三门湾大型底栖动物时空分布及其与环境因子的关系

2006年11月、2007年1月、4月和8月在三门湾18个采样点对大型底栖动物进行调查,分析了其时空分布及其与环境因子的关系.结果表明:调查共采集到大型底栖动物124种,其中多毛类44种、软体动物34种、甲壳动物22种、棘皮动物11种、其他类动物13种;多毛类和软体动物种数占总种数的62.9％,二者构成了三门湾大型底栖动物的主要类群.双鳃内卷齿蚕、小头虫和不倒翁虫是春季三门湾大型底栖动物的优势种;不倒翁虫、双鳃内卷齿蚕和海稚虫为夏季的优势种;不倒翁虫、小头虫、双鳃内卷齿蚕和白沙箸为秋季的优势种;双鳃内卷齿蚕、不倒翁虫、小头虫和海稚虫为冬季的优势种.三门湾大型底栖动物年均生物量为17.36 g·m-2,年均栖息密度为72 ind·m-2.不同季节大型底栖动物的平均生物量和平均栖息密度存在显著性差异.大型底栖动物群落平均Shannon多样性指数在1.53 ～ 1.89,平均Margalef物种丰富度指数在2.25 ～2.96,平均均匀度指数在0.83 ～0.94,3个指数在不同季节间均存在显著性差异.经典范对应分析,影响三门湾大型底栖动物群落的主要环境因子包括海水的温度、盐度、溶解性无机氮以及表层沉积物中的有机质、总氮和总磷等,环境变量可以较好地解释主要类群的变化.     

南韭山周围海域大型底栖动物种类与分布

2011 年12 月-2013 年1 月对南韭山周围海域15 个站位进行了大型底栖动物分布状况调查, 共获得大型底栖动物59 种, 其中甲壳类20 种, 鱼类14 种, 软体动物11 种, 腔肠动物6 种, 其他类动物8 种。相比于国内其他海域,数量处于较低水平。从平面布局上来看, 种数分布呈自北向南和由近岸(西部)向外海(东部)逐渐增多的趋势。各季节出现种类, 夏季34 种, 春季28 种, 秋季27 种, 冬季为19 种。优势种及特征种年均更替率分别是78.75%与82.78%, 表明南韭山海域大型底栖动物种类组成和群落结构季节更替显著。同2005-2006 年相比, 优势种组成变化较大, 优势种数量有所增加, 且个别种类优势度较高, 表明南韭山海域大型底栖动物的群落结构发生了较大程度的变化。     

乳山湾潮间带春季大型底栖动物群落结构

于2011年5月对乳山湾潮间带8条断面的大型底栖动物进行了定量调查,共鉴定出大型底栖动物116种,其中多毛类58种、软体动物15种、甲壳类27种、棘皮动物3种,其他动物13种.调查潮间带大型底栖动物的平均丰度为872.6 ind·m-2,平均生物量为9.37g·m-2,根据相对重要性指数(IRI)计算优势种为中蚓虫、沈氏厚蟹、纽虫和刺沙蚕等.丰富度指数(d)、多样性指数(H)和均匀度指数(J)平均值分别为2.119、2.384和0.608,为轻度污染海域.以30%的相似性尺度,可将所调查潮间带8个断面划分为3个群落.与同纬度海湾潮间带相比,乳山湾潮间带大型底栖动物具有种数多、个体小、丰度高的特点,仅从大型底栖动物群落结构和多样性指数方面不足以证实该海域贝类养殖对环境产生扰动并对底栖动物群落造成影响,还需要进行更深入的调查研究来综合判断.     

三门湾大型底栖动物群落结构及其与环境因子的关系

为了解三门湾大型底栖动物群落的现状和动态变化,分别于2015年11月、2016年2月、5月和8月在三门湾海域用阿氏拖网对大型底栖动物进行调查。结果表明: 经鉴定,大型底栖动物有119种,主要类群为鱼类、甲壳类和软体动物,占种类总数的79%。大型底栖动物全年优势种为细螯虾、长额超刺糠虾和六丝钝尾虾虎鱼,不同季节优势种的变化明显,种类差异性较大。大型底栖动物的年平均生物量和平均栖息密度分别为0.025 g·m^-2和0.07 ind·m^-2。三门湾大型底栖动物各季节的Shannon多样性指数为2.21～3.18,Margalef物种丰富度指数为3.25～3.78,Pielou均匀度指数为0.53～0.79。ABC曲线分析显示,在春季和冬季,群落受到中等程度干扰;而在夏季和秋季,群落受到轻微扰动。典范对应分析结果显示,水深、温度、盐度和pH值是影响大型底栖动物群落的最主要环境因子。     

浙江韭山列岛岩礁潮间带大型底栖动物群落特征和功能性状

根据2017年9月和2018年9月对韭山列岛岩礁潮间带大型底栖生物的调查资料,分析了韭山列岛岩礁潮间带大型底栖动物的群落组成和结构特征,包括群落种类组成、丰度、生物量、优势种和功能性状等,并对大型底栖动物群落进行聚类和排序.本次调查共鉴定出大型底栖动物25种,其中软体动物18种,甲壳动物6种,刺胞动物1种.韭山列岛潮间...     

江苏潮间带大型底栖动物群落组成及次级生产力

为研究江苏潮间带大型底栖动物资源变动状况,于2014年5月、8月、10月和2015年3月在江苏潮间带布设9条断面开展了4个航次的调查。结果表明:共采集潮间带大型底栖动物78种,其中环节动物39种,软体动物为23种,甲壳动物12种,其他类群4种;年平均丰度78.64 ind·m-2,年平均生物量13.01 g (AFDM)·m~(-2),年平均次级生产力和P/B值分别为8.57 g (AFDM)·m~(-2)·a~(-1)和0.66;与20世纪80年代江苏滩涂调查和"908"专项调查相比,江苏潮间带大型底栖动物主要类群未发生变化,均以环节动物、软体动物和甲壳动物为主,种类数量有所下降;江苏潮间带大型底栖动物平均次级生产力中潮区与高、低潮区间差异显著(P 0.05),季节间无显著差异(P 0.05)。     

黄河口潮间带大型底栖动物群落特征

2013年2月、5月和8月对黄河入海口附近潮间带的大型底栖动物进行了调查,调查工作涵盖3个季节2条断面的样品,分析了黄河口潮间带大型底栖动物的群落结构特征,包括群落种类组成、丰度和生物量、优势种、多样性,采用CLUSTER聚类分析了大型底栖动物的群落结构,并用AMBI和m-AMBI对底栖群落和环境质量进行了评估。本次调查共鉴定出大型底栖动物52种,其中,多毛纲动物24种,软体动物14种,甲壳动物12种,鱼类1种,纽虫1种。多毛纲动物为该海域底栖群落的主要成分,占据了群落总种数的46.15%。从季节来看,物种数春季最高(38种),夏季则处于最低水平(16种)。群落丰度和生物量均具有明显的季节变化,丰度在春季达到最高,为3 549.33 ind/m2,远高于冬季的256.67 ind/m2和夏季的100.67 ind/m2,其中扁玉螺(Neverita didyma)是丰度的主要贡献者,贡献了全年群落总丰度的75.44%。生物量春季最高,夏季次之,冬季最低。在全年尺度上,甲壳动物的日本大眼蟹(Macrophthalmusjaponicus)是生物量的主要贡献者,占据总生物量的49.86%。群落的季节变化也得到了群落CLUSTER分析与SIMPER分析结果的验证。这与黄河入海口附近底质不稳定,易受侵蚀、环境条件如盐度等具有明显季节差异,以及一定程度的人为扰动密切相关。AMBI和m-AMBI的分析结果显示,该区域环境质量状况较好,仅受到了轻微扰动影响。     

瓯江口海域大型底栖动物分布及其与环境的关系

对瓯江口及邻近海域大型底栖动物进行了春（2006年5月）、冬（2007年1月）两季的调查,分析了研究区大型底栖动物的季节分布及其与环境的关系.结果表明：共鉴定出大型底栖动物65种,多毛类和软体动物是该海域大型底栖动物的主要类群;春季,小头虫的优势度最高,冬季,红带织纹螺的优势度最高;研究区大型底栖动物的种类分布为河口区＜邻近海域、冬季＜春季;该区大型底栖动物两季平均生物量和栖息密度分别为19.66 g·m^-2和131 ind·m^-2,春、冬季的密度差异显著,但生物量差异不显著;春冬两季研究区大型底栖动物的Shannon-Weiner指数差异显著,Pielou均匀度指数、Margalef种类丰富度指数和Simpson优势度指数的差异不显著.春季,温度和浮游植物是影响研究区大型底栖动物类群的主要环境因子,冬季的主要影响因子为总有机碳和溶解氧.     

椒江口化工园区及其邻近区域潮间带大型底栖动物秋冬季分布特征

为了解椒江口化工园区及其邻近区域潮间带大型底栖动物分布特征,评价工厂排污对河口潮间带大型底栖动物生态的影响范围及程度,在椒江口共设置6条潮间带采样断面,于2007年10月和2008年1月进行了大型底栖动物野外调查.研究结果如下:(1) 秋冬两季共采集到大型底栖动物75种,其中秋季64种,冬季29种;(2) 物种数呈现河口外断面高于河口内断面的变化趋势;(3) 在各断面软相基质站位,化工园区及其邻近区域的大型底栖动物物种组成差异较大,栖息密度和生物量差异不显著;(4) 与国内其他河口近几年的调查数据相比,椒江口潮间带发现的大型底栖动物种数较高,且存在开敞型河口潮间带大型底栖动物种数大于内湾河口潮间带的现象.     

庙岛群岛南部海域大型底栖动物多样性

为了解庙岛群岛南部海域大型底栖动物群落多样性变化,我们在该海域设置了11个站位,于2012年11月、2013年2月、5月、8月共进行了4个航次的调查,对该海域大型底栖动物的生物多样性变化、种类组成以及优势种等进行了分析。在研究海域共采集到大型底栖动物164种,包括环节动物多毛类82种,节肢动物甲壳类38种,软体动物30种,棘皮动物9种,其他类群5种。各站位种类数在6–42种之间。物种数冬夏较多、春季较少。各站位Shannon-Wiener多样性指数未呈现明显的季节性变化;均匀度指数春夏最高;而丰富度指数春夏两季最低。沉积物中有机质与叶绿素含量是影响大型底栖动物多样性的主要因素。丰度–生物量比较曲线(ABC曲线)结果表明,位于庙岛与北长山岛之间的C13站、毗邻庙岛的C17站和C28站的底栖动物群落受到了中等程度的扰动,其余站位未受到明显扰动。     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Production of arsine and methylarsines in soil and in culture

Arsenate, arsenite, monomethylarsonate, and dimethylarsinate were added to different soils, and evolution of gaseous arsenical products was determined over 3 weeks. Arsine was produced in all three soils from all substrates, whereas methylarsine and dimethylarsine were produced only from methylarsonate and dimethylarsinate, respectively. At least three times more arsine than dimethylarsine was produced in soil incubated with dimethylarsinate. Resting cell suspensions of Pseudomonas and Alcaligenes produced arsine as the sole product when incubated anaerobically in the presence of arsenate or arsenite. In all instances, no trimethylarsine was observed, nor could any evidence be shown for the methylation of any arsenical substrate in soil or in culture. It was concluded that reduction to arsine, not methylation to trimethylarsine, was the primary mechanism for gaseous loss of arsenicals from soil.     

Development and comparison of in vivo and in vitro models for endometritis in cows and mares

In order to investigate pathogenic mechanisms of acute endometritis in cows and mares, we established an in vivo model in both species. Based on the results of an in vitro transmigration system, human recombinant interleukin-8 (rhIL-8; 1.25 microg per mare and 5 microg per cow in 50 ml phosphate-buffered saline) was used to attract polymorphonuclear neutrophil granulocytes (PMNs) into the uteri. Peak numbers of uterine neutrophils were attracted after 6h, in both cows and mares. On average, mares responded more sensitively than cows, with 15 times higher numbers of rhIL-8-attracted uterine neutrophils (72+/-8 x 10(7)cells). In contrast to in vitro studies, in vivo migrated neutrophils (uterine neutrophils) of both species displayed a significantly reduced MHC class I expression. Expression of the CD11a molecule was significantly enhanced on equine uterine neutrophils but downregulated on bovine cells. Compared with untreated autologous peripheral neutrophils, both uterine and in vitro migrated neutrophils showed no alteration of phagocytic capacity. The ability to generate reactive oxygen species (ROS) was significantly upregulated in bovine and equine uterine neutrophils. This was also observed after in vitro migration of equine neutrophils, whereas ROS generation by bovine neutrophils was significantly depressed. In summary, the concept of inducing endometritis directly by local application of human interleukin-8 has been reliably successful in cows and mares. The model permits the analysis of PMN migration into the uterus under defined and controlled conditions. The observed differences between cows and mares with respect to phenotypical and functional characteristics of in vivo attracted uterine cells point to species-related features of neutrophil migration. In vitro transmigrated bovine and equine cells partially differ in phenotype and function from uterine neutrophils. Therefore, the in vitro transmigration assay cannot completely represent the in vivo endometritis model described here.     

Interactions of cadmium and selenium in rat plasma in vivo and in vitro

⁷⁵Se and ¹⁰⁹Cd tracers were used to study the binding of Se and Cd to plasma proteins at various SeO₃^2? doses and times up to 24 h after the simultaneous subcutaneous administration of SeO₃^2? and CdCl₂ to adult male rats. The simultaneous injection of CdCl₂ and SeO₃^2? markedly increased both Se and Cd plasma levels over that in control animals. Gel permeation chromatography of plasma indicated that at all times up to 24 h Cd and Se were bound in an atomic ratio of approx. 1 : 1 in 330 000 and 130 000 dalton fractions. From 4 to 24 h, Cd and Se appeared in the 420 000 dalton fraction, also with an atomic ratio of approx. 1 : 1. The 330 000 dalton molecules appeared to have a maximal binding capacity for the Cd-Se complex at a concentration of approx. 30 μmol/ml of plasma, while the 130 000 and 420 000 dalton molecules show a higher binding capacity. Studies in vitro revealed that SeO₃^2? does not interact directly with Cd and plasma proteins. It is metabolized by erythrocytes to a form that interacts in an atomic ratio of 1 : 1 with Cd to form a protein-bound complex of 130 000 daltons.     

Activity of native and dextran-modified hyaluronidase in in vitro and in vivo systems

Modified hyaluronidase derivatives have been obtained. Covalent coupling of the enzyme with aldehyde dextran results in 65-85% protein binding to the carrier, residual catalytic activity accounting for 90-100% of the baseline. Modified hyaluronidase is more thermostable than the native enzyme. The data on intravenous drug distribution in the mouse organs are promising and ensure effective use of modified hyaluronidase for the treatment of pulmonary diseases.     

Importance of guanine nitration and hydroxylation in DNA in vitro and in vivo

Guanine (Gua) modification by nitrating and hydroxylating systems was investigated in DNA. In isolated calf thymus DNA, 8-NO(2)-Gua and 8-oxo-Gua were dose-dependently formed with peroxynitrite, and 8-NO(2)-Gua was released in substantial amounts. Myeloperoxidase (MPO) with H(2)O(2) and NO(2)(-) reacted with calf thymus DNA to form 8-NO(2)-Gua dose dependently without release of 8-NO(2)-Gua. The frequency of strand breaks was higher than the sum of 8-NO(2)-Gua and 8-oxo-Gua, particularly in the MPO-treated DNA, indicating the importance of other types of damage. The activation of human neutrophils and lymphocytes with phorbol ester did not induce 8-NO(2)-Gua and 8-oxo-Gua in their nuclear DNA. However, 8-NO(2)-Gua was found in calf thymus DNA co-incubated with activated neutrophils in the presence of NO(2)(-). No significant formation of 8-NO(2)-Gua was found in liver DNA from mice treated with Escherichia coli lipopolysaccharide. The incubation of peroxynitrite or MPO-H(2)O(2)-NO(2)(-)-treated DNA with formamidopyrimidine glycosylase (Fpg) released 8-oxo-Gua, but not 8-NO(2)-Gua, indicating that 8-NO(2)-Gua is not a substrate for Fpg. Although 8-NO(2)-Gua was generated in isolated DNA by different nitrating systems, other types of damage were formed in abundance, and the lesion could not be found reliably in nuclear DNA, suggesting that the biological importance is limited.     

Biosynthesis of beta-glucuronides of retinol and of retinoic acid in vivo and in vitro

After the intraportal injection of retinol-6,7-(14)C to rats, the O-ether derivative of retinol, retinyl -glucosiduronate, appears in the bile. Both retinoyl -glucuronide and retinyl -glucosiduronate are also synthesized in vitro when washed rat liver microsomes are incubated with uridine diphosphoglucuronic acid (UDPGA) and either retinoic acid or retinol, respectively. The synthesis of retinoyl -glucuronide was also demonstrated in microsomes of the kidney and in particulate fractions of the intestinal mucosa. The glucuronides were characterized by their UV absorption spectra, by their quenching of UV light or fluorescence under it, by their thin-layer chromatographic behavior in two solvent systems, and by the identification of products released during their hydrolysis by -glucuronidase. With retinoic acid as the substrate, the UDP glucuronyl transferase of rat liver microsomes had a pH optimum of 7.0, a temperature optimum of 38 degrees C, and a marked dependence on the concentrations of both retinoic acid and UDPGA, but was unaffected by a number of possible inhibitors, protective agents, and competitive substrates. The conversion of retinal to retinoic acid and the synthesis of retinoyl -glucuronide from retinoic acid could not be detected in whole homogenates, cell fractions, or outer segments of the bovine retina.