and laminin on adhesion and proliferation of human hepatocellular carcinoma cell

AIM:To explore the effects of PMA(phorbol-12-myristate-13-acetate, a tumor promoter, mimicking the action of diacylglycerol on PKC)and laminin on the adhesion and the proliferation of human hepatocellular carcinoma cells, and provide a new clue to liver cancer treatment.METHODS:Human hepatocellular carcinoma cell line(BEL-7402)was used to identify the endogenous laminin and protein kinase C-α(PKC-α) expression, and the effects of laminin and PMA on the adhesion and the proliferation were also investigatedin vitro.RESULTS:By the effect of exogenous laminin, human hepatocellular carcinoma cell (BEL-7402) possessed endogenous laminin expression and increased the adhesion and the proliferation, which was showed the synergistic action by the effect of PMA in combination. By the action of PMA alone, the proliferation and the PKC-α expression increased by exogenous laminin were decreased, and the adhesion and the endogenous laminin expression were increased.CONCLUSIONS:The finding suggested that the adhesion and the proliferation of human hepatocellular carcinoma cell were closely related to the effects of endogenous or exogenous laminin, which were associated with cPKC-α activity. Therefore, the application of anti-laminin antibody in combination with PKC antagonist might be a new clue to find out the therapy for liver cancer.     

Effects of changing PKC activity on proliferation and telomerase expression in human hepatocellular carcinoma cells

AIM: To investigate whether protein kinase C (PKC) is involved in the proliferation and the telomerase expression in human hepatocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cells (BEL-7402) were treated with exogenous phorbol-12-myristate-13-acetate (PMA, PKC activator) and staurosporine (SP, PKC inhibitor) for 48 hours. The techniques of cell culture and the telomeric repeat amplification protocol silver staining in combination with computer image scanning system in vitro were used to observe the variations of the growth and the telomerase expression. RESULTS: The proliferative potential of BEL-7402 cells was decreased by the action of PMA as well as SP, and the telomerase expression was also inhibited by PMA and SP. CONCLUSION: Our findings suggest that the proliferation of human hepatocellular carcinoma cells and the telomerase expression may be related to PKC.     

不同外源激素及活性炭的添加对白芨增殖的影响

[目的]研究不同外源激素配比以及不同量的活性炭添加对白芨丛生芽增殖的影响,以实现不同外源激素对白芨增殖的配比优化。[方法]以MS为基本培养基,通过细胞分裂素(6-BA)和生长素(NAA)的不同配比添加,研究其对白芨组培苗增殖的影响。[结果]当6-BA 2.0 mg/L+NAA 0.2 mg/L时,白芨增殖系数最高,达4.00;另外,活性炭添加可防止白芨苗褐化,但当添加量为0.20 g/L时,不仅有效地抑制了白芨组培苗的褐化,而且对白芨的生长分化影响最小。[结论]适合白芨增殖的培养基为MS+6-BA 2.0 mg/L+NAA0.2 mg/L,活性炭添加量为0.20 g/L。     

Role of ghrelin in regulating rabbit ovarian function and the response to LH and IGF-I

The aim of these in vivo and in vitro studies was to examine the role of ghrelin in the control of plasma hormone concentrations, the proliferation, apoptosis and secretory activity of ovarian granulosa cells and the response of these cells to hormonal treatments. Female rabbits were injected with ghrelin (10 μg/animal/day for one week before ovulation induced by 25 IU PMSG and 0.25 IU LHRH). On the day of ovulation, blood samples were collected and analyzed for concentrations of progesterone (P₄), testosterone (T), estradiol (E₂), estrone-sulphate (ES), insulin-like growth factor I (IGF-I) and leptin (L) by RIA. Some control and ghrelin-treated animals were killed in the periovulatory period, their ovaries were weighed and granulosa cells were isolated and cultured for 2 d. Cell proliferation (expression of PCNA) and apoptosis (expression of TdT) were evaluated by immunocytochemistry and TUNEL respectively. Secretion of P₄, T, E₂, IGF-I, and prostaglandin F (PGF) by granulosa cells cultured with and without LH or IGF-I (1, 10 or 100 ng/ml medium) was assessed by RIA. The remaining control and treated animals were kept until parturition, while the number, viability and body weight of pups were recorded.     

Salmonella enterica serovar Choleraesuis derivatives harbouring deletions in rpoS and phoP regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively

Live attenuated Salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. Due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, S. enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. In this study, two mutants of S. Choleraesuis were constructed and their attenuation and intracellular fate analysed with the purpose of engineering new attenuated live strains with improved properties as oral vaccine carriers. Those strains harboured a specific deletion either within the phoP or rpoS genes, which encode virulence-related regulators in S. Typhimurium. In comparison to the wild-type parental S. Choleraesuis, the mutant strains, especially DeltaphoP, were extremely low in virulence in the murine model and in the natural host, the pig. Moreover, when compared with a commercial live vaccine strain, SC-54, the two mutants showed a higher level of attenuation in mice and DeltaphoP also in pigs. In addition, DeltarpoS and DeltaphoP presented a proliferation and survival phenotype within swine intestinal primary fibroblast and macrophage cell cultures, respectively. Collectively, the present results indicate that the DeltarpoS and DeltaphoP strains of S. Choleraesuis gather adequate features to be potential candidates for vaccine vectors for the specific delivery of heterologous antigens adapted to pigs.     

‘红国王’葡萄组织培养快速繁殖

为建立‘红国王’葡萄组培快繁体系,本试验研究了生长素、接种材料类型、培养条件对组培苗继代增殖与生根的影响。结果表明,0.5 mg/L IAA适合‘红国王’的继代增殖,繁殖系数为5.49,在培养基中附加0.3 mg/L NAA,愈伤组织少且根系粗壮;适合‘红国王’组培苗生长的蔗糖浓度为25~30 g/L,在该浓度下植株长势健壮,生根条数多;带半叶单芽茎段为‘红国王’适宜接种材料类型;接种后第1天至第10天暗培养,可促进‘红国王’根系发育;放置于LED灯复合光红∶蓝∶白=3∶1∶1下,可获得长势强、根系强壮的组培苗;继代间隔为40 d时,繁殖速度较快。     

芍药台阁品种和托桂品种花芽分化过程

采用石蜡切片的办法对比观察台阁品种‘大富贵’和托桂品种‘莲台’花芽分化的过程。研究表明,托桂品种‘莲台’花芽分化过程与前人报道的芍药花芽分化过程相似,分为苞片原基分化期、萼片原基分化期、花瓣原基分化期、雄蕊原基分化期、雌蕊原基分化期及雄蕊原基瓣化期共6个时期;而台阁型品种‘大富贵’花芽分化前期与‘莲台’相似,然而在雄蕊原基分化期以后,并不相继产生雌蕊原基,而是在此部位又出现花瓣原基,随后出现雄蕊原基、雌蕊原基,发育形成"上方花",最终上下两花重叠,形成台阁。     

文冠果不定芽再生与快速繁殖

以成熟文冠果叶片作为外植体,通过器官直接发生途径,对其进行不定芽诱导、不定芽增殖及生根培养,建立了一种简单易行的、可再生的文冠果快速繁殖方法。结果表明,在不定芽诱导阶段,当MS培养基添加2.0mg.L-1BA和0.2mg.L-1 NAA时,不定芽诱导率最高;高浓度的BA显著降低不定芽诱导率;当MS培养基添加2.0mg.L-1 BA和0.1mg.L-1 NAA,每个外植体获得的不定芽数达到最大;当叶片远轴面接触培养基时,不定芽诱导率高于近轴面接触培养基。在增殖培养阶段,当MS培养基添加0.5mg.L-1 BA时,不定芽增殖率、增殖个数及增殖芽长均达到最大;在不同浓度的BA培养基中添加NAA降低了不定芽的增殖效果。在生根培养阶段,1/2MS培养基添加0.5mg.L-1 IBA的生根率最高;IBA的生根效果显著优于NAA或IAA。生根苗在含有土壤、沙子和泥炭的混合基质(1∶1∶1)中移栽成活。     

Ultrastructural study on scab resistance expressed in epidermal pectin layers of pear leaves

Proliferation and collapse of subcuticular hyphae of Venturia nashicola race 1 were studied ultrastructurally, after inoculation of susceptible Japanese pear cv. Kousui, resistant Japanese pear cv. Kinchaku, resistant Asian pear strain Mamenashi 12 and nonhost European pear cv. Flemish Beauty leaves, to understand the nature of the resistance mechanism. After cuticle penetration by the pathogen, the hyphae were observed at lower frequency in epidermal pectin layers and middle lamellae of leaves of the three resistant plants than in those of susceptible ones. This result suggested that fungal growth was suppressed in the incompatible interaction between pear and V. nashicola race 1. In the pectin layers of all inoculated plants, some hyphae had modifications such as breaks in the plasmalemma with plasmolysis, necrotic cytoplasm and degraded cell walls. More hyphae had collapsed in the leaves of the three resistant plants than in those of the susceptible cv. Kousui. In collapsed hyphae, the polymerized cell walls broke into numerous fibrous and amorphous pieces, showing that the scab resistance might be associated with cell wall-degrading enzymes from pear plants.     

脂肪间充质干细胞生物学特性及分泌功能研究

脂肪间充质干细胞(ADSCs)来源广泛,取材方便,易于获得大量细胞.其具有自我更新能力、多分化潜能和强大的免疫调节能力,同时能够分泌多种细胞因子,调节机体微环境,是目前干细胞应用的理想种子细胞.该文从ADSCs的定位、分离、表面标记物、增殖分化能力等方面阐述了ADSCs生物学特性,同时对ADSCs的分泌功能及分泌功能研究情况进行综述.以此为理论基础通过对ADSCs的深入研究,使其有望成为细胞治疗和组织工程应用的优秀种子细胞.