海洋红酵母多糖提取及其对日本蟳血清中部分免疫活性因子的影响

以海洋红酵母为材料, 通过化学抽提法得到多糖, 用经典的Sevag 法进行脱蛋白处理, 经多级沉淀得到纯糖并采用硫酸-蒽酮法测得其中葡萄糖含量; 考马斯亮蓝法分析蛋白质含量。以定量海洋红酵母多糖人工注射日本蟳, 注射等量生理盐水为对照, 定时测定其血清中部分免疫活性因子的活性; 实验表明: 提取多糖为蛋白多糖, 其中葡萄糖含量为3.6%, 蛋白质含量1.9%, 含有多种氨基酸, 其中天冬氨酸含量最多; 注射后12 h 日本蟳血清中总超氧化物歧化酶(T-SOD) 活力达到最高, 酸性磷酸酶(ACP) 活力在注射后24 h 达到最高, 碱性磷酸酶(AKP) 48 h 达到最高, 过氧化氢酶(CAT) 48 h 达到最高, 溶菌酶(LZM) 12 h 即达到最高, 最高点分别高于对照组24%、43%、25%、35%、95%; 72 h 后都恢复至对照组水平。结论: 海洋红酵母多糖注射48 h 内日本蟳体内免疫活性因子均有不同程度的提高, 对日本蟳有较强免疫刺激作用。     

中国树鼩实验动物化研究进展和展望

该文回顾了我国树鼩驯养繁殖和研究的发展历史,介绍了树鼩实验动物化研究的最新进展,并结合我国目前的状况,提出了今后的工作建议:加强实验树鼩标准化(包括地方和国家标准)的研究、近交系动物的研制、达到商业化树鼩的基础分子与细胞生物学研究工具的研制、人类重大疾病树鼩动物模型研究和建设国家实验树鼩种源基地等。     

LC/MS evaluation of metabolism and membrane transport of bombesin peptides

Two bombsin peptides, GRPR agonist [Aca-QWAVGHLM-NH₂] and antagonist [fQWAVGHL-NHEthyl] were evaluated. We employed the highly sensitive Waters Q-Tof Premier MS coupled with a UPLC system to identify the metabolites produced by rat hepatocytes or PC-3 human prostate cancer cells; and we utilized the AB/MDS 4000 Q-Trap LC/MS/MS system with highly sensitive quantitative and qualitative performance, to quantitatively analyze the internalization of GRPR agonist and antagonist in PC-3 cells. The major metabolites of both GRPR agonist and antagonist were the result of peptide bond hydrolysis between W and A which was demonstrated by observation of the N-terminal fragment m/z 446 (Aca-QW-OH) for agonist and m/z 480 (fQW-OH) for antagonist. Both peptides were also hydrolyzed between A and V which formed peaks m/z 517 [Aca-QWA-OH] and m/z 555 (VGHLM-NH2) for the agonist and m/z 551 [fQWA-OH] and m/z 452 (VGHL-NHEthyl) for the antagonist. The peptide agonist also formed a unique metabolite that resulted from hydrolysis of the C-terminal amide. The antagonist showed significantly slower metabolism as compared to the agonist in both rat hepatocytes and PC-3 cells. The antagonist also showed significantly lower PC-3 cell internalization rate than that of the agonist. In conclusion, the metabolism profiles of both GRPR agonist and antagonist peptides were identified by LC/MS. The antagonist peptide was more stable than the agonist peptide in rat hepatocyte incubation. One major factor could be the hydrolysis-resistant C-terminal L-NHEthyl group compared with the unsubstituted amide of the agonist. Another factor could be different amino acid sequences of the agonist and antagonist that may also influence the enzymatic hydrolysis. The antagonist ligand is potentially more useful for receptor-targeted imaging due primarily to its higher metabolic stability.     

幽门螺杆菌感染者CD4~+ CD25~+调节性T细胞的检测及其相关性分析

目的检测幽门螺杆菌(Helicobacter pylori,H.pylori)感染阳性的胃部疾病患者外周血中CD4+CD25+调节性T细胞(Treg细胞)的百分含量及转化生长因子-β1(transforming growth factor-β1,TGF-β1)的水平,探讨CD4+CD25+调节性T细胞在H.pylori感染中的免疫调节作用及意义。方法采用流式细胞术检测H.pylori感染的慢性浅表性胃炎、胃癌前病变和胃癌患者外周血中CD4+CD25+调节性T细胞的含量、CD4+CD25+T细胞中表达FOXP3的细胞比例;并采用ELISA方法检测H.pylori感染者血清中TGF-β1的含量,无H.pylori感染的患者作为阴性对照。结果 H.pylori感染的患者外周血中CD4+CD25+调节性T细胞的百分含量及TGF-β1的水平较不伴有H.pylori感染的患者显著升高(P<0.05);H.pylori感染的浅表性胃炎、胃癌前病变及胃癌患者外周血中CD4+CD25+T淋巴细胞的百分含量及CD4+CD25+T细胞中表达FOXP3的细胞比例随病变严重程度的进展逐渐升高,差异有统计学意义(P<0.05);H.pylori感染的患者血清中TGF-β1水平也随病变严重程度的进展逐渐升高,差异有统计学意义(P<0.05)。结论 H.pylori感染可增加CD4+CD25+调节性T细胞的含量和TGF-β1的水平;随着病变严重程度的进展,CD4+CD25+调节性T细胞的含量和TGF-β1的水平逐渐升高,CD4+CD25+调节性T细胞百分含量和TGF-β1水平可作为临床判断病情进展的指标。     

中国秋海棠属 (秋海棠科) 植物的DNA条形码评价

秋海棠属植物种类繁多,形态变异多样,导致种类的系统放置混乱,近缘种类鉴定困难。利用DNA条形码实现物种快速准确的鉴定技术具有不受形态特征约束的优势,为秋海棠属植物的分类鉴定提供了新的方法。本研究选择4个DNA条形码候选片段（rbcL,matK,trnH psbA,ITS）对中国秋海棠属26种136个个体进行了分析。结果显示：叶绿体基因rbcL,matK和trnH psbA种内和种间变异小,对秋海棠属植物的鉴别能力有限;ITS/ITS2种内和种间变异大,在本研究中物种正确鉴定率达到100%/96%,可考虑作为秋海棠属DNA条形码鉴定的候选片段。研究结果支持中国植物条形码研究组建议将核基因ITS/ITS2纳入种子植物DNA条形码核心片段中的观点。     

肝细胞生长因子对人羊水干细胞迁移和黏附能力的影响

目的分离培养及鉴定羊水干细胞（hAFSC）,并研究肝细胞生长因子（HGF）对羊水干细胞迁移、黏附能力的影响。方法使用细胞贴壁法分离培养羊水干细胞,细胞免疫荧光及westernblot鉴定羊水干细胞,Transwell小室分析HGF对羊水干细胞迁移的作用。明胶贴壁法分析HGF对羊水干细胞黏附能力的作用。两组之间数据的比较采用独立样本t检验。结果分离的羊水干细胞均表达特异性标记物Oct-4、c-kit、SSEA-4、CD105。HGF在体外对hAFSC的迁移有趋化作用,对照组和HGF组每个视野的迁移细胞数分别为38±2.5和80±3.2。对黏附能力有促进作用,对照组和HGF组每个视野的黏附细胞数分别为19±1.5和50±2.7,差异均有统计学意义（P〈0.01）。结论 HGF可趋化羊水干细胞的迁移,增强羊水干细胞的黏附能力。     

Paradoxical roles of autophagy in different stages of tumorigenesis: protector for normal or cancer cells

Autophagy serves as a dynamic degradation and recycling system that provides biological materials and energy in response to stress. The role of autophagy in tumor development is complex. Various studies suggest that autophagy mainly contributes to tumor suppression during the early stage of tumorigenesis and tumor promotion during the late stage of tumorigenesis. During the tumorization of normal cells, autophagy protects genomic stability by retarding stem cells-involved damage/repair cycle, and inhibits the formation of chronic inflammatory microenvironment, thus protecting normal cell homeostasis and preventing tumor generation. On the other hand, autophagy also protects tumor cells survival during malignant progression by supporting cellular metabolic demands, decreasing metabolic damage and supporting anoikis resistance and dormancy. Taken together, autophagy appears to play a role as a protector for either normal or tumor cells during the early or late stage of tumorigenesis, respectively. The process of tumorigenesis perhaps needs to undergo twice autophagy-associated screening. The normal cells that have lower autophagy capacity are prone to tumorization, and the incipient tumor cells that have higher autophagy capacity possibly are easier to survival in the hash microenvironment and accumulate more mutations to promote malignant progression.     

两种气候条件下不同有机质含量农田黑土真菌群落结构特征

【背景】东北黑土土壤肥沃,有机质含量丰富,是我国重要的粮食生产基地,同时也是受气候变化影响的敏感区。土壤微生物对环境因子变化的响应敏感,并且与土壤肥力密切相关,因此,研究环境因子改变对土壤微生物的影响有助于维持农田黑土生产力。【目的】探究有机质含量与气候条件对农田黑土真菌群落结构、多样性的影响,为全球气候变化条件下黑土区农业可持续发展提供重要基础数据和理论依据。【方法】利用黑土空间移位试验,采用Illumina MiSeq测序技术对农田黑土真菌种类进行预测,并对其进行多样性和群落结构分析。【结果】两种气候条件下不同有机质含量农田黑土真菌种类均较丰富,土壤有机质含量对真菌多样性指数的影响不大,气候条件和施肥对真菌多样性的影响较大。在已知的真菌群落中,5种不同有机质农田黑土的优势菌门均为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)和接合菌门(Zygomycota),占总序列的92.5%。在气候较冷条件下,OTU数量、Chao1指数、Shannon指数和Simpson指数均出现不同程度的降低;施肥也会降低各有机质含量农田黑土中真菌物种数量和多样性,但是降低幅度随有机质含量升高而逐渐减小。气候因子、有机质含量、全氮、施肥和pH是影响不同有机质含量农田黑土中真菌群落结构发生变化的主要因素。【结论】有机质含量、施肥和气候均一定程度上改变了农田黑土中真菌群落多样性和群落结构。气候条件和施肥对农田黑土真菌群落结构影响较大,而有机质含量对其影响较小,但前两者的影响会随土壤有机质含量的增加而呈减弱趋势。这些影响在子囊菌门群落结构中表现明显。     

Iminoheterocycles as γ-secretase modulators

The synthesis of a novel series of iminoheterocycles and their structure–activity relationship (SAR) as modulators of γ-secretase activity will be detailed. Encouraging SAR generated from a monocyclic core led to a structurally unique bicyclic core. Selected compounds exhibit good potency as γ-secretase modulators, excellent rat pharmacokinetics, and lowering of Aβ₄₂ levels in various in vivo models.