Biomedical subjects

Marco Fato

Publications and source records attributed to Marco Fato.

9 recordsLinked to original sources

PubMed2006

Endocytosis of GABAB receptors modulates membrane excitability in the single-celled organism Paramecium.

GABAB receptors modulate swimming behavior in Paramecium by inhibiting dihydropyridine-sensitive Ca2+ channels via G-proteins. Prolonged occupancy of GABAB receptors by baclofen results in a decrease in GABAB receptor functions. Since changes in the number of cell-surface GABAA receptors have been postulated to be of importance in modulating inhibitory synaptic transmission in neurons, we have studied the cell-surface expression and maintenance of GABAB receptors in P. primaurelia. In this study, we use immunostaining in electron and confocal microscopy to demonstrate that constitutive internalization of GABAB receptors in P. primaurelia is mediated by clathrin-dependent and -independent endocytosis. Indeed, GABAB receptors colocalize with the adaptin complex AP2, which is implicated in the selective recruitment of integral membrane proteins to clathrin-coated vesicles, and with caveolin 1, which is associated with uncoated membrane invaginations. Furthermore, when endocytosis is blocked with hypertonic medium, cytosol acidification, filipin or with a peptide that disrupts the association between amphiphysin and dynamin, the effect of baclofen on swimming is increased. These results suggest that GABAB receptor endocytosis into clathrin-coated and -uncoated vesicles represents an important mechanism in the modulation of swimming behavior in Paramecium.

Amino Acid Sequence↗

PubMed2005

GABAB receptor intracellular trafficking after internalization in Paramecium.

The number of neurotransmitter receptors on the plasma membrane is regulated by the traffic of intracellular vesicles. Golgi-derived vesicles provide newly synthesized receptors to the cell surface, whereas clathrin-coated vesicles are the initial vehicles for sequestration of surface receptors, which are ultimately degraded or recycled. We have previously shown that GABAB receptors display a punctuate vesicular pattern dispersed on the cell surface and throughout the cytoplasm and are internalized via clathrin-dependent and -independent endocytosis. Here we have studied constitutive GABAB receptor trafficking after internalization in Paramecium primaurelia by confocal laser scanning microscopy and multiple immunofluorescence analysis. After internalization, receptors are targeted to the early endosomes characterized by the molecular markers EEA1 and rab5. Some of these receptors, destined for recycling back to the plasma membrane, traffic from the early endosomes to the endosomal recycling compartment that is characterized by the presence of rab4-immunoreactivity (IR). Receptors that are destined for degradation exit the endosomal pathway at the early endosomes and traffic to the late endosome-lysosome pathway. In fact, some of the GABAB-positive compartments were identified as lysosomal structures by double staining with the lysosomal marker LAMP-1. GABAB vesicle structures also colocalize with TGN38-IR and rab11-IR. TGN38 and rab11 are proteins found in association with post-Golgi and recycling endosomes, respectively.

Animals↗

PubMed2005

Web and computer telephone-based diabetes education: lessons learnt from the development and use of a call center.

Diabetes is a chronic disease that causes a great deal of morbidity and mortality and poor quality of life for millions of people. Continuing care and patient education help maintain a good control of the disease and prevent complications. Since current available resources are limited to providing such an education during clinic or physician visits only, alternative ways to educate people about diabetes need to be identified. In this article we discuss the implementation of an automated diabetes education call center, we define the evaluation procedures we adopted, we summarize general guidelines for the implementation of the entire system based on our experience, and we present preliminary results about the use of the call center. We believe our system is providing "active health" since we deliver educational messages to patients at regular intervals and at the time of their choice without waiting for their actions.

Diabetes Mellitus↗

PubMed2005

An integrated environment for plastic surgery support: building virtual patients, simulating interventions, and supporting intraoperative decisions.

In the last decade a number of environments for Computer Supported Plastic Surgery have been presented. Nevertheless, an overall approach for training and intraoperative support is still missing or has not been widely exploited yet. We developed a fully integrated system which allows surgical simulation, planning, and support for computer-guided plastic surgery procedures starting from image acquisition to final intraoperative assistance. The system also provides the user with a radiological workstation able to analyse patient medical images and case studies, with advanced bidimensional and three dimensional image processing functionalities. We intend to demonstrate that such a platform can be built at an affordable cost. The radiological workstation is capable of supporting radiologists and surgeons in real patient case studies and the simulation workstation may be adopted by plastic surgeons in teaching and training of complex surgical planning. Moreover, results of simulation can be used in the operating room with a relatively high benefit in terms of improved accuracy, reduction of surgical risks, and decrease in training costs.

Decision Support Techniques↗

PubMed2005

Simulation of the biomechanical behavior of the skin in virtual surgical applications by finite element method.

The objective of this study was to develop a software application that is able to support plastic surgeons interested in applying simulations and soft tissue modeling during presurgical planning activities. By using our user-friendly interface and force-displacement graphs, users can analyze scalp skin behaviors when subjected to stress. Users can 1) determine the dynamic of a general point of scalp skin after the application of a specific force, 2) predict the force needed for displacement of a point, and 3) study the deformation of all the points of the entire scalp based on the force applied. Results showed how users are able to manipulate and analyze mechanical behaviors on a mechanical model rather than on a pure geometric qualitative physiological model. The entire application was developed on a Silicon Graphics workstation.

Animals↗

PubMed2004

GABAA receptor subunits identified in Paramecium by immunofluorescence confocal microscopy.

The presence of opioid, beta-adrenergic and cholinergic receptors has been demonstrated in ciliated protozoa, but little is known about gamma-aminobutyric acid (GABA) receptors. In this study we have analyzed the distribution of GABA(A)-type receptor subunits in Paramecium. Confocal laser microscopy using antibodies specific for alpha(1)-, alpha(2)-, alpha(3)-, alpha(6)-, beta(2/3)-, gamma(2)-, epsilon-, lambda-, and theta-subunits showed that most receptors are aggregated in clusters and are distributed both on cell surface and in the cytoplasm. The intensity of labelling of the alpha(6)-, beta(2/3)- and gamma(2)-subunits was more intense than the alpha(1)-, epsilon-, and theta-subunits, suggesting that the former are present in higher concentrations than the latter.

Animals↗

PubMed2003

Swimming behavior regulation by GABAB receptors in Paramecium.

In Paramecium, internal Ca(2+) concentration increase coupled to membrane depolarization induces a reversal in the direction of ciliary beating and, consequently, a reversal in swimming direction. The ciliary reversal (CR) duration is correlated to Ca(2+) influx, and the addition of drugs that block the Ca(2+) current leads to a reduction in the backward swimming duration. In this study we have examined the possible function of GABA(B) receptors in P. primaurelia swimming control. The presence of GABA(B) immunoanalogue in Paramecium was evidenced using SDS-PAGE, Western blotting, and confocal laser scanning microscopy. By applying the specific GABA(B) receptor agonist baclofen, a dose-dependent inhibition of the membrane depolarization-induced CR duration was observed. This inhibition was antagonized by phaclofen, persisted when K(+) channel blockers were applied, and disappeared after treatment with nifedipine and verapamil. Moreover, the action of baclofen on depolarization-induced CR was suppressed by treatment with pertussis toxin. Therefore, these experiments suggest that baclofen modulates CR by a G protein (G(0) or G(1)) mediated inhibition of dihydropyridine-sensible calcium channels. Finally, synthesis and release of GABA in the environment by Paramecium have been demonstrated by HPLC. Possible correlations between GABA(B) receptor activation and the regulation of intracellular Ca(2+) levels are discussed.

Animals↗

PubMed2003

A virtual reality system for the training of volunteers involved in health emergency situations.

In order to guarantee an effective and punctual medical intervention to injured people involved in health emergency situations, where usually both professional and non-professional health operators are involved, a fast and accurate treatment has to be carried out. In case of catastrophic or very critical situations, non-professional operators who did not receive proper training (volunteers are among them) could be affected by psychological inhibitions. Their performances could slow down in such way that would affect the quality of the treatment and increase both direct and indirect costs. Our virtual reality system that is currently in use at the health care emergency center of San Martino Hospital in Genoa, Italy, has been designed and developed to check health emergency operators' capabilities to adopt correct decision-making procedures, to make optimal use of new technological equipment and to overcome psychological barriers. Our system is composed of (1) a high-end simulation PC, whose main functions are execution of the main software module, rendering of 3D scenes in stereo mode, rendering of sound, and control of data transmission from/to VR devices; (2) a low-end control PC, which controls the VR simulation running on the simulation PC, manages medical emergency simulation scenarios, introduces unexpected events to the simulation and controls the simulation difficulty level; (3) a magnetic-based motion tracking device used for head and hand tracking; (4) a wireless pair of shutter glasses together with a cathode ray tube wall projector; and (5) a high-end surround sound system. The expected benefits have been verified through the design and implementation of controlled clinical trials.

Clinical Trials as Topic↗

PubMed2002

WEB-WAP based telecare.

We have developed two telecare applications based on mobile telephony (WAP) and WEB. The first can be used to request Basic Life Support (BLS) guidelines any time by using a WAP device and to teach people and non-professionals involved in health care emergency situations. The second is a WEB-WAP based tool for medical data retrieval and at-home health care monitoring of chronically ill patients with congestive heart failure (CHF) or diabetes. Medical education content related to these diseases is available on the WEB and on the WAP device. The WAP application uses the features found in the last generation of mobile phones such as better multimedia information presentations, better interactivity capabilities, and enhanced ease of use. Based on these two applications, a promising platform is offered for developing applications in health care, home care, medical monitoring and health education ensuring continuity of care. In the paper we present the preliminary results of a pilot test at Thessaloniki University (Greece) where the WEB-WAP based tool is used to monitor patients with diabetes or CHF.

Chronic Disease↗