We have developed a monoclonal antibody (BAT) to Daudi B lymphoblastoid cell line membranes. The antibody was selected for its ability to stimulate lymphocyte proliferation. Splenocytes of BALB/c or C57BL mice given i.v. injections of 10 micrograms/mouse of BAT exhibited increased proliferation and cytotoxic activity. A single i.v. administration of BAT monoclonal antibody 2 weeks after B16 melanoma cell inoculation resulted in a striking antitumor effect as manifested by the elimination of lung metastases and prolonged survival of the treated mice. BAT monoclonal antibody was also effective in the regression of tumors in mice bearing 3LL (Lewis lung carcinoma) and MCA-105 (fibrosarcoma). Transfer of 10(7)-10(8) splenocytes from mice that had been given injections of BAT to B16- or 3LL-inoculated recipients led to a reduction of lung metastases. Splenocytes from B16-inoculated mice that were cured by BAT were more effective than those from mice treated with BAT alone against recipients bearing either B16 or 3LL tumors. The antitumor activity of BAT is related to its immunostimulatory properties. 相似文献
The past decade revealed that cell identity changes, such as dedifferentiation or transdifferentiation, accompany the insulin-producing β-cell decay in most diabetes conditions. Mapping and controlling the mechanisms governing these processes is, thus, extremely valuable for managing the disease progression. Extracellular glucose is known to influence cell identity by impacting the redox balance. Here, we use global proteomics and pathway analysis to map the response of differentiating human pancreatic progenitors to chronically increased in vitro glucose levels. We show that exogenous high glucose levels impact different protein subsets in a concentration-dependent manner. In contrast, regardless of concentration, glucose elicits an antipodal effect on the proteome landscape, inducing both beneficial and detrimental changes in regard to achieving the desired islet cell fingerprint. Furthermore, we identified that only a subgroup of these effects and pathways are regulated by changes in redox balance. Our study highlights a complex effect of exogenous glucose on differentiating pancreas progenitors characterized by a distinct proteome signature. 相似文献
Summary: Syndiotactic polystyrene (sPS)/organophilic clay nanocomposites were obtained by in situ coordination‐insertion polymerization of styrene. Two cationic surfactants (alkylammonium and alkylphosphonium) were used for the intercalation of montmorillonite (MMT). For each organically modified clay, three protocols were performed using an MAO‐activated hemi‐metallocene catalyst, in order to compare the influence of experimental conditions on the composite microstructure and on its thermal stability. The microstructures of nanocomposites were investigated by wide angle X‐ray scattering and DSC. Partially exfoliated or intercalated materials were obtained in all cases and a decrease of crystallinity is observed. Thermal properties were also studied by DSC and thermogravimetric analysis. The presence of clay does not have a strong influence on the sPS thermal transitions but the thermal decomposition process of the material was slowed down in the presence of few organoclay percents, particularly in the degradation beginning. The influence of these two organically modified clays on the thermal stability of the material is discussed.
Gel and suspension formed from the combination of cloisite with toluene (left) and styrene (right), respectively. 相似文献
Homogeneous (Cu2+ ions) and heterogeneous (Cu2+-pillared clay) Fenton-like catalysts have been compared in the conversion of p-coumaric acid. The performances of the two classes of catalysts are similar for an analogous amount of copper, but there are
some relevant differences in terms of (i) the presence of an induction time, (ii) the turnover frequency, (iii) the efficiency
in the use of H2O2, (iv) the initial attack of p-coumaric acid (hydroxylation on the aromatic ring or oxidative attack on the double bond of the lateral chain), and (v) the
effect of dissolved oxygen on the removal of total organic carbon (TOC). These differences were interpreted in terms of reaction
network of generation of radical oxygen species and of organics conversion. The possible formation of a surface peroxo adduct
coordinated to a copper binulcear site was also evidenced for the solid heterogeneous catalyst. 相似文献
A systematic reactivity study of N2O, NO, and NO2 on highly dispersed CuO phases over modified silica supports (SiO2–Al2O3, SiO2–TiO2, and SiO2–ZrO2) has been performed. Different reaction paths for the nitrogen oxide species abatement were studied: from direct decomposition (N2O) to selective reductions by hydrocarbons (N2O, NO, and NO2) and oxidation (NO to NO2). The oxygen concentration, temperature, and contact time, were varied within suitable ranges in order to investigate the activity and in particular the selectivity in the different reactions studied. The support deeply influenced the catalytic properties of the active copper phase. The most acidic supports, SiO2–Al2O3 and SiO2–ZrO2, led to a better activity and selectivity of CuO for the reactions of N2O, NO, and NO2 reductions and N2O decomposition than SiO2–TiO2. The catalytic results are discussed in terms of actual turnover frequencies starting from the knowledge of the copper dispersion values. 相似文献