大花红景天悬浮颗粒、悬浮细胞体系的研究

为了探讨大花红景天悬浮体系中红景天苷含量与其颗粒大小、生长状态的关系及可能机制,以大花红景天叶片为外植体,获得愈伤组织,建立悬浮颗粒体系,并分别通过60、80、100和120目细胞筛筛选进而建立悬浮细胞体系。测定了相同培养条件下悬浮颗粒(平均直径约2.5 cm)、悬浮细胞(过80目细胞筛所得)及二者相应培养液中红景天苷的含量。结果表明:经80目细胞筛过滤所得滤液培养一段时间后,可获得大量增殖速度较快、大小均一的悬浮细胞,且这些悬浮细胞中红景天苷含量达0.606 mg/g,约为悬浮颗粒中红景天苷含量0.27 mg/g的2.2倍。而悬浮颗粒和悬浮细胞相应培养液中则均未检测到红景天苷。悬浮体系中细胞与氧气、光照、营养成分的接触程度对培养物中红景天苷的含量有着非常重要的影响。      

白花曼陀罗细胞悬浮培养生物转化外源氢醌合成熊果苷的研究*

 研究了白花曼陀罗细胞悬浮培养对外源氢醌的糖基化。转化细胞来自白花曼陀罗嫩茎在LS固体培养基上诱导产生的愈伤组织。白花曼陀罗悬浮培养细胞不能分泌熊果苷,但能糖基化外源氢醌合成熊果苷。当氢醌添加量达240μmol/100mL培养物时,约有93.4%的氢醌转化形成了熊果苷,并应用多种色谱技术进行分离纯化,进行了HPLC分析和结构鉴定。     

真菌诱导物对丹参毛状根和转化细胞过氧化物酶活力的影响

研究了大丽轮枝菌（Verticillium dahiliae Kleb.)激 发子V44和酵母提取物分别诱导丹参（Salvia miltiorrhiza)毛状根和丹参转化细胞后，过氧化物酶活力的变化，结果表明，诱导后过 氧化物酶活力显著提高，丹参毛状根酶活力变化大于丹参转化细胞，两种植物材料过氧化物酶活力变化与诱导浓度和诱导时间有关，实验提示，丹参毛状根可能对诱导物刺激具有更好的 抗性，且有利于次生代谢产物的积累。     

Antibody-dependent lymphocytotoxicity induced by immunoglobulin G from Hodgkin's disease splenic lymphocytes

Immunoglobulin G, produced in cultures of splenic lymphocytes obtained from patients with Hodgkin's disease, bound to a population of homologous peripheral blood lymphocytes and initiated antibody-dependent cell cytotoxicity in cultures from five out of eight patients. Two patients whose cultures produced negative results had minimal disease; the other was in remission. The target cells appear to be T lymphocytes; the effector cells bear Fc receptors that are inhibited by antigen-antibody complexes. Antibody-dependent cell cytotoxicity events may produce the anergy and lymphopenia often seen in Hodgkin's disease.     

Lability of host-cell DNA in growing cell cultures due to Mycoplasma

In HeLa-cell cultures chronically infected with Mycoplasma, (PPLO) host-cell DNA is unstable as detected by incorporation of H(3)-or C1 i-thymidine into DNA and subsequent release into the medium as acidsoluble radioactivity. This characteristic can be transmitted to PPLO-free cultures of strain L cells by inoculation with preparations of PPLO from the HeLa cells, although chronically infected cultures of L cells continue to multiply. In addition, virus preparations also may carry PPLO contamination through numerous passages.     

Differentiation of murine bone marrow stem cells in vitro: long-term growth promoted by a lymphocyte-derived mediator

In attempts to induce differentiation of lymphoid cells from hematopoietic stem cells in vitro, the effects of allogeneic effect factor on the growth of murine bone marrow cultures were studied. Allogeneic effect factor is a soluble mediator derived from mixed secondary murine leukocyte cultures. For several weeks it supported the growth of bone marrow cultures, as indicated by the maintenance of stem cell activity, cellular proliferation, and heterogeneity. Another lymphokine, T cell growth factor, did not, Pre-T lymphocytes could be detected in these cultures for several weeks.     

Probit transformation: improved method for defining synchrony of cell cultures

Cell numbers can be converted to probits that are used to compare the degree and timing of synchronized cell cultures. Data from synchronous cultures of Chlorella pyrenoidosa have been analyzed by this method by means of a readily available computer program. The method can be used with any biological system that generates normal sigmoidal data.     

Sulfatide synthesis: inhibition by experimental allergic encephalomyelitis serum

The rate of (35)S incorporation into cerebroside sulfate in cultures of embryo mouse spinal cord shows a rapid acceleration at the time of myelin formation. Exposure of cultures to dilute serum from rabbits with experimental allergic encephalomyelitis results in almost complete inhibition of sulfatide synthesis. Within 24 hours after replacement of inhibiting medium with normal medium there is an increase in sulfatide synthesis followed by myelination.     

Parasexual cycle in cultivated human somatic cells

Somatic segregation for three different autosomes was demonstrated in two strains of human diploid fibroblasts derived from subjects known to be heterozygous for chromosomal variants. Recombinant diploid cells appeared within cultures of tetraploid clones isolted from mass cultures. Tetraploid cells regularly occur in mass cultures and within clones of diploid cells. Such a parasexual cycle (2n-->4n-->2n), with recombination of entire linkage groups, could from the basis of a beginning formal genetic analysis in man.     

Cerebroside antibody inhibits sulfatide synthesis and myelination and demyelinates in cord tissue cultures

Antiserum to cerebroside was prepared in rabbits by injection of cerebroside together with bovine serum albumin in complete Freund's adjuvant. When applied to cultures of embryo mouse spinal cord at explantation, this antiserum inhibited sulfatide synthesis and myelination; when applied to myelinated cultures it inhibited sulfatide synthesis and produced demyelination. Complement fixation assays also show antibody to cerebroside in serums from rabbits with experimental allergic encephalomyelitis induced by injection of whole white matter. Absorption of such serum with cerebroside abolishes the inhibiting and demyelinating activities.     

Cell walls of crown-gall tumors and embryonic plant tissues lack agrobacterium adherence sites

Crown-gall tumor initiation by Agrobacterium tumefaciens is inhibited by cell walls from normal dicotyledonous plants but not by cell walls from crown-gall tumors apparently because of bacterial adherence or nonadherence, respectively, to the different cell walls. Cell walls from normal and tumor tissues in culture also show this difference, indicating that the two types of tissue stably maintain this difference under these conditions. Habituated tissue cultures, which resemble crown-gall tumor cultures, however, form cell walls that are inhibitory like those of the normal cultures from which they are derived. Monocotyledonous plants do not act as hosts for Agrobacterium and bacteria-specific inhibition is not shown by cell walls from several species of grass, a monocot family. Cell wallsfrom "embryonic" tissues (dicot seedlings less than 2 centimeters long), unlike those from older seedlings, are non-inhibitory. Crown-gall tumors thus resemble embryonic tissues in this respect.     

Subacute sclerosing panencephalitis: propagation of measles virus from brain biopsy in tissue culture

Measles virus was propagated in monolayer cultures established from brain tissue of a patient with subacute sclerosing panencephalitis. Syncytial cells were rendered fluorescent with measles specific antiserums only, by means of an indirect technique. The ultrastructural appearance of the microtubular aggregates was identical in brain tissue and in the cultured cells. Fusion experiments produced a cytopathic effect in humnan embryonic kidney and VERO cell cultures. The virus was identified by hemiagglutination-inhibition, but only in the supernatant of disrupted cultured cells.     

Trisporic acid synthesis in Blakeslea trispora

Cultures of the (-) strain of Blakeslea trispora synthesize trisporic acid C, a sex hormone, from precursors made by cultures of the (+) strain. The precursors are nonacidic compounds isolated from the culture medium of the (+) strain by chloroform extraction. Actidione does not inhibit trisporic acid synthesis from isolated precursors, suggesting that the enzymes involved in the synthesis in cultures of the (-) strain are constitutive.     

Bone resorbing activity in supernatant fluid from cultured human peripheral blood leukocytes

A new soluble mediator was found in supernatant fluid from cultures of human peripheral blood leukocytes that were stimulated by phytohemagglutinin, or by antigenic material present in human dental plaque deposits. This soluble Jactor produced bone resorption in organ cultures of fetal rat bones as measured by increased release of calcium-45, and also increased the number of active osteoclasts.     

Endogenous regulation of macrophage proliferative expansion by colony-stimulating factor-induced interferon

Stimulation of cultures of murine bone-marrow cells with specific macrophage growth factor (colony-stimulating factor I) resulted in the production of type I interferon. Neutralization of this endogenous interferon by antiserum directed against interferons alpha and beta resulted in a significant enhancement of mononuclear phagocyte proliferation from committed marrow precursors. The effect of the antiserum was lost in cultures depleted of adherent cells, an indication that an adherent regulatory cell (or cells) in the marrow limits mononuclear phagocyte proliferation by producing antiproliferative interferon in response to high levels of specific growth factor.     

Refsum's disease: nature of the enzyme defect

Two siblings with Refsum's disease, an inherited disorder of lipid metabolism, oxidized intravenously injected uniformly labeled phytanic acid-C(14) at rates less than 5 percent of those found in normal subjects. The defect in oxidation of phytanic acid persisted in cultures of fibroblasts from the patients' skin. The rate of oxidation of the phytanic acid-C(14) was less than 1 percent of that found in cultures of fibroblasts from normal skin. However, pristanic acid, previously shown to be the first product of phytanic acid degradation, was oxidized at a normal rate in the patients' cultures. These results indicate that the enzymatic defect in Refsum's disease is in the first step of the pathway for degradation of phytanic acid, that is, in the unusual alpha-oxidative process that leads to a shortening of phytanic acid by one carbon atom.     

大麦胚性悬浮细胞系的快速建立及其超低温保存

 禾谷类作物胚性悬浮细胞系的建立及其超低温保存是现代植物生物技术中的基础工作。本文分析了从大麦成熟胚培养快速建立胚性悬浮细胞系的两个关键步骤。愈伤组织的精心选择直接关系到建立细胞系的难易程度。悬浮培养过程中的细胞学观察可以用来判定2，4-D浓度和继代周期等因子是否需要调整。经过预培养和保护剂处理，用两步法冻存的大麦悬浮细胞能够高频率地恢复生长。在合适的条件下用玻璃化法冻存，TTC相对存活率可达51%，从恢复生长的细胞获得了再生植株。     

National character does not reflect mean personality trait levels in 49 cultures

Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity.     

籼稻花培胚性细胞的发现和利用

<正> 多年实践证明,花培育种是行之有效的快速育种方法之一。而花培的成败取决于试验材料和诱导分化率。从目前情况看,水稻花培诱导分化率不甚高,其中籼稻更低,影响了花培育种的选择和应用。1987年我们承担农业部“水稻花培新品种选育”课题任务后,当年花培籼稻杂交组合110个,从中发现3个材料出现花粉胚性细胞团,并及时加以繁殖利用,获得较为理想的结果。现报告如下: 一、材料和方法试验材料,是由本所常规育种室提供的籼稻杂交组合110个,每个组合取花粉发育为单核靠边期的花药接种。培养基有三种:诱导培养基为N6+2.4D 2毫克/升+谷氨酰氨100毫克/升