Browsing by Author "GOYCOOLEA, M"

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    DIAGNOSIS OF TYPHOID-FEVER BY 2 SEROLOGIC METHODS - ENZYME-LINKED-IMMUNOSORBENT-ASSAY OF ANTILIPOPOLYSACCHARIDE OF SALMONELLA-TYPHI ANTIBODIES AND WIDAL TEST
    (1992) QUIROGA, T; GOYCOOLEA, M; TAGLE, R; GONZALEZ, F; RODRIGUEZ, L; VILLARROEL, L
    Serum samples from 85 patients with proven typhoid fever, 11 patients with p-typhoidal fever, 101 patients with febrile non-typhoidal, and 130 healthy subjects were tested for immunoglobulin G (IgG), IgA, and IgM antilipopolysaccharide (LPS) of Salmonella typhi antibodies by enzyme-linked immunosorbent assay (ELISA) and Widal test. The levels of all three classes of immunoglobulin anti-LPS of S. typhi were higher in typhoid patients than in healthy or febrile nontyphoidal groups; we selected various combinations between the three classes of immunoglobulin to obtain the best combination of sensitivity and specificity. The sum of the absorbance values obtained from the ELISA assay for IgG + IgA + IgM (SIGMAlgs) was the best choice for diagnostic utility for typhoid fever. We selected a positive test at a decision level of SIGMAlgs greater-than-or-equal-to 1.2 with a sensitivity of 94% and a specificity of 92% with a frequency of false negative of 5.9%. The frequency of false positives for healthy controls was 7.7% and, for the febrile nontyphoidal group, it was 7.9%. We also compared receiver (or relative) operating characteristic (ROC) curves for the diagnostic usefulness of the ELISA with that of the Widal test, whose merits and limitations, especially in endemic regions, are discussed. The ELISA assay was much more sensitive and specific than any combination of the Widal test, and hence it could be a useful tool for the serologic diagnosis of typhoidal fever with a single blood sample.
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    MONITORING BACTERIAL CONSUMPTION OF LOW-MOLECULAR-WEIGHT LIGNIN DERIVATIVES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY
    (1986) GOYCOOLEA, M; SEELENFREUND, D; RUTTIMANN, C; GONZALEZ, B; VICUNA, R
    The lignolytic capacity of some natural bacterial isolates was examined. Strains were selected from samples of decaying wood by growth in a minimal medium containing aromatic compounds with a structural relationship to lignin as the sole carbon sources. These included derivatives of benzoic and phenylpropanoic acids, as well as a mixture of low molecular weight compounds obtained by fractionation of kraft lignin. Reversed-phase high-performance liquid chromatography analyses before and after cell growth in the latter revealed a degradation pattern of the different compounds present in the culture which was characteristic for each of the strains studied.