可乐定对背根神经节神经元GABA激活电流的抑制作用

本实验在新鲜分离大鼠背根神经节（ＤＲＧ）细胞上应用全细胞膜片的箝记录研究贤上腺素α２－受体激动剂可乐定（ｃｌｏｎｉｄｉｎｅ）对ＧＡＢＡ－激活电流的调制作用。发现缘大多数ＤＲＧ细胞对ＧＡＢＡ（１０＾－６￣１０＾－３ｍｏｌ／Ｌ）敏感（７２／７５）,产生浓度依赖性的内向电流;并且可被ｂｉｃｕｃｕｌｉｎｅ（１０＾－５￣１０＾－４ｍｏｌ／Ｌ）所阻断。在多数细胞中（５１／７２）预加可乐定（１０＾－８￣１０＾－     

P物质对GABAA和GABAB受体介导的DRG神经元膜反应的调制作用

实验在幼年大鼠ＤＲＧ标本上进行。应用细胞内记录观察了ＳＰ对ＧＡＢＡ反应的调制作用。结果证明：（１）单独滴加ＳＰ（５×１０（－６）－４×１０（－５）ｍｏｌ／Ｌ）或浴槽灌流ＳＰ（１０（－６）－５×１０（－６）ｍｏｌ／Ｌ）不引起膜电位的改变或仅有轻微的去极化,但却能使ＧＡＢＡ引起的去极化反应减小５０．８±２０．２％（±ＳＤ）（２０／３０）;（２）单独滴加ＳＰ可使多数受检细胞ＡＰＤ５０延长２８．７±９．１％（±ＳＤ）（１０／１８）;（３）在预加ＳＰ后,能使ｂａｃｌｏｆｅｎ所引起的ＡＰＤ５０缩短效应（２０．６±２．９％,±ＳＤ）完全消除（４／１２）或翻转成ＡＰＤ（５０）延长１９．３±８．９％（±ＳＤ）（８／１２）;（４）预加ＧＡＢＡＢ受体激动剂ｂａｃｌｏｆｅｎ（１０（－４）－１０（－３）ｍｏｌ／Ｌ）３０—９０ｓ后明显地抑制ｍｕｓｃｉｍｏｌ（１０－４－１０－３ｍｏｌ／Ｌ）引起的去极化反应,其抑制效应达５４．４±１８．８％（±ＳＤ）（１７／２０）。由于ＤＲＧ神经元的胞体通常可用来作为研究初级传入终末的模型,因而本文实验结果提示：介导伤害性刺激信息的Ｐ物质在背角的释放,可能作用于初级传入终末,从而产生对抗ＧＡＢＡ介导的突触     

缓激肽对大鼠背根神经节分离神经元ATP激活电流的调制作用

在新鲜分离大鼠背根神经节（ＤＲＧ）的５６个细胞标本上,应用全细胞膜片箝技术进行记录。胞外加缓激肽（ＢＫ,１０＾－６￣１０＾－４ｍｏｌ／Ｌ）引坊的ＤＲＧ细胞膜反应结果如下：（１）７１．４％的细胞为内向电流,其电流反应的幅值具有明显的浓度信赖性;（２）１２．５％的细胞为外向电流;（３）１６．１％的细胞未引起可检测的膜反应,单独给予ＡＴＰ（１０＾－６￣１０＾－３ｍｏｌ／Ｌ）在大多数受栓细胞（５４／５６）     

缓激肽抑制大鼠DRG分离神经元的GABA激活电流

本文应用全细胞膜片箝技术在新鲜分离的大鼠背根神经节（ＤＲＧ）神经元上研究缓激肽（ＢＫ）对γ－氨基丁酸（ＧＡＢＡ）反应的调制作用。结果发现：在３４个对ＧＡＢＡ反应的细胞中有３１个细胞对ＢＫ敏感。在对ＢＫ敏感并引起内向电流的２７个细胞中预加ＢＫ,对ＧＡＢＡ－激活电流具有明显的抑制作用,如１０＾－６ｍｏｌ／Ｌ的ＢＫ可抑制ＧＡＢＡ（１０＾－４ｍｏｌ／Ｌ）激活电流３０％。ＢＫ可将ＧＡＢＡ量效曲线明显下移,并     

皮质酮快速抑制PC12细胞乙酰胆碱诱发电流影响及机制探讨

目的和方法：本研究采用全细胞膜片箝技术,观察皮质酮（Ｂ）对ＰＣ１２细胞上乙酰胆碱诱发电流（ＩＡＣｈ）的快速作用并初步探讨其可能机制。结果：ＰＣ１２细胞上ＩＡＣｈ是通过烟碱受体（ｎＡＣｈＲ）引起的。箝制电压为－８０ｍＶ时,ＡＣｈ（３０μｍｏｌ／Ｌ）诱发一内向电流;细胞外灌流同时给予ＡＣｈ和Ｂ（１０－５ｍｏｌ／Ｌ）时,Ｂ对ＩＡＣｈ的抑制作用较弱;用Ｂ（１０－５ｍｏｌ／Ｌ）对细胞进行预处理,可提高Ｂ对ＩＡＣｈ峰值的抑制率,作用呈可逆性、浓度依赖性和非电压依赖性;细胞外用ＲＮＡ合成抑制剂放线菌素Ｄ（４×１０－５～４×１０－３ｍｏｌ／Ｌ）或蛋白合成抑制剂放线菌酮（１０－４～１０－３ｍｏｌ／Ｌ）孵育细胞１～２ｈ阻断基因机制,但均不影响Ｂ对ＩＡＣｈ的快速抑制作用。结论：Ｂ对ＰＣ１２细胞上ＩＡＣｈ有快速抑制作用,此作用可能是由非基因组机制介导的。     

P物质对大鼠分离的DRG细胞GABA激活电流的抑制作用

本文就用全细胞膜片箝技术,在新鲜分离的大鼠ＤＲＧ细胞上证明,在部分细胞Ｐ物质（１０＾－７－１０＾－５ｍｏｌ／Ｌ）可引起浓度依赖性的内向流（４／２６）;在多数细胞虽未检测到ＳＰ引起的膜电流,但却能对ＧＡＢＡＡ受体激活介导的膜内向流产生抑制效应（１８／２２）,并有加速去敏感的作用。本文就有关ＳＰ以ＧＡＢＡ激活电流抑制效应的可能意义进行了讨论。     

P物质对大鼠DRG神经元胞体膜的作用

本文在大鼠ＤＲＧ神经元标本上应用细胞内记录,以确定ＳＰ对ＤＲＧ细胞的膜反应及其可能的离子机制。实验所测ＤＲＧ细胞静息膜电位为－５８．９±８．２ｍＶ（Ｘ±ＳＥ,ｎ＝８１）。传导速度：Ａ_（α／β）细胞为２０．４±４．８ｍ／ｓ（Ｘ±ＳＥ）,范围１４．１－２８．７ｍ／ｓ（４７／６０）;Ａδ及Ｃ类细胞为９．８±５．２ｍ／ｓ,范围１．２－１３．７ｍ／ｓ（１３／６０）。浴槽滴加ＳＰ（１０￣（－７）－３×１０￣（－４）ｍｏｌ／Ｌ）在大多数细胞可引起明显的膜去极化反应（５６／６０）。少数细胞对ＳＰ无反应（４／６０）。在ＳＰ去极化期间膜电导值有所增加,从平均值２．７２×１０￣（－８）ｍｈｏ增加２４．６％（ｎ＝３）。所测逆转电位值在＋４０－＋５０ｍＶ之间（ｎ＝３）。浊流平衡液（ＢＳＳ）中ＮａＣｌ以氯化胆碱置代,或用含ＴＴＸ（１０￣（－５）ｍｏｌ／Ｌ）的ＢＳＳ灌流,可使ＳＰ－去极化幅值大大减小但不能完全消除。而高（２０ｍｍｏｌ／Ｌ）和低（０ｍｍｏｌ／Ｌ）Ｃａ￣（２＋）的ＢＳＳ灌流时,使ＳＰ－去极化幅值相应的增加和降低。用含１０￣（－４）ｍｏｌ／ＬＣｄ￣（２＋）及１０￣（－２）ｍｏｌ／ＬＴＥＡ的ＢＳＳ灌流,均使ＳＰ－去极化明显减小。     

SNP抑制5-HT诱导的胞内游离钙浓度升高和内钙释放

用Ｆｕｒａ － ２／ＡＭ 荧光测量技术研究了５ － 羟色胺（５－ ＨＴ） 诱导的大鼠尾动脉平滑肌细胞胞内钙升高和一氧化氮（ＮＯ） 的抑制效应。实验表明, 胞外０ｍ ｍｏｌ／ Ｌ Ｃａ２ ＋ 时胞内静息［Ｃａ２ ＋ ］ ｉ 为２０ ．２±８ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ８） 。１０μｍｏｌ／Ｌ ５－ ＨＴ 可诱导出胞内钙库释放引起的瞬态［Ｃａ２ ＋］ｉ 升高,其峰值达２４５ ．７ ±７１．６ｎｍｏｌ／ Ｌ（ｎ ＝ ６） 。１０ － ７ ｍｏｌ／Ｌ 硝普钠（ＳＮＰ） 可抑制５－ ＨＴ 诱导的［Ｃａ２ ＋］ｉ 升高,其峰值浓度降为７５．１±３５ ．９ｎｍｏｌ／Ｌ（ｎ ＝ ５） 。当细胞浴液含２．５ｍ ｍｏｌ／Ｌ Ｃａ２ ＋ 时,静息［Ｃａ２ ＋］ｉ为１１２ ．８ ±１０ ．３ｎｍｏｌ／ Ｌ（ｎ ＝ ５） , 这时１０μｍｏｌ／ Ｌ ５ － ＨＴ 可诱导［Ｃａ２ ＋ ］ ｉ 的峰值为２５２ ．３ ±８０ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,以及其后平台浓度为１４３ ．０ ±３７ ．６ｎｍｏｌ／Ｌ（ｎ ＝ ４） ,略大于［Ｃａ２ ＋］ｉ 为１１２．８ ±１０ ．３ｎｍｏｌ／Ｌ 的静息浓度,为外钙内流引起。１０ － ７ ｍｏｌ／Ｌ ＳＮＰ 也可抑制５－ ＨＴ 诱导［Ｃａ２ ＋ ］ｉ 平台相浓度。平台浓度由１４３ ±４７     

5－羟色胺对大鼠下丘脑脑片弓状核神经元自发电活动的影响

在７４张大鼠下丘脑脑片上,用玻璃微电极记录到弓状核自发放电单位１７６个,其放电形式有三种：慢不规则型（１１９个,６７．６％）;快连续型（４６个,２６．１％）;位相型（１１个,６．３％）。５－ＨＴ（１０－６ｍｏｌ／Ｌ,３ｍｉｎ）对不同形式放电单位的作用均以抑制为主：对部分慢不规则单位（９／１１９）则表现为先抑制后兴奋的双相性反应,对少数神经元有兴奋作用。１２个被５－ＨＴ抑制的单位,其抑制作用不能被噻庚啶（ＣＨＤ,１０－５ｍｏｌ／Ｌ）阻断,４个被５－ＨＴ抑制的的单位中,其抑制作用可被二甲基麦角新碱（ＭＳＧ１０－６ｍｏｌ／Ｌ）部分或完全阻断。７个被５－ＨＴ抑制的单位,其中４个单位中,５－ＨＴ的抑制作用可被特异性５－ＨＴ１Ａ受体阻断剂Ｐｉｎｄｏｂｉｎｄ－５－ＨＴ１Ａ部分阻断;但另外３个单位的阻断效果不明显。上述结果表明：５－ＨＴ对弓状核不同形式放电单位的作用均以抑制为主,其作用可能是通过５－羟色胺（５－ＨＴ１）受体介导的,部分还可能是通过５－ＨＴ１Ａ受体介导的。     

SKF38393抑制大鼠DRG分离神经元GABA-激活电流

在大鼠新鲜分离ＤＲＧ神经元标本上应用全细胞膜片箝记录,观察了多巴胺Ｄ１受体的选择性激动剂ＳＫＦ３８３９３ＨＣＩ对ＧＡＢＡ－激活电流的作用。大部分受检细胞对ＧＡＢＡ敏感,１０＾－６－１０＾－３－ｍｏｌ／Ｌ ＧＡＢＡ可于引起呈剂量依赖性的明显去敏感作用的内向电流。     

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.