叶下珠有效部位对血栓形成的影响及其作用机制初探

采用Born方法和改良的Hamburger方法分别测定叶下珠 (Phyllanthusurinaria)含corilagin的有效部位 (代号PUW )在体内外对血小板聚集功能和对血小板与中性粒细胞之间粘附反应的影响 ;应用Myers方法评价PUW灌胃对小鼠尾静脉注射花生四烯酸 (AA)引起猝死的保护作用 ;运用改良的Charl ton方法及陈长勋等方法分别观察PUW灌胃对电刺激大鼠颈动脉血栓形成和下腔静脉血栓形成的影响 ;采用Tomihisa方法 ,观察PUW对大鼠尾尖出血时间的影响。结果显示 ,PUW在体内外对ADP、AA或血小板活化因子 (PAF)诱导的血小板聚集均无明显抑制作用 ;PUW呈浓度依赖性明显阻抑AA激活的血小板与中性粒细胞之间的粘附反应 ,其半数抑制浓度 (IC50 )为 39 7mg/kg。PUW (10、2 0和 4 0mg/kg)灌胃呈剂量依赖性显著减少AA致小鼠死亡的数量 ,明显延长电刺激大鼠颈动脉血栓形成时间 ,减轻大鼠下腔静脉血栓的干、湿重。 2 0mg/kg的PUW对出血时间无明显影响 ,4 0mg/kg的PUW虽延长出血时间 ,但与阿司匹林 (2 0mg/kg)比较 ,出血时间明显缩短 (P <0 0 5 )。本实验结果提示 ,PUW灌胃在多种体内血栓模型中均具有明显的抗血栓形成作用 ,其机制可能与阻抑血小板和中性粒细胞之间的的粘附作用密切相关。     

眼镜蛇毒细胞毒素CTXn的致死毒性及药物依赖性研究

目的研究眼镜蛇毒细胞毒素CTXn的致死毒性和药物依赖性,评价其安全性。方法检测CTXn的LD50和对肝细胞色素P450含量的影响,采用大鼠催促戒断模型、自然戒断模型及大鼠条件性位置偏爱模型检测CTXn的药物依赖性。结果 CTXn的LD50为19.61 mg/kg,长期给药对肝细胞色素P450含量无影响。在催促戒断试验中,大鼠连续腹腔注射不同剂量CTXn(0.5、1.0、2.0 mg/kg)10天后经纳洛酮催促,未出现戒断症状及体重下降现象;在大鼠自然戒断试验中,CTXn连续给药21天,停药后大鼠没有出现戒断反应及体重下降现象;在大鼠条件性位置偏爱试验中,CTXn不同剂量组分别连续用药15天后,大鼠在伴药盒的逗留时间均无明显延长,不形成条件性位置偏爱。结论 CTXn毒性较小,长期给药对肝脏药物代谢功能无影响。且不具有身体依赖性及精神依赖性,有潜在的药物开发价值。     

东茛菪碱抗吗啡依赖作用与海马细胞内钙的关系

目的观察东莨菪碱(scopolamin,Sco)对吗啡(morphine,Mor)致小鼠依赖性作用的影响及其机制分析.方法连续7 d腹腔内注射吗啡建立吗啡依赖小鼠模型;热板法测定痛阈;纳络酮(naloxone,Nal)催促实验计数小鼠跳跃次数和跳跃动物率;流式细胞术测量海马细胞内游离Ca2+([Ca2+]i)浓度.结果吗啡依赖小鼠的痛阈明显下降,跳跃次数和跳跃动物率明显增加,海马[Ca2+]i明显增加.给予东莨菪碱(4mg·kg-1×7 d)后,吗啡依赖小鼠海马[Ca2+]i明显减少(P＜0.05),痛阈提高(P＜0.01),跳跃次数和跳跃动物率减少(P＜0.05).结论东莨菪碱具有对抗吗啡依赖性的作用,其机制可能与降低脑细胞内游离Ca2+水平有关.     

东莨菪碱抗吗啡依赖作用与海马细胞内钙的关系

目的:观察东莨菪碱(scopolamin,Sco)对吗啡(morphine,Mor)致小鼠依赖性作用的影响及其机制分析。方法:连续7 d腹腔内注射吗啡建立吗啡依赖小鼠模型;热板法测定痛阈;纳络酮(naloxone,Nal)催促实验计数小鼠跳跃次数和跳跃动物率;流式细胞术测量海马细胞内游离Ca2 ([Ca2 ]i)浓度。结果:吗啡依赖小鼠的痛阈明显下降,跳跃次数和跳跃动物率明显增加,海马[Ca2 ]i明显增加。给予东莨菪碱(4mg.kg-1×7 d)后,吗啡依赖小鼠海马[Ca2 ]i明显减少(P<0.05),痛阈提高(P<0.01),跳跃次数和跳跃动物率减少(P<0.05)。结论:东莨菪碱具有对抗吗啡依赖性的作用,其机制可能与降低脑细胞内游离Ca2 水平有关。     

苍耳子对速发型过敏反应的抑制作用

苍耳子 70 %醇提物 (5 0 0 ,10 0 0mg kg)剂量依赖性抑制compound 4 8 80引起的小鼠过敏性休克、卵白蛋白所致大鼠被动皮肤过敏反应 ;在体外 ,苍耳子 (2 0 ,5 0 μg ml)浓度依赖性减少大鼠肥大细胞释放组胺和 β -氨基己糖酶 ;苍耳子 (5 0 0 ,10 0 0mg kg)对组胺或 5 -羟色胺所致大鼠皮肤反应无明显作用。上述结果表明苍耳子通过稳定肥大细胞膜 ,减少组胺等过敏介质的释放 ,抑制肥大细胞依赖性速发型过敏反应     

大、小动脉内皮细胞乙酰胆碱作用靶标药理学特性的比较

目的 :比较大、小动脉内皮细胞乙酰胆碱作用靶标药理学特性的差异。方法 :采用大鼠尾动脉螺旋状血管条和主动脉离体血管环两种组织 ,对比观察乙酰胆碱 (ACh)诱发大、小动脉内皮依赖性舒张反应特征的差异 ,从而进一步研究小动脉内皮细胞乙酰胆碱作用靶标的药理学特性。结果 :氯化钾 (6 0mmol/L)预致血管收缩的尾动脉和主动脉对不同浓度ACh (10 -8～ 10 -4mol/L)产生内皮依赖性舒张反应 ,且呈剂量依赖性。L Nω 硝基精氨酸甲酯 (L NAME :10 -4mol/L)或美蓝 (MB :10 -5mol/L)与吲哚美辛 (Indo :10 -4mol/L)联用仅可部分地阻断ACh诱发尾动脉内皮依赖性舒张反应 ;而L NAME或MB可完全阻断ACh诱发主动脉内皮依赖性舒张反应。结论 :ACh激活大、小动脉上内皮细胞乙酰胆碱作用靶标诱发内皮依赖性舒张反应的药理学性质不同 ,在小动脉上 ,除了NO和PGI2介导外 ,还有一种非NO和非PGI2 的舒血管因子参与 ;在大动脉上 ,内皮依赖性舒张反应主要由NO介导     

溴隐亭和巴氯芬对吗啡诱导成瘾后戒断症状的协同抑制作用

皮下递增注射吗啡(25、50、75、100、125、150mg/kg)建立小鼠身体依赖动物模型,把6mg/kg纳络酮作用下的小鼠跳跃症状作为成瘾后戒断的行为学观测指标,检测DA受体激动剂溴隐亭和GABAB受体激动剂巴氯芬对戒断行为的影响;同时进一步研究激动二受体在戒断过程中的作用。结果表明:溴隐亭低剂量(10mg/kg)无抑制戒断症状的作用,中、高剂量(20、30mg/kg)能够明显抑制戒断症状;巴氯芬低、中剂量(0.5、1.0mg/kg)无抑制戒断症状的作用,高剂量(1.5mg/kg)则可以抑制戒断症状的作用。当无抑制作用剂量的溴隐亭(10mg/kg)和巴氯芬(1.0mg/kg)联合应用时能够明显抑制小鼠的戒断症状,说明此二受体在吗啡成瘾后戒断期间功能上具有协同作用,能够很好地抑制纳络酮诱导的成瘾小鼠跳跃症状。     

滇丹参、甘西鼠尾、褐毛甘西鼠尾水提取液对鼠血栓形成及微循环的影响

目的：观察云南产甘西鼠尾属药物滇丹参、甘西鼠尾、褐毛甘西鼠尾的水提取物对鼠血栓形成及微循环的影响。方法：用电刺激法造成大鼠颈动脉血栓形成,观察血流阻塞时间(OT值);小鼠尾静脉注射血栓形成诱导剂,观察滇丹参、甘西鼠尾、褐毛甘西鼠尾对抗肺血栓形成的作用;采用活体微循环观察方法,研究滇丹参、甘西鼠尾、褐毛甘西鼠尾对去甲肾上腺素和高分子右旋糖苷所致小鼠、大鼠肠系膜微循环障碍的影响。结果：滇丹参、甘西鼠尾、褐毛甘西鼠尾2、4g/kg时,能明显延长闭塞性血栓形成时间(OT值)(P＜0．01)。20、40g/kg时,能有效抑制胶原和肾上腺素复合液所致小鼠肺血栓形成(P＜0．0l,P＜0．05)。能显著改善微动脉、微静脉痉挛和血液流态,增加毛细血管开放数,加快血流速度(P＜0．0l,P＜0．05)。结论：滇丹参、甘西鼠尾、褐毛甘西鼠尾均能防止血栓形成、改善微循环障碍。     

昆明山海棠诱发小鼠精子8号染色体、不分离的研究

应用荧光原位杂交 (FISH)技术检测了昆明山海棠 (THH)水抽提物在小鼠生殖细胞形成过程中对 8号染色体不分离的诱发效应。以THH水抽提物 (12 0mg/kg、2 4 0mg/kg、4 80mg/kg)腹腔注射昆明种雄性小白鼠 ,于处理 2 2天后取小鼠附睾精子涂片 ,以生物素标记的 8号染色体着丝粒重复序列探针进行FISH ,结果发现 ,THH在中间剂量组(2 4 0mg/kg)和高剂量组 (480mg/kg)诱发精子 8号染色体非整倍体频率均显著高于溶剂对照 (P <0 .0 0 1) ,低剂量组(12 0mg/kg)的异常精子频率与溶剂对照无显著差异 (P >0 .0 5 )。研究表明 ,THH在雄性小鼠生殖细胞发育过程中具有染色体不分离诱发效应。     

OxLDL诱发大鼠血管内皮细胞凋亡模型的建立

目的　建立OxLDL诱发大鼠血管内皮细胞凋亡的模型。方法　SD大鼠尾静脉注射非氧化的LDL ,2 4h后取主动脉血管内皮细胞铺片 ,采用光学显微镜和荧光显微镜进行形态学观察 ,TUNEL法染色计算凋亡细胞比例。结果　( 1)静脉注射LDL组观察到明显的凋亡形态学改变 ,对照组未见凋亡内皮细胞 ;( 2 )静脉注射LDL ( 4mg/kg、 6mg/kg、8mg/kg)组凋亡细胞比例分别为 8 10 %、 18 92 %、 2 2 0 3 % ,三组间有非常显著性差异 (P <0 0 1)。结论　 ( 1)尾静脉注射LDL后 2 4h可引起血管内皮细胞凋亡 ;( 2 )静脉注射LDL引起大鼠血管内皮细胞凋亡呈剂量依赖性     

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.