一种简单有效的非损伤观测根瘤和根系形态的方法

实时观测根瘤及根系形态对于豆科植物研究具有重要意义, 但目前还缺乏一个便于观测根系、高效结瘤、适宜生长且经济实用的豆科植物培养体系。以蒺藜苜蓿(Medicago truncatula)为植物材料, 建立了一种可实时观测根瘤及根系形态的纸袋水培法, 并与其它常用方法进行对比。结果表明, 依赖于石英砂等固体介质栽培蒺藜苜蓿对根瘤和根系形态的实时观测造成障碍, 而水培和喷雾培养等方法的根瘤菌接种效率不高, 且不便观测侧根发育情况。采用纸袋水培法探讨了褪黑素对蒺藜苜蓿根系发育的影响, 发现褪黑素具有降低根瘤形成效率、抑制侧根伸长、增加侧根数目以及增大侧根与主根之间夹角等作用。因此, 纸袋水培法能够高效接种根瘤菌且为实时无损伤观测根瘤及根系形态提供了可能, 是一种适用于豆科植物简单有效的培养方法。     

The Injurious Effects of Hyperinsulinism on Blood Vessels

Insulin resistance (IR) is a common feature of hypertension, Type II diabetes, coronary heart disease, Syndrome X, and other vascular diseases. It refers to a state in which a certain concentration of insulin produces less biologic effect than expected in human body. When IR develops, the response of human body to insulin decreases accordingly, thus inducing the compensatory hyper-secretion of insulin and consequently hyperinsulinism. Many clinical and epidemiologic studies have demonstrated that IR and iatrogenic hyperinsulinism induced consequently play an essential role in the pathogenesis of hypertension and atherosclerotic cardiovascular diseases. Therefore, more and more attention should be paid to the mechanism of IR in order to explore more therapeutic basis and prospective for the treatment of atherosclerosis and other cardiovascular diseases. In this review, we provided a general overview on the known molecular mechanisms of IR and summarized the recent findings on the injurious effects of hyperinsulinism in vitro and in vivo, which might be important for researchers and clinicians to better understand the etiology and clinical significance of IR.     

小型猪急性心肌梗死模型的建立及其评价

目的探索结扎小型猪冠状动脉左前降支（LAD）建立急性心肌梗死模型及进行血流评价的方法。方法小型猪20头全麻下开胸暴露心脏,预阻断LAD（第二对角支）15min,后予结扎,术中心电图动态监测,术后进行冠状动脉造影,心肌酶学监测以确定模型建立情况,冠状动脉造影以及^13N-NH3 PET心肌血流测定评价手术后血流改变。结果20头小型猪中有16头存活4周,成活率80％,开胸手术中1头因麻醉意外死亡,3头死于术后呼吸不畅。结扎后心电图呈动态变化,24h后血清心肌酶谱（CK,CK—MB,cTnI）较术前明显增高,差异有统计学意义（P〈0．05）,冠状动脉造影显示LAD血流中断,TIMI分级为0级,^13N—NH3 PET检查显示手术后缺损面积百分比（27．0±5．0）较手术前（4．0±3．2）有显著性差异,证实心梗模型建立成功。结论本实验中开胸手术成功率高,术后血流评价方法可用于手术前后冠脉血流和心肌血流的比较以及对心肌梗死后治疗效果进行评价。     

美花石斛化学成分及其护肤活性研究

本文研究美花石斛(Dendrobium loddigesii)的化学成分及其护肤活性。采用色谱法从美花石斛粗提物中分离得到12个化合物,利用波谱学方法分别鉴定为拖鞋状石斛素(1)、2,4,7-三羟基-9,10-二氢菲(2)、3,6,9-三羟基-3,4-二氢蒽-1(2H)-酮(3)、3,5′-二甲氧基-3′,4,9′-三羟基-7′,9-环氧-8,8′-木酚素(4)、5-(4-羟基-3-甲氧基苯乙基)-2-(4-羟基-3-甲氧基苯基)苯并二氢呋喃-3,7-二醇(5)、5-(4′′-羟基-3′′-甲氧基苯乙基)-2-(4′-羟基-5′-甲氧基苯基)-7-甲氧基苯并二氢吡喃-3-醇(6)、丁香脂素(7)、异香草醛(8)、松柏醛(9)、2-甲氧基-5-羟甲基苯酚(10)、二氢松柏醇(11)、4-羟基-3-甲氧基苯乙醇(12)。其中化合物3～5、7～12为首次从美花石斛中分离得到;化合物1、2、6(100μg/mL)有一定的自由基清除活性(>80%);化合物2(10μg/mL)有一定促胶原蛋白分泌活性(>20%)。结果显示从美花石斛的茎中分离得到了12个化合物,3个表现出良好的护肤活性。     

斑背大尾莺繁殖期鸣声行为分析

2009年5-7月,在辽宁双台河口保护区录制了20只繁殖期斑背大尾莺雄性个体的鸣声.根据行为特征,该鸟鸣声定义为3种鸣声类型:求偶炫耀鸣唱、报警声和联络声.利用Wavesurfer软件对20只斑背大尾莺雄性个体543个鸣声的句子持续时间、句子音节个数、音节持续时间、音节间隔时间等4个参数进行分析测量,发现求偶炫耀鸣唱由节奏逐渐加快的前部句子和音节组成复杂的主体部两个句子组成; 报警声和联络声的句子均由单音节组成.音节类型总数为38种,其中包括前部句子的音节类型6种.采用单因素方差分析(one-way ANOVA)对求偶炫耀鸣唱的4个参数进行差异性检验发现,不同个体的各个参数均呈极显著差异(P<0.01).     

Enhanced welan gum production using a two-stage agitation speed control strategy in Alcaligenes sp. CGMCC2428

Batch fermentative production of welan gum by Alcaligenes sp. CGMCC2428 was investigated under various oxygen supply conditions using regulating agitation speed. Based on a three kinetic parameters analysis that includes specific cell growth rate (μ), specific glucose consumption rate (q _s), and specific welan formation rate (q _p), a two-stage agitation speed control strategy was proposed to achieve high concentration, high yield, and high viscosity of welan. During the first 22 h, the agitation speed in 7.5 L fermenter was controlled at 800 rpm to maintain high μ for cell growth. The agitation was then reduced step-wise to 600 rpm to maintain a changing profile with stable dissolved oxygen levels and obtain high qp for high welan accumulation. Finally, the maximum concentration of welan was reached at 26.3 ± 0.89 g L⁻¹ with a yield of 0.53 ± 0.003 g g⁻¹ and the welan gum viscosity of 3.05 ± 0.10 Pa s, which increased by an average of 15.4, 15.2, and 20.1% over the best results controlled by constant agitation speeds.     

The Frequency and Clinical Implication of ROS1 and RET Rearrangements in Resected Stage IIIA-N2 Non-Small Cell Lung Cancer Patients

To evaluate the frequency and clinicopathological features of ROS1 and RET rearrangements in N2 node positive stage IIIA (IIIA-N2) non-small cell lung cancer (NSCLC) patients, we retrospectively screened 204 cases with a tissue microarray (TMA) panel by fluorescent in situ hybridization (FISH), and confirmed by direct sequencing and immunohistochemistry (IHC). The relationship between ROS1 or RET rearrangements, clinicopathological features, and prognostic factors were analyzed in resected stage IIIA-N2 NSCLC. Of the 204 cases, 4 cases were confirmed with ROS1 rearrangement, but no RET rearrangement was detected. All 4 ROS1-rearranged cases were adenocarcinomas. The predominant pathological type was acinar pattern in ROS1-rearranged tumors, except for 1 case harboring a mixture acinar and mucous tumor cells. Variants of ROS1 rearrangement were SDC4-ROS1 (E2:E32), SDC4-ROS1 (E4:E32) and SDC4-ROS1 (E4:E34). There was no significant association between ROS1 rearrangement and clinicopathological characteristics. In this cohort, multivariate analysis for overall survival (OS) indicated that squamous cell carcinoma and lobectomy were independent predictors of poor prognosis; R0 surgical resection and non-pleural invasion were independent predictors of good prognosis. In resected stage IIIA-N2 NSCLC patients, ROS1-rearranged cases tended to occur in younger patients with adenocarcinomas. The prognosis of resected stage IIIA-N2 is generally considered poor, but patients with ROS1 rearrangement will benefit from the targeted therapy.     

A simple and biosafe method for isolation of human umbilical vein endothelial cells

Human umbilical vein endothelial cells (HUVEC_S) are used as an irreplaceable tool for the study of vascular diseases. However, the technicians who isolate HUVECs are largely exposed to potential infectious threats. Here we report the development of a specialized instrument to protect researchers from known or unknown infectious agents when they operate on human umbilical cords. This instrument can be assembled by common laboratory supplies and adapted to accommodate umbilical cords of different lengths. When the cord is enclosed within the instrument, the risk of sample contamination and operator infection is greatly reduced. Using our instrument, endothelial cells were successfully isolated from human umbilical veins without contamination. The cells were verified by their cobblestone-like morphology and by immunofluorescence staining (Factor VIII and CD31 positivity and α-SMA negativity). Our instrument simplifies and optimizes the cell extraction process, and most importantly elevates the biosafety to a higher level during the isolation of human umbilical vein endothelial cells.     

Repair mechanisms of bone marrow mesenchymal stem cells in myocardial infarction

The prognosis of patients with myocardial infarction (MI) and resultant chronic heart failure remains extremely poor despite advances in optimal medical therapy and interventional procedures. Animal experiments and clinical trials using adult stem cell therapy following MI have shown a global improvement of myocardial function. Bone marrow-derived mesenchymal stem cells (MSCs) hold promise for cardiac repair following MI, due to their multilineage, self-renewal and proliferation potential. In addition, MSCs can be easily isolated, expanded in culture, and have immunoprivileged properties to the host tissue. Experimental studies and clinical trials have revealed that MSCs not only differentiate into cardiomyocytes and vascular cells, but also secrete amounts of growth factors and cytokines which may mediate endogenous regeneration via activation of resident cardiac stem cells and other stem cells, as well as induce neovascularization, anti-inflammation, anti-apoptosis, anti-remodelling and cardiac contractility in a paracrine manner. It has also been postulated that the anti-arrhythmic and cardiac nerve sprouting potential of MSCs may contribute to their beneficial effects in cardiac repair. Most molecular and cellular mechanisms involved in the MSC-based therapy after MI are still unclear at present. This article reviews the potential repair mechanisms of MSCs in the setting of MI.