米碎花的酚苷类化合物及其鼻咽癌细胞毒活性

为了解米碎花(Eurya chinensis)的化学成分及其生物活性,运用多种色谱技术从其乙醇提取物分离得到11个化合物,并对化合物进行体外抗鼻咽癌细胞增殖活性评价。经波谱数据分析,分别为异落新妇苷(1)、3,5,7-三羟基色原酮-3-O-α-L-鼠李糖苷(2)、1-O-反式-桂皮酰基-β-D-葡萄糖(3)、1-O-(4-羟基苯乙基)-6-O-反式-桂皮酰基-β-D-葡萄糖(4)、eutigoside D (5)、1-O-(3,4-二羟基苯乙基)-6-O-反式-香豆酰基-β-D-葡萄糖(6)、eutigoside A (7)、1-O-(4-羟基苯乙基)-6-O-反式-咖啡酰基-β-D-葡萄糖(8)、grayanoside A (9)、1-O-(4-羟基苯乙基)-6-O-(4-羟基苯甲酰基)-β-D-葡萄糖(10)、3-O-β-D-葡萄糖基-4-羟基-苄基苯甲酸酯(11)。其中,化合物4为首次从天然来源获得,化合物2～4和8～11均为首次从该属植物中分离得到。MTT法表明,化合物10具有中等抑制5-8F细胞增殖活性。     

The interaction of histone H3 with histone H4 and with other histones studied by 19F nuclear magnetic resonance.

The behaviour, upon variations in ionic strength, pH and temperature of 19F nuclear nuclear magnetic resonance signals of the trifluoroacetonylated derivative of histone H3 is compared with those of the H3-H4 complex and of the Hv fraction (an equimolar mixture of H2A, H2B, H3 and h4). The line width of the 19F-labelled histone H3 signals increases with ionic strength or pH, an effect consistent with aggregation of the protein. In the case of H3-H4 complex or Hv the line width decreases at intermediate ionic strengths (0.1-0.25 M NaCl). This effect is interpreted as the consequence of the formation of a well defined structure with ionic strength. At high salt concentrations the line width increases as a consequence of the final rigid quaternary structure or of the formation of higher aggregates.     

Genotype and phenotype analysis of Friedreich's ataxia compound heterozygous patients

Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FRDA locus flanking markers. Seven compound heterozygous patients were identified. In four patients, a point mutation that predicts a truncated frataxin was detected. Three of them associated classic early-onset Friedreich's ataxia with an expanded GAA allele greater than 800 repeats. The other patient associated late-onset disease at the age of 29 years with a 350-GAA repeat expansion. In two patients manifesting the classical phenotype, no changes were observed by single-strand conformation polymorphism (SSCP) analysis. Linkage analysis in a family with two children affected by an ataxic syndrome, one of them showing heterozygosity for the GAA expansion, confirmed no linkage to the FRDA locus. Most point mutations in compound heterozygous Friedreich's ataxia patients are null mutations. In the present patients, clinical phenotype seems to be related to the GAA repeat number in the expanded allele. Complete molecular definition in these patients is required for clinical diagnosis and genetic counseling.     

The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events

BACKGROUND: Although lentiviral vectors have been widely used for in vitro and in vivo gene therapy researches, there have been few studies systematically examining various conditions that may affect the determination of the number of viable vector particles in a vector preparation and the use of Multiplicity of Infection (MOI) as a parameter for the prediction of gene transfer events. METHODS: Lentiviral vectors encoding a marker gene were packaged and supernatants concentrated. The number of viable vector particles was determined by in vitro transduction and fluorescent microscopy and FACs analyses. Various factors that may affect the transduction process, such as vector inoculum volume, target cell number and type, vector decay, variable vector - target cell contact and adsorption periods were studied. MOI between 0-32 was assessed on commonly used cell lines as well as a new cell line. RESULTS: We demonstrated that the resulting values of lentiviral vector titre varied with changes of conditions in the transduction process, including inoculum volume of the vector, the type and number of target cells, vector stability and the length of period of the vector adsorption to target cells. Vector inoculum and the number of target cells determine the frequencies of gene transfer event, although not proportionally. Vector exposure time to target cells also influenced transduction results. Varying these parameters resulted in a greater than 50-fold differences in the vector titre from the same vector stock. Commonly used cell lines in vector titration were less sensitive to lentiviral vector-mediated gene transfer than a new cell line, FRL 19. Within 0-32 of MOI used transducing four different cell lines, the higher the MOI applied, the higher the efficiency of gene transfer obtained. CONCLUSION: Several variables in the transduction process affected in in vitro vector titration and resulted in vastly different values from the same vector stock, thus complicating the use of MOI for predicting gene transfer events. Commonly used target cell lines underestimated vector titre. However, within a certain range of MOI, it is possible that, if strictly controlled conditions are observed in the vector titration process, including the use of a sensitive cell line, such as FRL 19 for vector titration, lentivector-mediated gene transfer events could be predicted.     

Direct evidence for RNA–RNA interactions at the 3′ end of the Hepatitis C virus genome using surface plasmon resonance

Surface plasmon resonance was used to investigate two previously described interactions analyzed by reverse genetics and complementation mutation experiments, involving 5BSL3.2, a stem–loop located in the NS5B coding region of HCV. 5BSL3.2 was immobilized on a sensor chip by streptavidin-biotin coupling, and its interaction either with the SL2 stem–loop of the 3′ end or with an upstream sequence centered on nucleotide 9110 (referred to as Seq9110) was monitored in real-time. In contrast with previous results obtained by NMR assays with the same short RNA sequences that we used or SHAPE analysis with longer RNAs, we demonstrate that recognition between 5BSL3.2 and SL2 can occur in solution through a kissing-loop interaction. We show that recognition between Seq9110 and the internal loop of 5BSL3.2 does not prevent binding of SL2 on the apical loop of 5BSL3.2 and does not influence the rate constants of the SL2-5BSL3.2 complex. Therefore, the two binding sites of 5BSL3.2, the apical and internal loops, are structurally independent and both interactions can coexist. We finally show that the stem–loop SL2 is a highly dynamic RNA motif that fluctuates between at least two conformations: One is able to hybridize with 5BSL3.2 through loop–loop interaction, and the other one is capable of self-associating in the absence of protein, reinforcing the hypothesis of SL2 being a dimerization sequence. This result suggests also that the conformational dynamics of SL2 could play a crucial role for controlling the destiny of the genomic RNA.     

Variation at interleukin-6 receptor gene is associated to joint damage in rheumatoid arthritis

IntroductionInterleukin-6 (IL-6) cytokine signaling is key in Rheumatoid Arthritis (RA) pathophysiology. Blocking IL-6 receptor (IL6R) has proven to be a highly effective treatment to prevent joint damage. This study was performed to investigate the association between the genetic variation at IL6R gene and the severity of joint damage in RA.MethodsIL6R gene tagging SNPs (n = 5) were genotyped in a discovery group of 527 RA patients from 5 different university hospitals from Spain. For each marker, a linear regression analysis was performed using an additive model and adjusting for the years of evolution of the disease, autoantibody status, gender and age. Haplotypes combining the SNPs were also estimated and tested for association with the level of joint destruction. Using an independent cohort of 705 RA patients from 6 university hospitals we performed a validation study of the SNPs associated in the discovery phase.ResultsIn the discovery group we found a highly significant association between IL6R SNP rs4845618 and the level of joint destruction in RA (P = 0.0058, P_corrected = 0.026), and a moderate association with SNP rs4453032 (P = 0.02, P_corrected = 0.05). The resulting haplotype from both SNPs was more significantly associated with joint damage (P = 0.0037, P_corrected = 0.011). Using the validation cohort, we replicated the association between the two IL-6R SNPs with the degree of joint destruction in RA (P = 0.007 and P = 0.04, meta-analysis P = 0.00011 and P = 0.0021, respectively), and the haplotype association (P = 0.0058, meta-analysis P = 6.64 e-5).ConclusionsGenetic variation at IL6R gene is associated with joint damage in RA.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0737-8) contains supplementary material, which is available to authorized users.     

BOLD钉治疗桡骨小头骨折的临床疗效分析

目的:报告BOLD钉治疗Mason II型、未累及桡骨颈的Mason III型桡骨小头骨折的临床疗效。方法:自2009年3月至2012年2月对25例Mason II型,12例Mason III型桡骨小头骨折均采用切开复位BOLD钉内固定。结果:所有患者术后均获得随访12-24个月,平均随访14个月,肘关节功能评分:Mason II型平均分94分(88-98分),其中,优20例,良3例,可2例,差0例,优良率92%;Mason III型平均分91分(80-95分)其中,优9例,良1例,可2例,差0例,优良率83.3%。结论:BOLD钉治疗Mason II型及未累及桡骨颈的Mason III型桡骨小头有手术操作简单,固定稳定,允许早期活动等优点,可以作为这类骨折治疗的新选择。     

烟田中静电喷雾和电动喷雾下噻虫嗪的防效及对昆虫群落的影响

【目的】探明静电喷雾与电动喷雾对噻虫嗪防治害虫效果及烟田昆虫群落的影响,为静电喷雾在烟草上的推广应用提供理论依据。【方法】利用静电喷雾与电动喷雾法喷施0.66 g·L~(-1)25%噻虫嗪水分散粒剂,施药1、3、7 d后,测定2种方法对烟蚜与斜纹夜蛾的防治效果、在烟株与土壤中的沉积以及对昆虫群落的影响。【结果】喷施25%噻虫嗪水分散粒剂1、3、7 d后,静电喷雾对烟蚜和斜纹夜蛾的防治效果均显著高于电动喷雾的防治效果,且防治效果均随时间的推移而升高。噻虫嗪在静电喷雾处理区烟叶上的沉积量高于电动喷雾处理区烟叶上的沉积量,而在静电喷雾处理区土壤中的沉积量低于电动喷雾处理区土壤中的沉积量,且都随时间的推移而降低。静电喷雾与电动喷雾均引起烟田昆虫群落的变化,静电喷雾引起的害虫和中性昆虫的数量变化大于电动喷雾,但天敌昆虫的数量变化小于电动喷雾,且静电喷雾区烟田的物种丰富度明显高于电动喷雾区,可见静电喷雾施药对烟田昆虫群落的影响小于电动喷雾施药。静电喷雾的S_t/S_i与S_n/S_p比值明显高于电动喷雾,说明静电喷雾烟田中昆虫群落稳定性高于电动喷雾烟田中昆虫群落的稳定性。【结论】相比电动喷雾,静电喷雾能够提高噻虫嗪在烟叶上的沉积量,从而提高噻虫嗪对害虫的防治效果,同时减少噻虫嗪在土壤中的沉积量,提高噻虫嗪的生态安全性,因此,静电喷雾在烟草病虫害防治上具有较好的应用前景。