66 results on '"Apostolos Christopoulos"'
Search Results
2. First record of Anatololacerta pelasgiana (Mertens, 1959) in mainland Greece: another new species in Athens
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Apostolos Christopoulos, Charikleia-Foteini Pantagaki, Nikos Poulakakis, and Panayiotis Pafilis
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Vertebrata ,Tetrapoda ,Sarcopterygii ,Anatololacerta pelasgiana ,phylogenetic analysis ,Lacertoidea ,Amniota ,Mediterranean ,Biota ,urban ecology ,Gnathostomata ,Osteichthyes ,introduction ,Squamata ,Animalia ,Animal Science and Zoology ,Chordata ,Lacertidae ,lizard ,Anatololacerta ,Ecology, Evolution, Behavior and Systematics - Abstract
Urban habitats receive an increasing number of species due to anthropogenic activities, mainly transportations. Here, we report a new addition to the herpetofauna of Athens (Greece): a small population of the Pelasgian wall lizard (Anatololacerta pelasgiana) was found in a suburb of the Athenian metropolitan area. The species normally occurs in southwestern Anatolia and southeastern Aegean islands and this is the first record in the Greek mainland. Allochthonous species that successfully colonize cities raise new challenges to urban ecology.
- Published
- 2022
3. C-CASE 2022: Competence to Excellence01. The Queen Bee phenomenon in Canadian surgical subspecialties: an evaluation of gender biases in the resident training environment02. Barriers to surgical peer coaching — What have we learned, and where do we go from here?03. Shared decision-making and evidence-based medicine: Pivotal or trivial to patient care in orthopedic trauma?04. Immersive virtual reality and cadaveric bone are equally effective in skeletal anatomy education: a randomized crossover noninferiority trial05. Development of simulators for decentralized simulation-based education IO training using design thinking and Delphi — a novel approach06. The impact of feedback on laparoscopic skills for surgical residents during COVID-1907. The role of collaborative feedback and remote practice in the acquisition of suturing skills by medical students at Université de Montréal08. Efficacy testing of an affordable and realistic small bowel simulator for hand-sewn anastomosis09. The LASER rating scale: a new teaching tool in otolaryngology10. Virtual patient case simulations: their role in undergraduate and postgraduate surgical training11. Evaluating the effectiveness of video-assisted informed consent in surgery: a systematic review12. Communication patterns in the cardiac surgery operating room are affected by task difficulty: a simulation model13. Improving adherence to postcall departure guidelines in orthopedics: a quality-improvement initiative14. Increasing familiarity among team members helps to reduce laparoscopic procedure time15. The effectiveness of a self-directed online learning module on trainee knowledge and confidence during plastic surgery clinical rotations16. Implementing an orientation handbook before a surgical rotation in urology17. An examination of equity-related experiences of surgical trainees at academic centres across Ontario: design of a targeted needs assessment18. Viewing differences between experts and trainees: implication for surgical education19. Assessment of medical student exposure to and satisfaction with surgical subspecialty education20. Assessment of student exposure to climate impacts of surgical personal protective equipment in the undergraduate medical curriculum21. Virtual reality simulation for the middle cranial fossa approach — a face, content and construct validation study22. Evaluating the Canadian Orthopaedic Surgery Medical Education Course (COSMEC)23. Subpial resection in a novel ex vivo calf brain epilepsy simulation model24. Effectiveness of the Eyesi augmented reality simulator for ophthalmology trainees: a systematic review and meta-analysis25. Learning beyond the objectives: an evidence-based analysis of AI-selected competencies in surgical simulation training26. Virtual compared with in-person surgical grand rounds: participants’ perceptions, preferences and directions for the future27. Quality of narrative feedback for entrustable professional activities assessed in the operating room: analysis of 4. years of assessments in the surgical foundations curriculum at Queen’s University28. SimOscopy: an accessible 3D-printed and laser-cut laparoscopic surgical simulator developed for a mobile device29. A debriefing tool to acquire nontechnical skills in trauma courses30. Capacity building using a hub-and-spokes model to produce customizable simulators for surgical education31. Exploring skin tone diversity in a plastic surgery resident education curriculum32. Video-based assessments of thoracic surgery trainees’ operative skills as adjuncts in competency-based medical education33. How do you feel? An examination of team leaders’ and members’ emotions in surgical simulations34. Comparing the efficacy of a real-time intelligent coaching system to human expert instruction in surgical technical skills training: randomized controlled trial35. Empowering women to pursue surgery: launching a pilot gender-congruent mentorship program for medical students36. Affective and cognitive responses to a virtual reality spine simulator37. Immersive virtual reality for patient-specific preoperative planning: a systematic review38. The categorization of surgical problems by junior and senior medical students39. The application of microlearning modules in surgical education to enhance procedural skills and surgical training40. Authorship gender disparity and trends in female authorship in 5 high-impact orthopedic journals from 2002 to 202241. The landscape of Canadian academic surgery: analysis of gender representation, academic rank, and research productivity
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Stuti M. Tanya, Reva Qiu, Basmah AlTinawi, Mathew N. Hindi, Trisha Tee, Sheharzad Mahmood, Recai Yilmaz, Keerat Grewal, Nicole Stachura, Raahulan Rathagirishnan, Julia Micallef, Fabio Botelho, Stephanie Roberts, Rosephine Del Fernandes, Giuseppe Retrosi, Ali M. Fazlollahi, Lauren Carr, Nour Abou Hamdan, Anser Daud, Carolyn Lai, Sébastien Belliveau, Morgan S. Gold, Yao Zhang, Ishita Aggarwal, Ioana Fugaru, Pedram Akbari, Ajay Shah, Abigail White, Apoorva Bhandari, David Fleiszer, Ève Sédillot-Daniel, Florence Bénard, Florence Pelletier, Chelsea Harris, Mithusa Sivanathan, Dario Ferri, Jenny W. Jing, Sofia Valanci Aroesty, Lydia Goff, Helena Greene, Alexandra Munn, Andrew Furey, Nicholas Smith, Rhonda St. Croix, Susan Moffatt-Bruce, Guylaine Lefebvre, Edward J. Harvey, Rudolph Reindl, Hamid Al Badi, Gregory K. Berry, Paul A. Martineau, Robert Koucheki, Johnathan R. Lex, Alexandra Morozova, Tyler M. Hauer, Sarah Mirzaie, Peter C. Ferguson, Barbara Ballyk, Luz Yanguez Franco, Ian R. Drennan, Dale Button, Adam Dubrowski, Casey Thorburn, Claire Skanes, Robert Kennedy, Chris Smith, Andrei Torres, Léamarie Meloche-Dumas, Natasha Guérard-Poirier, Ahmad Kaviani, Bill Kapralos, Frédéric Mercier, Erica Patocskai, Merieme Habti, Simon Bérubé, Dominic Cadoret, Artur Arutiunian, Yasmina Papas, Antoine Melkane, Carlos Chiesa, Nicolas Fakhry, Vyvy Young, Libby Smith, Jerome Lechien, Louis Guertin, Marie-Jo Olivier, Anastasios Maniakas, R. Jun Lin, Éric Bissada, Apostolos Christopoulos, Tareck Ayad, Andrée-Anne Leclerc, Nancy Posel, Alicia Rosenzveig, Peter Gariscsak, Laryssa Kemp, Faizal Haji, Andrew Reid, Surita Sidhu, Michael Moon, Simon Turner, Bin Zheng, Jesse Isaac Wolfstadt, Jeremy Hall, Sarah Ward, Abdulrahman Jad, Nicholas Yee, Tayler Declan Ross, Peter Ferguson, Chantal Valiquette, Shakira Brathwaite, Greg Hawley, Glykeria Martou, Michael Hendry, Victoria Schouela, Mélanie Aubé-Peterkin, Andrea Winthrop, Morgan Gold, Justin T. Lui, Madeleine de Lotbiniere-Bassett, Joseph M. Chen, Vincent Y. Lin, Sumit K. Agrawal, Nikolas H. Blevins, Hanif M. Ladak, Farhad Pirouzmand, Tyler Hauer, Jesse Wolfstadt, Abdulrahman Almansouri, Mohammadreza Eskandari, Chinyelum Agu, Puja Pachchigar, Bianca Giglio, Neevya Balasubramniam, Houssem-Eddine Gueziri, Rolando Del Maestro, Tyler McKechnie, Amin Hatamnejad, Jenny Chan, Anne Beattie, Ahmad Alsayegh, Mohamad Bakhaidar, Rolando F. Del Maestro, Nafisa Dharamsi, Ingrid de Vries, Steve Mann, Laura McEwen, Timothy Phillips, Boris Zevin, Andrew Robart, Hannah Brennan, Joshua Conway, Christopher Patey, Jason Harley, Dan Poenaru, Krystina Clarke, Marie-Ève Roy, Stephane Bedwani, Érica Patocskai, Jane Zhu, Alexander Adibfar, Laura Snell, Rahul Nayak, Richard Malthaner, Dalilah Fortin, Richard Inculet, Mehdi Qiabi, Sayed Azher, Matthew Moreno, Lucia Patino Melo, Reinhard Pekrun, Jeffrey Wiseman, Gerald M. Fried, Susanne Lajoie, Ryan Brydges, Allyson Hadwin, Ning-Zi Sun, Elene Khalil, Jason M. Harley, Sarah Almas, Joanna Ryan, Blaire Anderson, Bilal Tarabay, Lucy Lan, Randi Mao, Jeffrey Kay, SA Darren de, Geoffrey Blair, Alborz Noorani, Sama Noorani, Megan Mak, George Ibrahim, Mojgan Hodaie, Katie van Kampen, Emily Domerchie, Patricia Farrugia, Maxine Joly-Chevrier, Anne Xuan-Lan Nguyen, Daiana Roxana Pur, Rebecca J. Power, Sanjay Sharma, Fiona Costello, and Femida Kherani
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Surgery - Published
- 2022
4. FinTech’s rapid growth and its effect on the banking sector
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Charalampos Basdekis, Apostolos Christopoulos, Ioannis Katsampoxakis, and Aikaterini Vlachou
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General Agricultural and Biological Sciences - Abstract
FinTech is a New Financial Technology, which provides financial services through innovative information and communication technologies. It is widely accepted that 4th industrial revolution, has affected tremendously the living and working conditions of the societies. The convergence between advanced technologies, entrepreneurship becomes more complex and remarkably computerized. Within such significant changes it is rather expected that banking, has been one of the most challenged sectors. New players like FinTech and Big Tech companies try to capitalize the circumstances, by promoting new consumer patterns to gain market shares. The purpose of this study is to investigate the rapid expansion of FinTech and to evaluate its impact on the Greek banking system. This topic becomes very important nowadays as the number of FinTech companies, which compete with traditional banks on financial products and services, are increasing constantly as digital technology develops. In our study we apply a questionnaire method mainly with closed questions to collect data from the main players. To do this, we use two questionnaires each one for a different sample. The first sample consists of the consumers for financial products and services in the Greek banking sector and the second sample consists of the employees in the Greek banking sector. According to the results, customers of all ages seem to trust the traditional banks more than FinTech companies whereas the level of mobile transactions separately for each consumer, depends on age and education. From the answers of the consumers, it is clear that security is on the top of their worries for using financial services by FinTech companies. On the other hand, the second questionnaire with bank employees shows clearly that educational level is a critical factor for their readiness and response to new technologies.
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- 2022
5. Quantification and visualization of aerosols in ear, nose, and throat exam and flexible laryngoscopy
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Guillaume B. Cardin, Dominic Rivest, Tareck Ayad, Étienne Robert, Akram Rahal, and Apostolos Christopoulos
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General Medicine - Abstract
To measure and visualize aerosol generation during ear, nose, and throat (ENT) exam and flexible laryngoscopy, as safety recommendations are currently to defer routine and low-priority examinations.Aerosols generated during ENT examination and flexible laryngoscopy were quantified by laser aerosol spectrometry and visualized live by high-speed imaging during those procedures for three participants who were tested three times for each test.Routine ENT examination and flexible laryngoscopy produce aerosols at levels comparable to normal breathing and speech.During ENT examination and flexible laryngoscopy, the practitioner should wear a surgical mask and potentially contaminated surfaces should be cleaned after the procedure. For flexible laryngoscopy, it is recommended in addition that the patient wear a mask over the mouth in case the procedure induces a sneeze. The time during which the patient is unmasked should be minimized. In these settings, the risk to the practitioner is minimal unless the patient is sneezing or symptomatic.1.
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- 2022
6. French translation and validation of the Neck Dissection Impairment Index, a quality of life measure for the surgical oncology population
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Michel Khoury, William Guertin, Cameo Hao, Mikhail Saltychev, Tareck Ayad, Eric Bissada, Apostolos Christopoulos, Sami Moubayed, Marie-Jo Olivier, Douglas Chepeha, Stephen Y. Lai, and Anastasios Maniakas
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Background: Neck dissections (ND) are a routine procedure in head and neck oncology. Given the post-operative functional impact that some patients experience, it is imperative to identify and track quality of life (QoL) symptomatology in order to tailor each patient’s therapeutic needs. To date, there is no validated francophone questionnaire for this patient-population. We therefore sought to translate and validate the Neck Dissection Impairment Index (NDII) in French. Methods: A three-phased approach was used. Phase 1: The NDII was translated from English to French using a “forward and backward” translational technique following international guidelines. Phase 2: A cognitive debriefing session was held with ten French-speaking otolaryngology patients to evaluate understandability and acceptability. Phase 3: The final version was administered prospectively to 30 patients with prior history of ND and 30 control patients. These patients were asked to complete the questionnaire 2 weeks after their first response. Test-retest reliability was calculated with Spearman’s correlation. Internal consistency was elicited using Cronbach’s alpha. Results: NDII was successfully translated and validated to French. Cronbach’s alpha revealed high internal consistency (0.92, lower 95% CL 0.89). The correlation for test-retest validity were strong or very-strong (0.61-0.91). Conclusion: NDII is an internationally recognized QoL tool for the identification of ND-related impairments. This validated French version will allow clinicians to adequately assess the surgery-related QoL effect of neck surgery in the French-speaking population, while allowing French institutions to conduct and/or participate in multi-site clinical trials requiring the NDII as an outcome measure.
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- 2023
7. Phylogenetic analysis of the Critically Endangered Karpathos water frog (Anura, Amphibia): Conservation insights from complete mitochondrial genome sequencing
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Elisavet-Aspasia Toli, Anastasios Bounas, Apostolos Christopoulos, Panayiotis Pafilis, and Konstantinos Sotiropoulos
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Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics - Abstract
The Karpathos water frog (Pelophylax cerigensis) is classified as Critically Endangered according to the IUCN Red List and its distribution is restricted on the island of Karpathos, South Aegean Sea. Utilizing a next generation sequencing approach, we obtained whole mitochondrial genomes of P. cerigensis to determine the species phylogenetic position within the genus Pelophylax and to clarify the phylogenetic relationship between the species’ population on Karpathos Island and the population of P. cf. bedriagae from the neighboring Rhodes Island. High-throughput sequencing generated mean ± SD = 227 945 ± 18 306 reads averaged per sample. High quality reads were assembled resulting in the complete mitogenome of P. cerigensis of a total size of 17 922 bp. Mitogenome organization was similar to other Pelophylax species, comprising of 13 Protein Coding Genes (PCGs), 22 tRNAs, two rRNAs and one Control Region. Overall mean genetic distance for the 13 PCGs, within the Ranidae family, ranged from 8.01% (COIII) to 11.6% (ATP8), while ratios of synonymous and non-synonymous substitutions were p-distance = 0.1%). Hence, the Rhodes populations seem to belong to P. cerigensis and not to P. bedriagae as formerly thought, highlighting the need for revision of P. cerigensis current conservation status as well as further examination of the P. bedriagae species group.
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- 2023
- Full Text
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8. VaR as a risk management framework for the spot and futures tanker markets
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Ioannis Katsampoxakis, Charalampos Basdekis, Alexandros Gkolfinopoulos, and Apostolos Christopoulos
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Numerical Analysis ,business.industry ,Strategy and Management ,Autoregressive conditional heteroskedasticity ,Risk management framework ,Management Science and Operations Research ,Hedge fund ,Computational Theory and Mathematics ,Order (exchange) ,Management of Technology and Innovation ,Modeling and Simulation ,Econometrics ,Economics ,Statistics, Probability and Uncertainty ,business ,Rate risk ,Futures contract ,Value at risk ,Risk management - Abstract
The fluctuation of the freight rates is an important source of risk for all participants in the tanker shipping markets including ship-owners, charterers, traders, hedge funds, banks, etc. This study examines the freight rate risk involved in the most popular clean tanker route and the most popular dirty tanker route using historical prices from April 2008 to September 2015 for the routes TC5 and TD7 which are further divided into an in-sample period from 24 April 2008 to 7 November 2013, to estimate the coefficients and an out-of-sample period from 8 November 2013 to 2 September 2015, to measure the day to day Value at Risk performance. The analysis of the historical returns of both spot and future prices reveals historical distributions with high peaks and fat tails. The establishment of a risk management method that could capture these distribution characteristics is of paramount importance. For the quantification of the risk, the Value at Risk approach is applied. More specifically, a range of parametric (multiple GARCH family) and non-parametric (i.e. historical simulation) Value at Risk models are applied on the returns of both TC5 and TC7 spot and one and three months future markets. The results suggest substantial freight rate risk at both routes. The backtesting of the Value at Risk models is applied in two stages, firstly by the means of statistical accuracy of the results and secondly by the means of economic accuracy, in order to track down the best VAR models in the case of our research. According to the results, the simple GARCH and non-parametric models are proposed for risk management purposes, for both spot and future markets. The results are consistent for both long and short positions. According to the results, simple GARCH non-parametric models perform better in risk management, for both spot and futures markets. The results are consistent for both long and short positions.
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- 2021
9. Entrapped in Olive-Harvesting Nets: A Case of a Grass Snake Natrix natrix from an Olive-Growing Greek Aegean Island
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Yiannis G. Zevgolis and Apostolos Christopoulos
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Ecology ,Ecological Modeling ,Agricultural and Biological Sciences (miscellaneous) ,Nature and Landscape Conservation - Abstract
Despite a recent shift towards sustainable practices to support the conservation of traditional olive groves, little is known about their potential threats to herpetofauna species. On the island of Lesvos, one of the main olive-growing islands in the Mediterranean, olive cultivation often prioritizes the expeditious harvesting of olives with minimal or no supplementary intervention, resulting in their generally suboptimal management, a component of which also pertains to the olive nets that, in many cases, remain dispersed and unfurled throughout the groves. This particular practice affects the species living in the olive groves, making them more prone to risks related to their accidental trapping. In this study, we report the first case of a Grass snake being inadvertently trapped in an olive net laid out on an olive grove. The position of the snake under the net, within a folded tipping, made it difficult for it to escape, and it became increasingly entangled. Based on this incident, it is plausible to assume that similar cases may occur in areas where nets are used in olive groves, both in Greece and other olive-growing countries. Further systematic research is necessary to determine the extent of this issue.
- Published
- 2023
10. The effect of corruption on the level of real and accrual earnings management in cases of target firms
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Apostolos Christopoulos, Ioannis Dokas, Christos Leontidis, and Eleftherios Spyromitros
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General Business, Management and Accounting ,Finance - Abstract
PurposeThis paper attempts to investigate the effect of corruption on the real and accrual earnings management of target firms in the process of mergers and acquisitions.Design/methodology/approachThe sample includes target firms from the European area that participate in mergers or acquisitions announced during 2010–2020. The preliminary empirical part estimates the level of earnings management during the period two years before the deal's announcement to identify whether the sample follows the manipulation behavior that the literature suggests for target firms. The primary empirical analysis focuses on the impact of corruption on real and accrual-based earnings management proxies, employing regression models and two alternative proxies for corruption. The existing literature points out that the combination of low levels of corruption and an integrated legal system reduces earnings manipulation.FindingsThe findings provide strong evidence for systematic downwards accounting manipulation practices, whereas the findings for real earnings management are not significant. The findings of the main empirical part show that corruption is positively associated with accrual-based manipulation and negatively related to real earnings management. In essence, in economies with a high level of transparency, managers adopt the manipulation of operating activities as a less detectable practice of earnings management instead of engaging in accounting procedures.Originality/valueThis study contributes to the literature highlighting the diversification of these firms' manipulation strategies according to the national level's corruption status.
- Published
- 2022
11. Profitability and optimal debt ratio of the automobiles and parts sector in the Euro area
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Alexandros Lyras, Ioannis Katsampoxakis, Charalampos Basdekis, and Apostolos Christopoulos
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Index (economics) ,Capital structure ,media_common.quotation_subject ,05 social sciences ,Monetary economics ,0506 political science ,Interest rate ,Debt ,0502 economics and business ,050602 political science & public administration ,Per capita ,Economics ,050211 marketing ,Profitability index ,Debt ratio ,Panel data ,media_common - Abstract
PurposeThe goal of this paper is twofold: to assess the influence of specific corporate and market features on automobiles and parts sector's profitability in Euro area and to identify this particular sector's optimum debt level.Design/methodology/approachFor the paper's purposes, the authors applied a panel data analysis on an annual basis for the period 2005–2017.FindingsThere is a strong statistical significance of debt ratio, growth domestic product per capita growth, E.C.'s economic sentiment index (ESI), the European Central Bank key interest rate and the Euro area crisis on sector's profitability, while weak statistical significance appears to emerge for the firm's size. Moreover, the authors find average 14.4% profitability for the entire sector of the Euro area, without significant fluctuations among firms and/or during the examined time period. Another interesting finding of this study is that results are consistent with the theory of Modigliani Miller that financial leverage at a “low” level is beneficial for the firm, but beyond a turning point, it becomes counterproductive. This turning point for the automobiles and parts sector in Euro area has been computed at 47.3%.Originality/valueThe paper focuses on issues of profitability, capital structure and optimal debt ratio of an important sector of the economy, the automotive sector. As regards the Euro area automotive sector, it is a dynamic sector with a significant multiplier effect for the European economy as it is strongly correlated with other industrial sectors as chemicals, steel, textiles, information technology and so forth, having an outstanding multiplier effect on the economy.
- Published
- 2020
12. Phase II study of de‐intensified intensity‐modulated radiotherapy and concurrent carboplatin/5‐fluorouracil in lateralized p16‐associated oropharyngeal carcinoma
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Edith Filion, Apostolos Christopoulos, Tareck Ayad, M. Alizadeh, Eric Bissada, Louise Lambert, Phuc Felix Nguyen-Tan, Denis Soulières, Houda Bahig, Louis Guertin, and Manon Bélair
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medicine.medical_specialty ,medicine.medical_treatment ,Phases of clinical research ,Carboplatin ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Humans ,Stage (cooking) ,business.industry ,Cancer ,Radiotherapy Dosage ,medicine.disease ,humanities ,Radiation therapy ,Oropharyngeal Neoplasms ,stomatognathic diseases ,Otorhinolaryngology ,Oropharyngeal Carcinoma ,chemistry ,Fluorouracil ,030220 oncology & carcinogenesis ,Carcinoma, Squamous Cell ,Radiotherapy, Intensity-Modulated ,Radiology ,Intensity modulated radiotherapy ,business ,medicine.drug - Abstract
Purpose To assess cancer control and patient-reported outcomes (PROs) after de-intensified intensity-modulated radiotherapy (IMRT) in lateralized p16-associated oropharyngeal cancer (p16-OPC). Methods Lateralized p16-OPC treated with radiotherapy and concurrent Carboplatin/5-fluorouracil between 2011 and 2014 were enrolled. De-intensified IMRT consisted in elective neck dose of 43.2 Gy/24 fractions and omission of contralateral retropharyngeal/level IV nodes. PROs were assessed using the EORTC QLC-C30 and QLQ-HN35 scales. Results Twenty-nine patients were included. Median follow-up was 44 months. As per AJCC 7th Ed, 7%, 83% and 10% of patients had stage III, IVa and IVb. 5-year locoregional control and overall survival rates were 100% and 100%, respectively. Rates of acute were 52% and 35%, respectively. At 2 years post-treatment, 50% and 14% of patients had grade 1 xerostomia and dysgueusia, respectively. Most PROs scores returned to baseline within 8 months post-treatment. Conclusion De-intensified IMRT was associated with excellent cancer outcomes, and rapid recovery of PROs in lateralized p16-OPC.
- Published
- 2020
13. The Malmquist Productivity measure for UK-listed firms in the aftermath of the global financial crisis
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Sofia Katsimardou, Eleftherios Spyromitros, Apostolos Christopoulos, and Ioannis G. Dokas
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Numerical Analysis ,Index (economics) ,Emerging technologies ,Strategy and Management ,Sample (statistics) ,Monetary economics ,Management Science and Operations Research ,Computational Theory and Mathematics ,Stock exchange ,Management of Technology and Innovation ,Modeling and Simulation ,Financial crisis ,Business ,Statistics, Probability and Uncertainty ,Productivity ,Total factor productivity ,Capitalization - Abstract
Using a Bootstrap Malmquist Productivity Index approach, this paper investigates productivity changes of 24 high capitalization firms, listed in the London Stock Exchange over the period from 2009 to 2016. In the aftermath of the global financial crisis, we find evidence of technological and technical efficiency variations for our sample of industrial firms. Specifically, we show that, on average, only 26.2% of the examined firms managed to perform a positive increase in their Total Factor Productivity for the investigated period. There is an apparent deterioration in the technological efficiency for all firms, enhancing the view that these companies avoided investing in new technologies. However, in general, an improvement of technical efficiency is observed, meaning that firms improve the allocation of their available inputs in the production process.
- Published
- 2020
14. Predation of the <scp>Balkan</scp> frog <scp> Pelophylax kurtmuelleri </scp> ( <scp>Gayda</scp> , 1940) ( <scp>Anura: Ranidae</scp> ) by the giant water bug <scp> Lethocerus patruelis </scp> ( <scp>Stål</scp> , 1854) ( <scp>Hemiptera: Heteroptera: Belostomatidae</scp> )
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Apostolos Christopoulos, Hera Daskalaki, Konstantinos Vlachopoulos, and Panayiotis Pafilis
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Insect Science ,Ecology, Evolution, Behavior and Systematics - Published
- 2022
15. Preoperative evaluation of depth of invasion in oral tongue squamous cell carcinoma: A systematic review and meta-analysis
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Béatrice Voizard, Michel Khoury, Nadim Saydy, Kristoff Nelson, Guillaume B. Cardin, Laurent Létourneau-Guillon, Abdelali Filali-Mouhim, and Apostolos Christopoulos
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Cancer Research ,Oncology ,Oral Surgery - Abstract
The inclusion of depth of invasion (DOI) in the American Joint Committee on Cancer's staging system for oral cavity squamous cell carcinoma (SCC) has major clinical impacts. Recent studies have evaluated the reliability of imaging modalities and biopsy techniques to measure DOI preoperatively. The objective of this systematic review and meta-analysis was to comprehensively include all previously described methods to measure preoperative DOI in oral tongue SCC (OTSCC) and to compare their reliability. A systematic review was conducted on PubMed, Embase and Cochrane according to the PRISMA guidelines. Studies that evaluated the reliability of DOI measured on biopsy or imaging (rDOI) by comparing it to DOI on histopathology (pDOI) were included for extraction. A meta-analysis was conducted to obtain pooled correlation coefficients for each imaging modality. The pooled correlation coefficients between rDOI and pDOI were 0.86 (CI
- Published
- 2023
16. Reconstruction of medium-size defects of the oral cavity: radial forearm free flap vs facial artery musculo-mucosal flap
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Louis Guertin, Akram Rahal, Tareck Ayad, Eric Bissada, Badr Ibrahim, and Apostolos Christopoulos
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medicine.medical_specialty ,RD1-811 ,RFFF ,Facial artery ,Free flap ,Oral cavity ,Free Tissue Flaps ,Mucosal flap ,medicine.artery ,Chart review ,FAMM ,medicine ,Humans ,Original Research Article ,Retrospective Studies ,Mouth ,business.industry ,Locoregional flap ,Arteries ,Plastic Surgery Procedures ,Surgery ,Forearm ,Otorhinolaryngology ,Radial forearm free flap ,Difference analysis ,Complication ,business - Abstract
Background The radial forearm free flap (RFFF) is the most commonly used flap for defects of the oral cavity. The facial artery musculomucosal (FAMM) is a safe and effective method to reconstruct medium sized defects of the oral cavity. No comparison exists between the FAMM flap and RFFF. Methods 1) Retrospective chart review from 2007 to 2016. 2) Cost difference analysis. Results Thirteen FAMM flap cases and 18 RFFF met inclusion criteria. The FAMM flap showed a tendency to lower rates of return to the operating room (p = 0.065) as well as lower rates of complications not requiring return to the OR with 1 complication in 1 patient as opposed to 10 patients with 15 complications (p = 0.008). Also, FAMM flap had shorter operative times compared to the RFFF group (7.2HR and 8.9 HR respectively, p = 0.002). The average operative room related costs for a FAMM flap were 6510 CAD vs 10,703 CAD for RFFF (p p > 0.05). Conclusion The FAMM flap can be used for reconstruction of medium-size defects of the oral cavity with functional outcomes similar to the RFFF while decreasing the associated costs and morbidity. Graphical Abstract
- Published
- 2021
17. An (Un)Expected Threat for a Regionally Near-Threatened Species: A Predation Case of a Persian Squirrel on an Insular Ecosystem
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Yiannis G. Zevgolis, Apostolos Christopoulos, Ioannis Ilias Kalargalis, Stylianos P. Zannetos, Iosif Botetzagias, and Panayiotis G. Dimitrakopoulos
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General Veterinary ,Animal Science and Zoology - Abstract
One of the most successful predators on island ecosystems is the domestic cat, which is considered responsible for the decline of numerous species’ populations. This can be estimated by the analysis of cats’ dietary habits, yet prey identification is not always possible, and thus, in cases where precise prey identification is required, one of the most accurate methods derives from observing the hunting process. However, the cryptic nature of the feral cats and the constant vigilance of the species that are preyed upon make the observation process difficult, especially when the prey has a low population density. Here, we report for the first time such a case: a feral cat that has ambushed, killed, and consumed a regionally near-threatened species, the Persian squirrel. This incidental observation happened in the squirrel’s westernmost end of its distribution, the island of Lesvos, Greece. Due to the unexpectedness of the event, in the following days, we estimated both the squirrels’ and cats’ population density. Results showed that while the density of the squirrels is moderate, the population density of the feral cats is almost fifteen times higher. For this reason, management actions need to be taken in an effort to minimize the impacts of feral cats on the native species of the island.
- Published
- 2022
18. A New Invasion of the Common Slider on a Mediterranean Island (Lesvos, Greece): A Potential Threat to Native Terrapin Populations?
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Apostolos Christopoulos and Yiannis G. Zevgolis
- Subjects
Ecology ,Ecological Modeling ,Agricultural and Biological Sciences (miscellaneous) ,Nature and Landscape Conservation - Abstract
Island wetlands are considered crucial to biodiversity due to their unique ecological, biogeographical, and socioeconomic dynamics. However, these habitat types are particularly vulnerable to invasion; invasive species can cause severe ecological, evolutionary, and epidemiological impacts on native species. One of the most important invasive species, the common slider Trachemys scripta, an opportunistic inhabitant of freshwater habitats, has been released in multiple localities across Greece in recent years, and has expanded its range through random and unintentional releases in the Aegean islands. Since its first documented record on the island of Crete in 1998, the species has been observed on six more islands. Here, we report, for the first time, two subspecies of the common slider (T. scripta scripta and T. scripta elegans) on the wetlands of the island of Lesvos. We discuss the potential threats to native terrapins and we examine whether the introduction of this invasive species has affected native terrapins by monitoring their populations for 12 consecutive years (2010–2022). We found the common slider in 3 out of 110 wetlands surveyed. At one site, we document the presence of invasive terrapins belonging to two different subspecies. In all surveyed wetlands, we found stable populations of the two native freshwater terrapins, Mauremys rivulata and Emys orbicularis, with the first species found in much larger populations than the second. Despite these reassuring findings, the presence of this introduced species on the island of Lesvos raises serious concerns regarding its negative effects on the local terrapin populations. We propose that systematic and thorough monitoring of insular wetlands, as in the case of Lesvos, should be adopted on other islands as well, with priority on those where the common slider has been recorded.
- Published
- 2022
19. Rapid head and neck tissue identification in thyroid and parathyroid surgery using optical coherence tomography
- Author
-
Wendy-Julie Madore, Apostolos Christopoulos, Caroline Boudoux, Nathan Yang, Louis Guertin, Eric Bissada, Etienne De Montigny, Anastasios Maniakas, Olga Gologan, Tareck Ayad, and Sharmila Khullar
- Subjects
Adult ,Male ,Thyroid nodules ,Parathyroidectomy ,Pathology ,medicine.medical_specialty ,genetic structures ,medicine.medical_treatment ,Thyroid Gland ,030204 cardiovascular system & hematology ,01 natural sciences ,Parathyroid Glands ,010309 optics ,03 medical and health sciences ,0302 clinical medicine ,0103 physical sciences ,medicine ,Humans ,Thyroid Neoplasms ,Thyroid Nodule ,Lymph node ,Thyroid cancer ,Aged ,business.industry ,Thyroid ,Thyroidectomy ,Neck dissection ,Middle Aged ,medicine.disease ,3. Good health ,Parathyroid Neoplasms ,medicine.anatomical_structure ,Adipose Tissue ,Otorhinolaryngology ,Neck Dissection ,Female ,Parathyroid gland ,Lymph Nodes ,business ,Head ,Neck ,Tomography, Optical Coherence - Abstract
BACKGROUND Optical coherence tomography (OCT) is a noninvasive imaging modality that may reproduce the microarchitecture of tissues in real-time. This study examines whether OCT can render distinct images of thyroid, parathyroid glands, adipose tissue, and lymph nodes in both healthy and pathological states. METHODS Twenty-seven patients undergoing thyroidectomy, parathyroidectomy, and/or neck dissection for thyroid cancer were recruited prospectively for imaging prior to histopathological analysis. RESULTS Based on 122 imaged specimens, qualitative OCT descriptions were derived for healthy thyroid, parathyroid gland, adipose tissue, and lymph node. The frequencies at which distinguishing features were present for each tissue type were 88%, 83%, 100%, and 82%. OCT appearance of pathological specimens were also described. CONCLUSIONS Healthy neck tissues have distinct OCT appearances, which could facilitate parathyroid identification during thyroidectomies. However, images of parathyroid adenomas could be confused with those of lymph nodes, and benign and malignant thyroid nodules could not be differentiated.
- Published
- 2019
20. Crude Oil Price Shocks and European Stock Markets during the COVID-19 Period
- Author
-
Ioannis Katsampoxakis, Apostolos Christopoulos, Petros Kalantonis, and Vasileios Nastas
- Subjects
Control and Optimization ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Building and Construction ,Electrical and Electronic Engineering ,crude oil ,stock market ,VAR models ,COVID-19 ,Engineering (miscellaneous) ,health care economics and organizations ,Energy (miscellaneous) - Abstract
This paper investigates the interrelations between stock returns and crude oil prices for European oil-importing/exporting countries. A vector autoregression (VAR) model is applied to estimate the significance of stock market responses to changes in oil prices during the pandemic period 2019–2021. A Granger causality test is applied to find the direction and the intensity of the relation between crude oil and the indices of the European stock markets. The findings of this paper hold with or without the COVID-19 pandemic episode and reveal the interaction between the European stock markets and the crude oil prices. The results indicate that in steady periods, before the COVID-19 outbreak and after the announcement of vaccinations, there is no interdependence between crude oil and stock prices, whereas in high volatility periods, the causality from stock markets to oil prices increases and both oil-exporting and -importing countries are equally influenced. These findings have implications both for investors and fund managers.
- Published
- 2022
21. mTOR as a senescence manipulation target: A forked road
- Author
-
Sarah, Saoudaoui, Monique, Bernard, Guillaume B, Cardin, Nicolas, Malaquin, Apostolos, Christopoulos, and Francis, Rodier
- Subjects
Aging ,Neoplasms ,TOR Serine-Threonine Kinases ,Autophagy ,Animals ,Humans ,Antineoplastic Agents ,Molecular Targeted Therapy ,Protein Kinase Inhibitors ,Cellular Senescence - Abstract
Cellular senescence, cancer and aging are highly interconnected. Among many important molecular machines that lie at the intersection of this triad, the mechanistic (formerly mammalian) target of rapamycin (mTOR) is a central regulator of cell metabolism, proliferation, and survival. The mTOR signaling cascade is essential to maintain cellular homeostasis in normal biological processes or in response to stress, and its dysregulation is implicated in the progression of many disorders, including age-associated diseases. Accordingly, the pharmacological implications of mTOR inhibition using rapamycin or others rapalogs span the treatment of various human diseases from immune disorders to cancer. Importantly, rapamycin is one of the only known pan-species drugs that can extend lifespan. The molecular and cellular mechanisms explaining the phenotypic consequences of mTOR are vast and heavily studied. In this review, we will focus on the potential role of mTOR in the context of cellular senescence, a tumor suppressor mechanism and a pillar of aging. We will explore the link between senescence, autophagy and mTOR and discuss the opportunities to exploit senescence-associated mTOR functions to manipulate senescence phenotypes in age-associated diseases and cancer treatment.
- Published
- 2021
22. Development, translation, and preliminary validation of the neck dissection assessment tool
- Author
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Eric Bissada, Jean-Claude Tabet, Louis Guertin, Érika Mercier, Carlos M. Chiesa-Estomba, Tareck Ayad, Marie-Jo Olivier, Nathan Yang, and Apostolos Christopoulos
- Subjects
medicine.medical_specialty ,Psychometrics ,Intraclass correlation ,medicine.medical_treatment ,Modified delphi ,03 medical and health sciences ,symbols.namesake ,0302 clinical medicine ,medicine ,Humans ,Medical physics ,030223 otorhinolaryngology ,Reliability (statistics) ,business.industry ,Internship and Residency ,Reproducibility of Results ,Neck dissection ,Checklist ,Pearson product-moment correlation coefficient ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,symbols ,Neck Dissection ,Clinical Competence ,business - Abstract
Background The objective was to develop an assessment tool to evaluate residents' competency for neck dissection and provide preliminary evidence of feasibility, reliability, and validity. Methods Six surgeons developed a neck dissection assessment tool using a modified Delphi method and evaluated 58 neck dissections from six junior and six senior otolaryngology residents. Results The assessment tool uses a double checklist: a previously validated global rating scale (GRS) and a task-specific checklist (TSC). Use of the instrument appeared feasible and the average scores on the GRS and TSC differed significantly between junior and senior residents. The Pearson correlation coefficient between both checklists was 0.87. Intraclass correlation (ICC) for inter-rater reliability was 0.69 for the GRS, and 0.80 for the TSC. Conclusion This study provides preliminary evidence of feasibility, reliability, and validity for the first neck dissection assessment tool and provides a foundation for further psychometric analysis and research.
- Published
- 2021
23. Assessment of surgical competence for neck dissection: a pilot study
- Author
-
Érika Mercier, Louis Guertin, Eric Bissada, Apostolos Christopoulos, Marie-Jo Olivier, Jean-Claude Tabet, Nathan Yang, and Tareck Ayad
- Subjects
Humans ,Internship and Residency ,Neck Dissection ,Surgery ,Pilot Projects ,Clinical Competence ,Prospective Studies - Abstract
Progressive implementation of the milestone competence-based curriculum has created a need for new objective and validated means to assess resident surgical proficiency. A previous systematic review of the literature by our group has highlighted a shortage of tools assessing surgical competence in oncologic procedures in otolaryngology - head and neck surgery.We developed a procedure-specific assessment tool for neck dissection using a modified Delphi method. The 2-part design was modelled on the previously validated Objective Structured Assessment of Technical Skills checklist. The tool was then validated through a 1-year multicentric prospective study in collaboration with the residents and faculty from our academic centre. Additionally, we developed an online survey to assess the acceptability by residents and staff before and after the validation studies.A total of 29 evaluations were completed throughout the 2016-2017 academic year. Acceptability ranked high for both residents and staff, with a single discrepancy in responses regarding a potential formative as opposed to summative use of the tool. Validation study results showed significantly higher checklist scores among senior residents than junior residents, as well as a significant score progression over time (The first tool assessing surgical competence in oncologic otolaryngology - head and neck surgery has been developed and shows promising validity.
- Published
- 2021
24. DCBLD1 is associated with the integrin signaling pathway and has prognostic value in non-small cell lung and invasive breast carcinoma
- Author
-
Monique Bernard, Apostolos Christopoulos, Guillaume B Cardin, and Francis Rodier
- Subjects
Oncology ,Adult ,Male ,medicine.medical_specialty ,Integrins ,Lung Neoplasms ,DNA Copy Number Variations ,Science ,Down-Regulation ,Single-nucleotide polymorphism ,Breast Neoplasms ,Germline ,Article ,Internal medicine ,Carcinoma, Non-Small-Cell Lung ,medicine ,Carcinoma ,Humans ,Clinical significance ,Neoplasm Invasiveness ,Aged ,Retrospective Studies ,Cancer ,Aged, 80 and over ,Multidisciplinary ,business.industry ,Head and neck cancer ,Membrane Proteins ,Prostatic Neoplasms ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Prognosis ,Up-Regulation ,Cohort ,Medicine ,Female ,business ,Colorectal Neoplasms ,Signal Transduction - Abstract
Germline single nucleotide polymorphisms in the promoter region of the DCBLD1 gene are associated with non-smoking cases of both non-small cell lung carcinoma (NSCLC) and human papillomavirus-negative head and neck cancer. However the clinical relevance and function of DCBLD1 remain unclear. This multicenter retrospective study was designed to evaluate the prognostic value and function of DCBLD1 in the four main solid cancers: NSCLC, invasive breast carcinoma, colorectal adenocarcinoma and prostate adenocarcinoma. We included the following cohorts: GSE81089 NSCLC, METABRIC invasive breast carcinoma, GSE14333 colorectal adenocarcinoma, GSE70770 prostate adenocarcinoma and The Cancer Genome Atlas (TCGA) Firehose Legacy cohorts of all four cancers. DCBLD1 gene expression was associated with a worse overall survival in multivariate analyses for both NSCLC cohorts (TCGA: P = 0.03 and GSE81089: P = 0.04) and both invasive breast carcinoma cohorts (TCGA: P = 0.02 and METABRIC: P DCBLD1 expression showed an upregulation of the integrin signaling pathway in comparison to those with low DCBLD1 expression in the TCGA NSCLC cohort (FDR = 5.16 × 10–14) and TCGA invasive breast carcinoma cohort (FDR = 1.94 × 10–05).
- Published
- 2021
25. mTOR as a senescence manipulation target: A forked road
- Author
-
Sarah Saoudaoui, Guillaume B Cardin, Apostolos Christopoulos, Francis Rodier, Nicolas Malaquin, and Monique Bernard
- Subjects
Senescence ,Autophagy ,Regulator ,Cancer ,Cellular homeostasis ,Context (language use) ,Biology ,medicine.disease ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,Cell metabolism ,030220 oncology & carcinogenesis ,medicine ,PI3K/AKT/mTOR pathway - Abstract
Cellular senescence, cancer and aging are highly interconnected. Among many important molecular machines that lie at the intersection of this triad, the mechanistic (formerly mammalian) target of rapamycin (mTOR) is a central regulator of cell metabolism, proliferation, and survival. The mTOR signaling cascade is essential to maintain cellular homeostasis in normal biological processes or in response to stress, and its dysregulation is implicated in the progression of many disorders, including age-associated diseases. Accordingly, the pharmacological implications of mTOR inhibition using rapamycin or others rapalogs span the treatment of various human diseases from immune disorders to cancer. Importantly, rapamycin is one of the only known pan-species drugs that can extend lifespan. The molecular and cellular mechanisms explaining the phenotypic consequences of mTOR are vast and heavily studied. In this review, we will focus on the potential role of mTOR in the context of cellular senescence, a tumor suppressor mechanism and a pillar of aging. We will explore the link between senescence, autophagy and mTOR and discuss the opportunities to exploit senescence-associated mTOR functions to manipulate senescence phenotypes in age-associated diseases and cancer treatment.
- Published
- 2021
26. The rs6942067 genotype is associated with a worse overall survival in young or non-smoking HPV-negative patients with positive nodal status in head and neck squamous cell carcinoma
- Author
-
Guillaume B, Cardin, Monique, Bernard, Jessica, Bourbonnais, Houda, Bahig, Phuc Félix, Nguyen-Tan, Edith, Filion, Denis, Soulieres, Olguta, Gologan, Tareck, Ayad, Louis, Guertin, Eric, Bissada, Francis, Rodier, and Apostolos, Christopoulos
- Subjects
Oropharyngeal Neoplasms ,Cancer Research ,Genotype ,Oncology ,Head and Neck Neoplasms ,Squamous Cell Carcinoma of Head and Neck ,Papillomavirus Infections ,Humans ,Oral Surgery - Published
- 2022
27. Decreasing Revision Surgery in <scp>FAMM</scp> Flap Reconstruction of the Oral Cavity: Traditional Versus Modified Harvesting Technique
- Author
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Badr Ibrahim, Akram Rahal, Marie-Jo Olivier, Apostolos Christopoulos, Sami P. Moubayed, Tareck Ayad, Louis Guertin, Eric Bissada, and Jean-Claude Tabet
- Subjects
Male ,Reoperation ,medicine.medical_specialty ,Facial Muscles ,Facial artery ,Oral cavity ,Surgical Flaps ,03 medical and health sciences ,0302 clinical medicine ,medicine.artery ,Chart review ,Humans ,Medicine ,030223 otorhinolaryngology ,Aged ,Retrospective Studies ,Mouth ,business.industry ,Arteries ,Pedicled Flap ,Middle Aged ,Plastic Surgery Procedures ,Surgery ,Treatment Outcome ,Otorhinolaryngology ,Face ,030220 oncology & carcinogenesis ,Tissue and Organ Harvesting ,Female ,business ,Surgical interventions - Abstract
Objective To compare the surgical and functional outcomes between two harvesting techniques for the inferiorly based facial artery musculomucosal (FAMM) flap for oral cavity and oropharynx reconstructions. Methods Multicenter retrospective chart review. Results We reviewed 55 cases of FAMM flap, including 29 traditional cases and 26 performed using the modified harvesting method. The overall rate of surgical re-intervention in the traditional group was 31% (n = 9 of 29) and 15% (n = 4 of 26) in the modified group (P = 0.196). The specific re-intervention rate for pedicle sectioning was 27% (n = 8 of 29) in the traditional group versus 0% (n = 0 of 26) in the modified group. The overall rate of complications was 21%. Nine out of 10 dentate patients in the traditional group and four out of five in the modified group needed tooth extraction. There was no difference between the two groups in terms of tracheostomy duration (P = 0.338) and time to first oral intake (P = 0.629). Speech and feeding outcomes were similar among groups (P = 0.922; P = 0.700, respectively). Dental rehabilitation was achieved in 67% and 78% of patients in the traditional and modified groups, respectively. Conclusion The FAMM flap offers a low morbidity approach to reconstruct the oral cavity. The modified approach to harvesting the flap is a safe and effective technique, with similar functional results and equally low morbidity profile as the traditional technique. It has the added advantage of lower rates of secondary surgical interventions. Level of evidence 4. Laryngoscope, 1802-1805, 2018.
- Published
- 2018
28. Four <scp>PTEN</scp> ‐targeting co‐expressed mi <scp>RNA</scp> s and <scp>ACTN</scp> 4‐ targeting mi <scp>R</scp> ‐548b are independent prognostic biomarkers in human squamous cell carcinoma of the oral tongue
- Author
-
Edith Filion, Eric Bissada, Julie Guilmette, Denis Soulières, Guillaume B Cardin, Phuc Felix Nguyen-Tan, Louis Guertin, Philip Wong, Isabelle Clément, Tareck Ayad, Olguta Gologan, Ilyes Berania, Francis Rodier, and Apostolos Christopoulos
- Subjects
0301 basic medicine ,Oncology ,Cancer Research ,medicine.medical_specialty ,Bioinformatics analysis ,biology ,Bioinformatics ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Tongue ,030220 oncology & carcinogenesis ,Internal medicine ,Cohort ,microRNA ,medicine ,biology.protein ,PTEN ,Basal cell ,Gene ,PI3K/AKT/mTOR pathway - Abstract
The purpose of this study was to determine the prognostic value and oncogenic pathways associated to miRNA expression in squamous cell carcinoma of the oral tongue and to link these miRNA candidates with potential gene targets. We performed a miRNA screening within our institutional cohort (n = 58 patients) and reported five prognostic targets including a cluster of four co-expressed miRNAs (miR-18a, miR-92a, miR-103, and miR-205). Multivariate analysis showed that expression of miR-548b (p = 0.007) and miR-18a (p = 0.004, representative of co-expressed miRNAs) are independent prognostic markers for squamous cell carcinoma of the oral tongue. These findings were validated in The Cancer Genome Atlas (TCGA) cohort (n = 131) for both miRNAs (miR-548b: p = 0.027; miR-18a: p = 0.001). Bioinformatics analysis identified PTEN and ACTN4 as direct targets of the four co-expressed miRNAs and miR-548b, respectively. Correlations between the five identified miRNAs and their respective targeted genes were validated in the two merged cohorts and were concordantly significant (miR-18a/PTEN: p
- Published
- 2017
29. Perioperative practices in thyroid surgery: An international survey
- Author
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Tareck Ayad, Marie-Jo Olivier, Eric Bissada, Apostolos Christopoulos, Anastasios Maniakas, Jacques Malaise, and Louis Guertin
- Subjects
medicine.medical_specialty ,Cord ,business.industry ,Thyroid ,Specialty ,International survey ,Perioperative ,Surgery ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Epidemiology ,medicine ,Endocrine system ,030223 otorhinolaryngology ,business - Abstract
Background Perioperative practices in thyroid surgery vary from one specialty, institution, or country to the next. We evaluated the preoperative, intraoperative, and postoperative practices of thyroid surgeons focusing on preoperative ultrasound, vocal cord evaluation, wound drains, and hospitalization duration, among others. Methods A survey was sent to 7 different otolaryngology and endocrine/general surgery associations. Results There were 965 respondents from 52 countries. Surgeon-performed ultrasound is practiced by more than one third of respondents. Otolaryngologists perform preoperative and postoperative vocal cord evaluation more often than endocrine/general surgeons (p < .001). Sixty percent of respondents either never place drains or place drains
- Published
- 2017
30. Cancer Outcomes of Head and Neck Cancer Patients with Indeterminate Pulmonary Nodules at Diagnosis
- Author
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Tareck Ayad, Eric Bissada, Bernard Fortin, Manon Bélair, Laurent Létourneau-Guillon, O. Ballivy, Edith Filion, V. Côté Provencher, P.F. Nguyen-Tan, Houda Bahig, Louis Guertin, and Apostolos Christopoulos
- Subjects
Cancer Research ,medicine.medical_specialty ,Radiation ,Oncology ,business.industry ,Head and neck cancer ,medicine ,Cancer ,Radiology, Nuclear Medicine and imaging ,Radiology ,medicine.disease ,Indeterminate ,business - Published
- 2020
31. Dual Inhibition of Autophagy and PI3K/AKT/MTOR Pathway as a Therapeutic Strategy in Head and Neck Squamous Cell Carcinoma
- Author
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Eric Bissada, Denis Soulières, Francis Rodier, Guillaume B Cardin, Edith Filion, Phuc Felix Nguyen-Tan, Tareck Ayad, Monique Bernard, Louis Guertin, Houda Bahig, Maxime Cahuzac, Olivier Ballivy, and Apostolos Christopoulos
- Subjects
0301 basic medicine ,autophagy ,buparlisib ,Cancer Research ,omipalisib ,PI3K inhibitor ,lcsh:RC254-282 ,HNSCC ,Article ,combination therapy ,chloroquine ,PI3K signaling pathway ,03 medical and health sciences ,0302 clinical medicine ,medicine ,cancer ,Protein kinase B ,PI3K/AKT/mTOR pathway ,business.industry ,Autophagy ,oral tongue ,Cancer ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.disease ,Head and neck squamous-cell carcinoma ,030104 developmental biology ,Oncology ,Cell culture ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,Signal transduction ,business - Abstract
Genomic analyses of head and neck squamous cell carcinoma (HNSCC) have highlighted alterations in the phosphatidylinositol 3-kinase (PI3K) signaling pathway, presenting a therapeutic target for multiple ongoing clinical trials with PI3K or PI3K/MTOR inhibitors. However, these inhibitors can potentially increase autophagy in HNSCC and indirectly support cancer cell survival. Here, we sought to understand the relationship between the PI3K signaling pathway and autophagy during their dual inhibition in a panel of HNSCC cell lines. We used acridine orange staining, immunoblotting, and tandem sensor Red Fluorescent Protein- Green Fluorescent Protein-, microtubule-associated protein 1 light chain 3 beta (RFP-GFP-LC3B) expression analysis to show that PI3K inhibitors increase autophagosomes in HNSCC cells, but that chloroquine treatment effectively inhibits the autophagy that is induced by PI3K inhibitors. Using the Bliss independence model, we determined that the combination of chloroquine with PI3K inhibitors works in synergy to decrease cancer cell proliferation, independent of the PIK3CA status of the cell line. Our results indicate that a strategy focusing on autophagy inhibition enhances the efficacy of therapeutics already in clinical trials. Our results suggest a broader application for this combination therapy that can be promptly translated to in vivo studies.
- Published
- 2020
32. Breast Cancer with Supraclavicular and Internal Mammary Node Metastases: Therapeutic Options
- Author
-
Nohad El Sayed, Juliette Beaulieu, Pénélope Borduas, Kerianne Boulva, Léamarie Meloche-Dumas, Erica Patocskai, Xiya Ma, Apostolos Christopoulos, Rami Younan, Moishe Liberman, Ève Sédillot, Ahmad Kaviani, Tareck Ayad, and Andrée-Anne Berrnard
- Subjects
Oncology ,medicine.medical_specialty ,Breast cancer ,business.industry ,Node (networking) ,Internal medicine ,Medicine ,Surgery ,General Medicine ,business ,medicine.disease - Published
- 2020
33. Predictive factors of survival and treatment tolerance in older patients treated with chemotherapy and radiotherapy for locally advanced head and neck cancer
- Author
-
Edith Filion, Tareck Ayad, Houda Bahig, Apostolos Christopoulos, Louise Lambert, M. Alizadeh, Phuc Felix Nguyen-Tan, Eric Bissada, Denis Soulières, Bernard Fortin, Louis Guertin, and Francine Gaba Idiamey
- Subjects
Male ,Cancer Research ,medicine.medical_specialty ,Multivariate analysis ,Antineoplastic Agents ,Logistic regression ,Internal medicine ,medicine ,Humans ,Survival analysis ,Aged ,Retrospective Studies ,Geriatrics ,Radiotherapy ,business.industry ,Head and neck cancer ,Retrospective cohort study ,medicine.disease ,Combined Modality Therapy ,Survival Analysis ,Chemotherapy regimen ,Surgery ,Oncology ,Head and Neck Neoplasms ,Female ,Oral Surgery ,business ,Chemoradiotherapy - Abstract
Summary Purpose To report outcomes and predictive factors of overall survival, hospitalization and treatment completion rates in elderly patients with locally advanced head and neck cancer treated with concurrent chemoradiotherapy (CRT). Material and methods A retrospective analysis of patients aged 70 years or older treated with concurrent CRT for locally advanced head and neck cancer was conducted. Univariate and multivariate analysis as well as competing risk survival analysis were used to determine predictors of mortality. Logistic regression was used to predict for hospitalization and treatment completion rates. Results In total, 129 patients were included. Median follow-up was 27 months (range: 1.7–125 months). Completion rate of combined CRT was 84%. Actuarial OS and DSS at 4 years were 56% and 75%. Hospitalization rate was 36%. On multivariate analysis, a Karnofsky performance status (KPS) ⩽80 was predictive of mortality. Using competing risks, KPS ⩽80 and weight loss >5% were predictive of cancer mortality whereas Charlson score ⩾3 was predictive of mortality due to other causes. On logistic regression, patients with abnormal renal function and lower body mass index were more likely to be hospitalized during their treatment course. Charlson score and chemotherapy regimen were predictive of treatment completion. Conclusion Concurrent CRT may be a feasible treatment option for healthier older patients at the cost of high hospitalization rates. Pre-treatment factors linked to physiological age such as KPS ⩽80, Charlson score ⩾3, abnormal renal function should be considered at the time of treatment decision.
- Published
- 2015
34. Voice and Functional Outcomes of Transoral Laser Microsurgery for Early Glottic Cancer: Ventricular Fold Resection as a Surrogate
- Author
-
Marie-Jo Olivier, Eric Bissada, Louis Guertin, Apostolos Christopoulos, Sami P. Moubayed, Tareck Ayad, Jean-Claude Tabet, Christophe Dagenais, and Ilyes Berania
- Subjects
Quality of life ,medicine.medical_specialty ,Performance status ,Tumor size ,business.industry ,Cancer ,General Medicine ,medicine.disease ,Functional outcomes ,Glottic Squamous Cell Carcinoma ,Resection ,Surgery ,Glottic cancer ,Medicine ,Original Article ,Transoral laser microsurgery ,business - Abstract
Background The aim of the study was to evaluate the oncological and functional outcomes with transoral laser microsurgery (TOLM) of patients with early glottic cancer. Methods We have prospectively evaluated patients treated with TOLM for Tis, T1 or T2 glottic squamous cell carcinoma. Evaluation of oncological outcomes, and voice and functional outcomes was assessed using voice-handicap index 10 (VHI-10) and performance status scale for head & neck cancer patients (PSS-H&N). Predictors of poor voice quality were evaluated using Student’s t-test. Results Thirty patients were included, with 17.7 months mean follow-up. There were no cases of locoregional recurrence. Twelve patients (40%) were considered as having a problematic voice outcome. Four subjects out of 30 (13.3%) had significant problems with understandability of speech. Significant differences (P < 0.05) in VHI-10 score were found with tumor stage and partial resection of the ventricular fold. Conclusions We report excellent oncological and functional outcomes in early glottic cancer treated with TOLM, with advanced tumors and partial resection of the ventricular fold as a surrogate predicting worse voice outcomes.
- Published
- 2015
35. The Cost of Prolonged Hospitalization due to Postthyroidectomy Hypocalcemia: A Case-Control Study
- Author
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Eric Bissada, Sami P. Moubayed, Harmeet Singh, Marie-Jo Olivier, Tareck Ayad, Navid Zahedi Niaki, Apostolos Christopoulos, Louis Guertin, Jean-Claude Tabet, and Rebecca Leboeuf
- Subjects
Completion thyroidectomy ,medicine.medical_specialty ,Article Subject ,Calcitriol ,business.industry ,medicine.medical_treatment ,Incidence (epidemiology) ,Thyroidectomy ,Case-control study ,Neck dissection ,Surgery ,Female age ,Cytology ,medicine ,General Earth and Planetary Sciences ,business ,General Environmental Science ,medicine.drug - Abstract
The aim of this study is to evaluate the additional costs associated with calcium monitoring and treatment as well as evaluate the incidence and predictors of postthyroidectomy hypocalcemia. Methods. This case-control study involved thyroidectomy and completion thyroidectomy patients operated on between January 2012 and August 2013. Cases were defined as requiring calcitriol supplementation, and controls did not require supplementation. Patient (age, sex), nodule (cytology, pathology), surgical data (neck dissection, parathyroid identification, and reimplantation), and hospital stay (days hospitalized in total and after drain removal) were compared. Comparisons were made using t-tests and chi-square tests with an alpha of 0.05. The estimated cost associated with the extended stay was then compared with the cost of supplementation. Results. A total of 191 patients were evaluated (61 cases and 130 controls). Predictors of hypocalcemia include female age, neck dissection, and parathyroid reimplantation. Hypocalcemic patients were hospitalized for a longer period of time after drain removal (2.5 versus 0.8 days, P<0.001), and hospitalization costs after neck drain removal were higher in this group as well (8,367.32$ versus 2,534.32$, P<0.001). Conclusion. Postoperative hypocalcemia incurs significant additional health care costs at both the local and health care system levels.
- Published
- 2014
36. Work-related musculoskeletal symptoms amongst Otolaryngologists and Head and Neck surgeons in Canada
- Author
-
François Prince, Josiane Bolduc-Bégin, Tareck Ayad, and Apostolos Christopoulos
- Subjects
Male ,medicine.medical_specialty ,Canada ,Activities of daily living ,Exacerbation ,Work related ,03 medical and health sciences ,0302 clinical medicine ,Surveys and Questionnaires ,Otolaryngologists ,medicine ,Prevalence ,Humans ,Musculoskeletal Diseases ,030223 otorhinolaryngology ,Response rate (survey) ,Surgeons ,business.industry ,Human factors and ergonomics ,Workload ,General Medicine ,Anatomy ,Middle Aged ,030210 environmental & occupational health ,Occupational Diseases ,Otorhinolaryngology ,Physical therapy ,Female ,Neurosurgery ,business - Abstract
The first objective of this study was to identify work-related musculoskeletal symptoms and determine their prevalence in the practice of Otolaryngology and Head and Neck surgery in Canada. The second objective was to establish potential associations between those musculoskeletal symptoms and variables related to demographic status of the surgeons, their workload and work ergonomics. This study was designed as a Canadian census on work-related musculoskeletal symptoms amongst Otolaryngologist and Head and Neck surgeons. The census was a self-administered electronic survey. It was distributed to all Otolaryngologists and Head and Neck surgeons members of either the Canadian Society of Otolaryngology-Head and Neck Surgery or the Association of Oto-rhinolaryngology-Head and Neck Surgery of Quebec. The questionnaire contained three sections: demographic and workload-related data, identification of work-related musculoskeletal symptoms and evaluation of working ergonomics. The response rate was 23%. Ninety seven percent (97%) of respondents experienced some physical symptom in one or many regions of their body. Seventy-four percents (74%) of respondents noted an exacerbation of their musculoskeletal symptoms by work. Musculoskeletal symptoms limited the daily activities of 45% of respondents while 23% think that their occupational longevity will be diminished by these limitations. The prevalence of work-related musculoskeletal disorders is high among otolaryngologists and its impact on the surgeon's personal and professional life is high. There is a need to improve ergonomics in the clinical and operative room settings and to educate surgeons on ergonomic principles.
- Published
- 2017
37. Four PTEN-targeting co-expressed miRNAs and ACTN4- targeting miR-548b are independent prognostic biomarkers in human squamous cell carcinoma of the oral tongue
- Author
-
Ilyes, Berania, Guillaume B, Cardin, Isabelle, Clément, Louis, Guertin, Tareck, Ayad, Eric, Bissada, Phuc Felix, Nguyen-Tan, Edith, Filion, Julie, Guilmette, Olguta, Gologan, Denis, Soulieres, Francis, Rodier, Philip, Wong, and Apostolos, Christopoulos
- Subjects
Male ,Squamous Cell Carcinoma of Head and Neck ,PTEN Phosphohydrolase ,Fluorescent Antibody Technique ,Kaplan-Meier Estimate ,Middle Aged ,Prognosis ,Real-Time Polymerase Chain Reaction ,Tongue Neoplasms ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,ROC Curve ,Head and Neck Neoplasms ,Area Under Curve ,Biomarkers, Tumor ,Carcinoma, Squamous Cell ,Humans ,Actinin ,Female ,Aged - Abstract
The purpose of this study was to determine the prognostic value and oncogenic pathways associated to miRNA expression in squamous cell carcinoma of the oral tongue and to link these miRNA candidates with potential gene targets. We performed a miRNA screening within our institutional cohort (n = 58 patients) and reported five prognostic targets including a cluster of four co-expressed miRNAs (miR-18a, miR-92a, miR-103, and miR-205). Multivariate analysis showed that expression of miR-548b (p = 0.007) and miR-18a (p = 0.004, representative of co-expressed miRNAs) are independent prognostic markers for squamous cell carcinoma of the oral tongue. These findings were validated in The Cancer Genome Atlas (TCGA) cohort (n = 131) for both miRNAs (miR-548b: p = 0.027; miR-18a: p = 0.001). Bioinformatics analysis identified PTEN and ACTN4 as direct targets of the four co-expressed miRNAs and miR-548b, respectively. Correlations between the five identified miRNAs and their respective targeted genes were validated in the two merged cohorts and were concordantly significant (miR-18a/PTEN: p 0.0001; miR-92a/PTEN: p = 0.0008; miR-103/PTEN: p = 0.008; miR-203/PTEN: p = 0.019; miR-548b/ACTN4: p = 0.009).
- Published
- 2017
38. Predicting Depression and Quality of Life among Long‐term Head and Neck Cancer Survivors
- Author
-
Olguta Gologan, Louis Guertin, Louise Lambert, Sami P. Moubayed, John S. Sampalis, Denis Soulières, Edith Filion, Eric Bissada, Tareck Ayad, Phuc Felix Nguyen-Tan, and Apostolos Christopoulos
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,Depression ,Squamous Cell Carcinoma of Head and Neck ,business.industry ,Head and neck cancer ,Prognosis ,medicine.disease ,Head and neck squamous-cell carcinoma ,Cohort Studies ,Otorhinolaryngology ,Quality of life ,Head and Neck Neoplasms ,Carcinoma, Squamous Cell ,Quality of Life ,medicine ,Physical therapy ,Humans ,Female ,Surgery ,Survivors ,business ,Depression (differential diagnoses) - Abstract
The aim of this study is to identify clinical factors that are predictive of depression and quality of life (QOL) among long-term survivors of head and neck squamous cell carcinoma and to develop predictive scores using these factors.Cohort studyTertiary referral center.A total of 209 posttreatment (median follow-up, 38.7 months) head and neck cancer patients were prospectively evaluated using the Hospital Anxiety Depression Scale (HADS), the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30, and the EORTC Quality of Life Questionnaire Head and Neck 35, and pretreatment patient-related, tumor-related, and treatment-related predictors were identified using chart review. Bivariate (χ(2) and t test) and multivariate (linear regression) analyses were used to construct predictive models.Significant pretreatment predictors of depression were identified on multivariate analysis as smoking at diagnosis,14 alcoholic drinks per week, T3 or T4 status, and3 medications (P.001). Two or more of these factors yielded an 82.3% sensitivity in detecting significant depressive symptoms (defined as a HADS cutoff score of 5). Significant predictors of fatigue, global health/QOL, social contact, speech, pain, swallowing, and xerostomia were also identified.Pretreatment predictors of long-term depression and QOL have been defined using multivariate models, and an easily applicable predictive score of long-term depression is proposed. Potential eventual clinical applications include prophylactic intervention in at-risk patients.
- Published
- 2014
39. Perioperative practices in thyroid surgery: An international survey
- Author
-
Anastasios, Maniakas, Apostolos, Christopoulos, Eric, Bissada, Louis, Guertin, Marie-Jo, Olivier, Jacques, Malaise, and Tareck, Ayad
- Subjects
Male ,Postoperative Care ,Internationality ,Intraoperative Care ,Attitude of Health Personnel ,Length of Stay ,Prognosis ,Thyroid Diseases ,Perioperative Care ,Treatment Outcome ,Health Care Surveys ,Surveys and Questionnaires ,Preoperative Care ,Thyroidectomy ,Humans ,Female ,Thyroid Neoplasms ,Practice Patterns, Physicians' - Abstract
Perioperative practices in thyroid surgery vary from one specialty, institution, or country to the next. We evaluated the preoperative, intraoperative, and postoperative practices of thyroid surgeons focusing on preoperative ultrasound, vocal cord evaluation, wound drains, and hospitalization duration, among others.A survey was sent to 7 different otolaryngology and endocrine/general surgery associations.There were 965 respondents from 52 countries. Surgeon-performed ultrasound is practiced by more than one third of respondents. Otolaryngologists perform preoperative and postoperative vocal cord evaluation more often than endocrine/general surgeons (p.001). Sixty percent of respondents either never place drains or place drains50% of the time in thyroid lobectomies (43% for total thyroidectomies). Outpatient thyroid surgery is most frequently performed by surgeons in the United States (63%).This epidemiologic study is the first global thyroid survey of its kind and clearly demonstrates the variability and evolving trends in thyroid surgery. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1296-1305, 2017.
- Published
- 2016
40. Phase 1-2 Study of De-intensified IMRT and Concurrent Chemotherapy in Locally Advanced Oropharyngeal Carcinoma
- Author
-
P.F. Nguyen-Tan, Louise Lambert, Apostolos Christopoulos, Tareck Ayad, M. Alizadeh-Kashani, Eric Bissada, Manon Bélair, Houda Bahig, Denis Soulières, Louis Guertin, and Edith Filion
- Subjects
Cancer Research ,medicine.medical_specialty ,Radiation ,business.industry ,Locally advanced ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Concurrent chemotherapy ,Oncology ,Oropharyngeal Carcinoma ,030220 oncology & carcinogenesis ,Medicine ,Radiology, Nuclear Medicine and imaging ,Radiology ,business - Published
- 2018
41. Asset Markets Contagion During the Global Financial Crisis
- Author
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Dimitris Kenourgios, Dimitrios Dimitriou, and Apostolos Christopoulos
- Subjects
jel:G15 ,jel:C32 ,global financial crisis, asset markets, contagion, asymmetric dynamic conditional correlations ,jel:F30 - Abstract
This study investigates the contagion effects of the 2007-2009 global financial crisis across multiple asset markets and different regions. It uses daily return data of six asset classes: stocks, bonds, commodities, shipping, foreign exchange and real estate. A robust analysis of financial contagion is provided by estimating and comparing asymmetric conditional correlations among asset markets during stable and turmoil periods. Results provide evidence on the existence of a correlated-information channel as a contagion mechanism among the US stocks, real estate, commodities and emerging Brazilian bond index. The findings also support the decoupling of BRIC equity markets from the crisis, the diversification benefits of shipping and foreign exchange value of the US dollar indices, and the existence of a flight to quality mechanism from risky US assets to German bonds. This evidence has important implications for portfolio diversification strategies and the future work of policymakers.
- Published
- 2013
42. HPV Prevalence and Prognostic Value in a Prospective Cohort of 255 Patients with Locally Advanced HNSCC: A Single-Centre Experience
- Author
-
Bernard Fortin, Louis Guertin, Phuc Felix Nguyen-Tan, Apostolos Christopoulos, Olivier Abboud, Jean-Claude Tabet, Denis Soulières, François Coutlée, Marie-Lise Audet, E. Thibaudeau, and Xiaoduan Weng
- Subjects
Oncology ,medicine.medical_specialty ,education.field_of_study ,Article Subject ,business.industry ,Population ,lcsh:Surgery ,Cancer ,lcsh:RD1-811 ,lcsh:Otorhinolaryngology ,Bioinformatics ,medicine.disease ,lcsh:RF1-547 ,Chemotherapy regimen ,Clinical trial ,Concomitant ,Internal medicine ,Clinical Study ,medicine ,Stage (cooking) ,education ,Prospective cohort study ,business ,Survival analysis - Abstract
Background. HPV is a positive prognostic factor in HNSCC. We studied the prevalence and prognostic impact of HPV on survival parameters and treatment toxicity in patients with locally advanced HNSCC treated with concomitant chemoradiation therapy.Methods. Data on efficacy and toxicity were available for 560 patients. HPV was detected by PCR. Analysis was performed using Kaplan-Meier survival curves, Fisher’s test for categorical data, and log-rank statistics for failure times.Results. Median follow-up was 4.7 years. DNA extraction was successful in 255 cases. HPV prevalence was 68.6%, and 53.3% for HPV 16. For HPV+ and HPV−, median LRC was 8.9 and 2.2 years (P=0.0002), median DFS was 8.9 and 2.1 years (P=0.0014), and median OS was 8.9 and 3.1 years (P=0.0002). Survival was different based on HPV genotype, stage, treatment period, and chemotherapy regimen. COX adjusted analysis for T, N, age, and treatment remained significant (P=0.004).Conclusions. Oropharyngeal cancer is increasingly linked to HPV. This study confirms that HPV status is associated with improved prognosis among H&N cancer patients receiving CRT and should be a stratification factor for clinical trials including H&N cases. Toxicity of CRT is not modified for the HPV population.
- Published
- 2013
43. Internal Jugular Vein Duplication: Anatomic Relationship With the Spinal Accessory Nerve
- Author
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Badr Ibrahim, Tareck Ayad, Apostolos Christopoulos, Sami P. Moubayed, and Ilyes Berania
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Accessory nerve ,medicine.medical_treatment ,03 medical and health sciences ,0302 clinical medicine ,Accessory Nerve ,medicine ,Humans ,Thyroid Neoplasms ,030223 otorhinolaryngology ,Internal jugular vein ,Laryngeal Neoplasms ,Aged ,business.industry ,Thyroidectomy ,Neck dissection ,Middle Aged ,Surgery ,Otorhinolaryngology ,Head and neck surgery ,Carcinoma, Squamous Cell ,Neck Dissection ,Female ,030101 anatomy & morphology ,Level ii ,Oral Surgery ,Jugular Veins ,business ,Preoperative imaging - Abstract
Level II neck dissection is a commonly performed procedure in head and neck surgery. It carries the risk of injury to the spinal accessory nerve (SAN) and the internal jugular vein (IJV). Injury to any of these structures leads to increased intraoperative and postoperative complications and morbidity. Knowledge of the anatomic relation and possible variations from the norm is vital to decrease the morbidity of this frequently practiced procedure. This report describes 2 rare variations of the relation of the SAN to the IJV: 1) the IJV splitting with SAN passage through the IJV window and 2) the IJV splitting without SAN passage through the IJV window. Preoperative imaging and the pertinent literature regarding the variability in the relations of these structures are reviewed.
- Published
- 2016
44. Oncologic and Functional Outcomes of Partial Laryngeal Surgery for Intermediate‐Stage Laryngeal Cancer
- Author
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Dwight E. Heron, Ali Razfar, Apostolos Christopoulos, Robert L. Ferris, James Ohr, Daniel M. Beswick, Diana E. Cunningham, and Emiro Caicedo-Granados
- Subjects
Adult ,Male ,medicine.medical_specialty ,Biopsy ,medicine.medical_treatment ,Laryngectomy ,Statistics, Nonparametric ,Confidence Intervals ,medicine ,Carcinoma ,Humans ,Transoral laser microsurgery ,Laryngeal Neoplasms ,Survival rate ,Aged ,Neoplasm Staging ,Proportional Hazards Models ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Supracricoid Laryngectomy ,Retrospective cohort study ,Neck dissection ,Recovery of Function ,Middle Aged ,medicine.disease ,Surgery ,Survival Rate ,Treatment Outcome ,Otorhinolaryngology ,Cohort ,Carcinoma, Squamous Cell ,Neck Dissection ,Female ,business - Abstract
To evaluate the oncologic and functional outcomes of partial laryngeal surgery (PLS) using transoral laser microsurgery (TLM) and supracricoid laryngectomy (SCL) in patients with intermediate-stage laryngeal squamous cell carcinoma (LSCC).Historical cohort study.Single tertiary care center.Retrospective review of oncologic and functional outcomes in intermediate-stage (T2-3/N0-1, stage II and III) LSCC patients who underwent TLM or SCL from 1998 to 2010.Sixty patients were included, of whom 28 (47%) underwent TLM and 32 (53%) underwent SCL. For the entire cohort, 2- and 5-year probabilities were 86.2% (95% confidence interval [CI], 73.0%-93.2%) and 72.9% (95% CI, 52.4%-85.6%), respectively, for overall survival (OS) and 79.3% (95% CI, 65.6%-88.0%) and 62.4% (95% CI, 41.9%-77.4%), respectively, for recurrence-free survival (RFS). There was no difference between the TLM and SCL cohorts in OS (P = .542) or RFS (P = .483). More than 75% of patients avoided adjuvant therapy. Communication Scale and Functional Outcome Swallowing Scale scores at median follow-up of 33 months were 2 or better in 97% and 91% of patients, respectively, reflecting functional voice and swallowing postoperatively. Eighty-eight percent of patients retained a functional larynx.PLS provides excellent oncologic and functional outcomes for intermediate-stage LSCC and should be considered an alternative to chemoradiation or total laryngectomy in selected patients.
- Published
- 2012
45. Cervical Lymph Node Metastases From Unknown Primary Cancer: A Single-Institution Experience With Intensity-Modulated Radiotherapy
- Author
-
Bernard Fortin, Edith Filion, Tarek Ayad, Phuc Felix Nguyen-Tan, Philippe Després, Hugo Villeneuve, Apostolos Christopoulos, David Donath, Louis Guertin, and Denis Soulières
- Subjects
Adult ,Male ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,Xerostomia ,Carcinoma, Adenosquamous ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Carcinoma ,Humans ,Radiology, Nuclear Medicine and imaging ,Stage (cooking) ,Lymph node ,Survival analysis ,Aged ,Neoplasm Staging ,Retrospective Studies ,Lymphatic Irradiation ,Radiation ,business.industry ,Cancer ,Radiotherapy Dosage ,Neck dissection ,Chemoradiotherapy ,Middle Aged ,medicine.disease ,Survival Analysis ,Surgery ,Radiation therapy ,medicine.anatomical_structure ,Oncology ,Head and Neck Neoplasms ,Lymphatic Metastasis ,Carcinoma, Squamous Cell ,Neoplasms, Unknown Primary ,Female ,Radiotherapy, Intensity-Modulated ,business ,Neck - Abstract
Purpose To determine the effectiveness and rate of complications of intensity-modulated radiotherapy (IMRT) in the treatment of cervical lymph node metastases from unknown primary cancer. Methods and Materials Between February 2005 and November 2008, 25 patients with an unknown primary cancer underwent IMRT, with a median radiation dose of 70 Gy. The bilateral neck and ipsilateral putative pharyngeal mucosa were included in the target volume. All patients had squamous cell carcinoma, except for 1 patient who had adenosquamous differentiation. They were all treated with curative intent. Of the 25 included patients, 20 were men and 5 were women, with a median age of 54 years. Of these patients, 3 had Stage III, 18 had Stage IVa, and 4 had Stage IVb. Of the 25 patients, 18 (72%) received platinum-based chemotherapy in a combined-modality setting. Neck dissection was reserved for residual disease after definitive IMRT. Overall survival, disease-free survival, and locoregional control were calculated using the Kaplan-Meier method. Results With a median follow-up of 38 months, the overall survival, disease-free survival, and locoregional control rates were all 100% at 3 years. No occurrence of primary cancer was observed during the follow-up period. The reported rates of xerostomia reduced with the interval from the completion of treatment. Nine patients (36%) reported Grade 2 or greater xerostomia at 6 months, and only 2 (8%) of them reported the same grade of salivary function toxicity after 24 months of follow-up. Conclusion In our institution, IMRT for unknown primary cancer has provided good overall and disease-free survival in all the patients with an acceptable rate of complications. IMRT allowed us to address the bilateral neck and ipsilateral putative pharyngeal mucosa with minimal late salivary function toxicity. The use of concurrent chemotherapy and IMRT for more advanced disease led to good clinical results with reasonable toxicities.
- Published
- 2012
46. Prognostic Value of Cartilage Sclerosis in Laryngeal Cancer Treated with Primary Radiation Therapy
- Author
-
Manon Bélair, Jackie Bibeau-Poirier, Marie-Jo Olivier, Tareck Ayad, Louis Guertin, Apostolos Christopoulos, Sami P. Moubayed, Joe Saliba, Phuc-Felix Nguyen-Tan, and Louise Lambert
- Subjects
Male ,medicine.medical_specialty ,Laryngeal Cartilages ,medicine.medical_treatment ,Computed tomography ,Laryngeal cartilage ,Cohort Studies ,medicine ,Overall survival ,Humans ,In patient ,Laryngeal Neoplasms ,Retrospective Studies ,Sclerosis ,medicine.diagnostic_test ,business.industry ,Cartilage ,Cancer ,Middle Aged ,Prognosis ,medicine.disease ,Surgery ,Survival Rate ,Radiation therapy ,medicine.anatomical_structure ,Otorhinolaryngology ,Cohort ,Female ,Radiology ,Tomography, X-Ray Computed ,business - Abstract
In patients with laryngeal cancer, pretreatment diagnosis of cartilage invasion often warrants a surgical or a bimodal treatment. Controversy exists on whether laryngeal cartilage sclerosis on computed tomography (CT) scan is a sign of tumor invasion. Our objective is to evaluate locoregional, laryngectomy-free, disease-specific, and overall survival in patients with laryngeal cancer with or without laryngeal cartilage sclerosis treated with primary radiation therapy.Historical cohort study.Tertiary referral university center.All laryngeal cancer patients treated with primary radiation therapy between 2002 and 2007 were included. Patients with and without laryngeal cartilage sclerosis on CT scan were identified. Patient, tumor, and treatment data were collected. Univariate and multivariate analyses were conducted using Kaplan-Meier survival analyses and Cox proportional-hazards regression.One hundred eleven patients were included for analysis. Seventy-nine patients were classified as T1 or T2, and 32 patients were classified as T3 or T4. Twenty-three percent of patients had any laryngeal cartilage sclerosis, and 77% of patients had no sclerosis. On univariate and multivariate analyses, there was no statistically significant difference between patients with or without sclerosis. Results did not vary when studying each cartilage separately.Laryngeal cancer patients with cartilage sclerosis on CT scan do not have significantly different survival than patients without sclerosis. Validation of these results prospectively is warranted.
- Published
- 2012
47. Biology of vascular endothelial growth factor and its receptors in head and neck cancer: Beyond angiogenesis
- Author
-
Apostolos Christopoulos, Seungwon Kim, Sun M. Ahn, and Jonah D. Klein
- Subjects
Male ,Vascular Endothelial Growth Factor A ,Pathology ,medicine.medical_specialty ,Angiogenesis ,Angiogenesis Inhibitors ,Risk Assessment ,chemistry.chemical_compound ,Clinical Trials, Phase II as Topic ,Drug Delivery Systems ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Autocrine signalling ,Receptor ,Clinical Trials, Phase I as Topic ,Neovascularization, Pathologic ,Squamous Cell Carcinoma of Head and Neck ,business.industry ,Head and neck cancer ,Prognosis ,medicine.disease ,Survival Analysis ,Head and neck squamous-cell carcinoma ,Vascular endothelial growth factor ,Receptors, Vascular Endothelial Growth Factor ,Treatment Outcome ,Clinical Trials, Phase III as Topic ,Otorhinolaryngology ,chemistry ,Head and Neck Neoplasms ,Tumor progression ,Cancer cell ,Carcinoma, Squamous Cell ,Cancer research ,Female ,business - Abstract
Angiogenesis is a necessary process for tumor progression and is driven through molecular interactions between cancer cells and neighboring vascular endothelial cells. The primary mediators of angiogenesis are the vascular endothelial growth factors and their respective receptors on endothelial cells. There are several U.S. Food and Drug Administration–approved anti-angiogenic agents in clinical use. In head and neck cancer there are clinical trials assessing the efficacy of anti-angiogenic agents in combination with chemoradiation therapy. Although the aforementioned growth factors and receptors have been traditionally viewed as anti-angiogenic targets, there are concomitant efforts to understand the role these molecules play within the tumor cells. In this review, we first discuss the biology of angiogenic proteins and the targeting of angiogenic molecules for cancer treatment. We summarize the current clinical trials of anti-angiogenic therapies in head and neck squamous cell carcinoma. Finally, the additional role these molecules play in tumor progression independent of angiogenesis is discussed. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
- Published
- 2010
48. Recurrent Venous Thrombosis following Free Flap Surgery: The Role of Heparin-Induced Thrombocytopenia
- Author
-
Louis Guertin, Carlos Cordoba, Andreas Nikolis, Patrick G. Harris, Apostolos Christopoulos, and Michel Saint-Cyr
- Subjects
Recurrent venous thrombosis ,medicine.medical_specialty ,Floor of mouth ,business.industry ,medicine.medical_treatment ,Case Report ,Free flap failure ,Heparin ,Microsurgery ,medicine.disease ,Surgery ,Venous thrombosis ,Heparin-induced thrombocytopenia ,medicine ,Free flap surgery ,business ,medicine.drug - Abstract
Complications following free tissue transfer have been well established in the literature. Common and rare causes of free flap failure must be addressed by the treating surgeon when microvascular patency is threatened. With the evolution and prevalence of microsurgery, ‘rare’ causes of free flap failure will become increasingly frequent. A high index of suspicion must be established in patients with multiple failed operative interventions. A case of recurrent free flap failure secondary to heparin-induced thrombocytopenia is presented in a patient with a history of squamous cell carcinoma of the floor of the mouth, and a long-standing history of alcohol and tobacco consumption.
- Published
- 2003
49. Osteocutaneous free flaps for mandibular reconstruction: systematic review of their frequency of use and a preliminary quality of life comparison
- Author
-
Laurent Létourneau-Guillon, Eric Bissada, John S. Sampalis, Tareck Ayad, Apostolos Christopoulos, Louis Guertin, Patrick G. Harris, B. L'Heureux-Lebeau, Sami P. Moubayed, and Alain M. Danino
- Subjects
business.industry ,Squamous Cell Carcinoma of Head and Neck ,MEDLINE ,Mandible ,Dentistry ,General Medicine ,Free flap ,Iliac crest ,Free Tissue Flaps ,medicine.anatomical_structure ,Otorhinolaryngology ,Quality of life ,Fibula ,Head and Neck Neoplasms ,medicine ,Carcinoma, Squamous Cell ,Anxiety ,Humans ,Mouth Neoplasms ,medicine.symptom ,Mandibular Reconstruction ,business ,Depression (differential diagnoses) - Abstract
Objectives:To determine whether the fibula free flap is the most frequently used osteocutaneous flap for mandible reconstruction, and whether it provides quality of life, depression and anxiety advantages.Methods:A systematic review of the public Medline database was conducted. Thirteen patients who underwent mandibular reconstruction at our hospital centre completed questionnaires to evaluate quality of life, depression and anxiety outcomes.Results:The most frequently used free flaps are those of the fibula (n = 982), radial forearm (n = 201), iliac crest (n = 113), subscapular system (n = 50) and rib–serratus (n = 7). In our patient population, there was a trend towards a better quality of life in those with a fibula free flap. However, patients in this group were significantly younger than patients with other flap types (p = 0.025). Patients with a subscapular system free flap were more depressed (p = 0.031); however, they had large through-and-through defects.Conclusion:The flap used most frequently in the literature is the fibula free flap. Comparative quality of life data are lacking, and homogeneous populations should be used to reach significant conclusions.
- Published
- 2014
50. North-American survey on HPV-DNA and p16 testing for head and neck squamous cell carcinoma
- Author
-
Apostolos Christopoulos, Phuc Felix Nguyen-Tan, Anastasios Maniakas, Denis Soulières, Olga Gologan, Tareck Ayad, Louis Guertin, and Sami P. Moubayed
- Subjects
Cancer Research ,medicine.medical_specialty ,Canada ,Alphapapillomavirus ,Polymerase Chain Reaction ,Internal medicine ,medicine ,Humans ,Human papillomavirus ,Head and neck ,In Situ Hybridization ,Gynecology ,business.industry ,Data Collection ,Genes, p16 ,medicine.disease ,Head and neck squamous-cell carcinoma ,Test (assessment) ,Hpv testing ,Direct Treatment ,Oncology ,Treatment modality ,Head and Neck Neoplasms ,DNA, Viral ,Carcinoma, Squamous Cell ,Oral Surgery ,business ,Oropharyngeal Cancers - Abstract
Human papillomavirus (HPV)-positive head and neck squamous cell carcinomas (HNSCC) have been shown to have a significantly better prognosis and response to current treatment modalities. Current guidelines recommend systematic HPV-DNA and/or p16 testing on HNSCCs, although treatment approach should not be directed by test results. The objectives of this study were to (1) assess whether HPV-DNA and/or p16 status are systematically evaluated across North American otolaryngologists-head and neck surgeons and (2) whether the status is used to direct treatment approach.A 15-question online survey was sent to three associations: the Association of Oto-rhino-laryngology-Head and Neck Surgery of Quebec, the Canadian Society of Otolaryngology-Head and Neck Surgery, and the American Head and Neck Society.Sixty-seven percent of respondents systematically test for HPV-DNA and/or p16 on HNSCC sites, while 58.3% report using test results to direct treatment for oropharyngeal cancers. A lack of official guidelines was the primary reason (81.8%) physicians did not use test results to direct treatment. Academic centre physicians (83.3%) and physicians with ⩾50% oncologic practice (87.6%) were more likely to test for HPV-DNA and/or p16 in HNSCC compared to non-academic centre physicians (39.7%) and physicians with50% oncologic practices (51.4%) (p0.001). Cost of the tests (69.2%), lack of relevance (46.1%) and time constraints (30.8%) were the primary reasons HPV-DNA and/or p16 were not tested.The majority of North American respondents in this survey systematically test for HPV-DNA and/or p16 in HNSCC sites, and most indicate that test results influence their treatment approach for oropharyngeal cancers.
- Published
- 2013
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