碘化钾制备的碘涂层钛板的抗菌性能研究

目的探讨利用碘化钾制备碘涂层钛板的可行性,并验证其抗菌性能。方法以碘化钾作为电解液,使用电泳沉积法将碘负载到钛板表面,制备出碘涂层钛板。通过扫描电镜与能谱分析,观察碘涂层钛板的表面征象和成分结构。实验分组:对照组是经过预处理但未行载碘的钛板,共10块;实验组是经过预处理后再行载碘的碘涂层钛板,根据电解液浓度的不同分为3组:1000 mg/L、2000 mg/L、4000 mg/L组,每组各10块。使用1×106 CFU/mL的金黄色葡萄球菌(ATCC25923)进行体外抗菌实验,并对其抗菌性能进行研究。结果碘涂层钛板外观呈灰色,表面可均匀覆盖一层平整、无塌陷的涂层,电镜下见其表面可形成碘涂层,局部散在分布大小不等的不规则陷凹。对照组、1000 mg/L组、2000 mg/L组、4000 mg/L组的钛板碘含量分别为0、5.10、10.32、15.05 mass%;其体外抗菌菌落计数分别为56.00±5.09、21.40±2.76、9.10±2.51和2.00±1.88,4组之间菌落计数比较差异均有统计学意义(P<0.05)。结论碘化钾作为电解液,使用电泳沉积法可成功制备出碘含量稳定、涂层分布均匀的碘涂层钛板。体外抗菌实验证明碘涂层钛板的抗菌性能强于未载碘钛板。     

Hypoxia-induced lncRNA CASC9 enhances glycolysis and the epithelial-mesenchymal transition of pancreatic cancer by a positive feedback loop with AKT/HIF-1α signaling

Increasing evidence indicates the dysregulations and pivotal roles of lncRNAs in the development and progression of various cancers, including pancreatic cancer. Enhanced glycolytic flux and epithelial-to-mesenchymal transition (EMT) have been considered as important factors in driving the malignance of pancreatic cancer. Here, we sought to evaluate the biological role and involved mechanism of lncRNA CASC9 (CASC9) in pancreatic cancer. Our present study showed that CASC9 was upregulated in various pancreatic cancer cell lines. Loss- and gain-of function of CASC9 demonstrated its critical roles in promoting the glycolysis and EMT phenotypes of pancreatic cancer. Moreover, knockdown of CASC9 inhibited the tumorigenicity and metastasis in vivo. Additionally, our findings showed that hypoxia induced the expression of CASC9 and enhanced the binding of HIF-1α to its promoter. We also demonstrated that the positive feedback loop of CASC9 and the AKT/HIF-1α signaling cascade partially mediated this biological process. Altogether, our results suggest that CASC9 promotes the glycolysis and EMT of pancreatic cancer by a positive feedback loop with AKT/HIF-1α signaling, which is synergistically enhanced by the tumor hypoxic niche. Our study will provide potential therapeutic targets for treating pancreatic cancer.     

儿童多发性硬化生活能力、神经心理和眼科预后长期随访观察

目的通过对儿童多发性硬化（MS）系统随访,总结其躯体、心理预后及视力特点。方法回顾性收集首都医科大学附属北京儿童医院近10年来经McDonald诊断标准评估确诊的MS病历,对病程3年以上的MS病例进行系统的随访,随访内容包括日常生活活动能力评估（ADL）,扩展的功能障碍量表评分（EDSS）,神经心理评估（抑郁、焦虑、注意力、社会生活能力）和智力检测,眼科检查［最佳矫正视力、光学相干断层扫描(OCT)测量视神经纤维层(RNFL)厚度、图形视觉诱发电位(P-VEP)］等,对预后进行综合分析。 结果23例MS患儿进入分析。男10例,女13例,平均起病年龄7.7岁;复发缓解型20例,进展复发型2例,继发进展型1例。23例均复发,次数1～10次。平均随访7.7（3.6～14）年,均行ADL评分,完全依赖和中度依赖各1例,均为进展复发型;16例行EDSS评分,EDSS 0分 11例,EDSS≤2.5分4例,EDSS 4.0分1例（为进展复发型）;15例完成神经心理检查,韦氏智力测验2例低于平常,2例边界,1例社会适应能力临界,6例存在注意力缺陷,4例存在轻度焦虑情绪,均无抑郁情绪。16例患儿32眼完善眼科检查,30眼矫正视敏度0.5～1.5,视野无异常,余2眼仅存光感;合并视神经炎MS患儿眼底均提示视神经萎缩,OCT检查结果显示视神经眼在各个象限的RNFL厚度与无视神经炎眼相比明显变薄（P＜0.001）;P-VEP检查中视神经炎眼较无视神经炎眼P100潜伏期明显延长,振幅明显减低（P＜0.05） 结论儿童MS复发缓解型预后尚好,多合并视神经萎缩,但无视力严重受损;其他类型预后差,多遗留躯体残疾及视力残疾,OCT检查可对视神经受累程度定量测定。儿童MS可出现认知损害、焦虑和注意力缺陷等多种神经心理问题。     

分析探讨更年期卵巢衰退动物模型与肾虚动物模型

文章对现存更年期卵巢衰退动物模型与肾虚动物模型进行了深入的分析探讨,提出了西医卵巢衰退理论与中医肾虚理论相结合的新理念,为建立更为接近临床更年期综合征症状的动物模型的提供新思路。     

转染癌基因的骨髓基质干细胞体外分化特征

目的:观察转染癌基因的骨髓基质干细胞在体外分化情况,为肝细胞癌的细胞源研究提供实验依据。方法:实验于2003-05/2004-06在南方医科大学药理教研室实验室完成。①两步法获取大鼠肝细胞,梯度离心法分离大鼠骨髓基质干细胞。②单基因转染是单独将c-myc或K-ras癌基因瞬时转染大鼠骨髓基质干细胞,6孔培养板中培养,24h后荧光显微镜下观察骨髓基质干细胞转染结果。双基因转染步骤相同,只是将c-myc和K-ras癌基因同时转染大鼠骨髓基质干细胞。③c-myc癌基因转染组、K-ras癌基因转染组、双癌基因转染组常规培养,加入含体积分数为0.1胎牛血清的DMEM培养基,于37℃、体积分数为0.05的CO2孵箱培养,每24h半量更换培养液。④c-myc癌基因转染 肝细胞组、K-ras癌基因转染 肝细胞组、双癌基因转染 肝细胞组将已转染癌基因的骨髓基质干细胞,置于叠加的培养板半透膜的上方(细胞密度均为1×105个/cm2),再将肝细胞置于半透膜的下方(每孔细胞密度为3×105/cm2)进行共培养,其余步骤同常规培养。⑤通过反转录聚合酶式反应和细胞免疫组化检测骨髓基质干细胞分化情况。结果:①癌基因转染24h骨髓基质干细胞检测结果:单独转染c-myc或K-ras癌基因的细胞,其绿色荧光蛋白呈均匀一致分布;双基因转染的细胞,绿色荧光蛋白呈点片状分布。②各组骨髓基质干细胞向肿瘤细胞分化检测结果:c-myc癌基因转染组、K-ras癌基因转染组、双癌基因转染组的骨髓基质干细胞,均未向肿瘤细胞分化;c-myc癌基因转染 肝细胞组、K-ras癌基因转染 肝细胞组、双癌基因转染 肝细胞组的骨髓基质干细胞,均向肝细胞癌发展;空白对照组骨髓基质干细胞细胞均为阴性。此外,双癌基因转染 肝细胞组的骨髓基质干细胞分化增殖迅速,反转录聚合酶式反应和免疫组化检测发现,培养第7天出现甲胎蛋白表达,并迅速增加,而第7天出现的白蛋白和细胞角蛋白18表达迅速减弱,第14天消失。结论:转染癌基因的骨髓基质干细胞,在向肝细胞诱导的条件下,部分癌基因可以使干细胞分化为肝癌细胞;多癌基因转染时,更易于使干细胞分化为肝癌细胞。     

Binding and uptake of cationic lipid:pDNA complexes by polarized airway epithelial cells

To better understand the barriers associated with cationic lipid-mediated gene transfer to polarized epithelial cells, Fischer rat thyroid (FRT) cells and polarized normal human bronchial epithelial (NHBE) cells grown on filter supports at an air-liquid interface were used to study the binding and uptake of cationic lipid:plasmid DNA (pDNA) complexes. The efficiencies of binding and uptake of cationic lipid:pDNA complexes by these cell systems were monitored using fluorescence microscopy of fluorescently tagged lipid or pDNA probes. Fluorescent probe bound to the cell surface was differentiated from internalized probe by adding trypan blue, which quenched the fluorescence of bound but not internalized probes. For proliferating cells, binding and internalization of the cationic lipid:pDNA complexes were determined to be efficient. In contrast, little binding or internalization of the complexes was observed using polarized epithelial cells. However, after aspirating a small area of cells from the filter support, virtually all of the cells adjoining this newly formed edge bound and internalized the cationic lipid:pDNA complexes. To determine if their uptake in edge cells was related to the ability of the complexes to access the basolateral membranes of these cells, the binding and uptake of complexes was monitored in polarized NHBE cells that had been pretreated with EGTA or Ca2+-free media, strategies known to disrupt tight junctions. Cells treated in this manner bound and internalized cationic lipid:pDNA complexes efficiently and also expressed significant levels of transgene product. Control cells with intact tight junctions neither bound complexes nor expressed significant transgene product. These data confirm and extend earlier observations that the polarized apical membranes of airway epithelial cells are resistant to transfection by lipid:pDNA complexes. Further, in contrast to previous studies that have shown the entry step of complexes is not an important barrier for COS and HeLa cells, binding and entry of complexes in polarized NHBE cells appear to be rate limiting. These findings suggest that strategies designed to open the tight junctions of polarized epithelial cells may improve gene delivery to these cells for diseases such as cystic fibrosis (CF).     

脐带间充质干细胞移植治疗大鼠重症肌无力的研究

脐带间充质干细胞因其来源广泛,易扩增,低免疫原性等特点被人们越来越多地应用于疾病治疗的研究中。本研究旨在为重症肌无力疾病探求一种新的应用干细胞的治疗方法。将脐带间充质干细胞(UCMSC)移植到重症肌无力大鼠中,应用免疫荧光法观察人源化细胞的分布,ELISPOT法观察MSC对B细胞原位分泌抗体的影响,Transwell试验检测分泌IFN-γ的水平。结果发现,经静脉输注的UCMSC能快速的迁移到炎症部位和局部淋巴结,而且在淋巴结的髓质区也可以检测到人源化的细胞。体外原位检测乙酰胆碱受体(AchR)抗体分泌的试验发现,当MSC与淋巴结来源的淋巴细胞充分接触,能有效地抑制AchR抗体的产生。Transwell试验显示,UCMSC与CD4T细胞直接接触,能有效地降低IFN-γ的产生,在一定程度上缓解重症肌无力体内的Th1/Th2细胞失衡的免疫状态。结论 :在重症肌无力大鼠中,MSC可能通过相互接触或/和释放细胞因子而调节机体的免疫反应,这为重症肌无力提供了一种潜在的治疗新途径。