两种弹性模量水凝胶人工髓核对腰椎稳定性影响的比较

目的:比较两种弹性模量(3 MPa和1 MPa)的水凝胶人工髓核的生物力学特性。方法:实验于2002-12/2003-03在上海大学生物力学研究所实验室完成。实验材料:①新型改良聚乙烯醇水凝胶人工髓核,弹性模量为3 MPa和1 MPa。②新鲜青壮年腰椎脊柱标本7个(来源于自愿捐献者尸体)。实验分组:每个标本采用自身对照方法分为4组:完整髓核组、摘除髓核组、3 MPa人工髓核组、1 MPa人工髓核组。完整髓核组标本测试后,取出全部髓核组织,进行摘除髓核组的测量,然后植入人工髓核,进行3 MPa人工髓核组和1 MPa人工髓核组测试。椎间盘在WE-5液压万能试验机上进行测试,轴向载荷为0,100,200,300,400,500 N,弯曲载荷为0～5.0N·m。加载方式采用4种不同力学模拟生理状态(轴向压缩、前屈、后伸、侧屈)。实验评估:①各组椎间盘的水平膨出位移变化。②脊柱功能单元的弹性模量变化。③小关节的应变。结果:①各组椎间盘的水平膨出位移变化:生理载荷内属于线性位移,卸载后能恢复原状。在载荷作用下,摘除髓核组和1 MPa人工髓核组膨出位移大于完整髓核组,差异均有显著性意义[分别为(1.10±0.14),(0.91±0.12),(0.80±0.10)mm,t=14.55,12.43,P<0.05],3 MPa人工髓核组椎间盘的膨出与完整髓核组相近,差异无显著性意义(P>0.05)。②脊柱功能单元的弹性模量变化:摘除髓核组和1 MPa人工髓核组弹性模量均明显低于完整髓核组[分别为(1.085±0.102),(1.317±0.157),(3.628±0.201)MPa,t=18.48,14.07,P<0.05],3 MPa人工髓核组弹性模量略低于完整髓核组,差异无显著性意义(P>0.05)。③小关节的应变:摘除髓核组和1 MPa人工髓核组小关节的应变比完整髓核组分别增加45.0%,10.7%,差异有显著性意义(P<0.05)。3 MPa人工髓核组小关节的应变比完整髓核组略大,平均相差3.7%左右,比较接近于正常(P>0.05)。结论:人工髓核置换可纠正椎间盘摘除后的生物力学紊乱,弹性模量为3 MPa的髓核假体更加适合。     

针灸在多囊卵巢综合征患者宫腔内人工授精助孕术中的应用

目的:通过对近10年相关文献的研究,总结针灸在多囊卵巢综合征患者宫腔内人工授精助孕术中的影响以及在此方面的应用。方法:检索中国期刊全文数据库1996-01/2006-06与针灸对多囊卵巢综合征患者的影响有关的文章,检索词为"针灸,多囊卵巢综合征,人工授精助孕术",限定文章语言种类为中文。同时检索Elsevier-SDOL数据库1996-01/2006-06的相关文章,检索词为"acupuncture,polycystic ovary syndrome,intrauterine insemination",限定文章语言种类为英文。结果:选取文章应该是在下列范围内:针灸对多囊卵巢综合征患者的影响、针灸在宫腔内人工授精助孕术中的应用、多囊卵巢综合征患者在行宫腔内人工授精助孕术时的影响因素以及有关针灸在此方面的研究。共收集到200篇关于"针灸对多囊卵巢综合征患者的影响"的文章,300篇关于"多囊卵巢综合征患者在行宫腔内人工授精助孕术时的影响因素"的文章,30篇关于"针灸在宫腔内人工授精助孕术中的应用"的文章,16篇符合本文标准。既往大多数研究是集中在关于针灸治疗多囊卵巢综合征以及针灸促排卵的临床研究上,认为针灸可以有效治疗多囊卵巢综合征,还可以通过对卵巢的刺激作用而达到促进排卵的作用,并一致认为针灸促排卵不但无副作用而且疗效好,作用稳定、持久。另外曾有德国学者发现将针灸疗法应用于辅助体外授精或精子卵浆内注射技术中,其怀孕成功机率提高近50%。然而,关于针灸在多囊卵巢综合征患者宫腔内人工授精助孕技术中的应用国内外却均未见报道。结论:宫腔内人工授精助孕术已经广泛应用于不孕症的治疗中,而针灸又有很好的促排卵作用。因此可以尝试在多囊卵巢综合征患者行宫腔内人工授精术前后加用针灸疗法,从而研究针灸辅助卵巢诱导排卵在多囊卵巢综合征患者行宫腔内人工授精中的应用,观察针灸是否可以提高多囊卵巢综合征患者的宫腔内人工授精助孕术的成功率。     

Risk factors of atrial fibrillation following coronary artery bypass grafting: a preliminary report.

BACKGROUND: To evaluate the risks factors of atrial fibrillation (AF) following coronary artery bypass grafting (CABG). METHODS AND RESULTS: Twelve hundred patients subjected to CABG were included. Postoperative AF developed in 278 patients (23.2%). Statistical analysis identified 5 independent predictors of AF: advanced age, history of supraventricular arrhythmias, preoperative heart failure, operation with standard CABG technique and repeated revascularization. CONCLUSIONS: Postoperative AF caused a significant increase in mortality and hospitalization length. There were 4 independent risk factors of postoperative AF. Administration of beta-blockers and the OPCAB (off-pump CABG) operating technique were identified as protective factors.     

Changes in prostaglandin and nitric oxide levels in the hyperdynamic circulation following liver resection

BACKGROUND AND AIMS: Significant changes in hepatic haemodynamics occur after major hepatectomy, but the pathogenesis of this phenomenon is unclear. This study investigates the serum profile of prostaglandin and nitric oxide in the hepatic and systemic circulation before and after hepatectomy and the temporal relationship of these to changes in the hepatic blood flow. METHODS: Blood samples were collected from the internal jugular, portal and hepatic veins of six Yorkshire pigs (17-25 kg) before, immediately after and 48 h after partial hepatectomy. RESULTS: Serum levels of prostacyclin I2 (PGI2) and prostaglandin E2 (PGE2) from the systemic circulation, the portal circulation and from the hepatic veins were found to differ considerably even before hepatectomy. After the hepatectomy was performed, there was a significant rise in PGI2 levels in the systemic circulation (P=0.027). Hepatic blood flow and cardiac output were measured before hepatectomy, 24 and 48 h after hepatectomy in another six pigs. A significant increase in hepatic blood flow (P=0.029) occurred after the hepatectomy and this was accompanied by a concomitant increase in the cardiac output (P=0.042). The increase in PGI2 concentration in the systemic circulation after hepatectomy appears to accompany the development of hyperdynamic hepatic and systemic circulations. No significant change was found in circulating PGE2 levels in the systemic, portal and hepatic veins at the three collection intervals (i.e. pre, post and 48 h after hepatectomy). The PGE2 levels in the hepatic vein, however, were significantly higher from than in the portal vein (P=0.028). No significant changes were observed in the level of nitric oxide. CONCLUSION: This study demonstrates an increase in the total hepatic blood flow after hepatectomy together with a threefold increase in prostacyclin in the systemic circulation. The liver was identified as the main source of circulatory prostaglandin.     

HbHope/HbS and HbS/β-thal double compound heterozygosity in a Mauritanian family: clinical and biochemical studies

The hemoglobin Hope was discovered in a Mauritanian family that comes from Gorgol in the southwest of the country. The family belongs to the Soninké ethnic group, which is one of the black population groups in Mauritania. Along with this abnormal hemoglobin, HbS and beta-thalassemia were also found. This family, which we refer to as D, was encountered during a survey we conducted to study hemoglobinopathies in Mauritania. First the father was identified to carry an association of HbS and HbHope, then the study was extended to the entire family members: the wife who was found to have a beta-thalassemia trait and their three children who were found to carry HbS/beta-thalassemia mutations each. All together this family carries three different mutations that resulted in a double compound heterozygosity HbHope/HbS and HbS/beta-thal.     

Female-specific flightless phenotype for mosquito control

Dengue and dengue hemorrhagic fever are increasing public health problems with an estimated 50–100 million new infections each year. Aedes aegypti is the major vector of dengue viruses in its range and control of this mosquito would reduce significantly human morbidity and mortality. Present mosquito control methods are not sufficiently effective and new approaches are needed urgently. A “sterile-male-release” strategy based on the release of mosquitoes carrying a conditional dominant lethal gene is an attractive new control methodology. Transgenic strains of Aedes aegypti were engineered to have a repressible female-specific flightless phenotype using either two separate transgenes or a single transgene, based on the use of a female-specific indirect flight muscle promoter from the Aedes aegypti Actin-4 gene. These strains eliminate the need for sterilization by irradiation, permit male-only release (“genetic sexing”), and enable the release of eggs instead of adults. Furthermore, these strains are expected to facilitate area-wide control or elimination of dengue if adopted as part of an integrated pest management strategy.     

大鼠抗组胺药敏感性细胞色素P450基因的克隆及其反转录病毒载体的构建和鉴定

目的:构建反转录病毒表达载体pLXSN-HP450。方法:实验于2004-12/2006-05在广西医科大学生化药理实验室完成。提取正常的Wistar大鼠肝组织的总RNA,反转录-聚合酶链反应技术扩增出抗组胺药敏感性细胞色素P450(HP450)基因。并克隆到pMD18-T载体,经蓝白斑筛选后进行聚合酶链反应,酶切,测序鉴定。BamHI,EcoRI双酶切构建好的重组质粒和反转录病毒载体pLXSN在16℃下经T4连接酶连接过夜,并转化到感受态细胞DH5α,以菌液为模板做聚合酶链反应,结合酶切筛选及鉴定阳性重组反转录病毒载体pLXSN-HP450。结果:反转录-聚合酶链反应扩增出HP450基因。重组质粒pMD18-HP450经双酶切后得到1461bp的酶切产物。测序的结果用ClustalW在线与Genebank对比,此目的基因与基因库中的H1基因100%同源。阳性重组载体pLXSN用其菌液聚合酶链反应扩增出目的条带。对重组体pLXSN-HP450进行双酶切得到1461bp和5900bp两条特异性条带。结论:克隆了HP450基因,并成功构建了重组反转录病毒载体pLXSN-HP450,为进一步研究肝癌的基因治疗奠定了基础。     

重庆市两所大学学生营养知识、态度及行为的基线调查

目的:了解重庆市某两所大学学生的营养知识、态度和行为现况,为开展营养教育效果评价提供基线数据。方法:选取重庆渝中区某学院为干预学校,文理科各一个系,整群抽取一年级9个班的学生,共289人;选取九龙坡区某学院为对照学校,选择与干预学校相匹配的文理科各一个系,整群抽取9个班的学生,共344人。于2005-03采用自编调查问卷,对以上633名在校学生进行营养知识、态度和行为的调查。问卷内容包括一般人口统计学资料、营养知识、态度、行为情况,营养知识获取途径等,其中知识问题满分16分,有关态度问题满分9分,行为问题满分40分,得分越高越好。结果:发放问卷650份,回收有效问卷633份,有效率97.4%。①两组学生一般人口学特征和家庭背景均有可比性(P>0.05)。②干预学校学生营养知识、态度和行为得分分别为(9.04±2.43),(7.13±1.20),(16.27±3.53)分,对照学校得分分别为(9.23±2.22),(6.96±1.28),(16.38±3.39)分,两组比较无差异。③只有30.33%的同学每天吃早餐,只有37.91%的学生在选择食物时考虑了营养价值或自己的营养需要,不常吃水果,常吃零食现象严重。大部分学生都有良好的求知欲望,希望通过多种途径获得营养知识。结论:①大学生对营养知识缺乏全面深入的了解,大部分学生营养态度端正,行为良好,但部分学生也存在一些问题。②两所学校营养知识、态度与行为无显著差异。     

Effects of hypercholesterolemia on myocardial ischemia-reperfusion injury in LDL receptor-deficient mice

Hypercholesterolemia is a primary risk factor for atherosclerosis, coronary artery disease, and myocardial infarction. We subjected low density lipoprotein receptor-deficient (LDLr -/-) and control (wild-type) mice to 30 minutes of myocardial ischemia and 120 minutes of reperfusion. Myocardial infarction per area at risk (AAR) was noted under baseline conditions to be significantly (P<0.05) smaller in the LDLr -/- mice compared with wild-type mice (24.7+/-3. 2% and 38.8+/-4.3% of AAR, respectively). Subsequently, mice were fed a high-cholesterol diet (HCD) for 2 or 12 weeks, which resulted in significant increases in serum cholesterol levels in both LDLr -/- and wild-type groups. After 2 weeks of the HCD, the LDLr -/- mice demonstrated a significant elevation (P<0.01) in myocardial necrosis per AAR (50.2+/-5.36% of AAR) compared with the normal-diet LDLr -/- group, whereas the short-term HCD-fed wild-type mice demonstrated no significant difference from baseline. In contrast, wild-type mice fed the HCD for 12 weeks revealed a significant (P<0. 05) decrease in necrosis per AAR, which was 22.5+/-3.2% of the AAR in comparison with that in the normal-diet wild-type mice (38.8+/-4. 3% of AAR). LDLr -/- mice on the same long-term HCD showed a similar significantly (P<0.05) decreased infarct size, which was 13.2+/-4.0% of the AAR. In additional experiments, we determined that myocardial tissue total glutathione (GSH) levels were reduced after 2 weeks of the HCD and were significantly increased after 12 weeks of the HCD in the LDLr -/- mouse heart. These data suggest that short-term cholesterol feeding renders the myocardium of LDLr -/- mice more susceptible to ischemia-reperfusion injury, whereas more long-term hypercholesterolemia confers cardioprotection in the LDLr -/- mouse heart.