Recent reports have demonstrated that the new commercially available immobilized-type chiral stationary phases（CSPs） containing amylose tris（3-chloro-5-methylphenylcarbamate）（ACMPC） as a selector exhibit not onl...Recent reports have demonstrated that the new commercially available immobilized-type chiral stationary phases（CSPs） containing amylose tris（3-chloro-5-methylphenylcarbamate）（ACMPC） as a selector exhibit not only an exceptionally high enantioselectivity in high-performance liquid chromatography（HPLC） but they are also applicable to a wide range of chiral analytes. Herein, we report the results obtained in the HPLC analysis of omeprazole and its impurities B and E on the ACMPC-based Chiralpak IG-3 CSP（CSP） under polar organic conditions. A systematic evaluation of the retention characteristics of the selected benzimidazole chiral probes was carried out by changing the composition of the mobile phase and the column temperature. It is worth emphasizing that the high affinity of both enantiomers of all analytes recorded in pure methanol mode dramatically decreased incorporating small volumes of either basic or acid additives in the mobile phase. Unspecified sites of the IG-3 CSP presumably involved in strong and non-stereoselective H-bonding contacts with chiral analytes are assumed responsible for the unproductive retention process.展开更多
A differential pulse voltammetric immunoassay associated with the TMB-H2O2-HRP for the determination of IgE antibody was developed. The enzymatic reaction product produced by HRP catalyzing the oxidation of H2O2 with ...A differential pulse voltammetric immunoassay associated with the TMB-H2O2-HRP for the determination of IgE antibody was developed. The enzymatic reaction product produced by HRP catalyzing the oxidation of H2O2 with TMB exhibits a sensitive voltammet-ric response at 0.10V(vs.Ag/AgCl) in pH4.0 phosphate-citrate buffer solution. The de-tection limit of the present method for IgE antibody was 4.0IU/mL, which was four times lower than that obtained by traditional spectrophotometric ELISA procedure. It has been ap-plied to the determination of IgE in human serum with satisfactory results.展开更多
Numerous studies have demonstrated a relationship between the extracellular matrix protein BIGH3 and variations in the malignant properties of different cancer cell types, including osteosarcoma cells. BIGH3 protein c...Numerous studies have demonstrated a relationship between the extracellular matrix protein BIGH3 and variations in the malignant properties of different cancer cell types, including osteosarcoma cells. BIGH3 protein can suppress and promote tumor growth, even on the same cancer cell type, indicating that contextual cues regulate BIGH3-mediated divergent outcomes. We employed a multicellular tumor spheroid model to study the effects of BIGH3 with respect to physical and molecular features of three-dimensional tumor growth. The results demonstrated that exogenous recombinant BIGH3 blocked the development of multicellular large tumor spheroids so that only small spheroids formed. The effect was dependent on the BIGH3 concentration in the growth medium and the time of incubation of BIGH3 with the osteosarcoma cells in the spheroid model. TGF-β1 signaling induced multicellular tumor spheroids to synthesize a greater quantity of BIGH3 relative to non-treated spheroids. The TGF-β1-mediated increase in BIGH3 protein antagonized the development of multicellular large spheroids. Anti-BIGH3 antibody, and an inhibitor of TGF-β1 signaling, blocked the antagonistic effect induced through TGF-β1 stimulation and BIGH3 protein expression, resulting in the formation of multicellular large spheroids. Immunohistochemistry detected BIGH3 at cell bodies within the spheroid stroma, suggesting osteosarcoma cell-surface proteins bind BIGH3. Flow cytometry demonstrates that osteosarcoma cells interact with soluble BIGH3, and solid-phase cell adhesion assays show that osteosarcoma adhesion to BIGH3 substratum is mediated by integrin α4β1. However, anti-α4 antibody did not attenuate the BIGH3-mediated antagonism toward formation of multicellular large spheroids. We conclude that TGFβ1 and BIGH3 suppress the development of large osteosarcoma tumors.展开更多
基金funding from the European Community's Seventh Framework Programme under the grant agreement 602051 (Project HERACLES: Humancystic Echinococcosis Rese Arch in Centra L and Eastern Societies http://www.Heracles-fp7.eu/)
文摘Recent reports have demonstrated that the new commercially available immobilized-type chiral stationary phases（CSPs） containing amylose tris（3-chloro-5-methylphenylcarbamate）（ACMPC） as a selector exhibit not only an exceptionally high enantioselectivity in high-performance liquid chromatography（HPLC） but they are also applicable to a wide range of chiral analytes. Herein, we report the results obtained in the HPLC analysis of omeprazole and its impurities B and E on the ACMPC-based Chiralpak IG-3 CSP（CSP） under polar organic conditions. A systematic evaluation of the retention characteristics of the selected benzimidazole chiral probes was carried out by changing the composition of the mobile phase and the column temperature. It is worth emphasizing that the high affinity of both enantiomers of all analytes recorded in pure methanol mode dramatically decreased incorporating small volumes of either basic or acid additives in the mobile phase. Unspecified sites of the IG-3 CSP presumably involved in strong and non-stereoselective H-bonding contacts with chiral analytes are assumed responsible for the unproductive retention process.
文摘A differential pulse voltammetric immunoassay associated with the TMB-H2O2-HRP for the determination of IgE antibody was developed. The enzymatic reaction product produced by HRP catalyzing the oxidation of H2O2 with TMB exhibits a sensitive voltammet-ric response at 0.10V(vs.Ag/AgCl) in pH4.0 phosphate-citrate buffer solution. The de-tection limit of the present method for IgE antibody was 4.0IU/mL, which was four times lower than that obtained by traditional spectrophotometric ELISA procedure. It has been ap-plied to the determination of IgE in human serum with satisfactory results.
文摘Numerous studies have demonstrated a relationship between the extracellular matrix protein BIGH3 and variations in the malignant properties of different cancer cell types, including osteosarcoma cells. BIGH3 protein can suppress and promote tumor growth, even on the same cancer cell type, indicating that contextual cues regulate BIGH3-mediated divergent outcomes. We employed a multicellular tumor spheroid model to study the effects of BIGH3 with respect to physical and molecular features of three-dimensional tumor growth. The results demonstrated that exogenous recombinant BIGH3 blocked the development of multicellular large tumor spheroids so that only small spheroids formed. The effect was dependent on the BIGH3 concentration in the growth medium and the time of incubation of BIGH3 with the osteosarcoma cells in the spheroid model. TGF-β1 signaling induced multicellular tumor spheroids to synthesize a greater quantity of BIGH3 relative to non-treated spheroids. The TGF-β1-mediated increase in BIGH3 protein antagonized the development of multicellular large spheroids. Anti-BIGH3 antibody, and an inhibitor of TGF-β1 signaling, blocked the antagonistic effect induced through TGF-β1 stimulation and BIGH3 protein expression, resulting in the formation of multicellular large spheroids. Immunohistochemistry detected BIGH3 at cell bodies within the spheroid stroma, suggesting osteosarcoma cell-surface proteins bind BIGH3. Flow cytometry demonstrates that osteosarcoma cells interact with soluble BIGH3, and solid-phase cell adhesion assays show that osteosarcoma adhesion to BIGH3 substratum is mediated by integrin α4β1. However, anti-α4 antibody did not attenuate the BIGH3-mediated antagonism toward formation of multicellular large spheroids. We conclude that TGFβ1 and BIGH3 suppress the development of large osteosarcoma tumors.
