Study on the Adsorption Properties of Oxalic Acid-Modified Cordierite Honeycomb Ceramics for Neutral Red Dyes.

Removal of organic dyes from water by monolithic adsorbents is considered as an efficient and no-secondary pollution method. Herein, for the first time cordierite honeycomb ceramics (COR) treated with oxalic acid (CORA) were synthesized. This CORA exhibits outstanding removal efficiency toward the azo neutral red dyes (NR) from water. After optimizing the reaction conditions, the highest adsorption capacity of 7.35 mg·g-1 and a removal rate of 98.89% could be achieved within 300 min. Furthermore, investigation of the adsorption kinetics indicated this adsorption process could be described as a pseudo-second-order kinetic model with k 2 and q e of 0.0114 g·mg-1·min-1 and 6.94 mg·g-1, respectively. According to the fitting calculation, the adsorption isotherm could also be described as the Freundlich isotherm model. The removal efficiency could be maintained above 50% after 4 cycles, negating the need for toxic organic solvent extraction, offering a method for bringing the technology one step closer to industrial application and giving CORA promising potential in practical water treatment.

[Total cholesterol mediates the effect of ABO blood group on coronary heart disease].

OBJECTIVE: To find a potential link among ABO blood group, lipid profiles and coronary artery disease (CAD) and to estimate the effect size of connection using mediation analysis model. METHODS: A total of 898 consecutive patients undergoing coronary angiography were enrolled, and divided into CAD group and non-CAD group according to angiographic findings. According to ABO blood group, patients were divided into O blood group and non-O blood group, as well as A blood group and non-A blood group. Baseline characteristics among various groups were compared and the association of ABO blood group, CAD and lipid profile was explored. RESULTS: Subjects of blood type A had higher concentration of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) compared with that of non-A type (TC: (4.43 ± 1.12) mmol/L vs. (4.18 ± 1.09) mmol/L, LDL-C: (2.79 ± 0.99) mmo/L vs. (2.59 ± 1.01) mmol/L, all P < 0.01). TC and LDL-C were significantly higher while high density lipoprotein cholesterol (HDL-C) and ApoA I levels were significantly lower in CAD group than in non-CAD group (TC: (4.36 ± 1.05) mmol/L vs. (4.13 ± 1.16) mmol/L, LDL-C: (2.61 ± 0.87) mmol/L vs. (2.47 ± 0.94) mmol/L; ApoA I: (1.38 ± 0.29) mmol/L vs. (1.45 ± 0.33) mmol/L; all P < 0.01). After adjustment for traditional cardiovascular risk factors, blood group A and TC remained significantly associated with the risk of CAD (OR = 1.88, 95% CI 1.280-2.774, P < 0.01; OR = 1.03, 95% CI 1.018-1.033, P < 0.01, respectively). Specially, mediation analysis indicated that 10.5% of the effect of A blood group on CAD was mediated by TC levels (P < 0.01). CONCLUSION: Our data indicate that there is an association between ABO blood group, TC levels and risk of CAD. Around 10.5% of the effect of A blood group on CAD is mediated by TC levels.

Histone Deacetylase Inhibitors Activate Tristetraprolin Expression through Induction of Early Growth Response Protein 1 (EGR1) in Colorectal Cancer Cells.

The RNA-binding protein tristetraprolin (TTP) promotes rapid decay of mRNAs bearing 3' UTR AU-rich elements (ARE). In many cancer types, loss of TTP expression is observed allowing for stabilization of ARE-mRNAs and their pathologic overexpression. Here we demonstrate that histone deacetylase (HDAC) inhibitors (Trichostatin A, SAHA and sodium butyrate) promote TTP expression in colorectal cancer cells (HCA-7, HCT-116, Moser and SW480 cells) and cervix carcinoma cells (HeLa). We found that HDAC inhibitors-induced TTP expression, promote the decay of COX-2 mRNA, and inhibit cancer cell proliferation. HDAC inhibitors were found to promote TTP transcription through activation of the transcription factor Early Growth Response protein 1 (EGR1). Altogether, our findings indicate that loss of TTP in tumors occurs through silencing of EGR1 and suggests a therapeutic approach to rescue TTP expression in colorectal cancer.

Ligand-induced effects on pyruvate dehydrogenase kinase isoform 2.

Tryptophan fluorescence was used to analyze binding of ligands to human pyruvate dehydrogenase isoform 2 (PDHK2) and to demonstrate effects of ligand binding on distal structure of PDHK2 that is required for binding to the inner lipoyl domain (L2) of the dihydrolipoyl acetyltransferase. Ligand-altered binding of PDHK2 to L2 and effects of specific ligands on PDHK2 oligomeric state were characterized by analytical ultracentrifugation. ATP, ADP, and pyruvate markedly quenched the tryptophan fluorescence of PDHK2 and gave maximum quenching/L0.5 estimates: approximately 53%/3 microM for ATP; approximately 49%/15 microM for ADP; and approximately 71%/approximately 590 microM for pyruvate. The conversion of Trp-383 to phenylalanine completely removed ATP- and ADP-induced quenching and > or = 80% of the absolute decrease in fluorescence due to pyruvate. The W383F-PDHK2 mutant retained high catalytic activity. Pyruvate, added after ADP, quenched Trp fluorescence with an L0.5 of 3.4 microM pyruvate, > or = 150-fold lower concentration than needed with pyruvate alone. ADP-enhanced binding of pyruvate was maintained with W383F-PDHK2. Binding of PDHK2 dimer to L2 is enhanced when L2 are housed in oligomeric structures, including the glutathione S-transferase (GST)-L2 dimer, and further strengthened by reduction of the lipoyl groups (GST-L2(red)) (Hiromasa and Roche (2003) J. Biol. Chem. 278, 33681-33693). Binding of PDHK2 to GST-L2(red) was modestly hindered by 200 microM level of ATP or ADP or 5.0 mM pyruvate; a marked change to nearly complete prevention of binding was observed with ATP or ADP plus pyruvate at only 100 microM levels, and these conditions caused PDHK2 dimer to associate to a tetramer. These changes should make major contributions to synergistic inhibition of PDHK2 activity by ADP and pyruvate. Ligand-induced changes that interfere with PDHK2 binding to GST-L2(red) may involve release of an interdomain cross arm between PDHK2 subunits in which Trp-383 plays a critical anchoring role.

Comparison of the Catalytic Domains of Collagenase-1 and Stromelysin-1.

The catalytic domains of two matrix metalloproteinases--collagenase-1 and stromelysin-1 have been studied by means of fluorescence spectroscopy and high hydrostatic pressure. The hydrophobic fluorescence probe ANS could bind to stromelysin-1, with a dissociation constant of 26.3 &mgr;mol/L, but could not bind to collagenase-1, indicating that there exists a hydrophobic site on the surface of stromelysin-1. Further study suggests that the hydrophobic site may not be the catalytic site. The biological activity of catalytic domains of collagenase-1 and stromelysin-1 showed obvious difference under high pressure the activity of collagenase-1 increased with elevating pressure, with an activation volume of D18.9 ml/mol however, the activity of stromelysin-1 did not change under high pressure. The results indicate that there are some obvious differences between the catalytic domain conformations of these two enzymes, though the crystal analysis indicated that they were very similar as reported before.