An in vitro model for cell-cell interactions

Summary Heterotypic cell-cell interactions appear to be involved in the control of development and function in a wide variety of tissues. In the vasculature, endothelial cells and mural cells (smooth muscle cells or pericytes) make frequent contacts, suggesting a role for intercellular interactions in the regulation of vascular growth and function. We have previously grown endothelial cells and mural cells together in mixed cultures and found that heterocellular contact led to endothelial growth inhibition. However, this mixed culture system does not lend itself to the examination of the effects of contact on the phenotype of the individual cell types. We have therefore developed a co-culture system in which cells can be co-cultured across a porous membrane, permitting intercellular contact while maintaining pure cell populations. Co-culture of endothelial cells and smooth muscle cells across membranes with pore sizes of 0.02, 0.4, 0.6, and 0.8μm maintained the two cell types as homogeneous populations, whereas smooth muscle cells migrated across the membrane through pores of 2.0μm. Vascular cell co-culture across membranes with 0.8-μm pores resulted the inhibition of endothelial cell proliferation and the generation of conditioned media which inhibited endothelial cell growth. The arrangement of the cells in this co-culture system mimics thein vivo orientation of vascular cells in which mural cells are separated from the abluminal surface of the endothelium by a fenestrated internal elastic lamina or basement membrane. Because this co-culture system maintains separable populations of cells in contact or close proximity allowing for biochemical and molecular analyses of pure populations, it should prove useful for the study of cell-cell interactions in a variety of systems.     

冬小麦原生质体培养的胚状体直接发生

冬小麦品种“京花一号”胚性愈伤组织在改良的N₆培养基(NBD培养基)上继代得到易碎型胚性愈伤组织,转入改良MS液体培养基(MSDL培养基)后得到胚性悬浮系,分离的原生质体在改良的MS培养基(MSDP培养基)上培养,再生细胞直接产生体细胞胚胎,并再生出完整植株。体细胞胚胎形成过程与小麦合子胚的形成过程十分相似。     

中国水仙(Narcissus tazetta var.chinensis)的组织培养

以栽培的中国水仙Narcissus tazetta var.Chinensis鳞茎为实验材料,采取“无液处理”的简捷方法获取外植体,并筛选出中国水仙离体鳞茎培养的最佳培养基。     

培养大鼠颈上神经节单烟碱受体通道及突触电流的膜片钳研究

在培养１─２周的大鼠颈上神经节交感神经元标本上,用膜片钳技术记录了单烟碱受体通道电流及胆碱能突触电流,并分析了它们之间的关系。单烟碱受体通道至少有三种亚导状态,即１５ｐＳ,２７ｐＳ,３８ｐＳ,其中以２７ｐＳ最常见。通道有两种开放模式,即单个短促开放与长串开放。对应的平均开放时间分别为τ＿１＝１．７１ｍｓ,τ＿２＝１２．２４ｍｓ。对自发突触电流的分析表明,其下降相的衰减时间常数（τ＝１５．７±１ｍｓ）与上述长串开放的持续时间相当,提示在突触传递过程中,突触前末梢释放的ＡＣｈ引起了突触后神经元烟碱受体通道的长串开放。     

On-line monitoring of cell concentration of Perilla frutescens in a bioreactor

This article demonstrates the successful in situ real-time monitoring of the cell concentration of Perilla frutescens in a bioreactor by using a laser turbidimeter. It was found that turbidity measurements at 780 nm with the laser sensor were hardly affected by the red color of the anthocyanin produced by P. frutescens cells, nor by the aeration rate or agitation speed within the ranges investigated. There was an excellent linear relationship, with a correlation coefficient (r(2)) higher than 0.99, between the sensor's response and the cell concentration. The whole growth stage of the cells, i.e., lag, logarithmic, and stationary phases, in bioreactor cultivations, could be satisfactorily estimated on-line by means of the in situ turbidimeter. However, during the declining phase of the cells, an apparent deviation was observed between the on-line estimations and off-line measurements of cell concentrations by dry cell weight, while the wet cell weight could be estimated by the same turbidimeter system. We found that this deviation was caused by a decrease in the cell density due to an increase of the individual cell volume and a decrease of the cell dry weight during the declining phase. (c) 1993 John Wiley & Sons, Inc.     

两种药用黄芪比较生物学研究

通过栽培实验,本文对两种药用黄芪的个体发育节律,根,茎,叶,花及种子的生物学特性进行了较系统的比较研究,为确定蒙古黄芪（ＡｓｔｒａｇａｌｕｓｍｏｎｇｈｏｌｉｃｕｓＢｕｎｇｅ）为独立的种,提供了更为全面的依据。     

桔梗花药培养初报

本试验把花粉发育至单核靠边期的桔梗花药接在6种不同组合的培养基上诱导愈伤组织,并把诱导的愈伤组织转接到分化培养基,试图得出单倍体植株。结果表明：诱导率最高的培养基组合是N6 + 2,4-D 0.2mg·L^-1 + 6-BA1.0 mg·L-1,诱导率为89.6%;在N₆+6-BA1.0 mg·L^-1 + NAA0.5 mg·L^-1的分化培养基上最高分化率可达58.4%;经根尖压片检查染色体数目结果,分化的绿苗中弱小的植株是单倍体植株。     

Recent advances in plant cell cultures in bioreactors

Two key issues in the application of plant-cell-culture technology to the production of valuable secondary metabolites are reviewed: the selection of cell lines with suitable genetic, biochemical and physiological characteristics; and the optimization of bioreactor environments. Although great progress has been made in recent years in the design, selection and optimization of bioreactor hardware, optimization of environmental factors such as medium components, light irradiation and O₂ supply needs detailed investigations for each case. With a better understanding of plant cell metabolism and physiology, further developments in cultivation processes, such as process integration and on-line monitoring and control, can be expected in the near future.J.-J. Zhong and J.-T. Yu are with the Research Institute of Biochemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China T. Yoshida is with the International Center of Cooperative Research in Biotechnology (ICBiotech), Faculty of Engineering, Osaka University, Suita, Osaka 565, Japan.     

不同EGF和胰岛素水平对体外培养的大熊猫皮肤成纤维细胞的影响

用DME∶Ham sF12(1∶1)培养液,添加3个水平的EGF和2个水平的胰岛素,组合成6种培养体系(CS)分别培养大熊猫皮肤成纤维细胞。通过对细胞生长速度和染色体数目变异率进行测定,测得在添加10μg/ml的胰岛素和40 ng/ml的表皮生长因子的培养体系中,以1.673±0.185×105/ml密度接种细胞,经3.5天,密度达到6.890×105/ml,其生长速度最快;染色体数目为二倍体的百分率为75.77%。综合衡量,CS-5在本研究中更适合大熊猫皮肤成纤维细胞的培养。     

中国野生葡萄组织培养研究

对中国野生山葡萄左山—1、左山—2、燕山葡萄燕山—1和秋葡萄平利—7的叶片、叶柄、茎段及单芽茎段进行了离体培养研究。诱导左山—1叶片分化出不定芽的培养基为MS BA 5．0mg／L NAA0．1mg／L,诱导率2．5％;诱导平利—7叶柄分化出不定芽的培养基为MS BA7．0mg／L NAA0．1mg／L,诱导率1．95％;诱导左山—1、燕山—1和平利—7茎段分化出不定芽的培养基与叶柄相同,但诱导率相对较高,分别为8．25％、4．88％和6．49％;应用这一培养基对平利—7、左山—2的单芽茎段进行培养,丛状不定芽的诱导率均为100％。不定芽继代培养基为MS BA0．5mg／L IBA0．2mg／L;生根培养基为1／2MS IBA0．1—0.2mg／L。