河西走廊中部两种荒漠植物根系构型特征

在河西走廊中部,采用挖掘法挖取红砂和白刺根系,应用拓扑学与分形理论分析了根系构型的特征.结果表明: 2种荒漠植物根系的拓扑指数均较小,根系分支模式均近似为叉状分支结构.红砂和白刺根系具有较好的分形特征,其分形维数分别为(1.18±0.04)和(1.36±0.06);分形维数、分形丰度与根系平均连接长度均呈显著正相关.2种荒漠植物根系的平均连接长度均较大,以扩大植物的有效营养空间,从而适应干旱贫瘠的土壤环境.2种荒漠植物根系分支前的横截面积等于根系分支后的横截面积之和,验证了Leonardo da Vinci法则.对17个根系构型参数进行主成分分析,根系拓扑指数、根系连接数量、逐步分支率和根系直径4个根系构型参数能很好地表示2种荒漠植物根系构型特征.     

Evolutionary divergence of the APETALA1 and CAULIFLOWER proteins

Abstract APETALA1 (AP1) and CAULIFLOWER (CAL) are a pair of paralogous genes that were generated through the pre‐Brassicaceae whole‐genome duplication event. AP1 and CAL have both partially redundant and unique functions. Previous studies have shown that the K and C regions of their proteins are essential for the functional divergence. However, which differences in these regions are the major contributors and how the differences were accumulated remain unknown. In the present study, we compared the sequences of the two proteins and identified five gaps and 55 amino acid replacements between them. Investigation of genomic sequences further indicated that the differences in the proteins were caused by non‐synonymous substitutions and changes in exon–intron structures. Reconstruction of three‐dimensional structures revealed that the sequence divergence of AP1 and CAL has resulted in differences between the two in terms of the number, length, position and orientation of α‐helices, especially in the K and C regions. Comparisons of sequences and three‐dimensional structures of ancestral proteins with AP1 and CAL suggest that the ancestral AP1 protein experienced fewer changes, whereas the ancestral CAL protein accumulated more changes shortly after gene duplication, relative to their common ancestor. Thereafter, AP1‐like proteins experienced few mutations, whereas CAL‐like proteins were not conserved until the diversification of the Brassicaceae lineage I. This indicates that AP1‐ and CAL‐like proteins evolved asymmetrically after gene duplication. These findings provide new insights into the functional divergence of AP1 and CAL genes.     

靶向抑制铜伴侣蛋白CCS逆转卵巢癌C13*细胞的顺铂耐药性

顺铂（cisplatin）,即二胺二氯铂/diaminedichloroplatinum（DDP）,是治疗卵巢癌最有效的化疗药物;然而,耐药性是限制顺铂临床治疗效果的最重要因素。目前,卵巢癌对顺铂的耐药机制仍不十分清楚。超氧化物歧化酶1铜伴侣蛋白（copper chaperone for superoxide dismutase 1, CCS）介导Cu2+特异性传递给超氧化物歧化酶1（superoxide dismutase1, SOD1）,为维持细胞增殖和生存所必需;相反,抑制CCS可减缓肿瘤细胞增殖。本研究旨在证明,AMPK依赖的CCS表达与卵巢癌的顺铂耐药有关。实时定量PCR及免疫印迹结果显示,与顺铂敏感细胞株OV2008比较,顺铂耐药细胞株C13*中的CCS mRNA和蛋白质表达水平明显上调。shRNA靶向沉默CCS或采用抑制剂DC_AC50抑制CCS后,可明显增强顺铂对C13*细胞增殖的抑制作用,提示CCS高表达与顺铂耐药相关,而抑制CCS可逆转顺铂的耐药性。同样,免疫印迹结果证明,CCS在A549、H1944等6种不同肺癌细胞中的表达水平高低与顺铂敏感性密切相关。采用siRNA干扰CCS在A549细胞中的高表达,或在CCS低表达的H1944细胞中过表达CCS,可明显增加A549或减弱H1944细胞对顺铂的敏感性,进一步证明CCS表达与顺铂耐药性相关。此外,采用AMPK抑制剂化合物C阻断AMPKα Thr172磷酸化（激活）,即抑制AMPK信号通路,可明显抑制CCS在C13*细胞中的表达,提高其对顺铂的敏感性。以上研究结果提示,AMPK信号通路依赖的CCS表达参与肿瘤的顺铂耐药机制,而抑制CCS逆转顺铂耐药。本文的结果还提示,CCS有望成为克服顺铂耐药的潜在靶点。     

Influence of sCD40L on gastric cancer cell lines

The CD40 signaling pathway plays a key role in tumor cell proliferation, differentiation, and apoptosis. Gastric cancer usually possesses a higher level of CD40 expression than normal tissue. We evaluated inhibition of soluble CD40 ligand (sCD40L) in apoptosis induction of gastric cancer cells. Gastric cancer cells (AGS and BGC-823) were incubated with sCD40L. Cell viability and cell cycle were determined by methyl-tetrazolium (MTT) assay and flow cytometry, respectively. The results showed that sCD40L hindered cell growth, arrested cells at G0/G1 phase and induced apoptosis. In conclusion, sCD40L suppress growth of gastric cancer cells through apoptosis induction and cell cycle quiescence. This work will provided a new approach to gene therapy of gastric cancer.     

WBC27,an Adenosine Tri-phosphate-binding Cassette Protein,Controls Pollen Wall Formation and Patterning in Arabidopsis

In flowering plants,the exine components are derived from tapetum.Despite its importance to sexual plant reproduction,little is known about the translocation of exine materials from tapetum to developing microspores.Here we report functional characterization of the arabidopsis WBC27 gene.WBC27 encodes an adenosine tri-phosphate binding cassette(ABC) transporter and is expressed preferentially in tapetum.Mutation of WBC27 disrupted the exine formation.The wbc27 mutant microspores began to degenerate once rel...     

九种海滨沙生植物解剖构造及其生态适应性研究

利用常规石蜡制片法,对生长于北戴河海滨沙地的9种沙生植物的营养器官的形态结构进行比较观察。结果表明：(1)叶结构出现各种旱生和盐生植物特征,如一些植物叶的栅栏组织发达,海绵组织退化;多数植物的叶片较小;多数植物支脉和侧脉多等;(2)轴器官具有发达的表皮和机械组织,有异常结构的出现。说明北戴河海滨沙滩生长的9种植物的营养器官存在一系列的旱生结构特征,这些结构在减少蒸腾作用,增强光合作用,储存水分,增强器官的机械强度方面具有积极的作用。     

腹腔镜袖状胃切除术治疗病态性肥胖合并2型糖尿病近期疗效分析

目的:探讨行腹腔镜袖状胃切除术治疗合并2型糖尿病(type 2 diabetes mellitus,T2DM)肥胖症病人的效果。方法:回顾性分析上海长征医院普外三科2008年7月至2011年12月行腹腔镜袖状胃切除术治疗合并T2DM的肥胖症8例病人的术前资料和术后12个月的随访资料。结果:所有病人均在腹腔镜下完成手术,无中转开腹。术中术后均无严重并发症发生。在术后12个月的随访过程中,病人体重、体重指数均呈下降趋势,与术前相比,术后1月开始差异即有统计学意义(P0.01)。术后12个月T2DM临床完全缓解4例(50%),临床部分缓解4例(50%)。所有病人术后糖化血红蛋白、空腹血糖均呈下降趋势,从术后1个月开始,糖化血红蛋白与术前相比差异有统计学意义(P0.01),术后3个月复查5例(62.5%)已恢复正常水平;空腹血糖自术后1月开始与术前相比差异即有统计学意义(P0.01)。结论:腹腔镜袖状胃切除术是一种安全、有效的治疗肥胖症合并T2DM的手术方式。     

雷诺嗪缓释片在比格犬体内的药代动力学

目的:研究雷诺嗪缓释片在比格犬体内的药物代谢动力学,并与参照制剂比较,为其是否具有缓释特征提供依据。方法:首先建立血浆中雷诺嗪浓度的液相色谱-串联质谱联用检测方法,并考察方法的专属性、准确度、日内日间精密度、回收率、线性范围等。采用随机对照试验设计,将12只比格犬随机分为A、B组,每组6只,分别服用1片雷诺嗪缓释片(500 mg/片)和1片参比制剂雷诺嗪片(500 mg/片),均于给药前和给药后不同时间点采集血样,用已建立的液质联用方法检测血样中雷诺嗪的血药浓度,计算2组比格犬的药代动力学参数。结果:受试组和参照组半衰期t1/2分别为13.3±8.3和2.36±0.92 h,峰浓度Cmax分别为923.9±340.5和3205±1314 ng/mL,达峰时间Tmax分别为1.6±0.38和0.88±0.14 h,曲线下面积AUC0~∞分别为6252.1±2860.3和9916±4305(ng·h)/mL,清除率Cl分别为11.3±9.8和6.39±3.95 L/(kg·h)。受试制剂雷诺嗪缓释片和参比制剂雷诺嗪片的药代特征和血药浓度-时间变化趋势明显不同,受试组血药浓度缓慢上升和下降,峰值较低;而参照组血药浓度峰值显著高于受试组,有明显的突释效应。结论:液质联用检测方法准确可靠,适合体内药代动力学研究;与参比制剂雷诺嗪片相比,受试制剂雷诺嗪缓释片符合缓释片的基本药代动力学特点。     

雏议我国假马鞭属植物

本文报道中国一新纪录归化植物"荨麻叶假马鞭[Stachytarpheta urticaefolia (Salisb.) Sims]",并将其与近缘种假马鞭[Stachytarpheta jamaicensis (Linn.) Vahl]加以区别,对这两种植物的形态学特征进行重新描述,还就我国目前有关马鞭草科假马鞭属植物的重要文献中所存在的问题进行澄清。标本存放于海南大学儋州校区植物标本馆(SCUTA)。