Relationships among characiform fishes inferred from analysis of nuclear and mitochondrial gene sequences

Suprafamilial relationships among characiform fishes and implications for the taxonomy and biogeographic history of the Characiformes were investigated by parsimony analysis of four nuclear and two mitochondrial genes across 124 ingroup and 11 outgroup taxa. Simultaneous analysis of 3660 aligned base pairs from the mitochondrial 16S and cytochrome b genes and the nuclear recombination activating gene (RAG2), seven in absentia (sia), forkhead (fkh), and alpha-tropomyosin (trop) gene loci confirmed the non-monophyly of the African and Neotropical assemblages and corroborated many suprafamilial groups proposed previously on the basis of morphological features. The African distichodontids plus citharinids were strongly supported as a monophyletic Citharinoidei that is the sistergroup to all other characiforms, which form a monophyletic Characoidei composed of two large clades. The first represents an assemblage of both African and Neotropical taxa, wherein a monophyletic African Alestidae is sister to a smaller clade comprised of the Neotropical families Ctenolucidae, Lebiasinidae, and the African Hepsetidae, with that assemblage sister to a strictly Neotropical clade comprised of the Crenuchidae and Erythrinidae. The second clade within the Characoidei is strictly Neotropical and includes all other Characiformes grouped into two well supported major clades. The first, corresponding to a traditional definition of the Characidae, is congruent with some groupings previously supported by morphological evidence. The second clade comprises a monophyletic Anostomoidea that is sister to a clade formed by the families Hemiodontidae, Parodontidae, and Serrasalmidae, with that assemblage, in turn, the sistergroup of the Cynodontidae. Serrasalmidae, traditionally regarded as a subfamily of Characidae, was recovered as the sistergroup of (Anostomoidea (Parodontidae+Hemiodontidae)) and the family Cynodontidae was recovered with strong support as the sistergroup to this assemblage. Our results reveal three instances of trans-continental sistergroup relationships and, in light of the fossil evidence, suggest that marine dispersal cannot be ruled out a priori and that a simple model of vicariance does not readily explain the biogeographic history of the characiform fishes.     

Characterization of SPACR, a sialoprotein associated with cones and rods present in the interphotoreceptor matrix of the human retina: immunological and lectin binding analysis

Rod and cone photoreceptors project from the outer retinal surface into a carbohydrate-rich interphotoreceptor matrix (IPM). Unique IPM glycoconjugates are distributed around rods and cones. Wheat germ agglutinin (WGA) strongly decorates the rod matrix domains and weakly decorates the cone matrix domains. This study characterizes the major WGA-binding glycoprotein in the human IPM, which we refer to as SPACR (sialoprotein associated with cones and rods). SPACR, which has a molecular weight of 147 kDa, was isolated and purified from the IPM by lectin affinity chromatography. A polyclonal antibody to SPACR was prepared that colocalizes in tissue preparations with WGA-binding domains in the IPM. Sequential digestion of SPACR with N- and O- glycosidases results in a systematic increase in electrophorectic mobility, indicating the presence of both N- and O-linked glycoconjugates. Complete deglycosylation results in a reduction in the relative molecular mass of SPACR by about 30%. Analysis of lectin binding allowed us to identify some of the structural characteristics of SPACR glycoconjugates. Treatment with neuraminidase exposes Galbeta1- 3GalNAc disaccharide as indicated by positive peanut agglutinin (PNA) staining, accompanied by the loss of WGA staining. Maackia amurensis agglutinins (MAA-1 and MAA-2), specific for sialic acid in alpha2-3 linkage to Gal, bind SPACR, while Sambucus nigra agglutinin (SNA), specific for alpha2-6 linked sialic acid, does not, indicating that the dominant glycoconjugate determinant on SPACR is the O-linked carbohydrate, NeuAcalpha2-3Galbeta1-3GalNAc. The abundance of sialic acid in SPACR suggests that this glycoprotein may contribute substantially to the polyanionic nature of the IPM. The carbohydrate chains present on SPACR could also provide sites for extensive crosslinking and participate in the formation of the ordered IPM lattice that surrounds the elongate photoreceptors projecting from the outer retinal surface.      

每搏量变异度在围手术期容量治疗监测中的应用

每搏量变异度是动态的容量监测指标.机械通气患者心肺的相互作用是每搏量变异度的产生基础,通过动脉压力波形分析技术可以进行连续监测.每搏量变异度能够准确预测容量治疗反应,与静态的血流动力学参数相比,对于优化心输出量和组织氧供更有优势,但也存在一定的局限性.每搏量变异度受多种因素影响且不能用于自主呼吸和心律失常的患者.临床应用时应该综合考虑其影响因素,结合其他的指标和方法指导容量治疗.     

Preliminary studies on the effect of moderate physical activity on blood levels of glutathione

Molecular epidemiological approaches are being used to study how physical activity may protect against cancer. Prior epidemiological data suggest that physical activity protects against lung cancer; however, interpretation of these data is complicated by potential confounding by smoking. Glutathione (GSH) detoxifies cigarette smoke carcinogens and the paper tests whether physical activity levels are associated with blood GSH levels. Study subjects were enrolled in a chemoprevention trial testing whether antioxidant micronutrient supplementation reduces genetic damage from cigarette smoking. Physical activity data were collected by questionnaire from 178 subjects at 12 months of follow-up in the trial. Total GSH (tGSH), which is the sum of free and protein-bound GSH and glutathione disulfide levels, was measured using the 5,5′-dithiobis-(2-nitrobenzenoic acid) colormetric assay with red blood cell samples collected at the 12-month time point. In multivariate linear regression analyses that controlled for gender and cigarettes smoked per day, tGSH was positively associated with hours per week of moderate intensity activity (β=0.005, p=0.02). Hours per week of vigorous intensity activity were unassociated with tGSH and the effect of moderate activity remained after control for vigorous activity. The results are consistent with prior research showing differential effects of moderate and vigorous activity and suggest a mechanism through which physical activity may influence lung cancer risk.     

1590名农村中老年人生存质量调查分析(英文)

目的:采用SF-36量表中文版评价农村中老年人生存质量,并为提高农村中老年人的生存质量和健康水平提供科学依据和建议。方法:采用随机抽样的方法,采用面对面访谈的形式,记分方法参照国际生存质量评价计划(IQOLA)的制定标准,评价其生理和心理健康状况。结果:1590名农村中老年人男性生存质量得分高于女性。经济水平对农村中老年人的生理健康的影响大于对其心理健康的影响。配偶健在的农村中老年人的各维度得分均高于无配偶者。农村中老年人的各维度得分随教育水平的升高呈升高趋势。结论:农村中老年人的生存质量与年龄成负相关,同时也受文化程度和经济水平等多个因素的影响。因而,对农村中老年人这一弱势群体应该给予更多关注。     

Sea urchin Hox genes: insights into the ancestral Hox cluster

We describe the Hox cluster in the radially symmetric sea urchin and compare our findings to what is known from clusters in bilaterally symmetric animals. Several Hox genes from the direct-developing sea urchin Heliocidaris erythrogramma are described. CHEF gel analysis shows that the Hox genes are clustered on a < or = 300 kilobase (kb) fragment of DNA, and only a single cluster is present, as in lower chordates and other nonvertebrate metazoans. Phylogenetic analyses of sea urchin, amphioxus, Drosophila, and selected vertebrate Hox genes confirm that the H. erythrogramma genes, and others previously cloned from other sea urchins, belong to anterior, central, and posterior groups. Despite their radial body plan and lack of cephalization, echinoderms retain at least one of the anterior group Hox genes, an orthologue of Hox3. The structure of the echinoderm Hox cluster suggests that the ancestral deuterostome had a Hox cluster more similar to the current chordate cluster than was expected Sea urchins have at least three Abd-B type genes, suggesting that Abd-B expansion began before the radiation of deuterostomes.