Publications by authors named "Anna Vella"

5 Publications

  • Page 1 of 1

Incorporating oxygenation levels in analytical DNA-damage models-quantifying the oxygen fixation mechanism.

Phys Med Biol 2021 Jul 9;66(14). Epub 2021 Jul 9.

University of Oxford, Department of Oncology, Oxford, United Kingdom.

To develop a framework to include oxygenation effects in radiation therapy treatment planning which is valid for all modalities, energy spectra and oxygen levels. The framework is based on predicting the difference in DNA-damage resulting from ionising radiation at variable oxygenation levels.Oxygen fixation is treated as a statistical process in a simplified model of complex and simple damage. We show that a linear transformation of the microscopic oxygen fixation process allows to extend this to all energies and modalities, resulting in a relatively simple rational polynomial expression. The model is expanded such that it can be applied for polyenergetic beams. The methodology is validated using Microdosimetric Monte Carlo Damage Simulation code (MCDS). This serves as a bootstrap to determine relevant parameters in the analytical expression, as MCDS is shown to be extensively verified with published empirical data. Double-strand break induction as calculated by this methodology is compared to published proton experiments. Finally, an example is worked out where the oxygen enhancement ratio (OER) is calculated at different positions in a clinically relevant spread out Bragg peak (SOBP) dose deposition in water. This dose deposition is obtained using a general Monte Carlo code (FLUKA) to determine dose deposition and locate fluence spectra.For all modalities (electrons, protons), the damage categorised as complex could be parameterised to within 0.3% of the value calculated using microdosimetric Monte Carlo. The proton beam implementation showed some variation in OERs which differed slightly depending on where the assessment was made; before the SOBP, mid-SOBP or at the distal edge. Environment oxygenation was seen to be the more important variable.An analytic expression calculating complex damage depending on modality, energy spectrum, and oxygenation levels was shown to be effective and can be readily incorporated in treatment planning software, to take into account the impact of variable oxygenation, forming a first step to an optimised treatment based on biological factors.
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http://dx.doi.org/10.1088/1361-6560/ac0b80DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8273901PMC
July 2021

Citizen Consultation on Problematic Usage of the Internet: Ethical Considerations and Empirical Insights From Six Countries.

Front Public Health 2021 1;9:587459. Epub 2021 Apr 1.

Faculty of Psychology and Education Sciences, University of Porto, Porto, Portugal.

Citizens and scientists can work together to improve the collective well-being, if citizens are inspired to help the advancement of science, and researchers motivated to listen to the voices of citizens. The benefits of such collaboration are increasingly recognized by both citizens and scientists, as reflected in the growing number of related publications and initiatives. This is especially relevant for emerging areas of research, where early involvement of citizens could help to envision, prioritize, and plan prospective studies. The Problematic Usage of the Internet (PUI) is one such area, which is fast becoming a public mental health concern. However, there remains a lack of clarity regarding the practical guidelines and ethical requirements for citizen involvement at the earliest stages of PUI. In our paper, we propose a conceptual framework and a template for initial involvement of citizens in PUI. They are derived from our community case studies, conducted in six European countries (Georgia, Greece, Malta, North Macedonia, Portugal, and Spain) and consisting of consultation with diverse groups of interested citizens (students, parents, teachers, and health professionals). Informed by our consultation exercises, we also highlight four ethical aspects for citizen involvement in the research on PUI or novel disciplines in general. They follow simple guiding principles to ensure that scientists will: enable a long-term commitment and inclusive opportunities for citizens, challenge established power hierarchies, and support collaboration, co-production and co-authorship with citizens. We believe that the proposed practical guidelines and ethical considerations, provide a valuable foundation on which to advance our understanding and generate international strategies for citizen involvement in PUI.
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http://dx.doi.org/10.3389/fpubh.2021.587459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046911PMC
May 2021

Prognostic utility of quantitative offline 2D-echocardiography in hospitalized patients with COVID-19 disease.

Echocardiography 2020 12 22;37(12):2029-2039. Epub 2020 Sep 22.

Division of Cardiology, Heart and Lung Department, San Paolo Hospital, ASST Santi Paolo and Carlo, University of Milan, Milan, Italy.

Purpose: To assess the prognostic utility of quantitative 2D-echocardiography, including strain, in patients with COVID-19 disease.

Methods: COVID-19-infected patients admitted to the San Paolo University Hospital of Milan that underwent a clinically indicated echocardiographic examination were included in the study. To limit contamination, all measurements were performed offline. Quantitative measurements were obtained by an operator blinded to the clinical data.

Results: Among the 49 patients, nonsurvivors (33%) had worse respiratory parameters, index of multiorgan failure, and worse markers of lung involvement. Right ventricular (RV) dysfunction (as assessed by conventional and 2-dimensional speckle tracking) was a common finding and a powerful independent predictor of mortality. At the ROC curve analyses, RV free wall longitudinal strain (LS) showed an AUC 0.77 ± 0.08 in predicting death, P = .008, and global RV LS (RV-GLS) showed an AUC 0.79 ± 0.04, P = .004. This association remained significant after correction for age (OR = 1.16, 95%CI 1.01-1.34, P = .029 for RV free wall LS and OR = 1.20, 95%CI 1.01-1.42, P = .033 for RV-GLS), for oxygen partial pressure at arterial gas analysis/fraction of inspired oxygen (OR = 1.28, 95%CI 1.04-1.57, P = .021 for RV free wall-LS and OR = 1.30, 95%CI 1.04-1.62, P = .020 for RV-GLS) and for the severity of pulmonary involvement measured by a computed tomography lung score (OR = 1.27, 95%CI 1.02-1.19, P = .034 for RV free wall LS and OR = 1.30, 95%CI 1.04-1.63, P = .022 for RV-GLS).

Conclusions: In patients hospitalized with COVID-19, offline quantitative 2D-echocardiographic assessment of cardiac function is feasible. Parameters of RV function are frequently abnormal and have an independent prognostic value over markers of lung involvement.
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http://dx.doi.org/10.1111/echo.14869DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7646664PMC
December 2020

Extracorporeal myocardial shockwave therapy; a precious blast for refractory angina patients.

Cardiovasc Revasc Med 2018 04 3;19(3 Pt A):263-267. Epub 2017 Oct 3.

Division of Cardiology, IRCCS Ospedale San Raffaele, Milano, Italy.

Introduction: Refractory Angina Pectoris (RAP) dramatically affects patients' life quality and medical costs. External Shockwave Myocardial Revascularization (ESMR) improves the cardiac blood flow thanks to its pro-angiogenetic action on ischaemic tissues. We hereby describe our experience of ESMR in RAP patients.

Materials And Methods: This is a retrospective study encompassing all patients referred to OSR for RAP treatment. Efficacy of ESMR was assessed considering the difference between pre and post therapy data in SAQ score and CCS, stress test performance, 24h ECG monitoring, NT-proBNP and echocardiographic measures.

Results: From a total of 97 patients with RAP, 19 patients underwent ESMR, whereas 4 were considered as control group. After the end of the treatment, ESWT group showed a significant improvement in CCS class (-1.32±0.58; p<0.001) and in each of the five variables of the SAQ score (p<0.05). Patients also improved their exercise duration (50,74±29.40 seconds; p<0,001) and double product (1340,53±1321,77; p<0,001) and reduced the number of daily ST segment depression (-1,16±1,01; p<0,01). Ejection Fraction (2,05±1,84%; p<0,01) and Cardiac Output (0,20±0,28L, p<0,01) improved too. No changes were documented in the control group.

Conclusion: ESMR is an efficient therapy for refractory angina capable to improve both symptoms and instrumental tests.
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http://dx.doi.org/10.1016/j.carrev.2017.09.018DOI Listing
April 2018

Pregnancy outcomes in substance-misusing pregnant women: A 10-year retrospective study.

J Obstet Gynaecol 2016 May 14;36(4):468-72. Epub 2015 Oct 14.

d Institute of Pharmaceutical Science, King's College London , UK.

In this ten-year retrospective study we were able to show that Maltese substance-misusing mothers (SMMs) have significantly different socio-biological characteristics from mothers in the general population which seem to impact on neonatal outcomes. Significant differences from the general population were noted in the SMM's age, age at first pregnancy, marital status, educational background, number of cigarettes smoked, number of offspring and weight gained in pregnancy. SMMs booked their pregnancy in hospital later than the general population. On the other hand their infants had a lower mean birth weight and head circumference, had lower Apgar scores, were of lesser gestational age and premature. They were less breast-fed and stayed longer in hospital after their birth.
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http://dx.doi.org/10.3109/01443615.2015.1072805DOI Listing
May 2016