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The method for separation and quantitative determination of the main carotenoids in food by high-performance liquid chromatography (HPLC) was in-house validated. Tomato (Lycopersicon esculentum M.) as food matrix was used to demonstrate its linearity, repeatability, intermediate precision, detection and quantification limits, sensitivity and bias. In addition, stability of carotenoids was studied in function of temperature and time. Method accuracy was quantified through measurement uncertainties estimate based on this validation study. Furthermore, a study was conducted to evaluate variability coming from location in an experimental field composed by 12 subfields. The use of two metal free reverse phase columns and an organic mobile phase based on acetonitrile, methanol and dichloromethane enabled the separation of the six target comp...
Microcystin-LR (MCLR) is a peptide produced by freshwater cyanobacteria that induces severe hepatotoxicity in humans and animals. MCLR is also a potent tumour promoter and it has been proposed that this activity is mediated by the inhibition of protein phosphatases PP1/PP2A, possibly through the activation of proto-oncogenes c-jun, c-fos and c-myc. However, the mechanisms underlying MCLR-induced tumour promotion are still largely unknown, particularly in non-liver cells. In previous studies we have demonstrated that micromolar concentrations of MCLR induce cytotoxic effects in the kidney Vero-E6 cell line. The purpose of the present work was to evaluate whether the exposure to subcytotoxic concentrations of MCLR was sufficient to induce the proliferation of Vero-E6 cells. Through BrdU incorporation assay we show that at nanomolar conce...
Globin genes, which encode the protein subunits of hemoglobin (Hb), are organized in two different gene clusters and present a coordinated and differential pattern of expression during development. Concerning the human α-globin gene cluster (located at chromosome region 16p13.3), four upstream highly conserved elements known as multispecies conserved sequences (MCS-R1-4) or DNase I hypersensitive sites (HSs) are implicated in the long-range regulation of downstream gene expression. However, only the absence of the MCS-R2 site (HS-40) has proven to drastically downregulate the expression of those genes, and consequently, it has been regarded as the major and crucial distal regulatory element. In this study, Multiplex Ligation-dependent Probe Amplification was used to screen for deletions in the telomeric region of the short arm of chrom...
Information on distribution and relative abundance of the mosquito fauna of mainland Portugal has been collected by several surveillance programmes and projects over a long period. The work presented here documents additional information provided by capture of adult mosquitoes by the use of CDC light traps baited with CO2 in 48 localities in 13 districts in different parts of mainland Portugal during the period 2005-2008, and by larval surveys using dippers. More than 150,000 adult mosquitoes and 3,000 larvae belonging to 16 species were identified at the National Institute of Health / Centre for Vectors and Infectious Diseases Research. The three commonest species were Ochlerotatus caspius, Culex pipiens, and Cx. theileri. The most widespread species was Cx. pipiens, followed by Culiseta longiareolata. The composition and abundance of...
OBJECTIVES: Replication of GWAS association findings remains the gold standard for results validation. Our aim was to test the association of four polymorphisms (rs1671021 in LLGL2, rs753307 in RUVBL2, rs6007897 and rs4044210 in CELSR1) previously identified as ischemic stroke (IS) risk factors in a phased GWAS performed on 6341 Japanese individuals [1]. METHODS: These polymorphisms were genotyped in a Portuguese sample of 566 IS cases and 525 controls, and their allele, genotype and haplotype associations were assessed. RESULTS: rs6007897 and rs4044210 in CELSR1 were associated with stroke risk individually (OR[95%CI]=1.43[1.13-1.81], p=0.003 and 1.38[1.09-1.74], p=0.007, respectively), and in combination as a haplotype. These associations remain after correction for multiple testing and in a meta-analysis with the original findings...
BACKGROUND: The three azoospermia factor (AZF) regions of the Y chromosome represent genomic niches for spermatogenesis genes. Yet, the most distal region, AZFc, is a major generator of large-scale variation in the human genome. Determining to what extent this variability affects spermatogenesis is a highly contentious topic in human reproduction. METHODS: In this review, an extensive characterization of the molecular mechanisms responsible for AZFc genotypical variation is undertaken. Such data are complemented with the assessment of the clinical consequences for male fertility imputable to the different AZFc variants. For this, a critical re-evaluation of 23 association studies was performed in order to extract unifying conclusions by curtailing methodological heterogeneities. RESULTS: Intrachromosomal homologous recombination mech...
Objectives:  To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers. Design and setting:  Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.75 million births from 2000 to 2004. Participants:  A total of 38 958 cases of NCA that were live births, fetal deaths with gestational age ≥20 weeks or terminations of pregnancy following prenatal diagnosis of a congenital anomaly. Main outcome measures:  Prevalence of NCA according to maternal age, and relative risk (RR) of NCA and 84 standard NCA subgroups compared with mothers aged 25–29. Results:  The crude prevalence of all NCA was 26.5 per 1000 births in teenage mothers (<20 years), 23.8 for mothers 20–24 years, 22.5 for mothers 25–29 y...
Background - The present study protocol is designed to assess the relationship between outdoor air pollution and low birth weight and preterm births outcomes performing a semi-ecological analysis. Semi-ecological design studies are widely used to assess effects of air pollution in humans. In this type of analysis, health outcomes and covariates are measured in individuals and exposure assignments are usually based on air quality monitor stations. Therefore, estimating individual exposures are one of the major challenges when investigating these relationships with a semi-ecologic design. Methods/Design Semi-ecologic study consisting of a retrospective cohort study with ecologic assignment of exposure is applied. Health outcomes and covariates are collected at Primary Health Care Center. Data from pregnant registry, clinical record and...
Background: Chlamydia trachomatis is one of the most disseminated human pathogens, for which no vaccine is available yet. Understanding the impact of the host pressure on pathogen antigens is crucial, but so far it was only assessed for highly-restricted geographic areas. We aimed to evaluate the evolutionary picture of the chlamydial key antigen (MOMP), which is one of the leading multi-subunit vaccine candidates, in a worldwide basis. Methodology/Principal Findings: Using genetics, molecular evolution methods and mathematical modelling, we analyzed all MOMP sequences reported worldwide, composed by 5026 strains from 33 geographic regions of five continents. Overall, 35.9% of variants were detected. The evolutionary pattern of MOMP amino acid gains/losses was found to differ from the remaining chromosome, reflecting the demanding cons...
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