中国南海软体动物及其食源生物的化学、化学生态学和生物活性研究

海洋软体动物色彩艳丽、行动缓慢,主要依赖次生代谢产物形成的化学防御机制对抗天敌的捕食.多数软体动物可以通过选择适当的食物并将其中有用的代谢物质经过进一步的生物转化或积累到身体的特定部位而用作化学防御物质,以保护自己不受天敌的捕食;少数软体动物能够生物合成自身所需要的化学物质,从而建立起化学防御体系.研究软体动物及其食源生物的化学组成可以揭示它们之间的食物链关系,并进一步阐明这些化学物质的生态学作用.同时,这种进化的化学防御体系也能为我们提供一种从自然界寻找生物活性物质的新方法.近年来,我们研究小组对中国南海软体动物及其相关食源生物海绵、珊瑚和海藻等常见海洋生物物种之间的食物链关系进行了系统研究,获得了这些海洋生物的化学及生物学等方面的知识,并对这些化学物质的药理活性进行了系统考察,为更加系统、深入地开展中国海洋天然产物研究、开发具有自主知识产权的海洋新药打下了坚实的基础.     

海洋放线菌中具有抗肿瘤活性聚酮类化合物的研究进展

目的对海洋放线菌所产生的聚酮类化合物的结构特点与抗肿瘤活性进行阐述,为海洋放线菌的进一步研究与开发奠定基础。方法结合相关文献33篇,对近5年来海洋放线菌次级代谢产物中发现的结构新颖复杂的聚酮类化合物的结构特征和抗肿瘤活性研究进行综述。结果与结论聚酮类化合物结构新颖复杂,对多种瘤株都表现出较强的抑制作用,且部分化合物已经处于临床实验阶段。     

黄芪注射液联合博尔泰力注射液治疗失代偿期肝硬化的临床应用研究

目的：观察黄芪注射液联合博尔泰力注射液用于失代偿期肝硬化的治疗疗效,为临床用药提供科学依据.方法：将80例失代偿期肝硬化患者随机分为治疗组和对照组.治疗组在常规治疗的基础上,另给予黄芪注射液40mL和博尔泰力注射液6mL静脉滴注,1次/d,连用3mo.对照组采用常规治疗.观察实验指标变化和治疗效果.结果：治疗组肝功指标ALT,AST,TBIL,ALB均较治疗前有显著改善（P〈0.05）,对照组仅ALT,AST有改善（P〈0.05）;肝纤维化指标水平,治疗组治疗后较治疗前显著下降（P〈0.05）,且显著低于对照组治疗后（P〈0.05）;治疗组总有效率为92.5%,对照组总有效率为67.5%,两组比较有统计学差异（P〈0.05）;两组均无不良反应.结论：黄芪注射液联合博尔泰力注射液能明显控制失代偿期肝硬化的炎症活动,有抗纤维化的作用,治疗效果显著,且无不良反应发生,值得临床推广应用.     

Evaluation of Turkish seaweeds for antiprotozoal, antimycobacterial and cytotoxic activities

As part of our continuing research on seaweeds, crude MeOH extracts of two green, three brown and six red algae collected from Marmara, Black, Aegean and Mediterranean Seas were screened. Four parasitic protozoa, i.e. Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms for the in vitro assays. The selective toxicity of the extracts was also determined against mammalian L6 cells. All seaweed extracts were active against T. brucei rhodesiense; the Dasya pedicellata extract was the most potent (IC₅₀ value 0.37 µg/mL). The same extract also weakly inhibited the growth of T. cruzi (IC₅₀ 62.02 µg/mL). All seaweed extracts also showed leishmanicidal activity (IC₅₀ values 16.76–69.98 µg/mL). The majority of the extracts also exhibited antiplasmodial potential and the most potent extracts were those from D. pedicellata (IC₅₀ 0.38 µg/mL), Codium bursa (IC₅₀ 1.38 µg/mL) and Caulerpa rasemosa (IC₅₀ 3.12 µg/mL). One brown and two red algal extracts showed some weak activity against Mycobacterium tuberculosis (MIC values 125–256 µg/mL). Except for the extract of Dasya pedicellata, none of the extracts displayed any cytotoxicity. This is the second study investigating the antiprotozoal activities of Turkish marine algae and identifies Dasya pedicellata, an understudied algal species, as a candidate for further studies. Copyright © 2010 John Wiley & Sons, Ltd.     

Role of macroscopic particles in deep-sea oxygen consumption

Macroscopic particles (>500 μm), including marine snow, large migrating zooplankton, and their fast-sinking fecal pellets, represent primary vehicles of organic carbon flux from the surface to the deep sea. In contrast, freely suspended microscopic particles such as bacteria and protists do not sink, and they contribute the largest portion of metabolism in the upper ocean. In bathy- and abyssopelagic layers of the ocean (2,000–6,000 m), however, microscopic particles may not dominate oxygen consumption. In a section across the tropical Atlantic, we show that macroscopic particle peaks occurred frequently in the deep sea, whereas microscopic particles were barely detectable. In 10 of 17 deep-sea profiles (>2,000 m depth), macroscopic particle abundances were more strongly cross-correlated with oxygen deficits than microscopic particles, suggesting that biomass bound to large particles dominates overall deep-sea metabolism.     

Limits to gene flow in a cosmopolitan marine planktonic diatom

The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species Pseudo-nitzschia pungens (clade I) is limited and follows a strong isolation by distance pattern. Furthermore, phylogenetic analysis implies that under appropriate geographic and environmental circumstances, like the pronounced climatic changes in the Pleistocene, population structuring may lead to speciation and hence may play an important role in diversification of marine planktonic microorganisms. A better understanding of the factors that control population structuring is thus essential to reveal the role of allopatric speciation in marine microorganisms.     

Incorporating biogeography into evaluations of the Channel Islands marine reserve network

Networks of marine reserves are increasingly a major component of many ecosystem-based management plans designed to conserve biodiversity, protect the structure and function of ecosystems, and rebuild and sustain fisheries. There is a growing need for scientific guidance in the design of network-wide monitoring programs to evaluate the efficacy of reserves at meeting their conservation and management goals. Here, we present an evaluation of the Channel Islands reserve network, which was established in 2003 off the coast of southern California. This reserve network spans a major environmental and biogeographic gradient, making it a challenge to assess network-wide responses of many species. Using fish community structure data from a long-term, large-scale monitoring program, we first identified persistent geographic patterns of community structure and the scale at which sites should be grouped for analysis. Fish communities differed most among islands with densities of individual species varying from 3- to 250-fold. Habitat structure differed among islands but not based on reserve status. Across the network, we found that, after 5 years, species targeted by fishing had higher densities (1.5×) and biomass (1.8×) inside reserves, whereas nontargeted species showed no significant differences. Examining trophic groups, piscivore and carnivore biomass was significantly greater inside reserves (1.8× and 1.3× more, respectively), whereas the biomass of planktivores and herbivores was similar inside and out. A framework for incorporating biogeographic variation into reserve network assessments is critical as we move from the evaluation of single reserves to networks of reserves.     

微透析技术在药物-蛋白结合研究中的应用

目的介绍微透析技术在药物-蛋白结合研究中的应用。方法通过查阅近年来国内外相关文献,概述微透析技术的基本原理、特点、探针及影响探针相对回收率的主要因素,并重点介绍其在药物-蛋白结合研究中的应用。结果与结论与平衡透析法、超滤法相比,微透析技术是一项新兴的在体或离体取样技术,在药物-蛋白结合研究中具有显著的优越性和广阔的应用前景。     

石墨炉原子吸收法测定海洋生物中总砷

目的建立海洋生物中总砷的石墨炉原子吸收方法,测定广东沿海海洋生物中总砷含量。方法海洋生物样品经硝酸高压消解后,采用氯化钯+硝酸镍为基体改进剂,用石墨炉原子吸收法测定总砷含量。结果方法线性范围为0～40μg/L,线性相关系数为0.997,检出限为0.030mg/kg,精密度为3.7%～5.1%,国家标准参考物质的分析结果在证书值范围内。在所检的99个海洋生物中,以湿重计算的总砷含量为0.09～12.58mg/kg,平均含量为1.85mg/kg。结论该法能有效消除基体干扰,并具有良好的精密度和准确度,测量结果显示广东沿海海洋生物受到不同程度的砷污染。