998 resultados para 289.272
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BACKGROUND: Aromatase inhibitors provide superior disease control when compared with tamoxifen as adjuvant therapy for postmenopausal women with endocrine-responsive early breast cancer. PURPOSE: To present the design, history, and analytic challenges of the Breast International Group (BIG) 1-98 trial: an international, multicenter, randomized, double-blind, phase-III study comparing the aromatase inhibitor letrozole with tamoxifen in this clinical setting. METHODS: From 1998-2003, BIG 1-98 enrolled 8028 women to receive monotherapy with either tamoxifen or letrozole for 5 years, or sequential therapy of 2 years of one agent followed by 3 years of the other. Randomization to one of four treatment groups permitted two complementary analyses to be conducted several years apart. The first, reported in 2005, provided a head-to-head comparison of letrozole versus tamoxifen. Statistical power was increased by an enriched design, which included patients who were assigned sequential treatments until the time of the treatment switch. The second, reported in late 2008, used a conditional landmark approach to test the hypothesis that switching endocrine agents at approximately 2 years from randomization for patients who are disease-free is superior to continuing with the original agent. RESULTS: The 2005 analysis showed the superiority of letrozole compared with tamoxifen. The patients who were assigned tamoxifen alone were unblinded and offered the opportunity to switch to letrozole. Results from other trials increased the clinical relevance about whether or not to start treatment with letrozole or tamoxifen, and analysis plans were expanded to evaluate sequential versus single-agent strategies from randomization. LIMITATIONS: Due to the unblinding of patients assigned tamoxifen alone, analysis of updated data will require ascertainment of the influence of selective crossover from tamoxifen to letrozole. CONCLUSIONS: BIG 1-98 is an example of an enriched design, involving complementary analyses addressing different questions several years apart, and subject to evolving analytic plans influenced by new data that emerge over time.
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There is evidence across several species for genetic control of phenotypic variation of complex traits, such that the variance among phenotypes is genotype dependent. Understanding genetic control of variability is important in evolutionary biology, agricultural selection programmes and human medicine, yet for complex traits, no individual genetic variants associated with variance, as opposed to the mean, have been identified. Here we perform a meta-analysis of genome-wide association studies of phenotypic variation using ∼170,000 samples on height and body mass index (BMI) in human populations. We report evidence that the single nucleotide polymorphism (SNP) rs7202116 at the FTO gene locus, which is known to be associated with obesity (as measured by mean BMI for each rs7202116 genotype), is also associated with phenotypic variability. We show that the results are not due to scale effects or other artefacts, and find no other experiment-wise significant evidence for effects on variability, either at loci other than FTO for BMI or at any locus for height. The difference in variance for BMI among individuals with opposite homozygous genotypes at the FTO locus is approximately 7%, corresponding to a difference of ∼0.5 kilograms in the standard deviation of weight. Our results indicate that genetic variants can be discovered that are associated with variability, and that between-person variability in obesity can partly be explained by the genotype at the FTO locus. The results are consistent with reported FTO by environment interactions for BMI, possibly mediated by DNA methylation. Our BMI results for other SNPs and our height results for all SNPs suggest that most genetic variants, including those that influence mean height or mean BMI, are not associated with phenotypic variance, or that their effects on variability are too small to detect even with samples sizes greater than 100,000.
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Plântulas originárias de populações híbridas, em geração F2, de 26 cruzamentos entre cultivares de trigo tolerantes (BH-1146, IAC-227, IAC-24, IAC-60, C-3, IAC-5, IAC-18 e IAC-21) e sensíveis (Anahuac 75, IAC-287, IAC-289, Siete Cerros e Veery "S") à toxicidade de alumínio e de 18 cruzamentos entre cultivares tolerantes (BH-1146, IAC-227, IAC-24, IAC-60, C-3, IAC-5, IAC-21, C-17, IAC-74 e IAC-18) foram avaliadas em relação à tolerância a 3 mg/L de Al3+, empregando soluções nutritivas. A tolerância à toxicidade de alumínio foi medida pela capacidade de crescimento da raiz primária central em solução nutritiva completa, após um tratamento de 48 horas em solução contendo 3 mg/L de Al3+. Avaliando-se as plântulas das populações F2 provindas de cruzamentos entre cultivares tolerantes e sensíveis, verificou-se que a tolerância à toxicidade de Al3+ foi dominante, e que em 24 dos cruzamentos, as cultivares tolerantes diferiram das sensíveis por um par de genes. Não foi detectada diferença entre as cultivares tolerantes em relação ao par de genes dominantes em relação à tolerância. Qualquer uma dessas cultivares poderá ser utilizada como fonte de tolerância num programa de cruzamentos em que essa característica for desejada.
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Sarcoidosis is a systemic granulomatous disorder of unknown origin commonly affecting the lung, the lymphoid system and the skin. We report here two cases of cutaneous sarcoidosis in two former intravenous drug users following interferon (IFN)-α and ribavirin therapy for chronic hepatitis C. Both patients developed skin sarcoidosis along venous drainage lines of both forearms, coinciding with the areas of prior drug injections. The unique distribution of the skin lesions suggests that tissue damage induced by repeated percutaneous drug injections represents a trigger for the local skin manifestation of sarcoidosis. Interestingly, skin damage was recently found to induce the local expression IFN-α, a well-known trigger of sarcoidosis in predisposed individuals. Here we review the literature on sarcoidosis elicited in the context of IFN-α therapy and propose a new link between the endogenous expression of IFN-α and the induction of disease manifestations in injured skin. © 2013 S. Karger AG, Basel.
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O objetivo deste trabalho foi avaliar os efeitos da aplicação de 0, 20 e 40 Mg ha-1 de lodo de esgoto, na presença e ausência de fertilizante mineral (NPK) na fertilidade e nos teores de metais pesados de um Argissolo Vermelho-Amarelo distrófico, cultivado com cana-de-açúcar. Amostras de solo foram coletadas aos 146, 272 e 484 dias após o plantio da cultura de cana-de-açúcar e foram submetidas à análise de fertilidade pelo método do Instituto Agronômico de Campinas, incluindo a determinação do S, Cr, Cd, Cu, Fe, Mn, Pb e Zn. O lodo de esgoto diminuiu a acidez do solo e forneceu Ca, P, S e Zn, principalmente. Seus efeitos foram de curta duração, restringindo-se a um ano agrícola. Os teores dos metais pesados das amostras de solo tratado foram maiores que os da testemunha, mas menores que os valores considerados perigosos ao ambiente.
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Incomplet du commencement et de la fin. — Miniatures.
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Viral subversion of apoptosis regulation plays an important role in the outcome of host/virus interactions. Although human cytomegalovirus (HCMV) encodes several immediate early (IE) antiapoptotic proteins (IE1, IE2, vMIA and vICA), no proapoptotic HCMV protein has yet been identified. Here we show that US28, a functional IE HCMV-encoded chemokine receptor, which may be involved in both viral dissemination and immune evasion, constitutively induces apoptosis in several cell types. In contrast, none of nine human cellular chemokine receptors, belonging to three different subfamilies, induced any significant level of apoptosis. US28-induced cell death involves caspase 10 and caspase 8 activation, but does not depend on the engagement of cell-surface death receptors of the tumour necrosis factor receptor/CD95 family. US28 cell-death induction is prevented by coexpression of C-FLIP, a protein that inhibits Fas-associated death domain protein (FADD)-mediated activation of caspase 10 and caspase 8, and by coexpression of the HCMV antiapoptotic protein IE1. The use of US28 mutants indicated that the DRY sequence of its third transmenbrane domain, required for constitutive G-protein signalling, and the US28 intracellular terminal domain required for constitutive US28 endocytosis, are each partially required for cell-death induction. Thus, in HCMV-infected cells, US28 may function either as a chemokine receptor, a phospholipase C activator, or a proapoptotic factor, depending on expression levels of HCMV and/or cellular antiapoptotic proteins.
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O objetivo deste trabalho foi estudar o processo germinativo dos grãos na espiga, o rendimento de grãos, a adaptabilidade e a estabilidade em genótipos de trigo (Triticum aestivum L.) sensíveis às variações ambientais. Os experimentos foram instalados no Núcleo Experimental do Instituto Agronômico, em Campinas, SP, no período de 1996 a 1998. A germinação na espiga foi avaliada pelo método do "Falling Number", que consiste em determinar o nível de atividade da alfa-amilase nos grãos. A segunda e a terceira colheitas foram realizadas ao sete e quatorze dias após a primeira colheita. O atraso da colheita determinou redução no rendimento, notadamente na terceira colheita; os teores de alfa-amilase foram maiores também na terceira colheita, em virtude da degradação dos grãos expostos ao tempo. O genótipo IAC 289 apresentou adaptabilidade a ambientes favoráveis, mas apresentou suscetibilidade à ocorrência de germinação dos grãos na espiga. Os genótipos IAC 24, Mochis, IAC 370 e IAC 351 foram os mais resistentes à germinação dos grãos na espiga, apresentando baixa atividade de alfa-amilase.
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OBJECTIVES: Etravirine (ETV) is metabolized by cytochrome P450 (CYP) 3A, 2C9, and 2C19. Metabolites are glucuronidated by uridine diphosphate glucuronosyltransferases (UGT). To identify the potential impact of genetic and non-genetic factors involved in ETV metabolism, we carried out a two-step pharmacogenetics-based population pharmacokinetic study in HIV-1 infected individuals. MATERIALS AND METHODS: The study population included 144 individuals contributing 289 ETV plasma concentrations and four individuals contributing 23 ETV plasma concentrations collected in a rich sampling design. Genetic variants [n=125 single-nucleotide polymorphisms (SNPs)] in 34 genes with a predicted role in ETV metabolism were selected. A first step population pharmacokinetic model included non-genetic and known genetic factors (seven SNPs in CYP2C, one SNP in CYP3A5) as covariates. Post-hoc individual ETV clearance (CL) was used in a second (discovery) step, in which the effect of the remaining 98 SNPs in CYP3A, P450 cytochrome oxidoreductase (POR), nuclear receptor genes, and UGTs was investigated. RESULTS: A one-compartment model with zero-order absorption best characterized ETV pharmacokinetics. The average ETV CL was 41 (l/h) (CV 51.1%), the volume of distribution was 1325 l, and the mean absorption time was 1.2 h. The administration of darunavir/ritonavir or tenofovir was the only non-genetic covariate influencing ETV CL significantly, resulting in a 40% [95% confidence interval (CI): 13-69%] and a 42% (95% CI: 17-68%) increase in ETV CL, respectively. Carriers of rs4244285 (CYP2C19*2) had 23% (8-38%) lower ETV CL. Co-administered antiretroviral agents and genetic factors explained 16% of the variance in ETV concentrations. None of the SNPs in the discovery step influenced ETV CL. CONCLUSION: ETV concentrations are highly variable, and co-administered antiretroviral agents and genetic factors explained only a modest part of the interindividual variability in ETV elimination. Opposing effects of interacting drugs effectively abrogate genetic influences on ETV CL, and vice-versa.
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Iowa Ag Review is a quarterly newsletter published by the Center for Agricultural and Rural Development (CARD). This publication presents summarized results that emphasize the implications of ongoing agricultural policy analysis, analysis of the near-term agricultural situation, and discussion of agricultural policies currently under consideration.