PubMed Health⌕ Search

Biomedical subjects

M Maggini

Publications and source records attributed to M Maggini.

At least 19 recordsLinked to original sources
PubMed2005

Recursive neural networks for processing graphs with labelled edges: theory and applications.

In this paper, we introduce a new recursive neural network model able to process directed acyclic graphs with labelled edges. The model uses a state transition function which considers the edge labels and is independent both from the number and the order of the children of each node. The computational capabilities of the new recursive architecture are assessed. Moreover, in order to test the proposed architecture on a practical challenging application, the problem of object detection in images is also addressed. In fact, the localization of target objects is a preliminary step in any recognition system. The proposed technique is general and can be applied in different detection systems, since it does not exploit any a priori knowledge on the particular problem. Some experiments on face detection, carried out on scenes acquired by an indoor camera, are reported, showing very promising results.

Computer Simulation↗
PubMed2005

Pisa syndrome in a cohort of Alzheimer's disease patients.

Three Alzheimer's disease patients with Pisa syndrome were presented. These patients were treated with cholinesterase inhibitors within a post-marketing surveillance study. The clinical and pharmacological histories of these patients suggest a relation between cholinesterase inhibitors and the pleurothotonus. The diffuse use of cholinesterase inhibitors in the treatment of dementia may cause an increasing number of Pisa syndrome cases.

Aged↗
PubMed2003

Secondary prevention of coronary artery disease in high-risk diabetic patients.

BACKGROUND AND AIM: To compare guideline implementation and the actual delivery of secondary prevention for coronary artery disease in the cohort of Italian diabetic patients enrolled in the DAI study. METHODS AND RESULTS: The DAI study is a multicentre cohort study of the prevalence and incidence of macroangiopathic events among 19,570 type 2 diabetic patients attending 201 Diabetic Care Units. For this study, we selected 1,475 subjects with a history of myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty at enrollment. Only 25% of the coronary patients in secondary prevention were receiving lipid-lowering drugs, and 20% were receiving beta-blockers. None of the patients in 54/185 Diabetic Care Units were on statins, and none in 82/185 Units were on beta-blockers. Multivariate analysis showed a positive correlation between the number of treatments and the taking of statins, and a negative correlation with age. CONCLUSION: Our data highlight a gap between the therapeutic guidelines and actual treatment, with wide variability in the delivery of secondary prevention across Units. The out-of-pocket cost of medication, daily treatment burden and geographic area can be ruled out as possible explanatory factors. Physicians' prescription attitudes may be a possible reason.

Adrenergic beta-Antagonists↗
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↗
PubMed2001

A photosensitizer dinuclear ruthenium complex: intramolecular energy transfer to a covalently linked fullerene acceptor.

A fullerene derivative (5) in which a dinuclear ruthenium complex is covalently linked to a fulleropyrrolidine (FP) through a rigid spacer has been prepared through azomethine ylide cycloaddition to C60. Electrochemical and photophysical studies revealed that ground-state electronic interactions between the bimetallic ruthenium chromophore and the FP moiety are small. The absorption spectrum of 5 displays a metal-to-ligand charge transfer (MLCT) transition at about 620 nm in CH2Cl2 which is shifted by nearly 160 nm relative to that of a previously reported mononuclear dyad (8). The photophysical investigations have also shown that both in dichloromethane and acetonitrile the photoexcited MLCT state of dyad 5 transforms into the fullerene triplet excited state with a quantum yield of 0.19 and that, contrary to mononuclear dyad 8, electron transfer, if any under the applied conditions, is negligible relative to energy transfer.

Carbon↗
PubMed1999

Use of amoxicillin and amoxicillin-clavulanic acid and hospitalization for acute liver injury.

Increase of acute liver injury in patients taking amoxicillin-clavulanic acid (co-amoxiclav) as compared to those taking amoxicillin has been suggested. To further investigate the potential hepatotoxicity of the two drugs a historical cohort study was conducted in the Italian region of Friuli-Venezia Giulia. One hundred and eighteen potential cases of acute liver injury were identified through the regional hospital information system and medical records were reviewed for all of them. Overall, 12 cases of acute liver injury were identified: 3 cases occurred in the amoxicillin exposure category, 2 among co-amoxiclav group, and 7 in the non-use category. The adjusted estimate of the rate ratio was 5.7 (CI 95% 1.5-22.1) among users of amoxicillin alone and 6.2 (CI 95% 1.3-29.7) among users of co-amoxiclav.

Acute Disease↗
PubMed1998

Trans-cis amide bond isomerization in fulleroprolines.

The 1H NMR study of fulleroproline derivative Ac-Fpr-OtBu and its Pro analogue Ac-L-Pro-OtBu over a range of temperatures in toluene-d8 solution has enabled the comparison of their equilibrium and activation parameters for the trans/cis interconversion around the amide partial double bond.

Bacterial Proteins↗
PubMed1998

Ketorolac use in outpatients and gastrointestinal hospitalization: a comparison with other non-steroidal anti-inflammatory drugs in Italy.

OBJECTIVE: To compare the risk of hospitalization for gastroduodenal ulcer associated with the use of ketorolac and other non-steroidal anti-inflammatory drugs (NSAIDs). METHODS: A cohort and a nested case-control study were carried out. All residents in the region of Umbria (Italy), aged 35-84 years, who had been given at least one NSAID prescription in 1993 and 1994 were identified. Exposure to drugs was ascertained through a drug prescription database. We estimated rate ratios of hospitalization for gastroduodenal ulcer with or without complications in the current, recent or past period according to exposure to different NSAIDs. RESULTS: Rate ratio estimates, adjusted for age and sex, were 2.8 for any current NSAID and 1.4 for any recent NSAID. The highest rate ratios of lesions of any severity for current NSAID use were observed for piroxicam (RR: 4.6) and ketorolac (RR: 3.4). For gastrointestinal haemorrhage or perforation the highest rate ratios were those for ketorolac (RR: 5.9) and piroxicam (RR: 4.8). Rate ratio estimates did not change after adjustment for concomitant use of gastrotoxic drugs, use of gastroprotective agents not associated with NSAIDs and prior use of NSAIDs. CONCLUSION: Our study demonstrates the need to adhere to the restrictions relating to the indications and duration of use of ketorolac. At present piroxicam represents a greater public health concern since it is confirmed to be among the most gastrotoxic NSAIDs and is one of the most commonly prescribed NSAIDs in Italy.

Adult↗
PubMed1997

Beta-turn induction by C60-based fulleroproline: synthesis and conformational characterization of Fpr/Pro small peptides.

We have recently described the preparation of Fpr (C60-based fulleroproline). In this paper the synthesis and a conformational characterization of heterochiral di- and tripeptides containing this new alpha-amino acid are reported. A folded structure, induced by the -L-Fpr-D-Ala-sequence in chloroform solution and detected by Fourier transform infrared absorption and 1H nuclear magnetic resonance, has been compared with the known propensity of the cognate -L-Pro-D-Ala-sequence to adopt a beta II-turn conformation, which has also been confirmed in this work. The beta II-turn structure is retained in the crystal state by the Pro-peptides, as shown by the X-ray diffraction structures of Ibu-L-Pro-D-Ala-NHtBu and Z-L-Pro-D-Ala-L-Ala-OtBu.

Bacterial Proteins↗
PubMed1997

[Patterns of use of hormone replacement therapy in 2 Italian populations].

We analysed the pattern of hormone replacement therapy (HRT) use, over the period 1990-92, in a random sample of 76,537 women (45-74 years old) resident in the province of Rome, and in 1994 among all women (45-74 years old) resident in the Umbria region; data were collected through the regional drug prescription monitoring systems. During the three-year period an estimated 3.8% of women were prescribed HRT, among these 42% received estrogen with concomitant progestin therapy. The prevalence of use increased from 1.5% in 1990 to 2.2% in 1992 mainly because of an increased use of skin patches. In the Umbria region, out of the 166,112 women, 2.1% received at least one estrogen prescription. The prevalence of use increased in younger age classes but is almost unchanged over the sixties.

Aged↗
PubMed1996

Drug prescription in Italy.

Drug use in Italy in the period 1983-1991 has been analysed. The twenty most used substances accounted for about 20% of the sold packages. The effect of marketing of new drugs is worth noting: new and more expensive drugs are preferred even when effective, safe and less expensive alternatives are available. Prescribers have to face a highly dynamic pharmaceutical market in which 30% of substances (among the 300 most sold) changes every five years. Other than a more rational formulary, independent information and continuing education have to be considered as tools to improve a more rational prescribing.

Cost-Benefit Analysis↗
PubMed1995

Gangliosides and Guillain-Barré syndrome.

Cases of Guillain-Barré syndrome (GBS) associated with parenteral use of gangliosides have been reported in several European countries. To evaluate the hypothesis of association between ganglioside exposure and occurrence of GBS, a case-control study was conducted. GBS cases discharged during 1989 from public and private hospitals in three Italian provinces were identified: 42 GBS cases and 420 controls matched on age and gender were enrolled. Data of onset of symptoms of GBS was taken from clinical records. Exposure status of subjects was ascertained through the regional computerized drug prescription monitoring system. The odds ratio of association between ganglioside use, in the 30 days prior to onset of symptoms, and GBS was 9.1 (95% confidence interval 2.8-29.4). Although there are formidable difficulties in distinguishing prodromal therapy of GBS from drug causation, the association with ganglioside therapy is strong and supportive of the hypothesis of a role of ganglioside preparations in the occurrence of GBS.

Adult↗
PubMed1995

Gastroduodenal toxicity of different nonsteroidal antiinflammatory drugs.

Although the etiologic relation between nonsteroidal antiinflammatory drug (NSAID) use and gastrointestinal lesions is well documented, newly introduced NSAIDs deserve a fresh examination for their risk/benefit ratio. To estimate the association between consumption of ketorolac and the occurrence of gastroduodenal lesions, we conducted a case-control study. The study population comprised 600 outpatients with a confirmed endoscopic diagnosis of ulcer and erosion in 1991 and 1992 and 6,000 community controls matched by age and sex. We retrieved the prescription history through a computerized prescription monitoring system. We defined exposure to each study drug as "current" (month of endoscopy and preceding month), "recent" (second or third month preceding endoscopy). and "past" (fourth to sixth month preceding endoscopy). Current users of NSAIDs showed a 30% increase in the incidence of gastroduodenal lesions [odds ratio (OR) = 1.3; 95% confidence interval (CI) = 0.98 - 1.8] after adjustment for recent or past use of any NSAID, recent or past gastrotoxic therapy, recent or past use of gastroprotective drugs, and recent or past use of any other drug. Among NSAIDs, ketorolac was the only one showing a distinctly elevated risk of gastroduodenal lesions (OR = 4.2; 95% CI = 1.9-9.4). Current use of any NSAID was associated with almost a doubling of risk for ulcer alone (OR = 1.9; 95% CI = 1.3-3.0); no elevation in risk was found for erosions. The adjusted relative risk for ulcer associated with current use of ketorolac was 9.8 (95% CI = 3.4-28.10. Recent and past use of NSAIDs does not increase the risk of ulcer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

A bioactive fullerene peptide.

The highly hydrophobic C60 (buckminsterfullerene) was water solubilized by covalently linking the synthon 1,2-dihydro-1,2-methanofullerene [60]-61-carboxylic acid to the alpha-amino group of the hydrophilic 4-8 sequence of peptide T, known to display potent human monocyte chemotaxis. The resulting compound, characterized by a variety of analytical techniques, including a UV spectrum in aqueous solution, exhibits remarkable chemotactic potency, comparable to that of the parent pentapeptide. Furthermore, this fullerene-peptide conjugate inhibits, albeit weakly, HIV-1 protease.

Amino Acid Sequence↗
PubMed1993

Cancer mortality in ethylene oxide workers.

A cohort of 1971 chemical workers licensed to handle ethylene oxide was followed up retrospectively from 1940 to 1984 and the vital status of each subject was ascertained. No quantitative information on exposure was available and therefore cohort members were considered as presumably exposed to ethylene oxide. The cohort comprised 637 subjects allowed to handle only ethylene oxide and 1334 subjects who obtained a licence valid for ethylene oxide as well as other toxic gases. Potential confounding arising from the exposure to these other chemical agents was taken into consideration. Causes of death were found from death certificates and comparisons of mortality were made with the general population of the region where cohort members were resident. Seventy six deaths were reported whereas 98.8 were expected; the difference was statistically significant. The number of malignancies for any site exceeded the expected number (standardised mortality ratio (SMR) = 130; 43 observed deaths; 95% confidence interval (95% CI) 94-175) and approached statistical significance. For all considered cancer sites the SMRs were higher than 100 but the excess was only significant (p < 0.05, two sided test) for lymphosarcoma and reticulosarcoma (International Classification of Diseases--9th revision (ICD-9) = 200; SMR = 682; four observed deaths; 95% CI 186-1745). The excess of cases for all cancers of haematopoietic tissue (ICD-9 = 200-208) also approached statistical significance (SMR = 250; six observed deaths; 95% CI 91-544). Focusing the analysis on the subcohort of the ethylene oxide only licensed workers, who are likely to have experienced a more severe exposure to this gas, it became evident that all but one of the observed cases of haematopoietic tissue cancers in the cohort were confined to this subgroup, enhancing the relevant SMR to 700 (95% CI 237-1637) and the SMR of lymphosarcoma and reticulosarcoma to 1693 (95% CI 349-4953).

Adult↗