Meta-analysis of the influence of gender and age on the seasonal dynamics of cerebral strokes

The purpose of this work is to investigate dependence of the seasonal dynamics of HS (hemorrhagic strokes) and IS (ischemic strokes) risk on sex and age using meta-analysis. In total, 22 publications were selected for this meta-analysis, studying the seasonal dynamics of HS, of which 8 publications presented statistics separately for men and women, and three papers presented statistics for different age groups. Also, 28 publications studying the seasonal dynamics of IS were selected for meta-analysis, of which 11 publications presented statistics separately for men and women, and three papers presented statistics for different age groups. The meta-analysis of the seasonal dynamics of HS showed that HS risk is less likely in a warmer season compared with a colder one. In men, HS risk was the highest in winter and spring, and in women in winter. Dependence between HS risk and a decrease in air temperature was the same in men and women. According to the results of the meta-analysis (without regard to sex and age), the minimum probability of IS occurs in autumn. In women, IS risk was significantly higher in winter compared to other seasons. In men, the seasonal dynamics of IS was not expressed. In older people, the overall risk of stroke increased, especially IS. In people over 65 years of age, there was a significant dependence of an increase in HS risk on a decrease in air temperature. In people younger than 65 years, HS risk was not associated with cold. A decrease in temperature equally increased IS risk in both age groups. These results suggest that sex and age may influence the seasonal stroke risk

Perméabilités calciques modulant la différenciation neuronale in vitro chez l embryon de xénope (xenopus laevis)

L objectif de cette thèse a été d étudier le rôle des canaux calciques, des récepteurs nicotiniques et purinergiques ainsi que de l IGF-1 dans la différenciation neuronale (DN) chez l embryon de Xenopus laevis in vitro. Le calcium inhibe cette DN à tous les stades neurula étudiés (stades 13 à 20) et son action peut être partiellement reversée par des doses micromolaires de nickel, de lanthane et de gadolinium. Les canaux impliqués sont insensibles au potentiel de membrane et sont à identifier. Par ailleurs l action du calcium sur la DN est indépendante de son action sur la pousse neuritique (PN). L activation des canaux calciques voltage-dépendants de type N, des récepteurs nicotiniques et purinergiques de type P2X augmente la DN tandis que l activation des récepteurs purinergiques de types P2Y et P1 induit des effets opposés. L IGF-1 antagonise efficacement l action inhibitrice du calcium sur la DN et la PN in vitro. L ensemble de ces résultats montre que la voie d entrée du calcium dans la cellule détermine son effet spécifique sur l activité cellulaire.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF