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Background/Aim: The rapid spread of COVID-19 resulted in the revision of the value of ultraviolet C (UVC) sterilization in working spaces. This study aimed at re-evaluating the anti-UVC activity of four groups of natural products against human melanoma COLO679 and human normal dermal fibroblast (HDFa) cells, based on chemotherapeutic index. Materials and Methods: Various cell lines were exposed to UVC for 3 min in the presence of increasing concentrations of test compounds and viable cell numbers were determined with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The anti-UVC activity was quantified by the ratio of the 50% cytotoxic concentration (determined without irradiation) to the 50% effective concentration (which abolished by 50% the UVC-induced loss of viability). Apoptosis was quantified as the subG(1) population proportion following cell-cycle analysis. Results: Among four groups of major natural products, six phenylpropanoids showed the highest anti-UVC activity, followed by the lignified products and alkaline products that contain lignin and its degradation products. On the other hand, tannins and flavonoids showed lower activity due to their higher cytotoxicity. UVC-sensitive COLO679 cells lack dectin-1 protein expression. Conclusion: These data suggest the prominent anti-UVC activity of lignin degradation products, and the possible involvement of dectin-1 expression in UVC-sensitivity.

Pericytic tumors are subclassified as myopericytomas, myofibromas, angioleiomyomas, and glomus tumors according to the current World Health Organization classification and form a continuous morphological spectrum including those with combined morphology. However, no widely accepted criteria for classifying tumors with combined morphology are available. Recent studies have identified platelet-derived growth factor receptor-beta (PDGFRB) gene mutations in a subset of myofibromas, myopericytomas, and myopericytomatoses, but not in angioleiomyomas. NOTCH receptor 3 (NOTCH3) mutations have been reported in a subset of infantile myofibromatoses. We investigated PDGFRB and NOTCH3 mutations in 41 pericytic tumors of variable morphology, including some combined forms, to assess their potential role in classifying pericytic tumors. Our results show these mutations to be present in a variety of pericytic tumors, such as myopericytomas (PDGFRB, 3/11; NOTCH3, 4/11), myopericytomatoses (1/2, 1/2), myofibromas (3/6, 0/6), angioleiomyomas (2/13, 3/13), and glomus tumors (5/9, 1/9). Point mutations were identified in three tumors in PDGFRB exon 12 (Y562C, S574F, and G576S), twelve tumors in PDGFRB exon 14 (M655I, H657L, and N666K), and nine tumors in NOTCH3 exon 25 (A1480S/T, D1481N, G1482S, T1490A, E1491K, G1494S and V1512A). All PDGFRB mutations and NOTCH3 G1482S, T1490A and G1494S mutations were classified as ‘deleterious/damaging’ by more than four out of six pathogenicity prediction tools in silico. Five mutation-positive tumors, including myopericytoma-angioleiomyoma, myopericytomatosis-myofibroma, myofibroma-myopericytoma, and angioleiomyoma-myopericytoma, were of combined morphology. Thus, we found PDGFRB and NOTCH3 mutations to be detectable in a much wider variety of pericytic tumors than previously reported, and confirmed myopericytomas, myofibromas, angioleiomyomas, and glomus tumors as members harboring PDGFRB or NOTCH3 mutations. Our results thus suggest that PDGFRB or NOTCH3 mutations are not useful for subclassifying members of the pericytic tumor family.

Background/Aim: Rapid spread of COVID-19 resulted in the revision of the value of ultraviolet C (UVC) sterilization in working spaces. This study aimed at investigating the UVC sensitivity of eighteen malignant and nonmalignant cell lines, the protective activity of sodium ascorbate against UVC, and whether Dectin-2 is involved in UVC sensitivity. Materials and Methods: Various cell lines were exposed to UVC for 3 min, and cell viability was determined using the MTT assay. Anti-UV activity was determined as the ratio of 50% cytotoxic concentration (determined with unirradiated cells) to 50% effective concentration (that restored half of the UV-induced loss of viability). Dectin-2 expression was quantified using flow cytometry. Results: The use of culture medium rather than phosphate-buffered saline is recommended as irradiation solution, since several cells are easily detached during irradiation in phosphate-buffered saline. Oral squamous cell carcinoma cell lines showed the highest UV sensitivity, followed by neuroblastoma, glioblastoma, leukemia, melanoma, lung carcinoma cells, and normal oral and dermal fibroblasts. Human dermal fibroblasts were more resistant than melanoma cell lines; however, both expressed Dectin-2. Sodium ascorbate at micromolar concentrations eliminated the cytotoxicity of UVC in these cell lines. Conclusion: Normal cells are generally UVC-resistant compared to corresponding malignant cells, which have higher growth potential. Dectin-2 protein expression itself may not be determinant of UVC sensitivity.

The purpose of this study was to clarify the influence of different vibration frequencies on wakefulness level. Subjects were 7 healthy male university students aged 21.9+/-1.6 years (mean). All students were non-smokers. Three exposure conditions were used (10 Hz vibration, 20 Hz vibration, and no vibration). Whole-body vertical vibration was applied to subjects sitting on a car passenger seat using a whole-body vibration shaker (CV-300, Akashi) at a single frequency (10 or 20 Hz) at an acceleration level of 0.3 ms(-2) r.m.s. for 24 min. The objective wakefulness level based on EEGs was evaluated in terms of the alpha attenuation coefficient (AAC) obtained by the Alpha Attenuation Test (AAT). As parameters of psychological stress, salivary 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were used. The subjective wakefulness level was evaluated using a questionnaire based on the Kwansei Gakuin Sleepiness Scale (KSS), which is a scale developed for the Japanese based on the Stanford Sleepiness Scale (SSS). The KSS score, representing the subjective wakefulness level, decreased after the exposure irrespective of the exposure condition, but the decrease was not significant. The AAC, representing the objective wakefulness level, significantly decreased only after vibration exposure (10 Hz/20 Hz) but did not differ between the two vibration frequencies. No significant changes were observed after exposure to whole-body vibration in MHPG or HVA as parameters of vibration-related stress. The AAC decreased after exposure to whole-body vibration (10 Hz/20 Hz), suggesting a decrease in the wakefulness level. However, no differences were observed in the influence of the two different vibration frequencies test.