144 results on '"Hiromasa Kurosaki"'
Search Results
2. (5-Fluoro-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-1-ido-κN1)(1,4,8,11-tetraazacyclotetradecane-κ4N)zinc(II) perchlorate
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Yoshimi Ichimaru, Koichi Kato, Wanchun Jin, Masaaki Kurihara, and Hiromasa Kurosaki
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crystal structure ,zinc(ii) complex ,cyclam ,[14]anen4 ,fluorouracil ,Crystallography ,QD901-999 - Abstract
In the structure of the title complex, [Zn(C4H2FN2O2)(C10H24N4)]ClO4, the zinc(II) ion forms coordination bonds with the four nitrogen atoms of cyclam (1,4,8,11-tetraazacyclotetradecane or [14]aneN4) as well as with the nitrogen atom of a deprotonated 5-fluorouracil ion (FU−). Cyclam adopts a trans-I type conformation within this structure. The coordination structure of the zinc(II) ion is a square pyramid with a distorted base plane formed by the four nitrogen atoms of the cyclam. FU− engages in intermolecular hydrogen bonding with neighboring FU− molecules and with the cyclam molecule.
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- 2024
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3. Hydroxyhexylitaconic acids as potent IMP-type metallo-β-lactamase inhibitors for controlling carbapenem resistance in Enterobacterales
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Jun-ichi Wachino, Wanchun Jin, Chihiro Norizuki, Kouji Kimura, Motonori Tsuji, Hiromasa Kurosaki, and Yoshichika Arakawa
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metallo-β-lactamase ,Enterobacterales ,inhibitors ,Microbiology ,QR1-502 - Abstract
ABSTRACTMetallo-β-lactamases (MBLs) represent one of the main causes of carbapenem resistance in the order Enterobacterales. To combat MBL-producing carbapenem-resistant Enterobacterales, the development of MBL inhibitors can restore carbapenem efficacy for such resistant bacteria. Microbial natural products are a promising source of attractive seed compounds for the development of antimicrobial agents. Here, we report that hydroxyhexylitaconic acids (HHIAs) produced by a member of the genus Aspergillus can suppress carbapenem resistance conferred by MBLs, particularly IMP (imipenemase)-type MBLs. HHIAs were found to be competitive inhibitors with micromolar orders of magnitude against IMP-1 and showed weak inhibitory activity toward VIM-2, while no inhibitory activity against NDM-1 was observed despite the high dosage. The elongated methylene chains of HHIAs seem to play a crucial role in exerting inhibitory activity because itaconic acid, a structural analog without long methylene chains, did not show inhibitory activity against IMP-1. The addition of HHIAs restored meropenem and imipenem efficacy to satisfactory clinical levels against IMP-type MBL-producing Escherichia coli and Klebsiella pneumoniae clinical isolates. Unlike EDTA and Aspergillomarasmine A, HHIAs did not cause the loss of zinc ions from the active site, resulting in the structural instability of MBLs. X-ray crystallography and in silico docking simulation analyses revealed that two neighboring carboxylates of HHIAs coordinated with two zinc ions in the active sites of VIM-2 and IMP-1, which formed a key interaction observed in MBL inhibitors. Our results indicated that HHIAs are promising for initiating the design of potent inhibitors of IMP-type MBLs.IMPORTANCEThe number and type of metallo-β-lactamase (MΒL) are increasing over time. Carbapenem resistance conferred by MΒL is a significant threat to our antibiotic regimen, and the development of MΒL inhibitors is urgently required to restore carbapenem efficacy. Microbial natural products have served as important sources for developing antimicrobial agents targeting pathogenic bacteria since the discovery of antibiotics in the mid-20th century. MΒL inhibitors derived from microbial natural products are still rare compared to those derived from chemical compound libraries. Hydroxyhexylitaconic acids (HHIAs) produced by members of the genus Aspergillus have potent inhibitory activity against clinically relevant IMP-type MBL. HHIAs may be good lead compounds for the development of MBL inhibitors applicable for controlling carbapenem resistance in IMP-type MBL-producing Enterobacterales.
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- 2024
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4. Aqua{μ-1,4-bis[(1,4,7,10-tetraazacyclododecan-1-yl)methyl]benzene}(nitrato-κO)dicopper(II) tris(nitrate) trihydrate
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Yoshimi Ichimaru, Koichi Kato, Kirara Sugiura, Sarina Ogawa, Wanchun Jin, Masaaki Kurihara, Yoshihiro Yamaguchi, Masanori Imai, and Hiromasa Kurosaki
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crystal structure ,copper(ii) complex ,cyclen ,p-xylene ,dinuclear complex ,Crystallography ,QD901-999 - Abstract
In the title dinuclear CuII complex, [Cu2(NO3)(C24H46N8)(H2O)](NO3)3·3H2O, the two CuII molecules both have a square-pyramidal geometry, but the ligands in the axial positions are different: a water molecule and a nitrate ion. All nitrate ions, water molecules, and N—H groups are involved in an intermolecular hydrogen-bond network.
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- 2023
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5. Bis(nitrato-κO)(1,4,8,11-tetraazacyclotetradecane-κ4N)zinc(II) methanol monosolvate
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Yoshimi Ichimaru, Koichi Kato, Masaaki Kurihara, Wanchun Jin, Tohru Koike, and Hiromasa Kurosaki
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crystal structure ,zinc(ii) complex ,cyclam ,Crystallography ,QD901-999 - Abstract
The two ZnII atoms in the crystal structure of the title complex, [Zn(NO3)2(C10H24N4)]·CH3OH, have a distorted octahedral coordination sphere, defined by 1,4,8,11-tetraazacyclotetradecane (cyclam) N atoms in the equatorial plane and nitrate O atoms in the axial sites. The conformation of the cyclam is trans-III (R, R, S, S), which is typical for metal–cyclam complexes. Nitrate anions are involved in intra- and intermolecular hydrogen bonding with the N–H groups of the ZnII–cyclam unit. Together with the methanol solvent molecule, the hydrogen-bonding network connects the ZnII–cyclam units into ribbons running parallel to the a axis.
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- 2022
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6. Plan Quality Comparison Between Hippocampus-Sparing Whole-Brain Radiotherapy Treated With Halcyon and Tomotherapy Intensity-Modulated Radiotherapy
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Kazutoshi Yokoyama RT, Hiromasa Kurosaki MD, PhD, Hajime Oyoshi RT, Kosei Miura MD, PhD, and Nobuko Utsumi MD, PhD
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objective : Hippocampus-sparing whole-brain radiotherapy using Halcyon, an instrument dedicated to volumetric modulated arc therapy, has not been studied till date; hence, we aimed to examine whether it can meet the RTOG0933 criteria. Based on this, we compared Halcyon to Tomotherapy, which also uses an O-ring-type linear accelerator. Methods: This exploratory, experimental, and retrospective study used 5 sets of computed tomography images in the head area to investigate the planning target volume, hippocampal doses, and irradiation time. Calculations were performed from 1 to 4 arcs to determine the optimal number of arcs in the Halcyon plan, which were compared to those of Tomotherapy. Results: The Radiation Therapy Oncology Group 0933 criteria could not be satisfied in Halcyon with 1 arc. With 2 arcs, the condition D max
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- 2022
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7. Pretreatment PSA levels affects the completion rate of Ra-223 treatment
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Nobuko Utsumi, Hiromasa Kurosaki, Kosei Miura, Hiroki Kitoh, and Koichiro Akakura
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Medicine ,Science - Abstract
Abstract The aim of this study was to review our initial experience of using radium 223 (Ra-223) for metastatic castration-resistant prostate cancer (CRPC) and to evaluate whether pretreatment PSA levels correlate with completion of Ra-223 treatment. In addition, we examined change ratios of PSA, ALP and BAP after the third administration to evaluate the correlation of these change ratios with completion of the subsequent Ra-223 treatment. Forty patients were enrolled in this retrospective study. Ra-223 treatment was considered completed in patients who received five or six administrations. Patient backgrounds and changes in biomarkers were compared between patient groups (complete vs. incomplete Ra-223 treatment). PSA levels before treatment were significantly lower in the complete compared with the incomplete group (cutoff value; 21.7). ALP and BAP levels had decreased after the third administration in the complete group, compared with baseline levels, while levels in the incomplete group had increased. Significant difference was seen in ALP levels, while was not seen in BAP levels between the two groups. Ra-223 treatment should be considered for CRPC with low PSA levels. Changes in PSA and ALP during Ra-223 treatment might provide markers to identify patients likely to complete Ra-223 treatment, with implications for prognosis.
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- 2021
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8. Influence of Modulation Factor on Treatment Plan Quality and Irradiation Time in Hippocampus-Sparing Whole-Brain Radiotherapy Using Tomotherapy
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Akihiko Ishibashi RT, Hiromasa Kurosaki MD, PhD, Kosei Miura MD, Nobuko Utsumi MD, PhD, and Hideyuki Sakurai MD, PhD
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Objectives: Hippocampus-sparing whole-brain radiotherapy (HS-WBRT) using tomotherapy is known to provide a better dose distribution than volumetric-modulated arc therapy but requires an extended irradiation time. The present study aimed to investigate whether irradiation time can be shortened by reducing the modulation factor (MF) without losing the target dose distribution. Methods: Using six tilted computed tomography images in the head area, the planning target volume (PTV) and hippocampal doses, and the irradiation time was investigated with a jaw width of 1 cm, a pitch of 0.200, and the MF changed from 3.0 to 2.6, 2.2, 1.8, and 1.4. Results: No significant changes in the PTV or hippocampus were found with MF in the range from 3.0 to 1.8, but marked deterioration was found with that of 1.4. The irradiation time showed a linear relationship with the MF within the range from 3.0 to 1.8, with 1334, 1158, 986, and 817 s at modulation factors of 3.0, 2.6, 2.2, and 1.8, respectively. However, when the MF was 1.4, the irradiation time was 808 s. Conclusions: When HS-WBRT is performed with a tilted body position and a jaw width of 1 cm, with a MF of 1.8, a favorable balance between dose parameters and irradiation time is achieved, whereas with a MF of 1.4, the quality of the radiotherapy plan deteriorates, and the irradiation time is approximately the same as that with a MF of 1.8.
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- 2021
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9. Aqua(1,4,7,10-tetraazacyclododecane)zinc(II) bis(perchlorate)
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Yoshimi Ichimaru, Koichi Kato, Hiromasa Kurosaki, Haruto Fujioka, Misa Sakai, Yoshihiro Yamaguchi, Jin Wanchun, Kirara Sugiura, Masanori Imai, and Tohru Koike
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crystal structure ,zinc(ii) complex ,cyclen ,Crystallography ,QD901-999 - Abstract
The cationic ZnII part of aqua(1,4,7,10-tetraazacyclododecane)zinc(II) bis(perchlorate), [Zn(C8H20N4)(H2O)](ClO4)2, exhibits a slightly distorted square-pyramidal coordination environment with a water molecule in the apical position. In the crystal, the macrocyclic ring alternates between two conformations with equal occupancies. Two of the three perchlorate anions are situated about a twofold rotation axis, and one of them shows disorder of the O atoms with occupancies of 0.62 (7) and 0.38 (7). In the crystal, the complexes are connected by intermolecular hydrogen bonding via the perchlorate anions.
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- 2021
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10. Use of a Head-Tilting Baseplate During Tomotherapy to Shorten the Irradiation Time and Protect the Hippocampus and Lens in Hippocampal Sparing-Whole Brain Radiotherapy
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Kosei Miura MD, Hiromasa Kurosaki MD, PhD, Nobuko Utsumi MD, PhD, and Hideyuki Sakurai MD, PhD
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Purpose: The aim of this study is to comparatively examine the possibility of reducing the exposure dose to organs at risk, such as the hippocampus and lens, and improving the dose distribution of the planned target volume with and without the use of a head-tilting base plate in hippocampal-sparing whole-brain radiotherapy using tomotherapy. Methods: Five paired images of planned head computed tomography without and with tilt were analyzed. The hippocampus and planning target volume were contoured according to the RTOG 0933 contouring atlas protocol. The hippocampal zone to be avoided was delineated using a 5-mm margin. The prescribed radiation dose was 30 Gy in 10 fractions. The absorbed dose to planning target volume dose, absorbed dose to the organ at risk, and irradiation time were evaluated. The paired t-test was used to analyze the differences between hippocampal-sparing whole-brain radiotherapy with head tilts and without head tilts. Results: Hippocampal-sparing whole-brain radiotherapy with tilt was not superior in planning target volume doses using the homogeneity index than that without tilt; however, it showed better values, and for D mean and D 2% , the values were closer to 30 Gy. Regarding the hippocampus, dose reduction with tilt was significantly greater at D max , D mean , and D min , whereas regarding the lens, it was significantly greater at D max and D min . The irradiation time was also predominantly shorter. Conclusion: In our study, a tilted hippocampal-sparing whole-brain radiotherapy reduced the irradiation time by >10%. Therefore, our study indicated that hippocampal-sparing whole-brain radiotherapy with tomotherapy should be performed with a tilt. The head-tilting technique might be useful during hippocampal-sparing whole-brain radiotherapy. This method could decrease the radiation exposure time, while sparing healthy organs, including the hippocampus and lens.
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- 2021
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11. Author Correction: Pretreatment PSA levels affects the completion rate of Ra-223 treatment
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Nobuko Utsumi, Hiromasa Kurosaki, Kosei Miura, Hiroki Kitoh, and Koichiro Akakura
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Medicine ,Science - Published
- 2021
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12. Noncoplanar Radiation using Tomotherapy: A Phantom Study
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Masahiro Yuasa BS and Hiromasa Kurosaki MD, PhD
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background: There are very few studies on noncoplanar radiation in tomotherapy because deformable image registration is not implemented in the TomoTherapy Planning Station, a treatment planning device used in tomotherapy. This study examined whether noncoplanar radiation can be performed on the head using a tilt-type head and neck fixture and deformable image registration. Methods: Planning target volume spheres with diameters of 2, 3, and 4 cm were set on a head phantom, and computed tomography images were taken at 0° and 40° using a tilt-type head and neck fixture. Irradiation plans were created in the Tomotherapy Planning Station. Noncoplanar radiation was simulated, and the dose volume was evaluated by adding the 0° dose distribution and 40° dose distribution using the deformable image registration of the RayStation treatment planning system. Results: The ratio of the phantom volume to the irradiation dose for 20% to 30% of the planning target volume in noncoplanar radiation was smaller than that for 40% to 90% of the planning target volume in single-section irradiation at 0° or 40°. Conclusions: Noncoplanar radiation on the head region using tomotherapy was possible by using a tilt-type head and neck fixture, and the dose distribution could be evaluated using deformable image registration. This method helps reduce the dose of the organ-at-risk region located slightly away from the planning target volume.
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- 2020
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13. Sulfamoyl Heteroarylcarboxylic Acids as Promising Metallo-β-Lactamase Inhibitors for Controlling Bacterial Carbapenem Resistance
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Jun-ichi Wachino, Wanchun Jin, Kouji Kimura, Hiromasa Kurosaki, Ayato Sato, and Yoshichika Arakawa
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CRE ,sulfamoyl heteroarylcarboxylic acids ,carbapenems ,metallo-β-lactamase ,Microbiology ,QR1-502 - Abstract
ABSTRACT Production of metallo-β-lactamases (MBLs), which hydrolyze carbapenems, is a cause of carbapenem resistance in Enterobacteriaceae. Development of effective inhibitors for MBLs is one approach to restore carbapenem efficacy in carbapenem-resistant Enterobacteriaceae (CRE). We report here that sulfamoyl heteroarylcarboxylic acids (SHCs) can competitively inhibit the globally spreading and clinically relevant MBLs (i.e., IMP-, NDM-, and VIM-type MBLs) at nanomolar to micromolar orders of magnitude. Addition of SHCs restored meropenem efficacy against 17/19 IMP-type and 7/14 NDM-type MBL-producing Enterobacteriaceae to satisfactory clinical levels. SHCs were also effective against IMP-type MBL-producing Acinetobacter spp. and engineered Escherichia coli strains overproducing individual minor MBLs (i.e., TMB-2, SPM-1, DIM-1, SIM-1, and KHM-1). However, SHCs were less effective against MBL-producing Pseudomonas aeruginosa. Combination therapy with meropenem and SHCs successfully cured mice infected with IMP-1-producing E. coli and dually NDM-1/VIM-1-producing Klebsiella pneumoniae clinical isolates. X-ray crystallographic analyses revealed the inhibition mode of SHCs against MBLs; the sulfamoyl group of SHCs coordinated to two zinc ions, and the carboxylate group coordinated to one zinc ion and bound to positively charged amino acids Lys224/Arg228 conserved in MBLs. Preclinical testing revealed that the SHCs showed low toxicity in cell lines and mice and high stability in human liver microsomes. Our results indicate that SHCs are promising lead compounds for inhibitors of MBLs to combat MBL-producing CRE. IMPORTANCE Carbapenem antibiotics are the last resort for control of severe infectious diseases, bloodstream infections, and pneumonia caused by Gram-negative bacteria, including Enterobacteriaceae. However, carbapenem-resistant Enterobacteriaceae (CRE) strains have spread globally and are a critical concern in clinical settings because CRE infections are recognized as a leading cause of increased mortality among hospitalized patients. Most CRE produce certain kinds of serine carbapenemases (e.g., KPC- and GES-type β-lactamases) or metallo-β-lactamases (MBLs), which can hydrolyze carbapenems. Although effective MBL inhibitors are expected to restore carbapenem efficacy against MBL-producing CRE, no MBL inhibitor is currently clinically available. Here, we synthesized 2,5-diethyl-1-methyl-4-sulfamoylpyrrole-3-carboxylic acid (SPC), which is a potent inhibitor of MBLs. SPC is a remarkable lead compound for clinically useful MBL inhibitors and can potentially provide a considerable benefit to patients receiving treatment for lethal infectious diseases caused by MBL-producing CRE.
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- 2020
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14. Potential Anti-allergic Effects of Bibenzyl Derivatives from Liverworts, Radula perrottetii
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Haruka Asai, Koichi Kato, Moe Suzuki, Misato Takahashi, Erika Miyata, Moeka Aoi, Reika Kumazawa, Fumihiro Nagashima, Hiromasa Kurosaki, Yutaka Aoyagi, and Nobuyuki Fukuishi
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Hepatophyta ,Pharmacology ,Phospholipase C gamma ,Receptors, IgE ,Organic Chemistry ,Pharmaceutical Science ,Immunoglobulin E ,Leukotriene B4 ,Cell Degranulation ,Analytical Chemistry ,Mice, Inbred C57BL ,Mice ,Complementary and alternative medicine ,Anti-Allergic Agents ,Bibenzyls ,Drug Discovery ,Animals ,Molecular Medicine ,Interleukin-4 ,Mast Cells - Abstract
The liverwort Radula perrottetii contains various bibenzyl derivatives which are known to possess various biological activities, such as anti-inflammatory effects. Mast cells (MC) play crucial roles in allergic and inflammatory diseases; thus, inhibition of MC activation is pivotal for the treatment of allergic and inflammatory disorders. We investigated the effects of perrottetin D (perD), isolated from Radula perrottetii, and perD diacetate (Ac-perD) on antigen-induced activation of MCs. Bone marrow–derived MCs (BMMCs) were generated from C57BL/6 mice. The degranulation ratio, histamine release, and the interleukin (IL)-4 and leukotriene B4 productions on antigen-triggered BMMC were investigated. Additionally, the effects of the bibenzyls on binding of IgE to FcεRI were observed by flow cytometry, and signal transduction proteins was examined by Western blot. Furthermore, binding of the bibenzyls to the Fyn kinase domain was calculated. At 10 µM, perD decreased the degranulation ratio (p
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- 2022
15. Difference in the Inhibitory Effect of Thiol Compounds and Demetallation Rates from the Zn(II) Active Site of Metallo-β-lactamases (IMP-1 and IMP-6) Associated with a Single Amino Acid Substitution
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Yoshihiro Yamaguchi, Koichi Kato, Yoshimi Ichimaru, Yuya Uenosono, Sakiko Tawara, Rio Ito, Natsuki Matsuse, Jun-ichi Wachino, Sachiko Toma-Fukai, Wanchun Jin, Yoshichika Arakawa, Masami Otsuka, Mikako Fujita, Nobuyuki Fukuishi, Kirara Sugiura, Masanori Imai, and Hiromasa Kurosaki
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Infectious Diseases - Abstract
Gram-negative bacteria producing metallo-β-lactamases (MBLs) have become a considerable threat to public health. MBLs including the IMP, VIM, and NDM types are Zn(II) enzymes that hydrolyze the β-lactam ring present in a broad range of antibiotics, such as
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- 2022
16. Heating properties of resonant cavity applicator for treating rheumatoid arthritis by using 3-D FEM knee model.
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Kazuki Watanabe 0002, Hiromasa Kurosaki, Mitsunori Kubo, Kenji Takahashi, Kazuo Kato, and Yasuhiro Shindo
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- 2013
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17. Characterization of the Binding of Adenosine-5′-monophosphate to a µ-Type Alkoxide-Linked Dinuclear Zinc(II) Complex in Crystal and Solution State
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Tohru Koike, Yoshimi Ichimaru, Eiji Kinoshita, Emiko Kinoshita-Kikuta, Hiromasa Kurosaki, Koichi Kato, and Yoshi Yamano
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Crystal ,Adenosine monophosphate ,Crystallography ,chemistry.chemical_compound ,chemistry ,Solution state ,Alkoxide ,chemistry.chemical_element ,General Chemistry ,Zinc - Abstract
The binding of adenosine-5′-monophosphate dianion (AMP2−) to a μ-type alkoxide-linked dinuclear zinc(II) complex (Zn2L3+) has been studied {L = alkoxide form of 1,3-bis[bis(pyridin-2-ylmethyl)amino...
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- 2021
18. Tomotherapy: Comparison of Hi-ART, Tomo-HD, and Radixact
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Hiromasa Kurosaki, Kenta Hirayama, Masaki Takahashi, Masahiro Uematsu, and Etsuko Tate
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General Engineering - Abstract
Aim In this study, we compared three generations of tomotherapy (Hi-ART, Tomo-HD, and Radixact). This is to study the difference among tomotherapy systems in terms of dose distribution to planning target volume and organs at risk, and irradiation time. Materials and methods The treatment planning CT and contour information used were seven cases of rectum cancer pre-operative irradiation. The contour information used was the planning target volume, and the organs at risk were set as the bladder and body. Optimization was conducted at each planning station using the parameters that were actually used in a clinical setting. The prescribed radiation dose was 25 Gy in five fractions and normalized at the isodose line, covering 95% of the planning target volume. Results There were no significant differences in planning target volume among the three models. Meanwhile, Hi-ART had a significantly higher dose than Tomo-HD and Radixact at body D
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- 2022
19. Crystal Structure of [{m,m-bis(ZnII-cyclen)}3(μ2-CO3)2(H2O)2](ClO4)8·nH2O
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Yoshimi ICHIMARU, Koichi KATO, Kirara SUGIURA, Chisa HIRATA, Wanchun JIN, Haruto FUJIOKA, Hiromasa KUROSAKI, and Tohru KOIKE
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Materials Chemistry ,Analytical Chemistry - Published
- 2022
20. Artificial helix supramolecule by doubly p-xylyl bridged bis(ZnII–cyclen) (cyclen = 1,4,7,10-tetraazacyclododecane)
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Yoshimi Ichimaru, Koichi Kato, Kirara Sugiura, Risa Isomura, Haruto Fujioka, Tohru Koike, Sayuri Fujii-Kishida, Masaaki Kurihara, Yoshihiro Yamaguchi, Wanchun Jin, Masanori Imai, and Hiromasa Kurosaki
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Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2023
21. Crystal Structures of Metallo-β-Lactamase (IMP-1) and Its D120E Mutant in Complexes with Citrate and the Inhibitory Effect of the Benzyl Group in Citrate Monobenzyl Ester
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Yoshihiro Yamaguchi, Misa Sakai, Yukina Miyagi, Yoshimi Ichimaru, Wanchun Jin, Miki Abe, Mikako Fujita, Yuriko Yamagata, Hiromasa Kurosaki, Masanori Imai, Jun-ichi Wachino, Yoshichika Arakawa, Koichi Kato, Nobuyuki Fukuishi, and Masami Otsuka
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Stereochemistry ,Mutant ,Crystal structure ,Inhibitory postsynaptic potential ,Citric Acid ,Metallo β lactamase ,Structure-Activity Relationship ,chemistry.chemical_compound ,Benzyl Compounds ,Drug Discovery ,polycyclic compounds ,Humans ,IC50 ,Dose-Response Relationship, Drug ,Molecular Structure ,biology ,Chemistry ,RNA-Binding Proteins ,Esters ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Molecular Docking Simulation ,Square pyramid ,Mutation ,Serratia marcescens ,Benzyl group ,bacteria ,Molecular Medicine - Abstract
The emergence and rapid spread of carbapenem-resistant pathogens producing metallo-β-lactamases such as IMP-1 and NDM-1 have been of great concern in the global clinical setting. The X-ray crystal structures of IMP-1 from Serratia marcescens and its single mutant, D120E, in complexes with citrate were determined at resolutions of 2.00 and 1.85 A, respectively. Two crystal structures indicate that a single mutation at position 120 caused a structural change around Zn1, where the geometry changes from a tetrahedron in the native IMP-1 to a square pyramid in D120E. Based on these two complex structures, the authors synthesized citrate monobenzyl ester 1 to evaluate the structural requirement for the inhibitory activity against IMP-1 and compared the inhibitory activities with nonsubstituted citrate. The introduction of a benzyl group into citrate enhanced the inhibitory activity in comparison to citrate (IC50 > 5 mM).
- Published
- 2021
22. Bis(nitrato-κO)(1,4,8,11-tetraazacyclotetradecane-κ4 N)zinc(II) methanol monosolvate
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Yoshimi Ichimaru, Koichi Kato, Masaaki Kurihara, Wanchun Jin, Tohru Koike, and Hiromasa Kurosaki
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General Medicine - Abstract
The two ZnII atoms in the crystal structure of the title complex, [Zn(NO3)2(C10H24N4)]·CH3OH, have a distorted octahedral coordination sphere, defined by 1,4,8,11-tetraazacyclotetradecane (cyclam) N atoms in the equatorial plane and nitrate O atoms in the axial sites. The conformation of the cyclam is trans-III (R, R, S, S), which is typical for metal–cyclam complexes. Nitrate anions are involved in intra- and intermolecular hydrogen bonding with the N–H groups of the ZnII–cyclam unit. Together with the methanol solvent molecule, the hydrogen-bonding network connects the ZnII–cyclam units into ribbons running parallel to the a axis.
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- 2022
23. Bis(nitrato-κ
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Yoshimi, Ichimaru, Koichi, Kato, Masaaki, Kurihara, Wanchun, Jin, Tohru, Koike, and Hiromasa, Kurosaki
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The two Zn
- Published
- 2022
24. Improvement of Metastatic Spinal Cord Compression After Decompression Surgery and Radiotherapy in a Patient Initially Treated for Rectal Cancer
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Nobuko Utsumi, Hiromasa Kurosaki, Kosei Miura, Satoshi Baba, and Yoshin Koyama
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General Engineering - Published
- 2022
25. Characterization of zinc(II) complex of 1,4,7,10-tetrazacyclododecane and deprotonated 5-fluorouracil (FU) in crystalline/solution states and evaluation of anticancer activity: Approach for improving the anticancer activity of FU
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Yoshimi Ichimaru, Koichi Kato, Rina Nakatani, Kirara Sugiura, Hideki Mizutani, Emiko Kinoshita-Kikuta, Tohru Koike, Wanchun Jin, Masanori Imai, and Hiromasa Kurosaki
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Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2023
26. Influence of Modulation Factor on Treatment Plan Quality and Irradiation Time in Hippocampus-Sparing Whole-Brain Radiotherapy Using Tomotherapy
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Hiromasa Kurosaki, Hideyuki Sakurai, Akihiko Ishibashi, Kosei Miura, and Nobuko Utsumi
- Subjects
tilt heading ,Cancer Research ,hippocampus-sparing ,Time Factors ,medicine.medical_treatment ,tomotherapy ,Hippocampus ,Irradiation time ,Dose distribution ,Radiation Dosage ,whole-brain radiotherapy ,Patient Positioning ,Tomotherapy ,Treatment plan ,brain metastases ,Humans ,Medicine ,Radiation Injuries ,RC254-282 ,Brain Neoplasms ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Whole brain radiotherapy ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Modulation factor ,Radiation therapy ,Oncology ,Original Article ,Radiotherapy, Intensity-Modulated ,Cranial Irradiation ,Tomography, X-Ray Computed ,Nuclear medicine ,business ,Organ Sparing Treatments - Abstract
Objectives: Hippocampus-sparing whole-brain radiotherapy (HS-WBRT) using tomotherapy is known to provide a better dose distribution than volumetric-modulated arc therapy but requires an extended irradiation time. The present study aimed to investigate whether irradiation time can be shortened by reducing the modulation factor (MF) without losing the target dose distribution. Methods: Using six tilted computed tomography images in the head area, the planning target volume (PTV) and hippocampal doses, and the irradiation time was investigated with a jaw width of 1 cm, a pitch of 0.200, and the MF changed from 3.0 to 2.6, 2.2, 1.8, and 1.4. Results: No significant changes in the PTV or hippocampus were found with MF in the range from 3.0 to 1.8, but marked deterioration was found with that of 1.4. The irradiation time showed a linear relationship with the MF within the range from 3.0 to 1.8, with 1334, 1158, 986, and 817 s at modulation factors of 3.0, 2.6, 2.2, and 1.8, respectively. However, when the MF was 1.4, the irradiation time was 808 s. Conclusions: When HS-WBRT is performed with a tilted body position and a jaw width of 1 cm, with a MF of 1.8, a favorable balance between dose parameters and irradiation time is achieved, whereas with a MF of 1.4, the quality of the radiotherapy plan deteriorates, and the irradiation time is approximately the same as that with a MF of 1.8.
- Published
- 2021
27. Author Correction: Pretreatment PSA levels affects the completion rate of Ra-223 treatment
- Author
-
Koichiro Akakura, Nobuko Utsumi, Kosei Miura, Hiroki Kitoh, and Hiromasa Kurosaki
- Subjects
Male ,Oncology ,medicine.medical_specialty ,Science ,MEDLINE ,Text mining ,Internal medicine ,Completion rate ,medicine ,Humans ,Author Correction ,Aged ,Aged, 80 and over ,Multidisciplinary ,business.industry ,Published Erratum ,Prostatic Neoplasms ,Middle Aged ,Prostate-Specific Antigen ,Alkaline Phosphatase ,Treatment Outcome ,Medicine ,business ,Radium - Abstract
The aim of this study was to review our initial experience of using radium 223 (Ra-223) for metastatic castration-resistant prostate cancer (CRPC) and to evaluate whether pretreatment PSA levels correlate with completion of Ra-223 treatment. In addition, we examined change ratios of PSA, ALP and BAP after the third administration to evaluate the correlation of these change ratios with completion of the subsequent Ra-223 treatment. Forty patients were enrolled in this retrospective study. Ra-223 treatment was considered completed in patients who received five or six administrations. Patient backgrounds and changes in biomarkers were compared between patient groups (complete vs. incomplete Ra-223 treatment). PSA levels before treatment were significantly lower in the complete compared with the incomplete group (cutoff value; 21.7). ALP and BAP levels had decreased after the third administration in the complete group, compared with baseline levels, while levels in the incomplete group had increased. Significant difference was seen in ALP levels, while was not seen in BAP levels between the two groups. Ra-223 treatment should be considered for CRPC with low PSA levels. Changes in PSA and ALP during Ra-223 treatment might provide markers to identify patients likely to complete Ra-223 treatment, with implications for prognosis.
- Published
- 2021
28. Crystal Structure of Bis{1,3-bis[bis(pyridin-2-ylmethyl)amino]propan-2-olato-dizinc(II)}orthophosphate Tris(perchlorate) Octahydrate, [(Phos-tag)2-PO43−][ClO4−]3·8H2O
- Author
-
Yoshimi ICHIMARU, Koichi KATO, Wanchun JIN, Kirara SUGIURA, Emiko KINOSHITA-KIKUTA, Eiji KINOSHITA, Hiromasa KUROSAKI, and Tohru KOIKE
- Subjects
Materials Chemistry ,Analytical Chemistry - Published
- 2021
29. Aqua(1,4,7,10-tetraazacyclododecane)zinc(II) bis(perchlorate)
- Author
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Masanori Imai, Haruto Fujioka, Misa Sakai, Jin Wanchun, Koichi Kato, Yoshihiro Yamaguchi, Tohru Koike, Kirara Sugiura, Yoshimi Ichimaru, and Hiromasa Kurosaki
- Subjects
crystal structure ,Crystallography ,Hydrogen bond ,Cationic polymerization ,chemistry.chemical_element ,Zinc ,Crystal structure ,Ring (chemistry) ,cyclen ,Crystal ,Perchlorate ,chemistry.chemical_compound ,chemistry ,Cyclen ,QD901-999 ,zinc(ii) complex - Abstract
The cationic ZnII part of aqua(1,4,7,10-tetraazacyclododecane)zinc(II) bis(perchlorate), [Zn(C8H20N4)(H2O)](ClO4)2, exhibits a slightly distorted square-pyramidal coordination environment with a water molecule in the apical position. In the crystal, the macrocyclic ring alternates between two conformations with equal occupancies. Two of the three perchlorate anions are situated about a twofold rotation axis, and one of them shows disorder of the O atoms with occupancies of 0.62 (7) and 0.38 (7). In the crystal, the complexes are connected by intermolecular hydrogen bonding via the perchlorate anions.
- Published
- 2021
30. A Case of Suspected Radiation Recall Pneumonitis After a COVID-19 Infection
- Author
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Kosei Miura, Nobuko Utsumi, and Hiromasa Kurosaki
- Subjects
medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,Pulmonology ,medicine.medical_treatment ,Infectious Disease ,030204 cardiovascular system & hematology ,Asymptomatic ,Radiation recall ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Lung cancer ,radiotherapy ,Pneumonitis ,medicine.diagnostic_test ,business.industry ,General Engineering ,medicine.disease ,radiation recall reaction ,Definitive Radiation Therapy ,Radiation therapy ,lung cancer ,covid-19 ,Radiation Oncology ,Radiology ,medicine.symptom ,Chest radiograph ,business ,030217 neurology & neurosurgery - Abstract
We present the case of a 78-year-old woman who received definitive radiation therapy for small cell lung cancer three and a half years ago. She was asymptomatic when she tested positive for coronavirus disease 2019 (COVID-19). She then developed a rapid decline in respiratory status on day seven. Chest radiograph revealed a strong shadow at the prior irradiation site. Radiation recall reactions are usually caused by drug administration, but in this case, it was suspected to be caused by COVID-19.
- Published
- 2021
31. Pretreatment PSA levels affects the completion rate of Ra-223 treatment
- Author
-
Hiroki Kitoh, Koichiro Akakura, Kosei Miura, Hiromasa Kurosaki, and Nobuko Utsumi
- Subjects
Radium-223 ,medicine.medical_specialty ,Multidisciplinary ,Prostate cancer ,Radiotherapy ,business.industry ,Science ,Significant difference ,Urology ,Retrospective cohort study ,medicine.disease ,Article ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Completion rate ,medicine ,Medicine ,In patient ,030212 general & internal medicine ,business ,medicine.drug - Abstract
The aim of this study was to review our initial experience of using radium 223 (Ra-223) for metastatic castration-resistant prostate cancer (CRPC) and to evaluate whether pretreatment PSA levels correlate with completion of Ra-223 treatment. In addition, we examined change ratios of PSA, ALP and BAP after the third administration to evaluate the correlation of these change ratios with completion of the subsequent Ra-223 treatment. Forty patients were enrolled in this retrospective study. Ra-223 treatment was considered completed in patients who received five or six administrations. Patient backgrounds and changes in biomarkers were compared between patient groups (complete vs. incomplete Ra-223 treatment). PSA levels before treatment were significantly lower in the complete compared with the incomplete group (cutoff value; 21.7). ALP and BAP levels had decreased after the third administration in the complete group, compared with baseline levels, while levels in the incomplete group had increased. Significant difference was seen in ALP levels, while was not seen in BAP levels between the two groups. Ra-223 treatment should be considered for CRPC with low PSA levels. Changes in PSA and ALP during Ra-223 treatment might provide markers to identify patients likely to complete Ra-223 treatment, with implications for prognosis.
- Published
- 2021
32. Crystal Structure of 2-(1-Benzoylazetidin-3-yl)thio-1,3-thiazoline
- Author
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Yoshimi Ichimaru, Hiromasa Kurosaki, Kazuhiko Hayashi, Koichi Kato, Kirara Sugiura, and Masanori Imai
- Subjects
chemistry.chemical_compound ,Chemistry ,Thiazoline ,Materials Chemistry ,Thio ,Crystal structure ,Medicinal chemistry ,Analytical Chemistry - Published
- 2021
33. Radiotherapy Planning System to Measure Tumor Doubling Time in Cervical Cancer
- Author
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Hiromasa Kurosaki, Nobuko Utsumi, and Kosei Miura
- Subjects
medicine.medical_specialty ,cervical cancer ,medicine.medical_treatment ,radiotherapy planning system ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Doubling time ,Basal cell ,Cervical cancer ,medicine.diagnostic_test ,business.industry ,General Engineering ,Magnetic resonance imaging ,medicine.disease ,Definitive Radiation Therapy ,Radiation therapy ,Cervical cancer stage ,Oncology ,Radiation Oncology ,Obstetrics/Gynecology ,Radiology ,tumor doubling time ,business ,030217 neurology & neurosurgery - Abstract
Tumor doubling time is an important clinical parameter, but it is rarely reported in cervical cancer. We encountered a case in which the tumor doubling time could be measured using a radiotherapy planning device. A woman in her 40s was diagnosed with cervical cancer stage IB1 (squamous cell carcinoma) and refused treatment. One year and five months later, definitive radiation therapy was administered. Magnetic resonance imaging was performed five times before the start of treatment. When the tumor volume was measured using the radiotherapy planning system - RayStation🄬 (RaySearch Laboratories, Stockholm, Sweden) on the T2 sagittal image, the tumor doubling time was 76 days, and the tumor volume had increased exponentially.
- Published
- 2021
34. Design and synthesis of an anthranyl bridged optically active dinuclear iron(II)-ligand and evaluation of DNA-cleaving activity
- Author
-
Wanchun Jin, Yoshimi Ichimaru, Yoshihiro Yamaguchi, Yoshinori Okuno, Masami Otsuka, Mikako Fujita, Koichi Kato, Masanori Imai, and Hiromasa Kurosaki
- Subjects
In situ ,Stereochemistry ,Clinical Biochemistry ,Pharmaceutical Science ,Ligands ,01 natural sciences ,Biochemistry ,Metal ,chemistry.chemical_compound ,Structure-Activity Relationship ,Drug Discovery ,Molecule ,Ferrous Compounds ,Methylene ,DNA Cleavage ,Molecular Biology ,Anthracene ,Dose-Response Relationship, Drug ,Molecular Structure ,010405 organic chemistry ,Ligand ,Organic Chemistry ,DNA ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry ,visual_art ,Drug Design ,visual_art.visual_art_medium ,Molecular Medicine ,Enantiomer ,Plasmids - Abstract
It is necessary to design a ligand that is compatible with the target molecule to optimally use the DNA-cleaving ability of metal complexes. In this study, we synthesized an optically active dinuclear ligand, (1R,1'R,2R,2'R)-N1,N1'-(anthracene-1,8-diylbis(methylene))bis(N2,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine) (R-ABDC, 4a) and its enantiomer (S-ABDC, 4b). We then prepared their Fe(II) complexes by mixing the ligand with FeSO4·7H2O in situ and investigated DNA-cleaving activities using plasmid DNA in the presence of excess sodium ascorbate at atmospheric conditions. The Fe(II) complexes efficiently cleaved DNA and selectively recognized two consecutive A and/or T sequences.
- Published
- 2020
35. Activation of Ligand Reaction on an Iron Complex: H/D Exchange Reaction of a Low-Spin Bis[2-(Pyridylmethylidene)-1-(2-pyridyl)methylamine]iron(II) Complex
- Author
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Yoshihiro Yamaguchi, Hiromasa Kurosaki, Koichi Kato, Masami Otsuka, Masanori Imai, and Mikako Fujita
- Subjects
Reaction mechanism ,Magnetic Resonance Spectroscopy ,Chemistry ,Methylamine ,Ligand ,Molecular Conformation ,Deuterium Exchange Measurement ,General Chemistry ,General Medicine ,Medicinal chemistry ,Metal ,chemistry.chemical_compound ,Deuterium ,Coordination Complexes ,visual_art ,Drug Discovery ,visual_art.visual_art_medium ,Ethylamines ,Molecule ,Quantum Theory ,Ferrous Compounds ,Ethylamine ,Acetonitrile - Abstract
With the aim of shedding some light on the still scarcely investigated mechanism of transformation of imines in metal complexes, this study describes the investigation of the hydrogen-deuterium (H/D) exchange reaction of a bis[2-(pyridylmethylidene)-1-(2-pyridylmethylamine]iron(II) complex ([Fe(PMAP)2]2+), following our previous work on a low-spin iron(II) complex bearing two molecules of S-2-pyridylmethylidene-1-(2-pyridyl)ethylamine. This complex has been proven to undergo successive transiminations in acetonitrile, yielding a bis[1-(2-pyridyl)ethylidene-2-pyridylmethylamine]iron(II) complex. In the analogous [Fe(PMAP)2]2+ complex, a 1,3-hydrogen rearrangement occurs in a 10% deuterium oxide-acetonitrile-d3 (D2O-CD3CN) solution. The H/D exchange reaction of [Fe(PMAP)2]2+ was examined in the presence of various concentrations of 2,6-dimethylpyridine as a base in a 10% D2O-CD3CN solution at 45 °C, and the reaction mechanism was investigated.
- Published
- 2020
36. Sulfamoyl Heteroarylcarboxylic Acids as Promising Metallo-β-Lactamase Inhibitors for Controlling Bacterial Carbapenem Resistance
- Author
-
Hiromasa Kurosaki, Ayato Sato, Kouji Kimura, Yoshichika Arakawa, Wanchun Jin, and Jun-ichi Wachino
- Subjects
Male ,Carbapenem ,Klebsiella pneumoniae ,metallo-β-lactamase ,Carboxylic Acids ,Microbial Sensitivity Tests ,medicine.disease_cause ,Meropenem ,Microbiology ,Cell Line ,03 medical and health sciences ,Mice ,Enterobacteriaceae ,Virology ,Drug Discovery ,Drug Resistance, Bacterial ,medicine ,Escherichia coli ,polycyclic compounds ,Animals ,Humans ,030304 developmental biology ,0303 health sciences ,biology ,Acinetobacter ,030306 microbiology ,Pseudomonas aeruginosa ,Chemistry ,CRE ,Therapeutics and Prevention ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,bacterial infections and mycoses ,QR1-502 ,Anti-Bacterial Agents ,sulfamoyl heteroarylcarboxylic acids ,Microsomes, Liver ,carbapenems ,beta-Lactamase Inhibitors ,Bacteria ,medicine.drug ,Research Article - Abstract
Carbapenem antibiotics are the last resort for control of severe infectious diseases, bloodstream infections, and pneumonia caused by Gram-negative bacteria, including Enterobacteriaceae. However, carbapenem-resistant Enterobacteriaceae (CRE) strains have spread globally and are a critical concern in clinical settings because CRE infections are recognized as a leading cause of increased mortality among hospitalized patients. Most CRE produce certain kinds of serine carbapenemases (e.g., KPC- and GES-type β-lactamases) or metallo-β-lactamases (MBLs), which can hydrolyze carbapenems. Although effective MBL inhibitors are expected to restore carbapenem efficacy against MBL-producing CRE, no MBL inhibitor is currently clinically available. Here, we synthesized 2,5-diethyl-1-methyl-4-sulfamoylpyrrole-3-carboxylic acid (SPC), which is a potent inhibitor of MBLs. SPC is a remarkable lead compound for clinically useful MBL inhibitors and can potentially provide a considerable benefit to patients receiving treatment for lethal infectious diseases caused by MBL-producing CRE., Production of metallo-β-lactamases (MBLs), which hydrolyze carbapenems, is a cause of carbapenem resistance in Enterobacteriaceae. Development of effective inhibitors for MBLs is one approach to restore carbapenem efficacy in carbapenem-resistant Enterobacteriaceae (CRE). We report here that sulfamoyl heteroarylcarboxylic acids (SHCs) can competitively inhibit the globally spreading and clinically relevant MBLs (i.e., IMP-, NDM-, and VIM-type MBLs) at nanomolar to micromolar orders of magnitude. Addition of SHCs restored meropenem efficacy against 17/19 IMP-type and 7/14 NDM-type MBL-producing Enterobacteriaceae to satisfactory clinical levels. SHCs were also effective against IMP-type MBL-producing Acinetobacter spp. and engineered Escherichia coli strains overproducing individual minor MBLs (i.e., TMB-2, SPM-1, DIM-1, SIM-1, and KHM-1). However, SHCs were less effective against MBL-producing Pseudomonas aeruginosa. Combination therapy with meropenem and SHCs successfully cured mice infected with IMP-1-producing E. coli and dually NDM-1/VIM-1-producing Klebsiella pneumoniae clinical isolates. X-ray crystallographic analyses revealed the inhibition mode of SHCs against MBLs; the sulfamoyl group of SHCs coordinated to two zinc ions, and the carboxylate group coordinated to one zinc ion and bound to positively charged amino acids Lys224/Arg228 conserved in MBLs. Preclinical testing revealed that the SHCs showed low toxicity in cell lines and mice and high stability in human liver microsomes. Our results indicate that SHCs are promising lead compounds for inhibitors of MBLs to combat MBL-producing CRE.
- Published
- 2020
37. Crystal Structure of [11,14,17,110,51,54,57,510-Octaaza-1,5(1,4)-dicyclododecana-3,7(1,3)-dibenzenacyclooctaphane]zinc(II) tetrakis(nitrate), [m,m-bis(ZnII-cyclen)](NO3)4
- Author
-
Kirara Sugiura, Haruto Fujioka, Yoshihiro Yamaguchi, Tohru Koike, Yuhzo Hieda, Masanori Imai, Yoshimi Ichimaru, Koichi Kato, Wanchun Jin, and Hiromasa Kurosaki
- Subjects
chemistry.chemical_compound ,Nitrate ,chemistry ,Cyclen ,Materials Chemistry ,chemistry.chemical_element ,Crystal structure ,Zinc ,Analytical Chemistry ,Nuclear chemistry - Published
- 2021
38. Palliative radiation treatment used for multiple purposes in a single irradiation field
- Author
-
Kosei Miura, Nobuko Utsumi, and Hiromasa Kurosaki
- Subjects
medicine.medical_specialty ,Creatinine ,Ileus ,business.industry ,medicine.medical_treatment ,Palliative Care ,Pain ,Bone Neoplasms ,Breast Neoplasms ,Radiotherapy Dosage ,General Medicine ,medicine.disease ,Metastasis ,Radiation therapy ,chemistry.chemical_compound ,Breast cancer ,chemistry ,medicine ,Palliative radiation ,Humans ,Female ,Lumbar spine ,Irradiation ,Radiology ,business - Abstract
In this case report, radiation therapy was performed for bilateral hydronephrosis developed during multiple bone metastases of breast cancer and ileus due to peritoneal dissemination. The patient’s preirradiation creatinine level was 8.2 mg/dL, which decreased by the fourth day after starting irradiation therapy. Creatinine level ultimately decreased to 0.6 mg/dL. Pain due to lumbar spine metastasis alleviated and ileus was resolved, allowing the patient to live at home for approximately 5 weeks. The effect of radiotherapy for bilateral hydronephrosis and gastrointestinal obstruction was rapid and good. Palliative radiation treatment can be used for multiple purposes, and in the present patient, we were able to prolong the vital prognosis.
- Published
- 2021
39. Crystal Structure of 5-Methoxyindirubin 3′-Oxime
- Author
-
Shinichi Miyairi, Koichi Kato, Makoto Sano, Hiromasa Kurosaki, Yoshimi Ichimaru, Niina Nakamura, and Kazuhiko Hayashi
- Subjects
Crystallography ,chemistry.chemical_compound ,Chemistry ,Materials Chemistry ,Crystal structure ,Oxime ,Analytical Chemistry - Published
- 2020
40. Crystal Structure of [3-(1,4,7,10-Tetraazacyclododecan-1-yl)propan-1-amine]zinc(II) Bis(perchlorate), [ZnIIL](ClO4)2
- Author
-
Koichi Kato, Tohru Koike, Haruto Fujioka, Hiromasa Kurosaki, Yoshimi Ichimaru, Yuhzo Hieda, and Masanori Imai
- Subjects
Perchlorate ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,chemistry.chemical_element ,Amine gas treating ,Zinc ,Crystal structure ,Medicinal chemistry ,Analytical Chemistry - Published
- 2020
41. 4-Amino-2-Sulfanylbenzoic Acid as a Potent Subclass B3 Metallo-β-Lactamase-Specific Inhibitor Applicable for Distinguishing Metallo-β-Lactamase Subclasses
- Author
-
Erina Nishino, Jun-ichi Wachino, Yoshichika Arakawa, Marie Mochizuki, Hiromasa Kurosaki, Reo Kanechi, Wanchun Jin, and Kouji Kimura
- Subjects
Male ,Thiosalicylic acid ,Microbial Sensitivity Tests ,medicine.disease_cause ,Crystallography, X-Ray ,Meropenem ,Subclass ,beta-Lactamases ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Bacterial Proteins ,Enterobacteriaceae ,Mechanisms of Resistance ,Hydrolase ,medicine ,Animals ,Pharmacology (medical) ,Sulfhydryl Compounds ,IC50 ,Escherichia coli ,030304 developmental biology ,Pharmacology ,0303 health sciences ,biology ,030306 microbiology ,Active site ,biology.organism_classification ,bacterial infections and mycoses ,Salicylates ,Anti-Bacterial Agents ,Infectious Diseases ,chemistry ,biology.protein ,beta-Lactamase Inhibitors ,medicine.drug - Abstract
The number of cases of infection with carbapenem-resistant Enterobacteriaceae (CRE) has been increasing and has become a major clinical and public health concern. Production of metallo-β-lactamases (MBLs) is one of the principal carbapenem resistance mechanisms in CRE. Therefore, developing MBL inhibitors is a promising strategy to overcome the problems of carbapenem resistance conferred by MBLs. To date, the development and evaluation of MBL inhibitors have focused on subclass B1 MBLs but not on B3 MBLs. In the present study, we searched for B3 MBL (specifically, SMB-1) inhibitors and found thiosalicylic acid (TSA) to be a potent inhibitor of B3 SMB-1 MBL (50% inhibitory concentration [IC(50)], 0.95 μM). TSA inhibited the purified SMB-1 to a considerable degree but was not active against Escherichia coli cells producing SMB-1, as the meropenem (MEM) MIC for the SMB-1 producer was only slightly reduced with TSA. We then introduced a primary amine to TSA and synthesized 4-amino-2-sulfanylbenzoic acid (ASB), which substantially reduced the MEM MICs for SMB-1 producers. X-ray crystallographic analyses revealed that ASB binds to the two zinc ions, Ser221, and Thr223 at the active site of SMB-1. These are ubiquitously conserved residues across clinically relevant B3 MBLs. ASB also significantly inhibited other B3 MBLs, including AIM-1, LMB-1, and L1. Therefore, the characterization of ASB provides a starting point for the development of optimum B3 MBL inhibitors.
- Published
- 2019
42. Use of a Head-Tilting Baseplate During Tomotherapy to Shorten the Irradiation Time and Protect the Hippocampus and Lens in Hippocampal Sparing-Whole Brain Radiotherapy
- Author
-
Nobuko Utsumi, Hiromasa Kurosaki, Kosei Miura, and Hideyuki Sakurai
- Subjects
Cancer Research ,Time Factors ,medicine.medical_treatment ,tomotherapy ,Hippocampus ,Irradiation time ,Dose distribution ,Hippocampal formation ,lcsh:RC254-282 ,Tomotherapy ,030218 nuclear medicine & medical imaging ,Head-Down Tilt ,03 medical and health sciences ,0302 clinical medicine ,brain metastases ,Lens, Crystalline ,medicine ,Humans ,Radiometry ,business.industry ,Brain Neoplasms ,Whole brain radiotherapy ,Disease Management ,Head tilting ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Lens (anatomy) ,whole brain radiotherapy ,Original Article ,Radiotherapy, Intensity-Modulated ,hippocampal sparing ,Cranial Irradiation ,business ,Nuclear medicine ,Tomography, X-Ray Computed ,Organ Sparing Treatments ,Radiotherapy, Image-Guided - Abstract
Purpose: The aim of this study is to comparatively examine the possibility of reducing the exposure dose to organs at risk, such as the hippocampus and lens, and improving the dose distribution of the planned target volume with and without the use of a head-tilting base plate in hippocampal-sparing whole-brain radiotherapy using tomotherapy. Methods: Five paired images of planned head computed tomography without and with tilt were analyzed. The hippocampus and planning target volume were contoured according to the RTOG 0933 contouring atlas protocol. The hippocampal zone to be avoided was delineated using a 5-mm margin. The prescribed radiation dose was 30 Gy in 10 fractions. The absorbed dose to planning target volume dose, absorbed dose to the organ at risk, and irradiation time were evaluated. The paired t-test was used to analyze the differences between hippocampal-sparing whole-brain radiotherapy with head tilts and without head tilts. Results: Hippocampal-sparing whole-brain radiotherapy with tilt was not superior in planning target volume doses using the homogeneity index than that without tilt; however, it showed better values, and for Dmean and D2%, the values were closer to 30 Gy. Regarding the hippocampus, dose reduction with tilt was significantly greater at Dmax, Dmean, and Dmin, whereas regarding the lens, it was significantly greater at Dmax and Dmin. The irradiation time was also predominantly shorter. Conclusion: In our study, a tilted hippocampal-sparing whole-brain radiotherapy reduced the irradiation time by >10%. Therefore, our study indicated that hippocampal-sparing whole-brain radiotherapy with tomotherapy should be performed with a tilt. The head-tilting technique might be useful during hippocampal-sparing whole-brain radiotherapy. This method could decrease the radiation exposure time, while sparing healthy organs, including the hippocampus and lens.
- Published
- 2021
43. A pilot study comparing the efficacy of radiofrequency and microwave diathermy in combination with intra-articular injection of hyaluronic acid in knee osteoarthritis
- Author
-
Kazuo Kato, Shinro Takai, Hiromasa Kurosaki, Kenji Takahashi, Yusuke Mochizuki, Hiroshi Watanabe, Tokifumi Majima, Sanshiro Hashimoto, and Yasuhiro Shindo
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,Physical Therapy, Sports Therapy and Rehabilitation ,Osteoarthritis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Intra articular ,Symptom relief ,Diathermy ,Hyaluronic acid ,medicine ,Knee ,Lequesne index ,030203 arthritis & rheumatology ,business.industry ,Significant difference ,medicine.disease ,Surgery ,chemistry ,Microwave diathermy ,Original Article ,business ,030217 neurology & neurosurgery - Abstract
[Purpose] This study aimed to compare the efficacy of radiofrequency diathermy with that of microwave diathermy in combination with intra-articular injection of hyaluronic acid into the knee of patients with osteoarthritis (OA). [Subjects] A total of 17 patients with knee OA were enrolled. The participants were randomly divided into two groups: a radiofrequency diathermy group (RF group, 9 subjects), and a microwave diathermy group (MW group, 8 subjects). [Methods] Subjects received radiofrequency or microwave thermal therapy 3 times at 1-week intervals. Intra-articular injection of hyaluronic acid was administered 10 min before every thermal therapy session. The outcome was evaluated using the Japan Orthopaedic Association (JOA) and the Lequesne Index (LI) at baseline, at weeks 1 (1 week after the first thermal therapy) and 3 (1 week after the last thermal therapy). [Results] The JOA scale increased significantly after three sessions of thermal therapy in the RF group, while no significant increase was observed in the MW group. LI decreased significantly after 3 weeks in the RF group. In the MW group, there was no significant difference in LI between the two time points. [Conclusion] This study revealed that symptom relief in patients with knee OA was greater with radiofrequency diathermy than with microwave diathermy with concurrent use of hyaluronic acid injection, presumably due to the different heating characteristics of the two methods.
- Published
- 2016
44. HSP70 induction by bleomycin metal core analogs
- Author
-
Mohamed Abdel-Aziz, Mikako Fujita, Masami Otsuka, Kana Iwamaru, Mohamed O. Radwan, Hiroshi Tateishi, Ryoko Koga, Masahiro Kamo, Taha F.S. Ali, Gamal El-Din A. Abuo-Rahma, Eman A.M. Beshr, Hiromasa Kurosaki, and Naomi Taira
- Subjects
Pyridines ,Clinical Biochemistry ,Cell ,Pharmaceutical Science ,Bleomycin ,Iron chelate ,medicine.disease_cause ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Cell Line, Tumor ,Drug Discovery ,medicine ,Animals ,HSP70 Heat-Shock Proteins ,Histidine ,Inducer ,RNA, Messenger ,Molecular Biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Rats ,0104 chemical sciences ,Hsp70 ,010404 medicinal & biomolecular chemistry ,medicine.anatomical_structure ,Cell culture ,Toxicity ,Macaca ,Molecular Medicine ,Oxidative stress - Abstract
Induction of heat shock protein 70 (HSP70) is known to be effective against various diseases. We are interested in HSP70 induction capability of an antitumor antibiotic bleomycin which produces oxidative stress by iron chelate formation and oxygen activation in a cell. The HSP70 induction activity of bleomycin and its six metal core analogs was examined, and a compound HPH-1Trt of 10 μM was found to induce this protein in a pheochromocytoma cell line and some T cell and monocytic cell lines. Its mechanism is increase of HSP70 mRNA, but higher concentration of this compound showed toxicity. Two new derivatives were then synthesized, and one of them named DHPH-1Trt was shown to have less toxicity and higher HSP70 induction activity. This study would lead to a clue for new HSP70 inducer clinically used in near future.
- Published
- 2020
45. l-Histidyl-glycyl-glycyl-l-histidine. Amino-acid structuring of the bleomycin-type pentadentate metal-binding environment capable of efficient double-strand cleavage of plasmid DNA
- Author
-
Mikako Fujita, Masami Otsuka, Yuri Kudo, Satomi Ida, Hiromasa Kurosaki, Yoshinari Okamoto, and Kana Iwamaru
- Subjects
Sodium ascorbate ,Stereochemistry ,Ascorbic Acid ,Oxidative phosphorylation ,Cleavage (embryo) ,Biochemistry ,chemistry.chemical_compound ,Coordination Complexes ,Drug Discovery ,DNA Cleavage ,Molecular Biology ,chemistry.chemical_classification ,Tetrapeptide ,DNA, Superhelical ,Organic Chemistry ,Hydrogen Peroxide ,Amino acid ,chemistry ,Nucleic Acid Conformation ,DNA supercoil ,pUC19 ,Oligopeptides ,Oxidation-Reduction ,Copper ,DNA ,Plasmids - Abstract
A tetrapeptide, l-histidyl-glycyl-glycyl-l-histidine (HGGH), was synthesized and the pUC19 plasmid DNA cleaving activity by copper(II) complex of HGGH (Cu(II)-HGGH) was investigated. Cu(II)-HGGH showed bleomycin-like DNA cleaving activity and, at 50nM, converted a supercoiled DNA efficiently to a linear DNA in the presence of 500μM H2O2/sodium ascorbate through an oxidative pathway.
- Published
- 2015
46. Hyperthermia Treatment in Japan in View of a Review of Survey of Medical Care
- Author
-
Hiroya Ito and Hiromasa Kurosaki
- Subjects
medicine.medical_specialty ,business.industry ,Family medicine ,medicine ,Hyperthermia Treatment ,Intensive care medicine ,business ,Medical care - Published
- 2015
47. Significance of prostate-specific antigen kinetics after three-dimensional conformal radiotherapy with androgen deprivation therapy in patients with localized prostate cancer
- Author
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Masafumi Inoue, Koichiro Akakura, Takao Natsuyama, Wataru Fukuokaya, Kanako Matsuzaki, Hiromasa Kurosaki, Sangji Kim, Hiroki Kitoh, Homare Shiomi, and Nobuko Utsumi
- Subjects
Biochemical recurrence ,Oncology ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,030232 urology & nephrology ,Kaplan-Meier Estimate ,Androgen deprivation therapy ,Cohort Studies ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Interquartile range ,Internal medicine ,Medicine ,Humans ,Aged ,Retrospective Studies ,Univariate analysis ,business.industry ,Proportional hazards model ,Prostatic Neoplasms ,Androgen Antagonists ,Hematology ,General Medicine ,Prostate-Specific Antigen ,medicine.disease ,Radiation therapy ,Prostate-specific antigen ,030220 oncology & carcinogenesis ,Surgery ,Neoplasm Recurrence, Local ,Radiotherapy, Conformal ,business ,Follow-Up Studies - Abstract
To evaluate the relationship between biochemical recurrence and post-radiation prostate-specific antigen (PSA) kinetics in patients with localized prostate cancer treated by radiotherapy with various durations of androgen deprivation therapy (ADT). We reviewed our single-institution, retrospectively maintained data of 144 patients with T1c-T3N0M0 prostate cancer who underwent three-dimensional conformal radiotherapy (3D-CRT) between December 2005 and December 2015 and 113 patients were fulfilled the inclusion criteria. In this cohort, 3D-CRT was delivered with a dose in the range from 70.0 to 72.0 Gy with ADT. All patients received ADT as concurrent regimens. Biochemical recurrence was defined on the basis of the following: “PSA nadir + 2.0 ng/ml or the clinical judgement of attending physicians”. Kaplan–Meier, log-rank, and Cox regression analyses were carried out. The median follow-up period was 54.0 months. The median duration of ADT was 17 months (interquartile range, 10–24 months). There was a trend toward statistical significant correlation between post-radiation PSA decline rate of ≥ 90% and PSA recurrence (p = 0.056). The same correlation could be observed in D’Amico high-risk patients (p = 0.036). However, it was not observed between PSA nadir and PSA recurrence (p = 0.40) in univariate analysis. Furthermore, multivariate analysis showed that post-radiation PSA decline rate of ≥ 90% was a significant predictor of biochemical recurrence in patients who received radiotherapy with various durations of ADT (p = 0.044). Post-radiation PSA decline rate of ≥ 90% was a prognostic factor for biochemical recurrence in localized prostate cancer patients received 3D-CRT with various durations of ADT.
- Published
- 2017
48. Structural Insights into the TLA-3 Extended-Spectrum β-Lactamase and Its Inhibition by Avibactam and OP0595
- Author
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Akihiro Morinaka, Yoshiaki Sakamaki, Kouji Kimura, Mototsugu Yamada, Wanchun Jin, Jun-ichi Wachino, Minoru Yonezawa, Yoshichika Arakawa, Hiromasa Kurosaki, Yoshihiro Yamaguchi, and Anupriya Kumar
- Subjects
0301 basic medicine ,Cefotaxime ,Lactams ,medicine.drug_class ,Stereochemistry ,Avibactam ,030106 microbiology ,Cephalosporin ,Microbial Sensitivity Tests ,medicine.disease_cause ,Crystallography, X-Ray ,beta-Lactamases ,Acylation ,03 medical and health sciences ,chemistry.chemical_compound ,Mechanisms of Resistance ,Catalytic Domain ,Hydrolase ,medicine ,Escherichia coli ,Humans ,Pharmacology (medical) ,Enzyme kinetics ,Pharmacology ,biology ,biology.organism_classification ,Enterobacteriaceae ,Cephalosporins ,030104 developmental biology ,Infectious Diseases ,chemistry ,beta-Lactamase Inhibitors ,Azabicyclo Compounds ,medicine.drug - Abstract
The development of effective inhibitors that block extended-spectrum β-lactamases (ESBLs) and restore the action of β-lactams represents an effective strategy against ESBL-producing Enterobacteriaceae . We evaluated the inhibitory effects of the diazabicyclooctanes avibactam and OP0595 against TLA-3, an ESBL that we identified previously. Avibactam and OP0595 inhibited TLA-3 with apparent inhibitor constants ( K i app ) of 1.71 ± 0.10 and 1.49 ± 0.05 μM, respectively, and could restore susceptibility to cephalosporins in the TLA-3-producing Escherichia coli strain. The value of the second-order acylation rate constant ( k 2 / K , where k 2 is the acylation rate constant and K is the equilibrium constant) of avibactam [(3.25 ± 0.03) × 10 3 M −1 · s −1 ] was closer to that of class C and D β-lactamases ( k 2 / K , 4 M −1 · s −1 ) than that of class A β-lactamases ( k 2 / K , >10 4 M −1 · s −1 ). In addition, we determined the structure of TLA-3 and that of TLA-3 complexed with avibactam or OP0595 at resolutions of 1.6, 1.6, and 2.0 Å, respectively. TLA-3 contains an inverted Ω loop and an extended loop between the β5 and β6 strands (insertion after Ser237), which appear only in PER-type class A β-lactamases. These structures might favor the accommodation of cephalosporins harboring bulky R1 side chains. TLA-3 presented a high catalytic efficiency ( k cat / K m ) against cephalosporins, including cephalothin, cefuroxime, and cefotaxime. Avibactam and OP0595 bound covalently to TLA-3 via the Ser70 residue and made contacts with residues Ser130, Thr235, and Ser237, which are conserved in ESBLs. Additionally, the sulfate group of the inhibitors formed polar contacts with amino acid residues in a positively charged pocket of TLA-3. Our findings provide a structural template for designing improved diazabicyclooctane-based inhibitors that are effective against ESBL-producing Enterobacteriaceae .
- Published
- 2017
49. Simple enrichment of thiol-containing biomolecules by using zinc(II)-cyclen-functionalized magnetic beads
- Author
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Emiko Kinoshita-Kikuta, Yuhzo Hieda, Haruto Fujioka, Maho Kawaguchi, Yasuhiro Kuramoto, Tohru Koike, Masaya Tsunehiro, Hiromasa Kurosaki, and Eiji Kinoshita
- Subjects
chemistry.chemical_classification ,Aqueous solution ,Chromatography ,Chemistry ,Elution ,Biomolecule ,chemistry.chemical_element ,Filtration and Separation ,Zinc ,Bead ,equipment and supplies ,Analytical Chemistry ,chemistry.chemical_compound ,Cyclen ,visual_art ,Thiol ,visual_art.visual_art_medium ,Agarose ,human activities - Abstract
A simple and efficient method based on magnetic-bead technology has been developed for the enrichment of thiol-containing biomolecules, such as l-glutathione and cysteine-containing peptides. The thiol-binding site on the bead is a mononuclear complex of zinc(II) with 1,4,7,10-tetraazacyclododecane (cyclen); this is linked to a hydrophilic cross-linked agarose coating on a particle that has a magnetic core. All steps for the thiol-affinity separation are conducted in aqueous buffers with 0.10 mL of the magnetic beads in a 1.5 mL microtube. The entire separation protocol for thiol-containing compounds, from addition to elution, requires less than one hour per sample, provided the buffers and the zinc(II)-cyclen-functionalized magnetic beads have been prepared in advance. The thiol-affinity magnetic beads are reusable at least 15 times without a decrease in their thiol-binding ability, and they are stable for six months at room temperature.
- Published
- 2014
50. Heating Properties of Resonant Cavity Applicator for Treatment of Osteoarthritis
- Author
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Hiromasa Kurosaki, Yasuhiro Shindo, Kenji Takahashi, Kazuo Kato, Kyohei Kodera, and Kazuki Watanabe
- Subjects
Materials science ,business.industry ,medicine ,Optoelectronics ,Osteoarthritis ,Resonant cavity ,medicine.disease ,business - Published
- 2014
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