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61.
大黄素对豚鼠结肠带平滑肌细胞电和收缩性能的影响 总被引:5,自引:1,他引:4
联合应用平滑肌肌力张力测量技术和细胞内微电极记录技术,同步地现测豚鼠结肠带平滑肌自发的肌源性电活动和力学活动,研究了大黄素的药物作用。大黄素能缩短膜电位的波动周期,从而缩短峰电位集簇发放的周期;相应地,可使平滑肌的分节律收缩加快,幅值指数升高。大黄素又能促使细胞膜电位自发的周期性波动的出现,导致峰电位的集簇发放;相应地,可使强直收缩转化为分节律收缩,即促进收缩形式向有利于肠道推进功能的方向转化。以上结果表明,大黄素能有效地提高豚鼠结肠带平滑肌细胞的电兴奋性和收缩功能,并且对其电学和力学活动的影响之间有明确的对应关系。 相似文献
62.
采用核酸分子杂交Southern印迹法,以32P标记的HBVDNA为探针,检测HBsAg阳性母亲引产的40例胎儿的肝、肾组织。结果有2例胎肝和1例胎肾细胞DNA出现大于3.2kb的杂交带,表明HBVDNA已处于整合状态。胎肾细胞基因组中查出HBVDNA整合为首次报道。 相似文献
63.
Xin-Min Li† Jin Qi Augusto V. Juorio Alan A. Boulton 《Journal of neurochemistry》1993,61(4):1573-1576
Abstract: Gliosis is commonly observed in the CNS following tissue damage, and it also occurs in aging and in many neurodegen-erative diseases. Glial fibrillary acidic protein (GFAP) accumulation is a prominent feature of astrocytic gliosis. An inhibition or delay in GFAP synthesis could mitigate scar formation and thus reduce the formation of a physical barrier. The consequence of this would be to allow neurons and oligodendrocytes to reestablish a functional environment. (—)-Deprenyl, a specific monoamine oxidase (MAO) B inhibitor, has been used as an effective antipar-kinsonian drug, and it has been reported to possess neuroprotective and neurorescue properties. Using northern and slot blots to detect GFAP mRNA in C6 glioma cells, we have demonstrated that (—)-deprenyl decreases the abundance of GFAP mRNA in a time- and dose-dependent manner. The effect seems to be specific to MA0 B inhibitors because (+)-deprenyl and clorgyline exhibit no effect. This study indicates therefore that (-)-deprenyl may be useful for regulating astrogliosis following CNS injury as well as in some neurodegenerative diseases. 相似文献
64.
以草鱼ZC7901细胞株为材料,观察鱼类细胞从间期染色质到中期染色体的包装过程。主要通过(1)分裂期与间期细胞融合,诱导染色体早熟凝集;(2)染色体“伸长”处理;(3)培养细胞的低渗处理;(4)染色质辅展等方法,制作染色体标本,进行扫描和透射电镜观察。观察表明,鱼类染色质的基本结构与哺乳类细胞相同,也是直径约10nm的核丝。染色体的色装有两种形式:一种是多级螺旋化形成直径约300nm的染色单体, 相似文献
65.
对48例Ⅲ°烧伤病人的创面,定量植入枯草杆菌BS224菌后,分别在24h、48h、72h及96h做痂下组织细菌定量检测。结果显示:枯草杆菌对痂下组织的致病菌有明显的拮抗作用。感染创面的BS224菌体数量24—48小时显著增加,72—96小时而下降。与清洁创面的BS224菌动态变化上相同,呈常态曲线的规律变化。 相似文献
66.
67.
Qihe Tang Wanli Li Zhengwei Wang Zhixiang Dong Xijie Li Jiali Li Qi Huang Zhe Cao Wei Gong Yazhou Zhao Minzeng Wang Jun Guo 《Environmental microbiology》2023,25(10):2020-2031
Honeybee (Apis mellifera) ingestion of toxic nectar plants can threaten their health and survival. However, little is known about how to help honeybees mitigate the effects of toxic nectar plant poisoning. We exposed honeybees to different concentrations of Bidens pilosa flower extracts and found that B. pilosa exposure significantly reduced honeybee survival in a dose-dependent manner. By measuring changes in detoxification and antioxidant enzymes and the gut microbiome, we found that superoxide dismutase, glutathione-S-transferase and carboxylesterase activities were significantly activated with increasing concentrations of B. pilosa and that different concentrations of B. pilosa exposure changed the structure of the honeybee gut microbiome, causing a significant reduction in the abundance of Bartonella (p < 0.001) and an increase in Lactobacillus. Importantly, by using Germ-Free bees, we found that colonization by the gut microbes Bartonella apis and Apilactobacillus kunkeei (original classification as Lactobacillus kunkeei) significantly increased the resistance of honeybees to B. pilosa and significantly upregulated bee-associated immune genes. These results suggest that honeybee detoxification systems possess a level of resistance to the toxic nectar plant B. pilosa and that the gut microbes B. apis and A. kunkeei may augment resistance to B. pilosa stress by improving host immunity. 相似文献
68.
Shawn Thatcher April Leonard Marianna Lauer Gayathri Panangipalli Bret Norman Zhenglin Hou Victor Llaca Wang-Nan Hu Xiuli Qi Jennifer Jaqueth Dina Severns David Whitaker Bill Wilson Girma Tabor Bailin Li 《Molecular Plant Pathology》2023,24(7):758-767
Northern corn leaf blight, caused by the fungal pathogen Exserohilum turcicum, is a major disease of maize. The first major locus conferring resistance to E. turcicum race 0, Ht1, was identified over 50 years ago, but the underlying gene has remained unknown. We employed a map-based cloning strategy to identify the Ht1 causal gene, which was found to be a coiled-coil nucleotide-binding, leucine-rich repeat (NLR) gene, which we named PH4GP-Ht1. Transgenic testing confirmed that introducing the native PH4GP-Ht1 sequence to a susceptible maize variety resulted in resistance to E. turcicum race 0. A survey of the maize nested association mapping genomes revealed that susceptible Ht1 alleles had very low to no expression of the gene. Overexpression of the susceptible B73 allele, however, did not result in resistant plants, indicating that sequence variations may underlie the difference between resistant and susceptible phenotypes. Modelling of the PH4GP-Ht1 protein indicated that it has structural homology to the Arabidopsis NLR resistance gene ZAR1, and probably forms a similar homopentamer structure following activation. RNA sequencing data from an infection time course revealed that 1 week after inoculation there was a threefold reduction in fungal biomass in the PH4GP-Ht1 transgenic plants compared to wild-type plants. Furthermore, PH4GP-Ht1 transgenics had significantly more inoculation-responsive differentially expressed genes than wild-type plants, with enrichment seen in genes associated with both defence and photosynthesis. These results demonstrate that the NLR PH4GP-Ht1 is the causal gene underlying Ht1, which represents a different mode of action compared to the previously reported wall-associated kinase northern corn leaf blight resistance gene Htn1/Ht2/Ht3. 相似文献
69.
Tong Wu Qi Tian Ruiji Liu Ke Xu Shanshan Shi Xiudi Zhang Liming Gao Xiaobo Yin Shufeng Xu Ping Wang 《Journal of cellular and molecular medicine》2023,27(22):3526-3538
Exosomal microRNA (miRNA) exerts potential roles in non-small-cell lung cancer (NSCLC). The current study elucidated the role of miR-30b-5p shuttled by bone marrow mesenchymal stem cells (BMSCs)-derived exosomes in treating NSCLC. Bioinformatics analysis was performed with NSCLC-related miRNA microarray GSE169587 and mRNA data GSE74706 obtained for collection of the differentially expressed miRNAs and mRNAs. The relationship between miR-30b-5p and EZH2 was predicted and confirmed. Exosomes were isolated from BMSCs and identified. BMSCs-derived exosomes overexpressing miR-30b-5p were used to establish subcutaneous tumorigenesis models to study the effects of miR-30b-5p, EZH2 and PI3K/AKT signalling pathway on tumour growth. A total of 86 BMSC-exo-miRNAs were differentially expressed in NSCLC. Bioinfomatics analysis found that BMSC-exo-miR-30b-5p could regulate NSCLC progression by targeting EZH2, which was verified by in vitro cell experiments. Besides, the target genes of miR-30b-5p were enriched in PI3K/AKT signalling pathway. Animal experiments validated that BMSC-exo-miR-30b-5p promoted NSCLC cell apoptosis and prevented tumorigenesis in nude mice via EZH2/PI3K/AKT axis. Collectively, the inhibitory role of BMSC-derived exosomes-loaded miR-30b-5p in NSCLC was achieved through blocking the EZH2/PI3K/AKT axis. 相似文献
70.
泥河湾盆地发现短喙象化石 总被引:1,自引:1,他引:0
本文记述泥河湾盆地河北蔚县两个地点发现的化石,它们被鉴定为短喙象类的?Anancus和Pentalopodon两个属。 相似文献