铜纳米颗粒对缺血性卒中后神经血管单元的保护作用

目的:研究铜纳米颗粒(copper nanoparticle,Cu-nps)对缺血性卒中后神经血管单元(neurovascular units,NVU)的保护作用。方法:采用加热搅拌法合成Cu-nps。体内建立大鼠短暂大脑中动脉阻塞/再灌注模型(transient middle cerebral artery occlusion / reperfusion,tMCAO),实验分为正常组(sham)、模型组(tMCAO)、给药组(Cu-nps),检测各组脑梗死面积、神经凋亡情况、血脑屏障(blood-brain barrier,BBB)完整性以及相关蛋白表达。结果:制备出的Cu-nps以Cu²⁺、80 nm左右的粒径均匀存在,具有良好的生物相容性。Cu-nps靶向脑缺血部位受损神经元,提高神经元细胞活力,降低活性氧,减少神经元凋亡和脑梗死面积,降低伊文思蓝染料渗漏量和炎症因子表达。结论:Cu-nps可以减少氧化应激,保护BBB完整性,降低神经胶质细胞活化,保护NVU功能,从而降低脑缺血再灌注损伤。     

蝮蛇毒PCA对脑梗死大鼠PC活性变化的影响及其机制

目的探讨脑梗死大鼠血浆蛋白C(PC)活性变化与蝮蛇毒蛋白C激活物(PCA)对其的影响及其可能机制。方法将SD雄性大鼠32只,随机分为正常对照组(C组)、脑梗死组(CI组)、阳性对照组(UK组)和实验组(PCA组),每组8只。采用血管内直接线栓闭塞法制备大鼠缺血性脑梗死模型,UK组和PCA组分别静脉注射UK和PCA。实验1h后于颈总动脉取血,以发色底物法检测血浆PC活性;测定APTT值;观察血浆PC活性和凝血功能的变化。24h后处死大鼠,开颅取脑TTC染色且行HE染色。结果 CI组大鼠血浆PC活性明显低于C组(P<0.01),APTT无明显改变(P>0.05);PCA组PC活性较CI组明显升高(P<0.01)。病理切片HE染色显示,CI组神经细胞数明显减少,形态发生改变,形状不规则,细胞固缩、深染;UK组与PCA组注射药物后脑梗死病变区表现近似,与正常对照组比较无明显变化。结论缺血性脑梗死与血浆PC活性显著降低有关;PCA可在一定程度上恢复和提高PC的活性,降低脑梗死发生的风险。     

Exendin-4 对糖尿病脑缺血再灌注大鼠脑组织中MMP-9 表达的影响

目的:通过观察Exendin-4对糖尿病大鼠脑缺血再灌注后脑梗死体积百分比及脑组织中金属基质蛋白酶-9及基质金属蛋白酶抑制剂-1的变化,探讨Exendin-4对糖尿病大鼠脑缺血再灌注损伤的保护作用机制。方法:选用SD大鼠,给予链脲佐菌素(streptozocin,STZ)建立糖尿病大鼠模型后,随机分为A组:糖尿病对照组(n=6);B组:模型组(n=6);C组:Exendin-4低剂量组(n=6);D组:Exendin-4中剂量组(n=6);E组:Exendin-4高剂量组(n=6)。常规喂养6周后,A组给予假手术处理,B、C、D及E组采用线栓法制作大鼠大脑中动脉缺血90 min再灌注模型,24 h后处死大鼠取脑组织,采用2,3,5一氯化三苯四唑(2,3,5-triphenyltetrazolium chloride,TTC)染色测算脑梗死体积百分比;同时分别采用Western Blot法及RT-PCR测量脑组织中的MMP-9及TIMP-1表达量。结果:脑缺血再灌注能致脑组织中MMP-9及TIMP-1表达量增高,各组与A组比较,有显著差异(P<0.05);给予Exendin-4处理后脑组织中MMP-9及TIMP-1表达增高程度及脑梗死体积百分比明显降低,与B组比较有显著差异(P<0.05)。结论:Exendin-4对糖尿病大鼠脑缺血再灌注损伤有保护作用,其机制可能与抑制MMP-9及TIMP-1的表达有关。     

人参皂苷Rg1促进大鼠急性心肌梗死后血管新生

目的:明确人参皂苷Rg1在大鼠发生急性心肌梗死后是否能够促进心脏血管新生。方法:通过结扎SD大鼠左冠状动脉前降支建立大鼠急性心肌梗死模型,并将60只雄性SD大鼠随机分单纯手术组与人参皂苷Rg1治疗组。治疗组的大鼠造模1 h后将预先配成药液的人参皂甙Rgl按5 rag/(kg·d)剂量腹腔注射,1次/日至处死当日。对照组则腹腔注射等量生理盐水1次/日至处死当日。分别于手术后3、7天时对比两组大鼠的基本生命指标,后通过免疫荧光染色CD31对比观察两组大鼠心脏细胞中CD31的表达来评判血管新生水平。结果:①手术后3天、7天,两组大鼠的体重、心脏重量、心重/体重、鼠尾收缩压、心率比较差异均没有统计学意义(P0.05);②手术后3天、7天,人参皂苷Rg1治疗组心脏CD31表达水平明显高于对照组。结论:人参皂苷Rg1能够促进大鼠急性心肌梗后心脏的血管新生。     

人参皂苷Rg1对糖尿病肾病大鼠血清氧化应激指标、炎性因子及肾组织TGF-β1、MCP-1 mRNA的影响

目的:研究人参皂苷Rg1对糖尿病肾病(DN)大鼠血清氧化应激指标、炎性因子及肾组织生长转化因子-β1(TGF-β1)、单核细胞趋化因子蛋白-1(MCP-1)mRNA的影响。方法:选取60只SD大鼠,将其以随机抽签法分为Rg1组、模型组以及对照组,各20只。其中Rg1组与模型组大鼠均选择腹腔内一次性注射链脲佐菌素(STZ)55 mg/kg建立DN大鼠模型,Rg1组予以人参皂苷Rg1治疗,模型组与对照组则予以等量的生理盐水干预。比较干预12周后各组肾功能相关指标、血清氧化应激指标、炎性因子及肾组织TGF-β1、MCP-1 mRNA表达情况。结果:Rg1组、模型组大鼠干预12周后血肌酐(Scr)、尿素氮(BUN)、胱抑素C(CysC)水平均高于对照组,而Rg1组大鼠干预12周后Scr、BUN、CysC水平均低于模型组(均P0.05)。Rg1组、模型组大鼠干预12周后血清超氧化物歧化酶(SOD)、谷胱甘肽(GSH)水平均低于对照组,丙二醛(MDA)水平高于对照组(均P0.05);Rg1组大鼠干预12周后血清SOD、GSH水平均高于模型组,MDA水平低于模型组(均P0.05)。Rg1组、模型组大鼠干预12周后血清白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)水平均高于对照组,而Rg1组血清炎性因子水平低于模型组(均P0.05)。Rg1组、模型组大鼠干预12周后肾组织TGF-β1、MCP-1 mRNA表达水平均高于对照组,且Rg1组低于模型组(均P0.05)。结论:人参皂苷Rg1可显著改善DN大鼠血清氧化应激指标,下调血清炎性因子水平以及肾组织TGF-β1、MCP-1 mRNA表达。     

三七皂苷单体Rg1对低氧高二氧化碳肺动脉平滑肌细胞p38MAPK表达的影响

目的:研究三七皂苷单体Rg1对低氧高二氧化碳肺动脉平滑肌细胞(PASMCs)p38MAPK表达的影响。方法:分离、纯化SD大鼠PASMCs,实验用2至5代细胞,实验分六组:常氧组(N组),低氧高二氧化碳组(H组),DM-SO对照组(HD组),Rg1干预组(RgL、RgM、RgH组)。采用Western blot检测磷酸化p38MAPK蛋白表达,RT-PCR检测p38MAPK mRNA的表达。结果:Westernblot、RT-PCR结果显示,HD组p-p38MAPK蛋白和p38MAPK mRNA表达明显高于N组(P<0.01),RgL、RgM、RgH组不同程度抑制了p-p38MAPK蛋白和p38MAPK mRNA和的表达(P<0.01),并呈剂量依赖关系。结论:三七皂苷单体Rg1对低氧高二氧化碳条件下PASMCs有保护作用,其机制可能与抑制p38MAPK的表达有关。     

增殖细胞核抗原在低氧大鼠肺动脉平滑肌细胞中表达

目的通过建立低氧性肺动脉高压大鼠模型,探讨增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)在大鼠低氧性肺血管平滑肌细胞中的表达。方法将SPF级SD大鼠随机分为正常对照组(n=10)、模型组(n=10),通过间断常压低氧法建立大鼠低氧性肺动脉高压模型,肺组织切片经HE染色后图像分析技术定量检测大鼠肺小动脉的形态改变;免疫组织化学染色法测定肺血管平滑肌细胞内PCNA蛋白表达,并经图像分析半定量检测其表达强度。结果 4周后,模型组SD大鼠MT%、MA%与对照组比较,差异具有显著性(P<0.05);模型组SD大鼠肺血管平滑肌细胞内PCNA核蛋白表达(积分面积、累积光密度)与对照组比较,差异具有显著性(P<0.05)。结论常压低氧4周可成功建立肺动脉高压大鼠模型,PCNA在肺血管平滑肌细胞中的表达量具有差异性提示其可能在肺动脉高压形成过程中起重要作用。     

人参皂苷Rg1对脑缺血再灌注大鼠Caspase-3蛋白表达的影响

目的探讨人参皂苷Rg1对脑缺血再灌注大鼠脑组织半胱氨酸天冬氨酸酶3(Caspase-3)表达的影响。方法将大鼠随机分为假手术组、模型组、人参皂苷Rg110、20、40mg/kg组、尼莫地平组,每组10只。采用线栓法栓塞大脑中动脉2h制作大鼠脑缺血再灌注模型;观察再灌注22h后神经功能缺损评分;应用免疫组化、免疫印迹法检测大脑皮层缺血半暗带Caspase-3的表达。结果(1)假手术组、模型组、人参皂苷Rg110、20、40mg/kg组和尼莫地平组神经功能缺损评分分别为0、2.8±0.9、2.1±0.9、1.5±0.7、1.3±1.1、1.5±0.7,差异有统计学意义(P0.05)。人参皂苷Rg120、40mg/kg组与模型组比较,差异有统计学意义(P0.05);人参皂苷Rg110mg/kg组与尼莫地平组比较,差异有统计学意义(P0.05);人参皂苷Rg120、40mg/kg组与尼莫地平组比较,差异均无统计学意义(P0.05)。(2)免疫组化和免疫印迹结果显示各组大鼠皮层缺血半暗带均有Caspase-3的表达,其中假手术组仅有少量表达,模型组表达最多。与模型组比较,人参皂苷Rg1各剂量组及尼莫地平组Caspase-3表达量减少,差异有统计学意义(P0.05);与尼莫地平组比较,人参皂苷Rg110mg/kg组的Caspase-3表达量显著增高,40mg/kg组显著降低(P0.05),而20mg/kg组则差异无统计学意义(P0.05)。结论人参皂苷Rg1防治脑缺血再灌注的机制与抑制脑组织Caspase-3表达有关,且以高剂量效果较好。     

大鼠永久性大脑中动脉阻塞模型的建立

目的 建立稳定可靠的线栓法大鼠大脑中动脉阻塞(MCAO)永久性脑缺血模型.方法 对Koizumi和Zea Longa模型构建方法 加以改进.40只雄性SD大鼠随机均分为实验组和假手术组,分别进行模型制作和模型缺血的评价,采用2,3,5-氯化三苯四氮唑(2,3,5-Triphenyltetrazolium chloride,TTC)染色来计算大鼠脑梗死体积.结果 大鼠MCAO模型制作成功率为95%;神经功能缺失评分1～3级百分率为95%.结论 实验所采用的改良术式构建大鼠MCAO模型具有稳定性好、可重复率高、操作简便和手术时间短等优点,为基于大鼠永久性脑缺血模型开展的下游相关实验提供了良好的研究平台.     

缺氧诱导因子-1α与血管内皮生长因子及其受体2在大鼠3期压力性损伤皮肤组织中的表达及意义*

目的:分析缺氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)和血管内皮生长因子受体2(KDR)在不同受压时间点大鼠压力性损伤局部皮肤组织中的表达及相互关系,探讨3期压力性损伤慢性难愈的可能机制。方法:将40只SD雄性大鼠随机分为正常对照组、受压3 d、5 d、7 d、 9 d组( n=8 ),使用磁铁压迫法建立3期压力性损伤动物模型。HE染色观察皮肤组织形态;免疫组化法检测VEGF表达,Western blot 检测皮肤组织HIF-1α、VEGF、KDR蛋白表达;对数据行单因素方差分析、LSD检验。结果:①HE结果显示,与正常对照组相比,受压组大鼠表皮逐渐增厚,血管数量不断减少,胶原排列紊乱,炎症细胞浸润增加。②免疫组化结果显示:受压3 d组大鼠皮肤组织中VEGF蛋白表达量较正常对照组明显增高(P＜0.01);受压5 d、7 d和 9 d组大鼠皮肤组织中VEGF蛋白表达量均明显低于正常对照组(P＜0.05)。WB结果和免疫组化结果一致。③WB结果显示:受压3 d、5 d和7 d组大鼠皮肤组织中HIF-1α表达量均明显高于正常对照组(P＜0.01 或 P＜0.05);4组受压组大鼠皮肤组织KDR蛋白表达量均低于正常对照组(P＜0.05或P＜0.01)。结论:HIF-1α介导的VEGF和KDR蛋白表达减少引起组织血管生成减少可能是3期压力性损伤慢性难愈的重要原因之一。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.