Characterization of Communities of Heterotrophic Bacteria Associated with Healthy and Diseased Corals in Nha Trang Bay (Vietnam)

A comparative investigation of the heterotrophic microflora of 11 species of healthy corals and of white-band-diseased and yellow-band-diseased corals inhabiting the reefs of Nha Trang Bay (Vietnam), which has been exposed to anthropogenic impact, was performed. Fifty-nine strains of heterotrophic bacteria isolated on Y/K and Endo media were investigated and characterized. All the isolates were identified at the genus level by consideration of the results of analysis of their phenotypic properties, determination of the molar percent of G+C bases in their DNA, and the composition of the fatty acids of lipids. In the composition of the microflora of tissues of healthy corals, γ-proteobacteria prevailed, with halomonads being dominant among them. In addition, the gram-negative bacteria included Pseudomonas and Vibrio spp., members of the Cyto-phaga-Fla-vobacterium-Bacteroides (CFB) phylogenetic cluster, and Moraxella sp. The gram-positive bacteria revealed included Bacillus, Staphylococcus, Halococcus, and Micrococcus spp., and coryneform bacteria. In the composition of the microflora of the tissues of affected corals, bacteria of the family Enterobacteriaceae and of the genera Planococcus and Arthrobacter, which were not revealed in healthy hydrobionts, were found. The anthropogenic impact is not the sole factor determining the infection of corals.     

Fetuin-A and Albumin Alter Cytotoxic Effects of Calcium Phosphate Nanoparticles on Human Vascular Smooth Muscle Cells

Calcification is a detrimental process in vascular ageing and in diseases such as atherosclerosis and arthritis. In particular, small calcium phosphate (CaP) crystal deposits are associated with inflammation and atherosclerotic plaque de-stabilisation. We previously reported that CaP particles caused human vascular smooth muscle cell (VSMC) death and that serum reduced the toxic effects of the particles. Here, we found that the serum proteins fetuin-A and albumin (≥1 µM) reduced intracellular Ca²⁺ elevations and cell death in VSMCs in response to CaP particles. In addition, CaP particles functionalised with fetuin-A, but not albumin, were less toxic than naked CaP particles. Electron microscopic studies revealed that CaP particles were internalised in different ways; via macropinocytosis, membrane invagination or plasma membrane damage, which occurred within 10 minutes of exposure to particles. However, cell death did not occur until approximately 30 minutes, suggesting that plasma membrane repair and survival mechanisms were activated. In the presence of fetuin-A, CaP particle-induced damage was inhibited and CaP/plasma membrane interactions and particle uptake were delayed. Fetuin-A also reduced dissolution of CaP particles under acidic conditions, which may contribute to its cytoprotective effects after CaP particle exposure to VSMCs. These studies are particularly relevant to the calcification observed in blood vessels in patients with kidney disease, where circulating levels of fetuin-A and albumin are low, and in pathological situations where CaP crystal formation outweighs calcification-inhibitory mechanisms.     

Effects of dimethylsulfoxide on the ultrastructure of fixed cells

It has been reported that the use of dimethylsulfoxide (DMSO) as a solvent for fixatives enhances preservation of cellular ultrastructure. By contrast, we have shown that DMSO alters the ultrastructural integrity of glutaraldehyde fixed cells. The cell membrane, nuclear envelope, endoplasmic reticulum, ribosomes, microtubules and intracytoplasmic organelles are most susceptible to the action of DMSO. We hypothesize that DMSO exerts intracellular alterations via its interaction with remnant interfacial water in fixed cells. DMSO-induced alterations of these and related cellular components may result in the formation of artefactual structures and networks. Thus, it appears that DMSO containing glutaraldehyde neither accelerates fixation nor enhances stabilization of cellular ultrastructure. For these reasons, addition of DMSO to fixatives is not recommended.     

应用RNA干扰技术调节大鼠c-jun基因的表达

目的:应用RNA干扰(RNAi)技术调节大鼠c-jun基因在Cos-7细胞中的表达.方法:分别构建大鼠c-jun基因的RNA干扰载体和真核表达GFP(绿色荧光蛋白)载体,将两者共转染Cos-7细胞,镜下观察大鼠C-Jun-GFP融合蛋白的表达,应用Western blot方法检测抑制效率.结果:酶切和测序结果表明,大鼠c-jun基因的RNA干扰载体和真核表达GFP载体构建成功,镜下及Western blot共转染结果均显示随着RNA干扰载体浓度的增加C-Jun-GFP融合蛋白表达量逐渐减少.结论:在Cos-7细胞中应用RNAi技术成功调节大鼠c-jun基因的表达.     

拟巫山淫羊藿的megastigmane糖苷和苯丙醇类成分

为了解拟巫山淫羊藿(Epimedium pseudowushaneseB. L. Guo)的化学成分,其从地上部分水提物中分离得到2个megastigmane糖苷和4个苯丙醇类化合物。通过波谱分析,分别鉴定为淫羊藿次苷B6(1)、megastigman-5-ene-3,9-diol 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2)、丁香酚芸香糖苷(3)、2-羟基-1-(4-羟基-3,5-二甲氧基苯基)-1-丙酮(4)、2,3-二羟基-1-(4-羟基-3,5-二甲氧基苯基)-1-丙酮(5)、2,3-二羟基-1-(4-羟基-3-甲氧基苯基)-1-丙酮(6)、二氢松柏基醇γ-O-α-L-鼠李糖苷(7)。其中化合物2和7为新化合物,所有化合物均为首次从拟巫山淫羊藿中分离得到。     

Gorgonians (Anthozoa: Octocorallia) of the northwestern Sea of Japan

Three species of gorgonians (Primnoa pacifica, Calcigorgia japonica, and Thouarella superba) are reported as new records for the northwestern Sea of Japan; one of them (Calcigorgia japonica sp. n.) has been described as a new species. Variations of colony morphology in some species are described; the taxonomical value of specific characters is discussed. The geographical range of Primnoa pacifica in the northwestern Pacific is shown to be wider than was considered earlier. Variations of sclerite morphology (number of marginal plates, presence of additional basal plates, and number of marginal spines on the basal plate) are regarded as intracolonial or intraspecific variability. The distribution range of Thouarella superba described earlier from the Aleutian Islands (Nutting, 1912) was shown to extend into the low-boreal part of the boreal Pacific. An examined specimen of Paragorgia sp. differed from all known species and appeared similar only to P. regalis Nutting, 1912 reported from the eastern coast of Japan. The most distinctive characters of Calcigorgia japonica sp. n. were the shape of polyp, with a thin lower part looking like folded podia (in fixed specimens) and the presence of two types of clubs scattered among the sclerites of the polyp.     

Comparison of fatty acid compositions of azooxanthellate Dendronephthya and zooxanthellate soft coral species

Ten zooxanthellae-free Dendronephthya species , twelve zooxanthellate soft coral species of the genera Sarcophyton, Lobophytum, Cladiella, Lytophyton, Cespitularia, and Clavularia, and the hermatypic coral Caulastrea tumida were examined for the first time to elucidate the fatty acid (FA) composition of total lipids. In Dendronephthya species, the main FAs were 20:4n-6, 24:5n-6, 16:0, 18:0, 7-Me-16:1n-10, and 24:6n-3 which amounted on the average to 26.0, 12.7, 12.1, 6.0, 4.8, and 4.0% of the total FA contents, respectively. For zooxanthellate soft corals, the main FAs were 16:0 (25.7%), 20:4n-6 (18.2%), 24:5n-6 (6.2%), and 18:4n-3 (5.6%), as well as 16:2n-7, which amounted up to 11.8% in Sarcophyton aff. crassum. Corals with zooxanthellae had low contents of 24:6n-3. The significant difference (p<0.01) between azooxanthellate and zooxanthellate soft corals was indicated only for 12 of 46 FAs determined. The principal components analysis confirmed that 7-Me-16:1n-10, 17:0, 18:4n-3, 18:1n-7, 20:4n-6, 22:5n-6, 24:5n-6, and 24:6n-3 are useful for chemotaxonomy of Dendronephthya. The azooxanthellate soft corals studied were distinguished by the absence of significant depth-dependent and species-specific variations of FA composition, low content of 16:2n-7, an increased proportion of bacterial FAs, predominance of n-6 FAs connected with active preying, and a high ability for biosynthesis of tetracosapolyenoic FAs.     

天津市自然保护地与区域生境质量的时空演变格局

生境质量是反映区域生物多样性水平的重要指标,而规划科学、管理有效的自然保护地对于维护生境质量、巩固区域生态安全具有重要作用。以天津市为例,运用InVEST模型Habitat Quality模块评估了天津市2000、2005、2010、2015、2018年生境质量时空变化格局,基于叠加分析自然保护地内外生境质量变化探讨自然保护地对维护区域生境质量发挥的作用。结果表明：(1)2000—2018年间天津市生境质量总体下降了13.18%,并呈现出明显的由中心城区向环城四区扩散的趋势,高质量区域仅占天津陆域国土面积的4%,主要分布在天津北部山区和于桥水库、团泊洼、北大港、大黄堡等湿地。(2)天津保护地空间分布上呈集中分布态势,覆盖了天津市约75%的高质量生境区域和25%的较高质量生境区域。(3)从整体上看不同类型的自然保护地内生境质量保护效果不同,自然保护区优于其它类保护地,其生境质量明显得到提升。所有保护地中有10处保护地生境质量略有下降,但低于全域下降水平,只有盘山风景名胜区和古海岸与湿地自然保护区生境质量下降高于全域平均水平。(4)自然保护地对天津市生境质量下降的趋势起到了一定缓冲作用,其...