脂肪细胞新蛋白My027原核表达、纯化及生物活性研究

目的通过原核表达获得大量脂肪新蛋白质My027,并在体外初步研究其生物活性。方法RT-PCR法扩增出My027片段,插入原核表达载体pGEX-4T-2,构建质粒pGEX-My027。转化BL-21菌,IPTG低温诱导表达融合蛋白,经亲和层析法获得融合蛋白,利用SDS-PAGE、Western印迹及质谱进行鉴定。在还原性谷胱甘肽存在的条件下,将纯化得到的融合蛋白作用于乙二醛酶Ⅰ的底物甲基乙二醛,通过分光光度法检测产物乳酸谷胱甘肽的生成。结果融合蛋白以水溶形式分泌于大肠埃希菌BL-21胞浆中,纯化后的目的蛋白SDS-PAGE、Western印迹及质谱证实高效表达,氨基酸序列正确。结论人脂肪细胞新蛋白质My027在pGEX-4T-2原核表达载体中可获高效表达,所纯化蛋白具有类似于乙二醛酶Ⅰ的作用。     

ODC反义寡核苷酸对K562细胞生长抑制作用

鸟氨酸脱羧酶(ornithine decarboxylase,ODC)是催化多胺生物合成的限速酶.过去的研究表明多胺在维持肿瘤恶性表型中起着重要作用.用ODC不可逆抑制剂抑制多胺生物合成不仅能抑制肿瘤细胞的增殖而且还诱导细胞分化.近年我们采用反义技术,以ODC反义RNA转染肿瘤细胞,通过对ODC表达的封闭,成功地使其恶性表型得到了逆转.提示抑制肿瘤细胞的多胺合成可能是抗癌的有效途径.本文用ODC反义寡核苷酸控制肿瘤细胞的多胺生物合成,观察了其对K562细胞生长特性的影响,以期为ODC反义寡核苷酸在肿瘤临床的应用提供实验依据.     

A non-linear flow model for the flow behavior of water inrush induced by the karst collapse column

Water inrush induced by the karst collapse column (KCC) is a great threat to coal mine safety. In this study, a non-linear flow model that couples three flow types is built based on flow transition from laminar flow in the aquifer to turbulent flow in the mine roadways during the process of water inrush induced by KCC. The proposed model couples Darcy flow, Forchheimer flow, and turbulent flow, and is then used to simulate the flow behavior of water inrush induced by KCC. In particular, the “3.1” water inrush incident from the coal seam floor in the Luotuoshan coal mine, China, is numerically investigated. The numerical results show that with the increase of the inrush flow rate, Forchheimer flow in the water inrush channel is first controlled by viscous resistance, then affected by both viscous resistance and inertial resistance, and finally controlled by inertial resistance. Therefore, water inrush induced by KCC is a dynamic process with a transition from laminar to turbulent. The Forchheimer equation proved to be applicable in describing the high-velocity non-linear flow, and can also reflect the intermediate state of the flow translation from laminar flow in the aquifer to turbulent flow in the roadway during the water inrush process.

A non-linear flow model that couples three flow types is built based on flow transition to investigate the flow behavior of water inrush induced by KCC.     

Effective inhibition in animals of viral pathogenesis by a ribozyme derived from RNase P catalytic RNA

A functional RNase P ribozyme (M1GS RNA) was constructed to target the overlapping mRNA region of two murine cytomegalovirus (MCMV) capsid proteins essential for viral replication: the assembly protein (mAP) and M80. The customized ribozyme efficiently cleaved the target mRNA sequence in vitro. Moreover, 80% reduction in the expression of mAP and M80 and a 2,000-fold reduction in viral growth were observed in cells expressing the ribozyme. In contrast, there was no significant reduction in viral gene expression and growth in cells that either did not express the ribozyme or produced a “disabled” ribozyme carrying mutations that abolished its catalytic activity. When the ribozyme-expressing constructs were delivered into MCMV-infected SCID mice via a modified “hydrodynamic transfection” procedure, expression of ribozymes was observed in the livers and spleens. Compared with the control animals that did not receive any M1GS constructs or received the disabled ribozyme construct, animals receiving the functional ribozyme construct exhibited a significant reduction of viral gene expression and infection. Viral titers in the spleens, livers, lungs, and salivary glands of the functional ribozyme-treated SCID mice at 21 days after infection were 200- to 2,000-fold lower than those in the control animals. Moreover, survival of the infected animals significantly improved upon receiving the functional ribozyme construct. Our study examines the use of M1GS ribozymes for inhibition of gene expression in animals and demonstrates the utility of RNase P ribozymes for gene targeting applications in vivo.     

18F-FDG PET/CT影像组学在预测肺腺癌患者EGFR突变中的价值

目的分析并比较¹⁸F-脱氧葡萄糖(FDG)PET及CT影像组学参数在预测肺腺癌患者表皮生长因子受体(EGFR)表达中的作用。方法回顾性收集2017年1月至12月间于南方医院就诊的114例[男64例,女50例,年龄35~84(平均61)岁]肺腺癌初治患者的治疗前¹⁸F-FDG PET/CT图像及其EGFR表达资料。用LIFEx软件手动逐层勾画感兴趣体积并提取图像参数,通过最小绝对收缩和选择算子(LASSO)方法重复200次进行参数选择,经十倍交叉验证选择模型的最优调和参数λ,再采用logistics逐步回归进一步筛选参数建模。针对3种数据集(PET参数、CT参数、PET+CT参数)构建3种模型,分别记为MPET、MCT、MPET+CT。用受试者工作特征(ROC)曲线分析模型预测EGFR突变的价值,获得曲线下面积(AUC)、灵敏度、特异性、准确性,采用Delong检验比较三者的AUC。结果114例肺腺癌患者中,EGFR野生型61例(53.51%),EGFR突变型53例(46.49%)。最终从PET、CT、PET+CT图像参数中分别筛选出3、3、7个参数构成回归模型MPET、MCT、MPET+CT,三者AUC分别为0.730、0.752、0.866。当三者界值分别取0.427、0.522、0.378时,约登指数最大,分别为0.420、0.405、0.630,灵敏度分别为83.0%(44/53)、58.5%(31/53)、92.5%(49/53),特异性分别为59.0%(36/61)、82.0%(50/61)、70.5%(43/61),准确性分别为70.2%(80/114)、71.1%(81/114)、80.7%(92/114)。MPET与MCT的AUC之间差异无统计学意义(z=-0.320,P>0.05),MPET+CT与MPET、MCT之间AUC差异均有统计学意义(z值:2.963、2.523,均P<0.05)。结论PET、CT、PET+CT影像组学均与肺腺癌EGFR基因表达状态相关,其中MPET+CT预测效能最高。     

在校小学生意外伤害救护认知与教育需求调查

目的 了解小学生对意外伤害救护的认知水平、教育现状与需求,针对薄弱环节,探索适应小学生需求及学习特征的培训形式。 方法 通过学校微信平台,对武汉市江岸区某小学1 264名学生进行意外伤害救护认知与教育需求问卷调查,并进行统计学分析。 结果 小学生对心肺复苏有效时间、心肺复苏按压深度、按压部位、复苏抢救对象知晓率低,仅为12.82%、25.08%、50.55%、70.33%;溺水的急救知晓率仅30.46%;不同年级学生对学校易受伤地点、易受伤情境、易受伤原因、同学做危险活动时表现的认知及对心肺复苏知识的知晓和烫伤、眼部异物、气管异物的急救处理认知上存在统计学差异(P＜0.05);97.63%的小学生希望医院-学校建立联合培训模式;68.35%选择情景游戏方式进行培训。 结论 小学生对意外伤害救护认知存在局限,尤其心肺复苏知识与技能急待提升,学校及教育主管部门可探索医院-学校联合培训形式,建构科学规范的安全教育体系,提高小学生意外伤害救护能力。     

Functional photoacoustic/ultrasound imaging for the assessment of breast intraductal lesions: preliminary clinical findings

This study aimed to identify features of breast intraductal lesions in photoacoustic/ultrasound (PA/US) imaging and compare PA/US with color Doppler flow/ultrasound (CDFI/US) in the evaluation of breast intraductal lesions. In the nine patients with 10 breast intraductal lesions and 8 patients with 8 benign lesions, total vessel scores evaluated from PA/US are significantly greater than those from CDFI/US (p=0.005). PA internal vessel scores and oxygen saturation (SO₂) score are significantly increased in breast intraductal lesions than in benign lesions (p=0.016, p=0.006). With a cutoff PA score (sum of PA internal vessel score and SO₂ score) of 2.5, we obtained a sensitivity of 90% and a specificity of 87.5% in differentiation of two groups. PA/US upgraded 40% of breast intraductal lesions, and downgraded 50% of benign lesions from the Breast Imaging Reporting and Data System grading results based on CDFI/US. PA/US functional imaging has the potential in differentiating breast intraductal lesions.     

肾清汤灌肠联合结肠透析治疗慢性肾功能衰竭临床研究

目的:观察肾清汤灌肠联合结肠透析治疗慢性肾功能衰竭的临床疗效。方法:将慢性肾功能衰竭患者100例,随机分为治疗组和对照组各50例。对照组给予基础治疗(饮食教育、治疗原发病、控制血压、纠正电解质紊乱及代谢性酸中毒、纠正贫血、调节钙磷代谢、防止感染等);治疗组在对照组的基础上加用肾清汤灌肠联合结肠透析,2组均观察治疗10 d,统计2组临床疗效及不良反应情况,检测2组治疗前后肌酐(SCr)、尿素氮(BUN)、内生肌酐清除率(CCr)、血红蛋白(Hb)、血浆白蛋白(Alb)水平变化。结果:治疗组总有效率为86.0%,对照组为64.0%,2组比较,差异有统计学意义(P<0.05)。治疗后,2组SCr、BUN水平均较治疗前降低(P<0.05),CCr值较治疗前升高(P<0.05);且治疗组各项指标改善较对照组更显著(P<0.05)。治疗后2组患者Alb改善不大,治疗前后及组间比较,差异均无统计学意义(P>0.05)。治疗后,2组患者Hb均较治疗前升高(P<0.05),且治疗组Hb升高较对照组更显著(P<0.05)。治疗组不良反应发生率为26.0%,对照组为18.0%,2组比较,差异无统计学意义(P>0.05)。结论:肾清汤灌肠联合结肠透析治疗慢性肾功能衰竭疗效显著。     

Interactive effects of elevated ozone and UV-B radiation on soil nematode diversity

Ultraviolet-B (UV-B) radiation and elevated tropospheric ozone may cause reductions in the productivity and quality of important agricultural crops. However, research regarding their interactive effect is still scarce, especially on the belowground processes. Using the open top chambers experimental setup, we monitored the response of soil nematodes to the elevated O₃ and UV-B radiation individually as well as in combination. Our results indicated that elevated O₃ and UV-B radiation have impact not only on the belowground biomass of plants, but also on the community structure and functional diversity of soil nematodes. The canonical correspondence analysis suggested that soil pH, shoot biomass and microbial biomass C and N were relevant parameters that influencing soil nematode distribution. The interactive effects of elevated O₃ and UV-B radiation was only observed on the abundance of bacterivores. UV-B radiation significantly increased the abundance of total nematodes and bacterivores in comparison with the control at pod-filling stage of soybean. Following elevated O₃, nematode diversity index decreased and dominance index increased relative to the control at pod-filling stage of soybean. Nematode functional diversity showed response to the effects of elevated O₃ and UV-B radiation at pod-bearing stage. Higher enrichment index and lower structure index in the treatment with both elevated O₃ and UV-B radiation indicated a stressed soil condition and degraded soil food web. However, the ratios of nematode trophic groups suggested that the negative effects of elevated O₃ on soil food web may be weakened by the UV-B radiations.