不同纤维来源饲粮和细胞壁降解酶对猪肠道微生物菌群多样性的影响

本试验旨在利用末端限制性片段长度多态性技术研究不同纤维来源饲粮和细胞壁降解酶对猪肠道微生物菌群多样性及其组成结构的影响。试验选用8头平均体重为(35.0±2.5)kg的"杜×长×大"三元杂交生长猪,统一安装回肠末端T型瘘管,随机分为4组,每组2个重复。试验分4期,每期每组猪按4×4拉丁方设计饲喂小麦麸、小麦麸加酶、大豆皮和大豆皮加酶4种试验饲粮之一。每期预试期15 d,正试期6 d。试验结果表明:1)大豆皮饲粮组猪回肠食糜微生物的多样性显著高于小麦麸饲粮组(P0.05)。2)小麦麸饲粮组显著提高猪回肠食糜中普氏菌属(Prevotella)和乳酸杆菌属(Lactobacillus)的丰度(P0.05),而大豆皮饲粮组则显著提高猪回肠食糜中瘤胃球菌属(Ruminococcus)及粪便中拟杆菌属(Bacteroides)、毛螺菌属(Lachnospira)的丰度(P0.05)。3)添加细胞壁降解酶显著提高各饲粮组猪回肠食糜中Lachnospira、真细菌属(Eubacterium)及粪便中Lachnospira的丰度(P0.05),但也同时降低了回肠食糜中Lactobacillus、Prevotella及粪便中Lactobacillus、Bacteroides和克雷伯氏菌属(Klebsiella)的丰度(P0.05)。综上所述,纤维饲粮可显著提高猪肠道内非淀粉多糖降解菌的丰度,而细胞壁降解酶则可选择性改变肠道微生物菌群的多样性及其组成。     

西洋参和蜂花粉细粉及超微粉组织特征扫描电镜观察

将西洋参和蜂花粉分别进行常规粉碎和超微粉碎,利用扫描电镜对2种不同粉碎方式得到的粉末进行观察,比较2种中药细粉和超微粉形态学上的差异。结果表明：超微粉末颗粒变小,大小均匀,电镜下观察,绝大多数细胞壁破裂,基本无完整细胞存在。     

酵母富集微量元素铜的研究

酵母细胞具有富集某些微量元素的能力,它能将富集的无机态铜转化为有机态形式。采用富集培养方法,从22株酵母菌株中筛选出2株富集高含量铜的酵母菌,对其铜含量进行测定。结果表明：铜含量分别达到7．7mpdkg和7．9mpdkg,适宜的铜盐为氯化铜,其添加的离子浓度为90mpdkg。     

Quantitative Structure–Activity Relationships of DDT-Type Compounds in a Sodium Tail-Current in Crayfish Giant Axons

Effects of DDT-type compounds including 1,1-bis(para-substituted phenyl)-2,2-dichlorocyclopropanes (DCC-series compounds) on sodium currents in crayfish giant axons were measured under voltage-clamp conditions. Variations in the activity to prolong the tail-current that was observed upon step repolarization of the membrane were quantitatively analysed by use of physicochemical parameters of aromatic substituents and regression analysis. Introduction of lengthy and narrow substituents was favourable to the activity. Variations in the activity were parabolically related to the hydrophobicity, optimum value being around that of H. DDT- and prolan-series compounds were 2–3 times more active than DCC-series compounds when other structural factors were the same. Insecticidal activity of the compounds was linearly correlated with the tail-current activity when the hydrophobic factor was separately considered. The insecticidal activity of DDT-series compounds was 2·5 times higher than that of others when the other factors were the same. © 1997 SCI.     

Effect of Yiqi Huoxue Jiedu Fang on the growth,metastasis and angiogenesis of Lewis lung carcinomas

AIM: To study the effect of Yiqi Huoxue Jiedu Fang (YHJ), composed of ginsenoside, penex notogingseng and berberin, on tumor growth and metastasis and to explore its mechanism.METHODS: Murine Lewis lung carcinoma transplant model was established and mice were treated with YHJ by intraperitoneal injection. After 10 days, the inhibitory rate of tumor, pathology of tumor and PCNA of tumor cells were detected. After 20 days, numbers of metastatic foci on lung surface and microvessel density (MVD) were determined. Expression of VEGF in tumor and serum were also analyzed by immunohistochemical test and ELISA, respectively. RESULTS: YHJ reduced the weight of tumor and the amount of metastatic foci. The inhibitory rates of tumor at high and low dose of YHJ (24 mg·kg_^-1·d_^-1, 12 mg·kg_^-1·d_^-1) were 48.29% and 37.26%, and the number of metastatic foci was 1.67 and 3.50, while control was 6.44. Furthermore, PCNA of tumor cells, MVD of tumor and VEGF expression in serum and tumor were decreased in YHJ treatment goup as compared with control. CONCLUSION: YHJ remarkably inhibits Lewis lung carcinoma growth and metastasis in mice. Its mechanism may be related to inhibition of angiogenesis.     

平邑甜茶延长根和吸收根抗凋亡基因的表达差异及其对2,4-D 的响应

 以3 年生平邑甜茶[Malus hupehensis（Pamp）Rehd. var. pinyiensis Jiang]盆栽树为材料,通过2,4-D 水溶液灌根处理,探讨了新根（延长根和吸收根）细胞死亡及其抗凋亡基因的表达特征。结果表明,在60 mg · L^-1 2,4-D 处理后的70 d 内,新根细胞死亡量和类caspase3/7（半胱天冬酶）活性先上升后下降,ATP 含量和根系活力的变化与之相反。平邑甜茶抗凋亡基因MhBAG、MhBI-1 与MhHSP70 在新根中均受2,4-D 诱导,随着2,4-D 处理时间的延长,MhBAG 基因的表达水平先下降后逐渐升高,MhBI-1 与MhHSP70 则先升高后下降。在2,4-D 处理下,吸收根细胞死亡量与根系活力的变化幅度明显高于延长根,吸收根MhBI-1 与MhHSP70 表达量的早期升高幅度大于延长根,表明吸收根细胞对2,4-D 的敏感性高于延长根;但在基因表达高峰时,延长根抗凋亡基因表达量的升高倍数明显高于吸收根,暗示延长根比吸收根有更强的抗凋亡能力。     

Establishment,characterization, virus susceptibility and transfection of cell lines from cobia,Rachycentron canadum (L.), brain and fin

Establishment and characterization of two cobia, Rachycentron canadum, cell lines derived from cobia brain (CB) and cobia fin (CF) are described. Caudal fin and brain from juvenile cobia were dissociated for 30 and 10 min, respectively, in phosphate‐buffered saline containing 0.25% trypsin at 25 °C. The optimal culture condition for both dissociated cells (primary cell culture) was at 28 °C in Leibovitz‐15 medium containing 10% foetal bovine serum. The cells have been sub‐cultured at a ratio of 1:2 for more than 160 passages over a period of 3 years. Origin of the cultured cells was verified by comparison of their sequences of mitochondrial cytochrome oxidase subunit I genes (cox I) with the cox 1 sequence from cobia muscle tissue. The cell lines showed polyploidy. No mycoplasma contamination was detected. Susceptibility to grouper iridovirus was observed for the CB cell line but not the CF cell line. Both cell lines expressed green fluorescent protein after being transfected with green fluorescent reporter gene driven by the cytomegalovirus promoter.     

RNA干扰技术抑制新家坡石斑鱼虹彩病毒感染细胞多肽ICP46与绿色荧光蛋白融合基因的表达

新加坡石斑鱼虹彩病毒（singapore grouper iridovirus,SGIV）是一种严重的能引起全身性疾病的病原体,对石斑鱼养殖造成了重大的经济损失。将含有SGIV感染细胞多肽ICP46（infected cell polypeptides 46）基因的真核表达载体pEGFP-ICP46转染到胖头鲤细胞（fathead minnow cells,FHM）中进行融合表达,用荧光显微镜观察到ICP46-GFP融合蛋白主要分布于FHM细胞的细胞质中。根据SGIV-ICP46的序列,设计并体外化学合成了特异性干扰SGIV-ICP46的siRNA（siRNA-ICP46）,与pEGFP-ICP46共转染到FHM细胞中,通过荧光显微镜观察不同时间点荧光强度的变化。转染后24~48 h,实验细胞（共转染siRNA-ICP46和pEGFP-ICP46）和阳性对照细胞（共转染siRNA-GFP和pEGFP-ICP46）中的荧光微弱,发荧光的细胞数量较阴性对照（共转染siRNA-Negative和pEGFP-ICP46）少70%左右,但其后实验细胞和阳性对照细胞的荧光强度开始增强,在转染后72 h其与阴性对照组已差别不大。说明体外化学合成的siRNA-ICP46转染后24~48 h可有效抑制FHM细胞中外源导入SGIV-ICP46基因的表达。     

前体饲喂对细胞培养生产紫杉烷的促进作用

研究了前体化合物对中国红豆杉细胞培养生产紫杉烷的影响.0.5 mmol/L 丙酮酸钠使紫杉醇和1β-羟基巴卡亭Ⅰ的产率分别增加236 %和225.8 %.2 mmol/L 3-甲基 -2-丁烯 -1-醇和0.4 mmol/L苯甲酸钠使2α,5α,10β,14β-四乙酰氧基 -紫杉 -4(20),11-二烯产率分别提高218.6 %和245.2 %.1 mmol/L乙酸钠和0.5 mmol/L 丙酮酸钠使14β-2-甲基丁酰氧基 -2α,5α,10β-三乙酰氧基-紫杉 -4(20),11-二烯的产率分别提高193 %和210.4 %.结果表明添加适当浓度的前体有利于紫杉烷的合成.     

Identification of a cell-wall peptidase (NlpC/P60) from Nocardia seriolae which induces apoptosis in fathead minnow cells

Nocardia seriolae, a Gram-positive bacterium, is the main pathogen of fish nocardiosis. Protein NlpC/P60 is a cell-wall peptidase and a potential virulence factor of N. seriolae. Subcellular localization research revealed that both NlpC/P60-GFP and NlpC/P60Δsig-GFP fusion proteins were evenly distributed in the whole cell of fathead minnow (FHM) cells. Furthermore, typical apoptotic features, such as nuclear pyrosis and apoptotic bodies, were observed in the transfected FHM cells and grouper spleen cells by the overexpression of protein NlpC/P60. Then, quantitative assays of mitochondrial membrane potential (ΔΨm) value, caspase-3 activity and apoptosis-related gene (Bax, BNIP3, TNF1 and TNF6) mRNA expression were conducted. The results showed that ΔΨm was decreased, caspase-3 was significantly activated, and the mRNA expression of pro-apoptotic genes (Bax and BNIP3) and tumour necrosis factors (TNF1 and TNF6) was up-regulated in NlpC/P60-overexpressed cells. Taken together, the results indicated that the protein NlpC/P60 of N. seriolae might involve in apoptosis regulation. This study may lay the foundation for further study on the function of N. seriolae NlpC/P60 and promote the understanding of the virulence factors and pathogenic mechanism of N. seriolae.