胎儿骨髓间充质干细胞体外定向诱导分化为胰岛样细胞

目的探索体外诱导胎儿骨髓间充质干细胞(MSCs)分化为胰岛样细胞的最佳分化条件。方法取流产胎儿的长骨骨髓,体外培养扩增MSCs,先后予以2-巯基乙醇、表皮生长因子(EGF)、碱性成纤维细胞生长因子(bFGF)、B27及尼克酰胺,通过三阶段诱导MSCs分化为胰岛样细胞,观察细胞形态变化、免疫荧光鉴定巢素蛋白(nestin)、胰十二指肠同源异型盒基因(PDX-1)、胰岛素(insu lin)和胰高糖素(glucagon)的表达、双硫腙染色鉴定胰岛细胞中的锌离子、电化学发光法测定人胰岛素的分泌量。结果MSCs易于体外分离和扩增,诱导二阶段细胞表达nestin及PDX-1,诱导三阶段形成胰岛样细胞团,表达insu lin及glucagon;双硫腙染色呈棕红色;胞浆胰岛素分泌量为81.3±23.6μu/m l;有一定程度葡萄糖刺激的胰岛素释放。结论MSCs可以诱导分化为胰岛样细胞团,尼克酰胺20 mmol/L是合适的促进胰岛细胞分化和成熟的浓度。     

骨髓间充质干细胞诱导分化为胰岛样细胞及其功能的研究

目的体外诱导分化骨髓间充质干细胞(mesenchymal stem cells,MSCs)为胰岛样细胞,鉴定诱导细胞并检测其功能。方法取周龄大鼠骨髓细胞,进行MSC培养纯化扩增,用bFGF、EGF、条件培养液、高糖培养液、B27、地塞米松、胰岛素等培养体系诱导MSC向胰岛细胞转化。双硫腙染色鉴定胰岛样细胞;免疫细胞化学鉴定胰岛素抗原表达;Western blot检测胰岛样细胞胰岛素的表达。结果体外诱导的MSCs由长梭形变成多角形并逐渐聚集成团。双硫腙染色细胞团成亮红色,初步表明为胰岛样细胞。诱导的细胞具有胰岛素抗原表达;Western blot检测诱导分化为胰岛样细胞的胰岛素表达阳性。结论骨髓间充质干细胞能够分化成胰岛样细胞,并具有分泌胰岛素的功能。     

间充质干细胞的生物学特性和临床应用

间充质干细胞（MSCs）是主要存在于骨髓中的非造血性干细胞,可以从广泛的组织来源中提取,并可分化为多种细胞,如：成骨细胞,成软骨细胞,成脂肪细胞,神经样细胞,血管内皮细胞等。在体外培养MSCs过程中,胎牛血清和生长因子的选择,以及多能分化诱导控制等,对MSCs的体外繁殖和分化至关重要。大量的临床研究证明,经体外分化繁殖的MSCs,在疾病的再生医疗和组织工程领域有很大的应用潜能。牙周韧带来源的间充质干细胞（PDL-MSCs）经体外培养,贴壁,伸展性良好,将它移植于生物相容性支架材料中,具有高度伸展性和分化为成骨细胞的能力。因此,应用PDL-MSCs和骨髓来源的骨髓-MSCs制成的有效的移植生物材料,可用于牙周再生中的骨组织工程治疗。     

骨髓间充质干细胞对糖尿病大鼠疗效观察

目的 体外诱导骨髓问充质干细胞(mesenchymal stem cells,MSCs)分化为胰岛样细胞,用于干预治疗糖尿病大鼠.方法 取周龄大鼠骨髓细胞,进行MSC培养纯化扩增,用bFGF、胰岛素等培养体系诱导MSC向胰岛细胞转化;双硫腙染色鉴定胰岛样细胞.使用链脲菌素(Streptozotocin,STZ)制作糖尿病大鼠模型,将诱导分化的胰岛样细胞移植至糖尿病模型大鼠,观察干预治疗效果.结果 体外诱导MSCs由长梭形变成多角形并逐渐聚集成圆形,双硫腙染色后细胞团成亮红色,表明为胰岛样细胞.糖尿病模型大鼠移植诱导分化胰岛样细胞1周后,多饮、多尿症状减轻,10 d后,血糖值由(21.352±3.150)mmol/L降低为(14.604±3.236)mmol/L,与对照组(22.256±4.051)mmol/L比较,差异无统计学意义(P>0.05);尿糖值由(18.00±1.00)g/L降低为(8.50±0.25)g/L,与对照组(20.00±0.18)g/L比较,差异有统计学意义(P<0.05).结论 骨髓间充质于细胞可在体外诱导分化为胰岛样细胞;骨髓间充质干细胞诱导分化的胰岛样细胞可以降低糖尿病大鼠血糖、尿糖值水平,可能具有治疗糖尿病作用.     

间充质干细胞应用现状

<正>间充质干细胞(mesenchymal stem cells,MSCs)是一类多能干细胞,最初是从骨髓中发现的除造血干细胞以外的又一类干细胞。MSCs具有多向分化潜能,在体外不同诱导条件下可分化为骨、软骨、脂肪、肌肉、神经细胞等;其来源方便,目前可从多种组织中分离提取,如骨髓、脐带血、脐带、胎盘、脂肪组     

5-氮杂胞苷对大鼠骨髓间充质干细胞增殖与分化的影响

目的:探讨5-氮杂胞苷(5-azacytidine,5-aza)对体外骨髓间充质干细胞(Mesenchymal stem cells,MSCs)细胞增殖与分化潜能的影响。方法:从Wistar大鼠骨髓中获得MSCs,培养传代,透射电镜下观察诱导前后细胞形态变化;MTT法检测5-aza对MSCs生长的影响;免疫细胞化学方法检测Actin(α-Sarcomeric)、Desmin、Myoglobin、NSE、GFAP的表达。结果:5-aza对MSCs有抑制作用,在透射电镜下观察可见有心肌样细胞和神经元样细胞的形态变化。免疫细胞化学检测结果表明,MSCs经5-aza诱导14dactin、desmin、myoglobin、NSE和GFAP的表达均较对照组显著增高,P0.01。结论:5-aza对MSCs细胞生长有抑制作用,MSCs被5-aza诱导分化成心肌样细胞和神经元样细胞。     

骨髓间充质干细胞体外分化过程中细胞周期蛋白的表达变化

目的:研究大鼠骨髓间充质干细胞(MSCs)体外定向分化为多巴胺(DA)能神经元过程中细胞周期相关蛋白的表达变化。方法:体外分离、扩增和鉴定大鼠骨髓MSCs。碱性成纤维细胞生长因子(bFGF)预诱导24 h后,用1μmol/L全反式维甲酸(ATRA)和50 ng/ml GDNF联合诱导6 d,检测神经元特异性烯醇化酶(NSE)、胶质纤维酸性蛋白(GFAP)、酪氨酸羟化酶(TH)、增殖细胞核抗原(PCNA)、Bcl-2、细胞周期蛋白依赖性激酶(CDK2)、细胞周期蛋白(Cyclin)B1的表达。结果:诱导后大鼠骨髓MSCs能分化为具有典型神经元形态的细胞,大鼠MSCs经诱导后PCNA、CDK2、Cyclin B1的表达均较对照组明显减弱,Bcl-2表达与对照组无明显差别。结论:骨髓间充质干细胞体外开始分化后细胞增殖力下降。     

体外培养胰岛干细胞分化为类胰岛样组织的研究

目的观察体外培养的胰岛干细胞是否可以被诱导分化为类胰岛样组织.方法体外培养胰岛干细胞,在胰岛素等外源性复合成分(ITS)诱导分化后,分别进行胰腺上皮干细胞特异性标志物CK-19、胰腺β细胞特异性成分胰岛素和胰腺α细胞特异性成分胰高糖素等的免疫细胞化学染色鉴定.结果体外培养的胰岛干细胞经诱导分化3 d后,在胰岛干细胞集落附近可见散在或成群分布的上皮样细胞,并呈CK-19免疫阳性反应.继续培养2～4周后,上皮样细胞增多,细胞圆形或呈鹅卵石样排列,进一步增生形成类胰岛样组织,其中大多数细胞呈胰岛素免疫反应阳性,少数细胞呈胰高糖素免疫反应阳性.结论体外培养的胰岛干细胞具有向类胰岛样组织分化的潜能,它能分化为胰岛的α细胞和β细胞.     

脐带血清体外培养人骨髓间充质干细胞的生物学特性研究

目的观察脐带血清体外培养人骨髓间充质干细胞的生物学特性。方法抽取骨髓穿刺液10ml,采用含10％脐带血清的DMEM／F12培养,流式细胞仪检测细胞表面抗原,成骨诱导体系及脂肪诱导体系诱导BM—MSCs定向分化。结果BM—MSC—Ss高表达CD29、CD73、CD105,不表达CD34、CIM5、CD31,BM—MSCs体外能诱导为成骨细胞和脂肪细胞。结论脐带血清培养的BM—MSCs的具有较高的纯度和体外分化能力,脐带血清培养BM—MSCs适合临床应用。     

组织工程化胆管中平滑肌及内皮细胞的来源及培养研究

目的解决组织工程化胆管的支架材料及细胞来源⑴体外培养人胚动脉平滑肌细胞(VSMCs),并观察人胚VSMCs在乳酸与羟基乙酸共聚物(PLGA)上的三维培养情况。⑵探讨体外诱导大鼠骨髓间充质干细胞(rBMSCs)定向分化为肝干细胞的可行性。方法⑴成功培养人胚VSMCs后,将其与PLGA(膜材和三维材料)进行三维培养,通过倒置显微镜、扫描电镜和MTT法观察细胞的生长情况。⑵采用全骨髓培养法体外培养rBMSCs(设实验组及对照组)。应用肝细胞生长因子(HGF)诱导分化,采用倒置相差显微镜观察细胞形态变化,ELISA等方法检测甲胎蛋白,白(清)蛋白及碱性磷酸酶。结果⑴体外培养的人胚VSMCs生长旺盛,与PLGA具有良好的相容性,在PLGA上生长良好。⑵rBMSCs经体外培养诱导后呈多角形、卵圆形改变,白(清)蛋白,AFP表达阳性,碱性磷酸酶出现明显改变。结论⑴体外培养的人胚VSMCs成功培养纯化并与PLGA有良好的相容性,⑵在HGF诱导下,rBMSCs体外具有向肝干细胞分化的能力,为进一步分化为胆管内皮细胞提供实验依据。     

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.     

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.     

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.     

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.