Cell responses to xenobiotics: comparison of MCF7 multi-drug- and mussel blood cell multi-xenobiotic-defense mechanisms

Multi-drug resistance (MDR) in MCF7 breast cancer cells and multi-xenobiotic resistance (MXR) in mussel (Mytilus edulis) blood cells (MBC) are well known mechanisms that contribute to the decrease in intracellular concentrations of many unrelated but cytotoxic compounds. In the present work, we have carried out comparative investigations of the MDR/MXR protective mechanisms using a rapid colorimetric assay for cell viability and calcein accumulation for MDR/MXR activities. These studies were performed using cultured MCF7 and MBC before and after in vitro exposure to xenobiotics. Our results indicate that a 5-day exposure to doxorubicin or vincristine decreased calcein accumulation in MBC which is consistent with an induction of multi-xenobiotic resistance. The increase in calcein accumulation provoked by 1-h treatment with 50 microM verapamil was much lower in MBC when compared to the P-glycoprotein overexpressing MCF7 cell line. We conclude that such microplate assays could be used in primary cultures of MBC to estimate the effects of various chemicals on MXR activity.     

晚弗拉斯期缺氧事件——弗拉斯-法门阶动物危机的原因？

弗拉斯-法门期(晚泥盆世)动物灭绝事件是显生宙五次主要生物事件中的一次，在此事件中，大约有21％的海洋生物科和50％的生物属消亡，低纬度热带生物礁生态系和浅水海洋动物所受影响最为严重，而高纬度生态系，深水生物和陆地动、植物群仅受到微弱影响，对于该事件的持续时期和最终原因存在广泛分岐。     

长江口可溶态210Pb的来源、分布和逗留时间

于１９８６年１月，采取大体积取样，Ｃｏ－ＡＰＤＣ螯合并沉淀富集分离，银片上自沉积和ａ－计算分析，研究长江口区可溶态２１０Ｐｂ的来源，分布和逗留时间。结果表明，全区平均放射性比度为７．５ｄｐｍ／ｍ＾３，从河向海纵向分布呈口内段和近外海两端高，而低谷出现在中间的口门外最大浊度及稀释带高生产力区。２１０Ｐｂ明显因悬浮颗粒物的吸附絮凝沉降和浮游生物的吸收利用被清除。经探析，该区２１０Ｐｂ主要来源是大气气溶     

Bioaccumulation and depuration of Zn and Cd in mangrove oysters (Crassostrea rhizophorae, Guilding, 1828) transplanted to and from a contaminated tropical coastal lagoon

In order to study Zn and Cd accumulation and depuration, a set of oysters, Crassostrea rhizophorae, were transplanted to a metal contaminated coastal lagoon and another one was harvested there and transplanted to a non-polluted site. C. rhizophorae oysters and Perna perna mussels native from both sites were collected in order to monitor variability of metal concentration in resident populations. After three months exposure, oysters transplanted to the polluted site accumulated fourfold Zn (307-1319 microgg(-1)) without reaching the concentration level of resident oysters (9770 microgg(-1)). Cadmium concentrations had a slight but significant decrease during the same period (1.25-0.54 microgg(-1)). Oysters transplanted to the non-polluted site, showed threefold Zn depuration (6727-2404 microgg(-1)), while Cd had no significant variation (0.90-1.45 microgg(-1)). Results showed that transplanted oysters do not reach heavy metal concentrations in indigenous populations suggesting transplanted organisms would be better used to evaluate bioavailability instead of environmental concentrations.     

两种涡鞭毛藻生长特性的研究

运用单种培养的方法研究了分别于１９８７年和１９８９年采自葡萄牙沿海和德国湾的两种赤潮涡鞭毛藻Ａｌｅｘａｎｄｒｉｕｍ ｌｕｓｉｔａｎｉｃｕｍ（Ａ．Ｌ．）和Ｙ－１００在不同光、温、盐条件下的生长特性，结果表明，在较低温度条件下，藻的生长在较低的光照强度时就显示了光饱和现象；在较高温条件下，藻的生长随光照增加而加快，两种藻生长的最适温度随光照强度增加而增加，在低于最适温度条件下生长速率都随温度升高而加快     

环境样品中铈,钇和钍的测定

以下介绍海水、孔隙水,悬浮物,沉积物和生物群中Ce、Y和Th 的测定方法。该法包括用Mg(OH)_2和 CaC_2O_4双共沉淀法以便预富集海水和孔隙水中的Ce,Y和Th,同时在敞开容器进行酸溶以使沉积物、悬浮物和生物群溶解。用电感耦合等离子体原子发射光谱法进行测定。在不同步骤用放射示踪剂(~(144)Ce、~(88)Y和~(228)Tn)检验方法的化学效率。获得了生物群和沉积物(水)中的检测极限为 Ce,44ngg~(-1)(0.005ngml~(-1)),Y,0.62ngg~(-1)(0.0003ngml~(-1))和 Th。15ngg~(-1)(0.003ngml~(-1))。给出了从第勒尼安(Tyrrhenian)海收集到的海水、孔隙水、悬浮物、沉积物和生物群样品中 Ce、Y 和 Th 的测定结果。获得了各种海洋环境样品中的 Ce、Y 和Th 的高富集因子和回收率。采用较大数量的样品,以增大富集因子并改善检测极限。     

Meiofauna as descriptor of tourism-induced changes at sandy beaches

Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.     

A growth model for a hyalid amphipod Hyale perieri in the coastal water of Alexandria (Egypt)

Abstract-The growth rate of the hyalid amphipod Hyale perieri was studied on the bases of Ikeda'sgrowth model which is based on the inter moult period (IP) and moult increament (ΔBL). To applythis approach, laboratory experiments were carried out at three temperatures regimes (15℃, 20℃,25℃) to gain accurate data of IP and BL. The total number of specimens used in this study was 86 at15℃, 24 at 20℃ and 70 at 25℃. The number of flagellar segments of both antennae of the Hyaleperieri could not be used as an index of growth (instar criterion). The obtained results indicated that,the predicted IP of the specimens was inversely related to temperature and in good agreement with theobserved values at the experimental temperatures. IP data obtained from laboratory-reared specimes arecombined with ΔBL data to establish a growth model for Hyale perieri from its release from the mar-supium (1.64 mm BL) to the maximum size (12.67 mm BL) as a function of temperature. The maxi-mum numbers of consecutive moults