Sunscreens and hair photoprotection. [2006.01]
Photoprotection as it pertains to hair is not a common topic addressed by the dermatologist... The whole science of hair and photoprotection is currently in its infancy and an area of focused research within the hair care product and salon industries.
Evaluation of a multicomponent appearance-based sun-protective intervention for young women: uncovering the mechanisms of program efficacy. [2006.01]
An appearance-based sun-protection intervention program was developed, implemented, and evaluated in a sample of 211 Caucasian women (ages 18-25) randomly assigned to the sun-protection program or to a stress management (control) program.
The pathophysiology of aging-photo of the skin. [2005.02]
Exposure to solar UV radiation is the main environmental factor that causes premature aging of the skin (photoaging)...
A review of sunscreens and their adverse reactions. [2005.01]
Sunscreens are used to protect the skin from harmful effects of ultraviolet (UV) light but they do not completely prevent photocarcinogenesis, photoaging and photoimmunosuppression. They are useful for protection against UVB and short-wave UVA.An overview of sunscreens, their effectiveness, and adverse reactions is presented.
Solar ultraviolet irradiation reduces collagen in photoaged human skin by blocking transforming growth factor-beta type II receptor/Smad signaling. [2004.09]
Ultraviolet (UV) irradiation from the sun reduces production of type I procollagen (COLI), the major structural protein in human skin... UV-induced down-regulation of TbetaRII, with attendant reduction of type I procollagen production, is a critical molecular mechanism in the pathophysiology of photoaging.
Ectoin: an effective natural substance to prevent UVA-induced premature photoaging. [2004.09]
With the help of a new 'UVA stress model', it was shown that Ectoin protects the skin from the effects of UVA-induced cell damage in a number of different ways. Using cell cultures, high-performance thin-layer chromatography, gel electrophoresis mobility shift assays, reverse transcriptase polymerase chain reaction, ion exchange chromatography and UV spectroscopy, it was demonstrated that the UVA-induced second messenger release, transcription factor AP-2 activation, intercellular adhesion molecule-1 expression and mitochondrial DNA mutation could be prevented.
Responses of black and white skin to solar-simulating radiation: differences in DNA photodamage, infiltrating neutrophils, proteolytic enzymes induced, keratinocyte activation, and IL-10 expression. [2004.06]
Black skin is more resistant to the deleterious effects of ultraviolet radiation than white skin... Our data could provide an explanation as to why black skin is less susceptible to sunburn, photoaging, and skin carcinogenesis.
Induction of the photoaging-associated mitochondrial common deletion in vivo in normal human skin. [2004.05]
Mutations of mitochondrial (mt) DNA such as the 4977 base-pair large-scale deletion, also called common deletion, are increased in photoaged skin. Direct evidence for their induction by chronic exposure to ultraviolet (UV) radiation in vivo in human skin has remained elusive however...
The polyhydroxy acid gluconolactone protects against ultraviolet radiation in an in vitro model of cutaneous photoaging. [2004.02]
BACKGROUND: Ultraviolet (UV) radiation damages skin through a variety of mechanisms, including the generation of free radicals. Gluconolactone is a polyhydroxy acid (PHA) that is capable of chelating metals and may also function by scavenging free radicals, thereby protecting skin from some of the damaging effects of UV radiation. OBJECTIVE: This study measured the ability of gluconolactone to protect against UV radiation-induced damage... CONCLUSIONS: These results demonstrate the ability of the PHA gluconolactone to protect against UV radiation-induced elastin promoter activation. In addition, in vivo studies demonstrated that gluconolactone treatment does not result in a significant increase in sunburn cells. Further investigation of this and other PHAs is necessary to identify their potential role in preventing and repairing cutaneous photodamage.
Skin aging and natural photoprotection. [2004.01]
Aging of skin is a continuous process that may be enhanced by sun exposure... The minimal erythema dose is thus the same through life, when corrected for pigmentation or measured in areas with constitutive pigmentation.
A trial of short incubation, broad-area photodynamic therapy for facial actinic keratoses and diffuse photodamage. [2004.01]
BACKGROUND: There is no completely satisfactory treatment for multiple actinic keratoses (AKs). OBJECTIVE: To evaluate the efficacy of short incubation, broad-area application of delta-aminolevulinic acid followed by exposure to activating light-photodynamic therapy (delta-ALA/PDT) for treatment of AKs and background photodamage. The benefit of pretreatment with 40% urea cream to enhance penetration and the use of topical 3% lidocaine hydrochloride to decrease discomfort were also evaluated... CONCLUSIONS: This delta-ALA/PDT protocol is safe and effective for AK treatment as well as for improving photodamage. Further studies with a larger cohort, longer follow-up, and histologic confirmation of the clinical data would be of value.
Cutaneous photobiology. The melanocyte vs. the sun: who will win the final round? [2003.10]
Solar ultraviolet radiation (UV) is a major environmental factor that dramatically alters the homeostasis of the skin as an organ by affecting the survival, proliferation and differentiation of various cutaneous cell types. The effects of UV on the skin include direct damage to DNA, apoptosis, growth arrest, and stimulation of melanogenesis...
Cutaneous effects of infrared radiation: from clinical observations to molecular response mechanisms. [2003.10]
Human skin is exposed to infrared (IR) radiation (760 nm-1 mm) from natural as well as artificial sources that are increasingly used for cosmetic or medical purposes. Epidemiological data and clinical observations, however, indicate that IR radiation cannot be considered as totally innocuous to human skin...
Age-dependent generation of reactive oxygen species in the skin of live hairless rats exposed to UVA light. [2003.10]
Aging proceeds by highly complicated biochemical processes, in which the involvement of the reactive oxygen species (ROS) and free radicals has been implicated. Although the relationship between UV-induced photoaging and ROS generation has been proposed, it has been difficult to establish direct proof of the generation of ROS in the skin under UV exposure...
Photoaging in Asians. [2003.06]
The aging process of the skin can be divided into intrinsic and photoaging. Clinically, naturally aged skin is smooth, pale and finely wrinkled... This review provides an outline of the characteristic features of photoaging on the brown skin of Asians.
Topical N-acetyl cysteine and genistein prevent ultraviolet-light-induced signaling that leads to photoaging in human skin in vivo. [2003.05]
Human skin is exposed to solar ultraviolet radiation. Ultraviolet radiation damages human skin and results in an old and wrinkled appearance, called photoaging... These data indicate that compounds similar to genistein and n-acetyl cysteine, which possess tyrosine kinase inhibitory and/or antioxidant activities, may prevent photoaging.
The sun protection factor (SPF) inadequately defines broad spectrum photoprotection: demonstration using skin reconstructed in vitro exposed to UVA, UVBor UV-solar simulated radiation. [2003.05]
Wavelength specific biological damage has been previously identified in human skin reconstructed in vitro. Sunburn cell and pyrimidine dimers were found after UVB exposure, and alterations of dermal fibroblasts after UVA exposure... This study strikingly illustrates the fact that the photoprotection afforded by two sunscreen formulations having similar SPF values is not equal with regard to dermal damage related to photoaging.
CD11b+ cells are the major source of oxidative stress in UV radiation-irradiated skin: possible role in photoaging and photocarcinogenesis. [2003.03]
Exposure of skin to solar UV radiation induces oxidative stress and suppression of cell-mediated immune responses. These effects are associated with the greater risk of several skin disorders including photoaging and photocarcinogenesis...
Skin photodamage and lifetime photoprotection. [2003.01]
Ultraviolet (UV) radiation is a very small part of the electromagnetic radiation spectrum, released and transported from the source in the form of photons. Disposal of these photons within the skin causes cutaneous photodamage, which leads to clinical, histologic, and biochemical changes...
Photoaging and oxidative stress. [2003.01]
Photoaging is significantly different from chronological aging in both clinical and histological appearance... The pathophysiology of photoaging of the skin caused by chronic inflammation after UVR is reviewed and discussed, with a focus on oxidative stress.
Photosensitization of DNA damage by glycated proteins. [2002.05]
Photosensitized DNA damage in skin is thought to be an important mechanism of UV phototoxicity. Here we demonstrate that proteins modified by advanced glycation endproducts (AGE-proteins) are photosensitizers of DNA damage and show that multiple mechanisms are involved in AGE-sensitization.Glycated proteins in skin may equally function as potent photosensitizers of DNA damage with implications for photoaging and photocarcinogenesis.
Photoaging is associated with protein oxidation in human skin in vivo. [2002.04]
There is increasing evidence for the generation of reactive oxygen species in skin upon ultraviolet exposure, but little is known about their pathophysiologic relevance in human skin in vivo... In conclusion, the correlation between photodamage and protein oxidation was demonstrated for the first time, which hence may be a relevant pathophysiologic factor in photoaging.
The evaluation of aluminum oxide crystal microdermabrasion for photodamage. [2001.10]
BACKGROUND: Aluminum oxide crystal microdermabrasion has recently become popular for facial rejuvenation. Although it is a widely used technique with perceptible benefits, the clinical efficacy on photodamaged skin has yet to be established. OBJECTIVE: To measure and quantify the effect of microdermabrasion on photodamaged skin... CONCLUSION: Immediately following the procedure, changes occurring in skin characteristics can be measured that are consistent with mild abrasion and increased blood flow. Objective biomechanical analysis demonstrated a statistically significant decrease in skin stiffness and an increase in skin compliance consistent with persistent edema. Subjectively, patients and physicians report a mild improvement in the majority of subjects. Histology showed dramatic vascular changes in the reticular dermis below the level of direct abrasion. The effect of negative pressure may result in these vascular changes.
Photoaging of human skin. [2000.12]
Chronic sun exposure causes photoaging of human skin, a process that is characterized by clinical, histological and biochemical changes which differ from alterations in chronologically aged but sun-protected skin... This has increased our understanding of photoaging significantly and has led to new prophylactic and therapeutic strategies aimed at the prevention and repair of the detrimental effects of chronic sun-exposure on the skin.
Prevention of ultraviolet ray damage: external and internal sunscreens. [1999.04]
Acute and chronic exposures to non-physiological doses of UV-light lead to a variety of changes of the skin...
Molecular mechanisms of photoaging in human skin in vivo and their prevention by all-trans retinoic acid. [1999.02]
Solar UV radiation damages human skin, affecting skin tone and resiliency and leading to premature aging (photoaging), the symptoms of which include leathery texture, wrinkles, mottled pigmentation, laxity and sallowness... The tRA likely acts to reduce UV induction of c-Jun protein by stimulating its breakdown through the ubiquitin-proteasome pathway.
Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). [1998.01]
BACKGROUND: UV radiation causes acute adverse effects like sunburn, photosensitivity reactions, or immunologic suppression, as well as long-term sequelae like photoaging or malignant skin tumors. UV radiation induces tissues to produce reactive oxygen species, eicosanoids and cytokines. Inhibition of these mediators might reduce skin damage. Antioxidants such as ascorbic acid and d-alpha-tocopherol have been found to be photoprotective in some in vitro studies and animal experiments. OBJECTIVE: Our purpose was to assess the protective effect of systemic vitamins C and E against sunburn in human beings... CONCLUSION: Combined vitamins C and E reduce the sunburn reaction, which might indicate a consequent reduced risk for later sequelae of UV-induced skin damage. The increase of sunburn reactivity in the placebo group could be related to "priming" by the previous UV exposure.
The effects of chronic sunscreen use on the histologic changes of dermatoheliosis. [1995.12]
BACKGROUND: Sunscreen application to the skin of hairless mice is effective in reversing the histologic changes associated with photoaging (solar elastosis, epidermal thickening, collagen depletion, glycosaminoglycan deposition). These reparative processes have not been studied in human beings. OBJECTIVE: The aim of this study was to evaluate histologically the effects of daily application of a UVA/UVB sunscreen versus placebo... CONCLUSION: The dermal changes of photoaging may be affected differently than epidermal changes when UV radiation exposure is diminished. UVA and UVB may contribute diversely to these cutaneous changes. Computer-generated evaluation of dermatoheliosis may be more accurate than visual inspection.
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