十二烷醇对酵母细胞影响的研究

以残糖和细胞生长OD值为分析指标,探讨了十二烷醇对酵母游离细胞和固定化细胞的影响.结果表明:萃取剂对游离细胞毒害性比较大,发酵残糖含量高；固定化细胞采用外部随程萃取发酵则可以忽略其对细胞的毒害作用,发酵残糖几乎没有.     

亚硒酸钠在SGC-7901细胞生长中的抑制作用

目的：研究亚硒酸钠对SGC-7901细胞生长的影响。方法：应用细胞培养和SRB实验探讨了亚硒酸钠对SGC-7901细胞生长曲线的影响：应用集落形成试验、分裂指数试验研究了亚硒酸钠对SGC-7901细胞集落形成和分裂指数的影响；应用流式细胞仪检测了亚硒酸钠对SGC-7901细胞生长周期的影响；应用电镜、TUNEL染色及流式细胞仪观察了亚硒酸钠诱导SGC-7901细胞凋亡的作用。结果：亚硒酸钠溶液对SGC-7901细胞的生长曲线、集落形成、分裂指数有明显的抑制作用，其抑制作用与其作用浓度和作用时间呈正相关。流式细胞仪检测显示亚硒酸钠作用SGC-7901细胞24h后，细胞周期发生改变，G1期细胞百分率减少，S期细胞百分率增加，与对照组相比有显著性差异（p〈0．05）：电镜下，细胞核固缩，染色质凝集呈新月形紧贴于核膜周边，核膜扭曲；DNA直方图上出现典型的亚二倍体的“凋亡峰”；TUNEL染色法检测细胞凋亡指数在10．4％～33．4％。结论：亚硒酸钠溶液对SGC-7901细胞的生长具有抑制作用，其抑制作用程度与其作用浓度和时间呈正相关：亚硒酸钠通过阻滞细胞S期抑制细胞增殖及诱导细胞凋亡可能是其抑制SGC-7901细胞生长的机理之一。     

菱灵颗粒有效成分的抗肿瘤作用研究

目的:研究菱灵颗粒有效成分-化合物Ⅰ在体外对Hela细胞的作用及其作用机制。方法:采用四甲基偶氮唑盐(MTT)还原法检测化合物Ⅰ对肿瘤生长抑制作用,应用光学显微镜、透射电子显微镜观察细胞形态,流式细胞仪检测细胞周期及细胞凋亡情况。结果:化合物Ⅰ对人宫颈癌细胞生长具有明显的抑制作用及诱导细胞凋亡作用,且这种作用有剂量依赖关系,化合物Ⅰ25、12.5、6.25mg/L剂量组30h抑瘤率为52.04%、34.44%、23.72%,100、50、25、12.5、6.25、3.125mg/L剂量组30h抑瘤率显著正相关,相关系数r=0.9860(p<0.01),IC50值为10.9mg/L。透射电子显微镜对化合物Ⅰ25、12.5、6.25mg/L剂量组受试细胞观察,均出现不同程度细胞凋亡现象,细胞核明显皱缩、染色质趋边凝聚、线粒体空化等特征。流式细胞仪检测发现凋亡峰。结论:化合物Ⅰ对Hela细胞增殖抑制作用明显并且有诱导细胞凋亡作用。     

Cell microarray for screening feeder cells for differentiation of embryonic stem cells

Microarrays are currently recognized as one of major tools in the assessment of gene expression via cDNA or RNA analysis and are now accepted as a powerful experimental tool for high-throughput screening of a large number of samples, such as cDNA and siRNAs. In this study, we examined the potential of the microarray methodology for high-throughput screening of candidate cells as feeder cells which effectively differentiate embryonic stem (ES) cells to the specific lineage. Cell arrays were prepared by applying three kinds of cells, PA6, human umbilical vein endothelial, and COS-1 cells, to circular spots, 2 mm in diameter, on a glass plate, followed by the application of mouse ES cells to the cell microarray. After 8 d in culture, TuJ1 (neuron-specific class III beta-tubulin) immunocytochemical staining clearly demonstrated that only PA6 cell spots had the capability to induce ES cells to neuronal differentiation. Although this is a model experiment, these findings clearly indicate that the cell microarray will become a powerful tool for high-throughput screening large numbers of candidate feeder cells for specific differentiation.     

水凝胶封装细胞研究进展

近年来,活细胞广泛应用于组织工程、细胞治疗等领域。为了保证活细胞在应用过程中的活性与功能完整性,在细胞表面构建保护性外壳的细胞封装策略应运而生。细胞封装可以避免免疫细胞、抗体、酶等物质与细胞的直接接触,同时保证氧气、营养物质、代谢物等一些小尺寸物质的自由交换。水凝胶因其与细胞基质相似且可形成3D结构模拟细胞微环境而被广泛用于细胞封装。本文首先对细胞封装进行了简单介绍,随后在多细胞封装中重点介绍了木质纤维素基水凝胶在细胞封装中的应用;在单细胞封装中从层层（LbL）自组装、接枝到表面（grafting to）和从表面接枝（grafting from）的3种方法,分别阐述了水凝胶壳层对细胞活性与功能特性的影响。最后讨论了水凝胶封装细胞未来发展方向与前景,希望能为医药食品等领域活细胞的储存及应用提供参考。     

芹菜素对甲状腺癌BCPAP细胞生长及细胞周期的影响

研究芹菜素对人乳头状甲状腺癌BCPAP细胞生长的抑制作用及对细胞周期的影响。采用MTT法检测不同浓度芹菜素在24h对BCPAP细胞的抑制作用,以及12.5,25.0,50.0μmol/L芹菜素分别在24,48,72h对BCPAP细胞的抑制作用;通过明场细胞形态学照片分析,对比不同浓度芹菜素对BCPAP细胞形态的影响,评价其对细胞生长的抑制作用。利用流式细胞仪检测BCPAP细胞周期和凋亡。结果表明,不同浓度(12.5~100.0μmol/L)芹菜素对BCPAP细胞的毒性有明显剂量和时间依赖性,其24h的IC50值为40.65μmol/L。芹菜素对BCPAP细胞的形态学变化有显著影响,高浓度芹菜素强烈抑制BCPAP细胞数目的增长。芹菜素可使BCPAP细胞周期的构成发生明显的变化并诱导细胞凋亡。芹菜素对BCPAP细胞有较明显的细胞毒性和生长抑制作用,其抑制机制可能是使BCPAP细胞生长停滞在G2/M期并诱导细胞凋亡,使得细胞生存率下降,从而抑制细胞活性和数目增长。     

二氢杨梅素对骨肉瘤细胞增殖的抑制作用

本研究旨在探讨二氢杨梅素对骨肉瘤细胞增殖的抑制作用及其机制。采用MTT法检测不同浓度的二氢杨梅素溶液对骨肉瘤细胞增殖的抑制作用;采用倒置显微镜、Hoechst 33258荧光染色法和流式细胞术检测不同浓度的二氢杨梅素溶液对骨肉瘤细胞形态、凋亡和周期的影响;并进一步采用Western Blot法分析细胞周期蛋白和凋亡蛋白表达的影响。研究结果表明二氢杨梅素对骨肉瘤细胞增殖具有显著的抑制作用,细胞形态发生了明显变化,呈显著的剂量依赖型,其半数抑制浓度（IC50）值为24.41±1.25 μM。细胞周期实验结果表明,经二氢杨梅素处理后,G0/G1期细胞数百分比从60.20%下降到21.50%,而G2/M细胞数百分比从11.60%增加到45.30%,细胞周期蛋白Cyclin B1表达下降引起细胞周期阻滞;此外,抗凋亡蛋白Bcl-2表达和促凋亡蛋白Bax表达的比例显著下降,从而诱导细胞发生凋亡。结果表明二氢杨梅素具有显著的抗骨肉瘤增殖活性,可开发一种潜在的治疗骨肉瘤的功能食品或药物。     

枸杞子对人宫颈癌Hela细胞生长的影响

目的：体外实验探讨枸杞子对人宫颈癌细胞（Hela）生长的影响。方法：不同浓度的枸杞子水煎液处理Hela细胞．采用细胞贴壁率实验测定细胞的粘附能力,通过细胞划痕实验观察细胞的迁移能力、利用细胞增殖实验检测细胞增殖抑制率,运用流式细胞术分析细胞周期变化。结果：与对照组相比,5．0mg／mL枸杞子水煎液处理后的Hela细胞贴壁率减少（P〈0．01）,细胞迁移能力减弱（JP〈0．01）,对Hela细胞有显著的抑制作用,抑制率最高达84．88％（P〈0．01）,且呈现时效和量效关系;流式细胞术结果表明,枸杞子水煎液组对Hela细胞有一定的S期阻滞作用。结论：枸杞子能有效抑制人宫颈癌细胞的增殖、粘附和迁移能力,并改变细胞的周期分布。     

苦荞异槲皮苷对人胃癌细胞SGC-7901增殖及凋亡的影响

从苦荞中提取制备异槲皮苷,研究其对人胃癌细胞SGC-7901增殖、凋亡、迁移和细胞周期的影响。将异槲皮苷作用于人胃癌SGC-7901细胞和人肾上皮细胞系293T,通过噻唑蓝法检测异槲皮苷对其增殖的影响;4’,6-二脒基-2-苯基吲哚(4’,6-diamino-2-phenyl indole,DAPI) 荧光染色法观察细胞核的形态学变化;划痕擦伤迁移实验检测异槲皮苷对SGC-7901细胞迁移能力的影响;流式细胞术检测异槲皮苷对SGC-7901细胞凋亡及细胞周期的影响。结果表明：苦荞异槲皮苷可以抑制SGC-7901细胞的增殖,并呈时间和剂量依赖性,当用100 μmol/L异槲皮苷作用细胞48 h后,对SGC-7901细胞的增殖抑制率达到35.92%, 而对人肾上皮细胞系293T的增殖抑制率仅为 3.15%;DAPI荧光染色法观察异槲皮苷处理细胞后,染色体凝聚,有凋亡小体产生;划痕擦伤实验显示,异槲皮苷能抑制SGC-7901细胞的迁移;流式细胞术检测结果表明,异槲皮苷可使G1和S期细胞减少,G2/M期细胞增多,且细胞凋亡率明显增加。综上所述,苦荞麦异槲皮苷能够诱导SGC-7901细胞发生凋亡,阻断细胞周期并抑制细胞增殖和迁移。     

Cell surface hydrophobicity and colony morphology of Trichosporon asahii clinical isolates

Trichosporon asahii is a pathogenic basidiomycetous yeast. Individual strains of T. asahii have different colony morphologies. However, it is not clear whether cell surface phenotypes differ among the colony morphologies. Here we characterized the cell surface hydrophobicity and analysed the carbohydrate contents of the cell surface polysaccharides in T. asahii clinical isolates with various colony morphologies. Among the three distinctive colony morphologies obtained from one clinical isolate, the white‐type morphology exhibited higher hydrophobicity. The hydrophobicity of heat‐killed T. asahii cells was greatly reduced after periodate oxidation of the cell surface carbohydrates. Furthermore, the cell wall and extracellular polysaccharide components differed among the morphologies. Our results suggest that T. asahii cell surface hydrophobicity is affected by cell surface carbohydrate composition. Copyright © 2016 John Wiley & Sons, Ltd.     

植物乳杆菌胞外多糖对小鼠树突状细胞分泌的调控

采用细胞因子诱导法,以加入重组小鼠粒细胞巨噬细胞集落刺激因子(rmGM-CSF)、重组小鼠白细胞介素-4(rmIL-4)及10%胎牛血清的RPMI1640为完全培养基培养树突状细胞(DCs)。实验组加入植物乳杆菌胞外多糖,脂多糖LPS和RPMI1640分别作为阳性和空白对照。采用Griess法和双抗体夹心ELISA检测DCs分泌NO,促炎症因子IL-12p70,抗炎症因子IL-10和趋化因子RANTES的浓度。结果表明:植物乳杆菌胞外多糖刺激DCs后,DCs分泌NO、IL-12p70、IL-10和RANTES的浓度分别是空白组的110%、194%、76%和133%,且呈剂量依赖关系。植物乳杆菌胞外多糖能促进小鼠骨髓来源的DCs分泌能力。     

藏灵菇源干酪乳杆菌KL1胞外多糖抑制人结肠癌细胞增殖的研究

分离纯化藏灵菇源干酪乳杆菌KL1胞外多糖(EPS),研究EPS纯品对HCT-8人结肠癌细胞的增殖抑制和诱导细胞凋亡作用。利用Sepharose CL-6B凝胶柱探讨干酪乳杆菌KL1菌株EPS粗品的纯化条件,应用紫外全波长扫描及苯酚-硫酸法鉴定EPS纯度;采用CCK-8法和Annexin V-FITC细胞凋亡检测试剂盒研究EPS对HCT-8人结肠癌细胞的增殖抑制和凋亡作用。结果表明:在0.02～0.12mol/L磷酸盐缓冲液梯度洗脱、流速3mL/min、样品上样质量浓度15.0mg/mL、样品上样量2.0mL的纯化条件下获得EPSa和EPSb两个单一组分的胞外多糖,其纯度分别为91.67%和82.86%。EPSa处理HCT-8人结肠癌细胞体外实验发现,EPSa对HCT-8细胞的增殖有抑制作用,以及诱导细胞凋亡的发生,且细胞生长抑制率呈时间-剂量依赖性。提示藏灵菇源干酪乳杆菌KL1菌株的EPSa有抑制结肠癌细胞增殖的生物活性。     

参数化单胞计算三维编织预制件纤维体积含量

在Pro/E中建立了三维编织预制件的内部单胞、表面单胞和棱角单胞的3D实体模型,并对模型进行了参数化设计。当编织工艺参数改变时能自动生成新的单胞模型,单胞纤维体积由Pro/E的模型分析功能直接输出。提出了基于参数化单胞计算预制件纤维体积含量的公式。计算了长方体形预制件的纤维体积含量,并与实测值进行比较,理论计算与实验结果吻合良好。计算了扇环形预制件的纤维体积含量,为复杂外形预制件纤维体积含量的计算提供了新方法。     

大蒜素抗癌作用及其机制研究进展

大蒜素是大蒜中的主要生物活性成分,包含多种烯丙基有机硫化物。近年国内外的流行病学调查和实验研究表明,大蒜素对多种肿瘤均有明显抑制作用。其主要作用机制是通过影响肿瘤细胞调控基因表达、细胞周期及细胞内酶系等途径诱导肿瘤细胞凋亡。同时还与转基因肿瘤疫苗及抗癌药物协同作用,增强抗癌效果。本文就近年来大蒜素抗癌作用的研究进展作一综述。     

Saccharomyces cerevisiae YCRO17c/CWH43 encodes a putative sensor/transporter protein upstream of the BCK2 branch of the PKC1-dependent cell wall integrity pathway.

The Saccharomyces cerevisiae cwh43-2 mutant, originally isolated for its Calcofluor white hypersensitivity, displays several cell wall defects similar to mutants in the PKC1-MPK1 pathway, including a growth defect and increased release of beta-1,6-glucan and beta-glucosylated proteins into the growth medium at increased temperatures. The cloning of CWH43 showed that it corresponds to YCR017c and encodes a protein with 14-16 transmembrane segments containing several putative phosphorylation and glycosylation sites. The N-terminal part of the amino acid sequence of Cwh43p shows 40% similarity with the mammalian FRAG1, a membrane protein that activates the fibroblast growth factor receptor of rat osteosarcoma (FGFR2-ROS) and with protein sequences of four uncharacterized ORFs from Caenorhabditis elegans and one from Drosophila melanogaster. The C-terminus of Cwh43p shows low similarities with a xylose permease of Bacillus megaterium and with putative sugar transporter from D. melanogaster, and has 52% similarity with a protein sequence from a Schizosaccharomyces pombe cDNA. A Cwh43-GFP fusion protein suggested a plasma membrane localization, although localization to the internal structure of the cells could not be excluded, and it concentrates to the bud tip of small budded cells and to the neck of dividing cells. Deletion of CWH43 resulted in cell wall defects less pronounced than those of the cwh43-2 mutant. This allele-specific phenotype appears to be due to a G-R substitution at position 57 in a highly conserved region of the protein. Genetic analysis places CWH43 upstream of the BCK2 branch of the PKC1 signalling pathway, since cwh43 mutations were synthetic lethal with pkc1 deletion, whereas the cwh43 defects could be rescued by overexpression of BCK2 and not by high-copy-number expression of genes encoding downstream proteins of the PKC1 pathway However, unlike BCK2, whose disruption in a cln3 mutant resulted in growth arrest in G(1), no growth defect was observed in a double cwh43 cln3 mutants. Taken together, it is proposed that CWH43 encodes a protein with putative sensor and transporter domains acting in parallel to the main PKC1-dependent cell wall integrity pathway, and that this gene has evolved into two distinct genes in higher eukaryotes.     

酵母细胞破壁技术研究与应用进展

随着啤酒行业的发展,啤酒生产中带来的废酵母数量与日俱增,造成了环境污染,废酵母的再利用成为人们关注的焦点。酵母细胞内具有丰富的营养物质,充分利用这些营养物质需要对酵母细胞进行破壁,因而破壁技术就显得尤为重要。系统论述了当前破碎酵母细胞壁的方法和原理,以及各种方法的优缺点和应用现状,对酵母破壁技术的应用前景进行展望。     

Binding of heterocyclic amines by yeast cells and their fractions

The binding of mutagenic pyrolysis products to cells of 50 yeast strains and their cell fractions was investigated. Cells of all yeast strains effectively bound 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2). Cell walls (CW), and cell wall glucan and mannan (5 mg in each case) showed the highest binding of Trp-P-1 (50 μg ml^?1); glucan adsorbed virtually all of the Trp-P-1. Cytoplasm also showed some binding but was much less effective. Glucans also bound well with 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-3,8-dimethylimidazo 4,5-quinoxaline (MeIQX) much more than CW, but 2-amino-5-phenylpyridine (Phe-P-1) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MelQ) were not effectively bound. The quantity of IQ, MeIQ, Phe-P-1 and MeIQX bound was dependent on the strain of yeast. The mutagenic pyrolysis products bound to cells were effectively extracted by aqueous methanol, ammonia (50 g litre^?1) and alcohol, but not by water. The binding was pH dependent and inhibited by metal salts. When yeast cells were heated to 100° for 15 min, the binding of Trp-P-1 decreased by about 30% but Saccharomyces cerevisiae 50 heated to 100° did not differ much from untreated cells in its binding ability.     

Dynamics of somatic cell count patterns as a proxy for transmission of mastitis pathogens

Management of udder health is particularly focused on preventing new infections. Data from the DeLaval Online Cell Counter (DeLaval, Tumba, Sweden) may be used in forecasting to improve decision support for improved udder health management. It provides online cell counts (OCC) as a proxy for somatic cell counts from every milking at the cow level. However, these values are typically too insensitive and nonspecific to indicate subclinical intramammary infection (IMI). Our aim was to describe and evaluate use of dynamic transmission models to forecast subclinical IMI episodes using milk cultures or changes in OCC patterns over time. The latter was expressed by an elevated mastitis risk variable. Data were obtained from the dairy herd of the Norwegian University of Life Sciences (Oslo, Norway). In total, 173 cows were sampled monthly for bacteriological milk culture during a 17-mo study period and 5,330 quarter milk samples were cultured. Mastitis pathogens identified were assigned to 1 of 2 groups, Pat 1 or Pat 2. Pathogens from which a high cell count would be expected during a subclinical IMI episode were assigned to the Pat 1 group. Pathogens not in the Pat 1 group were assigned to the Pat 2 group. Staphylococcus epidermidis, Staphylococcus aureus, and Streptococcus dysgalactiae were the most common Pat 1 pathogens. Corynebacterium bovis, Staphylococcus chromogenes, and Staphylococcus haemolyticus were the most common Pat 2 pathogens. The OCC were successfully recorded from 82,182 of 96,542 milkings. The current study included 324 subclinical IMI episodes. None of the mastitis pathogens demonstrated a basic reproduction number (R₀) >1. Patterns of OCC change related to an episode of Pat 1 subclinical IMI at specificity levels of 80, 90, and 95% at sensitivity levels of 69, 59, and 48% respectively, demonstrated an R₀ >1. An existing infection was significant for transmission for several Pat 2 pathogens, but only for Staphylococcus aureus and Staphylococcus epidermidis among Pat 1 pathogens. Dynamic transmission models showed that patterns of OCC change related to an episode of Pat 1 subclinical IMI were significantly related to the same pattern occurring in susceptible cows at specificity levels of 80, 90, and 99% at sensitivity levels of 69, 48, and 8%, respectively. We conclude that changes in herd prevalence of subclinical IMI can be predicted using dynamic transmission models based on patterns of OCC change. Choice of specificity level depends on management goals and tolerance for false-positive alerts.