三七总皂苷传递体的制备及其治疗大鼠急性软组织损伤作用研究

目的优化三七总皂苷(PNS)传递体的处方,验证其治疗大鼠急性软组织损伤的作用。方法采用薄膜分散法制备PNS传递体,以传递体弹性为指标,通过均匀设计法优化其处方工艺;分别以挤出法、离心超滤法测定传递体的弹性与包封率;通过对实验动物的损伤症候指数、血液流变学及组织形态学的观测评价传递体对大鼠急性软组织损伤的治疗作用,并与阳性对照药青鹏软膏进行比较。结果 PNS传递体最佳处方为PNS 100 mg、胆固醇15 mg、大豆磷脂120 mg、维生素E 2 mg、中药挥发油(柠檬烯-柠檬醛4∶1)80 mg、水化液[磷酸盐缓冲液(PBS),p H 5.0]10 m L;以最佳处方制得的成品弹性为(2.74±0.32)min、粒径为(123.60±0.36)nm、Zeta电位为(-36.67±2.29)m V,人参皂苷Rg1与人参皂苷Rb1的包封率分别为(82.42±0.69)%、(94.40±0.74)%;药效学实验结果显示,与模型组相比PNS传递体可显著降低实验动物的损伤证候指数(P0.01)、全血黏度及血浆黏度(P0.05),有效改善病灶部位组织形态。结论所得PNS传递体粒径适宜,弹性与药物包封率良好,疗效确切。     

Effect of mechanical loading and substrate elasticity on the osteogenic and adipogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are highly sensitive to biomechanics of their extracellular environment. Generally, a higher elasticity of culture substrates can drive cells into the osteogenic lineage, whereas low substrate elasticity results in adipogenesis. Applied mechanical loading by cyclic strain is another major variable influencing cell fate. Yet, little is known about the simultaneous effect of both cues. Therefore, the present study investigated the relative importance of both cues on differentiation. MSCs were cultured in an osteogenic and also an adipogenic environment on soft polyacrylamide (PAAm; E = 23 ± 0.3 kPa), stiff PAAm (111 ± 2 kPa), and polydimethylsiloxane (PDMS; E = 1,5 ± 0.07 MPa) either unstrained or with 8% cyclic strain at 1 Hz. Without strain, the relative expression of the early osteogenic marker alkaline phosphatase (ALP) was significantly higher (78%) on PDMS than on both PAAm. With 8% cyclic strain, ALP expression increased for all groups in comparison with unstrained controls. The highest increase was observed for the soft PAAm by 36%. Moreover, relative oil red O (ORO) expression—indicating adipogenesis—was the highest for unstrained soft PAAm. On the other hand, the percentage of ORO positive cells significantly decreased by 57% and 69% for soft and stiff PAAm when strained. In conclusion, biomaterial elasticity and mechanical loading can act simultaneously on cell differentiation. Substrate elasticity is an important factor, regulating the differentiation, but cyclic strain can drive MSCs towards the osteogenesis even on the softest substrate. As such, the osteogenic effect of mechanical loading can overrule the adipogenic effect of soft substrates, thereby acting as an inhibitor.     

Real-time elastography for the differentiation of benign and malignant superficial lymph nodes: a meta-analysis

Background

Real-time elastography (RTE), as a non-invasive method, is used for the classification of benign and malignant lymph nodes (LNs) and developed as an alternative to biopsy. Elasticity score (ES) and strain ratio (SR) are used for the interpretation of RTE. We studied the performance of RTE for diagnosis of malignant LNs using meta-analysis.

Methods

PubMed, the Cochrane Library, ISI Web of Knowledge, China National Knowledge Infrastructure were searched. The studies published in English or Chinese relating to the diagnostic value of RTE for superficial LNs were collected. Hierarchical summary receiver operating characteristic (HSROC) curve was used to examine the RTE accuracy. Clinical utility of RTE for LNs was evaluated by Fagan plot analysis.

Results

A total of 9 studies which included 835 LNs were analyzed. The summary sensitivity and specificity for the diagnosis of malignant LNs were 0.74 (95% confidence interval (CI), 0.66–0.81) and 0.90 (95% CI, 0.82–0.94) for ES, and 0.88 (95% CI, 0.79–0.93) and 0.81 (95% CI, 0.49–0.95) for SR, respectively. Compared to ES, SR obviously improved the diagnostic sensitivity value. The HSROCs were 0.88 for ES and 0.91 for SR, respectively. After RTE results over the cut-off value for malignant LNs (“positive” result), the corresponding post-test probability for the presence (if pre-test probability was 50%) was 88% for ES and 82% for SR, respectively; while, in “negative” measurement, the post-test probability was 22% and 13%, respectively.

Conclusion

RTE has a high accuracy in the classification of superficial LNs and can potentially help to select suspicious LNs for biopsy.     

Early E‐modulus of healing Achilles tendons correlates with late function: Similar results with or without surgery

Non‐operative treatment of Achilles tendon ruptures is associated with an increased risk of rerupture. We hypothesized that this is due to inferior mechanical properties during an early phase of healing, and performed a randomized trial, using a new method to measure the mechanical properties. Tantalum markers were inserted in the tendon stumps, and tendon strain at different loadings was measured by stereo‐radiography (Roentgen stereophotogrammetric analysis) at 3, 7 and 19 weeks and 18 months after injury. Thirty patients were randomized to operative or non‐operative treatment. The primary out‐come variable was an estimate for the modulus of elasticity at 7 weeks. Strain per force, cross‐sectional area and tendon elongation were also measured. The functional outcome variable was the heel‐raise index after 18 months. There was no difference in the mean modulus of elasticity or other mechanical or functional variables between operative and non‐operative treatments at any time‐point, but strain per force at 7 and 19 weeks had a significantly larger variation in the non‐operative group. This group, therefore, might contain more outliers with poor healing. The modulus of elasticity at 7 weeks correlated with the heel‐raise index after 18 months in both treatment groups (r²=0.75; P=0.0001). This correlation is an intriguing finding.     

ROC方法评价高频彩超、超声弹性成像及钼靶X线在乳腺病变鉴别诊断中的价值

目的：比较高频彩超、超声弹性成像及钼靶X线对乳腺良恶性病变进行鉴别诊断的价值.材料与方法：回顾分析经病理证实的59例乳腺肿块的高频彩超、钼靶X线、超声弹性成像及高频彩超与弹性成像联合诊断结果的敏感性、特异性、准确性,并对诊断结果进行ROC分析.结果：超声弹性成像诊断乳腺良恶性病灶的准确性93.24％、敏感性89.6％、特异性90.6％,略高于钼靶X线的89.9％、89.7％和84.4％.高频超声诊断乳腺肿块良恶性具有较高的敏感性（75.9％）但特异性较差（62.5％）.高频彩超＋弹性成像组合得到最高的敏感性93.1％,但特异性提高不明显,仅为65.6％.超声弹性成像的AUC值0.958,高于钼靶X线、高频彩超和高频彩超＋弹性成像三者的AUC值（0.921、0.827和0.887）,弹性成像与高频彩超和二者结合的AUC之间的差异具有统计学意义（P=0.0077、0.0416）.结论：超声弹性成像对乳腺病变诊断具有较高的敏感性和特异性,与高频超声联合应用能够明显提高超声检查在乳腺良恶性病变中的鉴别诊断准确性.     

基于超高速成像技术的脉搏波传导速度检测颈动脉弹性的一致性和重复性研究

目的评价不同超声医师应用基于超高速成像技术的脉搏波传导速度检测颈动脉弹性的一致性,以及同一医师多次检测同一受检者的重复性。方法随机选取13名健康志愿者作为受检者。两名超声医师应用此技术检测志愿者的颈动脉弹性,获得收缩期起始时和结束时的脉搏波传导速度,即BS和ES。每名志愿者每侧颈动脉各检测5次,按左右标记为LBS、LES、RBS和RES。应用Bland-Altman检测两名医师测量数据的一致性,组内相关系数ICC检测同一名医师测量同一志愿者数据的重复性。结果 Bland-Altman图显示LBS和RBS的点都落在95%一致性界限内,LES和RES各仅有1个点落在95%一致性界限外,参数显示LBS、LES、RBS、RES在95%一致性界限较窄,且在界限范围内最大差值的绝对值均较小,在临床上是可以接受的。每名超声医师检测同一名志愿者的LBS、LES、RBS、RES各5次,ICC均大于0.75。结论基于超高速成像技术的脉搏波传导速度检测颈动脉弹性有着较好的一致性和重复性,是一项反映颈动脉弹性的可信指标。     

超声弹性评分联合实时超声弹性成像定量参数对良恶性甲状腺结节诊断价值分析

目的：探讨超声弹性评分联合弹性应变值[感兴趣区域（ROI）A值]对良、恶性甲状腺结节的诊断价值。方法对153例患者共计178个甲状腺结节进行超声弹性成像检查,计算弹性评分与ROI A值。以术后病理诊断为金标准,采用受试者工作特征曲线比较ROI A值、弹性评分与二者联合应用的诊断价值,并确定相应的最佳诊断界值。结果ROI A值诊断的最佳诊断界值为0．0017,此时灵敏度为82．46％、特异度为78．13％、准确度为80．90％、比值比为16．79;弹性评分诊断的最佳诊断界值为2．6,此时灵敏度为84．21％、特异度为81．25％、准确度为83．15％、比值比为23．11;以弹性评分2．6和ROI A值0．0017为界,二者联合诊断的灵敏度为78．95％、特异度为90．63％、准确度为84．15％、比值比为36．25。结论超声弹性评分联合实时超声弹性成像定量参数可以提高良、恶性甲状腺结节的诊断准确度。     

护理本科实习生情绪弹性与负性情绪调节能力的相关研究

目的探讨护理本科实习生情绪弹性与负性情绪调节能力的相关性。方法采用青少年情绪弹性问卷和负性情绪调节能力量表,对哈尔滨市某医院270名护理本科实习生进行调查。结果护理本科实习生的情绪弹性、情绪恢复能力及积极情绪能力得分分别为(3.07±0.97)分、(2.95±0.50)分、(2.82±0.44)分,均低于均分3.5分;负性情绪调节及其各因子得分分别为(3.36±0.27)分、(3.41±0.29)分、(3.30±0.35)分和(3.02±0.37)分,均高于平均分3.0分。负性情绪行为调节能力与负性情绪认知调节能力可预测情绪弹性的高低(P0.01或P0.05)。结论护理本科实习生情绪弹性、情绪恢复能力及积极情绪能力不容乐观,而负性调节能力处于中等偏上水平,负性情绪行为调节与负性情绪认知调节能力越高,情绪弹性越好。