基于循环血微小RNA预测心脏再同步化治疗疗效

心力衰竭是一类严重危害人类健康的重大疾病, 心脏再同步化是一种治疗心室收缩不同步的心力衰竭患者的疗法, 但并不是所有的患者都可以获益. 因此, 发掘可以预测心脏再同步化治疗反应性的生物标记物具有重大意义. 微小RNA 可以稳定地存在于循环血中, 反映各种疾病状态, 而本研究组的研究发现通过循环血微小RNA-30d 的高表达可以预测心脏再同步化治疗的反应性, 具有一定的应用前景.     

Circulating angiotensin II and adrenal receptors after nephrectomy

Mineralocorticoid secretion is predominantly controlled by the octapeptide angiotensin II, which exerts trophic actions on the adrenal glomerulosa and acute regulatory effects on aldosterone biosynthesis. The trophic actions include stimulation of angiotensin II receptors and enzymes of the aldosterone biosynthetic pathway, with corresponding enhancement of the aldosterone secretory capacity of the adrenal gland. The positive regulatory action of angiotensin II on its adrenal receptors occurs with elevations of the circulating peptide concentration within the physiological range and probably contributes to the increased sensitivity of the adrenal during sodium deficiency. In this action, angiotensin II differs from other hormones which decrease their target-cell receptors. However, the increase in adrenal angiotensin II receptors following nephrectomy has been interpreted as evidence for a tonic down-regulating effect of angiotensin II on its adrenal receptors. To clarify these conflicting views we evaluated the effects of nephrectomy on adrenal angiotensin II receptors in relation to blood angiotensin II and plasma electrolyte levels. We show here that hyperkalaemia contributes markedly to the post-nephrectomy increase in adrenal angiotensin II receptors, and that circulating angiotensin II levels persist for an unexpectedly long period after nephrectomy, presumably due to tissue generation of the octapeptide.     

In vitro effects of high molecular weight forms of ACTH on the fetal sheep adrenal

The direct involvement of the pituitary-adrenal axis in birth has been well established, at least in sheep, and its removal prolongs pregnancy. As part of the process the fetal sheep adrenal grows rapidly during the 10-15 d prepartum and is associated with a large rise in the plasma corticosteroid concentration. This does not seem to result from an increased ACTH secretion. The fetal adrenal in vivo seems refractory to circulating ACTH and shows poor response to elevation of plasma concentration. Thus the signal for the adrenal hypertrophy and the initiation of parturition remains unclear. The responsiveness of the fetal adrenal to ACTH has been re-examined using isolated adrenal cells. The study shows that in the fetal sheep these are not inherently unresponsive to ACTH, but that high-molecular-weight forms of ACTH block the action of ACTH. These peptides may be responsible for controlling the activity of the adrenal in situ.     

Psychology: red enhances human performance in contests

Red coloration is a sexually selected, testosterone-dependent signal of male quality in a variety of animals, and in some non-human species a male's dominance can be experimentally increased by attaching artificial red stimuli. Here we show that a similar effect can influence the outcome of physical contests in humans--across a range of sports, we find that wearing red is consistently associated with a higher probability of winning. These results indicate not only that sexual selection may have influenced the evolution of human response to colours, but also that the colour of sportswear needs to be taken into account to ensure a level playing field in sport.     

Evidence for local stimulation of ACTH secretion by corticotropin-releasing factor in human placenta

The hypothalamic-pituitary-adrenocortical axis is activated in pregnancy and parturition. Levels of immunoreactive corticotrophin releasing factor (irCRF), immunoreactive adrenocorticotropic hormone (irACTH) and cortisol concentrations in maternal plasma are elevated throughout gestation, increase further during labour and fall precipitously after parturition. The placenta contains biologically active CRF and ACTH and it has been suggested that the placenta produces these peptides during pregnancy. Here we show that irCRF is located in the cytotrophoblast cells of placenta collected at term. Using a monolayer primary culture of human placental cells we have found that CRF stimulates secretion of peptides containing the ACTH sequence in the placenta in a dose-dependent manner, as it does in the pituitary. This effect is reversed by a CRF antagonist and is mimicked by dibutyryl cyclic AMP and forskolin. Glucocorticoids, which suppress the secretion of pituitary ACTH, were found to have no influence on release of irACTH by the placenta. Oxytocin and prostaglandins stimulate irACTH and irCRF secretion from cultured placental cells and the irACTH-releasing activity of two prostaglandins is partially reversed by a CRF antagonist. Thus CRF may be involved in the paracrine regulation of placental irACTH secretion.     

Societal response to challenges of global change and human sustainable development

It is now widely accepted that carbon emission from human activities is an important driving force in global warming, and global change has a deep impact on sustainable development of human society. To meet the challenges of global change, the international community has reached a consensus that developed countries take strict actions in emission reduction, whereas developing countries take spontaneous efforts in reducing emissions under the guiding principle of common but differentiated responsibilities, with an agreed goal to restrict global surface temperature increase due to human activities to within 2℃ of pre-industrial levels. However, there is no clear pathway to reach this goal. A number of related questions must be addressed on principles to be followed, research emphasis and policy measures. Here we argue that response policies to address global change issues must be based on balanced development at regional and international levels, and on advancements in science and technology. This requires consideration of harmony not only between humans and nature but also within human societies, to properly deal with the relationship between global change and sustainable development. We must make equal efforts toward carbon emission reduction and carbon sequestration, and toward mitigation and adaptation. There should be more research support to reduce uncertainties in our understanding of global change. Addressing the challenges of global change creates great opportunities for the development of human society. This will facilitate transformation of energy use structure, improve and restore ecological functioning of the earth environment, transform production modes and ways of living in human society, and promote harmonic and balanced development at regional and international levels.