Search results for " Magne"
showing 10 items of 8203 documents
NeXt for neuro-radiosurgery: A fully automatic approach for necrosis extraction in brain tumor MRI using an unsupervised machine learning technique
2017
Stereotactic neuro-radiosurgery is a well-established therapy for intracranial diseases, especially brain metastases and highly invasive cancers that are difficult to treat with conventional surgery or radiotherapy. Nowadays, magnetic resonance imaging (MRI) is the most used modality in radiation therapy for soft-tissue anatomical districts, allowing for an accurate gross tumor volume (GTV) segmentation. Investigating also necrotic material within the whole tumor has significant clinical value in treatment planning and cancer progression assessment. These pathological necrotic regions are generally characterized by hypoxia, which is implicated in several aspects of tumor development and gro…
Gadolinium accumulation after contrast-enhanced magnetic resonance imaging: Which implications in patients with Crohn's disease?
2017
Crohn's disease (CD) is a chronic inflammatory condition of the bowel, characterized by an alternation of remission and relapse phases, leading to a progressive intestinal damage with loss of function. Magnetic resonance enterography has been widely used in the past for the evaluation of fistulizing disease, but its use increased over time, being considered helpful in different moments of disease course. Intravenous injection of Gadolinium-based contrast agents has been demonstrated to be crucial to assess mucosal inflammation, transmural involvement, and extraintestinal disease. Recently, Gadolinium accumulation in human tissues has been increasingly reported, although clinical implication…
Histopathology of the Harderian gland of rodents exposed to ELF magnetic fields
1993
Abstract The Harderian gland is a possible magnetosensitive organ. The aim of this study was to look at the possible effects on the Harderian gland of mice after exposure to an artificial magnetic field. Sixty 0F1 three-month old female mice were selected for this study. The mice were exposed continuously to an artificial magnetic field of 1 G (10 −4 T) and 50 Hz during a three-month period. The effects were evaluated histologically. The results show, only in the experimental group, non-reversible histopathological lesions with anaplasic foci in 26% of Harderian glands. These lesions also include in situ development of adenocarcinomas. Confidence intervals applied to the statistical studies…
SUBFRACTIONS AND SUBPOPULATIONS OF HDL: AN UPDATE
2014
High-density lipoproteins (HDL) are classified as atheroprotective because they are involved in transport of cholesterol to the liver, known as "reverse cholesterol transport (RCT)" exerting antioxidant and anti-inflammatory activities. There is also evidence for cytoprotective, vasodilatory, antithrombotic, and anti-infectious activities for these lipoproteins. HDLs are known by structural, metabolic and biologic heterogeneity. Thus, different methods are able to distinguish several subclasses of HDL. Different separation techniques appear to support different HDL fractions as being atheroprotective or related with lower cardiovascular (CV) risk. However, HDL particles are not always prote…
Conditioning effect of transcranial magnetic stimulation evoking motor‐evoked potential on V‐wave response
2014
Abstract The aim of this study was to examine the collision responsible for the volitional V‐wave evoked by supramaximal electrical stimulation of the motor nerve during voluntary contraction. V‐wave was conditioned by transcranial magnetic stimulation (TMS) over the motor cortex at several inter‐stimuli intervals (ISI) during weak voluntary plantar flexions (n = 10) and at rest for flexor carpi radialis muscle (FCR; n = 6). Conditioning stimulations were induced by TMS with intensity eliciting maximal motor‐evoked potential (MEPmax). ISIs used were ranging from −20 to +20 msec depending on muscles tested. The results showed that, for triceps surae muscles, conditioning TMS increased the V‐…
Modulatory effects of low- and high-frequency repetitive transcranial magnetic stimulation on visual cortex of healthy subjects undergoing light depr…
2005
The aim of the present study was to explore further the effects of light deprivation (LD) on visual cortex excitability. Healthy subjects reporting reliable induction of phosphenes by occipital transcranial magnetic stimulation (TMS) underwent 60 min of complete LD. Phosphene threshold (PT) was measured before (T0), after 45 min (T1) and 60 min (T2) of LD, and then every 10 min after light re-exposure until recovery to T0 values. Repetitive TMS (rTMS) (at 1 or 10 Hz) was applied in separate sessions during the last 15 min of LD. PTs significantly decreased after 45 min of LD. rTMS differentially modified the effects of 60 min LD on PTs depending on stimulation frequency. One hertz rTMS did …
Detection of central circuits implicated in the formation of novel pain memories
2016
Jaymin Upadhyay,1 Julia Granitzka,1 Thomas Bauermann,2 Ulf Baumgärtner,3 Markus Breimhorst,1 Rolf-Detlef Treede,3 Frank Birklein1 1Department of Neurology, 2Department of Neuroradiology, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, 3Department of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Mannheim, Germany Abstract: Being able to remember physically and emotionally painful events in one’s own past may shape behavior, and can create an aversion to a variety of situations. Pain imagination is a related process that may include recall of past experiences, in addition to production of sensor…
Value of serial magnetic resonance imaging in the assessment of brain metastases volume control during stereotactic radiosurgery
2016
AIM To evaluate brain metastases volume control capabilities of stereotactic radiosurgery (SRS) through serial magnetic resonance (MR) imaging follow-up. METHODS MR examinations of 54 brain metastases in 31 patients before and after SRS were reviewed. Patients were included in this study if they had a pre-treatment MR examination and serial follow-up MR examinations at 6 wk, 9 wk, 12 wk, and 12 mo after SRS. The metastasis volume change was categorized at each follow-up as increased (> 20% of the initial volume), stable (± 20% of the initial volume) or decreased (< 20% of the initial volume). RESULTS A local tumor control with a significant (P < 0.05) volume decrease was observed in 25 meta…
Distribution and course of cortico-respiratory projections for voluntary activation in man
2002
The function and course of the cortico-respiratory projections in man are not yet well established. In 30 normal volunteers respiratory muscles were activated by magnetic stimulation of the motor cortex and the cervical and thoracic spinal roots with bilateral recordings from the respiratory muscles. Following cortical stimulation contralateral responses were obtained in all subjects during voluntary inspiration showing a mean latency and amplitude of 13.4±1.4ms/1.6±1.2 mV (stimulation of the left hemisphere) and 13.2±1.3ms/2.5±2.5 mV (stimulation of the right hemisphere). Ipsilateral responses were obtained in only 18 (right side) and 21 (left side) subjects and had a significantly (p < 0.…
Die dynamische 31-Phosphor-Magnetresonanz-Spektroskopie des M. quadriceps: Einfluß von Geschlecht und Alter auf spektroskopische Parameter
1999
PURPOSE 31P-MRS is used to assess the influence of sex und age on quadriceps muscle metabolism before and after exercise. MATERIALS AND METHODS 32 healthy volunteers (15 women, 17 men, mean age: 38 +/- 17 yrs.) were examined by dynamic phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In the magnet, the quadriceps muscle was stressed by an isometric und an isotonic form of exercise until exhaustion, respectively. RESULTS Resting conditions: With increasing subjects' age, the ratio beta-adenosine triphosphate/total phosphate decreased (r = -0.37; p = 0.02). With increasing subjects' age, the ratios inorganic phosphate/phosphocreatine (r = 0.79; p = 5 x 10(-8), phosphomonoester/beta-…