Search

The efflux activity of transmembrane P-glycoprotein prevents various therapeutic drugs from reaching lethal concentrations in cancer cells, resulting in multidrug resistance. We investigated whether drug resistant bladder cancer cells could transfer functional P-glycoprotein to sensitive parental cells.Drug sensitive BIU-87 bladder cancer cells were co-cultured for 48 hours with BIU-87/ADM, a doxorubicin resistant derivative of the same cell line, in a Transwell® system that prevented cell-to-cell contact. The presence of P-glycoprotein in recipient cell membranes was established using fluorescein isothiocyanate, laser scanning confocal microscopy and Western blot. P-glycoprotein mRNA levels were compared between cell types. Rhodamine 123 efflux assay was done to confirm that P-glycoprotein was biologically active.The amount of P-glycoprotein protein in BIU-87 cells co-cultured with BIU-87/ADM was significantly higher than in BIU-87 cells (0.44 vs 0.25) and BIU-87/H33342 cells (0.44 vs 0.26, each p0.001), indicating P-glycoprotein transfer. P-glycoprotein mRNA expression was significantly higher in BIU-87/ADM cells than in co-cultured BIU-87 cells (1.28 vs 0.30), BIU-87/H33342 (0.28) and BIU-87 cells (0.25, each p0.001), ruling out a genetic mechanism. After 30 minutes of efflux, rhodamine 123 fluorescence intensity was significantly lower in BIU-87/ADM cells (5.55 vs 51.45, p = 0.004) and co-cultured BIU-87 cells than in BIU-87 cells (14.22 vs 51.45, p0.001), indicating that P-glycoprotein was functional.Bladder cancer cells can acquire functional P-glycoprotein through a nongenetic mechanism that does not require direct cell contact. This mechanism is consistent with a microparticle mediated process.

A 1-D polymeric copper(II) complex alternately bridged by N,N′-bis(N-hydroxyethylaminopropyl)oxamide (heap2−) and terephthalate (tpa2−), [Cu2(heap)(tpa)] n , has been synthesized and characterized by single-crystal X-ray diffraction. The crystal structure reveals that the asymmetric unit of the copper(II) polymer is half a dinuclear copper(II) complex, [Cu2(heap)(tpa)], in which Cu(II) is located in a square-pyramidal coordination environment. Separations of Cu(II) through heap2− and tpa2− bridges are 5.2459(6) and 11.1375(6) A, respectively. The complex chains, accompanied with glide planes parallel to the a0c plane, can be classified to two groups according to their extending direction. Hydrogen bonds occur between a complex chain and any adjacent ones in the other orientation. Consequently, a 3-D supramolecular network is completed. The polymeric copper(II) complex exhibits potent anticancer activities against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549 tested ...

Two complexes of general formula, [M(DABTA)]NO3 [M = CuII (1) or NiII (2), DABTA = N,N′-(4,4′-bithiazole-2,2′-diyl)diacetimidamide], have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR and electronic spectra studies and single-crystal X-ray diffraction. The crystal structures show that the two complexes have similar molecular structures in which each metal atom has a square-planar coordination environment. Hydrogen bonding interactions link each complex into a 2-D infinite network. The DNA-binding properties and cytotoxicities of the complexes were investigated. The results suggest that the two complexes can interact with DNA by intercalation, with binding affinities following the order of 1 > 2, which is consistent with their in vitro cytotoxicities.

A new one-dimensional polymeric copper(II) complex, [Cu2(bhpox)(phen)]+n·nClO4−·nH2O, where bhpox3− and phen stand for N-benzoate-N′-[3-(2-hydroxyethylammino)propyl]oxamide and 1,10-phenanthroline, respectively, has been synthesized and characterized by elemental analysis, molar conductivity measurement, IR and electronic spectra studies, and single-crystal X-ray diffraction. The complex crystallizes in monoclinic space group P21/c with crystallographic data: a = 13.8500(2) A, b = 13.3321(2) A, c = 15.8532(2) A, and Z = 4. In the crystal structure, the cation [Cu2(bhpox)(phen)]nn+ exhibits a one-dimensional zigzag-like structure for copper(II) ions alternately bridged by cis-oxamido and carboxylato groups, with the Cu⋯Cu separations of 5.1928(4) and 5.5240(5) A, respectively. Each copper(II) ion is located in a slightly distorted square–pyramidal environment. Hydrogen bonds and π–π stacking interactions contribute to a three-dimensional supramolecular structure in the crystal. The interactions between the copper(II) complex and herring sperm DNA (HS-DNA) have been investigated by using electronic absorption titration, fluorescence titration, electrochemical titration and viscometry. All the experiments reveal that the copper(II) complex interacts with HS-DNA in the mode of intercalation with the intrinsic binding constant Kb = 2.67 × 104 M−1. The copper(II) complex exhibits potent anticancer activities against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549.

Pseudo ternary phase diagrams of bmimPF6/Tween80/fatty acid/toluene systems were constructed with different linear-chain fatty acid. The results demonstrated that when surfactant/fatty acid weight ratio increased, the microemulsion domain became larger, but was less than that in the absence of fatty acid. Moreover, the different chain length of fatty acid affected the extent of microemulsion region, and medium-chain length of fatty acid maximized the single-phase area of bmimPF6-based microemulsion. In addition, the influence on the microstructure of the single-phase area in the different linear-chain length fatty acids was conducted by studying the electrical conductivity behavior. Preliminary investigation suggested that the O/IL (oil /ionic liquid) microemulsion in the presence of C5H11COOH and the IL/O (ionic liquid/oil) microemulsion in the presence of C3H7COOH were max.

Boric acid (H3BO3) was an inexpensive, efficient and mild catalyst for the synthesis of n-butyl salicylate from salicylic acid and n-butanol, the esterifcation process conditions were optimized, the experimental results showed that the new process used small amount of boric acid catalyst, got higher target product yield, thus reduced the cost of production.

A novel 2D sheet-like copper(II) complex formulated [Cu6(trans-oxen)3(μ3-OH)2(H2O)2]n-(ClO4) 4n . 2nH2O (1), where H2oxen is N,N’-bis(2-aminoethyl)oxamide, has been synthesized and characterized by elemental analysis, IR and UV–visible spectroscopy, and single-crystal X-ray diffraction. 1 crystallizes in triclinic space group P-1 with crystallographic data: a = 10.299(2) A, b = 10.833(2) A, c = 11.781(2) A, α = 69.95(3)°, β = 81.10(3)°, γ = 62.44(3)°, and Z = 2. In the crystal structure, the cation [Cu6(trans-oxen)3(μ3-OH)2(H2O)2] n 4n+ exhibits a two-dimensional sheet-like structure for Cu(II) ions bridged both by trans-oxen and hydroxyl groups. Each Cu(II) ion is located in a slightly distorted square-pyramidal environment. The hydroxyl group bridges three [Cu(oxen)Cu]2+ dications in which one oxen2− is μ2-bridge while the other two act as never before reported μ4-bridge. Perchlorate anions and H2O molecules are inserted between the sheets and bridge the 2D cations via N–H···O and O–H···O hydrogen bonds to form an infinite three-dimensional system. The cyclic voltammetric behavior of 1 and the influence of counter ions on structure are preliminarily investigated.

In this study, a new μ-oxamido-bridged binuclear copper(II) complex [Cu2(heap)(H2O)2](pic)2 ⋅ 2H2O, where heap and pic stand for the anion of N,N′-bis(N-hydroxyethylaminopropyl)oxamide and 2,4,6-trinitrophenol, respectively, has been synthesized and characterized by elemental analyses, IR, UV, molar conductance, and single-crystal X-ray diffraction. The complex has an embedded inversion center at the middle of the C–C bond of the oxamido group. Each copper(II) is in a square-pyramidal coordination geometry. The bridging ligand (heap) adopts a bis-tetradentate trans conformation and the oxamido group is in an imidic acid configuration. Hydrogen bonds contribute to a 3-D supramolecular structure in the crystal. The interaction of the binuclear complex with herring sperm deoxyribonucleic acid (HS-DNA) has been investigated by using absorption and emission spectra, electrochemical techniques, and viscometry. The results suggest that the binuclear copper(II) complex interacts with HS-DNA by electrostatic inter...

A novel one-dimensional copper(II) complex formulated as [Cu2(dmaeoxd)(ox)] n ·nH2O (dmaeoxd = N,N′-bis[2-(dimethylamino)ethyl]oxamide, ox = oxalate), which represents the first coordination polymer alternately bridged by oxalate and oxamidate ligands, has been synthesized and characterized by elemental analysis, conductivity measurement and IR spectra. The single-crystal X-ray analysis reveals that the [Cu2(dmaeoxd)]2+ building blocks are bridged by oxalate groups to form a neutral 1-D coordination polymer, which involves hydrogen bonds with lattice water molecules and results in a three dimensional supermolecular structure. The voltammetric studies of the copper(II) polymer with DNA interaction are preliminarily investigated.

Cerebral ischemic insult, mainly induced by cardiovascular disease, is one of the most severe neurological diseases in clinical. There's mounting evidence showing that delta opioid agonist [D-Ala2, D-Leu5] enkephalin (DADLE) has a tissue-protective effect. However, whether this property is effective to prevent neuronal death induced by forebrain ischemia is not clear. This study was aimed to investigate whether intracerebroventricular (ICV) administration of DADLE has a neuroprotective effect against forebrain ischemia in rats. We found in our study that administration of DADLE 45 min before forebrain ischemia had significant protective effect against CA1 neuronal lose. Further more, we found that DADLE had a dose-dependent protection for improving behavioral retardation revealed by Morris water maze and motor score test, while naltrindole, the antagonist of delta opioid receptor, partially abolished neuroprotective effect of DADLE, which implicated that both opioid and non-opioid systems are involved in ischemic insults and neuroprotection.

Six new iron(III) binuclear complexes have been synthesized and characterized, namely [Fe2(CA)L4](ClO4)4 [L denotes 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me2bpy); 5-methyl-1,10-phenanthroline (Me-phen); 5-chloro-1,10-phenanthroline (Cl-phen) and 5-nitro-1,10-phenantroline (NO2-phen)], where CA represents the dianion of chloranilic acid. Based on elemental analyses, molar conductivity and magnetic moment measurements, and spectroscopic studies, it is proposed that these complexes have CA-bridged structures and consist of two iron(III) ions in a distorted octahedral environment. The complexes [Fe2(CA)(bpy)4](ClO4)4 (1) and [Fe2(CA)(phen)4](ClO4)4 (2) were characterized by variable temperature magnetic susceptibility measurements (4–300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H = − 2J S 1 · S Pin2 , giving the exchange integral J = −2.1 cm−1 for (1) and J = −5.8 cm−1 for (2). This result indicates that there is a weak antiferromagnetic spin-exchange interaction between two of the Fe(III) ions within each molecule.

Hemodilution is a commonly used technique in cardiopulmonary bypass (CPB) and deep hypothermic circulation arrest (DHCA). Our previous study showed that lower hematocrit aggravated the brain injury after DCHA. Because the excitatory amino acids are critical pathways of ischemic neuronal damage, the purpose of the present study was to investigate the effects of different degrees of hemodilution on the excitatory amino acid content in different brain areas after DHCA Adult Sprague-Dawley rats were randomly divided into four groups: group I hematocrit (Hct) 10% (H1), group II Hct 20% (H2), group III Hct 30% (H3), and control group (C). All animals except those in the control group underwent DHCA at 18°C for 90 minutes. Different degrees of hemodilution were accomplished by changing the composition and volume of the priming solution used in CPB. High-performance liquid chromatography was used to determine the concentration of glutamate (Glu), aspartate (Asp), glycine (Gly), gamma-aminobutyric acid (GABA), and taurine (Tau) in the cerebral cortex, hippocampus, and thalamus. We found that the concentration of these five amino acids in the hippocampus and cortex were all increased after DHCA. Glu, Asp, and Gly in the hippocampus and cortex were significantly lower in the Hct 30% group than in the other two groups (p

Summary Introduction The delta opioid peptide [D-Ala2, D-Leu5]enkephalin (DADLE) plays a key role in neuronal protection against both hypoxic and ischemic conditions. However, the cellular mechanisms of action of DADLE under these conditions remain unclear. Methods Ischemia was simulated with perfusing the brain slices with glucose-free artificial cerebrospinal fluid. Apoptosis was examined using an in situ cell death detection kit and expressed as the percentage of positively labeled neurons relative to total number of neurons. PCR was performed by adding cDNA, 5 pm dNTP, 1 μL Taqase, and primers. PCR products were separated with electrophoresis, stained with ethidium bromide, and visualized under ultraviolet light. Aims To investigate the potential effects of DADLE in an ex vivo model of cerebral ischemia/reperfusion. Results DADLE attenuated lactic dehydrogenase release and neuronal apoptosis in a concentration-dependent manner. The protective effects of DADLE were attenuated by representative selective delta2, but not delta1 opioid antagonists. Treatment with PD98059, a selective inhibitor of ERK kinase (MEK), also blocked the protective effect of DADLE as well as ERK phosphorylation induced by DADLE. Conclusions Endogenous opioid peptides could promote cell survival via delta2 opioid receptors, possibly through the downstream MEK-ERK pathway.

Two new circular tetranuclear copper(II) complexes, [Cu(4)(dmoxba)(2)(bpy)(2)(CH(3)OH)(2)](pic)(2)·2H(2)O (1) and [Cu(4)(dmoxba)(2)(phen)(2)](pic)(2)·2CH(3)OH (2), where dmoxba, pic, bpy and phen stand for the anion of 2-{N'-[2-(dimethylamino)ethyl]oxamido}benzoate, picrate, 2,2'-bipyridine and 1,10-phenanthroline, respectively, have been synthesized and structurally characterized by X-ray single-crystal diffraction. Both the complexes have embedded inversion centers and similar complex cations assembled by the oxamide-bridges and carboxylate-bridges of two cis-dmoxba(3-) ligands. The Cu···Cu separations through the oxamide-bridge and the carboxylato-bridge are 5.1991(4) and 5.4674(4) A in 1 and 5.1843(5) and 5.2138(5) A in 2, respectively. Both copper(II) ions are in square-pyramidal environments in 1. While in complex 2, the inner and exo copper(II) ions have square-planar and square-pyramidal coordination geometries, respectively. In both the crystals, three-dimensional supramolecular structures are formed by hydrogen bonds and π-π stacking interactions. The DNA-binding properties and anticancer activities of the two complexes were investigated. The results suggest that the two complexes interact with HS-DNA in the mode of intercalation with the intrinsic binding constants 5.0×10(4) M(-1) (1) and 6.7×10(4) M(-1) (2). The influence of structural variation of the terminal ligands in the tetranuclear complexes on DNA-binding properties is preliminarily discussed.

A novel dissymmetrical N,N'-bis(substituted)oxamide ligand, N-(2-aminopropyl)-N'-(2-oxido- phenyl)oxamide (H(3)apopoxd) (L), and its three bicopper(II) complexes, [Cu(2)(apopoxd)(bpy)]- (ClO(4))·H(2)O (1), [Cu(2)(apopoxd)(dabt)](ClO(4))·2H(2)O (2), and [Cu(2)(apopoxd)(phen)(2)](ClO(4)) (3) (bpy = 2,2'-bipyridine; dabt = 2,2'-diamino-4,4'-bithiazole; phen = 1,10-phenanthroline) have been synthesized and characterized. The crystal structures of the three bicopper(II) complexes have been determined by X-ray single-crystal diffraction. In complexes 1 and 2, the cis-apopoxd(3-) ligands bridge two copper(II) ions in square-planar geometries with the corresponding separations of 5.1868(3) and 5.2016(4) Å, respectively. While in complex 3, the apopoxd(3-) ligand adopting a trans conformation bridges the two copper(II) ions in distorted square-pyramid environments with a Cu · · · Cu distance of 5.2508(7) Å. The anticancer activities and DNA-binding properties of L and the three complexes were investigated.

For a focal plane array (FPA) fabricated with a surface sacrificial layer process, the IR flux must transmit through the silicon substrate and the air gap before it reaches the cantilever pixels. Part of the IR radiation energy is therefore lost owing to the reflection and absorption caused by the silicon substrate. We fabricate an infrared FPA consisting of 128 × 128 microcantilever pixels by using a novel bulk micro-electro-mechanical-system process. Thermal images of persons at room temperature are captured to demonstrate the IR imaging capability of the FPA. For the proposed device, the thermal response is calculated to be 4.03 × 10−3, the thermo-mechanical sensitivity is measured to be 0.273 μm/K, the noise equivalent temperature difference is measured to be 200 mK by a gray level change method and the time constant is calculated to be 15 ms under a 10 mTorr pressure.

In the title compound, C(14)H(21)N(3)O(3), the oxamide group has a transoid conformation. In the crystal, the mol-ecules are connected by N-H⋯O and O-H⋯N hydrogen bonds into a double chain running along the b axis.