Post-Viking Microbiology: New Approaches,New Data,New Insights

In the 20 years since the Viking experiments, major advances have been made in the areas of microbial systematics, microbial metabolism, microbial survival capacity, and the definition of environments on earth, suggesting that life is more versatile and tenacious than was previously appreciated. Almost all niches on earth which have available energy, and which are compatible with the chemistry of carbon-carbon bonds, are known to be inhabited by bacteria. The oldest known bacteria on earth apparently evolved soon after the formation of the planet, and are heat loving, hydrogen and/or sulfur metabolizing forms. Among the two microbial domains (kingdoms) is a great deal of metabolic diversity, with members of these forms being able to grow on almost any known energy source, organic or inorganic, and to utilize an impressive array of electron acceptors for anaerobic respiration. Both hydrothermal environments and the deep subsurface environments have been shown to support large populations of bacteria, growing on energy supplied by geothermal energy, thus isolating these ecosystems from the rest of the global biogeochemical cycles. This knowledge, coupled with new insights into the history of the solar system, allow one to speculate on possible evolution and survival of life forms on Mars.     

编者按:非可控性炎症与肿瘤——古老的科学问题，新的研究前沿

正炎症(inflammation)是机体对病原体感染以及各种组织损伤等产生的一种防御反应,是最常见而又最重要的基本病理生理过程之一[1].炎症与肿瘤发生发展的关系是一个古老的科学问题,早在1863年,德国著名病理学家Rudolf Virchow就证实了肿瘤组织中有大量的白细胞浸润,从而提出肿瘤起源于慢性炎症这一假说[2],但这一假说当时并未引起足够的重视.直到21世纪初,炎症与肿瘤的关系才重新引起研究者们的极大兴趣[3],科学家们发现     

河南省蜥蜴新纪录——米仓山龙蜥

在近年的野外调查中,在河南省伏牛山国家级自然保护区(2011年7月1～9日)和太行山猕猴国家级自然保护区(济源管理局,2010～2011年)分别采集到7号和5号鬣蜥科蜥蜴标本,经鉴定确定为米仓山龙蜥(Japalura micangshanensis),为河南省蜥蜴新纪录。标本分别保存于河南大学生命科学学院动物标本室和郑州大学生物标本室。此新纪录为研究米仓山龙蜥的形态变异和地理分布提供了基础资料。     

广东省两栖动物新纪录——长肢林蛙

2011年10月,在广东古田省级自然保护区采集到5只长肢林蛙(Rana longicrus),为广东省两栖动物新纪录。长肢林蛙此前仅发现于台湾,主要分布在台湾北部、中部和西部地区。此新纪录的发现对于促进认识长肢林蛙的形态特征及地理分布格局具有重要意义。     

黑带腹链蛇:贵州省蛇类新纪录

2011年7月,在贵州省雷公山国家级自然保护区采集到2号游蛇科蛇类标本,经鉴定确定为黑带腹链蛇(Amphiesma bitaeniata),为贵州省蛇类新纪录种.此新纪录能为研究黑带腹链蛇的形态变化和地理分布提供基础资料.     

New Ras CAAX mimetics: Design, synthesis, antiproliferative activity, and RAS prenylation inhibition

Mimetics of the C-terminal CAAX tetrapeptide of Ras protein were designed replacing cysteine (C) by 2-hydroxymethylbenzodioxane or 2-aminomethylbenzodioxane, respectively etherified and amidified with 2′-methyl or 2′-methoxy substituted 2-carboxy-4-hydroxybiphenyl and 2,4-dicarboxybiphenyl. These pluri-substituted biphenyl systems, used as internal spacer and AA dipeptide bioisoster, were linked to the methyl ester of l-methionine, glycine or l-leucine by an amide bond. The resultant twelve pairs of stereoisomers at the dioxane C-2 were tested for antiproliferative effect finding the maximum activity for derivatives with methyleneoxy linker between benzodioxane and 2′-methylbiphenyl. Of these compounds, the one with terminal methionine and S configuration proved a good Ras prenylation inhibitor in a cell-based assay.     

Modified Oligonucleotides: New Structures,New Properties,and New Spheres of Application

Russian Journal of Bioorganic Chemistry - Nucleic acids have made a long and arduous journey “from the bench to the bedside.” At present, it can be assumed that drugs based on...     

Ganglioside/glycosphingolipid turnover: New concepts

In this review focus is given to the metabolic turnover of gangliosides/glycosphingolipids. The metabolism and accompanying intracellular trafficking of gangliosides/glycosphingolipids is illustrated with particular attention to the following events: (a) the de novo biosynthesis in the endoplasmic reticulum and Golgi apparatus, followed by vesicular sorting to the plasma membrane; (b) the enzyme-assisted chemical modifications occurring at the plasma membrane level; (c) the internalization via endocytosis and recycling to the plasma membrane; (d) the direct glycosylations taking place after sorting from endosomes to the Golgi apparatus; (e) the degradation at the late endosomal/lysosomal level with formation of fragments of sugar (glucose, galactose, hexosamine, sialic acid) and lipid (ceramide, sphingosine, fatty acid) nature; (f) the metabolic recycling of these fragments for biosynthetic purposes (salvage pathways); and (g) further degradation of fragments to waste products. Noteworthy, the correct course of ganglioside/glycosphingolipid metabolism requires the presence of the vimentin intracellular filament net work, likely to assist intracellular transport of sphingoid molecules. Out of the above events those that can be quantitatively evaluated with acceptable reliability are the processes of de novo biosynthesis, metabolic salvage and direct glycosylation. Depending on the cultured cells employed, the percentage of distribution of de novo biosynthesis, salvage pathways, and direct glycosylation, over total metabolism were reported to be: 35% (range: 10–90%) for de novo biosynthesis, 7% (range: 5–10%) for direct glycosylation, and 58% (range: 10–90%) for salvage pathways. The attempts made to calculate the half-life of overall ganglioside turnover provided data of unsure reliability, especially because in many studies salvage pathways were not taken into consideration. The values of half-life range from 2 to 6.5 h to 3 days depending on the cells used. Available evidence for changes of ganglioside/glycosphingolipid turnover, due to extracellular stimuli, is also considered and discussed. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.     

广东省蛇类新纪录-双全白环蛇

2011年9～10月,分别在广东省乳源瑶族自治县南岭国家森林公园和始兴县车八岭国家级自然保护区采集到游蛇科(Colubridae)白环蛇属(Lycodon)标本3号,经鉴定为双全白环蛇(Lfasciatus),为广东省蛇类新纪录.     

广东省蛇类新纪录——福清白环蛇

2004年5月至2010年6月,在广东省境内的深圳梧桐山、南岭国家森林公园、车八岭国家级自然保护区和天井山林场观察到福清白环蛇(Lycodon futsingensis) 8条,采集到标本5号,为广东省新纪录,标本保存在广东省昆虫研究所.     

New 1,3,4-oxadiazole/oxime hybrids: Design,synthesis, anti-inflammatory,COX inhibitory activities and ulcerogenic liability

A series of new 1,3,4-oxadiazole/oxime hybrids were synthesized and designed as potent COX inhibitors. The prepared compounds were evaluated for their anti-inflammatory, antioxidant and ulcerogenic activities. The results indicated that the prepared compounds exhibited remarkable anti-inflammatory activity with (69.60–109.60% of indomethacin activity) after 4 h. In vitro COX inhibitory assay showed that compounds 6d and 7h are potent COX inhibitors with IC₅₀ of (1.10–0.94) and (2.30–5.00) µM on both COX-1 and COX-2 respectively. Compound 7h was found to inhibit both COXs non-competitively with K_i values of 73 µM and 89 µM. Most of the tested compounds showed ulcer-free stomachs compared to indomethacin.     

Monocot Xylem Revisited: New Information,New Paradigms

Five sources of data force extensive revision of ideas about the nature and evolution of monocot xylem: scanning electron microscopy (SEM) studies of thick sections; availability of molecular phylogenies covering a relatively large number of families and genera; information on ecology and habitat; data concerning habit; and observations from xylem physiology. These five new sources of data, absent from the studies of Cheadle, plus added information from light microscopy, lead to a fresh understanding of how xylem has evolved in monocots. Tracheary elements hitherto recorded as vessel elements with scalariform end walls prove in a number of instances, to retain pit membranes (often porous or reticulate) in the end walls. There is not an inexorable progression from "primitive" to "specialized" xylem in monocots; apparent accelerations or reversions are also possible. The latter include such changes as the result of production of narrower vessel elements; or production of less metaxylem, which is probably heterochronic in nature (an extreme form of juvenilism). Tracheary elements intermediate between vessel elements and tracheids must be recognized for what they are, and not forced into mutually exclusive categories. Original data on tracheids and various types of vessel elements is related here to ecology and habit of groups such as Asteliaceae, Boryaceae, Cyclanthaceae, Orchidaceae, Pandanaceae, Taccaceae, Typhaceae, dracaenoid Asparagaceae, and Zingiberales. Data from palm xylem shows a nearly unique syndrome of features that can be explained with the aid of information from physiology and ecology. Vessellessness of stems and leaves characterizes a large number of monocot species; the physiological and ecological significance of these is highlighted. An understanding of how non-palm arborescent monocots combine an all-tracheid stem xylem with addition of bundles and vegetative modifications is attempted. The effect of the disjunction between xylems of adventitious roots and stems, providing a physiologically demonstrated valve ("rectifier") effect is discussed. "Ecological iteration" has occurred in some monocot lineages, so that early-departing branches in some cases may have more "specialized" xylem because of entry into xeric habitats, whereas nearby crown groups, which may have retained "primitive" xylem, probably represent long occupation of mesic habitats. Cheadle's use of xylem for "negations" of phyletic pathways can no longer be accepted. Symplesiomorphic mesomorphic xylem patterns do characterize many of the earlier-departing branches in the monocots as a whole, however. Cheadle's idea that monocots and non-monocot angiosperms attained vessels independently is improbable in the light of molecular trees for angiosperms. Vessels in roots seem an adaptation to major swings in moisture availability to adventitious roots as compared to taproots. The commonness of all-tracheid plans in stems and leaves in earlier-departing monocot clades is a feature that requires further clarification but is primarily related to the xylem disjunction that adventitious roots have. Secondary vessellessness or something very close to it can be hypothesized for Campynemataceae, Philesiaceae, Taccaceae, and some Orchidaceae. Eleven salient shifts in our conceptual views of monocot xylem are proposed and conclude the paper. Monocot xylem is not a collection of historical information, but a rigorously parsimonious system related to contemporary habits and habitats.