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The synthesis of α-pinene oxide was studied in a three-phase system where immobilized Candida antarctica lipase B (Novozyme 435) was used to catalyze the formation of peroxyoctanoic acid from the parent carboxylic acid and hydrogen peroxide in toluene. The peroxycarboxylic acid formed was then used in situ for the oxidation of α-pinene to the corresponding epoxide. When hydrogen peroxide was added in the reaction mixture gradually over 6 h, conversions increased up to 31.6%. Initial rates of α-pinene oxidation increased from 85 to 708 mmol L?1 h?1 when the amount of H2O2 increased from 5 to 60 mmol. When the lipase was exposed to 75 mmol H2O2 for 0.5 h before its addition in the reaction mixture, its activity decreased to about 50%. The reusability of lipase was studied in five reaction cycles and was found to depend on the concentration of the hydrogen peroxide used. 相似文献
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MUC1-specific immune responses in human MUC1 transgenic mice immunized with various human MUC1 vaccines 总被引:12,自引:0,他引:12
Acres B Apostolopoulos V Balloul JM Wreschner D Xing PX Ali-Hadji D Bizouarne N Kieny MP McKenzie IF 《Cancer immunology, immunotherapy : CII》2000,48(10):588-594
Analyses of MUC1-specific cytotoxic T cell precursor (CTLp) frequencies were performed in mice immunized with three different
MUC1 vaccine immunotherapeutic agents. Mice were immunized with either a fusion protein comprising MUC1 and glutathione S-transferase (MUC1-GST), MUC1-GST fusion protein coupled to mannan (MFP) or with a recombinant vaccinia virus expressing both
MUC1 and interleukin-2. Mouse strain variations in immune responsiveness have been observed with these vaccines. We have constructed
mice transgenic for the human MUC1 gene to study MUC1-specific immune responses and the risk of auto-immunity following MUC1 immunization. Transgenic mice immunized
with MUC1 were observed to be partially tolerant in that the MUC1-specific antibody response is lower than that observed in
syngeneic but non-transgenic mice. However, a significant MUC1-specific CTLp response to all three vaccines was observed,
indicating the ability to overcome T cell, but to a lesser extent B cell, tolerance to MUC1 in these mice. Histological analysis
indicates no evidence of auto-immunity to the cells expressing the human MUC1 molecule. These results suggest that it is possible
to generate an immune response to a cancer-related antigen without damage to normal tissues expressing the antigen.
Received: 7 July 1999 / Accepted: 26 August 1999 相似文献
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Anthi Tapeinou Maria-Eleni Androutsou Konstantina Kyrtata Alexios Vlamis-Gardikas Vasso Apostolopoulos John Matsoukas Theodore Tselios 《Analytical biochemistry》2015
The conjugation of polysaccharides to peptides is essential for antigen delivery and vaccine development. Herein, we show that tricine SDS-PAGE in combination with Coomassie Blue staining was adequate to determine the conjugation efficacy of a peptide (epitope 35–55 of myelin oligodendrocyte glycoprotein) to mannan. In addition, tricine SDS-PAGE and periodic acid–Schiff stains were able to monitor the redox state of mannan. Using the described protocol, more than 99.9% of a peptide containing five lysines at its N-terminus was confirmed conjugated to mannan. 相似文献
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Dimitra T. Stefanou Aristotelis Bamias Hara Episkopou Soterios A. Kyrtopoulos Maria Likka Theodore Kalampokas Stylianos Photiou Nikos Gavalas Petros P. Sfikakis Meletios A. Dimopoulos Vassilis L. Souliotis 《PloS one》2015,10(2)
Ovarian carcinoma (OC) is the most lethal gynecological malignancy. Despite the advances in the treatment of OC with combinatorial regimens, including surgery and platinum-based chemotherapy, patients generally exhibit poor prognosis due to high chemotherapy resistance. Herein, we tested the hypothesis that DNA damage response (DDR) pathways are involved in resistance of OC patients to platinum chemotherapy. Selected DDR signals were evaluated in two human ovarian carcinoma cell lines, one sensitive (A2780) and one resistant (A2780/C30) to platinum treatment as well as in peripheral blood mononuclear cells (PBMCs) from OC patients, sensitive (n = 7) or resistant (n = 4) to subsequent chemotherapy. PBMCs from healthy volunteers (n = 9) were studied in parallel. DNA damage was evaluated by immunofluorescence γH2AX staining and comet assay. Higher levels of intrinsic DNA damage were found in A2780 than in A2780/C30 cells. Moreover, the intrinsic DNA damage levels were significantly higher in OC patients relative to healthy volunteers, as well as in platinum-sensitive patients relative to platinum-resistant ones (all P<0.05). Following carboplatin treatment, A2780 cells showed lower DNA repair efficiency than A2780/C30 cells. Also, following carboplatin treatment of PBMCs ex vivo, the DNA repair efficiency was significantly higher in healthy volunteers than in platinum-resistant patients and lowest in platinum-sensitive ones (t1/2 for loss of γH2AX foci: 2.7±0.5h, 8.8±1.9h and 15.4±3.2h, respectively; using comet assay, t1/2 of platinum-induced damage repair: 4.8±1.4h, 12.9±1.9h and 21.4±2.6h, respectively; all P<0.03). Additionally, the carboplatin-induced apoptosis rate was higher in A2780 than in A2780/C30 cells. In PBMCs, apoptosis rates were inversely correlated with DNA repair efficiencies of these cells, being significantly higher in platinum-sensitive than in platinum-resistant patients and lowest in healthy volunteers (all P<0.05). We conclude that perturbations of DNA repair pathways as measured in PBMCs from OC patients correlate with the drug sensitivity of these cells and reflect the individualized response to platinum-based chemotherapy. 相似文献