真菌诱导物在滇紫草细胞培养中对紫草色素形成的影响

在滇紫草细胞悬浮培养中,真菌诱导物可抑制细胞生长,促进草色素的合成,将培养６ｄ的曲霉菌丝体的粗提物以６００μｇ碳水化合物／５０ｍｌ培养液的浓度加入到处于指数生长初期的滇紫草细胞悬浮培养物中,诱导物促进紫草色素合成的作用最大,紫草色素含量为对照的两倍,经高压锅处理２０ｍｉｎ到２ｈ不影响诱导物的活性,真菌诱导物还影响了紫草色素各衍生物的相对含量。     

米曲霉中的紫草色素诱导物对滇紫草细胞代谢的影响

在滇紫草细胞培养第８天时加入来源于米曲霉的紫草色素诱导物,１２ｈ后滇紫草细胞中紫草色素含量增加,其衍生物之一的乙酰紫草素的相对含量增加,胞内可溶蛋白合成量上升,细胞对碳源消耗增多,而细胞生长受到抑制。处理１２ｈ后,培养液电导率下降,ｐＨ上升,Ｋ＾＋外泄和Ｎａ＾＋大量内流,表明离子跨膜运输发生改变。     

米曲霉中的紫草色素诱导物对滇紫草细胞代谢的影响

在滇紫草细胞培养第８天时加入来源于米曲霉的紫草色素诱导物,１２ｈ后滇紫草细胞中紫草色素含量增加,其衍生物之一的乙酰紫草素的相对含量增加,胞内可溶蛋白合成量上升,细胞对碳源消耗增多,而细胞生长受到抑制。处理１２ｈ后,培养液电导率下降,ｐＨ上升,Ｋ＋外泄和Ｎａ＋大量内流,表明离子跨膜运输发生改变。     

真菌诱导子对新疆紫草悬浮培养细胞的生长和紫草素合成的影响

４种真菌诱导子诱导新疆紫草悬浮培养细胞对细胞紫草素的合成均有促进作用,其中以黑曲霉诱导子效果最高,而且促进细胞紫草素的外排,约３０％的紫草素存在于培养液中;诱导促使细胞苯丙氨酸解氨酶活性显著提高,培养液中紫草素的含量变化与苯丙氨酸解氨酶活性变化呈正相关性。     

真菌诱导子对新疆紫草悬浮培养细胞的生长和紫草素合成的影响

4种真菌诱导子诱导新疆紫草悬浮培养细胞对细胞紫草素的合成均有促进作用,其中以黑曲霉诱导子效果最高,而且促进细胞紫草素的外排,约30％的紫草素存在于培养液中;诱导促使细胞苯丙氨酸解氨酶活性显著提高,培养液中紫草素的含量变化与苯丙氨酸解氨酶活性变化呈正相关性。     

真菌诱导物对滇紫草细胞色素形成的影响（简报）

在滇紫草细胞培养中加入真菌诱导物后紫草色素的合成增强,培养液的电导率和pH值在24h内分别下降和上升,且三者均以指数生长初期加入时作用最为明显。     

外循环气升式反应器培养新疆紫草细胞

采用两步培养法进行新疆紫草细胞悬浮培养及5L外循环气升式反应器扩大培养,探讨了培养过程中细胞生长、紫草色素合成与培养液的电导率、可溶性糖含量变化之间的关系。第一步培养时细胞生长迅速,但也有一部分色素合成,电导率及可溶性糖含量迅速下降;第二步培养初期电导率也开始下降,但当色素合成达到高峰并有一部分外泌到培养基后,电导率又开始回升。可溶性糖捎耗很快,到后期巳测不出其存在。因此通过监测培养液中电导率及可溶性糖的变化情况,可以为新疆紫草细胞大规模培养与色素合成提供有用的参数指标。     

滇紫草培养细胞中色素合成的代谢调节

培养基中分别加入浓度为10^-5mol／L的铜离子,滇紫草愈伤组织中色素含量提高了5．5倍,悬浮细胞中色素含量提高8．1倍。细胞培养第21天,加入浓度为10^-5mol／L的L-Phe,色素的合成量最大。浓度为10^-6mol／L的抗坏血酸,能明显地促进培养细胞中色素的合成。     

紫草组织培养研究概况

本文简要综述硬紫草、滇紫草和新疆紫草在利用愈伤组织培养、细胞悬浮培养和固定化培养生产紫草及其衍生物方面的研究进展。     

激光和磁场对滇紫草愈伤组织色素含量的影响

用Ｈｅ－Ｎｅ激光和一定强度的磁场处理滇紫草愈伤组织,发现２～３ｈ激光辐照可提高色素含量;而１．０Ｔ磁场能促进细胞生长和色素形成,硅胶薄层层析比较两种物理因子对紫草色素成分无显著影响。     

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.