Redox Biomarkers - An Effective Tool for Diagnosing COVID-19 Patients and Convalescents.

Aim: COVID-19 triggers the overproduction of reactive oxygen species (ROS) which, in combination with a weakened antioxidant barrier, can lead to protein oxidation and lipid peroxidation. The aim of this study was to evaluate enzymatic and non-enzymatic antioxidants, the overall redox potential, and protein and lipid peroxidation products in COVID-19 patients, convalescents, and healthy subjects, and to the determine the diagnostic applicability of these parameters in COVID-19 patients. Materials and Methods: The study involved 218 patients with COVID-19, 69 convalescents, and 48 healthy subjects who were selected for the research based on age and sex. The study was conducted between 20 February 2021 and 20 November 2021 in Bialystok, Poland. The antioxidant barrier, redox status, and oxidative damage products were assessed in serum/plasma samples with the use of colorimetric and spectrophotometric assays. Results: Glutathione reductase (GR) activity was higher, whereas total antioxidant capacity (TAC) was lower in COVID-19 patients than in convalescents (p<0.0001) and the control group (p<0.0001). The concentrations of advanced glycation end products (AGEs), advanced oxidation protein products (AOPP), 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) were higher in COVID-19 patients (p<0.0001) and convalescents (p<0.0001) than in the control group. AGEs were the most effective diagnostic biomarker for differentiating COVID-19 patients from the control group (AUC=0.9971) and convalescents from the control group (AUC=1.000). Conclusion: An infection with the SARS-CoV-2 disrupts the redox balance and increases protein oxidation and lipid peroxidation. AGEs fulfill the criteria for a potential diagnostic biomarker in COVID-19 patients and convalescents.

Evaluation of Solvents Used as Keepers in the Determination of Organic Pollutants by GC/MS.

Solvent evaporation is often used in the sample preparation procedure for the determination of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organic pesticides. Because of the loss of analyte during this step, a high-boiling solvent, i.e., a keeper, is often added to the extract before evaporation. However, there are almost no basic studies found in the literature on the selection of keepers for the appropriate type of analytes (keepers are usually selected only on the basis of information provided by various recommendations). In this work, the effect of several keepers (isooctane, toluene, nonane, octanol, dodecane) on the recovery of various analytes (PAHs, PCBs, organic pesticides) was evaluated (during evaporation in a stream of nitrogen, at 40 °C). The analysis of the results obtained for the tested compounds shows that 1-octanol is a universal keeper for compounds with low volatility, i.e., PCBs (average recovery: 97.6%), organochlorine pesticides (average recovery: 95.0%), organophosphorus pesticides (OPPs; average recovery: 99.7%) and higher mass PAHs (average recovery: 91.9%). The use of isooctane as a keeper yields high recoveries for PAHs, regardless of their volatility (average recovery: 95.5%). When using 1-octanol or dodecane as a keeper, the reversed solvent effect (during GC analysis) was noted in relation to volatile analytes causing the distortion of their peaks. Additionally, the phenomenon of loss of some analytes (e.g., OPPs) was observed during evaporation without heating the vials. However, in the case of PCBs, organochlorine pesticides (OCPs) and o-hydroxybiphenyl, evaporation under such conditions yields recoveries greater than or equal to 90.0%. The results presented in this work can help in finding a suitable keeper for a specific group of analytes or an alternative to the commonly used one, especially in the case of recovery problems.

Evaluation of a Simplified Method for GC/MS Qualitative Analysis of Polycyclic Aromatic Hydrocarbons, Polychlorinated Biphenyls, and Organic Pesticides Using PARADISe Computer Program.

For complex matrices such as environmental samples, there is usually a problem with not fully resolved peaks during GC/MS analysis. The PARADISe computer program (based on the PARFAC2 model) allows the identification of peaks using the deconvoluted mass spectra and the NIST MS library. The number of repetitions required by this software (at least five) is a real limitation for the determination of semi-volatile compounds, like polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organic pesticides in environmental samples. In this work, the method to overcome this condition was proposed and evaluated. The sets of the five files required by PARADISe were prepared by mathematically modifying the original GC/MS chromatograms obtained for the standard mixture (C = 2 µg/mL of 40 compounds) and real sample extracts (soil samples with different total organic carbon content and one cardboard extract) spiked with standards. Total average match factor for all the substances identified in a standard mixture was 874 (near 900-"excellent match"), and for all the substances in the real samples, it was 786 (near 800-"good match"). The results from PARADISe were comparable to those obtained with other programs: AMDIS (NIST) and MassHunter (Agilent), tested also in this work. PARADISe software can be effectively used for chromatogram deconvolution and substance identification.

Coccidioidomycosis in infants: A retrospective case series.

INTRODUCTION: In contrast to adults, coccidioidomycosis is a rare disease in infants and the mechanisms of disease acquisition are not well described in infants. The purpose of this study was to describe the clinical presentation, treatment, and outcome of pulmonary coccidioidomycosis in infants in an endemic area. METHODS: We performed a retrospective observational study of all patients less than 12 months of age admitted to a tertiary free standing children's hospital from 2003-2012 diagnosed with coccidioidomycosis. RESULTS: Thirteen infants were hospitalized during the study period. The majority of the patients presented with upper and/or lower respiratory tract infection. The most common presenting symptoms included fever (77%), cough (61%), and respiratory distress (38%). Disseminated disease, included pericardial effusion, neck abscess, and lesions in the cerebellum, basal ganglia and left temporoparietal skull. Fluconazole was the initial, antifungal agent used. Amphotericin B was reserved for significant lung disease and disseminated cases. Failed response to fluconazole and amphotericin B were treated with a combination of voriconazole and caspofungin. Average length of treatment was 4 years. All patients survived to hospital discharge. The majority of the patients had resolution of chest radiograph and coccidiodal complement fixing antibody titers. DISCUSSION: Infant coccidioidomycosis has a non-specific presentation and can mimic common infant respiratory illnesses. In endemic areas, coccidioidomycosis should be considered in the differential diagnosis of infants with pulmonary symptoms unresponsive to conventional treatment. Pediatr Pulmonol. 2016;51:858-862. © 2016 Wiley Periodicals, Inc.

Pediatric coccidioidomycosis in central California: a retrospective case series.

BACKGROUND: Coccidioidomycosis, an endemic fungal infection seen throughout the southwestern United States, is not well described in children. METHODS: We performed a retrospective observational study of all children admitted to Children's Hospital Central California with coccidioidomycosis from 1 January 2010 to 1 September 2011. RESULTS: Thirty-three children, aged 6 months to 17 years, were hospitalized during the study period. These included patients with pneumonia (n = 28), pleural effusion (n = 13), pleural empyema (n = 4), lung abscess (n = 7), pericarditis (n = 2), osteomyelitis (n = 5), meningitis/cerebritis (n = 2), and vocal cord infection (n = 1). Mediastinitis, with radiographic evidence of purulence and necrotic/abscessed lymph nodes in the mediastinum, was present in 7 patients (21%) and tended to occur more often in younger children (median age, 3 years [range, 0.5-11 years] vs 7 years [range, 0.6-17 years] for non-mediastinitis patients; P = .10). Seven patients were admitted to the intensive care unit and 10 required surgical intervention. One patient died of meningitis. Hospitalizations were longer for patients with mediastinitis (median, 130 days [range, 58-200 days] vs 43 days [range, 3-273 days for non-mediastinitis patients]; P < .01) and those with maximum coccidioidal complement fixing antibody titers ≥1:128 (median, 174 days [range, 53-273 days] vs 33 days [range, 3-200 days] for those with maximum titers <1:128; P < .01). CONCLUSIONS: Coccidioidomycosis causes a substantial disease burden in the children of central California. Mediastinitis is common and tends to occur in younger children. Patients with mediastinitis or elevated coccidioidal complement fixation titers require longer hospitalizations. Further research is needed on the prevention and treatment of this disease.

Design and application of a gas chromatograph-gas chromatograph transfer line.

A simple innovation is proposed in this work: to use interface (transfer line, TL), which allows quantitative mass transfer between two gas chromatographs. This approach assumes that one chromatograph serves as a conventional GC apparatus and the second one only as a thermostat with the appropriate detector(s) mounted. Two possible applications of the TL were tested: an "inlet-TL-detector" system and a system for dual-detection analysis, i.e. mass spectrometry and atomic emission detection. Results obtained for both of the systems show that the interface enables effective connection of two independent chromatographs. The transfer line is a manufacturer-independent innovation (with its own electronics), easy to set up and maintain.

Some aspects of the analysis of environmental pollutants in sediments using pressurized liquid extraction and gas chromatography-mass spectrometry.

Pressurized liquid extraction (PLE) is a fully automated extraction technique for isolation of analytes from solid samples. This technique combines elevated temperature and pressure of liquid solvents during the extraction process. In this study the efficiency of a PLE system for the isolation of wide range of analytes (polychlorinated biphenyls and organic pesticides from sediments under different pressure and temperature conditions) was investigated. The temperature 100 degrees C and pressure 6.9 MPa (1000 p.s.i.; 1 p.s.i.=6894.76 Pa) were found to be the most efficient from all investigated conditions. Using these PLE parameters, the average recoveries for most of the analytes were in the range 80-105% and relative standard deviation was usually under 15%. The conditions of determination of analytes in the extracts using GC-MS were established. Some problems occurring during the analysis of real samples, such as coelution of analytes, were established. The influence of internal standard addition on the final analysis results was determined.