UV-radiation and health

Jaarlijks krijgen meer dan 51.000 mensen in Nederland te horen dat ze huidkanker hebben en overlijden ruim 900 mensen aan de gevolgen ervan. Sinds 1990 is het aantal gevallen verviervoudigd. Deze stijging is veel sterker dan bij andere vormen van kanker, en een verdere stijging dreigt (met een factor 2 tot 5). De gevaarlijkste vorm van huidkanker komt in Nederland relatief vaak voor, en binnen Europa behoort Nederland tot de koplopers. Blootstelling van de huid aan UV-straling is de voornaamste oorzaak van het ontstaan van huidkanker, en dan vooral door onverstandig zongedrag. De vergrijzing en de aantasting van de ozonlaag blijken slechts een deel van de toename aan huidkanker te verklaren. Het blootstellingsgedrag lijkt de hoofdrol te spelen en daarbij zijn het dragen van minder bedekkende kleding, meer vrije tijd en langere (zon/strand) vakanties van belang, maar ook klimaatverandering en het gebruik van kunstmatige UV-bronnen voor bruining dragen mogelijk bij. De belangrijkste manier om huidkanker te voorkomen is dan ook ervoor te zorgen dat de huid niet verbrandt door de zon of zonnebank. Maar ook zonder te verbranden kan de huid beschadigd raken. Daarom is het verstandig om de huiddelen die veelvuldig worden blootgesteld extra te beschermen en om daarbij rekening te houden met de zonkracht en de duur van het verblijf in de zon. Bij een hoogstaande (zomer)zon tussen 11 en 16 uur is meer bescherming nodig dan 's morgens vroeg en in de namiddag. Behalve aan huidkanker draagt UV-straling bij aan de vorming van staar en veroorzaakt het huidveroudering en sneeuwblindheid. Het is niet wenselijk om de zonblootstelling volledig te vermijden, omdat UV-blootstelling van de huid ook de voornaamste bron is van vitamine D. Deze vitamine is essentieel voor gezonde botten en spieren. Bovendien zijn er aanwijzingen dat vitamine D de kans op darmkanker kan verkleinen. Momenteel is er een felle wetenschappelijke discussie gaande welke hoeveelheid vitamine D de meeste gezondheidswinst oplevert. De kosten van de medische behandeling van huidkanker bedragen naar schatting circa 325 (250-400) miljoen euro per jaar. De kosten voor de behandeling van door UV veroorzaakte staar, worden geschat op 75-150 miljoen euro per jaar. De kosten zijn grotendeels vermijdbaar door verstandiger (zon)gedrag. De actuele zonkrachtmetingen (www.rivm.nl/zonkracht) en betere kennis over (ontwikkelingen in) blootstellingsgedrag en gezondheidseffecten dragen bij aan een goede voorlichting en preventie. Er is alle reden de kennisopbouw met betrekking tot UV-stralingsbescherming te versterken.Every year more than 51,000 new cases of skin cancer are diagnosed in the Netherlands and over 900 fatalities are reported. The number of new skin cancer cases is rising rapidly and since 1990 a fourfold increase has been observed. This increase is much stronger than for other types of cancer, and a further increase is expected (with a factor of 2-5). The incidence of melanoma of the skin in the Netherlands is among the highest in Europe. Exposure of the skin to UV-radiation is the primary cause of skin cancer, and sun-exposure is the primary source of UV-exposure. The increase in skin cancer incidence that has been observed is only partly explained by the ageing of the Dutch population and the depletion of the ozone layer. A change in exposure behaviour is probably the most dominant factor that could explain a major part of the increased skin cancer incidence. Changes in fashion, with more of the body exposed, shorter working hours and longer vacations, including an increase in summer holidays spent in southern Europe are likely causes. Climate change and the use of artificial tanning devices may also contribute. Skin cancer prevention should be focused on the avoidance of UV-induced erythema (sunburn) in solar and artificial exposures. Limiting the chronic exposure of the most exposed skin parts is also very important, because damage to the skin also occurs below the threshold of erythemal doses. It is, therefore, important to provide additional protection for the parts of the skin that are chronically exposed. Solar exposure is the most important UV-source and protection is most needed when the sun is high in the sky, in the summer months between 11:00 am and 16:00 (4 pm). The UV-index is a good indicator; it is much lower in the early morning or late afternoon/early evening. UV-exposure also contributes to the incidence of cataract and causes skin ageing and snow blindness (photokeratitis). Exposure of the skin to solar UV from the sun should not be completely avoided, however, as it is an important source of vitamin D. Vitamin D is essential for healthy bones and muscles, and there are indications that a high vitamin D status lowers the risk of developing colon cancer, and may also be a factor in the development of a number of other cancers and chronic diseases. At present, a scientific debate is ongoing regarding the minimally required and optimal levels of vitamin D, and how to best achieve them. In the Netherlands the estimated costs for medical treatments of skin cancer and precancerous skin lesions amount to 325 million Euro (250-400). Estimated medical costs for the UV-contribution to cataract formation are 75-150 million Euro per year. These costs can be substantially reduced if (solar) UV-exposure is restricted. Prevention is supported by Solar UV-index measurements (www.rivm.nl/zonkracht), and improved knowledge on UV-radiation exposure and associated health effects. Strengthening the knowledge building and dissemination of information about UV-radiation protection is vitally important.Ministerie van VW

Transcription-coupled and global genome repair differentially influence UV-B-induced acute skin effects and syste

Exposure to UV-B radiation impairs immune responses in mammals by inhibiting especially Th1-mediated contact hypersensitivity and delayed-type hypersensitivity. Immunomodulation is not restricted to the exposed skin, but is also observed at distant sites, indicating the existence of mediating factors such as products from exposed skin cells or photoactivated factors present in the superficial layers. DNA damage appears to play a key role, because enhanced nucleotide excision repair (NER) strongly counteracts immunosuppression. To determine the effects of the type and genomic location of UV-induced DNA damage on immunosuppression and acute skin reactions (edema and erythema) four congenic mouse strains carrying different defects in NER were compared: CSB and XPC mice lacking transcription-coupled or global genome NER, respectively, as well as XPA and TTD/XPD mice carrying complete or partial defects in both NER subpathways, respectively. The major conclusions are that 1) transcription-coupled DNA repair is the dominant determinant in protection against acute skin effects; 2) systemic immunomodulation is only affected when both NER subpathways are compromised; and 3) sunburn is not related to UV-B-induced immunosuppression

Photomyogenic response in Niemann–Pick type C: a case report

Contains fulltext : 98214.pdf (publisher's version ) (Closed access)1 maart 201

Influence of Anesthesia and Clinical Variables on the Firing Rate, Coefficient of Variation and Multi-Unit Activity of the Subthalamic Nucleus in Patients with Parkinson's Disease

BACKGROUND: Microelectrode recordings (MER) are used to optimize lead placement during subthalamic nucleus deep brain stimulation (STN-DBS). To obtain reliable MER, surgery is usually performed while patients are awake. Procedural sedation and analgesia (PSA) is often desirable to improve patient comfort, anxiolysis and pain relief. The effect of these agents on MER are largely unknown. The objective of this study was to determine the effects of commonly used PSA agents, dexmedetomidine, clonidine and remifentanil and patient characteristics on MER during DBS surgery. METHODS: Data from 78 patients with Parkinson's disease (PD) who underwent STN-DBS surgery were retrospectively reviewed. The procedures were performed under local anesthesia or under PSA with dexmedetomidine, clonidine or remifentanil. In total, 4082 sites with multi-unit activity (MUA) and 588 with single units were acquired. Single unit firing rates and coefficient of variation (CV), and MUA total power were compared between patient groups. RESULTS: We observed a significant reduction in MUA, an increase of the CV and a trend for reduced firing rate by dexmedetomidine. The effect of dexmedetomidine was dose-dependent for all measures. Remifentanil had no effect on the firing rate but was associated with a significant increase in CV and a decrease in MUA. Clonidine showed no significant effect on firing rate, CV or MUA. In addition to anesthetic effects, MUA and CV were also influenced by patient-dependent variables. CONCLUSION: Our results showed that PSA influenced neuronal properties in the STN and the dexmedetomidine (DEX) effect was dose-dependent. In addition, patient-dependent characteristics also influenced MER

Combining gamma with Alpha and Beta power modulation for enhanced cortical mapping in patients with focal epilepsy

About one third of patients with epilepsy have seizures refractory to the medical treatment. Electrical stimulation mapping (ESM) is the gold standard for the identification of "eloquent" areas prior to resection of epileptogenic tissue. However, it is time-consuming and may cause undesired side effects. Broadband gamma activity (55-200 Hz) recorded with extraoperative electrocorticography (ECoG) during cognitive tasks may be an alternative to ESM but until now has not proven of definitive clinical value. Considering their role in cognition, the alpha (8-12 Hz) and beta (15-25 Hz) bands could further improve the identification of eloquent cortex. We compared gamma, alpha and beta activity, and their combinations for the identification of eloquent cortical areas defined by ESM. Ten patients with intractable focal epilepsy (age: 35.9 ± 9.1 years, range: 22-48, 8 females, 9 right handed) participated in a delayed-match-to-sample task, where syllable sounds were compared to visually presented letters. We used a generalized linear model (GLM) approach to find the optimal weighting of each band for predicting ESM-defined categories and estimated the diagnostic ability by calculating the area under the receiver operating characteristic (ROC) curve. Gamma activity increased more in eloquent than in non-eloquent areas, whereas alpha and beta power decreased more in eloquent areas. Diagnostic ability of each band was close to 0.7 for all bands but depended on multiple factors including the time period of the cognitive task, the location of the electrodes and the patient's degree of attention to the stimulus. We show that diagnostic ability can be increased by 3-5% by combining gamma and alpha and by 7.5-11% when gamma and beta were combined. We then show how ECoG power modulation from cognitive testing can be used to map the probability of eloquence in individual patients and how this probability map can be used in clinical settings to optimize ESM planning. We conclude that the combination of gamma and beta power modulation during cognitive testing can contribute to the identification of eloquent areas prior to ESM in patients with refractory focal epilepsy.info:eu-repo/semantics/publishedVersio