实验性2型糖尿病大鼠模型的建立和评价(Ⅰ)——体重、血糖和肝糖原的变化

目的：用高脂饲料加小剂量STZ腹腔注射建立实验性2型糖尿病大鼠模型。方法：采用Wistar大鼠,分为正常对照组、高脂饲料组、小剂量STZ组（30 mg/kg）和高脂饲料加小剂量STZ（30 mg/kg）组,每10 d测定大鼠体重、空腹血糖和肝糖原等指标,连续50 d,对各组大鼠上述指标进行比较和评价。结果：①体重：高脂饲料组大鼠体重呈连续上升趋势,小剂量STZ组和高脂饲料加小剂量STZ组大鼠体重呈先降低再恢复的趋势;②空腹血糖：高脂饲料组大鼠空腹血糖轻微升高,小剂量STZ组大鼠空腹血糖呈上升的趋势,高脂饲料加小剂量STZ组大鼠空腹血糖呈明显上升趋势;③肝糖原：高脂饲料组大鼠肝糖原明显升高,小剂量STZ组、高脂饲料加小剂量STZ组大鼠肝糖原未见明显改变;结论：高脂饲料加小剂量STZ腹腔注射能成功诱导2型糖尿病大鼠模型,这种造模方法具有成模后血糖维持在较高水平、自身缓解较少、症状较轻和动物状态良好等优点。     

Poststroke DNA immunization against neurite growth inhibitors is beneficial to the recovery from local cerebral ischemia in rats

BACKGROUND： Inhibitory signals, i.e. neurite growth inhibitors （NGIs）, presenting on central nervous system （CNS） myelin have been shown to play a crucial role in inhibiting lesioned axonal sprouting and leading to less functional recovery. Vaccines targeting NGIs may provide multifactorial protection against brain insults by overcoming the inhibitory effects of these NGIs and boosting the body＇s immune repair mechanisms. OBJECTIVE： To evaluate the effect of poststroke DNA immunization against NGIs on the rehabilitation for sensorimotor function of rat models of local cerebral ischemia. DESIGN： Completely randomized grouping design, and controlled experiment. SETTING： Brain Injury Research Laboratory, Department of Neurosurgery, National Neuroscience Institute, Singapore. MATERIALS： Sixty adult male Sprague-Dawley rats ranging in age from 45 to 120 days and in weight from 180 to 250 grams were provided by Animal Center of Department of Anatomy, Faculty of Medicine, National University of Singapore. pcDNA3.1（＋）-neurite growth inhibitors （pcDNA-NGIs） a gift was provided by Dr. Xiao from Department of Clinical Research, Singapore General Hospital, Singapore. METHODS： The experiment was carried out at Brain Injury Research Laboratory, Department of Neurosurgery, National Neuroscience Institute, Singapore from August 2003 to April 2005. （1）The involved rats were randomized into 3 groups： pcDNA-NGIs group （group A）, pcDNA3.1 （＋） group （group B） and model group （group C）, with 20 rats in each group. Left focal cerebral ischemia （FCI） was permanently induced through middle cerebral artery occlusion （MCAO） with the assistance of an operating microscope. Successful MCAO was determined by a 20% decrease to baseline in the ipsilateral cerebral blood flow. 100 μg of pcDNA-NGIs eluted in phosphate-buffered saline （PBS） was intramuscularly injected into the tibial muscle once a week after MCAO for 6 weeks in group A. As control, pcDNA3.1 （＋） was also administrated in the same way in group B and nothing was administrated in group C. （2） The modified neurological severity score （mNSS）, a composite of motor, sensory, reflex and balance tests, was used to test the sensorimotor deficit. The mNSS was graded on a scale of 0 - 18, i.e. normal score was 0, maximal deficit score was 18, and 1 point was warded for the inability to perform the tasks or the lack of a tested reflex. （3） The newly generated axons of corticorubral projection were traced by stereotaxic guided injection of 100 g/L biotinylated dextran amine. Rats were sacrificed two weeks after tracing, and cryostat coronal sections of midbrains （30μm） were reacted to BDA according to the manufacturer＇s instruction by the free-floating method. Images were captured on a DM RXA2 LEICA Microscope with a Spot Digital Camera system （Germany）, and the numbers of labeled axons on the denervated side in four standard coronal sections including the red nucleus were manually quantified. MAIN OUTCOME MEASURES： （1） The number of newly generated axons of corticorubral projection. （2）The improvement in sensorimotor deficit. RESULTS： All the involved 60 rats entered the stage of final analysis. （1） The number of newly generated axons of corticorubral projection of rats： Only ipsilateral axons of CRP were noted with little evidence of fibers crossing to the contralateral red nucleus in rats of groups B and C. More BDA-positive fibers crossing the midline and terminating in the contralateral red nucleus in appropriate target areas mirroring the non-differentiated red nucleus were found in rats of group A. Quantitative analysis showed that BDA-labeled axons in the denervated side of rats in group A were more than those in group B （P 〈 0.05）. （2） Improvement in sensorimotor deficit of rats： At 2 weeks after immunization, significant improvement in sensorimotor deficit was found in rats of group A. There were significant differences of improvement in sensorimotor deficit of rats between group A and group B or group C at 12 and 14 weeks after immunization （P 〈 0.05）. CONCLUSION： （1） Poststroke DNA immunization against NGIs leads to increased sensorimotor recovery following FCI and compensatory newly growth of axons from corticorubral projection.     

老年男性2型糖尿病患者目标范围内时间与长期血糖变异性的关系研究

背景 目标范围内时间(TIR)作为血糖管理的新指标,与短期血糖波动相关,是否与长期血糖变异性相关尚不清楚。目的 探讨老年男性2型糖尿病患者TIR与长期随访期间糖化血红蛋白(HbA_1c)变异系数、HbA_1c变异性评分(HVS)的关系。方法 选取2007年1月至2011年1月在解放军总医院第二医学中心住院行动态血糖监测(CGM)的老年男性2型糖尿病患者200例,根据患者基线TIR水平,将其分为TIR≥85%组(n=141)和TIR<85%组(n=59)。对受试者随访观察(12.5±1.1)年,比较两组长期随访期间HbA_1c变异系数和HVS。采用Pearson相关、多元线性回归分析TIR与HbA_1c变异系数、HVS的关系。结果 TIR<85%组患者的长期HbA_1c变异系数[(9.7±3.8)%比(8.2±4.5)%,P=0.028)]、HVS[(48.7±20.4)分比(32.5±20.8)分,P<0.001)]均明显高于TIR≥85%组。Pearson相关分析结果...     

基于太赫兹时域光谱技术的名贵动物药材龟甲的真伪品鉴别

目的： 建立一种利用太赫兹时域光谱和多种化学计量学方法鉴别龟甲真伪的新方法。方法： 选用正品乌龟和伪品红耳彩龟的腹甲进行实验,先用经典的性状鉴别、显微鉴别方法比较两种样品的典型性状特征,后利用太赫兹时域光谱仪测得样品的光谱信息,对样品谱图进行平滑处理和基线校准,并运用化学计量方法进行数据分析以区分正品和伪品龟甲。结果： 性状鉴别结果显示完整正、伪品龟甲样品仅有细微差异,且其碎片或粉末基本无差异;显微鉴别未在两种样品中发现明显的特征差异性结构;两种样品的太赫兹时域光谱曲线图经快速傅里叶变换滤波器平滑滤波处理、正交偏最小二乘法判别分析处理后呈现显著差异。结论： 利用太赫兹时域光谱技术结合正交偏最小二乘法判别分析可以实现龟甲真伪品的精准鉴别。     

卡巴胆碱抑制肿瘤坏死因子所致微血管内皮细胞通透性增高

目的探讨卡巴胆碱对肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）诱导的增加微血管通透性的作用。方法采用FITC标记白蛋白漏出法、考马斯亮蓝染色法观察卡巴胆碱对TNF-α诱导微血管内皮细胞通透性，细胞形态和细胞骨架变化的影响。结果与对照组比较，TNF-α明显增加微血管内皮细胞通透性（P〈0．05），诱导细胞皱缩，细胞间隙增大和细胞骨架排列紊乱。给予卡巴胆碱可以明显抑制TNF-α诱导微血管内皮细胞通透性增加，并呈剂量依赖性，同时可以使细胞间隙明显减小，细胞骨架排列有序。结论卡巴胆碱可能通过抑制TNF-α对细胞骨架的损伤，进而抑制微血管通透性增加。     

人白内障球结膜微血管的电镜观察

目的 :观察人球结膜微血管的超微结构 ,认识白内障时球结膜微血管的电镜改变 ,为微循环和眼科研究工作提供参考。方法 :观察对象为 5例老年性白内障、1例糖尿病性白内障 ,术前一般状态良好。在白内障手术时取球结膜标本。电镜常规固定、包埋、定位、超薄切片、用电镜观察。结果 :球结膜毛细血管多由 2～ 3个内皮细胞围绕而成。核多为长椭圆形 ,核周缘有轻度凸凹。近腔侧胞浆细胞器较多 ,微丝和微管十分发达。基底膜、周细胞与一般毛细血管相似。 6例白内障球结膜毛细血管的内皮细胞、基底膜、周细胞、管腔都有不同程度的变化。其电镜改变可以分为三类 :( 1)代偿反应性增强改变 :微丝、微管十分发达、核周深凹、胞体突入管腔内、内皮细胞突起穿越基底膜、白细胞穿壁 ;( 2 )可恢复性退变 :线粒体退变、核质周集、胞浆出现空泡、基底膜分层、弥散、小量出血 ;( 3)严重不可恢复性改变 :核质固缩、腔内红细胞融合、血红蛋白溢出弥散、管壁断裂、腔内充满退变、裂解结构 ( 2例 ) ,并通过断裂处出至基底膜外。结论 :白内障病人球结膜微血管的超微结构有程度不等的改变     

核转录因子-κB在缺氧预处理抑制心肌细胞凋亡中的作用

目的 :研究缺氧预处理 (hypoxicpreconditioning ,HPC)对于心肌细胞蛋白激酶C(PKC)和核转录因子κB (NF κB)表达的影响 ,及其在缺氧复氧诱导心肌细胞凋亡中的作用。方法 :在培养的SD乳鼠心肌细胞制作缺氧 /复氧 (H/R)模型 ,以荧光素染料Hoechst3 3 2 5 8测定心肌细胞凋亡率 ;制备心肌细胞蛋白提取物 ,以新PKCε亚型 (nPKCε)特异性抗体测定nPKCε相对蛋白含量 ;以抗NF κB抗体检测NF κB的表达 ;并以PKC抑制剂H7与心肌细胞预孵育后 ,观察H7对于HPC诱导的PKC和NF κB表达上调以及心肌细胞保护作用的影响。结果 :缺氧复氧造成心肌细胞凋亡 ,HPC可以降低心肌细胞H/R后凋亡率 ,并诱导nPKCε和NF κB表达上调 ;PKC抑制剂H7可以消除HPC诱导的PKC、NF κB表达上调和心肌细胞保护作用。结论 :HPC可以提高乳鼠心肌细胞对于H/R的耐受性 ,其机制涉及PKC介导的NF κB表达上调。     

穿戴式呼吸感应体积描记用于睡眠呼吸事件检测

可穿戴式呼吸感应体积描记(背心式RIP)系统是我们根据呼吸感应体积描记技术的基本原理研发的一种可穿戴、低负荷的呼吸监测系统.在实现通气量无创测量的基础上,我们将该系统用于睡眠期呼吸事件检测,将该系统与多导睡眠图仪(PSG)对9例疑似睡眠呼吸暂停低通气综合症(SAHS)病人和7名健康男性志愿者进行同步对照检测与分析.通过对比实验,根据背心式RIP系统发生呼吸事件的特征性变化,提出了背心式RIP系统判别呼吸事件的规则.依据该规则,所有经背心式RIP系统诊断为SAHS患者的结果与PSG的诊断结果完全一致,背心式RIP系统检测呼吸事件的敏感性为97.8%,特异性为95.8%,实验结果表明背心式RIP系统能够可靠地检测出睡眠呼吸事件.由于其低生理、心理负荷特性,不需要佩带口鼻气流传感器,可用于家庭环境下、自然睡眠过程的睡眠呼吸紊乱性疾病的诊断.     

PLPP2: Potential therapeutic target of breast cancer in PLPP family

PLPPs (Phospholipid phosphatases) are widely expressed in different human tissues, regulate cell signal transduction, and are overexpressed in cancers such as gliomas, pancreatic adenocarcinoma, lung adenocarcinoma, and so on. As a member of the PLPP family, PLPP2 (phospholipid phosphatase 2) plays a vital role in the occurrence and development of breast cancer, but its mechanism is still unclear. Our research found that PLPP2 was overexpressed in breast cancer, and the higher expression level of PLPP2 showed a worse prognosis for breast cancer patients. Further analysis showed that overexpression of PLPP2 affected the expression of CDC34 (cell-division cycle 34), LSM7 (Like-Smith 7), and SGTA (small glutamine-rich tetratricopeptide repeat-containing protein alpha) through EMT (epigenetic-mesenchymal transition) related pathways to promote the occurrence and development of breast cancer. In vitro, silencing PLPP2 significantly reduced the proliferation, invasion, and migration abilities of human breast cancer cells MDA-MB-231. ER+ is a common subtype of breast cancer. Furthermore, we found that the overexpression of PLPP2 was significantly related to the poor prognosis of ER+ breast cancer. These results indicate that PLPP2 has value as a potential therapeutic target for breast cancer, especially for ER+ breast cancer.     

缺氧诱导因子-1在缺氧预处理心肌保护中的作用及其机制研究

目的:研究缺氧诱导因子-1(HIF-1)在缺氧预处理(HPC)心肌细胞保护中的作用及其机制。方法:在培养的SD乳鼠心肌细胞缺氧/复氧(H/R)模型上,观察HPC对于24h后心肌细胞H/R损伤的影响,以MTT法测定心肌细胞存活率,试剂盒测定培养液中乳酸脱氢酶(LDH)活性。制备心肌细胞蛋白提取物,以磷酸化的细胞外信号调节激酶(ERK1/2)抗体测定HPC后不同时间ERK1/2活性,以聚丙烯酰胺电泳迁移实验观察HIF-1α磷酸化,并观察蛋白磷酸酶激动剂BDM和ERKs的上游激酶(MEK1/2)抑制剂PD98059对于HPC诱导的HIF-1α磷酸化以及心肌细胞保护作用的影响。结果:HPC可以提高心肌细胞H/R后存活率、减少LDH漏出,并激活ERK1/2,使HIF-1α发生磷酸化;蛋白磷酸酶激动剂BDM和ERKs的上游激酶MEK抑制剂PD98059可以消除HPC诱导的HIF-1α磷酸化和心肌细胞保护作用。结论:HPC可以提高乳鼠心肌细胞对于H/R的耐受性,其机制涉及ERKs介导的HIF-1α磷酸化。