Wortmannin抑制PI3K途径对bcr/abl基因介导的白血病细胞增殖和凋亡抗性影响的研究

目的探讨磷酰肌醇-3激酶(PI3K)途径在K562、NB4和HL60细胞增殖和凋亡抗性中的不同作用。方法用磷酰肌醇-3激酶(PI3K)特异抑制剂Wortmannin(WT)抑制PI3K活性,经细胞生长曲线测定、半固体集落形成实验、流式细胞膜联蛋白V(Annexin-V-Flous)标记技术检测细胞凋亡百分比和凋亡指数。观察K562、NB4和HL60细胞增殖能力及凋亡抗性的变化。结果K562、NB4和HL60细胞在24、48、72h的增殖抑制率分别为41.33%、57.46%、65.85%和26.29%、5.51%、2.10%及32.14%、17.14%、13.14%。生长曲线显示WT抑制PI3K途径可显著抑制K562细胞的增殖,对NB4和HL60细胞增殖无明显影响。K562、NB4和HL60细胞加和不加WT,培养14d后的集落形成率分别为16.15%和7.60%,5.90%和6.10%,6.60%和6.40%。集落形成抑制率为52.94%、3.39%和3.03%。K562、NB4和HL60细胞加WT、AraC、WT+AraC作用24h后的凋亡细胞百分比分别为(17.27±1.94)%、(23.25±14.12)%、(17.60±1.27)%;(17.00±3.36)%、(20.55±8.57)%、(22.07±5.62)%;(27.60±4.36)%、(17.56±9.28)%、(20.50±7.97)%。凋亡指数分别为(6.88±2.66)、(7.79±2.75)、(3.03±0.56);(8.91±3.86)、(9.35±4.19)、(3.79±0.93);(13.39±4.49)、(7.61±6.35)、(5.27±2.69)。结论WT可以通过抑制PI3K通     

前列腺癌细胞DU145同步化诱导的DNA损伤反应通路和PI3K/Akt通路对凋亡抑制因子基因API2(BIRC3)mRNA表达的影响

目的探讨在前列腺癌细胞DU145同步化培养后引起的DNA损伤反应通路和PI3K/AKT通路对凋亡抑制因子(IAP)基因API2(BIRC3)mRNA表达的影响,同时分析API2基因所在染色体是否存在特异性的异常。方法采用无血清的饥饿培养法使细胞同步在G0期;分别用含羞草碱(mimosine)、胸腺嘧啶(thymidine)和噻氨酯哒唑(nocodazole)使细胞同步在G1期、S期和G2/M期并引起DNA损伤反应,同时加入PI3K的特异性抑制剂ly294002以阻止PI3K/AKT通路。通过RT-PCR半定量法检测API2 mRNA在各个细胞周期相的表达情况。通过细胞遗传学的常规G式显带法,分析凋亡抑制因子基因所在的染色体是否存在特异性的异常。结果 mimosine同步化的G0/G1期细胞达到了78.04%,thymidine同步化的S期细胞达到62.19%,nocodazole同步化的G2/M 60.5%。API2基因位于染色体11q22-q23,存在易位,如t(11;12)(q;q)。API2mRNA的表达,非同步化的ly294002组分别与同步化的mimosine+ly294002组、nocodazole+ly294002组和thymidine+ly294002组比较,差异均有统计学意义(P<0.05)。结论前列腺癌细胞株DU145存在某些染色体的结构和数目异常,这些异常可能影响某些基因的表达。药物的同步化激活了DNA损伤反应通路和生存信号通路,再通过PI3K/Akt通路,而不是通过P53通路,在细胞周期的某个时相调控API2(BIRC3)mRNA的表达。     

1，25-二羟基维生素D3对K562细胞周期及凋亡的影响

目的观察1，25-二羟基维生素D3[1，25（OH）2D3]对白血病细胞株K562细胞周期及细胞凋亡的作用。方法Western印迹检测维生素D受体（VDR）在K562细胞的表达；四噻唑蓝法（MTT）、AO／EB、流式细胞仪分析细胞生长抑制率、细胞凋亡率及细胞周期。结果（1）K562细胞核阳性表达VDR；（2）0-10^-6mol／L浓度的1，25（OH）2D3呈浓度依赖性抑制K562细胞增殖，10^-8mol／L 1，25（OH）2D3明显抑制K562细胞增殖，促进凋亡，细胞周期阻滞主要发生在G2期或M早期，凋亡率从4．1％（对照组）增至26．5％（P〈0．01）。结论1，25（OH）2D3可明显抑制K562细胞增殖，促进细胞凋亡。     

PI3K/Akt信号通路对胃癌细胞SGC7901细胞化疗效果的影响

目的运用磷脂酰肌醇3-激酶抑制剂(phosphatidylinositol 3-kinases,PI3-K)LY294002[2-(4-吗啉基)-8-苯基-4氢-1-苯并吡喃-4-酮]作用于胃癌细胞系SGC7901,探讨抑制PI3K/Akt信号转导通路对胃癌细胞化疗敏感性的影响。方法采用MTT比色法,流式细胞术检测5-FU、DDP及ADM单独或联合PI3K抑制剂LY294002对人胃癌细胞SGC7901的抑制率、凋亡率。并分析单独及联合应用LY294002对SGC7901细胞周期的影响。Western-blot检测单独及联合化疗药后P-Akt蛋白在SGC7901细胞中的表达水平。结果单独使用化疗药5-FU、DDP及ADM均可抑制SGC7901细胞增殖、诱导其凋亡。当化疗药与抑制剂联合应用,对细胞的抑制作用明显增强,促凋亡作用增强,与对照组比较(P0.05)。细胞周期同步分析显示,单独用药均可将SGC7901细胞阻滞于G0/G1期。联合使用抑制剂使处于G0/G1期细胞增加。Western blot显示化疗药上调P-Akt蛋白的表达,联合使用抑制剂后SGC7901细胞P-Akt蛋白的表达与未使用抑制剂比较减弱,差异有统计学意义(P0.05)。结论阻断PI3K/Akt信号通路可提高化疗药5-FU、DDP及ADM对胃癌细胞株SGC7901的抑制率,凋亡率并使阻滞于G0/G1期细胞增多;LY294002通过阻断PI3K/Akt信号通路,抑制P-Akt蛋白表达,增强化疗药的敏感性;LY294002阻断PI3K/Akt信号通路对5-FU、DDP、ADM治疗胃癌有一定的协同或增强作用。     

Wortmannin与ABT-737诱导卵巢癌细胞凋亡的协同作用研究

目的:探讨磷酸肌醇3-激酶(PI3K)抑制剂wortmannin单用以及与Bcl-2蛋白抑制剂ABT-737联合应用对人卵巢癌细胞系存活率和凋亡率的影响。方法:①CCK-8法分别测定Wortmannin、ABT-737单独以及联合应用对人卵巢癌细胞ES-2和SKVO-3生长的抑制率,并计算其IC50。②Annexin-V/PI法流式细胞仪检测细胞凋亡率以及对细胞周期的影响,Western blot法检测相关蛋白的表达水平,分别测定Wortmannin、ABT-737单独以及联合应用对人卵巢癌细胞ES-2和SKVO3凋亡的影响。结果:①Wortmannin和ABT-737单独作用对ES-2细胞株的IC50分别为14.12μM和31.31μM,两药联合应用的IC50为8.15μM;Wortmannin和ABT-737单独作用对SKVO-3细胞的IC50分别为16.72μM和37.56μM,联合用药的IC50为9.25μM。②0.2μM的Wortmannin作用48 h后ES-2和SKVO-3细胞的凋亡率分别为9.9%和8.7%,5μM的ABT-737作用48 h后ES-2和SKVO-3细胞凋亡率分别为10.2%和9.1%,两者联合应用对两种细胞的凋亡率分别为45.0%和53.0%,组间比较差异有统计学意义(P<0.01)。③Wortmannin和ABT-737联合应用可以明显的增加cleaved-caspase-3、细胞色素C以cleaved-PARP的表达量,Wortmannin和ABT-737联合应用可以明显的对人卵巢癌ES-2和SKVO-3细胞周期阻滞在G0/G1期。结论:Wortmannin和ABT-737能够通过线粒体途径抑制卵巢癌细胞株的生长并诱导其凋亡,且Wortmannin和ABT-737联合应用具有协同作用。     

lncRNA PlncRNA-1对胃癌SGC-7901细胞生物学行为及PI3K/AKT信号通路的影响

目的探讨长链非编码RNA(lncRNA)PlncRNA-1对胃癌SGC-7901细胞增殖、周期、凋亡和磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路的影响。方法采用实时荧光定量PCR(qPCR)检测PlncRNA-1在SGC-7901细胞和正常胃黏膜上皮GES-1细胞中的表达水平,将体外培养的SGC-7901细胞分为未转染组(正常培养)、阴性组(转染阴性对照siRNA)和干扰组(转染PlncRNA-1-siRNA),qPCR检测SGC-7901细胞中PlncRNA-1表达水平,噻唑蓝(MTT)法检测SGC-7901细胞增殖活力,流式细胞仪检测SGC-7901细胞周期和凋亡情况,免疫印迹法检测PI3K/AKT信号通路相关蛋白PI3K、AKT、磷酸化(p)-AKT、细胞周期素D1(CyclinD1)和B淋巴细胞瘤-2基因(Bcl-2)蛋白表达情况。结果与GES-1细胞比较,SGC-7901细胞中PlncRNA-1表达水平明显升高,差异有统计学意义(P 0.05);与未转染组比较,干扰组细胞中PlncRNA-1表达水平、细胞增殖活力和细胞在S期、G2/M期所占百分比以及PI3K、p-AKT、CyclinD1、Bcl-2蛋白表达水平均明显降低,而细胞凋亡率和细胞在G0/G1期所占百分比明显升高,差异有统计学意义(P 0.05);但阴性组和未转染组之间各指标差异均无统计学意义(P0.05)。结论 PlncRNA-1在胃癌SGC-7901细胞中表达升高,干扰其表达可抑制SGC-7901细胞增殖并诱导细胞周期阻滞和凋亡,其作用机制与抑制PI3K/AKT信号通路的活化有关。     

Rapamycin抑制PI3K/AKT/mTOR信号通路对胃癌MGC-803细胞影响

目的探讨rapamycin作用于胃癌细胞株MGC-803后对细胞生长影响及其作用机制。方法体外培养胃癌细胞株MGC-803,使用不同浓度rapamycin干预MGC-803细胞。采用MTT法检测细胞增殖变化;实时荧光定量PCR(QPCR)检测关键基因的表达;蛋白印迹法(WB)检测相关蛋白的表达;流式细胞术检测细胞周期及凋亡的变化。结果与对照组相比,rapamycin对胃癌MGC-803细胞的增殖活性有明显的抑制作用,呈现出剂量依赖性(P0.05)。Rapamycin显著抑制PI3K、AKT、m TOR、4EBP、P70S6K基因的m RNA表达,差异有统计学意义(P0.05);Rapamycin能抑制p-m TOR、p-P70S6K蛋白的表达;Rapamycin将细胞周期阻滞在G0/G1期,并诱导细胞凋亡(P0.05)。结论靶向m TOR抑制剂rapamycin可通过调控PI3K/AKT/m TOR信号通路进而调控胃癌细胞的生长。     

As2O3对NB4细胞增殖及凋亡的影响

目的研究不同浓度的三氧化二砷（As2O3）对急性粒细胞白血病细胞株NB4（APLM3）凋亡及细胞周期的影响。方法采用四甲基偶氮噻唑蓝（MTT）法测As2O3对NB4的细胞毒活性，流式细胞仪AnnexinVFITC-PI检测细胞凋亡率，溴化丙碇（PI）染色法检测细胞周期。结果1～8μmol／LAs2O3能显著抑制NB4细胞增殖，且这些变化呈明显的时间和浓度依赖关系（时间一剂量效应）。2～8μmol／LAs2O3能显著诱导NIM细胞凋亡，处理时间为12h，其早期凋亡率和总凋亡率均与剂量呈线性正相关；处理时间为24h，其早期凋亡率、中晚期凋亡率和总凋亡率与剂量呈线性正相关；As2O3处理时间为36h和48hNB4细胞以中晚期调亡为主。流式细胞检测表明，不同浓度的As2O3均使NB4细胞周期阻滞在G2／M期。结论As2O3能抑制人白血病NB4细胞增殖，其作用机制可能是通过诱导细胞凋亡和抑制细胞增殖使细胞受阻于G2／M期。其诱导凋亡作用具有时间和浓度依赖关系。     

塞来昔布抑制PI3K-Akt信号转导通路及COX-2表达的作用研究

目的:观察塞来昔布降调节COX-2的表达,诱导宫颈癌HeLa细胞的凋亡作用及阻止PI3K-Akt信号转导的可能机制。方法:采用MTT法检测塞来昔布对HeLa细胞的增殖抑制作用,应用流式细胞术检测塞来昔布对HeLa细胞增殖周期和凋亡的影响,并用免疫组化SP法和RT-PCR法检测塞来昔布对细胞PI3K-Akt信号转导通路的影响。结果:塞来昔布抑制HeLa细胞增殖和诱导HeLa细胞的凋亡作用均呈剂量和时间依赖性,经不同浓度的塞来昔布处理24 h后,HeLa细胞周期的G1期、G2/M期细胞比例明显增多,S期细胞比例明显下降,细胞被阻滞于G2/M期。塞来昔布能阻止PI3K-Akt的信号转导,并呈浓度和时间依赖性。结论:塞来昔布在体外能下调COX-2的表达,抑制HeLa细胞的增殖,并诱导其凋亡,其作用机制与阻滞细胞周期于G2/M期及阻止PI3K-Akt信号转导通路有关。     

家蝇幼虫抗菌蛋白诱导黑色素瘤A375细胞凋亡的探讨

目的 观察家蝇幼虫抗菌蛋白对黑色素瘤A375细胞凋亡的诱导，探讨其抗肿瘤作用机制。方法 流式细胞仪测定家蝇幼虫抗菌蛋白对细胞周期和细胞凋亡的影响；HE染色法观察细胞凋亡形态，并测定细胞凋亡指数（AI）。结果 在0．10％组A375的G／M期升高，S期降低。0．50％组G0／G1期、G2／M期和AI／PI（增殖指数）显著增加，S期及PI明显减少。2．50％组S期、PI、AI／PI及细胞凋亡率（Ap）显著增高，G0／G1期大大减少。12．50％组G2／M期、PI、AI／PI及Ap显著增高，G0／G1期和S期明显下降。结论 家蝇幼虫抗菌蛋白对黑色素瘤A375细胞有明显的抑杀作用；家蝇幼虫抗菌物质可能系通过细胞周期阻滞以及诱导细胞凋亡而抑制黑色素瘤A375细胞生长。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.