PRELIMINARY REPORT ON THE PUTATIVE ASSOCIATION OF IL10 -3575 T/A GENETIC POLYMORPHISM WITH MALARIA SYMPTOMS

Only a small percentage of individuals living in endemic areas develop severe malaria suggesting that host genetic factors may play a key role. This study has determined the frequency of single nucleotide polymorphisms (SNPs) in some pro and anti-inflammatory cytokine gene sequences: IL6 (-174; rs1800795), IL12p40 (+1188; rs3212227), IL4 (+33; rs2070874), IL10 (-3575; rs1800890) and TGFb1 (+869; rs1800470), by means of PCR-RFLP. Blood samples were collected from 104 symptomatic and 37 asymptomatic subjects. Laboratory diagnosis was assessed by the thick blood smear test and nested-PCR. No association was found between IL6 (-174), IL12p40 (+1188), IL4 (+33), IL10 (- 3575), TGFb1 (+869) SNPs and malaria symptoms. However, regarding the IL10 -3575 T/A SNP, there were significantly more AA and AT subjects, carrying the polymorphic allele A, in the symptomatic group (c2 = 4.54, p = 0.01, OR = 0.40 [95% CI - 0.17- 0.94]). When the analysis was performed by allele, the frequency of the polymorphic allele A was also significantly higher in the symptomatic group (c2 = 4.50, p = 0.01, OR = 0.45 [95% CI - 0.21-0.95]). In conclusion, this study has suggested the possibility that the IL10 - 3575 T/A SNP might be associated with the presence and maintenance of malaria symptoms in individuals living in endemic areas. Taking into account that this polymorphism is related to decreased IL10 production, a possible role of this SNP in the pathophysiology of malaria is also suggested, but replication studies with a higher number of patients and evaluation of IL10 levels are needed for confirmation

Genome-Wide Crossover Distribution in Arabidopsis thaliana Meiosis Reveals Sex-Specific Patterns along Chromosomes

In most species, crossovers (COs) are essential for the accurate segregation of homologous chromosomes at the first meiotic division. Their number and location are tightly regulated. Here, we report a detailed, genome-wide characterization of the rate and localization of COs in Arabidopsis thaliana, in male and female meiosis. We observed dramatic differences between male and female meiosis which included: (i) genetic map length; 575 cM versus 332 cM respectively; (ii) CO distribution patterns: male CO rates were very high at both ends of each chromosome, whereas female CO rates were very low; (iii) correlations between CO rates and various chromosome features: female CO rates correlated strongly and negatively with GC content and gene density but positively with transposable elements (TEs) density, whereas male CO rates correlated positively with the CpG ratio. However, except for CpG, the correlations could be explained by the unequal repartition of these sequences along the Arabidopsis chromosome. For both male and female meiosis, the number of COs per chromosome correlates with chromosome size expressed either in base pairs or as synaptonemal complex length. Finally, we show that interference modulates the CO distribution both in male and female meiosis

The Origins of Lactase Persistence in Europe

Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (−13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the −13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model where lactase persistence is only favoured in cultures practicing dairying, and dairying is more favoured in lactase persistent populations. We have developed a flexible demic computer simulation model to explore the spread of lactase persistence, dairying, other subsistence practices and unlinked genetic markers in Europe and western Asia's geographic space. Using data on −13,910*T allele frequency and farming arrival dates across Europe, and approximate Bayesian computation to estimate parameters of interest, we infer that the −13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe. Furthermore, our results suggest that natural selection favouring a lactase persistence allele was not higher in northern latitudes through an increased requirement for dietary vitamin D. Our results provide a coherent and spatially explicit picture of the coevolution of lactase persistence and dairying in Europe

Asymmetric reproductive isolation between terminal forms of the salamander ring species Ensatina eschscholtzii revealed by fine-scale genetic analysis of a hybrid zone

<p>Abstract</p> <p>Background</p> <p>Ring species, exemplified by salamanders of the <it>Ensatina eschscholtzii </it>complex, represent a special window into the speciation process because they allow the history of species formation to be traced back in time through the geographically differentiated forms connecting the two terminal forms of the ring. Of particular interest is the nature and extent of reproductive isolation between the geographically terminal forms, in this case <it>E. e. eschscholtzii </it>and <it>E. e. klauberi</it>. Previous studies have documented infrequent hybridization at the end of the ring. Here, we report the first fine-scale genetic analysis of a hybrid zone between the terminal forms in southern California using individual-based Bayesian analyses of multilocus genetic data to estimate levels and direction of hybridization and maximum-likelihood analysis of linkage disequilibrium and cline shape to make inferences about migration and selection in the hybrid zone.</p> <p>Results</p> <p>The center of the hybrid zone has a high proportion of hybrids, about half of which were classified as F1s. Clines are narrow with respect to dispersal, and there are significant deviations from Hardy-Weinberg equilibrium as well as nonrandom associations (linkage disequilibria) between alleles characteristic of each parental type. There is cytonuclear discordance, both in terms of introgression and the geographic position of mitochondrial versus nuclear clines. Genetic disequilibrium is concentrated on the <it>eschscholtzii </it>side of the zone. Nearly all hybrids possess <it>klauberi </it>mtDNA, indicating that most hybrids are formed from female <it>klauberi </it>mating with male <it>eschscholtzii </it>or male hybrids (but not vice versa).</p> <p>Conclusions</p> <p>Our results are consistent with a tension zone trapped at an ecotone, with gene combinations characteristic of <it>klauberi </it>showing up on the <it>eschscholtzii </it>side of the zone due to asymmetric hybridization. We suggest that the observed asymmetry is best explained by increased discriminatory power of <it>eschscholtzii </it>females, or asymmetric postzygotic isolation. The relatively high frequency of hybrids, particularly F1s, contrasts with other contacts between the terminal forms, and with other contacts between other divergent <it>Ensatina </it>lineages, highlighting the diverse outcomes of secondary contact within a single species complex.</p

Construction and validation of nursing diagnoses for people in palliative care

Objetivo: construir e validar diagnósticos de enfermagem para pessoas em cuidados paliativos, fundamentados no Modelo de Cuidados para Preservação da Dignidade e na Classificação Internacional para a Prática de Enfermagem. Método: estudo metodológico operacionalizado em duas etapas: 1) construção do banco de termos relevantes, clínica e culturalmente, para a assistência de enfermagem à pessoa em cuidados paliativos e 2) construção de diagnósticos de enfermagem a partir do banco de termos, com base nas diretrizes do Conselho Internacional de Enfermeiros. Resultados: os 262 termos validados constituíram um banco de termos a partir do qual foram desenvolvidos 56 diagnósticos de enfermagem. Desses, 33 foram validados por um grupo de 26 peritos, e classificados nas três categorias do Modelo de Cuidados para Preservação da Dignidade: preocupações relacionadas com a doença (21); repertório de conservação da dignidade (9); inventário da dignidade social (3). Conclusão: dos 33 diagnósticos validados, 18 deles poderão ser incluídos na atualização do Catálogo da Classificação Internacional para a Prática de Enfermagem - cuidados paliativos para uma morte digna. O estudo contribui para subsidiar o enfermeiro no raciocínio clínico e na tomada de decisão.Objetivo: construir y validar diagnósticos de enfermería para personas en cuidados paliativos, fundamentados en el Modelo de Cuidados para Preservación de la Dignidad y en la Clasificación Internacional para la Práctica de Enfermería. Método: estudio metodológico operacionalizado en dos etapas: 1) construcción del banco de términos relevantes, clínicamente y culturalmente, para la asistencia de enfermería a la persona en cuidados paliativos y 2) construcción de diagnósticos de enfermería a partir del banco de términos, con base en las directrices del Consejo Internacional de Enfermeros. Resultados: los 262 términos validados constituyeron un banco de términos a partir del cual fueron desarrollados 56 diagnósticos de enfermería. De esos, 33 fueron validados por un grupo de 26 peritos, y clasificados en las tres categorías del Modelo de Cuidados para Preservación de la Dignidad: preocupaciones relacionadas con la enfermedad (21); repertorio de conservación de la dignidad (9); inventario de la dignidad social (3). Conclusión: de los 33 diagnósticos validados, 18 de ellos podrán ser incluidos en la actualización del Catálogo de la Clasificación Internacional para la Práctica de Enfermería - cuidados paliativos para una muerte digna. El estudio contribuye para auxiliar al enfermero en el raciocinio clínico y en la toma de decisiones.Objective: to construct and validate nursing diagnoses for people in palliative care based on the Dignity-Conserving Care Model and the International Classification for Nursing Practice. Method: a two-stage methodological study: 1) construction of the database of clinically and culturally relevant terms for the nursing care for people in palliative care and 2) construction of nursing diagnoses from the database of terms, based on the guidelines of the International Council of Nurses. Results: the 262 terms validated constituted a database of terms from which 56 nursing diagnoses were developed. Of these, 33 were validated by a group of 26 experts, and classified in the three categories of the Dignity-Conserving Care Model: illness-related concerns (21); dignity-conserving repertoire (9); and social dignity inventory (3). Conclusion: of the 33 validated diagnoses, 18 of them could be included in the update of the Catalog of the International Classification for Nursing Practice - palliative care for a dignified death. The study contributes to support the clinical reasoning and decision making of the nurse