Jinguang Wu

The antiproliferative effects of calcitonin gene-related peptide in different passages of cultured vascular smooth muscle cells

Previously our laboratory showed that calcitonin gene-related peptide (CGRP) is released from perivascular nerves exposed to endotoxin or inflammatory mediators bradykinin and prostaglandins. CGRP contributes significantly to the vasodilation of inflammation and septic shock. Another potential action of CGRP is inhibition of vascular smooth muscle cell (VSMC) growth, which could serve to counterbalance the stimulatory effects of IL-1 and TNF on VSMC proliferation. VSMCs from rabbit and rat aorta (in the second and fifth passages) were plated at 100,000 cells/well in 24-well trays in 10% fetal bovine serum (FBS) for 24 h, incubated for an additional 24 h without FBS, and then exposed to 2.5% FBS for 24 h in the presence or absence of CGRP. 3H-thymidine incorporation was used to measure DNA synthesis and proliferation. CGRP caused significant inhibition of 3H-thymidine incorporation, which correlated with elevations of cAMP in both rat and rabbit aortic VSMCs. Interestingly, the responses of both the elevation of cAMP and the inhibition of DNA synthesis became larger in VSMCs with an increasing number of passages. The data suggest that the CGRP, released during vascular inflammation, may serve to inhibit the proliferation of VSMCs, thus limiting the growth of atheromatous lesions.

Orthogonal Sample Design Scheme for Two-Dimensional Synchronous Spectroscopy and Its Application in Probing Intermolecular Interactions

This paper introduces a new approach to probing intermolecular interactions based on a framework of two-dimensional (2D) synchronous spectroscopy. Mathematical analysis performed on 2D synchronous spectra using variable concentration as an external perturbation shows that the cross-peaks are composed of two parts. The first part reflects intermolecular interactions that manifest in the form of deviation from the Beer–Lambert law. The second part is related simply to the concentration variations of the solutes and is responsible for the generation of interfering cross-peaks not related to the intermolecular interactions in the system. It is the second part that prevents the reliable identification of intermolecular interactions. We propose a way of selecting the concentrations of solutes so that the resultant dynamic concentration vectors of different solutes become orthogonal to one another. Therefore, the contribution of the second part to the cross-peaks can be effectively removed by the dot product of orthogonal vectors. Our new approach has been tested on a simulated chemical system and a real chemical system. The results demonstrate that interfering cross-peaks can be successfully removed from a 2D synchronous spectrum so that the cross-peaks can be used as a reliable tool to characterize or probe intermolecular interactions.

Asynchronous Orthogonal Sample Design Scheme for Two-Dimensional Correlation Spectroscopy (2D-COS) and Its Application in Probing Intermolecular Interactions from Overlapping Infrared (IR) Bands

This paper introduces a new approach to analysis of spectra called asynchronous orthogonal sample design (AOSD). Specifically designed concentration series are selected according to mathematical analysis of orthogonal vectors. Based on the AOSD approach, the interfering portion of the spectra arising strictly from the concentration effect can be completely removed from the asynchronous spectra. Thus, two-dimensional (2D) asynchronous spectra can be used as an effective tool to characterize intermolecular interactions that lead to apparent deviations from the Beer–Lambert law, even if the characteristic peaks of two compounds are substantially overlapped. A model solution with two solutes is used to investigate the behavior of the 2D asynchronous spectra under different extents of overlap of the characteristic peaks. Simulation results demonstrate that the resulting spectral patterns can reflect subtle spectral variations in bandwidths, peak positions, and absorptivities brought about by intermolecular interaction, which are barely visualized in the conventional one-dimensional (1D) spectra. Intermolecular interactions between butanone and dimethyl formamide (DMF) in CCl4 solutions were investigated using the proposed AOSD approach to prove the applicability of the AOSD method in real chemical systems.

Double Orthogonal Sample Design Scheme and Corresponding Basic Patterns in Two-Dimensional Correlation Spectra for Probing Subtle Spectral Variations Caused by Intermolecular Interactions

This paper introduces a new approach named double orthogonal sample design scheme (DOSD) to probe intermolecular interactions based on a framework of two-dimensional (2D) correlated spectroscopy. In this approach, specifically designed concentration series are selected according to the mathematical analysis on orthogonal vectors to generate useful 2D correlated spectra. As a result, the interfering portion can be completely removed from both synchronous and asynchronous spectra, and complementary information concerning intermolecular interactions can be obtained from the set of 2D spectra. A model system, where intermolecular interactions occur between two solutes in a solution, is used to investigate the behavior of 2D correlated spectra generated by using the DOSD approach. Simulation results demonstrate that the resultant spectral patterns can reflect subtle spectral variation in bandwidths, peak positions, and absorptivities brought about by intermolecular interaction, which are hardly visualized in conventional 1D spectra because of the severe band-overlapping problem. The ability to reveal a subtle variation in a characteristic peak in detail by using the DOSD approach provides a new opportunity to understand the nature of intermolecular interactions from a molecular structural point of view. Intermolecular interactions between iodine and benzene in CCl(4) solutions were investigated by using the proposed DOSD approach to prove the applicability of the DOSD method in real chemical systems.

A spectroscopic study of pigment gallstones in China

Spectroscopic studies of various types of gallstones carried out in China are reviewed. Three basic classes of gallstones are surveyed: cholesterol stones, brown pigment stones, and black pigment stones. The emphasis of this review is on brown gallstones. The primary spectroscopic methods used in the studies surveyed are Fourier transform infrared absorption and Fourier transform Raman scattering. Chemical components studied in gallstones include cholesterol, bile pigments, glycoproteins, proteins, bilirubin metal complexes, and salts of calcium and other metals. Further studies are needed characterize the relationship of these components to more complex features of gallstones.

Calcium carbonate in cholesterol gallstones : polymorphism, distribution, and hypotheses about pathogenesis

This study of sets of cholesterol gallstones collected consecutively from 222 patients in La Paz, Bolivia, and Mexico City, Mexico, has developed a reliable infrared (IR) spectroscopic method for the detection of calcium carbonate in cholesterol gallstones and provided the basis for simultaneous identification of each of its three polymorphs: calcite, vaterite, and aragonite. The peaks in the 854 to 876 cm−1 region demonstrated 98% sensitivity and specificity for carbonate detection. As little as 3% carbonate by weight could be detected using these peaks. The overall incidence of carbonate was 19% in these populations containing a high proportion of Amerinds. Infrared microspectroscopy of 10 to 50 μm particles, dissected from stones, allowed a ring‐by‐ring examination of 11 carbonate‐containing stones. It was determined that different carbonate polymorphs, when present in the same gallstone, almost always occurred in separate rings. In approximately half of the gallstones, different polymorphs were present in successive layers in the same stone, indicating that conditions governing stone growth changed cyclically. Carbonates were usually precipitated in peripheral layers rather than in the center, supporting the theory that formation of calcium carbonates may be related to episodes of intermittent obstruction of the cystic duct, as opposed to being a major factor in stone nidation. (Hepatology 1995;22:488–496.)

Extraction and separation of gold (I) cyanide in polyethylene glycol-based aqueous biphasic systems

Abstract The extraction of gold (I) cyanide in polyethylene glycol-based aqueous biphasic systems has been investigated. Almost all of gold (I) cyanide (>96%) was transferred from salt-rich phase into the polyethylene glycol (PEG)-rich phase without addition of any extractant. No significant influence of solution pH on gold (I) cyanide extraction was observed. The aqueous biphasic systems have high capability of extraction. The gold (I) cyanide in the PEG-rich phase can be easily reduced by addition of zinc. The PEG-rich phase could be reused for extraction of gold (I) cyanide without decrease of extraction capability. The PEG/salt aqueous biphasic systems may provide a potential new technique for gold separation from cyanide solutions because all components of systems are virtually nontoxic and nonflammable.

Double asynchronous orthogonal sample design scheme for probing intermolecular interactions.

This paper introduces a new approach called double asynchronous orthogonal sample design (DAOSD) to probe intermolecular interactions. A specifically designed concentration series is selected according to the mathematical analysis to generate useful 2D correlated spectra. As a result, the interfering portions are completely removed and a pair of complementary sub-2D asynchronous spectra can be obtained. A computer simulation is applied on a model system with two solutes to study the spectral behavior of cross peaks in 2D asynchronous spectra generated by using the DAOSD approach. Variations on different spectral parameters, such as peak position, bandwidth, and absorptivity, caused by intermolecular interactions can be estimated by the characteristic spectral patterns of cross peaks in the pair of complementary sub-2D asynchronous spectra. Intermolecular interactions between benzene and iodine in CCl(4) solutions were investigated using the DAOSD approach to prove the applicability of the DAOSD method in real chemical system.

Interactions between metal ions and carbohydrates. Spectroscopic characterization and the topology coordination behavior of erythritol with trivalent lanthanide ions.

The coordination of carbohydrate to metal ions is important because it may be involved in many biochemical processes. The synthesis and characterization of several novel lanthanide-erythritol complexes (TbCl(3)·1.5C(4)H(10)O(4)·H(2)O (TbE(I)), Pr(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (PrEN), Ce(NO(3))(3)·C(4)H(10)O(4)·2H(2)O (CeEN), Y(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (YEN), Gd(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (GdEN)) and Tb(NO(3))(3)·C(4)H(10)O(4)·C(2)H(5)OH (TbEN) are reported. The structures of these complexes in the solid state have been determined by X-ray diffraction. Erythritol is used as two bidentate ligands or as three hydroxyl group donor in these complexes. FTIR spectra indicate that two kinds of structures, with water and without water involved in the coordination sphere, were observed for lanthanide nitrate-erythritol complexes. FIR and THz spectra show the formation of metal ion-erythritol complexes. Luminescence spectra of Tb-erythritol complexes have the characteristics of the Tb ion.

Extraction of gold from alkaline cyanide solution by the tetradecyldimethylbenzylammonium chloride/tri-n-butyl phosphate/n-heptane system based on a microemulsion mechanism

The mechanism of extraction of gold by tetradecyldimethylbenzylammonium chloride (TDMBAC)/tri-n-butyl phosphate (TBP)/n-heptane solution from an aqueous alkaline cyanide solution was studied by means of extraction equilibrium, Karl Fischer titration, electrical conductivity, FTIR spectroscopy and dynamic laser scattering (DLS). When the gold concentration is lower than 3 g L−1 and the volume percentage of TBP is less than 10%, the plots of the extraction percentage of gold against the molar ratio of [TDMBA+] to [Au(CN)2−] and logD–log[TBP](o) plot indicated that the stoichiometry of the extracted species is a 1 ∶ 1 ∶ 4 complex, TDMBA+ ∶ Au(CN)2− ∶ TBP. Karl Fischer titration showed that 4 H2O molecules participate in the formation of such a species. Electrical conductivity measurements confirmed its ionic character. Fourier self-deconvolution of the O–H stretching bands revealed 4 different kinds of water molecules contained in the organic phase, some of which were bound to TBP via hydrogen bonding. A supramolecule [TDMBA+] · [Au(CN)2−] · 4H2O · 4TBP is proposed for the extracted species. Two TBP molecules are bound to [Au(CN)2−] by two H2O bridges through hydrogen bonding, forming a [(RO)3PO⋯H–O–H⋯NC–Au–CN⋯H–O–H⋯O = P(OR)3]− moiety. Two hydrated TBP molecules, (RO)3PO⋯H–O–H, surround [TDMBA+] by ion–dipole interaction. The bulky anion and cation form a lipophilic supramolecule. The possible structure of the supramolecular anion was calculated with an ab initio molecular orbital (MO) method. The DLS study showed that mixing of TDMBAC and Au(CN)2− in the aqueous phase led to the formation of micelles. When an organic phase containing TBP was added to this aqueous phase, the complexes transferred into the organic phase and reversed micelles or a microemulsion (W/O) were formed when the gold concentration reached a certain limiting value.