[E-cigarette use in university students and its relationship to cigarette smoking]. / Vapotage chez les étudiants à l'université et relation avec le tabagisme.

INTRODUCTION: There is concern that e-cigarette use could be a risk factor for subsequent cigarette smoking. METHODS: This survey included a group of 1220 students at Aix-Marseille University who attended a check-up visit and volunteered to participate to the survey. They answered a standardized questionnaire relating to e-cigarette use, smoking habits and the relationship between both habits. Mean age of participants was 19.9 years and 56% of them were female. RESULTS: All students invited to the check-up examination attended and agreed to participate in the survey. 13.3% of students answered they had already used e-cigarettes, a higher proportion of boys (17.5%) than girls (10.0%), starting at a mean age equal to 19.2 years. Forty-six percent of them had already smoked cigarettes, more girls (55.0%) than boys (45.0%). Among current cigarette smokers, e-cigarette use had induced giving up smoking in 12.6% and a decrease in the number of cigarettes smoked in 30.1%. Twenty percent said they begun to smoke cigarettes after using e-cigarettes. DISCUSSION: E-cigarette use is much less prevalent than smoking conventional tobacco cigarettes. There is a strong link between both. E-cigarette use had allowed a cessation or reduction in tobacco smoking in half of users. E-cigarette users may go on to start tobacco smoking but prospective surveys are needed to know how this will evolve over time. E-cigarette use could also be a means to prevent or postpone cigarette smoking.

[Factors associated with smoking in sixth grade (11-13 years old)]. / Facteurs associés au tabagisme en classe de sixième.

Because smoking begins most often in adolescence it is important to define clearly, with a view to prevention, the motivation of an adolescent to smoke. The role of the social group is well known. The aim of this study was to evaluate the potentially preventative role of knowledge in the field of respiration and the effects of cigarette smoke on one hand and of involvement in activities involving breathing on the other. The group studied was made up of 1,802 pupils at state schools, randomly selected, in the city of Marseilles. These pupils filled in an anonymous questionnaire in the classroom. The overall percentage of non-responders was very small. Overall 10.5% if the children declared that they had already smoked, more often boys (13.1%) than girls (8.1%). In contrast to smoking by the father, smoking by the mother and siblings significantly influenced smoking in the child. The child was not influenced by smoking by a sibling of the same sex. The proportion of children having already smoked increased progressively in proportion to the number of smokers in the household. Using a logistical regression analysis the following were predictive of smoking: being a boy, having a best friend who smoked, and the number of smokers in the family. On the other hand a history of allergy, an understanding of the effects of the environment on the respiratory system, knowledge of the effects of cigarettes, and finally involvement in sport, playing a wind instrument or singing in a choir were not associated with a lower incidence of smoking. These results call into question the effectiveness of the standard preventative methods and of anti-smoking programmes that are based on such strategies.

[Evaluation of a questionnaire on the home environment of asthmatic patients]. / Evaluation d'un questionnaire sur l'environnement domestique des asthmatiques.

Indoor environment outpatient asthmatics plays a major role in modulating asthma severity. Therefore many surveys devoted to studying risk factors for asthma include a questionnaire about housing characteristics. However no such questionnaire has been to date validated. In this study, we tried to validate such a questionnaire by comparing answers of a group of asthmatics outpatient to a questionnaire to de visu finding performed by a field worker during a home visit. Thirty asthmatic patients were included in the study. Housing characteristics were generally correctly acknowledged. Questions on the heating system should be clearly and simply formulated. Energetic supply of stoves and ventilation system is not always known. In the field of house equipment, especially bedding, photographs or drawings can be useful.

Dog factor differences in Can f 1 allergen production.

BACKGROUND: The clinical importance of dog allergy is well known, but it is unknown if all types of dogs represent the same risk for allergic patients. The purpose of this work was to evaluate among 288 healthy dogs if the levels of Can f 1 on fur vary between breeds (German Shepherd, Pyrenean Shepherd, Poodle, Cocker spaniel, Spaniel, Griffon, Labrador retriever and Yorkshire terrier), gender, hormonal status, hair length, and according to the presence of seborrhea. METHODS: Each dog was shaved in a limited area and Can f 1 concentrations were measured in mug/g fur by ELISA. The results (geometric mean values and 95% confidence intervals) were analyzed using analysis of variance and with nonparametric tests. RESULTS: A wide variability in Can f 1 levels was found between dog breeds, from Labradors [1.99 (0.03-129.91)] to Yorkshires [16.72 (3.67-76.16)] and Poodles [17.04 (2.79-103.94)] but only the Labrador levels were significantly different from each other breed. Males produced more Can f 1 than females, 11.75 (1.27-108.40) vs 8.89 (0.91-86.39). No difference was found according to hair length or hormonal status. The seborrheic status highly (P = 0.0019) influenced the presence of Can f 1 on hair: 16.66 (1.59-173.96) vs 9.40 (1.03-85.70). CONCLUSION: Breeds (Labrador retriever), sex and seborrhea seem to influence the levels of Can f 1 on fur.

Triggers in intrinsic asthma in the EGEA study.

The objective of the study was to compare triggers for asthma attacks in a group of intrinsic (IA) and extrinsic asthmatic (EA) subjects. We included 205 asthmatic patients divided, according to skin-prick tests, in a group (n = 63) of IA and a group (n = 142) of EA. The questionnaire provided information on associated conditions (nasal polyps and intolerance to aspirin) as well as on allergenic and nonallergenic triggers. Data analysis demonstrated that in IA, some airborne nonallergenic factors were significantly more often involved. In addition, this association did hold true when comparing subgroups of patients with normal baseline FEV1 values. For those subjects, PC20 and the slopes of the dose-response curves to metacholine were comparable. In conclusion, the higher sensitivity of a group IA subjects to some nonallergenic factors is not related to a lower baseline spirometric value in this subgroup. It may be hypothesized that, in these patients, sensitivity of airways irritant receptors might be increased.

Hymenoptera ultra-rush venom immunotherapy (210 min): a safety study and risk factors.

BACKGROUND: In this study, which summarizes our last 5 years of experience, we evaluated the side-effects of ultra-rush venom immunotherapy and the possibility to define some risk factors for side-effects as age, Hymenoptera venom used for treatment, treatment phase, severity of prior insect sting reaction, concentration of skin test positivity, and level of specific IgE. METHODS: In our protocol on day 1, an initial venom dose of 0.1 microg was followed by 1, 10, 20 microg at 30-min intervals and then 30 and 40 microg at 60-min intervals. Patients who completed this protocol received two booster injections of 50 microg on day 15 and one of 100 microg on day 45. Subsequently, monthly 100 microg boosters were given. RESULTS: Fifty-one children (9.20 +/- 3.41 years) and 207 adults (40.62 +/- 14.00 years) underwent an ultra-rapid venom immunotherapy (ultra-RVIT). Single ultra-RVIT was administered to 195 patients: 69 with honeybee, 123 with yellow jacket and three with wasp venoms. Two venoms were injected into 59 patients: 42 with yellow jacket and wasp, 17 with yellow jacket and honeybee. Four patients received the three venoms. The frequency of immediate systemic reactions (SR) was not significantly different between adults and children: 11.2% vs. 10.8%. SR were experienced more frequently on day 1 (n= 33). They were uncommon on day 15 (n= 2) and on day 45 (n= 1). No late reactions have been observed. Honeybee venom induced significantly more SR (30%) vs. yellow jacket (3.2%) and wasp venom (6.1%). Among the 33 patients who experienced a SR on day 1, 24 had a reaction grade 1 or 2 and nine had a reaction grade 3 or 4. There is a significant risk for patients with a prior reaction grade 3 or 4 to experience a SR during venom immunotherapy (VIT). The strength of positive skin tests and the level of specific IgE were not related to an increased risk of SR (P= NS). CONCLUSION: Treatment with honeybee extract induced more SR than the treatment with yellow jacket and wasp venom. Doses increase phase on day 1 is risk factors for SR of ultra-RVIT, as well as the severity of the prior reaction. Age, degree of positive skin tests, and specific IgE are not risk factors.

Fel d 1 production in the cat skin varies according to anatomical sites.

BACKGROUND: Fel d 1 is the major cat allergen, inducing asthma in sensitized individuals. It is produced by the skin and lies on fur. Recently, it was established that the amount of Fel d 1 on fur varies among anatomical sites. However, it is not known whether the allergen production by skin varies in parallel. The objective was to compare the Fel d 1 production by male cat skin in two anatomical sites, the face and the chest, in order to correlate it with Fel d 1 amounts on fur, and to assess the reaccumulation of Fel d 1 after washing. METHODS: Ten intact male cats were shaved under general anesthesia at both areas, and the fur was collected. The skin was washed and the washing fluid collected for Fel d 1 assays. Fel d 1 levels were measured in microg/g fur and ng/cm2 skin by ELISA before and after washing and 48 h later. RESULTS: In skin washing, the mean Fel d 1 level was significantly higher in the face (1015.2 +/- 821.6 ng/cm2) than the chest (115.2 +/- 66.8 ng/cm2). In the fur, the respective levels were 63.6 +/- 34 and 29.6 +/- 13.6 microg/g. In the skin sample taken after skin washing, the level of Fel d 1 dropped to 25.1 +/- 25.7 ng/cm2 on the face and to 22 +/- 17.4 ng/cm2 on the chest. After 2 days, skin Fel d 1 levels returned to basal values, with higher values on the face than the chest. CONCLUSIONS: This study shows that Fel d 1 levels on the skin are dramatically higher on the facial area than chest. This anatomical variation is concordant with the levels of Fel d 1 found on fur. Washing reduces levels of major allergen on cat skin and fur, but the accumulation on skin is restored within 2 days.

Prevalence of asthma and rhinitis in relation to long-term exposure to gaseous air pollutants.

The relationship between long-term exposure to air pollutants, especially with regard to photochemical air pollutants, and asthma prevalence in developed countries is controversial. The objective of this cross-sectional survey was to compare mean levels of the main gaseous air pollutants and prevalence rates of rhinitis, asthma, and asthmatic symptoms. It included 2,445 children from the 8th and 9th school grades who had been living for at least 3 years in an area where some communities undergo the heaviest photochemical exposure in France. Data on rhinitis, asthmatic symptoms, and asthma prevalence were gathered with the ISAAC paper and video questionnaires. The relation between level of air pollutants and asthma was assessed first by comparison of crude prevalence rates (chi-square test), and then by simple regression analysis and multiple logistic regression analysis. No consistent association between mean SO2 and NO2 levels, and prevalence of rhinitis, asthma, or asthmatic symptoms could be demonstrated. In contrast, there were statistically significant associations between prevalence of asthmatic symptoms and mean ozone O3) concentration. The interpretation of such findings is not straightforward, as these symptoms can be interpreted either as respiratory irritation due to exposure to nonspecific airway stimuli or as a true asthmatic state. Additional studies are required to clarify this important issue. In conclusion, this large cross-sectional epidemiologic survey performed in an area of high photochemical air pollution did demonstrate statistically significant associations between the prevalence of asthmatic symptoms and mean O3 concentration.

Visits to the emergency room for asthma attacks and short-term variations in air pollution. A case-crossover study.

BACKGROUND: The 'case-crossover' design is a strategy fitted to studying transient effects of intermittent exposure on acute-onset disease occurring shortly after exposure. It has the important advantage of eliminating most confounding variables, allowing a stronger causality inference. OBJECTIVES: The objective of the study was to evaluate the relationships between emergency room (ER) visits for asthma attacks and gaseous air pollution changes. METHODS: The study included 549 individuals, 3-49 years old, visiting the ER during 1 year. Exposure to gaseous air pollutants (SO2, NO2, O3) on the same day and up to 4 days before was computed according to the patient's address. The statistical analysis included meteorological data as potential confounding variables. RESULTS: No association could be shown between ER visits and SO2 or NO2 levels. In contrast, there was a statistically significant association between ER visits and mean O3 levels, on the day of admission and also on D -2 and D -3. For an increase of 10 microg/m3, the risk of requiring an ER admission increased by 6-10%. CONCLUSIONS: Using this new strategy, we confirmed that ozone changes lead to a moderate increase in risk of requiring an ER admission in asthmatic subjects.

T cell activation, from atopy to asthma: more a paradox than a paradigm.

During the last 15 years, it was largely shown that allergic inflammation was orchestrated by activated Th2 lymphocytes, leading to IgE production and eosinophil activation. Indeed, Th2 activation was shown to be necessary to induce allergic sensitization in animal models. In humans, a Th2 skewing was shown in atopic children soon after birth. In asthma, descriptive studies showed that Th2 cells were more numerous in patients than in controls. In addition, during specific allergen stimulation, an increase of Th2 cells was described in most cases. According to this Th2 paradigm, it was proposed that early avoidance of microbial exposure could explain the increase of atopic diseases seen in the last 20 years in developed countries, as the "hygiene hypothesis". Recently, it was proposed that early exposure to lipopolysaccharide (LPS) could be protective against atopic diseases. However, it is well established that exposure to LPS can induce asthma symptoms, both in animals and humans, although it induces a Th1 inflammatory response. In addition, most infections induce asthma exacerbations and Th1 responses. Recently, some studies have showed that some Th1 cells were present in asthmatic patients, which could be related to bronchial hyperreactivity. There is therefore an "infectious paradox" in asthma, which contributes to show that the Th2 paradigm is insufficient to explain the whole inflammatory reaction of this disease. We propose that the Th2paradigm is relevant to atopy and inception of asthma albeit a Th1 activation would account at least in part for bronchial hyperreactivity and asthma symptoms.