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Biomedical subjects

V Lambert

Publications and source records attributed to V Lambert.

At least 19 recordsLinked to original sources
PubMed2006

[Large atrial septal defects in adults: results of attempted systematic percutaneous closure].

Percutaneous closure of ostium secundum atrial septal defects became routine practice from 1998 but remained limited by the size of their diameter at balloon calibration. In March 2004, after an experience of 551 patients, the maximum admissible diameter (40 mm), the biggest size available of the Amplatzer prosthesis, could often be exceeded. The essential anatomical condition was the presence of a circumferential edge--even minimal--except adjacent to the aorta where its absence was not a problem. From 31/03/04 to 31/12/05, 17 patients, 17 to 58 years of age, were included and underwent attempted percutaneous closure by the usual protocol. The insertion of the prosthesis was difficult in every case. It required the use of several techniques to orientate the prosthesis in a satisfactory plane without risking tearing part of the residual atrial septum. The attempt was successful in 16 of the 17 patients. The one failure occurred in a patient with complete absence of a posterior edge. The postoperative course was uncomplicated without residual shunt or displacement of the occluder in the follow-up studies. The authors conclude that very big atrial septal defects with diameters of over 40 mm may be closed percutaneously with the Amplatzer device with a reasonable chance of success. These attempts do not expose the patient to any particular risk and the results, in successful attempts, are comparable to those observed in smaller atrial septal defects.

Adolescent↗
PubMed2005

[Cardiac failure in children].

The understanding of cardiac failure pathophysiology in children has advanced greatly in recent years. Whilst cardiac failure secondary to left ventricular dysfunction with viral or metabolic cardiomyopathy is comparable in pathophysiological terms with adults, other aetiological mechanisms are also implicated, linked both to anatomical anomalies in congenital cardiopathy and their surgical repair. The role of the neuroendocrine system with adrenergic activation of the renin-angiotensin system, secretion of natriuretic peptides and the inflammatory system, before and during surgical repair procedures, have been proven both experimentally and clinically. Understanding these pathophysiological mechanisms opens new therapeutic perspectives for improving the management of children with congenital cardiopathy in cardiac failure and reducing postoperative mortality and morbidity.

Child↗
PubMed2005

[Congenital cardiopathy: indications for anticoagulant treatment].

Congenital cardiopathy is common in children with thromboembolic disease. There are no objective clinical data for medium and long term treatment. Vitamin K antagonists could be envisaged for this. Children with a mechanical valve should be anticoagulated. This has been validated in adults, there has been no study in children which contradicts this, and the serious nature of thromboembolic complications in this group is significant. In atrial fibrillation, the most frequent indication for oral anticoagulants is after a Fontan procedure, because of the thromboembolic risk factors. Anticoagulation following Fontan or similar procedures relies on the thrombotic factors and their temporal distribution, being more pronounced in the first postoperative year; anticoagulants should be given over this period. In Eisenmenger's syndrome haemorrhage is common: these patients are not anticoagulated unless there is an indication such as recent pulmonary embolus. During interventional catheterisation thromboembolic accidents are rare, occurring early, and more commonly with certain prostheses. In adults with an intra-atrial prosthesis oral anticoagulants are used for three months, and then replaced by antiplatelet drugs. In congenital cardiopathy the stent is often pulmonary or aortic, and the incidence of thromboembolic accident is therefore very low. For a venous channel or in the context of a Fontan procedure, oral anticoagulants are justified for between three and six months. It is to be hoped that prospective studies, of which some are in progress, will provide further guidance for these indications.

4-Hydroxycoumarins↗
PubMed2004

Setting up a health education website: practical advice for health professionals.

Recently, both popular and professional publications about health care have begun to express enthusiasm for the Internet as a source of medical information and possibly of psychological support for those with serious illnesses. However, there are pitfalls for practitioners and researchers who seek to capitalise on these patient education possibilities. We describe here the process and mixed outcomes of the efforts of a multidisciplinary team to set up and evaluate a website for rural women with breast cancer. We provide recommendations for other health professionals contemplating similar ventures, and also identify some future steps to develop and research this potentially valuable form of patient education and support.

Adaptation, Psychological↗
PubMed2003

Coronary events after arterial switch operation for transposition of the great arteries.

BACKGROUND: Transfer of the coronary arteries is a crucial step during the arterial switch operation (ASO) for transposition of the great arteries. This retrospective study aims to assess the incidence and risk factors of coronary events after ASO and sensitivity of noninvasive tests in the diagnosis of the coronary obstruction. METHODS AND RESULTS: Between 1982 and 2001, 1304 newborn and infants had an ASO and the 1 198 hospital survivors had a 59-month mean follow-up. Coronary events occurred in 94 patients (7.2%; 95% CI, 6 to 9). Survival without coronary events were 92.7, 91, and 88.2% at 1, 10, and 15 years, respectively. The incidence was bimodal: high early and slow later. Multivariate analysis showed correlation with type B or C coronary pattern and major operative events (P<0.0001 and P=0.0024). In a subset of 324 patients who underwent a coronary artery angiography, lesions were observed in 22 patients (6.8%; 95% CI, 5 to 10). Multivariate analysis showed correlation with only type B or C coronary pattern (OR=20.8, P=0.0002). All of these patients had electrocardiogram and echocardiogram, 174 patients also had a treadmill test, and 115 patients had a myocardial scintigraphy. The association of these tests had the highest diagnosis sensitivity, 75%. CONCLUSIONS: After ASO, coronary events are not rare, occurring most often early and are an important cause of death. Coronary repair can be needed lately. Noninvasive tests are not sensitive enough to detect significant delayed coronary artery stenosis and coronary artery angiography should be performed.

Coronary Angiography↗
PubMed2003

Role of plasminogen activator-plasmin system in tumor angiogenesis.

New blood formation or angiogenesis has become a key target in therapeutic strategies aimed at inhibiting tumor growth and other diseases associated with neovascularization. Angiogenesis is associated with important extracellular remodeling involving different proteolytic systems among which the plasminogen system plays an essential role. It belongs to the large serine proteinase family and can act directly or indirectly by activating matrix metalloproteinases or by liberating growth factors and cytokines sequestered within the extracellular matrix. Migration of endothelial cells is associated with significant upregulation of proteolysis and, conversely, immunoneutralization or chemical inhibition of the system reduces angiogenesis in vitro. On the other hand, genetically altered mice developed normally without overt vascular anomalies indicating the possibility of compensation by other proteases in vivo. Nevertheless, they have in some experimental settings revealed unanticipated roles for previously characterized proteinases or their inhibitors. In this review, the complex mechanisms of action of the serine proteases in pathological angiogenesis are summarized alongside possible therapeutic applications.

Animals↗
PubMed2003

[Prevalence and diagnosis of coronary lesions after arterial switch].

In anatomical repair procedure of transposition of the great arteries (arterial switch), translocation of the coronary arteries is crucial and coronary complications remain the principal cause of death. The aim of this retrospective study was to assess the prevalence of coronary lesions and to evaluate the diagnostic methods to prevent their consequences. From 1982 to 2001, 1,304 patients were operated for transposition of the great arteries by the switch procedure at the Marie Lannelongue Surgical Centre. The average follow-up of the survivors was 59 months (3 days to 17 years) during which 324 patients underwent coronary angiography. All had an ECG and an echocardiogram (N = 324); 174 underwent exercise stress testing and 115 had myocardial scintigraphy. Of the 324 patients who underwent coronary angiography, 22 had coronary lesions (6.8%; 95% CI 5-10). In multivariate analysis a type II coronary network by the Marie Lannelongue Classification was related to the risk of coronary lesions (OR = 0.28; p < 0.0002). Each non-invasive method studied separately had a low sensitivity (< 50%) for the detection of these lesions. The association of ECG, echocardiography and myocardial scintigraphy had the best sensitivity at 75%. Therefore, after the arterial switch procedure non-invasive investigations are not sensitive enough to diagnose coronary lesions and systematic coronary angiography and aortography should be performed in all patients.

Adolescent↗
PubMed2002

Severe cardiac failure in newborns with VGAM. Prognosis significance of hemodynamic parameters in neonates presenting with severe heart failure owing to vein of Galen arteriovenous malformation.

OBJECTIVE: Neonatal vein of Galen malformation complicated by severe cardiac failure is a rare disease. The purpose was to assess the outcome of this life-threatening malformation and identify hemodynamic prognostic factors. DESIGN: Retrospective study. PATIENTS: Twenty-four newborns with cardiac failure requiring mechanical ventilation were consecutively admitted from 1986 to 2000. INTERVENTIONS: Cardiovascular evaluation including echocardiogram was performed in all cases. Eighteen transarterial shunt occlusions with glue were applied by the same team of three physicians. MEASUREMENTS AND RESULTS: Twelve babies survived and underwent one endovascular session at least (median age 20 days) with a mean 63 months follow-up. Embolization was not performed in 6 of the 12 nonsurvivors because of severe brain damage or profound hypotension Cardiogenic shock occurred in all nonsurvivors, but also in one long-term survivor (p<0.0001). Echocardiogram showed signs of right ventricular failure, most often in the dead babies (p=0.005). The pulmonary systemic arterial pressure ratio was significantly higher in the nonsurvivor group (p=0.031), and it decreased significantly after the first embolization only in patients who survived (p=0.01). Patent ductus arteriosus and a diastolic aortic reversed-flow were present in all nonsurvivors in contrast to 30% of the long-term survivors (p=0.003 ). There was no difference in the left ventricular contractility and mean cardiac output between the two groups. CONCLUSIONS: The outcome of vein of Galen malformation complicated by severe cardiac failure requiring mechanical ventilation remains poor. Neonatal embolization seems to be beneficial only in babies without suprasystemic pulmonary hypertension.

Arteriovenous Malformations↗
PubMed2002

[Three-dimensional multislice CT scanner: value in patients with pulmonary atresia with septal defect].

The aim of this study was to evaluate the interest of multislice CT scanning using three-dimensional reconstructions for pre- or postoperative management of patients with pulmonary atresia with ventricular septal defect. Twenty-one consecutive patients (median age: 8 months, median weight: 5.6 kg) with pulmonary atresia with ventricular septal defect were explored by multislice CT. Standard protocol consisted in one helical thoracic acquisition, associated with an injection of 2 to 3 mL/kg of iodinated contrast medium at a flow rate from 0.5 to 1 mL/s. Three-dimensionnal reconstructions were systematically performed. Before operation, status and size of central pulmonary arteries, major aorto-pulmonary collateral arteries, and associated anomalies were analyzed. In 13 operated patients, the permeability of palliative anastomosis and postoperative anatomical changes were studied. The status of central pulmonary arteries was assessed in all cases and the sizes found were in agreement to surgical findings. Main aorto-pulmonary collateral arteries were depicted and their relative position to central airways was assessed. Various associated anomalies were found: right aortic arch, anomalous coronary artery, abnormal pulmonary venous return, left superior vena cava. The anastomosis and the surgical connections (unifocalization, complete repair) were clearly analyzed. The multislice CT with three-dimensional reconstructions is a complementary imaging technique, reliable, useful to pre-operative management and postoperative follow-up of patients with pulmonary atresia with ventricular septal defect.

Adolescent↗
PubMed2001

Late outcome after arterial switch operation for transposition of the great arteries.

BACKGROUND: Early and midterm results of the arterial switch operation (ASO) in transposition of the great arteries (TGA) are good, but late outcome data in large populations are still few. METHODS AND RESULTS: Twelve hundred patients had an ASO for TGA between 1982 and 1999, with prospective follow-up of 1095 survivors. Outcome measures included late death, reoperation, aortic insufficiency (AI), pulmonary stenosis (PS), and coronary anomaly. Median follow-up was 4.9 years (range 0.5 to 17 years). Late death occurred in 32 patients; survival was 88% at both 10 and 15 years. The hazard function for death declined rapidly, with no deaths after 5 years. Late mortality was correlated with reintervention and major events in the intensive care unit. Reoperation was performed in 103 patients, more often in complex TGA; the cause was mainly PS. Freedom from reintervention was 82% at 10 and 15 years, with a hazard function that declined rapidly but slowly increased after 3 years. At the last follow-up, PS was present in 3.9% of patients, and grade II or more AI was present in 3.2%, with a cumulative incidence of 9% at 15 years. Among the 278 patients who had a coronary arteriography, 8% had coronary lesions. Normal left ventricle and sinus rhythm were seen in 96.4% and 98.1%, respectively. CONCLUSIONS: Fifteen years after ASO, late mortality was low, with no deaths after 5 years; reoperation, mainly owing to PS, occurred throughout the follow-up. AI and coronary obstruction are rare but warrant further follow-up. Good left ventricular function and sinus rhythm are maintained.

Aortic Valve Insufficiency↗
PubMed2001

Detection of enteroviruses ribonucleic acid sequences in endomyocardial tissue from adult patients with chronic dilated cardiomyopathy by a rapid RT-PCR and hybridization assay.

A rapid reverse transcription polymerase chain reaction (RT-PCR) and microwell capture hybridisation assay with general specificity for enteroviruses was developed and compared with an improved nested RT-PCR for the detection of enteroviral RNA sequences in endomyocardial tissue from patients with chronic dilated cardiomyopathy. This method could detect as few as 20 genomic RNA copies per 100 mg of heart tissue homogenate and results could be obtained within 8 hours. Of the 55 biopsy specimens aseptically collected from the explanted hearts of 55 patients, 21 (38.2%) were positive by RT-PCR microplate assay, whereas only 19 (34.5%) were positive by nested RT-PCR assay and none were positive by classical cell culture assays. No enterovirus was detectable by RT-PCR or classical cell culture assays in any of the 55 heart biopsy specimens taken from organ donors without any known heart disease. Moreover, the nucleotide sequences of EV nested RT-PCR products showed greatest similarity to group B Coxsackieviruses [CVB3 (n = 12) or CVB5 (n = 3)], but also to group A Coxsackieviruses (CVA21 (n = 1) or CVA9 ( n= 3)]. The described RT-PCR and microwell capture hybridisation assay can be applied to the virological diagnosis of human enteroviral cardiac infections. Moreover our findings suggest that group B and group A Coxsackieviruses can persist in heart tissue from patients with end-stage chronic cardiomyopathy, supporting the hypothesis that these viruses could be implicated in the etiology of idiopathic dilated cardiomyopathy.

Adult↗
PubMed2001

[Aerosolized iloprost therapy in an infant with chronic pulmonary hypertension after a neonatal arterial switch operation].

UNLABELLED: The treatment of chronic pulmonary hypertension with prostacyclin in children is prone to severe complications due to mandatory long-term venous therapy. Inhaled iloprost has been evaluated in adult patients with good preliminary results. CASE REPORT: We report our experience of the use of aerosolized iloprost in an infant treated for pulmonary hypertension associated to a right ventricular failure, which occurred after a neonatal arterial switch operation for transposition of the great arteries. For nine months, hemodynamic and functional status improved and the quality of life was satisfactory at home. CONCLUSION: If further experiences and studies support this observation, aerosolized iloprost could be an alternative to prostacyclin venous therapy in treating children with chronic pulmonary hypertension.

Administration, Inhalation↗
PubMed2001

Percutaneous closure with Amplatzer device is a safe and efficient alternative to surgery in adults with large atrial septal defects.

BACKGROUND: In adults with atrial septal defect (ASD) and large right-to-left shunt, closure of the defect is recommended. Percutaneous closure is still rarely used in this population. This study presents the results of transcatheter closure with the Amplatzer occluder in such patients. METHODS AND RESULTS: We studied 44 consecutive adult patients with a secundum ASD and 2 of the 3 following criteria: QP/QS >/=2 by oximetry, echocardiographic right ventricle overload, and ASD size >20 mm. Forty-two patients had a successful implantation. In 1 patient an unstable device was withdrawn; in another one, the device embolized in the pulmonary artery. At 6-month median follow-up, 95% had a complete closure; 2 patients with an additional defect had a small residual shunt. Major complications were the aforementioned embolization and a cerebrovascular accident in a patient with atrial fibrillation treated with aspirin. Others were minor and transitory: premature atrial beats in 3 patients, and paroxysmal atrial fibrillation and pulmonary edema in 1 patient each. CONCLUSIONS: Transcatheter closure of large ASDs with the Amplatzer device is efficient with less morbidity than surgical closure.

Adolescent↗
PubMed2001

Surgically created double-orifice left atrioventricular valve: a valve-sparing repair in selected atrioventricular septal defects.

OBJECTIVES: Some features of the left atrioventricular valve (large mural leaflet, dystrophic tissue) represent a challenge for repair of atrioventricular septal defects without postoperative regurgitation. A retrospective study was conducted to evaluate the results of surgically creating a double-orifice left atrioventricular valve in such circumstances. Clinical results were analyzed according to valvular and subvalvular left atrioventricular valve measurements in pathologic specimens with atrioventricular septal defects. METHODS: Among 157 patients operated on for atrioventricular septal defect since October 1989, 10 patients underwent primary repair (n = 8) or reoperation (n = 2) by this procedure. Median age at repair was 3.3 years (0.1-33 years). Anatomic types were complete (n = 3), intermediate (n = 5), and partial (n = 2). Preoperative moderate to severe left atrioventricular valve regurgitation was present in 6 patients. After the repair (two-patch technique in complete atrioventricular septal defect, cleft closed in each case), these 10 patients were found to have moderate to severe residual regurgitation not amenable to repair by annuloplasty. The top edge of the mural leaflet was anchored to the facing free edge of the cleft. RESULTS: No hospital death or morbidity was observed. Left atrioventricular valve regurgitation was absent or trivial (8 patients) and mild (2 patients). Color-coded echocardiography did not show significant left atrioventricular valve stenosis. The mean diastolic pressure gradient across the left atrioventricular valve was 3.2 +/- 1.1 mm Hg (1.4-4.5 mm Hg). At a median follow-up of 72 months (6-91 months), there was 1 late death, unrelated to left atrioventricular valve malfunction, due to pulmonary vascular obstructive disease. Left atrioventricular valve regurgitation did not increase over time, except in 1 patient in whom regurgitation recently progressed from mild to moderate. At rest, the mean diastolic pressure gradient across the left atrioventricular valve was 3.8 +/- 2.9 mm Hg (1.5-11.2 mm Hg). One child had an early moderate stenosis without pulmonary hypertension. Studies on pathologic specimens (n = 34) indicated that long chordal lengths and large mural leaflet size are essential independent anatomic features to assess its feasibility. CONCLUSIONS: Surgical creation of a double-orifice left atrioventricular valve is an effective additional procedure for repair of atypical cases of atrioventricular septal defect. The operation may decrease the need for reoperation or left atrioventricular valve replacement.

Adult↗
PubMed2001

Translocation frequencies measured in patients one year after radioactive iodine therapy for thyrotoxicosis.

PURPOSE: To investigate the incidence of translocations induced by iodine-131 therapy in thyrotoxicosis patients 1 year after the administration of the radiolabelled compound. MATERIALS AND METHODS: Tricolour FISH with whole-chromosome-specific probes for chromosomes 2, 4 and 8 was used for scoring translocations. From the genomic translocation frequencies, derived using the Lucas formula, equivalent whole-body doses were calculated, based on the in vitro (60)Co gamma-ray dose-response curve. RESULTS: A total of 101 translocations were observed in 4864 metaphases, 63% being of the two-way type. In the control group used for obtaining dose-response data, nine translocations were observed in 5278 metaphases, 55% being two-way translocations. No correlation was found between the observed frequency of translocations and administered radioactivity. Using the in vitro dose-response, an estimated average dose for the group of nine patients of 0.79 +/- 0.22Gy was obtained. Compared with frequencies following the assumption that the involvement of a particular chromosome in a two-break exchange-type aberration is proportional to its DNA content, chromosome 4 was more frequently involved and chromosomes 2 and 8 less frequently involved in chromosomal rearrangements. CONCLUSION: This study shows that (131)I therapy for thyrotoxicosis patients induced translocations, especially in chromosome 4, which could be detected 1 year after the administration of the radiolabelled compound.

Adult↗
PubMed2001

Influence of plasminogen activator inhibitor type 1 on choroidal neovascularization.

High levels of the plasminogen activators, but also their inhibitor, plasminogen activator inhibitor 1 (PAI-1), have been documented in neovascularization of severe ocular pathologies such as diabetic retinopathy or age-related macular degeneration (AMD). AMD is the primary cause of irreversible photoreceptors loss, and current therapies are limited. PAI-1 has recently been shown to be essential for tumoral angiogenesis. We report here that deficient PAI-1 expression in mice prevented the development of subretinal choroidal angiogenesis induced by laser photocoagulation. When systemic and local PAI-1 expression was achieved by intravenous injection of a replication-defective adenoviral vector expressing human PAI-1 cDNA, the wild-type pattern of choroidal angiogenesis was restored. These observations demonstrate the proangiogenic activity of PAI-1 not only in tumoral models, but also in choroidal experimental neovascularization sharing similarities with human AMD. They identify therefore PAI-1 as a potential target for therapeutic ocular anti-angiogenic strategies.

Adenoviridae↗
PubMed2001

Presence of oestrogen receptor type beta in human retina.

BACKGROUND/AIMS: Recent studies have demonstrated the existence of two oestrogen receptor subtypes alpha (ORalpha) and beta (ORbeta) with significant differences of expression among organs. Since important pathologies of human eye could be linked to hormonal status, the expression of ORbeta in ocular posterior segment was sought. METHODS: Immunohistochemical localisation of ORbeta and ORalpha protein and detection of OR mRNAs by reverse transcription-polymerase chain reaction (RT-PCR) were performed in macular and extramacular regions of the retina and in the choroid on male and female donors eyes. RESULTS: ORbeta protein was localised in the ganglion cell layer and in the choroid. At the transcriptional level, mRNA for ORbeta and for ORalpha were both present. Local differences in the expression level were observed, however, suggesting the possibility of variation in the ratio of ORalpha v ORbeta. CONCLUSIONS: The coexistence of two oestrogen receptor subtypes in the human ocular posterior segment raises acute questions about their potential physiological role, but offers a perspective for preferential targeting of a specific receptor subtype.

Aged↗