胆囊收缩素对IL—1β损伤的胰岛β细胞功能的保护作用及其…

本实验在分离培养的新生在鼠胰岛上,观察了胆囊收缩素（ＣＣＫ－８）对白细胞介素－１β（ＩＬ－１β）损伤的胰β细胞功能的影响。并就其机制进行初步分析,结果表明：（１）ＩＬ－１β（５,１０,２０Ｕ／ｍｌ）能抑制葡萄糖（２０ｍｍｏｌ／Ｌ）刺激的胰岛素分泌其抑制作用具有量效关系,抑制率分别为５３．４％,６０．５％和７０．７％。（２）ＣＣＫ－８对ＩＬ－１损伤的胰岛β细胞的功能具有保护作用。预防性地给予ＣＣＫ－     

白细胞介素－1β对新生大鼠胰岛素分泌的作用及其机制分析

本实验采用分离培养的新生大鼠胰岛，观察了白细胞介素１β（ＩＬ－１β）和Ｎ￣Ｇ－甲基－Ｌ－精氨酸（ＮＭＭＡ，ＮＯ合成酶的竞争性阻断剂）对胰岛素分泌及对胰岛中ｃＧＭＰ水平和亚硝酸盐浓度的影响。结果如下：（１）ＩＬ－１β（５、１０、２０Ｕ／ｍｌ）能抑制基础的和由葡萄糖（２０ｍｍｏｌ／Ｌ）刺激的胰岛素分泌。ＩＬ－１β对葡萄糖刺激的胰岛素分泌的抑制作用呈明显的量效关系，抑制率分别为５３．％，６０．５％和７０．７％。（２）ＮＭＭＡ（０．５ｍｍｏｌ／Ｌ）能阻断ＩＬ－１β对葡萄糖刺激的胰岛素分泌的抑制作用。（３）ＩＬ－１β能增加胰岛内ｃＧＭＰ水平和亚硝酸盐浓度，而ＮＭＭＡ能阻断这一效应。以上结果表明，ＩＬ－１β能抑制新生大鼠胰岛β细胞的功能，这一作用可能是通过ＮＯ实现的。     

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）。     

红景天中药复方对低氧劳动能力的影响

我们研制了以藏产大花红景天为主要成分的中药复方用以提高机体的低氧劳动能力。在模拟海拔１００００ｍ的小鼠游泳实验中,药物组和对照组动物的存活时间分别为７３．２±３．８和６０．５±４．０ｍｍ（Ｐ＜０．０５）;游泳６０ｍｉｎ（相当于对照组的平均存活时间）以后死亡的百分数分别为５３．０％和３５．８％（Ｐ＜０．０５）。大鼠在模拟海拔５０００ｍ游泳１ｈ,药物组和对照组动物的血乳酸含量分别为１４．６±１．８和２１．１±１．９ｍｍｏｌ／Ｌ（Ｐ＜０．０５）。在模拟海拔４３００ｍ低压舱内人体运动负荷试验中,药物组和对照组受试者的ＰＷＣ１７０分别为９８０．４±５２．８和８６６．４±３０．０（Ｐ＜０．０１）。提示,红景天中药复方能明显提高低氧劳动能力。     

硒对培养人胚肝细胞Ⅲ型前胶原,羟脯氨酸合成的影响

原代培养人胚肝细胞经１．１５６×１０￣(－７）ｍｏｌ／Ｌ硒预处理４ｈ,加入２０ｍｍｏｌ／Ｌ四氟化碳作用２０ｈ,观察硒对其Ⅲ型前胶原（ＰＣⅢ）和羟脯氨酸（Ｈｙｐ）生成的影响。结果培养液中ＰＣⅢ水平、细胞内Ｈｙｐ含量及细胞内外丙二醛（ＭＤＡ）水平均降低,与未加硒对照组比较差别有显著性（Ｐ＜０．０１）。而硒谷腕甘肽过氧化物酶（Ｓｅ－ＧＳＨ－ＰＸ）活性则较对照组显著增高（Ｐ＜０．００１）,且ＰＣⅢ水平与Ｓｅ－ＧＳＨ－Ｐ＿Ｘ／ＭＤＡ比值呈负相关（ｒ＝－０．９１５６,Ｐ＜０．０１）。提示硒可提高Ｓｅ－ＧＳＨ－Ｐ＿Ｘ／ＭＤＡ比值,抑制脂质过氧化激发的肝细胞胶原合成。     

白细胞介素—1β对胰岛素分泌的抑制及睾酮的反转作用

离体培养新生大鼠胰岛细胞ＩＬ－１β（５－２０Ｕ／ｍｌ）处理２０ｈ后,可使胰岛细胞在高糖（２０ｍｍｏｌ／Ｌ）刺激下的胰岛素释放量明显降低。对ＩＬ－１β处理后的胰岛给予睾酮（１０＾－１０ｍｏｌ／Ｌ）,则能反转ＩＬ－１β的抑制效应,并且睾酮不仅增加胰岛素分泌,而且还可促进胰岛细胞内胰岛素含量的增加。     

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。     

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。     

运动对大鼠血小板L—精氨酸转运的影响

本工作在游泳大鼠模型上,观察血小板Ｌ－精氨酸（Ｌ－Ａｒｇ）转运特征,并观察凝血酶和ＰＡＦ对血小板Ｌ－Ａｒｇ转运的影响。结果发现,运动大鼠血小板Ｌ－Ａｒｇ转运明显高于未运动对照大鼠,表现在高亲和性最大转运速率（Ｖｍａｘ）明显增高（５０．５６±３．２７ｐｍｏｌ／１０８ｖｓ４５．８４±２．３６ｐｍｏｌ／１０８血小板／ｍｉｎ。Ｐ＜０．０５）,米氏常数亦显著增加（２．１４±０．２３μｍｏｌ／Ｌｖｓ１．４６±０．１３μｍｏｌ／Ｌ,Ｐ＜０．０１）。应用刺激剂凝血酶和ＰＡＦ诱导运动大鼠血小板Ｌ－Ａｒｇ转运速率增加的幅度明显高于未运动对照大鼠（Ｐ＜０．０１）。实验结果表明,运动能增强血小板转运Ｌ－Ａｒｇ的效率。提示,运动可能促进血小板一氧化氮（ＮＯ）生成,抑制血小板聚集,防治血管栓塞性疾病     

白细胞介素－1β对胰岛素分泌的抑制及睾酮的反转作用

离体培养新生大鼠胰岛细胞用ＩＬ－１β（５—２０Ｕ／ｍｌ）处理２０ｈ后，可使胰岛细胞在高糖（２０ｍｍｏｌ／Ｌ）刺激下的胰岛素释放量明显降低。对ＩＬ－１β处理后的胰岛给予睾酮（１０－１０ｍｏｌ／Ｌ），则能反转ＩＬ－１β的抑制效应，并且睾酮不仅增加胰岛素分泌，而且还可促进胰岛细胞内胰岛素含量的增加。     

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.