Dataset Information

Long-term Effects of 222-nm ultraviolet radiation C Sterilizing Lamps on Mice Susceptible to Ultraviolet Radiation.

ABSTRACT: Germicidal lamps that emit primarily 254 nm ultraviolet radiation (UV) are routinely utilized for surface sterilization but cannot be used for human skin because they cause genotoxicity. As an alternative, 222-nm UVC has been reported to exert sterilizing ability comparable to that of 254-nm UVC without producing cyclobutane pyrimidine dimers (CPDs), the major DNA lesions caused by UV. However, there has been no clear evidence for safety in chronic exposure to skin, particularly with respect to carcinogenesis. We therefore investigated the long-term effects of 222-nm UVC on skin using a highly photocarcinogenic phenotype mice that lack xeroderma pigmentosum complementation group A (Xpa-) gene, which is involved in repairing of CPDs. CPDs formation was recognized only uppermost layer of epidermis even with high dose of 222-nm UVC exposure. No tumors were observed in Xpa-knockout mice and wild-type mice by repetitive irradiation with 222-nm UVC, using a protocol which had shown to produce tumor in Xpa-knockout mice irradiated with broad-band UVB. Furthermore, erythema and ear swelling were not observed in both genotype mice following 222-nm UVC exposure. Our data suggest that 222-nm UVC lamps can be safely used for sterilizing human skin as far as the perspective of skin cancer development.

SUBMITTER: Yamano N

PROVIDER: S-EPMC7497027 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Long-term Effects of 222-nm ultraviolet radiation C Sterilizing Lamps on Mice Susceptible to Ultraviolet Radiation.

Yamano Nozomi N Kunisada Makoto M Kaidzu Sachiko S Sugihara Kazunobu K Nishiaki-Sawada Aiko A Ohashi Hiroyuki H Yoshioka Ai A Igarashi Tatsushi T Ohira Akihiro A Tanito Masaki M Nishigori Chikako C

Photochemistry and photobiology 20200531 4

Germicidal lamps that emit primarily 254 nm ultraviolet radiation (UV) are routinely utilized for surface sterilization but cannot be used for human skin because they cause genotoxicity. As an alternative, 222-nm UVC has been reported to exert sterilizing ability comparable to that of 254-nm UVC without producing cyclobutane pyrimidine dimers (CPDs), the major DNA lesions caused by UV. However, there has been no clear evidence for safety in chronic exposure to skin, particularly with respect to ...[more]

PMID: 32222977

Similar Datasets

Project description:BackgroundIn dentistry, instruments, appliances, and body fluids such as saliva or blood are possible sources of infection. Although conventional antiseptic procedures effectively prevent infection, spittoons cannot be sanitized between each treated patient and are usually washed only with running water. However, there is currently no fast and efficient disinfection method that can be implemented between treatments. An optically filtered krypton chloride excimer lamp using ultraviolet light (Far UV-C) in the 200-230 nm wavelength range (innocuous to humans) has been recently used as a virus- and bacteria-inactivating technology. This study aimed to identify the bioburden of a dental spittoon and examine the susceptibility of two oral Streptococcus and two Enterococci to 222-nm Far UV-C by irradiating the spittoon with 222 nm Far UV-C for 5 min before evaluating the disinfection effect.MethodsBacterial analysis and real-time polymerase-chain reaction testing was used to confirm the spittoon's biological contamination. Bacterial susceptibility to a 222-nm Far UV-C was determined with a graded dose irradiation test. After each treatment, the spittoon was irradiated with 222-nm Far UV-C for 5 min, and the disinfecting effect was evaluated. Microbial analysis of the spittoon's surface was performed using the Silva database.ResultsWe found that > 97% of the microbes consisted of six bacterial phyla, whereas no viruses were found. Pseudomonas aeruginosa was frequently detected. The 1-log reduction value of two oral-derived Streptococci and two Enterococci species at 222-nm Far UV-C was 4.5-7.3 mJ/cm2. Exposure of the spittoon to 222-nm Far UV-C at 3.6-13.5 mJ/cm2 significantly decreased bacterial counts (p < 0.001).ConclusionsIrradiation with 222-nm Far UV-C at 3.6-13.5 mJ/cm2 significantly eliminates bacteria in spittoons, even when they are only rinsed with water. Hence, 222-nm Far UV-C irradiation may inhibit the risk of bacterial transmission from droplets in sink surfaces.

Project description:The role of ultraviolet radiation (UVR) exposure in the aetiology of retinal degeneration has been debated for decades with epidemiological evidence failing to find a clear consensus for or against it playing a role. A key reason for this is a lack of foundational research into the response of living retinal tissue to UVR in regard to modern ageing-specific parameters of tissue function. We therefore explored the response of cultured retinal pigmented epithelium (RPE), the loss of which heralds advanced visual decline, to specific wavelengths of UVR across the UV-B and UV-A bands found in natural sunlight. Using a bespoke in vitro UVR exposure apparatus coupled with bandpass filters we exposed the immortalised RPE cell line, ARPE-19, to 10 nm bands of UVR between 290 and 405 nm. Physical cell dynamics were assessed during exposure in cells cultured upon specialist electrode culture plates which allow for continuous, non-invasive electrostatic interrogation of key cell parameters during exposure such as monolayer coverage and tight-junction integrity. UVR exposures were also utilised to quantify wavelength-specific effects using a rapid cell viability assay and a phenotypic profiling assay which was leveraged to simultaneously quantify intracellular reactive oxygen species (ROS), nuclear morphology, mitochondrial stress, epithelial integrity and cell viability as part of a phenotypic profiling approach to quantifying the effects of UVR. Electrical impedance assessment revealed unforeseen detrimental effects of UV-A, beginning at 350 nm, alongside previously demonstrated UV-B impacts. Cell viability analysis also highlighted increased effects at 350 nm as well as 380 nm. Effects at 350 nm were further substantiated by high content image analysis which highlighted increased mitochondrial dysfunction and oxidative stress. We conclude that ARPE-19 cells exhibit a previously uncharacterised sensitivity to UV-A radiation, specifically at 350 nm and somewhat less at 380 nm. If upheld in vivo, such sensitivity will have impacts upon geoepidemiological risk scoring of macular sensitivity.

Dataset Information

Long-term Effects of 222-nm ultraviolet radiation C Sterilizing Lamps on Mice Susceptible to Ultraviolet Radiation.

Publications

Long-term Effects of 222-nm ultraviolet radiation C Sterilizing Lamps on Mice Susceptible to Ultraviolet Radiation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets