Long-time discrete particle effects versus kinetic theory in the self-consistent single-wave model

The influence of the finite number N of particles coupled to a monochromatic wave in a collisionless plasma is investigated. For growth as well as damping of the wave, discrete particle numerical simulations show an N-dependent long time behavior resulting from the dynamics of individual particles. This behavior differs from the one due to the numerical errors incurred by Vlasov approaches. Trapping oscillations are crucial to long time dynamics, as the wave oscillations are controlled by the particle distribution inhomogeneities and the pulsating separatrix crossings drive the relaxation towards thermal equilibrium.Comment: 11 pages incl. 13 figs. Phys. Rev. E, in pres

Prolactinomas, Cushing's disease and acromegaly: debating the role of medical therapy for secretory pituitary adenomas

Pituitary adenomas are associated with a variety of clinical manifestations resulting from excessive hormone secretion and tumor mass effects, and require a multidisciplinary management approach. This article discusses the treatment modalities for the management of patients with a prolactinoma, Cushing's disease and acromegaly, and summarizes the options for medical therapy in these patients

Medical genetics in developing countries in the Asia-Pacific region: challenges and opportunities

Advances in genetic and genomic technology changed health-care services rapidly in low and middle income countries (LMICs) in the Asia-Pacific region. While genetic services were initially focused on population-based disease prevention strategies, they have evolved into clinic-based and therapeutics-oriented service. Many LMICs struggled with these noncommunicable diseases and were unprepared for the needs of a clinical genetic service. The emergence of a middle class population, the lack of regulatory oversight, and weak capacity-building in medical genetics expertise and genetic counseling services led to a range of genetic services of variable quality with minimal ethical oversight. Some of the current shortcomings faced include the lack of awareness of cultural values in genetic health care, the variable stages of socioeconomic development and educational background that led to increased demand and abuse of genetics, the role of women in society and the crisis of gender selection, the lack of preventive and care services for genetic and birth defects, the issues of gene ethics in medicine, and the lack of understanding of some religious controversies. These challenges provide opportunities for both developing and developed nations to work together to reduce the inequalities and to ensure a caring, inclusive, ethical, and cost-effective genetic service in the region

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Revisión sistemática del efecto de los folatos y otros nutrientes relacionados en la función cognitiva del adulto mayor Effect of folate and related nutrients on cognitive function in older people; systematic review

Antecedentes: El folato junto a otras vitaminas del complejo B cumplen importantes funciones en la modulación de la expresión génica y síntesis del ADN, siendo necesarios para la detoxificación de la homocisteína y la síntesis de neurotransmisores imprescindibles para el mantenimiento de la función cognitiva. Objetivo: Revisar sistemáticamente la evidencia científica sobre beneficios y/o riesgos de los folatos y nutrientes relacionados en la función cognitiva del adulto mayor. Material y método: "Revisión sistemática en Medline, vía Pubmed", y en referencias de artículos seleccionados entre los años 2005-2011, considerando específicamente nivel de folatos séricos e intraeritrocitarios, ingesta de folatos y función cognitiva en el adulto mayor. Resultados: Se encontraron doce estudios transversales, seis estudios de cohorte, y seis estudios clínicos randomizados a doble ciego que cumplieron con los criterios pre-establecidos. Conclusión: Esta revisión no permite concluir que la suplementación de ácido fólico tenga un efecto positivo sobre la función cognitiva en el adulto mayor. Considerando que bajos niveles séricos de folatos podrían relacionarse con un mayor riesgo de deterioro cognitivo y que altos niveles asociados a un bajo nivel de vitamina B12 sérica favorecería un mayor deterioro, se sugiere como medida precautoria revisar los niveles establecidos para fortificar alimentos con ácido fólico para limitar riesgos y maximizar beneficios.Background: Folate and other B complex vitamins play important roles in the synthesis of DNA, gene expression, homocysteine detoxification and synthesis of neurotransmitters necessary for the maintenance of cognitive function. Aim: Systematic literature review of benefit and/ risks of folate and related nutrients in cognitive function in older adults. Material and methods: "Medline via Pubmed systematic review" of selected articles from years 2010 and May 2011 and references of the selected articles looking specifically at serum and erythrocyte folate levels, and folate intake and cognitive function in older adults. Results: Twelve cross-sectional studies, six cohort studies and six randomized double-blind clinical studies that met pre-established criteria were selected for analysis. Conclusions: This review doesn´t support a benefit from folic acid supplementation on cognitive function in the elderly. Whereas low folate serum levels may be related to increased risk of cognitive impairment and high levels associated with low levels of vitamin B12 can contribute a further deterioration, it is suggested as precautory measure to re-examine the present level of food fortification with folic acid to maximize benefits and limit potential risks

FOLIC ACID SUPPLEMENTATION AND COLORRECTAL ADENOMA RECURRENCE; SYSTEMATIC REVIEW

Antecedentes: Estudios observacionales muestran que los niveles de folatos podrían estar asociados con el desarrollo de adenomas y cáncer colorrectal, sugiriendo que la suplementación de ácido fólico podría tener un efecto preventivo. Objetivo: Revisar sistemáticamente la evidencia científica proveniente de estudios clínicos randomizados con placebo y controlados que permitan conocer los efectos de la suplementación del ácido fólico sobre la recurrencia de adenomas colorrectales. Material y método: Revisión sistemática en Medline, vía Pubmed de estudios clínicos randomizados, con placebo y controlados a doble ciego y sus referencias, que evaluen específicamente el efecto de la suplementación de ácido sobre la recurrencia de adenomas colorrectales. Resultados: Siete estudios clínicos randomizados que cumplían los criterios de inclusión fueron seleccionados y evaluados. Conclusión: Los estudios seleccionados no permiten concluir que la suplementación de ácido fólico tenga un efecto beneficioso sobre la recurrencia de adenomas colorrectales. Se observa en algunos estudios diferencias de riesgo según tipo de folatos que sugieren revisar los criterios y niveles de suplementación en algunos subgrupos de población con mayores riesgos