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941.
Although developmental stuttering has been extensively studied with structural and task-based functional magnetic resonance imaging (fMRI), few studies have focused on resting-state brain activity in this disorder. We investigated resting-state brain activity of stuttering subjects by analyzing the amplitude of low-frequency fluctuation (ALFF), region of interest (ROI)-based functional connectivity (FC) and independent component analysis (ICA)-based FC. Forty-four adult males with developmental stuttering and 46 age-matched fluent male controls were scanned using resting-state fMRI. ALFF, ROI-based FCs and ICA-based FCs were compared between male stuttering subjects and fluent controls in a voxel-wise manner. Compared with fluent controls, stuttering subjects showed increased ALFF in left brain areas related to speech motor and auditory functions and bilateral prefrontal cortices related to cognitive control. However, stuttering subjects showed decreased ALFF in the left posterior language reception area and bilateral non-speech motor areas. ROI-based FC analysis revealed decreased FC between the posterior language area involved in the perception and decoding of sensory information and anterior brain area involved in the initiation of speech motor function, as well as increased FC within anterior or posterior speech- and language-associated areas and between the prefrontal areas and default-mode network (DMN) in stuttering subjects. ICA showed that stuttering subjects had decreased FC in the DMN and increased FC in the sensorimotor network. Our findings support the concept that stuttering subjects have deficits in multiple functional systems (motor, language, auditory and DMN) and in the connections between them. 相似文献
942.
943.
944.
Ceramidase hydrolyzes ceramide and produces sphingosine as a substrate of sphingosine kinase (SPHK), which transforms sphingosine to sphingosine-1-phosphate. It has been reported that cytokines elicit SPHK activation in rat β-cells. As a sphingosine provider, ceramidase should also be activated. In our previous work, we showed that the increase in mRNA and protein levels in cytokine-treated INS-1 rat β-cells resulted in chronic activation of neutral ceramidase. Here we found that acid ceramidase (AC) is activated by cytokines at an early stage via tyrosine phosphorylation. In addition, basal AC activity was first detected in INS-1 cells and isolated rat islets, and cytokine-induced cell growth was significantly repressed when AC was pharmacologically inhibited. 相似文献
945.
Overwhelming evidence from chronic myeloid leukaemia (CML) research indicates that patients harbour quiescent CML stem cells that are responsible for blast crisis. While the haematopoietic stem cell (HSC) origin of CML was first suggested over 30 years ago, recently CML-initiating cells beyond HSCs are also being investigated. We have previously isolated fetal liver kinase-1-positive (Flk1(+)) cells carrying the BCR/ABL fusion gene from the bone marrow of Philadelphia chromosome-positive (Ph(+)) patients with hemangioblast property. Here, we show that these cells behave abnormally comparing with the hemangioblasts in healthy donors. These Ph(+) putative CML hemangioblast up-regulated TGF-β1 and result in activating matrix metalloproteinase-9 to enhance s-KitL and s-ICAM-1 secretion. Further studies showed that phosphatidylinositol-3 kinase (PI3K)/Akt/nuclear factor-κB signalling pathway was involved in CML pathogenesis. These findings provide direct evidence for the first time that hemangioblasts beyond HSCs play a critical role in the progression of CML. 相似文献
946.
【目的】基于前期筛选到的P.aeruginosa PT121所产有机溶剂耐受性蛋白酶,本研究对该蛋白酶进行克隆表达,研究了重组蛋白的酶学性质及小肽合成上的应用。【方法】参考文献中报道的相似蛋白酶pseudolysin设计引物从菌株PT121基因组中克隆到耐有机溶剂蛋白酶PT121基因las B。构建诱导表达重组质粒p ET22b-las B,于大肠杆菌中进行表达。考察蛋白酶PT121酶学性质及小肽合成上的应用。【结果】序列分析表明las B基因编码信号肽、前肽及成熟肽3个部分,成熟肽部分含有301个氨基酸,分子量约33 k Da,属于金属蛋白酶M4家族。通过破碎条件优化,一步法制备得到较为纯净的重组蛋白酶PT121,其比活力达7700 U/mg,该酶呈现了较高的热稳定性,p H稳定性及溶剂耐受性,与野生菌P.aeruginosa PT121所产蛋白酶性质一致。在50%DMSO体系中高效催化合成了多种小肽,其中阿斯巴甜前体(Cbz-Asp-Phe-NH2)产率高达91%。【结论】蛋白酶PT121基因在大肠杆菌中克隆表达为进一步研究相关催化机理及分子改造奠定了基础。 相似文献
947.
Yuqi Zhu Xinyi Yang Jingna Xun Jun Liu Qing Wen Yixiao Lin Xiaoting Shen Jun Chen Songhua Yuan Xiaying Zhao Jing Wang Hanyu Pan Jinlong Yang Zhiming Liang Yue Liang Qinru Lin Huitong Liang Min Li Jianping Liu Yinzhong Shen Xiaoyan Zhang Pengfei Wang Daru Lu Chunhua Yin Jianqing Xu Shibo Jiang Hongzhou Lu Huanzhang Zhu 《中国病毒学》2022,37(6):831-841
The prevalence of SARS-CoV-2 variants of concern (VOCs) is still escalating throughout the world. However, the level of neutralization of the inactivated viral vaccine recipients’ sera and convalescent sera against all VOCs, including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron) remains to be lack of comparative analysis. Therefore, we constructed pseudoviruses of five VOCs using a lentiviral-based system and analyzed their viral infectivity and neutralization resistance to convalescent and BBIBP-CorV vaccinee serum at different times. Our results show that, compared with the wild-type strain (WT), five VOC pseudoviruses showed higher infection, of which B.1.617.2 and B.1.1.529 variant pseudoviruses exhibited higher infection rates than wild-type or other VOC strains, respectively. Sera from 10 vaccinated individuals at the 1, 3 and 5-month post second dose or from 10 convalescent at 14 and 200 days after discharge retained neutralizing activity against all strains but exhibited decreased neutralization activity significantly against the five VOC variant pseudoviruses over time compared to WT. Notably, 100% (30/30) of the vaccinee serum samples showed more than a 2.5-fold reduction in neutralizing activity against B.1.1.529, and 90% (18/20) of the convalescent serum samples showed more than 2.5-fold reduction in neutralization against B.1.1.529. These findings demonstrate the reduced protection against the VOCs in vaccinated and convalescent individuals over time, indicating that it is necessary to have a booster shot and develop new vaccines capable of eliciting broad neutralization antibodies. 相似文献
948.
Ting Zhu Shu An Man‐Ting Choy Junhao Zhou Shanshan Wu Shihua Liu Bangdong Liu Zhicheng Yao Xun Zhu Jueheng Wu Zhenjian He 《Journal of cellular and molecular medicine》2019,23(3):1852-1864
Long noncoding RNAs (lncRNAs) are involved in the pathology of various tumours, including non‐small cell lung cancer (NSCLC). However, the underlying molecular mechanisms of their specific association with NSCLC have not been fully elucidated. Here, we report that a cytoplasmic lncRNA, DUXAP9‐206 is overexpressed in NSCLC cells and closely related to NSCLC clinical features and poor patient survival. We reveal that DUXAP9‐206 induced NSCLC cell proliferation and metastasis by directly interacting with Cbl‐b, an E3 ubiquitin ligase, and reducing the degradation of epidermal growth factor receptor (EGFR) and thereby augmenting EGFR signaling in NSCLC. Notably, correlations between DUXAP9‐206 and activated EGFR signaling were also validated in NSCLC patient specimens. Collectively, our findings reveal the novel molecular mechanisms of DUXAP9‐206 in mediating the progression of NSCLC and DUXAP9‐206 may serve as a potential target for NSCLC therapy. 相似文献
949.
Yun Ren Dan Chen Wenjie Li Dan Zhou Tao Luo Guoqiang Yuan Jing Zeng Ye Cao Zhongshan He Ting Zou Qiming Deng Shiquan Wang Aiping Zheng Jun Zhu Yueyang Liang Huainian Liu Lingxia Wang Ping Li Shuangcheng Li 《The Plant journal : for cell and molecular biology》2019,98(2):315-328
Meiosis is essential for eukaryotic sexual reproduction and plant fertility, and crossovers (COs) are essential for meiosis and the formation of new allelic combinations in gametes. In this study, we report the isolation of a meiotic gene, OsSHOC1, and the identification of its partner, OsPTD1. Osshoc1 was sterile both in male and female gametophytes, and it showed a striking reduction in the number of meiotic COs, indicating that OsSHOC1 was required for normal CO formation. Further investigations showed that OsSHOC1 physically interacted with OsPTD1 and that the latter was also required for normal CO formation and plant fertility. Additionally, the expression profiles of both genes were consistent with their functions. Our results suggest that OsSHOC1 and OsPTD1 are essential for rice fertility and CO formation, possibly by stabilizing the recombinant intermediates during meiosis. 相似文献
950.
一株寒地高效解无机磷细菌的分离鉴定及拮抗作用 总被引:2,自引:0,他引:2
【目的】从北方寒地种植的不同农作物根际土壤中分离高效解磷的细菌,为微生物制剂和磷肥的开发提供适于本地区的优良菌种。【方法】通过初筛和复筛从26株解磷菌中筛选获得一株高效解磷细菌,对其进行生理生化和分子生物学鉴定,同时采用钼蓝比色法测定解磷能力。采用平板对峙法测定拮抗植物病原菌能力。【结果】通过筛选后获得的菌株B51-7经鉴定为伯克霍尔德菌属。菌株在发酵液中可溶性磷含量最高达到832.74 mg/L,同时具有很强的广谱抑菌作用,抑菌率最高为89.71%,可以显著促进水稻生长。【结论】菌株B51-7是一株具有生物防治作用的高效解磷细菌,可应用于生物菌肥和生防制剂中。 相似文献