A critical role for the T cell receptor alpha-chain connecting peptide domain in positive selection of CD1-independent NKT cells.

Natural killer T (NKT) cells are a subset of mature alpha beta TCR(+) cells that co-express NK lineage markers. Whereas most NKT cells express a canonical Valpha14/Vbeta8.2 TCR and are selected by CD1d, a minority of NKT cells express a diverse TCR repertoire and develop independently of CD1d. Little is known about the selection requirements of CD1d-independent NKT cells. We show here that NKT cells develop in RAG-deficient mice expressing an MHC class II-restricted transgenic TCR (Valpha2/Vbeta8.1) but only under conditions that lead to negative selection of conventional T cells. Moreover development of NKT cells in these mice is absolutely dependent upon an intact TCR alpha-chain connecting peptide domain, which is required for positive selection of conventional T cells via recruitment of the ERK signaling pathway. Collectively our data demonstrate that NKT cells can develop as a result of high avidity TCR/MHC class II interactions and suggest that common signaling pathways are involved in the positive selection of CD1d-independent NKT cells and conventional T cells.

Acceso a la propiedad y desigualdad social en el mundo rural catalán de mediados del siglo XIX

El análisis de la distribución de la propiedad de la tierra —y de las consecuencias sociales de ésta— entraña dificultades heurísticas y metodológicas importantes que suelen limitar la posibilidad de establecer comparaciones territoriales suficientemente sólidas y sistemáticas. Dicho análisis es difícilmente asumible a partir de aquellas estadísticas fiscales y catastrales que presentan los datos agregados y, por ello, ofrecen mayor cobertura territorial. Un acercamiento más realista y con mayor potencial sólo es posible combinando prospecciones locales en distintos ámbitos territoriales, en los cuales sea posible la identificación nominal tanto de los habitantes como de los propietarios de tierra usando simultáneamente padrones de población y relaciones catastrales. La presente comunicación pretende desarrollar un enfoque metodológico basado en el análisis de casos locales con el objetivo de analizar comparativamente el nivel de desigualdad social existente en la sociedad rural catalana de mediados del siglo XIX.

How critical is timing for the diagnosis of influenza in general practice?

Résumé La performance diagnostic des signes et symptômes de la grippe a principalement été étudiée dans le cadre d'études contrôlées avec des critères d'inclusion stricts. Il apparaît nécessaire d'évaluer ces prédicteurs dans le cadre d'une consultation ambulatoire habituelle en tenant compte du délai écoulé entre le début des symptômes et la première consultation ainsi que la situation épidémiologique. Cette étude prospective a été menée à la Policlinique Médicale Universitaire durant l'hiver 1999-2000. Les patients étaient inclus s'ils présentaient un syndrome grippal et si le praticien suspectait une infection à Influenza. Le médecin administrait un questionnaire puis une culture d'un frottis de gorge était réalisée afin de documenter l'infection. 201 patients ont été inclus dans l'étude. 52% avaient une culture positive pour Influenza. En analyse univariée, une température > 37.8° (OR 4.2; 95% CI 2.3-7.7), une durée des symptômes < 48h (OR 3.2; 1.8-5.7), une toux (OR 3.2; 1-10.4) et des myalgies (OR 2.8; 1.0-7.5) étaient associés au diagnostic de grippe. En analyse de régression logistique, le modèle le plus performant qui prédisait la grippe était l'association d'une durée des symptômes <48h, une consultation en début d'épidémie, une température > 37.8° et une toux (sensibilité 79%, spécificité 69%, valeur prédictive positive 67%, une valeur prédictive négative de 73% et aire sous la courbe (ROC) de 0.74). En plus des signes et symptômes prédicteurs de la grippe, le médecin de premier recours devrait prendre en compte dans son jugement la durée des symptômes avant la première consultation et le contexte épidémiologique (début, pic, fin de l'épidémie), car ces deux paramètres modifient considérablement la valeurs des prédicteurs lors de l'évaluation de la probabilité clinique d'un patient d'avoir une infection à Influenza.

La Societat rural de les riberes del Xúquer davant la inundació de 1864

Entre el quatre i el cinc de novembre del 1864 la vall baixa del Xúquer va patir la major inundació del segle i una de les més greus de les que es tenen registre històric. En 1864 el volum d’aigua desbordada, reflectit en l'altura inundada en diferents punts de referència, va ultrapassar el d'anteriors revingudes. A més, per l’extensió invadida i el nombre de localitats i de població afectades (les Riberes reunien 95.000 habitants i a la resta de la zona implicada vivien 88.000 persones més) l'episodi va constituir una de les majors catàstrofes naturals en Espanya durant aquell segle. Un fet diferencial destacat és que la inundació de 1864 s’esdevenia en una etapa històrica nova. La construcció de l’Estat liberal es podia considerar culminada a la dècada dels seixanta,encara que les disensions internes entre les èlits polítiques i el descontent social creixien i estaven a prop de provocar la ruptura de 1868.

Mejora del medio ambiente y nivel de desarrollo: elementos explicativos de las diferentes opciones en los programas de desarrollo rural (2007-2013) de la Unión Europea

Los programas de desarrollo rural del actual período de programación (2007-13) se han estructurado en 4 ejes. El eje 2 correspondiente a la Mejora del medio ambiente y del entorno rural es, con casi la mitad de los recursos públicos, el principal. El objetivo de este artículo es estudiar los elementos que explican los diferentes niveles de gasto adjudicados a este eje, que oscilan entre el 82,5% y el 25% del gasto público total según Estado Miembro. Se aprecia que el nivel de gasto en el eje 2 está correlacionado con el nivel de renta pero no guarda relación alguna con los indicadores que la Comisión Europea ha establecido en la priorización del la problemática e interés agroambiental de los diferentes territorios europeos.

Screening for elevated blood pressure in children and adolescents: a critical appraisal.

Although screening for elevated blood pressure (BP) in adults is beneficial, evidence of its beneficial effects in children is not clear. Elevated BP in children is associated with atherosclerosis early in life and tracks across the life course. However, because of the high variability in BP, tracking is weak, and having an elevated BP in childhood has a low predictive value for having elevated BP later in life. The absolute risk of cardiovascular diseases associated with a given level of BP in childhood and the long-term effect of treatment beginning in childhood are not known. No study has experimentally evaluated the benefits and harm of BP screening in children. One modeling study indicates that BP screen-and-treat strategies in adolescents are moderately cost-effective but less cost-effective than population-wide interventions to decrease BP for the reduction of coronary heart diseases. The US National Heart, Lung, and Blood Institute and the European Society of Hypertension recommend that children 3 years of age and older have their BP measured during every health care visit. According to the US Preventive Services Task Force, there is no sufficient evidence to recommend for or against screening, but their recommendations have to be updated. Whether the benefits of universal BP screening in children outweigh the harm has to be determined. Studies are needed to assess the absolute risk of cardiovascular diseases associated with elevated BP in childhood, to evaluate how to simplify the identification of elevated BP, to evaluate the long-term benefits and harm of treatment beginning in childhood, and to compare universal and targeted screening strategies.

Epidemiological Characteristics of Schistosoma mansoni Infection in Rural and Urban Endemic Areas of Minas Gerais, Brazil

To compare the epidemiological profile and socioeconomic factors associated to the infection by Schistosoma mansoni in a rural and an urban endemic area a cross-sectional study was performed in Água Branca de Minas (rural area) and Bela Fama (urban area), both situated in the State of Minas Gerais, Brazil. Two hundred and eighty eight individuals were surveyed in the rural area and 787 in the urban area. Water contact and socioeconomic questionnaires were used to identify risk factors for the infection. The prevalences of 38.8% and 9.7% and the geometric mean of eggs per gram of faeces of 117.8 and 62.3 were found in the rural and urban areas, respectively. By multivariate statistical analysis age groups over nine years old and previous specific treatment were associated with the infection in rural area. In urban area age over nine years old, low quality housing, weekly fishing and swimming were associated after adjustment by logistic regression

Factors Involved in Schistosoma mansoni Infection, in Rural Areas of Northeast Brazil

Two contiguous villages in Tracunhaém county (State of Pernambuco), endemic for schistosomiasis, were studied: Itapinassu (138 inhabitants) and São Joaquim (91 inhabitants). Agriculture predominates in the former region while ceramics is the main activity in the latter. Although no statistical difference was found regarding prevalence, severe infection (>400 epg) predominated in Itapinassu, probably related to the kind of occupation. No association was found between parasite burden and severity of disease, in spite of the high infection rates for Schistosoma mansoni in both communities (approx. 60%). Typical epidemiological features of schistosomiasis such as age-related prevalences and intensities of infection (high in children, low in adults) were also mutual characteristics. Nutritional status determined through anthropometric evaluation was carried out by measuring specific anthropometric indicators. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies were detected. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9% in Itapinassu and 24.1% in São Joaquim. In this group an association was found between prevalence of schistosomiasis and chronic undernutrition. Similarly, for patients over 18 year old the prevalence of undernutrition was higher than 20%. However, in this case no association between nutritional status and either prevalence of schistosomiasis or parasite burden could be detected. The two communities had not been treated for eight years.

Prevalence of Helicobacter pylori Infection in a Rural Area of the State of Mato Grosso, Brazil

The prevalence of Helicobacter pylori infection was evaluated by ELISA in 40 children and teenagers and in 164 adults from a rural area of the State of Mato Grosso, Brazil. Antibodies to H. pylori were detected in the serum of 31 (77.5%) children and teenagers and in 139 (84.7%) adults. The prevalence of infection increased with age (c2 for trend, p < 0.01) even though no variations occurred in the region in the present century in terms of living conditions or sanitation, economical development and migratory influx supporting the hypothesis that the infection is also acquired during later life in developing countries. An inverse correlation was observed between the prevalence of infection and annual family income (c2 for trend, p < 0.013). There was no correlation between type of system for sewage disposal and prevalence of infection (p = 0.8). In conclusion, the prevalence of H. pylori infection in Nossa Senhora do Livramento, a rural area from Brazil, is very high and similar to that observed in other developing countries. Furthermore, the increase in the prevalence of infection with age observed in this population seems to be due to both, cohort effect and acquisition of the infection during later life

A Many-to-many 'rural hospital theorem'

We show that the full version of the so-called 'rural hospital theorem' (Roth, 1986) generalizes to many-to-many matching where agents on both sides of the market have separable and substitutable preferences.

La llengua de l'enemic com a llengua pròpia: cultures translatives del paisatge indígena nord-americà

This research paper seeks to bring into view the present-day situation of Native-American narrative in English. It is divided into four chapters. The first deals with the emergence of what we might call a Native-American narrative style and its evolution from 1900 up until its particularly forceful expression in 1968 with the appearance of N. Scott Momaday’s novel House Made of Dawn. To trace this evolution, we follow the chronology set forth by Paula Gunn Allen in her anthology Voice of the Turtle: American Indian Literature 1900-1970. In the second chapter we hear various voices from contemporary Native-American literary production as we follow Simon J. Ortiz’s anthology Speaking for the Generations: Native Writers on Writing. Noteworthy among these are Leslie Marmon Silko and Gloria Bird, alongside new voices such as those of Esther G. Belin and Daniel David Moses, and closing with Guatemalan-Mayan Victor D. Montejo, exiled in the United States. These writers’ contributions gravitate around two fundamental notions: the interdependence between human beings and the surrounding landscape, and the struggle for survival, which of necessity involves the deconstruction of the (post-)colonial subject. The third chapter deals with an anthology of short stories and poems by present-day Native-American women writers, edited by Joy Harjo and Gloria Bird and entitled Reinventing the Enemy’s Language: Contemporary Native Women’s Writings of North America. It too exemplifies personal and cultural reaffirmation on a landscape rich in ancestral elements, but also where one’s own voice takes shape in the language which, historically, is that of the enemy. In the final chapter we see how translation studies provide a critical perspective and fruitful reflection on the literary production of Native-American translative cultures, where a wide range of writers struggle to bring about the affirmative deconstruction of the colonialised subject. Thus there comes a turnaround in the function of the “enemy’s language,” giving rise also to the question of cultural incommensurability.

Schistosomiasis control based on repeated chemotherapy in a rural village of the sugar-cane zone in Northeast Brazil

A schedule of repeated chemotherapy with oxamniquine, consisting of biannual treatment of school-aged (7-13 years) children and annual treatment of all other age groups, was used in a representative rural village from a highly endemic area of schistosomiasis in Pernambuco. Significant reductions in infection were obtained only after two cycles of treatment, as the overall prevalence decreased from 72.6% to 41.7% and the geometric mean egg counts per gram of faeces among positives fell from 188.4 to 76. In a school-aged cohort (n=29) three treatments at six-month intervals were necessary to significantly reduce the proportion of positives (from 75.9% to 51.7%). In a cohort of children under 7 years of age (n=20) the proportion of positives actually increased (from 30% to 45%) despite two annual treatments. Water contact was intense and host snail density was relatively high. As there is no short-term perspective of improved sanitation, auxiliary measures such as focal mollusciciding are needed for an adequate control of schistosomiasis in this and alike areas.

The nuclear matrix: a critical appraisal.

It is becoming increasingly clear that the cell nucleus is a highly structurized organelle. Because of its tight compartmentalization, it is generally believed that a framework must exist, responsible for maintaining such a spatial organization. Over the last twenty years many investigations have been devoted to identifying the nuclear framework. Structures isolated by different techniques have been obtained in vitro and are variously referred to as nuclear matrix, nucleoskeleton or nuclear scaffold. Many different functions, such as DNA replication and repair, mRNA transcription, processing and transport have been described to occur in close association with these structures. However, there is still much debate as to whether or not any of these preparations corresponds to a nuclear framework that exists in vivo. In this article we summarize the most commonly-used methods for obtaining preparations of nuclear frameworks and we also stress the possible artifacts that can be created in vitro during the isolation procedures. Emphasis is placed also on the protein composition of the frameworks as well as on some possible signalling functions that have been recently described to occur in tight association with the nuclear matrix.

T cell receptor specificity is critical for the development of epidermal gammadelta T cells.

A particular feature of gammadelta T cell biology is that cells expressing T cell receptor (TCR) using specific Vgamma/Vdelta segments are localized in distinct epithelial sites, e.g., in mouse epidermis nearly all gammadelta T cells express Vgamma3/Vdelta1. These cells, referred to as dendritic epidermal T cells (DETC) originate from fetal Vgamma3+ thymocytes. The role of gammadelta TCR specificity in DETC's migration/localization to the skin has remained controversial. To address this issue we have generated transgenic (Tg) mice expressing a TCR delta chain (Vdelta6.3-Ddelta1-Ddelta2-Jdelta1-Cdelta), which can pair with Vgamma3 in fetal thymocytes but is not normally expressed by DETC. In wild-type (wt) Vdelta6.3Tg mice DETC were present and virtually all of them express Vdelta6.3. However, DETC were absent in TCR-delta(-/-) Vdelta6.3Tg mice, despite the fact that Vdelta6.3Tg gammadelta T cells were present in normal numbers in other lymphoid and nonlymphoid tissues. In wt Vdelta6.3Tg mice, a high proportion of in-frame Vdelta1 transcripts were found in DETC, suggesting that the expression of an endogenous TCR-delta (most probably Vdelta1) was required for the development of Vdelta6.3+ epidermal gammadelta T cells. Collectively our data demonstrate that TCR specificity is essential for the development of gammadelta T cells in the epidermis. Moreover, they show that the TCR-delta locus is not allelically excluded.