Search results for "fields"
showing 10 items of 575 documents
No influence of magnetic fields on cell cycle progression using conditions relevant for patients during MRI.
2003
The purpose of this study was to examine whether exposure to magnetic fields (MFs) relevant for magnetic resonance imaging (MRI) in clinical routine influences cell cycle progression in two tumor cell lines in vitro. HL60 and EA2 cells were exposed to four types of MFs: (i) static MF of 1.5 and 7.05 T, (ii) extremely low frequency magnetic gradient fields (ELFMGFs) with ± 10 mT/m and 100 Hz, as well as ± 100 mT/m and 100 Hz, (iii) pulsed high frequency MF in the radiofrequency (RF) range (63.6 MHz, 5.8 μT), and (iv) a combination of (i–iii). Exposure periods ranged from 1 to 24 h. Cell cycle distribution (G0/G1, S, and G2/M phases) was analyzed by flow cytometry. Cell cycle analysis did not…
Study and modulation of human cortical excitability with transcranial magnetic stimulation.
1998
Transcranial magnetic stimulation (TMS) can be applied in different paradigms to obtain a measure of various aspects of cortical excitability. These different TMS paradigms provide information about different neurotransmitter systems, enhance our understanding about the pathophysiology of neuropsychiatric conditions, and in the future may be helpful as a guide for pharmacological interventions. In addition, repetitive TMS (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. These effects can be demonstrated neurophysiologically or by combining rTMS…
Is MRI imaging in pediatric age totally safe? A critical reprisal.
2017
Current radiological literature is strongly focussed on radiation imaging risks. Indeed, given there is a small but actual augment in cancer risk from exposure to ionizing radiation in children, it is important to understand what the risk of alternative techniques could be. We retrospectively review literature data concerning possible MR imaging risks, focussing on the biological effects of MR, sedation and gadolinium compound risks when dealing with infant patients. The main concerns can be summarized in: (1) Biological effects of non-ionizing electromagnetic fields (EMF) employed—whose mechanisms of interaction with human tissues are polarization, induced current, and thermal heating, res…
Current Clinical Application of Microperimetry: A Review.
2018
Microperimetry (MP) is a technology that allows the study of retinal sensitivity at different foveal and parafoveal areas as well as eye fixation. It is a technique of functional evaluation, providing a direct correlation between anatomical and functional outcomes. There are a great variety of studies which evaluate the repeatability or reliability of measurements obtained with this technology and also describe and explore different clinical applications. MP has been shown to be useful in the characterization of sensory and motor conditions, such as amblyopia or nystagmus. Concerning ocular pathology, several studies have confirmed the usefulness of MP for evaluating and analyzing different…
Mapping of the human visual cortex using image-guided transcranial magnetic stimulation
2002
We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…
Impact of selected magnetic fields on the therapeutic effect in patients with lumbar discopathy: A prospective, randomized, single-blinded, and place…
2018
Background. Interdisciplinary physical therapy together with pharmacological treatment constitute conservative treatment strategies related to low back pain (LBP). There is still a lack of high quality studies aimed at an objective evaluation of physiotherapeutic procedures according to their effectiveness in LBP. Objectives. The aim of this study is to carry out a prospective, randomized, single-blinded, and placebocontrolled clinical trial to evaluate the effectiveness of magnetic fields in discopathy-related LBP. Material and methods. A group of 177 patients was assessed for eligibility based on inclusion and exclusion criteria. In the end, 106 patients were randomly assigned into 5 comp…
Somatosensory Illusions Elicited by Sham Electromagnetic Field Exposure: Experimental Evidence for a Predictive Processing Account of Somatic Symptom…
2020
OBJECTIVE According to the predictive processing theory of somatic symptom generation, body sensations are determined by somatosensory input and central nervous predictions about this input. We examined how expectations shape predictions and consequently bodily perceptions in a task eliciting illusory sensations as laboratory analogue of medically unexplained symptoms. METHODS Using the framework of signal detection theory, the influence of sham Wi-Fi on response bias (c) and somatosensory sensitivity (d') for tactile stimuli was examined using the somatic signal detection task (SSDT). A healthy student sample (n = 83) completed the SSDT twice (sham Wi-Fi on/off) in a randomized order after…
Prospective study of nocebo effects related to symptoms of idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF).
2020
The exact causes of Idiopathic Environmental Intolerance Attributed to Electromagnetic Fields (IEI-EMF, i.e., experience of somatic symptoms attributed to low-level electromagnetic fields) are still unknown. Psychological causation such as nocebo effects seem plausible. This study aimed to experimentally induce a nocebo effect for somatic symptom perception and examined whether it was reproducible after one week. We also examined whether these effects were associated with increased sympathetic activity and whether interoceptive accuracy (IAcc) moderated these relationships. Participants were recruited from the general population and instructed that electromagnetic exposure can enhance somat…
Intravenous SPION-labeled adipocyte-derived stem cells targeted to the brain by magnetic attraction in a rat stroke model: An ultrastructural insight…
2021
Abstract Mesenchymal stem cell therapy after stroke is a promising option investigated in animal models and clinical trials. The intravenous route is commonly used in clinical settings guaranteeing an adequate safety profile although low yields of engraftment. In this report, rats subjected to ischemic stroke were injected with adipose-derived stem cells (ADSCs) labeled with superparamagnetic iron oxide nanoparticles (SPIONs) applying an external magnetic field in the skull to retain the cells. Although most published studies demonstrate viability of ADSCs, only a few have used ultrastructural techniques. In our study, the application of a local magnetic force resulted in a tendency for hig…
The relationship between navigation abilities and mental disorders: Poster
2021
This study examined the relationship between aspects of navigational ability and behavioral traits associated with various mental disorders. We propose that navigational ability may utilize the same brain circuitry that has dysfunction in certain mental disorders and may be a beneficial early marker for these disorders. This study was inspired by the Research Domain Criteria (RDoC), a framework outlined by NIMH to study the basic dimensions of functioning that span the range of behavior from normal to abnormal. For example, we hypothesized that spatial perspective taking, which is important for navigation, could be associated with social perspective taking in disorders such as autism spectr…