Tentative de suicide des adolescents: accueil, evaluation, orientation [Suicide attempt: encounter, evaluation, orientation].

Le suicide et les tentatives de suicide des adolescents sont des enjeux de santé publique majeurs. En s'appuyant sur le modèle de soins développé à Genève, nous décrivons les différents temps nécessaires pour accueillir, évaluer et orienter un adolescent pris dans un mouvement suicidaire. Un temps d'accueil et d'évaluation pédiatrique, puis un temps d'évaluation psychiatrique et enfin un temps d'orientation à l'issue duquel est proposée une prise en charge spécifique. En fonction des caractéristiques cliniques du jeune (impulsivité, symptomatologie anxio-dépressive...), de sa capacité d'engagement dans les soins et de la qualité des liens du réseau, la prise en charge sera soit ambulatoire intensive, soit hospitalière. Suicide and suicide attempts of adolescents are major public health issues. Based on a model of care developed in Geneva, we describe the conditions necessary to evaluate and guide a teenager trapped in a suicidal behavior. First of all, there must be some time dedicated to pediatric assessement followed by a psychiatric evaluation and finally, the adolescent can be oriented toward specific treatment. Depending on the clinical characteristics of the young adolescent and according to his willingness to engage himself in intensive follow-up (impulsivity, anxious?--depressive symptomatology...), cares will be given either as outpatient with close monitoring or inpatient.

Particle orientation distribution in Y-Fe2O3magnetic tapes by Mössbauer and hysteresis loop measurements

The particle orientation in several Y-Fe2O3magnetic tapes has been quantitatively evaluated by using the data of both Mössbauer and hysteresis loop measurements performed in the three orthogonal directions. A texture function has been obtained as a development of real harmonics. The profile of the texture function gives the quality of the different magnetic tapes. A different degree of particle orientation at the surface of the tape is evidenced by means of conversion electron Mössbauer spectra.

Molecular signaling in zebrafish development and the vertebrate phylotypic period

During development vertebrate embryos pass through a stage where their morphology is most conserved between species, the phylotypic period (approximately the pharyngula). To explain the resistance to evolutionary changes of this period, one hypothesis suggests that it is characterized by a high level of interactions. Based on this hypothesis, we examined protein-protein interactions, signal transduction cascades and miRNAs over the course of zebrafish development, and the conservation of expression of these genes in mouse development. We also investigated the characteristics of genes highly expressed before or during the presumed phylotypic period. We show that while there is a high diversity of interactions during the phylotypic period (protein-DNA, RNA-RNA, cell-cell, and between tissues), which is well conserved with mouse, there is no clear difference with later, more morphologically divergent, stages. We propose that the phylotypic period may rather be the expression at the morphological level of strong conservation of molecular processes earlier in development.

Sexual Orientation Gender Indentity, and Iowa's Safe Schools Law, 2007

Another recently enacted law is the Iowa Safe Schools Law. Effective September 1, 2007, Iowa Code Chapter 280 requires both public and private schools to establish policies prohibiting harassment and bullying against students by employees, school volunteers, or other students. Sexual Orientation and Gender identity are covered under the Safe Schools Law. Students may now seek remedies under both Chapter 216 and Chapter 280.

Sexual Orientation & Gener Indentity, 2007

Effective July 1, 2007, the Iowa Civil Rights Act (Iowa Code Chapter 216) was expanded to add sexual orientation and gender identity to the list of protected characteristics. It is now illegal in Iowa to discriminate against a person because of his/her actual or perceived sexual orientation or gender identity.

Sexual Orientation & Gender Indentity: A Housing Provider’s Guide to Iowa Law Compliance, 2007

Effective July 1, 2007, the Iowa Civil Rights Act (Iowa Code Chapter 216) was expanded to add sexual orientation and gender identity to the list of protected classes. It is now ILLEGAL in Iowa to discriminate against a person because of his/her sexual orientation or gender identity.

Sexual Orientation & Gender Identity: A Public Accommodations Provider’s Guide to Iowa Law, 2007

Effective July 1, 2007, the Iowa Civil Rights Act (Iowa Code Chapter 216) was expanded to add sexual orientation and gender identity to the list of protected classes. It is now ILLEGAL in Iowa to discriminate against a person because of his/her sexual orientation or gender identity.

TrkB signaling is required for postnatal survival of CNS neurons and protects hippocampal and motor neurons from axotomy-induced cell death

Newborn mice carrying targeted mutations in genes encoding neurotrophins or their signaling Trk receptors display severe neuronal deficits in the peripheral nervous system but not in the CNS. In this study, we show that trkB (¿/¿) mice have a significant increase in apoptotic cell death in different regions of the brain during early postnatal life. The most affected region in the brain is the dentate gyrus of the hippocampus, although elevated levels of pyknotic nuclei were also detected in cortical layers II and III and V and VI, the striatum, and the thalamus. Furthermore, axotomized hippocampal and motor neurons of trkB (¿/¿) mice have significantly lower survival rates than those of wild-type littermates. These results suggest that neurotrophin signaling through TrkB receptors plays a role in the survival of CNS neurons during postnatal development. Moreover, they indicate that TrkB receptor signaling protects subpopulations of CNS neurons from injury- and axotomy-induced cell death.

Increased Wnt signaling triggers oncogenic conversion of human breast epithelial cells by a Notch-dependent mechanism.

Wnt and Notch signaling have long been established as strongly oncogenic in the mouse mammary gland. Aberrant expression of several Wnts and other components of this pathway in human breast carcinomas has been reported, but evidence for a causative role in the human disease has been missing. Here we report that increased Wnt signaling, as achieved by ectopic expression of Wnt-1, triggers the DNA damage response (DDR) and an ensuing cascade of events resulting in tumorigenic conversion of primary human mammary epithelial cells. Wnt-1-transformed cells have high telomerase activity and compromised p53 and Rb function, grow as spheres in suspension, and in mice form tumors that closely resemble medullary carcinomas of the breast. Notch signaling is up-regulated through a mechanism involving increased expression of the Notch ligands Dll1, Dll3, and Dll4 and is required for expression of the tumorigenic phenotype. Increased Notch signaling in primary human mammary epithelial cells is sufficient to reproduce some aspects of Wnt-induced transformation. The relevance of these findings for human breast cancer is supported by the fact that expression of Wnt-1 and Wnt-4 and of established Wnt target genes, such as Axin-2 and Lef-1, as well as the Notch ligands, such as Dll3 and Dll4, is up-regulated in human breast carcinomas.

TrkB and TrkC signaling are required for maturation and synaptogenesis of hippocampal connections

Recent studies have suggested a role for neurotrophins in the growth and refinement of neural connections, in dendritic growth, and in activity-dependent adult plasticity. To unravel the role of endogenous neurotrophins in the development of neural connections in the CNS, we studied the ontogeny of hippocampal afferents intrkB (¿/¿) and trkC (¿/¿) mice. Injections of lipophilic tracers in the entorhinal cortex and hippocampus of newborn mutant mice showed that the ingrowth of entorhinal and commissural/associational afferents to the hippocampus was not affected by these mutations. Similarly, injections of biocytin in postnatal mutant mice (P10¿P16) did not reveal major differences in the topographic patterns of hippocampal connections. In contrast, quantification of biocytin-filled axons showed that commissural and entorhinal afferents have a reduced number of axon collaterals (21¿49%) and decreased densities of axonal varicosities (8¿17%) in both trkB (¿/¿) and trkC (¿/¿) mice. In addition, electron microscopic analyses showed thattrkB (¿/¿) and trkC (¿/¿) mice have lower densities of synaptic contacts and important structural alterations of presynaptic boutons, such as decreased density of synaptic vesicles. Finally, immunocytochemical studies revealed a reduced expression of the synaptic-associated proteins responsible for synaptic vesicle exocytosis and neurotransmitter release (v-SNAREs and t-SNAREs), especially in trkB (¿/¿) mice. We conclude that neither trkB nor trkC genes are essential for the ingrowth or layer-specific targeting of hippocampal connections, although the lack of these receptors results in reduced axonal arborization and synaptic density, which indicates a role for TrkB and TrkC receptors in the developmental regulation of synaptic inputs in the CNS in vivo. The data also suggest that the genes encoding for synaptic proteins may be targets of TrkB and TrkC signaling pathways.

Tuning the immune response of dendritic cells to surface-assembled poly(I:C) on microspheres through synergistic interactions between phagocytic and TLR3 signaling.

The artificial dsRNA polyriboinosinic acid-polyribocytidylic acid, poly(I:C), is a potent adjuvant candidate for vaccination, as it strongly drives cell-mediated immunity. However, because of its effects on non-immune bystander cells, poly(I:C) administration may bear danger for the development of autoimmune diseases. Thus poly(I:C) should be applied in the lowest dose possible. We investigated microspheres carrying surface-assembled poly(I:C) as a two-in-one adjuvant formulation to stimulate maturation of monocyte-derived dendritic cells (MoDCs). Negatively charged polystyrene microspheres were equipped with a poly(ethylene glycol) corona through electrostatically driven surface assembly of a library of polycationic poly(l-lysine)-graft-poly(ethylene glycol) copolymers, PLL-g-PEG. Stable surface assembly of poly(I:C) was achieved by incubation of polymer-coated microspheres in an aqueous poly(I:C) solution. Surface-assembled poly(I:C) exhibited a strongly enhanced efficacy to stimulate maturation of MoDCs by up to two orders of magnitude, as compared to free poly(I:C). Multiple phagocytosis events were the key factor to enhance the efficacy. The cytokine secretion pattern of MoDCs after exposure to surface-assembled poly(I:C) differed from that of free poly(I:C), while their ability to stimulate T cell proliferation was similar. Overall, phagocytic signaling plays an important role in defining the resulting immune response to such two-in-one adjuvant formulations.

Arabidopsis jasmonate signaling pathway.

Jasmonates control defense gene expression, growth, and fertility throughout the plant kingdom and have been studied extensively in Arabidopsis thaliana. The prohormone jasmonic acid (JA) is conjugated to amino acids such as isoleucine to form the active hormone jasmonoyl-isoleucine (JA-Ile). A series of breakthroughs has identified the SCF [SCF consists of four subunits: a cullin, SKP1 (S-phase kinase-associated protein 1), a RING finger protein (RBX1/HRT1/ROC1), and an F-box protein] CORONATINE INSENSITIVE1 (COI1) E3 ubiquitin ligase complex and the JASMONATE ZIM-DOMAIN (JAZ) proteins as central components in the perception of and transcriptional response to JA-Ile. JAZ proteins (most probably as dimers) bind transcription factors such as MYC2 before JA-Ile production. JA-Ile binds to COI1 to facilitate the formation of COI1-JAZ complexes, leading to ubiquitination and subsequent degradation of JAZ proteins. The degradation of JAZ proteins liberates transcription factors that function in the presence of the RNA polymerase II coregulatory complex Mediator to permit the expression of a number of jasmonate-regulated genes. Recent developments include the identification of COI1 as a receptor for jasmonates. Upstream of the signaling events, microRNA319 (miR319) negatively regulates the production of JA and JA-derived signals.

Introduction: L'orientation scolaire et professionnelle en Suisse

L'introduction au numéro thématique de L'OSP sur la Suisse décrit quelques particularités institutionnelles, politiques et socioéconomiques de ce pays, afin de situer les différentes contributions. Elle expose également les logiques retenues pour le choix des contributions.