热驯化对鼎突多刺蚁热适应和运动行为的影响

为比较恒温和变温驯化对鼎突多刺蚁（Polyrhachis vicina Roger）热适应和运动行为的影响,将鼎突多翅蚁分别在15℃恒温和13.4～21.6℃变温下进行驯化,定量分析两种驯化温度对鼎突多翅蚁热适应和运动行为的影响.结果表明,恒温和变温驯化对鼎突多刺蚁的最适温度、逃避高温、运动中的停顿频率、疾跑速度、最大持续运动距离均有显著影响（p＜0.01）,而对逃避低温的影响不显著（p=0.343）;变温驯化后鼎突多刺蚁的最适温度仅有一个峰值,这不符合最适性模型的预测;恒温和变温驯化下鼎突多刺蚁的疾跑速度与最大持续运动距离都呈显著的正相关（分别为p=0.017和p＜0.001）,且经过变温驯化的鼎突多刺蚁的运动能力明显强于恒温驯化下个体的运动能力.     

厦门凤林红树林湿地大型底栖动物群落

为摸清厦门集美凤林红树林湿地的大型底栖动物群落结构及其多样性现状,2002年1、4、7和10月在厦门集美凤林红树林区进行大型底栖动物调查,4个季度共获得大型底栖动物42种。生物量优势种是软体动物门的珠带拟蟹守螺(Cerithideacingulata)和节肢动物门的弧边招潮(Ucaarcuata)。密度优势种是软体动物门的短拟沼螺(Assimineabrevicula)和环节动物门的沼蚓(Limnodriloidessp.)。集美凤林红树林区大型底栖动物年平均密度和年平均生物量分别为1,990ind./m2和139.0g/m2。密度的季节变化是:1月>4月>10月>7月,生物量的季节变化是1月>10月>4月>7月。聚类分析和数量分布表明,优势种珠带拟蟹守螺、短拟沼螺、弧边招潮和沼蚓的季节变化各不相同。与2002年10月深圳湾福田红树林区大型底栖动物群落的物种多样性指数平均值(0.56)比较,厦门凤林红树林区的平均值较高(2.66)。文中分析了影响大型底栖动物多样性的环境因素。     

Expression and purification of the catalytic domain of human vascular endothelial growth factor receptor 2 for inhibitor screening

Vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, can act in tumor-induced angiogenesis by binding to specific receptors on the surface of endothelial cells. One such receptor, VEGFR-2/KDR, plays a key role in VEGF-induced angiogenesis. Here, we expressed the catalytic domain of VEGFR-2 as a soluble active kinase using Bac-to-Bac expression system, and investigated correlations between VEGFR-2 activity and enzyme concentration, ATP concentration, substrate concentration and divalent cation type. We used these data to establish a convenient, effective and non-radioactive ELISA screening technique for the identification and evaluation of potential inhibitors for VEGFR-2 kinase. We screened 200 RTK target-based compounds and identified one (TKI-31) that potently inhibited VEGFR-2 kinase activity (IC50=0.596 microM). Treatment of NIH3T3/KDR cells with TKI-31 blocked VEGF-induced phosphorylation of KDR in a dose-dependent manner. Moreover, TKI-31 dose-dependently suppressed HUVEC tube formation. Thus, we herein report a novel, efficient method for identifying VEGFR-2 kinase inhibitors and introduce one, TKI-31, that may prove to be a useful new angiogenesis inhibitor.     

Formation of collagen-glycosaminoglycan blended nanofibrous scaffolds and their biological properties

The development of blended collagen and glycosaminoglycan (GAG) scaffolds can potentially be used in many soft tissue engineering applications since the scaffolds mimic the structure and biological function of native extracellular matrix (ECM). In this study, we were able to obtain novel nanofibrous collagen-GAG scaffolds by electrospinning collagen blended with chondroitin sulfate (CS), a widely used GAG, in a mixed solvent of trifluoroethanol and water. The electrospun collagen-GAG scaffold with 4% CS (COLL-CS-04) exhibited a uniform fiber structure with nanoscale diameters. A second collagen-GAG scaffold with 10% CS consisted of smaller diameter fibers but exhibited a broader diameter distribution due to the different solution properties in comparison with COLL-CS-04. After cross-linking with glutaraldehyde vapor, the collagen-GAG scaffolds became more biostable and were resistant to collagenase degradation. This is evidently a more favorable environment allowing increased proliferation of rabbit conjunctiva fibroblast on the scaffolds. Incorporation of CS into collagen nanofibers without cross-linking did not increase the biostability but still promoted cell growth. The potential of applying the nanoscale collagen-GAG scaffold in tissue engineering is significant since the nanodimension fibers made of natural ECM mimic closely the native ECM found in the human body. The high surface area characteristic of this scaffold may maximize cell-ECM interaction and promote tissue regeneration faster than other conventional scaffolds.     

Monoclonal antibody-based quantitation of poly(ethylene glycol)-derivatized proteins, liposomes, and nanoparticles

Covalent attachment of poly(ethylene glycol) (PEG) molecules to drugs, proteins, and liposomes is a proven technology for improving their bioavailability, safety, and efficacy. Qualitative and quantitative analysis of PEG-derivatized molecules is important for both drug development and clinical applications. We previously reported the development of a monoclonal IgM antibody (AGP3) to PEG. We now describe a new IgG1 monoclonal antibody (E11) to PEG and show that it can be used in combination with AGP3 to detect and quantify PEG-derivatized molecules. Both antibodies bound the repeating subunits of the PEG backbone and could detect free PEG and PEG-modified proteins by ELISA, immunoblotting, and flow cytometry. Detection sensitivity increased with the length and the number of PEG chains on pegylated molecules. Both antibodies also efficiently accelerated the clearance of a PEG-modified enzyme in vivo. A sandwich ELISA in which E11/AGP3 were employed as the capture/detection antibodies was developed to detect PEG-modified proteins at concentrations as low as 1.2 ng/mL. In addition, the ELISA could also quantify, in the presence of 10% fetal bovine serum, free methoxy-PEG20,000, PEG2,000-quantum dots, and PEG2,000-liposomes at concentrations as low as 20 ng/mL (1.0 nM), 1.4 ng/mL (3.1 pM), and 2.4 ng/mL (3.13 nM phospholipids), respectively. Finally, we show that the sandwich ELISA could accurately measured the in vivo half-life of a PEG-modified enzyme. These antibodies should be generally applicable to the qualitative and quantitative analysis of all PEG-derivatized molecules.     

Intervention Strategies for Improving Patient Adherence to Follow-Up in the Era of Mobile Information Technology: A Systematic Review and Meta-Analysis

Background

Patient adherence to follow-up plays a key role in the medical surveillance of chronic diseases and affects the implementation of clinical research by influencing cost and validity. We previously reported a randomized controlled trial (RCT) on short message service (SMS) reminders, which significantly improved follow-up adherence in pediatric cataract treatment.

Methods

RCTs published in English that reported the impact of SMS or telephone reminders on increasing or decreasing the follow-up rate (FUR) were selected from Medline, EMBASE, PubMed, and the Cochrane Library through February 2014. The impacts of SMS and telephone reminders on the FUR of patients were systematically evaluated by meta-analysis and bias was assessed.

Results

We identified 13 RCTs reporting on 3276 patients with and 3402 patients without SMS reminders and 8 RCTs reporting on 2666 patients with and 3439 patients without telephone reminders. For the SMS reminders, the majority of the studies (>50%) were at low risk of bias, considering adequate sequence generation, allocation concealment, blinding, evaluation of incomplete outcome data, and lack of selective reporting. For the studies on the telephone reminders, only the evaluation of incomplete outcome data accounted for more than 50% of studies being at low risk of bias. The pooled odds ratio (OR) for the improvement of follow-up adherence in the SMS group compared with the control group was 1.76 (95% CI [1.37, 2.26]; P<0.01), and the pooled OR for the improvement of follow-up adherence in the telephone group compared with the control group was 2.09 (95% CI [1.85, 2.36]; P<0.01); both sets showed no evidence of publication bias.

Conclusions

SMS and telephone reminders could both significantly improve the FUR. Telephone reminders were more effective but had a higher risk of bias than SMS reminders.     

Nitric oxide and hydrogen peroxide are important signals mediating the allelopathic response of Arabidopsis to p‐hydroxybenzoic acid

Both nitric oxide (NO) and hydrogen peroxide (H₂O₂) are important signals that mediate plant response to environmental stimulation. Their role in plants' allelopathic interactions has also been reported, but the underlying mechanism remains little understood. p‐Hydroxybenzoic acid (pHBA) has been proposed to be an allelopathic chemical. Here, we found that pHBA at 0.4 mM efficiently suppressed Arabidopsis growth. Meanwhile, pHBA rapidly induced the accumulation of NO and H₂O₂, where such effect could be reversed by NO or H₂O₂ metabolism inhibitors or scavengers. Also, pHBA‐induced NO and H₂O₂ could be compromised in NO synthesis mutants noa1, nia1 and nia2, or H₂O₂ metabolism mutant rbohD/F, but suppressing NO accumulation with a NO synthesis inhibitor or using NO synthesis‐related mutants did not reduce pHBA‐induced H₂O₂ accumulation. Furthermore, we found that the effect of pHBA on allelopathic inhibition of growth was aggravated in NO/H₂O₂ metabolism‐related mutants or reducing NO/H₂O₂ by different inhibitors, whereas the addition of an NO/H₂O₂ donor could partly relieve the inhibitory effect of pHBA on the growth of wild type. However, adding only an NO donor, but not low concentration of H₂O₂ as the donor, could relieve the inhibitory effect of pHBA on root growth in NO metabolism mutants. On the basis of these results, we propose that both NO and H₂O₂ are important signals that mediate Arabidopsis response to the allelopathic chemical pHBA, where during this process H₂O₂ may work upstream of the NO signal.     

WJSC 6th Anniversary Special Issues（2）:Mesenchymal stem cells Enhancing the efficacy of mesenchymal stem cell therapy

Mesenchymal stem cell(MSC)therapy is entering a challenging phase after completion of many preclinical and clinical trials.Among the major hurdles encountered in MSC therapy are inconsistent stem cell potency,poor cell engraftment and survival,and age/disease-related host tissue impairment.The recognition that MSCs primarily mediate therapeutic benefits through paracrine mechanisms independent of cell differentiation provides a promising framework for enhancing stem cell potency and therapeutic benefits.Several MSC priming approaches are highlighted,which will likely allow us to harness the full potential of adult stem cells for their future routine clinical use.