种群密度和培养体积对发头裸腹溞生长和繁殖的影响

研究了不同培养密度(D1=100 ind·L-1,D2=150 ind·L-1,D3 =300 ind·L-1)和培养体积(V1 =50 mL,V2=100 mL,V3 =400 mL)对发头裸腹溞生长和生殖的影响.结果表明:在相同培养密度下,发头裸腹溞首次怀卵体长、雌体第一窝幼溞数和后代总数均随着培养体积的增大而减少,而雌体所产后代的性比(雄体∶雌体)随着培养体积的增大而增大.在相同培养体积下,雌体产出后代总数随着培养密度的增加而减少.雌体最大首次怀卵体长(0.95±0.10 mm)和最大后代总数(171.3±19.8 ind)均出现在D1V1组合,最大性比(0.54±0.05)出现在D3V2组合.培养密度和培养体积及其协同作用对发头裸腹溞雌体后代总数、后代性比均具有显著影响(P＜0.001).     

鱼类对重金属胁迫的分子反应机理

水体中浓度超标的重金属对鱼类的正常生命活动产生了严重影响,甚至导致鱼类的死亡.鱼体受重金属离子胁迫时体内会产生一系列相关基因的表达变化,并合成相关的蛋白和酶,如热激蛋白、金属硫蛋白、转运铁蛋白、谷胱甘肽转移酶、过氧化氢酶、超氧化物歧化酶等以应对重金属对机体产生的危害.这是生物体对环境的一种应激保护性反应,是生物体对周围环境中过量重金属的一种防御性机制.通过鱼类在重金属胁迫下组织中相关基因的表达可以从分子水平上来阐述有毒物质对鱼体产生的影响.综述了重金属离子胁迫下鱼类机体的分子反应机理.     

一期前路病灶清除植骨融合内固定术治疗短节段腰椎结核

目的:对比观察一期前路病灶清除减压植骨融合内固定术与分期前后路联合手术针对短节段腰椎结核的疗效.方法:抽取兰州军区兰州总医院骨科中心脊柱外科30例住院治疗短节段腰椎结核的患者,随机化分为两组,每组15例,分别施行一期前路病灶清除减压植骨融合内固定术和分期前后联合手术,观察比较两组术前、术后6个月、12个月、18个月Frankle神经功能分级,术后12个月及18个月Birdwell植骨融合分级.结果:试验组及对照组术前、术后6个月Frankle分级差异有统计学意义(P＜0.05).两组间术后6个月,术后12个月Frankle分级差异无统计学意义(P＞0.05).两组间术后18个月Frankle分级差异有统计学意义(P＜0.05).两组间术后12个月Birdwell分级差异无统计学意义(P＞0.05),而两组间术后18个月Birdwell分级差异有统计学意义(P＜0.05).随访期间,对照组有两例发生断钉.结论:一期前路病灶清除、植骨融合内固定术治疗脊柱结核,病灶清除彻底、融合率高,远期效果良好,复发率低并能够最大限度恢复脊柱生物力学稳定性.具有重要的临床应用价值.     

Phylogeographic studies of plants in China: Advances in the past and directions in the future

<正>Phylogeography has been one major focus of evolutionary biology in recent years,with many important advances in Chinese species.In this issue,we collected 11 phylogeographic studies of plants by Chinese laboratories. We further synthesized the main findings and patterns emerging from these and previous phylogeographic studies in China and asked where phylogeographic research should be directed in the coming years.Numerous examples have shown that phylogeographic patterns in China did not show an expected expansion-contraction pattern at large scale, mirroring the geological records showing that no unified ice sheet had developed in China during the Quaternary Period.Instead,regional expansions and intraspecific divergences are very common in most studied species during the Quaternary oscillations.Different intraspecific lineages or alleles(haplotypes) were detected in multiple localized refugia,from where regional or local expansions are likely to have started.Hybridizations and introgressions are frequent between intraspecific lineages or between different species.We also reviewed computational methods for phylogeographic analyses.Despite the great progress made in recent years,there remains much to discover about the spatial-temporal dimensions and underlying speciation mechanisms of Chinese plants.Phylogeographic studies represent a key knot that connects the genus phylogeny(macroevolution) and speciation and adaptation (microevolution).Therefore,we advocate that:(i) phylogeographic studies of plants in China should be directed to the closely related species or a monophyletic group(for example,a genus or a section) in the coming years;and (ii) population genetic data based on direct sequencing multiple loci,especially those from nuclear genome and statistical tests should be widely adopted and enforced.The recovered intraspecific divergences and phylogeographic patterns of multiple-species may allow us to better understand the high plant diversity in China and set up concrete hypotheses for studying plant speciation and diversification mechanisms in this region.     

Induction of metallothionein expression during monocyte to melanoma-associated macrophage differentiation

Tumor-associated macrophages (TAMs) play a critical role in melanoma growth and metastasis.Infiltration of TAMs correlates with the poor prognosis of melanoma.TAMs are differentiated from monocytes in ...     

低温胁迫对辣子草水浸提液化感作用的影响

采用蚕豆根尖细胞微核技术,研究了低温胁迫下辣子草（Gatinsoga parviflora Cav．）水浸提液的化感作用。结果表明：常温条件下,辣子草水浸提液使蚕豆根尖细胞有丝分裂指数下降,微核率和畸变率增大;低温处理后辣子草水浸提液对有丝分裂指数表现为“低浓度促进,高浓度抑制”效应,但显著提高了微核率和畸变率。这说明低温胁迫改变了辣子草的化感作用。     

敲减血管内皮生长因子受体-2表达抑制人乳腺癌裸鼠移植瘤的生长

应用化学修饰的小干扰RNA(small interference RNA,siRNA)抑制裸鼠乳腺癌移植瘤血管内皮生长因子受体-2基因（VEGFR2,又称kinase insert domain-containing receptor, KDR)的表达, 探讨抑制肿瘤血管生成对人乳腺癌(MCF-7)裸鼠移植瘤生长的影响．雌裸鼠皮下种植MCF 7 细胞,肿瘤长至一定大小时, 随机分为对照组（A）、转染试剂对照组（B）、小剂量治疗组（C）及大剂量治疗组（D）．肿瘤局部分别注射葡萄糖溶液、In vivo jetPEI^TM转染试剂和In vivo jetPEI^TM转染试剂包裹的KDRsiRNA．22 d后处死全部动物, 取肿瘤, 测其大小及重量, HE 及免疫组化染色,微血管密度计数,同时用RT-PCR检测KDR基因的表达水平．结果显示,siRNA治疗组瘤组织的增长受到明显抑制;HE染色显示,治疗组肿瘤中心区出现大面积细胞坏死;免疫组化结果显示,染色阳性血管数明显低于对照组;同时RT-PCR结果表明,治疗组KDR表达下调．对照组各指标无显著变化．因此,化学修饰的siRNA介导的RNAi可以降低人乳腺癌裸鼠移植瘤血管中KDR 表达, 抑制血管生成进而抑制肿瘤的生长,是潜在的肿瘤治疗新方法．     

饰纹姬蛙7个Dmrt基因DM结构域的克隆及序列分析

采用简并PCR技术扩增了饰纹姬蛙(Microhyla ornata)Dmrt基因的DM结构域,经分子克隆、SSCP和DNA序列分析,获得了该基因家族的7个成员并分别命名为MoDmrtla、MoDmrtlb、MoDmrt3al、MoDmrt3a2、MoDmrt3a3、MoDmrt3b和MoDmrt5.与不同进化地位其他动物相关的Dmrt基因进行比对和聚类分析,结果显示该基因在系统进化上具有高度的保守性.     

siRNA抑制c—myc基因的表达对宫颈癌细胞增殖的影响

目的：利用siRNA（small interference RNA）技术研究C-myc基因的对宫颈癌HeLa细胞增殖的影响。方法：依据Promega公司在网上提供的设计软件,设计针对C-myc基因的siRNA,合成DNA模板,体外转录合成siRNA。通过阳离子聚合物jet—SITM—ENDO将合成的siRNA转染入HeLa细胞,以未转染细胞以及错义序列siRNA—scr转染细胞为对照。用细胞计数法检测siRNA对HeLa细胞增殖的影响。流式细胞法检测细胞周期及蛋白表达的变化,RT—PCR法比较转染前后C-myc mRNA表达水平的变化。结果：细胞计数法结果显示,转染24h后c-myc基因siRNA明显抑制MCF-7细胞增殖,转染48h后,抑制效率稳定。c-myc基因siRNA转染后能有效地抑制HeLa细胞的增殖,阻滞细胞周期于G0／G1期,siRNA转染组c-myc mRNA、蛋白的表达量明显低于空白对照组、错义序列组。结论：体外转录合成的siRNA可有效降低HeLa细胞c-myc基因的表达,抑制细胞增殖。