Exogeneous energy supply and excitability of cells in embryonic atypical epidermis of Cynops cultured in vitro

Cells of in vitro cultured epidermis explants of ectoderm isolated at early gastrula stage,showed only weak excitability or even non-excitable at 6V when examined electrophysiologically.If non-excitable explants were treated with 100 mM glucose,the action potential (AP) appeared and within 1 hr reached its maximum.At the same time,their stimulus threshold became lowered gradually.And,if the glucose was washed out,AP gradually disappeared.If explants were treated with glucose of different concentrations,the percentage of explants which displayed AP increased with the increase of glucose concentration.When explants with approximately the same original stimulus threshold were treated with glucose of different concentrations,the stimulus threshold became lowered more in the more concentrated solution.If explants with different original stimulus thresholds were treated with glucose of the same concentration,the lowering of stimulus threshold was more obvious in those with higher original stimulus threshold.Other energy supplying substances used showed similar effect.     

SP500263, a novel SERM,blocks osteoclastogenesis in a human bone cell model: role of IL-6 and GM-CSF

Bone metabolism requires tightly coupled activities exhibited by two unique cell populations, the bone-resorbing osteoclasts and the bone-forming osteoblasts. Imbalance in the function of these two cell types can result in osteoporosis, a condition characterized by loss in bone integrity and of bone mass. We developed a human bone cell culture model that allows the in vitro study of bone formation and osteoclastogenesis and employed this bone model for the screening and pharmacological analyses of protein and small molecule therapeutics. The cytokines, interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF), play an intricate role in osteoclastogenesis in this system. Neutralizing antibodies to IL-6 and GM-CSF decreased the formation of osteoclast-like cells. SP500263, an early lead compound from a novel class of selective estrogen receptor modulators (SERMs), was more efficacious than estrogen and comparable to raloxifene in blocking cytokine production and formation of osteoclast-like cells. Our research demonstrates the usefulness of the in vitro co-culture model in the dissection of molecular events relevant to bone metabolism and provides greater insight into a potential novel role for cytokines in bone resorption. Furthermore, representatives of the SP500263 family of SERMs may be effective as therapeutics for the treatment of osteoporosis.     

SSR分子标记在作物遗传育种中的应用

SSR(simple sequence repeat)是建立在PCR技术上的一种广泛应用的分子标记,具有含量丰富、多态性高、共显性等优点。本文简要介绍了SSR分子标记技术的原理和特点,重点介绍了SSR分子标记技术在作物遗传育种中的应用,主要在作物遗传多样性、基因定位、分子辅助标记、遗传图谱构建、品种鉴定和纯度鉴定等方面进行阐述。     

红凤菜扦插繁殖技术研究

为了探讨红凤菜扦插繁殖的适宜条件,采用不同基质、不同成熟度插条及不同萘乙酸(NAA)浓度进行三个因素随机区组试验,萘乙酸、插条成熟度和基质组成对红凤菜插条生根数量均有显著影响,其中萘乙酸处理对红凤菜插条生根数量的影响最大,枝条成熟度其次,扦插基质影响较小,结果表明扦插生根的最佳组合为:1 000 mg/kgNAA×幼嫩枝条×泥炭土∶珍珠岩=1∶1,NAA极显著地促进插条生根,数量增多,同时又极显著地抑制根的伸长。     

肺腺癌干细胞表达小细胞肺癌相关抗原的实验研究

肿瘤干细胞（cancerstem cells,csc）是指一类具有自我更新（self-renewal）能力的未分化细胞。在肺腺癌中,csc的自我更新调控机制类似胚胎干细胞,即高表达OCT4、Nanog和Sox2}潜能基因,但目前对其表型特征尚存争议。该文采用成球试验（sphere—formingassay）AkSPC—A1细胞株中富集CSC后进行分子表型分析。结果显示,此类肺球体细胞（pulmospheres）同时表达肺脏近端和远端呼吸上皮的多个谱系（1ineage）标志,包括纤毛柱状细胞标志FoxJl、非纤毛柱状细胞（即Clara细胞）标志CCSP、肺神经肉分泌细胞标志GRP、II型肺泡细胞标志SP-C及其转录调控因子TTF-1。这些肺球体细胞也能够被3株小细胞肺癌特异性单抗（2F7、483和E6）所识别。通过基因沉默技术使得肺球体细胞中OCT4表达转阴后,上述标志（除E6P外）均消失。研究结果揭示,肺癌CSC具有肺脏呼吸上皮多潜能细胞的表型特征。此外,初步研究结果发现,中药冬虫夏草（Hirsutella Hepialid of Cordyceps Sinensis）的被毛孢菌丝体中含有新颖抗癌成分,能够显著遏制肺球体细胞增殖,提示对其进行分离鉴定,将是研制开发肺癌CSC靶向药物的一个发展方向。     

国家Ⅱ级重点保护野生植物驼峰藤的研究进展

通过对专著、文献和多个网络资源数据库(植物志、标本、图像等)分析考证,及赴部分产地的野外实地考察,对珍稀濒危植物驼峰藤(Merrillanthus hainanensis Chun et Tsiang)的分类地位、形态特征、标本记录与保存、产地与生境、濒危的野外生存现状等情况进行了综述,以期为该保护物种的生存和发展和保护提供参考。自1933年采集到标本和1941年命名驼峰藤以来,至今已有80多年的历史,研究表明它的分布区范围从原广东、海南省扩展到中国大陆西南部和中南半岛部分地区(缅甸和柬埔寨),部分原有记载分布点已无法找到野生植株,导致其濒危的主要原因是生境的破坏和质量下降,广东中山五桂山脉或许是目前发现的最大野生种群保存地,文中就其保护措施提出了相关建议。     

TAT-Mediated Protein Transduction of Nogo Extracellular Peptide 1-40 and its Biological Activity

Aim Nogo extracellular peptide 1-40 (NEP1-40), a Nogo-66 antagonistic peptide, is one of the potential candidates for therapeutic intervention after central nervous system injury. This study is focused on the generation of TAT-NEP1-40 fusion protein and its transducible effects and biological activity. Methods TAT-NEP1-40 fusion protein was expressed in vitro. Transducible effects of TAT-NEP1-40 were analyzed by using immunofluorescence staining or Western blot in vitro and in vivo. The biological activity of TAT-NEP1-40 was assessed by its effects against oxygen and glucose deprivation (OGD)-induced PC12 cell damages. Results Our results showed that the TAT-NEP1-40 fusion protein was successfully expressed, purified, and refolded. Western blot analysis and immunofluorescence staining confirmed the delivery of TAT-NEP1-40 protein into PC12 cells and rat brains. OGD caused cell apoptosis or death, decreased cell viability, increased lactate dehydrogenase release in medium and the Bax/Bcl-2 ratio, all of which were prevented by the TAT-NEP1-40 fusion proteins when added exogenously to culture medium. In addition, TAT-NEP1-40 promoted neurite outgrowth of PC12 cells exposed to OGD. Conclusion These results demonstrate that the TAT-NEP1-40 can be successfully generated and efficiently transduced into PC12 cells and rat brains. The TAT-NEP1-40 can protect PC12 cells against OGD and promote neurite outgrowth. This finding suggests that the transducible TAT-NEP1-40 fusion protein offers a possibility of the development of novel therapy for cerebral injuries via delivery of the biologically active TAT-NEP1-40 fusion protein into injured sites. Qiang Wang and Xingchun Gou contributed equally to this article.     

Unexpected rearrangement of enantiomerically pure 3-aminoquinuclidine as a simple way of preparing diastereomeric octahydropyrrolo[2,3-c]pyridine derivatives

Reaction of (S)- or (R)-3-aminoquinuclidine with 2-chloropyrimidine or 2-bromopyrimidine led to an unexpected formation of both cis- and trans-octahydropyrrolo [2,3]pyridine derivatives. A single-step synthesis of two of the four stereoisomers of these octahydropyrrolo[2,3]pyridine derivatives provides a convenient way of generating stereochemically defined isomers. Optimization of reaction conditions was carried out by (1)H NMR monitoring. The relative and absolute stereochemistry of all four stereoisomers was determined by a combination of (1)H, (13)C, and (15)N NMR spectroscopy and vibrational circular dichroism spectroscopy.     

A nonspecific lipid transfer protein,StLTP10, mediates resistance to Phytophthora infestans in potato

Nonspecific lipidtransfer proteins (nsLTPs), which are small, cysteine-rich proteins, belong to the pathogenesis-related protein family, and several of them act as positive regulators during plant disease resistance. However, the underlying molecular mechanisms of these proteins in plant immune responses are unclear. In this study, a typical nsLTP gene, StLTP10, was identified and functionally analysed in potato. StLTP10 expression was significantly induced by Phytophthora infestans, which causes late blight in potato, and defence-related phytohormones, including abscisic acid (ABA), salicylic acid, and jasmonic acid. Characterization of StLTP10-overexpressing and knockdown lines indicated that StLTP10 positively regulates plant resistance to P. infestans. This resistance was coupled with enhanced expression of reactive oxygen species scavenging- and defence-related genes. Furthermore, we identified that StLTP10 physically interacts with ABA receptor PYL4 and affects its subcellular localization. These two proteins work together to regulate stomatal closure during pathogen infection. Interestingly, we also found that wound-induced protein kinase interacts with StLTP10 and positively regulates its protein abundance. Taken together, our results provide insight into the role of StLTP10 in resistance to P. infestans and suggest candidates to enhance broad-spectrum resistance to pathogens in potato.