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N M Constantinescu

Publications and source records attributed to N M Constantinescu.

27 records · Page 2Linked to original sources
PubMedDate not supplied

Experimental investigations in prolonged myocardial ischaemia. Note I. Biology of the myocardial fiber after transient myocardial fiber after transient myocardial ischaemia.

The first ten days' evolution of post-ischaemic lesions of the premonitory or angina pectoris syndrome type was experimentally studied by the challenge of a short-term (10 and 15 min) ischaemia, of an adaptation to ischaemia and an adaptation followed by prolonged ischaemia (20 and 35 min). Worthy of note was the persistence of reversible lesions after short-term ischaemia and adaptation, and the progressive evolution towards cytolysis and cicatrization of some pancicellular foci after adaptation followed by prolonged ischaemia. The role of mitochondrial lesions, of lysosomal hydrolases, the inefficiency of renewed circulation, as well as problems of diagnosis are discussed.

Angina Pectoris↗
PubMedDate not supplied

Experimental investigations in prolonged myocardial ischaemia. Note II. Biology of the myocardial fiber during permanent ischaemia.

The dynamics of morphologic and biochemical lesions of the myocardial fiber during the first ten days after an experimental myocardial infarction showed an unequal evolution of the lesional picture in the ischaemic area, the intervention of lysosomal hydrolases and the reactions of inflammatory fibrocollagen substitution. Morphologic aspects in the areas neighbouring the infarction and other myocardial areas are discussed.

Animals↗
PubMedDate not supplied

Experimental study of myocardial bridges.

Myocardial bridges were reproduced in dogs by transfer of a fragment of the left ventricular wall above the upper portion of the anterior interventricular artery. The viability of this bridge was shown by coronarography, anatomic, histologic and electron microscopic studies, illustrating the vascular patency and the integrity of blood vessels and neighbouring myocardium in the cases postoperatively heparinized. The experimental model efficiency was also proved by ECG examinations revealing ischemic distresses induced by compression of the bridge against the underlying artery.

Animals↗
PubMedDate not supplied

[Adaptation of the myocardium to ischemia: study of suspension of the mitochondria as related to the development of the collateral circulation].

The authors developed an experimental model by means of which they established in the dog the role of short duration ischaemia (1-5 minutes) in triggering local haemodynamic changes that led to the rapid development of a collateral circulation, with retrograde filling, able to furnish subsequently blood supply to the distal segment of a main coronary artery obstructed for 20 minutes. Histological study, electron microscopy, biochemical tests and mitochondrial suspensions revealed the value of the latter method, being the most reliable test for appraising the remaining postischaemic functional potential. The data obtained may serve as a basis for understanding the role of the coronary colateral circulation in man, in coronary obstruction, and the means of developing this circulation.

Animals↗
PubMedDate not supplied

Investigations on the morphophysiological basis of revascularization of the myocardium by the Vineberg method.

A study was carried out on the dynamics of vasculogenesis and the formation of mammary-coronary anastomoses within the first seven months after implantation of the internal mammary artery in the left ventricular myocardium, according to the Vineberg method. The efficiency of these anastomoses was demonstrated 4 to 7 months later by the absence of lesions 8 to 10 days after transitory and permanent myocardial ischaemia induced by coronary obliteration. The lesions could not be prevented in the case of thrombosis of the internal mammary artery or when ischaemia was produced concomitantly with the implant or before the mammary-coronary arteriolo-arterial anastomotic network developed.

Animals↗
PubMedDate not supplied

Ultrastructural and biochemical alterations induced by propranolol treatment in experimental myocardial ischaemia.

The effect of propranolol within the first ten days after a transient experimental myocardial ischaemia was investigated. As compared to the untreated control lot, the ultrastructural and biochemical lesions appeared to be much reduced and within reversible limits. Worthy of note was the slight affection of mitochondria revealed by the level of mitochondrial enzymes, the presence of lysosomal and phagolysosomal structures and capillaries of normal aspect, and the absence of cytolysis. The favourable effect of this beta-blocking drug might be attributed to its protective action on the cellular and capillary membrane systems.

Animals↗