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Biomedical subjects

R Gilles

Publications and source records attributed to R Gilles.

At least 91 records · Page 5Linked to original sources

[Phonomechanographic evaluation of the severity of pulmonary stenosis].

External phonomechanographic methods allow us to obtain a fairly precise estimate of the degree of obstruction to the pulmonary outflow, whether such an obstruction is a single entity or associated with another intracardiac malformation. The greatest precision in this field is obtained with the cases of pure pulmonary stenosis. The findings on phonomechanographic investigation of 54 cases with pulmonary stenosis have been compared with the results of the haemodynamic tests (catheterisation and angiography) as well as with the anatomical findings after a surgical cure had been effected in a certain number of cases. This study has allowed us to pick out five phonomechanographic criteria of severity of pulmonary stenosis: an increased reduplication of the second sound, lenghening of the interval between the Q wave of the electrocardiogram and the maximum portion of the systolic murmur, an increase in Furuta's ratio and also in the amplitude of the jugular venous a-wave as a function of the total height t (the a/t ratio), but most especially the "corrected" Furuta ratio as a function of the length of the ejection phase of the right ventricle, as this has been shown to possess the best correlation with the right ventricular systolic pressures.

Adolescent↗

Effect of various ions on ATP determinations using the "luciferine-luciferase" system.

Various salts and buffers used in routine as part of the ATP extraction procedues induce an important inhibition of the peak light emission produced by the "luciferine-luciferase" system. The nature of the anion is more important in determining the inhibitory effect than the nature of the cation. The series obtained when placing the anions studied by order of increasing effectiveness is as follows Ac- less than Cl- less than I- less than ClO4-. KClO4 appears thus as a strong inhibitor of the enzyme activity. It appears moreover to act competitively with respect to ATP, one mole of inhibitor binding per mole of ATP active site. These results are discussed in connection with the use of the "luciferine-luciferase" system for ATP and other energy-rich compounds' concentration measurements.

Adenosine Triphosphate↗

[Indications for prosthetic replacement of the aortic valve].

There is no controversy about the prosthetic replacement of the aortic valve in cases in which there is a disorder of function or cardiac failure, or in cases with a tight aortic stenosis, even if it appears to be well-tolerated clinically. It is especially critical in cases of aortic incompetence with marked cardiac enlargement, but the problems are not overwhelming. The indications for operation in very advanced cases with cardiac failure which is refractory, or in aged patients, are discussed.

Age Factors↗

[Effect of antioxidant substances on the level of free organic radicals naturally present in the rat diaphragm].

Using the electron spin resonance method, the effect of antioxydants on the number of natural organic free radicals is studied in the case of the diaphragm of the Rat. The effect observed shows an important decrease in the free radical concentration, which may, in the case of ascorbic acid and BHT, lead to their complete disappearance. These results are discussed in the light of the hypothesis according to which antioxydants play a role in the lengthening of the life span because of their fundamental character of inhibitors of free radicals.

Animals↗

[Functional aortic systolic murmurs in the elderly].

The authors report a clinical and phonocardiographic study of functional aortic systolic murmurs in 26 elderly patients, in 19 of which the lesion was confirmed pathologically. Systolic murmurs radiating across the chest in elderly have the same clinical characteristics as aortic stenosis from which they may, however, be distinguished owing to the: absence of a thrill during systole. The brief duration and the proto-meso-systolic position of the murmur with early inscription of maximal oscillations on the phonocardiogram. Conversion of the second aortic sound. Almost constant absence of a diastolic murmur. Normal carotid arteriogram, including normal ejection time after correction and time of half rise. "Innocent" systolic murmurs are due to calcification of the aortic valve without stenosis, and/or dilatation of the ascending aorta. There is no systolic pressure gradient between the left ventricle and the aorta during cardiac catheterisation. No lesions were found in the mitral valve suggesting mitral incompetence, therefore, we consider the term mitro-aortic murmur used by Huchard should be dropped; Radiation of the murmur from the apex of the heart up into the neck may be explained by the simultaneous occurrence of anatomical changes due to age and/or hypertension and by the vibratory nature of the murmurs which become propagated above and below their origin, as shown by the intracardiac recordings.

Age Factors↗

[Various etiologies of systolic murmurs radiating from the apex of the heart to the neck].

The authors studied systolic murmurs in 89 cases, 50 of aortic stenosis, 14 cases of obstructive cardiomyopathy and 20 cases of mitral incompetence. This systolic murmur is characterised by its exceptional intensity, its raspy character at the base, becoming softer at the apex and in the axilla, the presence of a thrill and irradiation into the neck in 50 to 75% of cases. The etiological diagnosis was ensured precisely by 1) pharmaco-dynamic tests: amyl nitrite accentuates the systolic ejection murmurs and attenuates murmurs due to mitral regurgitation. 2) careful analysis of diastole: a systolic murmur extending into early diastole, a third sound or an opening snap and a low-pitched diastolic murmur, suggest mitral incompetence. A high-pitched diastolic murmur is in favour of aortic stenosis. 3) the carotid arteriogram and catheterisation show the characteristic abnormalities of the carotid arteriogram found in aortic valve disease and the existence of a trans-aortic or intra-ventricular pressure gradient, when there is an obstruction to left ventricular jection. The F wave of the apex cardiogram or left atrial reflux of the contrast medium during cineangiocardiography, confirm mitral incompetence. The main phono-hemodynamic and phono-anatomical correlations have been emphasized: 1. The intensity of the systolic murmur is directly proportional to the degree of obstructive cardiomyopathy or mitral incompetence, but does not parallel the degree of the sub-valvular apparatus. 3. The maximum intensity of the murmur occurs all the later when the stenosis is tight, whilst it is earlier in severe obstructive cardio-myopathy. 4. The lozange shape of the murmur of mitral incompetence on phono-cardiography is, above all, due to those cases with lesions of the sub-valvular apparatus. Finally, a study of the sound recorded by the Allard-Laurens micromanometer permitted us to determine the mechanism of this irradiating systolic murmur.

Aortic Valve↗