84 research outputs found

    Differential impact of two doses of antithymocyte globulin conditioning on lymphocyte recovery upon haploidentical hematopoietic stem cell transplantation

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    Background: In vivo depletion of host T cells with antithymocyte globulin (ATG) is a common strategy for preventing graft-versus-host disease in allogeneic hematopoietic stem cell transplantation (HSCT). The total dose of ATG in conditioning regimens appears to be an important factor that influences the outcome in recipients of transplants. However, the optimal ATG dosage has not been established to date. It remains unclear whether, in the setting of haploidentical HSCT (haploHSCT), different doses of ATG might exert differential influences on the recovery of lymphocyte subpopulations. Methods: This retrospective study analyzed lymphocyte recovery and its correlation to viral infection in two groups of patients that received different doses of ATG before haploHSCT. We performed flowcytometry to determine immunophenotypes of CD19(+) B cells and CD3(+), CD4(+), CD8(+), CD4(+) CD45RA(+), CD4(+) CD45RO(+), CD4(+) CD28(+), CD8(+) CD28(+), and CD4(-)CD8(-)T cells. Results: We found that, compared to 6 mg/kg, 10 mg/kg ATG significantly hampered the recoveries of CD4+, CD4(+) CD45RA(+), and CD4(+) CD45RO(+) T cells in the first 2 months following haploHSCT. Similarly, compared to 6 mg/kg, the 10 mg/kg dose of ATG negatively influenced the recoveries of CD4(-)CD8(-) and CD8(+) CD28(+) T cells; recovery was delayed for 6 and 12 months after transplantation, respectively. Moreover, we showed that an increase in Epstein-Barr virus (EBV) infections, associated with the higher dose of ATG, was correlated with the delayed recovery of CD4(-)CD8(-)double negative T cells. Conclusions: The present study revealed a differential impact of different ATG conditioning doses on the recoveries of T cell subpopulations post-haploHSCT. This study was the first to connect the recovery of CD4-CD8-T cells to the risk of EBV infection after HSCT. These findings will facilitate optimization of the ATG conditioning dosage and improve the outcome of patients with leukemia that receive haploHSCT.Key Program of the National Natural Science Foundation of China [81230013]; National Natural Science Foundation of China [81370666]SCI(E)[email protected]

    Electro- and photon-induced cooling in BNT-BT-SBET relaxors with in situ optical temperature sensing

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    A novel lead-free luminescent ferroelectric (FE) ceramic, Bi0.5Na0.5TiO3-0.06BaTiO3-0.055Sr0.7Bi0.18Er0.02□0.1TiO3, is developed with an adiabatic temperature change (ΔT) of 0.7 K under an electric-field (E) of 60 kV/cm at room temperature (RT), an anti-stokes fluorescence (FL) cooling and a maximum optical T sensitivity of 0.0055 K-1 at 522 K. Interestingly, the electrocaloric (EC) response reaches a saturation at permittivity-shoulder T of 100 oC, meanwhile the maximized emission intensity of 2H11/2→4I15/2 occurs. T- and E-tunable enhancement of 2H11/2→4I15/2 emission intensity is due to the population inversion from the 4S3/2 to 2H11/2 states caused by an incoherent regime consisting of FE phase and polar nanoregions (PNRs) in a relaxor (R) matrix

    Dendritic Cells Are Critical for the Activation and Expansion of Vδ2+ T Cells After Allogeneic Hematopoietic Transplantation

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    γδ T cells perform antitumor and antiviral effector functions and are involved in both innate and adaptive immunity. Vδ2+ T cells represent the predominant γδ T subset in the peripheral blood of healthy subjects. Vδ2+ T cells can be selectively activated and expanded by phosphoantigens (pAgs). Dendritic cells (DCs), as potent antigen-presenting cells, are capable of mediating pAgs–triggered Vδ2+ T cells expansion. However, the association between DCs and Vδ2+ T cell recovery in the context of hematopoietic stem cell transplantation (HSCT) remains unclear. We previously demonstrated that the recovery of Vδ2+ T cells was hampered and inversely correlated with Epstein-Barr virus (EBV) reactivation in patients undergoing haploidentical HSCT (haploHSCT). Whether Vδ2+ T cells from haploHSCT recipients can be expanded by stimulation with aminobisphosphonates or pAg–presenting DCs is of particular interest. Herein, we showed that Vδ2+ T cells recovered after haploHSCT failed to expand after ex-vivo stimulation with pamidronate. In addition, we found that the recovery of DC subsets was significantly decreased, and the concentration of myeloid DCs (mDCs) correlated significantly with Vδ2+ T cell recovery in the setting of allogeneic HSCT. Furthermore, coculture of peripheral lymphocytes from recipients with monocyte-derived and pamidronate-pretreated autologous or allogeneic DCs induced the successful expansion of Vδ2+ T cells. Of note, allogeneic DCs from third-party donors stimulated a significantly higher efficiency of Vδ2+ T cell expansion than autologous DCs. More importantly, the memory features were well-retained and the cytotoxic cytokines-production capacity was significantly enhanced in the expanded Vδ2+ T cells. Taken together, these results suggest that the frequency and function of DCs are critical for the recovery of Vδ2+ T cells after allogeneic HSCT. The fact that vigorous expansions of Vδ2+ T cells were induced by phosphoantigen-pretreated DCs, especially by allogeneic third-party DCs, provides additional options for the development of individualized immunotherapy strategies that utilize the anti-viral and anti-leukemic effects of γδ T cells in the context of hematopoietic transplantation

    Tunable replica symmetry breaking in random laser

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    Replica symmetry breaking (RSB) has been widely recognized as a statistical analysis approach to understand the disorder and nonlinear interactions in complex systems ranging from atoms to the cosmic scale. However, it is challenging to analyze the nonlinear optical characteristics of random laser (RL) in disordered gain medium via RSB due to the lack of a general RSB-based statistical analysis framework. In this work, we report the tunable RSB in polymer fiber RL, where the effects of temperature and different structures on RSB are investigated experimentally and theoretically. It experimentally proves that RSB in RL is not robust, and disorder and temperature are responsible for tunable RSB in RL, which contributes to the improvement of the statistical analysis framework for investigating the optical principles of RL using RSB. And the finding of the tunable RSB allows to investigate the dynamical differences for various RL systems, which broadens the directions for the use of spin-glass theory to explore the physical mechanism of RL

    Recurrence in oral and pharyngeal cancer is associated with quantitative MGMT promoter methylation

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    <p>Abstract</p> <p>Background</p> <p>Biomarkers that predict clinical response, tumor recurrence or patient survival are severely lacking for most cancers, particularly for oral and pharyngeal cancer. This study examines whether gene-promoter methylation of tumor DNA correlates with survival and recurrence rates in a population of patients with oral or pharyngeal cancer.</p> <p>Methods</p> <p>The promoter methylation status of the DNA repair gene <it>MGMT </it>and the tumor suppressor genes <it>CDKN2A and RASSF1 </it>were evaluated by methylation-specific PCR in 88 primary oral and pharyngeal tumors and correlated with survival and tumor recurrence. Quantitative <it>MGMT </it>methylation was also assessed.</p> <p>Results</p> <p>29.6% of the tumors presented with <it>MGMT </it>methylation, 11.5% with <it>CDKN2A </it>methylation and 12.1% with <it>RASSF1 </it>methylation. <it>MGMT </it>promoter methylation was significantly associated with poorer overall and disease-free survival. No differences in methylation status of <it>MGMT </it>and <it>RASSF1 </it>with HPV infection, smoking or drinking habits were observed. A significant inverse trend with the amount of <it>MGMT </it>methylation and overall and disease-free survival was observed (p<sub>trend </sub>= 0.002 and 0.001 respectively).</p> <p>Conclusion</p> <p>These results implicate <it>MGMT </it>promoter methylation as a possible biomarker for oral and pharyngeal cancer prognosis. The critical role of MGMT in DNA repair suggests that defective DNA repair may be correlative in the observed association between <it>MGMT </it>promoter methylation and tumor recurrence. Follow-up studies should include further quantitative MSP-PCR measurement, global methylation profiling and detailed analysis of downstream DNA repair genes regulated by promoter methylation.</p

    Sequence Requirements for miR-424-5p Regulating and Function in Cancers

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    MiRNAs (microRNAs) are the most abundant family of small noncoding RNAs in mammalian cells. Increasing evidence shows that miRNAs are crucial regulators of individual development and cell homeostasis by controlling various biological processes. Therefore, miRNA dysfunction can lead to human diseases, especially in cancers with high morbidity and mortality worldwide. MiRNAs play different roles in these processes. In recent years, studies have found that miR-424-5p is closely related to the occurrence, development, prognosis and treatment of tumors. This review discusses how miR-424-5p plays a role in different kinds of cancers from different stages of tumors, including its roles in (i) promoting or inhibiting tumorigenesis, (ii) regulating tumor development in the tumor microenvironment and (iii) participating in cancer chemotherapy. This review provides a deep discussion of the latest findings on miR-424-5p and its importance in cancer, as well as a mechanistic analysis of the role of miR-424-5p in various tissues through target gene verification and pathway analysis

    Heterologous expression, purification and biochemical characterization of a glutamate racemase (MurI) from Streptococcus mutans UA159

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    Background Glutamate racemase (MurI) is a cofactor-independent enzyme that is essential to the bacterial peptidoglycan biosynthesis pathway and has therefore been considered an attractive target for the development of antimicrobial drugs. While in our previous study the essentiality of the murI gene was shown in Streptococcus mutans, the primary aetiologic agent of human dental caries, studies on S. mutans MurI have not yet provided definitive results. This study aimed to produce and characterize the biochemical properties of the MurI from the S. mutans UA159 genome. Methods Structure characterization prediction and multiple sequence alignment were performed by bioinformatic analysis. Recombinant His6-tagged S. mutans MurI was overexpressed in the expression vector pColdII and further purified using a Ni2+ affinity chromatography method. Protein solubility, purity and aggregation state were analyzed by SDS–PAGE, Western blotting, native PAGE and SEC-HPLC. Kinetic parameters were assessed by a circular dichroism (CD) assay. Kinetic constants were calculated based on the curve fit for the Michaelis–Menten equation. The effects of temperature and pH on enzymatic activity were determined by a series of coupled enzyme reaction mixtures. Results The glutamate racemase gene from S. mutans UA159 was amplified by PCR, cloned and expressed in Escherichia coli BL21 (DE3). The 264-amino-acid protein, as a mixture of dimeric and monomeric enzymes, was purified to electrophoretic homogeneity. In the CD assay, S. mutans MurI displayed unique kinetic parameters (Km, d-Glu→l-Glu = 0.3631 ± 0.3205 mM, Vmax, d-Glu→l-Glu = 0.1963 ± 0.0361 mM min−1, kcat, d-Glu→l-Glu = 0.0306 ± 0.0065 s−1, kcat/Km, d-Glu→l-Glu = 0.0844 ± 0.0128 s−1 mM−1, with d-glutamate as substrate; Km, l-Glu→d-Glu = 0.8077 ± 0.5081 mM, Vmax, l-Glu→d-Glu = 0.2421 ± 0.0418 mM min−1, kcat, l-Glu→d-Glu = 0.0378 ± 0.0056 s−1, kcat/Km, l-Glu→d-Glu = 0.0468 ± 0.0176 s−1 mM−1, with l-glutamate as substrate). S. mutans MurI possessed an assay temperature optimum of 37.5 °C and its optimum pH was 8.0. Conclusion The findings of this study provide insight into the structure and biochemical traits of the glutamate racemase in S. mutans and supply a conceivable guideline for employing glutamate racemase in anti-caries drug design
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