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Chong S, Mu GY, Xiang Q, Cui YM. [The role of proprotein convertase subtilisin/kexin 9 in thrombosis]. Zhonghua Xin Xue Guan Bing Za Zhi 2024; 52:215-219. [PMID: 38326076 DOI: 10.3760/cma.j.cn112148-20231007-00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Affiliation(s)
- S Chong
- Department of Pharmacy, Peking University First Hospital, Beijing 100034, China
| | - G Y Mu
- Department of Pharmacy, Peking University First Hospital, Beijing 100034, China
| | - Q Xiang
- Department of Pharmacy, Peking University First Hospital, Beijing 100034, China
| | - Y M Cui
- Department of Pharmacy, Peking University First Hospital, Beijing 100034, China
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2
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Chan AW, Brem AG, Abd Rahim MH, Numpang A, Chong S. The Four Pillars for De-Risking Fluid Loss Potential Along Fault Damage Zone: A Framework for Well Designs and Drilling Operations. All Days 2022. [DOI: 10.56952/arma-2022-0197] [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] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
ABSTRACT:
Fluid loss along faults can pose significant operational challenges from drilling & completing wells to maintaining containment during fluid injection. While faults and fractures can be ubiquitous in the subsurface, not all of them pose the same threats to hydrocarbon extraction activities. During a drilling campaign in semi-consolidated deepwater clastics, a generic link between faults, fluid loss events, fluid circulation pressure and the fault strength parameters was established. In order to reduce the risks of fault-induced fluid loss along any proposed well path in future drilling campaigns, we developed and successfully implemented an integrated screening method that incorporates the observed correlation. The de-risking framework includes four elements (Geological, Geometrical, Mechanical and Dynamic considerations): Geological consideration highlighted the lithological influence on fault zone architecture and the confidence level on fault presences; Meanwhile, the placement of a well path relative to fault(s) will affect the exposure to potential leak paths; Thirdly, mechanical threshold of a fault will change the safe operation margin; And lastly, dynamic interaction between fluid and the fault zone during operation can alter fluid loss potential. Our proposed framework provides subsurface geoscientists and well engineers an efficient tool to quickly rank the integrated threats of fault-induced lost circulation to improve well design, optimize drilling and completion strategy along with appropriate level of mitigation and recovery measures. Unlike typical fault stability analyses that are primarily based on static fault zone architecture and/or stress-based slip potential, the integration and incorporation of engineering activities offers the missing link to de -risk and mitigate the threats posed by along fault fluid migration potential. With minor modifications, this framework can be extended for risk assessments related to containments, caprock or seal integrity evaluations related to other activities such as exploration, enhanced oil recovery or carbon capture and sequestration.
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McGaw C, Garrity AJ, Munoz GZ, Haswell JR, Sengupta S, Keston-Smith E, Hunnewell P, Ornstein A, Bose M, Wessells Q, Jakimo N, Yan P, Zhang H, Alfonse LE, Ziblat R, Carte JM, Lu WC, Cerchione D, Hilbert B, Sothiselvam S, Yan WX, Cheng DR, Scott DA, DiTommaso T, Chong S. Engineered Cas12i2 is a versatile high-efficiency platform for therapeutic genome editing. Nat Commun 2022; 13:2833. [PMID: 35595757 PMCID: PMC9122993 DOI: 10.1038/s41467-022-30465-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/03/2022] [Indexed: 12/11/2022] Open
Abstract
The CRISPR-Cas type V-I is a family of Cas12i-containing programmable nuclease systems guided by a short crRNA without requirement for a tracrRNA. Here we present an engineered Type V-I CRISPR system (Cas12i), ABR-001, which utilizes a tracr-less guide RNA. The compact Cas12i effector is capable of self-processing pre-crRNA and cleaving dsDNA targets, which facilitates versatile delivery options and multiplexing, respectively. We apply an unbiased mutational scanning approach to enhance initially low editing activity of Cas12i2. The engineered variant, ABR-001, exhibits broad genome editing capability in human cell lines, primary T cells, and CD34+ hematopoietic stem and progenitor cells, with both robust efficiency and high specificity. In addition, ABR-001 achieves a high level of genome editing when delivered via AAV vector to HEK293T cells. This work establishes ABR-001 as a versatile, specific, and high-performance platform for ex vivo and in vivo gene therapy.
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Affiliation(s)
- Colin McGaw
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Anthony J Garrity
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Gabrielle Z Munoz
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Jeffrey R Haswell
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Sejuti Sengupta
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Elise Keston-Smith
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | | | - Alexa Ornstein
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Mishti Bose
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Quinton Wessells
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Noah Jakimo
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Paul Yan
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Huaibin Zhang
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Lauren E Alfonse
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Roy Ziblat
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Jason M Carte
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Wei-Cheng Lu
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Derek Cerchione
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Brendan Hilbert
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | | | - Winston X Yan
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - David R Cheng
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - David A Scott
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Tia DiTommaso
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA.
| | - Shaorong Chong
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
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Wadhwa M, Kang HN, Thorpe R, Knezevic I, Aprea P, Bielsky MC, Ekman N, Heim HK, Joung J, Kurki P, Lacana E, Njue C, Nkansah E, Savkina M, Thorpe R, Yamaguchi T, Wadhwa M, Wang J, Weise M, Wolff-Holz E, Allam M, Bahaa H, Sayed M, Al-Oballi A, Alshahrani A, Baek D, Kim J, Chua H, Gangakhedkar J, Jagtap MP, Lyaskovsky T, Okudaira S, Ondee W, Sotomayor P, Ricra JS, Uviase J, Ahmed F, Rajendran Y, Defendi HT, Cho SO, Qu A, Acha V, Gencoglu M, Ho K, Baldrighi M, Schiestl M, Watson K, Spitzer E, Chong S, Fukushima A, Kang HN, Knezevic I, Pante G, Simao M. WHO informal consultation on revision of guidelines on evaluation of similar biotherapeutic products, virtual meeting, 30 June – 2 July 2021. Biologicals 2022; 76:1-9. [PMID: 35466023 PMCID: PMC9109723 DOI: 10.1016/j.biologicals.2022.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/28/2022] [Accepted: 03/29/2022] [Indexed: 11/26/2022] Open
Abstract
The WHO informal consultation was held to promote the revision of WHO guidelines on evaluation of similar biotherapeutic products (SBPs) adopted by the Expert Committee on Biological Standardization (ECBS) in 2009. It was agreed in the past consultations that the evaluation principles in the guidelines are still valid, but a review was recommended to provide more clarity and case-by-case flexibility. The opportunity was therefore taken to review the experience and identify areas where the current guidance could be more permissive without compromising its basic principles, and where additional explanation could be provided regarding the possibility of reducing the amount of data needed for regulatory approval. The meeting participants applauded the leading role taken by the WHO in providing a much-needed streamlined approach for development and evaluation of SBPs which will provide efficient and cost-effective product development and increase patient access to treatments. It was recognized that the principles as currently described in the draft WHO guidelines are based on sound science and experience gained over the last fifteen years of biosimilar approvals. However, since these guidelines when finalised will constitute the global standard for biosimilar evaluation and assist national regulatory authorities in establishing revised guidance and regulatory practice in this complex area, it was felt that further revision and clarity on certain perspectives in specific areas was necessary to dispel uncertainties arising in the current revised version. This report describes the principles in the draft guidelines, including topics discussed and consensus reached. WHO guidelines serve as a basis for the development of national regulatory framework for biosimilars. Revision of guidelines is to provide more flexibility and clarification on data required for regulatory approval. Revised guidelines would contribute to improving consistency on regulatory decision and patient access to treatments.
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Blaker K, Wijewardene A, White E, Stokes G, Chong S, Ganda K, Ridley L, Brown S, White C, Clifton-Bligh R, Seibel MJ. Electronic search programs are effective in identifying patients with minimal trauma fractures. Osteoporos Int 2022; 33:435-441. [PMID: 34510231 DOI: 10.1007/s00198-021-06105-z] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/16/2021] [Indexed: 11/24/2022]
Abstract
UNLABELLED We assessed two electronic search tools that screen medical records for documented fractures. Both programs reliably identified patients with any fracture but missed individuals with minimal trauma fracture to different degrees. A hybrid tool combining the methodology of both tools is likely to improve the identification of those with osteoporosis. PURPOSE Most patients who suffer a minimal trauma fracture remain undiagnosed, placing them at high risk of refracture. Case finding can be improved by electronic search tools that screen medical records for documented fractures. Here, we assessed the efficacy of two new programs, AES and XRAIT, in identifying patients with minimal trauma fracture. METHODS Each tool was applied to search the electronic medical record and/or radiology reports at two tertiary hospitals in Sydney, Australia, from 1 July to 31 December 2018. Samples of the extracted reports were then manually reviewed to determine the sensitivity of each program in detecting minimal trauma fractures. RESULTS At the two centers, AES detected 872 and 1364 cases, whereas XRAIT identified 1414 and 2180 patients with fractures, respectively. The true positive rate for "any fracture" was similar for both instruments (77-88%). However, the ability to detect "minimal trauma fractures" differed between programs and centers (53-75% accuracy), with each tool identifying separate subsets of patients. Concordance between both tools was less than half of the combined total number of minimal trauma fractures (43-45%). Considering the total number of minimal trauma fractures detected by both tools combined, AES correctly identified 52-55% of cases while XRAIT identified 88-93% of cases. CONCLUSION Both programs reliably identified patients with any fracture but missed individuals with minimal trauma fracture to different degrees. Hybrid tools combining the methodology of XRAIT and AES are likely to improve the identification of patients who require investigation and treatment for osteoporosis.
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Affiliation(s)
- K Blaker
- Department of Endocrinology & Metabolism, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia
| | - A Wijewardene
- Department of Endocrinology & Metabolism, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia.
- Department of Endocrinology, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia.
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - E White
- Department of Endocrinology, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia
| | - G Stokes
- Department of Endocrinology & Metabolism, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - S Chong
- Department of Endocrinology & Metabolism, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia
| | - K Ganda
- Department of Endocrinology & Metabolism, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
- Bone Research Program, ANZAC Research Institute, Concord, NSW, 2139, Australia
| | - L Ridley
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
- Department of Radiology, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia
| | - S Brown
- Abbot Diagnostics, Macquarie Park, NSW, 2113, Australia
| | - C White
- Department of Endocrinology & Metabolism, Prince of Wales Hospital, Randwick, NSW, 2031, Australia
| | - R Clifton-Bligh
- Department of Endocrinology, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
| | - M J Seibel
- Department of Endocrinology & Metabolism, Concord Repatriation General Hospital, Concord, NSW, 2139, Australia
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
- Bone Research Program, ANZAC Research Institute, Concord, NSW, 2139, Australia
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Abstract
Cell-free protein synthesis is a powerful tool to produce recombinant proteins, and as an open system, can often integrate all or part of downstream assays. Here we describe in vitro synthesis of the Streptococcus pyogenes type II-A CRISPR-Cas9 ribonucleoproteins (SpCas9 RNPs), consisting of the effector protein and the single guide RNAs (sgRNAs). In spite of its large molecular weight (160kDa), the SpCas9 effector is expressed relatively well from linear DNA templates under T7 promoter in commercial reconstituted cell-free protein synthesis systems. sgRNAs can be added before the effector synthesis reaction, or transcribed directly from linear DNA templates during the synthesis reaction. The newly synthesized SpCas9 effector forms an active RNP complex with sgRNAs. When a reconstituted cell-free system is used, the target DNA templates can also be added in the reactions, thereby combining CRISPR-Cas synthesis and activity assay.
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Affiliation(s)
- Colin McGaw
- Arbor Biotechnologies, Cambridge, MA, United States
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Choi B, Lasica M, Hare J, Chong S, Strachan L, Hocking J, Ting S, Gibbs S. 105 Diflunisal is Effective and Affordable Treatment in Transthyretin Cardiac Amyloidosis (ATTR-CM) - but Only Half of Patients can Tolerate It. Heart Lung Circ 2020. [DOI: 10.1016/j.hlc.2020.09.112] [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: 10/23/2022]
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Ding R, Hung KC, Mitra A, Ung LW, Lightwood D, Tu R, Starkie D, Cai L, Mazutis L, Chong S, Weitz DA, Heyman JA. Rapid isolation of antigen-specific B-cells using droplet microfluidics. RSC Adv 2020; 10:27006-27013. [PMID: 35515810 PMCID: PMC9055518 DOI: 10.1039/d0ra04328a] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/30/2020] [Indexed: 12/19/2022] Open
Abstract
Monoclonal antibodies are powerful tools for scientific research and are the basis of numerous therapeutics. However, traditional approaches to generate monoclonal antibodies against a desired target, such as hybridoma-based techniques and display library methods, are laborious and suffer from fusion inefficiency and display bias, respectively. Here we present a platform, featuring droplet microfluidics and a bead-based binding assay, to rapidly identify and verify antigen-binding antibody sequences from primary cells. We used a defined mixture of hybridoma cells to characterize the system, sorting droplets at up to 100 Hz and isolating desired hybridoma cells, comprising 0.1% of the input, with a false positive rate of less than 1%. We then applied the system to once-frozen primary B-cells to isolate rare cells secreting target-binding antibody. We performed RT-PCR on individual sorted cells to recover the correctly paired heavy- and light-chain antibody sequences, and we used rapid cell-free protein synthesis to generate single-chain variable fragment-format (scFv) antibodies from fourteen of the sorted cells. Twelve of these showed antigen-specific binding by ELISA. Our platform facilitates screening animal B-cell repertoires within days at low cost, increasing both rate and range of discovering antigen-specific antibodies from living organisms. Further, these techniques can be adapted to isolate cells based on virtually any secreted product. We use a droplet-microfluidics-based platform to rapidly identify and isolate individual primary cells that secrete desired antibodies. We then retrieve the antibody-encoding sequences and create recombinant antibodies that bind the target protein.![]()
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Affiliation(s)
- Ruihua Ding
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- Department of Chemistry and Chemical Biology
| | - Kuo-Chan Hung
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
| | - Anindita Mitra
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
| | - Lloyd W. Ung
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
| | | | - Ran Tu
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- CAS Key Laboratory of Systems Microbial Biotechnology
| | | | - Liheng Cai
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- Department of Materials Science and Engineering
| | - Linas Mazutis
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- Vilnius University
| | | | - David A. Weitz
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- Department of Physics
| | - John A. Heyman
- John A. Paulson School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
- SphereBio
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Choi B, Lasica M, Hare J, Chong S, Strachan L, Hocking J, Ting S, Gibbs S. 178 “The Giant Awakes” – Rapid Increases in the Diagnosis of Transthyretin (TTR) Amyloidosis After the ATTR-ACT Trial of Tafamidis. Heart Lung Circ 2020. [DOI: 10.1016/j.hlc.2020.09.185] [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: 11/25/2022]
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10
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Yan WX, Hunnewell P, Alfonse LE, Carte JM, Keston-Smith E, Sothiselvam S, Garrity AJ, Chong S, Makarova KS, Koonin EV, Cheng DR, Scott DA. Functionally diverse type V CRISPR-Cas systems. Science 2019; 363:88-91. [PMID: 30523077 DOI: 10.1126/science.aav7271] [Citation(s) in RCA: 260] [Impact Index Per Article: 52.0] [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: 10/14/2018] [Accepted: 11/20/2018] [Indexed: 01/05/2024]
Abstract
Type V CRISPR-Cas systems are distinguished by a single RNA-guided RuvC domain-containing effector, Cas12. Although effectors of subtypes V-A (Cas12a) and V-B (Cas12b) have been studied in detail, the distinct domain architectures and diverged RuvC sequences of uncharacterized Cas12 proteins suggest unexplored functional diversity. Here, we identify and characterize Cas12c, -g, -h, and -i. Cas12c, -h, and -i demonstrate RNA-guided double-stranded DNA (dsDNA) interference activity. Cas12i exhibits markedly different efficiencies of CRISPR RNA spacer complementary and noncomplementary strand cleavage resulting in predominant dsDNA nicking. Cas12g is an RNA-guided ribonuclease (RNase) with collateral RNase and single-strand DNase activities. Our study reveals the functional diversity emerging along different routes of type V CRISPR-Cas evolution and expands the CRISPR toolbox.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Ziblat R, Weaver JC, Arriaga LR, Chong S, Weitz DA. Determining the lipid specificity of insoluble protein transmembrane domains. Lab Chip 2018; 18:3561-3569. [PMID: 30406786 DOI: 10.1039/c8lc00311d] [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: 06/08/2023]
Abstract
While the specificity of protein-lipid interactions is a key feature in the function of biological membranes, studying the specifics of these interactions is challenging because most membrane proteins are insoluble in water due to the hydrophobic nature of their transmembrane domains (TMDs). Here, we introduce a method that overcomes this solubility limitation and identifies the affinity profile of protein TMDs to specific lipid formulations. Using 5 human TMDs as a sample group, our results demonstrate that TMDs are highly selective and that these specific lipid-TMD interactions can involve either a single lipid, or the combination of multiple lipid species.
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Affiliation(s)
- R Ziblat
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
| | - J C Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA
| | - L R Arriaga
- Department of Physical Chemistry, Universidad Complutense, Madrid, 28040, Spain
| | - S Chong
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - D A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. and Department of Physics, Harvard University, Cambridge, MA02138, USA
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12
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Woo S, Brenner N, Chong S, Benz P, Dubin J, Wilson M, Thorne J, Goyal M. 239 Advance Care Planning Among Patients With In-Hospital Cardiac Arrest. Ann Emerg Med 2018. [DOI: 10.1016/j.annemergmed.2018.08.244] [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: 11/16/2022]
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13
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Yan WX, Chong S, Zhang H, Makarova KS, Koonin EV, Cheng DR, Scott DA. Cas13d Is a Compact RNA-Targeting Type VI CRISPR Effector Positively Modulated by a WYL-Domain-Containing Accessory Protein. Mol Cell 2018; 70:327-339.e5. [PMID: 29551514 PMCID: PMC5935466 DOI: 10.1016/j.molcel.2018.02.028] [Citation(s) in RCA: 278] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 12/21/2022]
Abstract
Bacterial class 2 CRISPR-Cas systems utilize a single RNA-guided protein effector to mitigate viral infection. We aggregated genomic data from multiple sources and constructed an expanded database of predicted class 2 CRISPR-Cas systems. A search for novel RNA-targeting systems identified subtype VI-D, encoding dual HEPN domain-containing Cas13d effectors and putative WYL-domain-containing accessory proteins (WYL1 and WYL-b1 through WYL-b5). The median size of Cas13d proteins is 190 to 300 aa smaller than that of Cas13a-Cas13c. Despite their small size, Cas13d orthologs from Eubacterium siraeum (Es) and Ruminococcus sp. (Rsp) are active in both CRISPR RNA processing and targeting, as well as collateral RNA cleavage, with no target-flanking sequence requirements. The RspWYL1 protein stimulates RNA cleavage by both EsCas13d and RspCas13d, demonstrating a common regulatory mechanism for divergent Cas13d orthologs. The small size, minimal targeting constraints, and modular regulation of Cas13d effectors further expands the CRISPR toolkit for RNA manipulation and detection.
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MESH Headings
- Amino Acid Sequence
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- CRISPR-Associated Proteins/chemistry
- CRISPR-Associated Proteins/genetics
- CRISPR-Associated Proteins/metabolism
- CRISPR-Cas Systems
- Clustered Regularly Interspaced Short Palindromic Repeats
- Databases, Genetic
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Eubacterium/enzymology
- Eubacterium/genetics
- Gene Editing/methods
- Gene Expression Regulation, Bacterial
- Nucleic Acid Conformation
- Protein Domains
- Protein Structure, Secondary
- RNA Processing, Post-Transcriptional
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Guide, CRISPR-Cas Systems/genetics
- RNA, Guide, CRISPR-Cas Systems/metabolism
- Ruminococcus/enzymology
- Ruminococcus/genetics
- Structure-Activity Relationship
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Affiliation(s)
| | | | | | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Clifton V, Cuffe J, Moritz K, Cole T, Fuller P, Lu N, Kumar S, Chong S, Saif Z. Review: The role of multiple placental glucocorticoid receptor isoforms in adapting to the maternal environment and regulating fetal growth. Placenta 2017; 54:24-29. [DOI: 10.1016/j.placenta.2016.12.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 01/28/2023]
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15
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Srivastava A, Asahara H, Zhang M, Zhang W, Liu H, Cui S, Jin Q, Chong S. Reconstitution of Protein Translation of Mycobacterium Reveals Functional Conservation and Divergence with the Gram-Negative Bacterium Escherichia coli. PLoS One 2016; 11:e0162020. [PMID: 27564552 PMCID: PMC5001721 DOI: 10.1371/journal.pone.0162020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022] Open
Abstract
Protein translation is essential for all bacteria pathogens. It has also been a major focus of structural and functional studies and an important target of antibiotics. Here we report our attempts to biochemically reconstitute mycobacterial protein translation in vitro from purified components. This mycobacterial translation system consists of individually purified recombinant translation factors from Mycobacterium tuberculosis (M. tuberculosis), purified tRNAs and ribosomes from Mycobacterium smegmatis (M. smegmatis), and an aminoacyl-tRNA synthetase (AARS) mixture from the cell-extract of M. smegmatis. We demonstrate that such mycobacterial translation system was efficient in in vitro protein synthesis, and enabled functional comparisons of translational components between the gram-positive Mycobacterium and the gram-negative E. coli. Although mycobacterial translation factors and ribosomes were highly compatible with their E. coli counterparts, M. smegmatis tRNAs were not properly charged by the E. coli AARSs to allow efficient translation of a reporter. In contrast, both E. coli and M. smegmatis tRNAs exhibited similar activity with the semi-purified M. smegmatis AARSs mixture for in vitro translation. We further demonstrated the use of both mycobacterial and E. coli translation systems as comparative in vitro assays for small-molecule antibiotics that target protein translation. While mycobacterial and E. coli translation were both inhibited at the same IC50 by the antibiotic spectinomycin, mycobacterial translation was preferentially inhibited by the antibiotic tetracycline, suggesting that there may be structural differences at the antibiotic binding sites between the ribosomes of Mycobacterium and E. coli. Our results illustrate an alternative approach for antibiotic discovery and functional studies of protein translation in mycobacteria and possibly other bacterial pathogens.
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Affiliation(s)
- Aashish Srivastava
- New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, United States of America
| | - Haruichi Asahara
- New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, United States of America
| | - Meng Zhang
- Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, China
| | - Weijia Zhang
- Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, China
| | - Haiying Liu
- Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, China
| | - Sheng Cui
- Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, China
| | - Qi Jin
- Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100176, China
| | - Shaorong Chong
- New England Biolabs, Inc., 240 County Road, Ipswich, MA, 01938, United States of America
- * E-mail:
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Seow L, Subramanian M, Abdin E, Vaingankar J, Chong S. Sleep disturbance among people with major depressive disorders (MDD) in Singapore. Sleep Med 2015. [DOI: 10.1016/j.sleep.2015.02.1564] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bianco-Miotto T, Blundell C, Buckberry S, Chamley L, Chong S, Cottrell E, Dawson P, Hanna C, Holland O, Lewis RM, Moritz K, Myatt L, Perkins AV, Powell T, Saffery R, Sferruzzi-Perri A, Sibley C, Simmons D, O'Tierney-Ginn PF. IFPA meeting 2015 workshop report I: placental mitochondrial function, transport systems and epigenetics. Placenta 2015; 48 Suppl 1:S3-S6. [PMID: 26693894 DOI: 10.1016/j.placenta.2015.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022]
Abstract
Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops covered areas of placental regulation and nutrient handling: 1) placental epigenetics; 2) placental mitochondrial function; 3) placental transport systems.
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Affiliation(s)
| | - C Blundell
- University of Pennsylvania, Philadelphia, PA, USA
| | - S Buckberry
- The University of Western Australia, WA, Australia
| | | | - S Chong
- Mater Research Institute, University of Queensland, QLD, Australia
| | - E Cottrell
- Maternal and Fetal Health Research Centre, Institute of Human Development, The University of Manchester, Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester, United Kingdom
| | - P Dawson
- Mater Research Institute, University of Queensland, Australia
| | - C Hanna
- University of British Columbia, Vancouver, BC, Canada
| | - O Holland
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, QLD, Australia
| | - R M Lewis
- Faculty of Medicine, University of Southampton, UK
| | - K Moritz
- School of Biomedical Sciences, University of Queensland, QLD, Australia
| | - L Myatt
- Center for Pregnancy and Newborn Research, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - A V Perkins
- School of Medical Science, Menzies Health Institute Queensland, Griffith University, QLD, Australia
| | - T Powell
- University of Colorado Anschutz Medical Campus, Denver, CO, USA
| | | | - A Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - C Sibley
- Maternal and Fetal Health Research Centre, University of Manchester, UK
| | - D Simmons
- University of Queensland, QLD Australia
| | - P F O'Tierney-Ginn
- Center for Reproductive Health, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA.
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Abbaspourrad A, Zhang H, Tao Y, Cui N, Asahara H, Zhou Y, Yue D, Koehler SA, Ung LW, Heyman J, Ren Y, Ziblat R, Chong S, Weitz DA. Label-free single-cell protein quantification using a drop-based mix-and-read system. Sci Rep 2015; 5:12756. [PMID: 26234416 PMCID: PMC4522677 DOI: 10.1038/srep12756] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022] Open
Abstract
Quantitative protein analysis of single cells is rarely achieved due to technical difficulties of detecting minute amounts of proteins present in one cell. We develop a mix-and-read assay for drop-based label-free protein analysis of single cells. This high-throughput method quantifies absolute, rather than relative, amounts of proteins and does not involve antibody labeling or mass spectrometry.
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Affiliation(s)
- Alireza Abbaspourrad
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Huidan Zhang
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA [2] Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China
| | - Ye Tao
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA [2] School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Naiwen Cui
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Haruichi Asahara
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Ying Zhou
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Dongxian Yue
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Stephan A Koehler
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA [2] Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Lloyd W Ung
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - John Heyman
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Yukun Ren
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Roy Ziblat
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Shaorong Chong
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - David A Weitz
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA [2] Department of Physics, Harvard University, Cambridge, MA 02138, USA
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Abstract
Adrenal nodules are detected with increasing frequency. The National Institute of Health (NIH), American College of Radiology (ACR), and the American Association of Clinical Endocrinologists and American Association of Endocrine Surgeons (AACE/AAES) have produced guidelines for the management of incidental adrenal nodules. This review provides a summary of the consensus radiologic approach to these nodules.
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Affiliation(s)
- J. Willatt
- University of Michigan Health System, Ann Arbor, MI 48109, USA
- Veterans Administration Hospital, Ann Arbor, MI 48105, USA
- *J. Willatt:
| | - S. Chong
- University of Michigan Health System, Ann Arbor, MI 48109, USA
- Veterans Administration Hospital, Ann Arbor, MI 48105, USA
| | - J. A. Ruma
- University of Michigan Health System, Ann Arbor, MI 48109, USA
- Veterans Administration Hospital, Ann Arbor, MI 48105, USA
| | - J. Kuriakose
- University of Michigan Health System, Ann Arbor, MI 48109, USA
- Veterans Administration Hospital, Ann Arbor, MI 48105, USA
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Abstract
Most cell-free protein-synthesis systems are based on cell extracts, which often contain undesirable activities. Reconstituted systems, by contrast, are composed of a defined number of purified and recombinant components with minimal nuclease and protease activities. This unit describes the use of a particular commercial reconstituted system, PURExpress. This system allows in vitro synthesis of proteins from mRNA and circular and linear DNA templates, as well as co-translational labeling of proteins. Unique to this system, all recombinant protein components of the system are His-tagged, allowing purification of the synthesized untagged protein by removing the rest of the system's components. Newly synthesized proteins can often be visible on an SDS-PAGE gel and directly assayed for their functions without labeling and purification. Certain components of the system, such as ribosomes or release factors, can be omitted for specific applications. Such "delta" versions of the system are well suited for studies of bacterial translation, assays of ribosome function, incorporation of unnatural amino acids, and ribosome display of protein libraries.
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Abstract
During the early days of molecular biology, cell-free protein synthesis played an essential role in deciphering the genetic code and contributed to our understanding of translation of protein from messenger RNA. Owing to several decades of major and incremental improvements, modern cell-free systems have achieved higher protein synthesis yields at lower production costs. Commercial cell-free systems are now available from a variety of material sources, ranging from "traditional" E. coli, rabbit reticulocyte lysate, and wheat germ extracts, to recent insect and human cell extracts, to defined systems reconstituted from purified recombinant components. Although each cell-free system has certain advantages and disadvantages, the diversity of the cell-free systems allows in vitro synthesis of a wide range of proteins for a variety of downstream applications. In the post-genomic era, cell-free protein synthesis has rapidly become the preferred approach for high-throughput functional and structural studies of proteins and a versatile tool for in vitro protein evolution and synthetic biology. This unit provides a brief history of cell-free protein synthesis and describes key advances in modern cell-free systems, practical differences between widely used commercial cell-free systems, and applications of this important technology.
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Zhou Y, Asahara H, Schneider N, Dranchak P, Inglese J, Chong S. Engineering bacterial transcription regulation to create a synthetic in vitro two-hybrid system for protein interaction assays. J Am Chem Soc 2014; 136:14031-8. [PMID: 25188838 PMCID: PMC4195380 DOI: 10.1021/ja502512g] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Transcriptional activation of σ(54)-RNA polymerase holoenzyme (σ(54)-RNAP) in bacteria is dependent on a cis-acting DNA element (bacterial enhancer), which recruits the bacterial enhancer-binding protein to contact the holoenzyme via DNA looping. Using a constructive synthetic biology approach, we recapitulated such process of transcriptional activation by recruitment in a reconstituted cell-free system, assembled entirely from a defined number of purified components. We further engineered the bacterial enhancer-binding protein PspF to create an in vitro two-hybrid system (IVT2H), capable of carrying out gene regulation in response to expressed protein interactions. Compared with genetic systems and other in vitro methods, IVT2H not only allows detection of different types of protein interactions in just a few hours without involving cells but also provides a general correlation of the relative binding strength of the protein interaction with the IVT2H signal. Due to its reconstituted nature, IVT2H provides a biochemical assay platform with a clean and defined background. We demonstrated the proof-of-concept of using IVT2H as an alternative assay for high throughput screening of small-molecule inhibitors of protein-protein interaction.
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Affiliation(s)
- Ying Zhou
- New England Biolabs, Inc. 240 County Road, Ipswich, Massachusetts 01938, United States
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Mehta P, Chong S, Carulli MT, Haskard DO. Steroid-resistant remitting seronegative symmetrical synovitis with pitting oedema associated with gout treated with etanercept. Rheumatology (Oxford) 2014; 53:1908-10. [DOI: 10.1093/rheumatology/keu223] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chong S, Moloney E, Donnelly M, Fitzpatrick G. Compliance with protective lung ventilation in an Irish teaching hospital. Crit Care 2014. [PMCID: PMC4069429 DOI: 10.1186/cc13485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Rosenblum G, Chen C, Kaur J, Cui X, Zhang H, Asahara H, Chong S, Smilansky Z, Goldman YE, Cooperman BS. Quantifying elongation rhythm during full-length protein synthesis. J Am Chem Soc 2013; 135:11322-9. [PMID: 23822614 DOI: 10.1021/ja405205c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pauses regulate the rhythm of ribosomal protein synthesis. Mutations disrupting even minor pauses can give rise to improperly formed proteins and human disease. Such minor pauses are difficult to characterize by ensemble methods, but can be readily examined by single-molecule (sm) approaches. Here we use smFRET to carry out real-time monitoring of the expression of a full-length protein, the green fluorescent protein variant Emerald GFP. We demonstrate significant correlations between measured elongation rates and codon and isoacceptor tRNA usage, and provide a quantitative estimate of the effect on elongation rate of replacing a codon recognizing an abundant tRNA with a synonymous codon cognate to a rarer tRNA. Our results suggest that tRNA selection plays an important general role in modulating the rates and rhythms of protein synthesis, potentially influencing simultaneous co-translational processes such as folding and chemical modification.
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Affiliation(s)
- Gabriel Rosenblum
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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Rosenblum G, Chen C, Farrell I, Cui X, Zhang H, Asahara H, Chong S, Smilansky Z, Cooperman BS, Goldman YE. Single Molecule Measurement of Peptide Elongation Rate during Synthesis of a Full-Length Protein. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.1458] [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: 10/27/2022] Open
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Zhou Y, Asahara H, Gaucher EA, Chong S. Reconstitution of translation from Thermus thermophilus reveals a minimal set of components sufficient for protein synthesis at high temperatures and functional conservation of modern and ancient translation components. Nucleic Acids Res 2012; 40:7932-45. [PMID: 22723376 PMCID: PMC3439929 DOI: 10.1093/nar/gks568] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thermus thermophilus is a thermophilic model organism distantly related to the mesophilic model organism E. coli. We reconstituted protein translation of Thermus thermophilus in vitro from purified ribosomes, transfer ribonucleic acids (tRNAs) and 33 recombinant proteins. This reconstituted system was fully functional, capable of translating natural messenger RNA (mRNA) into active full-length proteins at temperatures up to 65°C and with yields up to 60 μg/ml. Surprisingly, the synthesis of active proteins also occurred at 37°C, a temperature well below the minimal growth temperature for T. thermophilus. A polyamine was required, with tetraamine being most effective, for translation at both high and low temperatures. Using such a defined in vitro system, we demonstrated a minimal set of components that are sufficient for synthesizing active proteins at high temperatures, the functional compatibility of key translation components between T. thermophilus and E. coli, and the functional conservation of a number of resurrected ancient elongation factors. This work sets the stage for future experiments that apply abundant structural information to biochemical characterization of protein translation and folding in T. thermophilus. Because it contains significantly reduced nucleases and proteases, this reconstituted thermostable cell-free protein synthesis system may enable in vitro engineering of proteins with improved thermostability.
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Affiliation(s)
- Ying Zhou
- New England Biolabs, Inc, 240 County Road, Ipswich, MA 01938, USA
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Lee WJ, Chong S, Seo JS, Shim HJ. Transthoracic fine-needle aspiration biopsy of the lungs using a C-arm cone-beam CT system: diagnostic accuracy and post-procedural complications. Br J Radiol 2011; 85:e217-22. [PMID: 22010033 DOI: 10.1259/bjr/64727750] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE The purpose of our study was to evaluate the diagnostic accuracy of transthoracic fine-needle aspiration biopsy (TFNAB) using a C-arm cone-beam CT (CBCT) system and to assess risk factors for immediate post-procedural complications in patients with lung lesions. METHODS From October 2007 to April 2009, 94 TFNAB procedures using a C-arm system were studied in 91 patients with pulmonary lesions a chest CT scans. We retrospectively reviewed the patients' radiological and histopathological findings. We evaluated the lesion size, lesion abutted to pleura and presence or absence of emphysema along the needle path, lesion depth, visibility of target lesion and patient's position. Pneumothorax and pulmonary haemorrhage were assessed after TFNAB. Overall diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analysed. RESULTS In 94 TFNAB procedures, 58 lesions were malignant and 36 were benign. The sensitivity, specificity, PPV, NPV and overall diagnostic accuracy rate of TFNAB were 93.1%, 100%, 100%, 90% and 97.9%, respectively. Pneumothorax was developed in 24 procedures. None of the parameters showed significant impact on the frequency of the pneumothorax. Overall haemorrhage occurred in 43 procedures. The incidence of overall haemorrhage was higher in patients with smaller lesions, longer pleural distance and pleural abutted lesions (p<0.05). Differences in visibility at projection radiographs were statistically significant between patients with or without perilesional haemorrhage (p<0.05). CONCLUSION Transthoracic fine-needle aspiration biopsy using a C-arm CBCT system is feasible for imaging guidance of lung lesion and early detection of the procedural-related complications.
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Affiliation(s)
- W J Lee
- Department of Radiology, Chung-Ang University Medical Center, Chung-Ang University College of Medicine, Seoul Republic of Korea
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Bradshaw D, Stylianou KC, Heck R, Bacsa J, Chong S, Rabone J, Khimyak YZ, Rosseinsky MJ. Flexible pyrene-derived frameworks for sensing and separation. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311097728] [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: 11/10/2022] Open
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Flatscher-Bader T, Foldi CJ, Chong S, Whitelaw E, Moser RJ, Burne THJ, Eyles DW, McGrath JJ. Increased de novo copy number variants in the offspring of older males. Transl Psychiatry 2011; 1:e34. [PMID: 22832608 PMCID: PMC3309504 DOI: 10.1038/tp.2011.30] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The offspring of older fathers have an increased risk of neurodevelopmental disorders, such as schizophrenia and autism. In light of the evidence implicating copy number variants (CNVs) with schizophrenia and autism, we used a mouse model to explore the hypothesis that the offspring of older males have an increased risk of de novo CNVs. C57BL/6J sires that were 3- and 12-16-months old were mated with 3-month-old dams to create control offspring and offspring of old sires, respectively. Applying genome-wide microarray screening technology, 7 distinct CNVs were identified in a set of 12 offspring and their parents. Competitive quantitative PCR confirmed these CNVs in the original set and also established their frequency in an independent set of 77 offspring and their parents. On the basis of the combined samples, six de novo CNVs were detected in the offspring of older sires, whereas none were detected in the control group. Two of the CNVs were associated with behavioral and/or neuroanatomical phenotypic features. One of the de novo CNVs involved Auts2 (autism susceptibility candidate 2), and other CNVs included genes linked to schizophrenia, autism and brain development. This is the first experimental demonstration that the offspring of older males have an increased risk of de novo CNVs. Our results support the hypothesis that the offspring of older fathers have an increased risk of neurodevelopmental disorders such as schizophrenia and autism by generation of de novo CNVs in the male germline.
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Affiliation(s)
- T Flatscher-Bader
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia,The Queensland Institute of Medical Research, Herston, QLD, Australia
| | - C J Foldi
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
| | - S Chong
- The Queensland Institute of Medical Research, Herston, QLD, Australia
| | - E Whitelaw
- The Queensland Institute of Medical Research, Herston, QLD, Australia
| | | | - T H J Burne
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia,Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia
| | - D W Eyles
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia,Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia
| | - J J McGrath
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia,Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD, Australia,Discipline of Psychiatry, The University of Queensland, St Lucia, QLD, Australia,Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia. E-mail:
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Chong S, Li S, Miyamoto C. SU-E-J-28: Clinical Evaluation of XVI-Guided VMAT and IMRT of Prostate Cancer. Med Phys 2011. [DOI: 10.1118/1.3611796] [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] Open
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Chong S, Anderson N, Finlay J. SU-E-T-259: Implementation of An Automated Workflow Auditing and Notification System for Radiation Oncology. Med Phys 2011. [DOI: 10.1118/1.3612210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Asahara H, Chong S. In vitro genetic reconstruction of bacterial transcription initiation by coupled synthesis and detection of RNA polymerase holoenzyme. Nucleic Acids Res 2010; 38:e141. [PMID: 20457746 PMCID: PMC2910072 DOI: 10.1093/nar/gkq377] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In vitro reconstitution of a biological complex or process normally involves assembly of multiple individually purified protein components. Here we present a strategy that couples expression and assembly of multiple gene products with functional detection in an in vitro reconstituted protein synthesis system. The strategy potentially allows experimental reconstruction of a multi-component biological complex or process using only DNA templates instead of purified proteins. We applied this strategy to bacterial transcription initiation by co-expressing genes encoding Escherichia coli RNA polymerase subunits and sigma factors in the reconstituted protein synthesis system and by coupling the synthesis and assembly of a functional RNA polymerase holoenzyme with the expression of a reporter gene. Using such a system, we demonstrated sigma-factor-dependent, promoter-specific transcription initiation. Since protein synthesis, complex formation and enzyme catalysis occur in the same in vitro reaction mixture, this reconstruction process resembles natural biosynthetic pathways and avoids time-consuming expression and purification of individual proteins. The strategy can significantly reduce the time normally required by conventional reconstitution methods, allow rapid generation and detection of genetic mutations, and provide an open and designable platform for in vitro study and intervention of complex biological processes.
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Affiliation(s)
- Haruichi Asahara
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938, USA
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Abstract
The purpose of this study was to evaluate the high-resolution computed tomographic (HRCT) findings of five adult patients (either immunocompromised or immunocompetent) with herpes simplex virus (HSV) pneumonia. We retrospectively assessed HRCT images of 5 patients (all male patients, age range 39-70 years; mean 62 years) with HSV pneumonia. The specific pathological findings that allowed for a definite diagnosis of HSV pneumonia included the presence of intranuclear inclusion bodies on haematoxylin and eosin staining, or positive immunohistochemical staining. High-resolution CT scans (HiSpeed Advantage or LightSpeed QX/i, GE Healthcare) using 1- or 1.25-mm collimation at 10-mm intervals without intravenous contrast medium injection were assessed, in particular for the presence and distribution of parenchymal abnormalities including ground-glass attenuation, airspace consolidation, nodules and interlobular septal thickening. In two patients, pathological specimens were obtained from open lung biopsy or bronchoscopic biopsy, and were correlated with HRCT findings. Three HRCT patterns of pulmonary abnormalities were identified in our series of HSV pneumonia: predominant areas of diffuse or multifocal ground-glass attenuation, predominant areas of multifocal peribronchial consolidations, and a mixed pattern of both. Histopathologically, areas of ground-glass attenuation seen on HRCT corresponded to diffuse alveolar damage in one patient who underwent open lung biopsy. No specific differences in HRCT findings were seen between the immunocompromised and the immunocompetent patients. In patients suspected of having an acute lower respiratory infection, whether immunocompromised or immunocompetent, a possibility of HSV pneumonia can be included in differential diagnoses when diffuse or multifocal areas of ground-glass attenuation and/or consolidations are seen on HRCT.
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Affiliation(s)
- S Chong
- Department of Radiology, Chung-Ang University Medical Center, Chung-Ang University College of Medicine, Seoul 156-755, South Korea
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Mistry R, Pasisi L, Chong S, Stewart J, She RW. Socioeconomic deprivation and burns. Burns 2010; 36:403-8. [DOI: 10.1016/j.burns.2009.05.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 05/21/2009] [Accepted: 05/28/2009] [Indexed: 10/20/2022]
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Sexton A, Whitney PG, De Rose R, Zelikin AN, Chong S, Johnston AP, Caruso F, Kent SJ. P17-03. Nanoengineered layer-by-layer capsules as a novel delivery system for HIV vaccines. Retrovirology 2009. [PMCID: PMC2767787 DOI: 10.1186/1742-4690-6-s3-p285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Castriciano S, Carruthers S, Ackerman M, Chong S, Luinstra C, Robinson G, So G, Petrich A, Mahony J, Smieja M. PX-16 Self-collected nasal mid-turbinate flocked swabs for molecular respiratory virus diagnosis in symptomatic volunteers. J Clin Virol 2009. [DOI: 10.1016/s1386-6532(09)70238-0] [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: 10/20/2022]
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Luinstra K, Castriciano S, Ackerman M, Petrich A, Chong S, Mahony J, Smieja M. P200 Improving pre-analytic collection systems: inactivation and preservation of influenza for rapid testing. Int J Antimicrob Agents 2009. [DOI: 10.1016/s0924-8579(09)70419-4] [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: 10/20/2022]
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Luinstra K, Chong S, Mahony J, Smieja M, Petrich A. P206 Results from the testing of a national influenza A RNA sensitivity panel. Int J Antimicrob Agents 2009. [PMCID: PMC7134854 DOI: 10.1016/s0924-8579(09)70425-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ammons B, Griffith L, Giglia L, Mahony J, Chong S, Luinstra K, Smieja M. P288 Estimating the disruptive effects of respiratory viruses on a child's family. Int J Antimicrob Agents 2009. [DOI: 10.1016/s0924-8579(09)70507-2] [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: 10/20/2022]
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Castriciano S, Carruthers S, Ackerman M, Chong S, Luinstra K, Robinson C, So G, Petrich A, Mahony J, Smieja M. P204 Self-collected nasal mid-turbinate flocked swabs for molecular respiratory virus diagnosis in symptomatic volunteers. Int J Antimicrob Agents 2009. [PMCID: PMC7134877 DOI: 10.1016/s0924-8579(09)70423-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Wang Z, Wang J, Chong S, Lee C. Mining Potential Functionally Significant Polymorphisms at the ATP-Binding- Cassette Transporter Genes. ACTA ACUST UNITED AC 2009. [DOI: 10.2174/187569209787582330] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Humphreys WG, Obermeier MT, Barrish JC, Chong S, Marino AM, Murugesan N, Wang-Iverson D, Morrison RA. Application of structure–metabolism relationships in the identification of a selective endothelin A antagonist, BMS-193884, with favourable pharmacokinetic properties. Xenobiotica 2008; 33:1109-23. [PMID: 14660175 DOI: 10.1080/00498250310001609147] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. Based on binding affinity, 2'-amino-N-(3,4-dimethyl-5-isoxazolyl)-4'-(2-methylpropyl)[1,1'-biphenyl]-2-sulfonamide (2) was identified as an initial lead in a programme to identify selective endothelin (ET) receptor antagonists. However, the compound was extensively metabolized in preclinical animal species and human in vitro systems due to oxidative biotransformation. 2. To optimize this structural class, the site of metabolism of 2 was determined. This allowed for focussed structure-activity and structure-metabolism studies aimed at finding more metabolically stable analogues that maintained potency. New analogues were screened for their ET binding characteristics and their stability in rat and human liver microsomes. 3. The use of the microsomal stability screen was tested by the determination of the pharmacokinetic parameters of select analogues. A good correlation was found between reduced rates of rat microsomal metabolism and reduced clearance in the rat. 4. N-(3,4-dimethyl-5-isoxazolyl)-4'-(2-oxazolyl)[1,1'-biphenyl]-2-sulfonamide (3) was identified as an analogue with improved in vitro properties and further studies revealed that the compound had improved pharmacokinetic properties. 5. N-[[2'-[[(3,4-dimethyl-5-isoxazolyl)amino]sulfonyl]-4-(2-oxazolyl)[1,1'-biphenyl]-2-yl]methyl]acetamide (4) was subsequently identified as a compound with superior in vitro properties compared with compound 3, but when tested in vivo it had a substantially increased rate of clearance. Further studies demonstrated that the clearance of this closely related structural analogue was not dictated by metabolic processes, but was mediated by transport-mediated direct biliary excretion. 6. The utility of screening for in vitro liver microsomal stability as part of the lead optimization process for compounds with metabolic liabilities was shown. It was also shown that relatively small molecular changes can dramatically change the disposition of closely related analogues and care must be used when screening for a single property.
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Affiliation(s)
- W G Humphreys
- Department of Metabolism and Pharmacokinetics, Preclinical Candidate Optimization, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, NJ 08543, USA.
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Hillebrecht JR, Chong S. A comparative study of protein synthesis in in vitro systems: from the prokaryotic reconstituted to the eukaryotic extract-based. BMC Biotechnol 2008; 8:58. [PMID: 18664286 PMCID: PMC2507708 DOI: 10.1186/1472-6750-8-58] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Accepted: 07/29/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cell-free protein synthesis is not only a rapid and high throughput technology to obtain proteins from their genes, but also provides an in vitro platform to study protein translation and folding. A detailed comparison of in vitro protein synthesis in different cell-free systems may provide insights to their biological differences and guidelines for their applications. RESULTS Protein synthesis was investigated in vitro in a reconstituted prokaryotic system, a S30 extract-based system and a eukaryotic system. Compared to the S30 system, protein synthesis in the reconstituted system resulted in a reduced yield, and was more cold-sensitive. Supplementing the reconstituted system with fractions from a size-exclusion separation of the S30 extract significantly increased the yield and activity, to a level close to that of the S30 system. Though protein synthesis in both prokaryotic and eukaryotic systems showed no significant differences for eukaryotic reporter proteins, drastic differences were observed when an artificial fusion protein was synthesized in vitro. The prokaryotic systems failed to synthesize and correctly fold a significant amount of the full-length fusion protein, even when supplemented with the eukaryotic lysate. The active full-length fusion protein was synthesized only in the eukaryotic system. CONCLUSION The reconstituted bacterial system is sufficient but not efficient in protein synthesis. The S30 system by comparison contains additional cellular factors capable of enhancing protein translation and folding. The eukaryotic translation machinery may have evolved from its prokaryotic counterpart in order to translate more complex (difficult-to-translate) templates into active proteins.
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Mahony J, Chong S, Merante F, Yaghoubian S, Sinha T, Lisle C, Janeczko R. Development of a respiratory virus panel test for detection of twenty human respiratory viruses by use of multiplex PCR and a fluid microbead-based assay. J Clin Microbiol 2007; 45:2965-70. [PMID: 17596360 PMCID: PMC2045291 DOI: 10.1128/jcm.02436-06] [Citation(s) in RCA: 292] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Virology laboratories historically have used direct fluorescent-antibody assay (DFA) and culture to detect six or seven respiratory viruses. Following the discovery of five new human respiratory viruses since 2000, there is an increasing need for diagnostic tests to detect these emerging viruses. We have developed a new test that can detect 20 different respiratory virus types/subtypes in a single 5-h test. The assay employs multiplex PCR using 14 virus-specific primer pairs, followed by a multiplexed target-specific primer extension (TSPE) reaction using 21 primers for specific respiratory virus types and subtypes. TSPE products were sorted and identified by using a fluid microsphere-based array (Universal Array; TmBioscience Corporation, Toronto, Canada) and the Luminex x-MAP system. The assay detected influenza A and B viruses; influenza A virus subtypes H1, H3, and H5 (including subtype H5N1 of the Asian lineage); parainfluenza virus types 1, 2, 3, and 4; respiratory syncytial virus types A and B; adenovirus; metapneumovirus; rhinovirus; enterovirus; and coronaviruses OC43, 229E, severe acute respiratory syndrome coronavirus, NL63, and HKU1. In a prospective evaluation using 294 nasopharyngeal swab specimens, DFA/culture detected 119 positives and the respiratory virus panel (RVP) test detected 112 positives, for a sensitivity of 97%. The RVP test detected an additional 61 positive specimens that either were not detected by DFA/culture or were positive for viruses not tested for by DFA/culture. After resolution of discordant results by using a second unique PCR assay and by using a combined reference standard of positivity, the RVP test detected 180 of 183 true positives, for a sensitivity of 98.5%, whereas DFA and culture detected only 126 of 183 true positives, for a sensitivity of 68.8%. The RVP test should improve the capabilities of hospital and public health laboratories for diagnosing viral respiratory tract infections and should assist public health agencies in identifying etiologic agents in respiratory tract infection outbreaks.
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Affiliation(s)
- J Mahony
- Department of Pathology and Molecular Medicine, McMaster University, and St. Joseph's Healthcare, Hamilton, Ontario, Canada.
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Chernesky M, Jang D, Portillo E, Chong S, Smieja M, Luinstra K, Petrich A, Macritchie C, Ewert R, Hayhoe B, Sarabia A, Thompson F. Abilities of APTIMA, AMPLICOR, and ProbeTec assays to detect Chlamydia trachomatis and Neisseria gonorrhoeae in PreservCyt ThinPrep Liquid-based Pap samples. J Clin Microbiol 2007; 45:2355-8. [PMID: 17537943 PMCID: PMC1951221 DOI: 10.1128/jcm.00405-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [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: 11/20/2022] Open
Abstract
Infections with Chlamydia trachomatis and Neisseria gonorrhoeae are often asymptomatic. Liquid-based Pap (L-Pap) screening may provide samples for testing by commercial assays. Women attending a health clinic or a street youth clinic had a PreservCyt ThinPrep sample and a cervical swab (CS) collected. The L-Pap sample was tested for cytopathology; then 1 ml was transferred to an L-Pap specimen transfer tube for testing by the Gen-Probe APTIMA assays (APTIMA Combo 2 [AC2], APTIMA C. trachomatis [ACT], and APTIMA N. gonorrhoeae [AGC]). The residual L-Pap sample was tested for C. trachomatis and N. gonorrhoeae using Roche AMPLICOR (AMP) and Becton Dickinson ProbeTec (PT). The CS was tested by AC2. A patient was considered infected if two specimens were positive or if a single specimen was positive in two tests. The prevalence of infection was 10% (29/290) for C. trachomatis and 2.4% (7/290) for N. gonorrhoeae. Most of the positive patients had specimens that were reactive in all assays (20/29 for C. trachomatis; 6/7 for N. gonorrhoeae). Four patients had double infections. The sensitivities and specificities of the various tests for the specimens tested were as follows. For C. trachomatis on L-Pap, sensitivity and specificity were 100 and 98.1%, respectively, for ACT, 93.1 and 98.8% for AC2, 86.2 and 91.2% for AMP, and 72.4 and 92.7% for PT. For N. gonorrhoeae on L-Pap, sensitivity and specificity were 100% for both AGC and AC2, 85.7 and 100% for AMP, and 85.7 and 100% for PT. For AC2 with CSs, sensitivity and specificity were 93.1 and 98.5%, respectively, for C. trachomatis, and both were 100% for N. gonorrhoeae. There were significant differences in sensitivity and specificity (P < 0.001). The APTIMA assays were more sensitive and specific than AMP or PT for detecting women's C. trachomatis and/or N. gonorrhoeae infections by testing ThinPrep samples.
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Affiliation(s)
- M Chernesky
- St. Joseph's Healthcare/McMaster University, Toronto, Ontario, Canada.
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Chong S, Adams D, Rahman H. TS20P LAPAROSCOPIC REPAIR OF TRAUMATIC DIAPHRAGMATIC HERNIAE: A CASE PRESENTATION AND SYNTHESIS OF THE LITERATURE EXPERIENCE. ANZ J Surg 2007. [DOI: 10.1111/j.1445-2197.2007.04133_20.x] [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: 11/30/2022]
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Mahony J, Chong S. O348 Clinical evaluation of a new ID-Tag RVP assay for the detection of 20 respiratory viruses. Int J Antimicrob Agents 2007. [PMCID: PMC7134723 DOI: 10.1016/s0924-8579(07)70230-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ashwal S, Tone B, Tian HR, Chong S, Obenaus A. Serial magnetic resonance imaging in a rat pup filament stroke model. Exp Neurol 2006; 202:294-301. [PMID: 16876160 DOI: 10.1016/j.expneurol.2006.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [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: 03/01/2006] [Revised: 06/02/2006] [Accepted: 06/07/2006] [Indexed: 11/22/2022]
Abstract
Neonatal stroke is increasingly recognized in preterm and term infants but the ability to study this condition has been limited by the technical challenges in developing suitable animal models. In the current study we report the use of transient filament middle cerebral artery occlusion for 1.5 h in 10-day-old rat pups in which we were able to perform serial magnetic resonance imaging (MRI) studies. Serial MRI was performed immediately after the onset of stroke until 28 days after injury in an 11.7 T scanner using diffusion weighted and T2-weighted images. At 28 days the rat pups were sacrificed and standard histological stains were performed to validate stroke area. Serial behavioral assessments were also performed on the day of each imaging study. The anatomical distribution of stroke was similar to that expected from occlusion of the middle cerebral artery in adult models and represents a specific model of neonatal stroke in contrast to the commonly used model of carotid artery occlusion with 8% hypoxia. The initial stroke volume from MR measurements was 39% of the ipsilateral hemisphere at 0 h post-occlusion, reached a maximum at 24 h (44%) and then decreased in size (17%) with subsequent cavitation by 28 days. Infarction was more visible early with diffusion weighted imaging whereas T2-mapping provided more accurate infarct volumes at later time points. Despite the relatively large infarct volume, we saw little evidence of behavioral neurological deficit suggesting that this may also serve as a model of developmental plasticity and recovery.
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Affiliation(s)
- S Ashwal
- Department of Pediatrics, Loma Linda University School of Medicine, 11175 Campus Street, Loma Linda, CA 92354, USA.
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