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Toogood K, Pike T, Coe P, Everett S, Huggett M, Paranandi B, Bassi V, Toogood G, Smith A. The role of cholecystectomy following endoscopic sphincterotomy and bile duct stone removal. Ann R Coll Surg Engl 2023; 105:607-613. [PMID: 35950513 PMCID: PMC10471440 DOI: 10.1308/rcsann.2022.0027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2022] [Indexed: 09/02/2023] Open
Abstract
INTRODUCTION Choledocholithiasis is common, with patients usually treated with endoscopic retrograde cholangiopancreatography (ERCP) and subsequent cholecystectomy to remove the presumed source of common bile duct (CBD) stones. However, previous investigations into the management of patients following ERCP have focused on recurrent CBD stones, negating the risks of cholecystectomy. This article appraises the role of cholecystectomy following successful endoscopic clearance of bile duct stones. METHODS Patients undergoing ERCP and CBD clearance for choledocholithiasis at St James's University Hospital January 2015-December 2018 were included. Patients were divided into those who received cholecystectomy and those managed non-operatively. Readmissions, operative morbidity, mortality and treatment costs were investigated. RESULTS Eight hundred and forty-four patients received ERCP and CBD clearance with 3.9 years follow-up. Two hundred and nine patients underwent cholecystectomy with 15% requiring complex surgery. Three hundred and seventy-three patients were non-operatively managed. Unplanned readmissions occurred in 15% following ERCP, mostly within two years. There was no difference in readmissions between the two groups. Accounting for the entire patient pathway, non-operative management was less expensive. CONCLUSIONS The majority of patients do not require readmission following ERCP for CBD stones, and cholecystectomy did not reduce the risk of readmission. Few patients have recurrent CBD stones, but complex biliary surgery is frequently required. Routine cholecystectomy following ERCP needs to be re-evaluated and a more stratified approach to future risk developed.
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Affiliation(s)
| | | | - P Coe
- St James’s University Hospital, UK
| | | | | | | | - V Bassi
- St James’s University Hospital, UK
| | | | - A Smith
- St James’s University Hospital, UK
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Pike T, Brownlow N, Kjaer S, Carlton J, Parker PJ. PKCɛ switches Aurora B specificity to exit the abscission checkpoint. Nat Commun 2016; 7:13853. [PMID: 28004745 PMCID: PMC5192180 DOI: 10.1038/ncomms13853] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [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: 01/04/2016] [Accepted: 11/03/2016] [Indexed: 01/21/2023] Open
Abstract
The 'NoCut', or Aurora B abscission checkpoint can be activated if DNA is retained in the cleavage furrow after completion of anaphase. Checkpoint failure leads to incomplete abscission and a binucleate outcome. These phenotypes are also observed after loss of PKCɛ in transformed cell models. Here we show that PKCɛ directly modulates the Aurora B-dependent abscission checkpoint by phosphorylating Aurora B at S227. This phosphorylation invokes a switch in Aurora B specificity, with increased phosphorylation of a subset of target substrates, including the CPC subunit Borealin. This switch is essential for abscission checkpoint exit. Preventing the phosphorylation of Borealin leads to abscission failure, as does expression of a non-phosphorylatable Aurora B S227A mutant. Further, depletion of the ESCRT-III component and Aurora B substrate CHMP4C enables abscission, bypassing the PKCɛ-Aurora B exit pathway. Thus, we demonstrate that PKCɛ signals through Aurora B to exit the abscission checkpoint and complete cell division.
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Affiliation(s)
- Tanya Pike
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nicola Brownlow
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Svend Kjaer
- Protein Purification Facility, Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jeremy Carlton
- Division of Cancer Studies King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Peter J. Parker
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Division of Cancer Studies King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
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Wood T, Faircloth DC, Lawrie SR, Letchford AP, Whitehead MO, Pike T, Perkins M. The ISIS pre-injector reconfiguration. Rev Sci Instrum 2016; 87:02B121. [PMID: 26932003 DOI: 10.1063/1.4934658] [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: 06/05/2023]
Abstract
With the introduction of a new "low energy beams" group at ISIS, the decision was taken to expand the ion source area. This paper will explain what actions were taken, how this has improved the present working environment and how the space will be used to accommodate a medium energy beam transport (MEBT) section after the existing radio-frequency quadrupole. The MEBT will incorporate three 202.5 MHz re-bunching cavities and will achieve a transmission of 96% with minimal emittance growth.
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Affiliation(s)
- T Wood
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - D C Faircloth
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - S R Lawrie
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - A P Letchford
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - M O Whitehead
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - T Pike
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
| | - M Perkins
- ISIS Pulsed Spallation Neutron and Muon Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, United Kingdom
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Sloboda R, Ballester F, Tedgren AC, Culberson W, Esthappan J, Haworth A, Lowenstein J, Ma Y, Mourtada F, Papagiannis P, Pike T, Rivard M, Siebert F, Smith R, Spadinger I, Taylor P, Verhaegen F, Vijande J, Beaulieu L. TH-AB-BRA-05: Infrastructure and Process for Model-Based Dose Calculation Software Commissioning in Brachytherapy. Med Phys 2015. [DOI: 10.1118/1.4926148] [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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Brownlow N, Pike T, Zicha D, Collinson L, Parker PJ. Mitotic catenation is monitored and resolved by a PKCε-regulated pathway. Nat Commun 2014; 5:5685. [PMID: 25483024 PMCID: PMC4272242 DOI: 10.1038/ncomms6685] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [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: 05/27/2014] [Accepted: 10/27/2014] [Indexed: 12/15/2022] Open
Abstract
Exit from mitosis is controlled by silencing of the spindle assembly checkpoint (SAC). It is important that preceding exit, all sister chromatid pairs are correctly bioriented, and that residual catenation is resolved, permitting complete sister chromatid separation in the ensuing anaphase. Here we determine that the metaphase response to catenation in mammalian cells operates through PKCε. The PKCε-controlled pathway regulates exit from the SAC only when mitotic cells are challenged by retained catenation and this delayed exit is characterized by BubR1-high and Mad2-low kinetochores. In addition, we show that this pathway is necessary to facilitate resolution of retained catenanes in mitosis. When delayed by catenation in mitosis, inhibition of PKCε results in premature entry into anaphase with PICH-positive strands and chromosome bridging. These findings demonstrate the importance of PKCε-mediated regulation in protection from loss of chromosome integrity in cells failing to resolve catenation in G2.
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Affiliation(s)
- Nicola Brownlow
- Protein Phosphorylation Laboratory, Cancer Research UK London
Research Institute, 44 Lincolns Inn Fields, London
WC2A 3LY, UK
| | - Tanya Pike
- Protein Phosphorylation Laboratory, Cancer Research UK London
Research Institute, 44 Lincolns Inn Fields, London
WC2A 3LY, UK
| | - Daniel Zicha
- Light Microscopy, Cancer Research UK London Research
Institute, London, WC2A 3LY, UK
| | - Lucy Collinson
- Electron Microscopy, Cancer Research UK London Research
Institute, London
WC2A 3LY, UK
| | - Peter J. Parker
- Protein Phosphorylation Laboratory, Cancer Research UK London
Research Institute, 44 Lincolns Inn Fields, London
WC2A 3LY, UK
- Division of Cancer Studies, King’s College London,
New Hunt’s House, Guy’s Campus, London
SE1 1UL, UK
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Abstract
Cytokinesis is the final act of the cell cycle where the replicated DNA and cellular contents are finally split into two daughter cells. This process is very tightly controlled as DNA segregation errors and cytokinesis failure is commonly associated with aneuploidy and aggressive tumours. Protein kinase Cε (PKCε) is a lipid-activated serine/threonine kinase that is part of the PKC superfamily. PKCε plays a complex role in the regulation of migration, adhesion and cytokinesis and in the present article we discuss the interplay between these processes. Integrin-mediated interaction with the actin cytoskeleton is a known regulator of cell adhesion and migration and there is emerging evidence that this pathway may also be essential for cytokinesis. We discuss evidence that a known actin-binding region in PKCε is involved in PKCε-mediated regulation of cytokinesis, providing a link between integrin-mediated stabilization of the cytokinesis furrow and PKCε recruitment.
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Affiliation(s)
- Nicola Brownlow
- *Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, London WC2A 3LY, U.K
| | - Tanya Pike
- *Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, London WC2A 3LY, U.K
| | - Victoria Crossland
- *Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, London WC2A 3LY, U.K
| | - Jeroen Claus
- *Protein Phosphorylation Laboratory, Cancer Research UK London Research Institute, London WC2A 3LY, U.K
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Farid SG, Shah N, Longbotham D, Pike T. Re: Ratios derived from an array of standard haematological indices predict the oncological outcome in colon cancer. Colorectal Dis 2014; 16:926. [PMID: 25040428 DOI: 10.1111/codi.12723] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 05/28/2014] [Indexed: 02/08/2023]
Affiliation(s)
- S G Farid
- Department of General Surgery, St James' Institute of Oncology, St James University Hospital, Beckett Street, Leeds, LS9 7T, UK.
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Farid SG, Shah N, Pike T, Wijetunga I. Re: 'Predicting postoperative mortality after colorectal surgery: a novel clinical model'. Colorectal Dis 2014; 16:926-7. [PMID: 25155406 DOI: 10.1111/codi.12750] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/04/2014] [Indexed: 02/08/2023]
Affiliation(s)
- S G Farid
- Department of Surgery, St James' University Hospital, Beckett Street, Leeds, LS9 7TF, UK.
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Simiele S, Pike T, Micka J, DeWerd L. WE-A-108-05: Experimental and Computational Dosimetric Characterization of the Xoft AxxentTM Electronic Brachytherapy Source Within a Titanium Cervical Applicator. Med Phys 2013. [DOI: 10.1118/1.4815498] [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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Li X, Flynn R, Pike T. SU-D-108-07: Experimental Verification of a Compensator-Based Brachytherapy System. Med Phys 2013. [DOI: 10.1118/1.4814017] [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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Pike T, Widberg C, Goodall A, Payne E, Giles N, Hancock J, Gabrielli B. Truncated MEK1 is required for transient activation of MAPK signalling in G2 phase cells. Cell Signal 2013; 25:1423-8. [DOI: 10.1016/j.cellsig.2013.03.014] [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] [Received: 01/31/2013] [Accepted: 03/16/2013] [Indexed: 02/08/2023]
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Pike T, Davis S, Micka J, DeWerd L. SU-E-T-85: Ionization Chamber Measured Dose-Rate Constant of the Xoft Axxent Electronic Brachytherapy Source. Med Phys 2011. [DOI: 10.1118/1.3612036] [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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13
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Pike T, Moga J, Davis S, DeWerd L. WE-D-BRB-05: Dose-Rate Constant Determination of the Xoft Axxent Electronic Brachytherapy Source Using Spectroscopic Methods. Med Phys 2010. [DOI: 10.1118/1.3469393] [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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14
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Kennedy R, Pike T, Davis S, DeWerd L. SU-GG-T-276: Dosimetric Characterization of a Set of Surface Applicators from Xoft Inc. Med Phys 2010. [DOI: 10.1118/1.3468668] [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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Astuti P, Pike T, Widberg C, Payne E, Harding A, Hancock J, Gabrielli B. MAPK pathway activation delays G2/M progression by destabilizing Cdc25B. J Biol Chem 2009; 284:33781-8. [PMID: 19801682 DOI: 10.1074/jbc.m109.027516] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Activation of the mitogen-activated protein kinase (MAPK) pathway by growth factors or phorbol esters during G(2) phase delays entry into mitosis; however, the role of the MAPK pathway during G(2)/M progression remains controversial. Here, we demonstrate that activation of the MAPK pathway with either epidermal growth factor or 12-O-tetradecanoylphorbol-13-acetate induces a G(2) phase delay independent of known G(2) phase checkpoint pathways but was specifically dependent on MAPK/extracellular signal-regulated kinase kinase (MEK1). Activation of MAPK signaling also blocked exit from a G(2) phase checkpoint arrest. Both the G(2) phase delay and blocked exit from the G(2) checkpoint arrest were mediated by the MEK1-dependent destabilization of the critical G(2)/M regulator cdc25B. Reintroduction of cdc25B overcame the MEK1-dependent G(2) phase delay. Thus, we have demonstrated a new function for MEK1 that controls G(2)/M progression by regulating the stability of cdc25B. This represents a novel mechanism by which factors that activate MAPK signaling can influence the timing of entry into mitosis, particularly exit from a G(2) phase checkpoint arrest.
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Affiliation(s)
- Puji Astuti
- Diamantina Institute for Cancer Immunology and Metabolic Medicine, University of Queensland, Brisbane 4102, Queensland, Australia
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Pike T, Raffi J, Davis S, DeWerd L. SU-FF-T-273: Energy Dependence of TLD-100 Chips and Microcubes for the Xoft Axxent® 50 KV Miniature X-Ray Source and Cs-137 Relative to Co-60. Med Phys 2009. [DOI: 10.1118/1.3181750] [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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Loh K, Chia JA, Greco S, Cozzi SJ, Buttenshaw RL, Bond CE, Simms LA, Pike T, Young JP, Jass JR, Spring KJ, Leggett BA, Whitehall VLJ. Bone morphogenic protein 3 inactivation is an early and frequent event in colorectal cancer development. Genes Chromosomes Cancer 2008; 47:449-60. [PMID: 18311777 DOI: 10.1002/gcc.20552] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Bone morphogenic proteins (BMPs) are members of the TGFB growth factor superfamily with well-described functions in bone formation. Although disrupted BMP signalling in tumor development has more recently been investigated, a role for BMP3 in colorectal cancer (CRC) has remained largely unexplored. The aim of this study was to investigate BMP3 disruption in CRCs in relation to both the traditional and serrated pathways of tumor progression. BMP3 was down-regulated as assessed by real-time PCR in 50 of 56 primary tumors (89%). Bisulfite sequencing of the putative promoter revealed extensive hypermethylation in the cell line HT29, in which expression could be restored by treatment with a methyltransferase inhibitor. Aberrant hypermethylation was observed in 33/60 (55%) tumors and was highly correlated with microsatellite instability (P < 0.01), the CpG Island Methylator Phenotype (P < 0.01), BRAF oncogene mutation (P < 0.01), and proximal location (P < 0.001). Methylation was also frequently observed in serrated and traditional adenomatous polyps (22/29, 76%). Re-introduction of BMP3 into cell lines revealed marked growth suppression supporting the functional relevance of this alteration in colorectal tumor development. This study provides molecular and functional data supporting the importance of BMP3 silencing as an early and frequent event in colorectal tumors progressing via the serrated and traditional pathways.
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Affiliation(s)
- Kim Loh
- Conjoint Gastroenterology Laboratory, Royal Brisbane and Women's Hospital Research Foundation Clinical Research Centre and Queensland Institute of Medical Research, Brisbane 4029, Australia
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Pike T, Davis S, Palmer B, DeWerd L. WE-E-AUD-02: Dose Rate Measurements of An Electronic Brachytherapy Source Using Thermoluminescent Dosimeters in Water. Med Phys 2007. [DOI: 10.1118/1.2761594] [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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Spring KJ, Zhao ZZ, Karamatic R, Walsh MD, Whitehall VLJ, Pike T, Simms LA, Young J, James M, Montgomery GW, Appleyard M, Hewett D, Togashi K, Jass JR, Leggett BA. High prevalence of sessile serrated adenomas with BRAF mutations: a prospective study of patients undergoing colonoscopy. Gastroenterology 2006; 131:1400-7. [PMID: 17101316 DOI: 10.1053/j.gastro.2006.08.038] [Citation(s) in RCA: 397] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 08/03/2006] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Sporadic colorectal cancers with a high degree of microsatellite instability are a clinically distinct subgroup with a high incidence of BRAF mutation and are widely considered to develop from serrated polyps. Previous studies of serrated polyps have been highly selected and largely retrospective. This prospective study examined the prevalence of sessile serrated adenomas and determined the incidence of BRAF and K-ras mutations in different types of polyps. METHODS An unselected consecutive series of 190 patients underwent magnifying chromoendoscopy. Polyp location, size, and histologic classification were recorded. All polyps were screened for BRAF V600E and K-ras codon 12 and 13 mutations. RESULTS Polyps were detected in 72% of patients. Most (60%) were adenomas (tubular adenomas, tubulovillous adenomas), followed by hyperplastic polyps (29%), sessile serrated adenomas (SSAs; 9%), traditional serrated adenomas (0.7%), and mixed polyps (1.7%). Adenomas were more prevalent in the proximal colon (73%), as were SSAs (75%), which tended to be large (64% >5 mm). The presence of at least one SSA was associated with increased polyp burden (5.0 vs 2.5; P < .0001) and female sex (P < .05). BRAF mutation was rare in adenomas (1/248 [0.4%]) but common in SSAs (78%), traditional serrated adenomas (66%), mixed polyps (57%), and microvesicular hyperplastic polyps (70%). K-ras mutations were significantly associated with goblet cell hyperplastic polyps and tubulovillous adenomas (P < .001). CONCLUSIONS The prevalence of SSAs is approximately 9% in patients undergoing colonoscopy. They are associated with BRAF mutation, proximal location, female sex, and presence of multiple polyps. These findings emphasize the importance of identifying and removing these lesions for endoscopic prevention of colorectal cancer.
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Affiliation(s)
- Kevin J Spring
- Conjoint Gastroenterology Laboratory, Queensland Institute of Medical Research, Herston, Brisbane, Australia
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Chassefière E, Bertaux JL, Berthelier JJ, Cabane M, Ciarletti V, Durry G, Forget F, Hamelin M, Leblanc F, Menvielle M, Gerasimov M, Korablev O, Linkin S, Managadze G, Jambon A, Manhès G, Lognonné P, Agrinier P, Cartigny P, Giardini D, Pike T, Kofman W, Herique A, Coll P, Person A, Costard F, Sarda P, Paillou P, Chaussidon M, Marty B, Robert F, Maurice S, Blanc M, d'Uston C, Sabroux JC, Pineau JF, Rochette P. MEP (Mars Environment Package): toward a package for studying environmental conditions at the surface of Mars from future lander/rover missions. Adv Space Res 2004; 34:1702-9. [PMID: 15934176 DOI: 10.1016/j.asr.2003.08.078] [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: 05/02/2023]
Abstract
In view to prepare Mars human exploration, it is necessary to promote and lead, at the international level, a highly interdisciplinary program, involving specialists of geochemistry, geophysics, atmospheric science, space weather, and biology. The goal of this program will be to elaborate concepts of individual instruments, then of integrated instrumental packages, able to collect exhaustive data sets of environmental parameters from future landers and rovers of Mars, and to favour the conditions of their implementation. Such a program is one of the most urgent need for preparing human exploration, in order to develop mitigation strategies aimed at ensuring the safety of human explorers, and minimizing risk for surface operations. A few main areas of investigation may be listed: particle and radiation environment, chemical composition of atmosphere, meteorology, chemical composition of dust, surface and subsurface material, water in the subsurface, physical properties of the soil, search for an hypothesized microbial activity, characterization of radio-electric properties of the Martian ionosphere. Scientists at the origin of the present paper, already involved at a high degree of responsibility in several Mars missions, and actively preparing in situ instrumentation for future landed platforms (Netlander--now cancelled, MSL-09), express their readiness to participate in both ESA/AURORA and NASA programs of Mars human exploration. They think that the formation of a Mars Environment working group at ESA, in the course of the AURORA definition phase, could act positively in favour of the program, by increasing its scientific cross-section and making it still more focused on human exploration.
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Affiliation(s)
- E Chassefière
- Pôle de Planétologie de l'IPSL, Université Pierre et Marie Curie, Paris, France.
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Diakoumis K, Dequet C, Pike T, Uphues M, Davison D. 958 CORRELATION BETWEEN INTERNAL ROTATION AND PAIN IN THE SUPRASPINATUS MUSCLE IN ADOLESCENT SWIMMERS. Med Sci Sports Exerc 1993. [DOI: 10.1249/00005768-199305001-00961] [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: 11/21/2022]
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Abstract
A data acquisition system that automatically discards corrupted or undesirable signals would save untold hours of drudgery for researchers. Continuous recording of variables to provide detailed behavior patterns generates huge amounts of raw data. Unfortunately waveforms usually require visual inspection for isolating desired behavior or validating signal integrity. This tedious and time-consuming step can potentially be eliminated using a novel computer science technique. We have trained a simulated neural network to recognize corrupted arterial pressure waveforms. Our system can now evaluate the validity of the arterial waveform without human intervention with an average false positive error rate of 2.2% and an average false negative error rate of 12.6%.
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Affiliation(s)
- T Pike
- Department of Surgery, Wellesley Hospital, University of Toronto, Ontario, Canada
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Abstract
A personal computer based system for data acquisition and analysis appropriate to physiological experiments is described in detail. The system is independent of the details of the analog signal generation. The software, written in C, is modular and easily portable to other PC systems. The system is capable of: (a) sampling many analog signals at an appropriate rate (100 Hz), (b) storing large quantities of digitized data, (c) analysing digitized waveforms to obtain signal parameters, and (d) storing signal parameters in a format suitable for statistical analysis. Computer processed cardiopulmonary data are compared with data derived from standard ICU equipment.
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Affiliation(s)
- R A Mustard
- Department of Surgery, Wellesley Hospital, University of Toronto, Ontario, Canada
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