48 research outputs found

    Transcriptional control of Flt3 ligand targeted by fluorouracil-induced Egr-1 promoter in hematopoietic damage

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    <p>Abstract</p> <p>Background</p> <p>Ionizing radiation (IR) activate the early growth response-1 (Egr-1) promoter by production of radical oxygen intermediates (ROIs). Egr-EF, an expression vector pCIneo containing Egr-1 promoter cloned upstream of the cDNA for Flt3 ligand, was used to treat hematopoietic damage. 5-fluorouracil, a commonly used chemotherapeutic agent, cause tumor cell death by producing DNA damage and generating ROIs. We therefore hypothesized that clinically employed chemotherapeutic agents that increase ROIs could also be employed to activate Egr-EF in a chemoinducible gene therapy strategy. The goal of this study was to explore the effect of Flt3 Ligand gene transcription regulated by fluorouracil-induced Egr-1 promoter on hematopoietic recovery.</p> <p>Methods</p> <p>Human Flt3 Ligand (FL) cDNA and enhanced green fluorescent protein (EGFP) cDNA were linked together with IRES and inserted into the expression vector pCI-neo under control of the Egr-1 promoter (Egr-EF). The vector was transfected into the HFCL human bone marrow stromal cell line, and these cells were exposed to 5-FU, a chemotherapeutic drug. Expression of FL by HFCL/EF cells after 5-FU treatment was determined with ELISA, western blot and RT-PCR assays. In addition, the effect of FL from HFCL/EF cell culture supernatants on growth of CD34<sup>+ </sup>cells from cord blood was also studied. HFCL/EF cells were injected into CB-17 combined immunodeficient (SCID) mice with B16 melanoma. 5-FU was given three days after injection of the HFCL/EF cells. In the recipient mice, white blood cell levels in peripheral blood and expression of EGFP and FL in human stromal cells were measured. Tumor volumes in tumor-bearing mice were also measured.</p> <p>Results</p> <p>5-FU treatment increased EGFP levels and secreted FL levels in HFCL/EF cells. Supernatants from HFCL/EF cell cultures treated with 5-FU increased CD34<sup>+ </sup>cell growth significantly. HFCL/EF exhibited an increase in the number of white blood cells after chemotherapy.</p> <p>Conclusion</p> <p>The data presented here support the use of transcriptional control mediated by chemoinducible gene therapy to reduce hematopoietic injury associated with 5-FU.</p

    Few-Layer Graphene Integrated Tilted Fiber Grating For All-Optical Switching

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    Recently, the integration of two-dimensional materials with optical fibers has opened up a great opportunity to develop all-fiber signal-processing devices. Graphene is an ideal material for all-optical signal processing via thermal-optic effect because of its high electrical and thermal conductivity, as well as broadband light-matter interactions with fast responses. Herein, we report the achievement of all-optical switching with fast response by integrating few-layer graphene onto a tilted fiber Bragg grating (TFBG) inscribed in a reduced-diameter fiber. Relying on graphene's decent photothermal effect, the transmission spectrum of the TFBG could be all-optically modulated by tuning the incident pump power. The all-optical switch can consequently operate at a series of wavelengths owing to the TFBG's comb-like resonances. The reduced diameter of the graphene-integrated TFBG and the pump at its resonant wavelength promise the all-optical switch to have a fast-dynamic response of around 1 μs and an extinction ratio exceeding 13 dB. This compact device with graphene integration has the potentials to be integrated into all-fiber system to extend the functions of all-optical signal processing

    Fano-like resonance in an all-in-fiber structure

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    We achieve Fano-like resonances in an all-in-fiber structure embedded with an in-line Mach-Zehnder interferometer (MZI). A fiber Bragg grating is inserted into MZI's one arm to form a resonance, which functions as the discrete state of the Fano-like resonance to couple with the continuum propagating mode of MZI in the fiber core. A theoretical model predicts the controllable resonance lineshape by changing the phase difference between the MZI's two interference pathways. Fano-like resonances with an extinction ratio over 20 dB are experimentally observed, which are reliably tuned into Lorentzian and electromagnetically induced transparency-like resonances by versatile methods. The realization of Fano-like resonances with broad tunability in this all-in-fiber structure holds potentials in fiber-based applications of sensing, signal processing and nonlinear optics

    Broadband and continuous wave pumped second-harmonic generation from microfiber coated with layered GaSe crystal

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    The conversion-efficiency for second-harmonic (SH) in optical fibers is significantly limited by extremely weak second-order nonlinearity of fused silica, and pulse pump lasers with high peak power are widely employed. Here, we propose a simple strategy to efficiently realize the broadband and continuous wave (CW) pumped SH, by transferring a crystalline GaSe coating onto a microfiber with phase-matching diameter. In the experiment, high efficiency up to 0.08 %W-1mm-1 is reached for a C-band pump laser. The high enough efficiency not only guarantees SH at a single frequency pumped by a CW laser, but also multi-frequencies mixing supported by three CW light sources. Moreover, broadband SH spectrum is also achieved under the pump of a superluminescent light-emitting diode source with a 79.3 nm bandwidth. The proposed scheme provides a beneficial method to the enhancement of various nonlinear parameter processes, development of quasi-monochromatic or broadband CW light sources at new wavelength regions

    Dysbiosis of vaginal and cervical microbiome is associated with uterine fibroids

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    Dysbiosis of the female reproductive tract is closely associated with gynecologic diseases. Here, we aim to explore the association between dysbiosis in the genital tract and uterine fibroids (UFs) to further provide new insights into UF etiology. We present an observational study to profile vaginal and cervical microbiome from 29 women with UFs and 38 healthy women, and 125 samples were obtained and sequenced. By comparing the microbial profiles between different parts of the reproductive tract, there is no significant difference in microbial diversity between healthy subjects and UF patients. However, alpha diversity of UF patients was negatively correlated with the number of fibroids. Increased Firmicutes were observed in both the cervical and vaginal microbiome of UF patients at the phylum level. In differential analysis of relative abundance, some genera were shown to be significantly enriched (e.g., Erysipelatoclostridium, Mucispirillum, and Finegoldia) and depleted (e.g., Erysipelotrichaceae UCG-003 and Sporolactobacillus) in UF patients. Furthermore, the microbial co-occurrence networks of UF patients showed lower connectivity and complexity, suggesting reduced interactions and stability of the cervical and vaginal microbiota in UF patients. In summary, our findings revealed the perturbation of microbiome in the presence of UFs and a distinct pattern of characteristic vaginal and cervical microbiome involved in UFs, offering new options to further improve prevention and management strategies

    Trichloroethylene and Its Oxidative Metabolites Enhance the Activated State and Th1 Cytokine Gene Expression in Jurkat Cells

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    Trichloroethylene (TCE) is an occupational and ubiquitous environmental contaminant, and TCE exposure will increase the risk of autoimmune diseases and allergic diseases. T cells play an important role in the pathogenesis of TCE-related immune disorders, but the effect of TCE and its oxidative metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA), on the activation of human T cells is still unknown. In this study, Jurkat cells were pre-treated with TCE, TCA and DCA overnight and then stimulated with phorbol 12-myristate 13-acetate and ionomycin for another 4, 8 and 24 hours. IL-2 secretion was detected by ELISA; the expressions of CD25 and CD69 were tested by flow cytometry; and IFN-γ and IL-2 mRNA expression levels were investigated by real-time PCR. The results showed that TCE and its oxidative metabolites, TCA and DCA, significantly enhanced IL-2 releasing and the expression of T cell activation markers, CD25 and CD69. Consistent with this result, these compounds markedly up-regulated the expression levels of IFN-γ and IL-2 mRNA. Collectively, these findings suggest that TCE and its metabolites, TCA and DCA, might enhance the activation of T cells and disrupt various activities of peripheral T cells

    Fenton-like catalytic oxidation of o-cresol wastewater by H2O2 over Fe2O3/AC catalysts

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    A series of high specific surface Fe _2 O _3 /AC catalysts for the Fenton-like catalytic oxidation of o-cresol wastewater was designed. The catalytic performance due to the characteristics of high specific surface area, large pore volume, high chemical stability and dispersive activity center. Under the suitable reaction conditions, the Fe _2 O _3 /AC with 3 wt.% Fe _2 O _3 loading catalyst can run efficiently and continuously for 500 h without being deactivated, meanwhile the removal efficiency of COD can still be maintained above 59%, even the activity of the catalyst can remain above 79%. As a result, this kind of high specific surface Fe _2 O _3 /AC catalysts used in the heterogeneous Fenton-like catalytic oxidation of o-cresol wastewater has a great potential for industrial application

    Study on the Virtual Care System for the Elderly

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    The virtual care system for the elderly is designed to make them healthier and safer under the increasingly serious aging situation. By using the image processing, speech recognition and relative sensors based on the intelligent terminals, the system accomplishes six functions: sports statistics, heart rate measurement, drug manager, intelligent navigation home and reminder, SOS voice for help and kitchen reminder. Experiments show that it can provide health analysis and safe tutelage for the elderly comprehensively and accurately

    Study on the Virtual Care System for the Elderly

    No full text
    The virtual care system for the elderly is designed to make them healthier and safer under the increasingly serious aging situation. By using the image processing, speech recognition and relative sensors based on the intelligent terminals, the system accomplishes six functions: sports statistics, heart rate measurement, drug manager, intelligent navigation home and reminder, SOS voice for help and kitchen reminder. Experiments show that it can provide health analysis and safe tutelage for the elderly comprehensively and accurately

    Study on the Virtual Care System for the Elderly

    No full text
    The virtual care system for the elderly is designed to make them healthier and safer under the increasingly serious aging situation. By using the image processing, speech recognition and relative sensors based on the intelligent terminals, the system accomplishes six functions: sports statistics, heart rate measurement, drug manager, intelligent navigation home and reminder, SOS voice for help and kitchen reminder. Experiments show that it can provide health analysis and safe tutelage for the elderly comprehensively and accurately
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