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Biomedical subjects

F Liot

Publications and source records attributed to F Liot.

At least 19 recordsLinked to original sources

Value of somatosensory evoked potentials in saphenous entrapment neuropathy.

Neuralgia of the saphenous nerve (SN) is a rare clinical syndrome simulating a vascular disorder of the lower extremities. In four cases, the presenting complaint was persistent pain on the medial aspect of the knee. Examination revealed tenderness over the site of exit of the SN form the femoral canal. Femoral nerve motor conduction, quadriceps H-reflex and EMG of the leg muscles were normal. The sensory nerve action potential of the SN in the leg was not obtained in some patients, even in the unaffected leg. SEP were therefore preferred for diagnosis and performed at the infrapatellar and descending branches of the right and left SN and recordings from the Cz'-Fz electrode. Latency and amplitude differences were evaluated and compared with a control group of healthy subjects. An alteration in the SEP from one branch was observed on the painful side. Posterior tibial responses were normal. In one case, pain resolved immediately after neurolysis, confirming SN entrapment above the femoral canal, before its division. Pain resolved in two other cases and persisted in the last after medical treatment. SEP studies are valuable in the diagnosis of an isolated lesion of the SN.

Adult

[Somatosensory evoked potential of the lower extremity in the premature neonate].

The morphology of SEP is a good index of cortical maturation. Cerebral SEP is elicited by stimulation of the posterior tibial nerve at 38 wk post-conceptional age in 37 neonates distributed in 3 groups: I = gestational age (GA) at birth less than 31 wk; II = GA 23-36 wk; III = full-term neonates (FTN). A somatosensory response was identified in only 21 cases (56.8%). The presence of SEP in 3 groups, ie I, II, III, was 45.5%, 53.8% and 69.2% respectively. The morphological characteristics studied (latencies, amplitude and rising time) in these neonates were different: the peak latencies of major positive wave (P1) and rising time were not significantly different between I and III. These parameters were statistically different between II and III. SEP development is linked to some morphological factors-height, and growth-but also to the maturation of the central nervous system (myelinisation and central pathway organization). These results indicate that until 38-39 wk post-conceptional age, the maturation of the central somatosensory pathway is variable at different birth periods; this suggest the possible role of extra-uterine factors of in the acceleration of neurological development.

Electric Stimulation

[Conduction disorders in Cheyne-Stokes respiration caused by cardiac insufficiency].

This report describes a case of Cheyne-Stokes respiration linked to heart failure, with periodic disturbances of atrioventricular conduction during the augmentation phase of the tidal volume. The circulatory retardation caused by heart failure induced a phase lag of the negative retroaction system and secondarily an oscillation in the respiratory command. The conduction disturbances resulted from vagal stimulation of multifactorial origin. The atrioventricular conduction disturbances were analogous to those seen in other periodic respiratory diseases.

Aged

Magnetopneumography: a general review.

Magnetopneumography is the study of the remanent magnetism of foreign intrathoracic ferromagnetic particles after magnetization by an external magnetic field. Given knowledge of the magnetic characteristics of the inhaled particles, this highly sensitive and non-invasive technique allows the measurement of lung dust loads. Many groups of workers have been examined in this way, e.g. welders, coalminers, asbestos, foundry and steel workers. Magnetopneumography also allows analysis of the distribution of aerocontaminants in the different anatomical structures and, when repeated, the study of clearance speeds and migration from site to site of such particles. Emphasis has been laid on the importance of study of the fading of the remanent magnetic signal as time elapses. This short-term phenomenon, called relaxation, seems highly significant for the study of the dynamic properties of the immediate environment of extra pulmonary particles and especially for the study of macrophage activity.

Air Pollutants, Occupational

Aortic percutaneous transluminal valvuloplasty in elderly patients by balloon larger than aortic anulus.

Twenty-four elderly patients (79 +/- 7 years) with long-standing calcified aortic stenosis have been divided in two comparable groups of 12. The first group was treated with 19 mm balloon percutaneous transluminal valvuloplasty, where the balloon diameter was always smaller than the aortic anulus diameter. Peak-to-peak aortic valve gradient decreased from 76 +/- 32 mmHg to 30 +/- 19 (P less than .05), and the aortic valve area, calculated by Gorlin formula, increased from 0.40 +/- 0.17 cm2 to 0.57 +/- 0.17 (P less than .05). The second group was treated with a trefoil 25 mm balloon, always larger than the aortic anulus diameter. In this second group, peak-to-peak aortic valve gradient decreased from 73 +/- 34 mmHg to 23 +/- 15 (P less than .05), and aortic valve area increased from 0.47 +/- 0.14 cm2 to 0.88 +/- 0.36 (P less than .05), increasing thus more than in group I (P less than .05). Clinical tolerance to balloon inflation was not the same according to individual patients but was similar between the two groups; complications were comparable in the two groups. These results suggest that aortic valvuloplasty by trefoil balloon larger than aortic anulus can provide wider aortic valve area without increasing complication rate.

Aged

[Estimation of pulmonary dust load using magnetic pneumography].

If an occupational history enables the identification of subjects at high risk from occupational disease, it yields no information on the individual dust level on account of very important inter-individual variations in pulmonary dust retention. Magnetopneumography is the only technique which enables pulmonary dust loads to be estimated on living subjects. The first measures of dust load by magnetopneumography made at the Ambroise Pare Hospital are reported. By knowing the magnetic properties of occupationally inhaled aero-contaminants, this technique is sensitive and non-invasive and enables the total pulmonary dust load to be estimated from the study of the residual magnetism in the ferromagnetic component of these aero-contaminants. A SQUID magnetometer measures this magnetism on 5 lines of the anterior surface of the thorax after overall magnetisation of the latter by an external magnetic field of 30 kA/m. Measurements were made on 18 male subjects: 5 non-exposed controls and 13 occupationally exposed subjects to these aero-contaminants. The dust load calculated was variable, 0 in the controls and between 0 and 3,065 mg in exposed subjects. For the first time measures were made in 4 dental technicians: their dust load was between 725 and 3,065 mg. The problems posed by this method are broached. Its principle objective is the surveillance of occupationally exposed population to these aero-contaminants of ferromagnetic composition. A decrease in the residual magnetic signal after the cessation of magnetisation was observed in keeping with the data of the literature. This phenomenon, recognised under the term of "relaxation", is evidence of the activity of alveolar macrophages.

Adult

Nitroglycerin-induced decrease of carbon monoxide diffusion capacity in acute myocardial infarction reversed by elevating legs.

Hemodynamic and respiratory variables were measured in 18 supine patients with acute myocardial infarction uncomplicated by left ventricular failure. Measurements were done during a control period and then when pulmonary capillary bed filling was decreased by iv injection of 3 mg nitroglycerin (NTG) and finally when pulmonary capillary bed filling was increased by raising the patients' legs. Heart rate increased significantly (p less than .05) ventricular filling, and mean aortic pressures dropped significantly (p less than .001) after NTG injection. Heart rate and mean aortic pressure returned to control level and ventricular filling pressures increased significantly (p less than .001) after elevating patients' legs. Mean carbon monoxide diffusion capacity decreased significantly (p less than .01) from 9.8 +/- 3.4 to 8.5 +/- 2.9 ml/min X mm Hg after NTG injection and increased significantly (p less than .02) to 9.3 +/- 3.5 ml/min X mm Hg after elevating patients' legs. Pulmonary wedge pressure decreased significantly (p less than .001) from 15 +/- 5 to 8 +/- 4 mm Hg after NTG injection and increased significantly (p less than .001) to 10 +/- 4 mm Hg after elevating patients' legs. We conclude that NTG reduces pulmonary capillary filling and pulmonary diffusion by reducing the available pulmonary gas exchange surface.

Adult

[Choriocarcinomatous neoplastic pulmonary embolism. A case].

Massive obstruction of the right branches of the pulmonary artery by choriocarcinomatous cells was found at embolectomy in a 36 year old woman who had had a hydatidiform mole 10 years previously. Several febrile lung infections resistant to antibiotic therapy over an 11 months period, had led to a reduction in the volume and vascularisation of the right lung. The diagnosis of recurrent pulmonary embolism was only suspected when a further embolic episode occurred after curettage for a spontaneous abortion at 9 weeks of pregnancy. The diagnostic value of increased HCG was masked by the pregnancy. The patient died a few days after surgery despite administration of chemotherapy postoperatively. The authors discuss the problems in the diagnosis of recurrent pulmonary embolism in the absence of a suggestive cause and the problem of detecting the tumoural nature of these emboli.

Adult

[Sarcoidosis and Whipple's disease. Association? Relation?].

On the basis of a personal case in which two successive diagnoses of sarcoidosis and Whipple's disease were made at an interval of four years, the authors discuss the possible association or relationship between these two disorders, both diffuse, affecting the reticulo-histiocytic system and diagnosed on a histological basis. Review in the literature of 54 cases of Whipple's disease with pleuro-pulmonary lesions makes it possible on the one hand to associate with the latter numerous examples of extra-intestinal involvement, the histological appearance of which of a non-specific epithelioid granuloma does not indicate the diagnosis during the long pre-intestinal phase, and on the other hand to explain that during this period, the presence of pleuro-pulmonary lesions leads to an initial diagnosis of the probability of sarcoidosis. The practical consequences are as follows: The appearance of intestinal signs during "sarcoidosis" should lead to intestinal or mesenteric node biopsy to seek the macrophages with highly PAS positive cytoplasm characteristic of Whipple's disease. Their discovery necessitats long term antibiotic therapy which has recently transformed the outlook in this disease, invariably fatal in the past.

Bronchi

[Action of acebutolol on heart rate and FEV1 in asthmatic patients. Single intravenous administration and long term oral administration].

In 7 asthmatic patients, intravenous injection of acebutolol resulted in a slowing of the heart rate by blocking the cardiac beta-receptors. An aerosol of isoprenaline, which accelerated the heart, is without effect after intravenous injection of acebutolol. On the contrary, isoprenaline caused similar changes in the FEV1 before and after acebutolol injection in the same patients. This effect confirms the slight action of the compound on the beta2-adrenergic receptors. Prolonged oral administration did not cause any adverse clinical effects in 6 asthmatic patients.

Acebutolol