Prognostic importance of hyponatremia in patients with acute pulmonary embolism

Rapport de synthèse Enjeux et contexte: L'hyponatrémie est un trouble électrolytique fréquent et associé à un pronostic défavorable dans de nombreuses affections card iovascu lai res (1-5), pour lesquelles il est un marqueur de l'activation neurohumorale (6). Sa valeur pronostique chez les patients se présentant avec une emboîie pulmonaire était jusque là inconnue ; elle fait l'objet de la présente étude.Objectifs: Examiner chez les patients hospitalisés pour une embolie pulmonaire, les associations entre hyponatrémie et mortalité ainsi qu'avec le taux de réhospitalisation. Méthodes: Nous avons étudié les données de 13728 patients avec un diagnostic principal d'embolie pulmonaire provenant de 185 hôpitaux en Pennsylvanie (janvier 2000 à novembre 2002.) Nous avons utilisé un modèle de régression logistique afin d'établir l'association indépendante entre le niveau de sodium lors de la présentation aux urgences et la mortalité ainsi que le taux de ^hospitalisation durant 30 jours. Nous avons ajusté pour les caractéristiques du patient (race, assurance, sévérité de la maladie, usage de la thrombolyse) et de l'hôpital (région, taille, avec ou sans médecins en formation.)Résultats principaux: Une hyponatrémie (sodium £ 135 mmol/l) était présente chez 2907 patients (21.1%). Les patients avec un sodium >135, 130-135, et <130 mmol/l avaient une mortalité cumulée à 30 jours de 8.0%, 13.6%, et 28.5% (P <0.001), et un taux de réadmission de 11.8%, 15.6%, et 19.3% (P <0.001), respectivement. Comparés aux patients avec un sodium >135 mmol/l, les odd ratios ajustés concernant la mortalité étaient significativement plus important pour les patients avec un sodium compris entre 130 et 135 mmol/l (OR 1.53, 95% Cl: 1.33-1.76) ou <130 mmol/l (OR 3.26, 95% Cl: 2.48-4.29). Les odd ratios ajustés concernant la réhospitalisation étaient également augmentés pour les patients présentant un sodium entre 130 et 135 mmol/l (OR 1.28, 95% Cl: 1.12-1.46) ou <130 mmol/l (OR 1.44, 95% Cl: 1.02-2.02). Conclusions et perspectives: L'hyponatrémie est fréquente chez les patients se présentant avec une embolie pulmonaire, de plus elle est un prédicateur indépendant de la mortalité à court terme, ainsi que du taux de réhospitalisation. La natrémie est une information généralement disponible lors de l'établissement d'un pronostic. Bien que cette association soit compatible avec une activation neurohumorale, nous ne pouvons pas attester des mécanismes impliqués, du fait que notre étude ne donne pas d'informations sur d'autres étapes de la physiologie de cette association.

Synapse formation on adult-born hippocampal neurons.

It is now widely accepted that adult neurogenesis plays a fundamental role in hippocampal function. Neurons born in the adult dentate gyrus of the hippocampus undergo a series of events before they fully integrate in the network and eventually become undistinguishable from neurons born during embryogenesis. Adult hippocampal neurogenesis is strongly regulated by neuronal activity and neurotransmitters, and the synaptic integration of adult-born neurons occurs in discrete steps, some of which are very different from perinatal synaptogenesis. Here, we review the current knowledge on the development of the synaptic input and output of neurons born in the adult hippocampus, from the stem/progenitor cell to the fully mature neuron. We also provide insight on the regulation of adult neurogenesis by some neurotransmitters and discuss some specificities of the integration of new neurons in an adult environment. The understanding of the mechanisms regulating the synaptic integration of adult-born neurons is not only crucial for our understanding of brain plasticity, but also provides a framework for the manipulation and monitoring of endogenous adult neurogenesis as well as grafted cells, for potential therapeutic applications.

Promotion de l'activité physique au cabinet médical: manuel de référence à l'intention des médecins

[Table des matières] 1. Introduction: que vais-je apprendre? - quelques définitions - recommandations pour une activité physique favorable à la santé - comment mesure-t-on l'activité physique? - déterminants de l'activité physique. - 2. Épidémiologie de la sédentarité: prévalence de la sédentarité - coûts imputables à la sédentarité. - 3. Bénéfices pour la santé: un effet dose-réponse non linéaire - estimation des bénéfices de l'activité physique. - 4. Rôle du médecin de premier recours. - 5. Prise en charge: description générale d'un modèle de prise en charge - comment s'y prendre dans les détails - appréciation des risques liés à l'activité physique. - 6. Exemples d'outils: brochure pour les patients - podomètre: 10000 pas quotidiens pour sa santé! - 7. Autres ressources à disposition: site internet: www.paprica.ch. - glossaire [Introduction (extrait)] Ce manuel décrit la perspective et le rôle du médecin de premier recours dans la promotion d'une activité physique bénéfique pour la santé. Il s'inscrit, avec la brochure d'accompagnement destinée aux patients, dans un concept global de promotion de l'activité physique au cabinet médical. Développé pour être le plus concis possible, ce manuel fait la synthèse des connaissances et des savoir-faire utiles à la pratique du conseil en activité physique au cabinet médical.

Dirigent domain-containing protein is part of the machinery required for formation of the lignin-based Casparian strip in the root.

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where the Casparian strip forms. Here, we show that the dirigent-domain containing protein, enhanced suberin1 (ESB1), is part of this machinery, playing an essential role in the correct formation of Casparian strips. ESB1 is localized to Casparian strips in a CASP-dependent manner, and in the absence of ESB1, disordered and defective Casparian strips are formed. In addition, loss of ESB1 disrupts the localization of the CASP1 protein at the casparian strip domain, suggesting a reciprocal requirement for both ESB1 and CASPs in forming the casparian strip domain.

La médecine de famille en Suisse à l'horizon 2030: quelle place pour la délégation des tâches médicales. [Family practitioners in Switzerland by 2030: which roles for medical task delegation?]

Due to population aging, by 2030 Switzerland may face a demand of 24 million family practitioner visits, a growth of 13 percent from the 2005 level. This result is based on the assumption that the per capita demand for doctor visits remains what was observed in 2005 by age groups and sex. During the same period, the total number of practitioners may decrease by 14 percent whereas the female proportion of such practitioners may double. These changes may cause a 33 percent decrease in the supply of physician visits to reach only 14 millions. The comparison of the demand and supply of family doctor visits reveals that by 2030, 10 million visits may be unmet which represents 40 percent of the demand. On the supply side, a full scale implementation of task delegation may partially reduce that gap (minus 2 millions). On the demand side, improved health status may bring in a larger decrease in the needs for visits (minus 4 million).

Biofilm formation by staphylococci on fresh, fresh-frozen and processed human and bovine bone grafts.

Biofilm formation is a multi-step process influenced by surface properties. We investigated early and mature biofilm of Staphylococcus aureus on 4 different biological calcium phosphate (CaP) bone grafts used for filling bone defects. We investigated standardised cylinders of fresh and fresh-frozen human bone grafts were harvested from femoral heads; processed humanand bovine bone grafts were obtained preformed. Biofilm formation was done in tryptic soy broth (TSB) using S. aureus (ATCC 29213) with static conditions. Biofilm density after 3 h (early biofilm) and 24 h (mature biofilm) was investigated by sonication and microcalorimetry. After 3 h, bacterial density was highest on fresh-frozenandfresh bone grafts. After 24 h, biofilm density was lowest on freshbone grafts (p < 0.001) compared to the other 3 materials, which did not differ quantitatively (p > 0.05). The lowest increase in bacterial density was detected on fresh bone grafts (p < 0.001). Despite normal shaped colonies, we found additional small colonies on the surface of the fresh and fresh-frozen samples by sonication. This was also apparent in microcalorimetric heat-flow curves. The four investigated CaP bone grafts showed minor structural differences in architecture but marked differences concerning serum coverage and the content of bone marrow, fibrous tissue and bone cells. These variations resulted in a decreased biofilm density on freshand fresh-frozenbone grafts after 24 h, despite an increased early biofilm formation and might also be responsible for the variations in colony morphology (small colonies). Detection of small colony variants by microcalorimetry might be a new approach to improve the understanding of biofilm formation.

Targeting mTORC2 inhibits colon cancer cell proliferation in vitro and tumor formation in vivo.

The mammalian target of rapamycin (mTOR), which exists in two functionally distinct complexes, mTORC1 and mTORC2 plays an important role in tumor growth. Whereas the role of mTORC1 has been well characterized in this process, little is known about the functions of mTORC2 in cancer progression. In this study, we explored the specific role of mTORC2 in colon cancer using a short hairpin RNA expression system to silence the mTORC2-associated protein rictor. We found that downregulation of rictor in HT29 and LS174T colon cancer cells significantly reduced cell proliferation. Knockdown of rictor also resulted in a G1 arrest as observed by cell cycle analysis. We further observed that LS174T cells deficient for rictor failed to form tumors in a nude mice xenograft model. Taken together, these results show that the inhibition of mTORC2 reduces colon cancer cell proliferation in vitro and tumor xenograft formation in vivo. They also suggest that specifically targeting mTORC2 may provide a novel treatment strategy for colorectal cancer.

Lamella formation and emigration from the water by a laboratory colony of Biomphalaria glabrata (SAY) in flow-through system

Lamella formation and emigration from the water were investigated in juvenile Biomphalaria glabrata reared at two temperatures in aquaria with a constant water flow. Most snails (97.4%) reared at the lower temperature (21- C) formed lamella at the shell aperture and emigrated from the water, whereas only 10.1% did so at 25- C. Eighty percent of emigrations at 21- C occurred within a period of 15 days, 70-85 days after hatching. A comparison of the studies done so far indicates that the phenomenon may be affected by the ageing of snail colonies kept in the laboratory and their geographic origin, rather than the rearing conditions. This hypothesis, however, requires experimental confirmation.

Agency cost of government ownership: a study of voluntary audit comitte formation in China

In this paper, we investigate the agency costs of government ownership and their impact on corporate governance and firm value. China is used as a laboratory because of the prevalent state shareholdings in exchange-listed firms. In this context, we specifically consider the trade-offs involved in the voluntary formation of an audit committee when the controlling shareholder is the state. The decision to improve corporate governance (in this case, introduce an audit committee) is shown to be value relevant and a function of existing agency relationships and non-trivial implementation costs. Our findings are robust to the level of pyramid groups, the ownership-control wedge, and financial leverage. The research adds to the debate regarding the effect of government shareholdings on corporate culture and performance - a topic that hastaken on renewed importance in recent times.

The role of egg antigens, cytokines in granuloma formation in murine schistosomiasis mansoni

The induction of granuloma formation by soluble egg antigens (SEA) of Schistosoma mansoni is accompanied by T cell-mediated lymphokine production that regulates the intensity of the response. In the present study we have examined the ability of SDS-PAGE fractioned SEA proteins to elicit granulomas and lymphokine production in infected and egg-immunized mice. At the acute stage of infection SEA fractions (<21, 25-30, 32-38, 60-66, 70-90, 93-125, and > 200 kD) that elicited pulmonary granulomas also elicited IL-2, IL-4 lymphokine production. At the chronic stage a diminished number of fractions (60-66, 70-90, 93-125, and > 200 kD) were able to elicit granulomas with an overall decrease in IL-2, IL-4 production. Granulomas were elicited by larval-egg crossreactive and egg-specific fractions at both the acute and chronic stage of the infection. Examination of lymphokine production from egg-immunized mice demonstrated that as early as 4 days IL-2 was produced by spleen cells stimulated with <21, 32-38, 40-46, 93-125, and >200 kD fractions. By 16 days, IL-2production was envoked by 8 of 9 fractions. IL-4 production at 4 days in response to all fractions was minimal while at 16 days IL-4 was elicited with the < 21, 25-30, 50-56, 93-125, and > 200 kD fractions. The present study reveals differences in the range of SEA fractions able to elicit granulomas and IL-2, IL-4 production between acute and chronic stages of infection. Additionally, this study demonstrates sequential (IL-2 followed by IL-4) lymphokine production during the primary egg antigen response.