茶多酚对+Gz过载的颞下颌关节影响分析

目的：观察茶多酚对持续性高正加速度（＋Gz）加载颞下颌关节的影响。方法：雄性Wistar大鼠随机分成5个不同处理条件的实验组，每组12只。A组为空白对照。B组地面固定5min。C 固定于离心机转臂上，俯卧位，头向轴向，＋Gz离心5min。D组体位同C组，＋10Gz离心30s，间隔时＋1Gz离心60s，连续每天5次，每周4天，共3周，E组实验参数同D组，并于＋Gz离心前1h灌胃给予茶多酚（200mg.kg^-1)，其余各组给予等量蒸馏水，通过光镜，扫描和透射电镜观察比较组颞下颌关节的组织形态学变化情况，结果：A、B、C三组颞下颌关节未见异常；D组颞下颌关节表面凝胶状物质缺失，胶原纤维断裂，成纤维细胞线粒体变性；E组颞下颌关节表面凝胶状物质变薄但完整，胶原纤维断裂，成纤维细胞线粒体较正常，结论：茶多酚能在一定程度上保护凝胶状物质和成纤维细胞来对抗持续性高正加速度对颞下颌关节的损伤。     

Can rotatory knee laxity be predicted in isolated anterior cruciate ligament surgery?

Purpose

Despite the overall success of the surgical anterior cruciate ligament (ACL) reconstruction, some patients still present with instability symptoms even after the surgery, mainly due to the presence of associated lesions. At present, the pivot shift test has been reported to be the benchmark to assess rotatory knee laxity. The purpose of this study was to quantitatively evaluate rotatory knee laxity at time-zero in order to determine whether detected post-reconstruction laxity was predictable by its value measured before the reconstruction, which was hypothized to be influenced by the presence of associated lesions.

Methods

Rotatory knee laxity was retrospectively analysed in 42 patients, including two different ACL reconstructions. The maximal anterior displacement and the absolute value of the posterior acceleration reached during the reduction of the tibial lateral compartment were intra-operatively acquired by using a navigation system and identified as discriminating parameters. For each parameter, statistical linear regression analysis (line slope and intercept) was performed between pre- and post-reconstruction values.

Results

No statistically significant influence of the initial posterior acceleration on the post-reconstruction outcome was found (line slope, p > 0.05), although a statistically significant line intercept was indeed identified (p < 0.001). A statistically significant influence on the surgery outcome was instead found for the initial value of the anterior tibial displacement (line slope = 0.39, p = 0.004), meaning that, on average, about 40 % of the post-reconstruction lateral compartment displacement could be explained by the corresponding pre-reconstruction value. Both of these findings highlighted the importance of intra-operative quantification of rotatory knee laxity to identify correct indications for the surgery.

Conclusions

This study provided important implications for the future possibility of defining a quantifying tool able to assess rotatory knee laxity during ACL reconstruction. This could allow detection of additional injuries to secondary restraints by easily performing rotatory knee laxity tests, which in turn could reduce post-surgical recurrence of knee instability.     

正常成人肾内动脉血流动力学的彩色多普勒研究

以彩色多普勒研究１７２例健康成人３４４只肾的肾内动脉（肾门部主肾动脉、段动脉、叶间动脉）血流收缩峰速度（ＳＶ）、阻力指数（ＲＩ）和加速度（ＡＣ），建立不同年龄组、不同分级血管各参数的正常值范围，旨在了解正常肾脏血流动力学变化并为超声评价各种肾脏病变提供对照依据。研究表明，随肾内动脉逐级分支，其ＳＶ、ＲＩ和ＡＣ值依次递减；ＳＶ与年龄呈负相关关系，ＲＩ与年龄呈密切正相关关系；６０岁以上ＲＩ值增高显著。     

Impact of aerobic training with and without whole-body vibration training on metabolic features and quality of life in non-alcoholic fatty liver disease patients

The present study examined the effectiveness of adding exercises with whole-body vibration (WBV) to aerobic training in terms of metabolic features and quality of life. Patients with non-alcoholic fatty liver disease (NAFLD), confirmed on imaging, underwent an 8-week individualized exercise program randomized between aerobic training with and without WBV. Training was performed at 60–80% heart rate workload for 165 min/week. The WBV amplitude was 2–4 mm and the training frequency was 30 Hz, for 15 min. Assessments were carried out on surrogate scores of steatosis and fibrosis including transient elastography (FibroScan), metabolic features (biochemical analysis) and quality of life (SF-36). Insulin resistance was markedly reduced (−2.36; 95% CI: −4.96 to −0.24; P: 0.049) in aerobic training with WBV. The decrease in serum aspartate transaminase was significantly greater in aerobic training without WBV (−14.81; 95% CI: −23.36 to −6.25; P: 0.029). There were no significant differences between groups for the other metabolic features (P < 0.05). All quality of life well-being domains improved in both groups (P < 0.05). Given this reduction in insulin resistance, WBV can usefully be added to aerobic training. However, WBV did not provide further benefits in improving metabolic properties or quality of life.     

缺氧或+Gz暴露对大鼠肾结石形成影响的实验研究

目的 研究低压缺氧、+Gz暴露等飞行环境因素对肾结石形成的影响. 方法 48只Wistar雄性大鼠用随机区组法分为对照组、低压缺氧组、+Gz暴露组和结石模型组,每组12只.施加相应干预因素饲养4周以后,检验各组大鼠血清生化指标:血尿素氮、血肌酐、血磷和血钙;尿液相关指标:24小时尿量、尿pH值、尿钙、尿酸和草酸含量.镜下观察大鼠肾苏木精和伊红( hematoxylin-eosin,HE)染色组织切片中结石结晶及肾小管扩张情况. 结果 ①+Gz暴露组及结石模型组大鼠血清尿素氮含量高于对照组(P＜0.05),其它指标组间差异无统计学意义.②各组大鼠24 h尿量和尿钙含量差异无统计学意义;大鼠尿液尿酸含量组间差异有统计学意义(F=33.064,P＜0.01),+Gz暴露组及结石模型组明显高于对照组(P＜0.01);尿草酸含量组间差异有统计学意义(F=4.877,P＜0.01),+Gz暴露组及结石模型组明显高于对照组(P＜0.05);各组大鼠尿pH值差异有统计学意义(F=3.555,P＜0.05),低压缺氧组大鼠尿pH值比对照组降低(P＜0.05).③对照组未见肾小管扩张及结晶体沉积;低压缺氧组未见肾小管扩张,其内可见极少量结石结晶;+Gz暴露组肾小管扩张不明显,其内可见无色透明的结石结晶;结石模型组肾小管扩张增粗,其内可见大量无色透明的结石结晶呈片状分布. 结论 +Gz暴露可能是泌尿系结石形成的危险因素之一,而低压缺氧对泌尿系结石形成的影响不明显.     

复方天葡片对高+Gz应激致大鼠肾损伤的保护作用

目的:观察模拟高正加速度(+Gz)暴露对大鼠肾脏损伤、中药复方天葡片对肾脏损伤的保护作用。方法:雄性SD大鼠随机分为空白对照、高+Gz应激、复方天葡片治疗组(n=12),提前给予复方天葡片(3.0 g/kg)14 d后进行+10Gz持续5 min,增长率为1 G/s的暴露。检测血常规,血肌酐(Scr)、尿素氮(BUN)水平,血清超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量,观察肾组织ATP酶活性及电镜下肾脏超微病理改变。结果:高+Gz应激后大鼠白细胞计数、红细胞计数、血红蛋白含量及血细胞比容升高(P<0.05),Scr、BUN水平显著升高(P<0.01),血清SOD活性显著减低(P<0.05),肾组织ATP酶活性显著降低,电镜下肾组织内细胞核周围线粒体数量与空白对照组相比无显著变化。给予复方天葡片干预后大鼠上述肾脏损伤及氧化应激指标改善,电镜下肾组织细胞核周围线粒体数量增加。结论:高+Gz暴露应激可导致大鼠抗氧化能力减弱,肾脏功能受损和超微结构变化。复方天葡片可改善肾组织有氧代谢,减少氧化产物的生成,促进肾内线粒体新生,有利大鼠高+Gz应激引起肾损伤修复。     

战斗机高+Gz环境导致飞行员颈部损伤的原因及预防措施

目的 综述战斗机高+Gz环境导致飞行员颈部损伤的致伤原因、发生机制及预防措施,探讨采取综合性措施提升预防效果的发展前景.资料来源与选择国内外相关领域的研究论文与综述.资料引用国内外公开发表的论文和综述50篇.资料综合高性能战斗机的高+Gz值、高+Gz增长率特性给飞行员颈部健康造成极大的危害.近20多年来,众多学者针对高+Gz环境导致飞行员颈部损伤的机制和致伤原因进行了研究.在致伤阈值、头戴装备负荷、被动带飞、不良飞行姿态和反复暴露于高+Gz环境等致伤因素方面取得了较为一致的结果,提出的预防措施主要有加强颈部肌肉力量训练,研制防护装备及改善装备人机适配性,建立常规化的健康检查、康复训练、功能评价机制等.结论 战斗机飞行员在飞行职业生涯中不可避免地受到高+Gz环境的威胁,在当前单一预防措施效果不显著的情况下,积极采取综合性预防措施,并加强其预防效果的研究,对增强飞行员的飞行适应能力,提高飞行员健康水平将有极大的推动作用,并为高+Gz环境导致腰部损伤的预防工作提供借鉴经验. Abstract： Objective To review the reasons, mechanism of fighter aircraft high +Gz induced pilot's neck injuries and prevention methods, and to expect the integrative methods for enhancing prevention effects.Literature resource and selection Professional references which were published at home and abroad were cited.Literature quotation Fifty published papers and reviews were referred.Literature synthesis The characters of modern high-performance fighter aircraft which was described as high +Gz and the rapid onset rate acceleration induced serious harm to pilot's neck.Since more than 20 years, many researches on mechanism and the reasons of inducing neck injuries had conducted by scholars.They indicated the consensus in the factors of inducing neck injuries, including +Gz threshold, the load on pilot's head, passive effect on back seat, unsuitable head posture in flight and frequent exposure in high +Gz.The preventions were primarily focused on leaning upon cervical spine function evaluation and neck muscle strength training, developing protective equipment and improving man-machine adaptability of equipment.Conclusions In fighter pilot's career, it is unavoidable that he will be threatened by high +Gz environment.At present, it is important to adopt integrative preventions and emphasize effective research for increasing pilot's capability for adapting high + Gz environment and protecting himself.Also such experience will be useful in preventing pilot's waist injuries induced by high +Gz.