Biomedical subjects

C Velican

Publications and source records attributed to C Velican.

At least 19 recordsLinked to original sources

PubMed1989

Are routine autopsy protocols adequate for accurate appraisal of coronary atherosclerosis?

Atherosclerotic involvement of 1,106 coronary arterial trees was investigated by means of gross inspection, light microscopy, and the method of successive observations of similar topographic sites placed in sequence according to age, sex, cause of death, and anatomic branching pattern. The results obtained, based on strict adherence to routine autopsy protocols, were compared with control studies, which demonstrated that such strict adherence had constrained us to overlook the following aspects: a) existence of particular anatomic branching patterns, such as those of atherogenic character and/or involved in onset of myocardial ischemia; b) development of obstructive plaques in coronary branch vessels; c) presence of obstructive lesions in vessels which supply the conduction system; d) the obstructive character of platelet and fibrin microemboli and thrombi which showered the intramyocardial vessels; e) accurate identification, classification, and grading of atherosclerotic lesions with the aid of routine autopsy protocols, which was not possible in our material.

Adolescent↗

PubMed1986

Atherosclerotic involvement of coronary branch vessels.

The atherosclerotic involvement of coronary branch vessels (first diagonal, first septal, posterior descending, left and right marginals, conus and the vessels supplying the conduction system) was investigated in 450 apparently healthy subjects aged 11-55 years who died of accidental causes. In subjects 35-55 years old, 1 out of every 3 persons with atherosclerotic plaques in the major coronary arteries also had atherosclerotic plaques in coronary branch vessels; the respective relation for fatty streaks was 1 out of every 12 subjects, for intimal necrotic areas 1 out of every 7 subjects and for incorporated microthrombi 1 out of every 9 subjects. One out of every 3 subjects 51-55 years old had more than 50% lumen reduction in the undistended major coronary arteries, compared to 1 out of every 6 subjects in undistended coronary branch vessels. A small subgroup (8.2%) showed more severe stenotic lesions in coronary branch vessels than in coronary major arteries. The atherosclerotic plaques of coronary branch vessels appeared as 'underdeveloped', lacking a thick fibrohyaline cap, a large detritus cavity, abundant lipid deposition, cholesterol crystals, basal vascularization, intraplaque hemorrhage, ulceration, calcification, occlusive thrombosis. On the other hand the stenotic character of these plaques was often severe (more than 75% lumen reduction). The questionable value of the estimation of the ischemic significance of a coronary stenosis in the absence of available data on the development of a compensatory collateral circulation is discussed.

Adolescent↗

PubMed1985

Study of coronary intimal thickening.

A light microscopic study on intimal thickening carried out on 932 subjects 1-50 years old and on 22 selected topographic sites of the coronary arterial bed, revealed: (a) In similar topographic sites intimal thickening developed 5-15 years earlier in subjects with than in subjects without minor deviations from the common type of distribution of the coronary arteries. (b) The most rapid development of the intimal layer was detected in children aged 11-15 years. (c) 6% of children who died of acute diseases (mainly acute peritonitis) showed intimal thickening in both major coronary arteries and branch vessels; in children who died of accidents thickening developed only in the major coronary arteries. (d) More than 50% of subjects 46-50 years old (considered to be in the preclinical stage of ischemic heart disease) exhibited intimal thickening in the branch vessels usually non-opened during routine autopsy and non-removed for light-microscopic examination. (e) An intima/media ratio between 2.0 and 3.0 was associated with a 50% reduction in the luminal diameter; this reduction increased up to 75% when the intima/media ratio surpassed 3.0, the very thick intima acquiring the feature of a 'fixed stenotic lesion' in spite of its apparent normal aspect on light-microscopic examination.

Acute Disease↗

PubMed1985

Differences in the pattern of atherosclerotic involvement between non-branched regions and adjacent branching points of human coronary arteries.

A light-microscopic study carried out on 816 coronary arterial trees revealed that the variety of atherosclerotic lesions detected in non-branched segments was 3-5 times greater than that recorded in branching points. The fibromuscular and fibronecrotic plaques, small fatty streaks, small intimal necrotic areas, incorporated microthrombi and intramural organized thrombi were recorded in both non-branched regions and branching points. The mucoid, foam cell-rich and necrotic plaques, large fatty streaks with abundant extracellular lipid and large intimal necrotic areas with lipid and fibrin deposition were recorded only in non-branched regions, whereas the fibrohyaline plaques were recorded only in the branching points. The complexity of atherosclerotic involvement of the branch areas increased with the branch mouth diameter: at a diameter of 1 mm only fibromuscular and fibrohyaline plaques were recorded; at a diameter between 1 and 2 mm the fibronecrotic plaques and at a diameter of more than 2 mm the small fatty streaks and small intimal necrotic areas were also detected. The results showed that along a distance of only 2-5 mm there are in the coronary arterial tree local hemodynamic and structural patterns which in non-branched regions favour and in adjacent branching sites restrict the onset and progression of atherosclerotic lesions; there are also local factors which in non-branched regions enlarge and in adjacent branching sites limit the types of atherosclerotic lesions which will develop. Any view on the etiopathogenesis of human coronary atherosclerosis needs to be considered in conjunction with the hemodynamic and structural patterns existing in the different parts of the coronary arterial tree, both closely related to the coronary branching anatomical pattern.

Adolescent↗

PubMed1984

Natural resistance to atherosclerosis exhibited by the first centimeter of left and right coronary arteries.

A combined gross and histologic study carried out on 270 selected male subjects with the common type of distribution of the coronary arteries revealed a natural resistance to intimal thickening and plaque development exhibited by the left main coronary artery and by the first centimeter of the right coronary artery. The importance of this natural resistance in children, adolescents, young and mature adults up to 55 years old was demonstrated by means of a comparative investigation, involving the degree of intimal thickness, the media thickness versus intima thickness ratio and the per cent of subjects with atherosclerotic plaques. These parameters were examined in 6 selected samples: (a) at 5 mm distal to the aortic origin of the left main coronary artery, compared with those detected at 10 mm and 20 mm distal to the point of origin of the anterior descending artery; (b) at 5 mm from the aortic origin of the right coronary artery, compared with those recorded at 20 mm and 30 mm from the same point of origin. The differences between the above-mentioned samples appeared statistically significant in all age groups investigated. The first atherosclerotic lesions developed about three decades later in the left main coronary artery than in the proximal segment of the anterior descending artery. In the age group 51-55 years old, only 13.3% of subjects showed atherosclerotic plaques in the left main coronary artery, compared to 77.6% in the proximal segment of the anterior descending artery. Also only 6.6% of subjects 51-55 years old showed atherosclerotic plaques at 5 mm distal to the aortic origin of the right coronary artery, compared to 50.0% at 30 mm.

Adolescent↗

PubMed1983

The neglected coronary atherosclerosis.

A study of the natural history of coronary heart disease by means of gross inspection and light microscopy, carried out on 640 subjects aged 1-50 years who had died of violent accidents, revealed a grossly neglected coronary atherosclerosis. It included fibromuscular plaques, intimal necrotic areas and incorporated microthrombi present in the longitudinally opened main coronary arteries but not visible to the naked eye, and some atherosclerotic lesions visible to the naked eye but present in branch vessels unopened or not removed during routine autopsy. There were approximately 500 grossly neglected intimal necrotic areas and approximately 120 grossly neglected incorporated microthrombi; from a total of 809 atherosclerotic plaques 261 (32%) were grossly neglected. The topographic distribution and the number of neglected and non-neglected atherosclerotic plaques, in successive age groups, were analyzed. A small subsample, including 32 patients 52-79 years old, dead of coronary heart disease, was used to demonstrate the importance of the detection of obstructive atherosclerotic lesions in some usually unopened or not removed branch vessels for a realistic anatomo-clinic-cardioangiographic and ECG correlation.

Adolescent↗

PubMed1983

Progression of coronary atherosclerosis from adolescents to mature adults.

Ten selected topographic sites of the coronary arteries were placed in sequence according to age, sex, branching anatomical pattern and smoking habit, in order to obtain an indirect sequencing of the pattern and rate of progression of early atherosclerotic lesions from adolescents to mature adults. The material came from 356 subjects aged 16-45 years who had died in violent accidents and included the light-microscopic examination of 3560 coronary artery samples. The dynamic reconstruction of thousands of static views revealed the existence of an age-related rate of progression of fibromuscular plaques, intimal necrotic areas, incorporated microthrombi and fatty streaks. All these early atherosclerotic lesions increased linearly and in parallel from one 5-year age group to the next and exhibited non-significant differences in their rate of progression over a period of 25 years. During this period the number of atherosclerotic plaques increased 4.7 times, of intimal necrotic areas 4.6 times, of incorporated microthrombi 4.3 times and of fatty streaks 3.9 times. Consequently, in the 10 selected topographic sites of the coronary arteries placed in sequence according to age, the pathological aspects became prevalent, microscopically, over the normal ones, starting from the fourth decade of life. This study also revealed that some endogenous and exogenous risk factors for coronary heart disease accelerated the age-related rate of progression of early atherosclerotic lesions. In addition, particular cycles of evolution towards advanced lesions appeared, leading to the onset of fibronecrotic and fibrohyaline plaques. Their obstructive character was related to both successive incorporation of microthrombi and the onset of large lipid deposits. Among the four types of early atherosclerotic lesions investigated, only the fatty streaks did not show this direct conversion to a lesion of possible clinical significance.

Adolescent↗

PubMed1982

Discrepancies between data on atherosclerotic involvement of human coronary arteries furnished by gross inspection and by light microscopy.

Intimal areas located at centimetre intervals from the points of origin of the anterior descending, circumflex and right coronary arteries, as well as intimal areas located at the main branching points of the coronary tree, were compared on macro- and microscopic levels, irrespective of the presence or absence of atherosclerotic lesions in the regions selected. The study, carried out on 606 subjects aged 1-70 years, revealed important discrepancies between data furnished by gross inspection and by light microscopy. These discrepancies occurred in the recorded character of atherosclerotic lesions; the meaning of the terms 'fibrous plaque', 'fatty streak' and 'normal intima'; the age period in which the first atherosclerotic lesions were detected; the features of these early lesions and their sequence of development; and the presence of atherosclerotic plaques in the main branch vessels. The fibromuscular and mucoid plaques, intimal necrotic areas and incorporated microthrombi, occurring as early stages of atherosclerotic involvement, were visualized only by light microscopy. In mature adults and elderly people the intimal surface of many coronary artery samples had a different appearance from the basal intimal regions.

Adolescent↗

PubMed1982

Atherosclerotic involvement of human intracranial arteries with special reference to intimal necrosis.

In a population sample aged 1-70 years where the cause of death was violent accident, the prevalence of intimal necrosis varied between 31.5 and 95.1% of cases in the basilar artery and between 10.5 and 59.6% of cases in the anterior cerebral arteries. In both basilar and anterior cerebral arteries the first areas of intimal necrosis occurred one or two decades earlier than the first fibromuscular plaques and the first fatty streaks. In each age group investigated the percentage of subjects with intimal necrosis appearing as an independent lesion was consistently greater than the percentage of subjects with atherosclerotic plaques, fatty streaks or incorporated microthrombi. Successive observations of similar topographic points placed in sequence according to age showed that many areas of intimal necrosis may represent the first stage in the development of atheromas or fibronecrotic plaques. On the other hand, using the same material and method, we were unable to reveal in intracranial arteries of subjects aged 31-70 years the conversion of fatty streaks to fibrous plaques.

Adolescent↗

PubMed1981

Coronary intimal necrosis occurring as an early stage of atherosclerotic involvement.

In a population sample in whom violent accident was the cause of death, the following prevalence of coronary intimal necrosis, occurring as an independent lesion and as an early step of atherosclerotic involvement, was revealed: 2% of children 6--10 years old, 6% of children and juveniles 11--15 years old, 14% of adolescents 16--20 years old, 32% of young adults 21--25 years old, 56% of young adults 26--30 years old, 72% of mature adults 31--35 years old and 84% of mature adults 36--40 years old. In each age subgroup, the percentage of subjects with coronary intimal necrosis was greater than the percentage of subjects with coronary atherosclerotic plaques. A centrifugal extension with age of intimal necrosis, along the coronary tree in the direction of blood flow, was observed. Histologically, the coronary intimal necrosis exhibited a mucoid form, a swelling form and a dissecting form. Indirect evidence was offered that some areas of coronary intimal necrosis formed an adequate nidus for lipid and fibrin accumulation and also induced the development of a peculiar type of subendothelial connective tissue. These successive changes led to the onset of atheroma-like lesions with a prevalence of lipid deposits, or of intramural thrombi or of a fibro-hyaline cap. The onset, extent and evolution of coronary intimal necrosis was accelerated by the male sex, by some minor deviations from the basal branching anatomical pattern of the coronary arteries, by the main risk factors for coronary heart disease, as well as by some terminal diseases, such as the generalized form of sarcoidosis and the renal complications of systemic lupus erythematosus.

Adolescent↗

PubMed1981

The hyperplastic muscle columns which encroach upon the branch mouths of the coronary arteries and their relation to coronary heart disease.

Hyperplastic muscle columns encroaching upon the branch mouths of the main coronary arteries were revealed in 1 out of every 5 infants, children, juveniles, adolescents, young adults, mature adults and elderly people. They prevailed at the branching points of the first diagonal and first septal vessels and occupied 1/3 to 2/3 of the coronary wall thickness. The presence of hyperplastic muscle bundles encroaching upon the branch mouths of the main coronary arteries was associated with the absence at the respective sites of branch pads or cushions, intimal connective tissue and atherosclerotic lesions. This peculiar microarchitecture was present in 3 times more frequently in patients who died of coronary heart disease than in subjects who died of non-cardiac causes (30% versus 10%). The existence of a relationship was suggested between the hyperplastic muscle columns encroaching upon the branch mouth of an artery and the infarction area in the myocardium supplied by the respective vessel. Likewise, a relationship seemed to exist between hyperplastic muscle columns encroaching upon the branch mouths of the vessels supplying the sinoatrial and atrioventricular nodes and the electrical instability of the heart, particularly of ventricular fibrillation leading to sudden cardiac death.

Adolescent↗

PubMed1980

Incidence, topography and light-microscopic feature of coronary atherosclerotic plaques in adults 26--35 years old.

Coronary atherosclerotic plaques have been found in 42% of adults 26--30 years old and in 58% of adults 31--35 years old. The incidence in these two age-groups of one, two and three vessel involvement is presented, as well as the age-related topography and prevalent histologic type of coronary atherosclerotic plaques. In 26--35 year-old adults, the coronary atherosclerotic plaques appeared non-complicated by thrombosis and/or hemorrhage and narrowed the lumen of undistended vessels up to 75%. The period of life from 26 to 35 years included the critical time for a massive necrosis of certain areas of the thickened intimas, as well as of preexisting and newly formed plaques; consequently, atheroma became prevalent over other atherosclerotic lesions. Necrosis did not result from a break up of lipid-filled and foam cells, its main pathogenetic mechanism being a complex hydrolysis involving progressively the components of the ground substance, fibers and cells.

Adult↗

PubMed1980

The precursors of coronary atherosclerotic plaques in subjects up to 40 years old.

The onset of coronary atherosclerotic plaques was investigated in 400 selected cases aged 1--40 years. During childhood the atherosclerotic plaques developed on their own, in preexisting branch pads or cushions. During adolescence the atherosclerotic plaques developed on their own, in both branch pads or cushions and thickened intimas. In young and mature adults the thickened intima became the main site for plaque histogenesis, whereas the role of branch pads or cushions decreased significantly. In mature adults incorporated microthrombi were accidentally involved in plaque development. In both branch pads or cushions and thickened intimas the atherosclerotic plaques developed through several stages including: histolysis, followed by nodular proliferation of smooth muscle cells (prevalent during childhood), insudation (prevalent during adolescence), accumulation of lipid-filled and foam cells (prevalent during early adulthood) and necrosis (prevalent in mature adults). Likewise the coronary fatty streaks developed on their own, through several stages, from early to advanced lesions. We were unable to reveal the conversion of fatty streaks into atherosclerotic plaques the two types of lesions occurring as unrelated pathological processes.

Adolescent↗

PubMed1980

Atherosclerotic involvement of the coronary arteries of adolescents and young adults.

Coronary atherosclerotic plaques were revealed by light microscopy in 12% of adolescents and in 28% of young adults. All the plaques of adolescents and one-third of the plaques of young adults escaped recognition on ordinary gross inspection, even after Sudan staining. A centrifugal extention of plaques, from the branching areas to the proximal segment of the main coronary arteries took place, starting from adolscence. During early adulthood this centrifugal extension continued involving the intermediate segments of the anterior descending and right coronary arteries. In undistended vessels, the coronary atherosclerotic plaques narrowed the lumenal diameter up to 55% in adolescents and up to 65% in young adults. Histologically, the mucoid type of plaque, rich in areas of edema, insudate and depolymerized ground substance, prevailed in the coronary arteries of adolescents; in young adults, the prevalent plaque was the lipid-rich variety, containing many clusters of lipid-filled and foam cells. In addition, necrotic plaques or atheromas have been revealed for the first time in young adults. A positive association appeared on our material between cigarette smoking and the presence of mucoid plaques in the proximal segment of the main coronary arteries of adolescents. On the other hand, no relation could be established between risk factors and the accumulation of lipid-filled and foam cells in the atherosclerotic plaques of young adults.

Adolescent↗

PubMed1979

Some particular aspects of the microarchitecture of human coronary arteries.

The following light-microscopic features characterize the microarchitecture of human coronary arteries compared with other organ arteries of muscular type and similar size: (a) the rapid development of a diffuse thickened intima which in adolescents becomes the main layer of the coronary artery wall; (b) the slow post-natal increase in the number of circularly oriented rows of smooth muscle cells of the media; (c) the occurrence of numerous longitudinal muscle columns, particularly in arterial segments and branches which run from the base to the apex of the heart; (d) the complex organization of branching points, including the presence of large pads or cushions, a very thick intima and many longitudinal muscle columns, some of which exhibit a spiral course at the level of the branch mouths with the formation of muscle rings round the entrance orifices.

Adolescent↗

PubMed1979

Study of fibrous plaques occurring in the coronary arteries of children.

The pathology of the coronary arteries of children, in relation to atherosclerotic involvement, appeared as a pathology of the main emergence areas and branching points of the left coronary artery and particularly of the anterior descending artery. The first atherosclerotic lesions occurred as non-raised fibrous plaques in 2% of children 6--10 years old and in 4% of children and juveniles 11--15 years old. In the latter age group fatty streaks and gelatinous plaques were also seen in 6% of the subjects; in their appearance they lag behind fibrous plaques by 5--8 years. Indirect evidence was obtained that some branch pads or cushions might be converted into fibrous plaques. The transitional aspects included edema, histolysis (elastolysis, collagenolysis, ground-substance depletion and degenerative cell changes), followed by reorganization and homogeneization of the pre-existing heterogeneous microarchitecture; in a final stage the prevalent processes seemed to be the nodular proliferation of smooth muscle cells and the abundant neoformation of collagen fibers. In essence the results show that in atherosclerosis the coronary arteries are involved in a different sequence and histogenetic pattern than the aorta.

Adolescent↗

PubMed1978

Heterogeneity in the composition and aggregation patterns of coronary intima acid mucopolysaccharides (glycosaminoglycans).

The thickened intima of human coronary arteries included acid mucopolysaccharides (glycosaminoglycans) with a large variety of patterns of composition and aggregation. This heterogeneity, detectable with histochemical methods, was related in our material to age, branching anatomical pattern, size of vessel, collateral or terminal character of the vessel, bifurcations, intimal histology, internal elastic membrane alterations, as well as to the onset of fatty streaks, gelatinous plaques and incorporated microthrombi.

Adolescent↗

PubMed1978

Human coronary arteries. II. Branching anatomical pattern and arterial wall microarchitecture.

A study on 22 pairs, including subjects of similar age, sex and cause of death but with different branching anatomical patterns, shows, that the amount and structural organization of elastic and muscular tissue of the thickened intima are strongly influenced by (a) the size, length, mode of ramification of the parent vessels of the coronary tree; (b) the number of branch orifices in a given arterial segment, and (c) the collateral or terminal character of certain daughter branches.

Adolescent↗