Involvement of regulatory volume decrease in the migration of nasopharyngeal carcinoma cells

The transwell chamber migration assay and CCD digital camera imaging techniques were used to investigate the relationship between regulatory volume decrease (RVD) and cell migration in nasopharyngeal carcinoma cells (CNE-2Z cells). Both migrated and non-migrated CNE-2Z cells, when swollen by 47% hypotonic solution, exhibited RVD which was inhibited by extracellular application of chloride channel blockers adenosine 5‘-triphosphate (ATP), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and tamoxifen. However, RVD rate in migrated CNE-2Z cells was bigger than that of non-migrated cells and the sensitivity of migrated cells to NPPB and tamoxifen was higher than that of nonmigrated cells. ATP, NPPB and tamoxifen also inhibited migration of CNE-2Z cells. The inhibition of migration was positively correlated to the blockage of RVD, with a correlation coefficient (r) = 0.99, suggesting a functional relationship between RVD and cell migration. We conclude that RVD is involved in cell migration and RVD may play an important role in migratory process in CNE-2Z cells.     

Nonlocal Immunized Mid-Infrared Magnetic Hot Spots in Graphene Junctions

Magnetic hot spots, which implies confinements and enhancements of magnetic fields, are demonstrated in graphene junctions (GJs) in the mid-infrared range. The appearance of magnetic hot spots in GJs comes from the conduction currents in the junction. In further, the extinction resonance peaks suffer blue shift, along with the increases in the magnetic fields inside junction area, when the junction width reduces. In opposite to the circumstances for electric field enhancements, neither magnetic field enhancements nor resonance frequency of GJs is perturbed by the intrinsic nonlocal electronic response of graphene. Such nonlocality immunized magnetic enhancement could be explained by the polarization dependent property of nonlocal effect.     

灰仓鼠重要内脏器官生长指数及其变化

对室内培育的灰仓鼠进行同一季节不同年龄段和同一年龄段不同季节某些器官的测量。结果显示, 在初生至25 d 的高速生长期, 体重与肝脏、心脏、肺、脾脏和肾的生长非常接近Huxley 的相对生长公式Y = b x^k , 其回归方程分别为: 肝脏Y = 0.013 47 x^{1.515 9} ; 心脏Y = 0.000 18 x^2.163 ; 肺Y = 0.028 48 x^{0.798 2} ; 脾脏Y = 0.000 24 x^{1.583 6} ; 肾脏Y = 0.000 2418 x^{2.310 4} , 并高度相关。睾丸的回归方程在60 日内与Y = b x^k公式非常拟合, Y = 0.000 0108 x^{3.049 4} , r = 0.989 9。除性腺外, 肝脏、心脏、肺、脾脏和肾脏的比值最高值均在25 d 之前。在性成熟期不同年龄段, 性腺比值较稳定, 其它器官比值在性别和年龄段有显著性差异, 雌性普遍高于雄性。在10 月龄不同季节, 只有体重和睾丸比值有显著性差异(7 月最高) , 表示在不同季节利用相近体重比较器官指数差异应将年龄因素作为重要参考依据。     

多发性骨髓瘤细胞中一个表达上调基因的克隆与分析

根据GenBank收录的多发性骨髓瘤细胞株 (ARH 77)表达上调ESTAF4 2 5 30 0设计引物 ,运用RT PCR检测了 5例多发性骨髓瘤患者及 4例正常人骨髓细胞中该EST的表达水平 .Northern印迹杂交分析该EST在多种组织中的表达 .进一步利用该EST作探针 ,筛选ARH 77cDNA文库 ,获得全长cDNA克隆 ,对该序列进行了分析 .结果显示 ,该EST在多发性骨髓瘤患者骨髓细胞中亦有较高的表达 ,而在正常人骨髓细胞中低表达 .经测序证实 ,该cDNA全长为 4 5 2bp(GenBank收录号 :AF4 87338) .预测其编码一个 5 7个氨基酸的小分子量蛋白质 ,属于与DNA复制有关的解旋酶 引物酶基因家族的新成员 .该基因在多发性骨髓瘤细胞中表达上调 ,其表达水平的改变可能与多发性骨髓瘤的发生与发展有关     

濒危植物桃儿七种子休眠特性的研究

桃儿七种子在自然条件下具有休眠期长、萌发不良的生理特性,为了探讨和研究桃儿七种子的休眠特性,利用分离胚培养、生物鉴定法、GA₃浸种、以及综合利用GA₃和低温层积处理等方法。结果表明：种皮和胚乳的限制以及生理后熟是引起桃儿七种子休眠的主要原因,用400 mg·L^-1的GA₃溶液浸种24 h或低温层积后用GA₃处理均能在一定程度上解除休眠促进萌发,其中以低温层积90 d后用500 mg·L^-1的GA₃浸种36 h效果最好,发芽率和发芽势分别达到81.11%和50.00%。     

Combination of bone tissue engineering and BMP-2 gene transfection promotes bone healing in osteoporotic rats

OBJECTIVE: The aim of this study was to develop a feasible approach to promote bone healing in osteoporotic rats using autogenous bone tissue-engineering and gene transfection of human bone morphogenetic protein 2 (hBMP-2). METHODS: Bone marrow stromal cells (BMSCs) from the left tibia of osteoporotic rats were transfected with the hBMP-2 gene in vitro which was confirmed by immunohistochemistry, in situ hybridization and Western blotting. Autogenous transfected or untransfected BMSCs were seeded on macroporous coral hydroxyapatite (CHA) scaffolds. Each cell-scaffold construct was implanted into a defect site which was created in the ramus of the mandible of osteoporotic rats. Four or eight weeks after implantation in situ hybridization was performed in BMSCs transfected with hBMP-2, X-ray examinations, histological and histomorphological analyses were used to evaluate the effect of tissue-engineered bone on osseous defect repair. RESULTS: Newly formed bone was observed at the margin of the defect 4 weeks after implantation with BMSCs transfected with BMP-2. Mature bone was observed 8 weeks after treatment. In the control group there was considerably less new bone and some adipose tissue was observed at the defect margins 8 weeks after implantation. CONCLUSIONS: Autogenous cells transfected with hBMP-2 promote bone formation in osteoporotic rats. BMSC-mediated BMP-2 gene therapy used in conjunction with bone tissue engineering may be used to successfully treat bone defects in osteoporotic rats. This method provides a powerful tool for bone regeneration and other tissue engineering.     

尼可霉素(Nikkomycins)多组分结构及其生物合成相关基因的研究进展

尼可霉素是一种新的抗真菌抗生素,在分离到的20多种活性单组分中,X、Z、I、J为主要生物活性组分。本文介绍了尼可霉素的结构,结构与活性的关系及其生物合成途径中有关基因的研究进展。     

生物素-亲和素偶联探针蛋白芯片检测技术

自行制备一种新型生物素-亲和素偶联探针分子并用于反相蛋白芯片的检测。首先, 将生物素-羊抗鼠IgG与亲和素按照不同比例混合后与鼠IgG蛋白芯片反应, 观察荧光信号的放大情况; 然后以鼠IgG-羊抗鼠IgG体系为研究模式, 对反相蛋白芯片的制备条件进行了考察和优化, 包括荧光分子的非特异性吸附、点样缓冲液的选择以及蛋白的活性等。最后, 采用此偶联探针对反相蛋白芯片进行了检测。结果表明, BSA缓冲液制备的反相蛋白芯片可以防止非特异性吸附, 并有利于保持固定蛋白活性和提高检测限; 另外, 与传统的与生物素-亲和素检测技术相比, 采用生物素-亲和素偶联探针对反相芯片的检测限可以提高4倍左右。表明亲和素-生物素偶联探针成本低、易于合成、并可以与其它的信号放大技术联用进一步提高检测的灵敏度, 有望用于蛋白质芯片的检测。     

高血压病患者肠系膜动脉平滑肌细胞钙激活钾通道研究

目的:研究高血压病患者肠系膜动脉平滑肌细胞钙激活钾通道(KCa)的功能活动。方法:应用膜片钳制技术内面向外式单通道记录方法。结果:①人肠系膜动脉平滑肌细胞KCa开放具有电压依赖性。KCa通道电导在高血压组、正常组分别为191.4pS、197.7pS。胞内侧应用TEA可阻断通道。②增加浴液中Ca2 浓度(从0增至10-8、10-7、5×10-7、10-6mol/L),各组KCa开放概率(Po)均呈浓度依赖性增加,高血压组Po从0.016增至0.023、0.031、0.053、0.094,正常组Po从0.004增至0.023、0.041、0.072、0.184。通道平均开放时间延长,平均关闭时间缩短。③Ca2 浓度为0时,高血压组KCa开放概率明显高于正常组,在其它Ca2 浓度下高血压组KCa开放概率等于或低于正常组。结论:高血压病患者肠系膜动脉平滑肌细胞KCa的Ca2 敏感性较低,可能促进高血压的发生。     

High-resolution nonlinear optical imaging of live cells by second harmonic generation

By adapting a laser scanning microscope with a titanium sapphire femtosecond pulsed laser and transmission optics, we are able to produce live cell images based on the nonlinear optical phenomenon of second harmonic generation (SHG). Second harmonic imaging (SHIM) is an ideal method for probing membranes of living cells because it offers the high resolution of nonlinear optical microscopy with the potential for near-total avoidance of photobleaching and phototoxicity. The technique has been implemented on three cell lines labeled with membrane-staining dyes that have large nonlinear optical coefficients. The images can be obtained within physiologically relevant time scales. Both achiral and chiral dyes were used to compare image formation for the case of single- and double-leaflet staining, and it was found that chirality plays a significant role in the mechanism of contrast generation. It is also shown that SHIM is highly sensitive to membrane potential, with a depolarization of 25 mV resulting in an approximately twofold loss of signal intensity.