Advance of exosomes in ischemic stroke

Stroke is one of the major causes of death and disability in China and even worldwide. At present, treatment of stroke has been traditionally focused on reducing death of ischemic cells. However, clinical trials have shown that none of neuroprotective drugs tested achieve clinical benefit after acute stroke. Exosomes are 30~100 nm extracellular vesicles derived from cells with cell membrane structure. Many studies suggest exosomes play essential roles in intercellular communication by transferring their cargo between source and target cells in brain. Emerging data show that exsomes also make a contribution to brain recovery via regulating highly interactive process pathway after stroke. Here, we review these advances and highlight the potential therapeutic functions of exosomes in brain remodeling after stroke.     

基于脑卒中患者活动模式的养老机构疗愈环境需求研究

疗愈环境的营造对于积极老龄化具有重要价值，是风景园林学科研究与实践中的重要议题。脑卒中患者一般有多种身心功能障碍，对物质环境设计有特殊需求。选择广州市老人院为研究对象，通过对75例脑卒中后遗症患者活动范围、频率、类型等活动模式及其影响因素进行问卷调查，依据结果并结合患者身心特点，分析其对于养老机构疗愈环境在空间布局与社会交往、康复训练、感官刺激等使用功能方面的潜在需求。     

Metformin attenuates nerve injury in stroke rats by regulating SIRT1/PGC-1α signaling pathway via miR-29c

AIM To explore the inhibitory effect of metformin （MET） on nerve injury in rats with stroke and its mechanism. METHODS SD rats were randomly divided into sham group （n=15）, model group （n=30）, MET group （n=30）, MET+agomir-NC group （n=30） and MET+agomir group （n=30）. The modified Puisinelli four-vessel occlusion method was used to prepare the model of global ischemic stroke, while the blood vessels in sham rats were isolated without clamping the common artery. One week before modeling, the rats in MET group, MET+agomir-NC group and MET+agomir group were given intraperitoneal injection of 100 mg·kg^-1·d^-1 MET, 100 mg·kg^-1·d^-1 MET+40 nmol/d agomir-NC, 100 mg·kg^-1·d^-1 MET+40 nmol/d miR-29c agomir, respectively, and the rats in sham group and model group were given intraperitoneal injection of the same amount of normal saline. Each treatment in the above groups was given once a day, 0.2 mL each time, for 7 consecutive days. The neurological deficit scores were measured 24, 48 and 72 h after operation. HE staining was used to observe the morphological changes of the hippocampus, and the living neurons were counted. RT-qPCR was used to detect the expression level of miR-29c, and the mRNA levels of silent information regulator 1 （SIRT1） and peroxisome proliferator-activated receptor γ coactivator 1α （PGC-1α） in hippocampus. The protein expression levels of SIRT1 and PGC-1α were determined by Western blot. RESULTS At the same time point, compared with model group, the neurological deficit score in MET group was significantly decreased, and the survival rate of the neurons was significantly increased （P<0.05）. Compared with MET+agomir-NC group, the neurological deficit score in MET+agomir group was increased, and the survival rate of the neurons was significantly decreased （P<0.05）. With the prolongation of time, except for sham group, the neurological deficit score was increased and the survival rate of the neurons was decreased. At 72 h after operation, compared with sham group, the expression of miR-29c in hippocampus of model group was significantly increased, and the mRNA and protein expression levels of SIRT1 and PGC-1α were significantly decreased （P<0.05）. Compared with model group, the expression of miR-29c in hippocampus of MET group was significantly decreased, and the expression of SIRT1 and PGC-1α at mRNA and protein levels was significantly increased （P< 0.05）. Compared with MET+agomir-NC group, the expression of miR-29c in hippocampus of MET+agomir group was significantly increased, and the mRNA and protein expression of SIRT1 and PGC-1α was significantly decreased （P<0.05）. CONCLUSIONS MET alleviates nerve injury in stroke rats, which may be related to down-regulation of miR-29c and promotion of SIRT1/PGC-1α signaling pathway activation.     

实验诱发长爪沙鼠中风模型的研究──方法的建立及中风发病情况与性别的关系

手术截断长爪沙鼠一侧颈动脉以引发沙鼠中风，总有效率为５４．４２％。手术后４～６ｈ，发现雄、雌沙鼠的总发病率分别为６４．０１％和４４．４４％。其中轻度中风率分别为３０．６７％和１９．４４％；中度中风率分别为１４．６７％和１５．２８％；严重中风率分别为１８．６７％和９．７２％。雄性发病率及中风程度明显比雌性严重（Ｐ＜０．０５）。建议采用雄性沙鼠作为中风模型的材料，有利于提高模型的成功率。经进一步观察，又发现术后４～６ｈ时所表现的体症可作为判断模型成功与否的依据。     

大兴安岭林区桩基础冲击钻孔效率的研究

通过对大兴安岭林区冲击钻孔灌注桩的施工钻具及施工工艺过程的现地考察,提出了切实可行的提高冲击钻孔效率的具体方法。在不改变动力设备条件下,开孔阶段、中孔阶段、终孔阶段的冲程H值分别为1.0、2.0、0.5m。冲击频率12～20次/h,改进的钻刃夹角α=90°～100°。     

Echocardiographic assessment of the left ventricular outflow tract in the Boxer

BACKGROUND: Soft, variable ejection murmurs are common in Boxers and are associated with increased left ventricular outflow tract (LVOT) ejection velocities. Whether these murmurs are physiologic or indicate mild aortic stenosis is controversial. Ejection velocity is impacted by LVOT area and ventricular stroke volume (SV), suggesting that these variables are pertinent to murmur development. HYPOTHESIS: Boxers with ejection murmurs have a smaller LVOT and equivalent SV indices, compared with values in dogs without murmurs. ANIMALS: Three age- and weight-matched groups of dogs--15 Boxers with soft ejection murmurs (group I); 15 Boxers without murmurs (group II); and 15 nonBoxer dogs without murmurs (group III)--were studied. METHODS: All dogs underwent 2-dimensional and Doppler echocardiographic examinations. The LVOT size at multiple levels; LVOT ejection velocity, stroke distance, and SV index; and right ventricular SV index were determined and compared by analysis of variance. RESULTS: Indexed LVOT areas in Boxer groups were not different, but were significantly smaller than those of non-Boxer dogs. Ejection velocities and stroke distances were significantly different across all groups, with group I having the highest and group III having the lowest values. Doppler SV indices (ml/m2) for group-I versus group-II Boxers were 70 +/- 16(SD) versus 62 +/- 12 for the LVOT (P = .27) and 58 +/- 12 versus 48 +/- 9 for the right ventricle (P = .14). CONCLUSIONS AND CLINICAL IMPORTANCE: These data suggest that a relatively smaller LVOT in Boxers predisposes them to increased ejection velocity and development of murmurs. The contribution of SV to the genesis of these often labile murmurs requires additional study.     

Role of HIF-1α/VEGF pathway in treatment of cerebral ischemia-reperfusion injury by hyperbaric oxygen pretreatment

AIM: To investigate the role of hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway in hyperbaric oxygen (HO) pretreatment in rats with cerebral ischemia-reperfusion (IR) injury. METHODS: Healthy male SD rats (n=32) were randomly divided into control group IR group, HO-IR group and HO-IR-HIF-1α inhibitor group (HO-IR-I group). The IR model was established by middle cerebral artery occlusion. The corresponding blood vessels of the rats in control group were only exposed. The rats in HO-IR group and HO-IR-I group were treated with HO for 4 weeks before the animal modeling. The rats in HO-IR-I group received 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazol (YC-1) by intraperitoneal injection at 4 mg/kg before HO preconditioning every day. At 1 d and 7 d after modeling, the neurological assessment was evaluated.At the end of the 7 th day, after observation, the rats were sacrificed by anesthesia to measure the infarct volume of the brain tissue. The protein levels of HIF-1α, VEGF and apoptosis-related proteins Bax and Bcl-2 were determined by Western blot. The number of apoptotic cells was detected by TUNEL. RESULTS: Compared with control group, the neurological function score was decreased, while the cerebral infarction volume ratio, the protein levels of HIF-1α, VEGF, Bcl-2 and Bax, and the apoptotic cells were increased in IR group, HO-IR group and HO-IR-I group (P<0.05). Compared with IR group, the neurological function score, and the protein levels of HIF-1α,VEGF and Bcl-2 were increased, while the cerebral infarction volume ratio, the protein level of Bax and apoptotic cells were decreased in HO-IR group and HO-IR-I group (P<0.05). Compared with HO-IR group, the neurological function score, and the protein levels of HIF-1α, VEGF and Bcl-2 were decreased, while the cerebral infarction volume ratio, the protein level of Bax and apoptotic cells were increased in HO-IR-I group (P<0.05). CONCLUSION: The mechanism of HO preconditioning attenuating cerebral IR injury may be related to the regulation of apoptosis by inducing HIF-1α/VEGF signaling pathway activation.     

基于数位笔压感的汽车三维手绘系统研究

在分析当前三维手绘系统问题的基础上,通过对数位笔压感信息的分析,提出了一种基于数位笔压力感应的三维手绘曲线生成方法,据此开发了基于数位笔压力感应的汽车三维手绘系统原型,并在汽车三维手绘造型Auto Sketch系统中进行了集成应用测试。测试结果表明,所开发的原型系统能够很好地融合到Auto Sketch系统中,并且操作命令识别效率高、计算时间短。