Análisis de la participación del virus de Epstein Barr en la patogénesis del linfoma difuso a grandes células B y su interacción con el microambiente tumoral

EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly is a provisional entity included in the 2008 WHO classification of lymphoid tumors, that occurs in immunocompetent patients >50 years. It was proposed that it is related to the senescence of the immune system inherent to the aging process. Our aim was to study the role of EBV in the DLBCL pathogenesis in pediatric, young and older patients from our country and to characterize tumor microenvironment. One-hundred and two DLBCL cases were collected. EBERs in situ hybridization and immunohistochemistry for EBV antigens and lymphocytes populations were performed. EBV gene expression, cytokine and chemokine transcripts were analyzed using real-time PCR. EBV+ and ? cases from all age-groups were compared. EBV+ DLBCL frequency was similar in all age-groups; II and III viral latency pattern together with lytic expression were prevalent. PD-1 was predominant in all cases of DLBCL, while GrB was markedly increased in EBV+ DLBCL cases, in which a trend to lower event-free survival was noticed. Finally, EBV+ DLBCL may be an entity that is not only restricted to patients who are older than 50 years of age, in consequence the revision of age cutoff may be a current goal.Fil: Cohen, Melina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaLa OMS en el 2008 incluyó una nueva entidad provisoria, el LDGCB EBV+ del adulto mayor, en pacientes mayores de 50 años inmunocompetentes, probablemente por la inmunosenescencia inherente al envejecimiento. Nuestro objetivo fue determinar la participación del virus de EBV en la patogénesis del LDGCB en pacientes pediátricos, adultos menores y mayores de 50 años de nuestro país, y caracterizar ciertos marcadores del microambiente tumoral. Se analizaron 102 casos de LDGCB. Se realizó hibridación in situ para EBERs e inmunohistoquímica para los antígenos virales y marcadores del microambiente tumoral. Se determinó la expresión relativa de transcriptos virales y de citoquinas y quimioquinas por PCR en tiempo real y se compararon los casos EBV+ y ? en los 3 grupos. El LDGCB EBV+ (con ?20% de células tumorales EBERs+) se vio en todos los grupos etarios y prevaleció el perfil de latencia II y III junto con perfil lítico. PD-1 prevaleció en todos los LDGCB, mientras que los casos EBV+ tuvieron un aumento significativo en la población de células citotóxicas GrB+ y una tendencia a una menor sobrevida libre de eventos. El virus cumpliría un rol en la patogénesis del LDGCB EBV+ en todos los grupos etarios. Este hallazgo avala la sugerencia de revisión del criterio de edad definido por la OMS

Do batismo de Leguizamón ao escritor como um shofar: apostas integrativas em Gerchunoff

Este trabajo aborda los libros de Alberto Gerchunoff Los gauchos judíos (1910) y El hombre importante (1934) con el fin principal de examinar en sus prólogos, y en los vínculos entre estos y los textos prologados, las concepciones que allí se presentan sobre los procesos de integración de los inmigrantes judíos a la Argentina y la construcción de la imagen de escritor de Gerchunoff. Como se demostrará, mientras en Los gauchos judíos prima una concepción de la integración coherente con el modelo del crisol de razas en El hombre importante se defiende el proyecto de una nación pluricultural, y esta transformación se verá reflejada en el modo en que Gerchunoff elabora su imagen de escritor en tanto autor nacional. Asimismo, el estudio de estas obras permitirá una reflexión sobre la función y los rasgos del prólogo como espacio liminar entre el texto prologado y su contexto socio-cultural de producción.This paper focuses on The Jewish Gauchos (1910) and The Important Man (1934) by Alberto Gerchunoff with the purpose of analyzing in their prologues, as well as in the links between these and the main texts, the conceptions about the integration processes of the Jewish immigrants to Argentina and the construction of Gerchunoff’s author figure. Firstly, I will demonstrate that while a conception of integration consistent with melting pot model prevails in The Jewish Gauchos, The Important Man defends the project of a pluricultural nation. Secondly, I will show that such transformation impacts, in turn, on the way of elaborating Gerchunoff´ self-representations as a national author. Finally, the study of these works will allow a reflection on the function of the prologue as a liminal space between the main text and its sociocultural context.Este trabalho analisa os livros Os gaúchos judeus (1910) e O homem importante (1934), de Alberto Gerchunoff, com o objetivo principal de examinar em seus prólogos, assim como nos vínculos entre eles e os textos centrais, as concepções que aí se apresentam sobre os processos de integração de judeus imigrantes na Argentina e a construção da imagem de Gerchunoff como escritor. Como será demonstrado, enquanto em Os gaúchos judeus prevalece uma concepção de integração coerente com o modelo do melting pot, em O homem importante defende-se o projeto de uma nação multicultural, e tal transformação se refletirá, por sua vez, no modo de elaboração de sua imagem de escritor como autor nacional. Da mesma forma, o estudo dessas obras permitirá uma reflexão sobre a função e as características do prólogo como espaço liminar entre o texto do prólogo e seu contexto sociocultural de produção

Analysis of Epstein-Barr virus infection models in a series of pediatric carriers from a developing country

Epstein-Barr virus (EBV) is a B lymphotropic human herpesvirus. Two models, germinal center (GC)and direct infection, describe how EBV infects B-cells. Since in Argentina primary infection is mostly subclinical at young ages, children represent an interesting population where to analyze EBV infection, especially considering that most studies are usually performed in adults. Tonsil biopsies from pediatriccarriers were studied to describe infection characteristics. EBV+ lymphocytes at the interfollicular region were mainly observed. Latency III pattern in subepithelial (SubEp) lymphocytes was observed at young ages, probably indicating a recent infection. In older patients EBV was mostly detected in epithelial cells, suggesting that they could have been infected some time ago. This finding was sustained by tonsillar viral load, which was higher in cases with LMP1+SubEp cells vs. LMP1+nonSubEp cells (p = 0.0237, Mann-Whiney test). Latency III was prevalent and related to the GC, while latency II was associated with non-GC (p = 0.0159, χ2 test). EBERs+/IgD+ cells were statistically prevalent over EBERs+/CD27+ cells (p = 0.0021, χ2 test). These findings indicated that both EBV infection models arenot mutually exclusive and provide some basis for further understanding of EBV infection dynamics. Moreover, we provide a more accurate explanation of EBV infection in pediatric asymptomatic carriers from a developing country.Fil: Vistarop, Aldana Georgina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Anatomía Patológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cohen, Melina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Anatomía Patológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Matteo, Elena Noemí. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Anatomía Patológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Preciado, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Anatomía Patológica; ArgentinaFil: Chabay, Paola Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Servicio de Anatomía Patológica; Argentin

Differences in Epstein-Barr virus characteristics and viral-related microenvironment could be responsible for Lymphomagenesis in children

In Argentina, Epstein-Barr virus (EBV) presence is associated with Hodgkin lymphoma (HL) in patients younger than 10 years, suggesting a relationship between low age of EBV infection and HL. Given that HL is derived from germinal centers (GC), our aim was to compare EBV protein expression and microenvironment markers between pediatric HL patients and EBV+GC in children. Methods: EBV presence and immune cell markers were assessed by in situ hybridization and immunohistochemistry (IHC). Results: Viral latency II pattern was proved in all HL patients and in 81.8% of EBV+ tonsillar GCs. LMP1 and LMP2 co-expression were proved in 45.7% HL cases, but only in 7.7% EBV+ GC in pediatric tonsils. An increase in CD4+, IL10, and CD68+ cells was observed in EBV+ GC. In pediatric HL patients, only the mean of IL10+ cells was statistically higher in EBV+ HL. Conclusions: Our findings point us out to suggest that LMP1 expression may be sufficient to drive neoplastic transformation, that an immune regulatory milieu counteracts cytotoxic environment in EBV-associated Hodgkin lymphoma, and that CD4+ and CD68+ cells may be recruited to act in a local collaborative way to restrict, at least in part, viral-mediated lymphomagenesis in tonsillar GC.Fil: Vistarop, Aldana Georgina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Jimenez, Oscar Eduardo. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Cohen, Melina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: de Matteo, Elena Noemí. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Preciado, María Victoria. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Chabay, Paola Andrea. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentin

Angiotensin II-upregulated MAP kinase phosphatase-3 modulates FOXO1 and p21 in adrenocortical H295R cells

MAPK phosphatases (MKP) downregulate the activity of mitogen-activated protein kinases (MAPK), such asERK1/2, and modulate the processes regulated by these kinases. ERK1/2 participate in a wide range of processesincluding tissue-specific hormone-stimulated steroidogenesis. H295R cells are a suitable model for the study ofhuman adrenal cortex functions, particularly steroid synthesis, and respond to angiotensin II (Ang II) triggeringERK1/2 phosphorylation in a transient fashion. MKP-3 dephosphorylates ERK1/2 and, as recently reported,forkhead box protein 1 (FOXO1). Here, we analyzed MKP-3 expression in H295R cells and its putative regulationby Ang II. Results showed the expression of MKP-3 full length (L) and a short splice variant (S), and the upregulationof both isoforms by Ang II. L and S messenger and protein levels increased 30 min after Ang II stimulationand declined over the next 3 h, a temporal frame compatible with ERK1/2 dephosphorylation. In addition, FOXO1activation is known to include its dephosphorylation and nuclear translocation. Therefore, we analyzed the effectof Ang II on FOXO1 modulation. Ang II induced FOXO1 transient phosphorylation and translocation and also theinduction of p21, a FOXO1-dependent gene, whereas MKP-3 knock-down reduced both FOXO1 translocation andp21 induction. These data suggest that, through MKP-3, Ang II counteracts its own effects on ERK1/2 activity andalso triggers the activation of FOXO-1 and the induction of cell cycle inhibitor p21. Taken together, the currentfindings reveal the participation of MKP-3 not only in turn?off but also in turn-on signals which control importantcellular processes.Fil: Mori Sequeiros, María de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Cohen Sabban, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Dattilo, Melina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mele, Pablo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Nudler, Silvana Iris. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mendez, Carlos Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Maloberti, Paula Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Paz, Cristina del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

Telephone conversation impairs sustained visual attention via a central bottleneck

Recent research has shown that holding telephone conversations disrupts one's driving ability. We asked whether this effect could be attributed to a visual attention impairment. In Experiment 1, participants conversed on a telephone or listened to a narrative while engaged in multiple object tracking (MOT), a task requiring sustained visual attention. We found that MOT was disrupted in the telephone conversation condition, relative to single-task MOT performance, but that listening to a narrative had no effect. In Experiment 2, we asked which component of conversation might be interfering with MOT performance. We replicated the conversation and single-task conditions of Experiment 1 and added two conditions in which participants heard a sequence of words over a telephone. In the shadowing condition, participants simply repeated each word in the sequence. In the generation condition, participants were asked to generate a new word based on each word in the sequence. Word generation interfered with MOT performance, but shadowing did not. The data indicate that telephone conversation disrupts attention at a central stage, the act of generating verbal stimuli, rather than at a peripheral stage, such as listening or speaking

Cellular and molecular changes and immune response in the intestinal mucosa during Trichinella spiralis early infection in rats

Background:: The main targets of the host's immune system in Trichinella spiralis infection are the adult worms (AW), at the gut level, and the migrant or newborn larvae (NBL), at systemic and pulmonary levels. Most of the studies carried out in the gut mucosa have been performed on the Payer's patches and/or the mesenteric lymph nodes but not on the lamina propria, therefore, knowledge on the gut immune response against T. spiralis remains incomplete. Methods: This study aimed at characterizing the early mucosal immune response against T. spiralis, particularly, the events taking place between 1 and 13 dpi. For this purpose, Wistar rats were orally infected with muscle larvae of T. spiralis and the humoral and cellular parameters of the gut immunity were analysed, including the evaluation of the ADCC mechanism exerted by lamina propria cells. Results: A marked inflammation and structural alteration of the mucosa was found. The changes involved an increase in goblet cells, eosinophils and mast cells, and B and T lymphocytes, initially displaying a Th1 profile, characterised by the secretion of IFN-γand IL-12, followed by a polarization towards a Th2 profile, with a marked increase in IgE, IgG1, IL-4, IL-5 and IL-13 levels, which occurred once the infection was established. In addition, the helminthotoxic activity of lamina propria cells demonstrated the role of the intestine as a place of migrant larvae destruction, indicating that not all the NBLs released in the gut will be able to reach the muscles. Conclusions: The characterization of the immune response triggered in the gut mucosa during T. spiralis infection showed that not only an effector mechanism is directed toward the AW but also towards the NBL as a cytotoxic activity was observed against NBL exerted by lamina propria cells.Fil: Saracino, María Priscila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Vila, Cecilia Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Cohen, Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Gentilini, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Falduto, Guido Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Calcagno, Marcela Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Roux, Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Venturiello, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Malchiodi, Emilio Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentin

"I'm not being rude, I'd want somebody normal" Adolescents' perception of their peers with Tourette's syndrome; an exploratory study

Background: Tourette’s syndrome (TS) is a highly stigmatised condition, and typically developing adolescents’ motives and reason for excluding individuals with TS have not been examined. Aims: The aim of the study was to understand how TS is conceptualised by adolescents and explore how individuals with TS are perceived by their typically developing peers. Method: Free text writing and focus groups were used to elicit the views of twenty-two year ten students from a secondary school in South East England. Grounded theory was used to develop an analytical framework. Result: Participants’ understanding about the condition was construed from misconceptions, unfamiliarity and unanswered questions. Adolescents who conceived TS as a disorder beyond the individual’s control perceived their peers as being deprived of agency and strength and as straying from the boundaries of normalcy. People with TS were viewed as individuals deserving pity, and in need of support. Although participants maintained they had feelings of social politeness towards those with TS, they would avoid initiating meaningful social relationships with them due to fear of “social contamination”. Intergroup anxiety would also inhibit a close degree of social contact. Participants that viewed those with TS as responsible for their condition expressed a plenary desire for social distance. However, these behavioural intentions were not limited to adolescents that elicited inferences of responsibility to people with TS, indicating that attributional models of stigmatisation may be of secondary importance in the case of TS. Implications for interventions to improve school belonging among youths with TS are discussed

Standardization of the NEO-PI-3 in the Greek general population

BACKGROUND: The revised NEO Personality Inventory (NEO-PI-3) includes 240 items corresponding to the Big Five personality traits (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) and subordinate dimensions (facets). It is suitable for use with adolescents and adults (12 years or older). The aim of the current study was to validate the Greek translation of the NEO-PI-3 in the general Greek population. MATERIAL AND METHODS: The study sample included 734 subjects from the general Greek population of whom 59.4% were females and 40.6% males aged 40.80 +/- 11.48. The NEO-PI-3 was translated into Greek and back-translated into English, and the accuracy of the translation was confirmed and established. The statistical analysis included descriptive statistics, confirmatory factorial analysis (CFA), the calculation of Cronbach's alpha, and the calculation of Pearson product-moment correlations. Sociodemographics groups were compared by ANOVA. RESULTS: Most facets had Cronbach's alpha above 0.60. Confirmatory factor analysis showed acceptable loading of the facets on their own hypothesized factors and very good estimations of Cronbach's alphas for the hypothesized factors, so it was partially supportive of the five-factor structure of the NEO-PI-3.The factors extracted with Procrustes rotation analysis can be considered reasonably homologous to the factors of the American normative sample. Correlations between dimensions were as expected and similar to those reported in the literature. DISCUSSION: The literature suggests that overall, the psychometric properties of NEO-PI-3 scales have been found to generalize across ages, cultures, and methods of measurement. In accord with this, the results of the current study confirm the reliability of the Greek translation and adaptation of the NEO-PI-3. The inventory has comparable psychometric properties in its Greek version in comparison to the original and other national translations, and it is suitable for clinical as well as research use

EphA3 Expressed in the Chicken Tectum Stimulates Nasal Retinal Ganglion Cell Axon Growth and Is Required for Retinotectal Topographic Map Formation

BACKGROUND: Retinotopic projection onto the tectum/colliculus constitutes the most studied model of topographic mapping and Eph receptors and their ligands, the ephrins, are the best characterized molecular system involved in this process. Ephrin-As, expressed in an increasing rostro-caudal gradient in the tectum/colliculus, repel temporal retinal ganglion cell (RGC) axons from the caudal tectum and inhibit their branching posterior to their termination zones. However, there are conflicting data regarding the nature of the second force that guides nasal axons to invade and branch only in the caudal tectum/colliculus. The predominant model postulates that this second force is produced by a decreasing rostro-caudal gradient of EphA7 which repels nasal optic fibers and prevents their branching in the rostral tectum/colliculus. However, as optic fibers invade the tectum/colliculus growing throughout this gradient, this model cannot explain how the axons grow throughout this repellent molecule. METHODOLOGY/PRINCIPAL FINDINGS: By using chicken retinal cultures we showed that EphA3 ectodomain stimulates nasal RGC axon growth in a concentration dependent way. Moreover, we showed that nasal axons choose growing on EphA3-expressing cells and that EphA3 diminishes the density of interstitial filopodia in nasal RGC axons. Accordingly, in vivo EphA3 ectodomain misexpression directs nasal optic fibers toward the caudal tectum preventing their branching in the rostral tectum. CONCLUSIONS: We demonstrated in vitro and in vivo that EphA3 ectodomain (which is expressed in a decreasing rostro-caudal gradient in the tectum) is necessary for topographic mapping by stimulating the nasal axon growth toward the caudal tectum and inhibiting their branching in the rostral tectum. Furthermore, the ability of EphA3 of stimulating axon growth allows understanding how optic fibers invade the tectum growing throughout this molecular gradient. Therefore, opposing tectal gradients of repellent ephrin-As and of axon growth stimulating EphA3 complement each other to map optic fibers along the rostro-caudal tectal axis