基本药物安全监管博弈分析

基本药物的安全监管是政府监管机构与基本药物经营者之间的博弈过程。该文通过对此博弈进行均衡分析,揭示了基本药物安全不仅取决于监管者的监管成本和基本药物生产者的违法收益及处罚,还取决于政府部门是否有效地对监管者施行了监管,从而提出了完善基本药物安全监管的相应措施。     

八段锦对2型糖尿病患者下肢肌力与身体成分的影响

[目的]观察规律性八段锦运动对2型糖尿病患者的血糖、下肢肌力与身体成分的影响。[方法]选取60例2型糖尿病患者,年龄45~67岁之间,随机分为八段锦运动干预组与对照组,分别给予12周八段锦运动（45~50分/次,5次/周）与糖尿病的病因、防治及饮食等教育（90分/次,1次/月）。比较两组空腹血糖、餐后血糖、糖化血红蛋白、股四头肌、腘绳肌、胫骨前肌与腓肠肌最大等长肌力,体脂百分比与腰臀比。[结果]组内比较八段锦运动干预组,患者的空腹血糖、餐后血糖、糖化血红蛋白与运动前相比均降低,差异有统计学意义（P<0.05）;干预后与对照组相比,差异有统计学意义（P<0.05）。女性体脂百分比下降,差异有统计学意义（P<0.05）;且与对照组相比,差异有统计学意义（P<0.05）。与本组干预前相比较,双侧股四头肌、胫骨前肌、腓肠肌最大等长肌力均增长,依次平均增长6.7 kg（增长率19.8%）、6.5 kg（增长率24.3%）、6.0 kg（增长率24.7%）,均P<0.05,与对照组相比,干预后,股四头肌、胫骨前肌与腓肠肌肌力增加,均P<0.05。[结论]12周规律性八段锦运动有效改善2型糖尿病患者的血糖、身体成分与肌肉力量,可为进一步研究传统体育运动八段锦防治糖尿病及其并发症如糖尿病足等提供基础。     

4种不同冠边缘形式的钴铬合金烤瓷冠强度的研究

目的 研究4种不同冠边缘形式的钴铬合金金属烤瓷冠的强度. 方法 按照4种不同的冠边缘形式制作4组钴铬合金烤瓷冠,其中第1组金属基底冠止于肩台唇侧边缘,第2组止于肩台唇侧中部,第3组止于肩台与轴壁交角,第4组止于肩台与轴壁交角冠方1 mm处.将粘固后的4组样本保存于37℃的人工唾液中24 h后,在Instron1342万能材料测试机上以1 mm/min的速度对样本施加平行于样本长轴的压力,直至样本边缘颈部崩瓷,记录并得出每个样本崩瓷时所承受的载荷力值. 结果 第2组样本崩瓷时所受平均载荷力值最大(P＜0.05);第4组样本崩瓷时所受平均载荷力值最小(P＜0.05);第1组与第3组的载荷力值间比较,差别无统计学意义(P＞0.05). 结论 金属基底冠止于肩台唇侧中部的金属烤瓷冠崩瓷时的所受载荷力值最大;金属基底冠唇侧止于肩台与轴壁交角冠方l mm处且颈部应用肩台瓷的金属烤瓷冠所受载荷力值最小.但4种不同冠边缘形式的钴铬合金烤瓷冠都能满足正常的咬合功能需要.     

Torsional Strength and Geometry of Diaphyseal Bone: An Experimental Study on Dogs

A previously presented method for measuring the torsional strength of diaphyseal bones has been used to study the effect of direction of twist upon the torsional strength and stiffness of diaphyseal canine bones. No significant effect of the direction of twist upon the studied properties has been found. The reason for the observed twist direction independence of the torsional strength and stiffness is assumed to be the adaptation of the diaphyseal bone architecture to functional demands.     

Influence of internal fixator flexibility on murine fracture healing as characterized by mechanical testing and microCT imaging

Mechanically well‐defined stabilization systems have only recently become available, providing standardized conditions for studying the role of the mechanical environment on mouse bone fracture healing. The aim of this study was to characterize the time course of strength recovery and callus development of mouse femoral osteotomies stabilized with either low or high flexibility (in bending and torsion) internal fixation plates. Animals were euthanized and femora excised at 14, 21, and 28 days post‐osteotomy for microCT analysis and torsional strength testing. While a larger mineralized callus was observed in osteotomies under more flexible conditions at all time points, the earlier bridging of the mineralized callus under less flexible conditions by 1 week resulted in an earlier recovery of torsional strength in mice stabilized with low flexibility fixation. Ultimate torque values for these bones were significantly higher at 14 and 21 days post‐osteotomy compared to bones with the more flexible stabilization. Our study confirms the high reproducibility of the results that are achieved with this new implant system, therefore making it ideal for studying the influence of the mechanical environment on murine fracture healing under highly standardized conditions. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1245–1250, 2011     

Comparison of modified Kessler and Yotsumoto-Dona suture: A biomechanical study on porcine tendons

Abstract

There is a need for a strong suture technique that allows early active mobilisation after repair of flexor tendons, but the best method has not yet been found. The aim of this study was to compare the modified Kessler suture biomechanically with a newer, two–strand suture. Eighteen porcine tendons were cut and repaired according to either the grasping modified Kessler suture or the combined side-locking loop technique (Yotsumoto) and interlocking horizontal mattress suture (Dona). The specimens were tested linearly to failure. The 2 mm gap force, yield force, ultimate force, stiffness, energy to yield, and energy to failure were all significantly higher (p value = 0.005, 0.003, <0.001, 0.001, 0.004, and 0.001, respectively) in the Yotsumoto-Dona group (median values (IQR): 30.9 (28.1-39.5) N, 82.7 (64.9-114.1) N, 82.7 (76.6-114.1) N, 12.5 (10-14.5) N/mm, 0.45 (0.2-0.5) J, and 0.45 (0.35-0.5) J) than in the modified Kessler group (25.8 (12.2-28.1) N, 35 (24.6-54.4) N, 50.9 (34.4-55.1) N, 7 (5.8-91) N/mm, 0.09 (0.06-0.18) J, and 0.21 (0.18-0.28) J). All Yotsumoto-Dona specimens had a yield force exceeding 35 N, while in the Kessler group only four did. The early yielding rate was 6/9 and 2/9 in the modified Kessler and the Yotsumoto-Dona groups, respectively (p = 0.15). Most of the core sutures failed by breakage, but three Yotsumoto knots loosened. All the simple running and six of the Dona epitendinous sutures failed predominantly by pulling-out, and by breakage at the intersections in three of the latter. The relatively easy two-strand Yotsumoto-Dona suture is likely to withstand the loads of active finger flexion, whereas the modified Kessler suture is probably not.     

The K153R variant in the myostatin gene and sarcopenia at the end of the human lifespan

We studied the A55T, E164K, I225T, K153R and P198A variants in the myostatin (GDF8) gene, muscle strength and mass, and physical function during daily living in 41 nonagenarians [33 women, age range, 90, 97]. No participant carried a mutant allele of the aforementioned variants, except three participants (all women), who carried the R allele of the K153R polymorphism, with one of them (woman aged 96 years) being homozygous. Overall, in KR women muscle phenotype values (1RM leg press and estimated muscle mass) were low-to-normal compared to the whole group (∼25th–50th percentile), and their functional capacity (Barthel and Tinetti tests) was normal. In the woman bearing the RR genotype, values of muscle mass and functional capacity were below the 25th percentile. She is the first RR Caucasian whose phenotype has been characterised specifically. In summary, heterozygosity for the GDF8 K153R polymorphism does not seem to exert a negative influence on the muscle phenotypes of women who are at the end of the human lifespan, yet homozygosity might do so. More research on larger cohorts of nonagenarians is needed to corroborate the present findings.     

Differences In Nutritional And Physical Health Indicators Among Older African Americans,European Americans,And Hispanic Americans

Abstract

Inadequate protein intake contributes to poor nutritional status, reduced muscle mass, strength and function, and increased mortality. Evaluating differences in protein intake and related health indicators among racial/ethnic groups enables the development of targeted interventions. This study’s purpose was to determine differences in protein intake, nutritional status, and muscle strength/function among 273 older African, European, and Hispanic Americans. Protein intake, nutritional status, grip strength, timed-up-and-go (TUG), and chair stand assessments were conducted. Protein intake was significantly greater among Hispanic Americans (0.96?g/kg body weight) followed by European Americans (0.83?g/kg body weight), and African Americans (0.64?g/kg body weight). Intakes by all groups were below recommendations. Low nutritional status, grip strength, chair rise, and TUG scores were observed in African Americans and European American females and were consistent with lower protein intakes. Results show significant differences among the groups and the need for interventions to improve diet and physical health.     

四种牙本质粘接系统的微拉伸强度测试评价

目的:评价四种牙本质粘接系统(SingleBond;Bond-1;Prime&BondNT;One-Step)在口内、外环境下粘接处理后的粘接强度。方法:将15名志愿者口内18颗无龋坏活髓磨牙,于局麻下用高速涡轮机金钢砂车针在喷水降温下磨切咬合面,暴露牙本质。随机选择四种牙本质粘接系统之一,按使用说明粘接处理其咬合面牙本质一半。即刻拔除。贮存于37℃生理盐水中24h后,使用同一粘接系统处理其咬合面牙本质另一半。二者分别制备成沙漏状试件。试件粘接界面面积控制在1mm2左右;测试同一颗牙齿标本上口内、外粘接处理的试件拉伸强度,并作统计学处理。结果:四种牙本质粘接系统在口内粘接处理的微拉伸强度分别为:26.09±3.78MPa(SingleBond),30.18±2.77MPa(Bond-1),29.10±3.03MPa(Prime&BondNT),29.95±3.81MPa(One-Step);在口外粘接处理的微拉伸强度为:25.80±2.41MPa(SingleBond),29.92±3.04MPa(Bond-1),28.97±2.73MPa(Prime&BondNT),30.03±2.96MPa(One-Step)。结论:四种牙本质粘接系统在口内与口外环境下粘接处理的微拉伸强度比较,无显著性差异。离体牙的体外粘接实验测试结果可以客观、真实地反映各粘接系统在口腔内的实际粘接强度。