Brain microvasculature and hypoxia-related proteins in Alzheimer's disease

Alzheimer's disease (AD) is a progressive, neurodegenerative disease of increasing incidence. The pathologic processes that underlie this disorder are incompletely understood, however, hypoperfusion/hypoxia is thought to contribute to disease pathogenesis. Hypoxia inducible factor 1-alpha (HIF-1α), a key regulator of cellular responses to hypoxia, is elevated in the microcirculation of AD patients. Cerebral hypoxia is a potent stimulus for vascular activation and angiogenesis. Microvessels isolated from the brains of AD patients express a large number of angiogenic proteins. Despite considerable data in human tissues regarding vascular expression of hypoxia-related angiogenic proteins, there is little information regarding these proteins in the brain vasculature of transgenic AD mice. The objectives of this study were to determine expression of HIF-1α, angiogenic proteins, angiopoietin-2 (Ang-2), and matrix metalloproteinase 2 (MMP2), and survival/apoptotic proteins (Bcl-xL, caspase 3) in the cerebromicrovasculature of AD transgenic mice and to determine the direct effect of hypoxia on cerebral endothelial expression of these proteins in vitro. Cultured brain endothelial cells were subjected to hypoxia for 4-6 h and analyzed by western blot and immunofluorescence. Our results demonstrated that HIF-1α is induced in cultured brain endothelial cells exposed to hypoxia and that expression of Ang-2, MMP2 and caspase 3 was elevated and the anti-apoptotic protein Bcl-xL decreased. Brain sections from AD and control mice showed that HIF-1α, Ang-2, MMP2 and caspase 3 are elevated and Bcl-xL decreased in the microvasculature of AD mice. These data suggest the cerebromicrovasculature is an important target for the effects of hypoxia in the AD brain.     

支架蛋白JLP基因敲除小鼠的构建及其肾脏表型的初步观察

目的 繁殖和鉴定支架蛋白JLP基因敲除小鼠,对其肾脏表型进行初步观察。方法 将JLP基因敲除杂合小鼠进行配种繁殖,提取子代小鼠的组织DNA,用PCR技术检测小鼠的基因型,并用Western blot法验证基因敲除效果。通过PAS病理染色等观察肾脏微观结构。结果 成功繁殖并获得子代小鼠,子代小鼠有3种基因型,包括纯合子（JLP+/+、JLP-/-）和杂合子（JLP+/-）。PCR检测基因型的方法方便且结果准确。结论 笔者成功建立了JLP基因敲除小鼠模型,能够进一步探究发现JLP基因对生物体的作用及机制。     

孕期酒精暴露致子代小鼠心肌致密化不全样改变

目的 探讨孕期酒精暴露致子代小鼠心肌致密化不全样改变的关系.方法 对孕期3.5～18.5 d的母鼠用56％酒精以5 mL/kg的剂量灌胃,收集孕期第19.5天子代小鼠心脏标本,电子透射显微镜观察肌丝、线粒体及肌浆网等心肌细胞超微结构,HE染色观察心室肌层结构,小鼠心脏超声心动图观察成年鼠心脏舒缩功能及心室肌层改变.结果 实验组子代心脏电镜下发现肌丝排列紊乱、溶解的现象;31.25％子代小鼠(5/16)的左心室肌呈非致密化样改变[病变组N/C值为(2.49±0.68),对照组N/C值为(0.62±0.23);t=10.397,P=0.000],且心脏体积变小,病变室腔明显扩大;成年后心脏超声提示实验组小鼠心功能减退、室间隔/左室后壁增厚.结论 孕期大量酒精暴露可致子代小鼠心室肌出现高度肌小梁化及心肌压实缺乏等改变,孕期酗酒可能是子代心肌致密化不全的病因之一.     

采用在体分时取样法研究2种咪喹莫特乳膏的裸鼠皮肤药动学行为

目的:采用裸鼠在体分时取样法比较国产和进口2种咪喹莫特乳膏的皮肤药动学行为。方法:分别在裸鼠相同面积的皮肤上涂抹2种乳膏各约0.03g(n=32)后,于0.25、0.5、1、2、4、6、8、24h取皮制备匀浆,采用高效液相色谱法测定皮肤中的药物浓度,比较2种制剂的药动学参数并计算偏差以对该方法进行评价。结果:国产和进口乳膏的咪喹莫特cmax分别为(82.80±8.13)、(76.46±13.08)μg·g-1,tmax分别为(6.0±0.0)、(5.0±1.2)h,t1/2分别为(25.28±4.27)、(23.30±7.42)h,AUC0～24h分别为(992.27±226.55)、(1037.02±175.93)μg·h·g-1,二者比较均无统计学差异(P>0.05)。2种制剂cmax、tmax、AUC0～24h的RSD分别为9.8%、17.1%,0、24.0%,22.8%、17.0%。结论:2种乳膏的裸鼠皮肤药动学行为无显著性差异;主要药动学参数的RSD偏差较小,表明在体给药分时取样法能较好地反映药物在裸鼠体内的经皮代谢过程,适用于临床前外用药物的皮肤药动学筛选与评价研究。     

基于蓖麻毒蛋白生物鼠药的制备及其杀鼠效果研究

目的开发与环境友好型生物鼠药,解决蓖麻毒素的有效利用问题。方法以蓖麻籽仁为试材,探讨蓖麻粗毒蛋白的提取方法,并以小白鼠的摄食量为指标,对鼠药的最佳基饵、引诱剂,以及其形状和大小进行筛选研究。结果①以粘米粉和糯米粉为基饵,对小白鼠均有一定的引诱性,且小白鼠对2种基饵的喜好程度差异无统计学意义;②葡萄糖和花生粉对小白鼠具有极强的引诱性,黑芝麻粉对小白鼠不具有引诱性,它们的摄食系数分别是7.40±0.70、2.96±0.03和1.10±0.01;③小白鼠对饵料的形状要求较低,对正方体、球形和圆柱形饵料摄入量之间差异无统计学意义;④小白鼠对不同大小的饵料摄入量差异有统计学意义,小白鼠最喜好？8～9mm饵料,其摄入率为（40.08±0.80）%;⑤用石油醚、乙酸乙酯以及氯仿去脂后提取的蓖麻粗毒蛋白制成的鼠药适口性差,小白鼠对其产生拒食现象;⑥以生理盐水为溶剂离心去脂后提取的蓖麻粗毒蛋白制备的鼠药适口性好;⑦当鼠药中蓖麻粗毒蛋白含量分别为0.91%、0.71%和0.53%时,试验小白鼠的平均死亡时间分别为（37.17±7.41）、（68.00±18.07）和（82.17±14.30）h。结论以粘米粉和糯米粉为基饵,葡萄糖（质量分数为3%）为引诱剂,加入生理盐水为溶剂离心去脂后提取的蓖麻粗毒蛋白制成？8～9mm的饵料是制备鼠药的最佳方案。     

小鼠肺炎支原体肺炎模型的建立及组织病理学评分方法的应用

目的试图建立一个由肺炎支原体(MP)感染引起的小鼠的急性肺炎的动物模型和对肺炎程度进行量化评价的组织病理学评分方法.方法 BALB/C小鼠按体重随机分8组,每组12只,在0、1、2d滴鼻感染MP菌液,在0、1、2、3、4、6、8、14、21d分批宰杀,并分批设立滴注培养基的对照组,每组4只,以0～26分的组织病理学评分来确定肺部的炎症反应程度,评分包括支气管周围浸润部位的百分比、支气管周围浸润的数量、支气管管腔内的渗出、血管周围的浸润、实质性肺炎五方面,所有实验组动物的病原学诊断均做了肺匀浆MP培养和肺匀浆的MP PCR鉴定.结果经接种菌液于感染后第1天每1例小鼠肺部均出现支气管肺炎的炎症反应,组织病理学评分平均为6.32分,于第3、4天达到最重,为11.60和9.58分,以后逐渐减轻,于第21天炎症基本消失.本实验组中动物的组织病理学评分为0～19分.培养基对照组未出现肺部炎症反应.感染后1、2、3、4d肺组织培养和PCR检测均有MP生长,检出率为100%(12/12).在6、8、14、21d分别有2/12、2/12、0/12、0/12检测出支原体.结论经3d滴鼻感染MP菌液,经组织病理学和肺组织培养和PCR检测证实可使小鼠出现明显的MP肺炎,小鼠急性MP肺炎的模型已经建立,对肺炎组织病理学评分系统可客观的量化的反映肺炎的严重程度.     

Effects of phlorizin on vascular complications in diabetes db/db mice

Background  Diabetic macrovascular complications are important causes of cardiovascular and cerebrovascular diseases and also one of the major causes of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). Phlorizin has been reported to be effective in reducing the blood glucose level in diabetic mellitus, while little is known about its effects on vascular complications. This study aimed to observe the effects of phlorizin on the aorta of diabetes db/db mice and explore its mechanism.

Methods  Diabetic db/db mice (n=16) and age-matched db/m mice (n=8) were divided into three groups: normal control group (CC group, db/m mice, n=8), untreated diabetic group (DM group, db/db mice, n=8) and diabetic group treated by phlorizin (DMT group, db/db mice, n=8). Phlorizin (20 mg/kg body weight) was given in normal saline solution intragastrically for 10 weeks. Animals were weighed weekly. At the 10th weekend, all mice were fasted overnight and then sacrificed. Fasting blood was collected, and the aortas were dissected. The blood samples were analyzed for fasting blood glucose (FBG), serum advanced glycation end products (AGEs), malondialdehyde (MDA) and superoxide dismutase (SOD) activity, the aortic ultrastructure was studied.

Results  The weight and serum concentration of FBG, AGEs, and MDA in the DM group were higher than that in the CC group (P <0.01), and they were significantly lower in the DMT group (P <0.05). Serum SOD activity was lower than that in the CC group (P <0.01), and it is significantly higher in the DMT group (P <0.05). The severity of aorta damage in the DMT group was less than that in the DM group.

Conclusions  Phlorizin protected the db/db mice from diabetic macrovascular complications, attributed to the decreasing of blood glucose and AGEs level, and its antioxidant potential. This study may provide a new natural medicine for treating diabetic macrovascular complications.

     

低氧预适应增强小鼠学习记忆能力

目的探讨脑低氧预适应对Balb／C小鼠学习记忆能力的影响，进一步研究低氧预适应的机制。方法选用清洁级成年健康雄性Balb／C交系小鼠，数字表法随机分为3组（n=12）：①对照组（H0）；②1次低氧组（H1）；③4次低氧组印低氧预适应组（H4）。然后行改良的Morris水迷宫测试：在一直径约为1米的圆形水槽边缘等距的四个点（NESW）处做好标记，在一固定位置放一玻璃平台，使槽中水面高于平台1．5厘米，水面覆以泡沫屑，小鼠在水迷宫中训练5日后，进行低氧预适应模型制备，随后分别在低氧处理后1小时、2小时、4小时、1天、2天、3天进行测试，共进行6个时段测试，每个时段4次，分别将小鼠从改良的Morris水迷宫的NESW4个起始点放入水槽中任其游动，寻找平台，记录每次的遗避潜伏期，将4次平均值作为该小鼠在该时段的成绩。然后比较各组测定的小鼠在迷宫中的逃避潜伏期，以确定低氧预适应对小鼠学习记忆能力的影响。结果H4组小鼠在低氧处理后4小时、1、2．3天的逃避潜伏期明显短于H0和H1组（P〈0．05）。结论脑低氧预适应能增强小鼠学习记忆能力，具体的产生机制需要进一步的研究。     

不同入肝血流阻断方式对小鼠肝癌生长和转移的影响

目的探讨不同血流阻断方式对肝癌生长和转移的影响。方法选择昆明小鼠24只,随机分为正常对照组(suspended operation,SO)、肝门阻断组(occlusion of the portal triad,OPT)、保留肝动脉持续阻断门静脉组(occlusion of portal vein,OPV)各8只。采用门静脉注射肿瘤的方法建立肝癌模型,建模后3d采用阻断范围为左外叶和中叶、阻断时间为60min的入肝血流阻断方式,复流后5d分别对三组动物测定肝脏置换区域(HRA)、增殖性细胞核抗原(PCNA)在肝癌组织中的阳性表达率。结果门静脉注射小鼠肝癌细胞8d后,对照组阻断叶HRA(%)值为7.658±2.552,OPT组升高到35.612±4.234,OPV组升高到9.02±3.006(P<0.01);对照组非阻断叶HRA(%)值为8.107±2.003,OPT组升高到8.698±3.021,OPV组升高到8.607±2.304(P<0.01)。对照组中阻断叶与非阻断叶肿瘤生长比率为1,OPT组值为2.82,OPV组值为1.1。对照组中肿瘤细胞PCNA阳性表达率为30%,OPT组为78%,OPV组为45%。结论保留肝动脉持续阻断门静脉可减缓肝癌的生长和转移。     

加味保安方对带瘤C57小鼠血液流变学的影响

目的探讨加味保安方对Lweis肺癌C57小鼠血液流变学的影响。方法将Lweis肺癌C57小鼠分为加味保安方大、小剂量组,西黄丸对照组和模型组,并设一未带瘤的正常组,观察各组给药后对小鼠血液流变学变化的影响。结果加味保安方大、小剂量及西黄丸均可降低抑制Lweis肺癌肺癌C57小鼠的血液黏稠度(P<0.05),且作用强于西黄丸组(P<0.05)。结论加味保安方能明显降低Lweis肺癌C57小鼠血液黏稠度。