莫桑比克罗非鱼孵卵期间口腔粘膜变化的研究

用组织学、组织化学和酶技术,对雌性莫桑比克罗非鱼在孵卵前后口腔粘膜的组织结构、抗菌酶的比活力变化进行初步研究。结果表明:在口腔粘膜的上皮中,杯状细胞是一个重要的结构,它随着雌鱼的生理状态的改变而变化。雄鱼、雌鱼和孵卵期的雌鱼口腔粘膜上皮中的杯状细胞数量上的差别显著。孵卵期的雌鱼口腔粘膜类似于哺乳动物的子宫粘膜也是受性激素影响的靶器官。该种鱼的口腔粘膜中存在着两种抗菌酶;蛋白质水解酶和壳多糖酶。孵卵前后,这两种酶的比活力分别提高1.4—2.03倍。说明孵卵时,口腔粘膜为使卵及仔鱼健康的发育,增强了抗菌能力。研究结果证明:抗菌力的增加与口腔粘膜中的杯状细胞的大量增生有着密切的关系。     

Alkaline Phosphatase Activity in the Red-Tide Dinoflagellate, Ptychodiscus brevis

Abstract. Alkaline phosphatase activity (APA) was found in a nearshore, natural population of the red-tide dinoflagellate Ptychodiscus brevis. Initial hydrolysis rates were enhanced by two orders of magnitude within 24 h upon addition of ammonium. Other nutrient (additions) or no additions also lead to a higher, although less pronounced increase in activity. Enhanced growth after nutrient additions combined with specific APA indicated that the bloom was both N and P limited. Since the natural population was a mixture of diatoms and the dinoflagellate, APA was also measured in unialgal cultures of P. brevis. APA was not reduced but enhanced by the addition of low concentrations of orthophosphate (0.5 and 1 μM). Higher orthophosphate concentrations (5 to 20 μM) reduced APA, although activity returned to control levels within 2 to 6h. Repression occurred within 30 sec after a 20 μM orthophosphate addition. Cells which had APA repressed by an orthophosphate addition regained their initial activity within 2 h after washing with phosphate-free media. Phosphorus-deficient cells of P. brevis possess an alkaline phosphatase system which is capable of continued activity at low in situ orthophosphate levels.     

Shallow-Water Gasohydrothermal Vents of Ushishir Volcano and the Ecosystem of Kraternaya Bight (The Kurile Islands)

Abstract. A marine ecosystem in the crater of the Ushishir Volcano (Kraternaya Bight, Yankich Island, the Kuriles) showing gasothcrmal activity was studied for hydrographical, hydrochemical, and biological characteristics. Maximal changes in chemical and biological characteristics were observed in the surface water layer of 0–5 m. This layer had higher water temperature, was saturated with volcanogcnic carbon dioxide (up to 2000 10^-6 torr), ovcrsaturatcd with oxygen (up to 200 %), and contained high concentrations of chlorophyll a. Hydrogen sulfide was found in the surface water layer and at a depth of 15 m in the area of maximal effect of volcanic effluents.
The planktonic community is characterized by high rates of production and destruction of organic matter only in the 0–5 m layer. Daily vertical migrations of the ciliatc Mesodinium rubrum were observed, which caused "red tides".
Bacterial, algobacterial, and diatom mats developed on the bottom of the bight in the zone of gasohydrothermal vents and in areas of volcanic water seeping. The rate of organic matter production in algobacterial mats reached 33.4g C-rrr²-d^-l, chcmolithotrophy predominating. Bottom settlements had high population density and great animal biomass, which reached 10 kg m^-2 in gasohydrothermal fields. They obtain sufficient energy from primary production of microphy-tobenthos, algobacterial, and bacterial mats. Bcnthic species dominant in the bight were not found off the Ushishir Islands.
Some species of macrobenthos inhabiting the Kraternaya Bight differ markedly in size and biomass from the same species found beyond the bight.     

甘糖酯对大鼠尿激酶型纤溶酶原激活物活性的诱导作用

为了研究甘糖酯对大鼠体内尿激酶型纤溶酶原激活物 (urokinase PlasminogenActivator,u PA)活性的影响 ,采用溶解圈中和抑制法和发色底物法检测了大鼠口服甘糖酯后体内u PA活性的变化情况。结果表明 :甘糖酯可提高大鼠体内血液的纤溶活性 ,主要表现为 u PA活性升高。以不同剂量的甘糖酯连续喂药 10 d后 ,发现喂药组大鼠 u PA活性明显高于对照组 ,喂药组大鼠血浆 u PA活性升高同喂药剂量正相关 ,在 0～ 10 0 mg/ kg的剂量范围内 ,随喂药剂量增加而升高。提示在一定的剂量范围内甘糖酯可提高大鼠体内 u PA活性 ,激活纤溶系统 ,提高血液纤溶活性 ,表现出良好的抗栓作用     

Elemental geochemical records of seafloor hydrothermal activities in the sediments from the Okinawa Trough

The major and minor element contents in the sediment core H9 from the hydrothermal fields of the Okinawa Trough show a sharp change at the depth of 80 cm. The elements enriched in the upper 80 cm core are those enriched in the hydrothermal deposits and in the surface sediments recovered from the hydrothermal fields in the trough, which indicates the input of hydrothermal materials. Comparing with other hydrothermal sediments from Mid-ocean Ridges or the Lau Basin, the degree of the enrichment of elements iron, copper,cobalt, and nickel is relatively low. However, the enrichment of elements manganese, lead, arsenic, antimony and mercury is remarkable. The average contents of these elements in the upper 80 cm core sediments are three to six times those in the lower section, and 3~12 times those in the surface sediments which are not influenced by hydrothermal activities. Hydrothermal activities have contributed significant manganese, lead, arsenic, antimony and mercury to the sediments, and these elements are distinct indicators for the hydrothermal activity in the Okinawa Trough. The significant enrichment of these elements in Core H9 upward from the depth 80 cm indicates the start or the significant enhancing of the hydrothermal activity in this area at about 5 740 aB.P. The average accumulation rate of manganese during this period is about 40 461 μg/(cm2·ka), which is similar to the hydrothermal sediments in the Lau Basin or the East Pacific Rise.     

山东沿海海藻抗肿瘤活性的筛选

于1997年4月和2000年5月对山东沿海海藻进行较系统的采集，对其中39种海藻的96个样品采用高通量方法进行选择性细胞毒筛选，结果表明，小粘膜藻（Leathesia dif-formes)、多管藻（Polysiphonia urcedata)、萱cytosiphon lomentarius)、海萝（Gloiopeliis fur-cata)、叉开网翼藻（Dictyopteris diuaricata)、点叶菜（Punctaria latifolia)等对KB细胞或HT-29细胞具有选择性抑制活性。局醇、氯仿的提取效率较高，多管藻的乙醇、氯仿提取物，萱藻的乙醇提取物和叉开网翼藻的正己烷提取物都有强的选择性细胞毒活性。     

近期黄河入海水量减少成因分析

利用黄河入海控制站利津的实测水文资料及黄河流域的降水和人类活动影响的相关资料等,分析了近期黄河入海水量变化的特征及变化的原因。结果表明,1986年以来黄河入海水量大幅减少,断流现象突出等,与其以前相比,入海水量减少64%;在减少的水量中,“准自然因素影响”约占55%,引黄用水约占31.5%,其它人类活动影响约占13.5%。     

培养基对海藻真菌PT2菌株的生长及活性代谢产物合成的影响

本文采用PD、GPY、YES、SYE、GPM5种不同培养基培养海藻真菌菌株PT2，并对其在不同培养基中的生长情况、代谢产物的形成及抗肿瘤活性进行分析，旨在了解不同培养基对菌株生长和活性物质合成的影响．结果显示，PT2菌株在不同培养基上的培养特征及生长速率有所不同，液体培养基发酵液抽提物的抗肿瘤活性也有较大差别，其中SYE发酵液抽提物活性最强，对KB、Raji和Hela 3种肿瘤细胞的IC50分别为7．6μg／cm^3、2．4μg／cm^3和3．3μg／cm^3．采用HPLC法对不同抽提物进行分析，发现它们之间的组成成分有显著差异．本文的实验结果表明，不同培养基对该菌株的生长及活性代谢产物的合成具有显著的影响。     

低分子量肝素的制备及其结构与活性差异(英文)

低分子肝素作为一种抗血栓的多糖药物在临床中已应用了二十多年 ,目前已作为外科预防血栓形成药物 ,并在治疗急性静脉栓塞紊乱方面取代了未分级肝素。因肝素的来源和制备的方法不同使低分子肝素的精细结构不同 ,低分子肝素结构的复杂性 ,使得各产品的生物活性 ,例如抗蛋白酶活性不同 ,从而导致其临床使用的标准不同。该文将对低分子肝素的制备方法及其结构和抗蛋白酶活性的差异进行报导     

肝素酶Ⅰ对合成的肝素五糖的酶解作用及对其抗Xa因子活性的影响

研究肝素酶Ⅰ(来源于Flavobacterumheparinase，EC4.2.2.7)对人工合成的且含有与抗凝血酶Ⅲ特定结合位点的肝素五糖(SHP)的酶解作用，并对酶解作用的动力学进行研究。利用强阴离子高效液相色谱(SAX-HPLC)对酶解混合物进行分离，利用质谱(ESIMS)和核磁共振波谱(1H-NMR)技术对得到的二糖和三糖的结构进行确证。研究结果表明，这种被作为肝素反向试剂的肝素酶Ⅰ可水解人工所合成的肝素五糖，从而使之丧失抗Xa因子活性。