The Odd Faces of Oligomers: The Case of TRAF2-C, A Trimeric C-Terminal Domain of TNF Receptor-Associated Factor.

TNF Receptor Associated Factor 2 (TRAF2) is a trimeric protein that belongs to the TNF receptor associated factor family (TRAFs). The TRAF2 oligomeric state is crucial for receptor binding and for its interaction with other proteins involved in the TNFR signaling. The monomer-trimer equilibrium of a C- terminal domain truncated form of TRAF2 (TRAF2-C), plays also a relevant role in binding the membrane, causing inward vesiculation. In this study, we have investigated the conformational dynamics of TRAF2-C through circular dichroism, fluorescence, and dynamic light scattering, performing temperature-dependent measurements. The data indicate that the protein retains its oligomeric state and most of its secondary structure, while displaying a significative increase in the heterogeneity of the tyrosines signal, increasing the temperature from ≈15 to ≈35 °C. The peculiar crowding of tyrosine residues (12 out of 18) at the three subunit interfaces and the strong dependence on the trimer concentration indicate that such conformational changes mainly involve the contact areas between each pair of monomers, affecting the oligomeric state. Molecular dynamic simulations in this temperature range suggest that the interfaces heterogeneity is an intrinsic property of the trimer that arises from the continuous, asymmetric approaching and distancing of its subunits. Such dynamics affect the results of molecular docking on the external protein surface using receptor peptides, indicating that the TRAF2-receptor interaction in the solution might not involve three subunits at the same time, as suggested by the static analysis obtainable from the crystal structure. These findings shed new light on the role that the TRAF2 oligomeric state might have in regulating the protein binding activity in vivo.

Expansion of Human Limbal Epithelial Stem/Progenitor Cells Using Different Human Sera: A Multivariate Statistical Analysis.

Transplantation of human cultured limbal epithelial stem/progenitor cells (LESCs) has demonstrated to restore the integrity and functionality of the corneal surface in about 76% of patients with limbal stem cell deficiency. However, there are different protocols for the expansion of LESCs, and many of them use xenogeneic products, being a risk for the patients' health. We compared the culture of limbal explants on the denuded amniotic membrane in the culture medium-supplemental hormone epithelial medium (SHEM)-supplemented with FBS or two differently produced human sera. Cell morphology, cell size, cell growth rate, and the expression level of differentiation and putative stem cell markers were examined. Several bioactive molecules were quantified in the human sera. In a novel approach, we performed a multivariate statistical analysis of data to investigate the culture factors, such as differently expressed molecules of human sera that specifically influence the cell phenotype. Our results showed that limbal cells cultured with human sera grew faster and contained similar amounts of small-sized cells, higher expression of the protein p63α, and lower of cytokeratin K12 than FBS cultures, thus, maintaining the stem/progenitor phenotype of LESCs. Furthermore, the multivariate analysis provided much data to better understand the obtaining of different cell phenotypes as a consequence of the use of different culture methodologies or different culture components.

Molecular Subtyping and Survival Analysis of Osteosarcoma Reveals Prognostic Biomarkers and Key Canonical Pathways.

Osteosarcoma (OS) is a common bone malignancy in children and adolescents. Although histological subtyping followed by improved OS treatment regimens have helped achieve favorable outcomes, a lack of understanding of the molecular subtypes remains a challenge to characterize its genetic heterogeneity and subsequently to identify diagnostic and prognostic biomarkers for developing effective treatments. In the present study, global analysis of DNA methylation, and mRNA and miRNA gene expression in OS patient samples were correlated with their clinical characteristics. The mucin family of genes, MUC6, MUC12, and MUC4, were found to be highly mutated in the OS patients. Results revealed the enrichment of molecular pathways including Wnt signaling, Calcium signaling, and PI3K-Akt signaling in the OS tumors. Survival analyses showed that the expression levels of several genes such as RAMP1, CRIP1, CORT, CHST13, and DDX60L, miRNAs and lncRNAs were associated with survival of OS patients. Molecular subtyping using Cluster-Of-Clusters Analysis (COCA) for mRNA, lncRNA, and miRNA expression; DNA methylation; and mutation data from the TARGET dataset revealed two distinct molecular subtypes, each with a distinctive gene expression profile. Between the two subtypes, three upregulated genes, POP4, HEY1, CERKL, and seven downregulated genes, CEACAM1, ABLIM1, LTBP2, ISLR, LRRC32, PTPRF, and GPX3, associated with OS metastasis were found to be differentially regulated. Thus, the molecular subtyping results provide a strong basis for classification of OS patients that could be used to develop better prognostic treatment strategies.

How to select the optimal monitoring locations for an aerobiological network: A case of study in central northwest of Spain.

Airborne pollen concentration varies depending on several factors, such as local plant biodiversity, geography and climatology. These particles are involved in triggering pollinosis in a share of worldwide human population, and adequate monitoring is, therefore, important. However, the pollen traps in aerobiological monitoring networks are usually installed in cities, and the features of the whole territory are not taken into account. The aim of this study was to analyze what environmental parameters are more suitable as regards setting up monitoring stations throughout a territory in order to obtain an aerobiological network that can represent environmental diversity. The analysis was carried out in 13 locations in Castilla y León over an 8 year period. This is a favorable territory in which to conduct this type of study owing to its climatic features, orography and biodiversity. The ten most abundant pollen types in the region were analyzed, and a clustering analysis was calculated with different distances so as to obtain homogeneous groups of stations. Moreover, the clusters obtained were analyzed in combination with altitudinal and different bioclimatic parameters, which derived from temperature and precipitation. The result here shows that the Castilla y León aerobiological network RACYL represents most of the environmental variability of the territory. Furthermore, it can be divided into two clusters and five sub-clusters for which the start of the main pollen season is different. This corresponds with the division of the territory as regards bioclimatic conditions. The most important bioclimatic parameters were the seasonality of the precipitation and the maximum temperature of the warmest month, although orography must also be taken into account. All of these help discover the optimal places in which to install traps and could reduce the number of monitoring stations. This study additionally provides data for unmonitored areas with similar bioclimatic conditions to those monitored.

Adolescent Profiles according to Their Beliefs and Affinity to Sexting. A Cluster Study.

Sexting consists of sending, receiving, and distributing images of sexually suggestive content through electronic devices. This practice is one of the new ways of linking sex affectively through virtual environments, especially in adolescence. However, not all young people have the same relationship with the practice of sexting. This study of a sample of 603 Spanish and Moroccan adolescents residing in Andalusia analyzes beliefs towards sexting as part of a virtual sexuality and the perception of those who carry it out, defining profiles of affinity to sexting. The cluster analysis reveals the existence of three predominant profiles: adolescents who show a sexting-philia, perceiving it as a fun, flirty, and daring practice; sexting-phobes, who consider sexting to be characteristic of people, or attitudes, who are desperate, impolite, and conflicting; and a third ambivalent profile of people who appreciate the practice as something fun but conflicting. The majority discourse is one that presents a positive view of this phenomenon. Young people also recognize that sexting has some characteristics of virtual sexuality, such as a loss of privacy and a distance between virtual and real behavior. These findings allow us to deepen our understanding of the new practices of relationships and offer measures for the prevention of the associated risks.

Defense Profiles in Adaptation Process to Sport Competition and Their Relationships with Coping, Stress and Control.

The purpose of this study was to identify the potentially distinct defense profiles of athletes in order to provide insight into the complex associations that can exist between defenses and other important variables tied to performance in sports (e.g., coping, perceived stress and control) and to further our understanding of the complexity of the adaptation process in sports. Two hundred and ninety-six (N = 296) athletes participated in a naturalistic study that involved a highly stressful situation: a sports competition. Participants were assessed before and after the competition. Hierarchical cluster analysis and a series of MANOVAs with post hoc comparisons indicated two stable defense profiles (high and low defense profiles) of athletes both before and during sport competition. These profiles differed with regards to coping, stress and control. Athletes with high defense profiles reported higher levels of coping strategies, perceived stress and control than athletes with low defense profiles. This study confirmed that defenses are involved in the psychological adaptation process and that research and intervention should not be based only on coping, but rather must include defense mechanisms in order to improve our understanding of psychological adaptation in competitive sports.

Postural orientation and standing postural alignment in ambulant children with bilateral cerebral palsy.

BACKGROUND: Standing postural alignment in children with cerebral palsy is usually altered by central postural control disorders. The primary aim of this study is to describe body alignment in a quiet standing position in ambulatory children with bilateral cerebral palsy compared with children with typical development. METHODS: Fifty-eight children with bilateral cerebral palsy (aged 7-13years) and 45 age-matched children with typical development underwent a surface topography examination based on Moiré topography and were classified according to their sagittal postural profiles. FINDINGS: The following eight grouping variables were extracted using a data reduction technique: angle of trunk inclination, pelvic tilt, and lordosis, the difference between kyphosis and lordosis, angle of vertebral lateral curvature, shoulder inclination, and shoulder and pelvic rotation. According to the cluster analysis results, 25% of the participants were classified into Cluster 1, 9% into Cluster 2, 49% in Cluster 3, and 17% in Cluster 4. INTERPRETATION: Three different postural patterns emerged in accordance with the sagittal postural profiles in children with bilateral cerebral palsy and were defined as follows: 1) a lordotic postural pattern corresponding to forward-leaning posture; 2) a swayback postural pattern corresponding to backward-leaning posture; and 3) a balanced postural pattern corresponding to balanced posture.

The E144 residue of Scherffelia dubia centrin discriminates between the DNA repair protein XPC and the centrosomal protein Sfi1.

Centrins are members of the EF-hand family of calcium-binding proteins, which are highly conserved among eukaryotes. Centrins bind to several cellular targets, through a hydrophobic triad. However, the W(1)xxL(4)xxxL(8) triad in XPC (Xeroderma Pigmentosum Group C protein) is found in the reverse orientation, as in the L(8)xxxL(4)xxW(1) triad in Sfi1 (Suppressor of Fermentation-Induced loss of stress resistance protein 1). As shown by previous NMR studies of human centrin 2 in complex with XPC or Sfi1, the E148 residue of human centrin 2 is in contact with XPC but is pushed away from the triad of Sfi1. We corroborated these findings using site-directed mutagenesis to generate mutations in Scherffelia dubia centrin (SdCen) and by using isothermal titration calorimetry to analyze the binding affinity of these mutants to XPC and Sfi1. We mutated the F109 residue, which is the main residue involved in target binding regardless of triad orientation, and the E144 residue, which was thought to be involved only in XPC binding. The F109L mutation reduced the binding of SdCen to XPC and Sfi1 and the negative effect was greater upon temperature increase. By contrast, the E144A mutation reduced the binding to XPC but had no effect on Sfi1 binding. The F109L-E144A mutation enhanced the negative effect of the two single mutations on XPC binding. Sfi1 proteins from Ostreococcus lucimarinus and Ostreococcus tauri, which belong to the same clade as S. dubia, were also investigated. A comparative analysis shows that the triad residues are more conserved than those in human Sfi1.

Cluster analysis as a tool for management improvement in the sus / Uso da análise de clusters como ferramenta de apoio à gestão no sus

The institutionalization of health services evaluation tools is a strategic challenge for the development of the Brazilian National Health System (SUS). The aim of the study was to explore the potential of cluster analysis as a technical tool to support the SUS management. Steps for constructing clusters applied to a concrete reality are presented and discussed, by analyzing a type of health care emergency services (AMA), in São Paulo city. The strategy was based on using secondary data to construct homogeneous groups, which allows multivariate analysis, enhancing the interpretation of the relationship between these data. The study findings indicate that this technique has the potential to be used by institutional actors in the SUS management to evaluate and to monitor health services in big cities or health regions.

A institucionalização de ferramentas de avaliação de serviços de saúde é um desafio estratégico para o desenvolvimento do Sistema Único de Saúde (SUS). O objetivo do estudo realizado foi explorar o potencial da análise de clusters (análise por conglomerados) enquanto ferramenta de apoio à gestão do SUS. São apresentadas e discutidas as etapas do processo de construção dos clusters aplicadas a uma realidade concreta, por meio da análise de serviços de saúde de tipo pronto atendimento (AMA), do município de São Paulo. A estratégia metodológica baseou-se na utilização de dados secundários para a construção de agrupamentos homogêneos, o que permite análise de múltiplas variáveis potencializando a interpretação da relação entre as mesmas. Os achados do estudo indicam que essa técnica tem potencialidade para ser utilizada por atores institucionais da gestão do SUS na avaliação e monitoramento de serviços de saúde, em municípios de grande porte ou em regiões de saúde.

Sentinel phenotype for rubella embryopathy: time-space distribution in Brazil / Fenótipo sentinela para embriopatia rubéolica: distribuição em tempo e espaço no Brasil

The dyad comprising eye anomalies and congenital heart defects in the same newborn has been proposed as the best sentinel phenotype for the early detection of rubella embryopathy. Time-space birth prevalence distributions of the eye-heart dyad were described in 36 Brazilian hospitals from the Latin-American Collaborative Study of Congenital Anomalies - ECLAMC network, for the period 1994-2008. Seventy dyad cases observed among 554,531 births showed seasonal variation (Χ2 = 5.84; p < 0.05), suggesting an environmental etiology, with an increase in cases in October-March and acrophase in December. The secular distribution of dyad prevalence rates was consistent with the distribution of rubella cases in Brazil, showing a decrease from 1994 to 2004, followed by an increase until 2008. Two geographic clusters were identified, one with high and the other with low dyad prevalence. In the high prevalence cluster, a secular increase was observed, starting in 1999, matching the rubella epidemic waves observed in Brazil in 1998-2000 and 2006.

A díade óculo-cardíaca havia sido proposta como o melhor fenótipo sentinela para detecção precoce da embriopatia rubéolica. Descrevem-se as distribuições têmporo-espaciais das prevalências ao nascimento dessa díade com material do Estudo Colaborativo Latino Americano de Malformações Congênitas (ECLAMC) em 36 hospitais brasileiros no período 1994-2008. Os 70 casos em 554.531 nascimentos mostraram uma variação sazonal significativa (Χ2 = 5,84; p < 0,05), o que sugere uma etiologia ambiental, com um aumento de casos de outubro a março com acrofase em dezembro. A variação secular das prevalências da díade foi compatível com o padrão observado para a distribuição da rubéola no país, com diminuição entre 1994-2004, e ulterior aumento até 2008. Identificaram-se dois conglomerados de alta e de baixa prevalência para a díade. Dentro do conglomerado de alta prevalência, observou-se significativo acréscimo secular a partir do ano 1999, não verificado no conglomerado de baixa prevalência, nem no resto dos hospitais em estudo, compatível com a série de surtos epidêmicos registrados para a infecção rubeólica no Brasil em 1998-2000 e em 2006.

Clasificación de los hogares según su perfil de salud, para la focalización de recursos destinados a prevención, promoción y recuperación, Medellín, 2004 / Classification of homes according to health profile for the purpose of prevention, promotion and recovery resource focus, Medellin, 2004

Objetivo: obtener un constructo de salud para clasificar hogares de la ciudad de Medellín según sus condiciones de vida y salud. Materiales y métodos: para la creación del constructo de salud, se partió de los datos obtenidos en la Encuesta de Calidad de Vida, Medellín, 2004, de donde se seleccionaron las variables referentes a condiciones de vida y determinantes de la salud. Se realizó un análisis de componentes principales para escoger aquellos que explicaban la mayor variabilidad de los hogares; posteriormente se hizo el análisis de conglomerados en dos pasos para agrupar los hogares según sus condiciones de vida y salud. Resultados: las correlaciones observadas estaban en la dirección prevista. Doce componentes principales explican el 69% de la variabilidad de los datos, aportando una mayor proporción de variabilidad las variables de las condiciones de vida. En Medellín se identificaron cinco tipologías de hogares que comparten las mismas condiciones de vida y salud. Conclusión: las técnicas multivariantes permiten concluir que la clasificación de los hogares de Medellín en cinco tipologías con respecto a los determinantes de la salud ofrece oportunidades para la formulación de programas de intervención a escala poblacional.

Objective: to obtain a health profile to classify homes of Medellín city, according to similarities due to life and health conditions. Materials and methods: for the creation of a health profile, information was taken from the data collected in the Quality of Life Survey, Medellín, 2004, where variables referring to life conditions and health determinants were selected. An analysis of mean components was made to choose those that explained the greater variability among homes, then a cluster analysis in 2 steps was performed to group the homes according to their life and health conditions. Results: the observed correlations appeared in the expected directions. A total of 12 components explain 69% of the variability of the data, contributing to a greater proportion of variability the variables of life conditions. In Medellín, 5 types of homes were identified sharing the same conditions of life and health. Conclusion: multivariant techniques allow to conclude that Medellín’s home classification into 5 types regarding their determinants of health provides opportunities to make formulation of intervention programs at the population level possible.