Effects of bFGF on neuronal apoptosis and fractalkine expression in cerebral ischemia/reperfusion rats

AIM: To study the effects of basic fibroblast growth factor (bFGF) on neuronal apoptosis and fractalkine expression in ischemic penumbra after cerebral ischemia/reperfusion in rats.METHODS: Thirty-six rats were randomly divided into 3 groups: sham operation group, ischemia/reperfusion group and bFGF group. The model of middle cerebral artery occlusion was established by the method of intraluminal filament blockage. The middle cerebral arteries were blocked for 1 h and then reperfused for 24 h. Neurological performances of all rats were scored with Bederson's standard. The brain tissues of the rats were stained and the average infarct volume was calculated. TUNEL method was used to determine the number of apoptotic neurons, and the expression of fractalkine was detected by the method of immunohistochemistry.RESULTS: The score of neurological performances in bFGF group was 2.23±0.59, lower than that in ischemia/reperfusion group (3.18±0.65). The number of apoptotic neurons in bFGF group (13.22±1.35) was lower than that in ischemia/reperfusion group (17.28±1.01, P<0.05), which was the lowest in sham operation group (0.91±0.65). Compared with sham operation group, the expression of fractalkine in ischemia/reperfusion group was decreased. The expression of fractalkine in bFGF group was mainly higher than that in ischemia/reperfusion group (P<0.05).CONCLUSION: Up-regulation of fractalkine may be one of the molecular mechanisms of bFGF to protect neurons against ischemia/reperfusion injury.     

Effect of microRNA-155 on regulation of angiogenesis in diabetic rats with cerebral ischemic injury

AIM: To evaluate the effect of microRNA-155(miRNA-155) on the regulation of angiogenesis in diabetic rats with cerebral ischemic injury. METHODS: Adult male Sprague-Dawley rats were randomly divided into 5 groups:sham group, cerebral ischemia group, diabetic cerebral ischemia group, diabetic cerebral ischemia+miRNA-155 inhibitors group and diabetic cerebral ischemia+scramble group. Diabetes model was made by injection of streptozocin and permanent cerebral ischemic model was developed by suture-occluded method. The scores of neurological deficit and infarct volume were estimated at 24 h after cerebral ischemia. miRNA-155 level was detected by real-time polymerase chain reaction. The expression of platelet endothelial cell adhesion molecule-1(PECAM-1/CD31) and vascular endothelial growth factor(VEGF) was detected by Western blotting. RESULTS: miRNA-155 inhibitor significantly reduced miRNA-155 levels in the ischemic cortex(P<0.05), improved the scores of neurological deficit, reduced infarction size and upregulated the levels of CD31 and VEGF(P<0.05). CONCLUSION: miRNA-155 has a critical role in the regulation of angiogenesis in diabetic rats with cerebral ischemia. Down-regulation of miRNA-155 using miRNA-155 inhibitor attenuates brain infarct injury in diabetic rats.     

不同剂量SO2保鲜剂对冷处理护色荔枝贮藏安全品质的影响

以糯米糍等五个中晚熟品种八至九成熟的荔枝果实为试材．研究不同剂量S0,缓释保鲜剂处理（每千克荔枝用量A：3．5g、B：4．2g、C：2．8g）对冷处理护色荔枝贮藏安全品质的影响。结果表明。A、B剂量处理的荔枝经3～5℃冷处理结合SO,缓释保鲜剂熏蒸48～72h后．果皮颜色褪变成青绿色．再继续于-2～O℃的自然通风库中贮藏100d,果皮颜色可恢复成自然的鲜红色。果肉晶莹洁白．保持了鲜果的品质,好果率可达97％以上,果肉的S02残留量均低于食品安全国家标准的规定（0．05g/kg）。其中,A剂量处理的糯米糍和玉荷包品种的荔枝保鲜及安全效果最好,SO2残留量为0．016g/kg和0．014g／kg,淮枝和蜜糖埕品种果肉的S02残留量仅为0．007g/kg和0．009g/kg,低于美国食品安全国家标准（0．0lg/kg）。     

北回归线以南地区银杏引种驯化研究——以珠海地区为例

为探究银杏在北回归线以南、温度较高的环境下的生长规律及存活情况,于珠海市斗门区对67株银杏进行引种驯化实验研究。分析引种驯化环境因素,并对银杏进行为期3年的性状测量和物候期观测。研究结果显示,银杏3年存活率为80.6%,存活植株的健康率为40.7%,整体表现良好。大部分个体叶片受温度气候的影响较大,无法在秋冬季节正常黄化,但观察到14.9%个体生长情况表现良好,显示出较强的适应性和景观性。通过对银杏的引种驯化实验,揭示了银杏在珠海地区的生长规律,可为探究银杏对高温等环境的适应性及生长规律提供参考。     

Effect of ischemic post-conditioning on Egr-1 and IL-1β expression in ischemia-reperfusion injured lung in rats

AIM: To investigate the protective effects of ischemic post-conditioning on the expression of early growth response factor 1 (Egr-1) and interleukin-1β(IL-1β) in ischemia-reperfusion injured lung in rats. METHODS: The model of lung ischemia-reperfusion injury was established in 24 rats and the rats were randomly allocated to 3 different groups (n=8 in each group): (1) sham group: only sham operation (thoracotomy) and no ischemia for 3 h; (2)ischemia-reperfusion group (I/R group): interruption of pulmonary perfusion and ventilation for 1 h followed by reperfusion for 2 h; (3) ischemic post-conditioning group (IPostC group): ischemic post-conditioning (5 min of reperfusion and 5 min of ischemia for 3 times) between the end of ischemia and the beginning of the reperfusion followed by reperfusion for 1.5 h. The lung tissues (prepared to small pieces of about 20 mg) were collected and homogenized at the end of the experiment. The concentration of myeloperoxidase (MPO) in the homogenate was determined. The wet to dry weight ratio (W/D) of the lung tissues was also measured at the end of reperfusion. The pathological changes of the lung tissues were observed under light microscope after reperfusion. The mRNA expression of Egr-1 and IL-1β in the lung tissues was detected by RT-PCR. RESULTS: Compared with sham group, the mRNA expression of Egr-1 and IL-1β, the levels of MPO and W/D were significantly increased in I/R group (P<0.05). The inflammatory responses of the lungs in I/R group were significantly severer than those in sham group. Compared with I/R group, the mRNA expression of Egr-1 and IL-1β, the levels of MPO and W/D in IPostC group were significantly decreased (P<0.05). The inflammatory responses of the lungs in IPostC group were also significantly attenuated. CONCLUSION: Ischemic post-conditioning significantly reduces ischemic reperfusion injury of the lung by inhibiting the expression of Egr-1 and IL-1β.     

优质荔枝新品种脆绿的选育及其性状表现

采用实生选种的方法,选出优质荔枝新品种"脆绿".脆绿果实6月中下旬成熟,平均单果重26.3g,可溶性固形物18.2%,可食率74.9%,果实美观, 肉质清甜爽脆,品质优良.栽培上应注意合理修剪、培养适时健壮结果母枝、合理疏果及适时采收.脆绿的选育对促进荔枝品种结构优化,提高荔枝种植效益具有重要意义.     

利用SNP和EST-SSR分子标记鉴定荔枝新种质御金球

本研究利用自主开发的荔枝SNP和EST-SSR两种分子标记技术,对近年发掘的荔枝优稀种质御金球进行分子鉴定,明确其与现有的363份荔枝种质的亲缘关系,以探索其是否为新种质,并揭示亲本来源,为进行新品种保护提供分子证据。结果表明,13对EST-SSR引物在364份种质中共产生122条谱带,其中多态性条带112条(91.8%);筛选出的17对SNP引物均表现为二等位性。御金球与363份荔枝种质的演化分化系数介于0.043~1.924之间,遗传相似性系数介于0.123~0.877之间。可见,御金球与现有的363份荔枝种质在分子水平上存在差异,证实御金球为一份全新荔枝种质。通过对该种质与22份疑似亲本进行EST-SSR和SNP分析,并结合表型资料及品种起源信息,初步认为御金球是杂交后代,且母本为糯米糍,父本为焦核怀枝的可能性最大。SNP分型技术首次成功地用于荔枝新种质御金球的亲本来源鉴定,为今后荔枝种质的鉴别提供了可借鉴手段。     

不同贮藏温度对冷处理护色荔枝贮藏品质的影响

以糯米糍等5个品种的荔枝果实为试材,研究经3～5℃冷处理结合护色后,不同贮藏温度（-2～0℃,1～4℃）对荔枝果实贮藏品质的影响。结果表明,荔枝采后经3～5℃冷处理结合保鲜剂护色后,快速置于-2～0℃条件下贮藏,可有效降低果实水分和糖、酸、VC等营养物质的损耗,保持良好的果皮、果肉色泽及口感,贮藏100～120d,好果率可达98％以上。     

马尾松毛虫对药剂的敏感性及防治应用

以马尾松毛虫４～５龄幼虫为对象，测定了南京、广州两地试虫在不同季节中对溴氰菊酯和灭幼脲Ⅲ号的敏感性。研究发现，不论是广州还是南京，在一年中该虫越冬代幼虫对杀虫剂均表现敏感，这是化学防治适期。研究中以血淋巴中的血细胞和酯酶为指标，分析了敏感性变化的生理生化机制，并对马尾松毛虫综合防治中的化学防治进行了探讨。     

盐胁迫对水松Glyptostrobus pensilis幼苗生长的影响研究

采用盆栽法,研究了不同浓度NaCl胁迫对水松Glyptostrobus pensilis幼苗生长表现的影响。结果表明：随着NaCl浓度的升高和胁迫时间的延长,水松幼苗的存活率逐渐下降,苗高和分枝生长受到明显的抑制作用。至第83天时收获幼苗,只有对照组（S0）和轻度盐胁迫处理组（S1）仍保留一定数量的苗木,其余处理组的苗木大都死亡。与对照组S0相比,S1处理组幼苗的根冠比增加,但总生物量明显下降。反映了水松幼苗能耐轻度盐胁迫,但不耐高盐度胁迫,可作为珠三角淡水或轻度盐胁迫区滨水绿化植物。