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Exposure to ultraviolet radiation is closely linked to the development of skin cancers in humans. The ultraviolet B ( UVB) radiation wavelength (280-320 nm), in particular, causes DNA damage in epidermal keratinocytes, which are linked to the generation of signature premalignant mutations. Interactions between dermal fibroblasts and keratinocytes play a role in epidermal repair and regeneration after UVB-induced damage. To investigate these processes, established two and three-dimensional culture models were utilized to study the impact of fibroblast-keratinocyte crosstalk during the acute UVB response. Using a coculture system it was observed that fibroblasts enhanced keratinocyte survival and the repair of cyclobutane pyrimidine dimers ( CPDs) after UVB radiation exposure. These findings were also mirrored in irradiated human skin coculture models employed in this study. Fibroblast coculture was shown to play a role in the expression and activation of members of the apoptotic cascade, including caspase-3 and Bad. Interestingly, the expression and phosphorylation of p53, a key player in the regulation of keratinocyte cell fate postirradiation, was also shown to be influenced by fibroblast-produced factors. This study highlights the importance of synergistic interactions between fibroblasts and keratinocytes in maintaining a functional epidermis while promoting repair and regeneration following UVB radiation-induced damage. [ABSTRACT FROM AUTHOR]

We conducted a clinical trial to compare the molecular and cellular responses of human melanocytes and keratinocytes in vivo to solar-simulated ultraviolet radiation ( SSUVR) in 57 Caucasian participants grouped according to MC1R genotype. We found that, on average, the density of epidermal melanocytes 14 days after exposure to 2 minimal erythemal dose ( MED) SSUVR was twofold higher than baseline (unirradiated) skin. However, the change in epidermal melanocyte counts among people carrying germline MC1R variants (97% increase) was significantly less than those with wild-type MC1R (164% increase; P = 0.01). We also found that sunscreen applied to the skin before exposure to 2 MED SSUVR completely blocked the effects of DNA damage, p53 induction, and cellular proliferation in both melanocytes and keratinocytes. [ABSTRACT FROM AUTHOR]

Objective There has been a dramatic increase in vitamin D testing in Australia in recent years, prompting calls for targeted testing. We sought to develop a model to identify people most at risk of vitamin D deficiency. Design and Participants This is a cross-sectional study of 644 60- to 84-year-old participants, 95% of whom were Caucasian, who took part in a pilot randomized controlled trial of vitamin D supplementation. Measurements Baseline 25( OH)D was measured using the Diasorin Liaison platform. Vitamin D insufficiency and deficiency were defined using 50 and 25 nmol/l as cut-points, respectively. A questionnaire was used to obtain information on demographic characteristics and lifestyle factors. We used multivariate logistic regression to predict low vitamin D and calculated the net benefit of using the model compared with 'test-all' and 'test-none' strategies. Results The mean serum 25( OH)D was 42 ( SD 14) nmol/1. Seventy-five per cent of participants were vitamin D insufficient and 10% deficient. Serum 25( OH)D was positively correlated with time outdoors, physical activity, vitamin D intake and ambient UVR, and inversely correlated with age, BMI and poor self-reported health status. These predictors explained approximately 21% of the variance in serum 25( OH)D. The area under the ROC curve predicting vitamin D deficiency was 0·82. Net benefit for the prediction model was higher than that for the 'test-all' strategy at all probability thresholds and higher than the 'test-none' strategy for probabilities up to 60%. Conclusion Our model could predict vitamin D deficiency with reasonable accuracy, but it needs to be validated in other populations before being implemented. [ABSTRACT FROM AUTHOR]

Results of recent studies suggest that circulating levels of vitamin D may play an important role in cancer-specific outcomes. The present systematic review was undertaken to determine the prevalence of vitamin D deficiency ( <25 nmol/L) and insufficiency (25-50 nmol/L) in cancer patients and to evaluate the association between circulating calcidiol (the indicator of vitamin D status) and clinical outcomes. A systematic search of original, peer-reviewed studies on calcidiol at cancer diagnosis, and throughout treatment and survival, was conducted yielding 4,706 studies. A total of 37 studies met the inclusion criteria for this review. Reported mean blood calcidiol levels ranged from 24.7 to 87.4 nmol/L, with up to 31% of patients identified as deficient and 67% as insufficient. The efficacy of cholecalciferol supplementation for raising the concentration of circulating calcidiol is unclear; standard supplement regimens of <1,000 IU D3/day may not be sufficient to maintain adequate concentrations or prevent decreasing calcidiol. Dose-response studies linking vitamin D status to musculoskeletal and survival outcomes in cancer patients are lacking. [ABSTRACT FROM AUTHOR]

Circulating 25-hydroxyvitamin D (25(OH)D), a marker for vitamin D status, is associated with bone health and possibly cancers and other diseases; yet, the determinants of 25(OH)D status, particularly ultraviolet radiation (UVR) exposure, are poorly understood. Determinants of 25(OH)D were analyzed in a subcohort of 1,500 participants of the US Radiologic Technologists (USRT) Study that included whites (n = 842), blacks (n = 646), and people of other races/ethnicities (n = 12). Participants were recruited monthly (2008–2009) across age, sex, race, and ambient UVR level groups. Questionnaires addressing UVR and other exposures were generally completed within 9 days of blood collection. The relation between potential determinants and 25(OH)D levels was examined through regression analysis in a random two-thirds sample and validated in the remaining one third. In the regression model for the full study population, age, race, body mass index, some seasons, hours outdoors being physically active, and vitamin D supplement use were associated with 25(OH)D levels. In whites, generally, the same factors were explanatory. In blacks, only age and vitamin D supplement use predicted 25(OH)D concentrations. In the full population, determinants accounted for 25% of circulating 25(OH)D variability, with similar correlations for subgroups. Despite detailed data on UVR and other factors near the time of blood collection, the ability to explain 25(OH)D was modest. [ABSTRACT FROM PUBLISHER]

Folate is essential for human health in the prevention of megaloblastic anemia and neural tube birth defects and plays important roles in cardiovascular disease and cancer. Therefore, research into environmental factors that may impact folate status, such as solar ultraviolet (UV) radiation, is of great health significance. In vitro studies have shown that UV radiation can degrade folate and folic acid in human blood and this has been confirmed in several human studies. Despite these findings, there is a dearth of epidemiological research into investigating the relationship between folate status and the links to solar UV exposure. [ABSTRACT FROM AUTHOR]

Objectives: To measure the thickness at which primary schoolchildren apply sunscreen on school day mornings and to compare it with the thickness (2.00 mg/ cm2) at which sunscreen is tested during product development, as well as to investigate how application thickness was influenced by age of the child (school grades 1-7) and by dispenser type (500-mL pump, 125-mL squeeze bottle, or 50-mL roll-on). Design :Across over quasi experimental study design comparing 3 sunscreen dispenser types. Setting: Children aged 5 to 12 years from public primary schools (grades 1-7) in Queensland, Australia. Participants: Children (n=87) and their parents randomly recruited from the enrollment lists of 7 primary schools. Each child provided up to 3 observations (n=258). Intervention: Children applied sunscreen during 3 consecutive school weeks (Monday through Friday) for the first application of the day using a different dispenser each week. Main Outcome Measure: Thickness of sunscreen application (in milligrams per square centimeter). The dispensers were weighed before and after use to calculate the weight of sunscreen applied. This was divided by the coverage area of application (in square centimeters), which was calculated by multiplying the children's body surface area by the percentage of the body covered with sunscreen. Results: Children applied their sunscreen at a median thickness of 0.48 mg/cm2. Children applied significantly more sunscreen when using the pump (0.75 mg/ cm2) and the squeeze bottle (0.57 mg/cm2) compared with the roll-on (0.22 mg/cm2) (P<.001 for both). Conclusions: Regardless of age, primary school children apply sunscreen at substantially less than 1.00 mg/ cm2, similar to what has been observed among adults. Some sunscreen dispensers seem to facilitate thicker application than others. [ABSTRACT FROM AUTHOR]

Polysulphone (PS) dosimetry has been a widely used technique for more than 30 years to quantify the erythemally effective UV dose received by anatomic sites (personal exposure). The calibration of PS dosimeters is an important issue as their spectral response is different from the erythemal action spectrum. It is performed exposing a set of PS dosimeters on a horizontal plane and measuring the UV doses received by dosimeters using calibrated spectroradiometers or radiometers. In this study, data collected during PS field campaigns (from 2004 to 2006), using horizontal and differently inclined dosimeters, were analyzed to provide some considerations on the transfer of the horizontal calibration to differently inclined dosimeters, as anatomic sites usually are. The role of sky conditions, of the angle of incidence between the sun and the normal to the slope, and of the type of surrounding surface on the calibration were investigated. It was concluded that PS horizontal calibrations apply to differently inclined dosimeters for incidence angles up to approximately 70° and for surfaces excluding ones with high albedo. Caution should be used in the application of horizontal calibrations for cases of high-incidence angle and/or high albedo surfaces. [ABSTRACT FROM AUTHOR]

Abstract: Recent epidemiologic studies have suggested that ultraviolet radiation (UV) may protect against non-Hodgkin lymphoma (NHL), but few, if any, have assessed multiple indicators of ambient and personal UV exposure. Using the US Radiologic Technologists study, we examined the association between NHL and self-reported time outdoors in summer, as well as average year-round and seasonal ambient exposures based on satellite estimates for different age periods, and sun susceptibility in participants who had responded to two questionnaires (1994–1998, 2003–2005) and who were cancer-free as of the earlier questionnaire. Using unconditional logistic regression, we estimated the odds ratio (OR) and 95% confidence intervals for 64,103 participants with 137 NHL cases. Self-reported time outdoors in summer was unrelated to risk. Lower risk was somewhat related to higher average year-round and winter ambient exposure for the period closest in time, and prior to, diagnosis (ages 20–39). Relative to 1.0 for the lowest quartile of average year-round ambient UV, the estimated OR for successively higher quartiles was 0.68 (0.42–1.10); 0.82 (0.52–1.29); and 0.64 (0.40–1.03), p-trend=0.06), for this age period. The lower NHL risk associated with higher year-round average and winter ambient UV provides modest additional support for a protective relationship between UV and NHL. [Copyright &y& Elsevier]

This paper provides an overview of the characteristics of a phenothiazine-mylar dosimeter which can be used as an effective solar UVA exposure assessment tool. This dosimeter is sensitive to UVA wavelengths (315–400 nm); its performance has been characterized in a series of tests such as (a) UVA exposure response (dose-response), (b) temperature stability of the response, (c) impact of long term storage, and (d) angular response. There is no effect of long term storage post-exposure and no effect of temperature up to 30 °C. For angles up to 70°, the cosine error of the normalized UVA is less than approximately 0.1. These characterizations have confirmed the reliability and reproducibility of a phenothiazine-mylar combined dosimeter as an effective solar UVA exposure tool for field-based studies of the UVA exposures to population groups. [ABSTRACT FROM AUTHOR]

Studies have examined the associations between cancers and circulating 25-hydroxyvitamin D [25(OH)D], but little is known about the impact of different laboratory practices on 25(OH)D concentrations. We examined the potential impact of delayed blood centrifuging, choice of collection tube, and type of assay on 25(OH)D concentrations. Blood samples from 20 healthy volunteers underwent alternative laboratory procedures: four centrifuging times (2, 24, 72, and 96 h after blood draw); three types of collection tubes (red top serum tube, two different plasma anticoagulant tubes containing heparin or EDTA); and two types of assays (DiaSorin radioimmunoassay [RIA] and chemiluminescence immunoassay [CLIA/LIAISON((R))]). Log-transformed 25(OH)D concentrations were analyzed using the generalized estimating equations (GEE) linear regression models. We found no difference in 25(OH)D concentrations by centrifuging times or type of assay. There was some indication of a difference in 25(OH)D concentrations by tube type in CLIA/LIAISON((R))-assayed samples, with concentrations in heparinized plasma (geometric mean, 16.1 ng ml(-1)) higher than those in serum (geometric mean, 15.3 ng ml(-1)) (p = 0.01), but the difference was significant only after substantial centrifuging delays (96 h). Our study suggests no necessity for requiring immediate processing of blood samples after collection or for the choice of a tube type or assay. [ABSTRACT FROM AUTHOR]

Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake, Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7-8 wk in the fall, winter, spring, and summer in Davis, CA [38.5° N, 121.7° W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R2 = 0.55; P< 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, ∼20 min/d, ∼18% body surface area (BSA) exposed] and high (80th percentile, ∼90 min/d, ∼35% BSA exposed) sun exposure, assuming an intake of 200 iu/d 15 ug/d). Predicted serum 25(OH)D concentrations for M individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D ⩾75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 IU/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 IU/d year-round. [ABSTRACT FROM AUTHOR]

Vitamin D, along with calcium, may help decrease the risk of falls and fractures in older adults. Sunlight and other sources of ultraviolet radiation are not recommended because they increase the risk of skin cancers and sun-induced eye disorders. Rather, vitamin D and calcium needs should be met through foods and dietary supplements. As a preventive measure to reduce the risk of falls and fractures, it is recommended that older adults meet the 2005 Dietary Guidelines and consume 1000 IU of vitamin D, preferably as vitamin D3. [ABSTRACT FROM PUBLISHER]

The article presents a study which aims to look on the reliability lifetime cumulative sun exposure activity-based assessment. The study consists of 124 participants who are radiologic technologists, where they composed of 64 females and 60 males, ages 48 to 80 years. However, it is determined that the said questionnaires need for further improvement.

Abstract: The literature reports strong correlations between UV exposure and latitude gradients of diseases. Evidence is emerging about the protective effects of UV exposure for cancer (breast, colo-rectal, prostate), autoimmune diseases (multiple sclerosis, type II diabetes) and even mental disorders, such as schizophrenia. For the first time, the available levels of vitamin D producing UV or “vitamin D UV” (determined from the previtamin D action spectrum) and erythemal (sunburning) UV from throughout the USA are measured and compared, using measurements from seven locations in the USA are measured and compared, using measurements from seven locations in the US EPA’s high accuracy Brewer Spectrophotometer network. The data contest longstanding beliefs on the location-dependence and latitude gradients of vitamin D UV. During eight months of the year centered around summer (March–October), for all sites (from 18°N to 44°N latitude) the level of vitamin D UV relative to erythemal UV was equal (within the 95% confidence interval of the mean level). Therefore, there was no measured latitude gradient of vitamin D UV during the majority of the year across the USA. During the four cooler months (November–February), latitude strongly determines vitamin D UV. As latitude increases, the amount of vitamin D UV decreases dramatically, which may inhibit vitamin D synthesis in humans. Therefore, a larger dose of UV relative to erythemal UV is required to produce the same amount of vitamin D in a high latitude location. However, the data shows that at lower latitude locations (<25°N), wintertime vitamin D UV levels are equal to summertime levels, and the message of increasing UV exposure during winter is irrelevant and may lead to excessive exposure. All results were confirmed by computer modeling, which was also used to generalize the conclusions for latitudes from 0° to 70°N. The results of this paper will impact on research into latitudinal gradients of diseases. In particular, it may no longer be correct to assume vitamin D levels in populations follow significant latitude gradients for a large proportion of the year. [Copyright &y& Elsevier]

Abstract: Exposure to solar ultraviolet (UV) radiation is the major environmental factor implicated in the development of melanoma and other skin cancers, as well as eye damage and skin photoaging. Outdoor recreational activities such as cycling are increasingly pursued for health benefits, however little information is available regarding potential adverse effects of excessive sun exposure in this setting, nor about the anatomical distribution of solar dose. Polysulphone badges (UV dosimeters) were attached to the head, backs of hands and ankles of 22 cyclists during a seven-day charity bicycle ride in Queensland, Australia. Average daily exposures exceeded one minimal erythemal dose (MED) at all body sites except the ankle. Significant differences in UV dose among the various body sites were noted, with highest exposures recorded on the top of the head. Mean doses received at the ankle (0.94MED), back of the hand (1.28MED) and side of the head (1.14MED) were 51%, 71% and 63% of those received at the top of the head (1.80MED), respectively. These data indicate that cycling exposes adherents to substantial doses of UV radiation. Moreover, our observations suggest that even vertically-oriented, potentially shaded sites such as the lower leg typically receive doses of solar radiation no less than half of maximally exposed sites. [Copyright &y& Elsevier]

The 2005 Dietary Guidelines for Americans recommend that older adults, people with dark skin, and those exposed to insufficient ultraviolet radiation (i.e., sunlight) consume extra vitamin D from vitamin D-fortified foods and/or supplements. Individuals in these high-risk groups should consume 25 μg (1000 IU) of vitamin D daily to maintain adequate blood concentrations of 25-hydroxyvitamin D, the biomarker for vitamin D status. This review considers recommendations for vitamin D-rich foods and dietary supplements, as well as specific problems with selfprescribing sun exposure or artificial sources of ultraviolet radiation to meet the vitamin D recommendations for older people. [ABSTRACT FROM AUTHOR]

Background: Evidence suggests that adults and adolescents throughout the United States are at risk of poor vitamin D status. However, vitamin D concentrations in young American children have not been assessed. Objective: The relations between serum 25-hydroxyvitamin D [25(OH)D] and bone were examined in prepubertal girls. Design: In the present cross-sectional study, serum 25(OH)D concentration was assessed in 168 prepubertal girls aged 4 - 8 y living in the southeastern United States with the use of radioimmunoassay. Bone area, bone mineral content, and areal bone mineral density were measured from total body, lumbar spine, proximal femur, and forearm with dual-energy X-ray absorptiometry. Data were analyzed with analysis of variance, analysis of covariance, stepwise multiple regression, and partial correlations. Results: The mean (±SD) serum 25(OH)D was 93.8 ±28.1 nmol/L (range: 31.1-181.4 nmol/L). In a multiple regression analysis, race and season were the strongest predictors of vitamin D status. The black girls had lower mean 25(OH)D values than did the white girls (P < 0.01), and 25(OH)D values were significantly different in the total sample between the seasons (P < 0.001), ranging from 74.4 nmol/L during the winter months to 107 nmol/L during the summer. After adjustment for season, age, race, and body mass index, 25(OH)D values were negatively correlated with forearm bone mineral content (r = - 0.18; P = 0.02). Conclusions: Unlike prior reports of adults and adolescents living in the southeastern United States, vitamin D status was adequate in the children of the present study. 25(OH)D concentrations were not positively associated with higher bone mineral. [ABSTRACT FROM AUTHOR]

Background: The global economic cost of cancer and the costs of ongoing care for survivors are increasing. Little is known about factors affecting hospitalisations and related costs for the growing number of cancer survivors. Our aim was to identify associated factors of cancer survivors admitted to hospital in the public system and their costs from a health services perspective. Methods: A population‐based, retrospective, data linkage study was conducted in Queensland (COS‐Q), Australia, including individuals diagnosed with a first primary cancer who incurred healthcare costs between 2013 and 2016. Generalised linear models were fitted to explore associations between socio‐demographic (age, sex, country of birth, marital status, occupation, geographic remoteness category and socio‐economic index) and clinical (cancer type, year of/time since diagnosis, vital status and care type) factors with mean annual hospital costs and mean episode costs. Results: Of the cohort (N = 230,380) 48.5% (n = 111,820) incurred hospitalisations in the public system (n = 682,483 admissions). Hospital costs were highest for individuals who died during the costing period (cost ratio 'CR': 1.79, p < 0.001) or living in very remote or remote location (CR: 1.71 and CR: 1.36, p < 0.001) or aged 0–24 years (CR: 1.63, p < 0.001). Episode costs were highest for individuals in rehabilitation or palliative care (CR: 2.94 and CR: 2.34, p < 0.001), or very remote location (CR: 2.10, p < 0.001). Higher contributors to overall hospital costs were 'diseases and disorders of the digestive system' (AU$661 m, 21% of admissions) and 'neoplastic disorders' (AU$554 m, 20% of admissions). Conclusions: We identified a range of factors associated with hospitalisation and higher hospital costs for cancer survivors, and our results clearly demonstrate very high public health costs of hospitalisation. There is a lack of obvious means to reduce these costs in the short or medium term which emphasises an increasing economic imperative to improving cancer prevention and investments in home‐ or community‐based patient support services. [ABSTRACT FROM AUTHOR]

Abstract [ABSTRACT FROM AUTHOR]

Describes an experiment to introduce students in a hands-on manner to the physics of instrumentation, measurement, electromagnetic radiation and ultraviolet radiation. Setting up of apparatus; Obtaining of reliable results; Undertaking of a science experiment relevant to everyday life.