Proteomic analysis of apoptosis initiation induced by all-trans retinoic acid in human acute promyelocytic leukemia cells

The irreversible destiny of apoptosis in its early stage might play a critical role in the apoptosis of human acute promyelocytic leukemia (APL) cell line induced by all-trans retinoic acid (ATRA). To characterize protein alterations during the apoptosis-initiation phase and to understand the metabolic status at that time, we investigated the protein profiles in the apoptosis-initiation phase of APL cell line HL-60 by proteomic analysis. ATRA-withdrawal was conducted to demonstrate that there was committed initiation phase of apoptosis triggered by 10(-6) M ATRA at day 3. Only after that time point, ATRA-treated cells irreversibly went to apoptosis. Also at that time point, the positive regulators of apoptosis such as STAT3 increased at protein level, whereas negative regulators (Bcl-2 and p-STAT3) decreased. In addition, caspase-3 also increased after that time. Furthermore, comparative proteomic analysis was utilized to examine the protein expression profiles during the initiation stage of apoptosis. Our results showed 12 upregulated and 7 downregulated proteins experiencing twofold alteration, including key regulators of signal transduction such as G-proteins and nucleic receptors, proteins related with metabolism, oxidation and reduction, proteins associated with the nucleus and cytoskeleton-related proteins. Some of them could be positive modulators to trigger apoptosis, whereas others could contribute to intracellular defense against apoptosis induced by exogenous triggers. The results above suggest that there is a subtle balance between apoptosis and the intracellular defense against apoptosis. Once the balance is disturbed, cells would irreversibly initiate to undergo the execution of apoptosis.     

Highly efficient separation of isomeric epoxy fatty acids by micellar electrokinetic chromatography

A capillary electrophoresis (CE) method has been developed for simple and direct separation of cis- and trans-12,13-epoxy-9(Z)-octadecenoic acid and 9,10-epoxy-12(Z)-octadecenoic acid isomers. Separation was performed in micellar electrokinetic capillary chromatography (MEKC) using a buffer consisting of 25 mM borate (pH 9.20), 10 mM sodium dodecyl sulfate (SDS) and 10% v/v acetonitrile. The key variables, concentrations of SDS and organic modifier, were optimized by the application of a factorial experimental design. The use of a low micellar concentration, just above critical micelle concentration (CMC), in a background electrolyte containing an organic modifier not only made it possible to dissolve and separate highly hydrophobic fatty acid isomers, but also resulted in improved separation efficiency and selectivity. Separation efficiency up to 4 x 10(5) theoretical plates/m was achieved under an optimized condition. Also investigated were the influence of temperature on separation and the effect of organic modifier concentration on the dynamic exchange of the analytes between micelles and the bulk of the buffer solution. Direct UV was applied for detection of the fatty acids.     

Supramolecular isomerism in the hydrogen-bonded network of (5<Emphasis Type="Italic">R</Emphasis>,10<Emphasis Type="Italic">R</Emphasis>)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-<Emphasis Type="Italic">cde</Emphasis>]chromene monohydrate

A new compound (5R, 10R)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-cde]chromene monohydrate was obtained from 3,4-dihydroxybenzaldehyde in aerobic basic aqueous ethanol solution in the presence of manganese chloride and triethylamine and crystallized in orthorhombic P2₁2₁2₁ space group (denoted as 1). When 1 was recrystallized from aqueous methanol, it was transformed to another crystal (2) with the same composition but in P2₁/n space group. The drastic difference in the extensive hydrogen bond network makes 1 a 3D and 2 a 2D infinite supramolecular structure, respectively.     

Rh(II)-catalyzed formation and rearrangement of trifluoroacetyl-containing sulfur ylides

A facile, convenient, efficient, and high yielding Rh(II)-catalyzed formation and rearrangement of trifluoroacetyl-containing sulfur ylides are reported. It is a Rh₂(OAc)₄-catalyzed [2,3]-sigmatropic rearrangement of sulfur ylide intermediates generated from α-diazo compounds.     

Native and stearic acid modified ceria-zirconia supports in normal and reversed-phase HPLC

Porous ceria-zirconia composite with narrow particle size distribution and large specific surface area was synthesized by a sol-gel process. Chromatographic properties of the native supports was investigated in normal phase mode for the separation of test mixtures of basic, neutral and acidic compounds. The new packing material exhibited polar and basic properties, which are suitable for the separation of basic compounds. Lypophilic packing has been obtained by the modification of the ceria-zirconia with stearic acid, which exhibited strong hydrophobicity relative to the native packing. Therefore, the modified ceria-zirconia behaves as a reversed-phase packing material. Different selectivity towards basic compounds was observed on the new packing compared to the native ceria-zirconia and conventional ODS stationary phase.     

High-dimensional architectures from the self-assembly of lanthanide ions with benzenedicarboxylates and 1,10-phenanthroline

Six new coordination polymers, [Eu(1,2-BDC)(1,2-HBDC)(phen)(H(2)O)](n) (1), [Eu(2)(1,3-BDC)(3)(phen)(2)(H(2)O)(2)](n).4nH(2)O (2), [Eu(1,4-BDC)(3/2)(phen)(H(2)O)](n) (3), [Yb(2)(1,2-BDC)(3)(phen)(H(2)O)(2)](n).3.5nH(2)O (4), [Yb(2)(1,3-BDC)(3)(phen)(1/2)](n) (5), and [Yb(2)(1,4-BDC)(3)(phen)(2)(H(2)O)](n) (6), were synthesized by hydrothermal reactions of lanthanide chlorides with three isomers of benzenedicarboxylic acid (H(2)BDC) and 1,10-phenanthroline (phen), and characterized by single-crystal X-ray diffraction. 1 has a 2-D herringbone architecture with a Z-shaped cavity. 2 and 5 have different 3-D networks, but both are formed by 1,3-BDC anions bridging metal centers (Eu or Yb) via carboxylate groups. 3 and 6 possess similar layer structures which are further constructed to form 3-D networks by hydrogen bonds and/or pi-pi aromatic interactions. 4 comprises 1-D chains that are further interlinked via hydrogen bonds, resulting in a 3-D network. In the three europium complexes, all the europium ions are eight-coordinated, while the coordination numbers of the ytterbium ions in other three-coordination polymers range from six to eight. Crystal data: for 1, monoclinic, space group P2(1)/c, with a = 12.565(6) A, b = 16.005(8) A, c = 12.891(6) A, beta = 102.173(8) degrees, and Z = 4; for 2, monoclinic, space group P2(1)/c, with a = 20.979(4) A, b = 11.5989(19) A, c = 20.810(3) A, beta = 110.391(3) degrees, and Z = 4; for 3, triclinic, space group P1, with a = 10.331(5) A, b = 10.887(5) A, c = 11.404(5) A, alpha = 107.660(7) degrees, beta = 91.787(7) degrees, gamma = 112.946(6) degrees, and Z = 2; for 4, triclinic, space group P1, with a = 11.517(5) A, b = 13.339(5) A, c = 13.595(6) A, alpha = 87.888(7) degrees, beta = 67.759(6) degrees, gamma = 68.070(6) degrees, and Z = 2; for 5, orthorhombic, space group C222(1), with a = 8.174(2) A, b = 24.497(7) A, c = 29.161(8) A, and Z = 8; for 6, triclinic, space group P1, with a = 10.349(3) A, b = 11.052(3) A, c = 19.431(6) A, alpha = 105.464(4) degrees, beta = 91.300(5) degrees, gamma = 93.655(5) degrees, and Z = 2. The magnetic properties of 1 and 4 were investigated. The photophysical properties of 1 were also studied.     

Fluorescence resonance energy transfer in doubly-quantum dot labeled IgG system

The mouse immunoglobulin G (mouse IgG) as a kind of bio-molecule was labeled with two different luminescent colloidal semiconductor quantum dots (QDs), green-emitting CdTe quantum dots and red-emitting CdTe quantum dots in this work. As a result of the fluorescence resonance energy transfer (FRET) between the two different sizes nanoparticles with mouse IgG as the binding bridge, a significant enhancement of the emission of the red-emitting CdTe quantum dots and the corresponding quenching of the emission of green-emitting CdTe quantum dots were observed. The relationship between the concentration of the mouse immunoglobulin G and the fluorescence intensity ratio (I_a/I_d) of acceptors and donors was studied also. Under optimal conditions, the calibration graph is linear over the range of 0.1–20.0 mg/L mouse IgG.     

The design of an irradiator for the continuous processing of liquid latex

This paper presents anew design concept for a gamma irradiation plant for the continuous processing of pumpable liquids. Typical applications of such a plant include

• * the irradiation vulcanisation of natural latex rubber

• * disinfection of municipal sewage sludge for agricultural use

• * sterilisation of liquids in the pharmaceutical and cosmetics industries

• * industrial processing of bulk liquids

The authors describe the design and operation of the latex irradiator now operating on a small production scale in Malaysia and proposed developments.

The design allows irradiation processing to be carried out under an inert or other gaseous environment.

State-of-the-art computer control system ensures the fully automatic processing operation needed by industrial computers.     

可再生甲壳素吸附铬（Ⅵ）的特性研究

可再生甲壳素吸附铬（Ⅵ）的特性研究陈炳稔＊汤又文李国明万春华（华南师范大学化学系广州５１０６３１）关键词可再生甲壳素，制备，铬（Ⅵ），吸附１９９７－０８－１９收稿，１９９７－１２－２３修回广东省科委及高教厅资助课题利用甲壳素作为铬（Ⅵ）的捕集剂已有报...