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931.
AIM: To investigate the neuroprotective effect of erythropoietin (EPO) on cognitive dysfunction and neuronal injury in hippocampal CA1 region induced by cerebral ischemia in mice. METHODS: Male C57BL/6 green fluorescent protein-transgenic mice were randomly divided into 3 groups: sham operation group (sham), ischemia/reperfusion group (I/R) and EPO-treated group. Transient cerebral global ischemia was induced by bilateral common carotid artery occlusion (2-VO). The step-down test was used to measure the capacity of learning and memory of the animals in each group. Nissl staining was applied to examine the neuronal number in hippocampal CA1 region. The expression of phosphorylated cAMP response element-binding protein (pCREB) was determined by Western blotting. Alterations of dendritic morphology in hippocampal CA1 region were evaluated using laser scanning confocal microscopy and Neurolucida software. RESULTS: Transient cerebral ischemia caused deficits of spatial learning and memory, and delayed neuronal death and loss of dendritic spines in hippocampal CA1 region were also obvious. The EPO treatment significantly improved the cognitive function in cerebral ischemic mice, and the protein expression of pCREB was obviously increased. At the same time, neuronal death and loss of dendritic spines were reduced in hippocampal CA1 region. CONCLUSION: Erythropoietin increases the protein expression of pCREB, and reduces neuronal death and loss of dendritic spines. These processes may be responsible for erythropoietin-mediated neuroprotective effects and the improvement of cognitive function in cerebral ischemic mice. 相似文献
932.
AIM: To observe the vascular normalization effect of nanogold on hepatic tumor by inhibiting angiopoietin-2 (Ang-2), regulator of G-protein signaling-5 (RGS-5) during certain time window. METHODS: H22 cells, the hepatocellular cancer cell line, were subcutaneously injected into the right armpits of 48 BALB/c nude mice. When the size of transplanted tumor reached 3~4 mm, the mice were divided into 2 groups: 36 mice in experiment group and 12 mice in control group. The mice in experimental group underwent injection of nanogold into the tumor once a day, and the mice in control group were injected with normal saline. After continuous treatment with nanogold for 3 days, 7 days and 11 days, the mice were sacrificed, the liver tumors were taken out to measure the size and weight. The expression of Ang-1,Ang-2 and RGS-5 in the tumor was detected by the method of immunohistochemical staining. The normalizing shapes of tumor vessels and the pericytes were observed under electronic microscope. RESULTS: With nanogold treatment for 3 days, 7 days and 11 days, the positive rates of Ang-1 were 16.7%, 50.0% and 16.7%, respectively. The positive rates of Ang-2 were 33.3%, 16.7% and 41.7%, respectively. The expression of Ang-1 in experiment group was higher than that in control group, especially at the 7th day in experiment group. The expression of Ang-2 in experiment group was lower than that in control group (58.3%), especially at the 7th day in experiment group. With nanogold treatment for 3 days, 7 days and 11 days, the positive rates of RGS-5 were 33.3%, 16.7% and 50.0%, respectively. The immature pericyte coverage indexes (IMPI) were 19.6%±4.3%, 32.5%±7.9% and 41.2%±9.1% respectively. At the 7th day in experiment group, the positive rates of RGS-5 and IMPI were lower than those in other experiment groups and control group. After treated with nanogold for 7 days, the pericytes in the parietal wall of the blood vessels in the tumor showed the tendency to grow normally in morphology and were completely covered by endothelial cells. However, the pericytes in the parietal wall of the blood vessels in control group showed differences in size, impaired integrity and only a few of the pericytes covered by endothelial cells. CONCLUSION: During the time window of nangold treatment for 7 days, the chemical can normalize the blood vessels in liver cancer by inhibiting the expression of Ang-2 and RGS-5. 相似文献
933.
ZHANG Jing-ge CHEN Hai-ying QIN Jin CONG Bin LI Qiao-xia JIA Xian-xian MA Chun-ling YU Feng 《园艺学报》2011,27(3):545-549
AIM: To observe the immunoregulatory effects of prostaglandin E2 receptor (EP) subtypes EP2/EP4 on the B-cells of collagen-induced arthritic(CIA)mice. METHODS: DBA/1 mice were immunized with chicken type II collagen emulsified in Freunds complete adjuvant to induce arthritis. B-cells were isolated from the splenocyte suspension by positive selection using anti-CD19 monoclonal antibody immunomagnetic beads. The expression of MHC II, CD 80 and CD86 was examined by flow cytometry. The mRNA levels of EPs, interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), IL-6, IL-4, IL-10 and transforming growth factor-β (TGF-β) were detected by real-time RT-PCR. RESULTS: The rank of the mRNA levels of EPs was EP2>EP1>EP3>EP4 in B-cells and EP2/EP4 mRNA expression was obviously increased in CIA mice. EP2 antagonists inhibited the expression of MHC II, CD80 and CD86. EP4 antagonist had little effect on CD80. EP2/EP4 antagonists inhibited the mRNA expression of IFN-γ, TNF-α, and IL-6 (P<0.05 or P<0.01) and increased the expression of IL-10 (P<0.01 or P<0.05). Furthermore, the antagonists of EP2 and EP4 also increased the mRNA expression of IL-4 and TGF-β (P<0.01), respectively. CONCLUSION: PGE2 modulate the pathogenesis of CIA via EP2/EP4 by regulating the expression of surface molecules and cytokines in B-cells. EP2/EP4 may be a new therapeutic target for treating rheumatoid arthritis. 相似文献
934.
935.
为了探讨氮磷的不同供应比例和频度对藻类水华形成的影响,本研究设计了7种氮磷添加比例(质量比):只添加氮(以+N表示)、50:1、20:1、7:1,1:1、1:7和只添加磷(以+P表示);2种添加频度:频度较大的L系列(实验前期每日均进行添加),频度较小的S系列(只在实验过程中添加1次)。两种添加频度下,相同添加比例的处理的营养盐添加量相近。在处理+N、50:1、20:1、7:1和1:1中以N浓度为基准进行相应比例的P添加,在处理1:1、1:7和+P中以P浓度为基准进行相应比例的N添加。在1:1处理缸中N、P净增加均约为2.4mg·L-1。实验水体来自一个浮游植物丰富但没有微囊藻水华的天然富营养池塘。实验于2007年8月1日—8月13日在室外采用玻璃缸进行。结果表明,两种添加频度以及不同氮磷添加比例下,实验过程中出现的水华种类均为微囊藻(Microcysti sspp.)水华,没有固氮藻类水华出现。在两种不同添加频度下,微囊藻水华在处理+N、50:1、20:1、7:1和1:1中明显形成,而处理+P和1:7中,微囊藻水华的出现会晚几天或者水华现象不明显,这表明本实验中单独添加氮比单独添加磷对微囊藻水华形成的促进作用要明显些。水体中微囊藻水华的出现与适宜的氮磷比例添加有关,氮磷添加比例适宜时,两种不同的添加频度下均可出现微囊藻水华,但氮磷营养盐的不同添加比例和频度均没有导致固氮藻类水华的出现。 相似文献
936.
圆叶乌桕(Triadica rotundifolia)和报春苣苔(Primulina tabacum)是石灰岩特有植物,具有较高的学术、观赏和经济价值。文章从形态特征、分布、生态习性及繁殖等方面对圆叶乌桕和报春苣苔进行介绍,并阐述其园林观赏及应用价值。 相似文献
937.
938.
翻压等量紫云英条件下不同化肥用量对土壤养分有效性及水稻产量的影响 总被引:13,自引:1,他引:12
在翻压等量紫云英条件下,研究了不同化肥用量对土壤养分有效性及水稻产量的影响.结果表明,早稻田翻压紫云英22500 kg/hm2后配施化肥,与施用100%化肥(MF100)相比,施用60%~80%化肥,土壤中碱解N、速效钾含量均有增加,增幅为10%~59%;施用40%化肥,土壤中有效磷含量显著增加25% ~ 80%.翻压... 相似文献
939.
940.