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PubMed1992

Prediction of cancer mortality in the Nordic countries in 2005: effects of various interventions.

Rough estimates of the effect in 2005 of various preventive measures aimed at reducing cancer mortality in the Nordic countries were made using the American software CAN*TROL. The effect was measured as the percentage reduction in cancer mortality in 2005. The calculations were performed for changes in the smoking, dietary and sunbathing habits of the population (primary prevention), earlier diagnosis (secondary prevention) and improvements in survival resulting from better treatment (tertiary prevention). The calculations incorporate many assumptions, some of them more firmly based than others, such as uniformity of incidence trend in all the Nordic countries and also concerning the causality of various relations. For lack of evaluated Nordic data, we have used American figures concerning stage distributions and stage-specific relative survival rates. These assumptions should be borne in mind when drawing conclusions from the results obtained. The results show that there is a potential of up to several tens of percent for reducing total cancer mortality by the year 2005.

Female↗
PubMed2004

Site-specific dissociation of DNA bases by slow electrons at early stages of irradiation.

At the very early time of irradiation, ballistic secondary electrons are produced as the most abundant of the radiolytic species directly within DNA or its environment. Here, we demonstrate the propensity of such low-energy (<3 eV) electrons to damage DNA bases via an effective loss of hydrogen located at the specific nitrogen positions. Since this site is directly implicated in the bonding of nucleobases within DNA and since dehydrogenation of the nucleic acid bases has been observed to be the predominant dissociative channel, the present findings foreshadow significant implications for the initial molecular processes leading to genotoxicity in living cells following unwanted or intended exposure to ionizing radiation (e.g., sunbathing, air travel, radiotherapy, etc.).

Adenine↗
PubMed1995

DNA repair capacity for ultraviolet light-induced damage is reduced in peripheral lymphocytes from patients with basal cell carcinoma.

Sunlight exposure and certain host factors such as red hair and fair skin are established risk factors for non-melanoma skin cancers. Because deficient DNA repair capacity has contributed to the development of skin cancers in a rare genetic disease, xeroderma pigmentosum, we explored this deficiency as an etiologic factor in a recent population study. We used a new DNA repair assay, the host-cell reactivation, in a clinic-based case-control study to test the hypothesis that reduced DNA repair is the underlying molecular mechanism for the development of sunlight-induced basal cell carcinoma. The peripheral lymphocytes from 88 patients with primary BCC and 135 cancer-free controls were tested for their capacity to repair ultraviolet light-induced DNA damage in a reporter gene, chloramphenicol acetyl transferase. All subjects were between the ages of 20 and 60 years and were frequency matched by age (+/- 5) and sex. Among those who reported frequent sunbathing, poor tanning ability, a history of multiple sunburns, exposure to chemicals, or multiple medical irradiations, the BCC patients had significantly lower DNA repair capacity than controls (p < 0.05). DNA repair capacity was also found substantially lower in the basal cell carcinoma patients who had red hair and light skin (type I). Compared to controls, basal cell carcinoma cases with selected risk factors had a relative decrease in DNA repair capacity of 10-28%. These findings provided evidence that reduced DNA repair capacity is one of the underlying molecular mechanisms for sunlight-induced skin carcinogenesis in the general population.

Adult↗
PubMed1992

Accelerated appearance of skin tumors in hairless mice by repeated UV irradiation with initial intense exposure and characterization of the tumors.

Skin tumors were produced on the back of hairless mice, HOS (HR/De), by exposure to ultraviolet B light (UVB, 290-320 nm) with 4 different protocols. The first tumors appeared earlier (in 10 weeks in group I and 7 weeks in group III) when initial intense exposure was given, followed by repeated lower-level exposures, than when the mice were exposed to the repeated UV only (in 16 weeks both in group II and group IV). All mice developed skin tumors earlier in the groups given the repeated UV exposures three times a week than in the groups given the exposures twice a week. Most of the skin tumors produced by the UVB exposure were histologically malignant, being transplantable to nude mice, and the cultured cells grown from the tumors were capable of producing tumors when injected into nude mice. The accelerated development of skin tumors by initial intense exposure and short intervals of repeated exposure observed in this study may have implications for humans who expose themselves to intense sunbathing and UV tanning (burning) by fluorescent sun lamps.

Animals↗
PubMed1978

Enhancement of comedogenic substances by ultraviolet radiation.

Ultraviolet radiation enhanced the capacity of human sebum, sulphur, cocoa butter, squalene, and coal tar to produce comedones in the external ear canals of rabbits. An enhancement of the comedogenicity of coal tar and squalene was similarly demonstrated in man. We conjecture that in occasional patients sunbathing may aggravate acne by augmenting the comedogenicity of sebum.

Acne Vulgaris↗
PubMed1995

Photoisomerization spectrum of urocanic acid in human skin and in vitro: effects of simulated solar and artificial ultraviolet radiation.

Ultraviolet (UV) irradiation of trans-urocanic acid (UCA), a major UV absorbing component of the epidermis, leads to the formation of cis-UCA, which mediates immunosuppressive effects. In this study, the net yield of cis-UCA was measured after the photoisomerization of urocanic acid by narrow UV wavebands (spectral range 295-405 nm), with the irradiation doses related to solar irradiance at sea level. The formation of cis-UCA in Caucasian skin (in vivo), as well as in aqueous solution (in vitro), was determined by HPLC analysis. The same irradiation conditions were met in both components of the study. The in vivo experiments showed high efficiency of cis-UCA formation in the spectral region of 305-341 nm, whereas high efficiency in vitro was found at 305 and 326 nm. At 350 and 363 nm, cis-UCA was formed in vivo, but not in vitro. At longer test wavelengths up to 405 nm, no significant formation of cis-UCA was detectable. The established partition between UVB and UVA at 320 nm is not relevant for the isomerization pattern of UCA. Additional studies revealed substantial cis-UCA formation in human skin by UVA phototherapy lamps. Furthermore, raised levels of 295 nm irradiation doses, a possible effect of stratospheric ozone depletion, were found to increase the cis-UCA yield. Our results demonstrate that the formation of cis-UCA in the skin with common exposures takes place over a broad spectrum range of UVB and UVA, up to at least 363 nm. These findings emphasize the potency of UVA to isomerize UCA, and they may contribute to further elucidation of the effects of phototherapy and sunbathing.

Chromatography, High Pressure Liquid↗
PubMed1995

Squamous cell carcinoma in Kauai, Hawaii.

BACKGROUND: It is estimated that over 100,000 new cases of squamous cell carcinoma are diagnosed in the United States annually. This number is compounded by an increasing concern over the ozone layer depletion and the continued sunbathing behavior of many individuals. This could be particularly acute in Hawaii, which may have the highest rates of skin cancer in the country. We believe the updated information on skin cancer is essential to address the magnitude of the problem. METHODS: A prospective 5-year population-based incidence study was conducted on Kauai, Hawaii, between 1983 and 1987 to investigate the frequency of squamous cell carcinomas in resident Caucasians. RESULTS: A total of 58 residents, 37 men and 21 women, were identified with an initial episode of squamous cell carcinoma during the 5-year period. The average annual incidence rate per 100,000 Kauai Caucasian residents, standardized to the 1980 U.S. white population, was 153 for men and 92 for women with a combined rate of 118. The average patient age was 66.4 years. The head and neck was the most common anatomic site, with the extremities second. Subsequent new squamous cell carcinoma occurred in 13.8% of patients. Only one patient (2%) developed a recurrence after treatment. Twenty-five patients (43%) had basal cell carcinoma simultaneously or at other earlier times. CONCLUSIONS: In Kauai the incidence rate of squamous cell carcinoma is the highest yet documented in the United States. No consistent trend in incidence rates was appreciated during this 5-year period.

Adult↗
PubMed1996

Primary school children's perceptions of the effects of sun on skin.

To assess whether young children understand the dangers and results of sun exposure, a novel Draw and Write technique was used to survey a group of 5-8 year old primary school children. One hundred and ninety-four children were invited to draw and write comments to six scenarios involving sun exposure. Of the children surveyed, 84% gave a negative sentiment to sunburn, with only 6% displaying positive sentiments towards sunbathing. Sixty-five per cent of children suggested the use of sun blocks, 69% the use of protective clothing, 45% the wearing of hats and 43% the use of shade as a mechanism for protecting the skin from sun damage. Only 2% of children made any reference to skin cancer. The primary school children surveyed had a good level of awareness of the dangers of sunburn and the need to take appropriate actions to avoid sun damage.

Attitude to Health↗
PubMed1997

Sun behaviour and perceptions of risk for melanoma among 21-year-old New Zealanders.

This study investigated perceived risk of melanoma, sunscreen use and frequency of sunburn in a large sample of young New Zealanders. A self-report questionnaire was administered to a sample of 909 21-year-olds to survey their perception of how sun behaviours affect their risk of getting melanoma, how often they get sunburn, how often they use sunscreen and what factors would get them to use sunscreen more often. Knowledge of melanoma was high, but myths concerning 'safe tanning' persisted. Many young adults believed that sunbathing regularly using a sunscreen and obtaining a good base tan from gradual sun exposure decreased their risk of getting melanoma. They were unsure about the use of artificial sun beds and if their use would increase or decrease their risk. Males and females differed significantly on many aspects of their sun behaviour. Most used sunscreen only 'sometimes' and its use was linked to knowledge of melanoma and perceptions of risk. The best way to modify the sun behaviour of young adults is to target both their knowledge of melanoma risk factors and their perceptions of risk.

Adult↗
PubMed2004

Benign summer light eruption and polymorphic light eruption: genetic and functional studies suggest that a revised nomenclature is required.

New research indicates that polymorphic light eruption (PLE) is an autoimmune disease against an ultraviolet radiation-induced cutaneous antigen. PLE may even confer some protection against skin cancer later in life. This new information demands a reassessment of the precise nature and nomenclature of PLE. Benign summer light eruption (BSLE) (lucite estivale bénigne) is the name used in continental Europe, and particularly France, to describe a clinically short-lived, itchy, papular eruption particularly affecting young women after several hours of sunbathing at the beginning of summer or on sunny vacations. Clinically more prolonged forms of solar eruption, starting early in spring and persisting for long periods, have been known in France as polymorphic light eruption (PLE) (lucite polymorphe) ('European PLE'). Investigative studies, however, now suggest that BSLE and some cases of 'European PLE' are part of the same spectrum. In the Anglo-Saxon literature, they are lumped together as PLE ('Anglo-Saxon PLE'). The other cases of 'European PLE', which do not fall within the compass of 'Anglo-Saxon PLE', are, in the Anglo-Saxon literature, classified as either actinic prurigo (AP) (a genetically determined, prolonged, excoriated form of Anglo-Saxon PLE), or chronic actinic dermatitis (CAD) (a sunlight-induced eczema precisely resembling allergic contact dermatitis, apparently to an ultraviolet radiation-induced antigen). It is therefore proposed that: i. the European term BSLE be dropped and that these patients be reclassified within the spectrum of (Anglo-Saxon) PLE, ii. the European use of the term PLE ('European PLE') be discontinued, iii. those previously diagnosed as having 'European PLE' be reclassified as (Anglo-Saxon) PLE, AP or CAD, as appropriate. The benefits of such a change in nomenclature would be twofold, firstly a uniformity of terminology and secondly, and more importantly, terminology would then correlate better with our recently improved understanding of the pathogenesis of these disorders.

Journal Article↗
PubMed1978

Thermal injury on the foot and ankle of a paraplegic: report of a case from exposure to sunshine.

The case of a paraplegic patient who sustained a fullthickness thermal injury to his left foot from exposure to sunshine is described. Electromagnetic energy from the sun can cause enough damage to full thickness of the skin when the heat is intense enough or not dissipated sufficiently. The lesson of it is that paralyzed and anesthetic individuals should be cautious about sunbathing.

Ankle↗
PubMedDate not supplied

Children and sun exposure in the northeast of Italy.

Excessive, incorrect exposure to the sun at a young age can be a risk factor for skin cancer at a later age. In this study we have investigated the exposure and protection habits of a group of children to see whether there are behavioral errors that should and possibly could be corrected. We handed out a multiple-choice questionnaire to 310 subjects, 212 boys and 98 girls between the ages of 6 and 14, all residents in the province of Udine in the northeastern part of Italy. Of these children, 24% had sunburn on several occasions; boys were four times more at risk than girls (OR = 0.4) and the frequency reduced by 30% for each skin phototype class higher. In children between 11 and 14 years of age, exposure was prolonged (43% for 2-4 hours, 38% for 4-8 hours) and 30% preferred peak hours. Eighty percent of the children, mostly girls, younger children (6-10), and the lower skin phototypes used sunscreens, but only 38% used them on a regular basis, whereas 20% applied them after sunbathing and 42% used a single daily application. Two percent of the children used sunglasses and 5% wore a T-shirt regularly. The dermatologist and pediatrician play an important role in advising parents that the sun is good for children, but appropriate measures must be taken to reduce any risks, both immediately and in the long term.

Adolescent↗
PubMed2005

Ultraviolet A exposure might increase metastasis of mouse melanoma: a pilot study.

BACKGROUND: The major sources of long-wave ultraviolet A radiation (UVA; 320-400 nm) exposure are extensive sunbathing and tanning in solaria. While the carcinogenic effects of mid-wave ultraviolet B radiation (UVB; 280-320 nm) are well recognized, the potentially hazardous effects of UVA are less understood. Several studies have shown that a variety of physiological processes in the cell are modified by UVA exposure, some of which might be involved in the regulation of tumor metastasis. In this study we suggest that UVA radiation could lead to the increase of metastatic capability of melanoma cells in mice. METHOD/RESULT: A pilot in vivo study was executed using C57BL/6 mice and syngeneic B16 melanoma cell lines. Mice were intravenously (i.v.) injected with either B16-F1 or B16-F10 melanoma cells into the tail vein and then immediately exposed to UVA. Fourteen days after melanoma injection, lungs were collected and the quantity and quality of metastases were determined under a dissecting microscope. As an outcome of the pilot study we observed that i.v. injected melanoma cells formed more lung metastases in the UVA-exposed mice in comparison with the control mice. CONCLUSION: This result suggests that the UVA exposure of mice, with melanoma cells present in blood circulation, increases the formation of melanoma metastases in lungs. Further studies should determine whether a similar pro-metastatic effect, as observed in mice, could occur in humans and whether other than melanoma tumors might be susceptible.

Animals↗
PubMed1985

Light effects on transport and excretion of bilirubin in newborns.

There is now firm evidence that phototherapy has the following effects on bilirubin metabolism in humans with unconjugated hyperbilirubinemia. It rather rapidly converts a substantial fraction of the normal toxic 4Z, 15Z form of bilirubin to the 4Z, 15E form, which probably is less toxic. Simultaneously it enhances the overall excretion of bilirubin by converting it to oxidation products and structural and configurational isomers that are excretable in bile and urine without the need for glucuronidation. We know that these reactions occur in vivo because we have synthesized the compounds involved and have identified them unambiguously in vivo in the tissues of jaundiced babies and rats undergoing phototherapy. It is unlikely that these photobiological effects on bilirubin metabolism and transport are restricted to babies undergoing purposeful phototherapy. All babies are exposed to visible light and all develop hyperbilirubinemia during early life, with many exhibiting jaundice. Because there is no lower intensity threshold for photochemical reactions, it seems probable that the photobiological effects described in this paper occur in most newborns to some degree. Furthermore, similar photoprocesses would be expected to occur in the approximately 2-5% of the population who have the benign condition known as Gilbert's syndrome, which is characterized by chronic mild unconjugated hyperbilirubinemia, particularly when they sunbathe. Clearly, in the particular instance of phototherapy of neonatal jaundice, blue light is therapeutic. In some respects it acts like a drug, almost like the ideal magic bullet, because it is specific for the target molecule and safe. The main limitation of phototherapy is that it is inefficient, a limitation that seems to be imposed by transport processes in the body and the optics of skin rather than by the photochemical reactions on which it depends.

Bilirubin↗
PubMed1991

Evaluation of skin cancer risk resulting from long term occupational exposure to radiation from ultraviolet lasers in the range from 190 to 400 nm.

The relative risk of occupational exposure to radiation from UV lasers was estimated using a mathematical model based on both epidemiological data and animal experiments. Calculations were performed for the 193 nm ArF excimer laser cornea shaping, the 308 nm XeCl excimer laser for coronary angioplasty, and other UV lasers in a laboratory environment. The model included the effects of direct exposure and exposure to scattered radiation. The results show that for the two medical applications the increase in the relative risk is comparable to that of one additional day of sunbathing per year. For subjects exposed to UV lasers in a laboratory setting, the relative risk may increase to a value comparable to that of people with an outdoor profession.

Erythema↗
PubMed1995

Skin cancer attitudes: a cross-national comparison.

A questionnaire concerning attitudes towards skin cancer, sun exposure and general environmental issues was administered to 132 holiday-makers on a beach in south-west England and (in translation) to 142 visitors to another beach in north-west Italy. Following the Janis & Mann (1977) classification of strategies for coping with decision conflicts, subscales were derived measuring tendencies to 'avoid' thinking about environmental issues, to 'bolster' prior attitudes (by playing down the seriousness of the risk of skin cancer while attending to the pleasures of sunbathing), and to be 'vigilant' concerning risk information and the need for specific protective behaviour (e.g. sunscreen use). The British scored higher than the Italians, and women higher than men, on vigilance, but there were no gender or nationality differences on the other subscales considered as a whole. Responses were also related to the covariates of age and self-reported vulnerability to sunburn. Those who showed less concern with environmental issues also tended to play down the risks of skin cancer and be less vigilant with regard to self-protection. It is suggested that health promotion should address both cultural norms concerning exposure to the sun and people's intuitive notions about their relative personal vulnerability.

Adult↗
PubMed1979

Response of term babies to a warm environment.

The response of healthy term babies to warm environments was assessed by placing them naked in incubators and increasing the air temperature in steps until either sweating occurred or the rectal temperature reached 37.9 degrees C. The rate of evaporation of water from the skin was measured by a method based on the estimation of vapour pressure gradient. When a 50% increase in the rate occurred at a given site, sweating was judged to have begun. 39 studies were made on 30 babies, aged from 4 hours to 11 days. As babies approached the point of sweating, spontaneous activity usually ceased, the skin reddened, and a sunbathing posture was adopted. Sweating was found on 35 occasions. It was most pronounced and often was found initially on the forehead but it was also detected on the trunk and limbs. No thermal sweating was noted on the palms or soles. Sweating generally began when the incubator air temperature exceeded 34 degrees C and the rectal temperature exceeded 37.1 degrees C, but there was wide individual variation. Older and more mature babies tended to sweat at lower air temperatures.

Age Factors↗