[The use of induced sputum in treatment of occupational asthma].
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Asthma, Occupational↗
Biomedical subjects
Yu Bai
Publications and source records attributed to Yu Bai.
High resolution mass spectrometric alveolar proteomics: identification of surfactant protein SP-A and SP-D modifications in proteinosis and cystic fibrosis patients.
In the present study, one- and two-dimensional gel electrophoresis combined with high resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) have been applied as powerful approaches for the proteome analysis of surfactant proteins SP-A and SP-D, including identification of structurally modified and truncation forms, in bronchoalveolar lavage fluid from patients with cystic fibrosis, chronic bronchitis and pulmonary alveolar proteinosis. Highly sensitive micropreparation techniques were developed for matrix-assisted laser desorption/ionization (MALDI) FT-ICR MS analysis which provided the identification of surfactant proteins at very low levels. Owing to the high resolution, FT-ICR MS was found to provide substantial advantages for the structural identification of surfactant proteins from complex biological matrices with high mass determination accuracy. Several protein bands corresponding to SP-A and SP-D were identified by MALDI-FT-ICR MS after electrophoretic separation by one- and two-dimensional gel electrophoresis, and provided the identification of structural modifications (hydroxy-proline) and degradation products. The high resolution mass spectrometric proteome analysis should facilitate the unequivocal identification of subunits, aggregations, modifications and degradation products of surfactant proteins and hence contribute to the understanding of the mechanistic basis of lung disease pathogenesis.
Bronchoalveolar Lavage Fluid↗
Characterization of the rutin-metal complex by electrospray ionization tandem mass spectrometry.
According to the strong application background of bioflavonoid and metal-flavonoid complexes, novel electrospray ionization tandem mass spectrometry (ESI-MSn) was applied to investigate the structure and fragmentation mechanism of transition metal-rutin complexes. In the full-scan mass spectra, different stoichiometric ratios of rutin-metal complexes were found. In the reaction between rutin and Cu, four kinds of complexes with four different stoichiometric ratios were produced. In the reaction between rutin and Zn, Mn(II), and Fe(II), only two kind of complexes with stoichiometric ratios of 1:1 and 1:2 occured. In further tandem mass spectrometric experiments of different rutin-metal complexes, product fragments came from the neutral loss of the external rhamnose and the internal glucose unit, oligosaccharide chain, aglycone, and small organic molecules. According to the MSn data, we proposed a mechanism for all fragments of the rutin-Cu complex A and the structure of two rutin-Cu complexes, C and D.
Copper↗
Isolation and characterization of deodorizing bacteria for organic sulfide malodor.
Strain JII screened out from different odor origins can efficiently degrade methyl mercaptan and ethanethiol whereas has no ability to remove dimethyl sulfide. The results indicated that the strain JII breaks only the C-SH bond. The optimum temperature and pH of JII are 20-30 degrees C and 6.0-8.3 respectively. A systematic identification method-16S rDNA gene sequence comparison, for deodorizing bacteria was carried out. The 16S rDNA gene sequence analysis of strain JII showed the highest level of 97% homology to Rape rhizosphere.
Bacteria↗
[Simultaneous determination of calcium and magnesium in urines by flame atomic absorption spectrometry].
The contents of calcium and magnesium in urines were simultaneously determined by flame atomic absorption spectrometry. The optimized working conditions were ascertained. For the determination of calcium, the used wavelength was 422.8 nm, and the current of HCL(Hollow Cathode Lamp) was 3 mA; for the determination of magnesium, the used wavelength was 285.2 nm, and the current of HCL (Hollow Cathode Lamp) was 4 mA. The height of burner and the air-acetylene ratio were 8 mm and 6:1, respectively, for the determination of both calcium and magnesium. In order to remove the disturbance of phosphate, sulphate and silicate on the determination of calcium, a releasing reagent can be used. Lanthanum chloride (LaCl3) was tested as a better releasing reagent than strontium chloride (SrCl2). The disturbance of urinary substrate could be avoided after the urines were diluted to 1:100 with distilled water. The concentrations of Ca and Mg in 15 urines were determined under the optimized conditions. The obtained results were consistent with the archived data. The recovery was 96%-104%, the relative standard deviation for a sample was 1.8% with P < 0.05.
Calcium↗
[XPS spectra of Langmuir-Blodgett films and their electroluminescence].
The coordination of monolayer of amphiphilic ligands, N, N-bis(8-quinolinyl)alkyl propanediamide, H2A(alkyl = dodecyl, H2A12; hexadecyl, H2A16) with Cu2+ at air-water interface was investigated by X-ray Photoelectron Spectroscopy (XPS) and UV-Vis spectra. The collapse pressure of the monolayers of H2A12 and H2A16 increased from 12.5 and 15.6 mN x m(-1) to 28.0 and 33.8 mN x m(-1) after their coordination with Cu2+ ions, respectively. XPS indicated that the coordination ratio between H2A and Cu2+ was 1:1. The binding energies of Cu2p were 935 and 955 eV. The Langmuir-Blodgett(LB) films of H2A12 and H2A16 can be used as transporting materials in three-layer electroluminescence devices: ITO/TPD/LB films/Alq3/Al. The driving voltages were 6.5 and 7.5 V, the maximum luminances were 621 and 201 cd x m(-2), respectively.
English Abstract↗
The fastest global events in RNA folding: electrostatic relaxation and tertiary collapse of the Tetrahymena ribozyme.
Large RNAs can collapse into compact conformations well before the stable formation of the tertiary contacts that define their final folds. This study identifies likely physical mechanisms driving these early compaction events in RNA folding. We have employed time-resolved small-angle X-ray scattering to monitor the fastest global shape changes of the Tetrahymena ribozyme under different ionic conditions and with RNA mutations that remove long-range tertiary contacts. A partial collapse in each of the folding time-courses occurs within tens of milliseconds with either monovalent or divalent cations. Combined with comparison to predictions from structural models, this observation suggests a relaxation of the RNA to a more compact but denatured conformational ensemble in response to enhanced electrostatic screening at higher ionic concentrations. Further, the results provide evidence against counterion-correlation-mediated attraction between RNA double helices, a recently proposed model for early collapse. A previous study revealed a second 100 ms phase of collapse to a globular state. Surprisingly, we find that progression to this second early folding intermediate requires RNA sequence motifs that eventually mediate native long-range tertiary interactions, even though these regions of the RNA were observed to be solvent-accessible in previous footprinting studies under similar conditions. These results help delineate an analogy between the early conformational changes in RNA folding and the "burst phase" changes and molten globule formation in protein folding.
Animals↗
[Antigenic analysis of the common recombinant mutant types of HBsAg].
BACKGROUND: To study the difference between the mutant types and the wild type of HBsAg on the binding efficiency with antibodies in order to find some methods to detect the mutants. METHODS: The recombinant wild type of HBsAg and the mutants including 145 R, 133 T, 126 S, 141 E, 126 S+133 T, 126 S+133 T+145 R and 126 S+133 T+141 E were cloned, respectively. Then the expression vector containing the wild or mutant gene was transfected into COS7 cells, and the recombinant proteins were expressed. The proteins were detected with the routine HBsAg kits. RESULTS: The binding efficiency with monoclonal antibodies of HBsAg expressed by 126 S was higher than that of the wild type, while the results of 145 R, 141 E, 126 S+133 T+145 R and 126 S+133 T+141 E were lower than that of the wild, and 133 T was similar to the wild. But most of the mutants had the same reactivity with the polyclonal antibody. CONCLUSIONS: The effect of mutations on antibody binding differs depending on the amino acid involved and on the location within the "a" loop. So it is necessary to use polyclonal antibody or to find new kits to detect the mutants of HBsAg.
Binding Sites, Antibody↗
Rapid analysis of a triterpenoid saponin mixture from plant extracts by electrospray ionization multi-stage tandem mass spectrometry (ESI-MSI).
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Apiaceae↗
[Immunogenicity of recombinant HEV ORF2 protein expressed in pichia pastoris].
BACKGROUND: To study to immunogenicity of recombinant HEV ORF2 protein expressed in pichia pastoris. METHODS: BALB/c mice were immunized with the recombinant HEV ORF2 protein. The ability of antiserum to bind HEV was tested using affinity-capture reverse transcription polymerase chain reaction (RT-PCR). Moreover, the recombinant protein was used to immunize BALB/c mice by different routes with different adjuvants. Serum conversion rate of anti-HEV antibody and the ELISA titer were detected. RESULTS: The antiserum could capture native HEV for RT-PCR. As to the immunization effect, the immune response by intramuscular route was better than that of the intraperitoneal route. The protein with alum and CpG adjuvant could elicits more significant immune responses than using the alum adjuvant alone. The best way was to immunize with the protein with alum and CpG adjuvant by intramuscular route with a boosted injection on the 4th week after the first immunization. The ED50 was 0.023 microgram. This is the first report that the antibody elicited by recombinant HEV ORF2 protein expressed in pichia pastoris recognizes native HEV. High immunogenicity of this kind of ORF2 was also demonstrated by inducing strong immune response in mice with good ED50 result. CONCLUSIONS: The high immunogenicity of this kind of HEV ORF2 may make a foundation for the development of new type of hepatitis E vaccine.
Animals↗
Communication and education about asthma in rural and urban schools.
OBJECTIVE: To assess the quality of communication and education about asthma in Pennsylvania public schools. METHODS: Survey of a stratified random sample of school nurses in rural and urban Pennsylvania public schools (n = 996) concerning communication with school nurses about asthma by physicians and parents, nurses' perceived obstacles to asthma management at school, and utilization of and need for education about asthma. RESULTS: A total of 757 surveys were received (response rate 76%). Thirty-nine percent of school nurses rated their communication with physicians about asthma as either poor or very poor. Urban nurses were significantly more likely to report poor/very poor physician communication (P = .09). Fifty-two percent of the nurses overall (43% rural, 56% urban) also cited lack of communication with parents as an important obstacle to asthma management. Forty-nine percent of school nurses (43% rural, 52% urban) reported attending an asthma education program during the previous year, and 75% (83% rural, 71% urban) expressed interest in additional education. Education about asthma was provided for classroom teachers in 54% of schools (56% rural, 54% urban) and provided for students in 58% of schools (54% rural, 60% urban). CONCLUSIONS: These findings document need for improvement in communication about children's asthma between school nurses and physicians. Although communication appears better in rural relative to urban schools, it is a salient issue in both settings. Study findings also indicate the need for expanded professional education opportunities for school nurses and improved access to appropriate curricular materials for school staff, parents, and students.
Asthma↗