Plasticity in Colorectal Cancer: Why Cancer Cells Differentiate

The cancer stem cell hypothesis poses that the bulk of differentiated cells are non-tumorigenic and only a subset of cells with self-renewal capabilities drive tumor initiation and progression. This means that differentiation could have a tumor-suppressive effect. Accumulating evidence shows, however, that in some solid tumors, like colorectal cancer, such a hierarchical organization is necessary. The identification of Lgr5 as a reliable marker of normal intestinal epithelial stem cells, together with strategies to trace cell lineages within tumors and the possibility to selectively ablate these cells, have proven the relevance of Lgr5+ cells for cancer progression. On the contrary, the role of Lgr5− cells during this process remains largely unknown. In this review, we explore available evidence pointing towards possible selective advantages of cancer cells organized hierarchically and its resulting cell heterogeneity. Clear evidence of plasticity between cell states, in which loss of Lgr5+ cells can be replenished by dedifferentiation of Lgr5− cells, shows that cell hierarchies could grant adaptive traits to tumors upon changing selective pressures, including those derived from anticancer therapy, as well as during tumor progression to metastasis

Pourquoi commencer ? L’initiation à l’injection de drogues selon les jeunes de la rue

Dans le cadre du développement d’une campagne de prévention du passage à l’injection de drogues chez les jeunes de la rue, nous avons mené sept groupes de discussion auprès de 37 d’entre eux âgés de 15 à 23 ans. L’analyse, à la fois déductive et inductive, a permis d’identifier les dimensions reflétant le point de vue des jeunes à propos de l’injection de drogues et des éléments qui favorisent le passage à l’injection dans leur milieu. Les résultats montrent que l’injection est généralement désapprouvée par les jeunes de la rue. Plusieurs ont des réserves, celles-ci étant liées aux conséquences négatives de l’injection. Ce que les jeunes redoutent le plus, c’est de devenir « accro », un risque qu’ils associent davantage à l’injection qu’aux autres modes de consommation. Malgré la désapprobation générale, au contact des utilisateurs de drogues par injection (UDI), il se produit une sorte de désensibilisation qui entraîne vers l’injection les plus vulnérables, soit les plus jeunes, surtout ceux qui satisfont leur besoin de sensations fortes à travers la drogue et recherchent une valorisation dans le monde de la rue. Divers éléments d’ordre individuel et social agissent alors pour amener ces jeunes à s’initier à l’injection. Plusieurs de ces éléments peuvent être modifiables par des interventions préventives.During the development of a media campaign, aimed at preventing initiation into injection drug use among street youth, we conducted seven focus groups with 37 youth aged between 15 and 23 years. The analysis process, at the same time deductive and inductive, permitted us to identify dimensions reflecting the viewpoint of street youth concerning injection drug use and the factors that favour initiation in their milieu. The results show that injection is generally disapproved of among street youth. Many have reservations because of the negative consequences linked to this behaviour. What youth fear most is becoming “an addict”, a risk that they associate especially with injection compared with other forms of drug use. Despite widespread disapproval, with continuing contact with injection drug user (IDUs), a kind of desensitization occurs which affects the most vulnerable youth, mainly the youngest, mostly those who satisfy their need for strong sensations through drugs and seek social valorisation in the street scene. Different factors, both on an individual level as well as a social level, influence these youth to start injecting. Some of these factors may be modifiable through preventive interventions.En el marco del desarrollo de una campaña de prevención del pasaje a la inyección de drogas en los jóvenes de la calle, hemos dirigido siete grupos de discusión en los que participaron 37 jóvenes de 15 a 23 años. El análisis, a la vez deductivo e inductivo, ha permitido identificar las dimensiones que reflejan el punto de vista de los jóvenes sobre la inyección de drogas y los elementos que favorecen el pasaje a la inyección en su medio. Los resultados muestran que los jóvenes de la calle desaprueban en general el uso de la inyección. Muchos de ellos tienen reservas sobre las consecuencias negativas de la inyección y lo que más temen es devenir adictos, riesgo que asocian a la inyección de drogas más que a cualquier otro modo de consumo. A pesar del rechazo general, en el contacto con los usuarios de droga por inyección (UDI) se produce un tipo de desensibilización que atrae hacia la inyección a los más vulnerables, es decir, a los más jóvenes, sobre todo los que satisfacen su necesidad de sensaciones fuertes a través de la droga y que buscan una valorización en el mundo de la calle. Actúan entonces diversos elementos de naturaleza individual y social que llevan a estos jóvenes a iniciarse en las drogas inyectables. Muchos de estos elementos pueden modificarse mediante intervenciones preventivas

Estimating pCO2 from remote sensing in the Belgian Coastal Zone

In coastal waters, a purely field observation based approach will probably be insufficient to better constrain estimates of air-sea CO2 fluxes, to study their inter-annual variability and their long-term changes. One approach to achieve these goals is to use remotely sensed fields of relevant biogeochemical variables to extrapolate available data, and produce maps of the partial pressure of CO2 (pCO2) and air-sea CO2 fluxes. In the open ocean this approach has to some extent been successfully used based on fields of chlorophyll-a (Chla) and sea surface temperature (SST). This approach remains challenging in coastal waters that have complex optical properties (Case-II waters) and that exhibit highly dynamic pCO2 temporal and spatial variations. In the frame of the Belgian funded BELCOLOUR-II project (Optical remote sensing of marine, coastal and inland waters; http://www.mumm.ac.be/BELCOLOUR/), three field cruises per year (April, July and September) for optical measurements were carried in 2007, 2008, 2009 in the Southern Bight of the North Sea (SBNS). Based on these data-sets, we derived algorithms to compute pCO2 from Chl-a and sea surface salinity (SSS) using multipolynomial regressions (MPR). Here we report the first application of the MPR algorithms to derive pCO2 fields in the Belgian coastal zone based on data gathered in 2007, using remote sensed Chl-a (MERIS) and SSS computed with a 3-D hydrodynamical model of SBNS (COHERENS).info:eu-repo/semantics/publishe

Quality of life in patients with locked-in syndrome: Evolution over a 6-year period

International audienceBackground: Improved knowledge of the quality of life (QoL) of locked-in syndrome (LIS) patients have implications for managing their care, and assists clinicians in choosing the most appropriate interventions. We performed a survey of a population of LIS patients to describe the course of the QoL of LIS patients over a 6-year period and to determine the potential predictive factors of QoL changes over time. Method: This is a study performed over a 6-year period in patients with a LIS diagnosis. Questionnaires were sent in 2007 and 2013. The following data were recorded: i) sociodemographic data; ii) clinical data related to LIS, physical/handicap status, psychological status; iii) self-reported QoL: Anamnestic Comparative Self-Assessment (ACSA); iv) Integration in life: French Reintegration to Normal Living Index (RNLI). Results: Among the 67 patients included in 2007, 39 (58 %) patients returned their questionnaire in 2013. The LIS etiology was stroke in 51 individuals. The QoL of the patients was relatively satisfactory compared to populations in other severe conditions. Twenty-one (70 %) individuals reported a stable/improved QoL between 2007 and 2013. The physical/handicap statuses in 2007 and 2013 were not related to the QoL 6 years later, with the exception of one communication parameter: the individuals who used yes-no code reported significantly lower QoL levels than those who did not in 2013. Discussion: In opposition to a widespread opinion, LIS persons report a relatively satisfactory QoL level that stays stable over time, suggesting that life with LIS is worth living. Preservation of autonomy and communication may help them to live as normal life as possible

REGARD PARENTAL SUR LES DEVOIRS ET LES LEÇONS EN FONCTION DES CARACTÉRISTIQUES FAMILIALES ET DU RENDEMENT DE L’ÉLÈVE

L’étude s’intéresse à certains aspects des devoirs et des leçons par l’entremise d’analyses menées à partir de regroupements de familles en fonction de la structure familiale, de la scolarité des parents et du rendement scolaire de l’enfant. L’échantillon est composé de 465 parents d’élèves de 1re et de 4e années du primaire. Les données ont été recueillies à l’aide de questionnaires autoadministrés au cours de la première année de l’étude. Les analyses de comparaison révèlent que les familles non traditionnelles et que les familles dont l’enfant éprouve des difficultés scolaires sont plus rébarbatives aux devoirs et aux leçons. Ces mêmes familles en perçoivent moins l’utilité que les autres. Les familles moins scolarisées et les familles ayant un enfant en difficulté se sentent moins compétentes pour intervenir de manière adéquate dans les devoirs et les leçons. Il appert que les besoins et les limites de ces familles doivent être pris en considération par les enseignants dans le cadre de l’assignation des devoirs et des leçons. Mots clés : devoirs et leçons, caractéristiques familiales, participation des parents, élèves du primaireIn the present study, various aspects of homework were examined in a sample of 465 parents of first and fourth grades students in relation to family structure, parent’s education and school achievement. Data were collected through self-report questionnaires during the first year of the study. Analyses show that non traditional families and families of children with learning difficulties are less willing to help with homework. Those families don’t perceive its benefits as much as other families do. Less schooling families and families of children with learning difficulties have low self-efficacy to intervene adequately in homework. Family needs and limits must be taken into consideration by teachers when assigning homework. Key words: homeworks and lessons, family characteristics, parents involvement, pupils of primary education

BeadNet: Deep learning-based bead detection and counting in low-resolution microscopy images

Motivation An automated counting of beads is required for many high-throughput experiments such as studying mimicked bacterial invasion processes. However, state-of-the-art algorithms under- or overestimate the number of beads in low-resolution images. In addition, expert knowledge is needed to adjust parameters. Results In combination with our image labeling tool, BeadNet enables biologists to easily annotate and process their data reducing the expertise required in many existing image analysis pipelines. BeadNet outperforms state-of-the-art-algorithms in terms of missing, added and total amount of beads. Availability and implementation BeadNet (software, code and dataset) is available at https://bitbucket.org/t_scherr/beadnet. The image labeling tool is available at https://bitbucket.org/abartschat/imagelabelingtool