1
|
Liu WQ, Lee BC, Song N, He Z, Shen ZA, Lu Y, Koh MJ. Electrochemical Synthesis of C(sp3)-Rich Amines by Aminative Carbofunctionalization of Carbonyl Compounds. Angew Chem Int Ed Engl 2024:e202402140. [PMID: 38650440 DOI: 10.1002/anie.202402140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/16/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Alkylamines form the backbone of countless nitrogen-containing small molecules possessing desirable biological properties. Despite advances in amine synthesis through transition metal catalysis and photoredox chemistry, multicomponent reactions that leverage inexpensive materials to transform abundant chemical feedstocks into three-dimensional α-substituted alkylamines bearing complex substitution patterns remain scarce. Here, we report the design of a catalyst-free electroreductive manifold that merges amines, carbonyl compounds and carbon-based radical acceptors under ambient conditions without rigorous exclusion of air and moisture. Key to this aminative carbofunctionalization process is the chemoselective generation of nucleophilic α-amino radical intermediates that readily couple with electrophilic partners, providing straightforward access to architecturally intricate alkylamines and drug-like scaffolds which are inaccessible by conventional means.
Collapse
Affiliation(s)
- Wen-Qiang Liu
- National University of Singapore, Chemistry, SINGAPORE
| | | | - NingXi Song
- National University of Singapore, Chemistry, SINGAPORE
| | - Zhenghao He
- National University of Singapore, Chemistry, SINGAPORE
| | - Zi-An Shen
- National University of Singapore, Chemistry, SINGAPORE
| | - Yixin Lu
- National University of Singapore, Chemistry, SINGAPORE
| | - Ming Joo Koh
- National University of Singapore, Chemistry, S9-14-01D, 4 Science Drive 2, 117544, Singapore, SINGAPORE
| |
Collapse
|
2
|
Wei Y, Lin LQH, Lee BC, Koh MJ. Recent Advances in First-Row Transition Metal-Catalyzed Reductive Coupling Reactions for π-Bond Functionalization and C-Glycosylation. Acc Chem Res 2023; 56:3292-3312. [PMID: 37917928 DOI: 10.1021/acs.accounts.3c00531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
ConspectusEfficient construction of ubiquitous carbon-carbon bonds between two electrophiles has garnered interest in recent decades, particularly if it is mediated by nonprecious, first-row transition metals. Reductive coupling has advantages over traditional cross-coupling by obviating the need for stoichiometric air- and moisture-sensitive organometallic reagents. By harnessing transition metal-catalyzed reductive coupling as a powerful tool, intricate molecular architectures can be readily assembled through the installation of two C-C bonds across π systems (alkenes/alkynes) via reaction with two appropriate electrophiles. Despite advances in reductive alkene difunctionalization, there remains significant potential for the discovery of novel reaction pathways. In this regard, development of reductive protocols that enable the union of challenging alkyl/alkynyl electrophiles in high regio- and chemoselectivity remains a highly sought-after goal.Apart from π-bond functionalization, reductive coupling has found application in carbohydrate chemistry, particularly in the synthesis of valuable C-glycosyl compounds. In this vein, suitable glycosyl donors can be used to generate reactive glycosyl radical intermediates under reductive conditions. Through elaborately designed reactions, these intermediates can be trapped to furnish pharmaceutically relevant glycoconjugates. Consequently, diversification in C-glycosyl compound synthesis using first-row transition metal catalysis holds strong appeal.In this Account, we summarize our efforts in the development of first-row transition metal-catalyzed reductive coupling reactions for applications in alkene/alkyne functionalization and C-glycosylation. We will first discuss the nickel (Ni)-catalyzed reductive difunctionalization of alkenes, aided by an 8-aminoquinoline (AQ) directing auxiliary. Next, we highlight the Ni-catalyzed hydroalkylation of alkenyl amides tethered with a similar AQ-derived directing auxiliary. Lastly, we discuss an efficient synthesis of 1,3-enynes involving site- and stereoselective reductive coupling of terminal alkynes with alkynyl halides and NHPI esters.Beyond alkene dicarbofunctionalization, we extended the paradigm of transition metal-catalyzed reductive coupling toward the construction of C-glycosidic linkages in carbohydrates. By employing an earth-abundant iron (Fe)-based catalyst, we show that useful glycosyl radicals can be generated from glycosyl chlorides under reductive conditions. These intermediates can be captured in C-C bond formation to furnish valuable C-aryl, C-alkenyl, and C-alkynyl glycosyl compounds with high diastereoselectivity. Our Ni-catalyzed multicomponent union of glycosyl chlorides, aryl/alkyl iodides, and isobutyl chloroformate under reductive conditions led to the stereoselective synthesis of C-acyl glycosides. In addition to Fe and Ni, we discovered a Ti-catalyzed/Mn-promoted synthetic route to access C-alkyl and C-alkenyl glycosyl compounds, through the reaction of glycosyl chlorides with electron-deficient alkenes/alkynes. We further developed an electron donor-acceptor (EDA) photoactivation system leveraging decarboxylative and deaminative strategies for C-glycosylation under Ni catalysis. This approach has been demonstrated to selectively activate carboxyl and amino motifs to furnish glycopeptide conjugates. Finally, through two distinct catalytic transformations of bench-stable heteroaryl glycosyl sulfones, we achieved stereodivergent access to both α- and β-anomers of C-aryl glycosides, one of which involves a Ni-catalyzed reductive coupling with aryl iodides.The findings presented in this Account are anticipated to have far-reaching implications beyond our research. We foresee that these results will pave the way for new transformations founded on the concept of reductive coupling, leading to the discovery of novel applications in the future.
Collapse
Affiliation(s)
- Yi Wei
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Republic of Singapore, 117544
| | - Leroy Qi Hao Lin
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Republic of Singapore, 117544
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Republic of Singapore, 117544
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Republic of Singapore, 117544
| |
Collapse
|
3
|
Jiang Y, Zhang Y, Lee BC, Koh MJ. Diversification of Glycosyl Compounds via Glycosyl Radicals. Angew Chem Int Ed Engl 2023; 62:e202305138. [PMID: 37278303 DOI: 10.1002/anie.202305138] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/07/2023]
Abstract
Glycosyl radical functionalization is one of the central topics in synthetic carbohydrate chemistry. Recent advances in metal-catalyzed cross-coupling chemistry and metallaphotoredox catalysis provided powerful platforms for glycosyl radical diversification. In particular, the discovery of new glycosyl radical precursors in conjunction with these advanced reaction technologies have significantly expanded the space for glycosyl compound synthesis. In this Review, we highlight the most recent progress in this area starting from 2021, and the reports included will be categorized based on different reaction types for better clarity.
Collapse
Affiliation(s)
- Yi Jiang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Yijun Zhang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
- Department of Chemistry, Southern University of Science and Technology, 1088 Xueyuan Road, Shenzhen, 518055, China
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| |
Collapse
|
4
|
Lee BC, Liu CF, Lin LQH, Yap KZ, Song N, Ko CHM, Chan PH, Koh MJ. N-Heterocyclic carbenes as privileged ligands for nickel-catalysed alkene functionalisation. Chem Soc Rev 2023; 52:2946-2991. [PMID: 37016986 DOI: 10.1039/d2cs00972b] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
Alkene functionalisation is a powerful strategy that has enabled access to a wide array of compounds including valuable pharmaceuticals and agrochemicals. The reactivity of the alkene π-bond has allowed incorporation of a diverse range of atoms and functional groups through a wide variety of reaction pathways. N-Heterocyclic carbenes (NHCs) are a class of persistent carbenes that are widely employed as ancillary ligands due to their ability to act as strong σ-donors compared to widely-applied conventional phosphine-based ligands. NHCs are also unique as their molecular bulk provides steric influence for regio- and stereo-control in many alkene functionalisation reactions, illustrated by the examples covered in this review. A combination of the unique reactivity of NHC ligands and nickel's characteristics has facilitated the design of reaction pathways that show distinct selectivity and reactivity, including the activation of bonds previously considered "inert", such as C-H bonds, the C-O bond of ethers and esters, and the C-N bonds of amides. This review summarises the advancements in Ni(NHC) catalysed alkene functionalisation up to 2022, covering the following major reaction classes: Heck-type reactions, hydrofunctionalisation and dicarbofunctionalisation.
Collapse
Affiliation(s)
- Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Chen-Fei Liu
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Leroy Qi Hao Lin
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Kang Zheng Yap
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - NingXi Song
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Charyl Hui Min Ko
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Priscilla Hee Chan
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore.
| |
Collapse
|
5
|
Wang Q, Lee BC, Song N, Koh MJ. Stereoselective C-Aryl Glycosylation by Catalytic Cross-Coupling of Heteroaryl Glycosyl Sulfones. Angew Chem Int Ed Engl 2023; 62:e202301081. [PMID: 36881462 DOI: 10.1002/anie.202301081] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/07/2023] [Accepted: 03/07/2023] [Indexed: 03/08/2023]
Abstract
Stereoselective C-glycosylation reactions are increasingly gaining attention in carbohydrate chemistry because they enable glycosyl precursors, readily accessible as anomeric mixtures, to converge to a single diastereomeric product. However, controlling the stereochemical outcome through transition-metal catalysis remains challenging, and methods that leverage bench-stable heteroaryl glycosyl sulfone donors to facilitate glycosylation are rare. Herein, we show two complementary nonprecious metal catalytic systems, based on iron or nickel, which are capable of promoting efficient C-C coupling between heteroaryl glycosyl sulfones and aromatic nucleophiles or electrophiles through distinct mechanisms and modes of activation. Diverse C-aryl glycosides were secured with excellent selectivity, scope, and functional-group compatibility, and reliable access to both α and β isomers was possible for key sugar residues.
Collapse
Affiliation(s)
- Quanquan Wang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - NingXi Song
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Republic of Singapore
| |
Collapse
|
6
|
Wang Q, Lee BC, Song N, Koh MJ. Stereoselective C‐Aryl Glycosylation by Catalytic Cross‐Coupling of Heteroaryl Glycosyl Sulfones. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202301081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Affiliation(s)
- Quanquan Wang
- National University of Singapore Chemistry SINGAPORE
| | | | - NingXi Song
- National University of Singapore Chemistry SINGAPORE
| | - Ming Joo Koh
- National University of Singapore Chemistry S9-14-01D, 4 Science Drive 2 117544 Singapore SINGAPORE
| |
Collapse
|
7
|
De Caterina R, Unverdorben M, Lee BC, Yamashita T, Lin WS, Wang CC, Pecen L, Borrow A, Chen C, Kirchhof P. Real-world effectiveness and safety of edoxaban in patients with and without a history of ischaemic stroke: results from the ETNA-AF programme. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Atrial fibrillation (AF) patients with a history of ischaemic stroke (IS) have a higher risk for recurrent IS events and were largely excluded from the pivotal, randomised, controlled phase 3 trials on oral anticoagulants. Thus, the effectiveness and safety of edoxaban in these patients need to be studied in a real-world setting.
Purpose
To compare edoxaban real-world effectiveness and safety in AF patients with or without an IS history.
Methods
The Global ETNA-AF programme (EU: NCT02944019, Japan: UMIN000017011, South Korea/Taiwan: NCT02951039) integrates data from multiple prospective, observational, noninterventional regional studies of AF patients receiving edoxaban for stroke prevention. This snapshot analysis summarises baseline characteristics with medical history and 2-year annualised rates of all-cause death, cardiovascular (CV) death, stroke (haemorrhagic, ischaemic, any), and bleeding (including major bleeding [MB], major gastrointestinal [GI] bleeding, intracranial haemorrhage [ICH], clinically relevant nonmajor bleeding [CRNMB], and any bleeding) in patients with or without IS history.
Results
Data from 27,333 patients (3215 with prior IS and 24,118 without) from Europe, Japan, South Korea, and Taiwan were analysed. Patients with IS history were significantly older, more likely ≥75 years of age, and had a lower mean body weight and creatinine clearance (P<0.0001 for all; Table). Patients with IS history also had significantly higher baseline stroke (CHA2DS2-VASc) and bleeding (HAS-BLED) risk scores (P<0.0001 for both; Table). A significantly higher percentage of patients with IS history had previous transient ischaemic attacks (TIA), MB, and ICH (P<0.0001 for all; Table). Patients with IS history more likely received edoxaban 30 mg vs 60 mg at baseline (P<0.0001). Effectiveness and safety outcomes hazard ratios are shown in the Figure. Patients with IS history had significantly higher rates of all-cause death (4.5% vs 3.0%; P<0.0001), CV death (1.9% vs 1.4%; P=0.004), IS (2.5% vs 0.5%; P<0.0001), any stroke (3.1% vs 0.7%; P<0.0001), and TIA (0.5% vs 0.2%; P=0.0002). Patients with IS history had significantly higher annualised rates of MB (1.6% vs 1.0%; P<0.0001), major GI bleeding (0.8% vs 0.5%; P=0.003), ICH (0.6% vs 0.3%; P<0.0001), haemorrhagic stroke (0.5% vs 0.2%; P<0.0001), CRNMB (2.3% vs 1.3%; P<0.0001), and any bleeding (6.1% vs 4.1%; P<0.0001).
Conclusions
Patients with AF who have a history of IS are more likely elderly; have histories of MB, ICH, and TIA; and have high baseline stroke and bleeding risk scores. Patients with IS history receiving edoxaban have a considerably higher likelihood of experiencing IS or TIA, whereas the risk of experiencing any bleeding event (with the exception of ICH) is only modestly higher than in those without IS history.
Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo
Collapse
Affiliation(s)
- R De Caterina
- University of Pisa and Pisa University Hospital , Pisa , Italy
| | - M Unverdorben
- Daiichi Sankyo, Inc., Basking Ridge , NJ , United States of America
| | - B C Lee
- Hallym University Sacred Heart Hospital , Anyang , Korea (Republic of)
| | | | - W S Lin
- Tri-Service General Hospital and National Defense Medical Center , Taipei , Taiwan
| | - C C Wang
- Linkou Chang Gung Memorial Hospital and Chang Gung University , Taoyuan , Taiwan
| | - L Pecen
- Institute of Computer Science ASCR , Prague , Czechia
| | - A Borrow
- Daiichi Sankyo, Inc., Basking Ridge , NJ , United States of America
| | - C Chen
- Daiichi Sankyo, Inc., Basking Ridge , NJ , United States of America
| | - P Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham , Birmingham , United Kingdom
| |
Collapse
|
8
|
Moser J, Unverdorben M, Wang CC, Bruggenjurgen B, Lee BC, Chen C, Pecen L, Yamashita T, De Caterina R, Kirchhof P. Effectiveness and safety of edoxaban in 27,333 patients from ETNA-AF with and without a history of intracranial haemorrhage after 2 years of treatment. Europace 2022. [DOI: 10.1093/europace/euac053.288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): This study was sponsored by Daiichi Sankyo, Inc. Medical writing and editorial support were provided by Atreju Lackey, PhD of AlphaBioCom, LLC, and funded by Daiichi Sankyo, Inc.
Background/Introduction
Once-daily edoxaban significantly reduced the risk of intracranial haemorrhage (ICH) compared with well-managed warfarin in atrial fibrillation (AF) patients in the ENGAGE AF-TIMI 48 trial. The effectiveness and safety of edoxaban in patients with prior ICH is unknown.
Purpose
To compare the effectiveness and safety of edoxaban in AF patients with or without a history of ICH.
Methods
The Global ETNA-AF programme is composed of and, thus, integrates data from multiple prospective, observational, and noninterventional regional studies collecting data of AF patients treated with edoxaban for stroke prevention. This snapshot analysis presents global and regional baseline characteristics with medical history and 2-year annualised rates of all-cause mortality, stroke (haemorrhagic, ischaemic, any), and bleeding (major bleeding [MB] including ICH, clinically relevant nonmajor bleeding [CRNMB], any bleeding), in patients with or without ICH history.
Results
Overall, 27,333 patients from Europe, Japan, South Korea, and Taiwan were analysed, including 367 with prior ICH and 26,966 without prior ICH. There were proportionally fewer patients with a history of ICH in the European population. Patients with a history of ICH were older (P=0.006), had a lower body mass index (P<0.0001), had a lower creatinine clearance (P=0.0001), and had more comorbidities, with a higher percentage of patients with a history of stroke, transient ischaemic attack (TIA), or MB (Table 1); the higher level of comorbidities noted in patients with a history of ICH was also reflected by higher baseline CHA2DS2-VASc and HAS-BLED scores (Table 1). Patients with a history of ICH were more likely receiving 30 mg edoxaban at baseline, whereas patients without ICH history were more often on 60 mg edoxaban (each P<0.0001). In patients with vs without ICH history, all-cause mortality (5.10% vs 3.14%; P=0.01), ischaemic stroke (1.79% vs 0.73%; P=0.006), and any stroke rates (3.25% vs 0.95%; P<0.0001) were higher (Table 2). Patients with vs without ICH history had higher annualised rates of MB (2.50% vs 1.00%; P=0.001), ICH (1.42% vs 0.27%; P<0.0001), haemorrhagic stroke (1.42% vs 0.20%; P<0.0001), CRNMB (2.49% vs 1.40%; P=0.04), and any bleeding (7.57% vs 4.27%; P=0.001), but these rates were low compared to other high-risk populations. ICH was not selected as a predictor of cardiovascular outcomes on multivariate prediction modelling. ICH had non-significant effects in predicting all-cause death (HR 1.22), ischemic stroke (HR 1.14), and major bleeding (HF 1.37) and repeat ICH (HR 1.94).
Conclusions
Patients with a history of ICH are a small, elderly, multimorbid subgroup of patients with AF. Treatment with the non-vitamin K antagonist oral anticoagulant edoxaban resulted in relatively low rates of major events.
Collapse
Affiliation(s)
- J Moser
- University Heart Centre Hamburg, Department of Cardiology, Hamburg, Germany
| | - M Unverdorben
- Daiichi Sankyo, Inc., Basking Ridge, United States of America
| | - CC Wang
- Linkou Chang Gung Memorial Hospital and Chang Gung University, Division of Cardiology, Department of Internal Medicine, Taoyuan, Taiwan
| | - B Bruggenjurgen
- Steinbeis-University, Institute for Health Economics, Berlin, Germany
| | - BC Lee
- Hallym University Sacred Heart Hospital, Department of Neurology, Anyang, Korea (Republic of)
| | - C Chen
- Daiichi Sankyo, Inc., Basking Ridge, United States of America
| | - L Pecen
- Institute of Computer Science ASCR, Prague, Czechia
| | - T Yamashita
- Cardiovascular Institute, Department of Cardiovascular Medicine, Tokyo, Japan
| | - R De Caterina
- University of Pisa, Department of Surgery, Medical, Molecular and Critical Area Pathology, Pisa, Italy
| | - P Kirchhof
- University Heart Centre Hamburg, Department of Cardiology, Hamburg, Germany
| |
Collapse
|
9
|
Abstract
AbstractWe present a base-mediated hydroamination protocol, using substoichiometric amounts of a hydrosilane and potassium tert-butoxide, that operates under mild conditions at 30 °C. Many aryl- and heteroatom-substituted olefins as well as arylamines are tolerated, affording the desired products with complete regioselectivity. Preliminary mechanistic investigations reveal a non-radical pathway for hydroamination. A sequential remote hydroamination strategy involving an initial Fe-catalysed olefin isomerisation followed by our base-mediated hydroamination was also developed to directly access β-arylamines from terminal aliphatic alkenes.
Collapse
Affiliation(s)
- Ping Li
- Henan Key Lab of Cable Structure and Materials, College of Cable Engineering, Henan Institute of Technology
- Co-Innovation Center for Efficient Processing and Utilization of Forest Products, College of Chemical Engineering, Nanjing Forestry University
- Department of Chemistry, National University of Singapore
| | - Boon Chong Lee
- Department of Chemistry, National University of Singapore
| | - Ming Joo Koh
- Department of Chemistry, National University of Singapore
| | - Xiaoxiang Zhang
- Co-Innovation Center for Efficient Processing and Utilization of Forest Products, College of Chemical Engineering, Nanjing Forestry University
| |
Collapse
|
10
|
Affiliation(s)
- Xiaolong Yu
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Hongling Zheng
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Haonan Zhao
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Boon Chong Lee
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| |
Collapse
|
11
|
Yu X, Zheng H, Zhao H, Lee BC, Koh MJ. Iron‐Catalyzed Regioselective Alkenylboration of Olefins. Angew Chem Int Ed Engl 2020; 60:2104-2109. [DOI: 10.1002/anie.202012607] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Xiaolong Yu
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Hongling Zheng
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Haonan Zhao
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Boon Chong Lee
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| | - Ming Joo Koh
- Department of Chemistry National University of Singapore 12 Science Drive 2 117549 Singapore Republic of Singapore
| |
Collapse
|
12
|
Kirchhof P, Unverdorben M, Koretsune Y, Wang CC, Kim YH, Brueggenjuergen B, Lee BC, Levy P, Rauer H, Reimitz PE, Yamashita T, De Caterina R. P4785Clinical characteristics and 1-year outcomes in atrial fibrillation patients with or without history of intracranial haemorrhage treated with edoxaban: snapshot analysis of the Global ETNA-AF program. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.1161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Patients with atrial fibrillation (AF) who survive an intracranial haemorrhage (ICH) are at high risk of stroke, death, and recurrent haemorrhage. Effectiveness and safety of the nonvitamin K antagonist oral anticoagulant (NOAC) edoxaban in this patient population has not been reported.
Purpose
This snapshot analysis from the global ETNA-AF program compared 1-year outcomes in AF patients with and without history of ICH treated with edoxaban from Europe, Japan, and Korea/Taiwan.
Methods
Global ETNA-AF (EU: NCT02944019, Japan: UMINehz745.116117011, Korea/Taiwan: NCT02951039) is a multinational, multicentre, prospective, noninterventional program of AF patients receiving edoxaban in regular clinical care. Demographics, baseline characteristics, and outcomes at 1-year follow-up were reported for 19416 patients with and without a history of ICH.
Results
Of the 19416 patients, 297 had a history of ICH. At 1-year follow-up, incidences of International Society on Thrombosis and Haemostasis (ISTH) major bleeding (including ICH) and clinically relevant nonmajor bleeding (CRNMB) were generally low. The rate of ischaemic stroke was higher in patients with a history of ICH than in those without prior ICH.
Europe (N=7672) Korea/Taiwan (N=1701) Japan (N=10043) History of ICH, n (%) Yes No Yes No Yes No 36 (0.5) 636 (99.5) 27 (1.6) 1674 (98.4) 234 (2.3) 9809 (97.7) Age, median (IQR) 75 (69, 78) 74 (68, 80) 70 (66, 76) 72 (66, 77) 76 (71, 82) 75 (68, 81) Gender, male % 72.2 57.4 70.4 59.9 60.7 59.3 Weight, median (IQR) kg 80.0 (75.0, 88.0) 80.0 (70.0, 92.0) 68.0 (54.0, 77.0) 65.0 (58.0, 73.0) 57.0 (50.0, 65.0) 59.0 (51.0, 68.0) CHA2DS2-VASc, mean (SD) 4.2 (1.44) 3.1 (1.38) 3.9 (1.63) 3.0 (1.43) 4.0 (1.56) 3.4 (1.64) HAS-BLED, mean (SD) 4.3 (1.23) 2.6 (1.12) 3.9 (1.55) 2.4 (10.7) 3.7 (1.07) 2.3 (1.12) CrCl [mL/min], median (IQR) 70.5 (58.8, 85.1) 70.4 (53.8, 90.1) 63.7 (45.8, 84.2) 61.6 (48.4, 78.1) 58.5 (46.0, 73.2) 60.2 (46.1, 77.0) Edoxaban 60/30 mg, % 83.3 / 16.7 77.1 / 22.9 55.6 / 44.4 50.2 / 49.8 21.8 / 78.2 27.8 / 72.2 1-year outcome, n (%/year) Major bleeding (ISTH) 2 (5.94) 66 (0.92) 0 (0) 13 (0.82) 3 (1.92) 66 (0.96) Intracranial haemorrhage 1 (2.91) 19 (0.26) 0 (0) 5 (0.32) 1 (0.64) 18 (0.26) Major GI* bleeding 0 (0.00) 20 (0.28) 0 (0) 2 (0.13) 2 (1.28) 30 (0.43) CRNMB 0 (0.00) 102 (1.43) 0 (0) 11 (0.70) 6 (3.82) 219 (3.20) Ischaemic stroke 1 (2.93) 41 (0.57) 1 (4.04) 11 (0.70) 4 (2.57) 78 (1.13) *Gastrointestinal.
Conclusion
Our data underpin the need for effective stroke prevention. In AF patients with a history of ICH, data suggest that edoxaban can be safely and effectively administered in patients with and without prior ICH in regular clinical care.
Acknowledgement/Funding
Daiichi Sankyo
Collapse
Affiliation(s)
- P Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham and SWBH and UHB NHS Trusts, Birmingham, United Kingdom
| | - M Unverdorben
- Daiichi Sankyo, Inc, Basking Ridge, United States of America
| | - Y Koretsune
- National Hospital Organization Osaka National Hospital, Osaka, Japan
| | - C C Wang
- Chang Gung University, Department of Cardiology, Taipei, Taiwan
| | - Y H Kim
- Korea University College of Medicine, Department of Internal Medicine, Seoul, Korea (Republic of)
| | - B Brueggenjuergen
- Steinbeis-University, Head Institute for Health Economics, Berlin, Germany
| | - B C Lee
- Hallym University Sacred Heart Hospital, Anyang-Si, Gyeonggi-Do, Korea (Republic of)
| | - P Levy
- Universite Paris-Dauphine, Paris, France
| | - H Rauer
- Daiichi Sankyo Europe GmbH, Munich, Germany
| | | | | | - R De Caterina
- University of Pisa, Chair of Cardiology, Pisa, Italy
| |
Collapse
|
13
|
Affiliation(s)
- S Lim
- Crop Production Technology Research Division, National Institute of Crop Science, RDA, Miryang 50424, Republic of Korea
| | - Y Yoon
- Crop Production Technology Research Division, National Institute of Crop Science, RDA, Miryang 50424, Republic of Korea
| | - Y-W Jang
- Crop Production Technology Research Division, National Institute of Crop Science, RDA, Miryang 50424, Republic of Korea
| | - S Bae
- Crop Production Technology Research Division, National Institute of Crop Science, RDA, Miryang 50424, Republic of Korea
| | - Y-H Lee
- Planning & Coordination Division, National Institute of Crop Science, RDA, Wanju 55365, Republic of Korea
| | - B C Lee
- Crop Foundation Division, National Institute of Crop Science, RDA, Wanju 55365, Republic of Korea
| |
Collapse
|
14
|
Jang YW, Jo Y, Cho WK, Choi H, Yoon YN, Lim SM, Lee YH, Bae JY, Lee BC. First Report of Bean Common Mosaic Necrosis Virus Infecting Soybean in Korea. Plant Dis 2018; 102:PDIS09171474PDN. [PMID: 30113257 DOI: 10.1094/pdis-09-17-1474-pdn] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Y W Jang
- Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Miryang 50426, Korea
| | - Y Jo
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - W K Cho
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - H Choi
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Y N Yoon
- Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Miryang 50426, Korea
| | - S M Lim
- Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Miryang 50426, Korea
| | - Y H Lee
- Planning and Coordination Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
| | - J Y Bae
- Crop Foundation Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
| | - B C Lee
- Crop Foundation Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
| |
Collapse
|
15
|
Jin JX, Lee S, Khoirinaya C, Oh A, Kim GA, Lee BC. Supplementation with spermine during in vitro maturation of porcine oocytes improves early embryonic development after parthenogenetic activation and somatic cell nuclear transfer. J Anim Sci 2016; 94:963-70. [PMID: 27065258 DOI: 10.2527/jas.2015-9761] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Spermine plays an important role in protection from reactive oxygen species (ROS) in bacteria, yeast, and mammalian cells, but there are few studies on the effects of spermine on porcine oocyte maturation and subsequent embryo development. The aim of this study was to determine the effects of spermine on in vitro maturation (IVM) of porcine oocytes and their developmental competence after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT). We evaluated nuclear maturation, intracellular glutathione (GSH), and ROS levels in oocytes, and their subsequent embryonic development, as well as gene expression in mature oocytes, cumulus cells, and PA blastocysts. After treatment with various concentrations of spermine in IVM culture medium, there was no significant difference in nuclear maturation rate. However, spermine treatment groups (10- 500 µM) showed significantly increased intracellular GSH levels and decreased ROS levels compared to the control ( < 0.05). Furthermore, 10 µM spermine supported significantly higher blastocyst formation rates after PA than the control group ( < 0.05). According to the optimal condition from the PA results, we investigated the effects of 10 µM spermine on SCNT, and it also significantly improved blastocyst formation rates compared with the control group ( < 0.05). In evaluating the effects of 10 µM spermine on gene expression, there was significantly lower expression of a proapoptotic gene () and higher expression of an antiapoptotic gene () in cumulus cells ( < 0.05). was increased in spermine-treated oocytes. Levels of transcription for and were significantly increased in PA blastocysts. In conclusion, 10 µM spermine supplementation during IVM improved the development of porcine PA and SCNT embryos by increasing intracellular GSH, scavenging ROS levels, and regulating gene expression.
Collapse
|
16
|
Taweechaipaisankul A, Jin JX, Lee S, Kim GA, Lee BC. The effects of canthaxanthin on porcine oocyte maturation and embryo development in vitro after parthenogenetic activation and somatic cell nuclear transfer. Reprod Domest Anim 2016; 51:870-876. [PMID: 27644134 DOI: 10.1111/rda.12748] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 07/07/2016] [Indexed: 11/30/2022]
Abstract
The objective of this study was to examine the effects of canthaxanthin (Cx) treatment during in vitro maturation (IVM) of porcine oocytes on embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), on intracellular glutathione (GSH) and reactive oxygen species (ROS) levels in mature oocytes, and on gene expression in both PA- and SCNT-derived blastocysts. To determine the optimal effective concentration of Cx, porcine oocytes were cultured in IVM medium supplemented with various concentrations (0, 20, 40 and 80 μM) of Cx for 22 hr. Compared to other groups, supplementation with 40 μM Cx significantly improved blastocyst formation rates after PA (p < .05), but no significant differences were observed among groups in total blastocyst cell numbers. Subsequently, oocytes were cultured in IVM medium supplemented with or without 40 μM Cx. Oocytes treated with 40 μM Cx showed significantly increased cleavage and blastocyst formation rates after SCNT compared to the control group (p < .05). Moreover, significantly increased intracellular GSH and reduced ROS levels were observed in the Cx-treated group (p < .05). In addition, both PA- and SCNT-derived blastocysts from the 40 μM Cx-treated group showed significantly increased mRNA expression of Bcl2 and Oct4 and decreased Caspase3 expression level (p < .05), when compared with the control group. PA-derived blastocysts from the 40 μM Cx-treated group also exhibited significantly decreased expression of Bax (p < .05). Our results demonstrated that treatment with 40 μM Cx during IVM improves the developmental competence of PA and SCNT embryos. Improvement of embryo development by Cx is most likely due to increased intracellular GSH synthesis, which reduces ROS levels in oocytes, and it may also positively regulate apoptosis- and development-related genes.
Collapse
Affiliation(s)
- A Taweechaipaisankul
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - J X Jin
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - S Lee
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - G A Kim
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - B C Lee
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,Institute of Green Bio Science and Technology, Seoul National University, Pyeongchang, Gangwon-do, Korea
| |
Collapse
|
17
|
Park HS, Kim E, Moon BS, Lim NH, Lee BC, Kim SE. In Vivo Tissue Pharmacokinetics of Carbon-11-Labeled Clozapine in Healthy Volunteers: A Positron Emission Tomography Study. CPT Pharmacometrics Syst Pharmacol 2015. [PMID: 26225256 PMCID: PMC4452936 DOI: 10.1002/psp4.38] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We investigated clozapine (CLZ) tissue pharmacokinetics in vivo by using carbon-11-labeled CLZ (11C-CLZ) and positron emission tomography (PET). Eight healthy volunteers underwent 11C-CLZ studies wherein computed tomography image acquisition was followed by PET scans (whole-body, four; brain, four). After bolus intravenous 11C-CLZ injection, PET images were acquired at various timepoints for 2–3 hours. Tissue 11C-CLZ signals were plotted over time, and pharmacokinetic parameters were determined. High 11C-CLZ radioactivity was detected in the liver and brain, implying CLZ hepatic metabolism and efficient blood–brain barrier penetration. The urinary and hepatobiliary tracts were involved in 11C-CLZ excretion. Moderate to high radioactivity was observed in the dopaminergic and serotonergic receptor-rich brain regions, indicating CLZ binding to multiple receptor types. To our knowledge, this is the first study to report the determination of 11C-CLZ tissue pharmacokinetics in humans. PET using radiolabeled drugs can provide valuable information that could complement plasma pharmacokinetic data.
Collapse
Affiliation(s)
- H S Park
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea ; Smart Humanity Convergence Center, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University Seoul, South Korea ; Advanced Institutes of Convergence Technology Suwon, South Korea
| | - E Kim
- Department of Neuropsychiatry, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea
| | - B S Moon
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea
| | - N H Lim
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea
| | - B C Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea ; Advanced Institutes of Convergence Technology Suwon, South Korea
| | - S E Kim
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital Seongnam, South Korea ; Smart Humanity Convergence Center, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University Seoul, South Korea ; Advanced Institutes of Convergence Technology Suwon, South Korea
| |
Collapse
|
18
|
Kwon D, Saadeldin IM, Kim SJ, Park SJ, Kang JT, Park HJ, Moon JH, Koo OJ, Jang G, Lee BC. Optimizing electrical activation of porcine oocytes by adjusting pre- and post-activation mannitol exposure times. Reprod Domest Anim 2014; 49:995-9. [PMID: 25256295 DOI: 10.1111/rda.12420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 08/10/2014] [Indexed: 11/29/2022]
Abstract
Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre- and post-activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre- or post-electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation showed significantly higher blastocyst development than 0 min pre- and 0 min post-activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre- and 0 min post-activation. In conclusion, exposure of oocytes to mannitol for 1 min pre- and 3 min post-activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre- and 3 min post-activation.
Collapse
Affiliation(s)
- D Kwon
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Lee BC, Huang W, Tao L, Yamamoto N, Gallimore AD, Yalin AP. A cavity ring-down spectroscopy sensor for real-time Hall thruster erosion measurements. Rev Sci Instrum 2014; 85:053111. [PMID: 24880357 DOI: 10.1063/1.4879135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A continuous-wave cavity ring-down spectroscopy sensor for real-time measurements of sputtered boron from Hall thrusters has been developed. The sensor uses a continuous-wave frequency-quadrupled diode laser at 250 nm to probe ground state atomic boron sputtered from the boron nitride insulating channel. Validation results from a controlled setup using an ion beam and target showed good agreement with a simple finite-element model. Application of the sensor for measurements of two Hall thrusters, the H6 and SPT-70, is described. The H6 was tested at power levels ranging from 1.5 to 10 kW. Peak boron densities of 10 ± 2 × 10(14) m(-3) were measured in the thruster plume, and the estimated eroded channel volume agreed within a factor of 2 of profilometry. The SPT-70 was tested at 600 and 660 W, yielding peak boron densities of 7.2 ± 1.1 × 10(14) m(-3), and the estimated erosion rate agreed within ~20% of profilometry. Technical challenges associated with operating a high-finesse cavity in the presence of energetic plasma are also discussed.
Collapse
Affiliation(s)
- B C Lee
- Physics Department, Colorado State University, Fort Collins, Colorado 80521, USA
| | - W Huang
- NASA Glenn Research Center, 2100 Brookpark Rd., Cleveland, Ohio 44135, USA
| | - L Tao
- Mechanical Engineering Department, Colorado State University, Fort Collins, Colorado 80521, USA
| | - N Yamamoto
- Mechanical Engineering Department, Colorado State University, Fort Collins, Colorado 80521, USA
| | - A D Gallimore
- Aerospace Engineering Department, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - A P Yalin
- Mechanical Engineering Department, Colorado State University, Fort Collins, Colorado 80521, USA
| |
Collapse
|
20
|
Kim GA, Oh HJ, Park JE, Kim MJ, Park EJ, Jo YK, Jang G, Kim MK, Kim HJ, Lee BC. Species-specific challenges in dog cloning. Reprod Domest Anim 2013; 47 Suppl 6:80-3. [PMID: 23279471 DOI: 10.1111/rda.12035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 07/06/2012] [Indexed: 11/28/2022]
Abstract
Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.
Collapse
Affiliation(s)
- G A Kim
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Seo HJ, Lee BC, Seok JH, Jeon HJ, Paik JW, Kim W, Kwak KP, Han C, Lee KU, Pae CU. An open-label, rater-blinded, 8-week trial of bupropion hydrochloride extended-release in patients with major depressive disorder with atypical features. Pharmacopsychiatry 2013; 46:221-6. [PMID: 23963965 DOI: 10.1055/s-0033-1353171] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The present study aimed at investigating the effectiveness and tolerability of -bupropion hydrochloride extended release (XL) in major depressive disorder (MDD) patients with atypical features (AF).51 patients were prescribed bupropion XL for 8 weeks (6 visits: screening, baseline, weeks 1, 2, 4 and 8). The primary efficacy measure was a change of the Structured Interview Guide for the Hamilton Depression Rating Scale-Seasonal Affective Disorder Version (SIGH-SAD) from baseline to endpoint. Secondary efficacy measures included the SIGH-SAD atypical symptoms subscale, Clinical Global Impression-Severity (CGI-S), Sheehan Disability Scale (SDS) and Epworth Sleepiness Questionnaire (ESQ). Response or remission was defined as ≥50% reduction or ≤7 in SIGH-SAD total scores, respectively, at end of treatment.The HAM-D-29 total score reduced by 55.3% from baseline (27.3±6.5) to end of treatment (12.2±6.3) (p<0.001). Atypical symptom subscale scores also reduced by 54.5% from baseline (9.2±3.0) to end of treatment (4.2±2.8) (p<0.001). At the end of treatment, 24.4% (n=10) and 51.2% (n=21) subjects were classified as remitters and responders, respectively. The most frequently reported AEs were headache (13.7%), dry mouth (11.8%), dizziness (9.8%), and dyspepsia (9.8%).Our preliminary study indicates that bupropion XL may be beneficial in the treatment of MDD with atypical features. Adequately powered, randomized, double-blind, placebo-controlled trials are necessary to determine our results.
Collapse
Affiliation(s)
- H-J Seo
- Department of Psychiatry, The Catholic University of Korea College of Medicine, Seoul, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Oh HJ, Park EJ, Lee SY, Soh JW, Kong IS, Choi SW, Ra JC, Kang SK, Lee BC. Comparison of cell proliferation and epigenetic modification of gene expression patterns in canine foetal fibroblasts and adipose tissue-derived mesenchymal stem cells. Cell Prolif 2012; 45:438-44. [PMID: 22925503 DOI: 10.1111/j.1365-2184.2012.00838.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES This study compared rate of cell proliferation, viability, cell size, expression patterns of genes related to pluripotency and epigenetic modification between canine foetal fibroblasts (cFF) and canine adipose tissue-derived mesenchymal stem cells (cAd-MSC). MATERIALS AND METHODS Proliferation pattern, cell viability as well as cell size at each passage of cFF and cAd-MSC were measured when cultures reached confluence. In addition, real-time PCR was performed to investigate expression of Dnmt1, HDAC1, OCT4, SOX2, BAX, BCL2 genes with reference to β-actin gene expression as an endogenous control in both cell lines. RESULTS cFF and cAd-MSC differed in number of generations, but not in doubling times, at all passages. Mean cell size of cAd-MSC was significantly smaller than that of cFF. Cell viability was significantly lower in cFFs and apoptotic level was significantly lower in cAd-MSC compared to passage-matched cFF. In the expression of genes related to pluripotency and epigenetic modification, level of HDAC1 in cAd-MSC was significantly higher than in cFF, but expression of Dnmt1 did not differ between the two groups. OCT4 and SOX2 were significantly more highly expressed in cAd-MSC compared to cFF. CONCLUSIONS cAd-MSC have higher stem-cell potential than cFF in terms of proliferation patterns, epigenetic modification and pluripotency, thus cAd-MSC could be more appropriate than cFF as donors of nuclei in somatic cell nuclear transfer for transgenesis.
Collapse
Affiliation(s)
- H J Oh
- Department of Theriogenology and Biotechnology, Seoul National University, Seoul, South Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Basu A, Bhatti N, Lee BC. Pregnancy outcome in women with gestational diabetes: results of a four-year audit. Practical Diabetes 2012. [DOI: 10.1002/pdi.1699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
25
|
Choresca CH, Koo OJ, Hong SG, Oh HJ, Gomez DK, Kim JH, Lee BC, Park SC. Effect of dimethyl sulfoxide on cell cycle synchronization of goldfish caudal fin derived fibroblasts cells. Reprod Domest Anim 2011; 45:e73-7. [PMID: 19788515 DOI: 10.1111/j.1439-0531.2009.01525.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin-derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.
Collapse
Affiliation(s)
- C H Choresca
- Laboratory of Aquatic Animal Medicine, Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul Brain Korea 21 Program for Veterinary Science, Seoul National University, Seoul, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Koo OJ, Kang JT, Kwon DK, Park HJ, Lee BC. Influence of ovulation status, seasonality and embryo transfer method on development of cloned porcine embryos. Reprod Domest Anim 2011; 45:773-8. [PMID: 19281594 DOI: 10.1111/j.1439-0531.2009.01346.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To improve pig cloning efficiency, the present study evaluated the effect of ovulation status, seasonality and embryo transfer (ET) method on in vivo development of cloned porcine embryos. Cloned embryos were transferred to surrogate mothers on the same day of somatic cell nuclear transfer. In pre-ovulation stage (PO), pregnancy rate (PR) and delivery rate (DR) were 36.3% and 9.4%, respectively. In post-ovulation stage, 22.7% PR and 2.1% DR were recorded (both PR and DR are significantly higher in PO). When ET was performed during winter (December-February), spring (March-May), summer (June-August) and autumn (September-November), the PRs were 13.4%, 37.3%, 24.6% and 51.0%, while DRs were 0%, 12.7%, 4.3% and 7.8%, respectively. The highest PRs were recorded in autumn groups. However, DRs were significantly lower in autumn (7.8%) group compared with spring (12.7%) group. The PR was the lowest and no piglets were born in winter group, which might be because of the effect of low temperature during ET. To overcome the low PR in winter group, 0.25 ml straws were used for ET to minimize exposure time of embryos to ambient temperature. The straw ET group showed significantly higher PR in the winter group (23. 9%) compared with the conventional catheter-loading group (7.7%). We suggest that using PO recipient and ET in spring is the best condition for pig cloning. In addition, alternative method to reduce cold shock during ET in winter is necessary.
Collapse
Affiliation(s)
- O J Koo
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | | | | | | | | |
Collapse
|
27
|
Abstract
Synchronization of the donor cell cycle is an important factor for successful animal cloning by nuclear transfer. To improve the efficiency of porcine cloning, in the present report, we evaluated effects of contact inhibition, serum starvation and roscovitine treatment of donor cells on in vitro and in vivo developmental potency of cloned porcine embryos. Fibroblasts derived from a porcine foetus at day 30 of gestation were isolated and cultured to 70% confluency. Then, cells were either cultured to 100% confluency for contact inhibition, or cultured in 0.5% serum for 72 h for serum starvation or with 15 μM roscovitine for 24 h. Cells were most effectively synchronized at G0/G1 in the serum starvation group (87.5%) compared with the contact inhibition and roscovitine treatment groups (76.3% and 79.9% respectively p < 0.05). However, after somatic cell nuclear transfer followed by in vitro culture, the serum starvation group showed a significantly lower blastocyst formation rate (5.6%) compared with the contact inhibition and roscovitine treatment groups (11.6% and 20.0% respectively). Differential expression of apoptosis-related genes and the level of apoptosis in each treatment group explain the variation in developmental competence among the groups. Significantly higher level of apoptosis was observed in the serum starvation group. On the other hand, the roscovitine treatment group shows the lowest level of apoptosis and the best in vitro development among the groups. Cloned embryos derived from roscovitine-treated donor cells were transferred to surrogate pigs. Three healthy live piglets were produced. In conclusion, we suggest that roscovitine treatment of donor cells improves development of cloned porcine embryos and can raise the efficiency of cloned piglet production.
Collapse
Affiliation(s)
- H J Park
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
28
|
Lee HJ, Lee BC, Kim YH, Paik NW, Rho HM. Characterization of Transgenic Pigs That Express Human Decay Accelerating Factor and Cell Membrane-tethered Human Tissue Factor Pathway Inhibitor. Reprod Domest Anim 2011; 46:325-32. [DOI: 10.1111/j.1439-0531.2010.01670.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
29
|
Ho CCK, Krishna KK, Praveen S, Goh EH, Lee BC, Zulkifli MZ. Proptosis: a rare presentation of metastatic renal cell carcinoma. Med J Malaysia 2010; 65:229-230. [PMID: 21939176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a case of a middle-aged man who was incidentally found to have right renal solid mass while investigating for his left eye proptosis. Computerised tomography (CT) scan confirmed the diagnosis of renal cell carcinoma and the tumour was successfully excised via open surgery. The histopathology examination revealed the 10x7x8 cm mass to be a clear cell type renal cell carcinoma. The rare presentation of this metastatic renal cell carcinoma, its diagnosis and management will be discussed.
Collapse
Affiliation(s)
- C C K Ho
- Urology Unit, Department of Surgery, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia.
| | | | | | | | | | | |
Collapse
|
30
|
Ho CCK, Hafidzul J, Praveen S, Goh EH, Bong JJ, Lee BC, Zulkifli MZ. Retrograde intrarenal surgery for renal stones smaller than 2 cm. Singapore Med J 2010; 51:512-515. [PMID: 20658113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Extracorporeal shock wave lithotripsy (ESWL) is accepted as the gold standard treatment for renal stones that are smaller than 2 cm. Recently, retrograde intrarenal surgery (RIRS) has been introduced as another form of treatment. We report our experience in dealing with renal stones smaller than 2 cm using RIRS as the primary treatment and following failed ESWL. METHODS A retrospective analysis was conducted over a five-year period on patients with stone(s) measuring less than 2 cm each and who had undergone RIRS. The patients were divided into two groups: RIRS as the primary procedure and RIRS post-ESWL. RESULTS A total of 46 patients underwent RIRS in our institute. The total stone clearance rate was 61 percent. The clearance rate was better for RIRS as the primary procedure when compared to RIRS as an adjunct procedure (70 percent versus 52 percent; p-value is 0.23). Patients with mid-pole stones achieved an 80 percent stone clearance rate as compared to 60 percent for those with lower pole stones. The clearance rate for upper pole stones was only 29 percent. When RIRS was the primary procedure for lower pole stones, the success rate was 75 percent, compared to 56 percent when it was used as an adjunct procedure post-ESWL. CONCLUSION For renal stones measuring less than 2 cm, the stone clearance rate for RIRS was as good as that for EWSL as a primary procedure and achieved a good clearance rate following the failure of ESWL.
Collapse
Affiliation(s)
- C C K Ho
- Department of Surgery, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Cheras, Kuala Lumpur, Malaysia.
| | | | | | | | | | | | | |
Collapse
|
31
|
Kim MJ, Oh HJ, Park JE, Hong SG, Kang JT, Koo OJ, Kang SK, Jang G, Lee BC. Influence of oocyte donor and embryo recipient conditions on cloning efficiency in dogs. Theriogenology 2010; 74:473-8. [PMID: 20452009 DOI: 10.1016/j.theriogenology.2010.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 01/26/2010] [Accepted: 03/07/2010] [Indexed: 11/16/2022]
Abstract
To determine factors that affect the efficiency of dog cloning by somatic cell nuclear transfer, the present study was performed to investigate 1) the effects of surgical history (non-operated/operated) and parity (nullipara/multipara) on the recovery of in vivo canine oocytes; 2) the effects of surgical history and parity of recipients on the pregnancy and delivery; and 3) the effects of synchronization state (AA, advanced asynchrony; SY, synchrony; RA, retarded asynchrony) between oocytes donor and recipient on the pregnancy and delivery. Oocyte recovery rate was significantly higher in non-operated dogs compared to operated dogs (93.8 vs. 89.6%, P < 0.05) and not different between nulliparous dogs and multiparous dogs. Delivery rate was also significantly higher in non-operated dogs compared to operated dogs (2.8 vs. 1.0%, P < 0.05) and in nulliparous dogs than multiparous dogs (3.0 vs. 1.7%, P < 0.05). Even though SY showed increased pregnancy and delivery rate (20.0% and 3.0%) compared to AA (15.0% and 2.0%) and RA (0.0% and 0.0%), there was no significant difference. In conclusion, we recommend non-operated dogs as experimental dogs and nulliparous dogs as recipient dogs to increase delivery rate after transfer of somatic cell nuclear transferred embryos, but further study is needed to find out appropriate synchrony status at the transfer.
Collapse
Affiliation(s)
- M J Kim
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, 151-742, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Kim JY, Kim SY, Kim JM, Kim YK, Yoon KY, Kim JY, Lee BC, Kim JS, Paek SH, Park SS, Kim SE, Jeon BS. Spinocerebellar ataxia type 17 mutation as a causative and susceptibility gene in parkinsonism. Neurology 2009; 72:1385-9. [PMID: 19380697 DOI: 10.1212/wnl.0b013e3181a18876] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate the role of spinocerebellar ataxia type 17 (SCA17) in the development of parkinsonism. METHOD We screened 1,155 parkinsonian patients (931 with Parkinson disease and 224 with multiple system atrophy) and 400 normal subjects for SCA17. 99mTc-TRODAT-1 SPECT was used to evaluate the striatal dopamine transporter (DAT) status. RESULTS Trinucleotide expansion in the SCA17 gene was found in 10 parkinsonian patients (8 with Parkinson disease, 2 with multiple system atrophy) using 42 repeats as an upper normal limit. The repeat sizes in the patients ranged from 43 to 46, which are considered to be low-range expansions. All patients had interrupted sequences. Three probands and three asymptomatic carriers underwent 99mTc-TRODAT-1 SPECT. Striatal DAT binding was markedly reduced in all probands and mildly decreased in one asymptomatic carrier. Among the 400 normal control subjects, there was one individual with an expansion of 44 repeats, another with 43 repeats, and two with 42 repeats. Striatal DAT binding was decreased not only in the control subjects with 44 or 43 repeats, but in ones with 42 repeats, suggesting that an expansion as low as 42 repeats might constitute a susceptibility gene for parkinsonism. CONCLUSIONS Low-range expansion of the SCA17 gene is not a rare genetic cause of parkinsonism without ataxia in our population. Reduced penetrance or variable expressivity in low-range expansion might be an explanation for the blurred cutoff point for normal expansion in SCA17.
Collapse
Affiliation(s)
- J-Y Kim
- Department of Neurology, Neuroscience Research Institute, Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Park JE, Oh HJ, Hong SG, Jang G, Kim MK, Lee BC. Effects of activin A on the in vitro development and mRNA expression of bovine embryos cultured in chemically-defined two-step culture medium. Reprod Domest Anim 2008; 45:585-93. [PMID: 19090825 DOI: 10.1111/j.1439-0531.2008.01306.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of the present study was to evaluate the effects of activin A on the developmental competence of in vitro fertilized (IVF) bovine embryos derived from a two-step defined culture system (C1/C2 medium) during the early or later stages of embryo development. To evaluate the effects of activin A on transcriptional levels, we analysed genes related to blastocyst hatching and implantation and to activin signalling pathway in IVF embryos. Cumulus-oocyte complexes were matured for 22 h and fertilized in vitro. Presumptive zygotes were cultured in the presence or absence of activin A during early (0-120 h, C1) or later (120-192 h, C2) stages. Although the developmental competence of embryos cultured with activin A in C1 medium was not significantly different from their corresponding controls, development to blastocysts (22.4% vs 34.7%; p < 0.05) and the blastocyst hatching rate (9.3% vs 22.4%; p < 0.05) in C2 medium supplemented with 100 ng/ml activin A were significantly higher than in the control group. To evaluate the effect of activin A on transcription, the relative expression levels of genes related to blastocyst hatching and implantation (Na/K-ATPase, E-cad and Glut-1) as well as activin signalling pathway (ActRII, ActRIIB and Smad2) were analysed. Compared to control medium, gene expression of Na/K-ATPase, E-cad, Glut-1, ActRII and ActRIIB was increased in medium supplemented with activin A. In conclusion, this study suggests that activin A, during the later stage of in vitro bovine embryo development, can enhance in vitro development of embryos by increasing hatching rates and affecting expression levels of genes related to hatching and implantation in defined culture medium.
Collapse
Affiliation(s)
- J E Park
- Department of Theriogenology and Biotechnology, SeoulNational University, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
34
|
Lee BC, Soh KS. Contrast-enhancing optical method to observe a Bonghan duct floating inside a lymph vessel of a rabbit. Lymphology 2008; 41:178-185. [PMID: 19306664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Novel threadlike structures, so-called Bonghan ducts (BHDs), were recently rediscovered inside large caliber lymphatic vessels using two different staining dyes in rabbits (Janus green B and Alcian blue) and fluorescent nanoparticles in rats. These three methods have the drawback of injecting chemical agents into the lymphatic vessels, which might damage the BHD and hinder further investigation of its physiological function. New methods to observe BHDs without using external chemical agents need to be developed. In the present work, we introduce a contrast enhancing optical method for in vivo observation of BHDs floating inside large caliber lymph vessels. The method uses a low-pass filter above about 650 nm, with an arrangement to minimize the light reflected from the surface of the lymph vessel. We captured films showing movement of a BHD as the animal respired. Applying the previous Alcian blue injection technique, we obtained BHD samples from the lymph vessel and observed the distribution of rod-shape nuclei (the essential feature of a BHD). BHDs can now be observed inside lymph vessels by using contrast-enhancing instrumentation without visualizing chemical agents.
Collapse
Affiliation(s)
- B C Lee
- Biomedical Physics Laboratory, Frontier Physics Research Division, Seoul National University, Seoul, Korea
| | | |
Collapse
|
35
|
Kim TN, Balakrishnan A, Lee BC, Kim WS, Dvorankova B, Smetana K, Park JK, Panigrahi BB. In vitro fibroblast response to ultra fine grained titanium produced by a severe plastic deformation process. J Mater Sci Mater Med 2008; 19:553-7. [PMID: 17619956 DOI: 10.1007/s10856-007-3204-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Accepted: 06/06/2007] [Indexed: 05/16/2023]
Abstract
The in vitro response of the mouse fibroblast cell line 3T3 on the surface of ultrafine grained titanium [produced by a severe plastic deformation (SPD) process] has been studied in this work. SPD Ti showed much higher strength than the coarse grained Ti and equivalent to that of Ti-6Al-4V alloy. Better cell proliferation was observed on SPD Ti compared to conventional Ti and Ti-6Al-4V alloy. This could be attributed to the increased surface free energy by reduction in the grain size and possibly the presence of a large number of nano size grooves at the triple point junctions in SPD Ti sample. There was no significant difference in the results of cytotoxicity tests of fine and coarse grained materials.
Collapse
Affiliation(s)
- Taik Nam Kim
- Department of Information and Electronic Materials Engineering, Paichai University, Daejeon, Korea.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Kim MK, Jee H, Shin SW, Lee BC, Pakhrin B, Yoo HS, Yoon JH, Kim DY. Outbreak and control of haemorrhagic pneumonia due to Streptococcus equi subspecies zooepidemicus in dogs. Vet Rec 2007; 161:528-30. [PMID: 17938413 DOI: 10.1136/vr.161.15.528] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- M K Kim
- Department of Veterinary Theriogenology, College of Veterinary Medicine, Seoul National University, 151-742, Seoul, Korea
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Lee S, Kim MS, Kim JS, Park HJ, Woo JS, Lee BC, Hwang SJ. Controlled delivery of a hydrophilic drug from a biodegradable microsphere system by supercritical anti-solvent precipitation technique. J Microencapsul 2007; 23:741-9. [PMID: 17123918 DOI: 10.1080/09687860600945552] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The purpose of this study was to prepare microspheres loaded with hydrophilic drug, bupivacaine HCl using poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(L-lactic acid) (PLLA). Microspheres were prepared with varying the PLGA/PLLA ratio with two different levels of bupivacaine HCl (5 and 10%) using a supercritical anti-solvent (SAS) technique. Microspheres ranging from 4-10 microm in geometric mean diameter could be prepared, with high loading efficiency. Powder X-ray diffraction (PXRD) revealed that bupivacaine HCl retained its crystalline state within the polymer and was present as a dispersion within the polymer phase after SAS processing. The release of bupivacaine HCl from biodegradable polymer microspheres was rapid up to 4 h, thereafter bupivacaine HCl was continuously and slowly released for at least 7 days according to the PLGA/PLLA ratio and the molecular weight of PLLA.
Collapse
Affiliation(s)
- S Lee
- National Research Lab of Pharmaceutical Technology, College of Pharmacy, Chungnam National University, Daejeon, Korea
| | | | | | | | | | | | | |
Collapse
|
38
|
Jang G, Oh HJ, Kim MK, Fibrianto YH, Hossein MS, Kim HJ, Kim JJ, Hong SG, Park JE, Kang SK, Lee BC. Improvement of canine somatic cell nuclear transfer procedure. Theriogenology 2007; 69:146-54. [PMID: 17949804 DOI: 10.1016/j.theriogenology.2007.08.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 05/21/2007] [Accepted: 08/08/2007] [Indexed: 10/22/2022]
Abstract
The purpose of the present study on canine somatic cell nuclear transfer (SCNT) was to evaluate the effects of fusion strength, type of activation, culture media and site of transfer on developmental potential of SCNT embryos. We also examined the potential of enucleated bovine oocytes to serve as cytoplast recipients of canine somatic cells. Firstly, we evaluated the morphological characteristics of in vivo-matured canine oocytes collected by retrograde flushing of the oviducts 72 h after ovulation. Secondly, the effectiveness of three electrical strengths (1.8, 2.3 and 3.3 kV/cm), used twice for 20 micros, on fusion of canine cytoplasts with somatic cells were compared. Then, we compared: (1) chemical versus electrical activation (a) after parthenogenetic activation or (b) after reconstruction of canine oocytes with somatic cells; (2) culture of resulting intergeneric (IG) embryos in either (a) mSOF or (b) TCM-199. The exposure time to 6-DMAP was standardized by using bovine oocytes reconstructed with canine somatic cells. Bovine oocytes were used for SCNT after a 22 h in vitro maturation interval. The fusion rate was significantly higher in the 3.3 kV/cm group than in the 1.8 and 2.3 kV/cm treatment groups. After parthenogenesis or SCNT with chemical activation, 3.4 and 5.8%, respectively, of the embryos developed to the morula stage, as compared to none of the embryos produced using electrical activation. Later developmental stages (8-16 cells) were transferred to the uterine horn of eight recipients, but no pregnancy was detected. However, IG cloned embryos (bovine cytoplast/canine somatic cell) were capable of in vitro blastocyst development. In vitro developmental competence of IG cloned embryos was improved after exposure to 6-DMAP for 4 h as compared to 0, 2 or 6h exposure, although the increase was not significantly different among culture media. In summary, for production of canine SCNT embryos, we recommend fusion at 3.3 kV/cm, chemical activation, culture in mSOF medium and transfer of presumptive zygotes to the oviduct of recipient animals. The feasibility of IG production of cloned canine embryos using bovine cytoplasts as recipient of canine somatic cells was demonstrated.
Collapse
Affiliation(s)
- G Jang
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Kim TN, Balakrishnan A, Lee BC, Kim WS, Smetana K, Park JK, Panigrahi BB. In vitro
biocompatibility of equal channel angular processed (ECAP) titanium. Biomed Mater 2007; 2:S117-20. [DOI: 10.1088/1748-6041/2/3/s06] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
40
|
Lee S, Lee BC, Lee KY, Lee SH, Iwamoto M. Phosphate sorption characteristics of zirconium meso-structure synthesized under different conditions. Environ Technol 2007; 28:785-92. [PMID: 17674652 DOI: 10.1080/09593332808618839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In this study, the phosphate sorption characteristics of zirconium meso-structures synthesized under different conditions were estimated. X-ray diffraction analysis, phosphate sorption isotherm test and kinetic test were performed for the zirconium meso-structures, synthesized at different inorganics/surfactant molar ratio and with different surfactant (C(x)TMA-Br) templates. From the test results, it was found that at the inorganic/surfactant molar ratio of 1/0.50 the meso-pores in the material were most uniformly and clearly formed and thus the sorption capacity and reaction rate of material were maximized. The pore size in meso-structure decreased with the increase in chain length of surfactant template used, and maximum phosphate sorption amount and reaction rate were achieved in the zirconium mesostructure synthesized with the surfactant of dodecyltrimethylammonium bromide (C12TMA-Br).
Collapse
Affiliation(s)
- S Lee
- Water Environment and Remediation Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea
| | | | | | | | | |
Collapse
|
41
|
Neo EN, Zulkifli Z, Sritharan S, Lee BC, Nazri J. Renal autotransplantation after an latrogenic left ureteric injury. Med J Malaysia 2007; 62:164-165. [PMID: 18705455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report a case of renal autotransplantation performed successfully for an iatrogenic ureteric injury with loss of 9 cm of ureteric length. The surgical options available for management of ureteric injuries are discussed, varying from a simple re-anastomosis to the more complex renal autotransplantation.
Collapse
Affiliation(s)
- E N Neo
- Department of Surgery, Faculty of Medicine, Universiti Kebangsaan Malaysia Hospital, Jalan Yaacob Latif, Bandar Tun Razak, Kuala Lumpur
| | | | | | | | | |
Collapse
|
42
|
Lee KI, Joo SJ, Lee JH, Rhie K, Kim TS, Lee WY, Shin KH, Lee BC, LeClair P, Lee JS, Park JH. Kondo effect in magnetic tunnel junctions. Phys Rev Lett 2007; 98:107202. [PMID: 17358561 DOI: 10.1103/physrevlett.98.107202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Indexed: 05/14/2023]
Abstract
Tunneling magnetoresistance was found to be suppressed with decreasing temperature for magnetic tunnel junctions (MTJs) oxidized under high plasma power. A strong temperature dependence of the junction resistance was observed, along with zero-bias anomalies of dynamic resistance at low temperatures. Resistance shows a logarithmic dependence on temperature, and resistance versus temperature exhibits a scaling behavior. Our experimental data can be explained in a consistent way by the Kondo effect in the MTJs with the Kondo temperature TK=20-30 K.
Collapse
Affiliation(s)
- K I Lee
- Nano Device Research Center, Korea Institute of Science and Technology, Seoul 136-792, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Bhuiyan MMU, Kang SK, Lee BC. Effects of fructose supplementation in chemically defined protein-free medium on development of bovine in vitro fertilized embryos. Anim Reprod Sci 2007; 102:137-44. [PMID: 17367961 DOI: 10.1016/j.anireprosci.2007.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2006] [Revised: 01/30/2007] [Accepted: 02/16/2007] [Indexed: 10/23/2022]
Abstract
The present study evaluated the possible embryotrophic role of fructose supplementation in potassium simplex optimization medium (KSOM) on preimplantation development of bovine in vitro matured and fertilized (IVF) embryos under chemically defined conditions. In Experiment 1, the rates of cleavage (74.0-75.5%) and blastocyst formation (21.0-24.5%) were not affected by the supplementation of fructose in KSOM in absence or presence of glucose. In Experiment 2, the rates of cleavage (71.7-77.3%) and blastocyst formation (19.9-26.3%) did not differ significantly among the concentrations (0.0, 0.2, 1.5, 3.0, 5.6mM) of fructose supplementations in KSOM in presence of glucose. Moreover, the number of total ICM and TE cells, and percentage of ICM to total cell in blastocysts did not differ significantly among the concentrations of fructose supplementations in presence of glucose. In Experiment 3, the rates of cleavage (67.3-74.7%) and blastocyst formation (14.4-19.3%) did not differ significantly among the concentrations (0.0, 0.2, 1.5, 3.0, 5.6mM) of fructose supplementations in KSOM in absence of glucose. Although the number of total and ICM cells, and percentage of ICM to total cells in blastocysts did not differ significantly among the concentrations of fructose supplementations, 1.5mM fructose supplementation in absence of glucose had significantly (P<0.05) higher number of TE cells (106.2) than that of 5.6mM (84.0) supplementation. The study indicates that, fructose up to 5.6mM concentration can be used as an alternative for energy substrate in culture media without any detrimental effect on pre-implantation development in bovine IVF embryos.
Collapse
Affiliation(s)
- M M U Bhuiyan
- Laboratory of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Republic of Korea.
| | | | | |
Collapse
|
44
|
Yoon BW, Bae HJ, Hong KS, Lee SM, Park BJ, Yu KH, Han MK, Lee YS, Chung DK, Park JM, Jeong SW, Lee BC, Cho KH, Kim JS, Lee SH, Yoo KM. Phenylpropanolamine contained in cold remedies and risk of hemorrhagic stroke. Neurology 2007; 68:146-9. [PMID: 17210897 DOI: 10.1212/01.wnl.0000250351.38999.f2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this study, we sought to elucidate whether phenylpropanolamine (PPA) in cold remedies (small and divided doses) increases the risk of hemorrhagic stroke (HS). PPA exposure significantly increased the risk, and the risk was much higher in women. In women, linear trends were also found in recency, duration, and dosage of PPA exposure. PPA contained in cold remedies increases the risk of HS, particularly in women.
Collapse
Affiliation(s)
- B W Yoon
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, 110-744, Republic of Korea.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Kim HK, Kim JM, Lee YJ, Kim BI, Lee BC, Chang NI. Vertical profile of algal distribution during aeration prior to intake tower for safe drinking water. Water Sci Technol 2007; 55:321-7. [PMID: 17305156 DOI: 10.2166/wst.2007.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Blue-green algae or cyanobacteria comprise a diverse group of organisms, all of which generate potent natural toxins, as well as characteristic odours. In particular, blue-green algae, such as Microcystis and Anabaena, are often detected abundantly in surface water used as a drinking water resource. In order to confirm our ability to provide safe drinking water even during a water bloom, we have conducted an investigation into the vertical distribution of algae during aeration prior to entry into the intake tower at a dam site. Our analysis of the vertical algal distribution during aeration indicated that aeration occurring at the intake tower exerts a significant influence on the safety of the drinking water. It was determined that the discontinuation of aeration and an increase in the depth at which water intake is conducted, constitutes a viable strategy for the maintenance of toxin- and odour-free drinking water, particularly during water bloom events.
Collapse
Affiliation(s)
- H K Kim
- Youngsan River Water Research Lab., National Institute of Environmental Research, 1110-8 Oryong-dong Buk-gu, Gwangju 500-480, Korea.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
The goal of the "Safety Training for Employers and Supervisors of Adolescent Farmworkers" initiative is to improve the occupational health and safety knowledge and practices of agricultural employers and supervisors responsible for employees, ages 14 to 17 years. Surveys were sent to members of the National Council of Agricultural Employers and the Washington Growers League to measure attitudes regarding adolescent employees, current hiring and training practices, and future intentions. More than half of the respondents hire adolescents. Two-thirds were male, nearly three-quarters of the respondents had college or post-graduate degrees, and more than half were 50 years or older. The majority of respondents had positive perceptions of adolescents in terms of dependability, helpfulness, and work ethic. Among those who currently hire young workers, the most common reasons were to provide a job for children of friends and family and because they can work part-time to fill a labor demand. Among those not hiring adolescents, the most common reason was concern about child labor regulations and associated tasks (e.g., paperwork, monitoring hours). Respondents use a variety of safety training resources, especially posters and safety meetings. For the future, they expect to need more handout materials and training videos. Study results provide insights into barriers to the employment of young workers and suggest methods by which agricultural safety specialists can best assist those employers and producers who are willing to hire adolescents into agricultural work settings.
Collapse
Affiliation(s)
- B C Lee
- Marshfield Clinic Research Foundation, Marshfield, Wisconsin 54449, USA.
| | | | | | | |
Collapse
|
47
|
Kim HK, Lee BC, Kim SD, Kamei T, Magara Y. Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters. Water Sci Technol 2007; 55:315-20. [PMID: 17305155 DOI: 10.2166/wst.2007.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.
Collapse
Affiliation(s)
- H K Kim
- Youngsan River water Research Lab., National Institute of Environmental Research, 1110-8 Oryong-dong, Buk-gu, Gwangju 500-480, Korea
| | | | | | | | | |
Collapse
|
48
|
Lee SH, Lee BC, Lee KW, Lee SH, Choi YS, Park KY, Iwamoto M. Phosphorus recovery by mesoporous structure material from wastewater. Water Sci Technol 2007; 55:169-76. [PMID: 17305137 DOI: 10.2166/wst.2007.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This study was designed to investigate the fundamental aspects of a possible removal of phosphorous from wastewater by using the mesoporous structure materials for wastewater reuse. The zirconium sulphate with mesoporous structure as a new type of ion exchangers was synthesised by hydrothermal reaction. From the results of X-ray diffraction and transmission electron microscope, it was discovered that the synthesised material had hexagonal mesoporous structure with a pore size of approximately 40-50A. Experimental results showed that the zirconium sulphate with mesoporous structure had very high sorption capacity for the phosphorus. The novel ion exchange occurred between PO4(3-) and SO4(2-), OH-. The amount of phosphate ions exchanged into the solid was as great as 3.4 mmol/g-ZS. Furthermore, it is possible to obtain a higher removal efficiency than other ion exchange media and adsorbents.
Collapse
Affiliation(s)
- S H Lee
- Water Environment & Remediation Center, Korea Institute of Science & Technology, Cheongryang, Seoul 130-650, Korea.
| | | | | | | | | | | | | |
Collapse
|
49
|
Jang G, Kim MK, Oh HJ, Hossein MS, Fibrianto YH, Hong SG, Park JE, Kim JJ, Kim HJ, Kang SK, Kim DY, Lee BC. Birth of viable female dogs produced by somatic cell nuclear transfer. Theriogenology 2006; 67:941-7. [PMID: 17169419 DOI: 10.1016/j.theriogenology.2006.11.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2006] [Accepted: 11/03/2006] [Indexed: 11/20/2022]
Abstract
Since the only viable cloned offspring born in dogs was a male, the purpose of the present study was to produce female puppies by somatic cell nuclear transfer (SCNT). Adult ear fibroblasts from a 2-month-old female Afghan hound were isolated and used as donor cells. In vivo-matured canine oocytes surgically collected (approximately 72h after ovulation) from the oviducts of 23 donors were used for SCNT. After removal of the cumulus cells, oocytes were enucleated, microinjected, fused with a donor cell, and activated. A total of 167 reconstructed SCNT embryos were surgically transferred (Day 0) into the oviducts of 12 recipient bitches (average 13.9 embryos/recipient, range 6-22) with spontaneous, synchronous estrous cycles. Three pregnancies were detected by ultrasonography on Day 23, maintained to term, and three healthy female puppies (520, 460, and 520g), were delivered by Caesarean section on Day 60. These puppies were phenotypically and genotypically identical to the cell donor. In conclusion, we have provided the first demonstration that female dogs can be produced by nuclear transfer of ear fibroblasts into enucleated canine oocytes.
Collapse
Affiliation(s)
- G Jang
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Ahn GJ, Sohn YS, Kang KK, Ahn BO, Kwon JW, Kang SK, Lee BC, Hwang WS. Erratum: The effect of PDE5 inhibition on the erectile function in streptozotocin-induced diabetic rats. Int J Impot Res 2006. [DOI: 10.1038/sj.ijir.3901474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|