纳米TiO2C薄膜涂层的生物相容性评价

背景：前期实验采用溶胶一凝胶法在纯钛片表面制备了纳米TiO2：C薄膜涂层。目的：评估纳米TiO2：C薄膜涂层的生物相容性。方法：①溶血实验：取新西兰大白兔静脉血，分别加到TiO2生理盐水、Ti02：c-生理盐水、蒸馏水和生理盐水中。②细胞毒性实验：将TiO2：C浸提液加入对数生长期的L929细胞培养基中。⑨短期全身毒性实验：将60只BALB，C小白鼠随机分为3组，分别灌胃给予TiO2浸提液、TiO2：C浸提液及生理盐水。④口腔黏膜刺激实验：将牙胶圆片与TiO2：C纳米薄膜涂片分别缝合固定于仓地鼠颊黏膜上。结果与结论：纳米TiO2：C涂层未引起急性溶血，毒性等级为0—1级，末对细胞产生明显毒性，细胞周期未见明显异常；TiO2：C浸提液对小鼠无短期全身毒性；对仓鼠口腔黏膜无刺激性。表明纳米TiO2：C薄膜涂层具有良好的生物安全性。     

强的松龙纳米微球缓释膜的生物安全性

背景：如何用药物去抑制神经修复后瘢痕的生长成为周围神经损伤后功能恢复的关键。课题组以往研究借鉴广泛应用于抗肿瘤药物局部释放的纳米微球缓释技术设计了一种强的松龙纳米微球缓释膜,取得了良好的体外药物缓释效果。目的：制备强的松龙纳米微球缓释膜,观察该膜的生物相容性及安全性。方法：采用反胶束乳化溶剂挥发法和球膜结合的方法制备强的松龙纳米微球缓释膜,用细胞毒性实验、溶血实验、急慢性全身毒性实验对药膜的生物安全性进行初步评价。结果与结论：培养第7天,L929小鼠成纤维细胞相对增殖率为92.6%,证实此膜无细胞毒性;该膜对新鲜的抗凝兔血溶血率为0.59%,无明显的溶血作用;此缓释膜的浸提液腹腔注射小鼠未见明显的生物学行为的异常,对大鼠肝肾功能无明显影响。结果证实,强的松龙纳米微球缓释膜具有良好的生物相容性,安全无毒性。     

纳米含氟羟基磷灰石牙种植体的生物相容性

背景：有关纳米含氟羟基磷灰石牙种植体材料生物相容性的报道较少。目的：检测纳米含氟羟基磷灰石牙种植体材料的体外生物相容性。方法：采用溶胶凝胶技术分别制备羟基磷灰石与纳米含氟羟基磷灰石。①溶血性实验：在0.2 mL稀释兔抗凝血中分别加入0.01,0.15,0.2 g/L纳米含氟羟基磷灰石溶液、生理盐水及蒸馏水各10 mL,检测各组上清液吸光度值。②体外细胞毒性实验：分别以100%,50%纳米含氟羟基磷灰石浸提液、100%羟基磷灰石浸提液、苯酚溶液及RPMI1640培养液培养传至第2代的L929细胞,MTT法检测培养2,4,7 d的吸光度值。结果与结论：体外溶血性实验显示,各浓度梯度纳米含氟羟基磷灰石的溶血率均在5%以内,符合医用材料的溶血要求。体外细胞毒性实验显示,随着培养时间的增加,100%,50%纳米含氟羟基磷灰石浸提液组细胞贴壁覆盖率增加,细胞密度增高,细胞为长梭形或多角形,细胞增殖及形态与RPMI1640培养液组、羟基磷灰石组无明显差别,细胞毒性为0级。     

载中药羟基磷灰石/壳聚糖骨支架的制备与生物相容性*

背景：中药来源的三七总皂甙苷可通过增加缺血部位血管再生及骨折愈合,因此推测载三七总皂苷的中药支架具有促进骨缺损部位骨痂再生的作用,但其生物相容性尚不清楚。
　　目的：制备三七总皂苷-羟基磷灰石/壳聚糖骨修复支架,评估其生物相容性。
　　方法：采用原位复合和冷冻干燥技术制备载三七总皂苷量分别为0,0.1,1,10 mg的羟基磷灰石/壳聚糖复合材料,采用扫描电镜观察复合支架形貌,并测试其机械性能。①细胞增殖实验：以4种载药羟基磷灰石/壳聚糖复合材料浸提液培养第3代兔骨髓间充质干细胞,以正常培养的细胞为对照,MTT法检测各组细胞A值。②溶血实验：在抗凝兔血中分别加入4种载药羟基磷灰石/壳聚糖复合材料浸提液,酶标仪检测各组A值。③热源实验：经兔耳缘静脉分别注射4种载药羟基磷灰石/壳聚糖复合材料浸提液与生理盐水,检测兔体温升高值。
　　结果与结论：载药羟基磷灰石/壳聚糖复合材料含有大量直径为110μm的三维多孔结构,三七总皂苷载药过程对复合材料的孔隙率、孔径、密度无显著影响,但却降低了其断裂强度和弹性模量,载药量越大效果越明显。单纯的羟基磷灰石/壳聚糖复合材料细胞相容性良好,载药后的复合材料明显抑制了细胞增殖,载药量越大效果越明显。载药前后的复合材料均具有良好的血液相容性。载药前后的复合材料均具有一定的热源作用,但符合热源实验的检测合格标准。     

羧甲基壳聚糖温敏凝胶的制备及其毒性实验

背景:与壳聚糖相比,羧甲基壳聚糖的水溶性提高,且安全、无毒、无害,具有成膜性、保湿性、生物相容性好的特点,是一种良好的药物载体.目的:自制羧甲基壳聚糖温敏凝胶,了解其对小鼠肺成纤维细胞L929的毒性作用.方法:利用羧甲基壳聚糖与甘油磷酸盐互配,制备羧甲基壳聚糖温敏凝胶.采用四甲基偶氮唑盐法测定50,10,2,0.4,0.08倍的羧甲基壳聚糖温敏凝胶浸提液对体外培养L929细胞的细胞毒性,并设定阳性与阴性对照组.测定加样后24,48,72,96 h的A值,计算细胞相对增殖率,评定细胞毒性等级.结果与结论:各组细胞不同时间点相对增殖率均在103%～228%之间,各浓度羧甲基壳聚糖温敏凝胶材料浸提液的细胞毒性均为0级.提示羧甲基壳聚糖温敏凝胶对L929细胞无毒性作用,且有良好的生物相容性,在牙周病治疗中具有潜在的应用价值.     

纳米羟基磷灰石/细菌纤维素复合组织工程支架的细胞毒性和生物相容性

背景：天津大学材料学院利用仿生学方法制备的纳米羟基磷灰石/细菌纤维素复合支架材料,具有与天然骨相似的结构和性能。目的：研究纳米羟基磷灰石/细菌纤维素复合组织工程支架的细胞毒性和生物相容性。方法：①急性全身性毒性实验：将纳米羟基磷灰石/细菌纤维素材料浸提液与生理盐水分别注射至昆明小鼠腹腔,注射24,48,72 h记录小鼠体质量。②致敏实验：在日本大耳白兔背部皮下分别注射纳米羟基磷灰石/细菌纤维素材料浸提液与生理盐水,72 h内观察注射部位水肿及红斑情况,间隔14 d后再次行激发实验。③热源实验：在日本大耳白兔耳缘静脉注射纳米羟基磷灰石/细菌纤维素材料浸提液,注射后检测体温变化。④溶血实验：在稀释的兔抗凝血中分别加入纳米羟基磷灰石/细菌纤维素材料浸提液、生理盐水与蒸馏水。⑤将第3代兔骨髓间充质干细胞与纳米羟基磷灰石/细菌纤维素材料共培养,观察材料表面细胞增殖、生长及黏附状态。结果与结论：纳米羟基磷灰石/细菌纤维素复合支架材料无急性全身毒性、无致敏性、无热源反应、无溶血反应,该支架材料具有三维网络结构,骨髓间充质干细胞在材料表面生长、增殖及黏附良好,表明纳米羟基磷灰石/细菌纤维素复合支架材料具有良好的生物相容性与细胞相容性。     

重组人骨形态发生蛋白2壳聚糖纳米微球的制备及体外细胞毒性

背景：通过各种微球负载骨生长因子使骨形态发生蛋白达到缓释效果逐渐成为研究热点,但关于载药壳聚糖纳米微球的生物相容性特别是细胞毒性的报道较少。目的：对重组人骨形态发生蛋白2壳聚糖纳米微球进行细胞毒性检测,评估应用壳聚糖纳米微球作为重组人骨形态发生蛋白2缓释载体的生物安全性。方法：通过离子交联法制备空白壳聚糖纳米微球,应用透视电镜观察微球的形态,激光粒径分析其粒径分布;通过重组人骨形态发生蛋白2壳聚糖纳米微球体外细胞毒性试验评估微球的生物安全性。结果与结论：离子交联法制备的壳聚糖微球,球形规整,分散均匀,微球平均粒径为230nm,分布较集中。载药及空白微球的反应分级为0或1级,均为合格。提示,离子交联法制备可成功制备出负载重组人骨形态发生蛋2的纳米微球,且微球细胞毒性检测合格,为进一步的骨组织工程研究提供理论实验基础。     

羟基磷灰石/聚苯硫醚复合材料的制备及体外生物相容性

背景：利用传统固相复合工艺难以将纳米级羟基磷灰石粉体与聚苯硫醚进行复合,从而无法发挥纳米材料的优势,并且目前缺少羟基磷灰石/聚苯硫醚复合材料生物相容性的相关研究。目的：应用液相复合工艺制备纳米羟基磷灰石/聚苯硫醚复合材料,评价其体外生物相容性。方法：应用液相复合工艺制备纳米羟基磷灰石/聚苯硫醚复合材料粉体和片材,利用红外光谱分析仪及扫描电镜分析复合材料的成分结构;利用接触角测试仪评估材料的亲水性,利用兔血及L929小鼠成纤维细胞进行材料的溶血实验及体外细胞毒性实验。结果与结论：通过液相复合工艺制备的羟基磷灰石/聚苯硫醚复合材料混合均匀,结合紧密;聚苯硫醚粉体的接触角为81.25＆#176;,而纳米羟基磷灰石/聚苯硫醚复合材料粉体接触角为16.1＆#176;;聚苯硫醚片材的接触角为83.5＆#176;,纳米羟基磷灰石/聚苯硫醚复合材料片材的接触角为42.5＆#176;,对比可知,纳米羟基磷灰石的加入明显改善了单纯聚苯硫醚材料的亲水性能。纳米羟基磷灰石/聚苯硫醚复合材料的溶血率为1.66%（〈5%）,提示材料血液相容性良好;L929细胞在材料浸提液中生长良好,CCK-8法检测提示体外细胞毒性属无毒范畴（0至1级）。以上结果表明羟基磷灰石/聚苯硫醚复合材料制备成功,体外生物相容性良好。     

海藻酸钠/壳聚糖复合凝胶的制备与细胞毒性评价

背景：海藻酸钠和壳聚糖分别是聚阳离子和聚阴离子的天然高分子材料,二者可以互为交联剂形成复合凝胶,避免使用普通交联剂产生的细胞毒性。 目的：制备海藻酸钠壳聚糖复合凝胶并评价其体外细胞毒性。 方法：以0.25 mol/L乙酸溶解壳聚糖,制成质量浓度30 g/L溶液,再以0.1 mol/L的NaOH中和酸性得到壳聚糖絮状沉淀,将壳聚糖絮状沉淀与质量浓度3%海藻酸钠等比例混合,高频振动混匀,使二者形成复合凝胶。使用傅里叶变换红外光谱、扫描电镜分析观察凝胶成分和交联纤维网络结构。分别以海藻酸钠壳聚糖复合凝胶24,72 h浸提液、聚乙烯24,72 h浸提液及苯酚溶液培养L-929细胞,体外检测其细胞毒性。 结果与结论：傅里叶变换红外光谱检测到海藻酸钠壳聚糖复合凝胶特征性峰值改变,扫描电镜显示其内部形成丰富间隙的空间网络结构。浸提液法检测海藻酸钠壳聚糖复合凝胶的细胞毒性为合格,表明海藻酸钠/壳聚糖复合凝胶具有成为组织工程支架材料的良好条件。     

新型生物可降解材料聚乳酸凝胶的生物相容性

目的：研究新型生物可降解材料聚乳酸凝胶的生物相容性，为此种材料的应用提供生物学依据。方法：实验于2002—11／2003—02在四川大学华西医院移植免疫实验室和动物实验外科完成。通过动物急性毒性试验、溶血试验、遗传毒性试验、肌腱鞘管内及硬膜外长期植入试验测定材料的动物毒性；并通过细胞毒性测定、细胞与材料混合培养，综合评价新材料的生物相容性。结果：聚乳酸凝胶注射入小鼠无急性毒性；材料浸提液无溶血反应(溶血率为0．22％)及遗传毒性(微核率为0．24％)；材料在动物体内长期埋植后局部和全身各器官无组织损伤，局部无明显粘连；材料浸提液(1000，500，100g／L)的细胞毒性及分级与阴性对照差异无显著性意义(P&;gt;0．05)，材料与细胞的混合培养中细胞生长良好。结论：聚乳酸凝胶具有良好的生物相容性。     

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.     

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.     

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.     

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.     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.