Analyse de la qualité du logiciel : une approche par visualisation et simulation

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Pulmonary functions of narghile smokers compared to cigarette smokers: a casecontrol study

Background: Studies of the lung function profiles of exclusive narghile smokers (ENS) are few, have some methodological limits, and present contradictory conclusions. The present study aimed to compare the plethysmographic profiles of ENS with age- and height-matched exclusive cigarette smokers (ECS).Methods: Males aged 35-60 living in Sousse, Tunisia, who have been smoking narghile exclusively for more than 10 narghile-years (n=36) or cigarettes exclusively for more than 10 pack-years (n=106) were recruited to participate in this casecontrol study. The anthropometric and plethysmographic data were measured according to international recommendations using a body plethysmograph (ZAN 500 Body II, Meβgreräte GmbH, Germany). Large-airway-obstructive-ventilatory-defect (LAOVD) was defined as: first second forced expiratory volume/forced vital capacity (FEV1/FVC) below the lower-limit-of-normal (LLN). Restrictiveventilatory- defect (RVD) was defined as total lung capacity <LLN. Lung hyperinflation was defined as residual volume>upper-limit-of-normal. Student t-test and x2 test were used to compare plethysmographic data and profiles of the two groups.Results: The subjects in the ENS and ECS groups are well matched in age (45+7 vs. 47+5 years) and height (1.73+0.06 vs. 1.72+0.06 m) and used similar quantities of tobacco (36+22 narghile-years vs. 35+19 packyears). Compared to the ENS group, the ECS group had significantly lower FEV1 (84+12 vs. 60+21%), FVC (90+12 vs. 76+18%), and FEV1/FVC (99+7 vs. 83+17%). The two groups had similar percentages of RVD (31 vs. 36%), while the ECS group had a significantly higher percentage of LAOVD (8 vs. 58%) and lung hyperinflation (36 vs.57%).Conclusion: Chronic exclusive narghile smoking has less adverse effects on pulmonary function tests than chronic exclusive cigarette smoking.Keywords: plethysmography; tobacco; narghile; tabamel; agein

Letter to the Editor: Critical analysis of the published literature about the effects of narghile use on oral health

No Abstrac

Oxidative stress and lung function profiles of male smokers free from COPD compared to those with COPD: A case-control study

Background: The mechanisms of smoking tobacco leading to chronic obstructive pulmonary disease (COPD) are beginning to be understood. However, conclusions about the role of blood or lung oxidative stressmarkers were disparate.Aims: To investigate the oxidative stress in blood or lung associated with tobacco smoke and to evaluate its effect on pulmonary function data and its relation with physical activity.Methods: It is a case-control study. Fifty-four male-smokers of more than five pack-years (PY) and aged 4060 years were included (29 Non-COPD, 16 COPD). Physical activity score was determined. Blood sample levels of malondialdehyde (MDA), protein-cys-SH (PSH), and Glutathione (GSH) were measured. Fractional exhaled nitric oxide (FeNO) and plethysmographic measurements were performed. Correlation coefficients (r) evaluated the association between oxidative stress markers and independent variables (plethysmographic data and physical activity score).Results: Non-COPD (4896 years) and COPD (4995 years) groups had  similar tobacco consumption patterns, that is, 27914 PY versus 30919 PY, respectively. Compared to the Non-COPD group, the COPD group had significantly lower levels of GSH and PSH, that is, mean9SE were 4096 versus 2595 mg/mL and 54910 versus 2695 mg/g of hemoglobin,  respectively. However, MDA level and FeNO values were similar. In the COPD group, none of the oxidative stress markers was significantly  correlated with plethysmographic data or physical activity score. In the Non-COPD group, GSH was significantly correlated with physical activity score (r0.47) and PSH was significantly correlated with total lung capacity (TLC) (r0.50), residual volume (r0.41), and physical activity score (r0.62). FeNO was significantly correlated with TLC of the COPD group (r0.48).Conclusion: Compared to the Non-COPD group, the COPD group had a marked decrease in blood antioxidant markers (GSH and PSH) but similar blood oxidant (MDA) or lung (FeNO) burden.Keywords: inflammation; lung disease; spirometry; tobacco; sedentarily; stress oxidan

Letter to the Editor: Critical analysis of the published literature about the effects of Ramadan intermittent fasting on healthy children’s physical capacities

No Abstrac

Severity assessment of non-cystic fibrosis bronchiectasis by the FACED score

Objectives: Bronchiectasis (BE) is a major health problem associated with a high morbidity and mortality. This study aimed to determine the relation of the FACED score (a multidimensional score contributing to stratify patients into risk categories) with the severity of non-cystic fibrosis bronchiectasis (NCFB) among our population.Materials and Methods: This is a retrospective single center study of 105 consecutive patients with NCFB hospitalized for acute exacerbations (AE) at the Department of Respiratory Medicine of Fattouma Bourguiba Teaching Hospital in Monastir (Tunisia) between January 2005 and December 2017. Patients were divided into two groups (G): G1: FACED Score ≤ 2 and G2: FACED score ≥3. We compared different severity parameters of BE between the two groups.Results: The study included 105 patients with NCFB. Patients of G2 had more comorbidities (P = 0.028), an altered respiratory function with a lower forced vital capacity (G1:2.73, G2:1.33 L; P < 0.001), a decreased PaO2 (88 vs. 68 mmHg; P < 0.001), a high CO2 level (P < 0.001), and a higher number of AE/year (0.96, 2.12 AE/year; P < 0.001). Hospitalizations for AE of G2 were characterized by a lower PaO2, a higher PaCO2 (P < 0.001), a longer course of antibiotic (P < 0.001) with an extended hospitalization (P = 0.007). An ultimate evolution toward chronic respiratory failure was more common in G2 (P < 0.001).Conclusion: A high FACED score is associated with more symptoms, an altered respiratory function, a higher number and more severe AE, more health-care utilization with worse outcomes. Further studies are necessary to evaluate the impact of such scales in clinical practice

Large shareholders and firm risk-taking behavior

We investigate whether multiple large shareholders (MLS) affect corporate risk-taking. Using hand-collected data on French publicly-listed companies over the period 2003-2007, we show that the presence, number and voting power of MLS, other than the largest controlling shareholder (LCS), are associated with greater variability in operating performance (ROA), market value (Tobin’s Q) and stock returns. In contrast, the presence of a single LCS is associated with less variability in firm performance, especially when the divergence between the LCS’s control and cash flow rights is large. This result suggests that MLS are able to prevent the LCS from dictating her preference for low-risk projects in order to protect her future consumption of private benefits. As a consequence, firms undertake better investments regardless of their intrinsic risks, and this eventually leads them to achieve higher performance. MLS are thus confirmed to play a critical role in corporate governance