Assessment of polynuclear aromatic hydrocarbons ecotoxicity threshold in marine sediments through in situ input/decay measurements

The ability of decomposers to process variable amounts of xenobiotics in the marine sediment is a useful aggregate indicator of their capacity to prevent their accumulation and eventual ecotoxic effects. Since decomposition processes depend on environmental factors at the sediment which are difficult to mimic in laboratory systems, in situ evaluations in undisturbed sediments are of great interest. A method and its results are presented to evaluate the decomposition rates of PAHs (polynuclear aromatic hydrocarbons) in coastal undisturbed marine sediments at different levels of pollution input. The method is based on the application of pulse chromatography concepts to interpret trap and bed sediment monitoring data obtained at regular time intervals, using models of the water column as an anisotropic carrying medium. The results are for a 14 month data series from moderately polluted sediments near an urban site and at a more distant nearly pristine site on the south Atlantic coast. QSAR (quantitative structure activity relations) indicate that decay rates increase with higher UV absorption and lipidic solubility. At low levels of total PAH input to the sediments (<0.05 g day^–1 g^–1), decomposition mechanisms effectively process these compounds within a few days. At higher input levels (up to 0.12 g day^–1 g^–1), decomposition lags behind the inputs by approximately 25% and PAHs accumulate in the sediment. In situ estimates of the PAH input/decay ratios provide reliable ecosystem indicators of a safe threshold for anthropogenic inputs of PAHs to the marine environment and a basis for receptor-based standards aimed at their regulation.     

Limitations in the use of tubulin polymerization assays as a screen for the identification of new antimitotic agents: The potent marine natural product curacin A as an example

Curacin A is a newly isolated lipid natural product that binds in the colchicine site of tubulin and inhibits mitosis. We have examined its effects on tubulin polymerization, studied by turbidimetry, under three reaction conditions. In 1.0 M glutamate + 1.0 mM MgCl₂, with a 37°C reaction temperature, we could find no concentration of curacin A that completely inhibited polymerization. A maximal inhibitory effect on turbidity development (about 50%) was observed with 5 m?M drug. Higher drug concentrations induced an abnormal polymerization reaction, which at 40 m?M differed little from the control reaction except for slightly delayed depolymerization in response to reducing the temperature to 0°C. In 0.8 M glutamate (no MgCl₂), with a 30°C reaction temperature, complete inhibition did occur at 3–5 m?M drug, but higher drug concentrations again induced an abnormal polymerization reaction. With 40 m?M curacin A this reaction was also similar to the control reaction, except that cold-induced depolymerization was slightly enhanced relative to the control. When polymerization was induced by microtubule-associated proteins, maximal inhibition of turbidity development (about 70%) occurred with 2 m?M drug, with higher curacin A concentrations inducing abnormal polymerization reactions that reached about 60% of the control turbidity readings. Under all three reaction conditions the polymer induced by high concentrations of curacin A consisted of large aggregates of tightly coiled spiral fibers that had a 2–3 filament substructure. The implications of these findings with curacin A are discussed in terms of the use of tubulin polymerization assays as a screen for identifying new antimitotic drugs. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Donor to host transmission of disease via corneal transplantation

A literature search was conducted to report all cases of documented transmission of infectious diseases from donors to recipients of corneal transplants. Fourteen such cases have been reported. There is no experimental or clinical evidence to suggest the transmissions of either hepatitis or syphilis via corneal grafting. Available evidence regarding a number of neurologic and other disorders in which a slow virus etiology has been implicated were reviewed. On the basis of this review, we are able to draw certain conclusions and guidelines for selection or rejection of donor material for transplant surgery.     

海绵动物的生物活性产物及其药理作用

概括来源于海洋海绵动物中新发现的36种生物活性次生代谢产物，阐述其化学成分及药理作用的研究进展。其化学成分具有生物碱、甾醇、萜类、大环内酯、肽类等。经药效评价且有抗菌、抗病毒、抗肿瘤以及心血管活性等药理作用。这些具明显药理作用的生理活性化合物，作为新药先导化合物进行研究开发，具有良好的应用前景。     

褐藻酸性寡糖对帕金森病大鼠纹状体、杏仁核多巴胺释放的影响

采用快速周期伏安法(FCV),在以6-羟基多巴胺(6-OHDA)制备的帕金森病(PD)模型大鼠上检测褐藻酸性寡糖HSH971对纹状体(Str)、杏仁核(Amy)多巴胺(DA)释放的影响。结果显示,腹腔注射HSH971 5mg·kg·d~(-1),7d能明显提高PD大鼠损毁侧Str、Amy的DA释放量,而对其健侧无影响。     

慢性阻塞性肺疾病继发院内真菌感染的危险因素及药物经济学分析

目的 :分析慢性阻塞性肺疾病 (COPD)急性加重期继发院内深部真菌感染的危险因素及其药物治疗的经济学意义。方法 :查阅 2 0 0 0年 10月～ 2 0 0 1年 10月我院 74例COPD急性加重期患者的病历 ,对其抗生素应用种类、应用时间、糖皮质激素应用情况、真菌感染部位、菌种类型、抗真菌药物、住院费用及平均住院日进行分析。结果 :高龄及营养状况差是院内真菌感染的危险因素之一 ,而广谱抗生素长期大量应用则是造成真菌感染的重要因素 ,另外 ,合并应用糖皮质激素也是院内真菌感染的又一发病因素。继发院内真菌感染 ,明显延长了住院时间 ,增加了住院费用。结论 :减少院内真菌感染 ,对遏制医疗费用的增长 ,节约国家的卫生资源 ,具有重大意义     

生化过程工程与中药现代化

在生化工程20余年的研究工作基础上。结合中药现代化开展了一些技术、材料与设备的研究开发工作。研究植物细胞、组织、器官大规模培养增殖技术，应用于细胞代谢产物、生物转化和人工育种及发根，实现了工厂化生产，并成功研制多种类型的生物反应器；在原有化学工程提取分离技术的基础上，发展了反应分离耦合、微波辅助提取等新技术，实现了高效浸出，并且节能、节水；此外，又发展了包括反胶团萃取、一步三相萃取青霉素、泡沫分级分离、膜分离、高速逆流色谱分离纯化等新技术。高速逆流色谱技术是一种没有固相载体的液一液多级逆流萃取技术，避免了不可逆吸附，已成功用于多种天然产物的分析和分离，作为研究中药指纹图谱的新方法具有很好的精密度和重现性。高效液相色谱、气相色谱、毛细管电泳、质谱等技术在指纹图谱研究中发挥了重要作用。与此同时，还研制了多种分离介质，并在药物的修饰与包埋方面做了大量工作。另外，在海洋药物研究领域，创造了连续培养连续采收的新流程、新技术．进行了转基因藻的培养。用于生产基因工程产品。     

半叶马尾藻化学成分的研究Ⅰ

 目的：对马尾藻科植物半叶马尾藻［Sargassum hemiphyllum(Turn.) Ag.］藻体的甾醇类成分进行研究。方法：利用真空液相层析、Sephadex LH-20层析和反复硅胶柱层析进行分离，根据甾醇的理化性质和光谱数据鉴定其结构。结果：得到5个甾醇类化合物，分别确定为岩藻甾醇(SPⅠ)、24 氢过氧基 24-乙烯基胆固醇(SPⅡ)，(22E，24S)24-甲基-5α胆甾7，22二烯3β，5，6β三醇(SAⅢ)，saringosterol (SPⅣ)和麦角甾醇过氧化物(ergosterol peroxide) (SAⅥ)。结论：SPⅡ，SAⅢ和SAⅥ为首次从褐藻类中发现。     

酸肉生产主发酵期发酵条件的确定

本文就影响发酵的因素:盐浓度、葡萄糖浓度、接种量、发酵时间和发酵温度对酸肉pH值的影响进行了研究,通过正交试验,确定了最佳发酵条件,即盐浓度0或1%,葡萄糖浓度2%,接种量8%,发酵时间16h,发酵温度34℃。并对优化工艺条件的酸肉发酵前后进行比较,说明了发酵肉制品的优越性。     

青岛沿海海洋附着生物抗肿瘤活性的筛选

对青岛沿海海洋附着生物资源进行调查，采用海虾细胞毒性法及流式细胞术对已鉴定的18种附着生物进行抗肿瘤活性筛选。结果表明，星座美洲海鞘Amaroucium ecostellatum Verril、大菊海鞘Botryllus magnicoecus Hartmeyer、山形海绵Mycale macilenta、海黍子Sargassum kjellmanianum Yendo、裙带菜Undaria pinnatifida(Harv．)Sur．甲醇提取物具有较强的抗肿瘤活性。并进一步进行活性成分追踪研究，确定星座美洲海鞘、大菊海鞘、山形海绵、海黍子、裙带菜的活性部位。