Traitement de tla sclérose en plaques: nouveautés et complications [New treatment options in multiple sclerosis and their complications].

A new therapeutic era opened for multiple sclerosis (MS) with the appearance of molecules given p.o. and/or molecules with greater efficiency. Early diagnosis is critical, as the time and the choice of therapeutic intervention. The initiation of treatments must be personalized, including the risks associated with MS and those potentially related to the treatment chosen, answering the question <Who, when and how to treat?>. Monitoring tools that allow to objectively evaluate: I) MS activity and aggressiveness for each patient and 2) the safety of treatments and their risks of complications, must be further investigated.

Towards a sedentary society: trends in adolescent sport practice in Switzerland (1993-2002).

The rate of overweight and obese children and adolescents is rapidly increasing in developed countries. Although a decrease in sport practice may be one of the several factors implicated, data on recent trends are scarce. This article presents the trends in sport practice among Swiss adolescents between 1993 and 2002, comparing data from two surveys.

Experimental conversion of colony social organization in fire ants (Solenopsis invicta): worker genotype manipulation in absence of queen effects

Colony social organization in the fire ant Solenopsis invicta appears to be under strong genetic control. In the invasive USA range, polygyny (multiple queens per colony) is marked by the presence of the Gp-9(b) allele in most of a colony's workers, whereas monogyny (single queen per colony) is associated with the exclusive occurrence of the Gp-9(B) allele. Ross and Keller, Behav Ecol Sociobiol 51:287-295 (2002) experimentally manipulated social organization by cross-fostering queens into colonies of the alternate form, thereby changing adult worker Gp-9 genotype frequencies over time. Although these authors showed that social behavior switched predictably when the frequency of b-bearing adult workers crossed a threshold of 5-10%, the possibility that queen effects caused the conversions could not be excluded entirely. We addressed this problem by fostering polygyne brood into queenright monogyne colonies. All such treatment colonies switched social organization to become polygyne, coincident with their proportions of b-bearing workers exceeding 12%. Our results support the conclusion that polygyny in S. invicta is induced by a minimum frequency of colony workers carrying the b allele, and further confirm that its expression is independent of queen genotype or history, worker genotypes at genes not linked to Gp-9, and colony genetic diversity.

Le médecin face aux inégalités sociales de santé: quel pouvoir d'action [General practitioners facing social inequalities in health: which power to act?].

The link between social inequalities and health has been known for many years, as attested by Villermé's work on the "mental and physical status of the working class" (1840). We have more and more insight into the nature of this relationship, which embraces not only material deprivation, but also psychological mechanisms related to social and interpersonal problems. Defining our possible role as physicians to fight against these inequalities has become a public health priority. Instruments and leads, which are now available to help us in our daily practice, are presented here.

Convergent genetic architecture underlies social organization in ants.

Complex adaptive polymorphisms are common in nature, but what mechanisms maintain the underlying favorable allelic combinations [1-4]? The convergent evolution of polymorphic social organization in two independent ant species provides a great opportunity to investigate how genomes evolved under parallel selection. Here, we demonstrate that a large, nonrecombining "social chromosome" is associated with social organization in the Alpine silver ant, Formica selysi. This social chromosome shares architectural characteristics with that of the fire ant Solenopsis invicta [2], but the two show no detectable similarity in gene content. The discovery of convergence at two levels-the phenotype and the genetic architecture associated with alternative social forms-points at general genetic mechanisms underlying transitions in social organization. More broadly, our findings are consistent with recent theoretical studies suggesting that suppression of recombination plays a key role in facilitating coordinated shifts in coadapted traits [5, 6].

Soziale Unterschiede in der vor- und nachgeburtlichen Sterblichkeit: Schweiz 1979-1985. [Social differences in the prenatal and postnatal mortality: Switzerland 1979-1985].

The influence of social factors on birthweight and fetal and infant mortality was investigated in the Swiss birth cohort from 1979-85 (N = 519,933). The proportion of newborns with low-birthweight (less than 2500 g) was higher in lower social classes. Stillbirth-rate, neonatal and postneonatal mortality were higher in lower social classes, too. When controlling for birthweight, the increase in mortality in the lower social classes became somewhat less striking. Marked social differences in perinatal mortality were found in the newborns with normal weight, whereas almost no difference could be detected in the low-birthweight-group.

Genetic regulation of colony social organization in fire ants: an integrative overview

Expression of colony social organization in fire ants appears to be under the control of a single Mendelian factor of large effect. Variation in colony queen number in Solenopsis invicta and its relatives is associated with allelic variation at the gene Gp-9, but not with variation at other unlinked genes; workers regulate queen identity and number on the basis of Gp-9 genotypic compatibility. Nongeneticfactors, such as prior social experience, queen reproductive status, and local environment, have negligible effects on queen number which illustrates the nearly complete penetrance of Gp-9. As predicted, queen number can be manipulated experimentally by altering worker Gp-9 genotype frequencies. The Gp-9 allele lineage associated with polygyny in South American fire? ants has been retained across multiple speciation events, which may signal the action of balancing selection to maintain social polymorphism in these species. Moreover positive selection is implicated in driving the molecular evolution of Gp-9 in association with the origin of polygyny. The identity of the product of Gp-9 as an odorant-binding protein suggests plausible scenarios for its direct involvement in the regulation of queen number via a role in chemical communication. While these and other lines of evidence show that Gp-9 represents a legitimate candidate gene of major effect, studies aimed at determining (i) the biochemical pathways in which GP-9 functions; (ii) the phenotypic effects of molecular variation at Gp-9 and other pathway genes; and (iii) the potential involvement of genes in linkage disequilibrium with Gp-9 are needed to elucidate the genetic architecture underlying social organization in fire ants. Information that reveals the links between molecular variation, individual phenotype, and colony-level behaviors, combined with behavioral models that incorporate details of the chemical communication involved in regulating queen number will yield a novel integrated view of the evolutionary changes underlying a key social adaptation.