350 research outputs found
Body iron metabolism and pathophysiology of iron overload
Iron is an essential metal for the body, while excess iron accumulation causes organ dysfunction through the production of reactive oxygen species. There is a sophisticated balance of body iron metabolism of storage and transport, which is regulated by several factors including the newly identified peptide hepcidin. As there is no passive excretory mechanism of iron, iron is easily accumulated when exogenous iron is loaded by hereditary factors, repeated transfusions, and other diseased conditions. The free irons, non-transferrin-bound iron, and labile plasma iron in the circulation, and the labile iron pool within the cells, are responsible for iron toxicity. The characteristic features of advanced iron overload are failure of vital organs such as liver and heart in addition to endocrine dysfunctions. For the estimation of body iron, there are direct and indirect methods available. Serum ferritin is the most convenient and widely available modality, even though its specificity is sometimes problematic. Recently, new physical detection methods using magnetic resonance imaging and superconducting quantum interference devices have become available to estimate iron concentration in liver and myocardium. The widely used application of iron chelators with high compliance will resolve the problems of organ dysfunction by excess iron and improve patient outcomes
Ancient Migratory Events in the Middle East: New Clues from the Y-Chromosome Variation of Modern Iranians
Knowledge of high resolution Y-chromosome haplogroup diversification within Iran provides important geographic context regarding the spread and compartmentalization of male lineages in the Middle East and southwestern Asia. At present, the Iranian population is characterized by an extraordinary mix of different ethnic groups speaking a variety of Indo-Iranian, Semitic and Turkic languages. Despite these features, only few studies have investigated the multiethnic components of the Iranian gene pool. In this survey 938 Iranian male DNAs belonging to 15 ethnic groups from 14 Iranian provinces were analyzed for 84 Y-chromosome biallelic markers and 10 STRs. The results show an autochthonous but non-homogeneous ancient background mainly composed by J2a sub-clades with different external contributions. The phylogeography of the main haplogroups allowed identifying post-glacial and Neolithic expansions toward western Eurasia but also recent movements towards the Iranian region from western Eurasia (R1b-L23), Central Asia (Q-M25), Asia Minor (J2a-M92) and southern Mesopotamia (J1-Page08). In spite of the presence of important geographic barriers (Zagros and Alborz mountain ranges, and the Dasht-e Kavir and Dash-e Lut deserts) which may have limited gene flow, AMOVA analysis revealed that language, in addition to geography, has played an important role in shaping the nowadays Iranian gene pool. Overall, this study provides a portrait of the Y-chromosomal variation in Iran, useful for depicting a more comprehensive history of the peoples of this area as well as for reconstructing ancient migration routes. In addition, our results evidence the important role of the Iranian plateau as source and recipient of gene flow between culturally and genetically distinct population
Phylogenetic Position of a Copper Age Sheep (Ovis aries) Mitochondrial DNA
BACKGROUND: Sheep (Ovis aries) were domesticated in the Fertile Crescent region about 9,000-8,000 years ago. Currently, few mitochondrial (mt) DNA studies are available on archaeological sheep. In particular, no data on archaeological European sheep are available. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe the first portion of mtDNA sequence of a Copper Age European sheep. DNA was extracted from hair shafts which were part of the clothes of the so-called Tyrolean Iceman or Ötzi (5,350-5,100 years before present). Mitochondrial DNA (a total of 2,429 base pairs, encompassing a portion of the control region, tRNA(Phe), a portion of the 12S rRNA gene, and the whole cytochrome B gene) was sequenced using a mixed sequencing procedure based on PCR amplification and 454 sequencing of pooled amplification products. We have compared the sequence with the corresponding sequence of 334 extant lineages. CONCLUSIONS/SIGNIFICANCE: A phylogenetic network based on a new cladistic notation for the mitochondrial diversity of domestic sheep shows that the Ötzi's sheep falls within haplogroup B, thus demonstrating that sheep belonging to this haplogroup were already present in the Alps more than 5,000 years ago. On the other hand, the lineage of the Ötzi's sheep is defined by two transitions (16147, and 16440) which, assembled together, define a motif that has not yet been identified in modern sheep populations
Plataforma de adquisición y monitoreo para el estudio de las condiciones ambientales externas y de confort en casas prototipo para la validación de un control térmico por medio de un sistema de muro verde y aislante térmico
En la actualidad un tema que ha cobrado gran importancia es el de las fachadas verdes dado que su principal aplicación es para mejorar el confort en las viviendas y el ahorro de energía, debido a que estos se encuentran directamente relacionados con el nivel de vida que se presenta en una casa habitación; aunque existen muchos factores que influyen en la calidad de la vivienda, se considera uno de los más importantes al material con la que ésta construida, porque de este dependen las condiciones ambientales que se generan dentro de la vivienda y que definen la calidad de la vivienda. En este proyecto se implementó un sistema que permite adquirir los diferentes datos de confort obtenidos en un par de casetas experimentales para comparar el efecto que se tiene al colocar un recubrimiento vegetal en la fachada sur a una caseta con respecto a otra a la que no se le colocó. El sistema es capaz de adquirir y transmitir de manera inalámbrica las señales de los sensores de temperatura, humedad y flujo de calor que fueron colocados en ambas casetas. Finalmente, los datos recibidos se procesan en una aplicación desarrollada en MATLAB para analizar y mostrar los datos de cada caseta.Palabra(s) Clave(s): aplicaciones de comunicación inalámbrica, aplicaciones de MATLAB, confort en viviendas, fachadas verdes
Manual del SoftwareIfs Construction kit para generar imágenes que representan fractales mediante sistemas de funciones iteradas
Los últimos avances en matemáticas en el campo de geometría fractal han permitido el surgimiento de una gran variedad de aplicaciones informáticas útiles para la representación de conjuntos fractales. Este trabajo pretende presentar a IFSConstruction Kit como una opción para construir fractales con base en los sistemas de funciones iteradas
Evaluation of Group Genetic Ancestry of Populations from Philadelphia and Dakar in the Context of Sex-Biased Admixture in the Americas
Population history can be reflected in group genetic ancestry, where genomic variation captured by the mitochondrial DNA (mtDNA) and non-recombining portion of the Y chromosome (NRY) can separate female- and male-specific admixture processes. Genetic ancestry may influence genetic association studies due to differences in individual admixture within recently admixed populations like African Americans.We evaluated the genetic ancestry of Senegalese as well as European Americans and African Americans from Philadelphia. Senegalese mtDNA consisted of approximately 12% U haplotypes (U6 and U5b1b haplotypes, common in North Africa) while the NRY haplotypes belonged solely to haplogroup E. In Philadelphia, we observed varying degrees of admixture. While African Americans have 9-10% mtDNAs and approximately 31% NRYs of European origin, these results are not mirrored in the mtDNA/NRY pools of European Americans: they have less than 7% mtDNAs and less than 2% NRYs from non-European sources. Additionally, there is <2% Native American contribution to Philadelphian African American ancestry and the admixture from combined mtDNA/NRY estimates is consistent with the admixture derived from autosomal genetic data. To further dissect these estimates, we have analyzed our samples in the context of different demographic groups in the Americas.We found that sex-biased admixture in African-derived populations is present throughout the Americas, with continual influence of European males, while Native American females contribute mainly to populations of the Caribbean and South America. The high non-European female contribution to the pool of European-derived populations is consistently characteristic of Iberian colonization. These data suggest that genomic data correlate well with historical records of colonization in the Americas
Selenium status is positively associated with bone mineral density in healthy aging European men
Objective It is still a matter of debate if subtle changes in selenium (Se) status affect thyroid function tests (TFTs) and bone mineral density (BMD). This is particularly relevant for the elderly, whose nutritional status is more vulnerable. Design and Methods We investigated Se status in a cohort of 387 healthy elderly men (median age 77 yrs; inter quartile range 75-80 yrs) in relation to TFTs and BMD. Se status was determined by measuring both plasma selenoprotein P (SePP) and Se. Results The overall Se status in our population was low normal with only 0.5% (2/387) of subjects meeting the criteria for Se deficiency. SePP and Se levels were not associated with thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), triiodothyronine (T3) or reverse triiodothyronine (rT3) levels. The T3/T4 and T3/rT3 ratios, reflecting peripheral metabolism of thyroid hormone, were not associated with Se status either. SePP and Se were positively associated with total BMD and femoral trochanter BMD. Se, but not SePP, was positively associated with femoral neck and ward's BMD. Multivariate linear analyses showed that these associations remain statistically significant in a model including TSH, FT4, body mass index, physical performance score, age, smoking, diabetes mellitus and number of medication use. Conclusion Our study demonstrates that Se status, within the normal European marginally supplied range, is positively associated with BMD in healthy aging men, independent of thyroid function. Thyroid function tests appear unaffected by Se status in this population
Stage-Specific Expression Profiling of Drosophila Spermatogenesis Suggests that Meiotic Sex Chromosome Inactivation Drives Genomic Relocation of Testis-Expressed Genes
In Drosophila, genes expressed in males tend to accumulate on autosomes and are underrepresented on the X chromosome. In particular, genes expressed in testis have been observed to frequently relocate from the X chromosome to the autosomes. The inactivation of X-linked genes during male meiosis (i.e., meiotic sex chromosome inactivation—MSCI) was first proposed to explain male sterility caused by X-autosomal translocation in Drosophila, and more recently it was suggested that MSCI might provide the conditions under which selection would favor the accumulation of testis-expressed genes on autosomes. In order to investigate the impact of MSCI on Drosophila testis-expressed genes, we performed a global gene expression analysis of the three major phases of D. melanogaster spermatogenesis: mitosis, meiosis, and post-meiosis. First, we found evidence supporting the existence of MSCI by comparing the expression levels of X- and autosome-linked genes, finding the former to be significantly reduced in meiosis. Second, we observed that the paucity of X-linked testis-expressed genes was restricted to those genes highly expressed in meiosis. Third, we found that autosomal genes relocated through retroposition from the X chromosome were more often highly expressed in meiosis in contrast to their X-linked parents. These results suggest MSCI as a general mechanism affecting the evolution of some testis-expressed genes
Saudi Arabian Y-Chromosome diversity and its relationship with nearby regions
<p>Abstract</p> <p>Background</p> <p>Human origins and migration models proposing the Horn of Africa as a prehistoric exit route to Asia have stimulated molecular genetic studies in the region using uniparental loci. However, from a Y-chromosome perspective, Saudi Arabia, the largest country of the region, has not yet been surveyed. To address this gap, a sample of 157 Saudi males was analyzed at high resolution using 67 Y-chromosome binary markers. In addition, haplotypic diversity for its most prominent J1-M267 lineage was estimated using a set of 17 Y-specific STR loci.</p> <p>Results</p> <p>Saudi Arabia differentiates from other Arabian Peninsula countries by a higher presence of J2-M172 lineages. It is significantly different from Yemen mainly due to a comparative reduction of sub-Saharan Africa E1-M123 and Levantine J1-M267 male lineages. Around 14% of the Saudi Arabia Y-chromosome pool is typical of African biogeographic ancestry, 17% arrived to the area from the East across Iran, while the remainder 69% could be considered of direct or indirect Levantine ascription. Interestingly, basal E-M96* (n = 2) and J-M304* (n = 3) lineages have been detected, for the first time, in the Arabian Peninsula. Coalescence time for the most prominent J1-M267 haplogroup in Saudi Arabia (11.6 ± 1.9 ky) is similar to that obtained previously for Yemen (11.3 ± 2) but significantly older that those estimated for Qatar (7.3 ± 1.8) and UAE (6.8 ± 1.5).</p> <p>Conclusion</p> <p>The Y-chromosome genetic structure of the Arabian Peninsula seems to be mainly modulated by geography. The data confirm that this area has mainly been a recipient of gene flow from its African and Asian surrounding areas, probably mainly since the last Glacial maximum onwards. Although rare deep rooting lineages for Y-chromosome haplogroups E and J have been detected, the presence of more basal clades supportive of the southern exit route of modern humans to Eurasian, were not found.</p
Echocardiography may help detect pulmonary vasculopathy in the early stages of pulmonary artery hypertension associated with systemic sclerosis
<p>Abstract</p> <p>Background</p> <p>Pulmonary arterial hypertension (PAH) in patients with systemic sclerosis is associated with a poor prognosis, but this can be improved by early disease detection. Abnormal pulmonary and cardiac function can be detected early by means of echocardiography, whereas right heart catheterization is usually performed later.</p> <p>Objectives</p> <p>The purpose of this prospective study was to detect early the presence of pulmonary artery vasculopathy in patients with verified systemic sclerosis without significant pulmonary fibrosis, normal lung volumes and a mildly reduced lung diffusion capacity of carbon monoxide (DLCO).</p> <p>Methods</p> <p>Nineteen consecutive female NYHA class I-II patients with scleroderma and a PAPs of < 35 mm/Hg measured by echocardiography, were enrolled between September 2007 and September 2009. They had a mean age of 51 ± 13 years, body mass index of 25 ± 5 kg/m<sup>2</sup>). They all underwent complete Doppler echocardiography, CPET, a pulmonary ventilation test (carbon monoxide lung diffusion, DLCO), HRCT. To investigate PAH by means of complete resting Doppler echocardiography estimates of systolic pulmonary artery pressure (PAPs) derived from tr icuspid regurgitation, mean PAP derived from pulmonary regurgitation, pulmonary vessel resistance (PVR) derived from the acceleration time of the pulmonary outflow tract (ACTpo), and right ventricular function derived from tricuspid annular plane systolic excursion (TAPSE). Right heart catheterisation was conducted only, if pulmonary hypertension was suggested by echocardiography and an abnormal ventilator test.</p> <p>The data are given as mean values ± SD, unless otherwise stated. The correlations between the variables were analysed using Pearson's <it>r </it>coefficient, and the predictive value of the variables was calculated using linear regression analysis. A p value of > 0.05 was considered significant.</p> <p>Results</p> <p>Right heart catheterization detected PAH in 15/19 patients; mean PAP was 30.5 mm/Hg and RVP 3.6 UW. Coronary angiography of the patients aged more than 55 years showed some evidence of significant coronary artery disease. Echocardiography showed high systolic PAP values (46 ± 8 mmHg), whereas right ventricular function was normal (TAPSE 23 ± 3 mm), and in line with the NYHA class. ACTpo was reduced in the patients with a systolic PAP of < 46 mm/Hg (p > 0.001) and positively correlated with DLCO (p > 0.001) and the hemodynamic data.</p> <p>There was a good correlation between ACTpo and PVR (hemodynamic data) (r = -0615; p > 0.01).</p> <p>Conclusions</p> <p>Although they need to be confirmed by studies of larger series of patients, our findings suggest that, in comparison with hemodynamic data, non-invasive echocardiographic measurements are an excellent means of identifying early-stage PAH.</p
- …