Evolutionary trends in Tetrastigma (Vitaceae): Morphological diversity and taxonomic implications

Tetrastigma (Miq.) Planch. (Vitaceae) is a genus with ca. 100 species showing great morphological diversity. Previous molecular phylogenetic studies suggested that traditional classification systems are not consistent with the molecular phylogeny, and Tetrastigma is undergoing further systematic investigation. We traced the evolutionary trends of 20 morphological characters within a robust phylogenetic framework. Our results revealed that many morphological characters show either multiple transitions or few state changes, however, some characters show distinct variation. The two subgenera in Tetrastigma (subgen. Tetrastigma and subgen. Palmicirrata) based on unbranched/bifurcate versus digitately branched tendrils are not supported because subgen. Tetrastigma is paraphyletic. However, the unbranched versus bifurcate/digitately branched tendril is of taxonomic utility to characterize some of the major clades. Inflorescences in Tetrastigma appear axillary, but are leaf‐opposed on a compressed axillary shoot. We found most of the species in Tetrastigma retained the ancestral compound dichasial inflorescence, except those of clade IV that have derived pseudo‐umbellate inflorescences. Other characters including habit, leaf organization, and berry shape provide additional morphological support for the major clades. Our morphological analysis and recent molecular study suggest each of the five major clades within Tetrastigma be treated as distinct taxonomic sections (five sections in the genus).     

葡萄糖氧化酶解除黄曲霉毒素M_1的应用研究

试验旨在研究葡萄糖氧化酶解除黄曲霉毒素M_1毒性的应用效果。选择含有7.2μg/kg(A组)和19.5μg/kg(B组)黄曲霉毒素B_1(AFB_1)的玉米饲料,分别添加5‰固体和液体葡萄糖氧化酶制剂,连续饲喂奶牛10 d,同时和延后测定鲜牛奶和尿中黄曲霉毒素M_1(AFM_1)量。测定数据表明,与AFB_1组相比,固体酶A组产牛奶中AFM_1未检出,B组中AFM_1含量平均减少了76.47%;液体酶A组产牛奶中AFM_1未检出,B组中AFM_1平均减少了82.35%。尿中AFM_1量减少了75%、70.5%和75%、73.1%;与对照组相比,牛奶产量、牛奶中蛋白质及脂肪含量没有变化。     

Localization and replication of the systemic lupus erythematosus linkage signal at 4p16: interaction with 2p11, 12q24 and 19q13 in European Americans

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by both population and phenotypic heterogeneity. Our group previously identified linkage to SLE at 4p16 in European Americans (EA). In the present study we replicate this linkage effect in a new cohort of 76 EA families multiplex for SLE by model-free linkage analysis. Using densely spaced microsatellite markers in the linkage region, we have localized the potential SLE susceptibility gene(s) to be telomeric to the marker D4S2928 by haplotype construction. In addition, marker D4S394 showed marginal evidence of linkage disequilibrium with the putative disease locus by the transmission disequilibrium test and significant evidence of association using a family-based association approach as implemented in the program ASSOC. We also performed both two-point and multipoint model-based analyses to characterize the genetic model of the potential SLE susceptibility gene(s), and the lod scores both maximized under a recessive model with penetrances of 0.8. Finally, we performed a genome-wide scan of the total 153 EA pedigrees and evaluated the possibility of interaction between linkage signals at 4p16 and other regions in the genome. Fourteen regions on 11 chromosomes (1q24, 1q42, 2p11, 2q32, 3p14.2, 4p16, 5p15, 7p21, 8p22, 10q22, 12p11, 12q24, 14q12, 19q13) showed evidence of linkage, among which, signals at 2p11, 12q24 and 19q13 also showed evidence of interaction with that at 4p16. These results provide important additional information about the SLE linkage effect at 4p16 and offer a unique approach to uncovering susceptibility loci involved in complex human diseases.     

海洋短小枯草芽胞杆菌的鉴定及抑菌活性分析

对从连云港东西连岛海泥样品中分离得到的菌株Bacillus pumilus HX2-2的分类地位、生长条件和抑菌活性进行了研究。经过形态特征、生理生化性质及16S r DNA序列分析鉴定,该菌属于短小芽胞杆菌。不同温度、盐度、pH培养条件下测定菌液吸光度OD600值,表明该菌是一株轻度嗜盐菌,最适温度、盐度、pH分别为30℃、3%、7.0~8.0。在不同病原真菌的平板抑菌活性试验中,该菌对草莓尖胞镰刀菌、马铃薯炭疽病菌和水稻立枯丝核菌表现出显著的抑菌作用。菌株B.pumilus HX2-2是一株短小芽胞杆菌,具有广谱抑菌活性,具有进一步研究的价值。     

Regulation of matrix remodelling phenotype in gingival fibroblasts by substratum topography

Gingival connective tissue often has a composition resembling that of scar surrounding dental implant abutments. Increased cell adhesion, α‐smooth muscle actin (α‐SMA) expression and increased extracellular matrix deposition are a hallmark of fibrotic cells, but how topographic features influence gingival fibroblast adhesion and adoption of the α‐SMA positive myofibroblast phenotype associated with scarring is unknown. The purpose of the present study was to demonstrate whether implant topographies that limit adhesion formation would reduce myofibroblast differentiation and extracellular matrix deposition. Human gingival fibroblasts were cultured on PT (smooth) and SLA (roughened) titanium discs for varying time‐points. At 1 and 2 weeks after seeding, incorporation of α‐SMA into stress‐fibre bundles and fibronectin deposition was significantly higher on PT than SLA surfaces indicating differentiation of the cells towards a myofibroblast phenotype. Analysis of adhesion formation demonstrated that cells formed larger adhesions and more stable adhesions on PT, with more nascent adhesions observed on SLA. Gene expression analysis identified up‐regulation of 15 genes at 24 hrs on SLA versus PT associated with matrix remodelling. Pharmacological inhibition of Src/FAK signalling in gingival fibroblasts on PT reduced fibronectin deposition and CCN2 expression. We conclude that topographical features that reduce focal adhesion stability could be applied to inhibit myofibroblast differentiation in gingival fibroblasts.