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  • Chemistry  (5)
  • Coproporphyrinogen oxidase  (1)
  • Enzymatic conversion  (1)
  • Key words: Hypersensitivity — Allergic rhinitis — Guinea pig — Cyclosporin A — Glucocorticosteroid  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of cyclosporin A and glucocorticosteroids on antigen-induced hypersensitivity to histamine in a guinea pig model of allergic rhinitis (1998)
    Springer
    Inflammation research 47 (1998), S. 62-66 
    Details
    ISSN: 1420-908X
    Keywords: Key words: Hypersensitivity — Allergic rhinitis — Guinea pig — Cyclosporin A — Glucocorticosteroid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective and Design: In an attempt to study the pathogenesis of mucosal hypersensitivity in allergic rhinitis, we investigated the suppressive effects of cyclosporin A (CyA) and glucocorticosteroids on ovalbumin (OA)-induced hypersensitivity to topical histamine challenge.¶Materials: Actively sensitized Dunkin-Hartley guinea pigs.¶Treatment: OA and alum were applied to guinea pigs intraperitoneally 3 times at two-week intervals. After general sensitization, OA inhalation was performed every day for 6 days as topical sensitization. Before inhalation, treatment with CyA (50 mg/kg, p.o.), glucocorticosteroids (beclomethasone propionate (1.0 mg/kg, i.p.), fluticasone propionate (FP, 0.5 mg/kg, i.p.)) or vehicle were performed, and the sensitivity to histamine was measured before and after the inhalation. Moreover, in actively (general and topical) sensitized guinea pigs, FP (0.5 mg/kg, i.p.) was applied every day for 5 days and histamine sensitivity was evaluated before and after the application.¶Results: We found that histamine sensitivity was significantly increased by nasal antigen challenge in this guinea pig model, and that the occurrence of histamine hypersensitivity was inhibited by the pretreatment with CyA and glucocorticosteroids. Although multiple administration of FP gradually reduced the histamine hypersensitivity according to the period of administration, it did not significantly alter the histamine hypersensitivity after the occurrence of hypersensitivity.¶Conclusion: It is concluded that CyA and glucocorticosteroids suppress antigen-induced histamine hypersensitivity in a guinea pig model of allergic rhinitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000110050274
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  • 2
    Electronic Resource
    Electronic Resource
    Oxidation of protoporphyrinogen IX in Escherichia coli is mediated by the aerobic coproporphyrinogen oxidase (1999)
    Springer
    Molecular genetics and genomics 261 (1999), S. 1012-1020 
    Details
    ISSN: 1617-4623
    Keywords: Key words Porphyrin biosynthesis ; Protoporphyrinogen oxidase ; Coproporphyrinogen oxidase ; Overexpression ; Enzymatic conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoporphyrinogen oxidase, the penultimate enzyme involved in the biosynthetic pathway for heme, catalyzes the removal of six electrons from protoporphyrinogen IX to generate protoporphyrin IX. In Escherichia coli, this enzyme is encoded by the hemG gene. In this study we examined possible alternate pathways for the oxidation of protoporphyrinogen IX to protoporphyrin IX, by isolating and investigating E. coli mutants that can still grow normally when the hemG gene is disrupted. One of these mutants was characterized in detail and had a mutation in the promoter region of the hemF gene, which encodes aerobic coproporphyrinogen oxidase, the enzyme involved in the step immediately before protoporphyrinogen oxidase. Measurement of the promoter activity of the hemF gene showed that the level of transcription was elevated by the mutation. Overexpression of a wild-type hemF gene cloned in a multicopy plasmid also restored the growth of ΔhemG strain. Extracts from cells that overexpress hemF exhibited an increased ability to oxidize protoporphyrinogen IX to protoporphyrin IX. These findings suggest that the E. coli aerobic coproporphyrinogen oxidase has an intrinsic capacity to oxidize not only coproporphyrinogen III but also protoporphyrinogen IX.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004380051050
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  • 3
    Electronic Resource
    Electronic Resource
    Infrared spectrum of polyvinylidene chloride. II (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 37 (1959), S. 263-271 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to complete the more advanced assignments of the bands in the spectrum of polyvinylidene chloride, we prepared deuterated polyvinylidene chloride and obtained its spectrum. With the assumption that frequencies of the skeletal stretching modes and the CCl2-stretching modes cannot change drastically by deuteration, we have achieved the following assignments. Since the frequencies of the bands at 516, 527, 565, 580, 600, and 655 cm.-1 did not change largely by deuteration, they are assigned to the CCl2-stretching modes. We can assign the crystallization sensitive band at 753 cm.-1 to the CH2-rocking mode, because it was shifted to 607 cm.-1 by deuteration. The other crystallization sensitive band at 884 cm. -1, which was shifted to 822 cm.-1 by deuteration, is assigned to the skeletal stretching mode. From the frequency changes by deuteration, we could conclude that our previously reported assignments of the bands at 1046, 1071, 1357, 1407, 2966, and 3010 cm. -1 are reasonable.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203713120
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  • 4
    Electronic Resource
    Electronic Resource
    Infrared spectrum of polyvinylidene chloride. I (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 37 (1959), S. 251-261 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to assign the infrared spectrum of polyvinylidene chloride, we studied the properties of the bands in the spectrum of this polymer and the spectrum of polyvinylidene bromide. We found that many bands disappeared or became weak in the region of 400 to 700 cm.-1, when polyvinylidene chloride was molten. From the relation between the absorption intesities and the density of the polymer, we could prove that the two bands at 753 and 884 cm.-1 are crystallization-sensitive bands. The doubt at 1046 and 1071 cm.-1 in the spectrum of polyvinylidene chloride showed an interesting behavior, i.e., one component at 1046 cm.-1 appeared more strongly than the other at 1071 cm.-1 in the spectrum of the unstretched sample, and their intensity relation was inversed by stretching the sample. The infrared spectrum of polyvinylidene bromide resembled very well to the spectrum of polyvinylidene chloride. We assigned several bands in the spectrum of polyvinylidene chloride from their polarizations and spectral regions, i.e., the doublet at 1046 and 1071 cm.-1 is assigned to the skeletal stretching mode, the parallel brand at 1357 cm.-1 to the CH2--wagging mode, the perpendicular band at 1407 cm.-1 to the CH2--bending mode, the band at 2966 cm. -1 to the CH2-symmetric stretching mode, and the band at 3010 cm.-1 to the CH2-antisymmetric stretching mode.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203713119
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  • 5
    Electronic Resource
    Electronic Resource
    Infrared spectrum of polyvinyl chloride. I (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 37 (1959), S. 273-280 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to assign the infrared spectrum of polyvinyl chloride, we obtained the polarized infrared spectra of polyvinyl chloride, the spectral changes of the molten sample, and the infrared spectrum of polyvinyl bromide. The polarized infrared spectra of polyvinyl chloride which we had obtained showed satisfactory agreement with previous reports. The infrared spectra of polyvinyl chloride and polyvinyl bromide resembled each other. From the frequency defferences of the corresponding bands of both polymers, we assigned the bands at 690, 635, and 615 cm.-1 to the C—Cl-stretching modes in the spectrum of polyvinyl chloride. We found four bands in the CH- and CH2-stretching region of polyvinyl chloride as Krimm and Liang stated in their paper.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203713121
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  • 6
    Electronic Resource
    Electronic Resource
    Infrared spectrum of polyvinyl chloride. II (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 37 (1959), S. 281-294 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to assign the CH, CH2-vibration modes and the skeletal modes in the spectrum of polyvinyl chloride, we obtained deuterated polyvinyl chloride and the infrared spectrum of it, and we assumed that frequencies of the skeletal modes and the C-Cl stretching modes may not change drastically by deuteration. The frequencies of the bands of polyvinyl chloride at 1428, 1333, and 1255 cm.-1 were largely shifted by deuteration and we assign the 1428 cm.-1 band to the CH2-bending mode and the bands at 1333 and 1255 cm.-1 to the CH-deformation modes. As the frequency of the band at 1094 cm.-1 was not largely shifted, we assign it to the skeletal stretching mode. As the band at 969 cm.-1 separated into two components at 937 and 787 cm.-1 by deuteration, we believe that this band consists of two overlapped bands, one caused by the skeletal stretching mode and the other by the CH2-rocking mode. Both the band of polyvinyl chloride at 837 cm.-1 and the band of the deuterated polymer at 806 cm.-1 disappear when they are molten. We think these two bands correspond to each other and assigned them to the skeletal stretching modes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203713122
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  • 7
    Electronic Resource
    Electronic Resource
    Infrared spectra of vinylidene chloride-vinyl chloride copolymer (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 36 (1959), S. 389-405 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Observation of the infrared spectra of vinylidene chloride and vinyl chloride copolymers permitted clarification of some points which were rather ambiguous from the study of the homopolymers, and gave some information on the bands of the copolymers. In particular, the band at 868 cm.-1, which had been considered to be that of polyvinylidene chloride, was observed only in the copolymer. Depending on the mode of arrangement of vinylidene chloride and vinyl chloride in the copolymer, the CH-deformation frequency appears at 1206, 1245, or 1255 cm.-1. The same behavior was observed with vinylidene chloride-vinyl bromide copolymers. With the copolymer rich in vinylidene chloride, the band at 1206 cm.-1 can be used for determination of vinyl chloride content. In deuterated vinylidene chloride-vinyl chloride copolymer, the CD2-bending frequency due to the —CDCl—CD2—CCl2—sequence appears at 1081 cm.-1.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1959.1203613033
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