三阴性乳腺癌细胞脂肪非典型钙黏蛋白4表达下调的生物学作用及机制

背景与目的 三阴性乳腺癌（TNBC）容易发生侵袭转移,恶性程度极高。笔者团队前期研究发现脂肪非典型钙黏蛋白4（FAT4）在TNBC组织中呈低表达且与预后相关,进而本研究进一步探讨FAT4对TNBC细胞生物学行为的影响,及其相关机制。方法 用qRT-PCR及Western blot检测正常人乳腺上皮细胞系（MCF-10A）及不同TNBC细胞系（BT-549、MDA-MB-231、MDA-MB-468、MDA-MB-436）中FAT4的表达水平。选择其中合适的TNBC细胞系,分别转染FAT4-shRNA（FAT4敲低组）、阴性对照序列（阴性对照组）,以未处理的TNBC细胞为空白对照组,分别采用CCK-8实验、流式细胞术、Transwell小室实验检测细胞增殖能力、凋亡率、侵袭与转移能力的变化,并用Western blot检细胞中Hippo信号通路下游靶点YAP及上皮间质转化（EMT）相关蛋白的变化。结果 与正常人乳腺上皮细胞比较,各TNBC细胞系中FAT4的mRNA与蛋白表达量均不同程度的降低（均P<0.05）。功能实验选用BT-549细胞和MDA-MB-436细胞。无论在BT-549细胞或MDA-MB-436细胞中,与空白对照组比较,FAT4敲低组在转染后24、48、72 h的增殖能力均明显升高、凋亡率明显降低、侵袭与转移能力明显增强（均P<0.05）;YAP蛋白表达量无明显变化（P>0.05）,但磷酸化YAP（p-YAP）表达量明显降低,上皮标志物E-cadherin水平明显降低,而间质标志物N-cadherin水平明显升高（均P<0.05）;阴性对照组与空白对照组间以上指标差异均无统计学意义（均P>0.05）。结论 FAT4表达水平在TNBC细胞中普遍降低,FAT4表达的降低能增强TNBC细胞增殖和侵袭迁移能力、减少TNBC细胞凋亡,其机制可能与FAT4降低后Hippo信号通路下游的YAP蛋白磷酸化减少,从而促进EMT进程有关。     

促红细胞生成素预处理增强大鼠骨髓间充质干细胞定向归巢能力的初步研究

目的探讨促红细胞生成素(EPO)对大鼠骨髓间充质干细胞(BMSC)增殖及迁移能力的影响。方法将第5代BMSC分为5组,分别为对照组(不加EPO)及10、100、500、1000 IU/mL EPO组,培养24 h和48 h后检测各组BMSC的增殖率、迁移能力以及趋化因子受体(CXCR)4的表达情况。将第5代BMSC分为BMSC组和EPO-BMSC组,培养48 h后观察EPO对两组BMSC的表面标志物、定向分化和细胞骨架形态的影响。结果EPO与BMSC共培养48 h后,与对照组比较,100、500 IU/mL EPO组BMSC增殖率和迁移能力增强,CXCR4蛋白表达量增高(均为P<0.05)。EPO-BMSC组BMSC表面标志物的表达和定向分化能力未受EPO影响。在EPO-BMSC组中,大多数细胞的纤维骨架沿细胞的长轴排列,呈平行状。结论EPO可提高BMSC的增殖率、迁移能力和组织修复治疗能力,可能通过增加CXCR4的表达,促进其向损伤器官组织的定向归巢。     

HIV感染者巨细胞病毒血症现患率Meta分析

目的 运用Meta分析了解HIV感染者巨细胞病毒（CMV）血症的流行情况及相关因素。方法 系统检索2011-2020年PubMed、中国知网、万方数据知识服务平台、维普数据库中关于HIV感染者CMV血症现患率的文献,文献筛选和数据提取后进行Meta分析。结果 共纳入15篇文献,总样本量为5 076例。Meta随机效应模型显示,HIV感染者CMV血症合并现患率为26.2%（95%CI：16.8%~35.6%,I²=99%）;亚组分析和Meta回归结果显示,不同研究间异质性来源可能为：研究样本中>30岁人群比例、同性性传播比例、HIV病毒载量>10⁴拷贝数/ml比例、CD4⁺T淋巴细胞计数<200个/μl比例。结论 HIV感染者CMV血症现患率较高,现患CMV血症可能与HIV感染者的年龄、HIV感染途径、艾滋病病程进展密切相关。     

台州市2017-2018年新报告HIV/AIDS巨细胞病毒血症现患率及影响因素研究

目的了解2017-2018年台州市新报告且未接受抗病毒治疗(ART)的HIV/AIDS血浆巨细胞病毒血症现患率及其影响因素。方法收集台州市新报告且未接受ART的成年HIV/AIDS血浆样本,提取核酸后采用荧光定量PCR检测巨细胞病毒DNA水平,采用单因素与多因素logistic回归分析其影响因素。结果研究对象612例HIV/AIDS中,男性480例(78.4%),年龄>60岁125例(20.4%),同性性传播者177例(28.9%),异性性传播者430例(70.3%)。巨细胞病毒血症现患率为13.4%(82/612)。多因素logistic回归分析结果显示,CD₄⁺T淋巴细胞计数(CD4)≤200个/μl者现患巨细胞病毒血症的风险显著高于CD4>500个/μl者(OR=5.10,95%CI:1.74~14.96,P=0.003);82例现患巨细胞病毒血症者的血浆巨细胞病毒DNA载量(log10)中位数为1.57(P₂₅,P₇₅:1.04,2.13),CD4≤200个/μl者的巨细胞病毒载量最高(P<0.01)。结论2017-2018年台州市新报告未接受ART的HIV/AIDS中,巨细胞病毒血症现患率与免疫缺陷状态显著关联,巨细胞病毒血症对HIV/AIDS病程的影响有待进一步研究。     

陕西产小麦不同加工程度的营养成分分析及评价

目的对陕西省种植的11种小麦采用不同方式加工后进行营养成分含量分析,同时对其营养价值进行评价。方法采用国标法测定小麦中的宏量营养素、水分、灰分、维生素等几项营养成分,采用营养质量指数法对小麦中的不同营养素进行评价,采用模糊隶属函数法对小麦的综合营养价值进行评价。结果小麦全麦粉中水分和碳水化合物含量低于特一粉和麦芯粉,灰分、脂肪、蛋白质、总膳食纤维、维生素含量高于特一粉和麦芯粉,差异均有统计学意义。全麦粉的综合营养价值整体高于特一粉和麦芯粉,晋麦54的综合营养价值最高。结论小麦中富含蛋白质、维生素等多种营养元素,去皮会使小麦粉中的维生素B和维生素E大量流失,全麦粉的综合营养价值高于特一粉和麦芯粉。     

Microiontophoresis of cocaine, desipramine, sulpiride, methysergide, and naloxone in habenula and parafasciculus

The effects of microiontophoretically applied cocaine, desipramine (DES), sulpiride (SUL), methysergide (METH), and naloxone (NAL) on the responses of physiologically identified single neurons in the habenula (Hab) and parafasciculus thalami nucleus (PF) were examined in rats. Three cell types were identified in both nuclei on the basis of the responses obtained following noxious stimulation that were classified as "nociceptive-on," "nociceptive-off," and "nonnociceptive" cells. Administration of cocaine generally resulted in a decrease in the firing rate of nociceptive-on and nonnociceptive neurons in both Hab and PF. In contrast, cocaine generally induced an excitation in the baseline firing of the nociceptive-off cells. Cocaine application concomitant with noxious stimulation prevented the evoked responses of the nociceptive-on and the nociceptive-off cells. DES, when applied alone, was found to induce excitation in neuronal discharge of all three cell types in both sites. Combined application of cocaine with DES resulted in no observable change in discharge frequency for the nociceptive-on and nonnociceptive cells, while inducing an additive excitatory effect on the nociceptive-off cells. SUL, in contrast, induced no observable effect on baseline firing when given alone, yet consistently antagonized cocaine-induced effects on all three cell types. Finally, METH and NAL induced no effects on baseline firing or cocaine-induced modifications in neuronal discharge frequency.     

In vitro assembly of infectious nucleocapsids of bacteriophage phi 6: formation of a recombinant double-stranded RNA virus.

A system is described for assembling infectious bacteriophage phi 6 nucleocapsids in vitro. Procapsids encoded by cDNA copies of genomic segment L in Escherichia coli were used to package and replicate viral RNA segments. The resulting filled particles were shown to be capable of infecting host cell spheroplasts after incubation with purified nucleocapsid shell protein P8. The infected spheroplasts yielded infectious virions. A modified cDNA-derived RNA segment was inserted into virions by this method. The resulting infectious virions contained the same 4-base-pair deletion as the modified cDNA. These findings support the contention that the preformed procapsids are the "machine" that replicates the phi 6 genome, by showing that the cDNA-derived procapsids are competent to package and replicate RNA properly.     

偶联剂CGE（N）—R型处理前后牙本质的表面状态及其...

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.     

Determination of trace selenium in human body by anodic stripping voltammetry at gold-disc electrode

Summary For determination of trace Se we used high-pressure wet digester to pretreat the specimens obtained from the human body. This method is very effective in preventing loss of Se by volatilization which often occurs in the sample pretreatment. We studied the method of using anodic stripping voltammetry at gold-disc electrode to measure the trace Se present in the human body and found it to be the optimal procedure. The detection limitation was about 2x10⁻⁸ g/L, the recovery rate of Se about 96.6±6,7 % , and the coefficient of variation CV = 7.0%.     

5-氨基水杨酸灌肠对大鼠免疫性结肠炎的影响

目的 探讨5-氨基水杨酸(5-ASA)灌肠对大鼠三硝基苯磺酸(TNBS)诱导的结肠炎的作用.方法用TNBS诱发大鼠结肠炎.造模7天后,用不同剂量的5-ASA(25、50、100mg·kg-1·d-1)开始灌肠.观察大鼠粪隐血(OB)反应强度、结肠大体形态和组织学改变,并检测肠黏膜髓过氧化物酶(MPO)活性.结果 5-ASA灌肠可明显降低结肠黏膜损伤指数(CMDI)、OB反应强度、MPO活性及组织学评分(HS),各剂量组间有一定的量效关系.结论 5-ASA灌肠对TNBS诱导的大鼠结肠炎有保护作用,且与剂量有一定关系.