Biomedical subjects

L Scebat

Publications and source records attributed to L Scebat.

At least 37 records · Page 2Linked to original sources

PubMed1976

Aortic smooth muscle cells reaction in rat spontaneous hypertension.

Parallel morphometric, karyometric and ultrastructural studies of the aortic wall in Okamoto-Aoki rats with short term (3-6 months) and long-term (12-16 months) spontaneous hypertension have revealed a progressive thickening of the medial layer, which is associated with an increaase in the mean nuclear area of the arterial medial smooth muscles and reduction in their mean number per unit area. Electron microscopic studies have shown a multiplication of the intracellular components of aortic smooth muscle cells as a base for their enlargement, as well as small single foci of smooth muscle hyperplasia in the area of the innermost interlamellar space in parts of the aortic wall with intimal thickening. Results of these studies allow the conclusion, that hypertrophy is a reaction of arterial smooth muscle cells to an increased mechanical load in hypertension which, in turn, is responsible for the thickening of arterial with Hyperplasia - increase in smooth muscle cells' number in the media - played a subordinate role. The reaction of the aortic wall to elevate blood pressure is interpreted as a manifestation of the normally limited division capacity of smooth muscle cells in mammals, which does not allow an increase in its cellular components. The function of existing arterial smooth muscle smooth cells is enhanced, instead, by hyperplasia of their specific organelles and augmentation of their volume.

Animals↗

PubMed1976

[Hypertensive arteriopathy: aortic histo-metabolic changes during postnatal ontogenesis in spontaneous hypertensive rats (Okamoto-Aoki strain) (author's transl)].

27 aortic histoenzymatic activities and 6 aortic macromolecular substances were comparatively studied in spontaneous hypertensive rats (SHR) and normotensive Wistar rats (3, 5, 13 and 16 month-old). The earlier aortic changes (3rd month) were only histoenzymatic: 5 Nase and LDH were increased in the entire aorta: some oxido-reductases increase near the intima. These early minor changes might represent some of the factors of the functional disturbance of the arterial smooth muscle cell. At the stage of stable hypertension (5th-13th month) two lesion patterns were seen: 1) metabolic: increase of the histoenzymatic activities involved in lipolysis, GAG anabolism, glycolysis, cell respiration, energizing metabolism and nucleotides-esterolysis. 2) Structural: cell hypertrophy and hyperplasia, interstitial fibrosis. The stimulus of the metabolic changes seems to be dual: 1) the hypertensive factor acting upon smooth muscle cells and/or vasa vasorum. 2) The intraarterial pressure increasing endothelial crossing and stimulating myocyte contraction. The structural change is more probably the reaction to elevated pressure; it has led to diffuse medial thickening providing a balance between hypertension and arterial wall stress. On the 16th month, the cell reaction developed in two ways: 1) increase of metabolic and morphogenetic activation of some cells. 2) irreversible degeneration in some other cell groups (media necrosis, cicatricial fibrosis, decrease of oxidoreductases and lipolytic activities, increase of lysosomal enzymes). Aortic lesions during spontaneous hypertension were less dramatic and occurred later than after experimental hypertension. Some of the observed histometabolic changes might lead to maintenance and worsening of hypertension.

Animals↗

PubMed1976

[Correlation between the angiographic appearance and the left intraventricular gradient in obstructive myocardiopathy. Apropos of 42 cases].

42 patients who were given the diagnosis of obstructive cardiomyopathy (OCM) on the basis of a basal left intraventricular systolic gradient equal to or in excess of 20 mmHg were divided into two groups, according to the angiocardiographic appearances (in the right anterior oblique projection) of the left ventricular cavity during systole. In 20 cases the appearances were those of a typical obstructive cardiomyopathy. In the other 22, despite the presence of a fairly large left intraventricular gradient, the appearances on angiocardiography were closest to those described for the non-obstructive cardiomyopathies with diffuse myocardial hypertrophy. These two groups were compared in the quest for a difference between the clinical, radiological, electrocardiographic, phonomechanographic, and haemodynamic picture on the one hand, and the appearances at angiography on the other. These two groups can only be separated by the mean value of the left intraventricular systolic gradient established under basal conditions; this is greater when the angiographic picture is less characteristic. However, the value of this gradient is shown by the positive correlation between the figure for the gradient and that for the left ventricular ejection time, as determined from external phonomecanographic measurements and from the catheter on the left side. This determination confirms the existance of obstruction to the outflow and the diagnosis of obstructive cardiomyopathy, even when the angiographic appearances are not typical.

Adolescent↗

PubMed1976

[Diagnosis of myxomas of the left auricle by ultrasonic echography].

The two case histories of myxoma of the left auricle reported in this paper illustrate how echography is a diagnostic method which is non-invasive, simple, and relatively accurate provided that different angles of incidence are used, and especially the "root aorta-left auricle" incidence. It is indicated especially in cases with variable mitral murmurs on auscultation, but also where there is a very large left auricle, heart failure of unknown cause, or even an apparently straightforward case of mital stenosis. Moreover, as one of these case histories demonstrates, the technique allows both short and long term postoperative follow-up to be carried out with ease and safety, so that a possible recurrence can be picked up later.

Adolescent↗

PubMed1976

[Value of caudo-cranial and left anterior obleque projections in the angiographic study of the left coronary artery].

The use of new apparatus which offers an unlimited choice of projections in the frontal and sagittal planes is a great step forward in the radiological investigation of the coronary arterial tree. The results obtained with the left anterior oblique caudo-cranial projection have been reported. In a series of 100 consecutive coronary arteriographies, this method showed up lesions which were passed over or unnoticed, or showed up the magnitude of stenoses which had been underestimated in the standard projections, in 24 cases. From among these, it was possible to show up 6 stenoses which were at or above the 75% level; 4 of these were on the diagonal artery, 1 on the anterior desceinding artery, and one on the left coronary trunk. In 16 other patients it confirmed the degree of stenosis, which had been uncertain when assessed by the usual technique. All in all, it gave useful information in 40% of cases. This new projection is especially useful for investigation the proximal parts of the branches of the trunk of the left coronary artery.

Coronary Angiography↗

PubMed1976

[Hemodynamic diagnosis of tricuspid insufficiency].

An analysis and comparison has been made of the value in the diagnosis and assessment of the degree of tricuspid incompetence of the following: the pressure curves of the right side of the heart, intracardiac phonocardiography and the venous dilution curves of ascorbic acid. The study was carried out on 49 patients, and a comparison made with selective right ventricular cineangiography, which was chosen arbitarily as a baseline. The information from the pressure curves and from intracardiac phonocardiography often contains errors of ommission or commission, but that from the venous dilution curves of ascorbic acid came out as the most reliable; these curves do tend to overestimate the degree of regurgitation, but they still allow us to reserve selective cineangiography, which is quantitatively a more precise method, for those cases in which the curves indicate a particularly severe degree of tricuspid incompetence.

Adolescent↗

PubMed1975

[Obstructive cardiomyopathy. A new surgical method of treatment].

A case of treatment of obstructive cardiomyopathy by insertion of a disc mistral prosthesis (Cooley's technique) is reported. The result obtained was satisfactory from a clinical, haemodynamic and angiocardiographic standpoint. The mode of action of this technique is discussed.

Adult↗

PubMed1975

[Clinical diagnosis of corrected transposition of the great vessels by bulbo-ventricular inversion].

29 cases of corrected transposition of great vessels (CTGV), of which 3 cases were isolated and 26 cases were associated with various malformations were studied. The aim was to make the diagnosis of CTGV were made evident, to differentiate those which came from the associated malformations. The specific signs for CTGV are as follows: 1) a slight systolic ejection murmur at the 2nd or 3rd left intercostal space along the sternal margin; 2) a loud 2nd tone in the same focal zone. Specific radiographic signs are that: 1) the aortic arch comes up to sternal-costal articulation; 2) the inferior left margin has a convex form; 3) in the right oblique-anterior projection it is possible to see 2 imprints on the opaque esophagus, which is represented by the aorta above and pulmonary artery below...

Adolescent↗

PubMed1974