Total saponins of Panax ginseng effects on proliferation and differentiation of human embryonic neural stem cells and in a Parkinson’s disease mouse model

BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells （NSCs） proliferation and differentiation into dopaminergic neurons using in vitro studies, and to observe NSC differentiation in a mouse model of Parkinson＇s disease, as well as behavioral changes before and after transplantation. DESIGN, TIME AND SETTING： In vitro neural cell biology trial and in vivo randomized, controlled animal trial were performed at the Institute of Basic Medical Sciences, Chongqing Medical University between September 2004 and December 2007. MATERIALS： TSPG （purity 〉 95%） was isolated, extracted, and identified by Chongqing Academy of Chinese Materia Medica. Recombinant human basic fibroblast growth factor （bFGF） and recombinant human epidermal growth factor （EGF） were purchased from PeproTech, USA. A total of 25 C57/BL6J mice, aged 18-20 weeks were included. Twenty were used to establish a Parkinson＇s disease model with i.p. injection of MPTP （1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine） and TSPG alone or combined with interleukin-1 （IL-1）-treated NSCs prior to transplantation into the corpus striatum. The remaining five mice were pretreated for 3 days with TSPG prior to MPTP injection, serving as the TSPG prevention group. METHODS： Primary NSCs were isolated, cultured and purified from embryonic cerebral cortex. Immunocytochemistry was employed to detect specific antigen expression in the NSCs. In vitro experiment： （1） to induce proliferation, NSCs were treated with TSPG, EGF＋bFGF, or TSPG＋EGF＋bFGF, respectively; （2） to induce dopaminergic neuronal differentiation, NSCs were treated with TSPG, IL-1, or TSPG＋IL-1, respectively. MAIN OUTCOME MEASURES： In vitro experiment： the effects of TSPG on NSCs proliferation were evaluated with flow cytometry and MTT assay. Tyrosine hydroxylase expression was determined by immunocytochemistry assay to observe effects of TSPG on dopaminergic neuronal differentiation. In vivo experiment： differentiation of grafted NSCs in the mouse brain was determined by immunohistochemical staining. Behavioral changes were evaluated by spontaneous activity frequency, memory function, and score of paralysis agitans. RESULTS： （1） NSCs were cultured and passaged for more than three passages. Immunocytochemistry revealed positive nestin staining, as well as neurofilament protein and glial fibrillary acidic protein. （2） TSPG significantly increased NSC proliferation, in particular when combined with EGF and bFGF, which was twice as effective as FGF or bFGF alone. TSPG also induced dopaminergic differentiation in NSCs, in particular when TSPG was added together with IL-1, resulting in an effect five times greater than that of IL-1 alone. （3） At day 30 following transplantation, most NSCs in the TSPG prevention group differentiated into dopaminergic neurons, and the scores of paralysis agitans, spontaneous activity, and memory function were significantly increased compared with TSPG alone or TSPG＋IL-1 groups （P 〈 0.05）. CONCLUSION： TSPG stimulated NSC proliferation, in particular when combined with FGF and bFGF. TSPG significantly induced dopaminergic neuronal differentiation of NSCs, and the effect was greater when combined with IL-1. In addition, TSPG greatly improved behavior in the Parkinson＇s disease mouse model following NSC transplantation. Following NSC transplantation, TSPG pretreatment exhibited superior efficacy over either TSPG alone or TSPG in combination with IL-1, in terms of behavioral improvements in the Parkinson＇s disease mouse model.     

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.     

Correlation of hypoxia-inducible factor-1 alpha and erythropoietin protein and mRNA to cerebral ischemic tolerance in a focal ischemia/reperfusion model using the twice suture method

BACKGROUND： Numerous studies have shown that transient ischemic preconditioning induces cerebral ischemic tolerance. However, the underlying mechanisms of endogenous protection following ischemic preconditioning remain unclear. OBJECTIVE： To dynamically measure erythropoietin and hypoxia-inducible factor-1α （HIF-1α） mRNA and protein expression at various times following preconditioning, and to investigate effects of erythropoietin and HIF-1α on cerebral ischemic tolerance in a model of focal ischemia/reperfusion established using the twice suture method. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Institute of Anatomy, Medical College, Qingdao University, China from March 2006 to March 2007. MATERIALS： Rabbit anti-rat HIF-1α monoclonal antibody and biotinylated goat anti-rabbit IgG （Boster, China）, rabbit anti-rat erythropoietin monoclonal antibody （Santa Cruz Biotechnology, USA）, and one-step RT-PCR kit （Qiagen, Germany） were used in this study. METHODS： A total of 99 healthy, male, Wistar rats were randomly assigned to three groups： sham surgery （n = 9）, non-ischemic preconditioning （n = 45）, and ischemic preconditioning （n = 45）. In the ischemic preconditioning group, rat models of pre-ischemia-reperfusion-ischemia-reperfusion were established by occluding the left middle cerebral artery using the twice suture method. In the non-ischemic preconditioning group, pre-ischemia was replaced by sham surgery. Subsequently, the ischemic preconditioning and non-ischemic preconditioning groups were equally divided into five subgroups according to time of first reperfusion, including 1-, 3-, 7-, 14-, and 21-day subgroups. The sham surgery group received the sham surgery twice. MAIN OUTCOME MEASURES： HIF-la and erythropoietin protein expression was measured in the cerebral cortex, corpus striatum, and hippocampus of the ischemic hemisphere. HIF-1α and erythropoietin mRNA expression were determined in the frontal and parietal cortex of the ischemic hemisphere. RESULTS： （1） Intergroup comparison： compared with the non-ischemic preconditioning group, HIF-1α protein expression significantly increased in the rat cerebral cortex, corpus striatum, and hippocampus in the ischemic hemisphere at 1,3, and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05 or P 〈 0.01）. Erythropoietin protein expression significantly increased in the cerebral cortex, corpus striatum, and hippocampus, as well as HIF-1α and erythropoietin mRNA expression in the frontal and parietal cortex in the ischemic hemisphere, at 3 and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05）. （2） Temporal expression： HIF-1α protein expression in the rat cerebral cortex, corpus striatum, and hippocampus, as well as HIF-la mRNA expression in the frontal and parietal cortex, in the ischemic hemisphere increased at 3 days, and gradually decreased from 7 days following reperfusion in the ischemic preconditioning group. Temporal erythropoietin protein and mRNA expression was consistent with HIF-1α protein expression. （3） Correlation： erythropoietin mRNA expression positively correlated with HIF-1α mRNA expression （r= 0.737, P 〈 0.01）. CONCLUSION： Ischemic preconditioning induced cerebral ischemic tolerance. Pre-ischemiainduced increase in endogenous HIF-1αexpression, as well as its target gene erythropoietin, participated in the formation of cerebral ischemic tolerance.     

TAT-PDX1融合蛋白诱导人胎肝间充质干细胞向胰岛β细胞分化*☆◆

BACKGROUND： In vitro cultures of neural stem cells have shown that estrogen can regulate beta-amyloid precursor protein （β-APP） metabolism and reduce amyloid-beta production.
OBJECTIVE： To investigate the effects of long-term oral administration of compound nylestriol or low-dose 17beta-estradiol on β-APP and mRNA expression in the hippocampus of ovariectomized （OVX） rats.
DESIGN, TIME AND SETTING： This randomized and controlled experiment was performed at the Animal Laboratory and Laboratory of Endocrine and Metabolic Disease, Xiangya Second Hospital of Central South University between April 2003 and May 2004. MATERIALS： According to body mass, 50 six-month-old female Sprague-Dawley rats were randomly divided into five groups （n = 10 per group）： normal control, sham operation, OVX model, 17beta-estradiol （Sigma, USA）, and compound nylestriol tablet （Laboratory of Endocrine and Metabolic Disease, Xiangya Second Hospital of Central South University） groups.
METHODS： Rats in OVX plus 17beta-estradiol and OVX plus compound nylestriol tablet groups underwent ovariectomy. On the second day after surgery, rats were intragastrically given 17beta-estradiol （100 μg/kg）, once per day or compound nylestriol tablet （0.5 mg/kg） and levonorgestrel （0.15 mg/kg） every 2 days. MAIN
OUTCOME MEASURES： β-APP expression in the hippocampus of OVX rats was determined using immunohistochemistry （SABC method） and β-APP mRNA expression was analyzed by in situ hybridization. The results were quantitatively analyzed using cell counting and average optical density.
RESULTS： The number and optical density of β-APP-positive neurons in every subregion of the hippocampus of OVX rats was dramatically increased compared with normal and sham operation groups following 35 weeks of administration （P 〈 0.05）. Levels of β-APP were decreased following oral administration of compound nylestriol or 17beta-estradiol. In situ hybridization showed that long-term estrogen deficiency and oral administration of compound nylestriol or 17beta-estradiol did not alter the number of β-APP mRNA-positive neurons.
CONCLUSION： The results show that long-term estrogen deficiency results in an increase of expression of β-APP though no changes in the expression of β-APP mRNA are detected. Replacement of estrogen with low-dose 17 beta-estradiol or compound nylestriol tablet inhibits the expression of β-APP in the hippocampus to the same extent.     

头颈部动脉夹层研究进展

头颈部动脉夹层,是指各种原因造成的头颈部动脉壁各层之间分离,血肿在动脉壁间积聚或血液在动脉壁间流通.按其发生的部位分为颅外段动脉夹层和颅内段动脉夹层,包括颈内动脉、椎动脉、基底动脉及其分支动脉的夹层形成,其中以颅外段颈内动脉夹层最为常见.     

醒脑开窍针刺超早期急性脑梗死患者血浆神经肽Y水平：随机对照

BACKGROUND： It is known that acupuncture therapy can decrease plasma neuropeptide Y （NPY） levels in patients with cerebral infarction, but different types of acupuncture therapy used in various stages of cerebral infarction have not been evaluated.
OBJECTIVE： To explore the effect of acupuncture therapy on resuscitation （Xingnao Kaiqiao） and plasma NPY levels in patients with very early stage acute cerebral infarction. DESIGN, TIME AND SETTING： This case-controlled study was
performed at the Affiliated Hospital of the Medical College of the Chinese People＇s Armed Police Force between September 2004 and October 2005.
PARTICIPANTS： Sixty patients with acute cerebral infarction of ≤ 6 hours were used in this study. Patients were randomly divided into an acupuncture therapy group （n = 30） and a routine treatment group （n = 30）. Another 30 healthy subjects were used as the control group.
METHODS： The acupuncture therapy of Xingnao Kaiqiao used in the acupuncture therapy group was based on routine western medical treatment and was performed at bilateral Neiguan （PCG） using the twirling, reinforcing-reducing method, Renzhong （DU26） using heavy bird-pecking needling, Sanyinjiao （SPG） using reinforcing and reducing by lifting and thrusting the needle, Jiquan （HT1）, Weizhong （BL40） and Chize （LU5） using reinforcing and reducing by lifting and thrusting the needle. The acupuncture lasted for 14 days. Patients in the routine treatment group underwent routine medical treatment and no intervention was given to subjects in the control group.
MAIN OUTCOME MEASURES： A 4 mL venous blood sample was obtained at different time points, i.e., immediately after hospitalization, the next morning, 7 and 14 days after treatment, to measure plasma NPY levels pre- and post-treatment using the radio-immunity method.
RESULTS： The plasma NPY levels were significantly higher in both the routine treatment group and the acupuncture therapy group than in the control group pre- and post-treatment （P 〈 0.01）. In particular, the plasma NPY levels in both the acupuncture therapy group and the routine treatment group were increased 7 days post-treatment but decreased from 7-14 days post-treatment. In addition, the plasma NPY levels were significantly lower in the acupuncture therapy group than in the routine treatment group on day 7 and 14 post-treatment （P 〈 0.01）.
CONCLUSION： Acupuncture therapy of Xingnao Kaiqiao can decrease plasma NPY levels in patients with very early stage acute cerebral infarction. In addition, the therapeutic effect of acupuncture with a prolonged therapy time is superior to routine treatment.     

Environmental factors in the development and progression of late-onset Alzheimer＇s disease

Late-onset Alzheimer＇s disease （LOAD） is an age-related neurodegenerative disorder characterized by gradual loss of synapses and neurons, but its pathogenesis remains to be clarified. Neurons live in an environment constituted by neurons themselves and glial cells. In this review, we propose that the neuronal degeneration in the AD brain is partially caused by diverse environmental factors. We first discuss various environmental stresses and the corresponding responses at different levels. Then we propose some mechanisms underlying the specific pathological changes, in particular, hypothalamic-pituitary adrenal axis dysfunction at the systemic level; cerebrovascular dysfunction, metal toxicity, glial activation, and Aβ toxicity at the intercellular level; and kinase-phosphatase imbalance and epigenetic modification at the intracellular level. Finally, we discuss the possibility of developing new strategies for the prevention and treatment of LOAD from the perspective of environmental stress. We conclude that environmental factors play a significant role in the development of LOAD through multiple pathological mechanisms.     

Effects of p75 neurotrophin receptor knockout on axonal regeneration in a mouse model of facial nerve injury

BACKGROUND： Previous studies have shown that p75 neurotrophin receptor plays an important role in peripheral nerve injury. However, the role of p75 neurotrophin receptor in the regeneration of peripheral nerves remains poorly understood. OBJECTIVE： To study the effect of p75 neurotrophin receptor on facial nerve regeneration. DESIGN, TIME AND SETTING： A randomized controlled experiment was performed in the Regeneration Laboratory of Flinders University, Australia and the Biomedical Laboratory of Dentistry School, Shandong University from March 2005 to February 2006. MATERIALS： Cholera toxin B subunit, fast blue, and biotin rabbit-anti goat IgG were provided by Sigma, USA; goat-anti choleratoxin B subunit ant/body was provided by List Biologicals, USA. METHODS： In p75 neurotrophin receptor knockout and wild type 129/sv mice, the facial nerves on one side were crushed. At days 2 and 4 following injury, regenerating motor neurons in the facial nuclei were labeled by fast blue, and the regenerating axon was labeled by the anterograde tracer choleratoxin B subunit. MAIN OUTCOME MEASURES： Axonal regenerative velocity and number were detected by immunohistochemical staining of choleratoxin B subunit, growth-associated protein, protein gene product 9.5, and calcitonin-gene-related peptide; survival of motor neurons in the facial nuclei was detected by retrograde fast blue. RESULTS： Axonal growth in the facial nerve of p75 neurotrophin receptor knockout mice was significantly less than in wild type mice. At day 7 after injury, the number of regenerating motor neurons in p75 neurotrophin receptor knockout mice remained significantly less than in wild type mice （P 〈 0.05）. The number of positively stained fibers for growth-associated protein-43, protein gene product 9.5, and calcitonin-gene-related peptide in p75 neurotrophin receptor knockout mice was significantly less than in wild type mice （P 〈 0.01）. CONCLUSION： p75 neurotrophin receptor promoted axonal regeneration and enhanced the survival rate of motor neurons following facial nerve injury.     

Caspase 3 siRNA decreases apoptosis in cultureC neuronal cells

BACKGROUND： Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction.
OBJECTIVE： To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid （shRNA） into Neuro 2a cells using a lentiviral vector.
DESIGN： TiME-AND SETTING： An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008.
MATERIALS： PLL3.7, PCMV-VSV-G, and PH＇8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.
METHODS： Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.
MAIN OUTCOME MEASURES： Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS： The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION： Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.     

叶酸、普伐他汀对急性脑梗死患者炎症因子的影响

目的 观察急性脑梗死患者应用叶酸和瞢伐他汀对其血C反应蛋白(CRP)、纤维蛋白原(FIB)、肿瘤坏死因子-α(TNF-α)、白介素6(I-一6)的影响.方法 124例急性脑梗死患者随机分为叶酸组、普伐他汀组及叶酸+普伐他汀组.分别在给药前及给药治疗4周后测定血中C反应蛋白、纤维蛋白原、肿瘤坏死因子-α、白介素6的数值,了解其变化情况.结果 三组治疗后血CRP、FIB、TNF-a、IL-6水平均较治疗前显著降低(P＜0.05),叶酸组与叶酸+普伐他汀组及普伐他汀组与叶酸+普伐他汀组CRP、FIB、TNF-α、IL-6水平比较差异均有统计学意义(P＜0.05).结论 叶酸和普伐他汀联合干预对降低血炎症因子CRP、FIB、TNF-α,IL-6水平效果显著,二者具有协同作用,对于延缓和逆转颈动脉粥样硬化疗效优于单一使用叶酸或普伐他汀,对临床预防脑梗死复发具有明显作用,值得推广使用.     

七氟醚单次给药预处理缺血再灌注大鼠脑蛋白激酶Cε的转位激活及其延迟性保护作用

BACKGROUND： Brief exposure to the anesthetic sevoflurane results in delayed neuroprotection, However, few studies have addressed delayed neuroprotection after preconditioning with a single administration of sevoflurane. OBJECTIVE： To explore the relationship between a single preconditioning administration of sevoflurane and reactive oxygen species production and protein kinase C-epsilon （PKC-ε ） translocation. DESIGN, TIME, AND SETTING： The randomized, controlled, animal experiment was conducted at the Central Laboratory, Xiangya Hospital, Central South University, China from November 2007 to April 2008. MATERIALS： A total of 120 healthy, male, Sprague Dawley rats were equally and randomly assigned into five groups： sham operation, ischemia/reperfusion, sevoflurane, 2-mercaptopropionylglycine （2-MPG, a selective reactive oxygen species scavenger） ＋ sevoflurane （MPG ＋ sevoflurane）, and MPG. Sevoflurane （Baxter, USA） and MPG （Sigma, USA） were used in this study. METHODS： Intervention consisted of three procedures. （1） MPG injection： a selective reactive oxygen species scavenger, MPG （20 mg/kg）, was infused into the rat caudal vein in the MPG and MPG ＋ sevoflurane groups. （2） Sevoflurane preconditioning： 30 minutes following MPG injection, rats in the sevoflurane and MPG ＋ sevoflurane groups breathed a mixed gas of 2.4% sevoflurane and 97.6% oxygen for 60 minutes. Rats in the sham operation, ischemia/reperfusion, and MPG groups breathed 100% pure oxygen for 60 minutes. （3） IschemiaJreperfusion： 24 hours after sevoflurane or pure oxygen preconditioning, middle cerebral artery occlusion models were established in the ischemia/reperfusion, sevoflurane, MPG ＋ sevoflurane, and MPG groups. Following 2 hours ischemia/6 hours and 24 hours reperfusion, the carotid artery was separated, but the middle cerebral artery was not occluded, in the sham operation group. MAIN OUTCOME MEASURES： In the ischemic hemisphere, PKC-ε translocation in the rat parietal cortex was measured by Western blot analysis. Infarct volume was calculated using the TTC assay. Neurological deficits were evaluated in rats using a scoring system of 8 points. RESULTS： After 6 hours reperfusion, the ratio of PKC-ε in membrane/（cytosol ＋ membrane） was significantly less in the sham operation group than in the ischemia/reperfusion, sevoflurane, MPG ＋ sevoflurane）, and MPG groups （P 〈 0.05）. The ratio of PKC-ε in membrane/（cytosol ＋ membrane） was significantly greater in the sevoflurane group than in the sham operation, ischemia/reperfusion, MPG ＋ sevoflurane, and MPG groups （P 〈 0.05）. No significant differences were observed in the ischemiaJreperfusJon, M PG ＋ sevoflurane, and MPG groups （P 〉 0.05）. Following 24 hours reperfusion, the ratio of PKC-ε in membrane/（cytosol ＋ membrane） was significantly less in the sham operation group than in the ischemia/reperfusion, sevoflurane, MPG ＋ sevoflurane, and MPG groups （P 〈 0.05）. No significant differences were detected in the ischemia/reperfusion, sevoflurane, MPG ＋ sevoflurane, and MPG groups （P 〉 0.05）. Compared with the ischemia/reperfusion, MPG ＋ sevoflurane, and MPG groups, infarct volume was significantly smaller, and neurological deficits were significantly improved, in the sevoflurane group （P 〈 0.05）. No significant differences in infarct volume and neurological deficits were observed among the ischemia/reperfusion, MPG ＋ sevoflurane, and MPG groups （P 〉 0.05）. Infarcts or neurological deficits were not detected in the sham operation group. CONCLUSION： A single preconditioning administration of sevoflurane reduced infarct volumes and improved neurological deficits in ischemic rats. Delayed neuroprotection may be mediated by reactive oxygen species and correlated to PKC- ε activation.     

Angiopoietin-1 mRNA and Bcl-2 expression following estradiol treatment in ovariectomized rats with focal cerebral ischemia/reperfusion injury

BACKGROUND： Estrogen has been clinically demonstrated to attenuate ischemic brain injury. However, the precise mechanisms remain controversial. OBJECTIVE： To investigate the effects of estradiol on angiopoietin-1 mRNA and Bcl-2 expression, as well as apoptosis and cerebral blood flow, in ovadectomized rats with focal cerebral ischemia following reperfusion. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment. The study was performed at the Central Laboratory, Chongqing Medical University from September to December 2005. MATERIALS： Estradiol benzoate was purchased from Shanghai Ninth Pharmaceutical Factory; corn oil was purchased from Walmart Supercenter; TUNEL kit, rabbit anti-rat Bcl-2 polyclonal antibody, and biotin-labeled goat anti-rabbit antibody were purchased from Wuhan Boster, China. METHODS： Healthy, female, 6-month-old Wistar rats-wild-type and estrogen alpha receptor gene knockout （ERKO）-were randomly divided into estradiol and control groups with 25 animals in each group. The rats were intramuscularly injected with estradiol benzoate （100 μg/kg per day） at 30 days following bilateral ovariectomy or corn oil （1 mL/kg per day） for seven consecutive days. Following administration, cerebral ischemia/reperfusion models were established using the right middle cerebral artery occlusion （MCAO） method. After 30 minutes of MCAO, estradiol and control groups were separately injected with estradiol benzoate and corn oil with the above-mentioned doses. MAIN OUTCOME MEASURES： Cell apoptosis was determined by TUNEL; angiopoietin-1 mRNA and Bcl-2 gene expression was determined, respectively, by immunohistochemical staining and RT-PCR. In addition, changes in cerebral blood flow were measured by laser Doppler flowmetry. RESULTS： Changes in angiopoietin-1 mRNA and cerebral blood flow in estradiol-treated, wild-type, MCAO rats following ischemia/reperfusion were greater than in control rats （P 〈 0.01 or 0.05）. However, no significant difference was observed between estradiol-treated ERKO MCAO rats and control rats. In addition, estradiol-treated wild-type and ERKO MCAO rats exhibited significantly increased Bcl-2 expression （P 〈 0.05） and decreased number of apoptotic cells in brain tissues compared with control groups （P 〈 0.05）. CONCLUSION： Estradiol upregulated angiopoietin-1 mRNA and Bcl-2 expression, suggesting that estradiol might be involved in protective mechanisms of cerebral ischemia/reperfusion injury.     

阿尔茨海默病治疗的研究进展

阿尔茨海默病（AD）是一种隐匿性起病,进行性恶化的神经退行性疾病,临床最初表现为认知功能障碍,并有可能在5～10年内完全衰退。患者往往伴随严重的记忆力丧失、精神行为异常、人格改变、言语功能障碍,无法独立生活,最终近乎于植物状态。Ferri等采用DISMOD软件在全球60岁以上人群中估计,全球的痴呆患者人数到2040年将达到8llO万左右。     

ATP结合盒转运子1基因R219K多态与脑梗死：病例对照分析

BACKGROUND： Studies have shown that adenosine triphosphate-binding cassette transporter 1 （ABCA1） gene influences atherosclerosis. Studies have also demonstrated that cerebral infarction does not occur often in pre-menopausal women. It has been, therefore, assumed that sex plays a role in R219K polymorphism of ABCA1 gene and cerebral infarction. OBJECTIVE： To explore the relationship between lipid metabolism-correlated R219K polymorphism of ABCA1 gene, risk factors of cerebral infarction and lipid level, and to determine whether there were significant differences in gender between R219K polymorphism of ABCA1 gene and cerebral infarction. DESIGN, TIME AND SETTING： A multicentral and non-randomized, controlled study based on gene polymorphism was performed at the Chinese National Human Genome Center, and lipid concentrations were measured at Beijing Xuanwu Hospital. Patients with cerebral infarction and healthy subjects were enrolled from eight hospitals of six provinces of China between October 2002 and December 2004. PARTICIPANTS： There were 177 patients in the cerebral infarction group, including 119 males and 58 females, with a mean age of （60 -＋ 13） years, and 234 healthy subjects in the normal control group, including 79 males and 155 females, with a mean age of （58 ± 12） years. METHODS： R219K polymorphism of the ABCA1 gene was detected using polymerase chain reaction-restriction fragment length polymorphism, and blood lipid concentrations were simultaneously measured. MAIN OUTCOME MEASURES： Genotype and allele frequency of R219K polymorphic site, and blood lipid concentrations. RESULTS： RR genotype and R allele frequency of males in the cerebral infarction were significantly greater than males in the normal control group [RR genotype： x2 = 5.305, OR （95% CO, 2.326 （1.120 4.828）, P〈 0.05; R allele： x2= 4.219, OR （95% CO, 1.528 （1.019 2.292）, P〈 0.05]. In addition, RR genotype and R allele frequency of males were significantly greater than females in the cerebral infarction group [RR genotype： x2= 5.172, OR （95% C/）, 2.604 （1.120-6.057）, P〈 0.05; R allele： x2= 4.818, OR （95% CO, 1.652 （1.053 2.589）, P〈 0.05]. There were no significant differences between genotype and lipid concentrations between the two groups （P〉 0.05）. CONCLUSION： The RR genotype of ABCA1 R219K might be associated with onset of cerebral infarction in males, but blood lipid concentrations do not relate to R219K polymorphism.     

Targeting 13-secretase with RNAi in neural stem cells for Alzheimer＇s disease therapy

There are several major pathological changes in Alzheimer＇s disease, including apoptosis of cho- linergic neurons, overactivity or overexpression of 13-site amyloid precursor protein cleaving enzyme 1 （BACE1） and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein （AI3） production, and introduced it into the pSilenCircle vector to construct a short hairpin （shRNA） expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing AI3 protein production. We anticipate that this technique combining cell transplantation and gene ther- apy will open up novel therapeutic avenues for Alzheimer＇s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.     

墨蝶呤还原酶基因与精神分裂症相关性的研究进展

墨蝶呤还原酶（SPR）催化四氢生物蝶呤（BH4）从头合成途径的最后一步反应。SPR基因遗传缺陷或突变可导致BH。的合成紊乱,影响单胺类神经递质（如多巴胺、5-羟色胺及谷氨酸等）的合成或释放,进而参与包括精神分裂症在内的多种神经精神系统疾病的发生发展过程。此外,SPR基因敲除小鼠表现出持续增强的自主活动等类精神分裂症症状,说明该基因在精神分裂症的发病中扮演重要的角色。进一步研究SPR基因及其单核苷酸多态性的功能,可为阐明精神分裂症的发病机制提供重要的线索,也为新一代抗精神病药物的研制及开发开拓新的视野。现对SPR基因与精神分裂症的相关研究做一综述。     

Mutant amyloid precursor protein and presenilin-1 genes effect on ischemia vulnerability via calcium homeostasis disturbance

BACKGROUND： Previous studies have demonstrated that mutant amyloid precursor protein （APP） or presenilin-1 （PS1） genes increase susceptibility to ischemic brain damage induced by middle cerebral artery occlusion. Possible mechanisms include over-production of beta-amyloid peptide （Aβ）. OBJECTIVE： Because Aβ is over-produced in the APP/PS1 double-transgenic mouse, the present study focused on mechanisms of increased ischemic damage due to mutant APP and PS1 genes by measuring oxidative stress, mitochondrial function, and calcium homeostasis. DESIGN, TIME AND SETTING： The non-randomized, controlled, in vivo and in vitro experiments were performed at the Medical Research Center, Second Clinical College, Jinan University between May and October 2008. MATERIALS： Male APP transgenic mice carrying the mutant 695swe gene and female PS1 transgenic mice carrying the mutant Leu235Pro gene were donated from the University of Hong Kong. SHSY5Y human neureblastoma cells were purchased from ATCC （Manassas, VA, USA）, and Aβ1-42 was obtained from Sigma-Aldrich （St. Louis, MO, USA）. METHODS： APP transgenic mice were mated with PS1 transgenic mice to produce APP/PS1 double-transgenic mice and wildtype littermates mice. The photothrombotic stroke model was induced in six APP/PS1 double-transgenic and 6 wildtype littermates mice. SHSY5Y human neuroblastoma cells were cultured in vitro, and were divided into 4 groups： Aβ group, cells were exposed to 5 pmol/L Aβ for 24 hours; oxygen-glucose deprivation （OGD） group, cells were exposed to OGD for 1 hour after treatment with sterile, ultra-pure water for 24 hours; OGD＋Aβ group, cells were exposed to OGD and Aβfor 1 hour after treatment with 5 pmol/L Aβ for 24 hours; sham control group： cells were exposed to sterile, ultra-pure water for 25 hours. OGD was achieved by exposing the cells to glucose-free DMEM and placing the cells in an anaerobic chamber flushed with 5% CO2 and 95% N2 （v/v） at 37 ℃ for 1 hour. MAIN OUTCOME MEASURES： TTC staining was used to measure infarct volume 7 days after photothrombotic stroke. Cell viability was evaluated using the MTT kit. Opening of the mitochondrial permeability transition pore, intracellular concentration of superoxide anion, and calcium after OGD were detected with fluorescence intensity of calcein-AM, hydroethidine, and fluo-3/AM. RESULTS： At 7 days after stroke, total infarct volume and cortical infarct volume were significantly greater in the APP/PS1 transgenic mice compared with the wildtype littermates mice （P 〈 0.01）. Aβ, OGD, and Aβ ＋ OGD significantly decreased cell viability and increased fluorescence intensity of hydroethidine and fluo-3/AM （P 〈 0.01）. Compared with the Aβ or OGD group, Aβ ＋ OGD significantly decreased cell viability （P 〈 0.01） and significantly increased fluorescence intensity of calcein-AM, hydroethidine, and fluo-3/AM （P 〈 0.01 or P 〈 0.05）. CONCLUSION： The APP/PS1 double-transgenic mice were more vulnerable to ischemia. The possible mechanisms included enhanced opening of the mitochondrial permeability transition pore, overproduction of superoxide anion due to pore opening, and disturbed calcium homeostasis induced by excess superoxide anion.     

Disrupted structural and functional brain connectomes in mild cognitive impairment and Alzheimer＇s disease

Alzheimer＇s disease （AD） is the most common type of dementia, comprising an estimated 60-80% of all dementia cases. It is clinically characterized by impairments of memory and other cognitive functions. Previous studies have demonstrated that these impairments are associated with abnormal structural and functional connections among brain regions, leading to a disconnection concept of AD. With the advent of a combination of non-invasive neuroimaging （structural magnetic resonance imaging （MRI）, diffusion MRI, and functional MRI） and neurophysiological techniques （electroencephalography and magnetoencephaJography） with graph theoretical analysis, recent studies have shown that patients with AD and mild cognitive impairment （MCI）, the prodromal stage of AD, exhibit disrupted topological organization in large-scale brain networks （i.e., connectomics） and that this disruption is significantly correlated with the decline of cognitive functions. In this review, we summarize the recent progress of brain connectomics in AD and MCI, focusing on the changes in the topological organization of large-scale structural and functional brain networks using graph theoretical approaches. Based on the two different perspectives of information segregation and integration, the literature reviewed here suggests that AD and MCI are associated with disrupted segregation and integration in brain networks. Thus, these connectomics studies open up a new window for understanding the pathophysiological mechanisms of AD and demonstrate the potential to uncover imaging biomarkers for clinical diagnosis and treatment evaluation for this disease.     

Wnt信号通路与骨髓间充质干细胞增殖及分化的关系

骨髓间充质干细胞（bonemarrow—derived mesenchymal stem cells,BMSCs）是骨髓中不同于造血干细胞的一类细胞,其来源丰富,取材简便,易分离、纯化、培养,在一定的条件下可以迅速体外扩增,具有多向分化潜能,可以通过不同的方法被诱导分化成骨细胞、软骨细胞、肌细胞、神经胶质细胞、神经元细胞等,而且它具有低免疫源性,向病变部位迁移的能力,     

胶质瘤的分子病理检测——进展与展望

胶质瘤是最常见的原发性脑肿瘤。目前的组织病理学诊断主要依据肿瘤细胞形态学上与各类胶质细胞的相似性将其分为星形细胞肿瘤、少枝胶质细胞肿瘤、混合性少枝一星形细胞肿瘤和室管膜源性肿瘤,然后进一步根据形态学特征划分为I-Ⅳ级（星形细胞肿瘤I-Ⅳ级,少枝胶质细胞肿瘤Ⅱ一Ⅲ级,混合性肿瘤Ⅱ-Ⅳ级）。目前组织学诊断仍是胶质瘤诊断和分级的金标准。然而,组织形态学相同的肿瘤预后仍可以有很大不同。分子遗传学研究结果显示组织学上相似的肿瘤中存在多个不同的分子亚型,各亚型临床病程和治疗反应可以有很大差别。随着近年来对脑胶质瘤诊断、预后和治疗反应预测的分子标志物的深入研究,我们对疾病的理解随之逐步加深,对患者的治疗正在向针对每个个体分子特征的个体化治疗转化。胶质瘤的分子病理检测在临床上的常规应用逐渐成为迫切的实际需求。现对脑胶质瘤分子病理的近期进展进行总结,并对未来进行展望。