冠状动脉球囊损伤后管壁原癌基因c-myc表达的变化

目的：探讨原癌基因c-myc的表达与冠状动脉球囊损伤后内膜增殖的关系。方法：建立猪的冠状动脉球囊损伤模型，观察形态学变化，并用RT-PCR的方法检测损伤冠状动脉壁内c-myc mRNA的表达。结果：冠状动脉球囊损伤后6周管壁内膜明显增生，管腔狭窄，c-myc mRNA的相对表达强度明显高于正常冠状动脉壁。结 论：c-myc基因与冠状动脉球囊损伤后内膜增殖密切相关。     

维生素D受体在1,25(OH)2D3调节人骨肉瘤细胞系HOS-8603增殖中的作用

目的:研究维生素D₃受体(VDR)在1,25(OH)₂D₃及其类似物调节人骨肉瘤细胞系HOS-8603增殖中的作用。方法:用RT-PCR和免疫组织化学技术分别在mRNA和蛋白水平上明确HOS-8603细胞中是否有VDR表达;瞬时转染VDR报告基因技术观察HOS-8603细胞中VDR的功能活性;并进一步利用稳定表达VDR反义mRNA的细胞株VDRas3细胞研究VDR被阻断后细胞增殖以及基因转录的变化。结果:HOS-8603细胞有VDR表达,此内源性VDR具有激素依赖性的转录激活活性。在内源性VDR被阻断后,1,25(OH)₂D₃及其类似物对细胞增殖的抑制作用以及对VDR的靶基因p21mRNA表达的诱导作用均明显减弱。结论:1,25(OH)₂D₃及其类似物对HOS-8603细胞增殖抑制作用是由VDR介导的。     

妊娠滋养细胞肿瘤组织中cyclin D1、Rb蛋白产物的表达

目的：探讨增殖相关基因cyclin D1、Rb在妊娠滋养细胞肿瘤中的表达变化。方法：采用免疫组化S－P法,检测20例葡萄胎、15例侵蚀性葡萄胎、15例绒毛膜癌组织中两种基因蛋白产物的表达。结果：在恶性滋养细胞肿瘤组织中,cyclinD1的阳性表达率随临床期别的增高呈递增趋势,而Rb呈递减趋势,二者在Ⅲ期的阳性表达率与Ⅰ期及Ⅱ期相比差异均具有显著性（P＜0．05）;化疗可降低cyclinD1在恶性滋养细胞肿瘤中的阳性表达,而对Rb无影响。结论：cyclin D1的过表达,Rb的缺失在妊娠滋养细胞肿瘤的发展中可能有重要的生物学意义。     

大蒜素包被支架术后冠状动脉管壁原癌基因c-fos表达的变化

目的：探讨大蒜素（DT）包被支架置入后对血管内膜增生及管壁原癌基因c-fos表达的影响。方法：直接支架置入术建立犬冠状动脉内膜损伤模型，观察血管形态学变化，并用RT-PCR方法检测不同时点冠状动脉壁内c-fos基因的表达丰度。结果：单纯蛋白包被支架置入后4周管壁内膜明显增生，DT包被支架明显抑制内膜增生。对照组c-fos基因在术后1 d有大量的表达，7 d达高峰，以后随时间的推移表达逐渐下降,28 d仍可检出。与对照组相比，各时点DT包被支架均显著抑制c-fos mRNA的表达。结论：DT包被支架具有抑制c-fos基因的表达与内膜增生的作用。     

KLF4抑制球囊损伤诱导的新生内膜形成

目的： 通过腺病毒载体介导外源性KLF4在大鼠颈动脉球囊剥脱血管中进行表达,观察新生内膜增生情况,研究外源性KLF4对球囊损伤诱导的新生内膜形成的影响及初步探讨其机制。方法： 构建含有KLF4基因的重组腺病毒载体pAd-KLF4,将其导入内皮剥脱的血管壁。用HE染色观察血管新生内膜的厚度,免疫组织化学染色和RT-PCR分别检测外源性KLF4在血管中的表达以及与增殖和分化标志基因表达的关系。结果： 重组腺病毒pAd-KLF4可在血管壁中稳定表达KLF4。KLF4的过表达可显著抑制球囊损伤后血管新生内膜的增厚,转染pAd-KLF4的血管,其内膜/中膜比值（I/M）（0.52±0.15）明显小于pAd对照组（2.48±0.38）,P<0.05。pAd-KLF4组血管壁增殖标志蛋白PCNA和c-Jun表达也较pAd组明显降低（P<0.05）。结论： KLF4过表达可阻断损伤诱导的血管平滑肌细胞表型转化,进而抑制球囊剥脱后血管内膜的增生。     

IGFBP7对人乳腺癌MCF-7细胞增殖的影响及其机制

目的: 探究胰岛素样生长因子结合蛋白7(IGFBP7)对人乳腺癌MCF-7细胞增殖的影响及其分子生物学机制。方法: 将质粒pCMV6-IGFBP7转染MCF-7细胞,构建稳定表达IGFBP7的MCF-7细胞系;采用Western blotting检测IGFBP7在MCF-7细胞稳定转染子的表达;采用软琼脂培养克隆形成实验检测IGFBP7对MCF-7细胞克隆形成能力的影响;采用流式细胞术检测IGFBP7对MCF-7细胞周期的影响;采用Western blotting检测IGFBP7对MCF-7细胞细胞外信号调节激酶1/2(ERK1/2)、p-ERK1/2、细胞周期素D1(cyclin D1)、细胞周期素依赖性激酶4(CDK4)、cyclin E、CDK2、p21^CIP1/WAF1、p27^KIP1、p53、视网膜母细胞瘤蛋白(Rb)和p-Rb蛋白含量的影响。结果: (1)只有稳定转染质粒pCMV6-IGFBP7的MCF-7细胞表达IGFBP7。(2)IGFBP7能够显著降低MCF-7细胞的克隆形成率(P<0.01),阻止细胞从G₁期进入S 期,使其停滞于G₁期(P<0.01)。(3)IGFBP7能够显著抑制ERK1/2的磷酸化(P<0.01)。(4)IGFBP7能够下调cyclin D1和cyclin E蛋白表达(P<0.01),上调p27^KIP1、p21^CIP1/WAF1和p53蛋白表达(P<0.01),抑制Rb的磷酸化(P<0.01)。(5)MEK1/2阻断剂PD98059可部分模拟IGFBP7的肿瘤抑制效应。结论: (1) IGFBP7可通过下调cyclin D1和cyclin E蛋白表达,上调p27^KIP1、p21^CIP1/WAF1和p53蛋白表达,以及抑制Rb磷酸化发挥抗肿瘤作用;(2) IGFBP7对cyclin D1和p27^KIP1的调节可能与其抑制ERK1/2信号通路有关。     

全反式维甲酸对大鼠腹主动脉球囊损伤后内膜增生和血管重塑的影响

目的：研究全反式维甲酸（ATRA）对球囊损伤大鼠腹主动脉内膜增生和血管重塑的影响。方法：复制球囊损伤的大鼠腹主动脉剥脱模型，12只Wistar大鼠随机分为①对照组：6只腹腔内注射intralipid（1 mL/d）；②ATRA组：6只腹腔内注射溶解于intralipid的ATRA（4 mg·kg^-1·d^-1）。球囊损伤14 d后，损伤区域的血管段用10%甲醛固定，然后染色，进行组织学观察。结果：ATRA组新生内膜面积（IA）明显小于对照组，管腔面积（LA）和外弹力膜包绕面积（EEL）则大于对照组。结论：ATRA具有抑制损伤血管的内膜增生和促进有益的血管重塑的作用。     

亚硒酸钠对子宫内膜癌细胞增殖能力的影响

目的: 研究亚硒酸钠(Na₂SeO₃)对子宫内膜癌细胞增殖能力的影响,并探讨其作用机制。方法: 用Na₂SeO₃作用于子宫内膜癌Ishikawa细胞和HEC-1A细胞,MTT法检测细胞增殖能力,流式细胞法测定Na₂SeO₃作用后细胞周期的变化及凋亡情况,Western blotting检测周期蛋白cyclin A的表达。结果: Na₂SeO₃对子宫内膜癌Ishikawa细胞和HEC-1A细胞的增殖均有抑制作用,抑制率在一定浓度范围内与Na₂SeO₃浓度呈正相关,对Ishikawa细胞作用48 h的IC₅₀为3.26 μmol/L,对HEC-1A细胞作用48 h的IC₅₀为4.77 μmol/L。Na₂SeO₃作用后两种细胞G₀/G₁期减少,S期细胞增多,G₂/M期细胞有所增加。作用48 h后两种细胞凋亡率增加。Na₂SeO₃使子宫内膜癌Ishikawa细胞和HEC-1A细胞的cyclin A表达增加。结论: 亚硒酸钠对子宫内膜癌Ishikawa细胞和HEC-1A细胞增殖有抑制作用,其作用机制与上调cyclin A表达,引起细胞周期阻滞和诱导凋亡有关。     

IL-32γ对大鼠血管平滑肌细胞增殖与细胞周期的影响

目的: 观察白细胞介素-32γ(IL-32γ)对大鼠血管平滑肌细胞(VSMCs)增殖与细胞周期的影响及机制。方法: 采用组织贴块法体外培养大鼠VSMCs并以IL-32γ处理。应用MTT法检测细胞增殖;流式细胞术检测细胞周期;免疫印迹方法检测cyclin D1和核内NF-κB p65蛋白含量;免疫细胞化学染色法检测增殖细胞核抗原(PCNA)表达的变化。结果: 不同浓度(10~50 μg/L)的IL-32γ在24~48 h范围内,浓度和时间依赖性促进VSMCs增殖;50 μg/L的IL-32γ作用VSMCs 24 h后促进了细胞周期由G₁期向S期,进而G₂/M期转化,同时上调NF-κB p65、cyclin D1和PCNA蛋白的表达水平;应用NF-κB抑制剂PDTC能逆转上述效应。结论: IL-32γ能促进大鼠VSMCs增殖和加速细胞周期转化。上调NF-κB p65和cyclin D1的表达可能是其作用机制之一。     

睾酮对雄性家兔血管损伤后内皮功能及内膜增生的影响

目的:探讨睾酮对雄性家兔腹主动脉球囊损伤后内皮功能及内膜增生的影响。方法:选择健康雄性新西兰白兔24只随机分成3组:对照组(假去势)、低睾酮血症组(去势)及睾酮替代组(去势1周后加用长效十一酸睾酮单次肌注,14mg/kg),每组8只。去势10d后对所有动物行腹主动脉球囊损伤术。损伤后两周测血浆睾酮、血脂、一氧化氮代谢产物(NO₂^-/NO₃^-)、超氧化物歧化酶(SOD)及丙二醛(MDA)水平,并截取腹主动脉进行图像分析。结果:睾酮替代组和对照组的血浆总胆固醇、甘油三酯、低密度脂蛋白及MDA水平和新生内膜面积明显低于低睾酮血症组(P＜0.01或P＜0.05),睾酮替代组和对照组的NO₂^-/NO₃^-及对照组的SOD水平高于低睾酮血症组(P均＜0.05),替代组和对照组两组间比较各数据无差异。结论:生理水平的睾酮(内源性或外源性替代)具有保护雄性家兔血管内皮,抑制动脉损伤后内膜增生的作用。     

Development in in vitro toxicology

There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93.     

Age-related changes in polyamines in memory-associated brain structures in rats

Polyamines putrescine, spermidine and spermine are positively charged aliphatic amines and have important roles in maintaining normal cellular function, regulating neurotransmitter receptors and modulating learning and memory. Recent evidence suggests a role of putrescine in hippocampal neurogenesis, that is significantly impaired during aging. The present study measured the polyamine levels in memory-related brain structures in 24- (aged), 12- (middle-aged) and 4- (young) month-old rats using liquid chromatography/mass spectrometry and high performance liquid chromatography. In the hippocampus, the putrescine levels were significantly decreased in the CA1 and dentate gyrus, and increased in the CA2/3 with age. Significant age-related increases in the spermidine levels were found in the CA1 and CA2/3. There was no difference between groups in spermine in any sub-regions examined. In the parahippocampal region, increased putrescine level with age was observed in the entorhinal cortex, and age did not alter the spermidine levels. The spermine level was significantly decreased in the perirhinal cortex and increased in the postrhinal cortex with age. In the prefrontal cortex, there was age-related decrease in putrescine, and the spermidine and spermine levels were significantly increased with age. This study, for the first time, demonstrates age-related region-specific changes in polyamines in memory-associated structures, suggesting that polyamine system dysfunction may potentially contribute to aged-related impairments in hippocampal neurogenesis and learning and memory.     

休克过程中肾上腺髓质素变化的研究进展

Adrenomedullin (AM) is a new peptidergic regulator of vascular function. AM serves as a hormone, which has many biological properties, plays an important role in the many pathophysiological processes, especially shock. This review will highlight the structure, biological properties of AM and the relationship between AM and shock.     

Seasonal variations in acute toxoplasmosis in pregnant women in Slovenia

Between December 1999 and December 2004, 40 081 pregnant women were examined for toxoplasmosis with Toxo-IgG, Toxo-IgM enzyme immunoassay. Women with positive results were then retested with the Toxo-IgG avidity assay for recent toxoplasmosis. Recent acute toxoplasmosis in pregnant women was found to be significantly more frequent (p < 0.01) during winter than summer. The incidence of acute toxoplasmosis during winter-spring was also significantly more frequent (p < 0.025) than summer-autumn. This phenomenon should be taken into account when formulating preventive measures for toxoplasmosis, especially for pregnant women.     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Uteroglobin in the developing rabbit conceptus in vivo and in vitro

Summary Uteroglobin (UGL) was measured in day- 4 to day-10 rabbit conceptuses by a competitive ELISA. Levels in blastocyst fluid, tissues, coverings and in the early fetus were determined separately. The total amount of UGL increased from 18.4 ng to 6.8 g per conceptus. The UGL content of individual day-6 blastocysts was studied in vitro. Culturing was carried out up to 60 h in Ham's F10 medium with polyvinylpyrrolidone as macromolecular component, with and without progesterone, and with progesterone plus estradiol. UGL was determined in the blastocyst fluids, tissues with coverings and in the culture media. After labelling with [³⁵S]-methionine, protein patterns of total blastocysts and of culture media were analysed by two-dimensional gel electrophoresis and fluorography. The morphology of cultured blastocysts was examined by electron microscopy. During 60 h of culture, the blastocysts expanded in diameter by 84%, and released 19% of their initial UGL content into the medium, independent of the hormonal substitution. Neither de novo synthesis, nor degradation of UGL was found: the protein remained unlabelled in fluorography, and its total quantity was not significantly different from that of non-cultured controls. Trophoblast, endoderm and embryoblast cells showed well preserved cell organelles and intercellular junctions, while the morphological differentiation of the germ layer was inhibited.