Search results for "Brain"
showing 10 items of 3997 documents
A dynamic extraversion model. The brain's response to a single dose of a stimulant drug.
2008
The aim of this paper is to present a mathematical dynamic modelling of the effect a stimulant drug has on different people which, at the same time, can be a useful tool for future brain studies. To this end, a dynamic model of the evolution of extraversion (considering its tonic and phasic aspects) has been constructed taking into account the unique personality trait theory and the general modelling methodology. This model consists of a delayed differential equation which, on one hand, considers that the active stimulus, a consequence of a single intake, is not constant; on the other hand, it contemplates that the state variable representing the phasic extraversion also represents the brai…
Cocaine addiction and personality: a mathematical model.
2010
The existence of a close relation between personality and drug consumption is recognized, but the corresponding causal connection is not well known. Neither is it well known whether personality exercises an influence predominantly at the beginning and development of addiction, nor whether drug consumption produces changes in personality. This paper presents a dynamic mathematical model of personality and addiction based on the unique personality trait theory (UPTT) and the general modelling methodology. This model attempts to integrate personality, the acute effect of drugs, and addiction. The UPTT states the existence of a unique trait of personality called extraversion, understood as a di…
A multi-scale approach for testing and detecting peaks in time series
2020
An approach is presented that combines a statistical test for peak detection with the estimation of peak positions in time series. Motivated by empirical observations in neuronal recordings, we aim at investigating peaks of different heights and widths. We use a moving window approach to compare the differences of estimated slope coefficients of local regression models. We combine multiple windows and use the global maximum of all different processes as a test statistic. After rejection, a multiple filter algorithm combines peak positions estimated from multiple windows. Analysing neuronal activity recorded in anaesthetized mice, the procedure could identify significant differences between …
[68Ga]Ga-DO2A-(OBu-l-tyr)2: Synthesis, 68Ga-radiolabeling and in vitro studies of a novel 68Ga-DO2A-tyrosine conjugate as potential tumor tracer for …
2009
The synthesis, (68)Ga-labeling and in vitro study of the novel tyrosine chelate derivative [(68)Ga]Ga-1,4,7,10-tetraazacyclododecane-1,7-diacetic acid-4,10-di-(O-butyl)-l-tyrosine ([(68)Ga]Ga-DO(2)A-(OBu-l-tyr)(2)) as a potential tracer for imaging tumor metabolism by positron emission tomography (PET) is presented. This approach combines the biological amino acid transporter targeting properties of l-tyrosine with the outstanding availability of (68)Ga(III) via the (68)Ge/(68)Ga generator. In vitro studies utilizing the F98-glioblastoma cell line revealed specific uptake of [(68)Ga]Ga-DO2A-(OBu-l-tyr)(2) that was comparable to that of the reference O-(2-[(18)F]fluoroethyl)-l-tyrosine (FET)…
Synthesis, benzodiazepine receptor binding and molecular modelling of isochromeno[4,3-c]pyrazol-5(1H)-one derivatives
2012
Abstract A series of isochromeno[4,3-c]pyrazole-5(1H)-one derivatives 7b–h were prepared and tested at 10 μM for their ability to displace specific [3H]flunitrazepam from bovine brain membranes. The substitution pattern of the above derivatives was shown to influence the receptor affinity. The most active compound of the series was 7e, showing a 54% inhibition of [3H]flunitrazepam binding. Compounds 7a–d,i were compared with the known isomers chromeno[4,3-c]pyrazole-4(1H)-ones 14a–d,i, showing that the isochromene/chromene isomerism influences the activity.
The value of serial MR imaging in the assessment of brain metastases volume control during stereotactic radiosurgery
2015
Purpose: To evaluate early tumour control capabilities of Stereotactic Radiosurgery (SRS) in the treatment of brain metastasis and the role of follow-up MR imaging. Methods and Materials: MR imaging of 54 metastases in 31 patients treated with SRS who underwent follow-up MR imaging within 12 months were retrospectively reviewed. Tumours were characterized as either enlarged (>20% volume increase), stable (follow-up volume ±20% of the initial volume), or decreased (> 0% volume decrease). Results: Within the first 6 weeks following SRS a decrease was observed in 25 (52%) of the tumours in the extent of 63% in size. Tumour reduction varied according to histopathological subtype with 38% of non…
MRgFUS results Italy
2017
PURPOSE: To present our preliminary results achieved with the first Italian installation of a trans-cranial MRI-guided Focused Ultrasound Surgery (tcMRgFUS) certified system for functional neurosurgery. Moreover, to our knowledge, this is the world-first tcMRgFUS system ever installed on a 1.5T MRI unit. Technical issues faced to achieve a safe and effective treatment will be discussed focusing on MR high-resolution live imaging and thermometry sequences optimization. METHOD AND MATERIALS: Patient enrollment was based on indication for functional neurosurgery and evidence of medication-refractory disease; a detailed medical history has been collected together with a complete clinical examin…
Role of hydrophobicity on the monoamine receptor binding affinities of central nervous system drugs: a quantitative retention-activity relationships …
2004
Abstract Biological action and activity reflect an aspect of the fundamental physicochemical properties of the bioactive compounds. As an alternative to classical QSAR studies, in this work different quantitative retention–activity relationships (QRAR) models are proposed, which are able to describe the role of hydrophobicity on the binding affinity to different brain monoamine receptors (H 1 -histamine, α 1 -noradrenergic and 5-HT 2 -serotonergic) of different families of psychotherapeutic drugs. The retention of compounds is measured in a biopartitioning micellar chromatography (BMC) system using Brij-35 mobile phases. The adequacy of the QRAR models developed is due to the fact that both…
An investigation of the neural circuits underlying reaching and reach-to-grasp movements: from planning to execution
2014
Experimental evidence suggests the existence of a sophisticated brain circuit specifically dedicated to reach-to-grasp planning and execution, both in human and non-human primates (Castiello, 2005). Studies accomplished by means of neuroimaging techniques suggest the hypothesis of a dichotomy between a "reach-to-grasp" circuit, involving the anterior intraparietal area, the dorsal and ventral premotor cortices (PMd and PMv - Castiello and Begliomini, 2008; Filimon, 2010) and a "reaching" circuit involving the medial intraparietal area and the superior parieto-occipital cortex (Culham et al., 2006). However, the time course characterizing the involvement of these regions during the planning …
Biomaterials coated by dental pulp cells as substrate for neural stem cell differentiation
2011
[EN] This study is focused on the development of an in vitro hybrid system, consisting in a polymeric biomaterial covered by a dental pulp cellular stroma that acts as a scaffold offering a neurotrophic support for the subsequent survival and differentiation of neural stem Cells. In the first place, the behavior of dental pulp stroma on the polymeric biomaterial based on ethyl acrylate and hydroxy ethyl acrylate copolymer was studied. For this purpose, cells from normal human third molars were grown onto 0.5-mm-diameter biomaterial discs. After cell culture, quantification of neurotrophic factors generated by the stromal cells was performed by means of an ELISA assay. In the second place, s…