Ultraviolet-A absorbance analysis in thin porcine corneas pre-and post-crosslinking

ABSTRACT Purpose: To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking. Methods: This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 μm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol. Results: The ultraviolet absorbance profiles of the 180, 300, and 360 μm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance. Conclusions: Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 μm safe and personalized energy delivery for each corneal thickness.

UV-C light as an alternative for disinfecting orthodontic pliers / Luz UV-C como alternativa para desinfecção de alicates ortodônticos

Objetivo: Os ortodontistas usam alicates ortodônticos continuamente, e essas ferramentas têm um forte potencial para infecções nosocomiais. Este estudo teve como objetivo comparar a eficiência de três métodos de desinfecção de alicates ortodônticos. Material e Métodos: As pontas ativas de 26 alicates ortodônticos (cortadores distais e alicates Weingart) foram contaminadas com microrganismos, vírus e esporos S. aureus, E. coli e C. albicans. Os métodos de controle microbiano foram desinfecção com álcool 70%, esterilização com esferas de vidro (250 °C calor seco) e irradiação com luz ultravioleta (250 nm UV-C) por 30 e 60 segundos. O número de unidades formadoras de colônias (UFC) e unidades formadoras de placas (UFP) foi quantificado e comparado para cada microrganismo após incubação em placas de cultura. Resultados: Todas as pontas do alicate dos grupos que receberam luz ultravioleta ou foram submetidos à esterilização com esferas de vidro apresentaram número significativamente menor de esporos, bactérias e fungos do que suas respectivas amostras controle (p<0,001). A desinfecção física com luz UV-C pode representar uma alternativa confiável em comparação com outros métodos químicos e físicos devido ao aumento de microrganismos resistentes a produtos químicos e à emissão de subprodutos nocivos após o tratamento químico. Conclusão: Os métodos de controle microbiano testados foram eficazes na desinfecção de alicates ortodônticos, tornando a luz ultravioleta-C uma alternativa promissora para eliminar os microrganismos dos alicates (AU)

Objective: Orthodontists use orthodontic pliers continuously, and these tools have a strong potential for nosocomial infections. This study aimed to compare the efficiency of three methods for disinfecting orthodontic pliers. Material and Methods: The active tips of 26 orthodontic pliers (distal end cutters and Weingart pliers) were contaminated with S. aureus, E. coli, and C. albicans microorganisms, viruses, and spores. The microbial control methods were 70% alcohol disinfection, glass bead sterilization (250 °C dry heat), and ultraviolet light irradiation (250 nm UV-C) for 30 and 60 seconds. The number of colony-forming units (CFU) and plaque-forming units (PFU) was quantified and compared for each microorganism after incubation in culture plates. Results: All tips of the pliers in the groups that received ultraviolet light or were subjected to glass bead sterilization showed a significantly lower number of spores, bacteria, and fungi than their respective control samples (p<0.001). Physical disinfection with UV-C light may represent a reliable alternative compared to other chemical and physical methods due to the increase in microorganisms resistant to chemical products and the emission of harmful by-products after chemical treatment. Conclusion: The tested microbial control methods were effective in the disinfection of orthodontic pliers, making ultraviolet-C light a promising alternative to eliminate microorganisms from pliers (AU)

Research progress on enhancing biological activity of titanium implants by chairside ultraviolet photofunctionalization / 口腔疾病防治

@#Excellent mechanical properties and biocompatibility resulted in titanium and titanium alloys being widely used in the medical field. However, the biological activity of atitanium surface will gradually fade with increasing exposure time, which affects its final osseointegration. As an effective surface modification method, ultraviolet (UV) photofunctionalization does not change the surface morphology of implants and is a suitable surface treatment for many brands of implants. This article summarizes the research progress on the effect of UV photofunctionalization technology on the characteristics of titanium surfaces, biological activity and implant osseointegration, as well as its current clinical applications. Studies have shown that the superhydrophilicity of the titanium surface and improved biological activity endowed by UV photofunctionalization can accelerate and enhance bone formation, resulting in a higher success rate of implant surgery. Therefore, UV photofunctionalization has great potential for clinical chairside applications.

Clinical observation on transepithelial rapid cross-linking combined with RGPCL in the treatment of keratoconus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the clinical effect of transepithelial rapid cross-linking combined with wearing rigid gas permeable contact lens(RGPCL)in keratoconus patients.<p>METHODS: This was a retrospective study of patients with progressive keratoconus diagnosed in the Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine in October 2014, and underwent transepithelial rapid keratoplasty. After surgery 16 patients(25 eyes)used RGPCL. Average age was 25.31±5.92 years old, maximum preoperative corneal curvature was 58.96±6.76D, thinnest corneal thickness was 439.52±53.24μm. Rapid cross-linking was performed using riboflavin and 45mW/cm² ultraviolet light(UV)irradiation with a total energy of 7.2J/cm². RGPCL was used after surgery. Follow up of 3-6a, average follow-up time was 52.44±11.39mo. The best corrected visual acuity \〖(BCVA), in RGPCL\〗, corneal curvature of flat meridian(K₁), corneal curvature of steep meridian(K₂), maximum corneal curvature(Kmax), corneal refractive power(MPP), Baiocchi Calossi Versaci index of anterior and posterior surface(BCVf and BCVb)asymmetry index of anterior surface curvature(SIf), asymmetry index of posterior surface curvature(SIb), the highest point of anterior cone cornea(KVf), the highest point of posterior cone cornea(KVb), the change of corneal thickness(ThkMin), lens opacity, and corneal endothelial cell count were observed.<p>RESULTS: All patients had a successful operation, and no intraoperative complications. On the first day after surgery, all cases felt slight tingling and slight photophobia tears. After 1d of operation, the corneal epithelium was removed in two eyes. While 3d after re-wearing the bandage, the epithelium healed. None of lens in the patients was opacified during follow-up, and there was no significant difference in corneal endothelial cell count compared with preoperative(<i>P</i>>0.05). The BCVA(wearing RGPCL)after operation is obviously improved compared with preoperative. All postoperative Kmax, SIf, KVf, BCVf, BCVb were lower than preoperative(<i>P</i><0.05). <p>CONCLUSION: Transepithelial rapid corneal cross-linking combined with RGPCL is safe and effective in controlling the progress of keratoconus. And the long-term effect is stable.

Effects of sunlight on the eye / 国际眼科杂志(Guoji Yanke Zazhi)

@#Sunlight consists of lights of continuous spectra. Ultraviolet light and blue light in the sunlight have higher energy. High dose exposure to sunlight can cause direct cellular damage. In the eye, sunlight is known to cause pathological changes in various eye structures. We reviewed the studies on the role of sunlight in corneal diseases, cataracts, glaucoma, and age-related macular degeneration in recent years. Possible sunlight-triggered signaling pathways and mechanisms in the eye are summarized. Excessive exposure to sunlight may lead to increased DNA damage, aberrant protein modification and aggregation, and oxidative stress of ocular tissues, and thus results in the development of ocular diseases. Accordingly, physical protection, topical and/or oral antioxidants and small molecules blocking sunlight-activated signal pathways could be used independently or combinedly to prevent and reduce sunlight-induced ocular damages.

Ultraviolet-C decontamination of a dental clinic setting: required dose and time of UVC light / Utilização de radiação ultravioleta-C para descontaminação de um consultorio odontológico: tempo e dose de UVC necessária

Viruses can spread to the environment, and it can be challenging to clear it. A direct approach to limit airborne transmission of pathogens in dental clinic offices is to inactivate viruses within a short time of their production and block the person-to-person transmission routes in dental clinics. For this, we can use chemical substances on surfaces and germicidal ultraviolet light (UV), typically at 254 nm, for complementary disinfection of surfaces and air contaminated by aerosols produced by high-speed handpiece or ultrasound scaler. Based on the literature review and the similarity of Sars-Cov-2 with other previously studied corovaviruses, COVID-19 is sensitive to UV irradiation that can break the genome of this virus, inactivating it. In our study, we performed the calculation of the time required to decontaminate a dental care room between each patient change. We can conclude that the use of UVC can be incorporated into the dental care routine to reduce cross contamination. (AU)

Os vírus podem se espalhar para o meio ambiente e pode ser um desafio eliminá-lo. Uma abordagem direta para limitar a transmissão aérea de patógenos nos consultórios de clínicas odontológicas é inativar os vírus o mais rápido possivel após sua produção e bloquear as rotas de transmissão de pessoa para pessoa nas clínicas odontológicas. Para isso, podemos usar substâncias químicas para limpar as superfícies e luz ultravioleta (UV) germicida (UV), normalmente a 254 nm, para desinfecção complementar de superfícies e ar contaminado por aerossóis produzidos pelo altarotação ou ultrassom periodontal. Com base na revisão de literatura e na semelhança do SarsCov-2 com outros corovavirus previamente estudados, o COVID-19 é sensível à irradiação UV que podem quebrar o genoma desse vírus, inativando-o. Em nosso estudo, realizamos o cálculo de tempo necessário para descontaminar uma sala de atendimento odontológico entre cada troca de paciente. Podemos concluir que a utilização de UVC pode ser incorporada à rotina de atendimento odontológico para reduzir a contaminação cruzada entre atendimentos. (AU)

Uso de cámaras de bronceado y cáncer de piel / Indoor tanning and skin cancer

ResumenEl cáncer de piel es la neoplasia más frecuente en Costa Rica.La constante exposición a luz ultravioleta es un factor de riesgo ampliamente reconocido para este cáncer.Las cámaras de bronceado que emiten radiación UV fueron clasificadas por un grupo de investigadores, IARC “International Agency for Research on Cáncer” como Grupo 1 “Cancerígeno para humanos”.El riesgo de melanoma aumenta en un 75% cuando las cámaras de bronceado son utilizadas en edades tempranas.Las campañas de salud enfocadas en foto protección han tenido un importante impacto en la prevención del cáncer de piel. Sin embargo, aún es necesario dar a conocer a la población general sobre la relación directa que existe entre el uso de fuentes artificiales de radiación ultravioleta (como cámaras de bronceado) con la aparición de cáncer de piel melanoma y no melanoma.

AbstractSkin cancer is the most common malignancy in Costa Rica.Constant exposure to ultraviolet light is a widely recognized risk factor for this neoplasm. Indoor tanning chambers that emit UV radiation were classified as Group 1 "Carcinogenic for humans" by the “International Agency for Research on Cancer” (IARC).The risk of melanoma increases in a 75% when the tanning beds are used in early ages.Health campaigns focused photo protective measures have had an important impact on skin cancer prevention.However, it is still necessary to inform general population about the direct relationship between the use of artificial sources of ultraviolet radiation like in tanning beds, with the development of melanoma and non-melanoma cancer.

Hazards Caused by UV Rays of Xenon Light Based High Performance Solar Simulators

BACKGROUND: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar–chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. METHODS: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. RESULTS: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. CONCLUSION: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.

The utility of dermoscopy in the diagnosis of evolving lesions of vitiligo.

Background: Early lesions of vitiligo can be confused with various other causes of hypopigmentation and depigmentation. Few workers have utilized dermoscopy for the diagnosis of evolving lesions of vitiligo. Aim: To analyze the dermoscopic findings of evolving lesions in diagnosed cases of vitiligo and to correlate them histopathologically. Methods: Dermoscopy of evolving lesions in 30 diagnosed cases of vitiligo was performed using both polarized light and ultraviolet light. Result: On polarized light examination, the pigmentary network was found to be reduced in 12 (40%) of 30 patients, absent in 9 (30%), and reversed in 6 (20%) patients; 2 patients (6.7%) showed perifollicular hyperpigmentation and 1 (3.3%) had perilesional hyperpigmentation. A diffuse white glow was demonstrable in 27 (90%) of 30 patients on ultraviolet light examination. Melanocytes were either reduced in number or absent in 12 (40%) of 30 patients on histopathology. Conclusion: Pigmentary network changes, and perifollicular and perilesional hyperpigmentation on polarized light examination, and a diffuse white glow on ultraviolet light examination were noted in evolving vitiligo lesions. Histopathological examination was comparatively less reliable. Dermoscopy appears to be better than routine histopathology in the diagnosis of evolving lesions of vitiligo and can obviate the need for a skin biopsy.

Effectiveness of different air disinfection methods for blood collection room / 中国感染控制杂志

Objective To compare disinfection efficacy of three different air disinfection methods on the air in blood collection room.Methods Air disinfection in blood collection room was conducted by ultraviolet (UV)light, ozone disinfector (OD)and air purification disinfector respectively ,natural sedimentation method was used to take air specimens before ,after disinfection ,and during working condition of staff ,air disinfection efficacy was detec-ted.Results All three methods could decrease air bacterial count after disinfection ,the total number of bacteria in indoor air after disinfection met the class Ⅲ environmental requirement.Under working condition of staff ,the num-ber of bacteria of OD and UV light group increased rapidly,at 4 hours was (7.53±1.28)CFU/5 min·Φ90petri dish and (8.16±1.57)CFU/5 min·Φ90petri dish respectively;air purification disinfector disinfected for 4 hours under the condition of movement of personnel in blood collection environment,bacteria count still remained <4.0 CFU/5 min·Φ90petri dish.Conclusion Disinfecting continuously by air purification disinfector can ensure the effectiveness of air cleanliness in blood collection room.

Métodos de conservação aplicados a melão minimamente processado / Conservation methods applied to fresh-cut melon

O objetivo desta revisão é apresentar alguns métodos de conservação que podem ser utilizados para prolongar a vida útil do melão minimamente processado. Dentre os métodos, serão abordados revestimento comestível, irradiação, antimicrobianos naturais, antioxidantes, agentes de firmeza, atmosfera modificada, branqueamento, luz ultravioleta e alta pressão. Dependendo do método pode haver redução das alterações associadas ao processo mínimo do melão, como a perda de água, alteração da cor e firmeza, alteração do metabolismo e crescimento de micro-organismos, sendo o resultado muitas vezes dependente da cultivar do melão utilizado.

The objective of this review is to present some conservation methods that can be used to prolong the life of fresh-cut melon. Among the methods, edible coating, irradiation, natural antimicrobials, antioxidants, firmness agent, modified atmosphere, whitening, ultraviolet light and high pressure will be discussed. Depending on the method, the changes associated to minimum process of melon, such as water loss, change in color and firmness, change in the metabolism and growth of micro-organisms can be reduced and the result is often dependent on the melon cultivar used.

Two methods for air disinfection in neurosurgical intensive care unit / 现代临床护理

Objective To compare the effects of Chinese herbal fumigation and ultraviolet light exposure on air disinfection in neurosurgical intensive care unit.Methods The floors and the tables in the rooms of ICU were all disinfected using 0.02%84 disinfectant.The air disinfection was performed in the rooms using Chinese herbal(elsholtziae,ramulus cinnamomi,forsythia suspense,flos caryophylli)fumigation as the experiment group and those using ultraviolet light exposure as the control group,both for 30 times.The two disinfection methods were compared before air disinfection,at hours 0,1,2,4,8 and 12 in terms of bacteria tests.Results The air quality on natural bacteria in both groups met the standard of Class Ⅱ Environmental Health Criteria at hour 0,l after air disinfection,without significant difference between the two groups at each time point(P>0.05).In the control group,the bacteria began to grow in number one hour after ultraviolet light exposure and overgrew two hours after air disinfection.In the experiment group,the bacteria grew less,never exceeding the standard level at all time points.The disinfection effect of the experimental group was all significantly better than that of the control group at the time points of 2 h,4 h,8 h,12 h(P<0.05 or P<0.01). Conclusions Chinese herbal fumigation is superior to the UV light irradiation disinfection.It is safe and harmless even in case of medical staff working in the unit.

Fotocatálise heterogênea de Enterococcus faecalis e Pseudomonas aeruginosa desencadeada pela ação da luz UV e branca em espátulas com revestimento de nanopartículas TiO2 e Ag / Heterogeneous photocatalysis of Enterococcus faecalis and Pseudomonas aeruginosa activated by the action of UV and visible light on dental instruments with TiO2 and Ag nanoparticles coating

Nanotecnologia, ciência do minúsculo, gera produtos capazes de manipular átomos e moléculas com aplicação no processo de esterilização de instrumentais odontológicos. Objetivo: Avaliar a ação autolimpante e esterilizante do processo de fotocatálise heterogênea desencadeado pela ação da luz UV e branca sobre o recobrimento de instrumentos odontológicos com nanopartículas de TiO2 e Ag. Material e método: Foram realizados testes bacteriológicos em espátulas odontológicas revestidas com nanopartículas de TiO2 e Ag (uma ou três camadas) e contaminadas com 10 mcrl dos microrganismos Enterococcus faecalis e Pseudomonas aeruginosa. Após contaminação, as espátulasforam expostas à luz UV e branca por 120 minutos, transferidas para tubos contendo meio BHI e incubadas a 35-37 °C. Foram feitas leituras em intervalos de 24, 48, 72 e 96 horas para verificação do crescimento das bactérias e testes de controle e recuperação. Resultado: A Pseudomonas aeruginosa foi inativada após exposição de 120 minutos à luz UV, indicando a ocorrência do processo de fotocatálise heterogênea no recobrimento de nanopartículas de TiO2 e Ag das espátulas. A Pseudomonas aeruginosa não foi inativada pela exposição à luz branca e o Enterococcus faecalis não foi inativado pela exposição à luz UV e à branca nas espátulas de cimento odontológico recobertas com nanopartículas de TiO2 e Ag, nas leituras de até 96 horas, ocorrendo o crescimento bacteriano. Conclusão: Não houve influência do revestimento das espátulas com uma ou três camadas de nanopartículas de TiO2 e Agnos resultados. A fotocatálise heterogênea da Pseudomonas aeruginosa foi confirmada pela exposição à luz UV da espátula com revestimento de TiO2 e Ag, mas não pela luz branca. A fotocatálise heterogênea do Enterococcus fecalis não foi confirmada tanto pela exposição do TiO2 e Ag à luz UV como à branca.

Nanotechnology, the science of minuscule, has developed products which are able t o manipulate atoms and molecules that could be applied in the sterilization process of dental instruments. Objetives: The objective of the present study was to evaluate the self-cleaning action of TiO2 and Ag nanoparticles coating on dental instruments by the photocataliys process under UV and visible light irradiation. Material and method: Microbiologic tests were done using dental cement spatulas coated with TiO2 and Ag nanoparticles (one or three layers), and contaminated with 10 mcrl of Pseudomonas aeruginosa and Enterococcus faecalis, respectively. After contamination, they were exposed to ultraviolet light and visible light for 120 minutes. Next, they were transferred to and stored in test tubeswith BHI (Brain Heart Infusion) and incubated in 35 to 37 °C. Checking times for bacterial growth and for control and retrieval tests were done at: 24, 48, 72 and 96 hours. Result: The Pseudomonas aeruginosa was inactive after120 minutes of ultraviolet light irradiation, thus confirming the heterogeneous photocatalytic activity of TiO2 and Ag. The Pseudomonas aeruginosa was not inactivated under visible light irradiation and the Enterococcus faecalis was not inactivated under UV and visible light irradiation of the dental cement spatulas coated with TiO2 and Agnanoparticles in the readings to 96 hours, showing bacterial growth. Conclusion: There were no influence of one or three layers of TiO2 and Ag nanoparticles coating of the spatulas in the results. The heterogeneous photocatalysis activity of TiO2 and Ag under UV light irradiation was confirmed for Pseudomonas aeruginosa but not under visible light. Enterococcus faecalis did not confirmed the photocatalytics activity of TiO2 and Ag under UV light irradiation and visible lights irradiation.

Efeito mutagênico de baixa dose de ultravioleta no sistema methG1 em Aspergillus nidulans / Mutagenic effect of ultraviolet low dose in Aspergillus nidulans Methg1 system

O câncer atualmente é um dos problemas mais comuns e graves. Esse grupo de doenças caracteriza-se pela formação de tumores malignos, em decorrência de mutações em genes responsáveis pelo controle da proliferação e diferenciação celular. Assim, os agentes mutagênicos são potencialmente carcinogênicos. Entre os agentes cancerígenos mais conhecidos está a radiação ultravioleta, por ser um conhecido fator de risco para câncer de pele. Neste sentido, o objetivo do presente trabalho foi analisar o potencial mutagênico de baixas doses de ultravioleta no sistema methG1. Para isto, foram tratados esporos da linhagem biA1methG1 de Aspergillus nidulans com um segundo de exposição à luz ultravioleta. Os resultados mostraram que, mesmo em dose mínima, este agente é capaz de causar danos ao genoma, diminuindo a viabilidade e aumentando significativamente a frequência de mutação, quando comparadas aos valores do controle (esporos não expostos ao tratamento). Estes resultados corroboram com a importância dos cuidados preventivos e de restrição à exposição demasiada a radiação ultravioleta da luz solar.

Cancer has been the most common and serious illness nowadays. It is characterized by former tumors presence because of mutations in cellular proliferation and differentiation controlling genes. Then, the mutagenic agents are potentially carcinogenic. Among the known carcinogenic agents there is the ultraviolet radiation, an important factor to skin cancer. In this sense, the aim of this work was to analyse the ultraviolet low dose mutagenicity in methG1 system. For this, biA1methG1 conidia of Aspergillus nidulans lineage were treated with one second (0,24mJ/cm2) of ultraviolet light exposure. The results had indicated that, even in minimal dose, this agent is able to cause genome damage, reducing the viability and increasing the mutation frequency significatively, when compared with the control (conidia not treated). This results corroborate others works that have demonstrate the importance of the preventive care and long exposure restriction to the solar ultraviolet radiation.

Xeroderma pigmettoso de kaposi: presentacion de un csso / Xeroderma Pigmentosum: A case presentation

El xeroderma pigmentoso es una enfermedad cutánea de origen genético, con patrón de herencia autosómico recesivo, que se traduce por una hipersen-sibilidad marcada a las radiaciones ultravioletas, con aparición de lesiones semejantes a pecas, hiperpigmentación, queratosis, lesiones malignas y cica-trices atróficas limitadas en su inicio a las zonas expuestas a la luz solar, hasta posteriormente generalizarse. En este trabajo, se presenta un caso, reportado en Venezuela, de una paciente de 22 años, raza blanca, con antecedentes de haber comenzado hace 8 años con cambios de pigmentación de la piel y la aparición de nevos en regiones expuestas al sol; tiene dos miembros e la familia que padecen la enfermedad (hermano y abuelo). Por la rareza de esta patología y su comportamiento genético, se decide presentar este caso.

Xeroderma Pigmentosum is a cutaneous disease with a recessive autosomal inheritance. It traduces into a extreme sensitivity to ultraviolet light (UV), with the onset of dark lesions similar to freckles, hyperpigmentation, keratoses, skin cancer, atrophic scars on the exposed areas to the sunlight, that finally affect the whole skin.We present a case reported in Venezuela of a 22 year old patient, white skin, with history of 8 years of skin colour changes and the onset of nevus in the sunlight exposed areas. Two more member of her family suffer this symptoms ( her brother and grandfather). Because of the unusual of this pathology and it´s genetic behaviour, we decided to report this case.

Effects of the Mixture of Vitamin C, Vitamin E, Pycnogenol and Evening Primrose Oil on the UV-Induced Pigmentation and Wrinkle Reductions in Human Skin

In this study, the effects of a mixture consisting of vitamin E, vitamin C, pycnogenol and evening primrose oil (mixture LGNC-5) on ultraviolet light (UV) induced pigmentation and wrinkle reductions of normal healthy volunteers were studied. In a double-blind placebo-controlled study, each of 54 subjects took daily either 4 capsules of the mixture LGNC-5 (Group ABC; 282.5 mg/capsule) or placebo (Group Ganada). We irradiated 2.5 MED UV on the upper arms and measured the whitening effect by colorimeter-based L value. The level of wrinkle reduction was determined by image analysis using skin replica around the crow' feet, and the level of serum vitamin E was determined at baseline and 12 weeks. After 12-week oral administration, the treated group showed a significant reduction in skin pigmentation and wrinkles compared with the placebo group (p = 0.011 and p = 0.000005 , respectively). Also, the level of serum vitamin E was significantly increased in the treated group after 12-week oral adminstration of the mixture compared with that in the placebo group (p = 0.0001). In conclusion, 12-week oral administration of LGNC-5 as a dietary supplement could be effective to reduce both UV induced pigmentation and skin wrinkle without side effects.

Effects of APP17-mer peptide on oxidative damage and expression of MMP-1 mRNA in cultured human skin fibrobiasts irradiated with ultraviolet light / 中华医学美学美容杂志

Objective To establish an ultraviolet-irradiation damage model in cultured fibroblasts derived from human skin and to explore the potential protective effects and mechanisms of amyloid precursor protein 17-met peptide (APP17-mer peptide) on the oxidative damage and collagen metabolism in cultured fibroblasts after ultraviolet irradiation. Methods Human dermal fibroblast cultures were established by outgrowth from foreskin biopsies of a healthy donor and were irradiated by a single exposure to ultraviolet rays and cultured in a series of concentrations of APP17-mer peptide (0, 20, 40, 80 μmol/L).The activity of fibroblasts was detected by the assay of MTT. The intracellular ROS level was measured with a confocal microscope. The expression of MMP-1 mRNA was analyzed real-time quantitatively following RT-PCR. Results Primary cultures of human skin fibroblasts were established from human foreskin in DMEM supplemented with 10 % fetal bovine serum. UV irradiation depressed cellular activity and increased intracellular level of ROS (P<0.05). 40μmol/L and 80μmol/L APP17-mer peptide increased the cellular activity in both UV irradiated fibroblasts and unirradiated fibroblasts (P<0.05), however,20 μmol/L did not show such protective effects (P>0. 05). 40μmol/L APP17-mer peptide could depress the level of ROS in irradiated libroblasts. A single exposure of fibroblasts to UV irradiation resulted in 1.78 foldup-regulation of MMP-1 mRNA compared with unirradiated sample, 40μmol/L and 80μmol/L APP17-mer peptide decreased the expression of MMP-1 mRNA (P<0.05 and P<0.01, respectively).Conclusion APP17-mer peptide can enhance cellular activity under UV-induced oxidative stress and in-hibit collagen degradation in fibroblasts irradiated with ultraviolet rays. Inhibition of ROS production may be involved in the protective mechanism of APP17 peptide.

Interacciones de las radiaciones electromagnéticas y especies reactivas del oxígeno sobre la piel / Interactions of electromagnetic radiations and reactive oxygen species on skin

La energía radiante abarca todo el espectro electromagnético y proviene de la fusión en el sol, de 4 núcleos de hidrógeno en uno de helio. Las radiaciones electromagnéticas tienen características de ondas, con la velocidad de la luz (c) y difieren en sus longitudes de ondas (λ). La energía lumínica es transmitida en unidades individuales o fotones: E = h c/λ así, los fotones de menores λs son los de mayor energía. Las radiaciones ultravioletas (UV) (λs de 200 - 400 nm) pueden dividirse: UVA (λs 315 - 400 nm); UVB (λs 280 - 315 nm) y UVC (λs < 280 nm). UVB y UVC son las más importantes, en inducir respuestas biológicas. Por acción de las radiaciones electromagnéticas el O2, da productos agrupados bajo la denominación de Especies Reactivas del Oxígeno (ROS). El alto contenido de O2 en los sistemas biológicos estimula la formación de ROS, que si no son controladas por el sistema endógeno de antioxidantes, afectan el estado redox de las células y generan daños tisulares ("stress oxidativo"). Inducen peroxidación de lípidos, entrecruzamiento de proteínas, inhibición de enzimas, pérdida de integridad y función de membranas plasmáticas y mitocondriales, ruptura de organelas intracelulares. Como consecuencias producen inflamación, envejecimiento, carcinogénesis y muerte celular. Mientras las radiaciones infrarrojas, inducen aumento de la temperatura cutánea, llegando a producir graves quemaduras, las UVA y UVB, en forma encubierta, reaccionan con cromóforos del tejido cutáneo, que absorben fotones y generan alteraciones fotoquímicas, implicadas en el envejecimiento celular e inducción de cáncer. La radiación UV al alcanzar el núcleo de las células causa daños en el ADN. Los seres humanos debemos protegernos de los efectos deletéreos del sol que representa un problema de salud pública, de suma importancia. Defensa que logramos con la vestimenta y uso de productos protectores de la piel. Las bacterias, así como otros procariotas, más expuestas a las radiaciones solares han generado plásmidos, que incrementan por medio de un sistema de reparación del ADN, la tolerancia a la UV y otros agentes mutagénicos.

The energy of electromagnetic radiation is derived from the fusion in the sun of four hydrogen nuclei to form a helium nucleus. The sun radiates energy representing the entire electromagnetic spectrum. Light is a form of electromagnetic radiation. All electromagnetic radiation has wave characteristics and travels at the same speed (c: speed of light). But radiations differ in wavelength (λ). Light energy is transmitted not in a continuum stream but only in individual units or photons: E = h c/λ. Short wave light is more energetic than photons of light of longer wavelength. Ultraviolet radiations (UV) (λs 200 - 400 nm) can be classified in UVA (λs 315 - 400 nm.); UVB (λs 280 - 315 nm) and UVC (λs < 280 nm). UVB and UVC are the most significant UV radiations to induce biological responses. Electromagnetic radiations on molecular oxygen lead to several reactive products known as Reactive Oxygen Species (ROS). High O2 content in biological systems promotes ROS synthesis. If ROS are not controlled by endogenous antioxidants, cell redox status is affected and tissue damage is produced ("oxidative stress"). ROS induce lipid peroxidation, protein cross-linking, enzyme inhibition, loss of integrity and function of plasmatic and mitochondrial membranes conducing to inflammation, aging, carcinogenesis and cell death. While infra-red radiations lead to noticeable tissue temperature conducing to severe burns, UVA and UVB undercover react with skin chromophores producing photochemical alterations involved in cellular aging and cancer induction. As UV radiations can reach cellular nucleus, DNA can be damage. Human beings need protection from the damaging sunbeams. This is a very important concern of public health. While humans need to protect their skin with appropriate clothing and/or by use of skin sunblocks of broad spectrum, some bacteria that are extensively exposed to sunlight have developed genomic evolution (plasmid-encoded DNA repair system) which confer protection from the damaging effect of UV radiation.

Effect of UV irradiation and rebamipide on the blood flow and viability of rabbit skin flap

This study was undertaken to examine the effects of ultraviolet light (UVL) and rebamipide on the cutaneous blood flow and tissue survival on rabbit skin flap. In a random bipedicle flap, Laser Doppler Flowmetry (LDF) was employed to measure the blood flow of flap (BFF). Wound Margin Strength (WMS) measured by force transducer and Light microscopy were used for evaluation of tissue viability. Single exposure to UVL increased the BFF gradually for more than 15 hours, and decreased the vasoconstrictor effect of intravenous phenylephrine. The UVL-induced increase in BFF regressed after 18 hours of irradiation, and this regression was tended to be enhanced by intradermal injection of L-NAME, a nitric oxide synthase (NOS) inhibitor, but the regression was significantly reversed by acetylcholine, an endothelial constitutive NOS (cNOS) activator and L-arginine, an NO precursor. Rebamipide, a novel antiulcer oxide synthase (NOS) inhibitor, but the regression was significantly reversed by acetylcholine, an endoagent known to scavenge the hydroxyl radical, abruptly reversed the spontaneous regression of the UVL-induced increase in BFF by the same manner as L-arginine. In ischemic skin flap, rebamipide increased the BFF abruptly by the same manner as sodium nitroprusside (SNP), an NO doner, while N-acetylcystein (NAC), a free radical scavenger, gradually increase the BFF. The rebamipide-induced increase in BFF was sustained at the level of the SNP-induced increase in BFF during the late period of experiment. Rebamipide increased the WMS of skin flaps and prevented the tissue necrosis in comparison with L-NAME. Based on these results, it is concluded that in rabbit skin, UVL irradiation increases the BFF by NO release, and rebamipide exerts a protective effect on the viability of ischemic skin flaps by either or both the increase in BFF by NO release and free radical scavenger effect.

Potentiating Effects of Bay K 8644 on the Relaxation Induced by Ultraviolet or Visible Light in Porcine Coronary Artery

BACKGROUND: This study was aimed at defining the varying responses of porcine coronary artery(PCA) to various wavelengths of ultraviolet irradiation, and at relating them to the changes in cyclic GMP contents. METHODS: The ring preparations of PCA with intact or removed endothelium were irradiated with the ultraviolet or visible light of wavelengths(240-520mm) from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorder on polygraph. For cyclic GMP assay, rat thoracic aorta was frozen after irradiation and homogenated. The supernatant was extracted with water-saturated ether and the cyclic GMP contents were measured with radioimmunoassay. RESULTS: Ultraviolet irradiation relaxed the preparations(UVR-relaxation) in resting state and those precontracted by prostaglandin F2alpha, the maximal relaxation occurring at 410nm, and the magnitude depending on the duration of irradiation. The UVR-relaxation was not affected by removing the endothelium, while it was markedly potentiated by pretreatment with Bay K 8644. The Bay K 8644-induced potentiation of UVR-relaxation was abolished by hemoglobin and slightly reduced by wrapping the rings with aluminum foil. Cyclic GMP contents in the increase was markedly potentiated by pretreatment with Bay K 8644. CONCLUSION: The observations suggest that UVR-relaxation in procine coronary artery is caused by activating the nitric oxide-cyclic GMP system, which is most sensitively activated by UVR of 410nm and that its potentiation induced by Bay K 8644 may be related nitrous substance released from the agent upon UVR.