649 research outputs found

    Population differences in allele frequencies at the OLR1 locus may suggest geographic disparities in cardiovascular risk events.

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    Abstract Background: Several studies have demonstrated a link between cardiovascular disease (CVD) susceptibility and the genetic background of populations. Endothelial activation and dysfunction induced by oxidized low-density lipoprotein (ox-LDL) is one of the key steps in the initiation of atherosclerosis. The oxidized low density lipoprotein (lectin-like) receptor 1 (OLR1) gene is the main receptor of ox-LDL. We have previously characterized two polymorphisms (rs3736235 and rs11053646) associated with the risk for coronary artery disease (CAD) and acute myocardial infarction (AMI). Aim: Given their clinical significance, it is of interest to know the distribution of these variants in populations from different continents. Subjects and methods: A total of 1229 individuals from 17 different African, Asian and European populations was genotyped for the two considered markers. Results: The high frequencies of ancestral alleles in South-Saharan populations is concordant with the African origin of our species. The results highlight that African populations are closer to Asians, and clearly separated from the Europeans. Conclusion: The results confirm significant genetic structuring among populations and suggest a possible basis for varying susceptibility to CVD among groups correlated with the geographical location of populations linked with the migrations out of Africa, or with different lifestyle

    16(th) IHIW: population global distribution of killer immunoglobulin-like receptor (KIR) and ligands.

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    In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide. However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels. Here, we present a summary of the collection of KIR gene-content data for 105 worldwide populations collected as part of the 15th and 16th International Histocompatibility and Immunogenetics Workshops, and preliminary results for data analysis

    Increased frequency of the immunoglobulin enhancer HS1,2 allele 2 in coeliac disease

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    Background: Coeliac disease ( CD) is characterized by increased immunological responsiveness to ingested gliadin in genetically predisposed individuals. This genetic predisposition is not completely defined. A dysregulation of immunoglobulins (Ig) is present in CD: since antiendomysium antibodies (anti-EMA) are of the IgA class. One polymorphic enhancer within the locus control region (LCR) of the immunoglobulin heavy chain cluster at the 3' of the C alpha-1 gene was investigated. The correlation of the penetrance of the four different alleles of the HS1,2-A enhancer of the LCR-1 3' to C alpha-1 in CD patients compared to a control population was analysed. Methods: A total of 115 consecutive CD outpatients, on a gluten-free diet, and 248 healthy donors, age- and sex-matched, from the same geographical area were enrolled in the study. HS1,2-A allele frequencies were investigated by nested polymerase chain reaction (PCR). Results: The frequency of allele 2 of the enhancer HS1,2-A gene was increased by 30.8% as compared to the control frequency. The frequency of homozygosity for allele 2 was significantly increased in CD patients. Crude odds ratio ( OR) showed that those with 2/2 and 2/4 ( OR 2.63, P < 0.001 and OR 2.01, P = 0.03) have a significantly higher risk of developing the disease. In contrast, allele 1/2 may represent a protective genetic factor against CD ( OR 0.52, P = 0.01). Conclusions: These data provide further evidence of a genetic predisposition in CD. Because of the Ig dysregulation in CD, the enhancer HS1,2-A may be involved in the pathogenesis

    Mitochondrial echoes of first settlement and genetic continuity in El Salvador

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    Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador. Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas. Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade

    How does diet influence our lives? Evaluating the relationship between isotopic signatures and mortality patterns in italian roman imperial and medieval periods

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    The present research investigates the relationship between dietary habits and mortality patterns in the Roman Imperial and Medieval periods. The reconstructions of population dynamics and subsistence strategies provide a fascinating source of information for understanding our history. This is particularly true given that the changes in social, economic, political, and religious aspects related to the transition from the Roman period to the Middle Ages have been widely discussed. We analyzed the isotopic and mortality patterns of 616 individuals from 18 archeological sites (the Medieval Latium sites of Colonna, Santa Severa, Allumiere, Cencelle, and 14 Medieval and Imperial funerary contexts from Rome) to compile a survivorship analysis. A semi-parametric approach was applied, suggesting variations in mortality patterns between sexes in the Roman period. Nitrogen isotopic signatures influenced mortality in both periods, showing a quadratic and a linear effect for Roman Imperial and Medieval populations, respectively. No influence of carbon isotopic signatures has been detected for Roman Imperial populations. Conversely, increased mortality risk for rising carbon isotopic values was observed in Medieval samples

    Bioarchaeological and palaeogenomic portrait of two Pompeians that died during the eruption of Vesuvius in 79 AD

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    The archaeological site of Pompeii is one of the 54 UNESCO World Heritage sites in Italy, thanks to its uniqueness: the town was completely destroyed and buried by a Vesuvius’ eruption in 79 AD. In this work, we present a multidisciplinary approach with bioarchaeological and palaeogenomic analyses of two Pompeian human remains from the Casa del Fabbro. We have been able to characterize the genetic profle of the frst Pompeian’ genome, which has strong afnities with the surrounding central Italian population from the Roman Imperial Age. Our fndings suggest that, despite the extensive connection between Rome and other Mediterranean populations, a noticeable degree of genetic homogeneity exists in the Italian peninsula at that time. Moreover, palaeopathological analyses identifed the presence of spinal tuberculosis and we further investigated the presence of ancient DNA from Mycobacterium tuberculosis. In conclusion, our study demonstrates the power of a combined approach to investigate ancient humans and confrms the possibility to retrieve ancient DNA from Pompeii human remains. Our initial fndings provide a foundation to promote an intensive and extensive paleogenetic analysis in order to reconstruct the genetic history of population from Pompeii, a unique archaeological site

    Can improving working memory prevent academic difficulties? A school based randomised controlled trial.

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    BACKGROUND: Low academic achievement is common and is associated with adverse outcomes such as grade repetition, behavioural disorders and unemployment. The ability to accurately identify these children and intervene before they experience academic failure would be a major advance over the current 'wait to fail' model. Recent research suggests that a possible modifiable factor for low academic achievement is working memory, the ability to temporarily store and manipulate information in a 'mental workspace'. Children with working memory difficulties are at high risk of academic failure. It has recently been demonstrated that working memory can be improved with adaptive training tasks that encourage improvements in working memory capacity. Our trial will determine whether the intervention is efficacious as a selective prevention strategy for young children at risk of academic difficulties and is cost-effective. METHODS/DESIGN: This randomised controlled trial aims to recruit 440 children with low working memory after a school-based screening of 2880 children in Grade one. We will approach caregivers of all children from 48 participating primary schools in metropolitan Melbourne for consent. Children with low working memory will be randomised to usual care or the intervention. The intervention will consist of 25 computerised working memory training sessions, which take approximately 35 minutes each to complete. Follow-up of children will be conducted at 6, 12 and 24 months post-randomisation through child face-to-face assessment, parent and teacher surveys and data from government authorities. The primary outcome is academic achievement at 12 and 24 months, and other outcomes include child behaviour, attention, health-related quality of life, working memory, and health and educational service utilisation. DISCUSSION: A successful start to formal learning in school sets the stage for future academic, psychological and economic well-being. If this preventive intervention can be shown to be efficacious, then we will have the potential to prevent academic underachievement in large numbers of at-risk children, to offer a ready-to-use intervention to the Australian school system and to build international research partnerships along the health-education interface, in order to carry our further studies of effectiveness and generalisability.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    How Mitochondrial DNA Can Write Pre-History: Kinship and Culture in Duero Basin (Spain) during Chalcolithic and Bronze Age

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    The chronological period from the beginning of the Chalcolithic Age to the end of the Bronze Age on the Iberian northern sub-plateau of the Iberic Peninsula involves interesting social and cultural phenomena, such as the appearance of the Bell Beaker and, later, the Cogotas I cultures. This work constructs a genetic characterisation of the maternal lineages of the human population that lived on the northern sub-plateau between 5000 and 3000 years ago through an analysis of mitochondrial DNA (mtDNA), a kind of genetic marker that is inherited through maternal lineages, unaltered from generation to generation. Population and cultural questions are investigated through mtDNA analyses. This study intends to shed light on the following questions. Were individuals who were buried together in multiple or collective burials biologically related through their maternal lineages? Were there distinct maternal human lineages in the same or different geographical areas if different material cultures (Bell Beaker and Cogotas I) were associated with the arrival of new human populations who established close biological relationships with the endogenous populations? Or could this be the result of the transmission of knowledge without human populations mixing? Another important question is whether the material cultures were related to the female populations. We analysed 91 individuals from 28 different archaeological sites of the Iberian northern sub-plateau from four different chrono-cultural periods (Pre-Bell Beaker, Bell Beaker, Proto-Cogotas I, and Cogotas I), from the end of the Chalcolithic Age up to the Bronze Age. There were two historical moments of new populations arriving: the first during the Pre-Bell Beaker period, associated with the K mtDNA haplogroup, and the second during the Proto-Cogotas I culture, with new lineages of the H, HVO, and T haplogroups. Neither of these new population flows were directly associated with the maximum development of the two main material cultures Bell Beaker and Cogotas I, so they must have occurred immediately beforehand, during the Pre-Bell Beaker and Proto-Cogotas I periods, respectively. However, we cannot discard an association between the populations and material cultures. Curiously, it has also been observed that there was also a tendency towards multiple burials, in which the individuals who were buried together belonged to the same maternal lineage, during these two periods of population change. This study has shed some light on the populational changes that occurred through these different periods in this specific geographical area of the northern sub-plateau of the Iberian Peninsula
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