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  • 1
    ISSN: 1432-1750
    Keywords: Sarcoidosis ; Tuberculosis ; TSA ; FPEC ; GLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To explore further the possible etiologic role of mycobacteria in the development of sarcoidosis, we measured free, nonbound tuberculostearic acid (TSA, 10-methyloctadecanoic), a component of mycobacteria, in the sera of subjects with sarcoidosis or active untreated pulmonary tuberculosis and in healthy controls by use of frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). The selective analytic system is capable of measuring as little as 15-fmol quantities of free, nonbound TSA in serum and cerebral spinal fluid. We found that TSA was present in the sera of all subjects with Mycobacterium tuberculosis (n = 10) but was undetectable in subjects with sarcoidosis (n = 15) and in healthy controls (n = 15), thereby suggesting that if sarcoidosis is caused by a mycobacterial organism, TSA is not produced or does not gain access to the systemic circulation in quantities sufficient for measurement. However, in the course of the studies we found that a peak, designated p11, was elevated in the sera of all subjects with acute sarcoidosis (n = 4). Also, a peak designated p3 was reduced significantly in all subjects with acute and chronic sarcoidosis and absent in subjects with M. tuberculosis compared with healthy controls. Both peaks were later shown by chemical analysis and mass spectral studies to be carboxylic acids not previously associated with specific disease entities. Follow-up detailed studies will be needed to determine if quantitation of these unique carboxylic acids will be useful in differentiating sarcoidosis from other disorders.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The bands at 2485 and 940 cm-1 observed in the Raman spectra of 2,5-dimercapto-1,3,4-thiadiazole represent the hydrogen-bonded ν(SH) stretching and δ(C-SH) in-plane bending modes, respectively. A quantitative study of the hydrogen bonding was carried out using intensity measurements of the bands assigned to the hydrogen-bonded and the free δ(C-SH) in-plane deformations at 940 and 919 cm-1, respectively, as a function of temperature. The Fourier transform (FT) Raman spectra were recorded over the temperature range 303-403 K using an environmental chamber fitted into the FT Raman sample compartment. The equilibrium constants between the free and the hydrogen-bonded molecules were determined over this temperature range and the average enthalpy for hydrogen-bond formation was obtained (ΔH° = -3.35 ± 0.2 kJ mol-1).
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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