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Biomedical subjects

J M Dupuis

Publications and source records attributed to J M Dupuis.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of computational algorithms applied on transthoracic impedance waveforms to predict head-up tilt table testing outcome.

The goal of the present study was to develop and evaluate new algorithms for the prediction of the outcome of a head-upright tilt test (HUTT). Using transthoracic impedance and its first derivative, we attempted to determine if indexes computed on these waveforms could detect a positive outcome to a 70 degrees -45min HUTT with reliable sensitivity and specificity. The methods were evaluated retrospectively in a group of 70 patients and validated prospectively in a group of 59 patients. The best detector obtained used a neural network. It compares very favorably with published results for other syncope detectors.

Adolescent↗
PubMed2005

[Kidney transplanted child and sport practices].

OBJECTIVE: Evaluation of physical capacity in kidney transplanted children for sport practice adequacy. POPULATION AND METHODS: A retrospective study was carried out in 32 children transplanted at least one year before evaluation. We studied auxology, respiratory function testing, cardiovascular parameters at rest and after exercise, and aerobic capacity performed during a triangular effort test. RESULTS: Kidney transplanted children were smaller and had a higher body mass index (IMC). Breathing parameters and cardiac ultrasound examinations were normal in all but one child. After exercise, four children had high systolic blood pressure requiring a treatment adaptation. Lower values of maximal aerobic power (Pmax) and oxygen maximal uptake (VO2max) were noticed, mainly in girls. CONCLUSION: Kidney transplanted children have a good physical exercise tolerance. Therefore they can be allowed to practise sports at school or in a club after a normal effort test (taking into account the risk of transplant trauma).

Adolescent↗
PubMed2004

[Cardiac manifestations of laminopathies].

Dilated cardiomyopathy (DCM) of genetic origin represents about 25% of all so-called primary DCM. Cases due to mutation of the gene which codes the lamins A and C (LMNA) carry a poor prognosis with a high risk of sudden death. The finding of primary DCM in a young person associated with conduction defects or arrhythmias should lead to investigation for mutation of the gene of lamins A and C, even in the absence of a suggestive family history. The authors report 5 cases of DCM, with and without associated skeletal muscular disease, due to laminopathies.

Adolescent↗
PubMed2003

[Psychiatric complication of an implanted automatic defibrillator].

The implantable automatic defibrillator has completely changed the prognosis of potentially fatal ventricular arrhythmias by the delivery of an electric shock in the event of ventricular tachycardia or fibrillation. This vital device is sometimes poorly accepted from the psychological point of view by patients having been traumatised by experiences of sudden death from which they have been rescuscitated. Anxiety and depression are common and they have an important effect on the quality of life. The unpredictable occurrence of painful, multiple and uncontrollable electrical shocks may induce a state of acute stress with stunning, the resemblance of which to the model of learned helplessness described experimentally in the animal by Seligman, is discussed. The authors report the case of a 20 year old man whose automatic defibrillator was activated twenty times in one night. His state of stress and impotence was such that he lay prostate in his bed. Suicide seemed to be the only possible way of escaping from the electrical shocks of the device which was perceived as being dangerous. The management of this condition is not standardised but it requires the collaboration of the cardiac rhythmological and psychiatric teams. Medication with antidepressant drugs alone is not sufficient. The regulation of the sensitivity of the defibrillator gives the patient a feeling of mastering the situation: submission is not total! Research along this line should improve the patients' acceptation of the device and their quality of life.

Adolescent↗
PubMed2001

Echocardiographic assessment of the interventricular delay of activation and correlation to the QRS width in dilated cardiomyopathy.

The aim of the study was to define criteria for left ventricular pacing in dilated cardiomyopathy (DCM) using an echocardiographic evaluation of interventricular electromechanical delay (IMD) and a correlation of IMD to QRS duration. Standard 12-lead ECG and echocardiography with pulsed Doppler tissue imaging (DTI) were recorded in 35 DCM patients (mean age 58 +/- 11 years) with QRS duration from narrow (80 ms) to broad (222 ms) patterns. The timefor left ventricular activation was evaluated from the onset of QRS to the onset of aortic flow (Q-Ao) by standard pulsed Doppler (SP) or to the onset of mitral annulus systolic wave (Q-Mit) (DTI). The time for right ventricular activation was determinedfrom the onset of QRS to the onset of pulmonary flow (Q-Pulm) (SP) or to the onset of tricuspid annulus systolic wave (Q-Tri) (DTI). (Q-Ao)-(Q-Pulm) and (Q-Mit)-(Q-Tri) determined IMD for each method, respectively. QRS width and IMD showed correlation coefficients of r = 0.86 ([Q-Ao]-[Q-Pulm]) and r = 0.82 ([Q-Mit]-[Q-Tri]) (P < or = 0.001 ). Mean IMD of 77 +/- 15 ms (SP) and 88 +/- 26 ms (DTI) were noted for QRS width above 150 ms. Left ventricle delayed activation was positively correlated to QRS widening with both methods, (r = 0.90, [Q-Ao]), (r = 0.83, [Q-Mit]) (P < or = 0.001). In conclusion, QRS duration is a good marker of an interventricular mechanical asynchrony. According to IMD correction, left ventricular pacing may be mainly proposed to symptomatic DCM patients with QRS duration > 150 ms.

Adult↗
PubMed2001

Transient ST segment elevation in right precordial leads induced by psychotropic drugs: relationship to the Brugada syndrome.

Psychotropic Drugs and ST Segment Elevation. Transient ST segment elevation in right precordial leads with use of psychotropic drugs is reported in two cases of overdose and one case of therapeutic administration. Flecainide did not reproduce ST segment elevation. The relationship of these abnormalities to the Brugada syndrome and the electrophysiologic hypothesis are discussed.

Adult↗
PubMed2001

[Incidence and timing of thyroid dysfunction with long-term amiodarone therapy].

The aim of this retrospective study was to assess the incidence, timing and classical presentations of thyroid dysfunction in patients treated long-term with amiodarone. Ninety patients (sex ratio M/W 67/33, mean age 71 years) were followed up for 48 months. The daily dose of amiodarone was 200 mg after loading doses during the hospital stay for atrial fibrillation. The average treatment period was 33 +/- 19 months. Hypothyroidism, observed in 5.5% of cases, occurred at variable intervals with few clinical manifestations. Hyperthyroidism was more common (12.2%), occurred increasingly with time, and was clinically symptomatic with recurrent supraventricular arrhythmias in 36% of cases. Long-term amiodarone therapy causes undesirable thyroid side-effects for nearly 1 out of 5 patients. Hyperthyroidism is more common than hypothyroidism and may be explained by increased iodine intake. The increasing incidence of hyperthyroidism with time suggests a cumulated dose relationship, a situation which is not observed with hypothyroidism.

Adult↗
PubMed2001

[Dual chamber rate responsive pacing and chronotropic insufficiency. Comparison of double and respiratory sensors].

Late responsive DDD pacemakers are the most technically advanced devices presently available. These pacemakers are particularly useful in patients with chronotropic insufficiency when the sinus node is incapable of accelerating during exercise. The latest pacemakers have two sensors to reproduce optimal physiological sinus acceleration. The aim of this study was to analyse the performances of a new rate responsive pacemaker with a double activity and respiratory sensor, the interaction of which is automatically controlled by a sophisticated algorithm, in 12 patients (8 men and 4 women) with a mean age of 75 +/- 7 years. Analysis was based on the performance of the sensors used singly or in association: during three exercise stress tests with measurement of the VO2 max; during everyday activities using the data archived by the pacemaker and the answers to a simplified questionnaire on quality of life. The results showed that during exercise stress testing with measurement of VO2 max, the best performances were obtained with the double sensor or the respiratory sensor compared with the activity sensor alone, suggesting that these two sensors are more effective in intense exercise. This tendency was also observed in the analysis of the memory bank of the pacemaker which showed that the total duration of the faster heart rates was greater with the two sensors. On the other hand, the quality of life was not significantly different, whichever sensor was studied. Longer scale trials are necessary to appreciate the real value of these new double sensor pacing devices and to identify the best indications for their usage.

Aged↗
PubMed2001

[Loffler's fibroblastic endocarditis. A report of a case complicating toxocarosis].

The authors report a case of Löffler's fibroblastic endocarditis complicating a toxocarosis infection. Parasitic infestation with toxocara canis is usually asymptomatic, but this was a very rare observation of cerebral involvement associated with symptomatic Löffler's endocarditis. This is an unusual form of restrictive cardiac disease constantly accompanied by prolonged hypereosinophilia. In addition to the classical signs of cardiac failure, an acute febrile illness imitating a connective tissue disease may be observed. Echocardiography helps diagnosis by showing endomyocardial fibrosis and adherent thrombosis at one or both ventricular apices. The management of cardiac failure should include, whenever possible, radical treatment of the hypereosinophilia. At an advanced stage, surgical endocardial decortication is the only means of improving symptoms and the prognosis of these patients.

Coronary Thrombosis↗
PubMed2000

Cerebral hemodynamics in carotid sinus syndrome and atrioventricular block.

Carotid sinus syndrome (CSS) is a cause of syncope due to exaggerated baroreceptor-mediated cardioinhibitory/vasodepressive reflexes. We sought to determine if cerebral hemodynamics and regulation were specifically altered in these patients by comparison with pure asystole without vasodepression in patients with atrioventricular block (AVB). Mean blood flow velocity (transcranial Doppler sonography) and mean arterial blood pressure (Finapres) were recorded during cardioinhibition induced by carotid massage in patients with CSS (n = 14, 75 +/- SD 8 years) and asystole induced by temporary pacemaker inhibition in patients with complete AVB (n = 10, 69 +/- 11 years). Cerebrovascular resistance was estimated by the arterial pressure/cerebral flow velocity ratio, and dynamic cerebral autoregulatory responses were determined by the rate of regulation and autoregulatory index. Asystole and cardioinhibition each induced a decrease in arterial pressure (CSS 55 +/- 9% vs AVB 40 +/- 14%, p <0.05) and cerebral flow velocity (CSS 66 +/- 19% vs AVB 69 +/- 14%, p = NS), with an initial transient increase in cerebrovascular resistance (CSS 102 +/- 136% vs AVB 128 +/- 92%, p = NS) followed by a decrease (CSS 38 +/- 12%, AVB 29 +/- 13%, p = NS). The rate of regulation and autoregulatory index were higher with AVB (0.43 +/- 0.20 and 8.5 +/- 1.1 second(-1)) than CSS (0.20 +/- 0.12 and 4.8 +/- 1.3 second(-1), respectively, p <0.01 and p <0.001 vs AVB). During asystole and vasodepression, cerebral hypoperfusion in CSS is normally compensated for by cerebral autoregulation. The lower rate of regulation in CSS compared with AVB likely results from persistent peripheral vasodepression triggered by carotid massage.

Aged↗
PubMed2000

[Personal sports training in the management of obese boys aged 12 to 16 years].

OBJECTIVE: Estimation of both physical and psychological effects of an adapted physical training on children undergoing an obesity treatment. MATERIAL AND METHODS: The survey was carried out on 36 obese boys (ages = 12-16 years) who stayed in the medical center for at least four months. Eighteen of them were trained with the SELF method (the SELF-training is global, progressive, adapted to each boy, controlled and takes place within a ten-week period with five sessions a fortnight, each session lasting 30 to 40 minutes). The parameters that were studied concerned auxology, breathing function exploration, aerobic and anaerobic capacities, muscle strength and psychomotor qualities; the subjective effects of the training were estimated with a questionnaire about life quality, and the hand test. At inclusion the results were reported to a standard kind of population. At the end of the training the results of the 18 boys that were trained were compared to those of the 18 controls. RESULTS: Compared to a standard population, the obese children' aerobic capacity is diminished for the maximum power but is identical in absolute value for the VO2 max; their anaerobic capacities, muscle strength and psychomotor capacities are lower and their psyche is affected by the disease. After a three-month training period and after comparison with the 'control' group, there can be noticed a significant improvement in the psychomotor capacities, a major tendency for the improvement of the aerobic capacities and very positive effects on the psyche. CONCLUSION: SELF-training in association with dietetics appears to be very useful in the therapeutic care of obese children. For the follow-up at home it would need to be registered within the domain of physiotherapy.

Adolescent↗
PubMed1999

Characterization of closely related delta-TIP genes encoding aquaporins which are differentially expressed in sunflower roots upon water deprivation through exposure to air.

We isolated five sunflower (Helianthus annuus) cDNAs belonging to the TIP (tonoplast intrinsic protein) family. SunRb7 and Sun gammaTIP (partial sequence) are homologous to tobacco TobRb7 and Arabidopsis gamma-TIP, respectively. SunTIP7, 18 and 20 (SunTIPs) are closely related and homologous to Arabidopsis delta-TIP (SunTIP7 and 20 have already been presented in Sarda et al., Plant J. 12 (1997) 1103-1111). As was previously shown for SunTIP7 and 20, expression of SunTIP18 and SunRb7 in Xenopus oocytes caused an increase in osmotic water permeability demonstrating that they are aquaporins. In roots, in situ hybridization revealed that SunTIP7 and 18 mRNAs accumulate in phloem tissues. The expression of TIP-like genes was studied in roots during 24 h water deprivation through exposure to air. During the course of the treatment, each SunTIP gene displayed an individual response: SunTIP7 transcript abundance increased, SunTIP18 decreased whereas that of SunTIP20 was transitorily enhanced. By contrast, SunRb7 and Sun gammaTIP mRNA levels did not fluctuate. Due to the changes in their transcript levels, it is proposed that SUNTIP aquaporins encoded by delta-TIP-like genes play a role in the sunflower response to drought.

Amino Acid Sequence↗
PubMed1998

Effect of head-upright tilt on the dynamic of cerebral autoregulation.

The effect of head-upright tilting on the rate of cerebral autoregulation was studied in 12 healthy volunteers (nine men and three women; age range 20-36 years). The dynamics of cerebral autoregulation was determined from the rate of change in cerebral resistance (RoR) during a drop in arterial blood pressure induced by rapid deflation of a 3-min ischaemic thigh cuff and from the ratio of changes in cerebral blood flow and arterial blood pressure (CAI) during the recovery period after the drop in arterial blood pressure. The test was performed supine and with 40 degrees head-up tilt (40 degrees HUT). Middle cerebral artery mean blood flow velocity was measured by transcranial Doppler simultaneously with peripheral arterial blood pressure using Finapres. The thigh cuff deflation induced a larger drop in arterial pressure during 40 degrees HUT [median -28% (25 percentile -36, 75 percentile -19)] than in the supine position [-16% (-23, -15)] (P < 0.01) and in cerebral resistance [supine: -12% (-15, -6); 40 degrees HUT: -15% (-20, -12); P < 0.05]. There was no significant change in RoR [15% s-1 (12, 15)] and CAI [1.9 (1.5, 3.1)] measured supine and during 40 degrees HUT [RoR: 13% s-1 (12, 15); CAI: 1.3 (0.99, 1.9)]. During the drop in arterial pressure, the relationship between arterial blood pressure and systolic peak-to-peak interval exhibited an hysteresis loop, indicating a cardiopulmonary and/or baroreflex activation that was not observed with cerebral resistance. The rate of autoregulation is an intrinsic property of the cerebral vascular bed and is not affected by the vasodilator state in the range of arterial blood pressure changes induced by the tight cuff method.

Adult↗
PubMed1998

Cerebral hemodynamics during carotid massage in patients with carotid sinus syndrome.

The effect of cardioinhibition and/or vasodepression on cerebral hemodynamics assessed by transcranial Doppler has been investigated during carotid massage in 11 patients (62-87 years, mean age 72) with carotid sinus syndrome. The patients were tested in the OOO mode (n = 11) with six tested in the DDD mode. Carotid massage in the OOO mode decreased mean arterial pressure by 44% (P < 0.01) and mean cerebral blood flow velocity by 50% (P < 0.01). Although not significant, cerebrovascular resistance increased transiently by 17% during massage, then decreased by 31% upon recovery. Carotid massage in the DDD mode decreased arterial pressure by 30% (P < 0.01), cerebral blood velocity by 23% (P < 0.01), and resistance by 15% (P < 0.05). The decreased cerebral perfusion induced by cardioinhibition and/or vasodepression results from the delayed onset of cerebral autoregulation. Pacing in the DDD mode temporarily assists the critical period preceding the onset of cerebral autoregulation that plays a key role in preventing the deleterious effects of vasodepression.

Aged↗
PubMed1998

[Plasma noradrenaline and the prognosis of chronic cardiac failure: a multicenter study].

Plasma noradrenaline is little used in evaluating the prognosis of cardiac failure because of the theoretical necessity of interrupting treatment for a few days before blood sampling. The present study reevaluated the prognostic value of this parameter with blood sampling performed during treatment and then 48 hours after withdrawal of treatment in 192 patients with chronic stable cardiac failure at an advanced stage (64% of patients in Classes III or IV with an average ejection fraction of 28.5 +/- 13.5%). During follow-up (average 43 months) there were 51 deaths and 17 transplants. None of the patients were lost to follow-up. Univariate analysis of 52 variable observers during the initial phase of evaluation found in decreasing order of predictive value for death plasma noradrenaline levels before and after withdrawal of treatment for 48 hours. Serum sodium, age, systolic mean and diastolic pulmonary artery pressures. In multivariate analysis: noradrenaline with or without withdrawal of treatment, hyponatraemia and systolic pulmonary artery pressure. Actuarial survival curves distinguished the following parameters: noradrenaline levels became predictive at concentrations of over 210 pg/mL and there was a significant difference in survival with respect to 4 levels of serum noradrenaline (with or without treatment) > 300 pg/mL, 300 to 600 pg/mL and > 900 pg/mL. This serum noradrenaline measured without withdrawal of treatment (especially angiotensin converting enzyme inhibitors) is a powerful predictor of mortality, carrying a progressively poorer prognosis as the concentration increases.

Adult↗
PubMed1997

Two TIP-like genes encoding aquaporins are expressed in sunflower guard cells.

SunTIP7 and SunTIP20 are closely related sunflower cDNAs showing a deduced amino acid sequence homologous to proteins of the tonoplast intrinsic protein (TIP) family. Their expression in Xenopus oocytes caused a marked increase in osmotic water permeability (demonstrating that they are water channels) which was sensitive to mercury. In leaves, in situ hybridization revealed that both SunTIP7 and SunTIP20 mRNA accumulated in the guard cells. The possible involvement of SunTIPs in stomatal movement was examined by comparing the time course of transcript accumulation and leaf conductance during the daily cycle and following a water limitation. SunTIP7 mRNA fluctuations fitted changes occurring in leaf conductance. The transcript levels were markedly and systematically increased during stomatal closure. It is suggested that aquaporin SunTIP7 facilitates water exit associated with a decrease in guard cell volume. In the same conditions, the transcript level of SunTIP20 remained constant indicating that SunTIP genes are differentially regulated within the same cell.

Amino Acid Sequence↗