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Conferences for Novice Researchers, on the theme of “addiction,” in 5 French cities

Throughout the school year, 33 junior and senior secondary school students have been hosted each month in 9 neuroscience laboratories specialising in addiction studies. The aim: to change the views of the young “Novice Researchers” of the hidden face of drugs (alcohol, tobacco, cannabis, etc.) and addiction, and to facilitate contact between young people and the world of research. From 27 May next, the Novice Researchers will present their research at 5 conferences organised in Marseille (27 May), Amiens (3 June), Bordeaux (4 June), Paris (5 June) and Poitiers (10 June).

The MAAD (Mechanisms of Addiction to Alcohol and Drugs) programme, launched by Inserm with the support of MILDECA (French Government’s Inter-Departmental Mission for the Fight against Drugs and Drug Addiction, formerly MILDT), is based on a “scientific education” style approach intended to increase the knowledge of young people on substances by introducing them to the scientific method.

Nine research laboratories specialising in the physiopathology of addictions hosted two pairs of students comprising one final year junior secondary school student and one second year senior secondary school student on one Wednesday of each month1. Under the supervision of a senior researcher, the adolescents conducted a research programme, did experiments, and interpreted the data. The conferences organised in the different research centres involved will enable these young Novice Researchers to share their results. The audience will be made up of their classmates, parents, teachers, etc.

The use of psychoactive substances (alcohol, tobacco, cannabis etc.) by young people is a constant preoccupation for the health authorities, since it is well known that early use, while the brain is still developing, is a risk factor for developing dependence during adulthood. This scheme for raising awareness about the toxicity of drugs is an attempt at innovation against a background of more traditional preventive actions (radio spots, video clips, television, newspapers, and mini-conferences in schools).

Inserm invites you to follow these conferences.

à In Paris, the conference will be held on Thursday, 5 June 2014 at 6:30 pm
Ministry of Agriculture, Gambetta Room,
78 rue de Varennes, Paris 5th Arrondissement
Registration required

Danièle Jourdain-Menninger, President of MILDECA, will open the event
The Novice Researchers’ presentations will be followed by a talk and discussion led by Renaud Bouthier, Director of the Avenir-Santé Association, on the theme of: “Marketing    strategies of alcohol producers.”

à Marseille: Tuesday, 27 May at 6:00 pm
à Amiens: Tuesday 3 June at 6:00 pm
à Bordeaux: Wednesday 4 June at 6:00 pm
à Poitiers: Tuesday 10 June at 6:15 pm

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The 9 participating laboratories are as follows:

Amiens: Inserm ERI 24, Prof. Mickaël Naassila; Bordeaux: Inserm U862 Neurosciences Magendie, Prof. Véronique Deroche; CNRS UMR 5287, Dr. Martine Cador; Marseille: UMR 7289 CNRS Cognitive Neurobiology Laboratory, Dr. Christelle Baunez; Paris: Inserm UMR 894, Dr. Laurence Lanfumey-Mongrédien; Inserm UMRS 952-CNRS UMR 7224, Prof. Jean-Pol Tassin; Inserm U 894, Prof. Philip Gorwood; CNRS UMR 7102, Dr. Philippe Faure; Poitiers: Inserm U1084 Experimental and Clinical Neurosciences Laboratory, Prof. Mohamed Jaber

 

Social inequalities in health linked to diet and physical activity

A collective expert review by Inserm

Major social inequalities in health exist in France like other countries. These are reflected in varying rates of morbidity and mortality depending on individuals’ position on the socio-economic scale. For example, at 35, senior executives’ life expectancy is 6 years longer than that of manual workers. Lifestyle habits such as drinking, smoking, diet and physical activity are recognised as key determiners of health. A social gradient exists for health-related behaviour which manifests in childhood and lasts until old age.

One of the new focuses of the third period of the Programme National Nutrition-Santé [National Nutrition and Health Programme] (PNNS) (2011-2015) is to minimise social inequalities in health linked to diet (diet and physical activity). In this context, the Direction Générale de la Santé [Directorate General for Healthcare] (DGS) has asked Inserm to perform a review of scientific knowledge on social differentiation determiners in the area of nutrition and of the various intervention strategies that could be used to limit these inequalities.

In response to this request, Inserm formed a multidisciplinary group of experts on epidemiology, public health, human and social sciences, health economics, clinical research and geography.

The experts’ analysis of data from recent international scientific literature was used to evaluate nutritional disparities based on individuals’ socio-economic standing. The social, cultural, economic and environmental factors involved in creating social inequalities in nutrition were analysed. The experts also studied the impact of interventions and prevention policies based on socio-economic standing and identified the most effective strategies for limiting social inequality in the area of diet and physical activity.

In conclusion, the experts recommend designing and promoting programmes which benefit the entire population as well as actions targeting various social groups based on the risks and requirements they face.

Read a summary of the collective expert review and the full review (only in French)

The pill crisis in France: towards a new contraceptive model?

The 3rd and 4th generation contraceptive pills were the subject of a serious controversy in late 2012/early 2013, due to the risk of venous thrombosis associated with their use. What were the consequences for contraception in France? By analysing the Fecond survey, conducted by Inserm and the French National Institute for Demographic Studies (INED) several months later, Nathalie Bajos, Mylène Rouzaud-Cornabas, Henri Panjo, Aline Bohet and Caroline Moreau examined the recent trends in contraceptive practices, and the contribution of media debate to these changes.

moyens contraceptifs

© Fotolia

The media debate on contraceptive pills in late 2012/early 2013 did not lead to disaffection with contraception: of the women involved—whether infertile, pregnant, or engaging in heterosexual relations and not wanting children—only 3% did not use any method of contraception in 2013, the same proportion as in 2010.

However, nearly one in five women claimed to have changed methods since the media debate.

Use of oral contraception decreased strongly, from 50% in 2010 to 41% in 2013, a decrease solely attributable to 3rd and 4th generation pills. Some women, especially the younger ones, stated that they were on second generation pills. Others opted for the IUD (the more highly educated), condoms or so-called natural methods—periodic abstinence or withdrawal (the more vulnerable).

Media and political coverage therefore seems to have contributed to diversification in contraceptive practices, and to a redistribution of socioeconomic inequalities regarding access to contraception.

Retired people continue to have cognitive impairment long after high occupational exposure to solvents

Exposure to solvents during working life may have a negative impact on cognitive performance. But do these effects abate once exposure has ceased? French researchers from Inserm Unit 1061, “Neuropsychiatry: Epidemiological and Clinical Research,” and their American colleagues at Harvard have just shown that retired people continued to be affected by their work with solvents in cases of high exposure. The results are published in Neurology.

solvants

©Inserm M Depardieu

Solvents are often used in the workplace. They are used for cleaning metals, diluting paints, stripping varnishes, purifying perfumes during manufacture, etc. However, repeated (or chronic) exposure to these liquids can cause cancer and be detrimental to fertility. It can also be a source of mobility problems, depression or cognitive (intellectual) impairment. “Until now, few studies have evaluated whether this impact on cognitive impairment continues after retirement, i.e. after occupational exposure to solvents has ended, and very few studies have properly documented the exposure,” indicates Dr Claudine Berr, a research director at Inserm Unit 1061, “Neuropsychiatry: Epidemiological and Clinical Research,” in Montpellier. The researcher and her French and American colleagues therefore addressed the question through the Gazel cohort (20,000 employees from Électricité de France-Gaz de France [EDF-GDF] monitored for the last 25 years, whose working lives have been well documented at every stage). Their study, published in Neurology, concerned 2,143 men aged over 55 years, who had been retired for an average of 10 years. Overall, 33% of participants had been exposed to chlorinated solvents during their working lives, 26% had been exposed to benzene, and 25% to petroleum solvents. These retirees underwent a battery of 8 cognitive tests. For example, they had to name in one minute as many names of animals or words beginning with P as they could.

The researchers showed that high exposure to solvents was associated with poorer cognitive performance. Thus, for high doses of chlorinated solvents, the retirees had a greater than 20-50% risk of poorer cognitive performance.

 This shows that “these employees retain the effects of their occupational exposure, even though they have retired and even though this exposure is long past,” concludes Dr Berr. “Treating physicians need to pay closer attention to these patients, for example by managing other risk factors for cognitive decline on which we can take action, namely vascular risk factors. They should also encourage them to have more leisure activities that stimulate their cognitive functions.”

The results of this study will have to be confirmed in the Constances cohort, which monitors 200,000 people aged 18-70 years in the general population. “In this cohort, 20-25% of people claim to have had occupational exposure to these solvents,” says Claudine Berr.

A new type of heredity described in Paramecia

Considered as an obsolete theory for many years, the transmission of acquired traits has returned to the forefront of debate thanks to the development of epigenetic research(1). In this context, a team from the Institut de biologie at the Ecole normale supérieure (CNRS/ENS/INSERM)(2) has described how in Paramecia, mating types are transmitted from generation to generation through an unexpected mechanism. These types are not determined by the genome sequence but by small RNA sequences transmitted via the maternal cytoplasm, which specifically inactivate certain genes during development. A Paramecium can thus acquire a new mating type that will be inherited by its progeny without any genetic modification being involved. Published in Nature on May 7, 2014, this work highlights a novel mechanism that may be governed by natural selection, thus allowing the evolution of species.

Paramecia, single – cell eukaryote organisms, are hermaphrodite: during their sexual reproduction (or conjugation), the partners exchange their genetic material. Paramecia nevertheless have two “mating types”, called E and O. Conjugation can only occur between different mating types. As early as the 1940s, scientists such as Tracy Sonneborn had noted that mating type was not transmitted to progeny in Mendelian fashion: a new type of trait transmission, not dependent on the chromosomes, had to be involved, but they did not succeed in elucidating it.

Today, the team led by Éric Meyer at the ENS Institut de Biologie 2 has described the mechanism underlying this alternative heredity. To achieve this, they first showed that the difference between the E and O matin g types was due to a transmembrane protein called mtA. Although its encoding gene is present in both types, it is only expressed in E individuals. The scientists then revealed the mechanism by which this gene is inactivated in type O individuals.

Paramecia have two nuclei: a germinal micronucleus that is transmitted during sexual reproduction and a somatic macronucleus – resulting from the latter – where the cell’s genes are expressed. The mechanism
for the transmission of mating types is based on small RNA, called scnARN, which are produced during meiosis. The original function of these RNA is to eliminate from the macronucleus a whole series of genetic sequences called transposable elements, which, like introns (3), have been introduced into the genes during evolution. As a first step, the scnARN scan the maternal macronucleus in order to identify the sequences that were deleted in the previous generation, and then make the same rearrangements in the new macronucleus. However, unexpectedly, this genome “cleaning” mechanism also allows the cell to silence functional genes. In type O individuals of Paramecium tetraurelia , scnARN eliminate the mtA gene promoter, thus deleting its expression. Thus, it is through the scnARN inherited from the maternal cytoplasm, and not from a particular gene sequence, that the mating type of Paramecium is defined.

This silencing process could in principle affect any gene. Thus in theory, Paramecia could transmit to their sexual progeny infinitely variable versions of the macronuclear genome from the same germline. As with
genetic heredity, this mechanism may cause errors that might occasionally endow progeny with a selective advantage. In other words, the somatic macronucleus genome of Paramecium may evolve continuously,
and in certain cases allow a short – term adaptation to changes in environmental conditions. And this can occur without any genetic mutations being involved. This type of Lamarckian heredity (4) may thus offer a
hitherto unsuspected lever for natural selection.

(1) Epigenetics forms part of genetics in its broadest sense; in other words, the study of the mechanisms of heredity. It refers specifically to the study of the hereditary transmission of variable traits that are not dependent on variable DNA sequences.
(2) In collaboration with the Centre de Génétique Moléculaire (CNRS), the Laboratoire Biométrie et biologie évolutive (CNRS/Université Claude Bernard Lyon 1), the Institut Jacques Monod (CNRS/Université Paris Diderot) and CEA (Institut de génomique). Polish, Russian and American teams also collaborated in this work.
(3) Portions of the gene sequence, often non – coding, which must be deleted for the sequence to be functional.
(4) Referring to Jean – Baptiste Lamarck (1744 – 1829) whose theory on the evolution of living beings considered the transmission of acquired traits.

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