Stress induces glucocorticoid-mediated apoptosis of rat Leydig cells in vivo

Stress can disrupt endocrine signalling in the male reproductive axis through high concentrations of glucocorticoids, the hallmark of stress. Our previous work revealed that a stress level of exogenous glucocorticoids could induce apoptosis of rat Leydig cells, which are the primary source of testosterone. The aim of this study was to investigate whether stress can induce apoptosis in rat Leydig cells in vivo and, if so, whether the process is the result of a direct effect of glucocorticoids. In a chronically stressed rat model, serum corticosterone concentration was increased significantly whereas serum testosterone was decreased. The frequency of apoptotic Leydig cells in stressed rats was also increased. Adrenalectomised rats subjected to chronic stress showed an elevated serum testosterone, while the apoptotic frequency of Leydig cells was not increased. It was established that glucocorticoid-induced Leydig cell apoptosis is mediated by glucocorticoid receptors (GRs), which translocate from cytoplasm to nucleus. Adenovirus microRNA-induced downregulation of GR expression in vitro alleviated the corticosterone-induced increase in apoptosis of Leydig cells. These results indicate that the stress-induced increase in corticosterone secretion resulted in apoptosis in rat Leydig cells in vivo, and thereby decreased testosterone synthesis.     

经皮肺活检对肺部病变的诊断价值

经皮肺活检技术应用已有100多年历史。随着影像技术的不断进步,目前已发展成为肺部疾病的重要诊断技术。本文综述了经皮肺活检对肺部病变的诊断价值。并探讨和比较了不同引导技术的特点,以及适应症、并发症及其处理。     

坚持中国化方向是我国伊斯兰教行稳致远的基础——高占福研究员访谈

―、学术研究缘起和经历问:高老师您好,我受《中国穆斯林》杂志委托,很高兴对您进行专访。您是从甘肃临夏走出来的回族学者,故乡是您驻留心间常思常念的一方热土,您在撰文或接受采访时曾多次表达自己浓厚的家乡情怀。有关故乡,您有哪些最值得回忆的往事?故乡对您走上学术研究之路,特别是您早期从事西北穆斯林问题研究产生了哪些重要影响?     

Patient Moral Relativism in the <Emphasis Type="Italic">Zhuangzi</Emphasis>

Moral relativism familiar in the Western philosophical tradition, according to David Lyons, is either agent relativism (moral judgments are relative to the standards of the agent or the agent group) or appraiser relativism (moral judgments are relative to the standards of the appraiser(s) or appraiser group(s)). As Lyons has convincingly argued, they are both problematic. However, in the ancient Chinese Daoist classic, the Zhuangzi, we can find a different type of moral relativism, which I call patient relativism (moral judgments are relative to the patients’ standards). In the essay, I aim to argue in what sense Zhuangzi is a patient relativist and how patient relativism can avoid the problem of agent relativism and appraiser relativism.     

Differences in Scope Assignments for Child and Adult Speakers of Mandarin

The present study used a Truth Value Judgment Task to investigate whether changes in sentence structure lead to corresponding changes in the assignment of scope relations by Mandarin-speaking children and adults. In one condition, participants were presented with ordinary negative sentences containing disjunction; this condition was designed to verify the existing claim that disjunction is a positive polarity item for adult speakers of Mandarin, but not for child speakers. In a second condition, participants were presented with negative sentences where the disjunction phrase was preposed from object position; this condition was designed to examine the extent to which changes in sentence structure can result in changes in scope assignments to negated disjunctions. The results indicate that the preposed disjunction phrase undergoes reconstruction for children, whereas reconstruction is blocked for adults. This finding also suggests that Mandarin-speaking children and adults exhibit different scope preferences for negated disjunctions, regardless of where the disjunction phrase appears in the surface syntax.