970 resultados para Sun Exposure


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The prevalence of vitamin D deficiency varies, with the groups at greatest risk including housebound, community-dwelling older and/or disabled people, those in residential care, dark-skinned people (particularly those modestly dressed), and other people who regularly avoid sun exposure or work indoors.

Most adults are unlikely to obtain more than 5%–10% of their vitamin D requirement from dietary sources. The main source of vitamin D for people residing in Australia and New Zealand is exposure to sunlight.

A serum 25-hydroxyvitamin D (25-OHD) level of ≥ 50 nmol/L at the end of winter (10–20 nmol/L higher at the end of summer, to allow for seasonal decrease) is required for optimal musculoskeletal health.

Although it is likely that higher serum 25-OHD levels play a role in the prevention of some disease states, there is insufficient evidence from randomised controlled trials to recommend higher targets.

For moderately fair-skinned people, a walk with arms exposed for 6–7 minutes mid morning or mid afternoon in summer, and with as much bare skin exposed as feasible for 7–40 minutes (depending on latitude) at noon in winter, on most days, is likely to be helpful in maintaining adequate vitamin D levels in the body.

When sun exposure is minimal, vitamin D intake from dietary sources and supplementation of at least 600 IU (15 μg) per day for people aged ≤ 70 years and 800 IU (20 μg) per day for those aged > 70 years is recommended. People in high-risk groups may require higher doses.

There is good evidence that vitamin D plus calcium supplementation effectively reduces fractures and falls in older men and women.

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The recommended level for serum 25-hydroxyvitamin D (25(OH)D) in infants,  children,  dolescents and during pregnancy and lactation is ≥ 50 nmol/L. This level may need to be 10-20 nmol/L higher at the end of summer to maintain levels ≥ 50 nmol/L over winter and spring. • Sunlight is the most important source of vitamin D. The US recommended dietary allowance for vitamin D is 600 IU daily in children aged over 12 months and during pregnancy and lactation, assuming minimal sun exposure. • Risk factors for low vitamin D are: lack of skin exposure to sunlight, dark skin, southerly latitude, conditions affecting vitamin D metabolism and storage (including obesity) and, for infants, being born to a mother with low vitamin D and exclusive breastfeeding combined with at least one other risk factor. • Targeted measurement of 25(OH)D levels is recommended for infants, children and adolescents with at least one risk factor for low vitamin D and for pregnant women with at least one risk factor for low vitamin D at the first antenatal visit. • Vitamin D deficiency can be treated with daily low-dose vitamin D supplements, although barriers to adherence have been identified. High-dose intermittent vitamin D can be used in children and adolescents. Treatment should be paired with health education and advice about sensible sun exposure. Infants at risk of low vitamin D should be supplemented with 400 IU vitamin D₃ daily for at least the first year of life. • There is increasing evidence of an association between low vitamin D and a range of non-bone health outcomes, however there is a lack of data from robust randomised controlled trials of vitamin D supplementation.

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A variety of hypotheses have been proposed to explain the recently described increase in food allergy among children living in developed countries. In this study, we summarize the emerging risk factors for IgE-mediated food allergy in early life, and then review the evidence for and against an association between low vitamin status (VDS) and food allergy.

We consider whether each of the epidemiological variables that have been associated with food allergy may also be associated with VDS; and argue that future studies must adequately account for the potential relationships between risk factors for food allergy and VDS, and must also discriminate between vitamin D derived by sun exposure, diet and oral supplementation.

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Studies from several countries have reported an association between latitudes further from the equator and proxy markers of food allergy prevalence. As latitudes further from the equator are associated with lower sun exposure and vitamin D status (VDS), it has been proposed that low VDS may be a risk factor for food allergy. A range of basic science evidence supports the biological plausibility of this hypothesis; and recent work has identified a cross sectional association between low VDS and challenge proven food allergy in infants. Overall, however, the evidence regarding the relationship between VDS and food allergy remains controversial and the limited longitudinal data are discouraging. In this review we consider the evidence for and against low VDS as a risk factor for food allergy and discuss the possibility that other factors (including genetic variables) may contribute to the inconsistent nature of the available observational evidence. We then discuss whether genetic and/or environmental factors may modify the potential influence of VDS on food allergy risk. Finally, we argue that given the rising burden of food allergy, the balance of available evidence regarding the potential relevance of VDS to this phenomenon, and the inherent limitations of the existing observational data, there is a compelling case for conducting randomised clinical trials of vitamin D supplementation for the prevention of food allergy during early life.

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Presents a composite formed by orthophthalic resin and fiber loading of carnauba straw. The fibers were first dried in direct sun exposure and subsequently ground into fodder for the reduction in size. Various formulations of the composite were preliminarily tested by choosing the one presenting the best processability in applying the mold. The composite produced is used for the manufacture of a parabolic surface subsequently coated with mirror segments, flexible plastic, for reflecting the solar rays incident on it. The reflective parable represents the main element of the solar cooker that works with the concentration of sunlight and has dimensions of 1.14 m in diameter and area of 1.0 m². Manufacturing processes and assembly of solar cooker concentration produced are presented. The results of tests for cooking and baking various foods, including rice, pasta, beans, cake, cassava, shrimp, beef, breaded demonstrating the competitiveness of solar cooker studied with other stoves already manufactured and tested in Brazil are presented and in the world. It was also demonstrated the feasibility of the proposed composite for Prototypes manufacture of solar and other structures that do not require great efforts resistance

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Introduction: Cancer of the lip is very common in tropical countries, being noticeable the squamous cell carcinoma as the main histological type. Objective: Evaluate the socialdemographic profile, habits, occupation, clinical characteristics of the cancer lesions and the aftermath of treatment of the patients treated on the Luiz Antônio Hospital (Natal-RN). Design: Retrospective cohort. Methods: We analyzed 181 medical records of patients from the Luiz Antônio Cancer Hospital (Natal-RN) in the period between 1997 and 2004. The statistic evaluation of time between the diagnosis and the relapse or the cure of the patient were done through the Kaplan-Meier method and the comparison of survivor functions were done through the Log-rank test. Later, was estimated the proportional risk model of Cox. Results: The study population were composed by 69,1% males, 95,2% unlettered, the mean age of 66,5 years, 89,0% of smokers and 64,1% had an occupation involving sun exposure. In regard to the clinical characteristics, most lesions were in the lower lip (77,9%), the size of the tumor was smaller than 2 cm (51,8%), 92,6% had localized lesions. Were verified 16,3% of local relapse and 13% of regional. Almost the totally of the cases corresponded to squamous cell carcinoma (97,2%). We observed smaller accumulated probability of not occurrence of local relapse when the base and borders were free of lesions (p=0,041), as well as a smaller probability of regional relapse when the sort of treatment was surgery, associated with other therapeutics modalities (p=0,001). The patients with advanced pathologic stage (p=0,016), treated with surgery associated with other therapeutics modalities (p=0,001) and diameter above 4cm (p=0,019) presented a bigger possibility of any kind of relapse. The multivariable analysis pointed the complex treatments (surgery plus other therapeutics modalities) as a predictor variable for occurrence of new local lesions (p=0,001) and total (p=0,046), besides the age above 70 years to the regional relapse (p=0,050). Conclusion: Cancer of the lip occur in the lower lip, in males, smokers and individuals exposed to Sun light. The relapse was frequent, even being localized and without great consequences to the patient s health. The probability of relapse is related to the size and borders of the lesion and to the histological exam, as well as to the patient s age and complexity of the treatment chosen

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This study aimed to verify the prevalence of lip and perioral lesions in worker who were under sunshine on the beaches of Natal/RN and to investigate possible associations of these with sociodemographic, occupational and general health variables. For this, 362 individuals who had one of the urban beaches (Ponta Negra / Environment / Redinha) in the city of Natal/RN as a working environment in the study. We excluded people under 18 years old. Data collection was done through epidemiological analysis and extra-oral validated questionnaire with questions that characterize socioeconomic and demographic factors, occupational exposure and general health. The male subjects (72.6%) were the majority in the sample. The people who worked directly exposed to high peaks of ultraviolet radiation, as well as informal workers predominated. Considering the total sample of individuals, ephelides in the perioral region (33.7%) and labial region (24.0%), solar lentigo perioral (15.2%) and actinic cheilitis (13.8%) stood out as the most prevalent lesions. Indoor workers and those who had a habit occurrence of injuries by 19% and 21% respectively higher when compared to outdoor workers and people without habits. The variable use of cap / hat was associated with the presence of cold sores (Qui2 = 1,328, p = 0,058). On the threshold of significance, the type of work was also associated with lesions in lip occurrence (p = 0,042). Men showed a lower incidence of perioral lesions when compared to female workers (PR=0,716, p valor = 0,002). The present study showed high prevalence of lip and perioral lesions. The premalignant lesions were the most identified, both as in lip skin. It is important therefore to be encouraged to adopt protective measures against excessive sun exposure, fairly and consistently

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Melasma is a common dermatosis that involves changes in normal skin pigmentation, resulting from the hyperactivity of epidermal melanocytes. The consequent hyperpigmentation is mostly induced by ultraviolet radiation.Clinically, melasma is characterized by light to dark brown macules that usually occur on the face, although they can also affect the cervical and anterior thoracic regions and upper members.Fertile age women and those with intermediate skin phototypes are most likely to develop melasma.Most of its physiopathogenics is not yet fully understood, but there is a relation with genetic and hormonal factors, drugs and cosmetics use, endocrinopathies and sun exposure.The authors discuss the main aspects associated with skin pigmentation and the development of melasma.

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OBJETIVO: Avaliar a prevalência de lesões cutâneas actínicas em portadores de carcinoma basocelular do segmento cefálico. MÉTODOS: Foi conduzido estudo tipo caso-controle. Os casos, constituídos por pacientes com carcinoma basocelular sólido, primário, menor que dois centímetros, no segmento cefálico; e controles, por pacientes com outras dermatoses. Foram analisadas variáveis constitucionais, comportamentais e lesões actínicas. RESULTADOS: Avaliaram-se 120 casos e 360 controles. Mílio facial (OR = 2,3), leucodermia puntacta de membros superiores (OR = 2,9) e cutis romboidalis nuchae (OR = 1,8) associaram-se à neoplasia independentemente das demais variáveis, sugerindo um fenótipo de risco. Houve ainda associação com fenótipos claros, genética familiar e exposição solar cumulativa. Queimadura solar, tabagismo e alcoolismo não foram identificados como fatores de risco. O uso de fotoprotetores não evidenciou proteção; porém, o grupo controle era composto por pacientes dermatológicos, aos quais são indicados fotoprotetores regularmente. CONCLUSÃO: Lesões actínicas foram mais prevalentes em portadores de carcinoma basocelular sólido do segmento cefálico que em controles, especialmente mílio, cutis romboidalis nuchae e leucodermia puntacta, independentemente dos demais fatores de risco conhecidos.

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O carcinoma basocelular é a neoplasia maligna mais comum em humanos e sua incidência vem aumentando nas últimas décadas. Sua grande frequência gera significativo ônus ao sistema de saúde, configurando problema de saúde pública. Apesar das baixas taxas de mortalidade e de rara ocorrência de metástases, o tumor pode apresentar comportamento invasivo local e recidivas após o tratamento, provocando importante morbidade. Exposição à radiação ultravioleta representa o principal fator de risco ambiental associado a sua gênese. Entretanto, descrevem-se outros elementos de risco: fotótipos claros, idade avançada, história familiar de carcinomas de pele, olhos e cabelos claros, sardas na infância e imunossupressão, além de aspectos comportamentais, como exercício profissional exposto ao sol, atividade rural e queimaduras solares na juventude. Entre 30% e 75% dos casos esporádicos estão associados à mutação do gene patched hedgehog, mas outras alterações genéticas são ainda descritas. A neoplasia é comumente encontrada concomitantemente com lesões cutâneas relacionadas à exposição solar crônica, tais como: queratoses actínicas, lentigos solares e telangiectasias faciais. A prevenção do carcinoma basocelular se baseia no conhecimento de fatores de risco, no diagnóstico e tratamento precoces e na adoção de medidas específicas, principalmente, nas populações susceptíveis. Os autores apresentam uma revisão da epidemiologia do carcinoma basocelular.

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A palmeira-ráfia possui grande importância econômica devido ao seu interesse comercial. É uma planta ornamental muito apreciada por sua beleza e utilização em ambiente interno, crescendo bem em locais com sombra e apresentando resistência à exposição solar. O valor econômico dessa planta está relacionado à altura e número de hastes. O objetivo do trabalho foi promover o crescimento da planta, através da aplicação do regulador de crescimento ácido giberélico (GA3). Mudas de palmeira-ráfia com aproximadamente um ano de idade foram aspergidas a cada 21 dias (quatro aplicações) com solução de ácido giberélico nas concentrações de 0; 75; 150; 225; e 300 mg.L-1. Os resultados indicaram que a aplicação do ácido giberélico foi eficiente na promoção do crescimento da espécie, sendo esse incremento significativo nas variáveis: comprimento dos pecíolos, lâminas foliares e altura da planta. Não se observou diferença no acúmulo de matéria seca ou fresca do pecíolo entre os tratamentos, e plantas do tratamento-controle foram superiores às dos tratamentos 225 e 300 mg L-1, nas variáveis diâmetro do colo e massa fresca e seca das raízes. Devido ao incremento na altura das mudas e à alteração da disposição das folhas da palmeira, a utilização do ácido giberélico pode ser recomendada para a produção de mudas de alta qualidade.

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Buscou-se junto a um grupo de risco para o câncer de pele seu o perfil demográfico e analisou-se o uso de medidas preventivas utilizadas pelos mesmos e pela empresa. Estudo quantitativo com 33 carteiros da Empresa Brasileira de Correios e Telégrafos em Botucatu, Brasil. Dados obtidos por meio de um formulário que investigava perfil demográfico, tempo de trabalho na empresa, horário de exposição ao sol, história de queimaduras solares, história de câncer na família e formas de prevenção do câncer de pele utilizadas. Na análise dos dados, utilizou-se estatística descritiva segundo Teste Exato de Fisher ao nível de 5% de probabilidade. Os resultados mostraram que a faixa etária predominante foi de 26 a 30 e de 31 a 35 anos, correspondendo a 42,42% da amostra, a cor da pele foi à branca com 93,94% e 81,82% trabalham há mais de cinco anos na empresa. O hábito de usar filtro solar foi encontrado em 63,63% dos entrevistados, sendo a não aderência a este justificada em 75% por falta de costume. em relação aos equipamentos protetores do sol a empresa fornece para 100% deles. Os achados permitem a caracterização da população estudada, identificada como de risco para o câncer de pele, propiciando a profilaxia através de ações em saúde, visando à sensibilização dos mesmos para com as medidas preventivas que podem ser adotadas.

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Skin cancers are the most common human malignant neoplasia and their incidence is growing, chiefly in tropical countries. There is evidence that ultraviolet (UV) radiation present in sunlight is important for genetic damage. Mutations due to such damage could be responsible for alterations in oncogenes and tumor suppressor genes. Recent studies have reported remarkable differences in mutation frequency of the RAS proto-oncogene in non-melanoma skin cancers. These findings may reflect differences in the molecular epidemiology of cutaneous tumors found in geographical areas with diverse sun exposure and ethnical origins of their populations. Our study proposed to perform molecular analyses of skin tumors on patients living in southeastern Brazil, in areas with high levels of sun exposure. DNA from eight solar keratose (SK), 26 basal cell carcinomas (BCC) and 19 squamous cell carcinomas (SCC) was submitted to PCR-SSCP analysis for codons 12, 13 and 61. Contradicting other authors, we found no mutations in codons 12,13 but detected two BCCs and one SCC with a mutation in codon 61. These findings suggest that the activation of KRAS oncogene may contribute to the pathogenicity of cutaneous lesions in southeastern Brazil.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background Melasma is a common acquired chronic hypermelanosis of sun-exposed areas which significantly impacts quality of life. There are few epidemiological studies in medical literature concerning these patients. Objective Characterize clinical and epidemiological data on Brazilian female patients with melasma. Methods A semi-structured questionnaire was administered to melasma patients treated at a dermatology clinic between 2005 and 2010. Association between variables was performed by multivariate regression models. Results We assessed 302 patients; intermediate skin phototypes III (34.4%) and IV (38.4%) were prevalent. Mean disease onset age was 27.5 ± 7.8 years and familiar occurrence of melasma was identified in 56.3%. The most commonly reported trigger factors were pregnancy (36.4%), contraceptive pills (16.2%) and intense sun exposure (27.2%). Preferred facial topographies were zygomatic (83.8%), labial superior (51.3%) and frontal (49.7%). Pregnancy induced melasma has been associated to early disease (OR = 0.86) and number of pregnancies (OR = 1.39). Childbearing was correlated to melasma extension. Older disease onset age was associated to darker skin phototypes. Co-occurrence of facial topographies supported clinical classification as centrofacial and peripheral melasma. Conclusion This population was characterized by: a high prevalence in adult females, intermediate skin phototypes, disease precipitation by hormonal stimulus and familiar genetic influence. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.