1,3-1,4-α-L-fucosynthase that specifically introduces Lewis a/x antigens into type-1/2 chains

α-L-fucosyl residues attached at the non-reducing ends of glycoconjugates constitute histo-blood group antigens Lewis (Le) and ABO and play fundamental roles in various biological processes. Therefore, establishing a method for synthesizing the antigens is important for functional glycomics studies. However, regiospecific synthesis of glycosyl linkages, especially α-L-fucosyl linkages, is quite difficult to control both by chemists and enzymologists. Here, we generated an α-L-fucosynthase that specifically introduces Le(a) and Le(x) antigens into the type-1 and type-2 chains, respectively; i.e. the enzyme specifically accepts the disaccharide structures (Galβ1-3/4GlcNAc) at the non-reducing ends and attaches a Fuc residue via an α-(1,4/3)-linkage to the GlcNAc. X-ray crystallographic studies revealed the structural basis of this strict regio- and acceptor specificity, which includes the induced fit movement of the catalytically important residues, and the difference between the active site structures of 1,3-1,4-α-L-fucosidase (EC 3.2.1.111) and α-L-fucosidase (EC 3.2.1.51) in glycoside hydrolase family 29. The glycosynthase developed in this study should serve as a potentially powerful tool to specifically introduce the Le(a/x) epitopes onto labile glycoconjugates including glycoproteins. Mining glycosidases with strict specificity may represent the most efficient route to the specific synthesis of glycosidic bonds.     

小鼠Lewis肺癌原位模型的建立

目的利用Matrigel与Lewis制备细胞混悬液注射于小鼠左肺内,建立小鼠Lewis肺癌原位模型,评价其肿瘤生长情况、转移情况,以期建立更稳定、更接近于人肺癌生长情况的小鼠肺癌原位模型。方法将处于对数生长期的Lewis肺癌细胞混悬于Matrigel中,接种于C57BL/6近交系小鼠左肺内。分别于第4、7、10、13、16天各处死5只小鼠,观察其局部成瘤率、肿瘤生长情况、中位生存期及肿瘤转移情况,并对各阶段小鼠行肺部,肝脏,肾脏,脾脏病理切片检查。结果术后第7天解剖的5只小鼠中,3只小鼠肺上可见小的瘤结节形成,其余2只肺上未见肉眼成瘤,行病理HE染色检查在显微镜下可见2只小鼠肺脏有小的瘤结节形成。术后第10天以后处死的所有小鼠肺上均有肉眼成瘤,术后第13天,所有小鼠肺原位成瘤并伴有血性胸腔积液、胸腔内转移。术后第25天,有1只小鼠出现上述转移的同时还出现了心包膜转移及肾脏远处转移。5只小鼠生存期分别为17 d、20 d、22 d、22 d、25 d,小鼠中位生存期为21.2 d（17~25 d）。成瘤率100%。结论利用Matrigel法成功建立小鼠Lewis肺癌原位模型,稳定性好,成瘤率高,并具有远处转移的特性,更接近于人肺癌的发生、发展过程。     

SARS冠状病毒感染Lewis大鼠模型的建立

目的通过观察SARS-CoV感染Lewis大鼠后,病理学、免疫学以及病毒的复制与外排情况变化,探讨其能否作为有效的SARS动物模型。方法SARS病毒感染9只Lewis大鼠,在感染后不同时间安乐死动物,应用光镜对动物的各脏器进行病理观察研究;用病毒分离和RT-PCR方法检测病毒外排与复制的情况;用ELISA法检测动物产生特异性抗体情况。结果在SARS-CoV感染Lewis大鼠后,肺组织出现一定的与人类SARS疾病相似的病理改变,在动物体内可检测到活病毒或病毒核酸,并可检测到特异性IgG抗体的存在。结论Lewis大鼠出现了特异的免疫反应及特征性病理改变,可做为灵长类SARS动物模型的有益补充用于SARS发病机理及疫苗的研发等。     

Lewis肺癌细胞与其衍生细胞系的比较

目的对比Lewis肺癌细胞(LLC)及LLC原位接种后获得的第一代衍生细胞(R1-LLC)和R1-LLC原位接种后获得的第二代衍生细胞(R2-LLC)间的生物学特性,比较该三种细胞在原位种植模型中的侵袭转移能力。方法离体实验:采用cck8法、克隆球形成实验、Tanswell侵袭试验分别检测细胞的增殖、侵袭能力,透射电镜观察细胞和组织的结构形态;活体实验:观察在7、14、21 d时LLC、R1-LLC、R2-LLC细胞分别原位种植模型中的成瘤与转移情况,统计成瘤率与成瘤时间。结果 LLC、R1-LLC、R2-LLC细胞的增殖能力差异无显著性(P0.05),侵袭能力R2-LLCR1-LLCLLC(P0.05)。活体实验显示LLC、R1-LLC、R2-LLC成瘤率分别为66.67%、80%、93.33%(P0.05)。结论在离体及活体实验中,R2-LLC比R1-LLC及LLC细胞具有更强的侵袭及转移特性。     

杀伤细胞对肺癌小鼠Lewis细胞增殖的抑制作用

目的:探讨杀伤细胞对人Lewis肺癌细胞增殖的抑制作用。方法:选择成年健康雄性ICR小鼠46只,随机选取10只作为正常对照组,其余36只进行模型复制,然后将造模成功的30只小鼠随机分为实验组与模型组,每组15只。实验组予以尾静脉注射杀伤细胞1×107个/0.2 m L,1次/d,模型组与对照组予尾静脉注射生理盐水。ELISA方法测定TNF-α、IL-2和IL-4的含量,采用流式细胞仪检测凋亡率,四氮唑蓝(MTT)比色法检测癌细胞抑制率。结果:1实验组小鼠右腋下瘤体重量明显低于模型组,差异有统计学意义(P0.01);2透射电镜下观察实验组人Lewis肺癌细胞出现大量凋亡,而模型组人Lewis肺癌细胞几乎未凋亡,与模型组比较,实验组细胞凋亡较多,差异具有统计学意义(P0.05);3实验组小鼠脾上清液中IL-2、TNF-α和IFN-γ含量明显高于模型组和正常对照组小鼠,差异有统计学意义(P0.01)。结论:杀伤细胞能够通过活化淋巴细胞、分泌细胞因子来抑制体内、体外人Lewis肺癌细胞的增殖和生长,对临床具有指导意义。     

山东胃癌高低发人群Lewis基因多态性分析

应用PCR产物直接测序的方法,检测山东省胃癌高发的临朐人群和低发的苍山人群中Lewis基因多态性T59G的分布,旨在探讨山东临朐和苍山地区胃癌发病率显著不同的内在原因,为阐明临朐地区胃癌高发的机制提供实验依据。结果表明,T59G突变个体在临朐和苍山人群中的分布频率分别为34.5%和31.6%,差别无统计学意义,P＞0.05,OR为1.14 （95% CI,0.59~2.19）。提示就此点突变而言,临朐人群和苍山人群为同一人群,具有极其相似的遗传背景;T59G不能作为区分临朐和苍山人群的遗传标志,与这两个地区胃癌发病的区别没有相关性。 Abstract:To explore the cause leading to the difference in incidence of gastric cancer between Linqu and Cangshan populations,Shandong Province,and to provide evidence for the possible mechanism of high incidence of gastric cancer in Linqu County,the distribution of T59G mutation in Lewis gene was screened between Linqu and Cangshan populations by PCR-sequencing.The frequency of individuals with T59G mutation was 34.5% in Linqu population and 31.6% in Cangshan population,respectively,with no significant difference,P＞0.05,and OR is 1.14 (95% CI,0.59~2.19).This suggests that Linqu and Cangshan populations may share the same genetic background.T59G mutation of Lewis gene could not be used as a genetic marker for Linqu and Cangshan populations and is not relevant to the difference in incidence of gastric cancer between them.     

x,i(xq)—x染色体长臂等臂一例

刘X,女,14岁。因生长发育迟缓就诊。患 者是第3胎足月顺产,2岁始会走路及说简单 话语,7岁上小学,二年级时因全部课程不及 格,被迫退学。患者生后即生长发育缓慢,现可 从事一般家务劳动,无月经来潮。母孕期未接 触有害物质,无流产史,家族中无类似患者     

VEGF反义寡核苷酸抑制小鼠Lewis肺癌生长的研究

目的探讨血管内皮生长因子(VEGF)反义寡核苷酸对C57BL/6小鼠Lewis肺癌肿瘤生长的抑制作用。方法制备C57BL/6小鼠皮下肺癌模型30只,随机分为3组,每组10只VEGF反义寡核苷酸(ASPODN)治疗组、VEGF正义寡核苷酸(SPODN)治疗组及对照组。接种Lewis肺癌细胞后24h内,分别皮下注射ASPODN及SPODN进行治疗,对照组只注射生理盐水,每周2次,连续4周;观察各组小鼠肿瘤的生长情况、游标卡尺测量肿瘤体积大小。所有C57BL/6小鼠于接种后第25天先用二维超声观察肿瘤的实时图象,利用脉冲多普勒获取血流频谱,获得收缩期峰值速度(PS),阻力指数(RI)。断颈处死小鼠,光镜及电镜下观察肿瘤组织形态学改变及超微结构变化,免疫组化法检测微血管密度(MVD)。结果与对照组瘤重比较(7.83±0.78)g、VEGF-ASPODN组(4.49±0.43)g能明显抑制小鼠肿瘤生长(P<0.01)、VEGF-SPODN组(7.73±0.69)g则无明显作用(P>0.05)。VEGF-ASPODN组、VEGF-SPODN组抑瘤率分别为42.7%、5.9%。组织形态学及超微结构观察,VEGF-ASPODN对肿瘤生长具有抑制作用。VEGF-ASPODN组与对照组相比较PS及RI有明显差异(P<0.01);VEGF-SPODN组与对照组相比无明显差异(P>0.05)。结论肿瘤原位注射VEGF反义寡核苷酸能抑制小鼠肺癌生长。     

Polyphyletic allopolyploid origin ofRanunculus cantoniensis (4x) fromR. silerifolius (2x) ×R. chinensis (2x)

Both diploid and tetraploid experimental interspecific hybrids betweenRanunculus silerifolius (2x) andR. chinensis (2x) exhibit normal bivalent pairing. However, microspores of diploid hybrids do not undergo mitosis and their pollen grains are highly sterile, whereas tetraploid hybrids form good pollen grains after microspore division. Evidence is forwarded for the assumption thatR. cantoniensis (4x) has originated by hybridization between these two diploid parental species and by polyploidization of the diploid hybrids. Parallelisms between the different karyotypes ofR. cantoniensis (4x) andR. silerifolius (2x) suggest that the former is a species of polyphyletic origin.     

Cytological and breeding behavior of pentaploids derived from 3x × 4x crosses in potato

Cytology and breeding behavior of Solanum commersonii - S. tuberosum hybrids derived from 3 x x 4 x crosses was examined. The chromosome number of hybrids ranged from hypo-pentaploid (2 n=5 x - 8=52), to hyper-pentaploid (2 n=5 x + 7=67), with the euploid pentaploid 2 n=5 x=60 class predominant. The high variability in chromosome number of the 3 x x 4 x hybrids was attributed to the fact that meiotic restitution during megasporogenesis of the 3 x female may have involved poles with various chromosome numbers, resulting in 2 n eggs with 24-48 chromosomes. Microsporogenesis analyses provided evidence that chromosome pairing between S. commersonii and S. tuberosum genomes occurred. In addition, chromosome distribution at anaphase I and anaphase II revealed an average chromosome number of 29.5 and 29.1 per pole, respectively. To further study the extent of transmission of extra genome chromosomes from pentaploids, 5 x x 4 x and 4 x x 5 x crosses were performed, and the chromosome number of resulting progeny was determined. Ploidy ranged from 2 n=4 x=48 to 2 n=5 x=60 following 5 x x 4 x crosses, and from 2 n=4 x + 1=49 to 2 n=5 x=60 following 4 x x 5 x crosses. These results provided indirect evidence that the pentaploid hybrids produced viable aneuploid gametes with a chromosome number ranging from 24 to 36. They also demonstrated that gametes with large numbers of extra chromosomes can be functional, resulting in sporophytes between the 4 x and 5 x ploidy level. Fertility parameters of crosses involving various (aneuploid) pentaploid genotypes were not influenced by chromosome number, suggesting a buffering effect of polyploidy on aneuploidy. The possibility of successfully using (aneuploid) pentaploid genotypes for further breeding efforts is discussed.     

Fertilization fitness and offspring ploidy in 3x × 2x matings in potato

Abstract

The main objective of the current research was to study the reproductive behaviour of artificial triploid potato hybrids between wild Solanum commersonii and the cultivated potato Solanum tuberosum. When used in 3x × 2x crosses, triploids gave aneuploid progenies with somatic chromosome number ranging from 29 to 36. Fertilization fitness data suggested that the survival rate of gametes produced by the triploid parents may be related to their chromosome number. In addition, consistent with molecular data, our results indicated that fitness of gametes and chromosome number of progenies are influenced by the genome dosage of interspecific triploids. Since a main route to polyploidy formation is via 2n gametes and triploids, our study may contribute to a better understanding of polyploid plant reproduction, evolution and breeding.     

小鼠Lewis肺癌不同部位皮下移植瘤模型的比较

目的探究不同部位肺癌皮下移植瘤存在的差异,为肺癌研究者提供提供基础依据。方法将稳定表达虫萤光素酶的小鼠Lewis肺腺癌细胞(ll2-luc-m38)分别注射于C57 BL/6小鼠的右腋皮下、右腹股沟皮下、脚垫皮下,定期利用小动物活体成像系统观察小鼠皮下移植瘤成瘤情况及转移情况,观察不同部位荷瘤小鼠的生存时间和死亡率,肿瘤组织取材,采用石蜡包埋、切片、HE染色做出病理学诊断。并将小鼠处死后立即进行肺部组织固定、观察转移灶。对皮下移植瘤行切除术观察小鼠术后生存情况和转移情况。结果腋下组和腹股沟组成瘤时间较早,成瘤率为100%,脚垫组成瘤时间较晚,成瘤率为33%;腹股沟组和腋下组瘤体积增长迅速,其中腹股沟组瘤体积增长最快;接种后第21天腋下组70%的小鼠出现了肺转移,转移灶数目较多;腹股沟组50%小鼠出现肺转移,且转移灶数目较少;脚垫组小鼠未观察到肺转移灶。脚垫组小鼠死亡率最高。腹股沟组和腋下组小鼠可行皮下移植瘤切除术,术后存活率为100%。结论小鼠lewis肺癌皮下移植瘤模型中,腹股沟组和腋下组成瘤率高,可耐受移植瘤切除术,手术死亡风险低,便于监测,操作简单且可重复性高,其中腋下组转移性更好。     

IL-4抑制Lewis肺癌生长和转移的实验研究

探讨 IL -4对 Lewis肺癌生长和转移的抑制作用。将 Lewis肺癌细胞接种于 C57BL /6小鼠皮下。将 2 0只小鼠随机分为两组 ,接种后第 5天起分别给予生理盐水或 IL-4。第 1 8天处死动物 ,测两组肿瘤的平均体积 ,平均瘤重及肺转移灶。 、 组肿瘤的平均体积为 ( 2 .0 0 7± 0 .0 0 6) cm3 ,( 0 .4 0 4± 0 .0 1 0 ) cm3 ;平均瘤重为 ( 2 .83 3± 0 .0 74 ) g、( 0 .586± 0 .0 4 0 ) g,肺转移灶为 ( 5.50 0± 0 .92 6) ,( 3 .3 75± 1 .0 61 )。 组与 I组比差异有显著性 ( P<0 .0 5) ;平均潜伏期为 :8.3 0± 0 .4 9;1 0 .56± 0 .3 6。 IL-4能抑制 Lewis肺癌生长和转移。     

Lewis大鼠下丘脑中肾阳虚相关mRNA表达及超微结构观察

目的通过对Lewis大鼠下丘脑肾阳虚相关基因表达和超微结构的观察,进一步对Lewis大鼠肾阳虚体质进行研究。方法采用Lewis大鼠与皮下注射氢化可的松法的肾阳虚模型进行比较,并通过检测各组大鼠下丘脑中TNF-α、IFN-γ、IL-10、CRH、MR、GR mRNA表达和下丘脑、肾上腺组织超微结构的观察等,对Lewis大鼠肾阳虚体质机制进行研究。结果与正常Wistar大鼠比较,Lewis组大鼠下丘脑GR、IL-2 mRNA表达明显升高(P0.01),而下丘脑CRH、TNF-α、IFN-γ、IL-10 mRNA表达明显降低(P0.01);Lewis大鼠肾上腺皮质束状带略变薄,线粒体减少,且有轻微变形肿胀;Lewis大鼠下丘脑神经元细胞体胞核大,核形不规则,线粒体明显减少,神经细胞突触减少,突触前部的分泌小泡减少。结论 Lewis大鼠下丘脑和肾上腺存在一定程度的超微结构改变,且免疫相关细胞因子和CRH mRNA的异常表达,这可能与其自身HPA轴的功能失衡有关。