Melatonin induces apoptosis of colorectal cancer cells through HDAC4 nuclear import mediated by CaMKII inactivation

Melatonin induces apoptosis in many different cancer cell lines, including colorectal cancer. However, the precise mechanisms involved remain largely unresolved. In this study, we provide evidence to reveal a new mechanism by which melatonin induces apoptosis of colorectal cancer LoVo cells. Melatonin at pharmacological concentrations significantly suppressed cell proliferation and induced apoptosis in a dose‐dependent manner. The observed apoptosis was accompanied by the melatonin‐induced dephosphorylation and nuclear import of histone deacetylase 4 (HDAC4). Pretreatment with a HDAC4‐specific siRNA effectively attenuated the melatonin‐induced apoptosis, indicating that nuclear localization of HDAC4 is required for melatonin‐induced apoptosis. Moreover, constitutively active Ca²⁺/calmodulin‐dependent protein kinase II alpha (CaMKIIα) abrogated the melatonin‐induced HDAC4 nuclear import and apoptosis of LoVo cells. Furthermore, melatonin decreased H3 acetylation on bcl‐2 promoter, leading to a reduction of bcl‐2 expression, whereas constitutively active CaMKIIα(T286D) or HDAC4‐specific siRNA abrogated the effect of melatonin. In conclusion, the present study provides evidence that melatonin‐induced apoptosis in colorectal cancer LoVo cells largely depends on the nuclear import of HDAC4 and subsequent H3 deacetylation via the inactivation of CaMKIIα.     

米索前列醇联合依沙吖啶在中晚期妊娠引产中的临床应用

目的 探讨米索前列醇联合依沙吖啶在中晚期妊娠引产中的应用效果。方法 选取西安交通大学附属3201医院2012年1月—2017年12月收治的138例中晚期妊娠引产患者，按引产方式分为对照组、观察组，各69例。对照组使用乳酸依沙吖啶注射液进行引产，观察组在对照组的基础上联合使用米索前列醇进行引产。比较两组引产效果、胎儿娩出时间、阴道出血量及不良反应的发生情况。结果 观察组引产有效率是100%，显著高于对照组的91.75%（P<0.05）。观察组胎儿娩出时间<35 h的人数占比显著高于对照组（P<0.05）。观察组患者阴道出血量显著低于对照组（P<0.05），两组不良反应的发生率间差异不显著。结论 米索前列醇联合依沙吖啶在中晚期妊娠引产中的效果较好，可显著提高引产有效率、缩短胎儿娩出时间，值得临床应用。     

Quantitative chemical exchange saturation transfer (qCEST) MRI – omega plot analysis of RF‐spillover‐corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate

Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST‐weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH‐dependent exchange rate followed a dominantly base‐catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd.     

探析新型冠状病毒肺炎的眼表损害及中西医治疗对策＊

新型冠状病毒肺炎（corona virus disease 2019，COVID-19）自2019年12月爆发以来，由于具有高传染性，迅速在世界各地蔓延，国内外疫情防治形势空前严峻。COVID-19不仅造成肺部、肠道、肾脏等多脏器损害，且部分患者以眼表损害为首发或伴发症状出现，临床上很容易被忽视。COVID-19的眼表损害归属于祖国医学“天行赤眼”范畴，本文结合国内外最新的文献报道，探讨新型冠状病毒（2019 novel corona virus，2019-nCoV）对眼表的损害，阐明其可能机制，并从中西医角度提出可行的治疗措施。     

翻转课堂教学法在消化内科临床带教的应用评价

目的 探讨翻转课堂教学法在消化内科临床带教的教学效果.方法 选取2018年10月—2019年10月在消化内科进行临床见习的护生48人(全部为女生),按照实习先后顺序,前24人作为试验组,给予翻转课堂教学法教学;后24人作为对照组,采用传统的带教模式.讨论两组护生在理论和操作成绩和对带教满意度方面有无差异.两组学生在试验开始之前的成绩相比较,差异无统计学意义(P>0.05).结果 试验组在理论、操作、教学满意度等方面的成绩均高于对照组,P<0.05.结论 翻转课堂教学法在消化内科的临床带教中有较好的教学效果,可以提高学生的学习成绩和教学满意度.