Browsing by Author "VILLARROEL, L"

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    ACUTE-RENAL-FAILURE IN THE ELDERLY - ASSESSMENT OF PROGNOSTIC FACTORS
    (1995) JALIL, R; DOWNEY, P; JARA, A; VACCAREZZA, A; MELLA, JG; CASTELLON, JM; HOYL, T; VILLARROEL, L
    We studied 45 patients, aged 50 years and older, with acute renal failure during their admission. We assessed the chance oi death using a logistic regression stepwise model, with 16 variables. The mean age of the group was 68,4 +/- 10 years; 13 patients were hemodialised and the global mortality was 37,8 %. Mortality was not increased in hemodialysed patients. The statistical model used was:
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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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    HIGH-DOSE INTRAVENOUS METHYLPREDNISOLONE THERAPY ASSOCIATED WITH OSTEONECROSIS IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS
    (1992) MASSARDO, L; JACOBELLI, S; LEISSNER, M; GONZALEZ, M; VILLARROEL, L; RIVERO, S
    Osteonecrosis is related to the use of steroids in patients with systemic lupus erythematosus (SLE); its association with the use of 'pulses' of methylprednisolone (PMP) is not clear at present. In a retrospective analysis of 190 patients with SLE we found that 19% of 36 patients treated with PMP had osteonecrosis compared with 6% of 154 patients without that treatment (P < 0.04). Risk factors associated with osteonecrosis were PMP treatment, cushingoid appearance, steroid doses greater-than-or-equal-to 40 mg/day during the first month of treatment, a ratio of steroid dose in grams/year greater-than-or-equal-to 12, hematuria and proteinuria. In a stepwise regression model, when cushingoid appearance was excluded, PMP became the only significant factor (P = 0.045).
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    SURVIVAL OF CHILEAN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS
    (1994) MASSARDO, L; MARTINEZ, ME; JACOBELLI, S; VILLARROEL, L; ROSENBERG, H; RIVERO, S
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    VENTILATORY DRIVE AND RESPIRATORY MUSCLE FUNCTION IN PREGNANCY
    (AMER LUNG ASSOC, 1991) CONTRERAS, G; GUTIERREZ, M; BEROIZA, T; FANTIN, A; ODDO, H; VILLARROEL, L; CRUZ, E; LISBOA, C
    It has been demonstrated that during pregnancy expiratory reserve volume (ERV) decreases and minute ventilation (VE) increases initially and then stabilizes. In order to determine the role of thoracoabdominal mechanics, control of breathing, and inspiratory muscle function in these alterations, we studied inspiratory pressures, lung volumes, thoracic configuration, and respiratory drive in 18 normal pregnant women at Weeks 13, 21, 30, and 37 of pregnancy. Ten of them were studied 6 months after delivery. Transdiaphragmatic pressure (Pdi) was measured at Week 37 and 3 months after delivery in an additional group of seven women. VE as well as VT/Tl increased early during gestation and remained unchanged thereafter. In contrast, mouth occlusion pressure (P0.1) increased progressively during pregnancy, from 1.53 +/- 0.16 (mean +/- SE) to 2.02 +/- 0.18 cm H2O, and fell significantly to 1.1 +/- 0.15 cm H2O after delivery, indicating that effective respiratory impedance increases during pregnancy. Mean P0.1 correlated with progesterone plasma levels (r = 0.918 p < 0.05). No changes in Plmax, PEmax, and Pdi(max), were observed. End-expiratory gastric pressure (Pga) increases significantly during pregnancy: 11.8 +/- 0.8 versus 8.4 +/- 1.12 cm H2O after delivery (p < 0.012). This increment was correlated with the fall in ERV observed in late pregnancy (r = 0.74 p < 0.05). Our results demonstrate that during pregnancy ventilatory drive and respiratory impedance increase with the consequent stabilization of VE, but our data do not permit us to differentiate whether the increment in P0.1 is secondary to the increase in impedance or to the rise in progesterone. Respiratory muscle function remains normal despite the alteration of thoracic configuration.