《免疫学基础与病原生物学》移动交互式数字教材在“抗疫”时期在线教学中的应用

新型冠状病毒肺炎疫情暴发以来,全国各级各类学校延期开学,但停课不停教、停课不停学。各学校教师利用各种网络资源开展在线教学,也为深入挖掘"互联网+教育"教学新模式带来了契机。本文以《免疫学基础与病原生物学》移动交互式数字教材(云教材)应用为例,介绍如何应用移动交互式数字教材创设合理的学习情境,从而实现交互式学习,提升线上学习教学效果。     

PP1-mediated moesin dephosphorylation couples polar relaxation to mitotic exit

Animal cells undergo dramatic actin-dependent changes in shape as they progress through mitosis; they round up upon mitotic entry and elongate during chromosome segregation before dividing into two [1-3]. Moesin, the sole Drosophila ERM-family protein [4], plays a critical role in this process, through the construction of a stiff, rounded metaphase cortex [5-7]. At mitotic exit, this rigid cortex must be dismantled to allow for anaphase elongation and cytokinesis through the loss of the active pool of phospho-Thr559moesin from cell poles. Here, in an RNA interference (RNAi) screen for phosphatases involved in the temporal and spatial control of moesin, we identify PP1-87B RNAi as having elevated p-moesin levels and reduced cortical compliance. In mitosis, RNAi-induced depletion of PP1-87B or depletion of a conserved noncatalytic PP1 phosphatase subunit Sds22 leads to defects in p-moesin clearance from cell poles at anaphase, a delay in anaphase elongation, together with defects in bipolar anaphase relaxation and cytokinesis. Importantly, similar cortical defects are seen at anaphase following the expression of a constitutively active, phosphomimetic version of moesin. These data reveal a new role for the PP1-87B/Sds22 phosphatase, an important regulator of the metaphase-anaphase transition, in coupling moesin-dependent cell shape changes to mitotic exit.     

The full-length genome analysis of a street rabies virus strain isolated in Yunnan province of China

The epidemic of rabies has rapidly increased and expanded in Yunnan province in recent years.In order to further analyze and understand the etiological reasons for the rapid expansion of rabies in Yunn...     

Analysis of the neutral polysaccharide fraction of MCP and its inhibitory activity on galectin-3

The pH-modified citrus pectin (MCP) has been demonstrated to inhibit galectin-3 in cancer progression. The components and structures of MCP related to this inhibition remained unknown. In this paper, we fractionated MCP on DEAE-cellulose column into a homogenous neutral fraction MCP-N (about 20?kDa) and a pectin mixture fraction MCP-A (wide molecular distribution on Sepharose CL-6B chromatography). Both MCP-N and MCP-A inhibited hemagglutination mediated by galectin-3 with minimum inhibition concentration (MIC) 625 and 0.5?μg/ml, respectively. MCP-N was identified to be a type I arabinogalactan (AG-I) with a main chain of β-1→4-galactan. MCP-N was digested by α-L-arabinofuranosidase to give its main chain structure fraction (M-galactan, around 18?kDa), which was more active than the original molecule, MIC 50?μg/ml. The acidic degradation of M-galactan increased the inhibitory activity, MIC about 5 times lower than M-galactan. These results above showed that the functional motif of the β-1→4-galactan fragment might lie in the terminal residues rather than in the internal region of the chain. Therefore, MCP-N and its degraded products might be developed to new potential galectin-3 inhibitors. This is the first report concerning the fractionation of MCP and its components on galectin-3 inhibition. The information provided in this paper is valuable for screening more active galectin-3 inhibitors from natural polysaccharides.     

D-ring modified novel isosteviol derivatives: Design, synthesis and cytotoxic activity evaluation

A series of polyhydric, amino alcohol and tricyclic derivatives were facilely synthesized by D-ring modification of isosteviol. These compounds were screened for their cytotoxic activities against four human tumor cell lines in vitro. Among them, the 15-α-aminomethyl-16-β-hydroxyl isosteviol 23 exhibits significant cytotoxicity superior to the positive control (cisplatin) against EC9706, PC-3 and HCT-116 cell lines.     

Increased intratumoral IL-22-producing CD4+ T cells and Th22 cells correlate with gastric cancer progression and predict poor patient survival

IL-22-producing CD4⁺ T cells (IL-22⁺CD4⁺ T cells) and Th22 cells (IL-22⁺IL-17^?IFN-γ^?CD4⁺ T cells) represent newly discovered T-cell subsets, but their nature, regulation, and clinical relevance in gastric cancer (GC) are presently unknown. In our study, the frequency of IL-22⁺CD4⁺ T cells in tumor tissues from 76 GC patients was significantly higher than that in tumor-draining lymph nodes, non-tumor, and peritumoral tissues. Most intratumoral IL-22⁺CD4⁺ T cells co-expressed IL-17 and IFN-γ and showed a memory phenotype. Locally enriched IL-22⁺CD4⁺ T cells positively correlated with increased CD14⁺ monocytes and IL-6 and IL-23 detection ex vivo, and in vitro IL-6 and IL-23 induced the polarization of IL-22⁺CD4⁺ T cells in a dose-dependent manner and the polarized IL-22⁺CD4⁺ T cells co-expressed of IL-17 and IFN-γ. Moreover, IL-22⁺CD4⁺ T-cell subsets (IL-22⁺IL-17⁺CD4⁺, IL-22⁺IL-17^?CD4⁺, IL-22⁺IFN-γ⁺CD4⁺, IL-22⁺IFN-γ^?CD4⁺, and IL-22⁺IL-17⁺IFN-γ⁺CD4⁺ T cells), and Th22 cells were also increased in tumors. Furthermore, higher intratumoral IL-22⁺CD4⁺ T-cell percentage and Th22-cell percentage were found in patients with tumor-node-metastasis stage advanced and predicted reduced overall survival. In conclusion, our data indicate that IL-22⁺CD4⁺ T cells and Th22 cells are likely important in establishing the tumor microenvironment for GC; increased intratumoral IL-22⁺CD4⁺ T cells and Th22 cells are associated with tumor progression and predict poorer patient survival, suggesting that tumor-infiltrating IL-22⁺CD4⁺ T cells and Th22 cells may be suitable therapeutic targets in patients with GC.     

韭菜迟眼蕈蚊发生规律及防治方法研究进展

韭菜迟眼蕈蚊是我国韭菜生产中的重要害虫,各韭菜种植区均有发生。随着北方设施农业的迅速发展,良好的温室环境使韭菜迟眼蕈蚊的为害愈加严重,已成为制约韭菜种植业发展的重要因素。上世纪80年代,分类学家正式确定韭菜迟眼蕈蚊Bradysia odoriphaga是我国韭菜根蛆类害虫的优势物种,此后,在生物学、生理学、生态学等基础研究领域和防治方法等应用研究领域,有关韭菜迟眼蕈蚊的研究都取得了很大进展。本文全面总结了韭菜迟眼蕈蚊在我国各韭菜种植区及不同种植模式下的发生规律,详细叙述了农业、物理、生物、化学等相关防治措施,综合介绍了韭菜迟眼蕈蚊防治方法近二十年内的研究成果,对未来韭菜迟眼蕈蚊的综合治理方向进行了展望。     

入侵植物喜旱莲子草和本地种接骨草光合生理特征对增温响应的差异

利用红外加热器模拟增温,比较入侵植物喜旱莲子草和本地种接骨草的光合特性对增温响应的差异,以预测气候变暖背景下入侵植物的入侵潜力,并为筛选替代控制植物提供依据。结果表明:增温导致喜旱莲子草和接骨草的叶绿素a/b值分别比对照显著提高6.21%和降低5.55%。无论增温与否,接骨草的叶绿素b含量显著高于喜旱莲子草,而叶绿素a/b值则相反。增温导致喜旱莲子草净光合速率显著提高9.23%,由于气孔导度增大引起蒸腾速率大幅度增加,使得其水分利用效率比对照显著降低10.64%。增温仅导致接骨草的气孔导度显著增加10.95%,而对其他气体交换特征无显著影响。对照条件下,尽管接骨草的气孔导度和胞间CO_2浓度分别显著低于喜旱莲子草7.03%和4.57%,但是前者的净光合速率和水分利用效率分别显著高于后者10.30%和11.92%。增温条件下,两种植物的净光合速率和气孔导度无显著差异,由于接骨草的蒸腾速率显著低于喜旱莲子草18.02%,故其水分利用效率显著高于后者26.45%。增温、物种及其两者的交互作用对光补偿点、光饱和点、最大净光合速率、暗呼吸速率和初始量子效率等光响应参数影响均不显著。总之,对照条件下,接骨草凭借较高的叶绿素b含量、净光合速率和水分利用效率,比喜旱莲子草具有更强的光合能力。但增温后,接骨草的光合优势被削弱。研究从光合生理角度证明接骨草有望作为喜旱莲子草的替代控制植物,但是未来气候变化背景下喜旱莲子草的入侵潜力可能增强。