Because alveolar macrophages generate and release reactive oxygen metabolites but also contain antioxidative enzymes, they have the potential of either damaging or protecting tissues. We investigated the relative role of the hydrogen peroxide (H2O2)-scavenging antioxidative enzymes in H2O2 disposal and cell protection using freshly isolated (5 h ex vivo) and overnight (24 h ex vivo) cultured human alveolar macrophages. Cell protection was assessed on the basis of maintenance of cellular high-energy phosphates, leakage of intact nucleotides into the extracellular medium, and appearance of the nucleotide catabolic products xanthine, hypoxanthine, and uric acid. To investigate the relative importance of catalase and the glutathione redox cycle, the experiments were conducted in cells pretreated with amino-triazole (ATZ) to inactivate catalase or with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) to inactivate glutathione reductase. Catalase, glutathione peroxidase, and glutathione reductase activities did not change significantly during overnight culture of the cells. Both freshly isolated and cultured cells consumed exogenous H2O2 mainly by the catalase-dependent pathway. When the cells were exposed to H2O2 (100 microM), catalase and the glutathione redox cycle equally participated in maintaining cellular high-energy nucleotides. However, when cultured cells were exposed to formylated peptide (FMLP) (10(-7) M), the glutathione redox cycle was responsible for the maintenance of high-energy nucleotides. Furthermore, in both exposures, the glutathione redox cycle was more important in maintaining cell membrane integrity and preventing nucleotide leakage from the cells. Immunocytochemical labeling showed that catalase was primarily localized in the peroxisomal compartment of these cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Purpose Due to the coronavirus disease of 2019 (COVID-19), teachers during the pandemic have had to adapt to online teaching at short notice. This study aims to investigate the voice symptoms and their environmental risk factors as well as the work ability associated with distance teaching and to compare these with symptoms in previous contact teaching. Methods We conducted a survey of 121 primary and secondary school teachers across Finland. The survey was advertised online through social media and the replies collected from voluntarily participating teachers. Results During distance teaching vocal symptoms appeared less often than in school with 71% teachers experiencing them in regular teaching and 44% in distance teaching, VHI result decreased from 7.88 in school teaching to 4.58 in distance teaching. Acoustic conditions were reported to be more suitable in distance teaching with 73% of teachers finding them adequate during distance teaching in comparison to 46% for those in regular teaching. Background noise was the most disturbing factor for a teacher’s voice in the classroom and in distance teaching and this was even more conspicuous in the classroom. Also, subjectively experienced poor indoor air quality at school influenced the voice negatively. Further, voice problems were associated with increased subjective stress levels and reduced ability to work. Conclusion Distance teaching has affected teachers’ voices in a positive way compared with regular teaching. This difference is likely to be due to better acoustics and indoor air quality in distance teaching conditions.

The significance of manganese superoxide dismutase (MnSOD) induction in cells and tissues during oxidant stress is still poorly understood. In this study, transformed human bronchial epithelial cells (BEAS 2B) were treated with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), or with combination of these cytokines (10 ng/ml concentrations) for 48 or 72 h and exposed to selected oxidants. TNF-alpha and IFN-gamma + TNF-alpha combination resulted in a marked increase of MnSOD protein and MnSOD activity. When cells pretreated with the cytokines were exposed to hyperoxia (95% O2, 72 h), menadione (5-50 microM, 4 h), or H2O2 (0.5 and 5 mM, 4 h), in all cases IFN-gamma and TNF-alpha enhanced oxidant-related cell injury. The effect was most significant with cells pretreated with a combination of IFN-gamma and TNF-alpha. Antioxidant enzymes such as total SOD, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase did not change significantly during the cytokine treatment. Catalase activity was not changed by IFN-gamma or TNF-alpha but it decreased significantly (34%) in IFN-gamma + TNF-alpha-treated cells. Free radical generation was not changed by these cytokines in acute (30 min) experimental conditions or after 48-h treatment. These results suggest that cytokine-induced MnSOD does not protect bronchial epithelial cells against endogenously or exogenously generated oxidants in vitro. In fact, cells that contained the highest MnSOD activity were the most sensitive to subsequent oxidant damage.

Globus patients with normal ear, nose, and throat (ENT) status are a diagnostic challenge. The symptom may be long lasting and cause concern about malignancy, leading to possibly unnecessary further investigation. The aim of the study was to assess whether radiological examinations are useful in globus diagnostics, how often patients suffer from persistent globus, and whether globus patients with normal ENT status develop a malignancy during a follow-up. We reviewed medical records of all 76 globus patients referred to Helsinki University Hospital, Department of Otorhinolaryngology-Head and Neck Surgery in 2009. Patient history and findings in physical and radiological examinations were registered. A questionnaire concerning patients' present pharyngeal symptoms was sent 3 and 6 years after their initial visit. Data from the Finnish Cancer Registry revealed whether patients developed malignancies within a 3-year follow-up. Based on medical records, neck ultrasound was performed for 37 (49 %) and videofluorography for 22 patients (29 %), with nonsignificant findings. After a 3- and 6-year follow-up, half patients indicated that they were asymptomatic or had fewer symptoms, whereas the rest had persistent symptoms. The Finnish Cancer Registry data confirmed that globus patients developed no head and neck malignancies during a 3-year follow-up. In the present study, neck ultrasound and videofluorography showed no additional benefit to evaluate the globus etiology in patients whose ENT status was normal. Half the globus patients suffered from persistent symptoms after a 3- and 6-year follow-up, indicating that globus may cause discomfort chronically. However, no patients developed malignancies during a 3-year follow-up.