Different effects of tocolytic medication on blood pressure and blood pressure amplification

Background The importance of tocolysis has been discussed extensively. Beta-2 adrenoceptor agonistic drugs like ritodrine have been the reference tocolytic drugs in most countries. Cardiovascular side-effects are frequent. Atosiban, a newer tocolytic drug, is a competitive antagonist of oxytocin and has fewer cardiovascular side effects. Although large studies exist, there is mainly subjective reporting of adverse reactions with a focus on blood pressure data. Objectives Evaluation of the acute effects of therapeutic doses of ritodrine and atosiban in comparison to placebo on central and peripheral blood pressures, central-to-peripheral blood pressure amplification and the augmentation index (AIx) in healthy non-pregnant female volunteers. Methods A double-blind, randomized, crossover trial was carried out in 20 healthy non-pregnant female volunteers. Hemodynamic measurements were performed under standardized conditions. Results At steady state, central and peripheral pressures did not differ from placebo in the atosiban group. During ritodrine-infusion, central SBP increased by 11% versus placebo (p = 0.012) and peripheral SBP by 10% (p = 0.004). In contrast to atosiban and placebo, blood pressure amplification was absent in the ritodrine group. While the AIx did not change in the atosiban group, with ritodrine, the AIx tended to decrease. Conclusions The present study shows the significant effects of ritodrine on the cardiovascular system. Atosiban has no significant effects and may be an appropriate alternative to tocolyticum, particularly in cardiovascularly complicated pregnancies

Determinants of Refusal of A/H1N1 Pandemic Vaccination in a High Risk Population: A Qualitative Approach

International audienceBackground: Our study analyses the main determinants of refusal or acceptance of the 2009 A/H1N1 vaccine in patients with cystic fibrosis, a high-risk population for severe flu infection, usually very compliant for seasonal flu vaccine.Methodology/Principal Findings: We conducted a qualitative study based on semi-structured interviews in 3 cystic fibrosis referral centres in Paris, France. The study included 42 patients with cystic fibrosis: 24 who refused the vaccine and 18 who were vaccinated. The two groups differed quite substantially in their perceptions of vaccine- and disease-related risks. Those who refused the vaccine were motivated mainly by the fears it aroused and did not explicitly consider the 2009 A/H1N1 flu a potentially severe disease. People who were vaccinated explained their choice, first and foremost, as intended to prevent the flu’s potential consequences on respiratory cystic fibrosis disease. Moreover, they considered vaccination to be an indirect collective prevention tool. Patients who refused the vaccine mentioned multiple, contradictory information sources and did not appear to consider the recommendation of their local health care provider as predominant. On the contrary, those who were vaccinated stated that they had based their decision solely on the clear and unequivocal advice of their health care provider.Conclusions/Significance: These results of our survey led us to formulate three main recommendations for improving adhesion to new pandemic vaccines. (1) it appears necessary to reinforce patient education about the disease and its specific risks, but also general population information about community immunity. (2) it is essential to disseminate a clear and effective message about the safety of novel vaccines. (3) this message should be conveyed by local health care providers, who should be involved in implementing immunization

Apparent competition or apparent mutualism? An analysis of the influence of rose bush strip management on aphid population in wheat field

Apparent competition, mediated by a shared predator, plays a key role in conservation biological control. Appropriate agroecosystems management may favour this type of indirect interaction. In that context, our aim was to test the effect of rose bush [Rosa rugosa (Thunb.)] strips on the building up of aphid populations and of their natural enemies in adjacent cereal habitats. Several aphid species are currently found on Rosa sp. including Metopolophium dirhodum (Walker) for which it is a primary host. Aphid predators and parasitoids may build their populations on the aphid population present on Rosa sp. and later on migrate to wheat field during the cereal aphid infestation. Moreover, the flowers of the rose bushes may provide a source of nectar and pollen to these natural enemies. Our experiment was conducted in three rose margin wheat plots with a strip of rose bushes of R. rugosa and three control plots. Plots were compared during 2 years (2003 and 2004). Aphid, parasitoid and predator densities were recorded from May to the harvest of wheat on rose bushes and in wheat. In 2003, the aphid densities were moderate but in 2004, the population of aphid was very high. Even if predator and parasitoids arrived earlier in rose margin field than in control ones, the presence of rose bushes did not influence the aphid population within the field. Metopolophium dirhodum did not seem to migrate from the rose bushes to wheat. The level of parasitism was weak in rose bushes and the natural enemy population was not different in rose margin wheat and in control plots. The causes of the lack of efficiency of this type of management are discussed as well as the high aphid population in wheat in 2004