Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Fumar/efectos adversos , Tomografía Computarizada por Rayos X/efectos adversos , Tomografía de Emisión de Positrones/efectos adversos , Neoplasias Pulmonares/diagnóstico , Neoplasias Inducidas por Radiación/diagnóstico , Dosis de Radiación , Tomografía Computarizada por Rayos X/métodos , Tamizaje Masivo/efectos adversos , Tamizaje Masivo/métodos , Factores de Riesgo , Medición de Riesgo , Tomografía de Emisión de Positrones/métodos , Detección Precoz del Cáncer , Italia , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/epidemiología , Neoplasias Inducidas por Radiación/etiología , Neoplasias Inducidas por Radiación/prevención & control , Neoplasias Inducidas por Radiación/epidemiologíaRESUMEN
Boron neutron capture therapy (BNCT) is based on selective accumulation of B-10 carriers in tumor followed by neutron irradiation. We demonstrated, in 2001, the therapeutic effect of BNCT mediated by BPA (boronophenylalanine) in the hamster cheek pouch model of oral cancer, at the RA-6 nuclear reactor. Between 2007 and 2011, the RA-6 was upgraded, leading to an improvement in the performance of the BNCT beam (B2 configuration). Our aim was to evaluate BPA-BNCT radiotoxicity and tumor control in the hamster cheek pouch model of oral cancer at the new "B2" configuration. We also evaluated, for the first time in the oral cancer model, the radioprotective effect of histamine against mucositis in precancerous tissue as the dose-limiting tissue. Cancerized pouches were exposed to: BPA-BNCT; BPA-BNCT + histamine; BO: Beam only; BO + histamine; CONTROL: cancerized, no-treatment. BNCT induced severe mucositis, with an incidence that was slightly higher than in "B1" experiments (86 vs 67%, respectively). BO induced low/moderate mucositis. Histamine slightly reduced the incidence of severe mucositis induced by BPA-BNCT (75 vs 86%) and prevented mucositis altogether in BO animals. Tumor overall response was significantly higher in BNCT (94-96%) than in control (16%) and BO groups (9-38%), and did not differ significantly from the "B1" results (91%). Histamine did not compromise BNCT therapeutic efficacy. BNCT radiotoxicity and therapeutic effect at the B1 and B2 configurations of RA-6 were consistent. Histamine slightly reduced mucositis in precancerous tissue even in this overly aggressive oral cancer model, without compromising tumor control.
Asunto(s)
Terapia por Captura de Neutrón de Boro/efectos adversos , Terapia por Captura de Neutrón de Boro/instrumentación , Mejilla , Neoplasias de la Boca/etiología , Neoplasias Inducidas por Radiación/etiología , Reactores Nucleares , Investigación Biomédica Traslacional , Animales , Cricetinae , Modelos Animales de Enfermedad , Histamina/farmacología , Neoplasias de la Boca/prevención & control , Neoplasias Inducidas por Radiación/prevención & control , Protectores contra Radiación/farmacologíaRESUMEN
BACKGROUND:: The incidence of skin cancer has increased worldwide, particularly melanoma rates, which had a mean development of 2.6 % a year in the last 10 years. The agreement on the relation between long-term or chronic exposure to the sun and the emergence of these neoplasias has made several workers who perform activities exposed to solar radiation to form a risk group for the development of skin cancer, community health agents included. OBJECTIVES:: To analyze the prevalence of sunscreen-use-related factors to skin cancer in a labor risk group. METHODOLOGY:: Cross-sectional study with community health agents selected through simple random sampling. After collecting data using semi-structured interviews, a descriptive analysis was performed for the qualitative variables, bivariate analysis was employed for checking the association between sunscreen use and sociodemographic, occupational and knowledge about skin variables, and multivariate analysis was conducted to check independent variables associated to sunscreen use. A 5% significance level was used. RESULTS:: Of 261 health gents selected, 243 were able to participate in the study. The prevalence rate of sunscreen use was 34.2% (95% CI: 28.2-40.2). Factors associated with sunscreen use were female sex, advanced age, use of sunscreen in situations when the skin got burnt, knowledge of the negative effects of the sun on the skin and skin cancer history. CONCLUSIONS:: The prevalence found reveals that there is a need for implementing educational strategies in health services regarding photoprotection.
Asunto(s)
Melanoma/epidemiología , Melanoma/prevención & control , Neoplasias Cutáneas/epidemiología , Neoplasias Cutáneas/prevención & control , Protectores Solares/uso terapéutico , Adulto , Factores de Edad , Brasil/epidemiología , Métodos Epidemiológicos , Femenino , Conocimientos, Actitudes y Práctica en Salud , Personal de Salud , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/prevención & control , Factores Sexuales , Luz Solar/efectos adversos , Rayos Ultravioleta/efectos adversos , Adulto JovenRESUMEN
Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members. We found that although the better description of the posture in which the aircrews are exposed, the results of the effective dose rate calculated with the phantom in the sitting posture were very similar to the results of the phantom in the standing posture. In fact we observed only a 1% difference. These findings indicate the adequacy of the use of dose conversion coefficients for the phantom in the standing posture in aircrew dosimetry. We also validated our results comparing the effective dose rate obtained using the standing phantom with values reported in the literature. It was observed that the results presented in this study are in good agreement with other authors (the differences are below 30%) who have measured and calculated effective dose rates using different phantoms.
Asunto(s)
Aeronaves , Radiación Cósmica , Exposición Profesional/análisis , Postura , Dosis de Radiación , Radiometría/métodos , Femenino , Humanos , Masculino , Neoplasias Inducidas por Radiación/prevención & control , Enfermedades Profesionales/prevención & control , Fantasmas de Imagen , Traumatismos por Radiación/prevención & controlRESUMEN
BACKGROUND: 'Keratinocyte cancer' is now the preferred term for the most commonly identified skin cancers basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), which were previously commonly categorised as non-melanoma skin cancers (NMSC). Keratinocyte cancer (KC) represents about 95% of malignant skin tumours. Lifestyle changes have led to increased exposure to the sun, which has, in turn, led to a significant increase of new cases of KC, with a worldwide annual incidence of between 3% and 8%. The successful use of preventive measures could mean a significant reduction in the resources used by health systems, compared with the high cost of the treatment of these conditions. At present, there is no information about the quality of the evidence for the use of these sun protection strategies with an assessment of their benefits and risks. OBJECTIVES: To assess the effects of sun protection strategies (i.e. sunscreen and barrier methods) for preventing keratinocyte cancer (that is, basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) of the skin) in the general population. SEARCH METHODS: We searched the following databases up to May 2016: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trial registries and the bibliographies of included studies for further references to relevant trials. SELECTION CRITERIA: We included randomised controlled clinical trials (RCTs) of preventive strategies for keratinocyte cancer, such as physical barriers and sunscreens, in the general population (children and adults), which may provide information about benefits and adverse events related to the use of solar protection measures. We did not include trials focused on educational strategies to prevent KC or preventive strategies in high-risk groups. Our prespecified primary outcomes were BCC or cSCC confirmed clinically or by histopathology at any follow-up and adverse events. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for eligibility using Early Review Organizing Software (EROS). Similarly, two review authors independently used predesigned data collection forms to extract information from the original study reports about the participants, methods of randomisation, blinding, comparisons of interest, number of participants originally randomised by arm, follow-up losses, and outcomes, and they assessed the risk of bias. We resolved any disagreement by consulting a third author and contacted trial investigators of identified trials to obtain additional information. We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included one RCT (factorial design) that randomised 1621 participants.This study compared the daily application of sunscreen compared with discretionary use of sunscreen, with or without beta-carotene administration, in the general population. The study was undertaken in Australia; 55.2% of participants had fair skin, and they were monitored for 4.5 years for new cases of BCC or cSCC assessed by histopathology. We found this study to be at low risk of bias for domains such as allocation, blinding, and incomplete outcome data. However, we found multiple unclear risks related to other biases, including an unclear assessment of possible interactions between the effects of the different interventions evaluated (that is, sunscreen and beta-carotene). We found no difference in terms of the number of participants developing BCC (n = 1621; risk ratio (RR) 1.03, 95% confidence interval (CI) 0.74 to 1.43) or cSCC (n = 1621; RR 0.88, 95% CI 0.50 to 1.54) when comparing daily application of sunscreen with discretionary use, even when analyses were restricted to groups without beta-carotene supplementation. This evidence was of low quality, which means that there is some certainty that future studies may alter our confidence in this evidence.We reported adverse events in a narrative way and included skin irritation or contact allergy.We identified no studies that evaluated other sun protection measures, such as the use of sun-protective clothing, sunglasses, or hats, or seeking the shade when outdoors. AUTHORS' CONCLUSIONS: In this review, we assessed the effect of solar protection in preventing the occurrence of new cases of keratinocyte cancer. We only found one study that was suitable for inclusion. This was a study of sunscreens, so we were unable to assess any other forms of sun protection. The study addressed our prespecified primary outcomes, but not most of our secondary outcomes. We were unable to demonstrate from the available evidence whether sunscreen was effective for the prevention of basal cell carcinoma (BCC) or cutaneous squamous cell carcinoma (cSCC).Our certainty in the evidence was low because there was a lack of histopathological confirmation of BCC or cSCC in a significant percentage of cases. Amongst other sources of bias, it was not clear whether the study authors had assessed any interaction effects between the sunscreen and beta-carotene interventions. We think that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Asunto(s)
Carcinoma Basocelular/prevención & control , Carcinoma de Células Escamosas/prevención & control , Neoplasias Inducidas por Radiación/prevención & control , Neoplasias Cutáneas/prevención & control , Luz Solar/efectos adversos , Protectores Solares/administración & dosificación , Adulto , Australia , Niño , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Protectores Solares/efectos adversos , Rayos Ultravioleta/efectos adversos , Vitaminas/administración & dosificación , Vitaminas/efectos adversos , beta Caroteno/administración & dosificación , beta Caroteno/efectos adversosRESUMEN
Effective dose of a skeletal survey in infants using digital radiography was estimated to be 0.2 mSv using Monte Carlo simulation. Radiation risk from this procedure is, therefore, low. Radiation concern should not be an overriding factor when deciding whether skeletal survey is needed in cases of possible physical abuse.
Asunto(s)
Huesos/efectos de la radiación , Maltrato a los Niños/diagnóstico , Dosis de Radiación , Simulación por Computador , Femenino , Humanos , Lactante , Masculino , Método de Montecarlo , Neoplasias Inducidas por Radiación/prevención & control , Fantasmas de Imagen , Exposición a la Radiación , Encuestas y Cuestionarios , Rayos XRESUMEN
The advance of medical imaging technology has led to an increase in the medical radiation exposure, especially derived from computed tomography (CT). Recent studies confirm a small but significant increase of cancer cases induced by CT radiation. Children are markedly more sensitive to radiation than adults and in addition, their life expectancy is longer, so we must use all resources to optimize and reduce the exposure dose using the ALARA concept. CT is an important diagnostic tool in medical practice and its benefits far outweigh the costs of radiation if the indication is properly justified.
El avance tecnológico de las imágenes para evaluación de enfermedades ha llevado a un aumento considerable de la radiación de origen médica, principalmente la proveniente de la tomografía computada (TC). Estudios recientes confirman un pequeño pero significativo incremento de casos de cáncer inducidos por radiación generada por la TC. Siendo los niños reconocidamente más sensibles a la radiación que los adultos y sumado a su mayor expectativa de vida, es que debemos usar todos los recursos para optimizar y reducir la dosis de exposición aplicando el concepto de ALARA. La TC es una herramienta diagnóstica importantísima en la práctica médica, y sus beneficios superan ampliamente los costos de la radiación si su indicación está adecuadamente justificada.
Asunto(s)
Humanos , Niño , Neoplasias Inducidas por Radiación/etiología , Tomografía Computarizada por Rayos X/efectos adversos , Dosis de Radiación , Neoplasias Inducidas por Radiación/prevención & control , Medición de Riesgo , Radiografía/efectos adversosRESUMEN
Objetivo: identificar la contribución relativa de diferentes factores de riesgo ocupacionales asociados a la ocurrencia de cáncer de piel en las provincias de Ciudad de La Habana y La Habana , Cuba, en el período 2006-2007. Material y método: se diseñó un estudio de casos y controles de base hospitalaria, en que se incluyeron 112 casos de cáncer de piel no melanoma y 448 testigos, siguiendo los criterios de inclusión-exclusión prefijados. Se consideró la totalidad de los pacientes diagnosticados de carcinoma de células basales y de células escamosas por estudio histológico de biopsia de piel o exéresis quirúrgica. Como factores de riesgo con posible asociación a la enfermedad, se estudiaron la exposición solar, a radiaciones ionizantes y no ionizantes y a un conjunto amplio de sustancias químicas y biológicas potencialmente cancerígenas. Resultados: en el estudio se corroboró que son múltiples los factores que explican la ocurrencia del cáncer de piel, fundamentalmente como efecto del sol, las radiaciones no ionizantes y el calor, en combinación con factores químicos. Conclusiones: la exposición combinada previa con diferentes duraciones e intensidades a factores del ambiente ocupacional, incrementa la probabilidad de la ocurrencia del carcinoma de piel, especialmente la luz solar, el calor, las radiaciones no ionizantes (incluidos los campos electromagnéticos) y factores químicos tales como el petróleo y sus derivados, el paraquat y el diclorofenildicloroetano(AU)
Objective: To identify the relative contribution of different occupational risk factors associated with the occurrence of skin cancer in the provinces of Havana City and Havana , Cuba , in 2006-2007. Material and methods: It was designed a case-control study of hospital base that included 112 cases of non-melanoma skin cancer and 448 witnesses, following the inclusion-exclusion criteria preset. We considered the totality of patients diagnosed with basal cell carcinoma and squamous cell histological study of skin biopsy or surgical excision. Risk factors with possible association with the disease were studied, such as sun exposure, ionizing and non-ionizing radiations and a wide range of chemical and biological substances potentially carcinogenic. Results: The study confirmed that there are multiple factors that explain the occurrence of skin cancer, mainly as an effect of the sun, non-ionizing radiation and heat, combined with chemical factors. Conclusions: Prior combined exposure with different durations and intensities of the workplace environment factors increases the likelihood of the occurrence of skin carcinoma, especially sunlight, heat, non-ionizing radiation (including electromagnetic fields) and chemical factors such as oil and its derivatives, paraquat and dichlorofenildichloroethane(AU)
Asunto(s)
Humanos , Masculino , Femenino , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Neoplasias Cutáneas , Factores de Riesgo , Neoplasias Inducidas por Radiación/prevención & control , Estudios de Casos y Controles , Efectos de la Radiación , Radiación no Ionizante/efectos adversosRESUMEN
The incidence of skin cancer after liver transplant ranges from 3% to 16%, considerably higher than that observed in the general population. Skin cancer causes 25% of deaths in patients who have survived more than 3 years after liver transplant. The objective of this study was to identify differences regarding the level of sun exposure, knowledge of potential risk factors, and photoprotection measures among liver transplant candidates and recipients. We carried out a prospective cross-sectional study with 100 patients enrolled at a liver transplant program in a Brazilian center. The patients were interviewed and received oral information regarding skin care and sun exposure. Results reveal that measures of photoprotection and photoeducation are more prevalent among recipients than among candidates. High degrees of solar exposure were observed more frequently among candidates, although recipients showed better knowledge about the risks of sun exposure. Educational actions concerning skin cancer prevention should be part of the guidelines given by the multidisciplinary team to the liver transplant patients, in particular, by the nursing team.
Asunto(s)
Trasplante de Hígado , Neoplasias Inducidas por Radiación/prevención & control , Educación del Paciente como Asunto/métodos , Neoplasias Cutáneas/prevención & control , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Trasplante de Hígado/enfermería , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/prevención & control , Luz Solar/efectos adversosRESUMEN
Non-melanoma skin cancer represents a quarter of the new cancer cases detected in Brazil. Despite the importance of this issue to public health, there are deficits in knowledge on the local UV radiation levels among physicians. In this work, we evaluate a set of daily erythemal UV doses measured in different Brazilian locations. Very high erythemal UV doses that often exceeded safe amounts were observed over almost the whole year, even during the time interval usually recommended as safe (before 10:00 h and after 16:00 h). These findings will hopefully enable foreign tourists, dermatologists, and decision-makers to implement new measures for solar protection according to South American standards.
Asunto(s)
Eritema/epidemiología , Neoplasias Inducidas por Radiación/epidemiología , Radiodermatitis/epidemiología , Neoplasias Cutáneas/epidemiología , Rayos Ultravioleta/efectos adversos , Brasil/epidemiología , Relación Dosis-Respuesta en la Radiación , Exposición a Riesgos Ambientales/efectos adversos , Humanos , Modelos Teóricos , Neoplasias Inducidas por Radiación/prevención & control , Radiodermatitis/prevención & control , Factores de Riesgo , Estaciones del Año , Luz Solar/efectos adversosRESUMEN
Probiotics are live micro-organisms that when administered in adequate amounts confer a health benefit on the host. Cell surface molecules of these micro-organisms are being studied in relation to their ability to interact with the host. The cell wall of lactobacilli possesses lipoteichoic acids (LTA) which are molecules with immunomodulatory properties. UV radiation (UVR) has been proposed as the main cause of skin cancer because of its mutagenic and immunosuppressive effects. Photoprotection with some nutrition interventions including probiotics has recently been shown. The aim of the present study was to investigate whether the oral administration of purified LTA from Lactobacillus rhamnosus GG can modulate the immune-suppressive effect of UVR and skin tumour development in female Crl:SKH-1-hrBR mice. For this purpose, two irradiation models were studied: (1) a chronic irradiation scheme consisting of daily irradiations during twenty consecutive days and (2) a long-term irradiation schedule, irradiating the animals three times per week, during 34 weeks for tumour development. The results showed that T-cells in the inguinal lymph node of LTA-treated mice produced higher levels of (1) interferon-γ and (2) a number of total, helper and cytotoxic T-cells compared with non-treated mice. Moreover, a significant delay in tumour appearance was found in LTA-treated mice. An increased IgA⺠cell number was found in the small intestine together with a higher number of activated dendritic cells in the mesenteric lymph nodes. The latter results might be indicative of a direct effect of LTA in the gut, affecting the cutaneous immune system and restoring homeostasis through the gut-skin axis.
Asunto(s)
Anticarcinógenos/uso terapéutico , Intestino Delgado/inmunología , Lipopolisacáridos/uso terapéutico , Neoplasias Inducidas por Radiación/prevención & control , Neoplasias Cutáneas/prevención & control , Piel/inmunología , Ácidos Teicoicos/uso terapéutico , Rayos Ultravioleta/efectos adversos , Animales , Anticarcinógenos/efectos adversos , Anticarcinógenos/aislamiento & purificación , Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Células Presentadoras de Antígenos/patología , Células Presentadoras de Antígenos/efectos de la radiación , Apoptosis/efectos de la radiación , Carcinogénesis/inmunología , Carcinogénesis/metabolismo , Carcinogénesis/patología , Carcinogénesis/efectos de la radiación , Células Cultivadas , Suplementos Dietéticos/efectos adversos , Femenino , Inmunomodulación/efectos de la radiación , Intestino Delgado/patología , Intestino Delgado/efectos de la radiación , Lacticaseibacillus rhamnosus/inmunología , Lacticaseibacillus rhamnosus/metabolismo , Lipopolisacáridos/efectos adversos , Lipopolisacáridos/aislamiento & purificación , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Ganglios Linfáticos/efectos de la radiación , Ratones , Ratones Pelados , Neoplasias Inducidas por Radiación/inmunología , Neoplasias Inducidas por Radiación/metabolismo , Neoplasias Inducidas por Radiación/patología , Probióticos/efectos adversos , Probióticos/metabolismo , Probióticos/uso terapéutico , Piel/metabolismo , Piel/patología , Piel/efectos de la radiación , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/patología , Bazo/inmunología , Bazo/metabolismo , Bazo/patología , Bazo/efectos de la radiación , Ácidos Teicoicos/efectos adversos , Ácidos Teicoicos/aislamiento & purificación , Carga Tumoral/efectos de la radiaciónRESUMEN
OBJECTIVE: To determine the optimal imaging strategy for young children with minor head injury considering health-related quality of life and radiation risk. In children with minor head trauma, the risk of missing a clinically important traumatic brain injury (ciTBI) must be weighed against the risk of radiation-induced malignancy from computed tomography (CT) to assess impact on public health. STUDY DESIGN: We included children <2 years old with minor blunt head trauma defined by a Glasgow Coma Scale score of 14-15. We used decision analysis to model a CT-all versus no-CT strategy and assigned values to clinical outcomes based on a validated health-related quality of life scale: (1) baseline health; (2) non-ciTBI; (3) ciTBI without neurosurgery, death, or intubation; and (4) ciTBI with neurosurgery, death, or intubation >24 hours with probabilities from a prospective study of 10000 children. Sensitivity analysis determined the optimal management strategy over a range of ciTBI risk. RESULTS: The no-CT strategy resulted in less risk with the expected probability of a ciTBI of 0.9%. Sensitivity analysis for the probability of ciTBI identified 4.8% as the threshold above which CT all becomes the preferred strategy and shows that the threshold decreases with less radiation. The CT all strategy represents the preferred approach for children identified as high-risk. CONCLUSION: Among children <2 years old with minor head trauma, the no-CT strategy is preferable for those at low risk, reserving CT for children at higher risk.
Asunto(s)
Lesiones Encefálicas/diagnóstico por imagen , Técnicas de Apoyo para la Decisión , Neoplasias Inducidas por Radiación/etiología , Neoplasias Inducidas por Radiación/prevención & control , Tomografía Computarizada por Rayos X/efectos adversos , Heridas no Penetrantes/diagnóstico por imagen , Humanos , Lactante , Estudios Prospectivos , Factores de RiesgoRESUMEN
Excessive exposure to solar or artificial sources of UV radiation is deleterious to the skin and can cause or worsen several diseases. Detrimental effects of UV radiation exert an important role in the development of skin cancers, cause alterations on the immune response, and act as a trigger or aggravating factor for pigmentary disorders. A group of measures, including education, change of habits, use of physical barriers and sunscreens constitutes a significant part of the treatment of many skin disorders and are valuable preventive tools. This article summarizes the relevant studies addressing these issues, emphasizing the many aspects of photoprotection.
Asunto(s)
Trastornos de la Pigmentación/prevención & control , Enfermedades de la Piel/prevención & control , Luz Solar/efectos adversos , Protectores Solares , Rayos Ultravioleta/efectos adversos , Antioxidantes/uso terapéutico , ADN/efectos de la radiación , Femenino , Humanos , Masculino , Neoplasias Inducidas por Radiación/etiología , Neoplasias Inducidas por Radiación/prevención & control , Trastornos por Fotosensibilidad/etiología , Trastornos por Fotosensibilidad/prevención & control , Trastornos de la Pigmentación/etiología , Embarazo , Complicaciones del Embarazo/etiología , Complicaciones del Embarazo/prevención & control , Ropa de Protección , Protectores contra Radiación/uso terapéutico , Piel/efectos de la radiación , Enfermedades de la Piel/etiología , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/prevención & control , Pigmentación de la Piel/efectos de la radiación , Protectores Solares/química , Protectores Solares/clasificación , Protectores Solares/farmacologíaRESUMEN
In this study we assessed the protective effect of topical application of Pothomorphe umbellata extract on ultraviolet B (UVB)-induced skin lesion parameters in hairless mouse epidermis. A single dose of UVB irradiation (0.23 kJ/m2) resulted in a significant decrease in thymine dimer-positive cells and apoptotic sunburn cells, with an increase in p53 and proliferating cell nuclear antigen-positive cells in the epidermis. After 5 weeks (total dose 13.17 kJ/m2) and 15 weeks (total dose 55.51 kJ/m2) of irradiation, P. umbellata treatment inhibited the hyperplasic response and induced an increase in p53-positive cells. These findings suggest that P. umbellata extract affords protection against UVB-induced skin lesions.
Asunto(s)
Epidermis/efectos de los fármacos , Neoplasias Inducidas por Radiación/prevención & control , Piperaceae/química , Protectores contra Radiación/uso terapéutico , Neoplasias Cutáneas/prevención & control , Rayos Ultravioleta/efectos adversos , Administración Cutánea , Animales , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Biomarcadores/metabolismo , Pruebas de Carcinogenicidad , Epidermis/metabolismo , Epidermis/patología , Epidermis/efectos de la radiación , Femenino , Hiperplasia , Inmunohistoquímica , Ratones , Ratones Pelados , Neoplasias Inducidas por Radiación/etiología , Neoplasias Inducidas por Radiación/metabolismo , Neoplasias Inducidas por Radiación/patología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Antígeno Nuclear de Célula en Proliferación/metabolismo , Dímeros de Pirimidina/metabolismo , Protectores contra Radiación/administración & dosificación , Protectores contra Radiación/aislamiento & purificación , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Proteína p53 Supresora de Tumor/biosíntesisRESUMEN
The results of five years of radiation monitoring of 590 radiation workers in Jamaica and an additional 88 in Barbados and The Turks and Caicos Islands show that the annual dose absorbed by Caribbean radiation workers is, with a single exception, well within the internationally accepted limits of 20 mSv per year. There were few cases of relatively high exposures. The dose equivalent of the radiation workers by category agrees with international trends; workers in nuclear medicine receive the highest doses and dental radiologists the lowest. The collective Effective Dose Equivalent has been calculated for each of the monitored populations and certain trends identified. The risk for development of fatal cancers from the occupational doses reported was very low. Consistent monitoring will identify aberrant conditions quickly and help maintain that record.
Asunto(s)
Neoplasias Inducidas por Radiación/prevención & control , Exposición Profesional/efectos adversos , Centrales Eléctricas , Monitoreo de Radiación/métodos , Dosimetría Termoluminiscente , Región del Caribe , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Masculino , Dosis Máxima Tolerada , Salud Laboral , Dosis de Radiación , Protección Radiológica/métodos , Medición de RiesgoRESUMEN
The results of five years of radiation monitoring of 590 radiation workers in Jamaica and an additional 88 in Barbados and The Turks and Caicos Islands show that the annual dose absorbed by Caribbean radiation workers is, with a single exception, well within the internationally accepted limits of 20 mSv per year. There were few cases of relatively high exposures. The dose equivalent of the radiation workers by category agrees with international trends; workers in nuclear medicine receive the highest doses and dental radiologists the lowest. The collective Effective Dose Equivalent has been calculated for each of the monitored populations and certain trends identified. The risk for development of fatal cancers from the occupational doses reported was very low. Consistent monitoring will identify aberrant conditions quickly and help maintain that record
Asunto(s)
Humanos , Masculino , Femenino , Centrales Eléctricas , Dosimetría Termoluminiscente , Exposición Profesional/efectos adversos , Monitoreo de Radiación/métodos , Neoplasias Inducidas por Radiación/prevención & control , Dosis de Radiación , Dosis Máxima Tolerada , Medición de Riesgo , Protección Radiológica/métodos , Región del Caribe , Relación Dosis-Respuesta en la Radiación , Salud LaboralRESUMEN
New methods to protect skin from photodamage from sun exposure are necessary if we are to conquer skin cancer and photoaging. Sunscreens are useful, but their protection is not ideal because of inadequate use, incomplete spectral protection, and toxicity. Skin naturally uses antioxidants (AOs) to protect itself from photodamage. This scientific review summarizes what is known about how photodamage occurs; why sunscreens--the current gold standard of photoprotection--are inadequate; and how topical AOs help protect against skin cancer and photoaging changes. This review is intended to be a reference source, including pertinent comprehensive reviews whenever available. Although not all AOs are included, an attempt has been made to select those AOs for which sufficient information is available to document their potential topical uses and benefits. Reviewed are the following physiologic and plant AOs: vitamin C, vitamin E, selenium, zinc, silymarin, soy isoflavones, and tea polyphenols. Their topical use may favorably supplement sunscreen protection and provide additional anticarcinogenic protection. (J Am Acad Dermatol 2003;48:1-19.) Learning objective: At the completion of this learning activity, participants should have an understanding of current information about how the sun damages skin to produce skin cancer and photoaging changes, how the skin naturally protects itself from the sun, the shortcomings of sunscreens, and the added advantages of topical AOs for photoprotection.