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排序方式: 共有369条查询结果,搜索用时 328 毫秒
331.
Baghbeheshti Sakineh Hadadian Shahin Eidi Akram Pishkar Leila Rahimi Hamzeh 《International journal of peptide research and therapeutics》2021,27(1):457-462
International Journal of Peptide Research and Therapeutics - Antimicrobial peptides (AMPs) mainly introduced as a new generation of antibiotics, could be used for broad medical and biotechnological... 相似文献
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Vahid Molla Kazemiha Amir Amanzadeh Arash Memarnejadian Shahram Azari Mohammad Ali Shokrgozar Reza Mahdian Shahin Bonakdar 《Cytotechnology》2014,66(5):861-873
Mycoplasma contamination in cell culture is considered as serious problem in the manufacturing of biological products. Our goal in this research is to find the best standard and rapid method with high sensitivity, specificity, accuracy and predictive values of positive and negative results for detection of mycoplasma contamination in cell cultures of the National Cell Bank of Iran. In this study, 40 cell lines suspected to mycoplasma contamination were evaluated by three different methods: microbial culture, enzymatic mycoalert® and molecular. Enzymatic evaluation was performed using the mycoalert® kit while in the molecular technique, a universal primer pair was designed based on the common and fixed 16SrRNA ribosomal sequences used. Mycoplasma contaminations in cell cultures with molecular, enzymatic and microbial culture methods were determined as 57.5, 52.5 and 40 %, respectively. These results confirmed the higher rate of sensitivity, specificity and accuracy for the molecular method in comparison with enzymatic and microbial methods. Polymerase chain reaction (PCR) assay based on fixed and common sequences in the 16SrRNA, is a useful valuable and reliable technique with high sensitivity, specificity and accuracy for detection of mycoplasma contamination in cell cultures and other biological products. The enzymatic mycoalert® method can be considered as a substitution for conventional microbial culture and DNA staining fluorochrome methods due to its higher sensitivity, specificity and speed of detection (<20 min). 相似文献
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Genome editing a mouse locus encoding a variant histone,H3.3B,to report on its expression in live animals
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Duancheng Wen Kyung‐Min Noh Aaron D. Goldberg C. David Allis Zev Rosenwaks Shahin Rafii Laura A. Banaszynski 《Genesis (New York, N.Y. : 2000)》2014,52(12):959-966
Chromatin remodeling via incorporation of histone variants plays a key role in the regulation of embryonic development. The histone variant H3.3 has been associated with a number of early events including formation of the paternal pronucleus upon fertilization. The small number of amino acid differences between H3.3 and its canonical counterparts (H3.1 and H3.2) has limited studies of the developmental significance of H3.3 deposition into chromatin due to difficulties in distinguishing the H3 isoforms. To this end, we used zinc‐finger nuclease (ZFN) mediated gene editing to introduce a small C‐terminal hemagglutinin (HA) tag to the endogenous H3.3B locus in mouse embryonic stem cells (ESCs), along with an internal ribosome entry site (IRES) and a separately translated fluorescent reporter of expression. This system will allow detection of expression driven by the reporter in cells, animals, and embryos, and will facilitate investigation of differential roles of paternal and maternal H3.3 protein during embryogenesis that would not be possible using variant‐specific antibodies. Further, the ability to monitor endogenous H3.3 protein in various cell lineages will enhance our understanding of the dynamics of this histone variant over the course of development. genesis 52:959–966, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
335.
Maria Eugenia Herva Shahin Zibaee Graham Fraser Roger A. Barker Michel Goedert Maria Grazia Spillantini 《The Journal of biological chemistry》2014,289(17):11897-11905
Filaments made of α-synuclein form the characteristic Lewy pathology in Parkinson and other diseases. The formation of α-synuclein filaments can be reproduced in vitro by incubation of recombinant protein, but the filament growth is very slow and highly variable and so unsuitable for fast high throughput anti-aggregation drug screening. To overcome this obstacle we have investigated whether the protein misfolding cyclic amplification (PMCA) technique, used for fast amplification of prion protein aggregates, could be adapted for growing α-synuclein aggregates and thus suitable for screening of drugs to affect α-synuclein aggregation for the treatment of the yet incurable α-synucleinopathies. Circular dichroism, electron microscopy, and native and SDS-polyacrylamide gels were used to demonstrate α-synuclein aggregate formation by PMCA, and the strain imprint of the α-synuclein fibrils was studied by proteinase K digestion. We also demonstrated that α-synuclein fibrils are able to seed new α-synuclein PMCA reactions and to enter and aggregate in cells in culture. In particular, we have generated a line of “chronically infected” cells, which transmit α-synuclein aggregates even after multiple passages. To evaluate the sensitivity of the PMCA system as an α-synuclein anti-aggregating drug screening assay a panel of 10 drugs was tested. Anti-amyloid compounds proved efficient in inhibiting α-synuclein fibril formation induced by PMCA. Our results show that α-synuclein PMCA is a fast and reproducible system that could be used as a high throughput screening method for finding new α-synuclein anti-aggregating compounds. 相似文献
336.
Hamid Moazzeni Shahin Zarre Bernard E. Pfeil Yann J. K. Bertrand Dmitry A. German Ihsan A. Al‐Shehbaz Klaus Mummenhoff Bengt Oxelman 《Botanical journal of the Linnean Society. Linnean Society of London》2014,175(4):497-522
Erysimum includes 150–350 species distributed in the Northern Hemisphere, with Eurasia being the centre of greatest diversity. It is well known for its taxonomic complexity as a result of overlapping morphological characters. We present the first densely sampled phylogenetic analysis of Erysimum using internal transcribed spacer (ITS) DNA sequences from c. 85% of the species (117 for the first time), representing the full range of morphological variation and geographical distribution. We used several approaches to reconstruct phylogenetic relationships, dating of diversification and patterns of evolution of morphological characters in the genus. Ancestral‐state reconstructions of four morphological diagnostic characters were performed using maximum parsimony, maximum likelihood and Bayesian methods. Our phylogenetic framework strongly supports the monophyly of Erysimum and recovers some well‐supported clades that are geographically, rather than morphologically, correlated. Our study confirms the placement of Erysimum in lineage I and reveals two Malcolmia spp. (M. maritima and M. orsiniana) as its sister taxa. The results suggest that the biennial duration and caespitose habit (vs. annual or perennial duration and herbaceous or woody habit) and large, yellow, glabrous (vs. small, non‐yellow, pubescent) petals are ancestral in Erysimum. The ancestral‐state reconstruction results show that annual vs. perennial and woody vs. herbaceous features have been independently derived several times. The dating analyses suggest an early radiation of Erysimum during the late Pliocene or early Pleistocene. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 497–522. 相似文献
337.
In this study, we measured the serum concentration of TIMP-2 in patients with systemic sclerosis (SSc) and explored its possible correlation with cardiac and pulmonary lesions. We studied 42 patients with SSc, with duration equal to or more than 2 years. CT chest, ECG, echocardiography, and serum TIMP-2 concentration measurement using ELISA technique were performed in all patients and in 25 normal controls. The mean serum levels of TIMP-2 in patients was higher than in controls (P = .005). The mean CT score of dSSc patients with elevated TIMP-2 levels was significantly higher than dSSc patients with normal levels (P = .013). Four patients out of five with elevated TIMP-2 levels showed diastolic dysfunction (80%), compared to 2 out of 15 lSSc patients with normal levels (13.3%), with P = .014. Our research, though involving a small group of patients, points to the probable role of TIMP-2 in the development of pulmonary lesions in dSSc patients and cardiac lesions in lSSc patients with duration equal to or more than 2 years. 相似文献
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Cytokine-mediated deployment of SDF-1 induces revascularization through recruitment of CXCR4+ hemangiocytes 总被引:19,自引:0,他引:19
Jin DK Shido K Kopp HG Petit I Shmelkov SV Young LM Hooper AT Amano H Avecilla ST Heissig B Hattori K Zhang F Hicklin DJ Wu Y Zhu Z Dunn A Salari H Werb Z Hackett NR Crystal RG Lyden D Rafii S 《Nature medicine》2006,12(5):557-567
The mechanisms through which hematopoietic cytokines accelerate revascularization are unknown. Here, we show that the magnitude of cytokine-mediated release of SDF-1 from platelets and the recruitment of nonendothelial CXCR4+ VEGFR1+ hematopoietic progenitors, 'hemangiocytes,' constitute the major determinant of revascularization. Soluble Kit-ligand (sKitL), thrombopoietin (TPO, encoded by Thpo) and, to a lesser extent, erythropoietin (EPO) and granulocyte-macrophage colony-stimulating factor (GM-CSF) induced the release of SDF-1 from platelets, enhancing neovascularization through mobilization of CXCR4+ VEGFR1+ hemangiocytes. Although revascularization of ischemic hindlimbs was partially diminished in mice deficient in both GM-CSF and G-CSF (Csf2-/- Csf3-/-), profound impairment in neovascularization was detected in sKitL-deficient Mmp9-/- as well as thrombocytopenic Thpo-/- and TPO receptor-deficient (Mpl-/-) mice. SDF-1-mediated mobilization and incorporation of hemangiocytes into ischemic limbs were impaired in Thpo-/-, Mpl-/- and Mmp9-/- mice. Transplantation of CXCR4+ VEGFR1+ hemangiocytes into Mmp9-/- mice restored revascularization, whereas inhibition of CXCR4 abrogated cytokine- and VEGF-A-mediated mobilization of CXCR4+ VEGFR1+ cells and suppressed angiogenesis. In conclusion, hematopoietic cytokines, through graded deployment of SDF-1 from platelets, support mobilization and recruitment of CXCR4+ VEGFR1+ hemangiocytes, whereas VEGFR1 is essential for their angiogenic competency for augmenting revascularization. Delivery of SDF-1 may be effective in restoring angiogenesis in individuals with vasculopathies. 相似文献