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P V Carlevaro

Publications and source records attributed to P V Carlevaro.

8 recordsLinked to original sources
PubMed1991

Atherometric system. A suitable methodology to characterize atherosclerotic lesions in any artery or group of patients.

The atherometric system (AS) is a set of methods and procedures derived from a group of interdependent and strongly interrelated variables, resulting from certain biophysical (rheological, geometrical, hemodynamic) and mathematical considerations and reasonings. The variables of the AS are divided into two groups: the arterial and the organ-related variables. Each of them is subdivided into (a) descriptive variables, since correct use of them and their different combinations will enable proper examination of all pathomorphological and pathophysiological alterations to arteries and to atherosclerotically affected organs and (b) weighting indices which yield accurate prediction of the atherosclerotic process, its severity and consequences. The AS is a tool for medical and biological investigations in relation with any vascular disease due to atherosclerosis. It is useful for etiological, pathogenetical, pathomorphological, morphometrical, pathophysiological, biochemical, and epidemiological studies. Also it has proved its facilities for experimental studies with a view to elucidating possible effects of therapeutic action and effectiveness of pharmaceuticals to which anti-atherogenetic or anti-atherosclerotic activities are attributed.

Arterial Occlusive Diseases↗
PubMed1991

Atherosclerotic lesion of the circle of Willis: its study applying an atherometric system using multivariate statistical techniques.

In 2043 autopsies divided into the high (HAG) and low (LAG) atherosclerosis group a set of variables of a new atherometric system (AS) was used to characterize the atherosclerotic lesion (AL) in the circle of Willis arteries: fatty streaks (X), fibrous plaques (Y), severe plaques (Z), index of stenosis (P) and index of benignity (B). Principal component analysis identified a first component of severity (Y, P and Z) and a second component of benignity (X and B). Fibrous plaques play the main role in the severity of AL in the circle of Willis. The new AS proved its usefulness in characterizing the state of AL, whereas discriminant analysis and AS distinguished between the HAG and the LAG. The classification was correct in 74.5% and 76.5% when using three (X, Y, Z) and five (X, Y, Z, P, B) variables, respectively.

Arteriosclerosis↗
PubMed1989

[The atherometric system].

Atherometric system designed for the evaluation of the atherosclerotic changes in the individual arteries and alterations in the organs affected is described. The system includes two groups of functions--arterial and organ-dependent. Using these interrelated functions and biophysical and mathematical methods it becomes possible to estimate quantitatively pathomorphological and pathophysiological changes in the arteries and organs supplied by them.

Arteries↗
PubMed1989

Atherometric system: morphometric standardized methodology to study atherosclerosis and its consequences.

A group of strong mutual dependent variables, obtained by measuring some morphological and pathomorphological characteristics of an artery affected by atherosclerosis (arterial variables) and its organ-related damage (organ-related variables DRV), yield a suitable methodology to study and characterize this disease and its further severe consequences. Applying some biophysical (rheological, geometrical, and haemodynamical) and mathematical reasonings to those measurements an atherometric system AS is derived. It is a new standardized morphometric methodology which allows, by the use of their variables, the development of useful pathomorphological, pathogenetical, statistical, and epidemiological investigations. The variables of the AS are divided into 1. descriptives and 2. weighting indices WI to estimate the severity of atherosclerosis. The descriptive arterial variables were obtained from each type of atherosclerotic lesion AL, fatty streak, fibrous plaque, and severe (complicated and calcified) plaques, latter normalize and further represented in a 3-dimensional vector, in order to conserve all the analytical information of each type of AL. Their WI are obstruction, stenosis, and benignity. The descriptives DRV (estimated volumes) and their respectively derived WI, are in relation with the pathological conditions: fibrosis, necrosis, haemoŕrhage, total damage, and their counterpart non-affected (sufficient) variables. A digitizer coupled to a personal computer LTEL (Cuba) to obtain the primary data was used. All data were processed in a computer EC-1040 (G.D.R.) using the statistical commercial package "SPSS" for scientific analysis.

Aorta, Abdominal↗
PubMed1988

Coronary atherosclerotic lesion: its characterization applying an atherometric system, using discriminant analysis.

A given set of autopsies (total 2043) divided into high and low atherosclerosis groups (HAG, LAG) according to the primary cause of death 1171 and 872 cases, respectively, was studied by an atherometric system. The variables of this system characterize the pathomorphological changes, i.e. fatty streaks (X), fibrous plaques (Y) and severe (complicated and calcified) plaques (Z) of atherosclerosis. In the present study were also included two indices, stenosis (P) and benignity (B), applicable for estimation of the severity of the process. In order to verify the discrimination between the HAG and LAG groups the utility of the classification should be demonstrated. The three main branches of the coronary arteries, right (RC), left anterior descending (LAD) and left circumflex (LC), were examined. Qualitative and quantitative analyses of the different vascular changes were made by means of a digitizer coupled to a personal computer NEC 9801 (Japan). The data were processed in a computer EC-1040 (GDR). The multivariate statistical techniques, including discriminant analysis were used applying the "SPSS" commercial statistical package programme. The atherometric system proved to be useful to distinguish between HAG and LAG. Correct classification was in all cases greater than 70% except for LC (68%). The three variables X, Y and Z were capable to separate the groups. The stenosis and benignity indices proved to be the most effective for discrimination. The sign of benignity index discriminating function is always the same of the LAG. This variable is indeed one to indicate benignity. The coherence and consistency of the atherometric system developed was proved by discriminant analysis.

Coronary Artery Disease↗
PubMed1987

Atherosclerotic lesion of the aorta: its study applying a biometric system using multivariate statistical techniques.

UNLABELLED: To study the atherosclerotic lesion (a.l.) in the two aorta segments (thoracic and abdominal) in a given set of autopsies (total 2043) performed during five years (1981-85) in one of the principal general hospitals in the city of Havana, a set of five variables was used as part of a new biometric system (BS), to characterize the a.l. in any vascular sector. Three of these variables represent the main types of a.l., fatty streaks (X), fibrous plaques (Y) and severe (complicated and calcified) plaques (Z), while the others were indices of stenosis (P) and benignity (B). Classical dissection and pathological laboratory procedures were performed. Qualitative and quantitative gross morphometric analyses were done by a digitilizer joined to a NEC (9801) personal microcomputer (Japan). These data were processed in a medium size computer EC-1040 (GDR). The multivariate statistical techniques, the principal component analysis (PCA) and the discriminant analysis (DA), were used applying the "SPSS" programme. CONCLUSIONS: (1) PCA revealed in the two aorta segments studied a first component of benignity, fatty streaks (X) and benignity index (B) and a second component of severity, severe plaques (Z) and stenosis number (P). Because of the dimensions of the two aorta segments (width and length) the dominant, first component, is benignity. So the BS is useful in characterizing and describing the lesional state of any aorta segments; (2) DA and BS proved to be useful to distinguish between the high atherosclerotic group (HAG) and the low atherosclerotic group (LAG). The correct classification rate exceed in all cases 70%. The three components of the lesional state vector (X,Y,Z) distinguish the groups. The stenosis (P) and benignity (B) indices proved to be most relevant. The sign of benignity index is always the same as that of the LAG. Thus this variable truly represents benignity. The coherence and consistency of the BS was also proved by DA.

Aorta, Abdominal↗
PubMed1987

The lesional state vector: a new approach to characterize atherosclerotic lesions.

A new approach to study the atherosclerotic lesions (AL) applying a vectorial system is presented. The "lesional state vector" (LSV) is formed by using as vectors the three main types of AL, e.g. fatty streak, fibrous plaque and severe plaque (complicated and calcified considered together) as the coordinates. This vectorial representation is part of a biometric system described in 1982 by Carlevaro and Fernández-Britto, to characterize the AL in any vascular sector or group of patients. The LSV is a suitable tool to study the AL since it conserves all the information available as primary data and it is extremely useful for comparative studies applying different statistical techniques, including multivariate approaches. To demonstrate its advantage, we studied the coronary vessels (right, left anterior descending and left circumflex arteries), the cerebral arteries (circle of Willis) and the aorta (thoracic and abdominal segments) in 2,043 autopsies performed during 5 years (1981-1985). The patients were classified according to the primary cause of death, as high atherosclerotic (HAG) or low atherosclerotic groups (LAG), comprising 1,171 and 872 cases, respectively. Qualitative and quantitative gross analysis were done by a digitizer joined to a personal computer (NEC 9801, Japan). These data were processed on computer ES 1040, GDR. The statistical techniques applied (including the multivariate analysis) were those available in the Statistical Package for Social Sciences (SPSS). Applying the LSV to the arteries studied it was found that in the coronary arteries and in the circle of Willis, the severe plaque and the fibrous plaque played the most important roles, respectively. Graphic representation can make differentiation between HAG and LAG easy.(ABSTRACT TRUNCATED AT 250 WORDS)

Arteriosclerosis↗