Antioxidant enzyme activities in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense

Information regarding antioxidant enzymes in amphioxus remains lacking, and this study was carried out to examine the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense. Results show that (1) CuZn-SOD, CAT and GPX activities in the whole amphioxus B. belcheri tsing- tauense were basically at the same levels in male and female amphioxus, whereas both T-SOD and Mn-SOD activities in male amphioxus were significantly higher than that in the female (P<0.05); (2) The testis had significantly higher T-SOD and CuZn-SOD activities than the ovary (P<0.05); (3) CuZn-SOD activity was undetectable in the guts of male and female amphioxus; (4) For both male and female am- phioxus, the activities of CAT and GPX in the gonads including testis and ovary were the lowest (P<0.05) among the tissues examined; (5) The gut and gill had the same level GPX activities while the gut had a higher CAT activity; (6) There was no clear difference in CAT and GPX activities in the corresponding tissues between male and female amphioxus. The study on SOD, CAT and GPX activities in different genders and tissues of the protochordate provides data for future comparison of amphioxus antioxidant enzymes with those of invertebrates and vertebrates.     

Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups.Each bullfrog in bacterium-injected group was injected intraperitoneally(i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml,while each one in control group injected i.p.with 0.2 ml sterile saline solution(0.85%,w/v).Three bullfrogs in both groups were sampled at 0,1,3,7,11,15 and 20 days post-injection(dpi) for the evaluation of non-specific immune parameters.It was observed that intraperitoneal injection of A.hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood.Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group.However,a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes.No significant difference in changes in the number of peripheral erythrocytes,serum superoxide dismutase(SOD) activity,and lysozyme activity was detected between the two groups.It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A.hydrophila infection.     

赤潮生物的毒害机理与毒素生物化学研究

对赤潮毒素的研究已成为当前国际上的一个研究热点。本文仅对赤潮生物的毒害机理与毒素生物化学的研究进展进行综述。１亚历山大藻（Ａｌｅｘａｎｄｒｉｕｍｓｐｐ．）的毒害机理亚历山大藻的毒害机理是在代谢过程中产生麻痹性贝毒。１９７５年,当第一个麻痹性贝毒石房蛤毒素(ＳＴＸ)的化学结构用Ｘ射线结晶学方法鉴定成功时,发现这个分子属于生物碱类型,其基本骨架单元是全氢化嘌呤。通过同位素分子对Ａｌｅｘａｎｄｒｉｕｍｔａｍａｒｅｎｓｅ和Ａｐｈａｎｉｚｏｍｅｎｏｆｌｏｓａｑｕａｅ的培养试验发现,该毒素是由精氨酸和乙酸通过一种…     

Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara

1 Introduction Groupers are commercially valuable species which attract considerable mariculture interest in Southeast Asia, especially in China’s Mainland, Tai- wan Province, Hong Kong District, and Singapore. In the recent years, groupers have become t…     

影响海水中二甲基硫（DMS）浓度的若干生物化学过程研究

影响海水中ＤＭＳ浓度大小的因素很多。本文综述了目前国仙外有关ＤＭＳ的生物和化学过程的研究进展。     

华南下二叠统层状硅岩的形成及意义

华南地区下二叠统的层状硅岩分布较稳定，厚度一般为几十米，含有数量不等的放射虫和海绵骨针等，并据此可分为放射虫硅岩、海绵骨针硅岩和贫化石硅岩。化学成分特点和硅氧同位素值，具有生物化学成因硅岩的特征，与火山成因和热水成因的硅岩也有一定联系。层状硅岩的形成明显受断裂控制，硅质生物、上升洋流和水平洋流则是硅质富集、保存和沉淀的主要因素，而海底火山和热水活动的参与也起到一定促进。层状硅岩中有机碳含量丰富，平均０．６９％，是潜在的有利烃源岩     

三丁基锡对文蛤外套膜代谢酶活性的影响

用实验生态学方法，观察浓度为0．1、1、10ng／dm^3的三丁基锡暴露2、8、20d以及恢复7、20d后对文蛤外套膜酸性磷酸酶、碱性磷酸酶以及Na^＋、K^＋-ATP酶活性的影响．结果表明各浓度组的三丁基锡在暴露早期（2d），外套膜中酸性、碱性磷酸酶和Na^＋、K^＋-ATP酶活性与对照组比较没有显著差异，随着暴露时间的延长，高浓度的TBT暴露对AKP表现出激活作用，对ACP和Na^＋、K^＋-ATP酶活性则具有抑制作用．结果显示Na^＋、K^＋-ATP酶可作为有机锡暴露的生物标志物．     

广西北海湾COD与水文生物要素及不同形态氮磷的关系

本文探讨了北海深COD值的分布特征及其与水文，生物要素及不同形态氮，磷含量的关系，结果表明；河流输入对本湾COD值的影响突出表现在春、夏季、冬季最小，秋季则以沿岸排废，排污影响为主，水文要素对COD值的分布起主导控制作用，生物化学作用仅占次要地位；春、夏、冬三个季度月COD值与氮含量的相关性较为显著，秋季则与磷含量的相关性较为显著。     

海洋中Redfield比值的研究

总结并评述了对海洋中的Redfield比值进行修正的研究成果。通过对文献结果的综合分析,获得了一些规律性认识：N／P=16这一传统的Redfield比值被广泛接受,个别大洋深层水中N／P比值小于16可归因于脱氮作用;海洋中实际的-O2／P和C／P比值大于传统的Redfield比值;海洋中浮游生物的实际元素组成中C／H、C／O比值显著高于Redfield给出的浮游生物元素组成中的比例。