PubMed Health⌕ Search

Biomedical subjects

P Mattioli

Publications and source records attributed to P Mattioli.

At least 19 recordsLinked to original sources
PubMed2000

Evaluation of radiolucency condition in total hip arthroplasty: a statistical comparison of the diagnostic capability of digitised image vs. conventional X-ray film.

This work analyses the diagnostic capability of radiographic images taken from patients with total hip arthroplasty and visualised on monitor. Images were obtained with digital acquisition of conventional X-ray films. The investigated pathology is the absence of direct contact between bone and prosthesis (radiolucency). Three senior orthopaedists defined the diagnostic "truth" on well-defined regions of interest on 22 conventional X-ray films of total hip arthroplasty, obtaining a total of 110 reference ratings. Films were digitised by use of an X-ray scanner. Four readers evaluated the X-ray images, applying conventional and monitor visualisation. To show any difference between ratings on film and ratings on monitor a sensitivity, specificity and accuracy study jointly with a receiver operating characteristics (ROC) study were performed for each reader and for all combined readings. The intra-observer reproducibility of the radiographic protocol was equal to 87% and the inter-observer one was in the range 85-92%. The sensitivity, specificity and accuracy study together with the ROC analysis did not show significant differences between the two evaluation modes. The evaluation of radiolucency from digitised X-ray films visualised on a monitor resulted statistically comparable with the conventional evaluation on X-ray films.

Diagnosis, Computer-Assisted↗
PubMed2000

Evaluation of the efficacy of potential antineoplastic drugs on tumour metastasis by a computer-assisted image analysis.

Computerised image analysis, performed on histological sections of (C57BL6/N) mouse lungs that had been intravenously (i.v.) injected with B16-F10 melanoma cells was used to develop a novel method to quantify the efficacy of potential antineoplastic drugs. This procedure allowed the evaluation of the rate of inhibition of growth and the anti-invasive capability of new molecules, thus resulting in more accurate data than that obtained from common macroscopical counting of surface metastatic foci. Several morphological parameters can be measured by this method: the percentage of tissue area occupied by metastases, which accounts for tumour implantation into the organ; the growth index, related to the size of the metastases, and the invasion index, related to the frequency of foci. These morphometric data were found to be correlated to the levels of lung hydroxyproline and transglutaminase activity, well known markers of tumour invasion and cell differentiation, respectively. The main objective of this computerised procedure was to evaluate how the tumour cell is affected in the host by the drug under investigation. The use of the method is exemplified by an analysis of the antitumour activity of some methylxanthines.

Animals↗
PubMed1999

A study of the application sharing capabilities in telemedicine.

The main aim of this study was to find out if the image format (TIFF or JPEG) influenced the time delay for transferring radiological images by the application sharing tool of a desktop videoconferencing system. The second task of the study was to define a procedure that optimized the time delay to load and remotely visualize the images. The results were achieved by applying a test procedure called 'benchmark protocol'. The videoconferencing system used for the test was Intel ProShare 200 v2.0. The image transfer was performed by a BRI ISDN connection. We showed that the image format had no significant influence on the time delay. We presented an optimal procedure for image transfer. Furthermore, store and forward procedures with simple file transfer were shown to be inferior to the use of application sharing. For radiological image transfer we recommend to use lossless file formats and application sharing with the image already loaded in because this method achieves the lowest time delays.

Computer Communication Networks↗
PubMed1999

The Telemedicine benchmark--a general tool to measure and compare the performance of video conferencing equipment in the telemedicine area.

In this paper, we describe the 'Telemedicine Benchmark' (TMB), which is a set of standard procedures, protocols and measurements to test reliability and levels of performance of data exchange in a telemedicine session. We have put special emphasis on medical imaging, i.e. digital image transfer, joint viewing and editing and 3D manipulation. With the TMB, we can compare the aptitude of different video conferencing software systems for telemedicine issues and the effect of different network technologies (ISDN, xDSL, ATM, Ethernet). The evaluation criteria used are length of delays and functionality. For the application of the TMB, a data set containing radiological images and medical reports was set up. Considering the Benchmark protocol, this data set has to be exchanged between the partners of the session. The Benchmark covers file transfer, whiteboard usage, application sharing and volume data analysis and compression. The TMB has proven to be a useful tool in several evaluation issues.

Benchmarking↗
PubMed1999

Technical validation of low-cost videoconferencing systems applied in orthopaedic teleconsulting services.

Investigation on the applicability of low-cost videoconferencing (VC) for health care services is becoming a real need. Reduced resources drive the administrators to evaluate inexpensive solutions for telemedicine. Considering this scenario, this work is a preliminary step to validate, from a technical point of view, if low-cost VC systems could be suitable for orthopaedic teleconsulting services. For this purpose, four different videoconferencing systems were tested. Each VC system was composed of a computer and a VC device installed in. VC devices were chosen among the most popular and distributed products (made by Intel, PictureTel and Aethra). The Telemedicine Benchmark, a specific tool defined by the authors, was applied to measure the overall systems performances in terms of time delays during basic rate ISDN connections (128 Kbit/s). Results showed that it is possible to apply low-cost videoconferencing systems for orthopaedic teleconsulting services. Most of the systems provided acceptable performance for medical image visualization and real time joint working. Further developments are recommendable to enhance the VC software tools capabilities and to improve software-user interface. reserved.

Costs and Cost Analysis↗
PubMed1999

Low-cost ISDN videoconferencing equipment for orthopaedic second opinions.

We validated the application of low-cost ISDN videoconferencing equipment for telemedicine. A telemedicine benchmark was designed and four different office videoconferencing systems were evaluated, all using basic-rate ISDN connections (128 kbit/s). All the low-cost systems showed generally good or acceptable performance for clinical use. We also investigated the feasibility of videoconferencing for an orthopaedic second-opinion service. Eight point-to-point conferences were conducted to discuss real clinical cases by use of interactive sharing of medical images. The average duration of each session was 35 min. Encouraging results were obtained.

Costs and Cost Analysis↗
PubMed1999

Guidelines for multipoint videoconferencing using low-cost, PC-based equipment.

We have compiled a set of guidelines for effective multipoint videoconferencing carried out with low-cost, PC-based systems. The guidelines are based on experience gained during multipoint videoconferences in epidemiology and orthopaedics/radiology. Joint data inspection and manipulation were carried out by application sharing between the PCs. The guidelines are categorized by the time of their application and also by their content. For effective multipoint videoconferences, preparation of the agenda and of digital documents is mandatory. The prevention of echo effects and half-duplex audio connections are of special importance. A protocol to optimize the order of speakers increases the efficient use of conference time. The guidelines worked well when used in a multisite research project and addressed the most important weak points of multipoint videoconferences using low-cost equipment.

Costs and Cost Analysis↗
PubMed1998

Inhibition of melanoma pulmonary metastasis by methylxanthines due to decreased invasion and proliferation.

Theophylline- and caffeine-treated B16-F10 cells exhibited low adhesion to laminin/collagen type IV and reduced invasion through Matrigel in an in vitro assay. In contrast, theobromine appeared ineffective. When young adult C57BL/6 mice were injected intravenously with theophylline-treated B16-F10 cells, the number of surface lung tumours was markedly reduced. Densitometric analyses performed on digitalized microscopic images of histological sections of lung were used to estimate the frequency (number of lung foci; NLF) and the size (average area of metastatic foci; AMF) of the resulting tumour foci. These parameters were correlated to the proliferation (AMF) and invasion (NLF) of melanoma cells in vivo. The data showed a similar theophylline-induced decrease in the AMF and NLF values (71%, P < 0.01). Caffeine treatment produced a more pronounced decrease in the AMF (61%, P < 0.01) than in the NLF (25%, P < 0.01). To our knowledge, this is the first demonstration that theophylline and caffeine possess the capacity to inhibit not only cell proliferation, but also the metastatic behaviour of melanoma cancer cells.

Animals↗
PubMed1993

Modulation of the expression of galactose-specific receptors on Kupffer cells after partial hepatectomy and zymosan stimulation.

Partial hepatectomy (PH) and a single intravenous injection of zymosan were used to provoke expansion of the Kupffer cell population in rat liver. The number of Kupffer cells per unit of area of liver increased after both stimulations. During these growth phases the number of binding sites for galactose-exposing ligands was studied on Kupffer cell plasma membranes. Both partial hepatectomy and zymosan stimulation affected the binding of lactosylated bovine serum albumin conjugated to gold particles (LacBSA-Au5). The reduction observed depended on the time after the PH or zymosan injection studied. Low levels of binding sites were found at 24 h from PH and 5 days after zymosan stimulation and represented only 1/4 or 1/10 of the binding sites expressed on the cell surface of Kupffer cells from normal adult rats. In addition, in both experimental situations we observed that the clustered distribution of gold particles typical of adult Kupffer cell was changed.

Animals↗
PubMed1993

Galactose-specific receptor modulation related to the onset of apoptosis in rat liver.

The expression of the asialoglycoprotein receptor of hepatocytes and the galactose-specific receptors of non-parenchymal liver cells during the onset of apoptosis in liver of rats treated with lead nitrate was studied. During the involution of lead nitrate-induced hyperplasia in rat liver (occurring at 5 days after the injection) a significant increase of asialoglycoprotein receptor (ASGP-R) expression on hepatocytes coincided with the massive death by apoptosis of the same cells. The increase in the receptor expression was sustained by a large increase in the level of its specific mRNA. As a consequence of lead nitrate injection, we also detected a drastic change of the galactose-specific receptor expression and distribution on the surface of rat liver sinusoidal cells. However, the modulation of the receptor expression on the Kupffer cells did not parallel that observed for the ASGP-R: the peak of surface expression measured on hepatocytes always followed the one observed on Kupffer cells. Our data show a first evidence of a receptor modulation during the process of apoptosis. In fact, the entire carbohydrate recognition system of the liver is modulated during the onset of apoptosis induced by lead nitrate injection, but the pattern of modulation depends on the cellular types. We suggest that a physiological role for the hepatic carbohydrate recognition systems is related to the apoptosis of liver.

Animals↗
PubMed1991

Chick hepatic lectins: an electron microscopic study on isolated hepatocytes during development.

We studied the carbohydrate recognition systems of hepatocytes isolated from 16-day-old embryos, 19-day-old embryos and chicks within 24 h of hatching. We localized and quantified at the ultrastructural level the binding sites for glycoproteins exposing terminal N-acetylglucosamine (GlcNAc), mannose and N-acetylgalactosamine (GalNAc) residues by means of protein-gold complexes. Binding sites specific for GlcNAc and mannose residues are present on hepatocytes from embryos and chicks. On the contrary GalNAc specific binding sites are exclusively observed on cells from 16-day-old embryos. The number and distribution of gold particles on hepatocyte cell surfaces depend on the binding sites and the age considered. We describe a modulation in the number of GlcNAc, and mannose specific receptors present on the cell surface between the embryonal stage and neonatal life.

Animals↗
PubMed1990

Carbohydrate recognition systems in avian sinusoidal liver cells.

We studied the carbohydrate recognition systems on liver sinusoidal cells of adult chicken and 20-day-old embryos. We localized and quantified the binding sites for glycoproteins exposing terminal N-acetylglucosamine (GlcNAc), mannose and galactose (Gal) residues. Sinusoidal liver cells from animals of both ages express on their cell surfaces binding sites for GlcNAc, mannose and galactose residues, while hepatocytes bind glycoproteins with GlcNAc residues. The gold particles distribution on Kupffer cells depend on the binding sites and the age considered. Binding sites for GlcNAc and Gal residues are generally present as clusters of gold granules, while mannose-specific binding sites are always as single gold granules. Ligand-gold complexes bound on endothelial cells are always present on the coated regions of the cell surface. The number of GlcNAc and Gal-specific receptors expressed on the cell surface of Kupffer cells undergoes modifications between embryonal and adult life.

Acetylglucosamine↗
PubMed1985

Alteration of erythrocyte membrane lipid fluidity in human obesity.

The lipophilic probe 1,6-diphenyl-1,3,5-hexatriene was incorporated into erythrocyte ghosts of either normal or obese humans, and the polarization of fluorescence was measured between 0 and 40 C. The membrane lipid fluidity, evaluated by fluorescence polarization, was consistently higher in the ghosts from obese subjects. A strong correlation was found between increased 1,6-diphenyl-1,3,5-hexatriene fluorescence polarization and excess body weight. Measurements of cholesterol and phospholipids indicated increased cholesterol and decreased phospholipids in erythrocyte ghosts from obese subjects. These data suggest that alterations in lipid composition in erythrocytes of obese subjects are responsible for abnormal physical properties of plasma membranes, which, in turn, may cause altered enzymatic activities.

Adolescent↗