Biomedical subjects

M Toussaint

Publications and source records attributed to M Toussaint.

At least 19 recordsLinked to original sources

PubMed1995

All-night EEG spectral analysis as a tool for the prediction of clinical response to antidepressant treatment.

Earlier investigations have suggested that variables derived from quantified electroencephalographic (EEG) sleep analysis might predict good clinical response in an early phase of antidepressant treatment. In this report we evaluate the predictive value of all-night sleep EEG spectral analysis during the washout period before treatment. We compared the spectral EEG sleep profiles of major depressed inpatients divided into two groups according to an improvement > or = 50% on the Hamilton Rating Scale for Depression. Findings in this population demonstrate the presence of specific characteristics of the responder group compared with the nonresponder group. Delta band relative power was increased in the former group, while theta, alpha, and beta relative power were decreased. All the bands showed decrease in absolute power in the responder group. These results can be interpreted as enhanced sleep intensity in the responder group. All-night sleep EEG spectral variables are valid baseline markers of the functional differences between treatment responders and nonresponders and thus might permit prediction of clinical outcome.

Adult↗

PubMed1995

First-night effect in normal subjects and psychiatric inpatients.

The goal of the present study was to evaluate the first-night effect in psychiatric inpatients using large subject samples (n > 30) in order to obtain a good statistical evaluation. Thirty-two normal subjects and 94 psychiatric inpatients (38 depressives and 56 insomniacs) were studied for three consecutive nights in the hospital sleep laboratory. Our results showed clearly that there was a first-night effect in normal subjects, similar to that reported in previously published data, characterized by a longer rapid eye movement (REM) sleep latency (p < 0.05), increased wakefulness (p < 0.01) and total sleep time (p < 0.02) and a decreased sleep efficiency (p < 0.01). REM sleep latency and stage REM in the first third of the night were still altered in the second night. Both clinical groups had a less marked first-night effect than normal subjects, showing alterations only observed in REM sleep (p < 0.01) (decreased REM sleep, longer REM sleep latency, increased REM sleep gravity center). However, the first-night effect was more pronounced in insomniacs than in depressed patients. No statistical differences between the second and third nights' recordings were found in sleep parameters. It is suggested that first-night data should not be simply discarded but could be used in subsequent analyses.

Adaptation, Psychological↗

PubMed1994

Initial experience with the Europass: a new ultra-low profile monorail balloon catheter.

One of the causes for percutaneous transluminal coronary angioplasty (PTCA) failure is the inability to cross the lesion with the balloon catheter after guidewire positioning. The Europass coronary angioplasty catheter is a monorail Duralyn balloon catheter developed to enhance lesion crossability and to overcome this limitation. This system was evaluated in 50 patients in which target lesions were chronic total coronary occlusions (12 cases) or stenoses that could not be reached or crossed by other new monorail balloon catheters. Overall procedural success was obtained in 49/50 patients (98%), using a single Europass balloon catheter in 46/50 patients (92%), with no in-hospital complications. Its low profile, small distal shaft, and excellent trackability allowed successful angioplasty in cases where other catheters failed. This balloon catheter represents a significant advance in angioplasty technology and can be considered as a first-choice device for a safe and expeditious single-operator procedure.

Aged↗

PubMed1994

An architecture for EEG signal processing and interpretation during sleep (ESPIS).

The project's aim is to develop a dedicated workstation in order to process multiple channels of electrophysiological signals in real-time during sleep. In ESPIS we are aiming to define both an architecture and an environment for EEG signal interpretation in medicine based on computer science gold standards (Unix, XWindow, Motif). Signal processing and pattern recognition analysis are provided by parallel processing on a specific developed acquisition architecture (DSP) based on transputers. The main result is a high performance prototype demonstrating signal interpretation during sleep which has already been tested in a medical environment. The overall specifications allow this biomedical device to be extended to other types of medical signals.

Algorithms↗

PubMed1994

Specific skin lesions in a patient with Niemann-Pick disease.

We report a patient with Niemann-Pick disease who developed papular lesions on the face. These showed ultrastructural findings typical of this disorder. Specific skin lesions such as these are an extremely rare manifestation of Niemann-Pick disease.

Adult↗

PubMed1993

[Left pulmonary artery originating from the ascending aorta in tetralogy of Fallot. Therapeutic strategy].

The authors report the rare case of a 12 year old child with an anomalous origin of the left pulmonary artery from the ascending aorta associated with Tetralogy of Fallot. This complex congenital malformation was treated surgically by a Deleval anastanosis between the right subclavian and right pulmonary arteries. The result was good with a 9 year follow-up, the patient having only Grade II effort duspnoea and cyanosis. The authors discuss the advantages and drawbacks of the different possible surgical approaches to this problem in the light of the outcome of this case and a review of the literature.

Anastomosis, Surgical↗

PubMed1992

[Primary leiomyosarcoma of the pulmonary artery. Apropos of a case. Review of the literature].

A 59-year-old woman hospitalised because of dyspnea and a heart murmur in a context of pyrexia was found to have evidence of obstruction of the pulmonary arterial system, clearly defined by ultrasonography, catheterisation and angiography and Imatron scan. The particular feature of this fifth reported case of pulmonary artery leiomyosarcoma is its documentation by transesophageal ultrasonography and tumor biopsy during catheterisation. Surgery with partial excision of the tumor was followed by survival for 6 months, bearing in mind the absence of chemo- or radiosensitivity of this type of tumor. Cases from the literature are reviewed.

Angiography↗

PubMed1992

[Tetralogy of Fallot and mitral valve stenosis].

The association of tetralogy of Fallot and mitral stenosis is extremely rare. This is probably the first description of this association. The clinical and haemodynamic presentation is similar to that of cyanotic heart disease with pulmonary stenosis and post-capillary pulmonary hypertension. The mitral stenosis was probably congenital as it was diagnosed at 14 months of age.

Adult↗

PubMed1991

[Neuro-electrophysiologic studies in abstinent and depressed alcoholic patients treated with tianeptine].

A concerted study of the clinical and electrophysiologic effects of tianeptine was conducted in alcoholic patients hospitalized for 5 weeks for alcohol withdrawal cures and subsequent depression. Because of the well known manifestations of infraclinical cognition impairment, sleep disorders and greater susceptibility to undesirable effects of psychotropic drugs, which hinder health care in this type of patient, the authors investigated changes in cognitive functions and the effect of tianeptine on sleep organization and daytime vigilance. Results after 4 weeks treatment (3 times 12.5 mg/day) included: besides its antidepressant effect, tianeptine reduces the manifestations of anxiety, without sedation effects, either clinical or electrophysiologic; tianeptine has no deleterious effect on cognitive functions, on the contrary, it appears to favour recovery when they are impaired; tianeptine does not modify sleep structure, notably in paradoxal sleep; tianeptine is an antidepressant which has a good acceptability, even for a population at "risk".

Adult↗

PubMed1991

A statistical evaluation of the main interpolation methods applied to 3-dimensional EEG mapping.

This paper is a review of the main interpolation methods applicable to 3-dimensional EEG mapping. The use of simple statistical comparison methods on recorded EEG maps allowed us to evaluate the qualities of interpolation methods belonging to 3 mathematical families (barycentric, polynomial, spline). A combination of a 3-dimensional representation of EEG maps and a reliable interpolation method makes it possible to obtain better spatial resolution than with standard planar mapping.

Brain Mapping↗

PubMed1991

[Demonstration of abnormalities of myocardial mitochondrial oxygenation in cardiac graft rejection].

Abnormalities of myocardial metabolism during acute rejection may be due to ischemia to primary metabolic changes related to rejection. An experimental study of heterotopic cardiac transplantation in the rat was undertaken to study myocardial mitochondrial oxidation during acute rejection. The receivers were Lewis rats and the donors Fischer (FL: allograft) or Lewis (LL: isograft) rats. The oxygen consumption of the mitochondria (VO2m) isolated from the transplanted and native hearts was measured by oxygraphy six days after transplantation. Using maleate and glutamate substrates, the VO2m of transplanted hearts was significantly lower than that of native hearts in the two groups of rats (FL, p less than 0.01; LL, p less than 0.01). In addition, the VO2m of FL allograft transplanted hearts was significantly lower than in the LL rats (30 +/- 9 vs 100 +/- 15 nanoatoms of oxygen/min.mg/prot, p less than 0.01) as was the VO2m of the native hearts (FL: 106 +/- 23 vs LL: 164 +/- 26, p less than 0.02). The respiratory control ratio (RCR) was significantly lower in the transplanted than in the native hearts in both the FL and LL groups (p less than 0.05 and p less than 0.01 respectively). The comparison of the RCR in the two groups (FL vs LL) showed no significant difference for transplanted or native hearts. Electron microscopy of transplanted (rejected or not) and native hearts showed no morphological abnormality of the mitochondria. The lower VO2m of the allograft group indicates a disturbance in the mitochondrial respiratory pathway during acute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Characterization of a glucuronide metabolite of 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its dose-dependent excretion in the urine of mice and rats.

Following analysis by reversed-phase HPLC, a previously uncharacterized metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was found in the urine of A/J mice treated with NNK. Treatment with beta-glucuronidase converted the metabolite to a peak that co-eluted with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). Treatment with sulfatase or beta-glucuronidase plus saccharic acid 1,4-lactone did not change the retention time of the metabolite. These data suggested that the unknown metabolite was a glucuronic acid conjugate of NNAL. Upon isolation and purification of larger quantities of the metabolite from the urine of A/J mice, CD-1 mice and F344 rats, 1H and 13C NMR and MS confirmed that the unknown metabolite was 4-(methylnitrosamino)-1-(3-pyridyl)-1-butyl beta-D-glucopyranosiduronic acid (NNAL Glu). To determine the quantitative relationship between NNK dose and NNAL Glu production and to compare the importance of glucuronidation relative to other metabolic pathways, [5-3H]NNK was administered to F344 rats and A/J mice at doses of 500-0.005 mumol/kg. At 500 mumol/kg, NNAL Glu accounted for 22% of the total urinary excretion of NNK in A/J mice, and for 8% in F344 rats 48 h after dosing. The proportions of excreted glucuronide and NNAL decreased with diminishing doses of NNK, yielding undetectable levels of each metabolite in both mice and rats at a dose of 0.005 mumol/kg NNK. Since substantial amounts of metabolites formed via alpha-hydroxylation and N-oxidation pathways were observed at the lower doses of NNK, these data demonstrate that NNAL glucuronidation is a quantitatively unimportant metabolic pathway at low doses of NNK.

Animals↗

PubMed1990

[Dilated cardiomyopathy with deep, completely reversible dysfunction of the left heart in alcoholic patients. Report of 2 cases].

Two cases of dilated, hypokinetic cardiomyopathy complicated by cardiac failure, are reported in a 29 year old woman and a 55 year old man, with no etiological factors other than chronic major alcoholism (consumption of over 100 ml of alcohol per day for over 5 years). This was completely reversed 10 and 14 months after cessation of alcohol consumption. The isotopic left ventricular ejection fraction increased from 22 to 70 p. 100 and from 12 to 73% respectively. These cases are are and are evidence in favour of an alcoholic cardiomyopathy rather than alcohol being an aggravating factor in patients with cardiomyopathy.

Adult↗

PubMed1990

Evidence of mitochondrial impairment during cardiac allograft rejection.

NADH laser fluorimetry and mitochondrial oxigraphy were used to study myocardial oxidative energy metabolism during cardiac allograft rejection. Heterotopic cardiac transplantation was performed on Lewis rats; allografts (with Fischer rat donors) were compared with isografts (with Lewis rat donors). In vivo and in vitro assays were performed six days after transplantation. Myocardial NADH fluorescence was recorded in vivo from grafted hearts, at baseline; during brief, complete ischemia; and during reperfusion. Oxygen consumption of mitochondria isolated from both native and grafted hearts was determined. Neither baseline levels nor maximum ischemic levels of NADH fluorescence (F0 = k[NADH]) were found to be significantly different between allografts (0.45 +/- 0.05 to 0.87 +/- 0.10) and isografts (0.45 +/- 0.04 to 1.11 +/- 0.05). During recovery, the rate of fluorescence decrease was significantly lower in allografts than in isografts (0.024 +/- 0.001 vs. 0.038 +/- 0.002 delta F0.s-1, P less than 10(-3], indicating a lower rate of NADH reoxidation. In the presence of malate and glutamate substrates, mitochondrial O2 consumption was significantly lower in allografts than in isografts (30 +/- 9 vs. 100 +/- 15 nanoatoms O2. min-1.mg prot-1, P less than 10(-2]. These results indicate that mitochondrial oxidative metabolism was impaired during the rejection process. Such energy production disturbances may contribute to the dysfunction of rejecting hearts.

Animals↗

PubMed1990

Intrauterine versus postnatal repair of created pulmonary artery stenosis in the lamb. Morphologic comparison.

Experimental lamb models were used for intrauterine creation of pulmonary artery stenosis and later intrauterine repair or postnatal repair. Intrauterine creation of pulmonary artery stenosis was performed in 23 fetal lambs at 90 +/- 1 days of gestation. Eight lambs underwent intrauterine repair of pulmonary artery stenosis at 135 +/- 1 days of gestation and were studied 110 +/- 13 days after repair. Seven lambs underwent postnatal repair at 57 +/- 9 days after birth and were studied 162 +/- 32 days after repair. Eight fetal lambs with unrepaired pulmonary artery stenosis were studied 89 +/- 18 days after birth. All study lambs were compared with normal control lambs. The systolic right ventricular pressure was significantly higher after unrepaired stenosis (78.6 +/- 6.8 mm Hg) than in other lambs, but there was no statistically significant difference after intrauterine repair (23.3 +/- 2.9 mm Hg), postnatal repair (25.9 +/- 3.4 mm Hg), and normal lambs (21.6 +/- 1.1 mm Hg). The systolic pulmonary artery pressure was also not statistically different in these three groups. The weight measurements were age-adjusted for comparison of postnatal and intrauterine repair with normal lambs. The adjusted heart weights were similar in the three groups. The comparison of the adjusted heart weight/adjusted body weight ratio (10(-3) showed a significantly higher ratio in postnatal repair (7.4 +/- 0.1) than in intrauterine repair (6.1 +/- 0.1). The adjusted right ventricular weight/adjusted left ventricular weight ratio was significantly higher in the postnatal repair group (0.71 +/- 0.01) than in both the intrauterine repair group (0.59 +/- 0.01) and normal lambs (0.59 +/- 0.01). The transverse myocyte diameter was not statistically different in all groups of animals and there were no ultrastructural changes even when the pulmonary stenosis was unrepaired. We conclude that intrauterine repair was more satisfactory than postnatal repair in terms of age-adjusted heart weight results, but we did not find any advantages of intrauterine repair in terms of histologic and ultrastructural changes.

Animals↗

PubMed1989

[Angina without involvement of large coronary trunks and precapillary pulmonary hypertension in a patient with periarteritis nodosa].

A patient affected with periarteritis nodosa and angina, presented a normal coronary angiography of the coronary trunks and an alteration of the left ventricular systolic function, improved by nicardipine, as well as a pre-capillary pulmonary hypertension with isolated, right cardiac repercussions, without pulmonary fibrosis nor thromboembolic disease. In addition, he presented three transient cerebral ischaemic accidents, with different localizations, which could not be related to a right aneurysm of the sylvian artery. Isolated precapillary pulmonary hypertension, without pulmonary fibrosis, which is not described in the course of periarteritis nodosa, seems related to an arteriolar involvement which is the known substratum of other visceral involvement in periarteritis nodosa. Improvement of the left ventricular function with nicardipine, administered acutely, suggest a partially reversible disorder of the coronary microcirculation.

Angina Pectoris↗

PubMed1988

[Caffeine and EEG mapping: effects of visuo-spatial task in healthy volunteers].

A group of 10 subjects, normal volunteers (6 men, 4 women), mean age 27.2 years, right-handers, has been selected for a double-blind study of caffeine effects (400 mg per os) versus placebo. One week delay separated the two EEG sessions quantified by spectral analysis. During each session (16 EEG channels, common reference), each subject was recorded four times: 2.5 min, in eyes-closed condition, under diffuse attention, followed by 2.5 min, during a visuo-spatial task ("eyes open" condition: presentation of a picture). These two EEG recordings were obtained before the oral administration and repeated 1 hr after the administration of caffeine or placebo. Individual and group results presented globally: 1) an increase in mean frequencies of alpha activity in "eyes closed" condition, and of delta activity in "eyes open" condition; 2) a decrease of alpha activity amplitudes (both RMS and % values) in both conditions; 3) a decrease of total RMS amplitudes in "eyes closed" condition; 4) an increase of relative % amplitudes for beta 2% fast activity in the "eyes open condition". These results characterize the psycho-stimulant effects of caffeine, especially over the left temporal area which was confirming an initial statistical hypothesis of specific cerebral local activation. The non-parametric permutation tests of Fisher, were not always reaching statistical significance for the same EEG channel quantified by one of the 17 analyzed spectral parameters, except on the left temporal area. During the visuo-spatial task, the decrease in alpha amplitudes (RMS and %) was also statistically significant, but over larger areas: over left and right temporal, central and parietal regions. In both conditions, eyes closed and eyes open, the alpha RMS amplitude was also decreased over the right anterior frontal area.

Administration, Oral↗

PubMed1988

Congenital valvular aortic stenosis in adults.

Based on a study of 20 patients operated on between the ages of 21 and 38 for congenital valvular aortic stenosis, the distinguishing features of congenital aortic valvular stenosis in adults are reviewed: valvular calcification (75%), valvular dome rarely present (10%), usually moderate cardiac disability (70%), diminished or inaudible second heart sound (50%), associated diastolic murmur (75%), electrocardiographic left ventricular hypertrophy (70%), and an infrequent protosystolic click (30%). Surgery is necessary for symptomatic patients. If patients are asymptomatic, surgery is decided after measuring the left ventricle-aortic pressure gradient by continuous Doppler wave study, or by cardiac catheterization. If surgery is not performed, a regular follow-up is necessary because stenosis can evolve. Valvular replacement by a mechanical valve is preferable. Even if the aortic valve is not calcified and a simple commissurotomy is technically possible, it is only a palliative method with unsatisfactory results and an annual mortality rate after surgery of 1%.

Adult↗