon. A modified diffuse reflectance infrared Fourier transform spectrometer equipped with a mass spectrometer was originally utilized to in situ characterize the surface intermediates of graphite on Au/γ-Al2 O3 and the gaseous products during the discharges processes in the O2 -He balanced gases. It was found that O atoms and O3 play important roles in the formation of surface oxygen complexes (SOCs) and facilitate the gasification of SOCs to CO2 in the presence of Au/γ-Al2 O3 . The findings are helpful to understand the plasma-catalytic oxidation mechanism of PM and further develop efficient plasma catalysts., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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26. Three-dimensional electron microscopy analysis reveals endopolygeny-like nuclear architecture segregation in Plasmodium oocyst development.
- Author
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Araki T, Kawai S, Kakuta S, Kobayashi H, Umeki Y, Saito-Nakano Y, Sasaki T, Nagamune K, Yasutomi Y, Nozaki T, Franke-Fayard B, Khan SM, Hisaeda H, and Annoura T
- Subjects
- Animals, Cell Division, Female, Imaging, Three-Dimensional, Macaca parasitology, Microscopy, Electron, Scanning, Oocysts growth & development, Plasmodium growth & development, Cell Nucleus ultrastructure, Cell Nucleus Division, Oocysts ultrastructure, Plasmodium ultrastructure
- Abstract
The genus Plasmodium is a unicellular eukaryotic parasite that is the causative agent of malaria, which is transmitted by Anopheline mosquito. There are a total of three developmental stages in the production of haploid parasites in the Plasmodium life cycle: the oocyst stage in mosquitoes and the liver and blood stages in mammalian hosts. The Plasmodium oocyst stage plays an important role in the production of the first generation of haploid parasites. Nuclear division is the most important event that occurs during the proliferation of all eukaryotes. However, obtaining the details of nuclear division at the oocyst stage is challenging owing to difficulties in preparation. In this study, we used focused-ion-beam-milling combined with scanning-electron-microscopy to report the 3D architecture during nuclear segregations in oocyst stage. This advanced technology allowed us to analyse the 3D details of organelle segregation inside the oocyst during sporogony formation. It was revealed that multiple nuclei were involved with several centrosomes in one germ nucleus during sporozoite budding (endopolygeny). Our high-resolution 3D analysis uncovered the endopolygeny-like nuclear architecture of Plasmodium in the definitive host. This nuclear segregation was different from that in the blood stage, and its similarity to other apicomplexan parasite nuclear divisions such as Sarcocystis is discussed., Competing Interests: Declaration of Competing Interest The authors have declared that no competing interests exist., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2020
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27. Falsely Elevated Serum Creatinine Associated With IgM Paraproteinemia.
- Author
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Mase H, Hamano N, Mizuhara R, Nozaki T, Saso T, Wada T, Asai S, Miyachi H, and Fukagawa M
- Published
- 2019
- Full Text
- View/download PDF
28. Mechanism of CO 2 -formation promotion by Au in plasma-catalytic oxidation of CH 4 over Au/γ-Al 2 O 3 at room temperature.
- Author
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Yao S, Chen Z, Weng S, Mao L, Zhang X, Han J, Wu Z, Lu H, Tang X, Jiang B, and Nozaki T
- Abstract
The plasma-catalytic oxidation of methane (CH
4 ) is a potential reaction for controlling CH4 emissions at low temperatures. However, the mechanism of the CH4 plasma-catalytic oxidation is still unknown, which inhibits the further optimization of the oxidation process. Herein, a CH4 oxidation mechanism over an Au/γ-Al2 O3 catalyst was proposed based on our experimental findings. CH4 is first decomposed to CH3 and H by the discharge, and a fraction of the CH3 is adsorbed on γ-Al2 O3 surface for deep oxidation. The oxygen atoms produced by the discharge react with H2 O to yield surface reactive OH groups that contribute to the CH3 oxidation. Oxygen atoms also promote the release of H2 O from the surfaces of the γ-Al2 O3 and Au/γ-Al2 O3 and especially promote CO2 desorption from the surface of the Au/γ-Al2 O3 . When γ-Al2 O3 was used as the catalyst, the CO2 selectivity was only 15 vol.%, and the CH4 conversion decreased after 7 h of plasma-catalytic oxidation. In contrast, when Au/γ-Al2 O3 was used, the CO2 selectivity was 80 vol.%, long-term CH4 conversion was obtained. Experimental results revealed that Au was beneficial for the decomposition of surface carbonate species into gaseous CO2 , whereas the carbonate species accumulated on γ-Al2 O3 when Au was absent., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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29. Promotion of graphitic carbon oxidation via stimulating CO 2 desorption by calcium carbonate.
- Author
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Yao S, Zhang H, Chen Z, Lin H, Han S, Wu X, Dong R, Wu Z, and Nozaki T
- Abstract
Carbon oxidation has two stages, the first is the formation of surface oxides and the second is the gasification of the surface oxides to CO
2 . Calcium carbonate (CaCO3 ) was used to catalyze the gasification of the surface oxides. The catalytic effect of on graphite oxidation and its catalytic mechanism were studied by using thermogravimetric technique and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). It was found that characteristic temperature (T50 ) of graphite oxidation with CaCO3 was 946 K, 113 K lower than that of graphite only. DRIFTS analysis results show that surface oxides (adsorbed CO2 and carbonate CO3 2- ) were formed on the graphite surface at a temperature above 473 K, carbonate products on graphite surface disappeared when CaCO3 was present; formation of CO3 2- on CaCO3 surface was confirmed, this CO3 2- may be more easily gasified into gaseous CO2 . The kinetic analysis results showed that CaCO3 promoted graphite oxidation has an activation energy of 74.3 kJ mol-1 , far lower than that of graphite (148 kJ mol-1 )., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2019
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30. Assessing patterns of T2/T1rho change in grade 1 cartilage lesions of the distal femur using an angle/layer dependent approach.
- Author
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Kaneko Y, Nozaki T, Yu H, Schwarzkopf R, Hara T, and Yoshioka H
- Subjects
- Adult, Female, Humans, Magnetic Resonance Imaging methods, Male, Protons, Young Adult, Cartilage, Articular pathology, Femur pathology, Knee pathology, Knee Joint pathology, Osteoarthritis, Knee pathology
- Abstract
Purpose: To assess changes in the patterns of T2 and T1rho values within grade 1 cartilage lesions of osteoarthritis (OA) patients compared to healthy controls., Materials and Methods: Twenty healthy knees and 25 OA knees were examined on a 3 T scanner. Areas of signal heterogeneity within the cartilage of the distal femur were identified using fat suppressed proton density-weighted imagines. T2 and T1rho values in each OA patient with grade 1 lesions were compared to average T2 and T1rho values of the corresponding areas in healthy subjects., Results: A total of 28 areas including grade 1 lesion were identified. Compared to normal cartilage, the majority of grade 1 cartilage lesions demonstrated either no significant change or a statistically significant increase in both T2 values (18/28, 64%) and T1rho values (23/28, 82%). Compared to T2, T1rho demonstrated a greater proportion of statistically significantly higher values in OA patients than those from the normal controls. However, T2 and T1rho values in grade 1 lesions can be decreased, or demonstrate mixed patterns compared to those in healthy cartilage., Conclusion: Our results suggest that early degenerative cartilage lesions can demonstrate various patterns of T2 and T1rho changes., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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31. Effect of Subthalamic Deep Brain Stimulation on Upper Limb Dexterity in Patients with Parkinson Disease.
- Author
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Nozaki T, Asakawa T, Sugiyama K, Koda Y, Shimoda A, Mizushima T, Sameshima T, and Namba H
- Subjects
- Aged, Dopamine Agents pharmacology, Dopamine Agents therapeutic use, Female, Humans, Hypokinesia diagnosis, Hypokinesia physiopathology, Male, Middle Aged, Motor Skills drug effects, Parkinson Disease diagnosis, Parkinson Disease physiopathology, Treatment Outcome, Deep Brain Stimulation methods, Hypokinesia therapy, Motor Skills physiology, Parkinson Disease therapy, Subthalamic Nucleus surgery, Upper Extremity physiology
- Abstract
Objective: The efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on dexterity remains controversial despite its recognition as an effective strategy for Parkinson disease. The present study investigated the efficacy of STN-DBS for ameliorating bradykinesia and dexterity compared with dopaminergic medications., Methods: Part III of the Unified Parkinson's Disease Rating Scale was used for the evaluation of bradykinesia, whereas the Purdue Pegboard Test and the Box and Block test were selected for dexterity., Results: Our findings indicate that bradykinesia is significantly improved with both DBS and dopaminergic medication, whereas dexterity is improved only with DBS. Dopaminergic medication did not show a satisfactory efficacy on dexterity, and there was little synergistic effect of dopaminergic medication and STN-DBS for improving dexterity associated with Parkinson disease., Conclusions: Our results suggest that DBS is potentially more effective than dopaminergic medications for improving dexterity. The disparities in efficacy for bradykinesia and dexterity between DBS and dopaminergic medication hint at the potential mechanisms of STN-DBS. We speculate that DBS follows at least 2 different mechanisms for improving parkinsonian symptoms: 1) the dopaminergic system, primarily for the improvement of bradykinesia and 2) the nondopaminergic system, for the improvement of dexterity. This hypothesis requires further verification and investigation., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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32. Next-generation sequencing-based miRNA expression analysis in Parp1-deficient embryonic stem cell-derived exosomes.
- Author
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Nozaki T, Sasaki Y, Fukuda I, Isumi M, Nakamoto K, Onodera T, and Masutani M
- Subjects
- Animals, Gene Expression Profiling, Gene Ontology, Humans, MicroRNAs metabolism, Poly(ADP-ribose) Polymerases metabolism, RNA metabolism, Reproducibility of Results, Signal Transduction, Up-Regulation genetics, Embryonic Stem Cells metabolism, Exosomes metabolism, Gene Expression Regulation, High-Throughput Nucleotide Sequencing methods, MicroRNAs genetics, Poly(ADP-ribose) Polymerases deficiency
- Abstract
Poly (ADP-ribose) polymerase family, member 1 (Parp1) has pleiotropic and disparate functions in multiple cellular signaling pathways through post-translational protein modification. It contributes to the regulation of various cellular processes, including DNA damage repair, cell death, and cell differentiation, genetically or epigenetically. Meanwhile, the functions of Parp1 in intercellular signaling remain to be established. To examine the functions of Parp1 in intercellular signaling, we examined microRNA (miRNA) regulation in exosomes derived from Parp1-deficient (Parp1
-/- ) embryonic stem (ES) cells. The percentages of miRNAs among total RNAs, including small RNAs such as miRNAs, snRNAs, snoRNAs, tRNAs, exonic RNAs, and intronic RNAs, in Parp1+/+ and Parp1-/- ES cell-derived exosomes were 8.2% and 3.5%, respectively. Overall, 329 distinct miRNAs exhibited ≥2-fold changes (118 upregulated; 211 downregulated). The upregulated miRNAs targeted 810 candidate genes, and the downregulated miRNAs targeted 716 candidate genes. Pathway analyses revealed that the upregulated miRNAs were significantly associated with five pathways including MAPK signaling cascades (p < 0.05), indicating that the target genes in these pathways were suppressed in Parp1-/- ES cells. In quantitative analyses of miRNA expression, miR365-3p, let-7a-5p, miR196b-5p, miR203-3p, miR98-5p, and miR146a-5p were increased by ≥ 2-fold in Parp1-/- ES cell-derived exosomes. Gene ontology enrichment analyses revealed that the upregulated miRNAs were significantly annotated for growth and stress-related cell signaling and cell communication (p < 0.05). Parp1 deficiency in ES cells led to inhibition of cell-cell communication, possibly by intercellular signal transduction, suggesting that Parp1 functions extracellularly by regulating exosomal miRNAs., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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33. Plasma-catalyst hybrid reactor with CeO 2 /γ-Al 2 O 3 for benzene decomposition with synergetic effect and nano particle by-product reduction.
- Author
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Mao L, Chen Z, Wu X, Tang X, Yao S, Zhang X, Jiang B, Han J, Wu Z, Lu H, and Nozaki T
- Abstract
A dielectric barrier discharge (DBD) catalyst hybrid reactor with CeO
2 /γ-Al2 O3 catalyst balls was investigated for benzene decomposition at atmospheric pressure and 30 °C. At an energy density of 37-40 J/L, benzene decomposition was as high as 92.5% when using the hybrid reactor with 5.0wt%CeO2 /γ-Al2 O3 ; while it was 10%-20% when using a normal DBD reactor without a catalyst. Benzene decomposition using the hybrid reactor was almost the same as that using an O3 catalyst reactor with the same CeO2 /γ-Al2 O3 catalyst, indicating that O3 plays a key role in the benzene decomposition. Fourier transform infrared spectroscopy analysis showed that O3 adsorption on CeO2 /γ-Al2 O3 promotes the production of adsorbed O2 - and O2 2‒ , which contribute benzene decomposition over heterogeneous catalysts. Nano particles as by-products (phenol and 1,4-benzoquinone) from benzene decomposition can be significantly reduced using the CeO2 /γ-Al2 O3 catalyst. H2 O inhibits benzene decomposition; however, it improves CO2 selectivity. The deactivated CeO2 /γ-Al2 O3 catalyst can be regenerated by performing discharges at 100 °C and 192-204 J/L. The decomposition mechanism of benzene over CeO2 /γ-Al2 O3 catalyst was proposed., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2018
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34. Characterization and validation of Entamoeba histolytica pantothenate kinase as a novel anti-amebic drug target.
- Author
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Nurkanto A, Jeelani G, Yamamoto T, Naito Y, Hishiki T, Mori M, Suematsu M, Shiomi K, Hashimoto T, and Nozaki T
- Subjects
- Amebiasis drug therapy, Biological Products, Biosynthetic Pathways genetics, Coenzyme A analysis, Coenzyme A biosynthesis, Coenzyme A genetics, Drug Delivery Systems, Drug Discovery, Entamoeba histolytica drug effects, Entamoeba histolytica genetics, Entamoeba histolytica growth & development, Epigenomics, Gene Silencing, Humans, Nucleotidyltransferases genetics, Nucleotidyltransferases isolation & purification, Peptide Synthases genetics, Peptide Synthases isolation & purification, Phosphotransferases (Alcohol Group Acceptor) genetics, Phylogeny, Small Molecule Libraries, Antiprotozoal Agents isolation & purification, Biosynthetic Pathways drug effects, Entamoeba histolytica enzymology, Phosphotransferases (Alcohol Group Acceptor) drug effects, Phosphotransferases (Alcohol Group Acceptor) isolation & purification
- Abstract
The Coenzyme A (CoA), as a cofactor involved in >100 metabolic reactions, is essential to the basic biochemistry of life. Here, we investigated the CoA biosynthetic pathway of Entamoeba histolytica (E. histolytica), an enteric protozoan parasite responsible for human amebiasis. We identified four key enzymes involved in the CoA pathway: pantothenate kinase (PanK, EC 2.7.1.33), bifunctional phosphopantothenate-cysteine ligase/decarboxylase (PPCS-PPCDC), phosphopantetheine adenylyltransferase (PPAT) and dephospho-CoA kinase (DPCK). Cytosolic enzyme PanK, was selected for further biochemical, genetic, and phylogenetic characterization. Since E. histolytica PanK (EhPanK) is physiologically important and sufficiently divergent from its human orthologs, this enzyme represents an attractive target for the development of novel anti-amebic chemotherapies. Epigenetic gene silencing of PanK resulted in a significant reduction of PanK activity, intracellular CoA concentrations, and growth retardation in vitro, reinforcing the importance of this gene in E. histolytica. Furthermore, we screened the Kitasato Natural Products Library for inhibitors of recombinant EhPanK, and identified 14 such compounds. One compound demonstrated moderate inhibition of PanK activity and cell growth at a low concentration, as well as differential toxicity towards E. histolytica and human cells., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2018
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35. Biochemical studies of membrane bound Plasmodium falciparum mitochondrial L-malate:quinone oxidoreductase, a potential drug target.
- Author
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Hartuti ED, Inaoka DK, Komatsuya K, Miyazaki Y, Miller RJ, Xinying W, Sadikin M, Prabandari EE, Waluyo D, Kuroda M, Amalia E, Matsuo Y, Nugroho NB, Saimoto H, Pramisandi A, Watanabe YI, Mori M, Shiomi K, Balogun EO, Shiba T, Harada S, Nozaki T, and Kita K
- Subjects
- Antimalarials pharmacology, Atovaquone pharmacology, Biocatalysis drug effects, Coumarins pharmacology, Drug Synergism, Enzyme Inhibitors pharmacology, Humans, Malaria, Falciparum parasitology, Malaria, Falciparum prevention & control, Malates metabolism, Mitochondrial Membranes drug effects, Oxaloacetic Acid metabolism, Oxidoreductases antagonists & inhibitors, Plasmodium falciparum drug effects, Protozoan Proteins antagonists & inhibitors, Mitochondrial Membranes enzymology, Oxidoreductases metabolism, Plasmodium falciparum enzymology, Protozoan Proteins metabolism
- Abstract
Plasmodium falciparum is an apicomplexan parasite that causes the most severe malaria in humans. Due to a lack of effective vaccines and emerging of drug resistance parasites, development of drugs with novel mechanisms of action and few side effects are imperative. To this end, ideal drug targets are those essential to parasite viability as well as absent in their mammalian hosts. The mitochondrial electron transport chain (ETC) of P. falciparum is one source of such potential targets because enzymes, such as L-malate:quinone oxidoreductase (PfMQO), in this pathway are absent humans. PfMQO catalyzes the oxidation of L-malate to oxaloacetate and the simultaneous reduction of ubiquinone to ubiquinol. It is a membrane protein, involved in three pathways (ETC, the tricarboxylic acid cycle and the fumarate cycle) and has been shown to be essential for parasite survival, at least, in the intra-erythrocytic asexual stage. These findings indicate that PfMQO would be a valuable drug target for development of antimalarial with novel mechanism of action. Up to this point in time, difficulty in producing active recombinant mitochondrial MQO has hampered biochemical characterization and targeted drug discovery with MQO. Here we report for the first time recombinant PfMQO overexpressed in bacterial membrane and the first biochemical study. Furthermore, about 113 compounds, consisting of ubiquinone binding site inhibitors and antiparasitic agents, were screened resulting in the discovery of ferulenol as a potent PfMQO inhibitor. Finally, ferulenol was shown to inhibit parasite growth and showed strong synergism in combination with atovaquone, a well-described anti-malarial and bc
1 complex inhibitor., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2018
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36. Plant hormone cytokinins control cell cycle progression and plastid replication in apicomplexan parasites.
- Author
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Andrabi SBA, Tahara M, Matsubara R, Toyama T, Aonuma H, Sakakibara H, Suematsu M, Tanabe K, Nozaki T, and Nagamune K
- Subjects
- Cytokinins metabolism, Phenylurea Compounds pharmacology, Plant Growth Regulators metabolism, Plant Growth Regulators pharmacology, Plasmodium berghei growth & development, Thiadiazoles pharmacology, Toxoplasma growth & development, Cell Cycle drug effects, Cytokinins pharmacology, Plasmodium berghei enzymology, Plasmodium berghei physiology, Toxoplasma drug effects, Toxoplasma physiology
- Abstract
Cytokinins are plant hormones that are involved in regulation of cell proliferation, cell cycle progression, and cell and plastid development. Here, we show that the apicomplexan parasites Toxoplasma gondii and Plasmodium berghei, an opportunistic human pathogen and a rodent malaria agent, respectively, produce cytokinins via a biosynthetic pathway similar to that in plants. Cytokinins regulate the growth and cell cycle progression of T. gondii by mediating expression of the cyclin gene TgCYC4. A natural form of cytokinin, trans-zeatin (t-zeatin), upregulated expression of this cyclin, while a synthetic cytokinin, thidiazuron, downregulated its expression. Immunofluorescence microscopy and quantitative PCR analysis showed that t-zeatin increased the genome-copy number of apicoplast, which are non-photosynthetic plastid, in the parasite, while thidiazuron led to their disappearance. Thidiazuron inhibited growth of T. gondii and Plasmodium falciparum, a human malaria parasite, suggesting that thidiazuron has therapeutic potential as an inhibitor of apicomplexan parasites., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2018
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37. Pre-procedural peripheral endothelial function is associated with increased serum creatinine following percutaneous coronary procedure in stable patients with a preserved estimated glomerular filtration rate.
- Author
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Sumida H, Matsuzawa Y, Sugiyama S, Sugamura K, Nozaki T, Akiyama E, Ohba K, Konishi M, Matsubara J, Fujisue K, Maeda H, Kurokawa H, Iwashita S, Ogawa H, and Tsujita K
- Subjects
- Aged, Creatinine blood, Female, Glomerular Filtration Rate, Humans, Kidney physiology, Male, Manometry, Middle Aged, Multivariate Analysis, Natriuretic Peptide, Brain blood, Odds Ratio, Risk Factors, Endothelium, Vascular physiology, Percutaneous Coronary Intervention
- Abstract
Background: Worsening renal function, indicated by increased serum creatinine (SCr), is a common complication of percutaneous coronary procedures. Risk factors for increased SCr overlap with coronary risk factors involved in endothelial dysfunction. We hypothesized that endothelial dysfunction, measured using the reactive hyperemia peripheral arterial tonometry index (RHI), can predict periprocedure-increased SCr., Methods: RHI was assessed before elective coronary procedures in 316 consecutive stable patients with a preserved estimated glomerular filtration rate (eGFR, >60mL/min/1.73m
2 ). SCr was measured before and 2 days after procedures., Results: There was no significant correlation between natural logarithmic transformations of RHI (Ln-RHI) and basal Ln-eGFR. Periprocedure increase in SCr was observed in 148 (47%) patients. The increased SCr group had significantly lower Ln-RHI [0.48 (0.36, 0.62) vs. 0.59 (0.49, 0.76), p<0.001]. Multivariate linear regression analysis identified body mass index (BMI) (β=0.148, p=0.005) and Ln-RHI (β=-0.365, p<0.001) as significant determinants of percent changes in SCr. Multivariate logistic regression analysis identified Ln-RHI (per 0.1) [odds ratio (OR) 0.672, 95% confidence interval (95% CI) 0.586-0.722; p<0.001], Ln-B-type natriuretic peptide (OR: 1.484, 95% CI: 1.130-1.974; p=0.004), current smoking (OR: 2.563, 95% CI: 1.379-4.763, p=0.003), BMI (OR: 1.113, 95% CI: 1.031-1.203; p=0.007), coronary intervention (OR: 1.736, 95% CI: 1.036-2.909; p=0.036), and Ln-hemoglobin A1c (OR: 6.728, 95% CI: 1.093-41.392, p=0.040) as independent determinants of increased SCr. Receiver-operating characteristics curve analysis showed that Ln-RHI correlated significantly with increased SCr (area under the curve, 0.684, 95% CI: 0.626-0.742, p<0.001). The optimum cut-off point of Ln-RHI for the periprocedure increased SCr was 0.545., Conclusions: Pre-procedure measurement of endothelial function by RHI is an effective strategy to assess the patient's risk conditions for worsening renal function after percutaneous coronary procedures., (Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)- Published
- 2017
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38. Complete sequence and characterization of the mitochondrial genome of Diphyllobothrium stemmacephalum, the type species of genus Diphyllobothrium (Cestoda: Diphyllobothriidae), using next generation sequencing.
- Author
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Yamasaki H, Izumiyama S, and Nozaki T
- Subjects
- Animals, DNA, Intergenic genetics, Diphyllobothriasis diagnosis, Diphyllobothriasis parasitology, Genome, Helminth, High-Throughput Nucleotide Sequencing methods, Phylogeny, Sequence Analysis, DNA, DNA, Helminth genetics, DNA, Mitochondrial genetics, Diphyllobothrium genetics, Genome, Mitochondrial
- Abstract
We first constructed and characterized the complete mitochondrial genome (mitogenome) sequence of Diphyllobothrium stemmacephalum, the type species of genus Diphyllobothrium, using next generation sequencing (NGS). The mitogenome of D. stemmacephalum was 13,716bp, including 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 2 longer intergenic non-coding regions, and has features common to mitogenomes of other cestodes. Although it has been accepted that tRNA for serine (trnS2
(UCN) ) in Platyhelminthes lacks a D arm, the trnS2(UCN) of D. stemmacephalum was predicted to have a paired D arm as in Diplogonoporus balaenopterae. The non-coding region 2 contained eight tandem repeat units (34nucleotides/unit). This study also corroborated that D. stemmacephalum is phylogenetically more closely related to Dip. balaenopterae than to Diphyllobothrium latum and Diphyllobothrium nihonkaiense. As demonstrated here, mitogenome sequence data obtained using NGS is useful for gaining a better understanding of the systematics, phylogeny and taxonomic revisions involving valuable specimens preserved in museums, universities or research institutes for which sequence data are not yet available, and also for making diagnoses based on clinical samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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39. Bone turnover markers and the factors associated with atypical femur fractures among Japanese patients.
- Author
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Iizuka Y, Iizuka H, Kaneko T, Mieda T, Takechi R, Suzuki H, Sorimachi Y, Suto T, Tachibana M, Yoneyama T, Omodaka T, Hashimoto S, Hamano N, Sakane H, Shimoyama D, Kohama I, Ohshima A, Nozaki T, Kamiyama M, Moteki T, Ohshima A, Takamine S, Honda A, Ueno A, Tajika T, Okamura K, Warita T, Yonemoto Y, Shitara H, Ohsawa T, and Takagishi K
- Subjects
- Aged, Aged, 80 and over, Asian People, Biomarkers blood, Collagen Diseases blood, Collagen Diseases epidemiology, Comorbidity, Cross-Sectional Studies, Female, Femoral Fractures blood, Femoral Fractures epidemiology, Granulomatous Disease, Chronic blood, Granulomatous Disease, Chronic epidemiology, Humans, Japan epidemiology, Male, Middle Aged, Osteoporosis blood, Osteoporosis drug therapy, Osteoporosis epidemiology, Peptide Fragments, Procollagen, Prospective Studies, Risk Factors, Tartrate-Resistant Acid Phosphatase, Bone Density Conservation Agents adverse effects, Bone Remodeling drug effects, Collagen Diseases pathology, Diphosphonates adverse effects, Femoral Fractures pathology, Fracture Healing physiology, Granulomatous Disease, Chronic pathology, Osteoporosis pathology
- Abstract
Many previous reports have indicated that atypical femur fractures (AFFs) are associated with the administration of bisphosphonates (BPs). A number of risk factors and hypotheses regarding the pathogenesis of AFFs have been reported to date. The purpose of the present study was to identify the factors associated with AFFs in Japanese individuals and to elucidate the association between bone metabolism and AFFs by evaluating bone turnover markers (BTMs). We prospectively reviewed all patients with femur fractures and identified the patients with AFFs and typical femur fractures (TFFs). We collected the demographic and clinical data that were relevant to the present study, namely age, gender, affected side, affected site, concomitant medical history, and comorbid conditions, and measured the levels of BTMs within 24h after trauma. Welch's test and Fisher's exact probability test were used for the statistical analyses. A total of 338 patients, including 10 patients with AFFs and 328 patients with TFFs, were analyzed under the inclusion criteria. The use of BPs (p<0.001) and collagen disease and chronic granulomatous disease (CD/CGD) (p=0.025) were more frequently observed in patients with AFFs than in patients with TFFs, while the levels of BTMs, including N-terminal propeptides of type 1 procollagen (P1NP), isoform 5b of tartrate-resistant acid phosphatase (TRACP-5b) and undercarboxylated osteocalcin (ucOC) were significantly lower in patients with AFFs than in patients with TFFs. Furthermore, the level of TRACP-5b was found to be significantly lower in patients with atypical subtrochanteric fractures than in atypical diaphyseal fractures (p=0.025). Moreover, the levels of P1NP (p=0.016) and TRACP-5b (p=0.015) were found to be significantly lower in patients with AFFs than in patients with TFFs in a subgroup analysis of BPs users. The use of BPs was considered to be a factor associated with AFFs. Our comparison of the BTMs in patients with AFFs and TFFs indicated that the severe suppression of bone turnover was associated with the pathogenesis of AFFs. The extent of the influence of suppressed turnover on the pathogenesis of AFFs may differ depending on the fracture site., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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40. Advanced peripheral microvascular endothelial dysfunction and polyvascular disease in patients with high cardiovascular risk.
- Author
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Maeda H, Sugiyama S, Jinnouchi H, Matsuzawa Y, Fujisue K, Hirata Y, Kurokawa H, Ohba K, Matsubara J, Nozaki T, Konishi M, Akiyama E, Sugamura K, Yamamoto E, Sumida H, and Ogawa H
- Subjects
- Aged, Ankle Brachial Index, Coronary Angiography, Cross-Sectional Studies, Female, Humans, Hyperemia, Male, Manometry, Risk Factors, Cerebrovascular Disorders physiopathology, Coronary Artery Disease physiopathology, Endothelium, Vascular physiopathology, Microvessels physiopathology, Peripheral Arterial Disease physiopathology
- Abstract
Background: Polyvascular disease (PolyVD) refers to the coexistence of coronary artery disease (CAD), peripheral arterial disease (PAD), and/or cerebrovascular disease (CVD), and carries a high risk of cardiovascular mortality. Endothelial dysfunction plays a crucial role in cardiovascular pathophysiology. This study investigated the association between PolyVD and the presence of microvascular endothelial dysfunction., Methods: Consecutive stable patients (n=533) with diabetes mellitus and/or multiple cardiovascular risk factors were enrolled. Peripheral microvascular endothelial function in the finger microvasculature was assessed using the reactive hyperemia peripheral arterial tonometry index (RHI), and ankle-brachial index was measured for diagnosis of lower-extremity PAD prior to coronary angiography. Diagnosis of CVD was based on clinical symptoms, carotid ultrasound, and magnetic resonance imaging. PolyVD was defined as two or more coexisting vascular diseases from CAD, lower-extremity PAD, and CVD., Results: Natural logarithmic transformations of RHI (Ln-RHI) were significantly attenuated in 93 patients with PolyVD (0.44±0.20) compared with those in 440 patients without PolyVD (0.56±0.19; p<0.001) or in 299 patients with a single vascular disease (0.54±0.19; p<0.001). There was an independent correlation between Ln-RHI (per 0.1) and the presence of PolyVD in all high-risk patients [odds ratio (OR): 0.724; 95% confidence interval (CI): 0.610-0.859; p<0.001] and one or more vascular diseases (OR: 0.724; 95% CI: 0.605-0.867, p<0.001). Receiver-operating characteristics curve analysis showed that Ln-RHI correlated significantly with PolyVD (area under the curve, 0.682, 95% CI: 0.625-0.740, p<0.001). The optimum cut-off point of Ln-RHI for the existence of PolyVD was 0.479., Conclusions: Microvascular endothelial dysfunction is significantly associated with the presence of PolyVD. Severe impairment of endothelial function in peripheral microvasculature may be an important pathophysiological component of PolyVD., (Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
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41. ABO-Incompatible Living Kidney Transplants: Evolution of Outcomes and Immunosuppressive Management.
- Author
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Okumi M, Toki D, Nozaki T, Shimizu T, Shirakawa H, Omoto K, Inui M, Ishida H, and Tanabe K
- Subjects
- Adult, Female, Follow-Up Studies, Glomerular Filtration Rate, Graft Survival, Humans, Immunosuppressive Agents therapeutic use, Kidney Function Tests, Living Donors, Male, Middle Aged, Prognosis, Prospective Studies, Retrospective Studies, Risk Factors, ABO Blood-Group System immunology, Blood Group Incompatibility immunology, Desensitization, Immunologic methods, Kidney Failure, Chronic surgery, Kidney Transplantation
- Abstract
ABO-incompatible living kidney transplantation (ABO-ILKT) has steadily become more widespread. However, the optimal immunosuppressive regimen for ABO-ILKT remains uncertain. We aimed to determine the longitudinal changes in the outcomes from ABO-ILKT compared with those from ABO-compatible living kidney transplantation (ABO-CLKT) over the last 25 years. Of 1195 patients who underwent living kidney transplantations (LKT) at our institute between 1989 and 2013, 1032-including 247 ABO-ILKT and 785 ABO-CLKT cases-were evaluated for graft survival, patient survival, infectious adverse events, and renal function. The patients were divided into four groups according to the transplantation era and ABO-compatibility. In the past decade, ABO-ILKT and ABO-CLKT recipients yielded almost equivalent outcomes with respect to the 9-year graft survival rates, which were 86.9% and 92.0%, respectively (hazard ratio [HR] 1.38, 95% confidence interval [CI] 0.59-3.22, p = 0.455). The graft survival rate for ABO-ILKT conducted between 2005 and 2013 was better than that for ABO-ILKT conducted between 1998 and 2004 (HR 0.30, 95% CI 0.13-0.72, p = 0.007). ABO-ILKT recipients showed substantial improvements in the graft survival rate over time. Graft survival was almost identical over the past decade, regardless of ABO-incompatibility. Currently, ABO-ILKT is an acceptable treatment for patients with end-stage renal disease., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)
- Published
- 2016
- Full Text
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42. Crystal Structure Analysis of Wild Type and Fast Hydrolyzing Mutant of EhRabX3, a Tandem Ras Superfamily GTPase from Entamoeba histolytica.
- Author
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Srivastava VK, Chandra M, Saito-Nakano Y, Nozaki T, and Datta S
- Subjects
- Crystallography, X-Ray, Entamoeba histolytica chemistry, Entamoeba histolytica genetics, GTP Phosphohydrolases genetics, Guanosine Diphosphate chemistry, Guanosine Triphosphate chemistry, Hydrolysis, Models, Molecular, Mutant Proteins genetics, Protein Conformation, Entamoeba histolytica enzymology, GTP Phosphohydrolases chemistry, GTP Phosphohydrolases metabolism, Guanosine Triphosphate metabolism, Mutant Proteins chemistry, Mutant Proteins metabolism
- Abstract
The enteric protozoan parasite, Entamoeba histolytica, is the causative agent of amoebic dysentery, liver abscess and colitis in human. Vesicular trafficking plays a key role in the survival and virulence of the protozoan and is regulated by various Rab GTPases. EhRabX3 is a catalytically inefficient amoebic Rab protein, which is unique among the eukaryotic Ras superfamily by virtue of its tandem domain organization. Here, we report the crystal structures of GDP-bound fast hydrolyzing mutant (V71A/K73Q) and GTP-bound wild type EhRabX3 at 3.1 and 2.8Å resolutions, respectively. Though both G-domains possess "phosphate binding loop containing nucleoside triphosphate hydrolases fold", only the N-terminal domain binds to guanine nucleotide. The relative orientation of the N-terminal domain and C-terminal domain is stabilized by numerous inter-domain interactions. Compared to other Ras superfamily members, both the GTPase domains displayed large deviation in switch II perhaps due to non-conservative substitutions in this region. As a result, entire switch II is restructured and moved away from the nucleotide binding pocket, providing a rationale for the diminished GTPase activity of EhRabX3. The N-terminal GTPase domain possesses unusually large number of cysteine residues. X-ray crystal structure of the fast hydrolyzing mutant of EhRabX3 revealed that C39 and C163 formed an intra-molecular disulfide bond. Subsequent mutational and biochemical studies suggest that C39 and C163 are critical for maintaining the structural integrity and function of EhRabX3. Structure-guided functional investigation of cysteine mutants could provide the physiological implications of the disulfide bond and could allow us to design potential inhibitors for the better treatment of intestinal amebiasis., (Copyright © 2015. Published by Elsevier Ltd.)
- Published
- 2016
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43. Self-assembly formed by a short DNA probe pair: Application for highly sensitive mRNA species detection without reverse transcription.
- Author
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Usui M, Fujikawa T, Osawa M, Hakii C, Ikumi N, Nozaki T, Kitamura N, Hatta Y, Fujiwara S, and Takei M
- Subjects
- Limit of Detection, DNA Probes, RNA, Messenger genetics, Reverse Transcription
- Abstract
We describe a novel technology for detecting nucleic acids: Probe Alteration Link Self-Assembly Reactions (PALSAR). PALSAR comprises DNA self-assembly of pairs of short DNA probes formed by alternate hybridization of three complementary regions in a pair of honeycomb probes (HCPs). Self-assembly occurs at designated salt concentrations and reaction temperatures and requires no enzymes. We prepared pairs of HCPs to detect mRNAs encoded by the GAPDH gene β-actin (BA) gene, CD3D gene, CD4 gene, major vault protein (MV) gene and the signalling lymphocytic activation molecule-associated protein (SAP) gene, and succeeded in quantitatively detecting these mRNAs. PALSAR could detect mRNA directly without synthesizing cDNA. Moreover, multiple mRNAs could be detected simultaneously in a single reaction tube and there was a good correlation between the results obtained PALSAR and those by real-time PCR., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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44. Characterization of pH-induced transitions of Entamoeba histolytica D-phosphoglycerate dehydrogenase.
- Author
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Mishra V, Kumar A, Ali V, Zhang KY, and Nozaki T
- Subjects
- Entamoeba histolytica chemistry, Entamoeba histolytica genetics, Gene Expression, Hydrogen-Ion Concentration, Kinetics, Molecular Dynamics Simulation, Phosphoglycerate Dehydrogenase genetics, Phosphoglycerate Dehydrogenase isolation & purification, Protein Folding, Protein Multimerization, Protein Stability, Protein Structure, Secondary, Protein Structure, Tertiary, Protozoan Proteins genetics, Protozoan Proteins isolation & purification, Thermodynamics, Entamoeba histolytica enzymology, Phosphoglycerate Dehydrogenase chemistry, Protozoan Proteins chemistry
- Abstract
Entamoeba histolytica D-phosphoglycerate dehydrogenase (EhPGDH) exists as a functionally active homodimer at pH 7. Our earlier studies have shown that ionic interactions are essentially required for the oligomeric status and activity of the protein. Present study focuses on pH associated structural modulations of EhPGDH. Far-UV CD spectra showed loss in the secondary structure of the protein as a function of low pH, however, the protein was not completely unfolded even at pH 2. Energy minimized average simulated models of EhPGDH at different pH show stable secondary structure elements in the nucleotide binding domain (NBD) however, the substrate binding domain (SBD) was more sensitive toward acidic pH and completely unfolds at pH 2. The data suggest presence of partially folded/unfolded intermediate state at pH 2. Size exclusion chromatography shows that this intermediate has larger hydrodynamic radius compared with dimer (pH 7) or monomer (pH 5). The intermediate has poor tertiary organization with significantly exposed hydrophobic patches monitored by pH-dependent fluorescence spectroscopy and molecular dynamic simulations. Collectively, the results suggest that the two domains (NBD and SBD) of EhPGDH have independent pH-dependent structural transitions with stabilization of an intermediate state at pH 2., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
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45. Telmisartan enhances mitochondrial activity and alters cellular functions in human coronary artery endothelial cells via AMP-activated protein kinase pathway.
- Author
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Kurokawa H, Sugiyama S, Nozaki T, Sugamura K, Toyama K, Matsubara J, Fujisue K, Ohba K, Maeda H, Konishi M, Akiyama E, Sumida H, Izumiya Y, Yasuda O, Kim-Mitsuyama S, and Ogawa H
- Subjects
- Cells, Cultured, Cellular Senescence drug effects, Coronary Vessels drug effects, Endothelial Cells drug effects, Gene Deletion, Humans, Nitric Oxide Synthase metabolism, RNA Interference, Telmisartan, beta-Galactosidase metabolism, AMP-Activated Protein Kinases metabolism, Antihypertensive Agents chemistry, Benzimidazoles chemistry, Benzoates chemistry, Coronary Vessels cytology, Endothelial Cells cytology, Mitochondria metabolism
- Abstract
Objective: Mitochondrial dysfunction plays an important role in cellular senescence and impaired function of vascular endothelium, resulted in cardiovascular diseases. Telmisartan is a unique angiotensin II type I receptor blocker that has been shown to prevent cardiovascular events in high risk patients. AMP-activated protein kinase (AMPK) plays a critical role in mitochondrial biogenesis and endothelial function. This study assessed whether telmisartan enhances mitochondrial function and alters cellular functions via AMPK in human coronary artery endothelial cells (HCAECs)., Methods and Results: In cultured HCAECs, telmisartan significantly enhanced mitochondrial activity assessed by mitochondrial reductase activity and intracellular ATP production and increased the expression of mitochondria related genes. Telmisartan prevented cellular senescence and exhibited the anti-apoptotic and pro-angiogenic properties. The expression of genes related anti-oxidant and pro-angiogenic properties were increased by telmisartan. Telmisartan increased endothelial NO synthase and AMPK phosphorylation. Peroxisome proliferator-activated receptor gamma signaling was not involved in telmisartan-induced improvement of mitochondrial function. All of these effects were abolished by inhibition of AMPK., Conclusions: Telmisartan enhanced mitochondrial activity and exhibited anti-senescence effects and improving endothelial function through AMPK in HCAECs. Telmisartan could provide beneficial effects on vascular diseases via enhancement of mitochondrial activity and modulating endothelial function through AMPK activation., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
- Full Text
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46. Proteomic analysis of Entamoeba histolytica in vivo assembled pre-mRNA splicing complexes.
- Author
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Valdés J, Nozaki T, Sato E, Chiba Y, Nakada-Tsukui K, Villegas-Sepúlveda N, Winkler R, Azuara-Liceaga E, Mendoza-Figueroa MS, Watanabe N, Santos HJ, Saito-Nakano Y, and Galindo-Rosales JM
- Subjects
- Alternative Splicing, Cell Nucleus metabolism, Databases, Protein, Introns, Proteomics, RNA Helicases metabolism, RNA Precursors metabolism, RNA, Messenger chemistry, Ribonucleoprotein, U2 Small Nuclear metabolism, Ribonucleoprotein, U4-U6 Small Nuclear metabolism, Spliceosomes metabolism, Tandem Mass Spectrometry, Entamoeba histolytica metabolism, Proteome, RNA Splicing
- Abstract
The genome of the human intestinal parasite Entamoeba histolytica contains nearly 3000 introns and bioinformatic predictions indicate that major and minor spliceosomes occur in Entamoeba. However, except for the U2-, U4-, U5- and U6 snRNAs, no other splicing factor has been cloned and characterized. Here, we HA-tagged cloned the snRNP component U1A and assessed its expression and nuclear localization. Because the snRNP-free U1A form interacts with polyadenylate-binding protein, HA-U1A immunoprecipitates could identify early and late splicing complexes. Avoiding Entamoeba's endonucleases and ensuring the precipitation of RNA-binding proteins, parasite cultures were UV cross-linked prior to nuclear fraction immunoprecipitations with HA antibodies, and precipitates were subjected to tandem mass spectrometry (MS/MS) analyses. To discriminate their nuclear roles (chromatin-, co-transcriptional-, splicing-related), MS/MS analyses were carried out with proteins eluted with MS2-GST-sepharose from nuclear extracts of an MS2 aptamer-tagged Rabx13 intron amoeba transformant. Thus, we probed thirty-six Entamoeba proteins corresponding to 32 cognate splicing-specific factors, including 13 DExH/D helicases required for all stages of splicing, and 12 different splicing-related helicases were identified also. Furthermore 50 additional proteins, possibly involved in co-transcriptional processes were identified, revealing the complexity of co-transcriptional splicing in Entamoeba. Some of these later factors were not previously found in splicing complex analyses., Biological Significance: Numerous facts about the splicing of the nearly 3000 introns of the Entamoeba genome have not been unraveled, particularly the splicing factors and their activities. Considering that many of such introns are located in metabolic genes, the knowledge of the splicing cues has the potential to be used to attack or control the parasite. We have found numerous new splicing-related factors which could have therapeutic benefit. We also detected all the DExH/A RNA helicases involved in splicing and splicing proofreading control. Still, Entamoeba is very inefficient in splicing fidelity, thus we may have found a possible model system to study these processes., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
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47. Multilocus sequence typing system (MLST) reveals a significant association of Entamoeba histolytica genetic patterns with disease outcome.
- Author
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Das K, Mukherjee AK, Chowdhury P, Sehgal R, Bhattacharya MK, Hashimoto T, Nozaki T, and Ganguly S
- Subjects
- Entamoebiasis epidemiology, Genotype, Humans, India, Liver Abscess, Amebic parasitology, Liver Abscess, Amebic pathology, DNA, Protozoan genetics, Entamoeba histolytica genetics, Entamoebiasis parasitology, Entamoebiasis pathology, Multilocus Sequence Typing, Polymorphism, Genetic
- Abstract
The relationship between parasite genotypes and outcome of amoebic infection is still a paradox and needed to be explored. Proper identification and genetic characterization of Entamoeba histolytica clinical isolates is an effective tool for exploring this relation. Along with conventional polymorphic marker (Chitinase), tRNA linked short tandem repeat (STR) loci has been employed as multilocus genotyping tool due to its better resolution and evolutionary significance. Some common as well as exclusive repeat patterns showing significant relation with disease outcome have been identified. Phylogenetic analysis revealed that repeat patterns exclusively found in asymptomatic and amoebic liver abscess derived isolates are placed in a common lineage and has similar association pattern with the disease outcome. Assumption can be made that isolates of E. histolytica remaining asymptomatic is genetically closer siblings of those causing liver abscess rather than the diarrheal isolates., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2014
- Full Text
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48. Regulation of miRNA during direct reprogramming of dental pulp cells to insulin-producing cells.
- Author
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Nozaki T and Ohura K
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors genetics, Cells, Cultured, Dental Pulp cytology, Forkhead Transcription Factors genetics, Forkhead Transcription Factors metabolism, Gene Expression Profiling, Homeodomain Proteins genetics, Immunohistochemistry, Insulin metabolism, Insulin-Secreting Cells cytology, Male, Nerve Tissue Proteins genetics, Nerve Tissue Proteins metabolism, Oligonucleotide Array Sequence Analysis, Rats, Rats, Wistar, Reverse Transcriptase Polymerase Chain Reaction, Trans-Activators genetics, Up-Regulation, Cell Differentiation genetics, Dental Pulp metabolism, Insulin genetics, Insulin-Secreting Cells metabolism, MicroRNAs genetics
- Abstract
To further evaluate the multipotency of dental pulp cells, and to investigate the possible direct reprogramming of these cells, we examined their in vitro induction of direct conversion to an endocrine cell lineage. In vitro induction was carried out using similar conditions to those reported for regulating the differentiation of undifferentiated intestinal cells into endocrine progenitor cells. Specifically, the transcription factors Pdx1 and Neurog3 were transfected into rat dental pulp cells to induce their direct conversion to endocrine lineage cells. The degree of induction was evaluated by detecting insulin-producing cells. Using a miRCURY LNA microRNA Array (Exiqon), the miRNA expression profiles were comprehensively analyzed. At 10 days after induction, insulin-producing cells were detected. Based on the expression profiles, eight miRNA probes showing significant differences at 10 days after induction compared with their pre-induction baseline values were extracted after filtering. Notably, miR-183 was downregulated by less than 40% after induction. Following a target scan of miR-183, we identified 242 conserved targets, including molecules crucial for the development of pancreatic beta-cells such as Foxo1. These findings indicate that dental pulp cells have potential for direct reprogramming to insulin-producing cells. This potential ability for direct reprogramming of dental pulp cells shows promise for clinically relevant tissue engineering materials., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
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49. Accumulation of pericardial fat correlates with left ventricular diastolic dysfunction in patients with normal ejection fraction.
- Author
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Konishi M, Sugiyama S, Sugamura K, Nozaki T, Matsubara J, Akiyama E, Utsunomiya D, Matsuzawa Y, Yamashita Y, Kimura K, Umemura S, and Ogawa H
- Subjects
- Adipose Tissue diagnostic imaging, Aged, Diastole, Echocardiography, Female, Heart Failure, Humans, Male, Middle Aged, Pericardium diagnostic imaging, Risk Factors, Tomography, X-Ray Computed, Ventricular Dysfunction, Left diagnosis, Ventricular Dysfunction, Left physiopathology, Adipose Tissue metabolism, Pericardium metabolism, Stroke Volume physiology, Ventricular Dysfunction, Left etiology, Ventricular Dysfunction, Left metabolism
- Abstract
Background: Left ventricular diastolic dysfunction (LVDD) plays an important role in heart failure with normal left ventricular ejection fraction (LVEF). Obesity is one of the major comorbid conditions of LVDD. Pericardial fat (PF) is an ectopic fat depot with possible paracrine or mechanical effects on the coronary circulation and myocardial function., Methods: We measured PF volume on 64 slice computed tomography and analyzed echocardiographic parameters to confirm LVDD in 229 consecutive patients suspected of coronary artery disease with LVEF of more than 50% and no symptomatic heart failure (59% men, 67±12 years). LVDD was defined as the ratio of transmitral Doppler early filling velocity to tissue Doppler early diastolic mitral annular velocity (E/e') >10., Results: PF volume correlated significantly with E/e' (r=0.21, p<0.01), left ventricular mass index (r=0.23, p<0.001), and left atrial diameter (r=0.32, p<0.001). The mean PF volume was significantly greater in patients with LVDD (184±61cm(3), n=141) than in those without LVDD (154±58, n=88, p<0.001). Multivariate logistic regression analysis indicated that PF volume correlated significantly with the presence of LVDD (odds ratio: 2.00 per 100cm(3) increase in PF volume, p=0.02) independent of age, gender, abdominal obesity, hypertension, and diabetes., Conclusions: PF volumes are significantly associated with LVDD, independent of other factors such as hypertension or diabetes. PF may be implicated in the pathogenesis of LVDD in patients with normal LVEF., (Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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50. Expanding the utility of heptamer-type sgRNA for TRUE gene silencing.
- Author
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Sano T, Takahashi M, Nozaki T, Takahashi Y, Tamura M, and Nashimoto M
- Subjects
- Endoribonucleases chemistry, HEK293 Cells, Humans, Jurkat Cells, RNA, Small Interfering genetics, RNA, Small Untranslated, Endoribonucleases metabolism, Gene Knockdown Techniques methods, Gene Silencing, Oligonucleotides chemistry, RNA Cleavage, RNA, Small Interfering chemistry
- Abstract
tRNase Z(L)-utilizing efficacious gene silencing (TRUE gene silencing) is a novel technology for suppressing gene expression. TRUE gene silencing is based on a unique enzymatic property of mammalian tRNase Z(L), which is that it can cleave any target RNA at any desired site by recognizing a pre-tRNA-like or micro-pre-tRNA-like complex formed between the target RNA and artificial small guide RNA (sgRNA). sgRNA is divided into four groups, 5'-half-tRNA, RNA heptamer, hook RNA, and ∼14-nt linear RNA. One of the final destinations of TRUE gene silencing is to generate cancer therapeutic sgRNAs, and from a pharmacological point of view, heptamer-type sgRNA appears to be the most appropriate for this purpose. In this paper, we present two strategies to expand the utility of heptamer-type sgRNA: one is about locked nucleic acid (LNA) modifications of heptamers and the other is about usage of double heptamers. We showed that RNA heptamers with LNA modifications can work as sgRNA in vitro and in vivo. We also demonstrated that two consecutively aligned heptamers can guide target RNA cleavage by human tRNase Z(L) as efficiently as a corresponding 14-nt sgRNA in vitro and that a double heptamer can work much better than a 14-nt sgRNA in vivo., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
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