Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0849640 (skin damage)
 1,516 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Skin reaction to X-irradiation has been studied in the albino guinea-pig; early response in limited-field irradiations of the flank is comparable to that commonly seen in rodents, swine and man, and is dose-dependent with a dynamic range from mild erythema to moist desquamation. The peak early skin reaction is seen between 14 and 21 days after irradiation, and declines before 30 days except at the highest doses used. Fractionation of the X-ray dose at 24 hours results in a 'sparing' of about 340 rad. Permanent partial epilation is detectable at doses in excess of 1400 rad, and complete epilation at 1 year occurs in 50 per cent of irradiated fields at 1740 rad. Twenty-four hour two-dose fractionation results in a 'sparing' of about 500 rad for epilation. Palpable dermal 'fibrosis' is detectable at 3 months after irradiation in fields given more than 2070 rad, and at 1 year after irradiation in fields given more than 1800 rad; 50 per cent of fields showed palpable 'fibrosis' at 1 year at 1930 rad. Unlike domestic swine and man, skin fields in the guinea-pig showed no dimensional contraction after X-ray doses which produced gross early skin damage.
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PMID:Skin response to X-irradiation in the guinea-pig. 108 93

The proportion of subjects recovering from skin erythema induced by a single ultraviolet radiation challenge of 6 times the minimal erythema dose during a 3-week period was lower in 47 patients with stage I cutaneous melanoma than in 48 healthy control subjects with similar risk factors of increased sensitivity to ultraviolet radiation (p = 0.045). This difference indicates that the patients with melanoma were more susceptible to prolonged ultraviolet radiation-induced skin damage than the control subjects. Prolonged erythema response was significantly associated in the melanoma group with decreased minimal erythema doses (odds ratio [OR] = 11.3) and with the presence of freckles (OR = 5.5), and was associated in the control group with light eye color (OR = 5.8). Prolonged ultraviolet radiation-induced erythema is neither a unique feature of melanoma patients nor a useful marker for identifying risk groups for cutaneous melanoma.
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PMID:The recovery from ultraviolet radiation-induced erythema and melanoma risk factors: a case-control study. 236 74

An experimental procedure is described as a means for assessing the efficiency of skin-protecting measures against the vapors of hazardous substances. Bis(2-chloroethyl)sulfide (S-mustard) is used as the test substance. A continuous flow of S-mustard vapor is conducted through an exposure cell which is attached to the inner side of a rabbit's ear. From the difference in the concentrations measured before and behind the exposure cell, the absorption and the permeation rate of mustard into the skin is calculated. The skin damage, consisting of a reversible erythema, is quantified by measuring the optical transmittance of the exposed skin area during the following days and correlated with the respective absorption (dose) and exposure parameters (ct-product, with c = 3-50 ng/cm3 and t = 60 and 120 min). Reversible, i.e., completely healing, erythema are evoked by ct-products in the range of 250-2000 ng.min/cm3 corresponding to doses from about 0.1 to 1.1 micrograms/cm2. A comparison with older data reveals that human skin, in this respect, is about eight times more sensitive than the inner side of the rabbit's ear.
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PMID:A method for correlating skin exposure to S-mustard vapor with skin damage. 259 97

A human sunburn cell (SBC) count is used to evaluate the reduction in UV-induced skin damage achieved by a highly protective sunscreen formulation containing 3 filters and reflective pigments (sun protection factor 34). Results indicate that, for the same minimal erythema level, SBC counts do not significantly differ between protected and unprotected skin, showing that the very high efficacy demonstrated against actinic erythema also extends to UV-induced skin damage.
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PMID:High-protection sunscreen formulation prevents UVB-induced sunburn cell formation. 273 40

In order to evaluate the photoprotective efficacy of sunscreens against the chronic actinic damage, we tested 3 sunscreens for their ability to reduce the induction of unscheduled DNA synthesis (UDS) and to prevent the inhibition of semi-conservative DNA synthesis by medium wavelength ultraviolet (UV-B) radiation in the normal human cultured fibroblasts in vitro. The values obtained are correlated with the sun protection factors (SPF) expressing the erythema inhibition in normal human skin. All sunscreens tested showed a protective effect. The protective factor for the induction of UDS is 10.1 for Spectraban 15 (SPF 15), 3.6 for Spectraban 5.6 (SPF 5.6) and 1.9 for 2.5% Indomethacin solution, whereas the protective factor for the inhibition of semi-conservative DNA synthesis of 15.2, 3.9 and 2.1 for each sunscreen was evaluated. These methods seem to be useful as a screening procedure for the evaluation of sunscreen effectiveness against chronic actinic skin damage including light induced skin malignancies.
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PMID:Sunscreens block the induction of unscheduled DNA synthesis and the inhibition of DNA synthesis by UV-B radiation in normal human fibroblasts. A new way of evaluating sunscreen efficacy in vitro. 387 13

Three hundred fifty albinos in the city of Dar-es-Salaam have been registered at the Tanzania Tumor Centre. Their skin changes were followed for at least 2 years. Chronic skin damage was evident in all albinos by the first year of life; by 20 years, the skin of every subject demonstrated subclinical malignant change, and some had clinical epitheliomas. Untreated, the latter tumors become intractable and disseminate, usually causing death in the third or fourth decade of life. Four clinical stages could be identified, each one associated with distinct pathologic changes: Stage 1, erythema; Stage 2, epidermal atrophy with dermal hypertrophy; Stage 3, solar keratosis; and Stage 4, clinical carcinoma (under 3 cm). It was found that clinical Stage 2 only occurs in those skin areas that show evidence of previous Stage 1 change. Similarly, Stage 3 occurs only in areas that have gone through Stages 1 and 2. Stage 4 cancers were only found in those areas that had gone through all of the three prior stages. During the 2-year period of this study, 104 skin cancers, both early and advanced, were recorded at the albino skin clinic. Thirty-three of the 104 cancers were advanced (over 4 cm in diameter). The median age of the latter group was 31.0 years. Whereas there was no sex bias in the distribution of clinical cancer, 28 of the 33 advanced cancers were in men. Histologically, the great majority of the advanced tumors were squamous cell carcinomas: 29 of 33. There was one melanoma and three basal cell tumors. The predominant site of advanced cancers in the study group was the head and neck region (30 patients); the other three occurred on the trunk, which is generally covered by clothes.
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PMID:The Tanzanian human albino skin. Natural history. 397 67

Several plant families contain species liable to cause phytophotodermatitis. They include the Umbelliferae of which Ammi majus has been known for centuries and the Rutacea to which Citrus bergamia belongs. Phototoxic plants are also found in, e.g., the Moraceae, Leguminosae, Rosaceae and Compositae plant families. The photoreactivity of the plants depends on their furocoumarins (psoralens) content. These cause skin damage by phototoxic mechanisms, when activated by longwave ultraviolet radiation (UVA). The results are clinical changes such as erythema, bullae in the skin 24-72 h later, followed by hyperpigmentation. For the strongest phototoxic plants the content of the major phototoxic furocoumarins like bergapten or xanthotoxin have been calculated at approximately 0.5 g/100 g dried plant weight, but it varies between plant parts and also with the age of the plant. Repeated contact may occasionally lead to photocontact allergy.
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PMID:Phytophotodermatitis. 639 34

The effect of bioflavonoid, O-(beta-hydroxyethyl)-rutoside (HR) on early radiation-induced skin damage was examined, using the mouse foot system; the response to radiation is not species specific and comparison with the clinical situation is therefore possible. The aim was to see whether HR, which is highly effective in protecting against late damage, is also able to reduce early effects. Early reactions were considered to be erythema, swelling and ulceration and occurring up to 30 days after irradiation. It was found that HR significantly reduces early damage, both after a single dose and after fractionated irradiation with low doses. A single pre-treatment dose of HR and pre-treatment together with 30 days post-treatment administration were both found to be effective. The protective effect became more marked with increasing radiation dose (single irradiation). Reduction of late effects is produced optimally by an interval of 0.25 hours between application of HR and irradiation, and this is also true for early skin damage. The early effects are partly reversible, but there is possibly an interesting correlation between these and irreversible late effects (such as loss of toes); a similar mechanism, presumably affecting the vascular system, may therefore be postulated. The protective action of this well tolerated, highly effective substance, which apparently protects normal tissues from early and late injury, is discussed.
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PMID:[Reduction of radiation-induced early skin damage (mouse foot) by O-(beta-hydroxyethyl)-rutoside (author's transl)]. 645 59

To clarify the role of squalene peroxide in the occurrence of skin damage from sunburn, the optimum condition of squalene peroxidation and the effect of squalene peroxide on cutaneous tissue were examined. Peroxidation of squalene was more easily induced than palmitoleic acid and oleic acid in the unsaturated lipid occurred in sebum. The peroxidation of squalene gradually occurred by U.V. irradation, and it is parallel to increases in the malonyldialdehyde production (production of lipoperoxide). This peroxidation easily carries out in the case of high temperature (40 degrees C than 30 degrees C), and in the case of low pH. Good correspondence was recognized among the spectrum of natural daylight, U.V. absorption spectrum of squalene and erythema curve. Squalene and its peroxide have an important role in the occurrence of sunburn, and/or protection from damage caused by U.V. irradiation.
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PMID:The possible role of squalene and its peroxide of the sebum in the occurrence of sunburn and protection from the damage caused by U.V. irradiation. 648 25

Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene.
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PMID:The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries. 708 23


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