Exposure to solar UV radiation of Polish teenagers after the first COVID-19 lockdown in March-April 2020.

In Poland, schools were closed from March to June 2020 due to the COVID-19 epidemic. During the lockdown (March-April), everyone was advised to stay at home. From May, students were allowed to spend time outdoors. We examine their exposure to solar UV radiation during the period of virtual learning at schools (May-June), vacations (July-August) and the first month of typical learning (September). Primary and high school students aged 12-18 completed a questionnaire on the details of their outdoor activities and the weather at the exposure site. A total of 146 anonymous questionnaires were registered for the study. The survey responses provided input to a radiative transfer model to estimate erythemal and vitamin D doses obtained by teenagers during outdoor activities. The results from 48% of the questionnaires indicated that students' exposure exceeded 1 minimal erythema dose (MED) during the day. Corresponding doses of sun-synthesized vitamin D, in excess of 1000 international units (IU) and 2000 IU, were found in 77% and 66% of the surveys, respectively. Only 12% of the teenagers declared that they use sunscreen. The overexposure (> 1 MED) increased with age. It was found in 72% and 26% of surveys among the students aged 17-18 and 12-14, respectively. Teenagers seem to have tried to compensate for the lack of sunlight during the lockdown by engaging in outdoor activities permitted since May. While those activities could have improved their vitamin D levels, they also put them at a higher risk of developing erythema.

The Effect of Simvastatin on Plasma Steroid Hormone Levels in Metformin-Treated Women with Non-Classic Congenital Adrenal Hyperplasia.

Non-classic congenital adrenal hyperplasia (NC-CAH), one of the most common genetic disorders, is often associated with the presence of hyperandrogenism. Recently both simvastatin and metformin were found to reduce plasma steroid hormone levels in this disorder. This study included 8 women with NC-CAH and diabetes or impaired glucose tolerance, as well as 12 matched women with similar glucose metabolism abnormalities but normal adrenal function. Both groups of women, receiving metformin for at least 6 months, were then treated with simvastatin (20 mg daily) for the following 12 weeks. Compared to patients with normal adrenal function, metformin-treated women with NC-CAH showed increased plasma levels of 17-hydroxyprogesterone, total testosterone, free testosterone, androstenedione and DHEA-S. Simvastatin reduced total and LDL cholesterol levels in both patients with NC-CAH and normal adrenal function. Moreover, in the former group of women, statin therapy decreased plasma levels of testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulphate and tended to reduce 17-hydroxyprogesterone. Our results suggest that metformin-statin combination therapy may be useful in the management of symptomatic women with NC-CAH.

24 hour forecast of the surface UV for the antipsoriatic heliotherapy in Poland.

Analyses of the spectral and broad-band UV data collected at Belsk (20.79°E, 51.84°N), Poland, show that standard broad-band instrument, Solar Light (SL) 501A, could be used for measurements of both erythemal and antipsoriatic irradiance. A prognostic model is proposed for the next-day duration of outdoor exposure required to receive a dose, the so-called minimum antipsoriatic dose (MAD), equivalent to that received by standard antipsoriatic daily treatment in the phototherapy cabinet containing TL-01 fluorescent tubes. The model uses the 24 h forecast of the column amount of ozone (to predict next day clear sky UV irradiance), and low- and mid-level cloudiness (to estimate a reduction of the clear-sky UV irradiation due to clouds). The predicted duration of sunbathing required to receive a dose of 1 MAD matches the observed value, i.e. the correlation coefficients is 0.68. If the model predicts the antipsoriatic exposure over 1 MAD threshold the observed dose will be also above this threshold in 91% of cases. Thus, the model could be used for planning the next-day outdoor exposure to clear psoriasis. Hourly resolved maps, starting from 6 am up to 1 pm (GMT), showing the duration of antipsoriatic exposure over Poland are made public. The model provides a tool for a psoriatic patient to find the sunbathing starting time and its duration, which has the same healing potential as a single indoor phototherapy session.

Perspectives of the antipsoriatic heliotherapy in Poland.

Statistical analysis of the daily course of exposures to TL-01 tube radiation for 93 psoriatic patients from the Medical University of Lódz during 20-day phototherapy shows that the dose of 1 J/cm(2) represents a unit of single exposure necessary for psoriasis healing. This value is converted to the antipsoriatic effective dose of 317.9 J/m(2) using the TL-01 lamp irradiance spectrum and the antipsoriatic action spectrum. It is proposed that the daily exposure of 317.9 J/m(2) serves as the standard antipsoriatic dose (SAPD) providing a link between the cabinet and the out-door exposures and it could be used for planning heliotherapy in Poland. A model is proposed to calculate ambient antipsoriatic doses for 3 h exposures around the local noon (9 am-12 am GMT) based on satellite measurements of ozone and cloud characteristics. The model constants are determined by a comparison with pertaining antipsoriatic doses measured by the Brewer spectrophotometer in central Poland. It is found that 3 h exposures to solar radiation in the period 15 May-15 September provides the mean (2005-2013) doses in the range 2.7-3.1 SAPD over Poland. Thus, heliotherapy could be treated as an alternative to the cabinet phototherapy for almost 4 months. It seems that the most effective site for antipsoriatic heliotherapy is the south/east part of Poland (the Bieszczady Mountains). The heliotherapy could be carried out in existing national health centers equipped with the standard easy-to-use biometers for on-line monitoring of UV level and controlling duration of sunbathing to avoid erythema risks. It is even possible to control the antipsoriatic heliotherapy by a patient himself, using low-cost hand-held instruments measuring UV index.

Mouse and human pluripotent stem cells and the means of their myogenic differentiation.

Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells, are an important tool in the studies focusing at the differentiation of various cell types, including skeletal myoblasts. They are also considered as a source of the cells that due to their pluripotent character and availability could be turned into any required tissue and then used in future in regenerative medicine. However, the methods of the derivation of some of cell types from pluripotent cells still need to be perfected. This chapter summarizes the history and current advancements in the derivation and testing of pluripotent stem cells-derived skeletal myoblasts. It focuses at the in vitro methods allowing the differentiation of stem cells grown in monolayer or propagated as embryoid bodies, and also at in vivo tests allowing the verification of the functionality of obtained skeletal myoblasts.

Construction of the geometrical-conductivity human chest model in simulation of the cardiac electrical field.

In this article the problem of the construction of the geometrical-conductivity model of a human chest in a computer simulation of the cardiac electrical field, applying image diagnostic data (CT, conventional radiography and 2D projections of a torso) is presented. On the basis of these data parameters are defined which allow the determination of locations and sizes of significant chest organs. Calculations and comparison of the values of these parameters for CT and radiographic data of the example patient, using image processing methods, have been carried out. A numerical experiment has been performed to determine the epicardial maps, applying two geometrical-conductivity models of the individual patient based on CT (accurate) and radiographic (approximate) image data, respectively. The credibility of the results obtained is discussed.

Investigation of the models of electrical field generated by the heart for cardiac surgery conditions.

In this work the investigations of the electrical field generated by the heart, carried out using a computer simulation method are presented. Two models have been constructed approximating the chest region for the following conditions: (a) normal heart activity, and (b) open chest during the cardiac surgery. For the above models the distribution of potentials on the heart surface are determined. The source field investigated takes the following forms: dipole, multidipole, and multipole. Numerical experiments for these models show a difference between normal heart activity and of the heart in the condition when the chest is open during surgery.