尼群地平对实验性糖尿病大鼠心肌收缩性的影响

腹腔注射链脲佐霉素（６５ｍｇ／ｋｇ）诱发Ｗｉｓｔａｒ大鼠糖尿病。糖尿病发病４周后,向饲料中加尼群地平（３０ｍｇ·ｋｇ－１·ｄ－１）。结果表明,糖尿病４周时大鼠心室舒张功能首先受损,８周后心室舒张和收缩功能均明显受累。尼群地平处理对糖尿病大鼠的心肌收缩性有一定的改善作用。提示尼群地平对大鼠糖尿病性心肌病有一定有益作用。     

藻－菌生态系统代谢功能的生态学研究

在室内模拟条件下,研究了一些生态因子对藻－菌（Ａ＋Ｂ）生态系统代谢有机碳（Ｃ６Ｈ１２Ｏ６）、ＮＨ３－Ｎ和无机磷（ＩＰ）的影响．研究结果表明,当藻－菌生态系统中藻（Ａ）或菌（Ｂ）的起始数量一定时,其代谢Ｃ６Ｈ１２Ｏ６的速率,随与之组合的Ｂ或Ａ的起始数量增加（数量比则相应降低）而增加．在光照和黑暗条件下,Ａ＋Ｂ系统代谢上述３种营养物质的速率均有一定的差异．黑暗下Ｃ６Ｈ１２Ｏ６的平均代谢速率较光照下高１２．３％（Ｐ＜０．０５）,ＩＰ和ＮＨ３－Ｎ的平均代谢速率则分别较光照下低１４．４％（Ｐ＜０．０５）和１６．２％（Ｐ＜０．００１）．在Ａ＋Ｂ系统和Ａ、Ｂ单培养物中,３种营养物质的代谢速率均随有机负荷量增加而增加,而且Ａ＋Ｂ系统的代谢速率分别高于单培养的Ａ和Ｂ,其中ＮＨ３－Ｎ代谢尤为显著．文章还就生态系统结构与功能的关系问题进行了讨论．     

不同感染状态下EB病毒核抗原亚型表达的研究

本实验用免疫印迹法纯化的抗ＥＢＮＡ亚型抗体,结合显微荧光分光光度检测技术,检测在不同感染状态下,三种亚型ＥＢＮＡ抗原在细胞中的表达程度。结果表明,处于潜伏感染状态下的Ｒａｊｉ细胞ＥＢＮＡ－１表达量较大,经巴豆油和正丁酸诱导进入钝挫感染状态后ＥＢＮＡ－１表达减少,而ＥＢＮＡ－２的表达增强。Ｂ＿（９５－８）细胞也有相似的趋势。表明ＥＢ病毒的激活可能与不同ＥＢＮＡ亚型表达量的改变有关。     

Modified nucleotides in Bacillus subtilis tRNA(Trp) hyperexpressed in Escherichia coli.

In the present study, modified nucleotides in the B. subtilis tRNA(Trp) cloned and hyperexpressed in E. coli have been identified by TLC and HPLC analyses. The modification patterns of the two isoacceptors of cloned B. subtilis tRNA(Trp) have been compared with those of native tRNA(Trp) from B. subtilis and from E. coli. The modifications of the A73 mutant of B. subtilis tRNA(Trp), which is inactive toward its cognate TrpRS, were also investigated. The results indicate the formation of the modified nucleotides S4U8, Gm18, D20, Cm32, i6A/ms2i6A37, T54 and psi 55 on cloned B. subtilis tRNA(Trp). This modification pattern resembles the pattern of E. coli tRNA(Trp), except that m7G is missing from the cloned tRNA(Trp), probably on account of its short extra loop. In contrast, the pattern departs substantially from that of native B. subtilis tRNA(Trp). Therefore, the cloned B. subtilis tRNA(Trp) has taken on largely the modification pattern of E. coli tRNA(Trp) despite the 26% sequence difference between the two species of tRNA, gaining in particular the Cm32 and Gm18 modifications from the E. coli host. A notable difference between the isoacceptors of the cloned tRNA(Trp) was seen in the extent of modification of A37, which occurred as either the hypomodified i6A or the hypermodified ms2i6A form. Surprisingly, base substitution of guanosine by adenosine at position 73 of the cloned tRNA(Trp) has led to the abolition of the 2'-O-methylation modification of the remote G18 residue.     

番茄种子经激光和咖啡因处理后其当代生物效应的研究

咖啡因具有抑制一些酶的活性,可减弱或消除生物体自身对激光引起的生物效应的修复作用。试验证明咖啡因对番茄种子萌发有强烈的抑制作用,咖啡因和激光复合处理生物效应显著,可降低番茄种子的发芽,并促进番茄果实增大和生长前期速率加快。     

Blockage of MDM2-mediated p53 ubiquitination by yuanhuacine restrains the carcinogenesis of prostate carcinoma cells by suppressing LncRNA LINC00665

Prostate cancer (PCa) is a challenging issue for men's health worldwide due to its uncontrolled proliferation and high metastatic potential. Increasing evidence has supported plant extracts and natural plant derivatives as promising antitumor therapy with less toxic side effects. Yuanhuacine is an active component isolated from Daphne genkwa and can effectively suppress the tumorigenesis of several cancers. However, its role in PCa remains unclear. In this study, yuanhuacine dose-dependently inhibited the proliferation and induced apoptosis of PCa cells. Moreover, yuanhuacine also restrained the invasion and migration of PCa cells. Mechanically, yuanhuacine decreased the ubiquitination and degradation of p53 protein, and ultimately increased p53 levels, which was regulated by inhibiting the phosphorylation and total protein levels of mouse double minute 2 (MDM2). Moreover, elevation of MDM2 reversed the suppressive efficacy of yuanhuacine in PCa cell viability, invasion, and migration. The network pharmacologic and bioinformatics analysis confirmed that MDM2 might be a common target of D. genkwa and LINC00665. Furthermore, yuanhuacine inhibited LINC00665 expression. Upregulation of LINC00665 reversed yuanhuacine-mediated inhibition in MDM2 protein expression and suppressed p53 levels by enhancing its ubiquitination in yuanhuacine-treated cells. Importantly, the inhibitory effects of yuanhuacine on cell viability and metastatic potential were offset after LINC00665 elevation. Together, the current findings highlight that yuanhuacine may possess tumor-suppressive efficacy by inhibiting LINC00665-mediated MDM2/p53 ubiquitination signaling. Therefore, this study indicates that yuanhuacine may be a promising candidate for the treatment of PCa.     

牙龈卟啉杆菌W83单克隆抗体的研制与鉴定

牙龈类杆菌曾是重要的产黑色素类杆菌群菌株,最近重新命名为牙龈卟啉杆菌,该菌为牙周病龈下菌斑中关键性厌氧菌,与成人慢性牙周炎的发生、发展有密切关系。作者用牙龈卟啉杆菌侵袭型菌株W83,作为免疫原,通过免疫小鼠、细胞融合、筛选、克隆化,最后得到一株能够稳定分泌抗牙龈卟啉杆菌W83的单克隆抗体杂交瘤细胞系,经鉴定该单抗特异性良好,可用于临床该菌的检出和生态学研究。     

一株C3形态多重耐药大肠杆菌噬菌体生物学特性和基因组分析

【目的】多重耐药菌的出现对公共卫生安全构成严重威胁,本研究分离多重耐药大肠杆菌噬菌体,研究其生物学特性和基因组特征,为耐药菌的噬菌体疗法提供理论依据。【方法】使用双层平板法从污水样本中分离纯化大肠杆菌噬菌体;磷钨酸染色后通过透射电镜观察形态;测定其宿主范围,测定温度和pH稳定性、一步生长曲线和体外抑菌效果等生物学特性;体内抑菌试验评估噬菌体对多重耐药大肠杆菌N1203-1Af感染的大蜡螟幼虫的保护作用;基于全基因组测序对其基因组特点进行分析。【结果】本研究分离共得到5株大肠杆菌噬菌体,分别命名为pEC-S163-2.1、pEC-S163-2.2、pEC-M1167-5Ar.1、pEC-m1291-2Dr.1和pEC-N1203-2Af.1;电镜结果显示噬菌体pEC-N1203-2Af.1属于短尾噬菌体中罕见的C3形态型,头部较长,长是宽的2–3倍;pEC-N1203-2Af.1可裂解受试15株大肠杆菌中的3株;感染10 min后进入指数增长期,–20-50℃、pH值为4.0–10.0的环境下均能够保持稳定活性;大蜡螟幼虫感染大肠杆菌N1203-2Af后噬菌体pEC-N1203-2Af....     

Upgrading the genome of an elite japonica rice variety Kongyu 131 for lodging resistance improvement

Developing a new rice variety requires tremendous efforts and years of input. To improve the defect traits of the excellent varieties becomes more cost and time efficient than breeding a completely new variety. Kongyu 131 is a high-performing japonica variety with early maturity, high yield, wide adaptability and cold resistance, but the poor-lodging resistance hinders the industrial production of Kongyu 131 in the Northeastern China. In this study, we attempted to improve the lodging resistance of Kongyu 131 from perspectives of both gene and trait. On the one hand, by QTL analysis and fine mapping we discovered the candidate gene loci. The following CRISPR/Cas9 and transgenic complementation study confirmed that Sd1 dominated the lodging resistance and favourable allele was mined for precise introduction and improvement. On the other hand, the Sd1 allelic variant was identified in Kongyu 131 by sequence alignment, then introduced another excellent allelic variation by backcrossing. Then, the two new resulting Kongyu 131 went through the field evaluation under different environments, planting densities and nitrogen fertilizer conditions. The results showed that the plant height of upgraded Kongyu 131 was 17%–26% lower than Kongyu 131 without penalty in yield. This study demonstrated a precise and targeted way to update the rice genome and upgrade the elite rice varieties by improving only a few gene defects from the perspective of breeding.