变异白色红花总黄酮提取物安全性毒理学评价

本文通过急性毒性试验、三项遗传毒性试验和30 d喂养试验,对变异白色红花总黄酮提取物(TFES)进行安全性毒理评价。结果表明,TFES对小鼠急性毒性试验,LD5010.0 g/kg·BW,按急性毒性剂量分级,属实际无毒物质;三项遗传毒性试验即Ames试验、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;TFES对大鼠30 d喂养试验,动物未见明显的中毒症状和死亡,TFES各剂量组大鼠体重、总食物利用率、血清生化指标、血液学指标、脏器系数指标以及病理组织学等指标与对照组比较,无显著性差异。TFES在本实验条件下,未观察到明显毒性作用,为其进一步开发应用提供了安全依据。     

桑色素对小鼠的急性毒性研究

桑色素是一种天然的黄酮类化合物,具有抗炎、抗肿瘤及抗氧化等作用,本实验中使用上下法主试验,腹腔注射给予ICR雌雄小鼠不同剂量的桑色素(230、280、330、390、450、530、630 mg/kg),观察动物的毒性反应,存活动物观察14 d,计算半数致死量LD50。观察期结束后,通过体重、外周血指标、血清生化指标和病理组织学检查来衡量桑色素对小鼠的急性毒性。研究发现,高剂量桑色素对小鼠有一定的急性毒性,腹腔注射半数致死量LD50为463.24 mg/kg,并且毒性强弱与给药剂量密切相关。     

热感赛比斯坦颗粒毒理学实验研究

观察热感赛比斯坦颗粒对小鼠的急性和大鼠长期毒性反应。将热感赛比斯坦颗粒生药浸膏液干燥,粉碎,以最大浓度及小鼠最大给药体积对小鼠灌胃,进行最大耐受量试验,观察两周之内出现的急性毒性反应。采用SD大鼠分别给予37.50 g/(kg·d)、12.50 g/(kg·d)、3.75 g/(kg·d)药物灌胃,空白组给予同等体积的蒸馏水,进行长期毒性试验。在给药30 d、停药15 d测定生化、血象指标、脏器系数和各主要脏器病理切片。急性毒性试验测得小鼠最大耐受量为299.70 g/kg,无死亡现象,解剖后发现小鼠各主要脏器无肉眼可见病变。长期毒性试验给药及恢复期间各组大鼠体重无统计学差异。血液学、血生化及脏器系数检查,给药组与对照组之间个别指标有差异,无毒性意义。主要脏器的病理组织学检查,未见明显病理改变。本研究证明热感赛比斯坦颗粒临床成人拟用给药剂量远低于其毒性剂量,安全性良好。     

犬传染性肝炎DNA疫苗安全性评价

目的研究犬传染性肝炎核酸疫苗pVAX1-CpG-Loop的安全性。方法 BALB/c小鼠随机分为4组,高剂量组(肌内注射每只200μg)、低剂量组(肌内注射每只100μg)、联合免疫组(肌内注射每只100μg,皮下注射50μg,滴鼻每只50μg)和PBS组,每两周免疫1次,共免疫3次。末次免疫后4周、6个月检测血常规和血液生化及对F1代的影响,用PCR和RT-PCR的方法检测DNA疫苗的生物学分布和存留时间,末次免疫后4周和6个月取脏器观察病理损伤。结果各剂量组的主要血液学检测指标、对F1代的影响差异无显著性。末次免疫后4周各剂量组AST明显高于对照组。DNA疫苗在注射部位可存留8周,其中高剂量组和低剂量组在肝、脾、肾和注射部位有分布,联合免疫组在肺组织也有分布。末次免疫后4周小鼠肝肾有淋巴细胞浸润,6个月后慢性炎症明显好转。结论由犬传染性肝炎病毒DNA疫苗引起的肝肾损伤是一过性的,并且pVAX1-CpG-Loop没有整合到宿主基因组,也没有传递给F1代。     

低聚肽和VC复合固体饮料的安全性毒理学评价

为了评价低聚肽和维生素C复合固体饮料作为功能性食品食用的毒理学安全性,根据我国卫生部《保健食品检验与评价技术规范》(2003)进行安全性毒理学研究。研究结果表明:低聚肽和维生素C复合固体饮料对小鼠急性经口最大耐受剂量大于20 g/kg BW,根据急性毒性分级标准规定,属无毒级;遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验)结果为阴性;30天喂养试验表明,按人体推荐量的25、50和100倍即2.1 g/kg、4.2 g/kg、8.3 g/kg为低、中、高剂量时,各剂量组动物生长发育良好,大鼠体重、增重、食物利用率、脏器重量、脏/体比、血液学指标及血生化指标与对照组比较均无显著性差异(P0.05);大体解剖和组织病理学检查未见与样品有关的异常改变。通过以上的试验结果可以判定低聚肽和维生素C复合固体饮料具有较好的食用安全性。     

薏米黄酒的急性毒性研究

目的：研究薏米黄酒的急性毒性,评价该酒的食用安全性。方法：以ICR小鼠为受试对象,一次性给予最大剂量,观察薏米黄酒对小鼠的急性毒性反应,测定薏米黄酒的LD50和最大耐受剂量。结果：小鼠无一只死亡,无法测出LD50,最大耐受量大于20400 mg/kg。结论：实验检测表明,该黄酒无毒,为薏米黄酒的应用提供了毒理学依据。     

四种不同方法注射眼镜蛇蛇毒对小鼠LD_(50)的影响分析

目的比较小鼠经不同途径注射眼镜蛇蛇毒的半数致死量(LD_(50)),并观察中毒症状。方法将小鼠分别经四种途径注射眼镜蛇毒冻干粉溶液,并根据各组小鼠死亡情况,运用Bliss软件测定LD_(50)估计值、置信区间等。观察各组小鼠生物学行为及死亡情况,并对死亡小鼠和存活小鼠进行解剖分析。结果小鼠经静脉、腹腔、肌肉和皮下注射眼镜蛇蛇毒的LD_(50)分别为0.691 mg/kg、0.741 mg/kg、0.803 mg/kg和0.915 mg/kg,95%CI分别为0.634～0.742 mg/kg、0.676～0.792 mg/kg、0.754～0.856 mg/kg和0.851～1.05 mg/kg。各组小鼠中毒症状明显,表现为呼吸困难、精神萎靡、眼球昏暗、眼角有分泌物、身体出现扭体抽搐等反应,均在2～9 h内死亡。结论小鼠经静脉注射眼镜蛇毒溶液中毒的毒性剂量最小,皮下注射眼镜蛇毒溶液中毒的毒性剂量最大。小鼠经四种不同途径注射眼镜蛇蛇毒的LD_(50)的值按从大到小的排序为皮下注射,肌肉注射,腹腔注射,静脉注射。     

汉坦病毒核酸疫苗在小鼠体内表达分布的初步研究

运用生物荧光技术,肌肉免疫接种小鼠含汉坦病毒S抗原基因片段的核酸疫苗,观察重组核酸疫苗在其体内的表达分布。进一步探讨汉坦病毒核酸疫苗的应用前景。扩增纯化已构建好的含有汉坦病毒S抗原基因片段和绿色荧光蛋白(GFP)基因的重组质粒pEGFP/S;免疫接种小鼠胫前肌,观察pEGFP/S在小鼠体内的表达分布。免疫接种3 d后在实验组小鼠肝、肾、脾、肌肉各组织均检测到较强的绿色荧光。重组质粒pEGFP/S能在小鼠的多个组织器官表达,为深入研究汉坦病毒核蛋白和有效的核酸疫苗奠定了基础。     

复合生物杀菌剂F6-11的安全性毒理学研究

目的：为研究复合生物杀菌剂F6．11毒性,采用动物实验法进行毒理学评价。方法：对复合生物杀菌剂F6-11进行小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、亚急性毒性试验、家兔多次完整皮肤刺激试验、急性眼刺激试验、豚鼠皮肤变态反应试验、鱼类延长毒性14天试验。结果：复合生物杀菌剂F6—11对小鼠急性毒性LD50〉5000mg／kg．bw,属于实际无毒级物质;小鼠微核试验该杀菌剂各剂量组与阴性对照组比较,微核率无显著性差异（P〉0．05）;亚急性毒性试验动物血常规、生化指标及各脏器均未发现异常;对家兔多次完整皮肤及眼刺激反应积分均为0,均属无刺激性;对豚鼠皮肤变态反应试验组动物与阴性对照组无可见不同．试验组动物皮肤致敏反应积分为0,无致敏作用;鱼类延长毒性14天试验无异常。结论：毒理学研究表明,复合生物杀菌剂F6．11具有良好的使用安全性。     

人参花食用安全性研究

目的:对人参花食用安全性进行毒理学评价.方法:采用大鼠经口急性毒性试验、遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验)、大鼠30 d喂养试验.结果:雌、雄大鼠经口最大耐受剂量(MTD)均大于17.4 g/kg·bw.3项遗传毒性试验结果均为阴性.在大鼠30 d喂养试验中,6.0 g/kg·bw,3.0 g/kg·bw及1.5g/kg· bw 3个剂量组的实验动物均生长发育良好,体重、摄食量、饮水量、血液学、血液生化学、脏器系数及病理组织学相关指标均未见异常变化.结论:人参花属于实际无毒物,未见遗传毒性,长期服用是安全的.     

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.