湖南省木本植物上的拟茎点霉新种

报道了采自湖南省木本植物上的10个拟茎点霉Phomopsis新种,即喜树拟茎点霉Ph. camptothecae、腊梅拟茎点霉Ph.chimonanthi、杜仲生拟茎点霉Ph.eucommiicola、紫薇拟茎点霉Ph.lagerstroemiae、红继木拟茎点霉Ph.loropetali、厚朴拟茎点霉Ph.magnolina、海桐拟茎点霉Ph.pittospori、竹柏拟茎点霉Phomopsis podocarpi、石榴拟茎点霉Ph.punicicola和酸枣拟茎点霉Ph.ziziphicola。对新种与其近似种在形态及ITS序列上的差异进行了讨论。文中附有新种的拉丁文、英文描述及显微结构图。模式标本保存于华南农业大学真菌标本室(SCHM)。     

大豆疫霉菌抗甲霜灵特性研究

大豆疫霉Phytophthorasojae易对甲霜灵产生抗性,从大豆疫霉野生型菌株可诱变筛选到对甲霜灵有抗性的菌株Mtr。Mtr抗性菌株的抗性水平可达野生型单游动孢子菌株的870倍以上。Mtr性状在无性后代稳定遗传,在游动孢子后代连续三代未发生抗药性分离。大豆疫霉Mtr性状的保持对甲霜灵没有表现依赖性。Mtr单游动孢子菌株在不含甲霜灵的胡萝卜培养基(CA)平板上培养30d后对甲霜灵的抗性没有下降,其单游动孢子后代也未出现抗药性分离。     

经皮给药载体载MD-CPT透明质酸纳米乳的细胞吞噬与体内药代动力学研究

本文在研究制备了包载10,11-亚甲二氧基喜树碱(MD-CPT)的透明质酸纳米乳(HANs)经皮给药系统的基础上,进一步研究了载MD-CPT透明质酸纳米乳的细胞吞噬,并进行了体内药代动力学分析.通过优化制备条件,得到了皮肤渗透性良好的缓释剂型.从CLSM观察到药物被细胞摄入并传递入细胞核,同时,载药纳米乳的细胞吞噬效率呈时间依赖性,不同细胞株HSF、HUVES、MCF-7、KF的细胞吞噬率略有不同.用Rhodanmine B标记HANs,通过荧光显微镜观察到载药纳米乳透过角质层到达真皮层的拟动态过程.利用HPLC检测MD-CPT血药浓度,测得经皮给药半衰期T1/2是静脉注射的3.6倍,肌肉注射的1.6倍,体内药物滞留时间显著增加;血药浓度峰谷值差异小,曲线平缓,说明经皮给药能保证血药浓度呈现可控的持续性.最终通过活体成像系统和组织切片荧光显微镜,直观地反映出经皮给药后药物在大鼠体内的分布情况和各组织器官药物含量,确定载药纳米乳主要采取胞间渗透的扩散方式,在局部给药的区域滞留时间较长,有利于对浅表性的病灶区持续给药,延长药效,而剩余的MD-CPT和解离的HANs都进入了血液循环,最终通过新陈代谢被排出体外.为无创型HANs经皮给药系统应用于浅表性肿瘤治疗提供了理论基础.     

Formation of soluble microbial products by activated sludge under anoxic conditions

In this work, both experimental and modeling approaches are used to explore the formation of soluble microbial products (SMP) by activated sludge under anoxic conditions. With substrate consumption, the SMP concentration increases gradually. Utilization associated products (UAP) are the main fraction of SMP when substrate is present; whereas biomass associated products (BAP) are the major content of SMP as substrate is completely consumed. The fraction of the accumulated SMP accounts for 3-4% of initial organic substrate. Three dimensional excitation emission matrix analysis results indicate that the SMP concentration increases in the denitrification process. The accumulation of nitrite up to 22.6 mg/l under anoxic conditions has no significant effect on the SMP formation. With a consideration of SMP formation under anoxic conditions, an ASM3-based denitrification model is developed. The results show that the developed model is able to capture the relationship between the SMP formation and the substrate consumption by activated sludge in the denitrification process.     

猪脂肪间充质干细胞的分离培养及其成脂分化

脂肪间充质干细胞(Adipose mesenchymal stemcell,AMSCs)是一类来源于脂肪组织并具有多向分化潜能的干细胞。近年来的研究证明,脂肪组织具有取材方便和干细胞含量高的优势,有望在研究与应用领域成为骨髓干细胞的替代物。猪是一种比啮齿类更接近人类的模式动物,具有较强的脂肪沉积能力。本研究探讨了猪脂肪间充质干细胞的体外分离纯化、培养扩增和向脂肪细胞诱导分化的条件。采用Ⅰ型胶原酶消化分离脂肪微管基质成分,传代培养扩增,流式细胞仪检测细胞表面标记。取第3-7代AMSCs,采用不同方法诱导AMSCs向脂肪细胞分化,光学显微镜下可观察到诱导后的细胞内有高折光性的小脂滴出现,油红O染色成阳性,不同诱导方法诱导率不同。被诱导细胞用RT-PCR可检测到脂肪细胞分化标志基因LPL和PPARγ的表达。结果表明可以从脂肪组织中分离培养出AMSCs,经传代后可提高其纯度。CD44、CD105表达呈阳性,CD14、CD34、S-100、HLA-DR呈阴性,在合适的诱导条件下,可向脂肪细胞分化。     

Ubiquitin E3 Ligase A20 Facilitates Processing Microbial Product in Nasal Epithelial Cells

Microbial products play a role in the pathogenesis of allergic diseases; ubiquitin E3 ligase A20 (A20) is an important molecule in regulating inflammation in the body. The present study aims to elucidate the role of A20 in processing the absorbed microbial products in nasal epithelial cells. Human nasal mucosal specimens were collected from patients with or without chronic rhinitis and analyzed by immunohistochemistry. Human nasal epithelial cell line, RPMI2650 cell, was employed to assess the role of A20 in processing the absorbed staphylococcal enterotoxin B (SEB). The RPMI2650 cells absorbed SEB in the culture. The increase in A20 was observed in RPMI2650 cells in parallel to the absorption of SEB. A20 is a critical molecule in the degradation of SEB in the nasal epithelial cells by promoting the tethering of endosomes and lysosomes. A20 plays a critical role in processing of the absorbed SEB in nasal epithelial cells.     

Sevoflurane postconditioning protects isolated rat hearts against ischemia-reperfusion injury: the role of radical oxygen species,extracellular signal-related kinases 1/2 and mitochondrial permeability transition pore

The roles of reactive oxygen species (ROS), extracellular signal-regulated kinase 1/2 (ERK 1/2) and mitochondrial permeability transition pore (mPTP) in sevoflurane postconditioning induced cardioprotection against ischemia-reperfusion injury in Langendorff rat hearts were investigated. When compared with the unprotected hearts subjected to 30 min of ischemia followed by 1 h of reperfusion, exposure of 3% sevoflurane during the first 15 min of reperfusion significantly improved functional recovery, decreased infarct size, reduced lactate dehydrogenase and creatine kinase-MB release, and reduced myocardial malondialdehyde production. However, these protective effects were abolished in the presence of either ROS scavenger N-acetylcysteine or ERK 1/2 inhibitor PD98059, and accompanied by prevention of ERK 1/2 phosphorylation and elimination of inhibitory effect on mPTP opening. These findings suggested that sevoflurane postconditioning protected isolated rat hearts against ischemia-reperfusion injury via the recruitment of the ROS-ERK 1/2-mPTP signaling cascade.     

一株新型裂解K63荚膜型肺炎克雷伯菌的噬菌体分离鉴定和生物学特性研究及全基因组分析

[背景]噬菌体具有特定的杀菌能力,对生态和细菌的进化具有重要影响。近年来由于多重耐药细菌的全球出现,噬菌体疗法逐渐引起了人们的关注。[目的]对一株新型裂解K63荚膜型肺炎克雷伯菌的噬菌体vB_KpnP_IME308进行生物学特性研究、测序和比较基因组学的分析。[方法]以一株从临床分离到的肺炎克雷伯菌为宿主菌分离噬菌体,应用双层平板法进行噬菌体最佳感染复数(optimal multiplicity of infection)、一步生长曲线(one-step growth curve)、温度以及pH敏感性实验测定,纯化噬菌体并通过透射电镜观察噬菌体形态;应用标准的苯酚-氯仿提取方案提取噬菌体全基因组,使用Illumina MiSeq测序平台进行噬菌体全基因组测序,测序后对噬菌体全基因组序列进行组装、注释、进化和比较基因组学分析。[结果]分离到一株新型的肺炎克雷伯菌噬菌体,命名为vB_KpnP_IME308;其最佳感染复数为0.001,一步生长曲线结果显示,其感染宿主菌的潜伏期约为20 min,裂解期约为80 min,平均裂解量330PFU/cell;噬菌体vB_KpnP_IME308在4-50℃和pH 5.0-10.0范围内稳定;电镜观察该噬菌体属于短尾噬菌体科(Podoviridae)。基因组测序结果表明,噬菌体基因组全长为43 091bp,(G+C)mol%含量为53.9%,(A+T)mol%含量为46.1%。BLASTn比对结果表明,该噬菌体与目前已知噬菌体基因组仅84%区域有相似性。噬菌体进化树结果表明该噬菌体属于Autographivirinae亚科的Drulisvirus属的成员。[结论]从医院污水中分离鉴定了一株新型的肺炎克雷伯菌噬菌体,表征并分析了噬菌体全基因组序列,这些结果均表明该噬菌体具有开发为抗肺炎克雷伯菌制剂的潜力,为噬菌体治疗多重耐药细菌感染奠定了基础。     

甘蔗鞭孢堆黑粉菌原生质体转化DNA双片段的基因敲除方法的建立

由甘蔗鞭孢堆黑粉菌Sporisorium scitamineum引起的甘蔗黑穗病是甘蔗生产的主要病害,严重影响了甘蔗的产量和品质,然而其分子致病机制报道很少,极大地影响了有效防控技术的开发。为了提高该病菌基因功能的研究效率,本研究以甘蔗鞭孢堆黑粉菌有性配合两个关键基因SsGPA3和SsPRF1为目标,建立了基于DNA双片段的甘蔗鞭孢堆黑粉菌原生质体转化基因敲除技术体系。结果表明甘蔗鞭孢堆黑粉菌单倍体细胞生长期在OD₆₀₀约为0.7,28℃下10mg/mL细胞壁裂解酶作用30min获得的原生质体产率最高,再生率最优;使用线性DNA双片段转化获得阳性转化子的成功率达90%以上,显著高于线性DNA单片段和质粒。本方法的建立将极大地提高甘蔗鞭孢堆黑粉菌的基因敲除效率,同时也为其他真菌的基因敲除提供借鉴。     

基因枪法获得无选择标记的1Dx5基因表达的转基因小麦

利用基因枪将无选择标记的优质高分子量麦谷蛋白亚基基因1Dx5导入新疆耐盐小麦品种新冬26,为利用优质基因进行小麦品质改良奠定基础。构建无选择标记的线性1Dx5表达框。利用基因枪将其转入不含该亚基的小麦品种新冬26幼胚盾片中,经PCR二分法筛选,从转化的1 000块幼胚盾片中共获得3株转基因阳性植株,转化效率0.3%。利用SDS-PAGE分析目的基因在转基因后代籽粒中的表达。转基因植株后代种子分析表明,1Dx5在转基因后代部分种子中表达。本研究成功地将无选择标记的线性1Dx5片段导入普通小麦新冬26中,并在后代部分种子中得到了表达。为利用优质亚基基因改良小麦加工品质奠定基础。