丝裂霉素C诱发人精子染色体畸变的研究

人精子经最终浓度分别为７．５,１５．３０μｇ／ｍｌ丝裂霉素Ｃ（ＭＭＣ）处理１ｈ后与去透明带地鼠卵受精,制备第１次卵裂中期相进行核型分析,以探讨ＭＭＣ对人精子的诱变效应。结果显示明显的量效关系。染色单体型畸变是诱发畸变的主要类型,但仍观察到一定数量染色体型畸变,表明ＭＭＣ作用于人精子与通常拟紫外线致断剂作用于体细胞诱变的结果并不完全一样。３６．８９％的诱发畸变为重接型,表明金黄地鼠卵母细胞内的修复系统能够修复ＭＭＣ所引起的人精子ＤＮＡ损伤     

脉冲电磁场对家猪淋巴细胞的细胞遗传学效应

以家猪外周血淋巴细胞为材料,研究了脉冲电磁场（pulsing electromagnetic fields,简称PEMFS)树细胞的遗传学效应,实验发现,100和200kHz的PEMFs对家猪的淋巴细胞照射培养12,24,48h后,染色体畸变（包括非整倍体,染色体断裂等）频率明显高于对照组（P＜0．05）,其中,56％的染色体或染色单体断裂和42％的间隙发生在家猪常见染色体脆性位点部位,同时, 经100kHz和200kHz的PEMFs照射48h后,淋巴细胞姐妹染色单体交换（SCE）频率也明显高于对照组（P＜0．05）,实验结果表明,PEMFS能诱导DNA损伤和染色体畸变。     

职业性接触砷、铅工人外周淋巴细胞染色体畸变和姐妹染色单体交换率的变化

本实验以个旧云南锡业公司某矿坑下作业工人和某冶炼厂尿砷,尿铅超标工人为检查对象,初步探讨了污染与人类染色体损伤的关系,结果是使以上受检对象的外周淋巴细胞的染色单体断裂率、裂隙率、畸变细胞率和姐妹染色单体交换率都明显增高,与对照组相比差异显著。尿铅和尿砷超标工人外周淋巴细胞的染色体畸变和姐妹染色单体交换率分别与对照组相比,经统计学处理差异显著(P<0.05),且随着砷、铅在体内蓄积量的增加而有上升的趋势,表明砷、铅污染是引起人类染色体损伤的一个因素。     

口服避孕药的细胞遗传学效应及其观察指标

口服避孕药的广泛使用,使人们对其安全性产生 很大的关注。染色体畸变和用姐妹染色单体分化染色 (SCD）来观察姐妹染色单体交换（SCE,是目前用于 探讨口服避孕药细胞遗传学效应的主要指标,特别是 SCE已作为检测染色体损伤的一种敏感而可靠的方 法被广泛应用。但是,SCE技术的应用和观察结果,又 提出了一些值得探讨的间题。为此,本文试就口服避 孕药对染色体畸变和SCE的研究概况综述如下。     

鲶鱼染色体的显带研究

对鲶鱼染色进行Ａｇ－ＮＯＲｓ、Ｃ－带,ＣＭＡ３／ＤＡ／ＤＡＰＩ三重荧光染色昨帛 带的研究。结果发现,鲶鱼Ａｇ－ＮＯＲｓ定位在ｍ１ｑ的末端,上有一种特殊的形态和数目多态现象,即染色体上的ＮＯＲｓ发生串联重复。该种鱼只有部分染色体呈现阳性Ｃ带,,所显示的异染色质可分为三类,有丝粒异染色质、端粒异染色质和居间异染色质,其中ｍ１的整佧长臂都被深染,是Ｃ－带染色最深、染色面积最大的区域。ＣＭＡ３染色显示,Ｎ     

年龄和性别对遗传安全性检测指标的影响

本文通过对男性、女性成年人和儿童的外周血淋巴细胞的染色体畸变率、染色体畸变类型性的染色体畸变分析,微核,姐妹染色单体交换,及细胞有丝分裂指数、细胞周期比率、细胞增值指数的细胞动力学研究等8项参数、综合分析年龄和性别对其遗传安全性检测指标的影响。结果8项参数在成年人中均显示男性高于女性的趋势;除细胞畸变率外,其他7项参数在男性和女性中均显示成年人高于儿童的趋势。由本试验初步认为,年龄和性别对遗传安全性检测指标存在一定影响。     

昆明水源水和自来水水质致突变性及化学背景值：II.蝌蚪红细胞微核…

本文研究的目的是以蝌蚪微核及ＣＨＯ培养细胞染色体畸变（ＣＡ）及姐妹染色单体交换（ＳＣＥ）为指示器,研究昆明市各水厂自来水和它们源水的潜在致突变性,结果表明：（１）各水厂自来水及它们的源水诱发蝌蚪微核率,除Ｙ－水厂自来水外都有显著性差异。（２）ＣＡ率的结果;各水厂自来水及源水和对照组除了Ｗ－水厂自来水外,都没有显著性差异（３）ＳＣＥ率;高浓度组（０．０６２５Ｌ／ｍｌ）滇池源水及Ｗ－水厂自来水和低浓度     

人白血病细胞系（J6-1,J6-2和J6-3）的SCE及其对MMC敏感性的研究

染色体或染色单体断裂可作为研究DNA 损伤的一个细胞遗传学指标,但是在正常情况 下染色体和染色单体断裂的出现率并不高,而 姐妹染色单体互换（简称SCE）频率则较高,因 而后者是研究染色体稳定性的一个较好指标。 丝裂霉素（MMC）是一种强的致突变和 致癌剂^[2],同时又是强的SCE诱发剂。     

强啡肽对脊髓原生型与诱生型一氧化氮合成酶活性、分布和基因表达的影响及机制

蛛网膜下腔注射（ｉ．ｔ．）强啡肽Ａ１－１７（Ｄｙｎ）引起剂量依赖性后肢和尾部瘫痪及甩尾甩足抑制。脊髓背角（侧）ＮＭＤＡ受体和ＮＯＳ／ＮＯ功能活性下降可能与Ｄｙｎ镇痛作用有关,脊髓腹角（侧）ＮＭＤＡ受体－Ｃａ２＋－ＮＯＳ／ＮＯ通路过度激活及ｃ－ｆｏｓ高表达可能与Ｄｙｎ致脊髓损伤（ＳＣＩ）作用有关。在Ｄｙｎ致ＳＣＩ机制中,过量ＮＯ（细胞水平）具有神经毒性作用,脑源性ＮＯＳ主要在早期,诱生型ＮＯＳ主要在后期起作用,而内皮细胞源性ＮＯＳ和适量ＮＯ（血管水平）可能具有保护作用。在原代培养脊髓神经元中,高浓度Ｄｙｎ可通过ＮＭＤＡ受体和κ受体直接引起细胞内Ｃａ２＋超负荷,低浓度Ｄｙｎ只通过κ受体抑制高钾刺激性Ｃａ２＋内流     

佛波酯能改变细胞表面糖蛋白N－糖链的结构

利用标记Ｎ－糖链的凝集素亲和层析法研究了佛波醇肉桂酸乙酸酯（ＰＭＡ）对人肝癌细胞ＳＭＭＣ－７７２１表面糖蛋白上Ｎ－糖链结构的影响,发现１００ｎｍｏｌ／Ｌ的ＰＭＡ处理５天后,可使细胞表面Ｎ－糖链中高甘露糖型和杂合型以及四天线、Ｃ２Ｃ２,６三天线复杂型的比例增高,而二天线复杂型降低。此结果与我们曾报道的视黄酸（ＲＡ）和双丁配环磷酸腺苷（ｄｂ－ｃＡＭＰ）对该细胞表面Ｎ－糖链的影响相反。因ＲＡ和ｄｂ－ｃＡＭＰ是ＳＭＭＣ－７７２１细胞的分化诱导剂,可抑制细胞生长;而ＰＭＡ是该细胞的增殖促进剂,故细胞表面Ｎ－糖链的变化与细胞的分化和增殖密切相关。     

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.