Proyecto de salud communitaria en un barrio marginal de Quito : evaluación de las necesidades y planteamiento de una red de prevención y attención primaria : documento para la acción local

Résumé du document de thèse Quito, capitale andine de près de deux millions d'habitants, a vu se développer des quartiers ghettos réunissant une population en constante évolution. Mouvements migratoires mal connus, hétérogénéité ethnique et socioculturelle, accès limité aux services publics et conditions de vie difficiles jouent un rôle essentiel mais complexe dans la planification des services de santé. L'étude ciblée de cette problématique est un sérieux défi à relever car les mégalopoles latino-américaines connaissent une importante urbanisation avec pour corollaire une augmentation de la pauvreté urbaine. Les indicateurs de santé tels que mortalité infantile, espérance de vie ou incidence des maladies infectieuses montrent une amélioration globale qui ne reflète toutefois pas les importantes disparités caractéristiques du continent. La démarche exposée dans ce document est une réponse à la demande d'un appui médical par une communauté urbaine défavorisée, pour laquelle peu de données étaient disponibles. Une évaluation des conditions de vie et des besoins en soins a donc été effectuée par trois étudiants en médecine de Lausanne au moyen d'une enquête et d'ateliers qui ont permis de réunir les opinions des différents acteurs sociaux et sanitaires. Cette étude a pu identifier et mesurer les déterminants de santé, comprendre certaines dynamiques locales pour enfin cibler les principales lignes d'actions d'un centre de santé communautaire. Ce document décrit l'ensemble du processus conduit durant cinq ans et expose les données brutes ainsi que leur analyse ; il propose des recommandations concrètes pour une promotion de la santé adaptée aux besoins d'une communauté urbaine défavorisée d'Amérique du Sud. Son objectif est de fournir des données utilisables par les acteurs de santé locaux et de participer ainsi à la réflexion en cours sur la réforme du système de santé équatorien. Il comporte également une bibliographie, point de départ pour d'autres études sur le sujet. Le dossier, construit de manière chronologique, présente l'information de façon accessible et cohérente. Il se veut un témoignage utile, avec ses forces et ses faiblesses, à l'action locale sous forme d'une publication en espagnol qui sera distribuée aux différents acteurs sociaux et sanitaires concernés.

Modelling the influence of change in fire regime on the local distribution of a Mediterranean pyrophytic plant species (Cistus salviifolius) at its northern range limit

Aims: To assess the potential distribution of an obligate seeder and active pyrophyte, Cistus salviifolius, a vulnerable species in the Swiss Red List; to derive scenarios by changing the fire return interval; and to discuss the results from a conservation perspective. A more general aim is to assess the impact of fire as a natural factor influencing the vegetation of the southern slopes of the Alps. Locations: Alps, southern Switzerland. Methods: Presence-absence data to fit the model were obtained from the most recent field mapping of C. salviifolius. The quantitative environmental predictors used in this study include topographic, climatic and disturbance (fire) predictors. Models were fitted by logistic regression and evaluated by jackknife and bootstrap approaches. Changes in fire regime were simulated by increasing the time-return interval of fire (simulating longer periods without fire). Two scenarios were considered: no fire in the past 15 years; or in the past 35 years. Results: Rock cover, slope, topographic position, potential evapotranspiration and time elapsed since the last fire were selected in the final model. The Nagelkerke R-2 of the model for C. salviifolius was 0.57 and the Jackknife area under the curve evaluation was 0.89. The bootstrap evaluation revealed model robustness. By increasing the return interval of fire by either up to 15 years, or 35 years, the modelled C. salviifolius population declined by 30-40%, respectively. Main conclusions: Although fire plays a significant role, topography and rock cover appear to be the most important predictors, suggesting that the distribution of C. salviifolius in the southern Swiss Alps is closely related to the availability of supposedly competition-free sites, such as emerging bedrock, ridge locations or steep slopes. Fire is more likely to play a secondary role in allowing C. salviifolius to extend its occurrence temporarily, by increasing germination rates and reducing the competition from surrounding vegetation. To maintain a viable dormant seed bank for C. salviifolius, conservation managers should consider carrying out vegetation clearing and managing wild fire propagation to reduce competition and ensure sufficient recruitment for this species.

Local shockwave-application prevents flap necrosis

Objective: Local shockwave-application (SW) has shown to improve healing of various tissues and decrease necrosis of flaps. Though, there is no data about the optimal time-point of SW-application with regard to induction of ischemia (i.e. flap elevation) and subsequent effect on flap survival. Therefore we compared 2 shock-wave protocols in a model of persistent ischemia and investigated underlying mechanisms. Methods: 18 C57BL/6-mice equipped with a skinfold chamber containing a musculocutaneous flap were assigned to 3 experimental groups: 1. One session of 500 SWimpulses at 0·15 mJ/mm2 applied 24 hrs before (preconditioning) or 2. Applied 30 min after flap elevation (treatment). 3. Untreated flaps (control). Tissue necrosis,microhemodynamics, inflammation, apoptosis and angiogenesis were assessed by intravital epi-fluorescence microscopy over 10 days. Results: SW significantly reduced flap necrosis independent from the application time-point (preconditioning: 29 ± 7%; treatment: 25 ± 7% vs. control: 47 ± 2%; d10, p<0·05). This was associated with an early increase of functional capillary density (preconditioning: 236 ± 39 cm/cm2; treatment: 211 ± 33 cm/cm2 vs. control: 141 ± 7 cm/cm2; day1, p<0·05). Arteriolar diameter, red blood cell velocity and blood flow were comparable between the 3 experimental groups. SW-application significantly decreased the ischemiainduced inflammatory response (apoptotic cell death and leukocyte-endothelial interaction: (p<0·05)). Sprouts indicating angiogenesis were observed from day 7 only after SW-application. Conclusions: SW protects ischemically challenged musculocutaneous tissue. Interestingly, postoperative SW-application is as efficient as preoperative SWapplication. The protective effect induced by mechanical stress might be based on an early recruitment of ''sleeping capillaries'' maintaining nutritive perfusion and an anti-inflammatory effect within the ischemically jeopardized tissue. SWapplication provides a non-invasive alternative to local thermic and systemic pre-treatment of endangered tissues.

Persisting atypical and cystic forms of Borrelia burgdorferi and local inflammation in Lyme neuroborreliosis

BACKGROUND: The long latent stage seen in syphilis, followed by chronic central nervous system infection and inflammation, can be explained by the persistence of atypical cystic and granular forms of Treponema pallidum. We investigated whether a similar situation may occur in Lyme neuroborreliosis. METHOD: Atypical forms of Borrelia burgdorferi spirochetes were induced exposing cultures of Borrelia burgdorferi (strains B31 and ADB1) to such unfavorable conditions as osmotic and heat shock, and exposure to the binding agents Thioflavin S and Congo red. We also analyzed whether these forms may be induced in vitro, following infection of primary chicken and rat neurons, as well as rat and human astrocytes. We further analyzed whether atypical forms similar to those induced in vitro may also occur in vivo, in brains of three patients with Lyme neuroborreliosis. We used immunohistochemical methods to detect evidence of neuroinflammation in the form of reactive microglia and astrocytes. RESULTS: Under these conditions we observed atypical cystic, rolled and granular forms of these spirochetes. We characterized these abnormal forms by histochemical, immunohistochemical, dark field and atomic force microscopy (AFM) methods. The atypical and cystic forms found in the brains of three patients with neuropathologically confirmed Lyme neuroborreliosis were identical to those induced in vitro. We also observed nuclear fragmentation of the infected astrocytes using the TUNEL method. Abundant HLA-DR positive microglia and GFAP positive reactive astrocytes were present in the cerebral cortex. CONCLUSION: The results indicate that atypical extra- and intracellular pleomorphic and cystic forms of Borrelia burgdorferi and local neuroinflammation occur in the brain in chronic Lyme neuroborreliosis. The persistence of these more resistant spirochete forms, and their intracellular location in neurons and glial cells, may explain the long latent stage and persistence of Borrelia infection. The results also suggest that Borrelia burgdorferi may induce cellular dysfunction and apoptosis. The detection and recognition of atypical, cystic and granular forms in infected tissues is essential for the diagnosis and the treatment as they can occur in the absence of the typical spiral Borrelia form.

Que faire du couple local/global ? Pour une anthropologie pleinement processuelle

This article examines the uses of the local/global dichotomy in anthropology. It is argued that the use of these terms as analytical tools tends to lead to a reification of "global forces" seen as external to the local site where the ethnographic study takes place. To avoid endless debates on whether or not the "global" can be the object of ethnographic scrutiny, anthropologists should treat the local and the global as scalar properties of social systems that are generated in the course of historical processes.

Influence of local environmental olfactory cues on place learning in rats

The aim of the present study was to assess the influence of local environmental olfactory cues on place learning in rats. We developed a new experimental design allowing the comparison of the use of local olfactory and visual cues in spatial and discrimination learning. We compared the effect of both types of cues on the discrimination of a single food source in an open-field arena. The goal was either in a fixed or in a variable location, and could be indicated by local olfactory and/or visual cues. The local cues enhanced the discrimination of the goal dish, whether it was in a fixed or in a variable location. However, we did not observe any overshadowing of the spatial information by the local olfactory or visual cue. Rats relied primarily on distant visuospatial information to locate the goal, neglecting local information when it was in conflict with the spatial information.

Modeling resting-state functional networks when the cortex falls asleep: local and global changes.

The transition from wakefulness to sleep represents the most conspicuous change in behavior and the level of consciousness occurring in the healthy brain. It is accompanied by similarly conspicuous changes in neural dynamics, traditionally exemplified by the change from "desynchronized" electroencephalogram activity in wake to globally synchronized slow wave activity of early sleep. However, unit and local field recordings indicate that the transition is more gradual than it might appear: On one hand, local slow waves already appear during wake; on the other hand, slow sleep waves are only rarely global. Studies with functional magnetic resonance imaging also reveal changes in resting-state functional connectivity (FC) between wake and slow wave sleep. However, it remains unclear how resting-state networks may change during this transition period. Here, we employ large-scale modeling of the human cortico-cortical anatomical connectivity to evaluate changes in resting-state FC when the model "falls asleep" due to the progressive decrease in arousal-promoting neuromodulation. When cholinergic neuromodulation is parametrically decreased, local slow waves appear, while the overall organization of resting-state networks does not change. Furthermore, we show that these local slow waves are structured macroscopically in networks that resemble the resting-state networks. In contrast, when the neuromodulator decrease further to very low levels, slow waves become global and resting-state networks merge into a single undifferentiated, broadly synchronized network.

Subcellular fractionation of stored red blood cells reveals a compartment-based protein carbonylation evolution.

During blood banking, erythrocytes undergo storage lesions, altering or degrading their metabolism, rheological properties, and protein content. Carbonylation is a hallmark of protein oxidative lesions, thus of red blood cell oxidative stress. In order to improve global erythrocyte protein carbonylation assessment, subcellular fractionation has been established, allowing us to work on four different protein populations, namely soluble hemoglobin, hemoglobin-depleted soluble fraction, integral membrane and cytoskeleton membrane protein fractions. Carbonylation in erythrocyte-derived microparticles has also been investigated. Carbonylated proteins were derivatized with 2,4-dinitrophenylhydrazine (2,4-DNPH) and quantified by western blot analyses. In particular, carbonylation in the cytoskeletal membrane fraction increased remarkably between day 29 and day 43 (P<0.01). Moreover, protein carbonylation within microparticles released during storage showed a two-fold increase along the storage period (P<0.01). As a result, carbonylation of cytoplasmic and membrane protein fractions differs along storage, and the present study allows explaining two distinct steps in global erythrocyte protein carbonylation evolution during blood banking. This article is part of a Special Issue entitled: Integrated omics.

First-line chemotherapy with local treatment can prevent external-beam irradiation and enucleation in low-stage intraocular retinoblastoma.

PURPOSE: To evaluate the efficacy of first-line chemotherapy (CT) in preventing external-beam radiotherapy (EBR) and/or enucleation in patients with retinoblastoma (Rbl). PATIENTS AND METHODS: Twenty-four patients with newly diagnosed unilateral or bilateral Rbl received CT associated with local treatment (LT). Two to five courses of etoposide and carboplatin were administered at 3- to 4-week intervals, depending on tumor response, and were completed each time by LT. RESULTS: Tumor response was observed in all eyes. Twenty-one of 24 patients showed a complete response (CR) that persisted at a median follow-up (FU) of 31 months (range, 4 to 41 months). Among the three patients who relapsed, two were lost to FU and one died of progressive disease. CR was achieved by CT and LT alone in 15 (71.4%) of 21 patients with less advanced disease (groups I to III). Six other patients with advanced disease (groups IV and V) experienced treatment failure and needed salvage treatment by EBR and/or enucleation. The difference between the two patient groups with regard to disease stage was statistically significant (P <.0001). EBR could be avoided in 13 (68.4%) of 19 patients, who presented with groups I to III (15 eyes) and group V (one eye) disease, whereas enucleation could be avoided in only two (40%) of five. CONCLUSION: CT combined with intensive LT is effective in patients with groups I to III Rbl, permitting the avoidance of EBR in the majority of these young children and, thus, reducing the risk of long-term sequelae. This is in contrast with the disappointing results for patients with groups IV and V Rbl, in whom EBR and/or enucleation was needed.

Adjonction d'un anesthésique local intra-articulaire lors d'arthro-TDM/IRM : utilité et avantages de la Bupivacaïne.

Objectifs: Une phase hyperalgique dans les 4 heures post-examen arthrographique est maintenant reconnue dans la littérature. Comment s'en amender ? Nous comparonsl'absence d'anesthésique à l'adjonction de deux différents anesthésiques locaux intra-articulaires(rapidocaïne/bupivacaïne) lors d'arthro-TDM/IRM. Matériels et méthodes: Après approbation du comité d'éthique, étude prospective chez 150 patients répartis aléatoirement en trois groupes : 1) sans anesthésique intra-articulaire, 2)rapidocaïne 1%, 3) bupivacaïne 0,25%. Recueil du score EVA (0-10) aux 5 temps suivants : avant injection (score de base), puis 20 minutes, 4 heures, 24 heureset 7 jours après la procédure. Résultats: Le pic douloureux maximal se trouve à 4h après la procédure (idem littérature). La douleur augmente en moyenne de 1,60 unités 4h après la procédure pour legroupe 1, de 1,22 unités pour le groupe 2 et de 0,29 unités pour le groupe 3. La différence entre les groupes 1 et 3 est statistiquement significative (p=0,002 -Tests ANOVA et de Sidak). Elle n'est pas significative entre les groupes 1 et 2 (p=0,536). La comparaison rapidocaïne et bupivacaïne est moins concluante(p=0,065). Conclusion: L'adjonction de bupivacaïne intra-articulaire devrait être réalisée lors d'examens arthrographiques, surtout afin d'améliorer le confort du patient mais aussi pourfavoriser son immobilité lors de l'acquisition des images TDM ou IRM .

Local adaptation and matching habitat choice in female barn owls with respect to melanic coloration.

Local adaptation is a major mechanism underlying the maintenance of phenotypic variation in spatially heterogeneous environments. In the barn owl (Tyto alba), dark and pale reddish-pheomelanic individuals are adapted to conditions prevailing in northern and southern Europe, respectively. Using a long-term dataset from Central Europe, we report results consistent with the hypothesis that the different pheomelanic phenotypes are adapted to specific local conditions in females, but not in males. Compared to whitish females, reddish females bred in sites surrounded by more arable fields and less forests. Colour-dependent habitat choice was apparently beneficial. First, whitish females produced more fledglings when breeding in wooded areas, whereas reddish females when breeding in sites with more arable fields. Second, cross-fostering experiments showed that female nestlings grew wings more rapidly when both their foster and biological mothers were of similar colour. The latter result suggests that mothers should particularly produce daughters in environments that best match their own coloration. Accordingly, whiter females produced fewer daughters in territories with more arable fields. In conclusion, females displaying alternative melanic phenotypes bred in habitats providing them with the highest fitness benefits. Although small in magnitude, matching habitat selection and local adaptation may help maintain variation in pheomelanin coloration in the barn owl.

Multilayer perceptron with local constraint as an emerging method in spatial data analysis

The use of Geographic Information Systems has revolutionalized the handling and the visualization of geo-referenced data and has underlined the critic role of spatial analysis. The usual tools for such a purpose are geostatistics which are widely used in Earth science. Geostatistics are based upon several hypothesis which are not always verified in practice. On the other hand, Artificial Neural Network (ANN) a priori can be used without special assumptions and are known to be flexible. This paper proposes to discuss the application of ANN in the case of the interpolation of a geo-referenced variable.