All-trans retinoic acid attenuates blood-brain barrier injury induced by cerebral ischemia-reperfusion in rats through JNK/P38 MAPK signaling pathway

AIM: To investigate the effect of all-trans retinoic acid (ATRA) on blood-brain barrier after cerebral ischemia-reperfusion (CIR) injury in rats and its possible role mechanism.METHODS: Male SD rats were randomly divided into sham group, model (CIR) group and CIR+ATRA (10, 30 and 90 mg/kg) groups. The rat model of CIR injury was established by MCAO thread occlusion method. After ischemia for 1.5 h and reperfusion for 24 h, the neurological functional behavioral score, cerebral infarction volume, brain water content and Evans blue content were determined. The activity of matrix metalloprotein-9 (MMP-9) was measured by gelatin zymography. The protein levels of claudin-5, occludin, ZO-1, JNK, p-JNK, P38, p-P38 and MMP-9 in the brain tissues were determined by Western blot.RESULTS: Compared with CIR model group, ATRA at 30 mg/kg significantly improved neurological function, and decreased cerebral infarction volume, brain water content, Evans blue content and the degradation of tight junction proteins in ischemic area (P<0.01). The activity and protein expression of MMP-9 in ischemic brain tissue were decreased (P<0.01). The phosphorylation of JNK and P38 was inhibited and the protein levels of p-JNK and p-P38 were decreased (P<0.01).CONCLUSION: ATRA reduces the damage of brain tissue and the destruction of blood-brain barrier induced by CIR in rats. The protective effect may be related to inhibiting the activation of JNK/P38 MAPK signaling pathway and MMP-9.     

多线圈薄板电磁加热的均匀性及可控性

以矩阵式多线圈结构电磁加热方式为研究对象,采用数值模拟仿真和对比研究的方法对薄板温度均匀性和可控性进行了分析,设计并优化多线圈电磁加热模型。首先,对加热薄板进行有限元分析与数值模拟,并在涡流损耗与模型尺寸相同条件下,对矩阵式线圈结构与蜂窝式线圈结构进行仿真结果比较;其次,分析电流强度以及线圈间距离对薄板温度均匀性影响;获得气隙尺寸与频率对温度的影响关系。结果表明:等温度区间,矩阵式多线圈结构在薄板温度均匀性以及可控性方面优于蜂窝结构;在电流密度一定条件下,薄板加热的径向温度梯度与电流呈正相关;适当调整相邻线圈的间距,薄板表面温度的均匀性得到改善;薄板表面温度,与气隙长度呈负相关,与频率呈正相关。     

驱蚊草扦插繁殖的基质配方初探

试验以珍珠岩、蛭石、沙子和锯末为基本材料,按照不同比例混合,配成6种新的基质,并以纯沙为对照,比较不同基质配方对驱蚊草扦插繁殖的影响。实验结果表明,驱蚊草扦插易于成活;处理4(珍珠岩∶锯末=1∶1)综合表现较优,可作为驱蚊草扦插繁殖的基质,其次为处理3(珍珠岩∶蛭石∶草炭=2∶1∶2);驱蚊草扦插苗的根部对基质配方更为敏感,可作为筛选驱蚊草扦插基质的较优指标。     

Expression of matrix metalloproteinases in bovine luteal cells induced by prostaglandin F2α, interferon γ and tumor necrosis factor α

We recently demonstrated that luteal cells flow out from the ovary via lymphatic vessels during luteolysis. However, the regulatory mechanisms of the outflow of luteal cells are not known. Matrix metalloproteinases (MMPs) can degrade the extracellular matrix and basal membrane, and tissue inhibitors of matrix metalloproteinases (TIMPs) inhibit the activity of MMPs. To test the hypothesis that MMP expression in luteal cells is regulated by luteolytic factors, we investigated the effects of prostaglandin F2α (PGF), interferon γ (IFNG) and tumor necrosis factor α (TNF) on the mRNA expression of MMPs and TIMPs in cultured luteal cells. Luteal cells obtained from the CL at the mid-luteal stage (days 8–12 after ovulation) were cultured with PGF (0.01, 0.1, 1 μM), IFNG (0.05, 0.5, 5 nM) and TNF (0.05, 0.5, 0.5 nM) alone or in combination for 24 h. PGF and IFNG significantly increased the expression of MMP-1 mRNA. In addition, 1 μM PGF in combination with 5 nM IFNG stimulated MMP-1 and MMP-9 mRNA expression significantly more than either treatment alone. In contrast, IFNG significantly decreased the level of MMP-14 mRNA. The mRNA expression of TIMP-1, which preferentially inhibits MMP-1, was suppressed by 5 nM INFG. One μM PGF and 5 nM IFNG suppressed TIMP-2 mRNA expression. These results suggest a new role of MMPs: luteal MMPs stimulated by PGF and IFNG break down the extracellular matrix surrounding luteal cells, which accelerates detachment from the CL during luteolysis, providing an essential prerequisite for outflow of luteal cells from the CL to lymphatic vessels.     

不同基质对红颊草莓生长发育及果实品质的影响

本研究以红颊草莓为试验材料,在温室立体阶梯式高架栽培模式下,通过对比国外专用基质和国内基质对“红颊”草莓的生长和果实品质的影响,从而筛选出适合“红颊”草莓的基质。结果表明上层国外专用基质红颊草莓在营养生长阶段比国内基质上层生长健壮;中层和下层国外专用基质和自己配制基质处理对草莓营养生长发育没有显著性差异;果实品质方面无论是上层、中层或下层,国外专用基质和国内基质处理也没有显著性差异。同一基质上、中、下三层之间果实品质也没有差异。综合这两种基质对草莓植株生长和果实品质等指标的影响,两种基质对草莓的生长发育差异不显著,国内基质完全可以代替国外专用基质使用。     

矩形区组方“RBS”设计及其在树木育种中的应用Ⅰ.单个“RBS”设计统计分析

本文介绍矩形区组方"RBS"设计的基本方法,单个"RBS"设计方差分析的数学模型,处理平均数效应,期望均方分解,遗传力及其遗传变异系数估值,并举例介绍"RBS"在树木育种中的应用。     

Effect of idazoxan on permeability of inflammatory blood-brain barrier model in vitro

AIM: To study the effect of idazoxan on the permeability of inflammatory blood-brain barrier (BBB) model in vitro and the expression of tight junction protein ZO-1.METHODS: In vitro BBB model was established by murine brain endothelial cell line bEnd.3 incubated for 7 d. The cells were treated with TNF-α (10 nmol/L) for additional 24 h to establish the inflammatory BBB model, which was pretreated with IDA at doses of 50, 100 and 200 μmol/L, respectively. The permeability was measured using fluorescein isothiocyanate-conjugated dextran (FD-40, MW 40,000), the expression of ZO-1 was detected by Western blot analysis, the distribution of ZO-1 was observed by immunofluorescence, and the mRNA expression of MMP-9/TIMP-1 was measured by RT-PCR.RESULTS: After incubated for 7 d, b.End3 cells converged to be confluent monolayer with low permeability. The inflammatory BBB model induced by TNF-α treatment displayed much higher permeability with decreased expression of tight junction protein ZO-1, destroyed distribution of ZO-1 and increased mRNA expression of MMP-9. When pretreated with IDA, the permeability was greatly decreased, the expression of ZO-1 was greatly increased, the abnormal distribution of ZO-1 was greatly ameliorated and the mRNA expression of MMP-9 was obviously reduced. The effect was most significant in IDA (200 μmol/L)-pretreated group (P<0.01).CONCLUSION: IDA directly acts on brain endothelial cells to reduce the expression of MMP-9, increase the expression of tight junction protein ZO-1 and ameliorate the destroyed distribution of ZO-1 in the inflammatory BBB, thus reversing the abnormally elevated permeability in a inflammatory BBB model in vitro induced by TNF-α.     

Effect of long non-coding RNA MEG3 on invasion and migration of colorectal cancer cells

AIM: To investigate the expression of long non-coding RNA maternally expressed gene 3(MEG3) in colorectal cancer(CRC) cells, and to observe the effect of MEG3 on the invasion and migration of CRC cells. METHODS: The levels of MEG3 in human normal colon cell NCM460 and CRC cells SW48 and LoVo were detected by real- time PCR. MEG3 was over-expressed by plasmid transfection, and the effects of MEG3 on the invasion and migration of SW48 and LoVo cells were analyzed by Transwell assay and wound healing assay. The expression of matrix metalloproteinase(MMP) family proteins was determined by Western blotting. RESULTS: The level of MEG3 was down-regulated in CRC cells compared with normal colon cell NCM460. The invasion and migration of CRC cells were reduced after MEG3 over-expression. Transwell invasion and migration assays showed that the numbers of transmembrane SW48 and LoVo cells were smaller in MEG3 over-expression group than control group(CONCLUSION: The expression of MEG3 is down-regulated in CRC cells. Over-expression of MEG3 inhibits the invasion and migration of CRC cells. TIMP-2, MMP-2 and MMP-9 might play an important role in this regulation.     

Predicting tree regeneration in <Emphasis Type="Italic">Picea abies</Emphasis> snag stands

A bark beetle (Ips typographus) infestation caused the death of almost all Norway spruce (Picea abies) trees in a mountain forest in the Swiss Alps. We developed a tree regeneration model, ‘RegSnag’ (=REGeneration in a SNAG stand), to project the future amount and height of tree regeneration in these snag stands. The model combines a height-class structured tree module with a microsite-based module of snag decay and ground-vegetation succession. Microsite-specific rates of germination, mortality and height growth were modelled for four tree species (Picea abies, Sorbus aucuparia, Acer pseudoplatanus and Betula pendula) in eight height classes (from seedlings to saplings 5 m tall) and on 26 microsite types (e.g. moss, grass). Model tests with independent field data from 8 years after the Picea die-back demonstrated that microsites had a considerable effect on the development of tree regeneration on both the montane and the subalpine level. With microsite-specific parameters, the height and frequency of Picea in each microsite could be simulated more accurately than without considering microsite effects (e.g. bias of 8 vs. 119 saplings ha⁻¹ on the montane level). Results of simulations 40 years into the future suggest that about 330–930 Picea saplings per ha out of those that germinated in 1994 and 1996 will reach a height of 5 m within 30–35 years after Picea die-back. This is due to differences in seed inflow and browsing intensities. Picea and not Betula or Sorbus trees will replace the current herbaceous vegetation in these snag stands.