549 research outputs found

    T.I.M.S: TaqMan Information Management System, tools to organize data flow in a genotyping laboratory

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    BACKGROUND: Single Nucleotide Polymorphism (SNP) genotyping is a major activity in biomedical research. The Taqman technology is one of the most commonly used approaches. It produces large amounts of data that are difficult to process by hand. Laboratories not equipped with a Laboratory Information Management System (LIMS) need tools to organize the data flow. RESULTS: We propose a package of Visual Basic programs focused on sample management and on the parsing of input and output TaqMan files. The code is written in Visual Basic, embedded in the Microsoft Office package, and it allows anyone to have access to those tools, without any programming skills and with basic computer requirements. CONCLUSION: We have created useful tools focused on management of TaqMan genotyping data, a critical issue in genotyping laboratories whithout a more sophisticated and expensive system, such as a LIMS

    Allelotyping of pooled DNA with 250 K SNP microarrays

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    BACKGROUND: Genotyping technologies for whole genome association studies are now available. To perform such studies to an affordable price, pooled DNA can be used. Recent studies have shown that GeneChip Human Mapping 10 K and 50 K arrays are suitable for the estimation of the allele frequency in pooled DNA. In the present study, we tested the accuracy of the 250 K Nsp array, which is part of the 500 K array set representing 500,568 SNPs. Furthermore, we compared different algorithms to estimate allele frequencies of pooled DNA. RESULTS: We could confirm that the polynomial based probe specific correction (PPC) was the most accurate method for allele frequency estimation. However, a simple k-correction, using the relative allele signal (RAS) of heterozygous individuals, performed only slightly worse and provided results for more SNPs. Using four replicates of the 250 K array and the k-correction using heterozygous RAS values, we obtained results for 104.141 SNPs. The correlation between estimated and real allele frequency was 0.983 and the average error was 0.046, which was comparable to the results obtained with the 10 K array. Furthermore, we could show how the estimation accuracy depended on the SNP type (average error for A/T SNPs: 0.043 and for G/C SNPs: 0.052). CONCLUSION: The combination of DNA pooling and analysis of single nucleotide polymorphisms (SNPs) on high density microarrays is a promising tool for whole genome association studies

    Recent Evolution and Current Situation of the Production and Diffusion of Electric Vehicles Globally and in Latin America

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    Incentivada por regulaciones que buscan mitigar la emisión de gases de efecto invernadero, la industria automotriz ha encarado una incipiente transición hacia la electromovilidad; acotada hasta el momento a algunos países desarrollados occidentales, Japón, Corea del Sur y China. Esta transición genera importantes mutaciones en las capacidades tecnológicas y recursos naturales necesarios para el desarrollo y producción de vehículos, por lo que se abre un escenario de potencial reposicionamiento en términos de firmas y países. En este contexto, la producción de vehículos eléctricos y sus regulaciones vienen rezagadas en México, Brasil y la Argentina; principales productores automotrices latinoamericanos. Sin embargo, presentan algunas ventajas que podrían ser aprovechadas para reposicionarse en las cadenas de valor automotrices.Encouraged by regulations that seek to mitigate the emission of greenhouse gases, the automotive industry has started an incipient transition to electromobility; so far, this transition has been limited to some of the Western developed countries, as well as Japan, South Korea and China. This transition generates important changes in the technological capabilities and natural resources needed for the development and production of vehicles, and opens a scenario of potential repositioning for firms and countries. In this context, the production of electric vehicles and their regulations are lagging behind in Mexico, Brazil and Argentina – the leading automotive producers in Latin America. However, they have some advantages that could be exploited to reposition themselves in automotive value chains.Fil: Dulcich, Federico Martín. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otero, Dino. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; ArgentinaFil: Canzian, Adrian Marcelo. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; Argentin

    History and current situation of the automotive value chain in Argentina and Mercosur

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    La cadena automotriz es muy relevante dentro de la estructura económica argentina: acapara una parte significativa del empleo y la producción industrial, genera importantes encadenamientos a nivel nacional y regional, y concentra la mayor parte de las exportaciones de medio y alto contenido tecnológico del país. Su trayectoria histórica demuestra que esta cadena ha sufrido los vaivenes macroeconómicos y regulatorios asociados a los cambios de orientación de la política económica en general, así como a las modificaciones regulatorias de sus sectores en particular. En este contexto, el objetivo del presente trabajo es analizar la trayectoria y situación actual de la cadena automotriz en la Argentina y el MERCOSUR, haciendo eje en la interacción de la producción e inserción externa de la misma, demostrando cómo están determinadas por la regulación y el marco institucional sectorial.The automotive value chain is highly relevant within the Argentine economic structure: it accounts for a significant share of industrial employment and production, generates important linkages at the national and regional level, and concentrates most of the country’s medium- and high-technology exports. Its history shows that the automotive value chain has suffered the macroeconomic and regulatory swings associated with the changes in the economic policy orientation in general, as well as the regulatory modifications of its sectors in particular. In this context, the objective of this paper is to analyze the history and current situation of the automotive value chain in Argentina and Mercosur, focusing on the interaction between production and the international trade of the chain, demonstrating how they are determined by the regulations and sectoral institutional framework.Fil: Dulcich, Federico Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; Argentina. Universidad de Buenos Aires; Argentina. Universidad Nacional de La Matanza; ArgentinaFil: Otero, Dino. Universidad Tecnologica Nacional. Facultad Regional General Pacheco. Centro de Investigacion, Desarrolloe Innovacion Vehicular.; ArgentinaFil: Canzian, Adrian Marcelo. Universidad Tecnológica Nacional. Facultad Regional General Pacheco; Argentin

    Polymorphisms in prostaglandin synthase 2/cyclooxygenase 2 (PTGS2/COX2) and risk of colorectal cancer

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    Inflammation plays a key role in the development of colorectal cancers. We have investigated the relationship between PTGS2 (COX2) polymorphisms and colorectal cancer risk in a hospital based case-control study. We recruited 292 patients with colorectal cancer and 274 controls from new patients admitted to Bellvitge Hospital, Barcelona, Spain, from 1996 to 1998. Subjects responded to a questionnaire on risk factors. Genotypes of the eight more frequent polymorphisms of PTGS2 were determined. Two polymorphisms are located in the promoter sequence, one in the untranslated region of exon 1, one in exon 3, one in intron 5, two in the untranslated region of exon 10, and one downstream of the last polyadenylation (poly-A) signal. Associations were analysed with logistic regression models assuming a dominant effect for rare variants to increase statistical power. An association was detected between colorectal cancer and a polymorphism in the untranslated region of exon 10 of PTGS2, with an odds ratio (OR) of 2.49, 95% confidence interval (CI) of 1.17-5.32, P=0.01. A nearby polymorphism downstream of the last poly-A signal also showed a nonsignificant increase in risk (OR 2.17, 95% CI 0.99-4.78, P=0.05). Analysis of haplotypes confirmed that individuals with these variants were at increased risk of colorectal cancer (OR compared to the most frequent haplotype: 2.17, 95% CI 0.97-4.84, P=0.06) Interactions between PTGS2 genotype and use of nonsteroidal anti-inflammatory drugs and risk of colorectal cancer were also explored

    Dietary inflammatory index and inflammatory gene interactions in relation to colorectal cancer risk in the Bellvitge colorectal cancer case-control study

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    Chronic inflammation is an important factor in colorectal carcinogenesis. However, evidence on the effect of pro-inflammatory and anti-inflammatory foods and nutrients is scarce. Moreover, there are few studies focusing on diet-gene interactions on inflammation and colorectal cancer (CRC). This study was designed to investigate the association between the novel dietary inflammatory index (DII) and CRC and its potential interaction with polymorphisms in inflammatory genes. Data from the Bellvitge Colorectal Cancer Study, a case-control study (424 cases with incident colorectal cancer and 401 hospital-based controls), were used. The DII score for each participant was obtained by multiplying intakes of dietary components from a validated dietary history questionnaire by literature-based dietary inflammatory weights that reflected the inflammatory potential of components. Data from four important single nucleotide polymorphisms located in genes thought to be important in inflammation-associated CRC: i.e., interleukin (IL)-4, IL-6, IL-8, and peroxisome proliferator-activated receptor-γ (PPARG) were analyzed. A direct association was observed between DII score and CRC risk (ORQ4 vs. Q1 1.65, 95 % CI 1.05-2.60, and P trend 0.011). A stronger association was found with colon cancer risk (ORQ4 vs. Q1 2.24, 95 % CI 1.33-3.77, and P trend 0.002) than rectal cancer risk (ORQ4 vs. Q1 1.12, 95 % CI 0.61-2.06, and P trend 0.37). DII score was inversely correlated with SNP rs2243250 in IL-4 among controls, and an interaction was observed with CRC risk. Neither correlation nor interaction was detected for other inflammatory genes. Overall, high-DII diets are associated with increased risk of CRC, particularly for colon cancer, suggesting that dietary-mediated inflammation plays an important role in colorectal carcinogenesis

    Association between TAS2R38 gene polymorphisms and colorectal cancer risk

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    Molecular sensing in the lingual mucosa and in the gastro-intestinal tract play a role in the detection of ingested harmful drugs and toxins. Therefore, genetic polymorphisms affecting the capability of initiating these responses may be critical for the subsequent efficiency of avoiding and/or eliminating possible threats to the organism. By using a tagging approach in the region of Taste Receptor 2R38 (TAS2R38) gene, we investigated all the common genetic variation of this gene region in relation to colorectal cancer risk with a case-control study in a German population (709 controls and 602 cases) and in a Czech population (623 controls and 601 cases). We found that there were no significant associations between individual SNPs of the TAS2R38 gene and colorectal cancer in the Czech or in the German population, nor in the joint analysis. However, when we analyzed the diplotypes and the phenotypes we found that the non-taster group had an increased risk of colorectal cancer in comparison to the taster group. This association was borderline significant in the Czech population, (OR = 1.28, 95% CI 0.99-1.67; P(value) = 0.058) and statistically significant in the German population (OR = 1.36, 95% CI 1.06-1.75; P(value) = 0.016) and in the joint analysis (OR = 1.34, 95% CI 1.12-1.61; P(value) = 0.001). In conclusion, we found a suggestive association between the human bitter tasting phenotype and the risk of CRC in two different populations of Caucasian origin

    Potential Role of Biofilm Formation in the Development of Digestive Tract Cancer With Special Reference to Helicobacter pylori Infection

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    Bacteria are highly social organisms that communicate via signaling molecules and can assume a multicellular lifestyle to build biofilm communities. Until recently, complications from biofilm-associated infection have been primarily ascribed to increased bacterial resistance to antibiotics and host immune evasion, leading to persistent infection. In this theory and hypothesis article we present a relatively new argument that biofilm formation has potential etiological role in the development of digestive tract cancer. First, we summarize recent new findings suggesting the potential link between bacterial biofilm and various types of cancer to build the foundation of our hypothesis. To date, evidence has been particularly convincing for colorectal cancer and its precursor, i.e., polyps, pointing to several key individual bacterial species, such as Bacteroides fragilis, Fusobacterium nucleatum, and Streptococcus gallolyticus subsp. Gallolyticus. Then, we further extend this hypothesis to one of the most common bacterial infection in humans, Helicobacter pylori (Hp), which is considered a major cause of gastric cancer. Thus far, there has been no direct evidence linking in vivo Hp gastric biofilm formation to gastric carcinogenesis. Yet, we synthesize the information to support an argument that biofilm associated-Hp is potentially more carcinogenic, summarizing biological characteristics of biofilm-associated bacteria. We also discuss mechanistic pathways as to how Hp or other biofilm-associated bacteria control biofilm formation and highlight recent findings on Hp genes that influence biofilm formation, which may lead to strain variability in biofilm formation. This knowledge may open a possibility of developing targeted intervention. We conclude, however, that this field is still in its infancy. To test the hypothesis rigorously and to link it ultimately to gastric pathologies (e.g., premalignant lesions and cancer), studies are needed to learn more about Hp biofilms, such as compositions and biological properties of extracellular polymeric substance (EPS), presence of non-Hp microbiome and geographical distribution of biofilms in relation to gastric gland types and structures. Identification of specific Hp strains with enhanced biofilm formation would be helpful not only for screening patients at high risk for sequelae from Hp infection, but also for development of new antibiotics to avoid resistance, regardless of its association with gastric cancer

    SLC22A3 polymorphisms do not modify pancreatic cancer risk, but may influence overall patient survival

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    Expression of the solute carrier (SLC) transporter SLC22A3 gene is associated with overall survival of pancreatic cancer patients. This study tested whether genetic variability in SLC22A3 associates with pancreatic cancer risk and prognosis. Twenty four single nucleotide polymorphisms (SNPs) tagging the SLC22A3 gene sequence and regulatory elements were selected for analysis. Of these, 22 were successfully evaluated in the discovery phase while six significant or suggestive variants entered the validation phase, comprising a total study number of 1,518 cases and 3,908 controls. In the discovery phase, rs2504938, rs9364554, and rs2457571 SNPs were significantly associated with pancreatic cancer risk. Moreover, rs7758229 associated with the presence of distant metastases, while rs512077 and rs2504956 correlated with overall survival of patients. Although replicated, the association for rs9364554 did not pass multiple testing corrections in the validation phase. Contrary to the discovery stage, rs2504938 associated with survival in the validation cohort, which was more pronounced in stage IV patients. In conclusion, common variation in the SLC22A3 gene is unlikely to significantly contribute to pancreatic cancer risk. The rs2504938 SNP in SLC22A3 significantly associates with an unfavorable prognosis of pancreatic cancer patients. Further investigation of this SNP effect on the molecular and clinical phenotype is warranted

    Genetic polymorphisms in the cag pathogenicity island of Helicobacter pylori and risk of stomach cancer and high‐grade premalignant gastric lesions

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    AbstractHelicobacter pylori (Hp) infects the stomach of about half of the human population and is strongly associated with the risk of gastric cancer (GC) and its premalignant precursors. The cag pathogenicity island (cagPAI) is a region of the Hp genome encoding for key molecular machinery involved in the infection process. Following a sequencing study, we selected 50 genetic polymorphisms located in seven cagPAI genes and tested their associations with the risk of advanced gastric premalignant lesions and GC in 1220 subjects from various Latin American populations showing the whole spectrum of phenotypes from gastritis to GC. We found that three polymorphisms of cagA are associated with the risk of advanced gastric premalignant lesions (incomplete intestinal metaplasia [ie, Type 2 and 3] or dysplasia), and that six polymorphisms located in cagA, cagL and cagI were associated with risk of GC. When corrected for multiple testing none of the associations were statistically significant. However, scores built by integrating the individual polymorphisms were significantly associated with the risk of advanced gastric premalignant lesions and GC. These results have the potential of establishing markers for risk stratification in the general population, in view of targeting Hp eradication to high‐risk population groups
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