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P Prati

Publications and source records attributed to P Prati.

17 recordsLinked to original sources
PubMed2006

Mannheim carotid intima-media thickness consensus (2004-2006). An update on behalf of the Advisory Board of the 3rd and 4th Watching the Risk Symposium, 13th and 15th European Stroke Conferences, Mannheim, Germany, 2004, and Brussels, Belgium, 2006.

Intima-media thickness (IMT) is increasingly used as a surrogate end point of vascular outcomes in clinical trials aimed at determining the success of interventions that lower risk factors for atherosclerosis and associated diseases (stroke, myocardial infarction and peripheral artery diseases). The necessity to promote further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is expressed through this updated consensus. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is based on physics, technical and disease-related principles as well as agreements on how to perform, interpret and document study results. Harmonization of carotid image acquisition and analysis is needed for the comparison of the IMT results obtained from epidemiological and interventional studies around the world. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from exceptions named, which emphasize that inside randomized clinical trials should be performed. Although IMT has been suggested to represent an important risk marker, according to the current evidence it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of randomized clinical trials incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Adult↗
PubMed2006

Activation measurement of the 3He(alpha,gamma)7Be cross section at low energy.

The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity, and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148, and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S factor to solar energies.

Journal Article↗
PubMed2006

Cognitive impairment and carotid atherosclerosis in a general Italian midlife and old population.

The authors describe the design and the general, ultrasonographic, neuropsychological methodology of an observational epidemiological population survey, named REMEMBER (Registry Evaluation Memory in Buttrio e Remanzacco) conducted in the northeast of Italy in a randomized stratified sample of 1,026 subjects (554 F and 472 M) aged 55-98 years. The study was planned as cross-sectional and longitudinal survey of cognitive impairment, cardiovascular risk factors, carotid atherosclerosis in a midlife and older Italian population sample. The objectives of the first phase are to assess the prevalence of the different types of dementia, the cognitive impairment non-dementia, the cardiovascular risk factors, the carotid intima-media thickness and arterial distensibility, and of depression. The conclusions of this study will make it possible to organize preventive and interventional strategies for these epidemic conditions.

Aged↗
PubMed2005

Elemental characterization of PM10, PM2.5 and PM1 in the town of Genoa (Italy).

The particulate matter (PM) concentration and composition, the PM10, PM2.5, PM1 fractions, were studied in the urban area of Genoa, a coastal town in the northwest of Italy. Two instruments, the continuous monitor TEOM and the sequential sampler PARTISOL, were operated almost continuously on the same site from July 2001 to September 2004. Samples collected by PARTISOL were weighted to obtain PM concentration and then analysed by PIXE (particle induced X-ray emission) and by ED-XRF (energy dispersion X-ray fluorescence), obtaining concentrations for elements from Na to Pb. Some of the filters used in the TEOM microbalance were analysed by ED-XRF to calculate Pb concentration values averaged over 7-30 d periods.

Air Pollutants↗
PubMed2005

Age-adjusted reference limits for carotid intima-media thickness as better indicator of vascular risk: population-based estimates from the VITA project.

BACKGROUND: An increase of carotid intima-media thickness (CIMT) has been demonstrated to be associated in many studies with the subsequent risk of cardio- and cerebrovascular events, but the threshold level of CIMT for an increased risk at different ages remains uncertain. OBJECTIVES: We aimed at establishing optimal reference limits associated with a definite increased vascular risk in the general population. METHODS: A cohort of 2580 subjects was enrolled in a population-based cross-sectional survey. CIMT was measured on both left and right common carotid arteries, and age-specific, percentile-based reference ranges for CIMT were computed together with the Framingham risk score. RESULTS: A significant, steady increase of CIMT reference ranges was observed within different age strata. CIMT levels were linearly related with an increase of the Framingham risk score, but after age-adjustment only the upper CIMT quintile was associated with a higher Framingham risk score. CONCLUSIONS: Age-specific reference limits provide better estimate of vascular risk in the population and correlation with established risk factors.

Age Distribution↗
PubMed2004

Mannheim intima-media thickness consensus.

Intima-media thickness (IMT) is increasingly used in clinical trials as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. The necessity for unified criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is addressed in this consensus statement. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of > or =1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from few exceptions. Although IMT has been suggested to represent an important risk marker, it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of studies incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Arteriosclerosis↗
PubMed2004

[Prevalence of Bartonella henselae in stray and domestic cats in different Italian areas: evaluation of the potential risk of transmission of Bartonella to humans].

Bartonella henselae is the major etiological agent of Cat Scratch Disease in humans. Cats act as the natural reservoir of B. henselae and can transmit the infection to humans by bite or scratch. The diffusion of B. henselae was evaluated by seroprevalence and bacteremic status in different stray cat populations located in nine areas of Northern Italy. A total of 1585 cats were tested by blood culture and 361 (23%) resulted bacteremic; 1416 out off 1585 cats were also tested for Bartonella henselae antibodies and 553 (39%) resulted seropositive. The molecular typing of the isolates showed that 26% of bacteremic cats were infected with B. henselae type I, 52% with B. henselae type II, 16% were co-infected with both and 5% infected with B. Clarridgeiae. Moreover 165 domestic cats were tested by blood culture and serological test (IFA test cut-off: 1:64). 35 cats (21%) resulted bacteremic and 49 (43.5%) were seropositive. The molecular typing of the Bartonella isolates of the domestic cats showed that 45% of bacteremic cats were infected with B. henselae type I, 36.5% with B. henselae type II, 12% were coinfected with both and 6% infected with B. Clarridgeiae. For a completely evaluation of health status of the cat for B. henselae infection, the authors suggest both blood culture and serological tests. Nevertheless a nonbacteremic cat with positive serology result should be reevaluated for possible recurrent bacteremia.

Animals↗
PubMed1994

The updated BESGE spectrometer for pure beta activities in environmental matrices.

This work describes an updated version of a beta spectrometer that measures pure beta emitter activities. The detection system consists of a plastic scintillator surrounded in a 4 pi geometry by large anticoincidence NaI(Tl) scintillators. A thin silicon detector, inserted between the plastic and the sample, helps to reduce the gamma background. A Monte Carlo code, used to calculate the quite complex spectrometer response function to any isotope, is also described.

Beta Particles↗
PubMed1993

Verification of the integral transformation of the projections technique for scatter correction in positron tomographs.

A scatter correction algorithm, based on the integral transformation of the projections, has been implemented when using the C.N.R. positron tomograph in Pisa. The performance of the method has been evaluated by measurements on ad hoc phantoms. The technique allows a significant average reduction of the reconstructed scatter fraction. The limitations of this approach have also been investigated.

Algorithms↗
PubMed1993

A personal dosimeter prototype for static magnetic fields.

A personal dosimeter prototype, for static magnetic fields with three Hall probes, has been designed and built to provide a reliable instrument for long-term analysis. The probe output signals, proportional to the magnetic flux density components of the vector B, are filtered, sampled, and stored in a buffer memory sufficient to cover a whole worker shift. The data sampling rate is high enough to record the operator movements within the fringes of the magnetic field. The content of the buffer memory is then transferred on a personal computer and registered on individual dosimetric cards. The data can be used for personal exposure monitoring.

Electromagnetic Fields↗
PubMed1992

A beta spectrometer for monitoring environmental matrices.

In environmental matrices, pure beta emitters are often present with other beta-gamma emitters. This work describes a beta spectrometer that allows measurement of pure beta-emitter activities of about 10(-2) Bq. The detection system consists of a plastic scintillator surrounded in a 4 pi geometry by large anticoincidence NaI(Tl) scintillators. Solid, liquid, and gaseous samples can be analyzed, and no chemical separation is necessary. The system is particularly useful for 90Sr measurement.

Beta Particles↗
PubMed1992

Prevalence and determinants of carotid atherosclerosis in a general population.

BACKGROUND AND PURPOSE: The aim of this study was to assess the prevalence of asymptomatic carotid atherosclerotic lesions and their relation to principal risk factors. The importance of the relation between asymptomatic carotid atherosclerotic lesions, stroke, and coronary atherosclerosis has been widely discussed, but there are few transversal and longitudinal studies on a general population. METHODS: A noninvasive examination was carried out using high-resolution B-mode ultrasonography, which has been shown to be a reliable tool for epidemiological studies. We examined 630 men and 718 women aged 18-99 years (participation rate, 74.9%). RESULTS: The global prevalence of carotid atherosclerosis was 25.4% in men and 26.4% in women. Intimal-medial thickening was found in 9.4% of men and 11.7% of women. Plaque prevalence was 13.3% in men and 13.4% in women; prevalence of stenotic plaques was 2.7% and 1.5%, respectively. Subjects aged < or = 39 years showed a very low prevalence of any asymptomatic carotid atherosclerotic lesions. In the multiple logistic regression, the analysis of subjects aged > or = 40 years showed a positive significant association between the severity of carotid atherosclerotic lesions (plaques and stenosis) and age (p < 0.001), systolic blood pressure (p < 0.01), cigarette smoking (p < 0.0001), and the protective effect of high density lipoprotein cholesterol (p < 0.037). This analysis did not provide evidence of a clear-cut association between risk factors and intimal-medial thickening. CONCLUSIONS: This population study shows the high prevalence of asymptomatic carotid atherosclerotic lesions in a general population (approximately 25% of adults) and its relation with the classic risk factors. It emphasizes the value of ultrasonography in the detection of early atherosclerotic lesions.

Adolescent↗
PubMed1992

Use of monitoring software to improve the measurement of carotid wall thickness by B-mode imaging.

METHODOLOGY: High-resolution B-mode imaging is a reliable, easily performed and non-invasive means of studying atherosclerosis in superficial blood vessels. Recently it has been used for in vivo studies on the thickness of the common carotid artery wall. It is very sensitive, although the results of practical investigations are highly dependent on both the operator and the direction and angle of ultrasound beams directed towards the vessel. PROTOCOL: We have assessed inter- and intra-observer reproducibility of the measurement of common carotid artery wall thickness in 13 subjects, using two procedures. The first was a standard echographical investigation. In the second procedure, the principal parameters recorded from the first investigation were used to reposition the beam with the same incident angle. RESULTS: Intra-observer variability (correlation coefficient, r = 0.61 for procedure 1 and r = 0.77 for procedure 2) and inter-observer variation (r = 0.58 for procedure 1 and r = 0.71 for procedure 2) were reduced when the second investigation was assisted by reproducibility software. CONCLUSIONS: The proposed method is a reliable and reproducible way of assessing combined intimal and medial wall thickness in the common carotid artery. It may be possible to improve reproducibility using specific software to aid the operator. Since the intimal and medial thickness of the common carotid artery appears to be a sensitive marker of vascular risk, the proposed standardized method of measuring these parameter may allow early detection and assessment of changes.

Aged↗
PubMedDate not supplied

An Italian chart for cardiovascular risk prediction. Its scientific basis.

A risk chart for primary prediction of major coronary and cerebrovascular events based on Italian population data was created. Material from three Italian population studies was available: the Italian Rural Areas of the Seven Countries Study (no. 1712), the Gubbio Study (no. 3061) and the ECCIS Study (no. 4998) for a total of 9771 men and women aged 35 to 74 years and followed-up from 5 to 15 years, for a total of over 55,000 person/years. Sex, age, diabetes, cigarette smoking, systolic blood pressure and serum cholesterol were selected as risk factors, while the endpoint was established as the occurrence of the first major coronary or cerebrovascular event in 10 years. The accelerated failure time model was used as the predictive model. Two models were adopted, i.e., for relatively younger subjects (45-59 years) and for relatively older subjects (60-74 years). Both produced highly significant coefficients for each of the selected risk factors. The two models carried a satisfactory discriminating power, with 40% to more than 50% of all events located in the upper quintile of the estimated risk. Sex, age (6 classes), diabetes, cigarette smoking (4 classes), systolic blood pressure (4 classes) and serum cholesterol (5 classes) were considered for the creation of a risk map derived from multivariate models. A total of 1920 cells were filled with different colors corresponding to 6 classes of absolute risk. A similar set of cells was filled with another color scale for the estimate of the relative risk versus subjects of the same age and sex carrying Italian mean levels of risk factors. The chart is being distributed to the Italian medical profession as a practical tool to select high-risk individuals for the primary prevention of major cardiovascular diseases.

Aged↗