链霉亲和素化载紫杉醇相变型PLGA纳米粒的制备及体外超声显影

目的制备链霉亲和素化载紫杉醇相变型PLGA纳米粒(PTX-PLGA-SA/PFPs),并观察其体外低强度聚焦超声(LIFU)致相变后超声增强显影特性。方法采用单乳化法(O/W)制备载紫杉醇相变型PLGA纳米粒,高效液相色谱法检测紫杉醇包封率;碳二亚胺法连接链霉亲和素(SA),共聚焦激光显微镜观察二者连接情况,流式细胞术检测二者链接率;体外LIFU致相变观察超声增强显影情况。结果制备的纳米粒粒径为(322.2±85.6)nm,表面电位(-5.66±3.46)mV。紫杉醇的包封率及载药量分别为(71.56±6.51)%、(6.57±0.61)%,与链霉亲和素的连接率为(97.16±1.20)%。LIFU功率7.5 W作用3min时可明显增强该纳米粒在体外的B-mode及造影模式下的超声显影。结论成功制备了PTX-PLGA-SA/PFPs纳米粒,其紫杉醇包封率高、链霉亲和素连接率高,体外声致相变后可显著增强超声显影。     

载10-羟基喜树碱的叶酸受体靶向相变超声造影剂的制备及一般特性

目的制备一种载10-羟基喜树碱(10-HCPT)的叶酸受体靶向相变纳米粒超声造影剂(FR-HCPT-PNPCA),评价其载药及在体外的相变能力、对肿瘤细胞的靶向能力等一般特性。方法通过双步乳化法制备以脂质为壳膜材料、液态氟碳为内核,且包裹抗癌药物10-HCPT的纳米粒,采用高效液相色谱研究其药物包封率和载药量,在体外通过加热法研究其相变产生微泡的能力,并在肝癌细胞株7721细胞上研究其体外寻靶能力。结果成功制备出载10-HCPT的靶向相变纳米粒FR-HCPT-PNPCA,其药物包封率为70.42%,载药量为20.05%。当加热至70℃时,显微镜下可以观察到明显的相变并产生微气泡,且大量纳米粒可特异性地黏附于肝癌细胞周围。结论 FR-HCPT-PNPCA载药率高,性质稳定,靶向肿瘤能力强,有望成为一种集肿瘤诊治于一体的多功能超声分子探针,具有良好的应用前景。     

含RGD修饰的丹参酮ⅡA多级靶虎纳米粒的质量评价

目的探讨丹参酮ⅡA多级靶向纳米粒的制备及其质量评价。方法采用乳化溶剂蒸发法制备丹参酮ⅡA多级纳米粒;测定丹参酮ⅡA多级靶向纳米粒的粒径分布及纳米微粒表面结构;并检测丹参酮ⅡA多级靶向纳米粒的载药量、包封率及体外药物释放规律。结果课题组制备的丹参酮ⅡA多级靶向纳米粒,大小均匀,载药纳米粒的平均粒径为190nm,Zeta电位为4．3mV,包封率（94．12±5．20）％,载药量（2．05±0．12）％。与游离的丹参酮ⅡA单体相比,丹参酮ⅡA多级靶向纳米粒释放速度明显减慢,在120h累积释放量为72．59％。结论采用乳化溶剂蒸发法成功制备了含RGD修饰的丹参酮ⅡA多级靶向纳米粒。与丹参酮ⅡA单体相比,制备成纳米制剂后,多级靶向载药纳米粒能随着时间的延长将药物逐步释放出来,具有良好的缓释特征。     

制备叶酸受体靶向载阿霉素/黑色素多功能造影剂及体外超声/光声显像

目的制备叶酸受体靶向载阿霉素/黑色素的多功能造影剂,评估其基本特性、体外细胞靶向能力、超声和光声显像效果以及对人乳腺癌MDA-MB-231细胞增殖活力的影响。方法采用单乳化法和冷冻干燥减压充入C3F8气体的方法制备叶酸受体靶向载阿霉素/黑色素多功能造影剂,以马尔文激光仪检测其平均粒径及表面电位,应用紫外-可见光分光光度法测量阿霉素载药量,于凝胶模型中观察其体外超声、光声增强显影能力,以人乳腺癌MDA-MB-231细胞验证其体外细胞靶向能力和细胞增殖活力的影响。结果叶酸受体靶向载阿霉素/黑色素脂质多功能造影剂平均粒径为(659.60±27.56)nm,Zeta电位为(-38.90±4.00)mV,阿霉素载药率为85.72μg/mg。叶酸受体靶向造影剂大量聚集在MDA-MB-231细胞表面,具有较好的体外超声、光声显像能力,对MDA-MB-231细胞增殖有显著抑制作用。结论叶酸受体靶向载阿霉素/黑色素多功能造影剂是集靶向治疗、超声和光声多模态显像于一体的多功能造影剂,有望成为乳腺癌精准显像和治疗的理想分子探针。     

携紫杉醇和Herceptin高分子超声造影剂体外寻靶及体内肿瘤药物含量分析

目的探讨携紫杉醇和Herceptin高分子造影剂(Pac-PLGA-HER)的体外寻靶能力及体内肿瘤药物含量。方法通过双乳化法及碳二亚胺法制备Pac-PLGA-HER,观察其与乳腺癌细胞MCF-7的结合能力。将25只种植有乳腺癌细胞MCF-7的裸鼠分为单纯紫杉醇(PTX)组、单纯载药微球(Pac-PLGA)组、单纯载药微球+超声(Pac-PLGA+US)组、靶向载药微球(Pac-PLGA-HER)组及靶向载药微球+超声(Pac-PLGA-HER+US)组,根据微球载药量调整到相应药物浓度,经尾静脉注入裸鼠体内,观察各组在荷瘤裸鼠肿瘤内药物含量情况。结果Pac-PLGA-HER平均粒径为(777.40±65.90)nm,包封率为(65.84±2.25)%,载药量为(6.58±0.23)%,体外寻靶实验可观察到Pac-PLGA-HER与乳腺癌细胞MCF-7大量结合。体内药物释放实验显示Pac-PLGA-HER+US组在裸鼠肿瘤内药物浓度高于其他各组(P0.01)。结论 Pac-PLGA-HER与乳腺癌细胞MCF-7有较好的结合能力,体内药物释放实验中Pac-PLGA-HER+US组在裸鼠肿瘤内有较高的药物浓度。     

半乳糖化白蛋白磁性阿霉素纳米粒制备工艺的优化及缓释性的研究

目的 制备具有稳定磁性、能够携带化疗药物的半乳糖化白蛋白磁性纳米粒,并对纳米粒的磁性、药物含量、包封率、粒径大小等物理性质进行检测。方法 运用正交试验设计方法设计实验,以粒径大小、纳米药物的载药量和包封率3个指标考察固化温度、固化时间、搅拌速度及糖化比率4个因素的4个水平,从中选出最优化组合,并以最优化组合重复实验,验证试验条件的稳定性以及实验的可重复性。先行制备半乳糖化白蛋白,将阿霉素、半乳糖化白蛋白、磁粉按一定比例混合,通过在精制棉籽油中超声乳化、加热变性固化、乙醚洗涤等工艺制作出载药纳米粒,用乙醇提取法提取纳米粒中的阿霉素,并用紫外分光光度计测定含量,激光粒度分析仪分析粒径大小。结果 运用最优化条件制备的纳米粒,其平均粒径为(197±32)mm,载药量(48.79±4.47)mg/L,包封率(94.34±3.32)％。结论 上述优化条件稳定,试验的可重复性高。     

靶向VEGFR2光声/超声双模态造影剂的制备及体外寻靶实验研究

目的制备一种特异性靶向新生血管内皮细胞的光声/超声双模态造影剂,探讨其体外寻靶能力及双模态显影效果。方法采用多步乳化法制备载有印度墨水和液态氟碳的高分子造影剂,用碳二亚胺法将造影剂与抗血管内皮生长因子受体2(VEGFR2)单克隆抗体相偶联,制备出靶向VEGFR2高分子造影剂(Vi-PFH-PLGA)。检测该造影剂的一般特性、体外寻靶能力及双模态显影效果,并与非靶向高分子造影剂进行比较。结果所制备的靶向高分子造影剂的平均粒径为(565.5±15.6)nm,间接免疫荧光法观察到抗体成功的连接到造影剂表面,流式细胞仪测得抗体微球连接率为99.72%,体外寻靶能力实验显示较多的靶向造影剂呈花环状牢固的聚集在人脐静脉内皮细胞HUVEC表面,而非靶向组和抗体干预组未见造影剂与HUVEC的特异性结合。体外光声/超声显影实验显示,经脉冲激光辐照后,靶向造影剂组可检测到明显的光声信号和超声信号,与非靶向造影剂相比差异无统计学意义(P均0.05)。结论成功制备出靶向VEGFR2的光声/超声双模态造影剂,该造影剂在体外与HUVEC细胞具有较强的靶向结合能力且具备较好的光声/超声双模态显影效果。     

VEGF靶向荷钆PLA-PEG-PLL纳米探针的制备及其在小肝癌成像中的价值

目的 制备VEGF靶向荷钆纳米探针,并研究其在小肝癌特异性成像中的价值.方法 采用生物相容性高分子材料聚乳酸-聚乙二醇聚赖氨酸(PLA-PEG-PLL)纳米粒为载体,分别将血管内皮生长因子(VEGF)抗体及钆基接合至载体表面得到靶向纳米探针.体外MR成像测定其驰豫率,再利用种植型H22肝癌小鼠模型进行靶向纳米探针MR增强扫描,探讨皮下种植肝癌及微小病灶的强化表现特点.结果 制备的靶向探针粒径和Zata电位分别为(85.8±7.2)nm和(21.63±2.4)mV,当其浓度为8.0 μmol/ml时测得的R1值为18.394 mmol· ml-1·s-1.靶向探针MR增强扫描显示皮下较大肝癌及小肝癌均表现为明显的特异性靶向延迟期增强,强化峰值分别在2h及3h时出现,而非靶向纳米粒增强扫描时肿瘤强化不明显.结论 成功制备了合适的高驰豫率VEGF靶向PLA-PEG-PLL荷钆纳米探针,并实现了小肝癌的特异性靶向成像.该纳米探针在肝癌检测方面具有较好的临床应用前景.     

荧光-磁共振双功能纳米探针标记乳腺癌细胞

目的探讨载Herceptin靶向聚乳酸-羟基乙酸[poly(1actic-co-glycolic acid),PLGA]-超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)分子探针的构建方法及对乳腺癌体外靶向结合的可行性。方法以PEG化端羧基PLGA作为成膜材料,采用双乳化法及碳二亚胺化学连接法,制备装载超顺磁性氧化铁的Herceptin-SPIO-PLGA探针,并对其粒径、表面形态等进行检测,体外培养高表达HER2的乳腺癌细胞株SK-BR-3,评价其体外寻靶能力及MTT法检测所制备探针对细胞活性的影响。结果光镜及扫描电镜观察所制备探针形态规则,呈球形,表面光滑,分散性好,大小较均匀,粒径为(281.5±81.2)nm。透射电镜结果显示探针为壳核结构,USPIO分布于壳膜中,且其分布具有随机性。Herceptin-SPIO-PLGA即使在Fe浓度达到400μg/m L,细胞存活率仍保持在90%以上,具有较低细胞毒性。在激光扫描共聚焦显微镜下,被SK-BR-3细胞吞噬的发出红色荧光。结论双靶点磁性、荧光双模态分子探针多肽Herceptin-SPIO-PLGA具有优良的理化性质及稳定性,生物安全性好,肿瘤靶向结合能力强。     

转运紫杉醇的PLGA纳米粒对膀胱癌的细胞毒作用

目的 研究可转运紫杉醇的多聚体纳米粒对膀胱癌的细胞毒作用. 方法 应用微乳化方法制备载紫杉醇的聚乳酸-羟基乙酸共聚物(PLGA)纳米粒,以聚乙烯醇(PVA)为表面稳定剂,并以转铁蛋白(Tf)表面修饰,分析纳米粒的大小、表面电荷、载药浓度、药物释放曲线以及空白纳米粒的安全性,观察紫杉醇溶液及载紫杉醇纳米粒对膀胱癌细胞系J-82的细胞毒作用. 结果 PVA纳米粒直径约200 nm,Z电势约-24 mV,载药浓度约6.5％ (w/w),药物释放曲线为双相性.Tf表面修饰的纳米粒直径比PVA纳米粒稍大,Z电势、载药浓度、药物释放曲线与PVA纳米粒相似.两种空白纳米粒不具有细胞毒性.紫杉醇溶液在50 ng/ml时J-82细胞存活率为82.0％,100 ng/ml时为36.0％.PVA纳米粒在50 ng/ml和100 ng/ml时细胞存活率分别为40.2％和15.8％,而Tf纳米粒分别为32.9％和7.2％,两种载药纳米粒抑制J-82细胞的作用明显强于紫杉醇溶液. 结论 PLGA纳米粒是安全有效的载药工具,可以明显增强紫杉醇对膀胱癌的细胞毒作用.     

Presenteeism and Absenteeism Before and After Total Hip and Knee Arthroplasty

BackgroundAbsenteeism is costly, yet evidence suggests that presenteeism—illness-related reduced productivity at work—is costlier. We quantified employed patients’ presenteeism and absenteeism before and after total joint arthroplasty (TJA).MethodsWe measured presenteeism (0-100 scale, 100 full performance) and absenteeism using the World Health Organization’s Health and Work Performance Questionnaire before and after TJA among a convenience sample of employed patients. We captured detailed information about employment and job characteristics and evaluated how and among whom presenteeism and absenteeism improved.ResultsIn total, 636 primary, unilateral TJA patients responded to an enrollment email, confirmed employment, and completed a preoperative survey (mean age: 62.1 years, 55.3% women). Full at-work performance was reported by 19.7%. Among 520 (81.8%) who responded to a 1-year follow-up, 473 (91.0%) were still employed, and 461 (88.7%) had resumed working. Among patients reporting at baseline and 1 year, average at-work performance improved from 80.7 to 89.4. A Wilcoxon signed-rank test indicated that postoperative performance was significantly higher than preoperative performance (P < .0001). The percentage of patients who reported full at-work performance increased from 20.9% to 36.8% (delta = 15.9%, 95% confidence interval = [10.0%, 21.9%], P < .0001). Presenteeism gains were concentrated among patients who reported declining work performance leading up to surgery. Average changes in absences were relatively small. Combined, the average monthly value lost by employers to presenteeism declined from 15.3% to 8.3% and to absenteeism from 16.9% to 15.5% (ie, mitigated loss of 8.4% of monthly value).ConclusionAmong employed patients before TJA, presenteeism and absenteeism were similarly costly. After, employed patients reported increased performance, concentrated among those with declining performance leading up to surgery.     

The German emergency and disaster medicine and management systemdhistory and present

As well for optimized emergency management in individual cases as for optimized mass medicine in disaster management, the principle of the medical doctors approaching the patient directly and timely, even close to the site of the incident, is a long-standing marker for quality of care and patient survival in Germany. Professional rescue and emergency forces, including medical services, are the “Golden Standard” of emergency management systems. Regulative laws, proper organization of resources, equipment, training and adequate delivery of medical measures are key factors in systematic approaches to manage emergencies and disasters alike and thus save lives. During disasters command, communication, coordination and cooperation are essential to cope with extreme situations, even more so in a globalized world. In this article, we describe the major historical milestones, the current state of the German system in emergency and disaster management and its integration into the broader European approach.     

Differences in Osteocyte Density and Bone Histomorphometry Between Men and Women and Between Healthy and Osteoporotic Subjects

Bone defects related to osteoporosis develop with increasing age and differ between males and females. It is currently thought that the bone remodeling process is supervised by osteocytes in a strain-dependent manner. We have shown an altered response of osteocytes from osteoporotic patients to mechanical loading, and osteocyte density is reduced in osteoporotic patients, which might relate to imperfect bone remodeling, leading to lack of bone mass and strength. Hence, information on osteocyte density will contribute to a better understanding of bone biology in males and females and to the assessment of osteoporosis. Osteocyte density as well as conventional histomorphometric parameters of trabecular bone were determined in cancellous iliac crest bone of healthy postmenopausal women and men and of osteoporotic women and men. Osteocyte density was higher in healthy females than in healthy males and lower in osteoporotic females than in healthy females. Bone mass was reduced in osteoporotic patients, both male and female. In females, trabecular number was reduced, whereas in males, trabecular thickness was reduced and eroded surface was increased. There were no correlations between the parameter groups bone architecture, bone formation, bone resorption, and osteocyte density. These results are consistent with impaired osteoblast function in osteoporotic patients and with a different mechanism of bone loss between men and women, in which osteocyte density might play a role. The reduced osteocyte numbers in female osteoporotic patients might relate to imperfect bone remodeling leading to lack of bone mass and strength. M. G. Mullender and S. D. Tan contributed equally to this work.     

肝内胆管囊腺瘤和囊腺癌的CT、MRI及病理表现

目的探讨肝内胆管囊腺瘤和囊腺癌的CT、MRI和病理特点。方法回顾性分析经手术病理证实的6例肝内胆管囊腺瘤和2例肝内胆管囊腺癌的影像及临床病理资料，将病变的影像表现与其病理大体形态及组织学表现作对照分析。结果6例肝内胆管囊腺瘤，女4例、男2例；2例肝内胆管囊腺癌均为女性病人；8例病人平均年龄55岁。所有病灶均表现为多房囊性肿块，肿瘤囊腔各分房内常为多种液体成分，在CT上可表现为不同密度、在MRI上可表现为不同信号强度。囊内出现多发大小不等的壁结节在胆管囊腺癌内更常见，囊内有分隔但无壁结节只见于胆管囊腺瘤。在7例CT扫描中，4例胆管囊腺瘤和1例胆管囊腺癌可见囊壁或分隔上钙化，囊壁、囊内分隔及囊内结节均为轻、中度延迟增强。肿瘤中出现卵巢样间质见于3例胆管囊腺瘤和1例胆管囊腺癌，且均为女性病人。结论肝内胆管囊腺瘤和囊腺癌是肝脏不常见的囊性肿瘤，影像上多房、囊内有分隔且各分房囊内密度或信号不一致，高度提示肝内胆管囊腺瘤或囊腺癌的诊断，如囊内伴有多发大小不等的结节，则进一步提示囊腺癌的可能。但影像学表现不能区分肿瘤中有无卵巢样间质。