半红树植物黄槿中的三萜和甾醇成分(英文)

目的:研究半红树植物黄槿(Hibiscus tiliaceus L.)的化学成分。方法:分离纯化采用硅胶色谱、Sephadex LH-20凝胶色谱、高效液相色谱等方法。结构鉴定通过理化常数和波谱数据与文献对照确定。结果:从黄槿中共分离鉴定了10个化合物,分别为:木栓酮(1)、粉蕊黄杨二醇(2)、β-粘霉烯醇(3)、羽扇豆醇(4)、日耳曼醇(5)、豆甾-4-烯-3-酮(6)、豆甾-4,22-二烯-3-酮(7)、麦角甾-4,6,8(14),22-四烯-3-酮(8)、β-谷甾醇(9)和豆甾醇(10)。结论:化合物3～5和8为首次从该植物中分离得到。     

欧白芷素对K562/A02细胞阿霉素耐药的逆转作用(英文)

目的:探讨欧白芷素对耐药细胞株K562/A02中P-糖蛋白(P-glycoprotein,P-gp)的影响,为抗白血病多药耐药(multi-drug resistance,MDR)提供新方法。方法:采用MTT法观察阿霉素对细胞活力的影响。应用流式细胞术检测欧白芷素对K562和K562/A02细胞内阿霉素累积和细胞中P-gp功能的影响。采用实时定量RT-PCR技术检测MDR1基因在mRNA表达水平的变化。结果:欧白芷素对耐药细胞株K562/A02有显著的逆转耐药活性,最大逆转倍数为7.36。在K562/A02细胞中,欧白芷素明显增加阿霉素的累积,增加了罗丹明123(rhodaminel123,Rh123)蓄积,抑制了Rh123的外排,同时欧白芷素还在mRNA水平抑制了K562/A02细胞中P-gp的表达。结论:欧白芷素能够抑制K562/A02耐药细胞株中MDR1基因表达和P-gp的功能。     

Comparison of ultrasonography and radiography of the wrist for diagnosis of calcium pyrophosphate deposition

Objective

Ultrasound (US) seems a useful tool for diagnosis of calcium pyrophosphate (CPP) deposition (CPPD). We aimed to compare the performance of US and conventional radiography of the wrist for diagnosis of CPPD.

Modelling copper bioaccumulation in Gammarus pulex and alterations of digestive metabolism

Bioaccumulation enables to integrate the ability of aquatic organisms to regulate metals and effects of water chemistry on metal bioavailability. Linking this process to biological responses offers thus promising lines of enquiry for protecting aquatic ecosystems. This study aims at characterizing the mechanisms involved in waterborne Cu bioaccumulation and assessing metal impact on digestive metabolism in an ecosystem engineer widely distributed in Europe, Gammarus pulex. The organism was exposed to several Cu concentrations (from 0.5 to 100?μg/L) in aquatic microcosms to establish kinetic parameters for the construction and comparison of two bioaccumulation models, i.e. the biodynamic and saturation models. Cu uptake was recorded in waters exhibiting various concentrations of Na, Mg and Ca at environmental levels to assess the influence of cationic composition on bioaccumulation. Then, the effect of increasing Cu in exposure media on the digestive metabolism of G. pulex was investigated by measuring enzymatic activities (β-glucosidase, N-acetyl-β-glucosaminidase, β-galactosidase). We showed that the saturation model is more suitable than the biodynamic model to describe Cu bioaccumulation in gammarids due to a maximal capacity of animals to accumulate the metal. Cationic composition of water affected insignificantly Cu uptake. All activities of tested enzymes decreased with increasing Cu in exposure media but with different degrees. High correlations were established between the inhibition of enzymatic activities and amounts of Cu bioaccumulated by gammarids. These biological responses could thus provide early-warming of Cu impact on aquatic biota.     

Genetic diversity of perch rhabdoviruses isolates based on the nucleoprotein and glycoprotein genes

Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in France and support the hypothesis of circulation of these viruses between other hosts and regions within Europe.     

Characterizing Brain Cortical Plasticity and Network Dynamics Across the Age-Span in Health and Disease with TMS-EEG and TMS-fMRI

Brain plasticity can be conceptualized as nature's invention to overcome limitations of the genome and adapt to a rapidly changing environment. As such, plasticity is an intrinsic property of the brain across the lifespan. However, mechanisms of plasticity may vary with age. The combination of transcranial magnetic stimulation (TMS) with electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) enables clinicians and researchers to directly study local and network cortical plasticity, in humans in vivo, and characterize their changes across the age-span. Parallel, translational studies in animals can provide mechanistic insights. Here, we argue that, for each individual, the efficiency of neuronal plasticity declines throughout the age-span and may do so more or less prominently depending on variable 'starting-points' and different 'slopes of change' defined by genetic, biological, and environmental factors. Furthermore, aberrant, excessive, insufficient, or mistimed plasticity may represent the proximal pathogenic cause of neurodevelopmental and neurodegenerative disorders such as autism spectrum disorders or Alzheimer's disease.