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Kinston R, Gay S, McKinley RK, Sam S, Yardley S, Lefroy J. How well do UK assistantships equip medical students for graduate practice? Think EPAs. Adv Health Sci Educ Theory Pract 2024; 29:173-198. [PMID: 37347459 DOI: 10.1007/s10459-023-10249-4] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/28/2023] [Indexed: 06/23/2023]
Abstract
The goal of better medical student preparation for clinical practice drives curricular initiatives worldwide. Learning theory underpins Entrustable Professional Activities (EPAs) as a means of safe transition to independent practice. Regulators mandate senior assistantships to improve practice readiness. It is important to know whether meaningful EPAs occur in assistantships, and with what impact. Final year students at one UK medical school kept learning logs and audio-diaries for six one-week periods during a year-long assistantship. Further data were also obtained through interviewing participants when students and after three months as junior doctors. This was combined with data from new doctors from 17 other UK schools. Realist methods explored what worked for whom and why. 32 medical students and 70 junior doctors participated. All assistantship students reported engaging with EPAs but gaps in the types of EPAs undertaken exist, with level of entrustment and frequency of access depending on the context. Engagement is enhanced by integration into the team and shared understanding of what constitutes legitimate activities. Improving the shared understanding between student and supervisor of what constitutes important assistantship activity may result in an increase in the amount and/or quality of EPAs achieved.
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Affiliation(s)
- Ruth Kinston
- School of Medicine, Keele University, Clinical Education Centre, University Hospital of North Midlands, Newcastle Road, Staffordshire, ST4 6QG, UK.
| | - Simon Gay
- University of Leicester School of Medicine, Leicester, UK
- Keele University School of Medicine, Keele, UK
| | | | - Sreya Sam
- Keele University School of Medicine, Keele, UK
| | - Sarah Yardley
- Marie Curie Palliative Care Research Department, University College London, London, UK
- Central & North West London NHS Foundation Trust, London, UK
| | - Janet Lefroy
- School of Medicine and Faculty Lead for the Health Professionals Education Research Theme, Keele University, Keele, UK
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Zala A, Jamnapara N, Sasmal C, Sam S, Ranjan M. Study of microstructure & mechanical properties of TIG welded aluminized 9Cr-1Mo steel. Fusion Engineering and Design 2022. [DOI: 10.1016/j.fusengdes.2022.113038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Sam S, Tai-MacArthur S, Shangaris P, Sankaran S. Trends of Selective Fetal Reduction and Selective Termination in Multiple Pregnancy, in England and Wales: a Cross-Sectional Study. Reprod Sci 2021; 29:1020-1027. [PMID: 34902100 PMCID: PMC8863756 DOI: 10.1007/s43032-021-00819-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 12/01/2021] [Indexed: 12/01/2022]
Abstract
Selective abortion was shown to be increasingly common in England and Wales over a 9-year period, occurring most frequently as twin to singleton reductions in the 1st trimester. We analysed the trends in selective abortion (SA) in multiple pregnancies in England and Wales between 2009 and 2018. This is a cross-sectional study looking at 1143 women with multiple pregnancies in England and Wales undergoing SA. There were a total of 1143 cases of SA between 2009 and 2018 in England and Wales, representing 0.07% of total abortions. There has been a steady increase in cases, from 90 in 2009 to 131 in 2018, with 82.3% justified under ground E of The Abortion Act 1967. The majority of SAs were carried out at 13–19 weeks gestation, and intracardiac injection of potassium chloride was the most prevalent method (75%). Twin to singleton reductions accounted for 59%, the most common form of SAs. Over half of all cases (59%) were performed in women aged 30–39 years, and 84% of all women were of White ethnicity. SA has been an option available for couples diagnosed with multiple pregnancy, especially when there are discordant anomalies. Although SA may decrease multiple pregnancy-related complications, preventative methods must be championed.
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Affiliation(s)
- Sreya Sam
- GKT School of Biomedical Sciences, Kings College London, Guy's Campus, Great Maze Pond, London, SE1 1UL, UK
| | - Sarah Tai-MacArthur
- School of Bioscience Education, Kings College London, Guy's Campus, Great Maze Pond, London, SE1 1UL, UK
| | - Panicos Shangaris
- Department of Women and Children's Health, School of Life Course & Population Sciences, Faculty of Life Sciences and Medicine, Kings College London, London, 10th Floor North Wing St Thomas' Hospital, London, SE1 7EH, UK. .,Department of Women and Children, Guy's and St Thomas' NHS Foundation Trust, London, SE1 7EH, UK.
| | - Srividhya Sankaran
- Department of Women and Children, Guy's and St Thomas' NHS Foundation Trust, London, SE1 7EH, UK
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Sam S, Sharma R, Corp N, Igwesi-Chidobe C, Babatunde OO. Shared decision making in musculoskeletal pain consultations in low- and middle-income countries: a systematic review. Int Health 2021; 12:455-471. [PMID: 31728513 DOI: 10.1093/inthealth/ihz077] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/19/2019] [Accepted: 07/29/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Global populations, especially those in low- and middle-income countries (LMICs), are at an increased risk of musculoskeletal (MSK) pain, a leading cause of years lived with disability. Shared decision making (SDM) in the management of these conditions may drive improvements in healthcare outcomes and quality. This study aimed to synthesize and appraise available evidence regarding SDM in MSK pain consultations in LMICs. METHODS Comprehensive literature searches were conducted in 12 databases for primary studies investigating SDM in MSK pain consultations across all healthcare and community settings in LMICs. Study eligibility screening, data extraction and quality appraisal (using the Critical Appraisals Skills Programme tool) were completed by pairs of reviewers. Findings were brought together using thematic synthesis of data from all the primary studies. RESULTS Seven studies (mostly moderate quality) were included. There was low awareness of SDM among healthcare professionals (HCPs); however, this is not explicitly practised due to cultural and operational barriers. HCP training and patient empowerment through health literacy were proposed facilitators. The traditional paternalistic approach to treatment poses a key barrier to SDM, decreases adherence to prescribed treatments and raises the risk of poor clinical outcomes. CONCLUSIONS SDM is still a relatively 'foreign concept' within consultations and management of MSK pain patients in LMICs. There is a dearth of research in SDM and patient-centred care. Given the socio-economic impact of MSK pain, further research into the value of SDM in LMIC healthcare settings requires further consideration.
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Affiliation(s)
- Sreya Sam
- University School of Medicine, Keele University, Staffordshire ST5 5BG, UK
| | - Radha Sharma
- University School of Medicine, Keele University, Staffordshire ST5 5BG, UK
| | - Nadia Corp
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Staffordshire ST5 5BG, UK
| | - Chinonso Igwesi-Chidobe
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Staffordshire ST5 5BG, UK
| | - Opeyemi O Babatunde
- Arthritis Research UK Primary Care Centre, Research Institute for Primary Care & Health Sciences, Keele University, Staffordshire ST5 5BG, UK
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Zala A, Jamnapara N, Badheka V, Sam S, Ranjan M. Effect of aluminide coatings on penetration and microstructure of TIG welded 9Cr-1Mo steel for fusion blanket applications. Fusion Engineering and Design 2019. [DOI: 10.1016/j.fusengdes.2019.04.080] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Sam MR, Esmaeillou M, Sam S, Shokrgozar MA. Fish-oil-derived eicosapentaenoic acid decreases survivin expression and induces wt-p53 accumulation with caspase-3 activation in acute lymphoblastic leukemia cells. Hum Exp Toxicol 2017; 37:714-724. [PMID: 28920465 DOI: 10.1177/0960327117730879] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Defects in modulating wild-type (wt) p53 and survivin are associated with a resistant disease in acute lymphoblastic leukemia (ALL). Yet, no wt-p53 and survivin modulating drugs have been approved for clinical application in ALL. Here, we investigated if in vitro eicosapentaenoic acid (EPA) concentrations equal to human plasma levels are able to target wt-p53 and survivin. METHODS Wt-p53 Molt-4 cells (ALL cell line) were treated with 50, 100, 150, and 200 µM of EPA after which cell number, viability, proliferation rate, survivin expression, wt-p53 accumulation, caspase-3 activation, and apoptosis were evaluated. RESULTS After 48- and 72-h treatments with EPA at concentrations ranging from 50 to 200 µM, cell proliferation rates were measured to be 71.5-32.6% and 68.2-13.7% and metabolic activities were measured to be 77-44% and 71-26%, respectively. Treatment with 50-200 µM of EPA for 48 h resulted in 14.1-74.6% and 69.5-45.5% decreases in survivin mRNA and protein levels, respectively. EPA induced 1.3-6 and 1.9-20-fold increases in caspase-3 activation and wt-p53 accumulation, respectively. Increase in wt-p53/survivin and caspase-3/survivin ratios from 1 in untreated cells to 20.3 and 5.8 was measured for 150 µM of EPA. Low necrotic rates ranging from 0.3% to 2.8% and an increase in the number of total apoptotic cells (early + late) ranging from 9.8% to 81% were also observed with increasing EPA concentrations. CONCLUSION EPA induces strongly wt-p53 with a remarkable decrease in survivin expression, representing an attractive compound to modulate wt-p53 and survivin in ALL cells.
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Affiliation(s)
- M R Sam
- 1 Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - M Esmaeillou
- 1 Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - S Sam
- 1 Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran
| | - M A Shokrgozar
- 2 National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran
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Lorent N, Kong C, Kim T, Sam S, Thai S, Colebunders R, Rigouts L, Lynen L. Systematic screening for drug-resistant tuberculosis with Xpert(®) MTB/RIF in a referral hospital in Cambodia. Int J Tuberc Lung Dis 2016; 19:1528-35. [PMID: 26614197 DOI: 10.5588/ijtld.14.0956] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Limited access to drug susceptibility testing (DST) in referral hospitals contributes to delayed detection of multidrug-resistant tuberculosis (MDR-TB). OBJECTIVE To document the impact of identifying rifampicin (RMP) resistance using Xpert(®) MTB/RIF on time to diagnosis and time to treatment, and evaluate its performance under programmatic conditions. METHODS Using a prospective observational study, we screened presumptive MDR-TB cases with Xpert and solid culture/conventional DST. RMP resistance was confirmed using a line-probe assay (LPA). We recorded diagnostic and treatment delays. We performed rpoB gene sequencing post hoc to resolve discordant RMP susceptibilities. RESULTS We screened 299 of 345 presumptive MDR-TB individuals, and identified 44 Xpert RMP-resistant cases: 16/165 (10%) were new and 28/136 (20%) retreated. The median time to diagnosis was 2 days (Xpert) vs. an additional 6 with LPA; the median time to treatment was 14 days. Confirmatory LPA on 39/44 revealed 27 concordant, 6 discordant and 6 invalid results. Xpert RMP resistance was confirmed in respectively 24/30 (80%) and 21/23 (91%) by phenotypic DST and rpoB sequencing. CONCLUSION Screening presumptive MDR-TB patients with Xpert enabled rapid diagnosis and treatment of MDR-TB. Xpert performed well, provided appropriate risk assessment was done. Rapid confirmatory testing added little to clinical decision making. Our findings support the latest World Health Organization guidelines to abandon confirmatory LPA in favour of repeat Xpert when in clinical doubt, pending phenotypic DST.
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Affiliation(s)
- N Lorent
- Infectious Diseases Department, Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia; Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - C Kong
- Infectious Diseases Department, Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia
| | - T Kim
- Mycobacteriology Laboratory, Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia
| | - S Sam
- Cambodian Health Committee, Phnom Penh, Cambodia
| | - S Thai
- Infectious Diseases Department, Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia
| | - R Colebunders
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium; Epidemiology and Social Medicine, University of Antwerp, Antwerp, Belgium
| | - L Rigouts
- Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium; Department of Biomedical Sciences, University of Antwerp, Belgium
| | - L Lynen
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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Lin P, Stoakes E, Scott A, Sam S, Chicco A. Clinical Impact of Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Carried Out for Non-Medicare Eligible Indications in Australia: A Prospective Study. Clin Oncol (R Coll Radiol) 2015; 27:753-4. [PMID: 26345249 DOI: 10.1016/j.clon.2015.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
Affiliation(s)
- P Lin
- Department of Nuclear Medicine and PET, Liverpool Hospital, Australia; University of New South Wales, Sydney, Australia; University of Western Sydney, Australia
| | - E Stoakes
- Department of Nuclear Medicine and PET, Liverpool Hospital, Australia
| | - A Scott
- Department of Nuclear Medicine and PET, Liverpool Hospital, Australia
| | - S Sam
- Department of Nuclear Medicine and PET, Liverpool Hospital, Australia
| | - A Chicco
- Department of Nuclear Medicine and PET, Liverpool Hospital, Australia
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Khaldi K, Sam S, Gouget-Laemmel AC, Henry de Villeneuve C, Moraillon A, Ozanam F, Yang J, Kermad A, Ghellai N, Gabouze N. Active Acetylcholinesterase Immobilization on a Functionalized Silicon Surface. Langmuir 2015; 31:8421-8428. [PMID: 26153025 DOI: 10.1021/acs.langmuir.5b01928] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this work, we studied the attachment of active acetylcholinesterase (AChE) enzyme on a silicon substrate as a potential biomarker for the detection of organophosphorous (OP) pesticides. A multistep functionalization strategy was developed on a crystalline silicon surface: a carboxylic acid-terminated monolayer was grafted onto a hydrogen-terminated silicon surface by photochemical hydrosilylation, and then AChE was covalently attached through amide bonds using an activation EDC/NHS process. Each step of the modification was quantitatively characterized by ex-situ Fourier transform infrared spectroscopy in attenuated-total-reflection geometry (ATR-FTIR) and atomic force microscopy (AFM). The kinetics of enzyme immobilization was investigated using in situ real-time infrared spectroscopy. The enzymatic activity of immobilized acetylcholinesterase enzymes was determined with a colorimetric test. The surface concentration of active AChE was estimated to be Γ = 1.72 × 10(10) cm(-2).
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Affiliation(s)
- K Khaldi
- ‡Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, 13000 Tlemcen, Algeria
| | | | - A C Gouget-Laemmel
- §Physique de la Matière Condensée, Ecole Polytechnique-CNRS, 91128 Palaiseau, France
| | - C Henry de Villeneuve
- §Physique de la Matière Condensée, Ecole Polytechnique-CNRS, 91128 Palaiseau, France
| | - A Moraillon
- §Physique de la Matière Condensée, Ecole Polytechnique-CNRS, 91128 Palaiseau, France
| | - F Ozanam
- §Physique de la Matière Condensée, Ecole Polytechnique-CNRS, 91128 Palaiseau, France
| | - J Yang
- §Physique de la Matière Condensée, Ecole Polytechnique-CNRS, 91128 Palaiseau, France
| | - A Kermad
- ‡Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, 13000 Tlemcen, Algeria
| | - N Ghellai
- ‡Unité de Recherche Matériaux et Energies Renouvelables (URMER), Département de Physique, Faculté des Sciences, Université Abou Baker Belkaid, B.P. 119, 13000 Tlemcen, Algeria
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Royce S, Khann S, Yadav RP, Mao ET, Cattamanchi A, Sam S, Handley MA. Identifying multidrug resistance in previously treated tuberculosis patients: a mixed-methods study in Cambodia. Int J Tuberc Lung Dis 2015; 18:1299-306. [PMID: 25299861 DOI: 10.5588/ijtld.14.0116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Previously treated tuberculosis (TB) patients are a priority for drug susceptibility testing (DST) to identify cases with multidrug-resistant TB (MDR-TB). A Cambodia study found that one third of smear-positive previously treated patients had DST results. OBJECTIVE To quantify the gaps in the detection of MDR-TB in previously treated TB patients in Cambodia, and describe health workers' perspectives on barriers, facilitators and potential interventions. DESIGN Analysis of Cambodia's 2004-2012 case notifications and semi-structured interviews with stakeholders. RESULTS The proportion of previously treated notifications varied significantly across provinces in 2010-2012. If there had been no attrition along the path to detecting MDR-TB among smear-positive notified cases in 2012, an estimated 75 additional MDR-TB cases could have been identified, which would double the number actually detected. Most were lost due to misclassification of previously treated patients as 'new'. Barriers include patients' reluctance to disclose and staff difficulty in eliciting treatment history, partly attributed to the availability of streptomycin (SM) only in hospitals. Facilitators include collection of sputum for DST even if previously treated patients are not receiving SM, streamlining sputum transportation and prompt reporting of results. CONCLUSION Improved monitoring, supportive staff supervision and training, patient education, and correct classification of previously treated cases are essential for improving the detection of MDR-TB.
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Affiliation(s)
- S Royce
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
| | - S Khann
- Cambodia Office, World Health Organization, Phnom Penh, Cambodia
| | - R P Yadav
- Cambodia Office, World Health Organization, Phnom Penh, Cambodia
| | - E T Mao
- National Centre for Tuberculosis and Leprosy Control, Phnom Penh, Cambodia
| | - A Cattamanchi
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California San Francisco, San Francisco, California, USA
| | - S Sam
- Cambodian Health Committee, Phnom Penh, Cambodia
| | - M A Handley
- Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA
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Ait Ahmed N, Eyraud M, Hammache H, Vacandio F, Sam S, Gabouze N, Knauth P, Pelzer K, Djenizian T. New insight into the mechanism of cathodic electrodeposition of zinc oxide thin films onto vitreous carbon. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.01.103] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sam S, Shon IH, Vinod SK, Lin P, Lin M. Workflow and Radiation Safety Implications of 18F-FDG PET/CT Scans for Radiotherapy Planning. J Nucl Med Technol 2012; 40:175-7. [DOI: 10.2967/jnmt.111.099440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Touahir L, Allongue P, Aureau D, Boukherroub R, Chazalviel JN, Galopin E, Gouget-Laemmel A, de Villeneuve CH, Moraillon A, Niedziółka-Jönsson J, Ozanam F, Andresa JS, Sam S, Solomon I, Szunerits S. Molecular monolayers on silicon as substrates for biosensors. Bioelectrochemistry 2010; 80:17-25. [DOI: 10.1016/j.bioelechem.2010.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 03/12/2010] [Accepted: 03/18/2010] [Indexed: 10/19/2022]
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Touahir L, Sam S, Moraillon A, Ozanam F, Chazalviel JN, Allongue P, de Villeneuve CH, Gabouze N, Djebbar S, Gouget-Laemmel AC. Functionalized Silicon Surfaces for Biological and Chemical Sensors. ACTA ACUST UNITED AC 2010. [DOI: 10.1166/sl.2010.1293] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Belhousse S, Boukherroub R, Szunerits S, Gabouze N, Keffous A, Sam S, Benaboura A. Electrochemical grafting of poly(3-hexylthiophene) on porous silicon for gas sensing. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3284] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sam S, Chazalviel JN, Gouget-Laemmel AC, Ozanam F, Allongue P, Henry de Villeneuve C, Gabouze N, Djebbar S. Covalent immobilization of amino acids on the porous silicon surface. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3285] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sam S, Touahir L, Salvador Andresa J, Allongue P, Chazalviel JN, Gouget-Laemmel AC, Henry de Villeneuve C, Moraillon A, Ozanam F, Gabouze N, Djebbar S. Semiquantitative study of the EDC/NHS activation of acid terminal groups at modified porous silicon surfaces. Langmuir 2010; 26:809-14. [PMID: 19725548 DOI: 10.1021/la902220a] [Citation(s) in RCA: 214] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Infrared spectroscopy is used to investigate the transformation of carboxyl-terminated alkyl chains immobilized on a surface into succinimidyl ester-terminated chains by reaction with an aqueous solution of N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The acid chains are covalently grafted at the surface of hydrogenated porous silicon whose large specific surface area allows for assessing the activation yield in a semiquantitative way by infrared (IR) spectroscopy and detecting trace amounts of surface products and/or reaction products of small IR cross section. In this way, we rationalize the different reaction paths and optimize the reaction conditions to obtain as pure as possible succinimidyl ester-terminated surfaces. A diagram mapping the surface composition after activation was constructed by systematically varying the solution composition. Results are accounted for by NHS surface adsorption and a kinetic competition between the various EDC-induced surface reactions.
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Affiliation(s)
- S Sam
- Physique de la Matière Condensée, Ecole Polytechnique, CNRS, 91128 Palaiseau, France
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Zouadi N, Belhousse S, Cheraga H, Ouadah Y, Sam S, Ouchabane M, Henda K, Mahmoudi B, Gabouze N. Influence of temperature on electrical characteristics of CHx/porous silicon/Si sensing device. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2247] [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: 11/06/2022]
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Benzekkour N, Gabouze N, Sam S, Saoula N, Henda K. Electrical and optical characterisation of TiN porous Si/Si structures. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2242] [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: 11/11/2022]
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Fortas G, Sam S, Gabouze N, Guerbous L, Belaroussi Y, Manseri A. Electroless deposition study of silver into porous silicon. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2254] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Martínez Sánchez G, Candelario-Jalil E, Giuliani A, León OS, Sam S, Delgado R, Núñez Sellés AJ. "Mangifera indica L. extract (QF808) reduces ischaemia-induced neuronal loss and oxidative damage in the gerbil brain". Free Radic Res 2001; 35:465-73. [PMID: 11767405 DOI: 10.1080/10715760100301481] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [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: 10/24/2022]
Abstract
The effect of oral administration of Mangifera indica L. extract (QF808) on ischemia-reperfusion-induced neuronal death in the gerbil hippocampal CA1 sector was examined. Oral administration of QF808 for 7 days dose-dependently protected against neuronal cell death following transient ischaemia and reperfusion as assessed by histopathology. In addition, locomotor activity assessment prior to ischaemia and 7 days after correlated well with the histological results. To evaluate redox alterations by reactive oxygen species, total sulfhydryl, non-protein sulfhydryl groups (NPSH), malondialdehyde + 4-hydroxyalkenals and total nitrogen oxide levels were assayed in hippocampus and cortex homogenates. QF808 treatment attenuated NPSH loss, nitrogen oxide levels and lipid peroxidation in the hippocampus. These results suggest that orally administered QF808 is absorbed across the blood-brain barrier and attenuates neuronal death of the hippocampal CA1 area after ischaemia-reperfusion. These protective effects are most likely due to the antioxidant activity of QF808.
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Affiliation(s)
- G Martínez Sánchez
- Centre for Research and Biological Evaluation, Pharmacy Institute, Havana University, PO 10 400, Havana, Cuba.
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Candelario-Jalil E, Mohammed-Al-Dalain S, Fernández OS, Menéndez S, Pérez-Davison G, Merino N, Sam S, Ajamieh HH. Oxidative preconditioning affords protection against carbon tetrachloride-induced glycogen depletion and oxidative stress in rats. J Appl Toxicol 2001; 21:297-301. [PMID: 11481663 DOI: 10.1002/jat.758] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [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: 11/09/2022]
Abstract
The rectal insufflation of a judicious dose of ozone, selected from that used in clinical practice, is able to promote oxidative preconditioning or oxidative stress tolerance preventing the hepatocellular damage mediated by free radicals. In order to evaluate the effects of ozone oxidative preconditioning on carbon tetrachloride-mediated hepatotoxicity, the following experimental protocol was designed: group 1 (negative control, sunflower oil i.p.); group 2 (CCl(4) in sunflower oil, 1 ml kg(-1) i.p.); group 3 (15 ozone-oxygen pretreatments at a dose of 1 mg kg(-1) via rectal insufflation + CCl(4) as in group 2); group 4 (ozone control group, 15 ozone-oxygen pretreatments + sunflower oil i.p.). Ozone pretreatment prevented glycogen depletion (as demonstrated by biochemical and histopathological findings) and avoided lactate overproduction associated with the hepatotoxic effects of CCl(4). The administration of CCl(4) increased lipid peroxidation (as measured by thiobarbituric acid-reactive substances) and uric acid levels and inhibited superoxide dismutase activity. All these deleterious effects induced by CCl(4) were prevented by ozone pretreatment. The administration of ozone without CCl(4) (ozone control group) did not produce any changes in the evaluated parameters. Our results showed that ozone treatment, in our experimental conditions, was able to prevent anaerobic glycolysis and oxidative stress induced by CCl(4).
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Affiliation(s)
- E Candelario-Jalil
- Center for Research and Biological Evaluation, University of Havana, Institute of Pharmacy and Food Sciences, Apartado Postal 6079, Havana City 10600, Cuba.
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Tahmaz FE, Sam S, Hoganson GE, Quan F. A partial deletion of the aspartoacylase gene is the cause of Canavan disease in a family from Mexico. J Med Genet 2001; 38:E9. [PMID: 11238686 PMCID: PMC1734832 DOI: 10.1136/jmg.38.3.e9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
Kainate induces a marked expression of cyclooxygenase-2 after its systemic administration. Because cyclooxygenase-2 activity is associated to the production of reactive oxygen species, we investigated the effects of nimesulide, a selective cyclooxygenase-2 inhibitor, on kainate-induced in vivo oxidative damage in the rat hippocampus. A clinically relevant dose of nimesulide (6 mg/kg, i.p. ) was administered three times following kainate application (9 mg/kg, i.p.). After 24 h of kainate administration, the drastic decrease in hippocampal glutathione content and the significant increase in lipid peroxidation were attenuated in nimesulide-treated rats, suggesting that the induction of cyclooxygenase-2 is involved in kainate-mediated free radicals formation.
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Affiliation(s)
- E Candelario-Jalil
- Center for Research and Biological Evaluation, Institute of Pharmacy and Food Sciences (CIEB-IFAL), University of Havana, Havana, Cuba.
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Alvarez S, Berlanga J, Silva R, Rodríguez S, Marrero G, Valenzuela C, Castañeda J, Sam S. Acute toxicity assessment in sprague-dawley rats after administering the Neisseria meningitidis-P64k recombinant protein. Intramuscular administration. Toxicol Lett 1998. [DOI: 10.1016/s0378-4274(98)80453-0] [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: 11/30/2022]
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León OS, Menéndez S, Merino N, Castillo R, Sam S, Pérez L, Cruz E, Bocci V. Ozone oxidative preconditioning: a protection against cellular damage by free radicals. Mediators Inflamm 1998; 7:289-94. [PMID: 9792340 PMCID: PMC1781855 DOI: 10.1080/09629359890983] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
There is some anecdotal evidence that oxygen-ozone therapy may be beneficial in some human diseases. However so far only a few biochemical and pharmacodynamic mechanisms have been elucidated. On the basis of preliminary data we postulated that controlled ozone administration would promote an oxidative preconditioning preventing the hepatocellular damage mediated by free radicals. Six groups of rats were classified as follows: (1) negative control, using intraperitoneal sunflower oil; (2) positive control using carbon tetrachloride (CCl4) as an oxidative challenge; (3) oxygen-ozone, pretreatment via rectal insufflation (15 sessions) and after it, CCl4; (4) oxygen, as group 3 but using oxygen only; (5) control oxygen-ozone, as group 3, but without CCl4; group (6) control oxygen, as group 5, but using oxygen only. We have evaluated critical biochemical parameters such as levels of transaminase, cholinesterase, superoxide dismutase, catalase, phospholipase A, calcium dependent ATPase, reduced glutathione, glucose 6 phosphate dehydrogenase and lipid peroxidation. Interestingly, in spite of CCl4 administration, group 3 did not differ from group 1, while groups 2 and 4 showed significant differences from groups 1 and 3 and displayed hepatic damage. To our knowledge these are the first experimental results showing that repeated administration of ozone in atoxic doses is able to induce an adaptation to oxidative stress thus enabling the animals to maintain hepatocellular integrity after CCl4 poisoning.
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Affiliation(s)
- O S León
- Center for Research and Biological Evaluation (Pharmacy Institute of Havana University), Cuba.
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Abstract
The serpent (srp) gene, also known as ABF, codes for a GATA-like transcription factor and is involved in the transcription activation of Adh in the larval fat body or adipose tissue. Here, we describe the tissue-specific distribution of SRP protein in various stages of embryonic development and describe srp's role in early fat-cell development. SRP protein was detected in the progenitor fat-body cells and is present in the developing fat-body cells and in the mature embryonic fat body. An analysis of srp embryos revealed a gradual loss of precursor fat cells that is likely due to apoptosis. Within the fat-cell lineage, srp is necessary for progression through early stages of fat-cell development and may be involved in the transactivation of genes necessary for fat-cell differentiation.
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Affiliation(s)
- S Sam
- Department of Biological Sciences, University of Nevada at Las Vegas 89154-4004, USA
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