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Biomedical subjects

A Constantinesco

Publications and source records attributed to A Constantinesco.

69 records · Page 4Linked to original sources
PubMed1977

Continuous blood velocity and flow measurements by intravascular elutherm probe.

A device for measuring the mean blood velocity (by means of a thermal equilibrium method) and the intravascular electrical impedance, which determines the mean sectional area of the vessel, have been mounted on the same probe (french catheter 7F). The validity, of the method has been confirmed in vitro and by 100 measurements carried out in dogs and compared with flow measurements by means of the cardio-green method. The correlation coefficient is found to be 0.98.

Animals↗
PubMed1977

[An intramural hematoma of the small intestine, during anticoagulant therapy: radiological course. Concerning one case].

The authors present a case of intramural hematoma of the small intestines during anticoagulant treatment. With reference to this case, they study the frequency, etiopathogenesis and anatomy of this hematoma and particularly look at the radiological manifestations. In this respect they distinguish three stages in the evolution. The first, when the straight X-ray of the abdomen and barium followthrough demonstrate an axial stenosis of the small intestines with dilation of the proximal loops; the second (between the 7th and 20th days) when the loop affected by the hematoma takes on a characteristic "palissade" or "spring" -like sausage appearance; finally the third (after the 3rd week), when only thickening of the haustrations persists with progressive return to normal. The radiological diagnosis is discussed, not only with intramural hematomas of the small intestines of other etiologies (traumatic, during pancreatitis, during disorders in hemostatis), but also with conditions giving rise to similar radiological pictures: malabsorption, inflammatory conditions, etc.

Acenocoumarol↗
PubMed1974

[Biomechanic study of sternal movements in adult man (author's transl)].

The study of the sternal movements by the use of biometry mensurations of 62 young adult men allows to precise the respiratory variations of the Louis's angle and sternal displacements in the sagittal plane. The sternal movements are successivly considered in standing and horizontal positions, at three respiratory moments corresponding to the respiratory rest, the forced inspiration and the forced expiration. The sternal displacements in the sagittal plane are the resultant of backward and forward movements and elevation and lowering movements. In standing position the amplitude of the forward movements can be compared to these of the backward movements while the amplitude of the elevation movements is four times more important than that of the lowering movements. In horizontal position the amplitude of the forward movements is twice more important than that of the backward movements and the amplitude of the elevation movements is twice more important than that of the lowering movements. The correlation research between the sternal movements and the vital capacity allows to precise that the vital capacity appears essentially in correlation with the maximum of the amplitude of the Louis's angle movements in horizontal position and with the forward and backward sternal movements in standing and horizontal positions.

Adult↗
PubMedDate not supplied

MR detection of quantitative and structural changes in human aortic aneurysms.

Collagen is a major component of the extracellular matrix and a determinant of the elastic behavior of the human aorta. To investigate the changes found in aneurysmal degeneration, the authors studied the solid-state hydrogen-1 nuclear magnetic resonance line shape of collagen in aneurysms and normal human aortas. A three-component decomposition of the free induction decay was performed, with collagen characterized by a T2 of about 18 microseconds. The second moment of the collagen line shape was found to be increased in aneurysms (5.3 vs 4.8 G2), while, correspondingly, the T2 of collagen was lower in aneurysms (16.3 vs 17.7 microseconds). This corresponds to a modification of collagen structure and molecular motion. Collagen concentration was lower in nondiseased aortic walls (9.4% vs 7.3%). These results are discussed in reference to the contradictory conclusions in the current literature. The increase in collagen and the modification of its structure and molecular motion are explained by the need to resist an increasing tangential tension due to increased aortic diameter and diminished wall thickness in aneurysms and by intercalation or site binding in the helices or electric dipolar interactions in the less mobile side groups.

Aorta, Abdominal↗
PubMedDate not supplied

In vitro 4 MHz NMR proton relaxation times and in vitro mechanical behavior at low extension of human common carotid arterial wall.

We investigated the influence of the biomechanical behavior of human common carotid arterial wall on the NMR proton relaxation times using a Bruker Minispec at 4 MHz. The study was limited to low extension in simple longitudinal elongation of the carotid wall (the maximum loading stretch ratio being 40%). Twenty-five carotid samples divided into 2 longitudinal strips were tested. The first strip was used to determine the nondimensional elastic parameter alpha according to the mechanical model of Fung. The second strip was used to measure the proton relaxation times. T1 value was 316.8 ms +/- 27.6 and T2 value was 59.9 ms +/- 6.8. A significant linear correlation was found between T1 and Ln alpha (p = 0.02). T1 and T2 were not correlated to the age but linearly correlated to the tissue water content (p less than 0.0001), however the age and alpha were not correlated to the tissue water content. These results may reflect the differences in the amount of water binding sites of the elastin which is involved in the elasticity of the carotid wall at low extension.

Adult↗
PubMedDate not supplied

Detection and quantification of recent myocardial infarction: diagnostic value of multiecho multislice spin echo imaging.

Thirty-four patients with documented transmural MI were studied with gated three echo, multislice MR imaging. In 12 patients MRI MI size was compared with CK release measurement, Tl-201 SPECT defect, and with Tc-99m LVEF. Infarct was visualised in 29/34 patients on 3rd echo images (18/34 on 2nd and 6/34 on 1st echo images). Mean MR infarct size (planimetered from 3rd echo images): 33.1 +/- 9% overestimated the SPECT defect (mean value of 23.8 +/- 15%). However, the overall correlation between MRI and Tl-201 sizing was significant: r = 0.82; p less than 0.001; SEE = 5.5%. The correlation with LVEF also appeared significant: r = -0.61; p less than 0.038.

Adult↗
PubMedDate not supplied

[Value of global ejection fractions based on the presence or absence of left ventricular dyskinesia. A comparison between contrast angiography and angioscintigraphy].

The total ejection fraction of the left ventricle is studied in 37 patients, most of them with coronary disease, according to two methods: contrast angiography in a single plane and angioscintigraphy (first passage and balanced), in order to compare the results according to the presence or the absence of dyskinesias. The two methods are performed in succession according to the usual views. The population is divided in two sub-groups according to the presence (17 patients) or the absence (20 patients) of segmental abnormalities. Segmental abnormalities are divided into 11 antero-apical aneurysms and 6 infero-posterior aneurysms. The correlations of the ejection fractions calculated according to the two methods and the two views, are usually satisfactory in the two sub-groups and especially as the parietal kinetics is homogeneous. In case of segmental abnormalities of the contraction, there are variations in the total ejection fractions depending on the technique and the views that are used, but the differences are not significant.

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Incidence of deep venous thromboses in traumatology and methods of early detection].

In this work carried out at the Traumatology Centre in Strasbourg, out of 227 patients operated for a fracture situated between the pelvis and the tibial plateau, the authors endeavoured to show a thrombosis of the lower limbs. The means of exploration included in addition to the clinical and biological blood tests an isotopic, rheographic and phlebographic surveillance. The latter three ways of exploration are particularly viewed in this study, during which it was possible to demonstrate 44 p. 100 thrombo-embolic manifestations of which 38 p. 100 were detected only by the isotopic method, the phlebographic check for its part confirming 80 p. 100 of the clinically undeclared cases of thrombosis.

Adolescent↗