Search PubMed⌕ Search

Biomedical subjects

D Bonnet

Publications and source records attributed to D Bonnet.

At least 163 records · Page 9Linked to original sources
PubMed1998

Maintaining tricuspid valve competence in double discordance: a challenge for the paediatric cardiologist.

OBJECTIVES: To establish the prevalence of tricuspid valve abnormalities in children with a double discordant heart (or congenitally corrected transposition of the great arteries); to study the influence of the loading conditions induced by various surgical interventions on the right and left ventricle in patients with double discordance and an abnormal tricuspid valve; and to propose a rational surgical approach. METHODS: Case notes were reviewed of 141 consecutive patients admitted in the first year of life with various types of double discordance (intact ventricular septum (group 1), ventricular septal defect (group 2), ventricular septal defect and pulmonary obstruction (group 3)). A study group of 62 patients with an abnormal tricuspid valve was selected by cross sectional echocardiography. These were followed up through palliative and open heart procedures with grading of tricuspid regurgitation. RESULTS: Tricuspid valve abnormalities were more common in groups 1 and 2 (60% and 56%) than in group 3 (31%). Preoperative tricuspid regurgitation was more common in group 2 (90%) than in groups 1 and 3 (38% and 36%). Ten patients in groups 1 and 2 died in the neonatal period with severe tricuspid regurgitation, associated with coarctation of the aorta in 60%. Eight patients in group 1 had no surgery and are doing well, with a competent tricuspid valve. Palliative procedures were undertaken in 28 patients: 14 had pulmonary artery banding, which resulted in a decrease in tricuspid regurgitation, 12 in group 2 by reducing the pulmonary blood flow and two in group 1 by changing the septal geometry; 14 in group 3 had an aortopulmonary shunt, which induced tricuspid regurgitation in two. Twenty patients are still alive after palliation, with stable tricuspid valve function. Repair of the tricuspid valve was unsuccessful in the three patients who underwent conventional surgery, leaving the right ventricle facing the systemic circulation. In two patients with a competent but abnormal tricuspid valve, conventional surgery induced severe tricuspid regurgitation. Of the 15 patients who underwent conventional surgery, only 10 survived (mortality 33%): eight with a tricuspid valve prosthesis and two with severe residual tricuspid regurgitation. However, tricuspid regurgitation decreased after anatomical correction (nine patients), restoring a systemic left ventricle and a subpulmonary right ventricle, even when the tricuspid valve was not repaired (five patients). Eight patients are doing well after anatomical correction (mortality 11%). CONCLUSIONS: Tricuspid valve function in double discordance with an abnormal tricuspid valve depends on the loading conditions of both ventricles and on the septal geometry. Interventions that increase right ventricular volume or decrease left ventricular pressure are likely to induce tricuspid regurgitation, while those that decrease right ventricular volume or increase left ventricular pressure are likely to improve tricuspid valve function. Repair of the tricuspid valve always failed when the right ventricle was left in a systemic position and always succeeded when the right ventricle was placed in a subpulmonary position. These results should be taken in to account when dealing with patients with double discordance and an abnormal tricuspid valve.

Female↗
PubMed1998

[American pulmonary histoplasmosis caused by Histoplasma capsulatum].

American pulmonary histoplasmosis is a deep mycosis imported from North America caused by the inhalation of Histoplasma capsulatum. It is endemic in several countries throughout the world and occasional cases have been reported in France, mainly imported from out lying French territories. The most frequent clinical forms observed in immunocompetent subjects are generally benign or silent and usually limited to a fortuitously discovered pulmonary nodule. Massive exposure may lead to an acute primary invasion producing a miliary aspect. Chronic forms simulating tuberculosis are exceptional. Inversely, opportunistic histoplasmosis in AIDS patients can produce an severe multiple organ disease. Ideally, mycelium should be isolated for diagnosis, a task which is easier in disseminated or operated nodular forms. More often, the epidemiological context, clinical and radiological features, the elimination of differential diagnoses and, retrospectively, serology are sufficient for diagnosis. The clinical course is usually favorable. Itraconazole is the treatment of choice for symptomatic or complicated forms.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Metropolitan pneumologists and exotic diseases].

Due to the increasingly widespread development of international exchanges, physicians, particularly pneumologists, working in metropolitan France may encounter patients with respiratory signs who have travelled or lived in tropical zones. In such cases, history taking, physical examination, imaging, bacteriological and parasitological explorations, pathology and immunology are all precious tools for diagnosis. All possible tropical diseases should be entertained, taking into account the geographical setting and the patient's lifestyle. The pneumologist must not forget that these exotic tropical diseases remain uncommon compared with cosmopolitan causes of lung disease: bacterial infections, tuberculosis, cancer.

AIDS-Related Opportunistic Infections↗
PubMed1998

[The eosinophilic lung].

Eosinophilic lung disease comprises a diverse group of disorders characterized by eosinophilic pulmonary infiltration in association with other inflammatory cells. In patients with respiratory symptoms, usually associated with radiographically documented infiltrates, blood eosinophilia is a helpful but inconsistent diagnostic finding. Currently diagnosis is confirmed more often by bronchoalveolar lavage than by lung biopsy. Possible etiologies include parasites, mycotic agents, drugs, and angeitis. Remaining cases are classified as idiopathic eosinophilic lung disease including Carrington's disease, idiopathic hypereosinophilic syndrome, acute eosinophilic pneumonia, and Loeffler's syndrome. Mild eosinophilia is also a possible finding of bronchoalveolar lavage in several other disorders but the role of eosinophils is less important. The prognosis and treatment of eosinophilic lung disease varies depending on etiology. Corticosteroids are frequently used but treatment modalities also depend on etiology.

Anti-Inflammatory Agents↗
PubMed1998

[Idiopathic chronic eosinophilic pneumonia].

Idiopathic chronic eosinophilic pneumonia is a rare disease first described by Carrington 30 years ago. The cause is unknown. As illustrated by the case described in this report, most cases occur in asthmatic patients in the fifth decade of life. Cardinal features are respiratory symptoms, altered general status, laboratory evidence of inflammation, blood eosinophilia in most cases, and x-ray images showing the presence of infiltrates in both lungs. Diagnosis can be confirmed by detection of eosinophils in broncho-alveolar lavage fluid. Extrapulmonary involvement is uncommon and is suggestive of Churg and Strauss syndrome. In atypical cases, diagnosis requires histological study demonstrating infiltration of interstitial tissue and alveolar spaces. Differential diagnosis can be difficult since several disorders identified within the last 10 years are nosologically similar, e.g. acute eosinophilic pneumonia. In many cases, diagnosis is based on response to corticosteroid treatment which is highly effective on idiopathic chronic eosinophilic pneumonia. Frequent recurrence leads to corticosteroid dependence in 20 to 30% of cases.

Anti-Inflammatory Agents↗
PubMed1998

[Acute eosinophilic myocarditis: a diagnostic and therapeutic emergency].

This report describes three histologically documented cases of acute eosinophilic myocarditis. These three cases illustrate the different clinical and therapeutic outcomes of this disease which can range from full recovery under prolonged corticosteroid treatment to requirement for emergency heart transplantation or death due to intractable cardiac insufficiency. In absence of specific clinical or laboratory data, diagnosis must be established in vivo by endomyocardial biopsy demonstrating eosinophil-rich inflammatory infiltration and necrotic lesions. Rapid decision-making is necessary to allow early initiation of intensive corticosteroid treatment without which the most likely outcome is death. Clinicopathological and experimental evidence suggests that acute eosinophilic myocarditis is caused by the cytotoxic effects of granule components (mainly major basic protein) released by activated polynuclear eosinophils.

Acute Disease↗
PubMed1998

[A pulmonary vascularization study in pulmonary atresia with an interventricular defect in relation to the presence of a chromosome 22 deletion].

A normal lung is supplied by a pulmonary artery branching from the pulmonary trunk. Major aorto-pulmonary collateral arteries (MAPCAs) are found in combination with various congenital heart malformations such as pulmonary atresia with ventricular septal defect (PA-VSD). Now that MAPCAs are used for unifocalization in patients with PA-VSD, the question arises as to whether the morphologic criteria of these collateral arteries could help to provide better results. We compared the morphology of the pulmonary vascular bed, the origin, course and connections of the MAPCAs in 40 consecutive infants with PA-VSD with or without 22q deletion (del22q11.2.). All underwent echocardiographic evaluation and catheterization. Identification of del22q11.2. was performed by FISH study. Del22q11.2. was identified in 16 pts (40%); the presence of MAPCAs was significantly higher in patients with del22q11.2. (9/16 vs 3/24, p = 0.01). While complex morphology of MAPCAs, anastomoses with the central pulmonary artery outside the lung and absent ductus arteriosus were associated with del22q11.2, confluence of the pulmonary arteries was not a relevant phenotypic difference. The size of the right and left pulmonary arteries expressed as a standard deviation difference of the normal range for body surface area was -4.2 (quartiles -3.1/-1.8) for PA-VSD with del22q11.2. and -2.6 (quartiles -5.3/-2.9) for PA-VSD without del22q11.2. (p = 0.02). The difference between measured and theoretical Nakata index was -373 +/- 94 for PA-VSD with del22q11.2. vs. -245 +/- 93 for PA-VSD without del22q11.2. (p = 0.0002). A specific pulmonary vascular bed phenotype could be defined in patients with PA-VSD with del22q11.2. deletion: MAPCAs with complex loop morphology and small but confluent central pulmonary arteries. These findings indicate a different timing of the faulty development pathway of the pulmonary vascular bed in patients with and without del22q11.2. This phenotype difference may help our understanding of maldevelopment and facilitate decisions concerning the suitability of these arteries for unifocalization procedures.

Angiography↗
PubMed1998

[Anatomic evaluation of ostium secundum atrial septal defects by tridimensional echocardiography].

The decision to close an ostium secundum atrial septal defect by interventional catheterisation implies knowing its size, form and the relationship of its borders to neighbouring structures as accurately as possible. Three-dimensional echocardiography provides unique views of the interatrial septum and the authors set out to assess its performance. Ten patients, aged 8 to 20 years, included in a multicenter European clinical trial of closure of atrial septal defects with the CardioSEAL prostheses, were examined by transoesophageal echocardiography with three-dimensional reconstruction of the interatrial septum viewed from the left or right atrium. The septal defect had a very variable morphology, round, oval raquet-shaped and occasionally multiple. The surface area of these defects varied by about 70% during the cardiac cycle, maximal during ventricular systole and minimal during atrial systole. The maximal diameter measured by two-dimensional transoesophageal echocardiography underestimated that measured by three-dimensional echocardiography by about 30%. Two patients had a juxta-aortic caudal border or a juxta-superior vena caval cephalic border making the defect unsuitable for catheter insertion of a CardioSEAL occluder. On the other hand, another patient had an adequate juxta-aortic border although it seemed too narrow with conventional imaging techniques. The authors conclude that three-dimensional reconstruction of transoesophageal echocardiography is the best method of selecting candidates for closure of ostium septum atrial septal defect by intervantional catheterisation.

Adolescent↗
PubMed1998

[Can partial cavo-pulmonary connection be considered an alternative to the Fontan procedure?].

The disappointing long-term results of the Fontan procedure led the authors to assess substitution with partial cavo-pulmonary connections for definitive palliative treatment of single ventricle malformations. One hundred and fifteen patients with a mean age of 4.3 +/- 4.5 years (1 month-22 years) were treated by termino-lateral anastomosis between the superior vena cava and corresponding pulmonary artery, either of necessity because of a contraindication to total cavo-pulmonary connections (31 cases) or electively (84 cases). Another source of pulmonary flow was preserved or added in 76% of children, the operative mortality was 4% and the secondary mortality 3.5%. Significant complications were observed in 15% of cases with a secondary morbidity of 13%. Reoperation was required in 18 cases (16%). In fact, the death rate was higher in indications of necessity (19 versus 3.6% in elective procedures). Similarly, the number of serious complications (veno-venous or pulmonary arterio-venous fistulae, ventricular dysfunction) was higher in this group than in patients undergoing an elective procedure (23 versus 2.4%). After 4.8 +/- 3.2 years' follow-up, 73% of children treated of necessity and 95% of children treated electively were well despite mild cyanosis (average saturation of 86 +/- 6%). On condition that these results are confirmed at long-term as present follow-up is relatively short, this strategy would seem to be justified, providing mild cyanosis with little functional impairment is accepted, so avoiding the serious complications of Fontan-like circulations.

Adolescent↗
PubMed1998

[Aortocoronary bypass in children. Apropos of 6 cases].

The improvement in diagnostic techniques for myocardial ischaemia and in imaging of coronary anomalies in children has increased the number of coronary revascularisation procedures. Moreover, the indications are more diverse with the emergence of acquired coronary disease which was unknown until recently, related to operations comprising manipulation of the coronary arteries. The authors report their experience of 7 internal mammary artery bypass grafts in 6 children aged 3 days to 11.5 years (average 2 years): 3 left main coronary stenosis after arterial switch for transposition of the great arteries, 1 peroperative lesion of an intramural left coronary in a case of simple transposition of the great arteries, 1 congenital atresia of the right ostium associated with Tetralogy of Fallot, and 1 right coronary occlusion with giant aneurysms of the left coronary in a case of Kawasaki's disease. There were no operative fatalities. All the coronary grafts were patent at early postoperative control. These results indicate clearly that the method is very feasible from a very early age. Long-term patency, the growth of the anastomosis and of the distal vessels are questions which await a reply in the future.

Child↗
PubMed1998

[Neonatal ventricular tachycardia].

Ventricular tachycardia is rare and poorly understood in the neonate. The authors undertook a retrospective study in 2 foetus and 8 neonates aged 1 to 20 days at the time of diagnosis. The tachycardia was permanent in 2 cases, observed in runs of variable variation in the other 8, incessant in 7 of these cases. Only two cases were symptomatic: cardiac failure with shock 16 hours after birth and hydramnios at 16 weeks gestation. The electrocardiographic criteria of ventricular tachycardia (wide QRS complexes of different morphology to the sinus QRS complexes, atrioventricular dissociation) were fulfilled in all patients. The arrhythmia was monomorphic 9 times out of 10 with a fixed (3 cases) or variable (7 cases) rate which was always > 150/min. Intravenous magnesium sulphate in the severe and permanent forms, oral betablockers in forms triggered by acceleration of the sinus rhythm, oral amiodarone alone or associated in one case with propranolol were prescribed but three neonates were not treated, either from the outset or after inefficacy of amiodarone: nine of the patients were cured and are treatment-free 12 to 24 months later: the other patient has a slow, well tolerated ventricular tachycardia. No aetiology was detected in 9 cases; the other had a metabolic disease of B-oxidation of long chain fatty acids. The authors conclude that isolated, idiopathic ventricular tachycardia of the neonate usually carry a good prognosis which is not dependent on the tachycardia of the permanence of the arrhythmia. Simple treatment (betablocker or amiodarone) is usually associate with restoration of sinus rhythm and definitive cure during the first year of life.

Adrenergic beta-Antagonists↗
PubMed1998

[Acute pericarditis of unusual etiology].

Extrapulmonary manifestations of Legionella pneumophilia infection are infrequent. Cardiac involvement can occur. We observed an unusual case which led to acute pericarditis and reviewed the literature on cardiac involvement, particularly pericarditis, in patients which legionellosis.

Acute Disease↗
PubMed1998

[An unusual tumor of the mediastinum].

We report a case of dual parathyroid adenoma associated with an ectopic gland in the right latero-esophageal region of the mediastinum revealed by asymptomatic hypercalcemia. Because of this dual localization and the lack of MBI uptake on the mediastinal scintigram, thoracotomy was used as the first line approach instead of cervicotomy.

Adenoma↗
PubMed1998

[Moebius syndrome. Three different forms of presentation].

INTRODUCTION: Moebius's syndrome is an entity present at birth, characterized by oculofacial paralysis and external ophthalmoplegia. Other cranial nerves can also be affected and associated to skeletal abnormalities and neurologic symptoms. It appears sporadically, sometimes of familiar nature, presenting special facies with total absence of facial expression and severe strabismus. The pathogenesis of the syndrome still remains unknown, being the transitory situation of fetal hypoxia/ischemic the most accepted theory. In some cases chromosomal abnormalities have been detected. CLINICAL CASE: We reported three children with different symptoms, two of them are siblings whose father is affected, but he was not diagnosed until adult age. CONCLUSIONS: We conclude pointing out the different presentation of the disease, the appearance in several members of a family and its chronically evolution.

Child, Preschool↗
PubMed1997

Quantitative analysis reveals expansion of human hematopoietic repopulating cells after short-term ex vivo culture.

Ex vivo culture of human hematopoietic cells is a crucial component of many therapeutic applications. Although current culture conditions have been optimized using quantitative in vitro progenitor assays, knowledge of the conditions that permit maintenance of primitive human repopulating cells is lacking. We report that primitive human cells capable of repopulating nonobese diabetic (NOD)/severe combined immunodeficiency (SCID) mice (SCID-repopulating cells; SRC) can be maintained and/or modestly increased after culture of CD34+CD38- cord blood cells in serum-free conditions. Quantitative analysis demonstrated a 4- and 10-fold increase in the number of CD34+CD38- cells and colony-forming cells, respectively, as well as a 2- to 4-fold increase in SRC after 4 d of culture. However, after 9 d of culture, all SRC were lost, despite further increases in total cells, CFC content, and CD34+ cells. These studies indicate that caution must be exercised in extending the duration of ex vivo cultures used for transplantation, and demonstrate the importance of the SRC assay in the development of culture conditions that support primitive cells.

ADP-ribosyl Cyclase↗
PubMed1997

Highly efficient control of iron-containing nitrile hydratases by stoichiometric amounts of nitric oxide and light.

The reaction of two iron-containing nitrile hydratases (NHase) with NO has been studied: NHase from Rhodococcus sp. R312, which is probably similar to the photosensitive N771 NHase, and the new NHase from Comamonas testosteroni NI1 whose aminoacid sequence is quite different from those of BR312 and N771 NHases. Both enzymes are equally inactivated after addition of stoichiometric amounts of NO added as an anaerobic solution or produced in situ under physiological conditions by a rat brain NO-synthase. Both enzymes are reactivated by photoirradiation, and two cycles of NO inactivation/photoactivation can be performed without significant loss of activity. Both iron-containing NHases have a high affinity for NO, similar to that of methemoglobin.

Animals↗