RESUMO
INTRODUCTION: Dehydration of the stratum corneum leads to sensations and symptoms of 'dry skin' such as skin tightness and itchiness. As these complaints are frequently experienced by airline travellers, the aim of this study was to investigate the changes in skin surface hydration during long distance flights. METHODS: The study was performed on four healthy Caucasian, and on four Japanese women aged 29-39 years, travelling on long distance flights. They had stopped using skin care products at least 12 h before, and did not apply them during the flights. The air temperature and relative humidity inside the cabin, as well as skin capacitance of the face and forearm of participants, were registered at several time points before and during the flights. RESULTS: Relative humidity of the aircraft cabin dropped to levels below 10% within 2 h after take-off and stayed at this value throughout the flight. Skin capacitance decreased rapidly on both the face and forearms with most pronounced changes on the cheeks where it decreased by up to 37%. CONCLUSION: Our results demonstrate that during long distance flights, the aircraft cabin environment leads to a rapid decrease in stratum corneum hydration, an alteration, which probably accounts for the discomfort experienced by long distance aircraft travellers.
Assuntos
Aeronaves , Desidratação/etiologia , Prurido/etiologia , Pele/metabolismo , Viagem , Perda Insensível de Água/fisiologia , Adulto , Povo Asiático , Desidratação/metabolismo , Capacitância Elétrica , Feminino , Humanos , Umidade , Prurido/metabolismo , Temperatura , Água/metabolismo , População BrancaRESUMO
Several reports indicated that Alzheimer's disease (AD) and age-related macular degeneration (AMD) may share similar genetic and pathological features. We postulated that the functional Y402H polymorphism within the CFH gene and unambiguously recognised as a major genetic determinant of AMD, may also be a risk factor of AD. We analysed the association of this polymorphism with the AD risk in both prospective and cross-sectional studies. We were not able to detect such an association whatever the studied population, suggesting that the CFH gene is not a genetic determinant of AD.
Assuntos
Doença de Alzheimer/genética , Estudos de Associação Genética/métodos , Predisposição Genética para Doença/genética , Degeneração Macular/genética , Polimorfismo Genético/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Fator H do Complemento/genética , Estudos Transversais , Análise Mutacional de DNA , Frequência do Gene/genética , Ligação Genética/genética , Marcadores Genéticos/genética , Testes Genéticos , Genótipo , Humanos , Degeneração Macular/metabolismo , Degeneração Macular/fisiopatologia , Estudos ProspectivosRESUMO
OBJECTIVE: To assess the relative contribution of intrinsic aging vs lifestyle factors to facial skin age. DESIGN: Prospective analysis of a cohort. SETTING: Skin research institute. STUDY SUBJECTS: A cohort of 361 white women (age range, 18-80 years) with apparently healthy skin. MEASUREMENTS: Visual and tactile assessment of facial skin features. RESULTS: Twenty-four skin characteristics were used to build a skin age score (SAS). The relationship between the SAS and chronological age followed a linear model with 2 plateaus--1 before age 30 years and 1 after age 71 years. An analysis was performed to determine whether certain lifestyle habits known to have effects on skin aging were related to the discrepancies between chronological age and the SAS. Significant effects were identified for phototype, body mass index, menopausal status, degree of lifetime sun exposure, and number of years of cigarette smoking. However, these factors accounted for only 10% of the discrepancies. Moreover, most skin characteristics used reflected changes understood to represent intrinsic aging rather than photodamage or other extrinsic factors. CONCLUSIONS: An SAS can be generated from multiple discrete signs evaluated on facial skin and is an informative tool for quantifying skin aging. The SAS is influenced by factors already recognized to affect the aging phenotypes; however, factors related to the rate of intrinsic aging, presumably genetic in character, seem to play a larger role than previously suspected.
Assuntos
Envelhecimento da Pele/genética , Envelhecimento da Pele/fisiologia , Luz Solar/efeitos adversos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Estilo de Vida , Pessoa de Meia-Idade , Exame Físico , Estudos Prospectivos , Valores de Referência , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Higiene da Pele/métodos , Fenômenos Fisiológicos da PeleRESUMO
BACKGROUND/AIMS: The aim of this study was to compare the biophysical properties of different facial zones. METHODS: We investigated transepidermal water loss (TEWL), skin temperature and sebum casual level (CL) on 90 adjacent test sites distributed on the forehead, cheeks and chin of five women. RESULTS: All three parameters showed a symmetrical distribution around the facial median line. Only minor variations of individual values were found within the forehead and the chin areas. In contrast, the cheeks exhibited a distinct gradient with highest values in the paranasal zones and lowest on the cheek bones for all of the three parameters. The mean values on both cheeks of a given individual were nearly identical, and the patterns within the two cheeks were superimposable. Both CL and skin temperature distributions pointed out a "T-zone" with highest values on the forehead, on the chin and on the median part of the cheek. CONCLUSIONS: Our data demonstrate that biophysical skin properties differ considerably between different facial areas but that they follow a characteristic distribution.