Antiglioma activity of GoPI-sugar,a novel gold(I)–phosphole inhibitor: Chemical synthesis,mechanistic studies,and effectiveness in vivo

Glioblastoma, an aggressive brain tumor, has a poor prognosis and a high risk of recurrence. An improved chemotherapeutic approach is required to complement radiation therapy. Gold(I) complexes bearing phosphole ligands are promising agents in the treatment of cancer and disturb the redox balance and proliferation of cancer cells by inhibiting disulfide reductases. Here, we report on the antitumor properties of the gold(I) complex 1-phenyl-bis(2-pyridyl)phosphole gold chloride thio-β-d-glucose tetraacetate (GoPI-sugar), which exhibits antiproliferative effects on human (NCH82, NCH89) and rat (C6) glioma cell lines. Compared to carmustine (BCNU), an established nitrosourea compound for the treatment of glioblastomas that inhibits the proliferation of these glioma cell lines with an IC₅₀ of 430 μM, GoPI-sugar is more effective by two orders of magnitude. Moreover, GoPI-sugar inhibits malignant glioma growth in vivo in a C6 glioma rat model and significantly reduces tumor volume while being well tolerated. Both the gold(I) chloro- and thiosugar-substituted phospholes interact with DNA albeit more weakly for the latter. Furthermore, GoPI-sugar irreversibly and potently inhibits thioredoxin reductase (IC₅₀ 4.3 nM) and human glutathione reductase (IC₅₀ 88.5 nM). However, treatment with GoPI-sugar did not significantly alter redox parameters in the brain tissue of treated animals. This might be due to compensatory upregulation of redox-related enzymes but might also indicate that the antiproliferative effects of GoPI-sugar in vivo are rather based on DNA interaction and inhibition of topoisomerase I than on the disturbance of redox equilibrium. Since GoPI-sugar is highly effective against glioblastomas and well tolerated, it represents a most promising lead for drug development. This article is part of a Special Issue entitled: Thiol-Based Redox Processes.     

甲型肝炎病毒对理化因子的稳定性

用放射免疫成斑法研究了甲型肝炎病毒FM-175株的理化稳定性和灭活条件,证明甲型肝炎病毒理化稳定性与其它肠道病毒相似,具有广范围的pH(2～10)稳定性;Mg~(++)和Ca可增强其热稳定性,不能抵抗冷冻干燥,但对热的抵抗力明显高于普通肠道病毒,可被紫外线迅速杀灭,也可被多种消毒剂如3～8％的甲醛液,50～90％的乙醇,2％的石炭酸及400ppm的有效氯等杀灭,但可抵抗0.1％甲醛液,2～5％的来苏儿及200ppm的有效氯1小时以上,本研究工作为甲型肝炎病毒的理化性状、保存及消毒条件等提供了实验数据。     

应用Illumina MiSeq高通量测序技术分析河西走廊地区盐碱土壤微生物多样性

【目的】以甘肃省河西走廊地区的9个盐碱土壤样品(原生盐碱土、次生盐碱土、农田土)为材料,研究该地区盐碱土壤中微生物群落的多样性。【方法】提取土壤微生物总DNA,应用Illumina Mi Seq高通量测序技术进行分析。【结果】从分布在河西走廊3个流域的9个盐碱土样品中共获得325 089条微生物的16S r RNA基因序列。冗余分析和热图分析表明,原生盐碱土与次生盐碱土、原生盐碱土与农田土微生物群落构成差异较大,次生盐碱土与农田土微生物群落差异较小。土壤p H对微生物群落组成的影响最显著。多样性指数和稀释性曲线分析得出,在9个土壤样品中,S6号Shannon指数最大,S1号Shannon指数最小,S1号Simpson指数最大,S6号Simpson指数最小,说明原生盐碱土的微生物群落多样性最低,次生盐碱土的微生物群落多样性最高。盐碱土壤中主要的微生物群落包括9个门,其中变形菌门占主导地位,其余依次是放线菌门、拟杆菌门、酸杆菌门、浮霉菌门、绿弯菌门、芽单胞菌门、厚壁菌门和疣微菌门。原生盐碱土和农田土中占优势的微生物群落是变形菌门,次生盐碱土中占优势的微生物群落是放线菌门。【结论】河西走廊地区盐碱土壤中微生物多样性非常丰富,存在大量的微生物类群,尤其是在次生盐碱土壤中。     

Karyotype analysis in South American species of Myrtaceae

In Myrtaceae (Myrteae), the diploid chromosome number 2 n  = 2 x  = 22 is the most common, although variations of ploidy level occur, with some triploid (2 n  = 3 x  = 33) and tetraploid (2 n  = 4 x  = 44) records. Karyotype details in this group are scarce because the chromosomes are small (< 2 μm). In this work, we carried out a karyotypic analysis of 15 species of Myrtaceae grouped in different subtribes and genera. Measurements of chromosome length (long arm, L ; short arm, S ) were taken and several karyotypic parameters were calculated for each species. The karyotypes in fleshy-fruited taxa (Myrteae) were more varied than in the other previously analysed dry-fruited group ( Eucalyptus , Eucalypteae), in which the chromosomes were exclusively metacentric.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 571–580.     

A single early activation of invariant NK T cells confers long-term protection against collagen-induced arthritis in a ligand-specific manner

The glycosphingolipid alpha-galactosylceramide (alpha-GalCer) has been shown to be a potent activator of invariant NKT (iNKT) cells, rapidly inducing large amounts of both Th1 and Th2 cytokines upon injection in mice. The C-glycoside analog of alpha-GalCer (alpha-C-GalCer), by contrast, results in an enhanced Th1-type response upon activation of iNKT cells. We administered a single dose of these Ags to DBA/1 mice during the early induction phase of collagen-induced arthritis and demonstrated therapeutic efficacy of alpha-GalCer when administered early rather than late during the disease. Surprisingly, the Th1-polarizing analog alpha-C-GalCer also conferred protection. Furthermore, a biphasic role of IFN-gamma in the effect of iNKT cell stimulation was observed. Whereas in vivo neutralization of IFN-gamma release induced by either alpha-GalCer or alpha-C-GalCer early during the course of disease resulted in partial improvement of clinical arthritis symptoms, blockade of IFN-gamma release later on resulted in a more rapid onset of arthritis. Although no phenotypic changes in conventional T cells, macrophages, or APCs could be detected, important functional differences in T cell cytokine production in serum were observed upon polyclonal T cell activation, 2 wk after onset of arthritis. Whereas alpha-GalCer-treated mice produced significantly higher amounts of IL-10 upon systemic anti-CD3 stimulation compared with PBS controls, T cells from alpha-C-GalCer-treated mice, by contrast, produced substantially lower levels of cytokines, suggesting the involvement of different protective mechanisms. In conclusion, these findings suggest long-term, ligand-specific, time-dependent, and partially IFN-gamma-dependent immunomodulatory effects of iNKT cells in collagen-induced arthritis.     

Adenoviral transduction is more efficient in alginate-derived chondrocytes than in monolayer chondrocytes

Gene transfer into cultured chondrocytes by using adenoviral vectors has potential applications in treating cartilage disorders. The present study was undertaken to compare and optimize two chondrocyte culture conditions for adenoviral transduction efficacy by using primary human articular chondrocytes cultivated either directly in a monolayer condition or as outgrowths from alginate-stored chondrocyte cultures. Isolated primary chondrocytes from human articular cartilage were either immediately transduced with an EGFP (enhanced green fluorescent protein)-gene-bearing adenoviral vector (1,000 and 3,000 virus particles/cell) or cultured in alginate before transduction. Immunohistochemistry and flow cytometric analysis were employed to determine the expression of extracellular matrix proteins and of the αvβ5 integrin receptor involved in adenoviral cell entry. Monolayer chondrocytes exhibited moderate transduction rates (mean 22.2% and 46.9% EGFP-positive cells at 1,000 and 3,000 virus particles/cell by 72 h post-transduction), whereas alginate-derived chondrocytes revealed significantly higher transduction efficacies (95.7% and 99%). Both monolayer and alginate-derived chondrocytes expressed αvβ5 integrin, type II collagen and cartilage proteoglycans. The mean fluorescence intensity of type II collagen was significantly higher in the alginate-derived chondrocytes, whereas that of αvβ5 integrin was higher in the monolayer chondrocytes. Our results indicate that transduction efficacy is independent of αvβ5 integrin expression levels in chondrocytes. Moreover, adenoviral transduction of alginate-derived chondrocytes is more efficient than that for monolayer chondrocytes and may be a suitable tool to achieve sufficient numbers of transduced and differentiated chondrocytes for experimental applications and cartilage repair. Dr. Gundula Schulze-Tanzil is supported by a grant awarded by the Rahel Hirsh Foundation from the Charité Medical Schools Berlin. The study was supported by a grant from the Deutsche Arthrosehilfe e.V.     

功能矫形前伸青春期大鼠下颌后浅层嚼肌细胞凋亡的研究

目的：研究功能矫形前伸大鼠下颌后浅层嚼肌细胞凋亡的变化规律,探讨功能矫形的肌肉改建机理。方法：选用50只5周龄Sprague-Dawley（SD）雄性大白鼠,随机分为实验组和对照组各25只。实验组大鼠戴自制上颌功能矫治嚣,引导下颌前伸,并打开咬合。利用RT-PCR方法检测两组大鼠浅层嚼肌Bcl-2和Bax基因表达情况,利用TUNEL方法检测浅层嚼肌细胞凋亡情况。结果：①Bcl-2和Bax基因表达随大鼠戴用矫治器时间的延长而升高,至第3周开始下降但仍高于对照组,但Bax的表达高于Bcl-2。Bax/Bcl-2比值随大鼠戴用矫治器时间的延长而升高,至第4周开始下降。②TUNEL实验结果显示浅层嚼肌细胞在戴用矫治器1天后,开始出现凋亡,随着时间延长而增加,至第3周达到顶峰,第4周开始下降。结论：①Bax/Bcl-2比值升高促进浅层嚼肌细胞凋亡。②功能矫形可引起浅层嚼肌细胞凋亡,导致肌肉的结构和功能发生适应性改建。     

功能矫形前伸青春期大鼠下颌后翼外肌MyoD、myogenin的表达

目的：探讨＂应力-生长（改建）＂在细胞水平上的体现,为功能矫形治疗和矫治效果的保持提供新思路和实验依据。方法：本实验选用20只4周龄,雄性SD大鼠随机分为8组。其中实验组大鼠经戊巴比妥麻醉后佩戴上颌斜面导板,对照组未佩用。依据时间不同又分为四组：1d,7d,14d,21d。采用RT-PCR技术分析各组大鼠翼外肌组织中肌分化相关基因MyoD、myogenin mRNA的表达变化。结果：未施加功能矫形力的大鼠翼外肌组织MyoD表达伴随其生长发育呈现递减趋势,实验组在第7 d出现表达上调。同时,力学刺激后实验组动物myogenin的表达与对照组相比较在14 d组出现明显上调。结论：功能矫形力作用于翼外肌组织可以诱导MyoD和myogenin的表达上调进而诱导成肌细胞的分化。