88 research outputs found

    Review of epidemiologic data on the debate over smokeless tobacco's role in harm reduction

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    Some tobacco researchers have argued that the European Union should remove its ban on a form of low-nitrosamine smokeless tobacco referred to as Swedish 'snus'. This argument has developed in to an international debate over the use of smokeless tobacco as a measure of harm reduction for smokers. Leading authorities in the USA have firmly stated that there is no safe tobacco - a message which does not allow for any discussion of comparative tobacco risks. This commentary is intended to review the origin of the controversy over Swedish 'snus', to examine briefly the meta-analysis on cancer risks by Peter Lee and Jan Hamling (published in July in BMC Medicine) and to discuss the anticipated direction of the debate on tobacco-harm reduction in the USA. We anticipate that much of the debate will shift from the discussion of epidemiologic data to the discussion of the marketing, health communication and economics of smokeless tobacco. While the Food and Drug Administration's newly approved authority over tobacco will undoubtedly affect the smokeless products, it may not be the sole determinant of harm reduction's fate in the USA

    A Note on False Positives and Power in G × E Modelling of Twin Data

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    The variance components models for gene–environment interaction proposed by Purcell in 2002 are widely used. In both the bivariate and the univariate parameterization of these models, the variance decomposition of trait T is a function of moderator M. We show that if M and T are correlated, and moderator M is correlated between twins as well, the univariate parameterization produces a considerable increase in false positive moderation effects. A simple extension of this univariate moderation model prevents this elevation of the false positive rate provided the covariance between M and T is itself not also subject to moderation. If the covariance between M and T varies as a function of M, then moderation effects observed in the univariate setting should be interpreted with care as these can have their origin in either moderation of the covariance between M and T or in moderation of the unique paths of T. We conclude that researchers should use the full bivariate moderation model to study the presence of moderation on the covariance between M and T. If such moderation can be ruled out, subsequent use of the extended univariate moderation model, as proposed in this paper, is recommended as this model is more powerful than the full bivariate moderation model

    The Dopamine Transporter Gene, a Spectrum of Most Common Risky Behaviors, and the Legal Status of the Behaviors

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    This study tests the specific hypothesis that the 9R/9R genotype in the VNTR of the dopamine transporter gene (DAT1) exerts a general protective effect against a spectrum of risky behaviors in comparison to the 10R/9R and 10R/10R genotypes, drawing on three-time repeated measures of risky behaviors in adolescence and young adulthood on about 822 non-Hispanic white males from the Add Health study. Our data have established two empirical findings. The first is a protective main effect in the DAT1 gene against risky behaviors. The second finding is that the protective effect varies over age, with the effect prominent at ages when a behavior is illegal and the effect largely vanished at ages when the behavior becomes legal or more socially tolerated. Both the protective main effect and the gene-lifecourse interaction effect are replicated across a spectrum of most common risky behaviors: delinquency, variety of sexual partners, binge drinking, drinking quantity, smoking quantity, smoking frequency, marijuana use, cocaine use, other illegal drug use, and seatbelt non-wearing. We also compared individuals with the protective genotype and individuals without it in terms of age, physical maturity, verbal IQ, GPA, received popularity, sent popularity, church attendance, two biological parents, and parental education. These comparisons indicate that the protective effect of DAT1*9R/9R cannot be explained away by these background characteristics. Our work demonstrates how legal/social contexts can enhance or reduce a genetic effect on risky behaviors

    The mammals of Angola

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    Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the countryinfo:eu-repo/semantics/publishedVersio

    Dietary factors as novel therapies for muscle pain

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    Fecal microbiota transplantation in patients with primary sclerosing cholangitis: A pilot clinical trial

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    Background: Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with no effective medical therapies. A perturbation of the gut microbiota has been described in association with PSC, and fecal microbiota transplantation (FMT) has been reported to restore the microbiome in other disease states. Accordingly, we aimed to evaluate the safety, change in liver enzymes, microbiota and metabolomic profiles in PSC patients after FMT. Methods: Open-label pilot study of PSC patients with concurrent inflammatory bowel disease (IBD) and ALP > 1.5X the upper limit of normal. Participants underwent a single FMT by colonoscopy. Liver enzyme profiles and stool microbiome and metabolomic analysis was conducted at baseline and week 1, 4, 8, 12 and 24 post-FMT. The primary outcome was safety and secondary outcomes include a decrease in ALP ≥50% from baseline by week 24 post-FMT, as well as stool microbiota (by 16S rRNA gene profiling) and metabonomic dynamics were assessed. Results. Ten patients underwent FMT. Nine patients had ulcerative colitis and 1 with Crohn’s colitis. The mean baseline ALP was 489 U/L. There were no related adverse events. Overall, 30% (3/10) experienced a ≥50% decrease ALP. The diversity increased in all patients post-FMT, as early as week 1 (p<0.01). Importantly, abundance of engrafter operational taxanomic units (OTUs) in patients post-FMT correlated with decreased ALP (p=0.02). Conclusion: To our knowledge, this first study to demonstrate that FMT in PSC is safe. Additionally, increases in bacterial diversity and engraftment may correlate with an improvement in ALP among PSC patients
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