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Biomedical subjects

A Evangelisti

Publications and source records attributed to A Evangelisti.

At least 19 recordsLinked to original sources
PubMed2002

EEG signal processing in anaesthesia. Use of a neural network technique for monitoring depth of anaesthesia.

BACKGROUND: The Bispectral Index (BIS) is a proprietary index of anaesthesia depth, which is correlated with the level of consciousness and probability of intraoperative recall. The present study investigates the use of a neural network technique to obtain a non-proprietary index of the depth of anaesthesia from the processed EEG data. METHODS: Two hundred patients, who underwent general abdominal surgery, were recruited for our trial. For anaesthesia we used a total i.v. technique, tracheal intubation, and artificial ventilation. Fourteen EEG variables, including the BIS, were extracted from the EEG, monitored with an EEG computerized monitor, and then stored on a computer. Data from 150 patients were used to train the neural network. All the variables, excluding the BIS, were used as input data in the neural network. The output targets of the network were provided by anaesthesia scores ranging from 10 to 100 assigned by the anaesthesiologist according to the observer's assessment of alertness and sedation (OAA/S) and other clinical means of assessing depth of anaesthesia. Data from the other 50 patients were used to test the model and for statistical analysis. RESULTS: The artificial neural network was successfully trained to predict an anaesthesia depth index, the NED (neural network evaluated depth), ranging from 0 to 100. The correlation coefficient between the NED and the BIS over the test set was 0.94 (P<0.0001). CONCLUSION: We have developed a neural network model, which evaluates 13 processed EEG parameters to produce an index of anaesthesia depth, which correlates very well with the BIS during total i.v. anaesthesia with propofol.

Abdomen↗
PubMed1999

Fat-free mass qualitative assessment with bioelectric impedance analysis (BIA).

Body composition studies, when based on two-compartment volumetric estimates, can hardly assess nutritional states. Phase-sensitive impedance analysis can be used to reflect directly the proportions between intra- and extracellular spaces (ECM/BCM), which is one of the most sensitive indexes of malnutrition. Resistance and reactance values actually measured with BIA are referred to as the series RC model; however, due to the morphology of the FFM, which is composed of cells surrounded by interstitial fluids, in reality this should be modeled as a parallel RC circuit. A nomogram developed with series-to-parallel transformations of resistance and reactance measured with commercial BIA on controls and patients shows interesting gender and disease sensitivity and specificity.

Anorexia Nervosa↗
PubMed1999

Is there any relationship between cold-induced vasodilatation and vasomotion?

There are many analogies between cold-induced vasodilatation (CIV) and vasomotion (VM), but the demonstration of any relationship between these two microvascular homeostatic reactions is to date lacking. In a group of seven controls and seven patients with Raynaud phenomenon in the vasomotor stage of the disease, we studied, by means of laser Doppler fluxmetry, the fingertip flow at room temperature (15 min), during hand immersion into cold water (0-6 degreesC, 30 min), and at room temperature again (15 min). The Fourier spectral analysis of the laser Doppler signal revealed in both groups two different patterns of the fingertip flow oscillations: the first was characterized by continued oscillations with small amplitude and median frequency of 2-8 cycles/min occurring both at room temperature and during cold stimulation. The second was characterized by continued oscillations of high amplitude and median frequency of 1 cycle/4-6 min occurring during cold stimulation only. The first pattern of flow oscillations still occurred during the second. The high-frequency oscillations are similar to the waves of vasomotion and the low-frequency oscillations are similar to the waves of cold-induced vasodilatation. Because 90-98% of the fingertip flow passes through arteriolar-venular anastomosis (AVAs), our results suggest that the CIV flow oscillations may be an expression of the AVA's VM.

Adult↗
PubMed1996

Relevance of postprandial glycosuria in survey for diabetes mellitus.

Since the oral glucose tolerance test is not applicable in large surveys for diabetes mellitus, economic tests or clinical criteria are required to select subjects needing a complete glycometabolic assessment. This study evaluated, in a selected high risk population (110 subjects; 71 males; median age: 53 years, range 30-70), the utility of glycosuria after a meal rich in carbohydrates in the detecting of diabetes, compared to other tests for glycosuria (fasting glycosuria, glycosuria after a glucose load) and clinical criteria (diabetic family history, overweight and their combination). For each test and, retrospectively, for clinical criteria, sensitivity, sensibility, predictive value positive (PVP) and predictive value negative (PVN) were calculated. Postprandial glycosuria resulted to be an effective approach (sensitivity: 100%; specificity: 44%; PVP: 23%, PVN: 100%) in people over 50 years old, in which both clinical criteria (sensitivity: 22-78%; PVN: 81-90%) and fasting glycosuria (sensitivity 11%; PVN: 86%) proved defective. In younger subjects both the presence of fasting glycosuria (sensitivity: 100%; specificity: 96%; PVP: 33%; PVN: 100%) and of relevant diabetic family history (sensitivity: 100%; specificity: 85%; PVN: 100%) proved more adequate as screening procedures.

Adult↗
PubMed1995

[Acute hepatotoxicity from amiodarone].

The functional and histological liver alterations induced by amiodarone treatment have been well known for some time and often consist in isolated increases in transaminase levels during long-term treatment. Secondary phospholipidosis was observed in these cases, an alteration which suggests the presence of toxic damage. Reports in the literature also indicate acute liver intoxication, including a number of fatal cases. This paper reports the finding of acute alterations of laboratory parameters indicative of hepatocytonecrosis with alterations of protein synthesis capacity following the first dose of the drug and which regressed after its suspension. On the basis of a review of the literature the authors propose that, in addition to a dose-dependent toxic mechanism, immunogenic or idiosyncratic mechanisms may also play a role in the onset and manifestation of acute liver intoxication by amiodarone.

Acute Disease↗
PubMed1993

Zinc supplementation restores plasma concentrations of zinc and thymulin in patients with Crohn's disease.

The aim of this work was to evaluate whether oral supplementation with zinc sulphate (ZnSO4) could restore thymic endocrine function in patients with Crohn's disease who showed decreased plasma concentrations of zinc and active thymulin, a zinc-dependent thymic hormone. Twenty-seven patients in clinical remission were randomly assigned to receive, for 3 months, one of the following treatments: 60 mg/day ZnSO4; 200 mg/day ZnSO4 or placebo. Plasma thymulin activity and zinc concentrations significantly increased only in patients treated with 200 mg/day ZnSO4. Lymphocyte subpopulations, within the range of normality before zinc supplementation, were unaffected by any of the administered treatments. In conclusion, low plasma concentrations of zinc and thymulin in Crohn's disease patients were restored by the administration of high doses of zinc.

Adult↗
PubMed1992

Influence of steroid treatment's duration in patients with active Crohn's disease.

Steroids are very useful drugs in the treatment of active Crohn's disease (CD), but clinical relapses after steroid withdrawal may be very high. We investigated the efficacy of two steroid regimens of different duration in inducing remission and in maintaining it after drug suspension. Patients with active CD were randomly assigned to scheme A, lasting 7 weeks (27 patients), or to scheme B, lasting 15 weeks (27 patients). Remission rates at the end of the treatment were 81% for scheme A and 85% for scheme B. Relapse rates at 6 months after stopping the treatment were 50% (11 patients) and 52% (12 patients), respectively. Remission rates seem not to be influenced by the duration of the treatment, but patients recently treated with steroids showed a higher relapse rate if they received the short-duration treatment.

Adult↗
PubMed1989

[A new lining material, B-tricalcium phosphate MG substitute].

Powder of not-sintered beta-tricalcium phosphate granules was used as capping material in deep cavities of monkey and human teeth. The authors have demonstrated by SEM with E-DAX the dispersion of beta-TCP in the dentinal tubules and in predentin. Histological sections didn't show any inflammation or degeneration of the pulp.

Animals↗
PubMed1989

[Surface polishing of posterior composites].

In this research we have valued at SEM the smoothness degree of the surface obtained in vitro on three kinds of composite resins for posterior restoration (P-30, P-50, Clearfil Photo Posterior); then we have compared it with the result obtained in vitro with an alloy not gamma-2 (Dispersalloy). The surfaces of the composite restorations show at SEM irregularities more or less accentuated for the presence of particles of filling got in comparison with the matrix. The surface of alloy restorations results on the contrary perfectly polished and completely comparable with the enamel surface.

Bicuspid↗
PubMed1983

[Construction of a genome library from a beta-0-thalassemic individual from Ferrara: characterization of clones containing beta globin genes].

A library of genomic DNA was prepared from a patient with beta o Ferrara thalassaemia: random human DNA fragments (15 - 20 Kb) have been joined to phage lambda vectors and cloned has viable phage particles (4). 4x10(5) phages have been screened for their content in beta globin gene sequences, using a human beta cDNA plasmid (5) as hybridization probe. Five positive clones have been isolated and characterized by restriction endonuclease cleavage analysis and by the hybridization experiments. The results obtained allow the precise localization of the human fragments inside the beta like globin gene cluster (6). The comparison of the thalassaemic fragments with the normal DNA (6 - 7) shows two different restriction endonuclease sites, for Xba I and Eco RI respectively, downstream from the human beta globin gene.

Cloning, Molecular↗
PubMedDate not supplied

The Doppler ophthalmic test: report of a study on its value in diagnosis of internal carotid artery insufficiency.

The Authors have investigated the significance and the limits of the directional Doppler method in a group of subjects affected by internal carotid obstruction in various sites and degree. On the basis of the obtained results the Authors point out how this method represents a concrete progress in the field of non invasive diagnosis of the insufficiency of this artery.

Arterial Occlusive Diseases↗