排序方式: 共有122条查询结果,搜索用时 15 毫秒
11.
Bosnakovski D Xu Z Gang EJ Galindo CL Liu M Simsek T Garner HR Agha-Mohammadi S Tassin A Coppée F Belayew A Perlingeiro RR Kyba M 《The EMBO journal》2008,27(20):2766-2779
Facioscapulohumeral muscular dystrophy (FSHD) is caused by an unusual deletion with neomorphic activity. This deletion derepresses genes in cis; however which candidate gene causes the FSHD phenotype, and through what mechanism, is unknown. We describe a novel genetic tool, inducible cassette exchange, enabling rapid generation of isogenetically modified cells with conditional and variable transgene expression. We compare the effects of expressing variable levels of each FSHD candidate gene on myoblasts. This screen identified only one gene with overt toxicity: DUX4 (double homeobox, chromosome 4), a protein with two homeodomains, each similar in sequence to Pax3 and Pax7. DUX4 expression recapitulates key features of the FSHD molecular phenotype, including repression of MyoD and its target genes, diminished myogenic differentiation, repression of glutathione redox pathway components, and sensitivity to oxidative stress. We further demonstrate competition between DUX4 and Pax3/Pax7: when either Pax3 or Pax7 is expressed at high levels, DUX4 is no longer toxic. We propose a hypothesis for FSHD in which DUX4 expression interferes with Pax7 in satellite cells, and inappropriately regulates Pax targets, including myogenic regulatory factors, during regeneration. 相似文献
12.
Nasser Hashemi Goradel Siamak Heidarzadeh Samira Jahangiri Bagher Farhood Keywan Mortezaee Neda Khanlarkhani Babak Negahdari 《Journal of cellular physiology》2019,234(3):2337-2344
Colorectal cancer (CRC) is the third most prevalent cancer in the world. There are many risk factors involved in CRC. According to recent findings, the tumor microenvironment and feces samples of patients with CRC are enriched by Fusobacterium nucleatum. Thus, F. nucleatum is proposed as one of the risk factors in the initiation and progression of CRC. The most important mechanisms of Fusobacterium nucleatum involved in CRC carcinogenesis are immune modulation (such as increasing myeloid-derived suppressor cells and inhibitory receptors of natural killer cells), virulence factors (such as FadA and Fap2), microRNAs (such as miR-21), and bacteria metabolism. The aim of this review was to evaluate the mechanisms underlying the action of F. nucleatum in CRC. 相似文献
13.
Maryam Gazor Seyed Siamak Ashraf Talesh Alireza kavianpour Maryam Khatami Amin Javidanbardan Seyed Nezamedin Hosseini 《Biotechnology and Bioprocess Engineering》2018,23(1):49-54
In biotechnological processes, often cell disruption has been an inevitable step as current host cells express most of the desired products intracellularly. Thus, an appropriate cell disruption technique must be selected considering different factors including the target product, process scale, and cell wall structure. In the current study, as a novel method, the efficacy of cell disruption via laser was tested qualitatively and quantitatively in batch and continuous systems, respectively. Laser-induced cell lysis can be a clean, rapid and convenient alternative to the other conventional disruption techniques. Our investigations in the continuous system with a flow rate of 800 μL/sec proved efficient (~ 90%) Pichia pastoris cell disruption at the wavenumber 1,064 nm with the energy input of 284 mW after four complete rounds of circulation. The main mechanism of cell disruption is assumed to be thermolysis via instant heat increase in the laser-treated spot. The results of the current study showed that continuous laser system could be applied in laboratory and industry scale for cell disruption. 相似文献
14.
We report a selective, differential stimulus-dependent enrichment of the actin-associated protein α-actinin and of isoforms of the signaling enzyme protein kinase C (PKC) in the neutrophil cytoskeleton. Chemotactic peptide, activators of PKC, and cell adhesion all induce a significant increase in the amount of cytoskeletal α-actinin and actin. Increased association of PKCβI and βII with the cytoskeletal fraction of stimulated cells was also observed, with phorbol ester being more effective than chemotactic peptide. A fraction of phosphatase 2A was constitutively associated with the cytoskeleton independent of cell activation. None of the stimuli promoted association of vinculin or myosin II with the cytoskeleton. Phosphatase inhibitors okadaic acid and calyculin A prevented increases in cytoskeletal actin, α-actinin, and PKCβII induced by phorbol ester, suggesting the requirement for phosphatase activity in these events. Increases in cytoskeletal α-actinin and PKCβII showed differing sensitivity to agents that prevent actin polymerization (cytochalasin D, latrunculin A). Latrunculin A (1 μM) completely blocked PMA-induced increases in cytoskeletal α-actinin but reduced cytoskeletal recruitment of PKCβII only by 16%. Higher concentrations of latrunculin A (4 μM), which almost abolished the cytoskeletal actin pool, reduced cytoskeletal PKCβII by 43%. In conclusion, a selective enrichment of cytoskeletal and signaling proteins in the cytoskeleton of human neutrophils is induced by specific stimuli. 相似文献
15.
Siamak N. Doost Boyang Su Yosry S. Morsi 《Computer methods in biomechanics and biomedical engineering》2017,20(5):492-507
The image-based computational fluid dynamics (IB-CFD) technique, as the combination of medical images and the CFD method, is utilized in this research to analyze the left ventricle (LV) hemodynamics. The research primarily aims to propose a semi-automated technique utilizing some freely available and commercial software packages in order to simulate the LV hemodynamics using the IB-CFD technique. In this research, moreover, two different physiological time-resolved 2D models of a patient-specific LV with two different types of aortic and mitral valves, including the orifice-type valves and integrated with rigid leaflets, are adopted to visualize the process of developing intraventricular vortex formation and propagation. The blood flow pattern over the whole cardiac cycle of two models is also compared to investigate the effect of utilizing different valve types in the process of the intraventricular vortex formation. Numerical findings indicate that the model with integrated valves can predict more complex intraventricular flow that can match better the physiological flow pattern in comparison to the orifice-type model. 相似文献
16.
Jianguo Chen Zhaoliang Su Yingzhao Liu Siamak Sandoghchian Dong Zheng Shengjun Wang Huaxi Xu 《Current microbiology》2011,62(1):331-333
Herbaspirillum species, colonized the plant rhizosphere, also called rhizobacteria, are plant growth-promoting bacteria. Recently we isolated
Herbaspirillum from blood cultures of acute lymphoblastic leukemia (ALL) and identified by PCR and gene sequencing. Herbaspirillum may be a potential pathogenic bacteria. Although the exact role that these species play in ALL patients is unknown, their
differentiation from other species has serious implications for clinical care and patient well-being. 相似文献
17.
Kuzmenko ES Djafarzadeh S Cakar ZP Fiedler K 《The international journal of biochemistry & cell biology》2004,36(3):519-534
Endothelial cell (EC) cultures of different, selected vascular beds and/or organs were screened for receptor-mediated transport of proteins with a semipermeable filter assay. In SVEC4-10 cells, a mouse lymphoid endothelial cell line, orosomucoid, albumin, insulin and LDL were transcytosed from the apical (luminal) to basal (abluminal) side by a receptor-mediated pathway. Specific LDL transcytosis involved transport of intact LDL. A pathway of degradation of LDL and basal release involved vesicles in transport to lysosomes and amino acid merocrine secretion. This newly described transcellular passage of LDL via lysosomes, as well as the standard pathway, were reduced to 70% by PEG(50)-cholesterol (PEG-Chol). Combined results of temperature-dependence analysis and PEG(50)-cholesterol sensitivity show that two pathways contribute to general LDL transcellular passage. We suggest a mechanism of domain hopping by protein membrane diffusion of receptors as the pathway for intact LDL delivery. Based on theoretical considerations we propose that active transport by protein membrane diffusion can be facilitated by an organizational structure of lipid microdomains and polar cellular organization. 相似文献
18.
Reza Ebrahimzadeh-Vesal Roza Azam Arvin Ghazarian Mogge Hajesmaeili Najmeh Ranji Mohammad Reza Ezzati Mehrdad Sadri Mohammad Ali Mohammadi Siamak Khavandi 《Reports of Biochemistry & Molecular Biology》2014,2(2):98-102
Recurrent pregnancy loss is usually defined as the loss of two or more consecutive pregnancies before 20 weeks of gestation, which occurs in approximately 5% of reproductive-aged women. It has been suggested that women with thrombophilia have an increased risk of pregnancy loss and other adverse pregnancy outcomes. Thrombophilia is an important predisposition to blood clot formation and is considered as a significant risk factor for recurrent pregnancy loss. The inherited predisposition to thrombophilia is most often associated with factor V Leiden mutation, prothrombin G20210A mutation, and methylenetetrahydrofolate reductase C677T and A1298C gene variants. The net effect is an increased cleavage of prothrombin to thrombin and excessive blood coagulation. Key Words: Recurrent pregnancy loss, Hereditary thrombophilia, Factor V Leiden mutation 相似文献
19.
Siamak Shirani Bidabadi Reza Abolghasemi Si-Jun Zheng 《International journal of phytoremediation》2018,20(7):730-738
To test the possibility that using appropriate rootstocks could improve the tolerance of watermelon to cadmium (Cd) toxicity, a greenhouse experiment was conducted to determine growth and antioxidant activities of watermelons, either nongrafted or grafted onto summer squash and winter squash. We provided nutrient solutions having four levels (0, 50, 100, and 200 μM) of cadmium to treat the plants. Shoot and root biomass reduction were significantly lower in summer squash rootstock-grafted watermelon than winter squash rootstock-grafted and nongrafted watermelons. Cadmium induced a smaller decrease in leaf area index in grafted watermelons compared with nongrafted plants. The Cd- related reductions in chlorophyll content and efficiency of photosynthesis were more severe in nongrafted watermelons compared with dose grafted onto summer squash. Cd accumulation in shoot at the highest dose (200 µM) of CdCl2 was significantly lower (19.76 mg/kg) in summer squash rootstock-grafted watermelon compared with winter squash rootstock-grafted (37.58 mg/kg) and nongrafted watermelon (72.12 mg/kg). H2O2, MDA production and electrolyte leakage of summer squash rootstock-grafted watermelon showed less increase, which was associated with a significant increase in the activities of antioxidant. The improved crop performance of grafted watermelons was attributed to their strong capacity to inhibit Cd accumulation in the aerial parts. 相似文献
20.
Rouya Ebrahimi Siamak Rahmanpour Youbert Ghosta Saeed Rezaee Masoud Soltani Najafabadi 《Archives Of Phytopathology And Plant Protection》2013,46(7):825-840
Sunflower cultivation is affected seriously by Sclerotinia sclerotiorum (Lib.) de Bary in Iran, particularly north-western areas. Because of economic and environmental harms by chemical control, it is necessary to develop cultivars with adequate genetic resistance for reduction of yield losses. The purpose of this study was to find an effective method of inoculation with S. sclerotiorum under field evaluations. Three stem-inoculation techniques including: 1 – mycelium plug, 2 – oxalic acid solution (OAS) and 3 – infested wheat seeds with Sclerotinia mycelium were employed under field conditions. Four genotypes including Ghalami (local variety in market), Confeta, Allstar and Master were used in this study. The lesion length, lesion width and lesion as up and down leading on the stem from inoculation site were measured after 3, 7, 10 and 14 days of inoculation. The analysis of variance showed significant difference between all employed techniques and incubation days after inoculation. Mycelial plug (MP) inoculation technique produced significantly more developed lesions on the treated stems. In spite of this effect, Master variety demonstrated reasonable resistance reaction against the disease. The progress of disease in wounded treatments was also faster than the non-wounded ones. And, the shortest time to obtain significant differences between varieties was 10?days after inoculation. By comparison of results of lesion length at flowering and seed-filling stages, the more obvious effectiveness of the disease was observed at the second stage. Finally, there were negative correlations between mean temperature and mean lesion length in all three inoculation methods. 相似文献