用无血清培养基在填充床生物反应生产rHuEPO

在填充床生物反应器用含５％ＦＢＳ的ＤＭＥＭ：Ｆ１２培养基培养产重组人促红细胞生成素（ｒＨｕＥＰＯ）的细胞Ｃ２８￣１０ｄ后,使用自制的无血清生产培养基（ＳＦＭ－ｐ）生产ｒＨｕＥＰＯ。ＳＦＭ－ｐ培养基既能维持细胞生长,又能生产ＥＰＯ,也便于纯化分离ｒＨｕＥＰＯ。使用填充床生物反应器培养细胞,能维持培养２０￣２５ｄ,ｒＨｕＥＰＯ表达水平达１２￣２８．４ｍｇ／Ｌ之间,反应器的产率达到７１．０ｍｇ／Ｌ／ｄ,     

生长抑素对羟自由基损伤的人胃粘膜上皮细胞系GES—1的影响

目的和方法：采用人胃粘膜上皮细胞系ＧＥＳ１细胞传代培养技术,利用Ｆｅ２＋与Ｈ２Ｏ２反应生成的羟自由基（ｈｙｄｒｏｘｙｌｒａｄｉｃａｌ,ＯＨ·）建立细胞损伤模型,探讨ＯＨ·损伤人胃粘膜细胞的机制,观察生长抑素（ｓｏｍａｔｏｓｔａｔｉｎ,ＳＳ）对ＧＥＳ１细胞抗ＯＨ·损伤的影响。结果：（１）ＯＨ·可直接损伤ＧＥＳ１细胞,表现为细胞存活率下降而细胞乳酸脱氢酶（ｌａｃｔａｔｅｄｅｈｙｄｒｏｇｅｎａｓｅ,ＬＤＨ）漏出量增多;预先在细胞培养液中加入ＯＨ·特异性清除剂二甲基亚砜（５ｍｍｏｌ／Ｌ）,可预防该损伤。预先加入ＳＳ（０．０１ｍｇ／Ｌ,０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ）对细胞存活率和细胞ＬＤＨ漏出量无影响;（２）加入ＯＨ·后,细胞丙二醛（ＭＤＡ）、氧化型谷胱甘肽（ＧＳＳＧ）含量上升而还原型谷胱甘肽（ＧＳＨ）含量下降。以ＳＳ０．１ｍｇ／Ｌ,１．０ｍｇ／Ｌ,１０ｍｇ／Ｌ预处理,可部分减轻上述改变。结论：ＯＨ·可直接损伤ＧＥＳ１细胞,其机制与破坏细胞的巯基稳态及加重细胞的脂质过氧化程度有关;ＳＳ可通过维持细胞的巯基稳态,部分减轻ＯＨ·所致的ＧＥＳ１细胞脂质过氧化程度。     

高产稳产聚羟基烷酸的重组大肠杆菌的构建

重组大肠杆菌Ｅｓｃｈｅｒｉｃｈｉａ ｃｏｌｉＨＭＳ１７４（ｐＴＺ１８ＵＰＨＢ） 含有携带聚羟基烷酸（ＰＨＡ） 合成基因（ ｐｈａＣＡＢ）＊＊ 的质粒ｐＴＺ１８ＵＰＨＢ,是很有潜力的ＰＨＡ 生产菌,但存在着质粒不稳定和不能合成３羟基丁酸（３ＨＢ） 与３羟基戊酸（３ＨＶ） 共聚物［Ｐ（３ＨＢｃｏ３ＨＶ）］ 的缺陷。将ＲＫ２ 质粒上的ｐａｒ ＤＥ 基因引入ｐＴＺ１８ＵＰＨＢ 构成质粒ｐＪＭＣ２ ,该质粒可以在宿主Ｅ．ＣｏｌｉＨＭＳ１７４ 中稳定遗传。将培养基中的磷酸盐浓度降至１８ ｍ ｍｏｌ／Ｌ,发现Ｅ．Ｃｏｌｉ ＨＭＳ１７４（ｐＪＭＣ２） 能够以丙酸为前体合成Ｐ（３ＨＢｃｏ３ＨＶ） ,其中３ＨＶ 在共聚物中的含量为５ ％ ～８ ％ 。在５Ｌ自动发酵罐中分批补料培养Ｅ．Ｃｏｌｉ ＨＭＳ１７４（ｐＪＭＣ２） ,培养基初始磷酸盐浓度为１５ ｍ ｍｏｌ／Ｌ,３０ ｈ 后每升培养液中干菌体可达４２－５ ｇ,Ｐ（３ＨＢｃｏ３ＨＶ） 占干重的７０ ％ ,其中３ＨＶ 在共聚物中的含量为４－９ ％ 。     

生物反应器中芹菜体胚发生的大规模培养

通过固体液体培养方式筛选得到的芹菜胚性愈伤组织悬浮物接种于低剪切力的搅拌通气式反应器中。在ＭＳ附加ＫＴ０５ｍｇ／Ｌ＋ＣＨ５００ｍｇ／Ｌ的分化培养基中,２４ｄ后获大量正常芹菜体胚。对芹菜愈伤组织培养物在反应器分化培养过程中通气与搅拌速率,ｐＨ值的调节控制,反应器中溶解氧（ＤＯ）及生长曲线和生长动力学参数均作了研究,以２０％（鲜重）的接种培养时,较佳的初始ｐＨ值为５.３～５．８,控制ｐＨ值在５８上下波动,通气量及搅拌浆速率操作范围分别为６００～８００ｃｍ^３／ｍｉｎ及４０～６０ｒ／ｍｉｎ,随着不同生长时期的不同需要在此范围内调节。培养２４ｄ后,获得正常子叶期体胚为１０２个／ｍｌ,用海藻酸钠包埋后获得的人工种子在无菌条件下的萌发率为６４％,接近摇床培养结果。     

风信子花被外植体年龄对花器官分化的影响

离体培养风信子（ＨｙａｃｉｎｔｈｕｓｏｒｉｅｎｔａｌｉｓＬ．）不同年龄的花被外植体诱导花器官直接再生的实验表明：１．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,年龄Ｖ的外植体大量衰老,基本丧失器官再生能力,处于年龄段ＩＩ～ＩＶ的外植体可发生玻璃化反应。２．玻璃化反应的外植体转移至ＭＳ附加６ＢＡ０．２ｍｇ／Ｌ、ＮＡＡ０．００５ｍｇ／Ｌ的培养基上继续培养３０ｄ后可再生正常的花被片,表明降低培养基中外源激素浓度能够阻止玻璃化反应继续发生。３．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,外植体形态学下部可再生雌蕊状早期结构。平均每块外植体分化雌蕊状早期结构数以年龄Ⅲ的外植体最多     

丁酸钠对CHO-EPO工程细胞株rhEPO表达量的影响

以稳定整合有ｐＥＤＥＰＯ的ＣＨＯＥＰＯ工程细胞株为研究对象,在无血清条件下,系统观察了０５、１０、２５和５０ｍｍｏｌ／Ｌ４个浓度的丁酸钠作用于该细胞株的情况,结果表明：丁酸钠对ＣＨＯＥＰＯ工程细胞的生长有明显的抑制作用;影响ＣＨＯＥＰＯ工程细胞ＥＰＯ表达,浓度１０ｍｍｏｌ／Ｌ可提高ＥＰＯ表达量２５倍左右,并可持续较长的一段时间;延缓ＣＨＯＥＰＯ工程细胞在无血清培养时的细胞脱落;提高ＣＨＯＥＰＯ工程细胞ＥＰＯｍＲＮＡ水平     

多孔微球固定化CHO工程细胞生产rt-PA的研究

以 Ｃｙｔｏｐｏｒｅ 多孔微球固定产重组组织型纤溶酶原激活剂（ｒｔ Ｐ Ａ） Ｃ Ｈ Ｏ 工程细胞株４ Ｂ３ ,在２ Ｌ 搅拌式生物反应器用无血清培养基 Ｄ Ｆ５ Ｓ 连续灌流培养。４ Ｂ３ 细胞的最大活细胞密度和ｒｔ Ｐ Ａ 生产水平分别达到８８３ ×１０６／ ｍ Ｌ 和１２４７３ Ｉ Ｕ／ ｍ Ｌ。含ｒｔ Ｐ Ａ 的４ Ｂ３ 细胞培养上清经 Ｍ Ｐ Ｇ 吸附层析和 Ｌｙｓｉｎｅｓｅｐｈａｒｏｓｅ ４ Ｂ 亲和层析两步纯化,ｒｔ Ｐ Ａ 的纯度达到９８ ％ 。     

甘薯叶柄原生质体有效植株再生

将甘薯（Ｉｐｏｍｏｅａｂａｔａｔａｓ（Ｌ．）Ｌａｍ．）‘元气’和‘白星’（‘ＷｈｉｔｅＳｔａｒ’）的叶柄原生质体培养在含有０．０５ｍｇ·Ｌ－１２,４Ｄ和０．５ｍｇ·Ｌ－１ＫＴ的改良ＭＳ液体培养基中,３～４ｄ后细胞开始分裂。培养８～９周后,将直径达１～２ｍｍ的愈伤组织转移到添加０．０５～０．２ｍｇ·Ｌ－１２,４Ｄ和０～０．５ｍｇ·Ｌ－１ＫＴ或添加０．５～２．０ｍｇ·Ｌ－１ＮＡＡ和１．０～３．０ｍｇ·Ｌ－１ＢＡＰ的ＭＳ固体增殖培养基上使其增殖。转移３～５周后,将愈伤组织再转移到ＭＳ基本培养基或转移到添加２．０～３．０ｍｇ·Ｌ－１ＢＡＰ的ＭＳ培养基上。当进一步转移到ＭＳ基本培养基上后,从愈伤组织或从愈伤组织形成的不定根上再生出植株。‘元气’植株再生率高达６０．０％,ＷｈｉｔｅＳｔａｒ高达４３．４％。     

重组人粒-巨噬细胞集落刺激因子的实验室培养、复性和分离纯化

建立了一个实验室制备重组ｈＧＭ-ＣＳＦ的培养、复性和分离纯化的技术工艺。通过对ＰＥＧＭ工程菌的生长和诱导表达等条件的初步调整,使ｈＧＭ-ＣＳＦ的表达量从１６.９％提高到３２.３％,获得０.７４９ｇ／Ｌ的包含体,纯度为６５％;包含体用６ｍｏｌ／Ｌ盐酸胍溶解和稀释复性后,经ＣＭＳｅｐｈａｒｏｓｅＦＦ．ＤＥＡＥＳｅｐｈａｒｏｓｅＦＦ和ＳｅｐｈａｃｒｙｌＳ２００ＨＲ层析分离,制得纯度达９７％以上、比活性为３.０×１０^７ｕ／ｍｇ的ｈＧＭ-ＣＳＦ,纯化总回收率约为５％     

大叶紫花苜蓿愈伤组织原生质体再生植株

大叶紫花苜蓿下胚轴诱导的愈伤组织在继代培养基上生长快速,易于分散。继代第１２ｄ的愈伤组织原生质体的得率为６．５×１０７／ｇ鲜重。原生质体培养基为ＳＨ基本培养基,含有１．０ｍｇ／Ｌ２,４－０、０．５ｍｇ／ＬＢＡ、２．０ｇ／ＬＣＨ、２％蔗糖、６％葡萄糖、５ｍｍｏｌ／ＬＭＥＳ,培养密度为１．０×１０５／ｍＬ。培养至第１２ｄ时的原生质体再生细胞植板率为３．７％。由原生质体形成的小愈伤组织在含２．０ｍｇ／Ｌ２,４－Ｄ的ＭＳ固体培养基上大量增殖。增殖的愈伤组织转移至２．０ｍｇ／Ｌ２－ｉｐ＋０．１ｍｇ／ＬＮＡＡ的Ｂ５培养基上,形成体细胞胚并发育成完整植株。     

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.