53 research outputs found

    The interface between assisted reproductive technologies and genetics: technical, social, ethical and legal issues

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    The interface between assisted reproductive technologies (ART) and genetics comprises several sensitive and important issues that affect infertile couples, families with severe genetic diseases, potential children, professionals in ART and genetics, health care, researchers and the society in general. Genetic causes have a considerable involvement in infertility. Genetic conditions may also be transmitted to the offspring and hence create transgenerational infertility or other serious health problems. Several studies also suggest a slightly elevated risk of birth defects in children born following ART. Preimplantation genetic diagnosis (PGD) has become widely practiced throughout the world for various medical indications, but its limits are being debated. The attitudes towards ART and PGD vary substantially within Europe. The purpose of the present paper was to outline a framework for development of guidelines to be issued jointly by European Society of Human Genetics and European Society of Human Reproduction and Embryology for the interface between genetics and ART. Technical, social, ethical and legal issues of ART and genetics will be reviewed.JRC.J.5-Agriculture and Life Sciences in the Econom

    A Phase 1 Trial of MSP2-C1, a Blood-Stage Malaria Vaccine Containing 2 Isoforms of MSP2 Formulated with MontanideÂź ISA 720

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    Background: In a previous Phase 1/2b malaria vaccine trial testing the 3D7 isoform of the malaria vaccine candidate Merozoite surface protein 2 (MSP2), parasite densities in children were reduced by 62%. However, breakthrough parasitemias were disproportionately of the alternate dimorphic form of MSP2, the FC27 genotype. We therefore undertook a dose-escalating, double-blinded, placebo-controlled Phase 1 trial in healthy, malaria-naĂŻve adults of MSP2-C1, a vaccine containing recombinant forms of the two families of msp2 alleles, 3D7 and FC27 (EcMSP2-3D7 and EcMSP2-FC27), formulated in equal amounts with MontanideÂź ISA 720 as a water-in-oil emulsion. Methodology/Principal Findings: The trial was designed to include three dose cohorts (10, 40, and 80 ÎŒg), each with twelve subjects receiving the vaccine and three control subjects receiving MontanideÂź ISA 720 adjuvant emulsion alone, in a schedule of three doses at 12-week intervals. Due to unexpected local reactogenicity and concern regarding vaccine stability, the trial was terminated after the second immunisation of the cohort receiving the 40 ÎŒg dose; no subjects received the 80 ÎŒg dose. Immunization induced significant IgG responses to both isoforms of MSP2 in the 10 ÎŒg and 40 ÎŒg dose cohorts, with antibody levels by ELISA higher in the 40 ÎŒg cohort. Vaccine-induced antibodies recognised native protein by Western blots of parasite protein extracts and by immunofluorescence microscopy. Although the induced anti-MSP2 antibodies did not directly inhibit parasite growth in vitro, IgG from the majority of individuals tested caused significant antibody-dependent cellular inhibition (ADCI) of parasite growth. Conclusions/Significance: As the majority of subjects vaccinated with MSP2-C1 developed an antibody responses to both forms of MSP2, and that these antibodies mediated ADCI provide further support for MSP2 as a malaria vaccine candidate. However, in view of the reactogenicity of this formulation, further clinical development of MSP2-C1 will require formulation of MSP2 in an alternative adjuvant. Trial Registration: Australian New Zealand Clinical Trials Registry 12607000552482

    The ProPrems trial: investigating the effects of probiotics on late onset sepsis in very preterm infants

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    BACKGROUND: Late onset sepsis is a frequent complication of prematurity associated with increased mortality and morbidity. The commensal bacteria of the gastrointestinal tract play a key role in the development of healthy immune responses. Healthy term infants acquire these commensal organisms rapidly after birth. However, colonisation in preterm infants is adversely affected by delivery mode, antibiotic treatment and the intensive care environment. Altered microbiota composition may lead to increased colonisation with pathogenic bacteria, poor immune development and susceptibility to sepsis in the preterm infant.Probiotics are live microorganisms, which when administered in adequate amounts confer health benefits on the host. Amongst numerous bacteriocidal and nutritional roles, they may also favourably modulate host immune responses in local and remote tissues. Meta-analyses of probiotic supplementation in preterm infants report a reduction in mortality and necrotising enterocolitis. Studies with sepsis as an outcome have reported mixed results to date.Allergic diseases are increasing in incidence in "westernised" countries. There is evidence that probiotics may reduce the incidence of these diseases by altering the intestinal microbiota to influence immune function. METHODS/DESIGN: This is a multi-centre, randomised, double blinded, placebo controlled trial investigating supplementing preterm infants born at < 32 weeks' gestation weighing < 1500 g, with a probiotic combination (Bifidobacterium infantis, Streptococcus thermophilus and Bifidobacterium lactis). A total of 1,100 subjects are being recruited in Australia and New Zealand. Infants commence the allocated intervention from soon after the start of feeds until discharge home or term corrected age. The primary outcome is the incidence of at least one episode of definite (blood culture positive) late onset sepsis before 40 weeks corrected age or discharge home. Secondary outcomes include: Necrotising enterocolitis, mortality, antibiotic usage, time to establish full enteral feeds, duration of hospital stay, growth measurements at 6 and 12 months' corrected age and evidence of atopic conditions at 12 months' corrected age. DISCUSSION: Results from previous studies on the use of probiotics to prevent diseases in preterm infants are promising. However, a large clinical trial is required to address outstanding issues regarding safety and efficacy in this vulnerable population. This study will address these important issues. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN012607000144415The product "ABC Dophilus Probiotic Powder for InfantsÂź", Solgar, USA has its 3 probiotics strains registered with the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ--German Collection of Microorganisms and Cell Cultures) as BB-12 15954, B-02 96579, Th-4 15957

    Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

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    The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods - recursive partitioning and regression - to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; Pcombined = 2.01 × 10-19 and 2.35 × 10-13, respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes. ©2007 Nature Publishing Group

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P &lt; 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    ECOVAL: A Framework fot Increasing the Ecological Validity in Usability Testing

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    The term ecological validity refers to the study of the measurable correspondence between experimental design and ecological setting (i.e., representative users performing real tasks in their natural environment). Therefore, it is important to anyone intending to generalize the conclusions from the particular circumstances of an experiment to wider ecological situations. However, there is no operational definition that enables to objectively quantify the ecological validity of an experimental design. The ECOVAL framework offers a formal starting point to bridge this gap by helping to both define and increase the ecological validity in usability testing. A methodology, a tool and guidelines to increase ecological validity are presented in an industrial case study. The return on investment of increasing ecological validity is examined in terms of user efficiencies and usability practice. Finally, recommendations to increase ecological validity are introduced, contributions discussed, and outlines for future work presented

    Testing for Structural Breaks in the Evaluation of Programs

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    A youth homicide reduction initiative in Boston in the mid-1990s poses particular difficulties for program evaluation because it did not have a control group and the exact implementation date is unknown. A standard methodology in program evaluation is to use time series variation to compare pre- and post-program outcomes. Such an approach is not valid, however, when the timing of a potential break is unknown. To evaluate the Boston initiative, we adapt from the macroeconomics literature a test of unknown break point to test for a change in regime. Tests for parameter instability provide a flexible framework for testing a range of hypotheses commonly posed in program evaluation. These tests both pinpoint the timing of maximal break and provide a valid test of statistical significance. We evaluate the results of the estimation using the asymptotic results in the literature and with our own Monte Carlo analyses. We conclude there was a statistically significant discontinuity in youth homicide incidents (on the order of 60 percent) shortly after the intervention was unveiled.

    TransformaçÔes na trajetĂłria dos sistemas agroflorestais no municĂ­pio de Irituia – PA

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    In long colonized areas of the Amazon, such as northeast ParĂĄ, agricultural production systems, based mainly on annual crops in slash and burn systems, face challenges to maintain themselves. In this context, actors are promoting agroforestry systems (AFSs) to make viable the restoration of degraded areas, income generation, and food sovereignty of farming families. This transition requires the transformation of the entire agrarian system. This article aims to identify historical events and changes in factors external to the production system that have conditioned the transformations for the introduction/modification of AFS in Irituia – PA. We used systemic approach, historical interviews, questionnaires, documentary analysis and landscape analysis. Local public incentives were the main precursors to the consolidation of AFS within family production systems. With these initiatives that provided multi-scale structural changes, the trajectory of production systems indicates a differentiated perspective, with increased sustainability.Em zonas de colonização antiga da AmazĂŽnia, como o Nordeste do ParĂĄ, os sistemas de produção agrĂ­cola, baseados principalmente em cultivos anuais em sistemas de corte e queima, enfrentam desafios para se manter. Nesse contexto, atores estĂŁo promovendo Sistemas Agroflorestais (SAF) para viabilizar a restauração das ĂĄreas degradadas, geração de renda e soberania alimentar das famĂ­lias agrĂ­colas. Essa transição requer a transformação de todo o sistema agrĂĄrio. Neste artigo objetiva-se identificar os eventos histĂłricos e as mudanças nos fatores externos ao sistema de produção que condicionaram as transformaçÔes para a introdução/modificação dos SAF em Irituia –PA. Utilizou-se a abordagem sistĂȘmica, entrevistas histĂłricas, questionĂĄrios, anĂĄlise documental e anĂĄlise de paisagem. Os incentivos pĂșblicos locais foram os principais precursores da consolidação dos SAFs dentro dos sistemas de produção familiares. Com essas iniciativas, que proporcionaram mudanças estruturais multiescalares, a trajetĂłria dos sistemas de produção indica uma perspectiva diferenciada, com incremento de sustentabilidade
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