A general model to predict individual exposure to solar UV by using ambient irradiance data

Excessive exposure to solar ultraviolet (UV) is the main cause of skin cancer. Specific prevention should be further developed to target overexposed or highly vulnerable populations. A better characterisation of anatomical UV exposure patterns is however needed for specific prevention. To develop a regression model for predicting the UV exposure ratio (ER, ratio between the anatomical dose and the corresponding ground level dose) for each body site without requiring individual measurements. A 3D numeric model (SimUVEx) was used to compute ER for various body sites and postures. A multiple fractional polynomial regression analysis was performed to identify predictors of ER. The regression model used simulation data and its performance was tested on an independent data set. Two input variables were sufficient to explain ER: the cosine of the maximal daily solar zenith angle and the fraction of the sky visible from the body site. The regression model was in good agreement with the simulated data ER (R(2)=0.988). Relative errors up to +20% and -10% were found in daily doses predictions, whereas an average relative error of only 2.4% (-0.03% to 5.4%) was found in yearly dose predictions. The regression model predicts accurately ER and UV doses on the basis of readily available data such as global UV erythemal irradiance measured at ground surface stations or inferred from satellite information. It renders the development of exposure data on a wide temporal and geographical scale possible and opens broad perspectives for epidemiological studies and skin cancer prevention.

Multilocus sequence analysis reveals the genetic diversity of European fruit tree phytoplasmas and supports the existence of inter-species recombination

The genetic diversity of three temperate fruit tree phytoplasmas ‘Candidatus Phytoplasma prunorum’, ‘Ca. P. mali’ and ‘Ca. P. pyri’ has been established by multilocus sequence analysis. Among the four genetic loci used, the genes imp and aceF distinguished 30 and 24 genotypes, respectively, and showed the highest variability. Percentage of substitution for imp ranged from 50 to 68% according to species. Percentage of substitution varied between 9 and 12% for aceF, whereas it was between 5 and 6% for pnp and secY. In the case of ‘Ca P. prunorum’ the three most prevalent aceF genotypes were detected in both plants and insect vectors, confirming that the prevalent isolates are propagated by insects. The four isolates known to be hypo-virulent had the same aceF sequence, indicating a possible monophyletic origin. Haplotype network reconstructed by eBURST revealed that among the 34 haplotypes of ‘Ca. P. prunorum’, the four hypo-virulent isolates also grouped together in the same clade. Genotyping of some Spanish and Azerbaijanese ‘Ca. P. pyri’ isolates showed that they shared some alleles with ‘Ca. P. prunorum’, supporting for the first time to our knowledge, the existence of inter-species recombination between these two species.

Drug monographs on drugs which are frequently analysed in the context of Therapeutic Drug Monitoring = Arzneimittel-Monographien für Medikamente, die regelmässig im Rahmen des Therapeutic Drug Monitorings analysiert werden

In addition to the monographs which were published last year by the working group "Drug Monitoring" of the Swiss Society of Clinical Chemistry (SSCC) [1], new monographs have been written. The aim of these monographs is to give an overview of the most important information necessary for ordering a drug analysis or interpreting the results. Therefore, the targeted readers comprise laboratory health professionals and all receivers of laboratory reports. There is information provided on the indication for therapeutic drug monitoring, protein binding, metabolic pathways and enzymes involved, elimination half-life and elimination routes, and on therapeutic or toxic concentrations. Preanalytical considerations are of particular importance for therapeutic drug monitoring. Therefore, information is provided regarding a reasonable timing for the determination of drug concentrations as well as steady-state concentrations after changing the dose. Furthermore, the stability of the drug and its metabolite(s) after blood sampling is described. For readers with a specific interest in drug analysis, references to important publications are given. The number of monographs will be continuously enlarged. The updated files are presented on the homepage of the SSCC (www.sscc.ch).

Dépistage organisé du cancer colorectal: défis et enjeux pour un essai pilote en Suisse. [Organized screening for colorectal cancer: challenges and issues for a Swiss pilot study].

Colorectal cancer is among the three most common and lethal neoplasms in Switzerland (about 4,000 new cases and 1,600 deaths per year, respectively). Several screening modalities are available. The effectiveness of colorectal cancer screening on mortality is established. The implementation of a successful screening intervention shall follow specified phases and conditions, and abide with global principles: pooling and coordinating efforts from all partners, setting goals and priorities, and identifying action plans. A feasibility (pilot) study is needed to verify requirements for quality, effectiveness, efficiency and innocuousness. Endeavours towards implementing a pilot programme for colorectal cancer screening in the Vaud canton (Switzerland) are presented and discussed.

Effective exposure to solar UV in building workers: influence of local and individual factors.

Excessive exposure to solar UV light is the main cause of skin cancers in humans. UV exposure depends on environmental as well as individual factors related to activity. Although outdoor occupational activities contribute significantly to the individual dose received, data on effective exposure are scarce and limited to a few occupations. A study was undertaken in order to assess effective short-term exposure among building workers and characterize the influence of individual and local factors on exposure. The effective exposure of construction workers in a mountainous area in the southern part of Switzerland was investigated through short-term dosimetry (97 dosimeters). Three altitudes, of about 500, 1500 and 2500 m were considered. Individual measurements over 20 working periods were performed using Spore film dosimeters on five body locations. The postural activity of workers was concomitantly recorded and static UV measurements were also performed. Effective exposure among building workers was high and exceeded occupational recommendations, for all individuals for at least one body location. The mean daily UV dose in plain was 11.9 SED (0.0-31.3 SED), in middle mountain 21.4 SED (6.6-46.8 SED) and in high mountain 28.6 SED (0.0-91.1 SED). Measured doses between workers and anatomical locations exhibited a high variability, stressing the role of local exposure conditions and individual factors. Short-term effective exposure ranged between 0 and 200% of ambient irradiation, indicating the occurrence of intense, subacute exposures. A predictive irradiation model was developed to investigate the role of individual factors. Posture and orientation were found to account for at least 38% of the total variance of relative individual exposure, and were also found to account more than altitude on the total variance of effective daily exposures. Targeted sensitization actions through professional information channels and specific prevention messages are recommended. Altitude outdoor workers should also benefit from preventive medical examination.

Dépistage du cancer du sein: doit-on réévaluer son efficacité ?

Quintessence: L'impact du dépistage sur la mortalité du cancer du sein est avéré. Il baisse, indépendamment de la qualité du dépistage, en raison des importants progrès thérapeutiques des 20 dernières années.Les programmes de dépistage ont contribué à sensibiliser à la détection précoce, à améliorer la qualité de la mammographie et la prise en charge du cancer mammaire. Ces bénéfices s'étendent au-delà du dépistage et conduisent à sous-estimer l'effet du dépistage sur la mortalité.Les risques et les bénéfices du dépistage sont plus complexes à quantifier dans les programmes que dans les essais randomisés ; le recours à des méthodes appropriées et rigoureuses est nécessaire.Les faux-positifs et le surdiagnostic liés au dépistage n'ont pas diminué, augmentant le rapport risque/bénéfice de la mammographie.

Inferring ultraviolet anatomical exposure patterns while distinguishing the relative contribution of radiation components

Exposure to solar ultraviolet (UV) radiation is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors, but individual exposure data remain scarce. While ground UV irradiance is monitored via different techniques, it is difficult to translate such observations into human UV exposure or dose because of confounding factors. A multi-disciplinary collaboration developed a model predicting the dose and distribution of UV exposure on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop a simulation tool that estimates solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by various body locations is computed for direct, diffuse and reflected radiation separately. Dosimetric measurements obtained in field conditions were used to assess the model performance. The model predicted exposure to solar UV adequately with a symmetric mean absolute percentage error of 13% and half of the predictions within 17% range of the measurements. Using this tool, solar UV exposure patterns were investigated with respect to the relative contribution of the direct, diffuse and reflected radiation. Exposure doses for various body parts and exposure scenarios of a standing individual were assessed using erythemally-weighted UV ground irradiance data measured in 2009 at Payerne, Switzerland as input. For most anatomical sites, mean daily doses were high (typically 6.2-14.6 Standard Erythemal Dose, SED) and exceeded recommended exposure values. Direct exposure was important during specific periods (e. g. midday during summer), but contributed moderately to the annual dose, ranging from 15 to 24% for vertical and horizontal body parts, respectively. Diffuse irradiation explained about 80% of the cumulative annual exposure dose.