一氧化氮与光化学法诱导大鼠脑缺血早期损伤的关系和绞股蓝总皂苷对脑缺血损伤的保护作用

目的：探讨一氧化氮(NO)与光化学法诱导大鼠脑缺血早期损伤的关系和绞股蓝总皂苷(Gyp)对脑缺血损伤的保护作用。方法：应用光化学法诱导大鼠大脑中动脉栓塞(MCAO)模型，观察氧合血红蛋白(OHb)和Gyp对MCAO后脑梗死范围，脑组织含水量、NO及超氧化歧化酶(SOD)、脂质过氧化产物TBARS含量的影响。结果：MCAO6h可导致大鼠局部脑组织明显梗死、脑水肿，同时SOD活力下降，TBARS含量升高，NO释放减少。OHb能进一步强化上述改变而Gyp能逆转上述变化。结论：脑内过氧化反应水平增高导致早期NO含量减少是脑缺血形成的重要原因之一，Gyp可通过影响脑缺血损伤早期脑内NO水平发挥对脑缺血的保护作用。     

The value of pulse wave velocity in the diagnosis of coronary heart disease

Objective: Using receiver operating characteristics (ROC) curve to evaluate the value of pulse wave velocity (PWV) in the diagnosis of coronary heart disease (CHD). Methods: By using coronary angiography as golden diagnostic standard of CHD, 218 patients were divided into both CHD group (n=121) and non-CHD group (n = 97). All these patients received PWV test. The efficacy of PWV of each artery segments in the diagnosis of CHD was evaluated by ROC curve. The sensitivity and specificity were calculated with the golden diagnostic standard of CHD. Results:The PWV of right carotid to femoral artery (Rc-f), left carotid to femoral artery (Lc-f), right radial to carotid artery (Rc-r), left radial to carotid artery (Lc-r) in CHD group were significantly higher than that of non-CHD group (9. 31±1. 75 vs 7.60±1.59, P<0. 01; 9. 02±1.71 vs 7. 52±1.50, P<0. 01; 8. 69±1. 37 vs 8. 00±1. 27, P<0. 01; 8.52±1. 03 vs 8. 03±1. 2, P<0. 01 respectively). However, the PWV of both right and left femoral to ankle artery (Rf-a and Lf-a) had no significant differences between the two groups. We then compared the area under curve (AUC) of each ROC(AUCROC) of PWV of Rc-f, Lc-f Rc-r and Lc-r to evaluate their diagnostic efficacy for CHD. We found that AUCROC of Rc-f PWV was the biggest (AUCROC = 0. 818), at the peak point of its ROC curve, the PWV was 8. 32 m/s. PWV>8. 32 m/s of Rc-f could predict the presence of CHD with a sensitivity of 79% and specificity of 77%. Conclusion: The PWV of Rc-f, Lc-f, Rc-r, Lc-r are significantly higher in CHD group than that in non-CHD group, and PWV of Rc-f is the most accurate in the detection of CHD. The PWV>8. 32 m/s of RC-F is a valuable predictor of CHD.     

低分子量肝素治疗进展型脑梗死及对血流变影响

目的:探讨低分子量肝素对进展型脑梗死的疗效及血流变影响.方法:将80例进展型脑梗死患者,随机分为治疗组40例,对照组40例.两组在治疗前后均行神经功能缺损评分和临床疗效评定,并观察其疗效及有关实验室指标,追踪随访1年.结果:治疗组的有效率明显高于对照组,不良反应轻微,PLT、APTT无明显变化,但血流变指标明显下降,1年内复发率明显小于对照组.结论:低分子肝素治疗进展型脑梗死疗效肯定,对于减少复发亦有一定作用,并可改善血流变.     

N-乙酰-5-羟色胺的电化学检测研究

采用方波溶出伏安法(OSWSV),建立了N-乙酰-5-羟色胺的—种新型快速、灵敏的测定体系。实验研究了富集条件、pH值对方波溶出伏安法对N-乙酰-5-羟色胺的影响。在pH=9.33的硼砂-氢氧化钠缓冲液中,N-乙酰-5-羟色胺在约0.2V(vs.Ag/AgCl)电位处产生一个阳极氧化峰,峰电流与浓度在1.0×10-7~1.0×10-4mol.L-1范围内成线性关系,N-乙酰-5-羟色胺检测限为1.2×10-8mol.L-1。进行尿样样品测定,回收率为81.8%,结果良好。     

全视网膜光凝治疗糖尿病视网膜病变对视野影响的研究进展

糖尿病视网膜病变(DR)早期视野改变往往比视力更能及时反映病情进展。而全视网膜光凝(PRP)治疗DR在延缓病情进展的同时也造成了患眼视力下降和视野缩小等副作用。有研究表明,PRP治疗后的DR患者可因中心20°范围内的视野缺损而导致驾驶测试失败。为保证PRP疗效同时达到降低并发症的目的,激光技术不断改进与发展,通过调整激光参数、使用新型激光系统、与抗血管内皮生长因子(VEGF)药物联合、中西医结合治疗等方式可一定程度改善患眼视野,实现更佳疗效。未来可考虑在缺血指数(ISI)量化分析下,对视网膜缺血程度进行分级,依据ISI指标和视网膜无灌注区分布探索PRP治疗建议的最佳阈值及光凝范围,从而为DR患者提供更及时、更合理的个性化治疗方案。文章就PRP治疗DR对视野的影响进行简要综述。     

缬沙坦对颈动脉不稳定斑块患者血清炎症介质及缺血性脑卒中复发的影响

目的探讨缬沙坦对颈动脉不稳定斑块患者血清C-反应蛋白(CRP)、可溶性血管内皮细胞黏附分子-1(sVCAM-1)、白细胞介素-6(IL-6)的影响及对缺血性脑卒中复发干预的临床研究。方法不稳定斑块65例,缬沙坦治疗组33例,缬沙坦胶囊,80 mg,每日1次,口服,其他治疗措施与对照组基本相同。对照组32例,利尿降压药,口服。治疗前、1个月、2个月、38个月抽空腹静脉血共计5 ml,检测CRP、sVCAM-1、IL-6、血糖,同时监测血压。38个月时统计两组脑梗死复发和死亡情况,以CT或磁共振成像(MRI)出现新的梗塞灶为准。结果在1、2、38个月后治疗组血清CRP、sVCAM-1I、L-6浓度逐渐降低,组内相比差异有统计学意义(P<0.05),对照组除转变为硬斑者外其余变化不大。治疗组和对照组组间相比变化较大,差异有统计学意义(P<0.05)。终点38个月时,治疗组、对照组经CT或MRI证实脑梗死复发为7例(21.2%)和15例(46.9%)例,死亡为2例(6.1%)和5例(15.6%)例,治疗组复发率和病死率明显低于对照组(P<0.05)。结论缬沙坦稳定颈动脉斑块与血清中CRP、sVCAM-1I、L-6炎症介质的降低密切相关,降低不稳定斑块的破裂,从而减少了缺血性脑卒中的复发和死亡。     

Proteomic analysis of the effects of caffeine in a neonatal rat model of hypoxic‐ischemic white matter damage

AimWhite matter damage (WMD) is the main cause of cerebral palsy and cognitive impairment in premature infants. Although caffeine has been shown to possess neuroprotective effects in neonatal rats with hypoxic‐ischemic WMD, the mechanisms underlying these protective effects are unclear. Herein, proteins modulated by caffeine in neonatal rats with hypoxic‐ischemic WMD were evaluated.MethodsWe identified differential proteins and performed functional enrichment analyses between the Sham, hypoxic‐ischemic WMD (HI), and HI+caffeine‐treated WMD (Caffeine) groups. Confirmed the changes and effect of proteins in animal models and determined cognitive impairment via water maze experiments.ResultsIn paraventricular tissue, 47 differential proteins were identified between the Sham, HI, and Caffeine groups. Functional enrichment analyses showed that these proteins were related to myelination and axon formation. In particular, the myelin basic protein (MBP), proteolipid protein, myelin‐associated glycoprotein precursor, and sirtiun 2 (SIRT2) levels were reduced in the hypoxic‐ischemic WMD group, and this effect could be prevented by caffeine. Caffeine alleviated the hypoxic‐ischemic WMD‐induced cognitive impairment and improved MBP, synaptophysin, and postsynaptic density protein 95 protein levels after hypoxic‐ischemic WMD by preventing the HI‐induced downregulation of SIRT2; these effects were subsequently attenuated by the SIRT2 inhibitor AK‐7.ConclusionCaffeine may have clinical applications in the management of prophylactic hypoxic‐ischemic WMD; its effects may be mediated by proteins related to myelin development and synapse formation through SIRT2.     

Development and Optimization of Broadband Acoustic Metamaterial Absorber Based on Parallel–Connection Square Helmholtz Resonators

An acoustic metamaterial absorber of parallel–connection square Helmholtz resonators is proposed in this study, and its sound absorption coefficients are optimized to reduce the noise for the given conditions in the factory. A two–dimensional equivalent simulation model is built to obtain the initial value of parameters and a three–dimensional finite element model is constructed to simulate the sound absorption performance of the metamaterial cell, which aims to improve the research efficiency. The optimal parameters of metamaterial cells are obtained through the particle swarm optimization algorithm, and its effectiveness and accuracy are validated through preparing the experimental sample using 3D printing and measuring the sound absorption coefficient by the standing wave tube detection. The consistency between the experimental data and simulation data verifies feasibility of the proposed optimization method and usefulness of the developed acoustic metamaterial absorber, and the desired sound absorption performances for given conditions are achieved. The experimental results prove that parallel–connection square Helmholtz resonators can achieve an adjustable frequency spectrum for the low frequency noise control by parameter optimization, which is propitious to promote its application in reducing the noise in the factory.     

手十二井穴刺络放血法对MCAO模型大鼠大脑皮层c-fos蛋白表达的影响

目的 从脑内c-fos蛋白表达的角度观察井穴放血法对急性缺血性脑损伤的脑保护作用。方法 以凝结法阻断大鼠一侧大脑中动脉造成急性局灶性缺血性脑损伤模型(MCAO)，用免疫组织化学法观察缺血区皮层脑组织c-fos阳性细胞的表达变化及施加手十二井穴放血法后对其的干预治疗作用。结果 急性缺血性脑损伤可快速诱导c-fos蛋白在皮层缺血区脑组织的表达，其表达有随缺血时间延长逐渐增多的趋势，而缺血后即刻施加井穴放血的干预治疗．在1h、3h、6h、24h各缺血时间段均可明显上调缺血区皮层脑组织c-fos蛋白的表达水平。结论 c-fos蛋白表达既与缺血的严重程度有关．也反应神经元的应激反应能力，脑缺血能诱导c-fos蛋白的逐渐表达，提示脑的缺血性损伤可应激性地增强神经细胞对缺血、缺氧的耐受和适应能力。而早期施加井穴刺络放血疗法能进一步增强c-fos蛋白表达，提高神经细胞的应激能力，从而提高缺血区脑组织的抗损伤修复能力，减缓神经细胞凋亡，抵抗缺血性脑损害的进一步发展，产生有效的脑保护作用，表明井穴放血法对中风早期有一定的急救作用。