Regulatory effects of resveratrol on antioxidant enzymes: A mechanism of growth inhibition and apoptosis induction in cancer cells

Resveratrol (RSV) is a natural polyphenol that is known as a powerful chemopreventive and chemotherapeutic anticancer molecule. This study focused on the effects of RSV on the activities and expression levels of antioxidant enzymes in the cancer cells. Prostate cancer PC-3 cells, hepatic cancer HepG2 cells, breast cancer MCF-7 cells and the non-cancerous HEK293T kidney epithelial cells were treated with a wide range of RSV concentrations (10-100 μM) for 24–72 h. Cell growth was estimated by trypan blue staining, activities of the antioxidant enzymes were measured spectrophotometrically, expression levels of the antioxidant enzymes were quantified by digitalizing the protein band intensities on Western blots, and the percentage of apoptotic cells was determined by flow cytometry. Treatment with a low concentration of RSV (25 μM) significantly increased superoxide dismutase (SOD) activity in PC-3, HepG2 and MCF-7 cells, but not in HEK293T cells. Catalase (CAT) activity was increased in HepG2 cells, but no effect was found on glutathione peroxidase (GPX) upon RSV treatment. RSV-induced SOD2 expression was observed in cancer cells, although the expression of SOD1, CAT and GPX1 was unaffected. Apoptosis increased upon RSV treatment of cancer cells, especially in PC-3 and HepG2 cells. Together, our data demonstrated that RSV inhibits cancer cell growth with minimal effects on non-cancerous cells. We postulate that the disproportional up-regulation of SOD, CAT and GPX expression and enzymatic activity in cancer cells results in the mitochondrial accumulation of H₂O₂, which in turn induces cancer cell apoptosis.     

白音华矿区土壤重金属含量的空间异质性

为探讨开矿对白音华矿区土壤重金属空间分布的影响, 本研究以内蒙古西乌珠穆沁旗白音华煤矿区周边土壤为对象,分析了距离矿区8 km内的重金属Cu、Cr、Pb和Mn含量的空间异质性。结果表明: 土壤重金属Cu、Cr、Pb和Mn的平均含量分别为12.7、32.6、29.9和201.3 mg·kg^-1,其变异系数分别为26.8%、33.9%、27.1%和45.7%。采用半方差函数进行模型拟合, Cu、Cr、Pb和Mn空间分布分别符合高斯模型、高斯模型、高斯模型和线性模型。对其空间分布格局分析发现,Mn、Cr 和 Cu的空间自相关水平较高,主要受结构性因素影响,受随机性因素影响很小,Pb的空间相关性水平适中,同时受结构性因素和随机性因素影响。分形维数分析表明,4种土壤重金属含量空间分布简单,结合2D及3D图看,4种土壤重金属均呈现梯度分布,随着距离增加其含量逐步降低,Cu和Mn主要集中分布在距离矿区1.5 km内,Cr与Pb则分别集中分布在距离矿区2.0与3.0 km内。     

小鼠HSP60基因的克隆与表达条件的优化

目的:克隆小鼠热休克蛋白60(HSP60)基因,在大肠杆菌中表达,并进一步对其表达条件进行优化.方法:采用RTPCR技术克隆出非肥胖性糖尿病(NOD)小鼠HSP60的cDNA序列.构建重组表达载体pET28a- HSP60,以其转化大肠杆菌感受态细胞BL21( DE3),在不同的菌体浓度、不同浓度的异丙基-β-D-硫代半乳糖苷(IPTG)、不同诱导时间以及不同温度条件下诱导,检测重组蛋白的表达情况.结果:获得一个含有1 721bp的cDNA的片段,重组蛋白HSP60在E.coli BL -21 (DE3)中的最佳表达条件是菌体密度A600nm为0.6,诱导时间为5h,诱导物(IPTG)浓度为4mmol/L,诱导温度为35℃,重组蛋白大小约为60kD.结论:成功克隆了小鼠HSP60基因,并在大肠杆菌中获得高效表达,为重组蛋白的分离纯化及进一步研究其生物学功能奠定了基础.     

血清降钙素原与C反应蛋白的检测对下呼吸道感染性疾病的诊断价值

目的测定血清中血清降钙素原(PCT)、C反应蛋白(CRP)的含量,探讨其在下呼吸道感染性疾病诊断中的应用价值。方法选取辽宁中医药大学附属医院呼吸科2009年8月至2010年11月住院的下呼吸道感染患者35例,同期健康对照组20例,采用自动免疫透射比浊法测定PCT,胶乳增强免疫比浊法检测血清中CRP,同时检测患者白细胞计数。结果 35例下呼吸道感染患者中,PCT、CRP、WBC计数的对感染诊断的敏感性分别为77.1%、85.7%和40%,特异性分别为70%、100%和100%;对细菌性感染诊断的敏感性分别为100%、100%和63.2%,特异性为81.3%、37.5%和68.8%,且在细菌性感染中,PCT、CRP、WBC计数升高较非细菌性感染显著。结论测定血清中PCT、CRP含量对下呼吸道感染性疾病的诊断有一定临床应用价值。     

白斑综合征病毒囊膜蛋白在对虾免疫保护应用中的研究进展

白斑综合征自上世纪90年代初在水产养殖业中爆发以来,其病原体白斑综合征病毒的研究一直在深入开展,特别是WSSV结构蛋白的功能学研究尤为广泛,其主要方向集中在病毒囊膜蛋白对虾体的免疫保护上,并取得了显著的保护效果。从利用病毒囊膜蛋白作为亚单位疫苗免疫虾体、利用囊膜蛋白对应抗体保护虾体、构建囊膜蛋白基因核酸疫苗和利用RNAi干扰技术保护虾体等四个方面,对当前WSSV囊膜蛋白在对虾免疫保护中的应用进行了概述,并对其应用前景作一展望,旨在为及早开发出有效防治白斑综合征疾病的技术途径提供借鉴参考。     

肝硬化患者乙肝表面抗原的定量检测及意义

目的：探讨HBsAg定量测定在乙肝相关性肝硬化病程中的变化和意义。方法：选择乙肝相关性肝硬化患者60例纳入实验对象,根据2000年9月（西安）第10次全国病毒性肝炎学术会议修订的《病毒性肝炎防治方案》中的诊断标准分为代偿期组和失代偿期组,其中代偿期组35例,失代偿期组25例。另选取20例乙型肝炎病毒携带者作为对照组。应用电化学发光免疫分析法测定患者血清中HBsAg和HBeAg滴度,免疫荧光定量PCR法检测HBVDNA载量。结果：对照组、肝硬化代偿期组和肝硬化失代偿期组HBsAg滴度分别为：2574.73±3252.27COI、5494.35±2129.84COI和6921.25±1957.60COI,三组之间差别均有统计学意义（P〈0.05）。肝硬化代偿期组中,HBsAg滴度与HBVDNA、HBeAg水平呈负相关性（P〈0.05（）r=-0.350;r=-0.514）。肝硬化失代偿期组中,HBsAg滴度与HBVDNA及HBeAg水平均无明显相关性（r=-0.020;r=0.154）。结论：肝硬化失代偿期HBsAg滴度明显高于肝硬化代偿期,代偿期HBsAg滴度高于HBV携带者组,即HBsAg滴度随肝脏疾病进展呈阶梯型递增。肝硬化代偿期,HBsAg滴度与HBVDNA、HBeAg水平呈负相关性,HBsAg水平可以作为评估病毒复制的参考指标。肝硬化失代偿期,HBsAg滴度与HBVDNA和HBeAg无相关性,不能反映病毒复制水平,不能作为评估病毒复制的参考指标。     

超声诊断巨大毛发性胃结石一例及文献复习

目的：探讨毛发性胃结石的影像表现、临床特点及治疗。方法：回顾性分析1例毛发性胃结石患者的临床资料,结合文献报道,对其影像、临床表现和治疗方法进行探讨。结果：患者为一女性患儿,上腹痛不适半年余,既往有拔毛癖,超声诊断胃巨大毛发性结石,内镜证实后开腹手术,取石成功,随访痊愈。结论：毛发性胃结石与其它胃结石相比,影像表现、临床特点无明显差异,超声检查可提供可靠的诊断提示,治疗需取出结石以消除症状,并注意心理干预,防止复发。     

复方环丙酮胺治疗浅部真菌病的疗效观察

观察复方环丙酮胺喷剂治疗浅部真菌病的疗效。第Ⅰ批给予复方环丙酮胺喷剂,1次/d喷于患处,用药4周后观察疗效;第Ⅱ批随机入A、B组,A组给予复方环丙酮胺喷剂+曲安奈德喷剂,B组给予复方环丙酮胺喷剂,均1次/d喷于患处,用药2周、4周后观察疗效。第Ⅰ批治疗4周总有效率为80%;第Ⅱ批A、B组治疗2周总有效率分别为75%及82.35%,治疗4周总有效率分别为94.74%及100%。复方环丙酮胺喷剂和复方环丙酮胺喷剂+曲安奈德喷剂治疗浅部真菌病的疗效相似(P>0.05),且疗效显著、局部刺激小、瘙痒缓解明显、安全性较高。     

大鼠脑缺血再灌注后血清中血管内皮生长因子与神经元凋亡的研究

目的:通过检测SD大鼠脑缺血再灌注模型血清中血管内皮生长因子(VEGF)与神经元凋亡动态表达变化的关系,以探讨两者之间的相关性。方法:将40只大鼠随机分为8组:对照组、假手术组和脑缺血30min再灌注12h组、1d组、3d组、5d组、7d组、及14d组,每组5只。采用ELISA双抗夹心法检测大鼠血清中血管内皮生长因子、原位细胞凋亡TUNEL法检测脑组织中的凋亡神经细胞数。结果:再灌注12h、1d、3d、5d、7d及14d大鼠血清VEGF表达和凋亡神经元百分比的变化均为负相关性(均为P<0.05)。结论:在脑缺血再灌注大鼠模型中,缺血诱导使VEGF的表达发生变化,VEGF通过直接或间接的途径抑制神经元凋亡。     

Enhancing electro-transformation competency of recalcitrant Bacillus amyloliquefaciens by combining cell-wall weakening and cell-membrane fluidity disturbing

Bacillus amyloliquefaciens has been a major workhorse for the production of a variety of commercially important enzymes and metabolites for the past decades. Some subspecies of this bacterium are recalcitrant to exogenous DNA, and transformation with plasmid DNA is usually less efficient, thereby limiting the genetic manipulation of the recalcitrant species. In this work, a methodology based on electro-transformation has been developed, in which the cells were grown in a semicomplex hypertonic medium, cell walls were weakened by adding glycine (Gly) and dl-threonine (dl-Thr), and the cell-membrane fluidity was elevated by supplementing Tween 80. After optimization of the cell-loosening recipe by response surface methodology (RSM), the transformation efficiency reached 1.13 ± 0.34 × 10⁷ cfu/μg syngeneic pUB110 DNA in a low conductivity electroporation buffer. Moreover, by temporary heat inactivation of the host restriction enzyme, a transformation efficiency of 8.94 ± 0.77 × 10⁵ cfu/μg DNA was achieved with xenogeneic shuttle plasmids, a 10³-fold increase compared to that reported previously. The optimized protocol was also applicable to other recalcitrant B. amyloliquefaciens strains used in this study. This work could shed light on the functional genomics and subsequent strain improvement of the recalcitrant Bacillus, which are difficult to be transformed using conventional methods.