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Biomedical subjects

J Faure

Publications and source records attributed to J Faure.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Standardization of the anatomic study of the brain stem in x-ray computed tomography and magnetic resonance imaging].

The presence of flexures between the mesencephalon, pons and medulla oblongata implies the definition of specific orientations of axial sections for each level of the brain stem. These axial sections have to be perpendicular to the axis of the corresponding segment. For the mesencephalon, we have defined an axis corresponding to a straight line of best fit to the mesencephalic anatomical axis; the whole of the rhombencephalon has been referred to an axis taken through the pons and the intracranial medulla that is tangential to the floor of the IV ventricle. Identical reference planes can be obtained in CT by programming, on the scout view of the skull, perpendicular sections of the clivus that allow the study of the axial aspect of the mesencephalon, with sections at - 7 degrees through Chamberlain's line for visualization of the same aspect of the rhombencephalon. We have thus defined the referential planes to analyse every level of the brain stem using reproducible axial sections, able to be applied to different patients as well as to different examining techniques (TDM, MRI).

Adult↗
PubMed1988

Sino-atrial dissociation: evidence by intracardiac recordings in man and by microelectrode studies on isolated rabbit atrium.

The electrophysiologic mechanisms of sinus dysfunction have recently been determined by direct recordings of the sinus node electrogram. The association of various degrees of abnormalities in the formation of the impulse within the sinus node and of sinoatrial conduction block, represents the pathophysiological substrate of the mechanism of sinus node dysfunction. The purpose of this work is to present clinical and experimental data supporting the concept of sinus node isolation. In our clinical case, the sinus node was probably intact despite aspects of sinus node dysfunction on the surface ECG. Sinus node electrograms were recorded with a sinoatrial conduction time of 100 ms (normal values in our laboratory: 83 ms +/- 38 ms). Atrial mapping demonstrated that the area depolarized by the sinus node involved a 2 cm2 zone surrounding it. This perisinusal activity could not be recorded on the surface ECG. Both exit and entry blocks in the sinus node were demonstrated. Our experimental data showed a total desynchronization between the electrical activity of the sinus node and that of the atrium under hypoxic conditions. Both types of cases demonstrated that an atrial dysrhythmia was coexisting with regular sinus activity. From these data we concluded that a sinus node free from any pathological involvement could be associated with severe symptoms of sinus node dysfunction on the surface ECG.

Animals↗
PubMed1988

[An electron paramagnetic resonance study of 4 salivary calculi treated in an ionized oxygen atmosphere].

Four salivary calculi and synthetically prepared hydroxyapatite, tricalcium phosphate and B-type carbonated fluorapatite or hydroxyapatite were treated under excited oxygen atmosphere. All these samples were studied by Electron Spin Resonance at 100 K. The presence of paramagnetic ozonide ions was observed only in the salivary calculi and in the hydroxyapatite. This indicates that the dominant apatite phase in salivary calculi is weakly carbonated hydroxyapatite.

Apatites↗
PubMed1986

[Intra-sinus echo: demonstration using direct intracavitary recording of the sinus potential].

The authors searched for intra-sinusal echos during electrophysiological investigation of 53 patients (41 men, 12 women, average age: 61 +/- 12 years). Cycles of sinus echos were recorded in 8 patients (15 per cent). The period during which sinus echos could be recorded was 125 ms (average 40.6 +/- 34 ms). Indirect assessment of sinus node function in patients with sinus echos was normal (corrected sinus node recovery time, estimated atrio-sino atrial conduction times using Narula's technique). A valid and reproducible direct recording of the sinus node potential was only possible in one patient. In this case the echo cycles were provoked by stimulation periods of between 440 and 320 ms (echo zone of 120 ms). All the echos obtained were preceded by a sinus node potential with a different duration and morphology to that observed during basal sinus cycles (respective sino-atrial conduction times 105 and 115 ms). In this patient we were also able to induce sinus echos after a single extrastimulus during the spontaneous rhythm. the echo zone was 130 ms and with a shorter coupling interval (310 ms) two successive sinus echos were recorded. The demonstration of intrasinusal echos by direct recording of the sinus node potential supports the experimental data of Allessie and Bonke on isolated right atrial tissues of the rabbit. Improvements in the technique of endocavitary direct recording of the sinus node potential in man should complete this data by showing the possibility of sinoatrial tachycardias due to reentry.

Action Potentials↗
PubMed1986

[Microanalysis of salivary calculi].

Eight salivary calculi were sectioned along a plane of symmetry and the sections studied by microanalysis. Three different regions were observed: a central region with one or several strongly mineralized nuclei, a stratified, less mineralized region with a lower Ca/P ratio and finally a peripheral weakly calcified region. Although inclusions with high silicium or sulfur concentrations were found in all samples, their role in the genesis of calculus is not clear. Most often filamentous mineralized bacteria were observed by scanning electron microscopy on the external stone surface.

Microscopy, Electron, Scanning↗
PubMed1985

Carbon monoxide poisoning, a diagnosis frequently overlooked.

Carbon monoxide (CO) is a common source of poisoning, yet the diagnosis is often overlooked. A study was undertaken to establish the true incidence of missed diagnosis and to assess retrospectively the effects of a campaign of public medical information on this subject. The wrong diagnoses reflected all the unusual clinical presentations that CO could produce. The high initial rate of wrong diagnoses (30% in 1975-1977) was reduced following the campaign (12% in 1978 and 5% in 1980) despite a considerable increase in the rate of admission to hospital of confirmed CO poisoning cases.

Carbon Monoxide Poisoning↗
PubMed1984

Trichloroethylene occupational exposure: elements for better prevention.

One hundred and eighty-eight workers occupationally exposed to trichloroethylene (TRI) were studied by physical examination, exposure parameters (measure of atmospheric TRI and urinary trichloroacetic acid (CA) and evaluation of personal factors (age, alcoholic and tobacco consumption). A statistical comparison (chi 2 test) of the frequency of the symptoms observed in the high- and low-exposure populations with an analysis of nonprofessional factors allowed us to distinguish different classes of symptoms. Those more likely linked with TRI exposure are trigeminal and optic nerve impairment, asthenia, headache and dizziness. An interaction between TRI exposure and alcohol intake on the occurrence of clinical liver impairment and degreaser flush is suggested.

Adult↗
PubMed1984

[Sinoatrial and intra-atrial conductive disorders. The value of recording the sinus node potential].

Direct recording of the sinus node potential in the bipolar mode using two electrodes of a quadripolar recording catheter positioned in the region of the sinus node at the junction of the superior vena cava to the right atrium was performed in 24 patients. Asynchronous overdrive atrial pacing was carried out using Strauss 'technique. Pharmacological denervation was carried out using intravenous propranolol (0,02 mg/kg) and atropine (0,04 mg/kg) using Jose's technique. An intravenous injection of a bolus of 20 mg of ATP was given in 3 cases. The sinus potential was identified by morphological criteria and confirmed after carotid sinus compression and atrial extrastimuli to exclude artefacts, especially the end of ventricular repolarisation of the preceding complex. The sinoatrial conduction time measured directly under basal conditions was considered normal when within 80 to 150 ms. Direct measurement of the sinus potential in the diagnosis of sinus node dysfunction seems to be less useful than the indirect techniques. On the other hand, it does confirm the diagnosis of sinoatrial block: five cases of special interest are described; in four cases the degree of sinoatrial block was variable: a significant increase of sinoatrial conduction time under basal conditions in 1 case; paroxysmal 3rd degree sinoatrial block revealed by programmed atrial stimulation in 2 cases; 2nd degree 2/1 sinoatrial block after injection of ATP in which the direct sinoatrial conduction time and sinus node function had been considered to be normal (1 case).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Exposure to anesthetic gases: risk and prevention].

Several studies published during the last fifteen years seem to demonstrate that major risks, i.e. congenital malformations in the offspring and increased rate of spontaneous abortions, are associated with occupational exposure to anesthetic gases (halothane and nitrous oxide) in operating rooms. In view of the severity of the potential risk, we have: 1) analyzed risk factors in the light of epidermiologic and experimental studies; 2) determined the threshold levels of air pollution for these risk factors; 3) analyzed the situation in the Grenoble Hospital and the means of dealing with it.

Abnormalities, Drug-Induced↗
PubMed1983

[Levels of lead, cadmium and mercury in the hair of inhabitants of the Nantes and Grenoble areas].

Lead, cadmium and mercury were measured in the air of 398 inhabitants of the Grenoble area and 341 inhabitants of the Nantes area. The hair was washed with hor solution of EDTA, dissolved in nitric acid and analyzed by electrothermal atomic absorption spectrometry. The average concentrations are 6,23 micrograms/g for lead, 0,40 microgram/g for cadmium and 1,06 microgram/g for mercury. There is no difference between found data of the two areas for lead and cadmium. Mercury levels are higher in the Nantes area. Lead content is higher in male hair than in female hair, but the difference is not significant. In the Grenoble area, mercury levels are higher in males than in females; the process is reversed in the Nantes area. We have found no relation between metal levels and age of persons, but lead content is high in the hair of people under ten. Artisans and mechanics have lead content higher than the general people, though exposed people to occupational risks is excluded. We have found to relation between metal in the hair and the size of the town. It seems that the use of tobacco is without influence. Mercury content is related to the eating of fish. It is not increased in the population because of dental amalgams.

Adolescent↗
PubMed1983

[Poisoning with chlorine gas. Immediate and late sequelae].

The goal of this study is to appreciate the early and late sequelae caused by Chlorine Gas. 186 exposed patients have been admitted to our unit since 1962-119 had functional respiratory explorations (FRE) with an analysis of blood gases, 79 underwent a study of carbon monoxide transfer. The results are in accordance with the literature for example 25% of the CO transfer test were pathological. 56 occupationally exposed subjects having had at least three acute episodes of exposure have been compared to 197 control subjects (groups were classed in function of age, tobacco intake, and pulmonary antecedent). Chlorine exposure even when frequent has no the influence on the FRE results or the appearance of pulmonary pathology. The pre-existence of a pulmonary disease doesn't affect the prognosis.

Adult↗