BACKGROUND/AIMS: In this study, the sensitivity-specificity of galactomannan-enzyme immunoassay (GM-EIA) with a cut-off value of 0.5 for a single, two, or three consecutive positivity in the diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients with hematological malignancy was investigated. METHODS: IPA was classified as "proven," "probable," or "possible" as described in the guidelines prepared by the European Organization for Research and Treatment of Cancer and Mycoses Study Group." Serum samples were collected from the patients twice a week throughout their hospitalization. A total of 1,385 serum samples, with an average of 8.3 samples per episode, were examined. RESULTS: Based on the 165 febrile episodes in 106 patients, 80 (48.5%) were classified as IPA (4 proven, 11 probable, 65 possible) and 85 (51.5%) as non-IPA. The sensitivity/ specificity was 100%/27.1% for a single proven/probable IPA with the cut of value of GM-EIA > or = 0.5, 86.7%/71.8% for two consecutive positive results, and 73.3%/85.9% for three consecutive positive results. CONCLUSIONS: With the galactomannan levels measured twice a week, consecutive sensitivity decreased and specificity increased. Therefore, an increase may be obtained in sensitivity-specificity by more frequent monitoring of GM-EIA starting from the first day of positivity is detected.
Adult ; Aged ; Antineoplastic Agents/*adverse effects ; Biomarkers/blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Hematologic Neoplasms/diagnosis/*therapy ; Hematopoietic Stem Cell Transplantation/*adverse effects ; Humans ; Immunocompromised Host ; Immunosuppressive Agents/*adverse effects ; Invasive Pulmonary Aspergillosis/*blood/diagnosis/immunology/microbiology ; Male ; Mannans/*blood ; Middle Aged ; Opportunistic Infections/*blood/diagnosis/immunology/microbiology ; Predictive Value of Tests ; Reproducibility of Results ; Time Factors

In this study, an electrochemical DNA biosensor was developed using a straightforward methodology to investigate the interaction of indinavir with calf thymus double-stranded deoxyribonucleic acid (ct-dsDNA) for the first time. The decrease in the oxidation signals of deoxyguanosine (dGuo) and deoxy-adenosine (dAdo), measured by differential pulse voltammetry, upon incubation with different con-centrations of indinavir can be attributed to the binding mode of indinavir to ct-dsDNA. The currents of the dGuo and dAdo peaks decreased linearly with the concentration of indinavir in the range of 1.0-10.0μg/mL. The limit of detection and limit of quantification for indinavir were 0.29 and 0.98μg/mL, respectively, based on the dGuo signal, and 0.23 and 0.78μg/mL, respectively, based on the dAdo signal. To gain further insights into the interaction mechanism between indinavir and ct-dsDNA, spectroscopic measurements and molecular docking simulations were performed. The binding constant (Kb) between indinavir and ct-dsDNA was calculated to be 1.64 × 108 M-1, based on spectrofluorometric measure-ments. The obtained results can offer insights into the inhibitory activity of indinavir, which could help to broaden its applications. That is, indinavir can be used to inhibit other mechanisms and/or hallmarks of viral diseases.