Julgando sob incerteza: heurísticas e vieses e o ensino de probabilidade e estatística

Este artigo procurou apresentar as heurísticas e vieses de representatividade e de disponibilidade que podem levar a conclusões enganosas, e que estão ligadas ao julgamento e/ou previsão de cenários de incerteza. O ensino de probabilidade e estatística no ensino médio no Brasil tem se voltado à forma matemática da teoria, sem discussões e situações práticas que permitiriam uma visão consistente da teoria, facilitando o aparecimento destes vieses. A análise constou da aplicação de um pré-teste, seguida de discussões e atividades na área de probabilidade e estatística, finalizando com um pós-teste, para analisar o raciocínio de alunos do ensino médio diante de padrões que podem levar a erros de julgamento. A resistência das heurísticas foi verificada de forma mais expressiva em um determinado tipo e moderadamente em outro

P11-05. Induction of CD8+ T cell mediated immune responses through skin and mucosa: identification of immunostimulatory versus tolerogenic dendritic cells

International audiencen.

Invariant NKT Cells Suppress CD8+ T-Cell–Mediated Allergic Contact Dermatitis Independently of Regulatory CD4+ T Cells

Invariant natural killer T (iNKT) cells expressing a CD1d-restricted invariant αβTCR have key regulatory roles in autoimmunity, pathogen immunity, and tumor surveillance, but their function in the control of allergic skin diseases remains poorly documented. Using a model of contact hypersensitivity (CHS) to the hapten DNFB, we show here that iNKT cell deficiency results in enhanced skin inflammation due to augmented hapten-specific IFN-γ-producing CD8+ effectors in skin draining lymph nodes (dLNs) and their massive recruitment into the allergen-exposed skin. Adoptive transfer and antibody depletion experiments as well as in vitro studies revealed that iNKT cells (1) reduce the severity of CHS, even in presensitized mice, (2) require hapten presentation by CD1d+ dendritic cells (DCs) to dampen skin inflammation, and (3) produce IL-4 and IL-13 after CD1d-dependent in vitro stimulation by hapten-loaded DCs only in the presence of IFN-γ released from activated CD8+ effector T cells. In corollary, mice double deficient in IL-4 and IL-13 exhibit an exacerbated CHS. Finally, iNKT-suppressive function is independent of Foxp3+ regulatory T cells (Tregs). These data highlight that, besides Foxp3+ Tregs, iNKT cells are potent downregulators of CD8+ T cell–mediated CHS, and underscore that both cell types are important for the regulation of allergic skin inflammation

Eczéma allergique de contact : Comment ré-induire une tolérance ?

L’eczéma allergique de contact est une dermatose inflammatoire fréquente, due à l’activation de lymphocytes T (LT) CD8+ cytotoxiques spécifiques d’haptènes en contact avec la peau. Les LT CD4+ sont, quant à eux, doués d’une fonction régulatrice et tolérogène, puisqu’ils limitent l’inflammation cutanée chez les patients (régulation) et préviennent le développement des LT effecteurs chez les individus sains (tolérance) : l’eczéma correspond donc à une rupture de la tolérance immunitaire aux haptènes présents dans l’environnement quotidien. Plusieurs sous-populations de LT CD4+ régulateurs (LT reg), parmi lesquelles celle des LT CD4+CD25+ naturels, sont impliquées dans la tolérance et la régulation de l’eczéma, via la production des cytokines immunosuppressives IL-10 (interleukine-10) et TGFβ (transforming growth factor β). Les travaux en cours ont pour objectif de ré-induire une tolérance immunitaire dans l’eczéma, soit en améliorant les méthodes existantes d’induction de tolérance aux haptènes (tolérance orale, tolérance à faibles doses, immunothérapie spécifique, tolérance induite par les rayons ultraviolets), soit en développant de nouvelles molécules capables d’activer les LT reg. Plus généralement, les données issues de ces travaux devraient pouvoir être appliquées au traitement des maladies auto-immunes ou allergiques, caractérisées par un déficit fonctionnel ou quantitatif en Ltreg à l’origine d’une rupture de la tolérance aux auto-antigènes ou aux allergènes de l’environnement.Allergic contact dermatitis (ACD) is a skin inflammatory disease mediated by activation of CD8+ cytotoxic T cells specific for haptens in contact with the skin. CD4+ T cells behave as both regulatory and tolerogenic cells since they down-regulate the skin inflammation in patients with ACD (regulation) and prevent the developement of eczema (tolerance) in normal individuals. Thus, ACD corresponds to a breakdown of immune tolerance to haptens in contact with the skin. Several regulatory CD4+ T cell subsets (Treg), especially CD4+CD25+ natural Treg cells, are involved in immunological tolerance and regulation to haptens through the production of the immunosuppressive cytokines IL-10 and TGF-β. Ongoing strategies to re-induce immune tolerance to haptens in patients with eczema include improvement of existing methods of tolerance induction (oral tolerance, low dose tolerance, allergen-specific immunotherapy, UV-induced tolerance) as well as development of new drugs able to activate IL-10 producing Treg cells in vivo. Ongoing and future progress in this area will open up new avenues for treatment of eczema and more generally autoimmune and allergic diseases resulting from a breakdown of tolerance to autoantigens and allergens, respectively

Application of pediatric evaluation disability inventory in children with cerebral palsy quadriplegic spastic

This study presents some data collected through Pediatric Evaluation Disability Inventory (PEDI), using a sample of children with spastic tetrapresis. The application in each child has been done twice within intervals from 12 to 24 months. Although the descriptive analysis has shown an average evolution between those applications, only in the self - care area the difference has proved meaningful (p < 0,005) while the mobility area has presented less progress. In this article, although with a reduced sample, the potential of this instrument as a parameter of evolution for these children will be discussed.No presente artigo são analisados os dados coletados através do Inventário de Avaliação Pediátrica de Incapacidade (PEDI) em amostra de 10 crianças portadoras de tetraparesia espástica. A aplicação em cada criança foi feita em dois instantes, com intervalos que variaram entre 12 e 24 meses. Embora a análise descritiva tenha mostrado uma evolução média entre as duas aplicações do PEDI, somente na área de Auto-Cuidado a diferença se mostrou significativa (p < 0,005) sendo que visivelmente a Mobilidade foi a área que menos progrediu. Neste artigo será discutido o potencial deste instrumento como parâmetro de evolução para estas crianças, ressalvado o fato de a amostra ser bem reduzida

Comparison of CD23 staining patterns in Merkel cell carcinoma and non-cutaneous small cell carcinoma

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72874/1/j.1600-0560.2008.00999.x.pd

The identification of a low molecular mass bacteriocin, rhamnosin A, produced by Lactobacillus rhamnosus strain 68

Aims: This study focuses on the isolation and characterization of a peptide with bacteriocin-like properties isolated from Lactobacillus rhamnosus strain 68, previously identified by 16S rRNA gene sequencing and originating from human gastrointestinal flora. Methods and Results: The peptide was isolated from a supernatant of bacteria maintained under restrictive conditions by a combination of ethanol precipitation and reversed-phase chromatography. The molecular mass of the peptide as assessed by mass spectrometry was 6433 center dot 8 Da. An isoelectric point of 9 center dot 8 was determined by 2D-PAGE. The peptide designated rhamnosin A inhibited Micrococcus lysodeikticus ATCC 4698 but did not inhibit Lactobacillus plantarum 8014 or Lact. plantarum 39268. Inhibitory activity against M. lysodeikticus at concentrations used in this study was shown to be bacteriostatic rather than bacteriolytic or bactericidal. Rhamnosin A retained biological activity after heat treatment (95 degrees C, 30 min) but was sensitive to proteolytic activity of pepsin and trypsin. Conclusions: The N-terminal sequence of rhamnosin A, as determined by Edman degradation and in more detail by blast analysis, did not show identity with any currently available Lact. rhamnosus HN001-translated protein sequences, nor any significant similarity with other sequences in the nonredundant protein sequence database. Being a small, heat-stable, nonlanthionine-containing peptide, rhamnosin A should be categorized as a class II bacteriocin. Significance and Impact of the Study: This study describes a partial bacteriocin sequence isolated from Lact. rhamnosus 68 and broadens our understanding of bacteriocins