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41.
Oresitrophe and Mukdenia (Saxifragaceae) are epilithic sister genera used in traditional Chinese medicine. The taxonomy of Mukdenia, especially of M. acanthifolia, has been controversial. To address this, we produced plastid and mitochondrial data using genome skimming for Mukdenia acanthifolia and Mukdenia rossii, including three individuals of each species. We assembled complete plastomes, mitochondrial CDS and nuclear ribosomal ETS/ITS sequences using these data. Comparative analysis shows that the plastomes of Mukdenia and Oresitrophe are relatively conservative in terms of genome size, structure, gene content, RNA editing sites and codon usage. Five plastid regions that represent hotspots of change (trnH-psbA, psbC-trnS, trnM-atpE, petA-psbJ and ccsA-ndhD) are identified within Mukdenia, and six regions (trnH-psbA, petN-psbM, trnM-atpE, rps16-trnQ, ycf1 and ndhF) contain a higher number of species-specific parsimony-informative sites that may serve as potential DNA barcodes for species identification. To infer phylogenetic relationships between Mukdenia and Oresitrophe, we combined our data with published data based on three different datasets. The monophyly of each species (Oresitrophe rupifraga, M. acanthifolia and M. rossii) and the inferred topology ((M. rossii, M. acanthifolia), O. rupifraga) are well supported in trees reconstructed using the complete plastome sequences, but M. acanthifolia and M. rossii did not form a separate clade in the trees based on ETS + ITS data, while the mitochondrial CDS trees are not well-resolved. We found low recovery of genes in the Angiosperms353 target enrichment panel from our unenriched genome skimming data. Hybridization or incomplete lineage sorting may be the cause of discordance between trees reconstructed from organellar and nuclear data. Considering its morphological distinctiveness and our molecular phylogenetic results, we strongly recommend that M. acanthifolia be treated as a distinct species.  相似文献   
42.
目的:观察异丙酚对全脑缺血/再灌注大鼠海马细胞外谷氨酸(Glu)和抗坏血酸(AA)的影响,探讨异丙酚脑保护作用机制。方法:采用Pulsinelli-Brlerley四血管阻断法制备全脑缺血模型,应用脑微透析技术结合高效液相色谱(HPLc)检测大鼠海马细胞外Glu、AA含量的变化。结果:与缺血/再灌注组各对应时点相比较,异丙酚处理组大鼠海马细胞外Glu、AA含量明显降低,统计结果差异均有显著性(P〈0.05,或〈0.01)。结论:缺血/再灌注早期应用异丙酚不仅减少兴奋性氨基酸释放,还能清除自由基、抑制脂质过氧化反应而产生脑保护作用。  相似文献   
43.
The rational of neural stem cells (NSCs) in the therapy of neurological disease is either to replace dead neurons or to improve host neuronal survival, the latter of which has got less attention and the underlying mechanism is as yet little known. Using a transwell co‐culture system, we reported that, in organotypic brain slice cultures, NSCs significantly improved host neuronal viability. Interestingly, this beneficial effect of NSCs was abrogated by a microglial inhibitor minocycline, while it was mimicked by a microglial agonist, Toll‐like receptor 9 (TLR9) ligand CpG‐ODN, which supports the pro‐vital mediation by microglia on this NSCs‐improved neuronal survival. Moreover, we showed that NSCs significantly induced host microglial movement and higher expression of a microglial marker IBA‐1, the latter of which was positively correlated with TLR9 or extracellular‐regulated protein kinases 1/2 (ERK1/2) activation. Real‐time PCR revealed that NSCs inhibited the expression of pro‐inflammatory molecules, but significantly increased the expression of molecules associated with a neuroprotective phenotype such as CX3CR1, triggering receptor expressed on myeloid cells‐2 (TREM2) and insulin growth factor 1 (IGF‐1). Similarly, in the microglia cells, NSCs induced the same microglial response as that in the slices. Further treatment with TLR9 ligand CpG‐ODN, TLR9 inhibitor chloroquine (CQ) or ERK1/2 inhibitor U0126 demonstrated that TLR9‐ERK1/2 pathway was involved in the NSCs‐induced microglial activation. Collectively, this study indicated that NSCs improve host neuronal survival by switching microglia from a detrimental to a neuroprotective phenotype in adult mouse brain, and the microglial TLR9‐ERK1/2 pathway seems to participate in this NSCs‐mediated rescue action.  相似文献   
44.
牛分枝杆菌减毒活疫苗--卡介苗(bacillus Calmette-Guérin,BCG)对预防严重的儿童结核病有效,但其免疫保护效率随儿童年龄增长而降低。BCG不能提供终身免疫保护可能与其诱导的记忆性T细胞主要是寿命较短的效应记忆性T细胞有关。新型结核分枝杆菌蛋白亚单位疫苗将有效的抗原有机组合起来,在适宜的疫苗佐剂辅助下诱导Th1型免疫应答。动物实验表明,增加抗原谱可有效提高亚单位疫苗的保护效率。更重要的是,亚单位疫苗在体内持续时间较短,可诱导寿命较长的中央记忆性T细胞,提供比BCG更持久的免疫保护力。记忆性T细胞的分化受抗原特性与剂量、细胞因子、转录因子及雷帕霉素等的调控。对亚单位疫苗及其诱导的免疫记忆进行研究将对新型结核分枝杆菌疫苗的设计与评价产生积极影响。  相似文献   
45.
We studied the structures of the cerebellar cortex of young adult and old cats for age-related changes, which were statistically analysed. Nissl staining was used to visualize the cortical neurons. The immunohistochemical method was used to display glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytes and neurofilament-immunoreactive (NF-IR) neurons. Under the microscope, the thickness of the cerebellar cortex was measured; and the density of neurons in all the layers as well as that of GFAP-IR cells in the granular layer was analysed. Compared with young adult cats, the thickness of the molecular layer and total cerebellar cortex was significantly decreased in old cats, and that of the granular layer increased. The density of neurons in each layer was significantly lower in old cats than in young adult ones. Astrocytes in old cats were significantly denser than in young adult ones, and accompanied by evident hypertrophy of the cell bodies and enhanced immunoreaction of GFAP substance. Purkinje cells (PCs) in old cats showed much fewer NF-IR dendrites than those in young adults. The above findings indicate a loss of neurons and decrease in the number of dendrites of the PCs in the aged cerebellar cortex, which might underlie the functional decline of afferent efficacy and information integration in the senescent cerebellum. An age-dependent enhancement of activity of the astrocytes may exert a protective effect on neurons in the aged cerebellum  相似文献   
46.
贵州南部6个民族5对遗传性状的基因频率   总被引:20,自引:0,他引:20  
张勋  余跃生  曹显明  何学华 《遗传》2006,28(4):399-402
对贵州南部地区布依族、苗族、水族、侗族、毛南族和汉族5对遗传性状的基因频率进行了研究,并对民族间基因频率差异进行显著性检验。结果显示:(1)发型和鼻梁侧面观的显性基因频率均明显低于隐性基因频率,而鼻孔形状则相反。(2)内眦褶、鼻梁侧面观、发型和上眼睑皱褶的基因频率在民族间差异较大,而鼻孔形状则较小。  相似文献   
47.
硫氧还蛋白与心血管疾病   总被引:4,自引:0,他引:4  
硫氧还蛋白是细胞内最重要的二硫键还原酶,对维持细胞内蛋白质的还原状态并正常发挥功能着重要的作用,此外。硫氧还蛋白、硫氧还蛋白还原酶和硫氧还蛋白过氧化物酶组成了细胞内最重要的抗氧化系统之一,在对抗细胞的氧化应激上起着重要作用。心血管疾病是威胁人类健康的主要疾病,它与炎症反应和氧化应激有着密切的联系。文章将从硫氧还蛋白的抗氧化、抗炎、抗细胞凋亡,调控与炎症基因表达有关的核转录因子的转录活性,以及调节细胞内蛋白质的亚硝基化等诸多方面阐述硫氧还蛋白在防御心血管疾病方面可能具有的生物学功能。  相似文献   
48.
CircRNAs are reported to be implicated in the development of lung cancer. This study focused on assessing the expression, functions and molecular mechanism of circPUM1 in lung adenocarcinoma. Here, it showed that circPUM1 is significantly upregulated in both lung adenocarcinoma cell lines and tissues. Furthermore, silencing of circPUM1 impaired the proliferation, migration and invasion ability, and increased apoptosis in A549?cells. Nevertheless, overexpression of circPUM1 in SPC-A1 cells has the opposite effect. Silencing of circPUM1 inhibits the tumorigenesis in nude mice. Mechanistically, circPUM1 could sponge miR-326 and promote the expression of its downstream proteins Cyclin D1 and Bcl-2. In summary, this present study revealed that circPUM1 functions as an oncogene to promote the tumorigenesis of lung adenocarcinoma through circPUM1/miR-326/Cyclin D1 and Bcl-2 axis. This indicates that circPUM1 may act as a potential therapeutic target for lung adenocarcinoma.  相似文献   
49.
沈进军  张孝才  罗虹  康迅  贺晓武  李传明 《生物磁学》2011,(19):3678-3679,3712
目的:探讨总结高海拔地区肺结核的影像特点,更好的指导临床早期诊断。方法:回顾分析65例西藏高原肺结核的影像特点,总结分析其征象及价值。结果:原发型肺结核3例(5%),影像表现边缘清楚、密度均匀的致密影,伴有淋巴结增大;侵润型结核31例(48%),影像表现成分混杂的致密影,可见钙化及卫星灶;血行播散型结核27例(42%),影像表现两肺弥漫分布的结节影;纤维空洞肺结核4例(5%),影像表现空洞、纤维化、支气管播散三大特征。结论:高原地区肺结核以侵润型和血行播散型为主,有特定的影像特点,可以用来进行诊断。  相似文献   
50.
20℃下后熟果实的LOX活性增加先于自由基产生和乙烯生成;JA处理对果实后熟软化启动期(采后1d)和果实快速软化期(采后5d)果实切片中的LOX活性、自由基产生和乙烯生物合成有促进作用,至果实软化后期(采后7d)这种效应消失;亚油酸只在采后1d果实切片中促使LOX活性和乙烯生成;SA处理抑制了果实后熟进程中组织切片的LOX活性、自由基产生和乙烯的生物合成;SA和JA对LOX活性和乙烯生物合成具有明显的拮抗作用。  相似文献   
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