Immobilized cultivation of Dictyostelium discoideum with polyurethane foam

研究了聚氨酯泡沫应用于固定化盘基网柄菌的可行性,发现以简单处理过的聚氨酯泡沫为载体,能够高效实现盘基网柄菌的固定化培养。考察了载体粒径大小、载体量和摇床转速等对固定化培养的影响,在优化的培养条件和固定化条件下,盘基网柄菌的最大细胞密度是悬浮培养的2~4倍。The immobilization of D.discoideum with polyurethane foam(PUF) was proposed and the effects of PUF's properties on the immobilization was examined.The results showed that PUF was a suitable carrier for the efficient imoblization of D.discoideum.The effects of PUF addition and culture conditions were optimized to attain high density of D.discoideum.Under optimized culture conditions,high cell density of D.discoideum(4.56×107 cells/mL) has been achieved in the shake flasks,which was 2～4 times higher than that of free-cell culture in the axenic medium.国家自然科学基金资助项目(30370039

Improving the Expression Level of Soluble Human Fas Ligand by Cultivating Recombinant Dictyostelium discoideum in CMC-ALG Microcapsules

首先研究了应用于液芯羧甲基纤维素钠-海藻酸钙(CMC-ALG)微胶囊制备中的各种化学组分对重组盘基网柄菌生长的影响,然后考察不同组分浓度制备而成的各种CMC-ALG微胶囊内重组盘基网柄菌的生长情况,从而得到较适的微胶囊制备的组分配比(CMC12g·L-1,SA8g·L-1,CaCl2100g·L-1)。结果表明,在以上较适条件下制备的微胶囊内重组盘基网柄菌的生长得到了极大的改善,最大的细胞密度比游离培养时提高了4倍,达到了8.0×107mL-1;相应的人类可溶性Fas配体(FasL)的表达水平也提高了1.5倍,达到了315μg·L-1。最后,开展了微胶囊化重组盘基网柄菌的二次重复发酵FasL的研究,结果表明,经过二次重复批次培养,最大细胞密度可达到1.24×108mL-1,为游离培养的8～10倍,而且FasL的表达水平还能维持高水平(280μg·L-1),为游离培养时的2倍。The biocompatibility between the growth of Dictyostelium discoideum AX3-pLu8 and chemical components used for the preparation of carboxy methyl cellulose-alginate(CMC-ALG)microcapsules was evaluated at first,and then the effects of the concentrations of each component forming the capsule on the growth behaviors of D.discoideum cultivated in it were studied.For microencapsulated cultivating D.discoideum,it was found that the most suitable capsule components are 12 g?L?1 of CMC,8 g?L?1 of sodium alginate(SA)and 100 g?L?1 of CaCl2.Using the microcapsules with mentioned composition,the cell density in it can reach 8.0×107 mL?1,this value is about 5 times that could be observed in suspension culture,and correspondently,in the capsules a high concentration(315 μg?L?1)of soluble human Fas ligand(shFasL)was detected,which is about 2.5 times higher than that obtained in suspension culture under the same culture condition.In addition,the immobilized cells could be used effectively for repeated batch cultivation and in the second repeated batch cultivation,a very high cell density(up to 1.24×108 mL?1)and still a high expression of FasL(280 μg?L?1)could be obtained.国家自然科学基金资助(20306025,30370039

Expression of the Soluble Human Fas Ligand in Dictyostelium discoideum

［中文文摘］用PCR扩增从激活的人中性粒细胞中得到的编码可溶性Fas配体胞外区中第14 1个到第2 81个氨基酸的cDNA ,将其与hCG_β信号肽片段融合到质粒MB12neo中,随后导入到盘基网柄菌AX3细胞中,得到分泌性表达hFasL的重组菌AX3_H3。为提高shFasL的表达量,对质粒pMB12neo作了改造,得到衍生质粒pMB74。利用质粒pMB74克隆表达shFasL ,得到高通量表达shFasL的重组菌AX3_pLu8。在复杂培养基HL_5C中,重组菌的细胞密度可达(1 5～2 )×10 7 mL ,AX3_H3及AX3_pLu8分泌的shFasL浓度分别为2 3 5 μg L及2 0 6 μg L。利用合成培养基SIH培养重组菌AX3_H3及AX3_pLu8,细胞密度均达到(4～5 )×10 7 mL ,shFasL浓度则分别达到111μg L和4 2 0 μg L。［英文文摘］An expression system is described for high-yield production of recombinant soluble human FasL (shFasL) in Dictyostelium discoideum cells. DNA encoding amino acids 141～281 of hFasL was PCR amplified from cDNA derived from activated human neutrophils. The resulting product was fused with a DNA fragment encoding hCG-β signal peptide and cloned in the expression vector pMB12neo. Dictyostelium strain AX3 was transfected with this plasmid, yielding a recombinant strain called AX3-pCESFL95-H3. In order to mprove the shFasL expression level , pMB12neo was optimized by replacing its transcriptional terminatorPpolyadenylation segment of the 2H3 gene with an actin8 terminatorPpolyadenylation segment , yielding derived expression vector pMB741 The recombinant Dictyostelium strain called AX3-pLu8 was generated with this new plasmid. When the recombinant cells were cultivated in a complex HL-5C medium, a cell density of (115～2) ×107PmL was reached , and the shFasL level expressed by strains AX3-pCESFL95-H3 and AX3-pLu8 was 2315 μgPL and 206μgPL , respectively. By using a newly developed synthetic medium called SIH as culture medium, higher cell density of (4～5) ×107PmL was achieved. Correspondently, 111 μgPL and 420 μgPL shFasL were secreted by recombinant strains AX3-pCESFL95-H3 and AX3-pLu8 ,respectively.国家自然科学基金资助项目(No.20306025,30370039

光学微球腔谐振模式间隔参数的一种简便计算方法

从光学微球腔谐振模式的本征方程出发,提出了一种利用求导法计算谐振模式间尺寸参数(x)间隔的有效方法。在Lam求得的尺寸参数计算公式基础上,依据谐振模式角量子数(l)必须为整数且远远大于1的性质,相邻模式(Δl=1)间的尺寸参数间隔可近似表示为相应尺寸参数的导数,从而可利用求导法计算谐振模式之间的尺寸参数间隔。研究表明,径向量子数i=1的谐振模式的尺寸参数间隔与Mie散射理论求得的精确数值解之间的相对误差在0.05%以内,并且与实验测量数据基本一致。求导法因不需要进行繁琐的级数展开,从而大大简化了计算程序,为光学微球腔的实验研究提供了理论指导

〓

キンミズヒキのタンニンの1種であるagrimoniinの抗腫瘍作用を検討した。AgrimoniinはC57BL/6マウスに移植したE.L.4およびBALB/cマウスに移植したMethA腫瘍の増殖を有意に抑制し, MethAを移植したマウスの生存期間の延長傾向を示した。また, agrimoniinはE.L.4,MethAおよびL-929細胞に対してin vitroで用量依存的な障害作用を示し, その細胞障害性は4時間以内のincubationによってみられた。一方, agrimoniinはヒツジ赤血球で免疫したhemolytic plaque forming cellおよびhemolysinの産生に影響を及ぼさず, また, picrylchlorideによる細胞性免疫の成立に対しても影響を及ぼさなかった。以上のことから, agrimoniinはキンミズヒキの抗腫瘍成分の一つであり, その作用機序は直接的な細胞障害作用によるものと思われる。Studies were carried out to examine the antitumor activity of agrimoniin, one of tannins isolated from Agrimonia pilosa Ledeb., using syngeneic systems including C57BL/6 mice-E.L.4 lymphosarcoma and BALB/C mice-Meth A fibrosarcoma, and the effect on immune responses. Agrimoniin significantly inhibited the growth of both the tumors and showed a tendency to prolong the survival period of BALB/C mice bearing Meth A fibrosarcoma. In the in vitro study the tannin also exhibited a cytotoxic activity against E. L. 4 lymphosarcoma, Meth A fibrosarcoma and L-929 cells in a dosedependent fashion, and the activity was seen within 4 hour-incubation. Agrimoniin, however, neither affected the production of humoral antibodies such as hemolytic plaque forming cell and hemolysin against sheep red blood cells nor the formation of cellular immune response induced by picryl chloride These results suggest that agrimoniin may be one of the antitumor constituents of A. pilosa and display the activity through the direct cytotoxicity rather than host-mediated mechanism

ST段抬高型急性心肌梗死院前溶栓治疗中国专家共识

急性心肌梗死仍然严重威胁我国人民健康,在我国广大城乡地区,形势更为严峻[1,2]。及时救治急性心肌梗死患者,降低死亡率和保护心脏功能刻不容缓。鉴于我国的实际情况,院前溶栓治疗在大城市以外的城乡地区具有重要意义。为此,中国医师协会胸痛专业委员会及中国医学救援协会心血管急救分会专门组织有关专家制订了本共识,旨在帮助院前医疗急救人员对急性心肌梗死患者选择最佳

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家