The effect of vindoline C-16 substituents on the biomimetic coupling reaction: synthesis and cytotoxicity evaluation of the corresponding vinorelbine analogues

A new series of vinorelbine analogues are designed and synthesized to explore the vindoline C-16 substituent effects on the biomimetic coupling with catharanthine, and the structure-activity relationships of these vinorelbine analogues as cytotoxic agents are also studied. The results show that introduction of severe steric hindrance and/or electron-withdrawing group at C-16 site are not propitious to improving the yields of the coupling reaction, and the SAR information collected so far suggests that small alkyl groups substituted at C-16 of vindoline are conductive to maintaining the cytotoxicity.     

Can puzzle feeders be used as cognitive screening instruments? Differential performance of young and aged female monkeys on a puzzle feeder task

Conventional cognitive testing of monkeys is time‐consuming and involves single‐caging and food or water deprivation. Here we report a novel test of global cognitive performance that can be completed in a short time period without food/water or social restrictions. Nine mazes of increasing difficulty were developed using a standard puzzle feeder, and the maze‐solving performance of ten young and five aged female cynomolgus monkeys (Macaca fascicularis) was tested. The young monkeys solved maze configurations at higher levels of difficulty and solved the first level of difficulty more quickly than aged monkeys. This task discriminated performance by age in nonhuman primates as do more conventional forms of cognitive testing and indicates that this task may be a quick and easy assessment of global cognitive function. Am. J. Primatol. 49:195–202, 1999. © 1999 Wiley‐Liss, Inc.     

异育淇鲫及其双亲同工酶的比较研究

用4.5％聚丙烯酰胺凝胶平板电泳研究了异育淇鲫及其母本淇鲫和父本兴国红鲤的肌可溶性蛋白以及肾、肝、眼、背白肌和心等五种组织的乳酸脱氢酶(LDH)、苹果酸脱氢酶(MDH)和酯酶(EST)。结果发现:异育淇鲫的肌可溶性蛋白以及同工酶的电泳图谱与母本淇鲫相同而与父本兴国红鲤显著不同,因而认为异育淇鲫是淇鲫雌核发育的产物,父本基因对子代基本无影响。在此基础上,本文对异源精子在雌核发育中所起的生物学作用进行了初步探讨。     

甘松醛：一个新的倍半萜过氧化物

从甘松(Nardostachys chinensis.Batal)的根中分离到了一个新的倍半萜过氧化物——甘松醛(Nardosaldehyde),并通过J-分解谱等二维核磁共振技术鉴定了其结构。     

培养的内皮细胞和平滑肌细胞之间间隙连接形成及连接通讯的研究

本实验以离子电渗法将荧光黄注入细胞内,观察培养的EC 与SMC 同类及异类细胞间连接通讯现象,证实SMC 与EC 在培养中可形成同类或异类细胞GJ 结构,两种细胞间有接触介导的物质交流。EC-EC 之间的细胞通讯比SMC-SMC 和SMC-EC 之间为强。对SMC 有促增殖作用的LDL(100 μg LDL-蛋白质/ml)及胰岛素(15 mu/ml)对这种连接通讯有抑制作用,促癌剂TPA 几乎完全抑制此种连接通讯。结果提示高浓度LDL 及胰岛素等可能通过抑制SMC 与EC 之间的连接通讯而使SMC 脱离正常控制而大量增殖,促进AS发生、发展。故推论促进细胞连接通讯的因子,可能对AS 有防治作用,值得进一步研究。     

Naringenin Decreases Invasiveness and Metastasis by Inhibiting TGF-β-Induced Epithelial to Mesenchymal Transition in Pancreatic Cancer Cells

Epithelial to mesenchymal transition (EMT) promotes cellular motility, invasiveness and metastasis during embryonic development and tumorigenesis. Transforming growth factor-β (TGF-β) signaling pathway is a key regulator of EMT. A lot of evidences suggest that this process is Smad3-dependent. Herein we showed that exposure of aspc-1 and panc-1 pancreatic cancer cells to TGF-β1 resulted in characteristic morphological alterations of EMT, and enhancement of cell motility and gemcitabine (Gem) resistance along with an up-regulation of EMT markers genes such as vimentin, N-cadherin, MMP2 and MMP9. Naringenin (Nar) down-regulated EMT markers expression in both mRNA and protein levels by inhibiting TGF-β1/Smad3 signal pathway in the pancreatic cancer cells. Consequently, Nar suppressed the cells migration and invasion and reversed their resistance to Gem.     

调蓄河湖群菹草(Potamogeton crispus L.)功能性状特征及其与环境因子的关系

调水工程引起的多环境因子关联变化对沉水植物群落的影响机制有待深入探讨。以南水北调东线工程调蓄河湖群中菹草种群为研究对象,分析了京杭运河(YH)、高邮湖(GY)、洪泽湖(HZ)、骆马湖(LM)、南四湖上级湖(NS1)、南四湖下级湖(NS2)和东平湖(DP)7个调蓄河湖中菹草个体功能性状特征及其与环境因子间的关系。结果表明:(1)除高锰酸盐指数(COD_(Mn))、浊度(Tur)和底泥有机质含量(S_o)外,总氮(TN)、硝氮(NO_3-N)、氨氮(NH_4-N)、总磷(TP)、正磷酸盐(PO_4-P)、硅酸盐(SiO_4-Si)、叶绿素a(Chla)、总溶解性固体(TDS)、透明度(SD)、消光系数(K)、水温(T)、电导率(Cond)、酸碱度(pH)、溶解氧(DO)和底泥含水率(S_w)在河湖间差异达到了极显著水平;(2)菹草株高、茎分支数、茎节数、茎节长、茎直径、相对茎长、叶片数、叶厚、叶长、叶宽、叶面积、比叶面积、株重、茎重、叶重、茎叶比、茎干物质比、叶干物质比在河湖间差异极显著;(3)河湖群内菹草种群18个功能性状中,按变异系数从小到大依次为:叶宽、茎直径、叶长、茎干物质比、叶干物质比、叶面积、株高、茎节长、相对茎长、茎叶比、叶厚、茎节数、茎重、叶片数、株重、比叶面积、叶重、茎分支数;7个调蓄河湖间,按照所有性状变异系数平均值从大到小排序依次为:南四湖下级湖、洪泽湖和京杭运河、高邮湖、东平湖、南四湖上级湖、骆马湖;(4)环境因子共解释了功能性状方差变异的49.43%;叶性状主要受营养因子(TN、NO_3-N、SiO_4-Si)影响;茎性状与光照因子(Chla和SD)密切相关;底泥因子(S_o)对茎叶生物量分配起主要作用。