Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Evol Lett ; 8(2): 189-199, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-39070288

RESUMO

Identifying along which lineages shifts in diversification rates occur is a central goal of comparative phylogenetics; these shifts may coincide with key evolutionary events such as the development of novel morphological characters, the acquisition of adaptive traits, polyploidization or other structural genomic changes, or dispersal to a new habitat and subsequent increase in environmental niche space. However, while multiple methods now exist to estimate diversification rates and identify shifts using phylogenetic topologies, the appropriate use and accuracy of these methods are hotly debated. Here we test whether five Bayesian methods-Bayesian Analysis of Macroevolutionary Mixtures (BAMM), two implementations of the Lineage-Specific Birth-Death-Shift model (LSBDS and PESTO), the approximate Multi-Type Birth-Death model (MTBD; implemented in BEAST2), and the Cladogenetic Diversification Rate Shift model (ClaDS2)-produce comparable results. We apply each of these methods to a set of 65 empirical time-calibrated phylogenies and compare inferences of speciation rate, extinction rate, and net diversification rate. We find that the five methods often infer different speciation, extinction, and net-diversification rates. Consequently, these different estimates may lead to different interpretations of the macroevolutionary dynamics. The different estimates can be attributed to fundamental differences among the compared models. Therefore, the inference of shifts in diversification rates is strongly method dependent. We advise biologists to apply multiple methods to test the robustness of the conclusions or to carefully select the method based on the validity of the underlying model assumptions to their particular empirical system.

2.
Clin Nutr ; 43(8): 1865-1871, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38964203

RESUMO

BACKGROUND: Metabolic syndrome (MetS) in adolescence is a risk factor for future cardiovascular disease. The chronic inflammation associated with MetS can be attenuated by the anti-inflammatory effect of polyphenols. We aimed to evaluate total urinary polyphenols as a biomarker of anti-inflammatory diets and their effect on MetS in adolescents. METHODS: In this retrospective analysis of a longitudinal cohort study, the relationship between total polyphenol excretion (TPE) in urine, the inflammatory potential of the diet measured through the Children's Dietary Inflammatory Index (C-DII), and the presence of metabolic syndrome was evaluated. The study population consisted of adolescents enrolled in the SI! Program for Secondary Schools trial, who had completed all the study forms and provided urine samples at baseline and at the two-year follow-up. Multivariate linear regression and multinominal logistic regression models were generated to evaluate the relationship of changes in TPE with changes in the C-DII score and changes in MetS status, respectively. An analysis of the ROC curve was performed to assess the potential of TPE as a biomarker of an anti-inflammatory diet. RESULTS: This study included 662 adolescents, 51.2% were males, and 48.8% were females, with a mean age of 12 (0.38) years at baseline. The relationship between changes in TPE and changes in the C-DII score was stratified by sex with a p-value <0.001 for the interaction. TPE and C-DII were inversely associated in males (-0.13 mg GAE/g creatinine [-0.26; -0.01] per 1-SD increase, p-value = 0.037). In addition, an increase in changes in TPE levels were associated with a reversal in MetS status in all adolescents (1.30 [1.27; 1.34] per 1-SD increase, p-value<0.001). The ROC curve showed that urinary TPE levels can predict dietary inflammatory potential with an AUC = 0.793 (0.725; 0.863) in males. CONCLUSION: Polyphenols excreted in urine are a potential biomarker of anti-inflammatory diets in males and are associated with a reversal of MetS status in adolescents. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT03504059, https://clinicaltrials.gov/study/NCT03504059.


Assuntos
Biomarcadores , Dieta , Síndrome Metabólica , Polifenóis , Humanos , Masculino , Feminino , Polifenóis/administração & dosagem , Polifenóis/urina , Adolescente , Biomarcadores/urina , Síndrome Metabólica/urina , Estudos Longitudinais , Estudos Retrospectivos , Dieta/métodos , Inflamação/urina , Criança , Anti-Inflamatórios/administração & dosagem
3.
J Adolesc Health ; 74(5): 1039-1048, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38323971

RESUMO

PURPOSE: To determine cardiovascular health (CVH) trajectories and their association with sociodemographic and cardiometabolic outcomes in adolescence. METHODS: One thousand eighty adolescents attending 24 secondary schools enrolled in the SI! Program for Secondary Schools trial in Spain were assessed at approximately 12, 14, and 16 years of age. CVH was assessed according to American Heart Association criteria based on seven metrics (smoking status, body mass index, physical activity, diet, blood pressure, total cholesterol, and blood glucose), and CVH trajectories were identified by latent class trajectory modeling. Associations between CVH trajectories, sociodemographic characteristics, and cardiometabolic outcomes were analyzed using generalized linear and Poisson models. RESULTS: Five CVH trajectory groups were identified: poor-stable (27 adolescents [2.5%]), intermediate-substantial rise (79 [7.3%]), intermediate-substantial decline (63 [5.8%]), intermediate-mild decline (403 [37.3%]), and intermediate-mild rise (508 [47.1%]). Boys and adolescents from families with low-average income, low-intermediate educational attainment, and a migrant background more frequently belonged to groups with lower baseline CVH and poor or declining trajectories. The intermediate-substantial decline group had the highest prevalence ratio for overweight/obesity (3.84; 95% confidence interval: 2.86-5.16) and metabolic syndrome (4.93; 95% confidence interval: 1.21-20.04) at age 16, whereas prevalence was lowest in the intermediate-mild rise group. DISCUSSION: Adolescent CVH trajectories differ according to socioeconomic characteristics and are associated with cardiometabolic outcomes. Primordial prevention interventions should be implemented early in life, taking into account CVH trajectories and with a particular focus on vulnerable populations.


Assuntos
Doenças Cardiovasculares , Masculino , Estados Unidos , Humanos , Adolescente , Doenças Cardiovasculares/epidemiologia , Espanha/epidemiologia , Dieta , Índice de Massa Corporal , Pressão Sanguínea/fisiologia , Nível de Saúde , Fatores de Risco
4.
EClinicalMedicine ; 57: 101885, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37064511

RESUMO

Background: Cardiovascular magnetic resonance (CMR) is a precise tool for the assessment of cardiac anatomy, function, and tissue composition. However, studies providing CMR reference values in adolescence are scarce. We aim to provide sex-specific CMR reference values for biventricular and atrial dimensions and function and myocardial relaxation times in this population. Methods: Adolescents aged 15-18 years with no known cardiovascular disease underwent a non-contrast 3-T CMR scan between March 2021 and October 2021. The imaging protocol included a cine steady-state free-precession sequence for the analysis of chamber size and function, as well as T2-GraSE and native MOLLI T1-mapping for the characterization of myocardial tissue. Findings: CMR scans were performed in 123 adolescents (mean age 16 ± 0.5 years, 52% girls). Mean left and right ventricular end-diastolic indexed volumes were higher in boys than in girls (91.7 ± 11.6 vs 78.1 ± 8.3 ml/m2, p < 0.001; and 101.3 ± 14.1 vs 84.1 ± 10.5 ml/m2, p < 0.001), as was the indexed left ventricular mass (48.5 ± 9.6 vs 36.6 ± 6.0 g/m2, p < 0.001). Left ventricular ejection fraction showed no significant difference by sex (62.2 ± 4.1 vs 62.8 ± 4.2%, p = 0.412), whereas right ventricular ejection fraction trended slightly lower in boys (55.4 ± 4.7 vs. 56.8 ± 4.4%, p = 0.085). Indexed atrial size and function parameters did not differ significantly between sexes. Global myocardial native T1 relaxation time was lower in boys than in girls (1215 ± 23 vs 1252 ± 28 ms, p < 0.001), whereas global myocardial T2 relaxation time did not differ by sex (44.4 ± 2.0 vs 44.1 ± 2.4 ms, p = 0.384). Sex-stratified comprehensive percentile tables are provided for most relevant cardiac parameters. Interpretation: This cross-sectional study provides overall and sex-stratified CMR reference values for cardiac dimensions and function, and myocardial tissue properties, in adolescents. This information is useful for clinical practice and may help in the differential diagnosis of cardiac diseases, such as cardiomyopathies and myocarditis, in this population. Funding: Instituto de Salud Carlos III (PI19/01704).

5.
Antioxidants (Basel) ; 11(11)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36358511

RESUMO

Nitric oxide (NO) is important to cardiovascular health (CVH), and its bioavailability could be regulated by the antioxidant effect of polyphenols, improving endothelial function and consequently blood pressure (BP). However, scant research has been carried out on NO and CVH correlates in adolescent populations. Therefore, our aim was to investigate the association between NO and the CVH status and other health factors in adolescents. NO, total polyphenol excretion (TPE), anthropometric measurements, BP, blood lipid profile, blood glucose, diet, physical activity, and smoking status were recorded, while CVH score was classified as ideal, intermediate, and poor. Negative associations were observed between NO and body mass index, body fat percentage, BP, and triglycerides; and positive associations between NO and skeletal muscle percentage, HDL-cholesterol, fruit and vegetable intake, and TPE was observed. To capture more complex interactions among different factors, multiple linear regression was performed, obtaining a significant association between NO and fruit and vegetable intake (ß = 0.175), TPE (ß = 0.225), and systolic BP (ß = -0.235). We conclude that urinary NO levels are positively associated with the consumption of fruits and vegetables rich in antioxidants such as polyphenols and negatively associated with systolic BP.

6.
Antioxidants (Basel) ; 11(6)2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35740067

RESUMO

This study aimed to develop and validate a liquid chromatography/electrospray ionization-linear ion trap quadrupole-Orbitrap-high-resolution mass spectrometry (HPLC/ESI-LTQ-Orbitrap-HRMS) method to identify and quantify urinary microbial phenolic metabolites (MPM), as well as to explore the relationship between MPM and dietary (poly)phenols in Spanish adolescents. A total of 601 spot urine samples of adolescents aged 12.02 ± 0.41 years were analyzed. The quantitative method was validated for linearity, limit of detection, limit of quantification, recovery, intra- and inter-day accuracy and precision, as well as postpreparative stability according to the criteria established by the Association of Official Agricultural Chemists International. A total of 17 aglycones and 37 phase II MPM were identified and quantified in 601 spot urine samples. Phenolic acids were the most abundant urinary MPM, whereas stilbenes, hydroxytyrosol, and enterodiol were the least abundant. Urinary hydroxycoumarin acids (urolithins) were positively correlated with flavonoid and total (poly)phenol intake. An HPLC-ESI-LTQ-Orbitrap-HRMS method was developed and fully validated to quantify MPM. The new method was performed accurately and is suitable for MPM quantification in large epidemiological studies. Urinary lignans and urolithins are proposed as potential biomarkers of grain and nut intake in an adolescent population.

7.
Proc Natl Acad Sci U S A ; 117(34): 20785-20793, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32778592

RESUMO

Transfer RNA (tRNA) activity is tightly regulated to provide a physiological protein translation, and tRNA chemical modifications control its function in a complex with ribosomes and messenger RNAs (mRNAs). In this regard, the correct hypermodification of position G37 of phenylalanine-tRNA, adjacent to the anticodon, is critical to prevent ribosome frameshifting events. Here we report that the tRNA-yW Synthesizing Protein 2 (TYW2) undergoes promoter hypermethylation-associated transcriptional silencing in human cancer, particularly in colorectal tumors. The epigenetic loss of TYW2 induces guanosine hypomodification in phenylalanine-tRNA, an increase in -1 ribosome frameshift events, and down-regulation of transcripts by mRNA decay, such as of the key cancer gene ROBO1. Importantly, TYW2 epigenetic inactivation is linked to poor overall survival in patients with early-stage colorectal cancer, a finding that could be related to the observed acquisition of enhanced migration properties and epithelial-to-mesenchymal features in the colon cancer cells that harbor TYW2 DNA methylation-associated loss. These findings provide an illustrative example of how epigenetic changes can modify the epitranscriptome and further support a role for tRNA modifications in cancer biology.


Assuntos
Neoplasias do Colo/genética , Mudança da Fase de Leitura do Gene Ribossômico , RNA de Transferência/genética , Ribossomos/genética , tRNA Metiltransferases/deficiência , Adulto , Idoso , Anticódon/genética , Anticódon/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/enzimologia , Neoplasias do Colo/metabolismo , Ilhas de CpG , Epigênese Genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Conformação de Ácido Nucleico , Fenilalanina/genética , Fenilalanina/metabolismo , Regiões Promotoras Genéticas , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Transferência/metabolismo , Ribossomos/metabolismo , tRNA Metiltransferases/genética , tRNA Metiltransferases/metabolismo
8.
Rev. cuba. salud pública ; 36(4): 353-357, dic. 2010.
Artigo em Espanhol | LILACS | ID: lil-571728

RESUMO

Se aborda el estudio del por qué, siendo la bioética una ética para la vida, se ha dedicado mucha menos atención en su discurso al derecho a la vida, que al derecho a elegir la forma de morir. Ello tiene mucho que ver con el predominio del enfoque filosófico-metodológico principialista de corte anglosajón en el discurso bioético contemporáneo, el cual se analiza y se propone su complementación con el principio de la solidaridad, lo que favorecería la atención preferencial que merece el derecho a la vida como fundamental y preocupante


This article addressed why bioethics, which is ethics for life, has paid much more attention to the right of choosing the way of dying than to the right to life. This has a lot to do with the predominant Anglo-Saxon-type principled methodological and philosophical approach in the contemporary bioethical discourse that is also analyzed. It was suggested that this approach be supplemented with the principle of solidarity, all of which will encourage paying preferential attention to the right to life as fundamental and worrying


Assuntos
Bioética/educação , Bioética/tendências
9.
Rev. habanera cienc. méd ; 6(supl.5)oct.-dic. 2007.
Artigo em Espanhol | LILACS | ID: lil-629806

RESUMO

Se hace una breve introducción a la historia de los Comités de Etica de la Investigación que sirve de contexto para analizar su creación en Cuba, a partir de lo cual se enuncia que la falta de preparación de los miembros es la causa fundamental de las dificultades que presenta el funcionamiento de los mismos en nuestro país. Seguidamente se describen y analizan estas dificultades haciendo propuestas para su erradicación consistentes en delimitar quiénes deben responsabilizarse con la formación de sus miembros y qué contenidos y habilidades deben enseñar.


In the work begins making a brief introduction to the history of the Committees of Ethics of the Investigation that serves as context to analyze their creation in Cuba , starting from that which is enunciated that the lack of preparation of their members is the fundamental cause of the difficulties that presents its operation in our country. Subsequently are described and analyzed the difficulties making proposals for their eradication consistent in defining who should take the responsibility with the formation of their members and how contained and abilities should teach.

10.
Gac. méd. espirit ; 1(1): [7], ene.- abr. 1999.
Artigo em Espanhol | LILACS | ID: biblio-1518464

RESUMO

El presente artículo da respuesta a una interrogante que siempre ha preocupado al hombre: ¿por qué las personas se suicidan?. La solución a este problema se hace valorando distintas soluciones teóricas, filosóficas y médicas, que han tratado de explicar el mismo, fundamentando estas tesis con argumentos filosóficos que pueden ser de gran utilidad al médico en su labor de diagnóstico y prevención de la conducta suicida.


Assuntos
Suicídio/prevenção & controle
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA