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1.
人胚胎胰腺结缔组织经分离培养成人成纤维细胞系HF-91,传40代。该细胞贴壁生长,具有密度依赖性抑制性质。它的生长依赖于成纤维细胞生长因子的存在,在10ng/100ng/ml浓度范围内,细胞生长与bFGF的浓度成正相关。细胞群体倍增时间23.8±5.3h。有丝分裂指数49.3%±4.1%染色体众数2n=46,占87.5%±4.1%。染色体众数2n=46,占87.5%-91.0%,乳酸脱氢酮同工酶L  相似文献   

2.
本研究着重探讨表皮生长因子(EGF)对大鼠肺动脉的收缩作用及对肺动脉平滑肌细胞分裂增殖的影响。浓度为1×10-9-1×10-7mol/L的EGF可引起大鼠肺动脉剂量依赖性收缩(r=0.968,P<0,001),其Emax为100.6mg,EC50为11.96nmol/L。在同时存在0.5%胎牛血清(FCS)时,EGF能促进平滑肌细胞的3H-TdR参入率,该作用与剂量呈正相关(r=0.823,P<0.05),其EC50为6.5×1O-12mol/L。1×10-9mol/L的EGF+0.5%FCS能产生与10%FCS相当的促细胞分裂增殖能力(在培养的第1,3,5,7天,二者促分裂增殖能力相差不明显,P均>0.05,第9天时,前者大于后者,P<0.05)。1×10-9mol/LEGF单独存在时对平滑肌细胞未显示出明显的致分裂活性。上述作用提示ECF在某些肺血管病变如缺氧性肺动脉高压中可能有一定意义。  相似文献   

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在家兔离体肺内动脉、脑基底动脉环观察了过氧化氢(H2O2)及次黄嘌呤+黄嘌呤氧化酶(HX+XO)对动脉环缺氧反应的影响。结果发现:(1)H2O21×10-5mol/L加强f去内皮肺动脉环(PA-)的缺氧收缩幅度(TIH),而H2O23×10-5mol/L、HX10-4mol/L+XO0.1及0.03U/ml则可抑制内皮完整肺动脉环(PA+)及PA-的TIH(P<0.05);(2)各剂量H2O2及HX+XO对有、无内皮的脑基底动脉环的TIH均无显著影响。  相似文献   

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报道了缢蛏碱性磷酸酶(简称ALP)经不同浓度盐酸胍处理时酶的分子构象所发生的变化以及酶变化和失活的动力学过程。在胍中酶荧光发射峰强度下降,紫外差光谱在246nm和285nm处出现2个负峰,CD谱中酶的α螺旋度下降,且随浓度增大,变化程度也加大。动力学研究表明,酶在0.5mol/L、1.0mol/L、2.0mol/L3.0mol/L、4.0mol/L盐酸胍中的变性速度常数分别为3.21×10~(-4)s~(-1)、6.38×10~(-4)s~(-1)、2.17×10~(-3)s~(-1)、2.33×10~(-3)s~9-1)、5.17×10~(-3)s~(-1);而酶在相应盐酸胍中的失活速度常数分别为2.33×10~(-4)s~(-1)、3.57×10~(-4)s~(-1)、5.86×10~(-4)s~(-1)、1.14×10~(-3)s~(-1)、3.45×10~(-3)s~(-1);表现为失活与构象伸展变化基本平行。  相似文献   

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剪切应力对毛细血管内皮细胞代谢的影响   总被引:3,自引:0,他引:3  
建立的平行平板流动腔装置适用于研究血管内皮细胞代谢对剪切流场的响应。将培养的人胚肾小球血管单层内皮细胞置于剪应力分别为5×10-5N/cm2,1×10-4N/cm2和1.5×10-4N/cm2的定常层流中剪切25小时,样品中的内皮素分泌量用放射免疫法测定。结果表明,剪应力水平对内皮细胞内皮素的代谢活动有显著影响。与静态培养对照,低水平的剪应力(5×10-5N/cm2、1×10-4N/cm2)促进内皮素的分泌,而较高水平的剪应力(1.5×10-4N/cm2)抑制内皮素的分泌;剪应力对内皮素累积含量的影响比之分泌速率更大  相似文献   

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前已报道[1]从唇形科香茶菜属植物细锥香茶菜(Rabdosiacoetsa(Buch.Han.exD.Don)Hara)中分离到3个结晶单体,并测定了其中两个单体——细锥香茶菜甲素(1)和乙素的结构。本文通过1H-1HCOSY、13C-1HCOSY和NOESY,修订细锥香茶菜甲素(1)的结构为(2),并经理化常数测定和光谱分析,确定了另一结晶单体——微量新成分细锥香茶菜丙素(3)的结构。(2)R1=R2=R4=H,R3=OAc,R5=OCH3(3)R1=R3=R4=H,R2=OAc,R5=OCH…  相似文献   

7.
温度对中华鳖卵孵化和胚胎发育的影响   总被引:8,自引:0,他引:8  
在25℃,27.5℃,30℃,32.5℃和35℃条件下,分别研究了中华鳖(Trionyx sinensis)卵的孵化和胚胎的发育。卵黄和卵壳的湿重分别占卵重的85.10%和14.90%,含水量分别为76.63%和21.01%。中华鳖胚胎重随孵化时间呈逻辑斯谛曲线增长,孵化温度越高,胚胎发育速度r越大。25℃-30℃的胚胎发育仅表现为‘S’型生长曲线的前,中段,在孵化后期发育速度未受到明显的抑制,32.5℃和35℃温度条件下,后期发育速度受到了较大的影响。孵出稚鳖湿重和干重均与初始孵重存在极显著的经性相关关系。孵化温度对孵出稚鳖湿重没有显著影响,但对孵出稚鳖干重的影响极显著。随孵化温度的升高,孵出稚鳖干重吾‘U’形变化,在适中温度下,胚胎的生长效率最低。卵黄干重随孵化时间呈指数递减,温度越高,孵黄的利用速度越快。在孵化过程中,卵重,卵干重和卵内水总量都随孵化时间的延长,孵化温度的上升而略有下降。孵化期随温度升高呈双曲线缩短,其相关关系可用方程I=30.6+109/(T-22.5)来表示。中华鳖卵的最适孵化温度在32.5℃左右,胚胎孵化后期比早期对温度的需求可能要低一些。  相似文献   

8.
小麦HMW-GS1Dx5基因的克隆及其特异性表达   总被引:3,自引:0,他引:3  
显微切割了普通小麦钢82-122(Triticumaestivum2n=42)具有1Dx5+1Dy10亚基的1D染色体长臂端,利用PCR扩增得到了HMW-GS1Dx5亚基的5(端400bp序列片段.以此作为探针从基因的组织特异性和特定发育阶段的表达两个方面研究了HMW-GS1Dx5基因表达的规律.结果表明,干种子及萌发种子中存在此基因,而在发育的幼苗中此基因未表达.HMW-GS1Dx5基因可能从开花初期开始表达.HMW-GS1Dx5基因在籽粒成熟期表达,然而在营养器官如叶片中未表达,其表达存在组织特异性.HMW-GS1Dx5基因在蜡熟期籽粒表达水平最高,其次是乳熟期籽粒.从开花15d至蜡熟期籽粒,表达趋于增加.开花15d其mRNA水平是蜡熟期籽粒mRNA的28%,灌浆期为40%、乳熟期为72%、完熟期为54%.这为进一步研究其表达调控和改善小麦品质打下基础  相似文献   

9.
“缺血”心肌起搏离子流If的观察研究   总被引:12,自引:1,他引:11  
本文观察“缺血”及肾上腺素能激动剂对绵羊心室浦肯野纤维起搏离子流If的影响。用模拟缺血溶液灌流15,30和60min后,在Ec—60mV—120mV之间的各不同指令电位水平If离子流幅值均降低(n=7,P<0.05),激活达稳态时间及半激活时间延长(n=7,P<O.05),激活曲线向超极化方向移位。1×10-6mol/L异丙基肾上腺素能使If离子流幅值增加(n=10,P>0.05),激活达稳态时间及半激活时间缩短(n=10,P<0.05),激活曲线向除极化方向移位,但不能完全逆转“缺血”对If离子流的抑制作用。在5×10-7mol/L普萘洛尔存在条件下,5×10-5mol/L新福林对正常绵羊心室浦肯野纤维If离子流影响不一致,但可加剧“缺血”对If离子流的抑制作用。上述结果表明:急性心肌缺血时,心室浦肯野纤维正常起搏活动不是增强,而是减弱。提示急性缺血性室性心律失常不是由于心室正常自律活动异常增强引起。  相似文献   

10.
应用细胞培养、3H-TdR和3H-Leucine掺入方法,观察血小板生长因子BB(Platelet-derivedGrowthFactorBB)对体外培养兔肺动脉平滑肌细胞DNA和蛋白质合成的影响。结果表明:(1)当PDGF-BB浓度为10ng/ml时,3H-TdR掺入值已较对照组显著增高(6262.5±412.9vs833.5±124.0,P<0.05);当PDGF-BB浓度为20ng/ml时,3H-Leucine掺入值亦较对照线显著增高(10212.8±638.3vs7340.3±1197.9,P<0.05)。(2)PDGF-BB浓度在5-25ng/ml范围内,3H-TdR,3H-Leucine掺入值与剂量直线相关(rDNA=0.97,rprot=0.90P<0.05)。说明PDGF-BB刺激体外培养兔肺动脉平滑肌细胞DNA和蛋白质合成。  相似文献   

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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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
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  相似文献   

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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.  相似文献   

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