Generation of reactive oxygen species in different fractions of the coelomocytes of holothurian Eupentacta fraudatrix in response to the thermostable toxin of Yersinia pseudotuberculosis in vitro     

Dolmatova L. S.  Eliseykina M. G.  Timchenko N. F.  Kovaleva A. L.  Shitkova O. A. 《中国海洋湖沼学报》2003,21(4):293-304

Pure fraction (92%–95%) of phagocytes (FP) and a mixture of amoebocytes (62%) and morula cells (38%)-FPMC- of the holothurianEupentacta fraudatrix' (Holothuroidea, Dendrochirota) were obtained by using ficoll-verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin ofYersinia pseudotuberculosis (TST) at different concentrations (0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in concentration-dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 h treatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5-fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians. This work was financially supported by the Russian Foundation for Fundamental Research Grant (No. 00-04-48949).  相似文献   

Potential protostars in cloud cores     

Robert L. Hurt  Mary Barsony  Alwyn Wootten 《Astrophysics and Space Science》1995,224(1-2):489-490

We present H₂CO observations of young protostar candidates in the Serpens Cloud Core. We find evidence for dense molecular gas in the cores of these objects that is warmer than the surrounding dust. The strong emission and gas properties support the premise that many of these sources may be very young protostars.  相似文献   

甲醛标准储备液浓度的不确定度评定     

陈志清  辛运菊  梅祖明 《岩矿测试》2008,27(1):45-48

讨论了影响甲醛标准溶液浓度标定值不确定的各种因素,并评定了甲醛标准溶液浓度标定值的不确定度。当甲醛标准溶液浓度为1058 mg/L时,它的相对标准不确定度为0.70%(K=2)。  相似文献   

Response of antioxidant systems to copper in the gills of the clam Ruditapes decussatus     

Florence Geret  Angela Serafim  Luisa Barreira  Maria Joo Bebianno 《Marine environmental research》2002,54(3-5)

Copper (Cu) is an essential element for biological systems, however, when present in excess, is toxic. Metallothioneins can play an important role in Cu homeostasis and detoxification. Moreover, Cu can catalyse the production of toxic hydroxyl radicals that cause lipid peroxidation but defence systems in the cells can limit the oxidative damage. The present study was performed to investigate the effect of three Cu concentrations (0.5, 2.5 and 25 μg l⁻¹) on the response of antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathion peroxidase and total glutathion peroxidase), total proteins, metallothioneins (MT), malondialdehyde (MDA) concentrations in the gills of the clam, Ruditapes decussatus. The activity of antioxidant enzymes and total proteins, MT and MDA concentrations were measured in the gills of the clams after 1, 3, 7, 14, 21 and 28 days of Cu exposure. Results indicate that Cu only induces an imbalance in the oxygen metabolism during the first week of Cu exposure due to a decrease in mitochondrial SOD and CAT, selenium-dependent and total glutathion peroxidase activities. Cu also causes lipid peroxidation, measured by the MDA formation, that was Cu dependent. In the gills of clams exposed to 25 μg Cu/l, the excess of Cu triggers the induction of MT synthesis after 3 days of exposure.  相似文献   

三丁基锡对牡蛎吞噬细胞和保护酶系统活力的影响          下载免费PDF全文

李张伟  韩雅莉  李平 《海洋科学》2007,31(12):38-42

检测了受三丁基锡(tributyltin,TBT)污染的牡蛎的吞噬细胞活力、超氧化物歧化酶活性、过氧化氢酶活性、脂质过氧化作用等生理生化指标。实验结果表明,牡蛎血细胞的吞噬活力随着TBT浓度的增加而下降;对不同TBT浓度下牡蛎的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性测定发现,在较低浓度下(TBT质量浓度<10μg/L),SOD和CAT的酶活力被抑制,随着TBT浓度的增大,SOD和CAT的比活力也随着增大,但当TBT达到较高浓度时,SOD和CAT的比活力开始下降,而过氧化脂质(LPO)却随着TBT的浓度的增加而增大。  相似文献   

SiO2-TiO2薄膜制备及其光催化性能研究     

李发亮  张定国刘芬 《华东地质学院学报》2005,28(4):377-380

Sol-gel法制备SiO2-TiO2复合薄膜，进行甲醛的光催化降解实验，研究了SiO2掺杂量、薄膜焙烧温度、甲醛溶液pH值及初始浓度对光催化性能的影响。结果表明，500℃焙烧1h，掺杂质量SiO2：TiO2=12：100时，SiO2-TiO2薄膜的光催化活性最高，150min后甲醛降解率达76％，是单纯TiO2薄膜的1．3倍，该薄膜稳定性较好，经重复8次使用，最大降解率只下降4％。  相似文献   

Measurements of tropospheric OH concentrations: A comparison of field data with model predictions     

D. Perner  U. Platt  M. Trainer  G. Hübler  J. Drummond  W. Junkermann  J. Rudolph  B. Schubert  A. Volz  D. H. Ehhalt  K. J. Rumpel  G. Helas 《Journal of Atmospheric Chemistry》1987,5(2):185-216

Using long path UV absorption spectroscopy we have measured OH concentrations close to the earth's surface. The OH values observed at two locations in Germany during 1980 through 1983 range from 0.7×10⁶ to 3.2×10⁶ cm^-3. Simultaneously we measured the concentrations of O₃, H₂O, NO, NO₂, CH₄, CO, and the light non methane hydrocarbons. We also determined the photolysis rates of O₃ and NO₂. This allows calculations of OH using a zero dimensional time depdendent model. The modelled OH concentrations significantly exceed the measured values for low NO _x concentrations. It is argued that additional, so far unidentified. HO _x loss reactions must be responsible for that discrepancy.  相似文献   

The tropospheric distribution of formaldehyde during TROPOZ II     

D. W. Arlander  D. Brüning  U. Schmidt  D. H. Ehhalt 《Journal of Atmospheric Chemistry》1995,22(3):251-269

A series of 149 measurements of the HCHO mixing ratio were made between 0 and 10 km altitude and 70° N to 60° S latitude during TROPOZ II. The data show a vertical decrease of the HCHO mixing ratio with altitude at all latitudes and a broad latitudinal maximum in the HCHO mixing ratio between 30° N and 30° S at all altitudes. The measured mixing ratios of HCHO are considerably higher than those expected from CH₄ oxidation alone, but agree broadly with the average latitude by altitude distribution of HCHO derived by a 2D model including emissions of C₁–C₇ hydrocarbons. A number of the regional scale deviations of the measured HCHO distribution from the average modelled one can be explained in terms of the local wind field.  相似文献   

Transcript profiles of mitochondrial and cytoplasmic manganese superoxide dismutases in Exopalaemon carinicauda under ammonia stress     

任海  李健  李吉涛  刘萍  梁忠秀  吴建华 《中国海洋湖沼学报》2015,33(3):714-724

  相似文献   

栉孔扇贝不同组织SOD、CAT和MPO活力的比较分析   总被引：4，自引：0，他引：4  

费来华  邵雁群  李赟 《海洋湖沼通报》2008,(3)

对2龄和3龄栉孔扇贝外套膜、鳃、消化盲囊、肾、闭壳肌、性腺组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和髓过氧化物酶(MPO)活力分析表明,检测组织均存在这三种酶,且在不同组织中活力表现存在明显差别,其中肾组织SOD、CAT活力最高,而MPO在消化盲囊中表现最高活力,与其它组织相比均呈显著性差异(P＜0.05).不同贝龄的栉孔扇贝酶活力比较表明,三龄贝各组织SOD、CAT和MPO活力均高于二龄贝.  相似文献