Contraception during medical studies: A French study of 2,323 residents.

Objective: The main objective of this work was to establish the contraceptive profile of French female medical residents and to assess the impact of workload on their choice of contraception method as well as difficulties encountered.

Study Design: We conducted a descriptive, cross-sectional, prospective national study over six months, between May and October 2019, using an anonymous online survey sent to all female medical residents in France. We formed two study groups according to reported working hours: W+ and W-.

[Electronic cigarettes and fertility: True or false friends?].

While electronic cigarettes have been on the rise in France for the past ten years, data on their prevalence, use patterns and safety have remained fragmented and controversial. Electronic cigarettes seem to not be a harmless product to use, because although they contain fewer harmful substances than traditional cigarettes, they still contain toxic products such as endocrine disruptors, which appear to have a negative impact on hormonal homeostasis, morphology and functioning of the animal reproductive system. Mostly presented as a harmless alternative to traditional cigarettes by industry lobbies, electronic cigarettes are often offered as an aid to smoking cessation in the same way as nicotinic substitutes.

Follicular GH and IGF1 Levels Are Associated With Oocyte Cohort Quality: A Pilot Study.

Introduction: Oocyte quality contributes to the development of an optimal embryo and thus a successful pregnancy. The objective of this study was to analyse the association between oocyte cohort quality and the follicular levels of growth hormone (GH), insulin-like growth factor 1 (IGF1), 25-hydroxy vitamin D (25OHD), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) and antithyroid antibodies, as a function of intracytoplasmic sperm injection (ICSI) outcomes.

Material And Methods: We conducted a prospective comparative pilot study from January 2013 to December 2017.

Functional differences of tau isoforms containing 3 or 4 C-terminal repeat regions and the influence of oxidative stress.

We report functional differences between tau isoforms with 3 or 4 C-terminal repeats and a difference in susceptibility to oxidative conditions, with respect to the regulation of microtubule dynamics in vitro and tau-microtubule binding in cultured cells. In the presence of dithiothreitol in vitro, a 3-repeat tau isoform promotes microtubule nucleation, reduces the tubulin critical concentration for microtubule assembly, and suppresses dynamic instability. Under non-reducing conditions, threshold concentrations of 3-repeat tau and tubulin exist below which this isoform still promotes microtubule nucleation and assembly but fails to reduce the tubulin critical concentration or suppress dynamic instability; above these threshold concentrations, amorphous aggregates of 3-repeat tau and tubulin can be produced at the expense of microtubule formation.

Phosphate release during microtubule assembly: what stabilizes growing microtubules?

The molecular mechanism underlying microtubule dynamic instability depends on the relationship between the addition of tubulin-GTP to a growing microtubule and its hydrolysis in the microtubule lattice to tubulin-GDP, with release of inorganic phosphate (Pi). Since this relationship remains controversial, we have re-examined the release of Pi upon microtubule assembly using a fluorometric assay for Pi, based on the phosphate-binding protein of Escherichia coli [Brune M., Hunter, J.