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991.
Shengyu Lv Hongrui Liu Jian Cui Tomoka Hasegawa Hiromi Hongo Wei Feng Juan Li Bao Sun Akira Kudo Norio Amizuka Minqi Li 《Journal of molecular histology》2014,45(3):303-309
The purpose of this study was to investigate immunolocalization of collagenolytic enzymes including cathepsin K, matrix metalloproteinase (MMP) 1 and 2 in the compressed periodontal ligament (PDL) during orthodontic tooth movement using a periostin deficient (Pn-/-) mouse model. Twelve-week-old male mice homozygous for the disrupted periostin gene and their wild type (WT) littermates were used in these experiments. The tooth movement was performed according to Waldo’s method, in which elastic bands of 0.5 mm thickness were inserted between the first and second upper molars of mice under anesthesia. At 1 and 3 days after orthodontic force application, mice were fixed with transcardial perfusion of 4 % paraformaldehyde in 0.1 M phosphate buffer (pH 7.4), and the first molars and peripheral alveolar bones were extracted for histochemical analyses. Compared with WT mice, immunolocalization of cathepsin K, MMP1 and MMP2 was significantly decreased at 1 and 3 days after orthodontic tooth movement in the compressed PDL of Pn-/- mice, although MMP1-reactivity and MMP2-reactivity decreased at different amounts. Very little cathepsin K-immunoreactivity was observed in the assessed regions of Pn-/- mice, both before and after orthodontic force application. Furthermore, Pn-/- mice showed a much wider residual PDL than WT mice. Taken together, we concluded that periostin plays an essential role in the function of collagenolytic enzymes like cathepsin K, MMP1 and MMP2 in the compressed PDL after orthodontic force application. 相似文献
992.
Artesunate exerts an anti‐immunosuppressive effect on cervical cancer by inhibiting PGE2 production and Foxp3 expression 下载免费PDF全文
993.
离子型谷氨酸受体(iGLuR)是哺乳动物中一类由L-氨基酸(如谷氨酸、甘氨酸)等配体门控的阳离子通道, 具有调节兴奋性神经信号传递和引导神经元发育等分子功能。1998年研究者在拟南芥(Arabidopsis thaliana)中发现了20个与iGLuRs同源的序列(即AtGLRs), 它们的功能涉及植物光信号传递、根尖分生细胞活性、花粉管生长、胞质Ca2+流以及应答多种生物和非生物环境胁迫等。该文从谷氨酸受体(GLR)的结构特征、离子通道激活与配体的关系、表达模式及可能的生物学功能等方面, 综述了近十几年来关于植物GLR和氨基酸信号的研究成果, 旨在为相关领域的同行提供有益的参考。 相似文献
994.
995.
Kawakami N Lee JM Mon H Kubo Y Banno Y Kawaguchi Y Maenaka K Park EY Koga K Kusakabe T 《Molecular biotechnology》2008,40(2):180-185
The recombinant protein expression by Bombyx mori nucleopolyhedrovirus (BmNPV) infecting silkworm larvae or pupae may endow us with a potent system for the production of large
eukaryotic proteins. However, the screening of silkworm strains ideally suited to this method has scarcely been conducted.
In the present study, we injected recombinant BmNPV containing a reporter gene, luciferase or DsRed, into hemocoel of fifth
instar larvae of selected 12 silkworm strains. Among them, the strain d17 is found to be the highest in reporter expression
from the intrinsic polyhedrin promoter of Autographa californica NPV or the silkworm actin A3 promoter. These results suggest that the d17 strain is highly permissive for BmNPV replication
and is the most likely candidate of a “factory” for large-scale expression using the BmNPV bacmid system. 相似文献
996.
目的:检测寒颤对呼吸道复温的影响。方法:采用冷水浸泡降温和注射卡肌宁抑制寒颤的方法建立抑制寒颤的低体温犬模型。受试犬吸湿热空气(40.45℃,RH99.9%)及室温空气(19±1℃,RH30%~75%)复温各2h,不同温度空气复温的先后顺序随机安排。复温4h后,加压呼吸湿热空气复温使其恢复自主呼吸,继续呼吸湿热空气复温直至直肠温度(Tr)和食道温度(Te)恢复入水时温度。实验过程中采用间接测热法测定代谢产热量。结果:①抑制寒颤时,吸湿热空气2h可使Tr和Te平均每小时分别增高0.26~0.39℃和0.44—1.11℃,吸室温空气2h可使Tr和re平均每小时分别降低0.24-0.51℃和0.58~0.67℃,Tr和Te的变化与呼吸不同温度空气的先后顺序无关。②有寒颤、自主呼吸湿热空气时,Tr和Te的复温速度分别为2.26~2.33℃/h和1.96~2.38℃/h,较抑制寒颤、呼吸湿热空气时明显加快。③与抑制寒颤、加压呼吸湿热空气时的代谢产热量比较,受试犬恢复寒颤自主呼吸湿热空气时代谢产热量明显增高,使复温速度明显加快。结论:呼吸道复温有助于低体温机体复温。寒颤时机体代谢产热量明显增高,使复温速度明显加快。因此,检测呼吸道复温作用时应抑制寒颤,排除寒颤产热的干扰。 相似文献
997.
Don A. Driscoll Annabel L. Smith Samantha Blight John Maindonald 《Biodiversity and Conservation》2012,21(6):1607-1625
Altered fire regimes are a driver of biodiversity decline. To plan effective management, we need to know how species are influenced
by fire and to develop theory describing fire responses. Animal responses to fire are usually measured using methods that
rely on animal activity, but animal activity may vary with time since fire, potentially biasing results. Using a novel approach
for detecting bias in the pit-fall trap method, we found that leaf-litter dependent reptiles were more active up to 6 weeks
after fire, giving a misleading impression of abundance. This effect was not discovered when modelling detectability with
zero-inflated binomial models. Two species without detection bias showed early-successional responses to time since fire,
consistent with a habitat-accommodation succession model. However, a habitat specialist did not have the predicted low abundance
after fire due to increased post-fire movement and non-linear recovery of a key habitat component. Interactions between fire
and other processes therefore must be better understood to predict reptile responses to changing fire-regimes. We conclude
that there is substantial bias when trapping reptiles after fire, with species that are otherwise hard to detect appearing
to be abundant. Studies that use a survey method based on animal activity such as bird calls or animal movements, likely face
a similar risk of bias when comparing recently-disturbed with control sites. 相似文献
998.
Jia Liu Aihua Yang Jie Liu Xiaofan Ding Liming Liu Zhongping Shi 《Biotechnology letters》2014,36(7):1469-1477
Escherichia coli K4 synthesizes a capsular polysaccharide (CPS) consisting of a fructose-branched chondroitin (GalNAc-GlcA(fructose)n), which is a biosynthetic precursor of chondroitin sulfate. Here, the role of kfoE in the modification of the chondroitin backbone was investigated using knock-out and recombinant complementation experiments. kfoE disruption and complementation had no significant effect on cell growth. CPS production was increased by 15 % in the knock-out strain, and decreased by 21 % in the knock-out strain complemented with recombinant kfoE. CPS extracted from the knock-out strain was chondroitin, whereas CPS extracted from the complemented strain was a fructose-branched chondroitin. The results demonstrated that the kfoE gene product altered the fructose group at the C3 position of the GlcA residue during production of K4CPS. 相似文献
999.
Hai-Jun Huang Xia Peng Bing Deng Cong Huang Jie Li Yun-Guo Qian Qi-Shuang Gao Min Xiang Shun Lu Zhi-Hua Chen Cai-Yao Zhan Li Zhou Bi-Fei Tao Jie Liu Ben-Zhong Tan 《Cytotechnology》2016,68(2):203-211
Despite the powerful impact gene expression markers like the green fluorescent protein (GFP) or enhanced GFP (EGFP) exert on linking the expression of recombinant protein for selection of high producers in recent years, there is still a strong incentive to develop more economical and efficient methods for isolating mammalian cell clones secreting high levels of recombinant proteins. Here we present a new method based on the co-expression of EGFP that allows clonal selection in standard 96-well cell culture plates. The genes encoding the EGFP protein and the related protein are linked by an internal ribosome entry site and thus are transcribed into the same mRNA in an independent translation process. Since both proteins arise from a common mRNA, the EGFP expression level correlates with the expression level of the therapeutic protein in each clone. By expressing recombinant porcine β-defensin 1 in Marc 145 cells, we demonstrate the robustness and performance of this technique. The method can be served as an alternative to identify high-producer clones with various cell sorting methods. 相似文献
1000.
女性怀孕前后饮酒会对胎儿的发育及神经系统造成不利影响,称为“胎儿酒精综合征”(fetal alcohol spectrum disorders,FASD)。小鼠通常作为研究该病的动物模型。该实验采用体外培养技术及体内冲胚法研究雌鼠怀孕前后酒精摄入对各期植入前胚胎全基因组DNAT基化模式建立的影响。小鼠植入前胚胎体外培养实验发现,体外实验组I(怀孕前酒精处理组1,除8-cell外,其他各期胚胎的DNA甲基化水平明显低于体外对照组;体外实验组II(正常胚胎在含乙醇的培养基中培养),各期植入前胚胎DNA甲基化水平均明显低于体外对照组。体内实验发现,体内实验组I(怀孕前酒精处理组)与体内的实验组II(怀孕后酒精处理组),各期植入前胚胎DNA甲基化水平明显低于体内对照组。体内、外实验结果表明:受精前后酒精对各期植入前胚胎DNA甲基化模式的正确建立造成紊乱,该结果可为进一步揭示FSAD发病机制提供一定的实验基础。 相似文献