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Biomedical subjects

M Dumoulin

Publications and source records attributed to M Dumoulin.

At least 37 records · Page 2Linked to original sources

Neurofibromatosis type I gene mutation in a patient with features of LEOPARD syndrome.

Multiple lentigines (LEOPARD) syndrome has been delineated as an autosomal dominant disorder with lentigines, cardiac abnormalities, variable mental retardation, and typical craniofacial features as the most characteristic findings. LEOPARD syndrome shows a great clinical overlap with neurofibromatosis type 1 (NF1). In this report we describe a de novo missense mutation (M 1035R) in exon 18 of the NF1 gene in a young woman with a prior diagnosis of LEOPARD syndrome. We hypothesize that some patients now diagnosed with LEOPARD syndrome have in fact a mutation in the NF1 gene, whereas in other patients with LEOPARD syndrome, a different gene might be involved.

Abnormalities, Multiple↗

Obstetric patients treated in intensive care units and maternal mortality. Regional Teams for the Survey.

OBJECTIVE: To ascertain the frequency of serious diseases in pregnant women. STUDY DESIGN: A population based survey was performed in France. The cases were all the women admitted for treatment in intensive care unit (ICU). The severity of the cases was measured with the simplified acute physiology score (SAPS) the lethality and the rate of still birth. RESULTS: 435 obstetric patients were included. The estimated frequency of severe diseases was 310 S.D.36 per 100,000 live births. The most frequent diagnose that motived admission in ICU was hypertensive diseases. The lethality rates differed greatly between specific disorders. The lethality rate was lower when scheduled maternity was located in a teaching hospital. CONCLUSION: Regarding these results it appears that the majority of obstetric patients with severe diseases are referred to suitable care, but a small proportion of women who had to change their type of care registered a significant higher lethality.

Female↗

Idiopathic restrictive cardiomyopathy in childhood. A diastolic disorder characterized by delayed relaxation.

Six children with idiopathic restrictive cardiomyopathy were evaluated. Electrocardiographic evaluation disclosed left atrial dilatation and repolarization abnormalities. Echocardiographic examination showed gross left atrial enlargement (182 +/- 29% of predicted values, P < 0.001) in the presence of normal left ventricular cavity dimensions (99 +/- 6%, P: ns). Left ventricular wall thickness varied from normal to mild concentric hypertrophy (septum: 116 +/- 16%, P < 0.05). Global left ventricular systolic function was normal or slightly subnormal; however, the relaxation was significantly delayed throughout diastole. E/A ratio was 4.1 +/- 1.4 and deceleration time 94 +/- 7 ms. Marked ventricular filling occurred in mid-diastole as could be deduced from a prominent mid-diastolic mitral L wave on the Doppler flow tracing. Early filling contributed 56 +/- 6%, mid-diastolic filling 28 +/- 4% and atrial contraction 16 +/- 3% to total ventricular filling as estimated by determining E-area, L-area and A-area, respectively. The left ventricular pressure curve showed a steady decline during mid-diastolic filling. This implies that the driving force for mid-diastolic filling is not the increased left atrial pressure but suction by the ventricle. The restrictive haemodynamics are therefore not caused by increased intrinsic stiffness of the ventricular wall, but most likely result from serious dysfunction and delay of the active relaxation of the ventricle. Progression of the disease was observed in three out of six patients, resulting in death or extreme low cardiac output. The three other patients remained clinically stable during the follow-up period of 6-10 years.

Adolescent↗

Dynamics of respiratory gas exchange during exercise after correction of congenital heart disease.

In pediatric exercise testing, conventional measures of aerobic exercise function such as maximal O2 uptake or the ventilatory anaerobic threshold (VAT) use only one value for the assessment of exercise capacity. We studied a more comprehensive approach to evaluate aerobic exercise function by analyzing the steepness of the slope of CO2 production (VCO2) vs. VO2 above the VAT (S3). This was calculated in 32 patients operated on for congenital heart disease [16 for transposition of the great arteries (TGA) and 16 for tetralogy of Fallot (TF)] and was compared with 16 age-matched controls (nl). The results show that the reproducibility of this new assessment method was excellent (coefficient of variation for S3: 8.6%). S3 was significantly steeper (P<0.05) in the patients (1.31 +/- 0.22 for TGA and 1.28 +/- 0.16 for TF) compared with the nl (1.10 +/- 0.22). Also, the difference between S3 and the slope of VCO2 vs. VO2 below the VAT was significantly higher in the patients (0.37 +/- 0.22 for TGA and 0.31 +/- 0.10 for TF) than in controls (0.22 +/- 0.06). The steeper slopes were associated with lower than normal values for VAT and O2 during exercise. It is concluded that the analysis of the steepness of the slope of CO2 is a sensitive, reproducible, and objective approach to evaluate the integrative cardiopulmonary response to exercise. It complements the assessment of a subnormal VAT by reflecting the extent of anaerobic metabolism.

Aerobiosis↗

Congenitally absent pulmonary veins--diagnostic pitfalls. Two case reports.

Two patients with partial absence of the right and left pulmonary veins respectively are described. Congenitally absent pulmonary veins are a rare phenomenon and the diagnosis is often missed or delayed. When children present with haemoptysis and/or recurrent respiratory infections with no obvious underlying cause, absence of the pulmonary veins must be part of the differential diagnosis. Special investigations to be done in these patients are chest roentgenograph to compare the lung volumes, radio-isotope scan, echocardiography and cardiac catheterisation. Magnetic resonance imaging may be helpful in defining the cause and site of obstruction of the pulmonary veins. Depending on the cause, surgery might be considered.

Child↗

Serial cardiorespiratory exercise testing in patients with congenital heart disease.

Aerobic capacity of patients with different forms of congenital heart disease was serially evaluated in 79 patients and the evolution was correlated with the lesion and the level of daily activity. The patients were divided into six groups: patients with a small ventricular septal defect (VSD) with mini shunt (n = 14), mild pulmonary valve stenosis with gradient < 40 mm Hg (PS) (n = 12), mild to moderate aortic valve stenosis (gradient 36 +/- 17 mmHg) (AS) (n = 12), patients 4.7 +/- 2.1 years after repair of tetralogy of Fallot (PO-TF) (n = 16), patients 2.2 +/- 2.9 years after closure of a high flow/high gradient VSD (PO-VSD) (n = 13), and patients 2.6 +/- 1.7 years after Fontan repair (Fontan-PO) (n = 12). Aerobic capacity was assessed by determination of the ventilatory anaerobic threshold (VAT). VAT reflects the highest aerobic exercise level prior to a disproportionate increase of CO2 and ventilation relative to O2 uptake; it is independent of patient motivation. Data are expressed as percentage of normal O2 uptake at VAT, determined in 234 age/gender matched controls. The habitual level of physical activity was assessed by a standardised questionnaire. Aerobic capacity in all subgroups of patients, even with very mild defects, was at or below the lower limit of normal. Children left unrestricted from physical exercise (VSD, PS, PO-VSD) had no change over the study period. However, aerobic capacity of patients with medically imposed physical restrictions (AS) and significant residual haemodynamic lesions (PO-TF, Fontan) decreased with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Dopamine suppresses thyroid-stimulating hormone secretion in neonatal hypothyroidism.

The infusion of dopamine, a hypophysiotropic catecholamine, which inhibits release of thyroid stimulating hormone (TSH), is the inotropic therapy of first choice in neonatal intensive care. Newborns with primary hypothyroidism are at increased risk of cardiocirculatory morbidity and are screened by measuring serum TSH concentrations. In an infant with both congenital heart disease and neonatal hypothyroidism, withdrawal of dopamine infusion was documented to evoke a doubling of serum TSH levels within 40 min, a finding suggestive of an inhibitory effect of dopamine administration on neonatal TSH hypersecretion. As a result, dopamine therapy may be a pitfall in TSH screening for neonatal hypothyroidism.

Congenital Hypothyroidism↗

Asplenia syndrome and isolated total anomalous pulmonary venous connection in siblings.

We report on a family with asplenia syndrome in one and total anomalous pulmonary venous connection (TAPVC) in the other sib. Both conditions are rare, may have a genetic cause and belong to a spectrum of laterality disorders. This suggests that both asplenia syndrome and TAPVC in this family are the clinical expression of a single genetic disorder.

Heart Defects, Congenital↗

Reliability of subjective estimates of exercise capacity after total repair of tetralogy of Fallot.

Sixty-nine patients (age 10 +/- 3.5 years, median 9.7 years) operated on for tetralogy of Fallot, underwent exercise testing 5.1 +/- 2.5 years after total correction. Aerobic capacity was assessed by the ventilatory threshold method. After the exercise test, parents completed a validated standardized questionnaire to evaluate the habitual level of physical activity of their child. They were then asked to place their child into one of three groups, describing their child's activity level, compared to normals (below average, average and above average). In the average and above-average groups, 73% and 65% of the patients were misclassified when compared to objective exercise testing. However, in the below-average group, no misclassifications were found. Subjective estimates of activity level, and consequently exercise tolerance, were poorly associated with objective measurements of exercise performance in these patient groups. Our results question the reliability of self-reported estimates of physical activity level and consequently exercise capacity in children after surgical correction of tetralogy of Fallot.

Activities of Daily Living↗

Cardiorespiratory exercise performance after Senning operation for transposition of the great arteries.

OBJECTIVE: To assess the cardiorespiratory response to graded exercise in patients after the Senning operation for transposition of the great arteries. DESIGN: Cross sectional study. Exercise performance was assessed by determination of the ventilatory anaerobic threshold. This was defined as the exercise intensity at which the ventilatory equivalent for oxygen (VE/VO2) started to increase systematically without a concomitant increase in the ventilatory equivalent for carbon dioxide (VE/VCO2). SETTING: Outpatient department. PATIENTS: Sequential sample of 20 patients studied 5-10 years (mean 7.3 years) after the Senning operation. Age at exercise testing varied from 5 to 11 (mean 7.8) years. RESULTS: The ventilatory threshold in the patients was significantly lower than normal (p < 0.005) and averaged 79.3% (SD 13%) and 80% (12%) of the predicted normal value for age and weight, respectively. Also, the ventilatory threshold was surpassed sooner (mean 3.2 (range 2-5) minutes) in the patients than in normal controls (3.9 (2.6-4.6) minutes). The lower ventilatory threshold was associated with a subnormal oxygen uptake (ml/min/kg) during submaximal exercise, a higher than normal ventilatory equivalent for oxygen ratio, and a lower end tidal carbon dioxide tension in the patients compared with normal controls. In half of the patients heart rate was lower during graded exercise. This relative bradycardia was not associated with a normal ventilatory threshold, as often seen in fit young people. No major disturbances in rhythm were observed during exercise. CONCLUSION: Exercise performance, assessed by respiratory gas exchange, was slightly but significantly lower than normal in patients after the Senning operation. A subnormal ventilatory threshold, associated with a higher than normal ventilatory response during submaximal exercise, supports the hypothesis that oxygen delivery to tissues is slightly impaired in these patients.

Anaerobic Threshold↗

[To be born or not to be. Epidemiologic, judicial and psychological aspects].

The requisites for filling up birth certificates in France (> or = 180 days of pregnancy and vitality at the registration of birth) are different from the criteria recommended by the World Health Organisation (WHO) (at least 500 g) for national statistics. The number of stillborn babies and neonatal deaths known from two different sources in the Nord-Pas de Calais Region in 1988-1989 have been compared ie: the vital statistics published by INSEE and the data of a survey carried out in hospitals according to the WHO criteria. Among the 808 known perinatal deaths in the survey, 305 (37.7%) were ignored or were not classified in the same categories by the registration services for vital statistics. 230 children including 29 born alive had not been registered and 75 children born alive had been registered as still born. The disparity in these definitions between INSEE and the WHO has serious consequences: the perinatal mortality measured by INSEE is underestimated by 28%, in comparison with mortality registered according to the WHO criteria. The 180 day threshold of viability reduces the social rights of employed women and makes it more difficult for them to have the money they spent on medical care refunded. Finally, as it is impossible to find a trace of these children who were not legally registered since they were under the threshold of viability, the mourning response of parents to perinatal deaths is all the more difficult. Current evolution in the threshold of viability observed in maternity units, makes it necessary to change the criteria which are applied for the legal registration of births.

Attitude to Death↗

Rheologic genesis of discrete subvalvular aortic stenosis: a Doppler echocardiographic study.

To determine whether morphologic structures or abnormal flow patterns predispose to pathologic proliferation of subvalvular tissue, 26 patients (mean age 19.8 +/- 10.3 years) were studied greater than or equal to 6 months after operation for isolated discrete subvalvular aortic stenosis. The aortic root diameter and the mitral-aortic separation were measured with sector echocardiography. Flow patterns in the left ventricular outflow tract of these patients and control subjects were evaluated with a color flow mapping system optimized for the detection of turbulence. All control subjects had laminar flow throughout systole in the left ventricular outflow tract. By contrast, turbulence originating well below the site where the shelf had previously been resected was observed in 20 (77%) of the 26 patients. In 16 of these 20 patients turbulence was caused by a ridge, which in 13 patients could be identified as the offshoot of a ventricular band. In four patients the turbulence was caused by malalignment of the muscular and membranous septum, resulting in protrusion of the muscular septum into the outflow tract. Except for the latter four patients, the aortic root diameter was 84 +/- 10% of values predicted by body surface area, with values in six patients falling below the third percentile (p less than 0.01). The mitral-aortic separation was 9.7 +/- 3.5 mm, values in 21 patients falling above the 97th percentile (p less than 0.001). These data support the theory that discrete subvalvular aortic stenosis may be caused by a chronic flow disturbance, preferably in a small and long outflow tract. Left ventricular bands, if reaching the outflow tract, may be a factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Cardiorespiratory exercise capacity after surgical closure of atrial septal defect is influenced by the age at surgery.

To study the influence of age at the time of the operation on long-term functional performance in children undergoing surgery for atrial septal defect (ASD) of the secundum type, exercise tolerance was assessed in 24 patients and values were compared with those of normal subjects. Patients were divided into two groups: 11 patients had surgery before the age of 5 years (group 1) and 13 patients had surgery at a later age (group 2). There were no significant differences between groups 1 and 2 with regard to the pulmonary-to-systemic flow ratio, pulmonary artery pressure, and the interval between surgery and exercise testing. Performance capacity was assessed by determination of the ventilatory threshold during submaximal exercise. The mean value for the ventilatory threshold in group 1 was normal (99.4 +/- 15.1% of the age-predicted normal value). In the children who were more than 5 years of age at the time of the operation, the ventilatory threshold was below normal (84.5 +/- 10.9% of the age-predicted normal value). Furthermore, in group 2 more patients (77%) had values that were below normal (below the 95% confidence limit of the age-predicted normal value) compared with group 1 (27%). It is concluded that functional performance capacity is better when surgical closure of ASD is performed in early childhood and before the age of 5 years rather than at a later age.

Adolescent↗

[Cerebral magnetic resonance imaging in the neonatal period. Initial results].

The place of neonatal cerebral MRI and its specific contribution compared with conventional imaging techniques were evaluated in 36 patients. The difficulties specific to the patient population studied met during this preliminary period are described, with their local solutions. A preliminary evaluation of the diagnostic and prognostic value of MRI according to the disease state and gestational age is presented. The specific contribution of MRI compared with transfontanellar ultrasonography and CT scan is discussed.

Anesthesia↗

DNA-binding and dimerization domains of adenosine 3',5'- cyclic monophosphate-responsive protein CREB reside in the carboxyl-terminal 66 amino acids.

The expression of genes in response to cAMP is mediated by one or more trans-activator proteins, CREBs, that bind to cAMP-responsive enhancers (CREs) of the general motif 5'-TGACGTCA-3'. The carboxyl-terminal amino acid sequences of two isoforms of CREB, CREB-327 and CREB-341, deduced from the cDNAs consist of a positively charged (basic) region adjacent to a leucine zipper motif. Three peptides corresponding to the hypothetical DNA-binding and dimerization domains of CREB-327 were synthesized. A peptide that includes both the basic and leucine zipper domains binds to the CRE specifically. Moreover, this peptide readily forms CRE-binding heterodimers with full-length CREB both synthesized by in vitro cell-free translation and isolated from PC-12 cells, but did not heterodimerize with in vitro translated jun or fos. Two other peptides, either partially or totally lacking the basic region, but containing the intact leucine zipper domain, readily form dimers but do not bind to the CRE. We conclude that the carboxy-terminal basic and leucine zipper regions are necessary and sufficient for specific binding of CREB to the CRE as a homodimer. The leucine zipper domain is responsible for the dimerization, and the basic region confers binding specificity for the CRE. Heterodimerization of CREB-327 does not form heterodimers with jun or fos.

Amino Acid Sequence↗

Cardiorespiratory response to exercise in congenital complete atrioventricular block.

In 8 patients aged 8 to 17 years with congenital complete atrioventricular (AV) block, exercise testing was performed on a treadmill. Cardiorespiratory endurance performance was assessed by determination of the ventilatory threshold. The mean value for ventilatory threshold was significantly lower (p less than 0.005) than the normal mean value and averaged 76 +/- 16%, 75 +/- 17% and 75 +/- 16% of the predicted normal value in children of the same sex and comparable age, weight and height, respectively. The ventricular rate at rest varied from 36 to 56 beats/min and increased to a mean value of 106 +/- 25 on exercise. When expressed as a percentage of the normal value, the heart rate was subnormal (below the 95% confidence limit) in all patients, throughout different exercise levels. For the same exercise intensity the oxygen uptake, expressed as ml/min/kg, was significantly lower (p less than 0.02) in patients than in normal individuals. This suggests an inadequate hemodynamic adjustment to the relative exercise bradycardia and a higher than normal anaerobic/aerobic energy supply. Exercise testing was found to be useful in the assessment of congenital AV block, because the resting heart rate did not permit prediction of the relative exercise bradycardia or the degree of exercise intolerance.

Adolescent↗