野生型p53基因对K562细胞中心体数量和蛋白的影响

目的 研究重组腺病毒介导的野生型p53基因(Ad5wtp53)对人慢性粒细胞白血病(CML)K562细胞系中心体数量和中心体蛋白表达的影响.探讨应用重组腺病毒p53基因对CML进行基因治疗的可行性.方法 分别将含有野生型p53基因、突变型p53基因和绿色荧光蛋白基因的重组腺病毒表达载体(AdSwtp53、Ad5mtp53和Ad5GFP)反复扩增,联合多聚季胺共同感染K562细胞.观察感染效率.MTT法确定最适重组腺病毒感染滴度和感染时间.然后用RT-PCR和Western blot检测p53 mRNA和蛋白的表达.最后应用间接免疫荧光染色法对中心体γ-微管蛋白和纺锤体α-微管蛋白同时进行标记,在激光共聚焦显微镜下观察中心体γ-微管蛋白的表达和有丝分裂,并对中心体进行计数.结果 多聚季胺可显著提高腺病毒载体对K562细胞的感染效率.多聚季胺的剂量选择为4μg/ml;感染K562细胞的最适腺病毒滴度为20 000 MOI,感染时间为72 h;Ad5wtp53和AdSmtp53转染的K562细胞均可表达p53 mRNA和蛋白.Ad5wtp53感染K562细胞后,中心体数量减少,γ-微管蛋白的表达降低.结论 重组腺病毒介导的野生型p53基因能够在白血病K562细胞中持续表达;野生型P53蛋白能够降低K562细胞中心体数量及中心体γ-微管蛋白的表达.     

三元复合因子Net嵌合型重组腺病毒载体的构建及鉴定

目的:克隆人三元复合因子Net全长基因,构建其重组腺病毒载体。方法 :抽提正常人胰腺组织中总RNA,经RT-PCR扩增出全长Net基因,利用同源重组的方法将腺病毒骨架质粒pBHG35和穿梭质粒pDC316-Net共转染293细胞,获得腺病毒重组质粒Ad5/F35-Net,在293细胞中包装和扩增后,获得高滴度的腺病毒重组质粒Ad5/F35-Net。采用PCR和蛋白印迹法检测Net基因的表达。结果 :用RT-PCR方法 ,从人胰腺癌组织中扩增出1224 bp的cDNA片段,经测序证实为人Net基因。最终构建及包装出高滴度的重组腺病毒载体Ad5/F35-Net。结论:成功克隆了人Net全长基因,并构建其重组腺病毒表达载体,为进一步研究人Net基因在相关肿瘤疾病中的生物学作用奠定了基础。     

MicroRNA-21调控口腔鳞癌细胞顺铂耐药及其作用机制

目的:探讨micro RNA-21(mi RNA-21)在人口腔鳞癌顺铂耐药细胞中的表达及其作用机制。方法 :采用实时荧光定量PCR(RT-PCR)法检测mi RNA-21在口腔鳞癌细胞株Tca8113及顺铂耐药细胞株Tca8113/DDP的表达;采用体外转染法将mi RNA-21模拟物(mimics)或抑制物(inhibitor)分别转染Tca8113和Tca8113/DDP细胞,采用RT-PCR检测转染前后细胞中mi RNA-21的表达情况;采用CCK8实验检测转染前后细胞对顺铂敏感性的变化;并用Western blot检测转染前后细胞中PTEN的表达变化。采用双荧光素酶报告基因验证mi RNA-21是否作用于PTEN基因的3’-UTR区预测靶位。结果:mi RNA-21在Tca8113/DDP细胞中的表达水平是Tca8113细胞的(8.26±1.37)倍(P<0.01)。Tca8113细胞转染mi RNA-21 mimics后,细胞中mi RNA-21表达水平是转染前的(10.51±2.18)倍(P<0.01),顺铂对Tca8113细胞增殖的抑制率较转染前明显下降(P<0.05),细胞内PTEN表达水平较转染前明显下降(P<0.05)。Tca8113/DDP细胞在转染mi RNA-21 inhibitor后,细胞中mi RNA-21表达水平是转染前的(0.32±0.14)倍(P<0.01),顺铂对Tca8113/DDP细胞增殖的抑制率与转染前比较明显增加(P<0.05),细胞内PTEN表达水平较转染前明显增高(P<0.05)。经双荧光素酶报告基因验证PTEN是mi RNA-21的靶基因。结论:mi RNA-21在口腔鳞癌顺铂耐药细胞Tca8113/DDP中异常高表达,下调其表达可部分逆转细胞耐药性,mi RNA-21可能通过作用于PTEN参与口腔鳞癌细胞顺铂耐药的发生和发展。     

EGFP标记的hVEGF165重组腺病毒构建新方法及其相关特性的体外研究

利用细菌内同源重组法快速构建增强型绿色荧光蛋白 (EGFP)标记的人血管内皮细胞生长因子 16 5(hVEGF165)重组腺病毒载体 ,并对其相关特性进行体外研究。首先将hVEGF165cDNA亚克隆到含EGFP基因的腺病毒穿梭质粒 pAdTrack CMV中 ,然后与腺病毒骨架质粒pAdEasy 1共同电击转化大肠杆菌BJ5183 ,同源重组获得重组腺病毒质粒 pAd EGFP/hVEGF165,鉴定后通过脂质体法转染HEK2 93细胞 ,产生重组腺病毒Ad EGFP/hVEGF165。通过体外试验观察病毒的形态、均一性和安全性 ,靶细胞的感染效率及hVEGF165的表达情况。结果显示 ,通过细菌内质粒间同源重组法在短期内成功地构建了复制缺陷型重组腺病毒载体Ad EGFP/hVEGF165;借助于EGFP的表达 ,直接在荧光显微镜下观测到靶细胞的感染效率和外源基因的表达。经纯化的病毒颗粒在电镜下成分均一 ,滴度可达 2× 10 12 pfu/ml。病毒感染Hela细胞后经多次传代未见细胞病变。以感染复数 (MOI) =10 0感染hUVEC可获得最大增殖刺激作用。同样浓度感染小鼠骨髓单个核细胞效率达 2 7.3% ,培养上清中hVEGF165蛋白含量达 1385± 332 pg/ 10 6cells。结论 :细菌内同源重组法构建腺病毒载体具有高效、省时、省力的特点 ,辅以EGFP为标记基因可以直观检测靶细胞感染和外源基因的表达情况。利用该     

表达胰高血糖素样肽1重组腺伴随病毒载体的构建

背景:胰高血糖素样肽1(glucagon-like peptide-1,GLP-1)在人体内半衰期过短限制了其应用.目的:构建可表达GLP-1的重组腺伴随病毒.方法:将NT4-GLP-1融合基因插入腺伴随病毒包装质粒pSSHG-CMV中,构建pSSHG/NT4-GLP-1重组腺伴随病毒包装质粒.采用磷酸钙共沉淀法将辅助质粒pAAV/Ad、腺病毒质粒pFG140及pSSHG/NT4-GLP-1转染至293细胞系,用其感染Hela细胞.结果与结论:重组质粒pSSHG/NT4-GLP-1经限制性内切酶EcoRⅠ酶切鉴定可见342 bp的目的片段,说明NT4-GLP-1融合基因已经成功重组于腺伴随病毒包装质粒pSSHG-CMV内.免疫细胞化学结果显示,转染pSSHG/NT4-GLP-1重组腺伴随病毒包装质粒的Hela细胞内有大量棕黄色颗粒,阳性率达到70%以上,说明NT4-GLP-1重组腺伴随病毒在细胞中可以表达GLP-1.     

生长抑制因子4基因表达对K562细胞生长的影响

目的 研究生长抑制因子4（ING4）基因表达对K562细胞增殖的影响。方法 将经过定点突变技术人源化改造的ING4（鼠→人）生长抑制因子4基因酶切并连接到pAdTrack-CMV转移质粒上，然后与腺病毒质粒pAdEasy-1共转化BJ5183细菌，获得重组腺病毒质粒pAdEasy-1-pAdTrack—CMV—hING4，将它转染QBI-293A细胞后收获重组腺病毒Ad—hING4（以下简称为Ad-ING4）。将Ad-ING4感染K562细胞，光学显微镜下观察病毒感染前后细胞形态的变化，免疫细胞化学分析凋亡因子的改变，激光扫描共聚焦显微镜观察K562细胞的凋亡，流式细胞术（FCM）检测细胞凋亡率。结果 成功构建了人ING4腺病毒质粒，获得高滴度的重组腺病毒Ad-ING4，用它感染K562细胞72h后，FCM法测定细胞凋亡率为19．7％，与空病毒对照组相比差异有统计学意义（P〈0．01），ING4基因能下调K562细胞bcl-2的表达并上调bax的表达，多种方法检测结果表明ING4基因能抑制K562细胞生长，诱导凋亡。结论 重组腺病毒Ad—ING4可以显著抑制K562细胞的生长。     

人白细胞介素12腺病毒载体构建及在人骨髓间充质干细胞中的表达

背景:研究表明,白细胞介素12是一种强有力的抗肿瘤细胞因子,骨髓间充质干细胞易于外源基因的导入和表达,且具有较弱的免疫抗原性和免疫调节功能,因此,利用携带白细胞介素12基因的间充质干细胞对于肿瘤的治疗具有极大的发展前景.目的:构建人白细胞介素12 5型腺病毒载体(Ad hIL-12),感染人骨髓间充质干细胞,检测白细胞介素12的表达.方法:提取成熟的树突状细胞的总RNA,用RT-PCR方法获得hIL-12 p35和p40基因cDNA,p35和p40 cDNA通过脑心肌炎病毒内部核酸进入位点连接,构建pDC515 hIL-12 p35/IRES/p40腺病毒穿梭质粒.采用Ad MaxTM腺病毒载体体系,pDC515 hIL-12 p35/IRES/p40穿梭质粒与pBHGfrt△E1,3FLP骨架质粒共转染至293细胞,通过重组酶位点特异性重组获得Ad hIL-12.Ad hIL-12感染人骨髓间充质干细胞后经γ射线照射使细胞失去增殖能力,用hIL-12p70 ELISA试剂盒检测细胞上清中白细胞介素12的水平.结果与结论:经测序证实,RT-PCR所获得的hIL-12 p35和p40基因cDNA序列与GenBank NM_000882(762 bp)和NM_002187(987 bp)提供的序列完全一致.用Ad MaxTM腺病毒载体体系可高效、快捷地获得所要包装的腺病毒载体,通过IRES连接hIL-12的两个亚基p40和p35可有效地表达IL-12p70蛋白;Ad hIL-12腺病毒载体感染人骨髓间充质干细胞后可持续高水平分泌白细胞介素12,在以人骨髓间充质干细胞为载体细胞的基因治疗中有潜在的应用前景.     

力生长因子重组腺病毒载体构建及其在成骨细胞中的表达

背景:研究表明,力生长因子(mechano-growth faotor,MGF)能激活卫星细胞,促进成肌细胞增殖.在治疗肌损失、预防心肌损伤和修复神经损伤等方面有重要的作用.机械拉伸可使成骨细胞表达MGF,但是MGF对骨组织生理生化行为的影响机制尚不清楚.目的:应用携带MGF基因的重组腺病毒载体转染成骨细胞,观察MGF在成骨细胞中的表达.方法:将MGF基因插入到腺病毒穿梭质粒pAdTrack-CMV中,构建pAdTmck-MGF重组体.pAdTrack-MGF与腺病毒骨架质粒pAdEasy-1在BJ5183菌中进行同源重组,生成重组腺病毒质粒pAdEasy-MGF.脂质体介导pAdEasy-MGF转染293A细胞,包装成整的重组腺病毒Ad/MGF.用Ad/MGF感染原代培养的大鼠成骨细胞,荧光示踪计数法测定感染效率,RT-PCR法对重组腺病毒感染结果进行鉴定.结果与结论:实验构建的重组腺病毒载体Ad/MGF滴度可达8.5×108pfu/mL.Ad/MGF能高效感染体外培养的Wistar大鼠成骨细胞并表达目的基因,当感染复数为100时,感染效率最高.说明实验构建的Ad/MGF重组腺病毒可在大鼠成骨细胞中有效表达.     

趋化因子受体4基因重组腺病毒载体的构建及鉴定

背景:目前研究发现,基质细胞衍生因子1/趋化因子受体4轴具有介导骨髓间充质干细胞定向迁移的作用。目的:构建小鼠趋化因子受体4基因重组腺病毒载体。方法:从C57BL/6小鼠中提取总RNA,以RT-PCR方法获得小鼠趋化因子受体4基因全长1080bp的完整编码序列,通过穿梭质粒pAdTrack-CMV,将目的片段克隆入AdEasy-1腺病毒DNA中,获得重组腺病毒DNA,通过脂质体转染293细胞,经包装扩增后,获得重组腺病毒pAdTrack-CMV-CXCR4,并感染293细胞,PCR鉴定、Western blot检测蛋白表达。结果与结论:含趋化因子受体4基因的重组腺病毒pAdTrack-CMV-CXCR4构建成功,经PCR鉴定鉴定重组病毒中含有趋化因子受体4cDNA全长,经序列测定表明趋化因子受体4cDNA序列正确无丢失和错配现象,病毒滴度高,Western blot检测感染后293细胞趋化因子受体4的蛋白表达较未感染293细胞明显增加。     

表达胰高血糖素样肽1重组腺伴随病毒载体的构建

背景：胰高血糖素样肽1（glucagon-like peptide-1,GLP-1）在人体内半衰期过短限制了其应用。目的：构建可表达GLP-1的重组腺伴随病毒。方法：将NT4-GLP-1融合基因插入腺伴随病毒包装质粒pSSHG-CMV中,构建pSSHG/NT4-GLP-1重组腺伴随病毒包装质粒。采用磷酸钙共沉淀法将辅助质粒pAAV/Ad、腺病毒质粒pFG140及pSSHG/NT4-GLP-1转染至293细胞系,用其感染Hela细胞。结果与结论：重组质粒pSSHG/NT4-GLP-1经限制性内切酶EcoRⅠ酶切鉴定可见342bp的目的片段,说明NT4-GLP-1融合基因已经成功重组于腺伴随病毒包装质粒pSSHG-CMV内。免疫细胞化学结果显示,转染pSSHG/NT4-GLP-1重组腺伴随病毒包装质粒的Hela细胞内有大量棕黄色颗粒,阳性率达到70%以上,说明NT4-GLP-1重组腺伴随病毒在细胞中可以表达GLP-1。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Prospects for the control of neglected tropical diseases by mass drug administration

The prospects for the control of neglected tropical diseases, including soil-transmitted helminthiasis, shistosomiasis, lymphatic filariasis, onchocerciasis and trachoma, through mass drug administration, are exemplified by the elimination of the trachoma as a public-health problem in Morocco. In spite of this and other striking successes, mass drug administration programs are faced with major challenges resulting from suboptimal coverage and lack of efficacy. At current suboptimal coverage rates, programs may need prolongation for an extended period, increasing costs and undermining sustainability. Community participation through health education and information appears to be crucial to improve coverage and to achieve sustainability. Implementation of complementary measures, such as vector control, improved hygiene and environmental sanitation, are important to further control transmission and to prevent re-emergence of the infection and, again, may only be achieved effectively through community-based initiatives. To reduce costs and to relieve pressure on the health system, combining neglected tropical disease programs in areas where diseases coexist and integration with existing control programs for malaria, tuberculosis and HIV/AIDS is advocated. The risk of developing drug resistance is of particular concern in view of the lack of alternative drugs, and reduced treatment efficacy due to emerging resistance is evident for the soil-transmitted helminths and onchocerciasis. Given the risk for the development of drug resistance and the need for a high degree of participation, close attention should be paid to the monitoring of the coverage and efficacy of the different program components.     

Bacterial meningitis: an update of new treatment options

The outcome of bacterial meningitis critically depends on the rapid initiation of bactericidal antibiotic therapy and adequate management of septic shock. In community-acquired meningitis, the choice of an optimum initial empirical antibiotic regimen depends on the regional resistance patterns. Pathogens resistant to antibacterials prevail in nosocomial bacterial meningitis. Dexamethasone is recommended as adjunctive therapy for community-acquired meningitis in developed countries. In comatose patients, aggressive measures to lower intracranial pressure <20 mmHg (in particular, external ventriculostomy, osmotherapy and temporary hyperventilation) were effective in a case–control study. Although many experimental approaches were protective in animal models, none of them has been proven effective in patients. Antibiotics, which are bactericidal but do not lyse bacteria, and inhibitors of matrix metalloproteinases or complement factor C5 appear the most promising therapeutic options. At present, vaccination is the most efficient method to reduce disease burden. Palmitoylethanolamide appears promising to enhance the resistance of the brain to infections.     

Prise en charge des entorses externes de cheville : étude clinique préliminaire sur l’efficacité du dispositif Myolux™

Ankle sprains are the most common injury of the musculoskeletal system and are associated with significant societal and economic impacts. It has been proven that classical therapeutic strategies may not be effective in preventing recurrent injuries: the recurrence rates reported in the literature can reach 73%. In order to provide an effective rehabilitation solution, a destabilizing orthosis was developed. This device is equipped with a mechanical articulator reproducing the subtalar mechanics and placed under the heel. In this paper, we present the main results of a preliminary clinical study conducted between 2004 and 2007. All subjects included in this study were treated with the abovementioned orthosis during 10 rehabilitation sessions of 30 minutes each. Data show a relatively low recurrence rate of 12% for the overall population. Moreover, it's of primary importance to note that this satisfactory ratio is largely reduced (3% of recurrence rate) for the 29 patients who performed one training session per month after the 10th initial rehabilitation sessions. Hence, the destabilizing orthosis appears to be an effective solution to prevent recurrent ankle sprains. However, joint protection requires long-term and regular training sessions. This result has motivated the development of a similar device allowing patients to perform training sessions at home. Finally, data obtained in this study are promising awaiting the final results of the comparative, multicentric and independent clinical trials currently managed by the Hospices Civils de Lyon.     

Imaging choices in occult hip fracture

Background: Hip fracture is a common injury, with an incidence rate of > 250,000 per year in the United States. Diagnosis is particularly important due to the high dependence on the integrity of the hip in the daily life of most people. Objectives: In this article we review the literature focused on hip fracture detection and discuss advantages and limitations of each major imaging modality. Discussion: Plain radiographs are usually sufficient for diagnosis as they are at least 90% sensitive for hip fracture. However, in the 3–4% of Emergency Department (ED) patients having hip X-ray studies who harbor an occult hip fracture, the Emergency Physician must choose among several methods, each with intrinsic limitations, for further evaluation. These methods include computed tomography, scintigraphy, and magnetic resonance imaging. Conclusion: We present an evidence-based algorithm for the evaluation of a patient suspected to have an occult hip fracture in the ED. Also outlined are future directions for research to distinguish more effective techniques for identifying occult hip fractures.     

Systematic Reviews Published in the April 2012 Issue of the Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD but monthly online. The April 2012 issue (second DVD for 2012) contains 5045 complete reviews, 2182 protocols for reviews in production, and 17,084 short summaries of systematic reviews published in the general medical literature. In addition, there are citations of 674,000 randomized controlled trials, and 15,400 cited papers in the Cochrane methodology register. The health technology assessment database contains just over 11,000 citations. One hundred and seventeen new reviews have been published in the last 3 months of which 12 have potential relevance for practitioners in pain and palliative medicine. The impact factor of the Cochrane Library stands at 6.186. Readers are encouraged to access the full report for any articles of interest as only a brief commentary is provided.     

Platelets,thrombosis, coagulation,and atherosclerosis

When I first got the invitation to join a medical delegation going to Moldova, I thought for a moment that our destination was the fictional country in the old Marx Brothers movie Duck Soup. On further checking, it turns out that entertaining place was called Freedonia. I now know that Moldova is indeed a real country, bordered on the west by Romania and on the other three sides by the Ukraine. It is a proud country, rich with traditions, and its people are warm, giving, eager to learn ways to improve their healthcare system, and deeply appreciative of our attempts to help them in the task.