大黄素甲醚对神经细胞缺氧性损伤保护作用的实验研究

目的:研究大黄素甲醚对缺氧引起的PC12神经细胞损伤的保护作用。方法:培养PC12细胞,建立神经细胞缺氧损伤模型,观察组细胞在缺氧损伤前采用大黄素甲醚进行预处理。MTT检测PC12细胞增殖活性,光学显微镜观察PC12细胞形态学、测定上清液中乳酸脱氢酶(LDH)含量、荧光免疫组化法测定c-fos蛋白表达、RT-PCR检测nNOS、iNOS mRNA表达。结果:细胞形态学研究提示大黄素甲醚明显提高PC12细胞的抗缺氧活性。大黄素甲醚处理后,细胞存活率明显提高,上清液LDH水平明显下降,c-fos表达明显降低(P<0.05)。RT-PCR结果分析显示nNOS mRNA在缺氧早期表达,iNOS mRNA主要在缺氧中晚期表达。结论:大黄素甲醚能减轻缺氧所致的神经元损伤,对神经元起保护作用。     

干扰HERG钾通道表达可抑制成神经细胞瘤细胞增殖

目的：采用RNA干扰（RNA interference，RNAi）技术抑制HERG基因的表达，探讨HERG基因编码钾通道对人成神经细胞瘤细胞（SH-SY5Y）存活及增殖的影响。方法：构建发卡状RNA干扰质粒（shRNA-HERG）转染SH-SY5Y细胞，再分别使用半定量RT-PCR和Western印迹方法观察shRNA-HERG对SH-SY5Y细胞中HERG基因mRNA及其编码蛋白表达的干扰效果。利用SH-SY5Y细胞的生长曲线和集落形成实验，观察转染shRNA-HERG质粒对SH-SY5Y细胞存活及增殖能力的影响。结果：转染shRNA-HERG干扰质粒后，SH—SY5Y细胞中HERG基因的mRNA水平及其编码的钾通道蛋白表达水平显著下降。与对照组相比，shRNA—HERG使SH-SY5Y细胞生长曲线明显下压，细胞倍增时间延长136．8％。集落形成实验结果显示，无论接种细胞数为50，100或200，shRNA-HERG组克隆形成率均显著下降，与shRNA-control组和未干扰组相比，差异有统计学意义（P〈0．01）。结论：所构建的shRNA-HERG表达质粒能有效抑制HERG基因编码钾通道蛋白的表达，明显抑制SH-SY5Y细胞的生长和增殖。     

丹参酮ⅡA对缺氧诱导下鼻咽癌CNE-2细胞增殖、VEGF表达及NO分泌水平的影响

目的研究丹参酮ⅡA对缺氧诱导下鼻咽癌CNE-2细胞增殖、VEGF表达及NO分泌水平的影响。方法实验设常氧对照组、缺氧组(CoCl2处理进行缺氧诱导)和实验组(CoCl2缺氧诱导加不同浓度丹参酮ⅡA处理)。丹参酮ⅡA浓度分别取0.5、1.0、2.0、5.0mg/L,处理时间分别为12h、24h和48h;MTT法检测丹参酮ⅡA对CNE-2细胞增殖的影响;ELISA方法检测VEGF蛋白表达水平;硝酸还原酶法检测NO分泌水平。结果 MTT实验表明,丹参酮ⅡA呈时间、剂量依赖性抑制缺氧诱导下CNE-2细胞的增殖(均P<0.05),5.0mg/L丹参酮ⅡA处理48h后其抑制率达到52.79%。ELISA实验发现丹参酮ⅡA可呈剂量依赖性降低缺氧诱导下CNE-2细胞VEGF的蛋白表达水平(剂量大于1.0mg/L后均P<0.05),5.0mg/L丹参酮ⅡA处理24h后VEGF表达水平降低37.21%;丹参酮可呈剂量依赖性降低CNE-2细胞NO分泌水平。结论丹参酮ⅡA可有效抑制缺氧诱导下CNE-2细胞的增殖,降低其VEGF蛋白的表达及NO分泌水平。     

红景天苷对心肌细胞缺氧/复氧的保护作用

目的观察红景天苷抗心肌缺氧/复氧损伤的保护作用,探讨红景天苷抗心肌缺氧可能的信号通路。方法原代培养的心肌细胞加入不同浓度的红景天苷缺氧24h,噻唑蓝法测定细胞增殖;原代培养的心肌细胞分为5组：正常对照组;缺氧/复氧组;缺氧/复氧加红景天苷100μg/ml组;缺氧/复氧加红景天苷100μg/ml再加细胞外调节激酶抑制剂20μg组;缺氧/复氧加细胞外调节激酶抑制剂20μg组。加药后先孵育60min,再缺氧培养4h,随后常氧培养2h。全自动生化分析仪测定心肌酶（乳酸脱氢酶、肌酸肌酶、谷草转氨酶）含量,Westernblot法检测细胞外信号调节激酶蛋白表达。结果红景天苷增加了缺氧/复氧损伤心肌细胞的活力,降低了心肌细胞乳酸脱氢酶和肌酸激酶的渗漏,使磷酸化细胞外信号调节激酶蛋白表达水平明显降低。结论红景天苷对缺氧诱导的心肌细胞损伤有保护作用,此作用可能通过细胞外信号调节激酶信号通路发挥作用。     

缺氧对PC12细胞中活性氧含量和缺氧诱导因子 血管内皮生长因子表达的影响

目的研究缺氧对PC12细胞中ROS含量和HIF-1α、VEGF表达的影响,初步探讨缺氧损伤的分子机制。方法使用三气培养箱建立PC12细胞缺氧损伤模型;观察缺氧环境下细胞形态的改变;MTT法检测细胞存活率;DCHF-A染色检测ROS的含量;RT-PCR检测HIF-1α、VEGF mRNA的表达;Western Blot检测HIF-1α、VEGF蛋白的表达。结果与正常组相比较,缺氧24 h后ROS明显升高;HIF-1α、VEGF mRNA和蛋白表达较正常组明显升高。结论缺氧24 h后可以导致PC12细胞中ROS含量、HIF-1α、VEGF mRNA和蛋白表达升高。     

预缺氧对PC12细胞缺氧后细胞内游离Ca^2＋的影响

目的：建立PC12细胞预缺氧模型；观察预缺氧对PC12缺氧后细胞内游离Ca^2＋的影响。方法：PC12细胞分为对照组、缺氧组、预缺氧组。检测缺氧及预缺氧对PC12细胞LDH释放率的影响；采用荧光分光光度法，检测PC12细胞内游离Ca^2＋浓度和PC12细胞线粒体膜电位的变化。结果：①缺氧组LDH释放率和细胞内游离Ca^2＋浓度比对照组显著升高（P〈0．01），而线粒体膜电位显著低于对照组；②预缺氧组LDH释放率和细胞内游离Ca^2＋浓度显著低于缺氧组（P〈0．01），线粒体膜电位显著高于缺氧组。结论：预缺氧对PC12细胞的缺氧损伤具有保护作用，其机制可能与减轻缺氧时细胞内的游离Ca^2＋浓度与稳定线粒体膜电位有关。     

槲皮素对缺氧人肝癌细胞HepG2增殖及HIF-1α、VEGF的影响

 目的 探讨槲皮素对缺氧人肝癌细胞HepG2增殖能力、HIF-1α以及VEGF表达的影响及其可能机制。方法 实验的细胞分为正常对照组、缺氧组、槲皮素+缺氧组,采用CoCl₂法诱导缺氧环境。采用MTT 法检测各组细胞增殖能力,实时定量PCR 及Western blot检测各组细胞缺氧诱导因子HIF-1α 和VEGF mRNA及蛋白表达。结果 与正常对照组比较,缺氧组细胞在24、48、72 h增殖能力降低(P<0.05),与缺氧组比较,槲皮素+缺氧组细胞在24、48、72 h增殖能力显著降低(P<0.05),正常组在24、48、72 h的光密度值分别为0.640±0.016、1.287±0.025、1.738±0.027,缺氧组的光密度值分别为0.551±0.021、0.851±0.028、1.268±0.018,槲皮素+缺氧组的光密度值分别为0.435±0.023、0.717±0.013、0.984±0.037。与正常对照组比较,缺氧组细胞HIF-1α、VEGF的mRNA及蛋白表达上调(P<0.05),而槲皮素可下调缺氧细胞中VEGF mRNA及蛋白表达,对HIF-1α mRNA及蛋白表达无影响(P>0.05):正常对照组HIF-1α、VEGF的mRNA表达均为1.000±0.000,蛋白表达分别为0.616±0.016、0.831±0.034,缺氧组HIF-1α、VEGF的mRNA表达分别为2.298±0.031、2.065±0.090,蛋白表达分别为1.385±0.047、2.022±0.076,槲皮素+缺氧组HIF-1α、VEGF的mRNA表达2.326±0.027、0.990±0.077,蛋白表达分别为1.406±0.029、1.137±0.054。结论 槲皮素可抑制缺氧肝癌细胞HepG2 增殖能力,这可能与槲皮素下调细胞中VEGF表达有关。     

碱性成纤维生长因子对大鼠骨骼肌细胞缺氧复氧损伤的影响

应用培养的新生Wistar大鼠骨骼肌细胞缺氧复氧（A/R）损伤模型，观察碱性成纤维细胞生工因子（bFGF）对A/R损伤及损伤后骨骼肌细胞凋亡（apoptosis)的影响，以探讨bFGF作物药物预处理保护骨骼肌细胞的可行性。结果表明，bFGF预处理呈浓度依赖性地提高了A/R后肌细胞存活率，减少了胞浆乳酸脱氢酶（LDH）的漏出，明显上调了骨骼肌细胞凋亡相关基因蛋白Bcl-2的表达，提示bGFG对A/R损伤的骨骼肌细胞有明显保护作用。     

体外培养星形胶质细胞缺氧／复氧后EAAT2、谷氨酰胺合成酶的表达

目的对体外培养的星形胶质细胞（AC）进行缺氧／复氧及亚低温干预。观察兴奋性氨基酸转运体2（EAAT2）、谷氨酰胺合成酶（GS）的表达及亚低温干预对其的影响。方法选用新生大鼠的大脑皮层组织培养的AC。分为对照组（C）、缺氧／复氧组（H／R）、亚低温组（H／M＋R）,缺氧12h后H／R组及H／M＋R组分别于37℃及32℃复氧。每组设复氧2h、4h、8h、12h、24h、48h等时间点。MTT测定细胞活力,Western—blot半定量分析EAAT2、GS的表达情况。结果①MTT法检测细胞活力：H／R组与H／M＋R组的细胞活力均比C组的细胞活力低,而H／M＋R组的细胞活力较H／R组高,差异有统计学意义（P〈0．05）。（2）Western—blot检测结果：H／R组与H／M＋R组的EAAT2表达与C组相比较,均先减少,后随着复氧时间延长逐渐增多,差异有统计学意义（P〈0．05）,H／M＋R组的EAAT2表达与H／R组相比较,表达量下降趋势小,差异有统计学意义（P〈0．05）;H／R组与H／M＋R组的GS表达量随着复氧时间延长。均呈现增高趋势,与C组比较增高显著,差异有统计学意义（P〈0．05）,H／M＋R组的GS表达量与H／R组比较增高趋势更加明显,差异有统计学意义（P〈0．05）。结论缺氧／复氧及亚低温干预可引起星形胶质细胞EAAT2、GS表达的改变：32℃～35℃亚低温干预可以抑制缺氧／复氧损伤后兴奋性氨基酸的释放,这可能是脑保护作用的重要机制之一。     

远志寡糖酯化合物的神经保护作用及初步构效关系研究

目的研究远志中寡糖酯类化合物的神经保护作用和探讨化合物的初步构效关系。方法采用MTT法和BrdU标记法评价寡糖酯单体化合物对神经细胞的保护作用。结果在体外皮质酮诱导的SH-SY5Y神经细胞损伤模型上,化合物tenifoliside A、tenuifoliose J、tenuifolioses A、1-o-（E）-Benzoyl-[3-o-（E）-Alphatolluyl]-β-D-fructofuranosy-（2→1）-[β-D-glu-copyranosyl-（1→2）]-α-D-gluc-opyranosid表现出了很好的神经保护作用,并呈一定的剂量依赖性。结论远志寡糖酯类化合物对皮质酮诱导损伤的SH-SY5Y神经细胞有保护作用,其保护作用强弱与化合物类型及其浓度,化合物的母核结构,取代基位置和取代基种类有关。     

成批煤气爆燃烧伤的救治体会

报道治疗因煤气泄漏爆炸烧伤病员7例，经应用MEBT技术积极救治，其中6例于伤后17天痊愈出院，另一例特重伤员也于伤后30天康复出院。作者认为：应严格按照MEBT／MEBO要求进行规范治疗，正确处理生命体征、休克、感染、脏器功能和创面的辨证关系。同时，不能忽视外科营养在过程中的重要作用，它是创面修复的物质保证。     

Glutamine supplementation in vitro and in vivo,in exercise and in immunodepression

In situations of stress, such as clinical trauma, starvation or prolonged, strenuous exercise, the concentration of glutamine in the blood is decreased, often substantially. In endurance athletes this decrease occurs concomitantly with relatively transient immunodepression. Glutamine is used as a fuel by some cells of the immune system. Provision of glutamine or a glutamine precursor, such as branched chain amino acids, has been seen to have a beneficial effect on gut function, on morbidity and mortality, and on some aspects of immune cell function in clinical studies. It has also been seen to decrease the self-reported incidence of illness in endurance athletes. So far, there is no firm evidence as to precisely which aspect of the immune system is affected by glutamine feeding during the transient immunodepression that occurs after prolonged, strenuous exercise. However, there is increasing evidence that neutrophils may be implicated. Other aspects of glutamine and glutamine supplementation are also addressed.     

Sex differences in neuromuscular fatigability in response to load carriage in the field in British Army recruits

Objectives

Women are resistant to neuromuscular fatigue compared to men in response to a range of exercise tasks. The sex differences in the neuromuscular responses to load carriage have yet to be investigated.

新疆石河子地区奶牛隐性乳房炎的调查与分析

采用LMT法对新疆石河子地区三个规模化奶牛场泌乳牛群进行了隐性乳房炎检测,共检测994头泌乳牛3976个乳区.结果表明:奶牛隐性乳房炎阳性率为81.9%,乳区阳性率为49.1%.数据分析表明,不同年龄、胎次以及有无卧床奶牛的隐性乳房炎阳性率差异显著(P<0.05),后乳区的隐性乳房炎感染率显著高于前乳区感染率(P<0.05),隐性乳房炎乳区发生数也明显影响当日产奶量(P<0.05).     

Decrease in eccentric hamstring strength in runners in the Tirol Speed Marathon

Background

The local muscular endurance of knee flexors, during eccentric work in particular, is important in preventing or delaying kinematic changes associated with fatigue during treadmill running. This result, however, may not be transferable to overground running.

Objective

To test the hypothesis that overground running is associated with eccentric hamstring fatigue.

Methods

Thirteen runners (12 male and one female) performed an isokinetic muscle test three to four days before and 18 hours after a marathon. Both legs were tested. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions.

Results

There were no significant differences between peak torque before and after the race, except that eccentric peak hamstring torque (both thighs) was reduced.

Conclusion

Overground running (running a marathon) is associated with eccentric hamstring fatigue. Eccentric hamstring fatigue may be a potential risk factor for knee and soft tissue injuries during running. Eccentric hamstring training should therefore be introduced as an integral part of the training programme of runners.     

Oxalosis in primary hyperoxaluria in infancy

Primary hyperoxaluria (PH1) is a rare inborn autosomal recessive metabolic disorder due to the deficiency of hepatic alanine-glyoxylate-aminotransferase. This deficiency results in excessive synthesis and urinary excretion of oxalate, inducing renal stone formation and deposition of calcium oxalate in the kidney, bone, myocardium, and vessels (systemic oxalosis, SO) in the most severely affected individuals. We report renal and skeletal changes in a 3-month-old girl with PH1 and SO. Intense cortico-medullary hyperechogenicity and increased homogeneous radiopacity of normal-sized kidneys suggested the diagnosis of SO. Skeletal survey showed osteopenia and characteristic symmetrical metaphyseal transverse bands in long bones, progressively becoming more dense and migrating towards the diaphysis. Multiple pathological and slowly healing fractures of the limbs occurred at the dense band level. A radiopaque rim was then observed in flat bones, epiphyseal nuclei, and vertebral bodies. Inflammatory granulomatous reaction, induced by the presence of oxalate crystals in the marrow spaces, coexisted with progressively evident radiological signs of secondary hyperparathyroidism, with partially overlapping features. The patient was treated by peritoneal dialysis and hemodialysis until combined liver–kidney transplantation. There are no previous reports of infants treated with hemodialysis for more than 2 years.     

Interventional radiology in oncology in private practice

Interventional oncology in private practice requires expert training and can be performed in a stand-alone facility for type 1 procedures in a hospital setting for type 2 and 3 procedures where subspecialized radiologists, state-of-the-art equipment, and postprocedure hospital monitoring are available. A multidisciplinary effort with oncologists, internal medicine physicians and anesthesiologists is necessary. The practice of interventional oncology requires around the clock availability, meticulous and established protocols and procedures and a financial investment. On the other hand, it is professionally gratifying because of constant technical advances and the impact on patients.     

胎龄和日龄对新生儿局部脑血流的影响

目的探讨胎龄及日龄对新生儿局部脑血流(rCBF)变化的影响及规律.方法对早产儿组、足月早期新生儿组、足月晚期新生儿组进行99Tcm-双半胱乙酯(ECD)SPECT脑血流灌注断层显像,并作半定量分析和读片分析.结果早产儿组原始感觉运动区和枕叶rCBF低于足月早期新生儿组(P<0.05),显著低于足月晚期新生儿组(P<0.01),其额叶中份、顶叶rCBF也低于足月晚期新生儿组(P<0.05),其余各叶皮质rCBF随胎龄和日龄的增大有增加趋势.早产儿组脑血流显像图与足月早期新生儿组和晚期新生儿组比较有明显差异.结论早产儿与足月儿rCBF的变化可能与新生儿大脑皮质相应区域发育成熟度和时间顺序有关.     

Radiological strategy in acute stroke in children

The aim of the study was to estimate the preponderance of patterns of pediatric stroke, ischemic or hemorrhagic, their etiologies and the correct diagnostic protocol for acute management.Forty-one consecutive pediatric patients (age range 5-16 years) with an acute stroke observed in acute phase during a 10-year period, were retrospectively evaluated. Twenty-three patients underwent magnetic resonance imaging (MRI), 3 cases were studied by computed tomography (CT) without MRI, and 15 underwent both CT and MRI studies. In 9 cases, intra-arterial digital subtraction angiography (IADSA) was performed after non-invasive preliminary assessment.Seventeen hemorrhagic (41%) and 24 ischemic (59%) strokes were found. Among hemorrhagic forms, 5 cases were due to arteriovenous malformation (AVM), 7 to cavernoma, and 2 to aneurysm. Among ischemic forms, 2 were due to sickle-cell disease, 1 to hyperomocysteinemia, 1 to moyamoya syndrome, 1 to pseudoxantoma elasticum, 3 to prothrombotic state, 1 to Fabry's disease, 1 concomitant with CO intoxication, 5 to venous sinus thrombosis, and 4 to cardio-embolic state. Etiology remains unknown in 8 cases (20.5%).This study shows a moderate prevalence of ischemic over hemorrhagic strokes. Moreover, personal experience suggests that MRI is always more informative than CT and in selected cases should be the first-choice examination in the acute phase.