276 research outputs found

    Wavelength tuning in GaAsAlGaAs quantum wells by InAs submonolayer insertion

    Get PDF
    Wavelength tuning of exciton emissions has been achieved simply by inserting an InAs submonolayer at the centre of GaAs quantum wells during molecular beam epitaxy growth. Photoluminescence measurements show that the emission energy can be effectively tuned from the quantum-well-determined energy down to less than the band gap of GaAs, depending on the well width as well as the InAs layer thickness. Using the effective-mass approximation, the tuning effect can be well predicted theoretically The results reported here may provide an alternative way to tune the wavelength in optoelectronic devices

    The effective expression of xylanase gene in Candida utilis by 18S rDNA targeted homologous recombination in pGLR9K

    Get PDF
    In order to test whether 18S rDNA can influence positively xylanase gene effective expression in the yeast of Candida utilis, a targeting vector pGLR9K-XA was constructed by adding an interested gene xynA from Streptomyces olivaceoviridis into the vector pGLR9K which is constructed by ourselves. pGLR9K contains the 18S rDNA, GAP promoter and CYH resistance gene sequence, all of which is from C. utilis. Then the vector pGLR9K-XA was transformed into C. utilis. To test the vector and transformed system, PCR, Southern blot and DNS methods were used. The results showed that xylanase gene can be detected in the chromosome DNA of recombinant C. utilis and the enzyme activity of xylanase is up to 60 IU ml(-1) in the study. It is suggested that this system can be used to express exogenous genes in C. utilis as a bioreactors. This is the first report that xylanase gene was expressed in C. utilis

    Quantitative Phosphoproteomics of Proteasome Inhibition in Multiple Myeloma Cells

    Get PDF
    BACKGROUND: The proteasome inhibitor bortezomib represents an important advance in the treatment of multiple myeloma (MM). Bortezomib inhibits the activity of the 26S proteasome and induces cell death in a variety of tumor cells; however, the mechanism of cytotoxicity is not well understood. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the differential phosphoproteome upon proteasome inhibition by using stable isotope labeling by amino acids in cell culture (SILAC) in combination with phosphoprotein enrichment and LC-MS/MS analysis. In total 233 phosphoproteins were identified and 72 phosphoproteins showed a 1.5-fold or greater change upon bortezomib treatment. The phosphoproteins with expression alterations encompass all major protein classes, including a large number of nucleic acid binding proteins. Site-specific phosphopeptide quantitation revealed that Ser38 phosphorylation on stathmin increased upon bortezomib treatment, suggesting new mechanisms associated to bortezomib-induced apoptosis in MM cells. Further studies demonstrated that stathmin phosphorylation profile was modified in response to bortezomib treatment and the regulation of stathmin by phosphorylation at specific Ser/Thr residues participated in the cellular response induced by bortezomib. CONCLUSIONS/SIGNIFICANCE: Our systematic profiling of phosphorylation changes in response to bortezomib treatment not only advanced the global mechanistic understanding of the action of bortezomib on myeloma cells but also identified previously uncharacterized signaling proteins in myeloma cells

    Tumor-Infiltrating T Cells Correlate with NY-ESO-1-Specific Autoantibodies in Ovarian Cancer

    Get PDF
    BACKGROUND: Tumor-infiltrating CD8+ T cells are correlated with prolonged progression-free and overall survival in epithelial ovarian cancer (EOC). A significant fraction of EOC patients mount autoantibody responses to various tumor antigens, however the relationship between autoantibodies and tumor-infiltrating T cells has not been investigated in EOC or any other human cancer. We hypothesized that autoantibody and T cell responses may be correlated in EOC and directed toward the same antigens. METHODOLOGY AND PRINCIPAL FINDINGS: We obtained matched serum and tumor tissue from 35 patients with high-grade serous ovarian cancer. Serum samples were assessed by ELISA for autoantibodies to the common tumor antigen NY-ESO-1. Tumor tissue was examined by immunohistochemistry for expression of NY-ESO-1, various T cell markers (CD3, CD4, CD8, CD25, FoxP3, TIA-1 and Granzyme B) and other immunological markers (CD20, MHC class I and MHC class II). Lymphocytic infiltrates varied widely among tumors and included cells positive for CD3, CD8, TIA-1, CD25, FoxP3 and CD4. Twenty-six percent (9/35) of patients demonstrated serum IgG autoantibodies to NY-ESO-1, which were positively correlated with expression of NY-ESO-1 antigen by tumor cells (r = 0.57, p = 0.0004). Autoantibodies to NY-ESO-1 were associated with increased tumor-infiltrating CD8+, CD4+ and FoxP3+ cells. In an individual HLA-A2+ patient with autoantibodies to NY-ESO-1, CD8+ T cells isolated from solid tumor and ascites were reactive to NY-ESO-1 by IFN-gamma ELISPOT and MHC class I pentamer staining. CONCLUSION AND SIGNIFICANCE: We demonstrate that tumor-specific autoantibodies and tumor-infiltrating T cells are correlated in human cancer and can be directed against the same target antigen. This implies that autoantibodies may collaborate with tumor-infiltrating T cells to influence clinical outcomes in EOC. Furthermore, serological screening methods may prove useful for identifying clinically relevant T cell antigens for immunotherapy

    Engineered artificial antigen presenting cells facilitate direct and efficient expansion of tumor infiltrating lymphocytes

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Development of a standardized platform for the rapid expansion of tumor-infiltrating lymphocytes (TILs) with anti-tumor function from patients with limited TIL numbers or tumor tissues challenges their clinical application.</p> <p>Methods</p> <p>To facilitate adoptive immunotherapy, we applied genetically-engineered K562 cell-based artificial antigen presenting cells (aAPCs) for the direct and rapid expansion of TILs isolated from primary cancer specimens.</p> <p>Results</p> <p>TILs outgrown in IL-2 undergo rapid, CD28-independent expansion in response to aAPC stimulation that requires provision of exogenous IL-2 cytokine support. aAPCs induce numerical expansion of TILs that is statistically similar to an established rapid expansion method at a 100-fold lower feeder cell to TIL ratio, and greater than those achievable using anti-CD3/CD28 activation beads or extended IL-2 culture. aAPC-expanded TILs undergo numerical expansion of tumor antigen-specific cells, remain amenable to secondary aAPC-based expansion, and have low CD4/CD8 ratios and FOXP3+ CD4+ cell frequencies. TILs can also be expanded directly from fresh enzyme-digested tumor specimens when pulsed with aAPCs. These "young" TILs are tumor-reactive, positively skewed in CD8+ lymphocyte composition, CD28 and CD27 expression, and contain fewer FOXP3+ T cells compared to parallel IL-2 cultures.</p> <p>Conclusion</p> <p>Genetically-enhanced aAPCs represent a standardized, "off-the-shelf" platform for the direct ex vivo expansion of TILs of suitable number, phenotype and function for use in adoptive immunotherapy.</p

    Comparison of Post-injection Site Pain Between Technetium Sulfur Colloid and Technetium Tilmanocept in Breast Cancer Patients Undergoing Sentinel Lymph Node Biopsy

    Get PDF
    BACKGROUND: No prior studies have examined injection pain associated with Technetium-99m Tilmanocept (TcTM). METHODS: This was a randomized, double-blinded study comparing postinjection site pain between filtered Technetium Sulfur Colloid (fTcSC) and TcTM in breast cancer lymphoscintigraphy. Pain was evaluated with a visual analogue scale (VAS) (0–100 mm) and the short-form McGill Pain Questionnaire (SF-MPQ). The primary endpoint was mean difference in VAS scores at 1-min postinjection between fTcSC and TcTM. Secondary endpoints included a comparison of SF-MPQ scores between the groups at 5 min postinjection and construction of a linear mixed effects model to evaluate the changes in pain during the 5-min postinjection period. RESULTS: Fifty-two patients underwent injection (27-fTcSC, 25-TcTM). At 1-min postinjection, patients who received fTcSC experienced a mean change in pain of 16.8 mm (standard deviation (SD) 19.5) compared with 0.2 mm (SD 7.3) in TcTM (p = 0.0002). At 5 min postinjection, the mean total score on the SF-MPQ was 2.8 (SD 3.0) for fTcSC versus 2.1 (SD 2.5) for TcTM (p = 0.36). In the mixed effects model, injection agent (p < 0.001), time (p < 0.001) and their interaction (p < 0.001) were associated with change in pain during the 5-min postinjection period. The model found fTcSC resulted in significantly more pain of 15.2 mm (p < 0.001), 11.3 mm (p = 0.001), and 7.5 mm (p = 0.013) at 1, 2, and 3 min postinjection, respectively. CONCLUSIONS: Injection with fTcSC causes significantly more pain during the first 3 min postinjection compared with TcTM in women undergoing lymphoscintigraphy for breast cancer

    ANALYSIS OF SPONTANEOUS IMBIBITION IN FRACTAL TREE-LIKE NETWORK SYSTEM

    Get PDF
    Spontaneous imbibition in porous media is common in nature, imbibition potential is very important for understanding the imbibition ability, or the ability to keep high imbibition rate for a long time. Structure parameters have influence on imbibition potential. This work investigates the process of spontaneous imbibition of liquid into a fractal tree-like network, taking fractal structure parameters into consideration. The analytical expression for dimensionless imbibition rate with this fractal tree-like network is derived. The influence of structure parameters on imbibition potential is discussed. It is found that optimal diameter ratio beta is important for networks to have imbibition potential. Moreover, with liquid imbibed in more sub-branches, some structures of parameter combinations will show the characteristic of imbibition potential gradually. Finally, a parameter plane is made to visualize the percentage of good parameter in all possible combinations and to evaluate the imbibition potential of a specific network system more directly. It is also helpful to design and to optimize a fractal network with good imbibition potential
    corecore