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The Dead Sea basin is lowest terrestrial site on the globe. A meteorological station monitoring the global, UVB and UVA irradiation and the dry bulb temperature was established in 1995 in conjunction with a study of bio-climatological properties of the region with regard to photoclimatherapy treatment of dermatological diseases. The availability of such irradiation and dry bulb temperature databases has been utilized to perform a study to determine if any trends regarding either irradiation or dry bulb temperature exist at this unique site. There was no indication of any trends, based upon a p-value analysis, regarding the global, UVB and UVA irradiation. The global irradiation database included the time interval 1995-2020; whereas the corresponding time interval for the UVB and UVA irradiation databases was 1995-2018. The dry bulb temperature database consisted of the time interval 1995-2020 and, once again, no trends were observed throughout the year with the exception of the nocturnal time interval, between 18:00 to 06:00, during the month of October which exhibited a warming trend of 0.78°C/decade

Many cell-matrix interaction studies have proved that dynamic changes in the extracellular matrix (ECM) are crucial to maintain cellular properties and behaviors. Thus, developing materials that can recapitulate the dynamic attributes of the ECM is highly desired for three-dimensional (3D) cell culture platforms. To this end, we sought to develop a hydrogel system that would enable dynamic and reversible turning of its mechanical and biochemical properties, thus facilitating the control of cell culture to imitate the natural ECM. Herein, a hydrogel with dynamic mechanics and a biochemistry based on an addition-fragmentation chain transfer (AFCT) reaction was constructed. Thiol-modified hyaluronic acid (HA) and allyl sulfide-modified e-poly-L-lysine (EPL) were synthesized to form hydrogels, which were non-swellable and biocompatible. The reversible modulus of the hydrogel was first achieved through the AFCT reaction; the modulus can also be regulated stepwise by changing the dose of UVA irradiation. Dynamic patterning of fluorescent markers in the hydrogel was also realized. Therefore, this dynamically controllable hydrogel has great potential as a 3D cell culture platform for tissue engineering applications.

Background: Keratoconus is a condition characterized by biomechanical instability of cornea presenting in a progressive asymmetry and bilateral way. Corneal collagen cross-linking with riboflavin and UVA is a technique that has influenced the treatment of Keratoconus by arresting the progression. Aims and Objectives: The aim of the study was to assess the short-term efficacy and safety of collagen cross-linking in Keratoconus. Materials and Methods: This prospective, nonrandomized, interventional case study was conducted at Aravind Eye hospital and PGI, Puducherry from June 2012 to April 2013. Statistical analysis was done using repeated measures ANOVA and Bonferonn’s using IBM SPSS Inc. 20.Version. Results: A total of 30 patients were enrolled in this study and standard cross linking procedure was done. It was found that UCVA, BSCVA both improved about 40%. Spherical Equivalent reduced by 0.7 D, cylinder reduced by 0.8 D and total astigmatism decreased by about 0.4 D. Steepest K value reduced by 2 D, Irregularity and astigmatism at 3 and 5 mm also changed significantly (P

BACKGROUND: Grape seed proanthocyanidin extract (GSPE) has a certain resistance to contrast light, which makes the boundary of the imaging image unclear. OBJECTIVE: Because of this, an image processing algorithm is needed to process the contrast image to study the role of GSPE in the process of anti-ultraviolet. METHODS: In this paper, the fuzzy edges of contrast images were processed by deep learning algorithm, and the changes of VEGF and PEDF expression in HaCaT cells before and after UVA irradiation and after GSPE intervention were studied. RESULTS: The experiment results show that after processing, the edge and boundary of the image become clear and separable, which can be used to compare and analyze the test process. The image comparison results show that GSPE can down regulate the expression of VEGF gene and protein, and up regulate the expression of PEDF gene and protein. The synergistic effect of GSPE and GSPE can inhibit angiogenesis. It is confirmed that GSPE has the effect of anti-ultraviolet ray induced early angiogenesis.

BACKGROUND We have observed an increasing number of patients referred to the Scottish Photobiology Service (SPS), who were later diagnosed with actinic folliculitis (AF) and had positive phototesting results. Treatment options for AF are limited, with only a few reports in the literature. The use of prophylactic narrowband ultraviolet B (NB-UVB) phototherapy for AF has not previously been described, and we report on this for the first time. AIM To analyse the clinical characteristics, phototesting results and responses to treatment for patients with AF diagnosed by the SPS. METHODS We undertook a retrospective review over 10 years of all case notes of patients who were assessed and diagnosed with AF through the SPS, based at the Photobiology Unit, Dundee, UK. RESULTS All 10 patients were women. Mean age of onset was 25 years and mean time to referral for investigation was 7 years. The commonest site involved was the face, with the main clinical feature being monomorphic pustules appearing after sunlight exposure. The eruption could be provoked with iterative doses of broadband UVA irradiation in five patients. All patients were offered photoprotective advice and prophylactic NB-UVB phototherapy. Five patients proceeded with phototherapy; four of these completed the desensitization course and all four reported either a delay in symptom onset or total prevention of rash induction, with complete efficacy of desensitization maintained for 3 years in one patient. CONCLUSION We demonstrate the successful use of UVA provocation testing as a diagnostic tool in AF. Additionally, we recommend the use of prophylactic NB-UVB phototherapy in AF as an effective and well-tolerated approach.

PURPOSE To assess corneal biomechanical changes after conventional corneal crosslinking (CXL), with and without oxygen enrichment. METHODS Sixty fresh porcine corneas were randomly divided into group 1 (control), group 2 (conventional CXL), and group 3 (conventional CXL in a high-oxygen environment during ultraviolet A [UVA] irradiation). After crosslinking, a 5-mm wide corneal strip was extracted using a double-bladed knife from 12 to 6'o clock. The Young's modulus of each strip was determined by stress-strain measurements. A comparison between the three groups was performed with a one-way analysis of variance. RESULTS At 4% strain, the Young's modulus of the corneas in groups 1, 2, and 3 were: 0.68±0.20 megapascal (MPa), 1.01±0.23 MPa, and 1.12±0.24 MPa, respectively. The Young's modulus values for groups 2 and 3 showed no statistical significance (P>0.05), However, both groups 2 and 3 were significantly higher than group 1 (P

Purpose To evaluate whether Accelerated CXL for 10 minutes is as effective as standard CXL for 30 minutes for the treatment of progressive keratoconus. Patients and methods Eighty-two eyes of 62 patients with keratometry examinations performed before and 6 months after surgery were studied. A total of 39 eyes underwent standard CXL with UVA irradiation of 3 mW/cm2 for 30 minutes and 32 eyes underwent Accelerated CXL UVA irradiation of 9 mW/cm2 for 10 minutes. The eyes of all patients had corneal thicknesses of at least 450 microns (400 microns after epithelium removal). Results The means of the keratometry measurements in the preoperative period for the eyes subjected to standard CXL were 46.27 dioptres (D) on the flat axis (K1) and 48.93 D on the steep axis (K2). Postoperatively, K1 was 46.21 D and K2 was 48.97 D, a difference without statistical significance (p = 0.47 and p = 0.48, respectively). In the Accelerated CXL protocol, the preoperative measurements were 44.55 D and 46.19 D for K1 and K2, respectively. In the postoperative period, K1 was 43.37 D, and K2 was 46.64 D (p = 0.38 and p = 0.27, respectively). In the standard group, the mean maximum keratometry (Kmax) preoperatively was 55.87 D, with no statistical significance (p = 0.29). In the preoperative period, the Kmax of the Accelerated group was 51.15 D, with no statistical significance (p = 0.32). Conclusion Based on the keratometry results, the accelerated protocol was as effective as the standard protocol for keratoconus stabilization.

The effects of phlorotannin extracts (PTE) (from sporophyll of Undaria pinnatifida) added at different concentration (0, 1.6, 8, and 40 mg/g protein) with and without ultraviolet A (UVA) irradiation treatment on gel properties of mackerel (Scomberomorus niphonius) mince (MM) were investigated. The results indicated that both the breaking force and water-holding capacity (WHC) of the MM gel increased with addition of PTE, and the highest breaking force and WHC were observed with 40 mg/g PTE under UVA irradiation. Low-field nuclear magnetic resonance revealed that free water significantly decreased in this PTE-MM gel as well. UVA irradiation treatment led to reduction of total sulfhydryls and free amines in the PTE-MM gel, indicating more cross-linking between proteins. Electrophoresis results indicated that myosin heavy chains were aggregated in the UVA-treated PTE-MM gel. The microstructure of the UVA-treated PTE-MM gel showed that protein formed more evenly distributed cross-linked structures and was more compact than the untreated control gel. As a conclusion, PTE addition with UVA irradiation is shown to improve gelling properties of mackerel mince.

The decolorization of azo dye Orange II using a UVA-Fe3+-PMS-oxalate system was studied. A series of experiments was performed to investigate the effects of several variables, including the pH, PMS dosage, Fe3+ concentration, oxalate concentration, and coexisting anions. The results revealed that a lower pH facilitated the decolorization, and relatively high decolorization efficiency (97.5%) could be achieved within 5 min at pH 3.0. The electron paramagnetic resonance (ESR) and radical quenching experiments revealed that SO4•− played a crucial role in the decolorization of Orange II (85.8%), •OH was of secondary importance (9%), and 1O2 made a small contribution to the decolorization (5.2%). Furthermore, the formation of •OH in the experimental system strongly depended on HO2•/O2•−. These reactive oxidants were able to directly attack the azo bond of the luminescent group in Orange II and initiate the decolorization process. The efficient UVA-Fe3+-PMS-oxalate system showed great application potential in the treatment of wastewater contaminated by azo dyes.

The objectives of this study were to characterize zein fibers and capsules prepared by electrospinning and electrospraying techniques, respectively, and then use them to encapsulate folic acid. Folic acid containing fibers and capsules (0.5, 1.0, and 1.5%, w/v) were submitted to thermal treatment (100, 140, and 180 °C) and ultraviolet A light (UVA) irradiation to evaluate the resistance of folic acid. Zein fibers and capsules containing folic acid showed high encapsulation efficiency (>80%). Unencapsulated folic acid showed a reduction in folic acid content from 17.17 μg/mL to 5.44 μg/mL (approximately 70%) when exposed to 180 °C. Photodegradation of unencapsulated folic acid lowered its concentration from 17.17 μg/mL to 12.58 μg/mL (~26% of reduction), when exposed for 1 h to UVA irradiation. However, folic acid concentration when encapsulated in fibers (1.5%) was maintained or only slightly reduced from 9.73 μg/mg to 8.88 μg/mg after thermal treatment at 180 °C. The capsules containing 1.5% of folic acid also presented a slight reduction in folic acid concentration from 8.84 μg/mg to 7.88 μg/mg when exposed to 24 h of UVA irradiation. Zein fibers and capsules containing folic acid present promising characteristics for application in foods that require thermal processing or exposure to irradiation.

Aim. In this work, the authors set out to develop an effective method for the intrafollicular delivery of “Ammi majus fructuum furocumarines” photosensitizer (AMFF) followed by UVA irradiation (λ = 320–400 nm). Materials and methods. The proposed delivery method consists in using calcium carbonate particles acting as AMFF carriers. In vivo monitoring of hair follicle filling was carried out via optical coherence tomography, as well as by means of analyzing epilated hair using confocal laser scanning microscopy. Following the administration of free and encapsulated AMFF to three healthy volunteers, the character of UVA-induced skin pigmentation was registered under dermatoscopic examination. Results. The obtained results demonstrate a profuse filling of hair follicles with calcium carbonate particles, thus confirming the possibility of intrafollicular photosensitizer delivery. It was established that exposure to UVA irradiation causes intense pigment accumulation in the area of AMFF carrier administration. Conclusion. The proposed method of the targeted photosensitizer delivery allows photochemical therapy to be improved.

In the present study (clinical trial registration number: NCT05019768), we compared the clinical outcome of corneal cross-linking with either the standard Dresden (sCXL) or the accelerated custom-fast (aCFXL) ultraviolet A irradiation protocol using riboflavin–D-α-tocopheryl poly(ethylene glycol)-1000 succinate for progressive keratoconus. Fifty-four eyes of forty-one patients were randomized to either of the two CXL protocols and checked before treatment and at the 2-year follow-up. The sCXL group was subjected to CXL with 30 min of pre-soaking and 3 mW/cm2 UVA irradiation for 30 min. The aCFXL group was subjected to CXL with 10 min of pre-soaking and UVA irradiation of 1.8 ± 0.9 mW/cm2 for 10 min ± 1.5 min. In both groups, a solution of riboflavin–vitamin E TPGS was used. Uncorrected distance visual acuity, corrected distance visual acuity, pachymetry, Scheimpflug tomography, and corneal hysteresis were performed at baseline and after 24 months. Both groups showed a statistically significant improvement in corrected distance visual acuity, and keratometric and corneal hysteresis compared to baseline conditions, no statistically significant differences in outcomes between the two groups were observed. Improvement in refractive, topographic, and biomechanical parameters were observed after sCXL and aCFXL, making the riboflavin–VE-TPGS solution an effective option as a permeation enhancer in CXL procedures. Deeper stromal penetration of riboflavin could be complemented by photo-protection against UVA and free radicals formed during photoinduced processes.

BACKGROUND Oxidized phlorotannin can be used as a protein crosslinking agent to produce high-quality fish gel products. Phlorotannin can be easily induced to form quinone compounds in an oxidizing environment, while o-quinone has been proven to be a reactive, electrophilic intermediate that easily reacts with proteins to form rigid molecular crosslinking networks. The objective of this study was to investigate the synergistic effects of ultraviolet A (UVA) irradiation (1 h, 15 W m-2 ) and various concentrations of Laminaria japonica phlorotannin extracts (PTE) on the gel properties of grass carp myofibrillar protein (MP). RESULTS UVA treatment and PTE could synergistically improve the MP gel properties more than PTE alone (P

Photoageing and skin cancer are major causes of morbidity and are a high cost to society. Interest in the development of photoprotective agents for inclusion in topical cosmetic and sunscreen products is profound. Recently, amino acids with a sulfinic group, notably hypotaurine, have been included as ingredients in cosmetic preparations. However, the mechanism of action of hypotaurine as a possible anti-aging agent is unknown, despite its use as a free radical scavenger. To address this issue, we investigated hypotaurine uptake in a human keratinocyte model and examined its effect on UVR-induced cytotoxicity. Hypotaurine was taken up by keratinocytes in a time- and concentration-dependent manner, with levels remaining significantly above baseline 48 h after washout. A cytoprotective effect of pre-incubation with 2.5-5 mMhypotaurine was shown as indicated by increased cell viability when keratinocytes were irradiated with UVA at 5 or 10 Jcm-2 , with the level of hypotaurine also significantly reduced. These findings indicate a potential cytoprotective effect of hypotaurine against the deleterious effects of UVA irradiation. This provides support for further studies to evaluate the potential photoprotective benefits of hypotaurine supplementation of topical cosmetic and sunscreen products.

Electron paramagnetic resonance (EPR) spectroscopy is an established method for the measurement of free radicals. Solar radiation is essential for human life as it stimulates vitamin D synthesis and well-being. However, an excessive dose of solar radiation leads to the formation of free radicals. Here, we describe an EPR method for measuring the amount of radicals induced by UVA irradiation in excised skin. For the first time, a wavelength stable UVA LED (365 nm) was used. The method allows the quantitative determination of radicals in skin before, during, and after UVA irradiation. A dose-dependent radical production could be demonstrated, independent of the yielded power.

Aim: UVA radiation drives skin photoaging in the dermis, plausibly via persistent changes to DNA methylation in dermal fibroblasts. Methods: Genome-wide DNA methylation changes after five repeated daily UVA doses were determined at 48 h (transitionary) and 1 week (recovery) post final irradiation. Results: Differential methylation was found at the transitionary time point in active chromatin states near genes that are highly expressed in fibroblasts and are involved in cellular defensive mechanisms; the majority of these methylation differences were restored to control levels after 7 day recovery. At the recovery time point, new differential methylation occurred at repressed regions near developmental genes, normally weakly expressed in fibroblasts. Conclusion: UVA irradiation induces transitionary and recovery-associated DNA methylation responses in fibroblasts with contrasting functional characteristics.

The photochemical behavior of several dienones was studied under aerobic conditions. 2-Allylidene-1,3-cycloalkanediones prepared via Knoevenagel-type condensation between simple readily available 1,3-dicarbonyl substrates and á,â-unsaturated aldehydes afforded 1,2,4-trioxane derivatives upon UVA irradiation in the presence of oxygen. This domino self-sensitized photooxygenation cascade of conjugated carbonyl systems proceeds stereoselectively and involves the formation of two new oxa-cycles, three new bonds (two C-O), and three stereocenters. Fil: Riveira, Martín Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Martiren, Nadia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Mischne, Mirta Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina

The photostability of drugs administered topically on unprotected skin is a complex phenomenon that could be connected with the loss of activity or, rather rarely, the occurrence of toxic degradation products. In this study, an in-depth investigation of the photostability of terbinafine, in both solutions and formulations, was conducted, taking into account the presence of UV absorbers such as TiO2 , ZnO, avobenzone, 3-(4-methylbenzylidene)camphor, octocrylene, benzophenone-1 and benzophenone-2. The clear photocatalytic degradation of terbinafine in ethanol solution was observed in the presence of TiO2 and/or ZnO. In other cases, terbinafine was stable, with the exception of, in the presence of octocrylene. The presumed degradation products of terbinafine were identified for the first time using LC/MS/MS, and transformation pathways were proposed. In the case of a cream formulation, the percentage of initial terbinafine content was almost unchanged in the presence of the UV absorbers benzophenone-1, benzophenone-2 and 3-(4-methylbenzylidene)camphor. In vitro cytotoxicity risk assessment of terbinafine based on photostability under UVA irradiation was evaluated using the human skin fibroblast BJ (ATCC® CRL-2522™), and this showed no statistically significant difference in cell viability for all samples analyzed.

Repair of ribosomal DNA (rDNA) is a very important nuclear process due to the most active transcription of ribosomal genes. Proper repair of rDNA is required for physiological biogenesis of ribosomes. Here, we analyzed the epigenetics of the DNA damage response in a nucleolar compartment, thus in the ribosomal genes studied in nonirradiated and UVA-irradiated mouse embryonic fibroblasts (MEFs). We found that the promoter of ribosomal genes is not abundant on H4K20me2, but it is densely occupied by H4K20me3. Ribosomal genes, regulated via UBF1/2 proteins, were characterized by an interaction between UBF1/2 and H4K20me2/me3. This interaction was strengthened by UVA irradiation that additionally causes a focal accumulation of H4K20me3 in the nucleolus. No interaction has been found between UBF1/2 and H3K9me3. Interestingly, UVA irradiation decreases the levels of H3K9me3 and H4K20me3 at 28S rDNA. Altogether, the UVA light affects the epigenetic status of ribosomal genes at 28S rDNA and strengthens an interaction between UBF1/2 proteins and H4K20me2/me3.

In this study, we explored the effects of unripe fruit extracts of Mangifera indica L. on the anti-aging activity in skin cells. Mangifera indica L. is a popular economical and medicinal plant with numerous health-beneficial properties. The aqueous extracts of unripe fruit of Mangifera indica L. were obtained and subjected to HPLC and NMR analyses for the identification of bioactive compounds. The anti-glycation effect of Mango unripe fruit extracts was monitored by in vitro model system of AGEs (Advanced glycation end products) formation. Mango unripe fruit extracts significantly inhibited the AGEs formation in a dose-dependent manner. Meanwhile, Mango unripe fruit extracts possessed a comparable efficiency to commercialized Kojic acids in the inhibition of melanogenesis in B16-F10 melanoma cells. The UVA-induced cell damages can be prevented and repaired by Mango unripe fruit extracts in skin fibroblast CCD-966SK. Compared to the untreated control, Mango unripe fruit extracts significantly increased the cell viability while being applied before (36%) or after (43%) UVA irradiation. These results verified the potential application of Mango unripe fruit extracts in the skin protection and recovery from UVA irradiation, as well as the suppression of AGEs formation and melanogenesis.

Purpose: To evaluate the long-term outcomes of collagen crosslinking in early keratoconus. Methods: Thirty eyes of twenty patients with early keratoconus were enrolled. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), objective refraction, subjective refraction, corneal topography and pachymetry were assessed before and 3, 6, 12 months and 9 years after performing collagen crosslinking surgery. Results: The patients' mean age was 31.2 ± 5.59 years at nine-year follow-up (range, 25–44 years). The means of preoperative UCVA and BSCVA were 0.57 ± 0.34 and 0.15 ± 0.12 logMAR, respectively, and these values remained stable at the final follow-up (P = 0.990 and P = 0.227, respectively). The mean objective spherical equivalent decreased considerably from –6.00 ± 4.05 D preoperatively to –5.22 ± 3.71 D at the final follow-up (P < 0.05). The mean subjective spherical equivalent was –4.25 ± 2.87 D preoperatively and this value was stable at the last follow-up (P = 0.92). No considerable difference was found between the post- and preoperative mean objective cylinder values (P = 0.34). The mean subjective cylinder value changed significantly from –4.05 ± 1.85 D preoperatively to –3.1 ± 1.42 D at the final follow-up (P < 0.05). The mean central corneal thickness was 496.97 ± 45.95 µm preoperatively and this value was stable at nine-year follow-up (P = 0.183). No significant difference was found between the pre- and postoperative mean maximum and mean minimum corneal curvature values (P = 0.429 and P = 0.248, respectively). There were no significant postoperative complications. Conclusion: Corneal crosslinking in early keratoconus seems to be a safe procedure that can effectively stabilize UCVA, BSCVA, subjective SE and CCT, while improving objective spherical equivalent.

Photostability of all-trans retinyl palmitate (RP) (100% bioactivity) was studied in policosanol oleogels (PCOs) (7–12% w/w policosanol in soybean oil) after UVA irradiation. RP was incorporated into PCOs at levels of 0.04%, 0.1% and 1% (w/w). PCOs efficiently protected RP from UVA-mediated degradation. Over 75% RP-activity remained in PCOs after 4 days of UVA irradiation, while 12% RP-activity remained in soybean oil. HPLC analysis showed that cis-RP was formed in liquid soybean oil after 2 days of UVA irradiation while it was absent in PCOs matrices. PCOs blocked the energy absorption from UVA and further dampened the UVA-mediated ionic photodissociation and free radical reaction due to matrix immobilization. For all samples, RP photodegradation followed a 2nd order reaction. From the reaction kinetics, it would be possible to predict the RP photodegradation rate in PCO matrices. PCOs were shown to be a promising matrix to protect RP from photodegradation.

International audience; Although there is a growing interest in Fenton oxidation processes based on natural catalysts, the use of laterite soil to promote sequential adsorption/oxidation treatments of fluoroquinolone antibiotics has been scarcely investigated. In this work, the ability of an african laterite containing goethite and hematite to remove flumequine (FLU), used as a representative compound of fluoroquinolone antibiotics, was evaluated under dark and UVA irradiation. Batch experiments and liquid chromatography analyses showed that the presence of laterite can enhance FLU removal from heavily contaminated water through both sorption and oxidation reactions (up to 94% removal of 77 μmol L−1 of FLU and 72% of mineralization). The heterogeneous reaction rate is dominated by the rate of intrinsic surface chemical reactions including sorption and oxidation of FLU, and light-induced reduction of FeIII sites to produce FeII. Based on the probe and scavenging experiments, [rad]OH radicals were mainly involved in the heterogeneous oxidation reaction. The photo-assisted Fenton process showed a high efficiency of FLU removal even in the presence of a second fluoroquinolone antibiotic, norfloxacin (NOR), which can be co-found with FLU in affected environments. Determinations of kinetic rate constants and total organic carbon (TOC) for five sequential adsorption/oxidation cycles showed that laterite exhibited no deactivation of surface sites and an excellent catalytic stability. This cost-effective and environmentally friendly remediation technology may appear as a promising way for the removal of fluoroquinolone antibiotics from multi-contaminated waters. © 2017 Elsevier Ltd

International audience; Few studies have focused on the protective role of selenium (Se) against skin aging and photoaging even though selenoproteins are essential for keratinocyte function and skin development. To the best of our knowledge, the impact of Se supplementation on skin cells from elderly and young donors has not been reported. Therefore, the main objective of our study was to evaluate the effects of Se supplementation on skin keratinocytes at baseline and after exposure to ultraviolet A (UVA) irradiation. Low doses of Se (30 nM) were very potently protective against UVA-induced cytotoxicity in young keratinocytes, whereas the protection efficiency of Se in old keratinocytes required higher concentrations (240 nM). Additionally, the DNA repair ability of the old keratinocytes drastically decreased compared with that of the young keratinocytes at baseline and after the UVA exposure. The Se supplementation significantly enhanced the DNA repair of 8-oxoguanine (8oxoG) only in the keratinocytes isolated from young donors. Therefore, aged keratinocytes have an increased vulnerability to oxidative DNA damage, and the Se needs in the elderly should be considered. Strengthening DNA repair activities with Se supplementation may represent a new strategy to combat aging and skin photoaging.

11 páginas.-- 7 figuras.-- 4 tablas.-- 56referencias, The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO 2) coatings have been employed on building materials for degrading organic compounds deposited on building surfaces, improving their durability and performance. In this study, the self-cleaning effect of TiO 2-containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO 2 (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state 13C NMR spectroscopy. The FESEM and colour spectrophotometry revealed that the soot-coated TiO 2-containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and 13C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. Our findings also revealed that the inclusion of TiO 2 in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO 2 and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition, J.M. de la Rosa and A.Z. Miller thank The Spanish Ministry of Economy and Competitiveness (MINECO) for the “Ramón y Cajal” and Juan de la Cierva postdoctoral contracts, respectively. J.S. Pozo-Antonio was supported by a postdoctoral contract within the framework of the 2011–2015 Galician Plan for Research, Innovation and Growth (Plan I2C) for 2014. This work was also co-funded by the Strategic project FCT - UID/ECI/04028/2013.

PURPOSE: To evaluate the performance of different customized corneal cross-linking (CXL) methods. METHODS: This was a single-center interventional, prospective, longitudinal case series. Four different customized CXL methods were evaluated in keratoconic eyes: (1) uniform (uniform intensity ultraviolet-A [UVA] beam [9 mW/cm 2 ] for 10 minutes) (n = 12 eyes); (2) sector axial map (sector-based UVA irradiation) (n = 12 eyes); (3) ring axial map (concentric rings of UVA beam intensity centered at the steepest curvature of the anterior axial map) (n = 12 eyes); and ring tangential map (same as the ring axial map but centered at the steepest curvature of the anterior tangential map) (n = 14 eyes). Peak UVA energy density in the sector and ring axial map (and ring tangential map) protocols did not exceed 15.0 and 10.8 J/cm 2 , respectively. A 0.1% riboflavin solution was applied after epithelium removal. Corneal tomography and visual acuity were assessed before and 6 months after CXL. RESULTS: Average and peak energy density was lowest in the ring tangential protocol and highest in the sector axial map group ( P < .001). Treated area was lowest in the ring tangential map group and highest in the uniform group ( P < .001). Decrease in curvature was similar among the uniform, sector axial map, and ring axial map groups ( P < .05). The ring tangential map group had the greatest decrease in curvature per unit energy dose to the cornea ( P < .05). Improvement in uncorrected (0.081 ± 0.056 logMAR) and corrected (0.041 ± 0.026 logMAR) distance visual acuity per unit energy density was greatest in the ring tangential map group ( P > .05). CONCLUSIONS: When normalized to the average energy density, the ring tangential map protocol appeared to provide maximum flattening and improvement in visual acuity. Further studies with larger sample sizes are needed to validate the findings of this pilot study. [ J Refract Surg. 2017;33(10):676–682.]

Herein, we report a systematic investigation into the role of particle size of Bi2O3 nanoparticles on their photocatalytic activity. The range of particle size is from 11 to 27 nm. Using degradation and mineralization of atrazine under UVA light as probe reactions, we show that photocatalytic activity is very sensitive to particle size. A slight difference in particle size leads to a significant difference in photocatalytic activity. Photocatalytic activity does not linearly increase with increasing particle size. Within 1 h of 2.42 W/m2 UVA irradiation at pH 6, the degradation efficiency for 5 mg/L of atrazine using 1 g/L of Bi2O3 with an average particle size of 11, 16.7, 20.1 and 26.8 nm is 84.9, 87.5, 92.1 and 75.5%, respectively. There is an optimum particle size, which is found to be 20.1 nm, as the best compromise between surface area and surface recombination. With these results, the particle size effect should be really taken into account so as to achieve appreciable performance for further development of photocatalytic system involving Bi2O3.

Purpose To determine the intrastromal concentration of riboflavin in nanotechnology-based transepithelial corneal crosslinking. Setting Consiglio Nazionale delle Ricerche, Messina, Italy. Design Experimental study. Methods Six human donor sclerocorneal tissues were used to evaluate penetration of nanotechnology-based riboflavin 0.1% solution in the stroma through the intact epithelium. Three additional tissues were deepithelialized and soaked with dextran 20.0%–enriched riboflavin 0.1% solution for 30 minutes. After corneal soaking with riboflavin, all tissues were irradiated using a 10 mW/cm2 device for 9 minutes. Two-photon emission fluorescence (TPEF) axial scanning measurements were collected in all specimens before treatment and immediately after corneal soaking with riboflavin and ultraviolet-A (UVA) irradiation of the cornea. The absorbance spectra of each tissue were collected at the same time intervals. The TPEF signals and absorbance spectra were used to calculate the concentration-depth profile of riboflavin in the corneal stroma during treatments. Results The mean stromal riboflavin concentration was 0.008% ± 0.003% (SD) and 0.017% ± 0.001% after transepithelial soaking with the nanotechnology-based solution and standard soaking, respectively (P = .001). After UVA irradiation of the cornea, the mean consumption of riboflavin was 52% ± 13% and 67% ± 2% in the study group and control group, respectively (P Conclusions The nanotechnology-based platform was effective in enriching the anterior stroma with riboflavin through the intact epithelium, although the riboflavin concentration–depth profile rapidly decreased across the mid and posterior stroma. The treatment-induced stiffening effect on the corneal stroma was not assessed in this study.

The combination of light activation and N‐heterocyclic carbene (NHC) organocatalysis has enabled the use of acid fluorides as substrates in a UVA‐light‐mediated photochemical transformation previously observed only with aromatic aldehydes and ketones. Stoichiometric studies and TD‐DFT calculations support a mechanism involving the photoactivation of an ortho‐toluoyl azolium intermediate, which exhibits “ketone‐like” photochemical reactivity under UVA irradiation. Using this photo‐NHC catalysis approach, a novel photoenolization/Diels–Alder (PEDA) process was developed that leads to diverse isochroman‐1‐one derivatives., Photo‐NHC catalysis is introduced as a strategy for engaging hitherto unsuitable carbonyl substrates at the carboxylic acid oxidation level in photochemical transformations of aldehydes and ketones. This approach enables an NHC‐catalyzed photoenolization/Diels–Alder (PEDA) reaction of acid fluorides to isochroman‐1‐ones. The NHC likely acts as a “transient aryl group” that temporarily changes the photochemical properties of the carbonyl substrate.

To date, the degradation of microplastics (MPs;5 mm) in different environments, particularly their adsorption characteristics for coexisted metal pollutants remains to be elucidated. Thus, this study investigated the effects of aging MPs, including polyamide (mPA), polyethylene terephthalate (mPET), polystyrene (mPS), and polyvinyl chloride (mPVC) for 3 months under UVA irradiation in four environmental media (air, seawater, sand, and soil) and adsorption of heavy metals (Cu, Cd) onto seawater-aged mPS and mPVC. The results showed that surface morphological changes, including cracks, oxidized particles, and wrinkles, appeared on aged MPs. The heavy metal adsorption capacity decreased in the order aged mPVCaged mPS unaged mPS unaged mPVC, and the Cu

In many developing countries no infrastructure for providing people with microbiological safe drinking water exists. This demands for decentralized water disinfection that is inexpensive and requires no consumables. The casualties are often recommended the application of SODIS for drinking water treatment. There are numerous scientific studies on this disinfection method, which however are still leaving questions on the mode of functioning which is often reduced to the effect caused by the UV part of the solar radiation and there is almost no discussion in the literature what happens to the disinfected water after the SODIS treatment.In this paper disinfection experiments with Escherichia coli in isotonic saline solutions and real surface water are performed for a set of realistic conditions for UVA irradiation and for heating but separated from each other. The results confirm that SODIS is based on the combined effect of UVA radiation and increased temperature. Further experiments lead to the recommendation that once disinfected water should be consumed without a large delay, otherwise the germ concentration rises again.Int J Appl Sci Biotechnol, Vol 4(4): 430-435

Under mild UVA irradiation, the C Br bond of bromodiazines can be activated to generate the corresponding radical intermediate. In the presence of alkynes, alkenylation reactions occurred to afford vinyl pyrimidine in moderate yields. Csp2-phosphorous bond can also be easily created in a photochemical version of the Arbuzov reaction. With UVA and a stoichiometric amount of trimethyl phosphite, the corresponding phosphonates were isolated in good to high yields. Very interesting selectivities were observed under these mild irradiation conditions. Functionalized substrates can be engaged and the resulting products could be further derivatized.

BACKGROUND Extracorporeal photopheresis (ECP) is a therapeutic technique that combines leukapheresis and ultraviolet (UV)A irradiation of the leukapheresate after 8-methoxypsoralen treatment with subsequent retransfusion. It can be achieved with a single device (online) or by combining an apheresis machine with a separate UVA light source (offline). The comparability of both established methods is unknown. STUDY DESIGN AND METHODS In a prospective setting, four ECP systems were evaluated: one with integrated UVA irradiation for online ECP (Therakos) and three with external UVA irradiation for offline ECP (Amicus, Optia, and Cobe Spectra). Apheresis variables and cell counts were determined by methods including flow cytometry. RESULTS The duration of apheresis ranged from 120 minutes (Amicus, Optia) to 275 minutes (Therakos). Mononuclear cell (MNC) counts in the treatment bags were comparable between offline ECP methods (median, 57 × 108 – 66 × 108) and lower for online ECP (14 × 108). CD16+ monocytes were abundant in online ECP (82%) but rarer in offline ECP (median, 14% – 19%). Hematocrit ranged from 0.1% (Therakos) to 8% (Amicus). There were no side effects in any patients. DISCUSSION All offline ECP systems studied yielded comparable cellular compositions and highly enriched populations of MNCs. In contrast, white blood cells from online ECP displayed enrichment of nonclassical monocytes. The relevance of these findings is unknown as there is no established biomarker to predict the therapeutic efficacy of these procedures.

Epoxy resin samples were cyclically exposed to ultraviolet A (UVA) and a 5 wt% salt solution in a specially designed marine environment simulation system. Surface analyses indicated that UVA irradiation could accelerate the degradation of the epoxy surface and the dissolution of the degraded products, while the salt crystallization in the drying process could further accelerate the chalking and peeling of the degraded products. A possible synergistic effect between the UVA irradiation and salt crystallization was proposed to interpret the degradation, which may provide a new insight into the damage of organic polymer materials in marine environments.

In this paper we will describe a non-intrusive, optically-based instrument that can quantitatively measure singlet molecular oxygen, a constituent of reactive oxygen species (ROS) produced by irradiation of human skin by the longer wavelength UV radiation known as UVA. UVA is causally associated with DNA damage and subsequent development of melanoma. We will present data from healthy human subjects that show formation of singlet molecular oxygen and concomitant production of thymine dimers, indicative of DNA damage. We will also discuss how this instrument may be a valuable tool for the development of more effective sunblock formulations for UVA.

Friendreich's ataxia skin cells are highly sensitive to ultraviolet A due to their high levels of mitochondrial redox-active iron., Mitochondrial labile iron (LI) is a major contributor to the susceptibility of skin fibroblasts to ultraviolet A (UVA)-induced oxidative damage leading to necrotic cell death via ATP depletion. Mitochondria iron overload is a key feature of the neurodegenerative disease Friedreich's ataxia (FRDA). Here we show that cultured primary skin fibroblasts from FRDA patients are 4 to 10-fold more sensitive to UVA-induced death than their healthy counterparts. We demonstrate that FRDA cells display higher levels of mitochondrial LI (up to 6-fold on average compared to healthy counterparts) and show higher increase in mitochondrial reactive oxygen species (ROS) generation after UVA irradiation (up to 2-fold on average), consistent with their differential sensitivity to UVA. Pre-treatment of the FRDA cells with a bespoke mitochondrial iron chelator fully abrogates the UVA-mediated cell death and reduces UVA-induced damage to mitochondrial membrane and the resulting ATP depletion by a factor of 2. Our results reveal a link between FRDA as a disease of mitochondrial iron overload and sensitivity to UVA of skin fibroblasts. Our findings suggest that the high levels of mitochondrial LI in FRDA cells which contribute to high levels of mitochondrial ROS production after UVA irradiation are likely to play a crucial role in the marked sensitivity of these cells to UVA-induced oxidative damage. This study may have implications not only for FRDA but also for other diseases of mitochondrial iron overload, with the view to develop topical mitochondria-targeted iron chelators as skin photoprotective agents.

The number of plant factories in which crops are cultivated in an artificial environment has been increasing every year. In cultivation techniques involving hydroponics, plants are supplied with a circulating nutrient solution, which can become contaminated by pathogens that can propagate and spread throughout plant factories. Therefore, strategies to disinfect hydroponic nutrient solutions are needed. In this study, we developed a new disinfection device equipped with an ultraviolet A (UVA) light emitting diode (LED) that can be used to disinfect hydroponic nutrient solutions in plant factories. We first evaluated the basic disinfection capability of the device and then estimated its bactericidal effect in a small scale model system. The log survival ratio was related to UVA irradiation fluence and the volume of nutrient solution. From the assay results, we devised a kinetics equation to describe the relationship between nutrient solution volume, log survival ratio, and UVA fluence. Together our results show that UVA irradiation could be used to disinfect hydroponic nutrient solutions, and the derived kinetics equations can be used to determine optimal conditions, such as nutrient solution volume, UVA irradiation, and killing activity, to develop devices that disinfect hydroponic nutrient solutions. J. Med. Invest. 65:171-176, August, 2018.

An innovative procedure for the iodoperfluoroalkylation of alkenes/alkynes is described. These reactions, including iodotrifluoromethylations of alkenes, proceed very efficiently under low intensity UVA irradiation in deoxygenated methanol solutions containing catalytic amounts of NaCl or Bu4NCl. Preliminary mechanistic studies indicate that the light-promoted homolytic cleavage of the Rf-I bond that initiates the reaction is facilitated by the halogen bonding interaction between RfI and chloride ions.

Purpose To estimate the noninvasive riboflavin concentration in the corneal stroma using a new ultraviolet-A (UVA) theranostic device for corneal crosslinking (CXL). Setting Vision Engineering Italy srl, Rome, Italy. Design Experimental study. Methods Fourteen human donor corneas were treated according to conventional (UVA irradiance of 3 mW/cm2 for 30 minutes) and rapid (10 mW/cm2 for 9 minutes) riboflavin–UVA CXL protocols using a theranostic UVA device. Five additional samples were treated by 0.5 mW/cm2 for 9 minutes and used as positive controls to determine riboflavin photodegradation under near ambient lighting conditions. A 20% dextran–enriched 0.1% riboflavin solution was used in all cases. The device consisted of a UVA light source; a red–green–blue camera, which acquires the fluorescence images of the cornea during treatment; and a single-board computer for managing the overall operations and the raw data processing. Results Preirradiation stromal soaking for 30 minutes achieved highly consistent intrastromal riboflavin concentration in all tissues (mean 0.015% ± 0.003% [SD]). There were no differences in the kinetics curves of riboflavin consumption between the 2 UVA irradiation protocols; the intrastromal riboflavin concentration decreased exponentially, with a mean constant energy rate of 2.8 ± 0.2 J/cm2. In the control group, the intrastromal riboflavin concentration decreased quasilinearly. Conclusions The theranostic device provided estimates of the intrastromal concentration of riboflavin noninvasively during treatment. In the 3 to 10 mW/cm2 range of power densities, the consumption of riboflavin in the stroma by UVA irradiation was only energy dependent in accordance with the Bunsen-Roscoe law.

As a component of sunscreen formulations, TiO2 engineered nanomaterials (ENM) are coated to prevent reactive oxygen species from causing damage to skin. We investigated the stability of an Al(OH)3 coating by exposing 25 nm Al(OH)3·TiO2 ENM to simulated swimming pool water (SPW) for 45 minutes, 1, 3, 10, or 14 days. Electron microscopy and spectroscopy indicated that exposure to SPW caused a redistribution of the Al(OH)3 coating allowing photocatalytic formation of hydroxyl radicals. Aged ENM showed significantly greater phototoxicity under UVA irradiation than un-aged ENM in a human-derived retinal pigment epithelium cell line (ARPE-19). Photocatalytic activity and phototoxicity of aged Al(OH)3·TiO2 was significantly less than that of the positive control—uncoated P25 TiO2. In summary, the aging of Al(OH)3·TiO2 ENM in SPW redistributed the coating and reduced its protective properties, thereby increasing reactivity and potential phototoxicity.

Extracts from 37 fruits and vegetables were tested as ultraviolet (UV) protectants for the nucleopolyhedrovirus (SeMNPV) of the beet armyworm, Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae). Only one extract (black currant) provided almost complete protection following UVB/UVA irradiation for 30 minutes under laboratory conditions. As a group, fruit and vegetable extracts were significantly less effective than published values for herb and spice extracts. Based on analyses of antioxidant capacity and total phenolic content of selected plants, it was determined that (1) herbs and spices contained much higher levels of antioxidants and phenolics than fruits and vegetables, (2) neither high levels of antioxidants nor high levels of phenolics alone could account for UV protection, and (3) selection of extracts with high levels of both antioxidants and total phenolics resulted in increased UV protection.

The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and UVA irradiation was more bactericidal than UVA irradiation or antibacterial drugs alone. The bactericidal synergy was observed at low concentrations of each drug that are normally unable to kill the bacteria. This combination has the potential to become a sterilization technology.

The addition of Fe 3+ salts to a TiO 2 suspension is one of the methods used to extend the useful radiation range in photocatalytic processes. The aim of this study was to determine how the presence of FeCl 3 affects the photocatalytic reaction mechanism and TiO 2 activity under UVa and vis irradiation. The photocatalytic degradation of eleven sulfonamides was investigated in the presence of a TiO 2 –P25 suspension, FeCl 3 and a TiO 2 /FeCl 3 mixture. The addition of FeCl 3 decreased the TiO 2 activity under vis light irradiation but the photocatalytic degradation rate of sulfonamides improved significantly under UVa irradiation. For example, the initial photodegradation rate of sulfisoxazole increased approximately 85 times. The processes carried out in the TiO 2 /FeCl 3 mixture were less sensitive to the presence of free radical scavengers, and the photocatalytic reaction rates were directly proportional to the concentrations of cationic form of the substrates. This result indicates that the photocatalytic degradation rate of the sulfonamides depends on the possibility for direct oxidation of the cationic form of the substrate and its interaction with the catalyst particles via labile electrostatic interactions.

Objective Bullous keratopathy (BK) is a serious corneal condition leading to impaired vision and ocular pain, due to chronic corneal edema and recurrent superficial ulceration. BK is refractory to conventional therapy. In human patients, corneal collagen cross-linking (CXL) has been used for the treatment of BK, and CXL treatment was recently described for canine patients. The aim of this study was to evaluate the clinical and pachymetric effects of accelerated CXL in dogs affected by BK. Animal studied Eight dogs (10 eyes) with BK underwent accelerated CXL. Procedures CXL treatment comprised 30 min of riboflavin–dextran instillation, followed by 3 min of UVA irradiation at 30 mW/cm². Ocular pain, corneal edema, corneal ulceration, and pachymetry were evaluated 7, 14, 30, 90, and 180 days after treatment. Results Corneal ulceration and ocular pain were resolved by 1 week after CXL treatment and did not recur during the 6-month follow-up period. Corneal edema improved in the first 3 months, but worsened from months 3 to 6. Corneal thickness initially decreased, but returned to baseline by 6 months post-CXL. Conclusions CXL is a useful treatment option for BK in dogs, despite the short-lasting effects on corneal thickness. Patient comfort improved rapidly after a single procedure, although CXL did not achieve resolution of corneal edema. Treatment protocols may be refined to produce more durable effects on corneal edema.

A novel 5-fluorouracil (5-FU)-based anticancer prodrugs consisting of pyrene and oligonucleotide trimer having 5-halouracils were designed. The UVA-induced electron injection from photoexcited pyre...

The discovery of biomarkers for Parkinson's disease (PD) is challenging due to the heterogeneous nature of this disorder, and a poor correlation between the underlying pathology and the clinically expressed phenotype. An ideal biomarker would inform on PD-relevant pathological changes via an easily assayed biological characteristic, which reliably tracks clinical symptoms. Human dermal (skin) fibroblasts are accessible peripheral cells that constitute a patient-specific system, which potentially recapitulates the PD chronological and epigenetic aging history. Here, we compared primary skin fibroblasts obtained from individuals diagnosed with late-onset sporadic PD, and healthy age-matched controls. These fibroblasts were studied from fundamental viewpoints of growth and morphology, as well as redox, mitochondrial, and autophagic function. It was observed that fibroblasts from PD subjects had higher growth rates, and appeared distinctly different in terms of morphology and spatial organization in culture, compared to control cells. It was also found that the PD fibroblasts exhibited significantly compromised mitochondrial structure and function when assessed via morphological and oxidative phosphorylation assays. Additionally, a striking increase in baseline macroautophagy levels was seen in cells from PD subjects. Exposure of the skin fibroblasts to physiologically relevant stress, specifically ultraviolet irradiation (UVA), further exaggerated the autophagic dysfunction in the PD cells. Moreover, the PD fibroblasts accumulated higher levels of reactive oxygen species (ROS) coupled with lower cell viability upon UVA treatment. In essence, these studies highlight primary skin fibroblasts as a patient-relevant model that captures fundamental PD molecular mechanisms, and supports their potential utility to develop diagnostic and prognostic biomarkers for the disease.

Background Ultraviolet A (UVA) irradiation before allergic sensitization induces immunosuppression, but the precise mechanism remained unclear. In this study, we examined the influence of UVA irradiation of the eye on contact hypersensitivity (CHS) and the role of mast cells in CHS. Methods We used two types of haptens, fluorescein isothiocyanate (FITC: a Th2 type hapten) and 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone: a Th1 type hapten). A 300 kJ/m2 dose of UVA irradiation was delivered to the eyes. After UVA irradiation, we sensitized abdominal shaved skin and challenged the ear epidermis and colons of these mice with each hapten. Results After UVA irradiation, the CHS of the skin and colon were not inhibited in the FITC-sensitized mice. However, in the oxazolone-sensitized mice, only the CHS of the skin was inhibited by UVA irradiation. The inflammation of the colon became more severe after UVA irradiation. In mast cell–deficient (W/Wv) mice sensitized to FITC, the CHS was weaker than that in WT mice. Moreover, the reduction of immunosuppression in ear swelling was seen for one of the two models they used. Conclusions These results suggest that the mast cells induced by UVA irradiation of the eye have different roles in the epidermis and colon and have different responses to different haptens.

To understand a role of UVA radiation in photoaging of the skin, we established a model of photoaging cells using cultured human dermal fibroblasts. Repeated low-dose UVA radiation for 10 consecutive days induced senescence in fibroblasts, characterized with (1) increased level of senescence-associated β-galactosidase, (2) flattened large cell shape, (3) accumulation of reactive oxygen species, (4) yellowish coloration and (5) expression of p16. These were also observed in chronologically aged fibroblasts (doubling times >20), whereas none of these were detected in young cells (doubling times