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  • β-cyclodextrin  (3)
  • Bone mineral density  (2)
  • Springer  (5)
  • Oxford University Press
  • 1
    ISSN: 1573-1111
    Keywords: Azure A ; β-cyclodextrin ; inclusion complex ; photochemically induced fluorescence spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The photooxidation of Azure A and fluorescence properties of Azure A and its photoproduct have been investigated in aqueous media and in the presence ofβ-cyclodextrin (β-CD). The fluorescence intensity of the complex formed between the photoproduct and β-CD was found to be three times higher than that of the uncomplexed Azure A photoproduct. A complex formation constant of 110±40 M−1 was calculated using the Benesi-Hildebrand treatment of the fluorescence emission data. Although the stoichiometry of the Azure A photoproduct: β-CD complex was found to be 1: 1, it seems that the Azure A structure is only partially included. Calibration graphs were plotted for the free Azure A photoproduct and the photogenerated product included in β-CD. The analytical parameters and quantification limits were determined.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-1111
    Keywords: β-cyclodextrin ; 2-hydroxypropyl β-CD ; phenothiazine ; photochemically-induced fluorescence spectroscopy ; molecular absorption spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The photo-oxidation reaction of phenothiazine has been studied in the presence ofβ-cyclodextrin (β-CD) and 2-hydroxypropylβ-cyclodextrin (HP β-CD). The influence of these organized media on the formation of the oxidation photoproduct upon UV irradiation has been investigated. Phenothiazine forms an inclusion complex with the cyclodextrins. The stoichiometry and formation constant of the complex formed with 2-hydroxypropyl β-CD have been calculated using the changes of the fluorescence emission signal and of the absorbance of the drug upon inclusion. An increase of the fluorescence intensity of the photogenerated product is attained when it becomes included inside the cyclodextrin cavity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 10 (1991), S. 471-484 
    ISSN: 1573-1111
    Keywords: β-cyclodextrin ; Triton X-100 ; cyclodextrin inclusion ; fluorescence spectroscopy ; nuclear magnetic resonance spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The spectral characteristics of the surfactant, Triton X-100, in the absence and presence ofβ-cyclodextrin have been examined. The fluorescence of Triton X-100 is concentration dependent and is markedly enhanced in the presence ofβ-cyclodextrin. Analysis of the variations in the excitation-emission profiles of the surfactant with concentration suggests excimer emission at concentrations above the critical micelle concentration (CMC). Nuclear magnetic resonance (NMR) spectroscopy suggests that the phenyl group is included inside the CD cavity while a portion of the ethylene oxide chain extends outside the cavity. Benesi-Hildebrand type equations were derived to determine the stoichiometry and to estimate the formation constant of the CD: Sf complex.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0827
    Keywords: Bone mineral density ; Smokers ; Premenopausal women ; Mineral metabolism ; Sex steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Smoking is related to decreased bone mass and increased risk of osteoporotic fractures. However, the harmful effects of smoking on bone have not been well characterized. The purpose of this study was to assess the repercussions of smoking on bone mass in premenopausal women, and the relationship between these effects and parameters of mineral metabolism and hormone profile. We measured bone mineral density (BMD) in 101 premenopausal women (47 smokers, 54 nonsmokers) with dualenergy X-ray absorptiometry (DeXA) of the proximal femur and lumbar spine. In a subgroup of the sample (16 smokers, 15 nonsmokers) we measured biochemical indicators of mineral metabolism and hormone profile. BMD in the femoral neck, Ward's triangle, and the intertrochanter region was significantly lower in smoker (P〈0.05) than in nonsmokers. Concentrations of sex hormone-binding globulin were higher, and free testosterone index (FTI) was lower (P〈0.05) in smokers. We found no significant differences between the groups in parameters of mineral metabolism. Concentrations of dehydroepiandrosterone sulfate and free testosterone index were directly correlated with values of BMD in different sites. Our findings show that smoking by premenopausal women is associated with decreased BMD and characteristic changes in the hormone profile.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 57 (1995), S. 94-96 
    ISSN: 1432-0827
    Keywords: Androgen insensitivity syndrome ; Hormone replacement therapy ; Bone mineral density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The response of bone mass to long-term treatment with estrogen and progesterone in patients with complete androgen-insensitivity syndrome (AIS) is unknown. We report a 17-year-old female patient (karyotype 46 X, Y) with AIS studied during a 4-year period. Bone mineral density (BMD) measured by dual X-ray absorptiometry in lumbar spine and proximal femur was sharply reduced at the initial visit, and remained unchanged during long-term follow-up on hormone replacement therapy with estrogens and progestin. Bone metabolism markers were all in the normal range. The lack of significant increase in BMD highlights the importance of androgens on bone physiology that cannot be balanced in spite of an appropriate estrogenic milieu.
    Type of Medium: Electronic Resource
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