Monoclonal antibodies directed against chicken ß2-microglobulin developed with a synthesized peptide.

We developed a panel of monoclonal antibodies (MAb) against chicken ß2-microglobulin (chß2M) by fusions between SP2/0 myeloma cells and spleen cells from mice immunized with a synthesized peptide corresponding to positions 91-119 of the COOH domain of chß2M. Two of them, 6E7 and 3D1, identified as IgG1/κ, could react with chß2M protein from avian macrophage HD11 cells and human 293T cells transfected with pcDNA3.1-chß2M in immunofluorescence assays. Only a 12 kDa protein band of chß2M could be detected in the HD11 and 293T/chß2M cell lysates by Western blot analysis. Chicken ß2M in serum and plasma could be found in Western blot by MAb 3D1. Moreover, MAb 3D1 also recognized the chß2M antigen on the cell membranes in flow cytometry. Immunohistochemical staining with these MAbs revealed that chß2M was present in chicken thymus, spleen, and bursa. These MAbs will be good tools for analyzing the mechanism of the chicken immune system.

Structural transitions in mixed ternary noble gas clusters.

The properties of noble gas systems can be greatly extended by heterogeneous mixtures of elements. The geometrical structures and energies of mixed Ar-Kr-Xe clusters were investigated using ternary Lennard-Jones (TLJ) potential. For the Ar19Kr n Xe19, Ar19Kr19Xe n , and Ar n Kr19Xe19 (n = 0-17) clusters investigated, the results show that only two minimum energy configurations exist, i.e., polytetrahedron and six-fold pancake. The inner core of all these clusters is composed mainly of Ar atoms, and Kr and Xe atoms are distributed on the surface with well mixed pattern for polytetrahedral and segregate pattern for six-fold pancake configurations. The relative stability property of Ar-Kr-Xe clusters with a certain composition is discussed. Moreover, the role of heterogeneity on the strain was investigated, and reduced strain energies in Ar-Kr-Xe clusters were studied to find possible ways of reducing strain. The results showed that the strain energies were affected mainly by Ar-Ar, Ar-Kr, and Xe-Xe bonds.

[Bovine serum albumin in the presence of zinc (II) by fluorescence method].

The interaction between norfloxacin and bovine serum albumin, and the influence of Zinc (II) on the system of norfloxacin and bovine serum albumin was studied under physiological condition by fluorescence method. It was shown that norfloxacin has a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. The fluorescence quenching data were analyzed according to Stern-Volmer equation and double-reciprocal equation, and the binding constant (K) and the binding sites (n) were obtained. In the system of binary complex of NFLX and BSA, K = 6.80 x 10(5) and n = 1.21. There is a strong combination between NFLX and BSA, which offers the condition for the serum protein to be deposited and transported in vivo. Besides, the combination between NFLX and BSA becomes stronger in the presence of Zinc (II). According to Stern-Volmer equation and double-reciprocal equation, the concentration of Znic (II) is denser, and the binding constant (K) and the binding sites (n) are bigger. By studying the binding interaction between Zinc (II), norfloxacin and BSA, the mechanism of the interaction among norfloxacin, Zinc (II) and protein in organism, is furtherly discussed.

2'-Amino-3,6-dihydroxyxanthene-9-spiro-1'-isoindolin-3'-one monohydrate.

The title compound, C(20)H(14)N(2)O(4)·H(2)O, was synthesized by the reaction of fluorescein and hydrazine hydrate in ethanol. In the crystal structure, the organic mol-ecules are linked into extended two-dimensional networks by inter-molecular hydrogen bonding. Additional face-to-face π-π stacking inter-actions between the phenolic benzene rings in two adjacent mol-ecules [centroid-to-centroid separation = 3.773 (3) Å] link the mol-ecules into a three-dimensional framework.

3,6-Dihydr-oxy-2'-[(2-hydr-oxy-1-naphth-yl)methyl-eneamino]xanthene-9-spiro-1'-isoindolin-3'-one acetonitrile solvate.

The title compound, C(31)H(20)N(2)O(5)·C(2)H(3)N, was synthesized by the reaction of fluorescein hydrazide and excess 2-hydr-oxy-1-naphthaldehyde in acetonitrile. The spirolactam ring is planar and is nearly at right angles to the two benzene rings of the xanthene system. The dihedral angle between the two benzene rings of the xanthene system is 9.92 (4)°. In the crystal structure, the mol-ecules are linked into extended two-dimensional networks by inter-molecular hydrogen bonding. Acetonitrile mol-ecules are located in the voids between the two-dimensional networks.

[Study on the ternary complex of FLRX, zinc(II) and BSA by the method of fluorescence].

The influences of fleroxacin (FLRX) on the fluorescence of bovine serum albumin(BSA), zinc(II) on that of bovine serum albumin, and zinc(II) on the of fleroxacin and bovine serum albumin were studied under imitated the physiological condition. It was shown that both fleroxacin and zinc(II) have a powerful ability to quench the BSA fluorescence via a nonradiative energy transfer mechanism. But the fluorescence quenching action of fleroxacin on BSA was much stronger in the presence of zinc (II). The fluorescence quenching data were analyzed according to Stern-Volmer equation and double-reciprocal equation, and the binding constant(K) and the binding sites(n) were obtained. In the system of binary complex of FLRX and BSA, K = 5.44 x 10(4) and n = 1.05, while in the system of binary complex of zinc(II) and BSA, K = 2.19 x 10(9) and n = 2.

[Study on the interaction of Pb2+ and bovine serum albumin by fluorescence].

The interaction of Pb2+ and bovine serum albumin (BSA) was studied under conditions similar to those in human bodies by fluorescence spectra. The results indicated that tryptophan and tyrosine, which were located in BSA, had a max fluorescence emission peak at 341 nm with an excitation wavelength of 283 nm. It was shown that Pb2+ had a powerful ability to quench the BSA fluorescence with a mechanism of a static process rather than a dynamic one. The apparent quenching constant Kq was obtained to be 9.5 x 10(12) L x mol(-1) x s(-1) by Stern-Volmer equation. The apparent complexation constant of Pb2 x BSA is lgK = 11.61. The nitrogen in BSA could coordinate with lead in Pb2-BSA.

[Simultaneous determination of copper and iron by catalytic kinetic spectrophotometry].

A simultaneous catalytic effect copper (II) and iron (III) on the oxidation of acid chrome blue K by potassium bromate in dilute sulfuric acid medium was observed. But there was an obvious difference in their reaction rates, and the ratio of the reaction constant changed with time. And their spectral addiitive properties were not satisfactory. The simultaneous determination of copper and iron by catalytic kinetic spectrophotometric method was realized by using a three-layer Levenberg-Marquardt BP neural network to cope with the experimental data. The optimum conditions of reaction and determination were studied. The calculation results of the determination in synthetic samples and human hair were satisfactory.

[Simultaneous determination of tryptophan and tyrosine in injection by artificial neural network and fluorescence spectrum method].

A new fluorescence method by artificial neural network for the simultaneous determination of tryptophan and tyrosine was developed. The determination was carried out in the KH2PO4-K2HPO4 buffer solution (pH = 7.15) and at the EX (excitation) wavelength of 224 nm. In the range of 290-400 nm, the fluorescence intensities at fourteen wavelengths were taken as characteristic parameters of the artificial neural network, and the samples were arranged by the method of equality design. The mean recoveries of tryptophan and tyrosine were 100.9% and 101.6% respectively. The RSDs of the results were 4.18% and 4.17%. The method has been applied to the determination of tryptophan and tyrosine in compound amino acid injection, and the relative errors were 4.0% and 2.6%, respectively. The results were better than those of other networks in training speed and accuracy. In conclusion, the new network spectrofluorimetry is a good choice for multicomponent resolving analysis.

[Application of artificial neural network to simultaneous spectrofluorimetric determination of vitamin B1, B2 and B6].

By means of artificial neural network and Levenberg-Marquardt back-propagation training algorithm, the three components of vitamin B1, B2, B6 were determined simultaneously, in which the spectra overlapped. In the range of 390-520 nm, the fluorescence intensities at 15 wavelengths were taken as a character of the artificial neural network, and samples were arranged by the method of equality design. The mean recoveries of vitamin B1, vitamin B2, and vitamin B6 were 99.86%, 99.60% and 99.49% respectively. The RSDs of the results were 1.7%, 1.6%, and 1.7%.

[Application of artificial neural network to simultaneous spectro-fluorimetric determination of phenol and resorcinol].

By the means of artificial neural network and Levenberg-Marquardt back-propagation train algorithm, the two components of phenol, resorcinol were determined simultaneously, in which the fluorescence spectra overlapped. In 290-345 nm, the fluorescence intensity at 14 wavelengths were taken as character of artificial neural network, and samples were arranged by method of equality design. The mean recovery of phenol and resorcinol were 100.2%, 99.99% respectively. The RSD of the results were 0.4% and 1.3%.