Substance P and acetylcholine are co-localized in the pathway mediating mucociliary activity in Rana pipiens

Mucociliary activity is an important clearance mechanism in the respiratory system of air breathing vertebrates. Substance P (SP) and acetylcholine play a key role in the stimulation of the mucociliary transport in the frog palate. In this study, retrograde neuronal tracing was combined with immunocytochemistry for SP and choline acetyl transferase (ChAT) in the trigeminal ganglion and for neurokinin-1 receptor (NK1R) in the palate of Rana pipiens. The cells of origin of the palatine nerve were identified in the trigeminal ganglion using the retrograde tracer Fluorogold (FG). Optimal labeling of FG cells in the trigeminal ganglion was obtained at 96 h of exposure. Immunoflorescent shows that SP and acetylcholine are co-localized in 92% of the cells labeled with FG in the trigeminal ganglion. NK1 receptors were found in the membrane of epithelial and goblet cells of the palate. Ultrastructural study of the palate showed axonal-like endings with vesicles in connection with epithelial and goblet cells. These results further support the concerted action of both neurotransmitters in the regulation of mucociliary activity in the frog palate.     

Clonal differences in rooting ofAlnus incana leafy cuttings

Summary Green cuttings ofAlnus incana (L.) Moench, consisting of one internode and one leaf with its axillary bud, were easily rooted in aerated liquid substrate under growth-chamber conditions. In tests on material of up to 8 years-old, the age of the stock plants was shown to have no influence on rooting. Tap water or a diluted nutrient solution gave higher rooting percentages than a full strength nutrient solution. Root growth was most rapid in the diluted nutrient solution. Eight out of 9 clones ofA. incana gave a rooting percentage of 80–100% while one clone gave only 40%. Good rooting ofA. incana leafy cuttings, therefore, seems to be genetically controlled.     

双Intein介导3片段vWF的反式剪接

von Willebrand因子(vWF)基因突变导致血管性血友病(VWD),由于其基因过大在基因治疗研究中难以为多数病毒载体携带.利用双内含肽(intein)的蛋白质反式剪接功能研究断裂成3段的vWF基因分别表达后在蛋白水平的连接,旨在为vWF基因的3载体联合转移应用于VWD基因治疗研究提供依据.将vWF cDNA于满足剪接所需的保守性氨基酸Cys1099、Ser2004的密码子前断裂为3段(N、M和C),分别与splitSspDnaE intein的N端(En)、C端(Ec)和splitSspDnaB intein的N端(Bn)、C端(Bc)编码序列融合,构建到原核表达载体pET-28a(+)中的His-Tag的下游,得到3种表达载体pET-NEn、pET-EcMBn和pET-BcC.分别转化感受态大肠杆菌BL21(DE3)细胞,经IPTG诱导表达后,以SDS-PAGE分析融合蛋白的表达,并进一步用His-Tag的特异性抗体进行分析;亲和层析纯化分别表达的带His-Tag标签的3段蛋白,复性后体外混合进行剪接实验以观察3片段vWF的连接.结果显示,3段预期大小的融合intein的vWF蛋白均有表达,用His-Tag抗体进行的Western印迹得到进一步证实;3段纯化的蛋白混合后可见明显的剪接条带形成,与vWF的预期分子量大小一致,表明双intein通过蛋白质反式剪接可有效连接3个片段的vWF,为进一步应用蛋白质剪接技术的3重载体真核细胞转vWF基因奠定了基础.     

记澜沧江河谷一硬叶小叶常绿阔叶林类型——锈鳞木樨榄、清香木群丛

采用法瑞地植物学派的样地调查法记录了澜沧江中上游河谷中一独特的硬叶小叶常绿阔叶林类型——锈鳞木樨榄、清香木群丛。该群丛由南向北分布于1300~1900m的河谷下部,对群落外貌、生活型与生长型、植物种类科属的组成、分布区类型等进行了分析。结果表明：（1） 群落结构简单,物种数平均为18种;（2） 生活型以高位芽植物居多,生长型以草本居多;（3） 群落中计有维管植物116种,隶属于39科,84属;（4） 植物科级、属级水平上均显示出了热带性质,植物区系表现出一定的古老性,反映了与古地中海硬叶小叶林的历史渊源。该植物群丛适应澜沧江干热-干暖河谷气候,分布区域狭窄,是一类值得重点保护和深入研究的植被类型。     

不同群落类型柔毛淫羊藿总黄酮和淫羊藿苷含量及其与土壤因子的关系

2009年8月,采用高效液相色谱法和紫外分光光度法测定了唐家河自然保护区次生落叶阔叶林红桦群落(群落Ⅰ)、常绿落叶阔叶混交林细叶青冈群落(群落Ⅱ)和常绿阔叶林油樟群落(群落Ⅲ)下生长的柔毛淫羊藿各器官的总黄酮和淫羊藿苷含量,分析其与土壤因子的关系结果表明：柔毛淫羊藿叶片中总黄酮和淫羊藿苷含量最高、茎中最低;群落Ⅰ的柔毛淫羊藿总黄酮和淫羊藿苷含量［(5.32±0.23)%和(0.47±0.05)%］均显著高于群落Ⅱ［(4.06±0.03)%和(0.32±0.01)%］和群落Ⅲ［(4.15±0.07)%和(0.28±0.09)%］;土壤氮含量和pH值对柔毛淫羊藿的总黄酮和淫羊藿苷含量影响较大,柔毛淫羊藿总黄酮和淫羊藿苷含量与土壤全氮和碱解氮呈显著负相关(P<0.05),与土壤pH值呈极显著正相关(P<0.01).土壤较低的氮供应水平和较高的土壤酸度可能使群落Ⅰ柔毛淫羊藿的总黄酮和淫羊藿苷含量增加.     

Neurotrophins,but not depolarization,regulate substance P expression in the developing optic tectum

Neurotransmitter expression can be regulated by both activity and neurotrophins in a number of in vitro systems. We examined whether either of these factors was likely to play a role in the in vivo optic nerve‐dependent regulation of a substance P‐like immunoreactive (SP‐ir) population of cells in the developing optic tectum of the frog. In contrast to our previous results with the adult system, blocking tectal cell responses to glutamate release by retinal ganglion cells with 6‐cyano‐7‐nitroquinoxaline‐2,3 dione (CNQX) did not affect the percent of SP‐ir cells in the developing tectum. Treatment with d‐(‐)‐2‐amino‐5‐phosphonovaleric acid (d‐AP‐5) was also ineffective in this regard, although both it and CNQX treatment disrupted visual map topography. Chronic treatment with brain‐derived neurotrophic factor (BDNF) and neurotrophin‐4/5 (NT‐4/5) produced increases in SP‐ir cells in the treated lobes of normal animals, which were significant in the case of NT‐4/5. Both substances also prevented the decrease of SP cells that would otherwise occur in the deafferented lobe of unilaterally optic nerve‐transected tadpoles. These changes in the percent of SP‐ir cells occurred without any detectable changes in the overall number of tectal cells. NGF had no effect on SP expression. Nor did it affect topographic map formation, which was disrupted by treatment with either BDNF or NT‐4/5. Our results demonstrate that different mechanisms regulate SP expression in the developing and adult tectum. They indicate that neurotrophin levels in the developing optic tectum may selectively regulate a specific neuropeptide‐expressing population of cells. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 131–149, 2001     

濒危植物香果树（Emmenopterys henryi）种群结构与动态

香果树（Emmenopterys henryi）为我国特有种,属国家Ⅱ级重点保护植物。主要分布于江西、安徽等地亚热带中山或低山区的森林中。文中对武夷山自然保护区4个群落类型的香果树种群数量动态进行了系统研究,统计其径级结构、建立生命表,应用谱分析方法分析种群数量的动态变化,并对影响该种群结构的环境因子进行了分析。结果表明：（1）武夷山自然保护区香果树种群基本属于衰退型,幼苗少,中树、大树个体丰富。不同生境的种群密度存在差异,其中香果树纯林密度较大（8.45±0.818株·100 m^-2）,幼苗数量较多,更新较好（幼苗密度1.05±0.326株·100 m^-2）,针阔混交林中香果树密度较小（6.58±0.76株·100 m^-2）,无幼苗;（2）香果树种群中树死亡率较高,其他各级死亡率较低;（3）香果树种群自然更新过程存在明显的周期。（4）对影响香果树种群结构的13个环境因子通过主成分分析（PCA）发现,较高的光强、土壤含水量、弱酸性土壤、土壤有机质、大气湿度、大气温度和适量的人为干扰对种群增长发挥有利影响,而高海拔、阴坡、陡坡度和大的乔灌层盖度对香果树种群增长则发挥不利影响。（5）充分利用香果树幼树喜荫、大树喜光的特点,加强现有林分的就地保护,特别是具有结实能力的母树,并就地采种育苗,扩大人工种群数量。     

缺血性脑卒中二级预防研究进展

脑卒中是一种危害人类健康的全球性问题。缺血性脑卒中复发是此类疾病患者面临的最严重问题之一,而且复发后会进一步加重患者功能障碍,甚至导致死亡。二级预防的主要目的是阻止短暂性脑缺血发作后发生的脑卒中或首次脑卒中后再发的脑卒中。所以,首次卒中后尽早开展二级预防显得尤为重要。下面,我们就有关缺血性脑卒中二级预防的控制危险因素、抗栓治疗、手术治疗、及生活习惯改变等方面,将近年来研究的新进展进行总结。