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Biomedical subjects

M Bove

Publications and source records attributed to M Bove.

15 recordsLinked to original sources
PubMed1997

Experimental analysis of neuronal dynamics in cultured cortical networks and transitions between different patterns of activity.

Experimental investigation of the dynamics of biological networks is a fundamental step towards understanding how the nervous system works. Spontaneous activity in cultured networks of cortical neurons has been investigated by using a multisite recording technique with planar electrode arrays. In these networks, the spatiotemporal firing patterns were studied in the presence of different extracellular solutions. Transitions from asynchronous firing dynamics to synchronous firing dynamics were observed when the extracellular Ca2+ concentration was increased from 0.1 mM to 1 mM. Addition of extracellular Mg2+ reduced the spontaneous activity at any Ca2+ concentration, and an increase in the extracellular K+ concentration enhanced the frequency of periodical synchronous bursts. N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor antagonists inhibited synchronous activity. A spatiotemporal analysis of the data has been performed, and the properties of the network such as the synchronization and the periodicity have been quantified in order to clarify how variations of intrinsic parameters of the network can induce structural transitions in the neural dynamics. This experimental study is a possible approach to investigate the computational properties of a neuronal network.

Animals↗
PubMed1997

The effect of administered crystalloid fluid temperature on aural temperature of moderately and severely injured children.

OBJECTIVE: Warm intravenous fluid (W-IVF) administration is the standard of care to prevent hypothermia in injured adults. It is argued that such administration may not be helpful for treating injured children, because children often do not require as much intravenous fluid (i.v.f.) as adults. The purpose of this study was to compare the effects of W-i.v.f. to room temperature intravenous fluid (RT-i.v.f.) administration on aural temperature (Ta) in injured children during the first hour of trauma resuscitation. DESIGN: A randomized, controlled repeated-measures trial. SETTING: Emergency department, intensive care unit, and diagnostic areas in a level I pediatric trauma center. SAMPLE: Thirty moderately or severely injured children, ranging in age from 2 to 17 years (mean age = 8.9 years; SD = 4.4). METHODS: Eligible children were randomly assigned to receive either W-i.v.f. or RT-i.v.f. on ED arrival. Warmed IVF was administered with the Hotline fluid warmer (SIMS Level 1, Rockland, Mass). Aural temperatures were measured on arrival and every 10 minutes for 1 hour with a Core-Check Tympanic Thermometer (IVAC Medical Systems, San Diego, Calif). The level of significance for hypothesis testing was set at 0.05 (two-tailed). RESULTS: Groups were comparable in age, gender, weight, amount of infused i.v.f., Revised Trauma Score, room temperature, and baseline Ta. On average, Ta for the W-i.v.f. group increased by 0.25 degree C from baseline to final Ta, whereas Ta for the RT-i.v.f. group decreased by 0.32 degree C from baseline to final Ta. Repeated-measures analysis of covariance, treating baseline Ta as a covariate, demonstrated that Ta response profiles were similar (p = 0.06). CONCLUSIONS: When comparing the changes between baseline and final Ta for the W-i.v.f. and RT-i.v.f. groups, the standardized difference in temperature change was 0.62. Although results of the repeated measures analysis of covariance were not statistically significant, the standardized difference in temperature changes was large enough to warrant administration of W-i.v.f., even at slow flow rates, to prevent hypothermia in injured children.

Adolescent↗
PubMed1997

In vitro 2-D networks of neurons characterized by processing the signals recorded with a planar microtransducer array.

The purpose of this paper is to extensively analyze and utilize the key features that characterize the recently available electrophysiological technique of growing selected populations of neurons on planar substrate microelectrode arrays. This experimental configuration is first simulated by modeling the signal transduction operated by an array of microtransducers coupled to a network of Hodgkin-Huxley-like neurons, connected to each other with given levels of synaptic strength. Signal processing tools are then described and validated by identifying the various degrees of connectivity previously introduced into the simulated network. Finally, these software tools are utilized to characterize the activity and identify the synaptic connectivity of networks of cultured neurons extracted from dorsal root ganglia (DRG) of chick embryos and exposed to synapse inhibiting/reinforcing ions. As a result, correlations between various regimens of electrophysiological activity and synaptic strength are obtained.

Algorithms↗
PubMed1997

Simulations of the behavior of synaptically driven neurons via time-invariant circuit models.

This paper describes computer simulations of the behavior of Hodgkin-Huxley neurons, based on a redefinition of membrane and synaptic connections as time-invariant circuit elements. Examples are given showing that this self-consistent equivalent circuit representation allows very efficient computer simulations and could facilitate the introduction of detailed biological neurons into formal neural networks.

Action Potentials↗
PubMed1996

Characterization and interpretation of electrical signals from random networks of cultured neurons.

The main purpose of this paper is to describe several software tools specifically adapted to characterize the electrophysiological behavior of a population of neurons coupled to a planar array of microtransducers by analyzing the recorded signals. Both graphic and signal processing tools are considered. They include: image analysis of the neuronal network topology, peak detection procedure, multi-graphics visualization, spike classification, cross-correlation, interspike and interbursting interval analysis. These tools are utilized to characterize changes induced in the electrophysiological behavior of populations of cultured neurons by modifications to the medium-culture.

Animals↗
PubMed1995

Silicon neuron simulation with SPICE: tool for neurobiology and neural networks.

The paper deals with computer simulations of 'silicon neurons', which are assemblies of CMOS circuits that generate the equivalents of the ionic currents and of the action potentials of real (biological) neurons. The circuit simulation program SPICE is used to simulate the generation of action potentials by a silicon neuron. Moreover, the equivalent circuits of silicon synapses are described and the behaviours of simple two- and three-neuron networks are analysed. Implications for the areas of neurobiology and formal neural networks are briefly considered.

Computer Simulation↗
PubMed1994

Realistic simulations of neurons by means of an ad hoc modified version of SPICE.

This paper describes an ad hoc modified version of the electrical circuit analysis program SPICE, which has been optimized for detailed simulations of the behaviour of neurons. An equivalent-circuit description of the simulation building blocks is provided, and the SPICE modifications are specified. These modifications, in contrast to previous uses of SPICE, allows one to simulate the behaviour of neurons of Hodgkin-Huxley type (excitable membrane) and of postsynaptic membranes without any approximations. Simulation results are reported and compared, both with data previously analysed in the literature by other authors and with experimental data recently obtained by coupling neurons to planar extracellular microelectrodes. Details of the circuit elements used in the simulations are reported. The improvements of our proposed model are discussed in comparison with a previous SPICE-based model described in the literature.

Action Potentials↗
PubMed1993

Images of cultured neurons: morphological and functional information.

The in vitro culture of neuronal cells is a useful tool for studying, in a controlled way, neurobiological and neuropharmacological phenomena. A first step towards the understanding of these phenomena is described. Effects of simulated excitatory/inhibitory synapses, artificially positioned along the digitized image of neural arborizations, are presented.

Animals↗
PubMed1988

Delivery circumstances in relation to adult septum deviation.

The present study elucidates whether factors correlated to septum dislocation in newborns have quantitative significance for septum deviation demanding surgery in adults. The delivery circumstances of 95 patients operated upon for septum deviation were compared to those of 79 control subjects with straight septa. Patients and control subjects were born in the same area and at the same period of time. Eleven possible nose traumatizing factors were analyzed. No difference was found. There was, however, a male overrepresentation by 3:1 amongst the operated patients which may be explained by postnatal nose trauma. It is concluded that delivery circumstances have only minor influence on the number of adults demanding septum surgery.

Adolescent↗
PubMed1987

Transient hearing loss following spinal anaesthesia.

Audiograms were performed pre-operatively in 14 patients scheduled for transurethral resection of the prostate under spinal anaesthesia and again 2 days postoperatively. Six of the 14 patients showed a minor reduction of hearing in the low frequency range. Follow-up audiograms showed full recovery after 1-7 months. No significant hearing loss was found in 12 patients who underwent the same procedure with epidural anaesthesia.

Aged↗
PubMedDate not supplied

Combined modality (ABVD plus radiotherapy) versus radiotherapy in the management of early stage (IIA) Hodgkin's disease with mediastinal involvement.

The aim of this study was to establish whether combined modality treatment (ABVD plus radiotherapy) can reduce the risk of relapse in Hodgkin's disease patients with mediastinal involvement, as compared to radiotherapy alone. The results obtained suggest that one course of ABVD before irradiation can reduce the incidence of relapse. These findings, however, should be considered preliminary and need to be confirmed in larger studies.

Adult↗
PubMedDate not supplied

[Elastoviscosimetry in maxillo-facial pathology].

In the oro-maxillo-facial pathology it may be useful to perform hematochimical and saliva tests which can clarify the kind of the pathology and which can be used in the post-surgical follow-up because of incidental modifications. Saliva compliance and viscosity and blood hemorrheology variations always result lower than in normal population. The Authors are going to value which kind of oro-maxillo-facial pathologies shows a significant reduction of saliva elastoviscosity and blood hemorrheology. Yet, in a further study, they will try to explain that reduction and the connection with the specific pathology and the medical and/or surgical treatment.

Adult↗