抑菌生的致突变性试验

本文应用Ames试验、微核试验,对中国人民解放军224医院及沈阳军区军事医学研究所研制的具有抗感染作用的枯草杆菌BS_(224)生态制剂即抑菌生进行了致突变性检测。结果表明:BS_(224)生态制剂不能使鼠伤寒沙门氏菌株发生回复突变,不引起小鼠骨髓嗜多染红细胞微核率升高,初步认为BS_(224)生态制剂无突变性,推测无致癌性。     

小鼠腹腔注射甲醛后骨髓细胞微核变化检测

本实验目的是检测不同剂量甲醛经腹腔注射染毒小鼠后,小鼠骨髓嗜多染红细胞数量和微核的数量与注射剂量之间的关系。结果甲醛剂量和嗜多染红细胞数、微核数、微核率(‰)均呈正相关。     

镰形棘豆正丁醇提取物对小鼠的致突变试验

目的:评价镰形棘豆的正丁醇提取物对小鼠的致突变性.方法:小鼠随机分成6组,设阴性对照组(Ⅰ组)、阳性对照组(Ⅱ组)和4个剂量组(Ⅲ组、Ⅳ组、Ⅴ组和Ⅵ组),4个剂量组经口给予镰形棘豆正丁醇提取物的剂量分别为800mg/kg、100mg/kg、2000mg/kg、4000mg/kg,于给药后第2d取材观察小鼠骨髓嗜多染红细胞(PCE)微核率,于第35d取材来观察精子畸形率的变化.结果:镰形棘豆正丁醇提取物对小鼠微核细胞的产生及致精子畸形存在剂量-效应关系.Ⅲ组、Ⅳ组与Ⅰ组比较差异不显著(P＞0.05);Ⅴ组、Ⅵ组与Ⅰ组比较均差异显著(P＜0.05).结论:低浓度的镰形棘豆正丁醇提取物对小鼠的骨髓嗜多染红细胞和精子没有致突变作用,而高浓度的对小鼠的骨髓嗜多染红细胞和精子具有致突变作用.     

牡蒿提取物抗氧化作用和遗传毒性研究

本文旨在研究牡蒿提取物(Artemisia japonica Extract,AJE)对小鼠抗氧化作用和遗传毒性效果。在建立卡介苗(BCG)+脂多糖(LPS)诱导免疫性肝损伤小鼠模型的基础上,采用给小鼠灌胃不同浓度的AJE后,分别测定小鼠肝组织中丙二醛(MDA)、谷胱甘肽氧化酶(GSH-Px)和超氧化歧化酶(SOD)的活性。检查小鼠骨髓嗜多染红细胞微核率和小鼠精子畸形率。结果表明,在一定剂量范围内,牡蒿提取物有降低小鼠肝组织中MDA含量、升高GSH-Px和SOD活性的作用,微核试验和精子畸形试验结果均为阴性。说明AJE具有较强的抗氧化作用,无遗传毒性。     

乌龙茶降低氟化钠和三氧化二砷诱发的小鼠骨髓细胞微核率的研究

本文以乌龙茶黄金桂为材料,以氟化钠(NaF)和三氧化二砷(As_2O_3)为诱发剂,以骨髓嗜多染红细胞微核率(PCE)为指标,在实验室对不同组别的小白鼠进行遗传毒理实验。结果表明:乌龙茶具抗砷、氟诱发的细胞遗传损伤的作用。     

丝裂霉素致小鼠骨髓淋巴细胞遗传损伤及西洋参的干预作用研究

目的:研究西洋参(Panax quinguefolium L)抗突变作用和对细胞增殖的影响.方法:采用小鼠骨髓淋巴细胞有丝分裂指数试验、染色体畸变试验和微核试验,观察西洋参对小鼠骨髓淋巴细胞遗传损伤效应的影响.结果:丝裂霉素(Mitomycin-c MMC)单独作用时,能抑制小鼠骨髓淋巴细胞的增殖(P<0.01),提高小鼠骨髓淋巴细胞的染色体突变(P<0.01)和微核率(P<0.01).西洋参高、中、低剂量组与MMC联合作用时,有丝分裂指数明显比模型组提高(P<0.01),并且均能显著地抑制由于MMC引起的染色体突变,其抑制率分别为68.25%、34.97%和14.29%,同时对MMC诱发的微核率也有明显的抑制效应.结论:西洋参能抑制MMC诱发的染色体畸变率和微核率,促进细胞的增殖能力.     

金荞麦的致突、致畸研究

本文报道了中草药金荞麦的致突、致畸试验。研究结果表明,金荞麦1-5000μg/皿的7个剂量,对Ames 4个标准菌株（±S9）未诱发阳性突变;对正定霉素和甲基甲烷磺酸醋所诱发的TA98和TA100菌株的回复突变,具有杭突变作用;对NIH系小鼠未见诱发骨髓嗜多染红细胞微核率增加;对中国仓鼠卵巢细胞染色体（±S9)无诱发畸变作用;对NIH系小鼠的生殖能力和胎鼠的生长发育未见不良影响,对胎鼠外观、骨骼、内脏无致畸作用。     

梨果仙人掌红花品系的毒性研究

通过对梨果仙人掌红花品系的小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验研究,梨果仙人掌红花品系雌、雄小鼠LD50均大于170．0g／kgBw,属无毒物质;小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验结果均为阴性。因此在本次实验条件下,梨果仙人掌红花品系为无毒物质,未显示有遗传毒性作用。     

萝卜过氧化物酶的毒理学研究

为了探讨萝卜过氧化物酶应用的安全性,对其进行了小鼠经口急性毒性实验、小鼠骨髓嗜多染红细胞微核实验和小鼠精子畸形实验等急性和遗传毒性实验.结果表明,受试物对小鼠的LD50(半数致死剂量)大于10.0g/kg体重,属实际无毒物质.小鼠骨髓嗜多染红细胞微核实验及小鼠精子畸形实验结果均为阴性.受试物未显示有遗传毒性.     

嗜硷性芽孢杆菌硷性蛋白酶的研究——Ⅲ.产品的急性毒性及微核试验

为了解嗜硷性芽孢杆菌(Bacillus basophilus)硷性蛋白酶用于洗涤剂中的安全性,对该酶进行了急性毒性及微核试验的研究。结果表明,嗜硷性芽孢杆菌硷性蛋白酶由小鼠经口剂量达10g/kg时,未见动物死亡;小鼠骨髓嗜多染红细胞微核试验,未见微核率有异常增加。所以,认为嗜硷性芽孢杆菌硷性蛋白酶可广泛应用于洗涤剂中。     

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.