What type of face mask should we choose in coronavirus disease 2019 pandemic considering photoprotective effectiveness?

BACKGROUND: Wearing a face mask is one of the most effective personal protective strategies to diminish the spread of coronavirus disease 2019 (COVID-19). Several dermatological outcomes were reported because of the prolonged use of face masks, especially due to the constant mask-on policy, but the photoprotective effect of face masks has received less attention. OBJECTIVE: The aim of this study was to provide guidance in the use of face masks by comparing the photoprotective effects of routinely used masks. METHODS: A total of 12 frequently used face masks were tested, including certified respirators, Korea filter (KF)94, KF-anti-droplet (KF-AD), and KF80. The amount of light that penetrates each face mask was measured using a light sensor that can quantify Ultraviolet A (UVA), visible light (VL), and infrared A (IR-A) rays. RESULTS: Black-colored KF94 masks and surgical masks reduced penetration of UVA, VL, and IR-A by approximately 100%. The UVA penetration decreased on average by 95.51%, 90.97%, 85.06%, and 86.41% with white-colored KF94, KF-AD, KF80, and surgical masks, respectively. The VL and IR-A were blocked by approximately 75.58%, 66.16%, 59.18%, and 64.48% with white-colored KF94, KF-AD, KF80, and surgical masks, respectively. CONCLUSION: In conclusion, the different photoprotective effectiveness of face masks was mainly determined by colors, and therefore, black-colored, multi-layered respirators can be recommended in terms of photoprotection in the COVID-19 pandemic. The quantified comparative results will be helpful to the person with pre-existing photo-aggravated dermatosis, especially in the season of the high intensity of sunlight.

An assessment method for dermal structures using cross-polarized light imaging with a green light-emitting diode.

BACKGROUND: Several experimental methods for evaluating dermal structures exist; however, most of these are not used in dermatology clinics because of cost and functional limitations. OBJECTIVE: To propose a simple, non-invasive method for dermal structure evaluation using a green light-emitting diode (LED) with cross-polarized light (CPL) imaging and compare the quality of the images taken using either green or white LED. MATERIALS AND METHODS: Skin specimens were taken from fifteen cadavers. Images were captured using CPL photography with a green or white LED. The Commission International d'Eclairage L*a*b* (CIELAB) values were calculated for each image. The skin specimens were processed and stained with Masson's trichrome to visualize collagen fibers with major image scattering. The images were histologically analyzed, and correlational and regression analyses were performed to determine the relationship between the L* values and histologic measurements. RESULTS: The L* values for the green images were positively correlated with collagen fiber density, reticular collagen bundle diameter, and dermal thickness. They were effective for estimating dermal properties. The L* values for the white images were positively correlated with reticular collagen bundle diameter and dermal thickness. Correlational coefficients for white images were lower than those for green images. In regression analysis, green images showed a higher coefficient of determination (R2 ) for predicting reticular collagen bundle diameter than white images (0.1128 vs. 0.0827). CONCLUSION: Cross-polarized light imaging with a green LED is a simple, non-invasive method for evaluating dermal structures. The use of a green LED was also more effective for image analysis.

High-Performance Acellular Tissue Scaffold Combined with Hydrogel Polymers for Regenerative Medicine.

Decellularization of tissues provides extracellular matrix (ECM) scaffolds for regeneration therapy and an experimental model to understand ECM and cellular interactions. However, decellularization often causes microstructure disintegration and reduction of physical strength, which greatly limits the use of this technique in soft organs or in applications that require maintenance of physical strength. Here, we present a new tissue decellularization procedure, namely CASPER (Clinically and Experimentally Applicable Acellular Tissue Scaffold Production for Tissue Engineering and Regenerative Medicine), which includes infusion and hydrogel polymerization steps prior to robust chemical decellularization treatments. Polymerized hydrogels serve to prevent excessive damage to the ECM while maintaining the sophisticated structures and biological activities of ECM components in various organs, including soft tissues such as brains and embryos. CASPERized tissues were successfully recellularized to stimulate a tissue-regeneration-like process after implantation without signs of pathological inflammation or fibrosis in vivo, suggesting that CASPERized tissues can be used for monitoring cell-ECM interactions and for surrogate organ transplantation.

Lipoteichoic acid from Lactobacillus plantarum elicits both the production of interleukin-23p19 and suppression of pathogen-mediated interleukin-10 in THP-1 cells.

In this study, the stimulatory effects of different lactic acid bacteria strains, and their subcellular fractions, on the THP-1 cell line were evaluated. Lactobacillus plantarum was found in particular to induce high levels of IL-23p19 mRNA, but it moderately induced TNF-alpha production. IL-10 production was not entirely affected by L. plantarum stimulation. When subcellular fractions of L. plantarum were used to treat THP-1 cells, IL-23p19 mRNA expression was enhanced in a dose-responsive manner, specifically by lipoteichoic acid (LTA). The cotreatment of THP-1 cells by both L. plantarum and Staphylococcus aureus LTA resulted in decreased IL-10 production when compared with cells treated by S. aureus LTA alone. Taken together, these data suggest that LTA isolated from L. plantarum elicits stimulatory effects upon the expression of IL-23p19 and inhibitory effects on pathogen-mediated IL-10 production.

New integration vector using a cellulase gene as a screening marker for Lactobacillus.

The new integration vector for Lactobacillus, pJC4, was developed using the extracellular endoglucanase A gene (celA) of Clostridium thermocellum as a screening marker. pJC4 was transformed into four Lactobacillus species, Lb. johnsonii, Lb. gasseri, Lb. bulgaricus, and Lb. plantarum. In each species, the pJC4 integrants were easily and accurately detected by the appearance of a clear halo on a cellulase screening plate without any false transformants. Polymerase chain reaction and Southern hybridization indicated that all transformants with clear halos contained pJC4 in their chromosomal DNAs. The celA gene could be a useful screening marker for other lactic acid bacteria.