A survey on electromagnetic hypersensitivity: the example from Poland.

Idiopathic environmental intolerance attributed to electromagnetic field (IEI-EMF) called electromagnetic hypersensitivity or electrosensitivity appeared in Polish society awareness due to a considerable change made at the end of 2019 in Polish telecommunication laws. The aims of the project were to access the prevalence of IEI-EMF in Poland and to define a reliable methodology to study this phenomenon. The first step was the internet survey performed at the end of 2018. The IEI-EMF prevalence estimated at the level of 39.7% suggested considerable bias affecting the results. The faults of the first approach were analysed and then a second study stage was performed as a telephone survey at the end of 2020. The latter survey allowed estimating the prevalence of IEI-EMF as less than 1.8%. These discrepancies in the results of both surveys were connected to the medium used in the first survey (Internet) indirectly causing that the group pooled was not representative. The second pitfall was the definition of the criteria used for an electrosensitive person classification. This is why the IEI-EMF prevalence was investigated in the second stage with the use of numerous criteria. The application of different criteria allowed for essential conclusions concerning the appropriate methodology for such kinds of studies. Corrections of the methodology before the second survey allowed reliable results consistent with the results obtained in similar studies performed in other countries. Our findings also show that the IEI-EMF frequency reports presented in the literature have to be treated carefully and with some dose of scepticism.

Physics Doesn't Bite-A Simple Experiment for Introducing Biomechanical Operational Principles of the Temporomandibular Joint.

Biophysics is rarely mentioned as one of the most useful parts of dental and medical students' curricula. However, with the growing complexity of tools and methods used in diagnostics and therapy, the knowledge of their physical foundations becomes important and helps with choosing the optimal solutions for both, a patient and a doctor. The aim of the proposed activity is to develop students' intuition about simple physical models that help with understanding fundamental properties of temporomandibular joint (TMJ). A simple device, which allows for bite force measurement, is proposed. It is based on beam bending and a strain gauge Wheatstone bridge circuit mounted on two connected arms: the stiff one and the more elastic one. Linear regression is the only mathematical concept needed for understanding the physical background of the proposed activity. During the proposed activity-measuring of bite force for incisors, premolars, and molars-students are confronted with basic concepts, such as lever, torque, electrical circuit, calibration curve. By utilizing a simple idea, instead of a commercially available device, students can understand where the data come from. Proposed system delivers physiologically reasonable results.

The Impact of Mobile Phone Use on Tinnitus: A Systematic Review and Meta-Analysis.

Tinnitus is a perception of sound in the absence of an external source. The aim of our study was to investigate with a meta-analytical approach, whether mobile phone (MP) use increases the risk of tinnitus. Eight studies reporting the risk of tinnitus in relation to MP use were identified, and six high-quality studies (two cohort studies, one case-control study, and three cross-sectional ones) were included in the meta-analysis. The quality assessment was performed using the Newcastle-Ottawa scale. The risk of tinnitus was analyzed depending on the exposure to MPs in subgroups according to the study design and method of exposure assessment. Two cohort studies, which assessed the exposure to MPs using network operator data, indicated no significantly increased risk of tinnitus among highly exposed MP users in comparison to lightly exposed individuals (odds ratio [OR]: 1.03 [95% confidence interval [CI]: 0.93-1.15]). Likewise, the self-reported exposure data from two cohorts/case-control and four cross-sectional studies did not find an association between exposure to MPs and tinnitus (OR: 1.20 [95% CI: 0.40-3.61] and OR: 1.73 [95% CI: 0.67-4.49], respectively). Current scientific knowledge, including high-quality studies with a reliable exposure assessment based on network operator data, does not support the hypothesis that MP use is associated with tinnitus. © 2020 Bioelectromagnetics Society.

The influence of aging on the insertion of the Achilles tendon: A magnetic resonance study.

The aim of this study was to examine the variations of the Achilles tendon (AT) insertion point into the calcaneal bone (CB) in relation to age and sex using magnetic resonance imaging (MRI). A total of 202 foot and ankle MRIs were reviewed and patients were allocated into three age groups: (I) <18, (II) 18-65, and (III) >65 years. All measurements were obtained on a mid-sagittal scan. The mean measurement values were used to assess the relationships among the AT insertion point, sex, and age. Our main findings revealed that (1) the distance between the most inferior point of the CB and the most inferior part of the AT insertion into the CB increases with age, (2) the height of the AT insertion into the posterior aspect of the CB decreases with age, and (3) the length of the AT insertion into the posterior aspect of the CB decreases with age. The terminal insertion point of the AT on the CB in younger subjects was more distal, whereas in older individuals it was more proximal. These results could help in developing novel strategies for the treatment and prophylaxis of AT injuries in particular patient age groups. Anatomical data about the AT insertion are crucial for developing a computer model of the AT and for biomechanical considerations regarding this tendon. Clin. Anat. 33:545-551, 2020. © 2019 Wiley Periodicals, Inc.

Thermographic assessment of skin prick tests in comparison with the routine evaluation methods.

INTRODUCTION: The skin prick test is still the first and basic procedure in the diagnosis of allergic diseases. The possibility of using a sensitive thermographic method supported by the mathematical model for the assessment of skin test results will be highlighted in the studies. AIM: To compare the proposed approach with routine planimetric and thermographic methods. MATERIAL AND METHODS: A mathematical model of allergic reaction was developed. Simplifying assumptions of the IgE-mediated skin reaction is the essence of the model. Investigations were performed in a group of 40 patients. RESULTS: Using the spatio-temporal evolution of temperature distributions, the ratios of the histamine released from mast cells to the control histamine were determined. The obtained values very well correlate with the standard evaluation of skin prick tests (correlation coefficient = 0.98). CONCLUSIONS: The proposed method of skin test evaluation presents several advantages. The continuous acquisition of data provides the monitoring of time course of the allergic response. The transport of mediator and its concentration were distinctly discriminated, which may be diagnostically useful, especially for abnormal cases. The high sensitivity of the method enables studying patients regardless of age and skin sensitivity.

Oversampling in the computed tomography measurements applied for bone structure studies as a method of spatial resolution improvement.

BACKGROUND: Our purpose was to check the potential ability of oversampling as a method for computed tomography axial resolution improvement. The method of achieving isotropic and fine resolution, when the scanning system is characterized by anisotropic resolutions is proposed. In case of typical clinical system the axial resolution is much lower than the planar one. The idea relies on the scanning with a wide overlapping layers and subsequent resolution recovery on the level of scanning step. MATERIAL/METHODS: Simulated three-dimensional images, as well as the real microtomographic images of rat femoral bone were used in proposed solution tests. Original high resolution images were virtually scanned with a wide beam and a small step in order to simulate the real measurements. The low resolution image series were subsequently processed in order to back to the original fine one. Original, virtually scanned and recovered images resolutions were compared with the use of modulation transfer function (MTF). RESULTS/CONCLUSIONS: A good ability of oversampling as a method for the resolution recovery was showed. It was confirmed by comparing the resolving powers after and before resolution recovery. The MTF analysis showed resolution improvement. The resolution improvement was achieved but the image noise raised considerably, which is clearly visible on image histograms. Despite this disadvantage the proposed method can be successfully used in practice, especially in the trabecular bone studies because of high contrast between trabeculae and intertrabecular spaces.

Application of thermography for the assessment of allergen-induced skin reactions.

PURPOSE: The allergic response is commonly identified and assessed by skin testing. The usual method to quantify skin reactions is to mark wheal and erythema regions and assess the surfaces affected by the reactions; however, subjective interpretation of the outcome may cause errors. Skin thermography supplemented by a mathematical model based on the pathophysiology of heat generation was evaluated as a novel, objective, and sensitive indicator of the skin prick test result. METHODS: TH measurements were performed simultaneously with routine skin prick tests for 24 patients. Eight allergens and control (histamine) were examined. Thermographic images of both forearms were acquired every 70 s from 0 to 910 s after skin prick and analyzed with the use of dedicated software. The introduction of potential allergens and histamine at sites on the skin induces a complex sequence of events known as the local inflammatory response. The crucial steps of the process have been considered in the model. In the model, the authors assumed that the reaction takes place in the thin skin layer and that histamine is the principal mediator of the allergic reaction. Histamine penetrates the skin and binds to receptors of nearby capillaries and venules. The engorged vessels are, in turn, responsible for skin redness and an increase in skin temperature. RESULTS: The model parameters were determined by fitting the analytical solutions to the spatiotemporal distributions of the differences between measured and baseline temperatures. The model reproduces experimental data very well. The coefficient of determination ranged from 0.805 to 0.995. Seven model parameters were tested to find the optimal marker of the intensity and kinetics of the allergic reaction. The parameter which quantifies a release of histamine after allergen injection has appeared to be the best indicator of the allergen-induced response. The parameter correlates with the routine assessment based on wheal and erythema areas (correlation coefficient = 0.98). CONCLUSIONS: It was demonstrated that the thermographic measurements supplemented by the mathematical model offer a new approach to the quantification of allergen-induced skin reactions. Despite the applied simplifications, the proposed model reflected properly the mechanism of heat generation during skin prick test. Moreover, the continuous recording of the skin temperature represents an additional possibility to investigate the mechanism of the allergic reaction.