1,760 research outputs found

    Recent advances in cardiovascular research: systems biology

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    The authors describe different bioinformatic approaches to cardiovascular research, focusing on: i) the complexity of cardiovascular diseases; ii) how does systems biology work and its application to cardiology; iii) new systems research in cardiology; iv) clinical cardiological practice; v) perspectives and limitations of systems biology in cardiology

    A new understanding of endurance exercise

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    Longevity gained through regular exercise is cemented into popular wisdom. Today the cardiovascular benefits from moderate exercise are undeniable and the data from large cohort studies keep piling up. But the benefits from endurance exercise are less clear and even less is known about its effects on longevity. What endurance exercise cannot do is explain away myocardial remodeling and arrhythmias.Despite this, until now no underlying mechanism to explain increased life expectancy resulting from endurance exercise has been very convincing. Harman suggested in a groundbreaking paper that mitochondria are the orchestrators of aging. He argued that mitochondria are both producing and being damaged by free radicals, but antioxidants do not enter the mitochondria...</p

    PRGdb 2.0 : towards a community-based database model for the analysis of R-genes in plants

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    The Plant Resistance Genes database (PRGdb; http://prgdb.org) is a comprehensive resource on resistance genes (R-genes), a major class of genes in plant genomes that convey disease resistance against pathogens. Initiated in 2009, the database has grown more than 6-fold to recently include annotation derived from recent plant genome sequencing projects. Release 2.0 currently hosts useful biological information on a set of 112 known and 104 310 putative R-genes present in 233 plant species and conferring resistance to 122 different pathogens. Moreover, the website has been completely redesigned with the implementation of Semantic MediaWiki technologies, which makes our repository freely accessed and easily edited by any scientists. To this purpose, we encourage plant biologist experts to join our annotation effort and share their knowledge on resistance-gene biology with the rest of the scientific community

    Multimedia Informed Consent Tool for a Low Literacy African Research Population: Development and Pilot-Testing.

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    BACKGROUND: International guidelines recommend the use of appropriate informed consent procedures in low literacy research settings because written information is not known to guarantee comprehension of study information. OBJECTIVES: This study developed and evaluated a multimedia informed consent tool for people with low literacy in an area where a malaria treatment trial was being planned in The Gambia. METHODS: We developed the informed consent document of the malaria treatment trial into a multimedia tool integrating video, animations and audio narrations in three major Gambian languages. Acceptability and ease of use of the multimedia tool were assessed using quantitative and qualitative methods. In two separate visits, the participants' comprehension of the study information was measured by using a validated digitised audio questionnaire. RESULTS: The majority of participants (70%) reported that the multimedia tool was clear and easy to understand. Participants had high scores on the domains of adverse events/risk, voluntary participation, study procedures while lowest scores were recorded on the question items on randomisation. The differences in mean scores for participants' 'recall' and 'understanding' between first and second visits were statistically significant (F (1,41)=25.38, p<0.00001 and (F (1, 41) = 31.61, p<0.00001 respectively. CONCLUSIONS: Our locally developed multimedia tool was acceptable and easy to administer among low literacy participants in The Gambia. It also proved to be effective in delivering and sustaining comprehension of study information across a diverse group of participants. Additional research is needed to compare the tool to the traditional consent interview, both in The Gambia and in other sub-Saharan settings

    Digitised audio questionnaire for assessment of informed consent comprehension in a low-literacy African research population: development and psychometric evaluation.

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    OBJECTIVE: To develop and psychometrically evaluate an audio digitised tool for assessment of comprehension of informed consent among low-literacy Gambian research participants. SETTING: We conducted this study in the Gambia where a high illiteracy rate and absence of standardised writing formats of local languages pose major challenges for research participants to comprehend consent information. We developed a 34-item questionnaire to assess participants' comprehension of key elements of informed consent. The questionnaire was face validated and content validated by experienced researchers. To bypass the challenge of a lack of standardised writing formats, we audiorecorded the questionnaire in three major Gambian languages: Mandinka, Wolof and Fula. The questionnaire was further developed into an audio computer-assisted interview format. PARTICIPANTS: The digitised questionnaire was administered to 250 participants enrolled in two clinical trials in the urban and rural areas of the Gambia. One week after first administration, the questionnaire was readministered to half of the participants who were randomly selected. Participants were eligible if enrolled in the parent trials and could speak any of the three major Gambian languages. OUTCOME MEASURE: The primary outcome measure was reliability and validity of the questionnaire. RESULTS: Item reduction by factor analysis showed that 21 of the question items have strong factor loadings. These were retained along with five other items which were fundamental components of informed consent. The 26-item questionnaire has high internal consistency with a Cronbach's α of 0.73-0.79 and an intraclass correlation coefficient of 0.94 (95% CI 0.923 to 0.954). Hypotheses testing also showed that the questionnaire has a positive correlation with a similar questionnaire and discriminates between participants with and without education. CONCLUSIONS: We have developed a reliable and valid measure of comprehension of informed consent information for the Gambian context, which might be easily adapted to similar settings. This is a major step towards engendering comprehension of informed consent information among low-literacy participants

    Fetal biometry assessment with Intergrowth 21st's and Salomon's equations in rural Burkina Faso.

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    BACKGROUND: Ultrasound scanning during the 2nd or the 3rd trimester of pregnancy for fetal size disturbances screening is heavily dependent of the choice of the reference chart. This study aimed to assess the agreement of Salomon and the Intergrowth 21st equations in evaluating fetal biometric measurements in a rural area of Burkina Faso, and to measure the effect of changing a reference chart. METHODS: Data collected in Nazoanga, Burkina Faso, between October 2010 and October 2012, during a clinical trial evaluating the safety and efficacy of several antimalarial treatments in pregnant women were analyzed. We included singleton pregnancies at 16-36 weeks gestation as determined by ultrasound measurements of fetal bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Expected mean and standard deviation at a given gestational age was computed using equations from Salomon references and using Intergrowth 21st standard. Then, z-scores were calculated and used subsequently to compare Salomon references with Intergrowth 21st standards. RESULTS: The analysis included 276 singleton pregnancies. Agreement was poor except for HC: mean difference - 0.01, limits of agreement - 0.60 and 0.59. When AC was used as a surrogate of fetal size, switching from the reference of Salomon to the standards of Intergrowth 21st increased ten times the proportion of fetuses above the 90th percentile: 2.9 and 31.2%, respectively. Mean differences were larger in the third trimester than in the second trimester. However, agreement remained good for HC in both trimesters. Difference in the proportion of AC measurements above the 90th percentile using Salomon and Intergrowth 21st equations was greater in the second trimester (2.6 and 36.3%, respectively) than in the third trimester (3.5 and 19.8%, respectively). The greatest difference between the two charts was observed in the number of FL measurements classified as large in the second trimester (6.8 and 54.2%, using Salomon and Intergrowth 21st equations, respectively). CONCLUSION: The agreement between Intergrowth 21st and Salomon equations is poor apart from HC. This would imply different clinical decision regarding the management of the pregnancy

    Assessment of DNA Damage by RAPD in Paracentrotus lividus Embryos Exposed to Amniotic Fluid from Residents Living Close to Waste Landfill Sites

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    The aim of this study was to assess the genotoxic effects of environmental chemicals on residents living near landfills. The study was based on samples of amniotic fluid from women living in the intensely polluted areas around the Campania region of Italy compared to a nonexposed control group. We evaluated the genetic effects that this amniotic fluids collected in contaminated sites had on Paracentrotus lividus embryos. DNA damage was detected through changes in RAPD (Random Amplified Polymorphism DNA) profiles. The absence of the amplified DNA fragments indicated deletions in Paracentrotus lividus DNA exposed to the contaminated amniotic fluids when compared to equal exposure to uncontaminated fluids. These results show the ability of RAPD-PCR to detect and isolate DNA sequences representing genetic alterations induced in P. lividus embryos. Using this method, we identified two candidate target regions for DNA alterations in the genome of P. lividus. Our research indicates that RAPD-PCR in P. lividus embryo DNA can provide a molecular approach for studying DNA damage from pollutants that can impact human health. To our knowledge, this is the first time that assessment of DNA damage in P. lividus embryos has been tested using the RAPD strategy after exposure to amniotic fluid from residents near waste landfill sites

    A multimedia consent tool for research participants in the Gambia: a randomized controlled trial.

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    OBJECTIVE: To assess the effectiveness of a multimedia informed consent tool for adults participating in a clinical trial in the Gambia. METHODS: Adults eligible for inclusion in a malaria treatment trial (n = 311) were randomized to receive information needed for informed consent using either a multimedia tool (intervention arm) or a standard procedure (control arm). A computerized, audio questionnaire was used to assess participants' comprehension of informed consent. This was done immediately after consent had been obtained (at day 0) and at subsequent follow-up visits (days 7, 14, 21 and 28). The acceptability and ease of use of the multimedia tool were assessed in focus groups. FINDINGS: On day 0, the median comprehension score in the intervention arm was 64% compared with 40% in the control arm (P = 0.042). The difference remained significant at all follow-up visits. Poorer comprehension was independently associated with female sex (odds ratio, OR: 0.29; 95% confidence interval, CI: 0.12-0.70) and residing in Jahaly rather than Basse province (OR: 0.33; 95% CI: 0.13-0.82). There was no significant independent association with educational level. The risk that a participant's comprehension score would drop to half of the initial value was lower in the intervention arm (hazard ratio 0.22, 95% CI: 0.16-0.31). Overall, 70% (42/60) of focus group participants from the intervention arm found the multimedia tool clear and easy to understand. CONCLUSION: A multimedia informed consent tool significantly improved comprehension and retention of consent information by research participants with low levels of literacy

    ALLELE-SPECIFIC TRANSCRIPTIONAL ACTIVITY OF THE VARIABLE NUMBER OF TANDEM REPEATS OF THE INDUCIBLE NITRIC OXIDE SYNTHASE GENE IS ASSOCIATED WITH IDIOPATHIC ACHALASIA

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    Background: Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved in both immune function and inhibitory neurotransmission. Objective: to assess the association and the functional relevance of the CCTTT inducible Nitric Oxide Synthase (NOS2) gene promoter polymorphism in achalasia. Methods: Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n. Results: The alleles’ distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p<0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13-2.53, p=0.01). Transfection experiments’ revealed a similar allele-specific iNOS transcriptional activity. Conclusion: The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele-specific modulation of nitric oxide production
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