丹皮酚对心肌细胞自律性和延迟后除极的影响

目的与方法：采用常规玻璃微电极技术研究丹皮酚对离体心肌细胞自律性（ＡＭ）、延迟后除极（ＤＡＤ） 及触发活动（ＴＡ）的影响。结果：１．８×１０－４ｍｏｌ／Ｌ丹皮酚灌流组,肾上腺素（Ａｄｒ）的阈浓度空白对照组为（１．２８±０．５７）μｍｏｌ／Ｌ,药后为（１．５６±０．５３）μｍｏｌ／Ｌ（ｎ＝９,Ｐ＞０．０５）;用（１．８×１０－ ３） ｍｏｌ／Ｌ丹皮酚（Ｐａｅ）灌流组,Ａｄｒ 浓度由空白对照组的（１．２２ ±０．６２）μｍｏｌ／Ｌ升高到（６．２２±２．１１）μｍｏｌ／Ｌ（ｎ＝９,Ｐ＜０．０１）。１．８×１０－３ｍｏｌ／Ｌ的Ｐａｅ 能明显抑制哇巴因（Ｏｕａ）诱发的ＤＡＤ的幅值,当基本刺激周长为５００,４００,３００ 和２００ ｍｓ 时,其ＤＡＤ幅值从（５．５±２．０）ｍＶ,（７．３±２．１）ｍＶ,（８．０ ±２．４）ｍＶ和（９．２±１．９）ｍＶ减小到（３．０±１．１）ｍＶ、（３．６±１．７）ｍＶ,（４．３±２．０） ｍＶ和（５．９ ±１．６） ｍＶ,Ｐ＜０．０１。当基本刺激周长为２００ ｍｓ时,ＴＡ 数目由５．５±１．０ 降至０．７±０．３（Ｐ＜０．０１）。结论：丹皮酚能抑制心肌细胞ＡＭ、ＤＡＤ及ＴＡ,具有抗心律失常作用     

α受体激动对绵羊心肌瞬时性内向离子流的影响

用乙酰毒毛旋花子甙元（ＡＳ）０．０５μｍｏｌ／Ｌ诱发绵羊心浦肯野纤维产生稳定的瞬时性内向离子流（Ｉｔｉ）,用普萘洛尔０．５μｍｏｌ／Ｌ阻断β受体,观察α受体激动剂苯肾上腺素（ＰＥ）０．３,１．０μｍｏｌ／Ｌ对Ｉｔｉ幅值与时程的影响。ＰＥ１．０μｍｏｌ／Ｌ灌流２０,５０ｍｉｎ时Ｉｔｉ幅值分别由对照值１２．８±１．９ｎＡ减小至１０．７±１．２ｎＡ（ｎ＝５,Ｐ＜０．０５）与９．６±１．９ｎＡ（ｎ＝５,Ｐ＜０．０１）;ＩｔｉＤ５０时程分别由对照值１４５±２４．４ｍｓ延长至１８３．３±２８．１ｍｓ（ｎ＝５,Ｐ＜０．０５）与２０７．５±３４．２ｍｓ（ｎ＝５,Ｐ＜０．０１）,ＰＥ对Ｉｔｉ的抑制作用呈剂量依赖性与时间依赖性。Ｉｔｉ到达峰值的时间和回复到基线的时间都延长,提示ＰＥ作用下Ｉｔｉ通道动力学发生了变化。如果在β受体激动剂异丙肾上腺素（ＩＳＯ）１．０μｍｏｌ／Ｌ增强Ｉｔｉ的基础上,ＰＥ１．０μｍｏｌ／Ｌ灌流１０ｍｉｎ,对Ｉｔｉ幅值的抑制及时程的延长作用更显著,Ｉｔｉ幅值由对照值１５．６±３．２ｎＡ减小到１０．３±２．２ｎＡ;ＩｔｉＤ５０由９２．５±１４．３ｍｓ延长到１３２．５±３６．０ｍｓ（ｎ＝５,Ｐ＜０．０１）。     

表皮生长因子对离体大鼠肺动脉及肺动脉平滑肌细胞作用的研究

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。     

兴奋性氨基酸介导的膜电流可被吗啡阻断

在Ｓｐｒａｙｕｅ－Ｄａｗｉｅｙ大鼠的含有孤束核中央亚核及疑核神经元密集区的脑薄片上,吗啡（３—５ｐｍｏｌ）对疑核细胞内记录到的自发兴奋性突触后电位有抑制作用;向灌流液内注入吗啡可使电刺激孤束核在疑核记录到的兴奋性突触后电位的幅度降低７１．１±６．２％（Ｐ＜Ｏ．００１）,纳洛酮（５０ｎｍｏｌ／Ｌ）可翻转这种抑制效应;含有１０μｍｏｌ／Ｌ吗啡的灌流液对ＮＭＤＡ（０．５—１ｐｍｏｌ）、乙酰胆碱（３ｐｍｏｌ）及ＱＵｉｓｑｕａｌａｔｅ（０．１—０．５ｐｍｏｌ）引起的细胞膜去极化有不同程度的抑制作用,分别为３８．１±５．７％（Ｐ＜０．００１）,３２．８±５．５％（Ｐ＜０．０１）和２９．６±７．１％（Ｐ＜０．０５）。这些结果可能是由于吗啡兴奋μ和δ受体后,增加了Ｋ＋电流而降低Ｎａ＋,Ｃａ２＋离子通透性的缘故。     

P物质对大鼠DRG神经元胞体膜的作用

本文在大鼠ＤＲＧ神经元标本上应用细胞内记录,以确定ＳＰ对ＤＲＧ细胞的膜反应及其可能的离子机制。实验所测ＤＲＧ细胞静息膜电位为－５８．９±８．２ｍＶ（Ｘ±ＳＥ,ｎ＝８１）。传导速度：Ａ_（α／β）细胞为２０．４±４．８ｍ／ｓ（Ｘ±ＳＥ）,范围１４．１－２８．７ｍ／ｓ（４７／６０）;Ａδ及Ｃ类细胞为９．８±５．２ｍ／ｓ,范围１．２－１３．７ｍ／ｓ（１３／６０）。浴槽滴加ＳＰ（１０￣（－７）－３×１０￣（－４）ｍｏｌ／Ｌ）在大多数细胞可引起明显的膜去极化反应（５６／６０）。少数细胞对ＳＰ无反应（４／６０）。在ＳＰ去极化期间膜电导值有所增加,从平均值２．７２×１０￣（－８）ｍｈｏ增加２４．６％（ｎ＝３）。所测逆转电位值在＋４０－＋５０ｍＶ之间（ｎ＝３）。浊流平衡液（ＢＳＳ）中ＮａＣｌ以氯化胆碱置代,或用含ＴＴＸ（１０￣（－５）ｍｏｌ／Ｌ）的ＢＳＳ灌流,可使ＳＰ－去极化幅值大大减小但不能完全消除。而高（２０ｍｍｏｌ／Ｌ）和低（０ｍｍｏｌ／Ｌ）Ｃａ￣（２＋）的ＢＳＳ灌流时,使ＳＰ－去极化幅值相应的增加和降低。用含１０￣（－４）ｍｏｌ／ＬＣｄ￣（２＋）及１０￣（－２）ｍｏｌ／ＬＴＥＡ的ＢＳＳ灌流,均使ＳＰ－去极化明显减小。     

汉防己甲素对四氧嘧啶引致大鼠胰岛β细胞损伤的保护作用

本实验采用四氧嘧啶损伤大鼠胰岛β细胞,复制糖尿病动物模型。若预先腹腔注射汉防己甲素（１００ｍｇ／ｋｇ）则可完全预防引发的糖尿病。预防组血糖（７．６３±０．４４ｍｍｏｌ／Ｌ）明显低于对照组（２５．４６±１．２１ｍｍｏｌ／Ｌ,Ｐ＜０．００１）;血清胰岛素水平（１１．３３±１．９７μＵ／ｍｌ）高于对照组（７．１３±０．４５μＵ／ｍｌ,Ｐ＜０．０５）;血浆胰高血糖素（６６．８５±５．０７ｐｇ／ｍｌ）明显低于对照组（９０．３５±３．１５ｐｇ／ｍｌ,Ｐ＜０．０１）．口服葡萄糖耐量实验显示预防组耐糖功能较对照组明显改善,糖耐量曲线下血糖面积预防组（２９．４５±１．６３ｍｌ·ｈ／Ｌ）低于对照组（１１３．２８±５．０２ｍｍｏｌ·ｈ／Ｌ,ｐ＜０．００１）。胰岛β细胞免疫组织化学染色结果显示,预防组胰岛β细胞数目及胰岛素分泌颗粒的含量均与正常大鼠胰岛相同,无形态学改变,而对照组胰岛内β细胞免疫反应阳性产物减少甚至消失。结果表明,汉防己甲素对四氧嘧啶引起的胰岛β细胞急性损伤有保护作用。     

SNP抑制5-HT诱导的胞内游离钙浓度升高和内钙释放

用Ｆｕｒａ － ２／ＡＭ 荧光测量技术研究了５ － 羟色胺（５－ ＨＴ） 诱导的大鼠尾动脉平滑肌细胞胞内钙升高和一氧化氮（ＮＯ） 的抑制效应。实验表明, 胞外０ｍ ｍｏｌ／ Ｌ Ｃａ２ ＋ 时胞内静息［Ｃａ２ ＋ ］ ｉ 为２０ ．２±８ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ８） 。１０μｍｏｌ／Ｌ ５－ ＨＴ 可诱导出胞内钙库释放引起的瞬态［Ｃａ２ ＋］ｉ 升高,其峰值达２４５ ．７ ±７１．６ｎｍｏｌ／ Ｌ（ｎ ＝ ６） 。１０ － ７ ｍｏｌ／Ｌ 硝普钠（ＳＮＰ） 可抑制５－ ＨＴ 诱导的［Ｃａ２ ＋］ｉ 升高,其峰值浓度降为７５．１±３５ ．９ｎｍｏｌ／Ｌ（ｎ ＝ ５） 。当细胞浴液含２．５ｍ ｍｏｌ／Ｌ Ｃａ２ ＋ 时,静息［Ｃａ２ ＋］ｉ为１１２ ．８ ±１０ ．３ｎｍｏｌ／ Ｌ（ｎ ＝ ５） , 这时１０μｍｏｌ／ Ｌ ５ － ＨＴ 可诱导［Ｃａ２ ＋ ］ ｉ 的峰值为２５２ ．３ ±８０ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,以及其后平台浓度为１４３ ．０ ±３７ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,略大于［Ｃａ２ ＋］ｉ 为１１２．８ ±１０ ．３ｎｍｏｌ／Ｌ 的静息浓度,为外钙内流引起。１０ － ７ ｍｏｌ／Ｌ ＳＮＰ 也可抑制５－ ＨＴ 诱导［Ｃａ２ ＋ ］ｉ 平台相浓度。平台浓度由１４３ ±４７     

EDRF对PE引起的大鼠主动脉缩血管效应的作用

本文研究ＥＤＲＦ（ｅｎｄｏｔｈｅｌｉｕｍ－ｄｅｒｉｖｅｄｒｅｌａｘｉｎｇｆａｃｔｏｒ,ＥＤＲＦ）对ＰＥ（ｐｈｅｎｙｌｅｐｈｒｉｎｅ）引起的大鼠主动脉收缩反应的影响。内皮完整和去内皮的大鼠主动脉环悬挂于器官浴槽中,测定血管的张力和收缩速度的变化。所有的实验在消炎痛（ｉｎｄｏｍｅｔｈａｃｉｎ,１０μｍｏｌ／Ｌ）存在下进行。用美兰（ｍｅｔｈｙｌｅｎｅｂｌｕｅ,ＭＢ,１０μｍｏｌ／Ｌ）或左旋硝基精氨酸（ＮＧ－ｎｉｔｒｏ－Ｌ－ａｒｇｉｎｉｎｅ,Ｌ－ＮＮＡ,３０μｍｏｌ／Ｌ）处理内皮完整的大鼠主动脉环,ＰＥ的剂量－收缩张力曲线明显左移,ＥＣ３０值均降低５倍,最大反应比率分别为１．６±０．４和１．６±０．５。在去内皮的大鼠主动脉环中,经ＭＢ和Ｌ－ＮＮＡ处理后,仍可见ＥＣ３０下降３倍,最大反应比率均为１．０±０．２。后者可能与血管平滑肌产生少量ＥＤＲＦ有关。我们的结果提示ＰＥ对血管的收缩反应也受血管内皮和平滑肌产生的ＥＤＲＦ的调控     

过氧化氢和次黄嘌呤＋黄嘌呤氧化酶对家兔离体肺、脑动脉环缺氧反应的影响

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。     

α受体激动对绵羊心脏浦肯野纤维延迟后除极的影响

用乙酰毒毛旋花子成元０．２μｍｏｌ／Ｌ诱发绵羊心脏浦肯野纤维产生延迟后除极（ＤＡＤ）,采用细胞内微电极记录。在用普奈洛尔１．０μｍｏｌ／Ｌ阻断β受体条件下,苯肾上腺素１．０μｍｏｌ／Ｌ使ＤＡＤ幅值由８．１±２．２ｍＶ增至９．５±２．８ｍＶ,时程由２４０±４７ｍｓ延长到２７３±４７ｍｓ（ｎ＝１３,ＰＭ＜０．０１）,ＤＡＤ上升速率由０．０３９±０．０２３Ｖ／ｓ增至０．０５１±０．０２６Ｖ／ｓ（ｎ＝１３,Ｐ＜０．０５）,ＤＡＤ在动作电位后出现的时间提前了３０±４７ｍｓ（ｎ＝１３,Ｐ＜０．０５）。用去甲肾上腺素１．０μｍｏｌ／Ｌ增强ＤＡＤ引起触发活动时,酚妥０拉明１．８μｍｏｌ／Ｌ不能抑制触发活动,普奈洛尔１．０μｍｏｌ／Ｌ能抑制之。上述结果表明α受体激动对ＤＡＤ有轻度增强作用,但由ＤＡＤ引起的触发活动,α受体阻滞剂的抑制作用不如β受体阻滞剂有效。     

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.