What differentiates youths who use e-cigarettes from those who smoke traditional tobacco products?

Background: Electronic cigarette (e-cigarette) use has spread among adolescents in many countries, however users' characteristics are not well known. We aimed to compare characteristics of exclusive e-cigarette users to those of exclusive tobacco users and dual users.

Methods: Data come from a representative sample of 11-19 years old students in Paris, surveyed each year between 2013 and 2017.

[Where do Parisian teenagers buy their cigarettes?].

Introduction: The objective of this work was to assess the background of the implementation of the ban of tobacco sales to minors before the change of French law in 2016.

Methods: The analysis focused on two questions to teenagers on buying tobacco, added to the four cross-sectional annual surveys of the association "Paris Sans Tabac" from 2012 to 2015.

Results: In total, 7025 schoolchildren (12-15 years old), 3299 high school students (16-17 years old) and 3243 adult students (18-20 years old) responded.

Factors associated with experimentation of electronic cigarettes among Parisian teenagers in 2013.

Background: Electronic cigarettes (e-cig.) became widely used among adults. Data are insufficient about e-cig.

[The e-cigarette disrupts other consumptions in Parisian teenagers (2012-2014)].

Objectives: To analyze experimentation with and use of e-cigarette by middle school and high school students in Paris.

Method: Since 2012, questions about e-cigarette use have been included in the cross-sectional survey on tobacco that is administered annually since 1991 by the Paris sans tabac association. Overall, 2% of the 12-19 years-old attending school in Paris were surveyed.

Secondhand smoke exposure in hospitality venues in Europe.

Background: Although in the last few years some European countries have implemented smoking bans in hospitality venues, the levels of secondhand smoke (SHS) in this occupational sector could still be extremely high in most countries.

Objective: The aim of this study was to assess exposure to SHS in hospitality venues in 10 European cities.

Methods: We included 167 hospitality venues (58 discotheques and pubs, 82 restaurants and cafeterias, and 27 fast-food restaurants) in this cross-sectional study.

[Decrease in smoking by Parisians students after the launch and implementation of a national cancer prevention plan].

Unlabelled: The French national cancer prevention plan launched in 2003 led many smokers to quit; however, no data is available on the rates of French adolescents who have begun smoking.

Method: Every year since 1991, the Paris without Tobacco (PST) organisation carries out a cross-sectional survey among Parisian teenagers. The data from 2003-2004 have been compared with data from years prior to the implementation of the cancer prevention plan.

Modeling of cardiac electrophysiological mechanisms: from action potential genesis to its propagation in myocardium.

The aim of the present paper is to describe the different attempts at modeling cardiac electrophysiological mechanisms, mainly at the membrane and cellular level, from action potential genesis to its propagation in myocardium. The Hodgkin and Huxley model describing the nervous action potential's theoretical reconstruction is first recalled, for it represents the basic model for a large part of cardiac action potential models. These models (Beeler and Reuter, Van Capelle and Durrer, Luo and Rudy) are then successively studied as their main applications by diverse authors.

Effect of myocardial infarction and ischemia on induction of cardiac reentries and ventricular fibrillation.

The present work is aimed at investigating the effects of myocardial infarction and ischemia on induction of ventricular fibrillation. Electrophysiologic effects of global and local ischemia (variation of the dispersion of refractory periods as well as conduction velocity) on initiation of reentry mechanisms was studied by means of computer simulations based on a cellular automata model of propagation of activation wave through a ventricular surface element. A local area of ischemia where effects of the dispersion of refractory periods are investigated is then simulated.

Electrode polarity does not alter the initial ventricular activation sequence during pacing with extracardiac electrodes.

Ventricular epicardial mapping was performed in six closed-chest anesthetized dogs to investigate the cardiac electrical response to external pacing. A right thoracotomy was performed, complete AV block was produced by formaldehyde injected into the AV node and a sock electrode array, comprised of 127 unipolar electrodes, was placed over the ventricles. Isopotential and isochronal epicardial maps were generated by computer from the unipolar electrograms.

Noninvasive transcutaneous cardiac pacing: modern instrumentation and new perspectives.

Noninvasive transcutaneous cardiac pacing has evolved from a simple stand alone unit with no ventricular sensing to a complete cardiac arrest resuscitation system combining synchronous pacing and defibrillation capabilities and using a single set of multifunction electrodes. In current instrumentation, four configurations exist including stand alone unit, modular configuration, built-in monitor and recorder, and built-in monitor, recorder and defibrillator. In present day devices, ventricular sensing, extensive programmability, and large surface electrodes are general features.

[Thoracic transcutaneous cardiac pacing].

Transcutaneous cardiac pacing was abandoned when endocardial pacing was developed, but it has now come back, with a new methodology, in cardiological intensive care. Its safety and efficacy have been improved by 50 to 100 sq. cm electrodes, impulses of 20 to 40 ms duration and programmed energy.

[Then hemodynamic efficacy of transcutaneous cardiac stimulation].

Bradyarrhythmia or asystole is the most common rhythm disturbance with ventricular fibrillation and tachycardia, for 30-40% of patients admitted in intensive coronary care units. Already use in the therapy of bradyarrhythmia or asystole, as a method of emergency, immediately in place, the external pacing is very useful in an out of hospital therapy with personnel skilled in its use until the initiation of support therapy in coronary care units. Actually, with less significant side effects (no severe pain, no strong muscular contractions, no skin burns) and a best innocuity and tolerance based on the employment of larger adhesive pre-gelled patches, temporary transcutaneous cardiac stimulation is not only confined to unconscious patients but also in case of severe bradycardia, complete AV block in conscious patients.

Directional variability of stimulation threshold measurements in isolated guinea pig cardiomyocytes: relationship with orthogonal sequential defibrillating pulses.

Reports on delivery of separated orthogonal pulses markedly improving cardiac defibrillation have suggested that the stimulation threshold of heart fibers varies in accordance with their orientation within the electric field. The present work was aimed at investigating the directional variability of stimulation thresholds in isolated guinea pig cardiomyocytes. This variability was measured in 48 single myocytes by rotating each one through a theta (theta) angle between two-fixed parallel electrodes 1.

Left ventricular pressure measurement during noninvasive transcutaneous cardiac pacing.

In a pacemaker-dependent patient, the hemodynamic response during external transcutaneous and endocardial sequential pacing was evaluated by left ventricular pressure monitoring. A single ventricular pacing mode with hemodynamic effect of atrioventricular asynchrony was shown during external pacing.

Reduction of energy required for defibrillation by delivering shocks in orthogonal directions in the dog.

Reduction of energy required to defibrillate (ERD) seems to represent a necessary condition for intensive development of implantable defibrillator, so as for minimization of cardiac and pulmonary damages provoked by high energy transthoracic defibrillation electric shocks. The present work describes a defibrillation method using shocks delivered in orthogonal directions and separated by a 100 ms delay. Defibrillation threshold measured with classical unidirectional shocks on 30 dogs has been found to be 286.

[Tobacco dependence: first risk factor of atherosclerosis. Survey among smokers and non-smokers in group dynamics].

Several epidemiological and experimental studies have demonstrated an increased risk of atherosclerosis in smokers. The secondary prevention of this risk factor is only possible, presently, through anti-tobacco consultations. Several approaches are possible but there are many recurrences within the year following the wean-off.

[TM-mode echocardiography in the evaluation of ventricular function in convalescent patients after recent infarction. Correlations with hemodynamic parameters recorded at rest and after a cycloergometric test].

133 patients (50 +/- 11 years), under observation at 1 to 2 months after the acute episode (38 +/- 10 days) and in the absence of medical treatment in most cases (90%), underwent the same day a maximal cycloergometric test, limited to symptoms of clinostatism with hemodynamic monitoring (Swan-Ganz 7F for pressure and thermodilution), and a good quality echocardiogram in TM mode (semi-automatic reading) in order to identify every valvular lesion. The ECHO-TM parameters of the left ventricular function (LV) taken into consideration (circumferential velocity of shortening of LV : CVSLV, percentage of systolic shortening of LV, telediastolic dimension of LV,E-septum distance, PR-AC, relation between the intervals Q-mitral block and aortic block-mitral point E,QC/A2E, left auricular dimension and mitral point B) have shown a low correlation (0.31) with the telediastolic pulmonary arterial pressure (TDPAP) at rest and after effort.

Limitations of fluorocarbons in reducing myocardial infarct size.

The effects of the oxygen-carrier fluorocarbons on myocardial infarct size were assessed in non-exchange-transfused dogs subjected either to a 3-hour occlusion of the left anterior descending coronary artery (LAD) followed by 2 hours of reperfusion (protocol I) or to a 5-hour permanent LAD occlusion (protocol II). Fluorocarbon administration was begun 30 minutes after LAD occlusion and was continued over the entire period of ischemia. After 5 hours, the hearts were excised and areas of necrosis were visualized by triphenyl tetrazolium chloride staining while risk regions were assessed by radiolabeled microspheres injected after coronary occlusion just before the onset of therapy, and further, in protocol I, by thallium-201 perfusion imaging performed at the end of fluorocarbon administration.

The use of detachable balloons in neuroradiology.

The development of the detachable balloon allows treatment of many neurological lesions, both congenital and acquired. We describe here a device that may be used easily. Complications and main indications are discussed on the basis of our experience with 114 cases.

Reduction of myocardial infarct size by a fluorocarbon-oxygenated reperfusate.

This investigation assesses whether the size of an acutely revascularized myocardial infarct (MI) could be reduced by altering the composition of the initial reperfusate. Nineteen open-chest dogs underwent 4-hour occlusion of the left anterior descending coronary artery and were then assigned to a treatment group: 12 dogs to selective intracoronary infusion of the modified reperfusate over 30 minutes before resumption of blood flow for 60 minutes and 7 to a control group (90 minutes of unmodified blood reperfusion). The modified reperfusate consisted of 500 ml of a fluorocarbon-oxygenated crystalloid solution (PO2 650 mm Hg; total O2 content 5.

[Placement of catheters for intra-arterial chemotherapy. A new technic using balloon microcatheters].

A system employing a micro-balloon catheter is proposed for the introduction of catheters for intra-arterial chemotherapy.

[Evaluation of physical fitness following uncomplicated myocardial infarct by bicycle ergometry in horizontal and vertical position].

For an increasingly early mobilisation after uncomplicated myocardial infarction, the stress tests appraised the individual physicalal aptitude in supine and upright positions without incident, in a simple and objective way. To complete this evaluation, the calculation of an energetic index EI was proposed as soon as the initial level of 25 watts during cycloergometric symptom-limited stress tests in 17 male patients (increment of 25 watts for each 6 minutes and interval of one hour between the two positions). The pulmonary wedge pressure (Swan Ganz) at 15 mmHg in upright position as soon as 25 watts separated the subjects into two groups GI (N = 5) and G II (N = 12).