Biomedical subjects

J L Bonnet

Publications and source records attributed to J L Bonnet.

At least 19 recordsLinked to original sources

PubMed2005

Assessment of anthracene toxicity toward environmental eukaryotic microorganisms: Tetrahymena pyriformis and selected micromycetes.

The toxicity of anthracene, a nonmutagenic, noncarcinogenic, low-molecular-weight polycyclic aromatic hydrocarbon present in the environment, was assessed using a ciliated protozoan, Tetrahymena pyriformis, and a selection of 10 micromycetes from different taxonomic groups living in two environmental compartments, namely aquatic and soil ecosystems. With T. pyriformis, a concentration-dependent inhibitory effect was shown on the cell proliferation rate, IC(50) = 33.40+/-4.84 mg/L (kinetic method). Phagocytosis of nonsoluble anthracene was confirmed by the presence of digestive vacuoles with photon microscopy. In fungi, anthracene did not exhibit a fungicide effect but showed a fungistatic action. Except for Absidia fusca and Cladosporium herbarum, the micromycetes showed a concentration-dependent decrease in growth. From IC(50) values determined by endpoint or kinetic methods, Rhodotorula glutinis and all of the Ascomycotina (except for Penicillium chrysogenum) were the most sensitive species, while Phanerochaete chrysosporium, P. chrysogenum, and the two Deuteromycotina were more resistant to anthracene. Our discussion focuses on the evaluation of toxicity by the two methods used for the calculation of the IC(50) values (endpoint and kinetic), the advantages of studying growth by a kinetic method (the dynamic aspect), and a comparison of toxicity to T. pyriformis and the different micromycetes.

Animals↗

PubMed2005

[Tako-tsubo: a rare form of transient left ventricular dysfunction].

The authors report the case of a 67 year old caucasian female admitted for suspected acute coronary syndrome with ST segment elevation. Coronary angiography did not show any coronary lesion but ventriculography revealed akinesia of the middle and apical segments with hyperkinesia at the base. An isolated moderate elevation of troponine Ic was noted. On the 10th day the methergin test was negative and ventriculography showed complete recovery of the left ventricular segmental kinetics. Left ventricular transient apical ballooning, or tako-tsubo syndrome, is characterised by reversible akinesia of the middle and apical segments with no associated coronary lesion or enzymatic elevation concordant with the extent of the akinetic areas. It mainly affects women between 50 and 60 years old and follows emotional or physical stress. The prognosis is excellent in survivors with a rapid return of normal systolic function. The pathophysiology remains debatable, excluding myocarditis in favour of sideration.

Acute Disease↗

PubMed2004

[Acute myocarditis and eosinophilic pneumonia: good outcome after medical treatment and long-term follow-up].

The authors report a case of acute eosinophilic myocarditis (AEM) with acute left ventricular failure preceded by an acute hypoxaemic eosinophilic pneumonia. The diagnosis of myocarditis was confirmed histologically. That of the eosinophilic pneumonia was base on the abundance of eosinophilic polynuclear cells in the bronchoalveolar lavage and appearances on computerised tomography. The pulmonary lesions rapidly and definitely regressed and complete recovery of left ventricular function was obtained by long-term steroid therapy. This favourable outcome has been sustained after 11 years of follow-up despite the presence of chronic mild hypereosinophilia. In the absence of specific clinical and paraclinical data, the diagnosis of AEM was based on the demonstration of an inflammatory infiltrate rich in polynuclear eosinophils and necrotic myocardial lesions. This histological signature may be obtained in vivo by endomyocardial biopsy, the indication of which must be rapidly recognised. Only the instauration of early and intensive steroid therapy seems to influence the outcome which is frequently poor. The synthesis of the anatomo-clinical and experimental data suggests a myocardial aggression by cytotoxic effects of granular protein components released during activation of polynuclear eosinophils. The role of AEM is discussed in the different aspects of cardiac hypereosinophilia.

Acute Disease↗

PubMed2004

[Efficacy of angioplasty of native coarctations of the aorta of the big infant and of the adult with systematic endoprosthesis implantation].

The angioplasty of native coarcatations of the aorta remains a controversial treatment due to recurrences and the potential risk of aneurysm or of descending aorta dissection during catheterization. The interest of a systematic implantation of an endoprothesis is poorly documented. We report our experience in a small series of 3 patients aged from 7, 28 to 52 years at the moment of the angioplasty of their native aortic coarctation. In all the three cases it corresponded to a "membranous" type, localized a the level of the isthmus without hypoplasia of the aortic arch. All presented a refractory hypertension. One patient presented an intermittent claudication related to a low perfusion of lower limbs. The angioplasty was performed with BIB balloon, associated at the same time with the implantation of a Palmaz P308 stent in two cases and Genesis PG2910P in the last patient. The efficacy was immediate in all the 3 cases with stopping antihypertensive drugs at the very day of the procedure. The immediate results were complicated by a bilateral hematoma of the scarpa in a context of excessive anticoagulation in one patient requiring blood tranfusion. After a follow-up of one, 12 and 21 months, all the 3 patients are asymptomatic without any significant residual hypertension. The control scan of the infant confirmed the absence of re-coarctation. In conclusion, the angioplasty followed by systematic implantation of an endoprosthesis is a safe and effective technique for treating simple forms of native coarctations of the aortic isthmus. It can be proposed as a first line treatment for big infants and adults affected by localized types.

Adult↗

PubMed2003

[Restrictive cardiomyopathy due to myofibrillar myopathy].

UNLABELLED: Early and severe cardiomyopathy may be related to myofibrillar myopathy. CASE REPORT: We report a one-year-old child with early and severe restrictive cardiomyopathy. The diagnosis of myofibrillar myopathy was obtained on skeletal muscle and endomyocardial biopsies. The patient died despite inotropic support and mechanical ventilation. CONCLUSION: Myofibrillar myopathy must be considered when exploring the etiology of a restrictive cardiomyopathy in children. The diagnosis relies on examination of endomyocardial or skeletal muscle biopsy samples.

Biopsy↗

PubMed2003

[Mitral insufficiency related to a spasm of the left anterior descending artery. A case report].

We report the case of a female patient of 76 years old admitted to our hospital for a pre-operative assessment of a symptomatic mitral regurgitation (MR) whose transthoracic echocardiography revealed only a trivial regurgitation. The occurrence during hospital stay of an acute pulmonary edema contemporary to the occurrence of a huge MR permitted to suspect the diagnosis of a paroxystic ischemic MR. Angiographic and hemodynamic evaluation revealed only a non-significant atheromateous plaque located in the distal LAD. The infusion of Methylergometrine triggered a severe spasm at the site of that plaque, associated with a huge MR visualized by TTE with restricted movements of both leaflets, responsible for an acute pulmonary edema occurring on the table of the catheterization laboratory. Recovery was quickly obtained after intravenous injection of Nitroglycerin, which removed the spasm and valvular regurgitation. The diagnosis of paroxystic ischemic mitral regurgitation was confirmed and a treatment based on high dosage of calcium-blocker was decided. After a follow-up of more than one year, the patient remains asymptomatic and the regurgitation has never occurred.

Aged↗

PubMed2003

[Medico-economic study of percutaneous and surgical closure of ostium secundum type interatrial communications].

The aim of this study was the medico-economic evaluation of the closure of ostium secundum type interatrial communications in 32 patients, treated by cardiac catheterisation (group A: n = 17) or by surgery (group B: n = 15). The success rate was 100% with the 2 techniques. With national cost scale data we evaluated the overall cost of the 2 treatments using the information system medical program, starting from homogenous groups of patients: 150 catheterisation, 169 and 170 surgery. As the value for the homogenous group of 150 patients was much lower than the price of the material used for catheterisation, an adjusted group of 150 patients including the price of this material was created. An evaluation in terms of an artificial index of activity was also performed. The average duration of hospital stay for group A was reduced by 6.1 days compared to group B (p < 0.001). The overall cost was lower in group A than in group B (p < 0.001), using the real and "adjusted" homogenous group of 150 patients, with a respective reduction of 7,582 Euros and 3,731 Euros. Surgery and catheterisation scored 8,167 points (17,756 Euros) and 2,726 points (5,926 Euros) per patient respectively on the artificial activity index. In conclusion, catheterisation reduced the duration of hospital stay and brought an economic benefit for the Assurance Maladie compared to surgery. However, surgery is more profitable for the hospital than catheterisation because of the high cost of the prosthesis, which is not taken into account with a homogenous group of non-specific patients. This could hamper the development of this innovative technique in a hospital subjected to overall budgetary constraints.

Adolescent↗

PubMed2002

[Outcome of infants with hypoplastic left heart syndrome diagnosed in utero].

The authors report the results of prenatal diagnosis of the hypoplastic left heart syndrome since 1998 in the University Hospitals of Marseille and Montpellier. Twenty-four prenatal diagnoses of this condition were made in mothers with a mean age of 29 (18 to 40 years) and after a mean term of 22 (18.5 to 33) weeks of amenorrhea. Seventeen therapeutic abortions were carried out and 7 neonates born after a mean term of 39 (28 to 40) weeks, were admitted to the paediatric intensive care unit. Two patients required ventilatory assistance with one early death. The other patients were stable after surgery. A Norwood (first stage) procedure was carried out in 6 neonates at a mean age of 5 (1 to 6) days. There was only one survivor (17%). Prenatal diagnosis of the hypoplastic left heart syndrome allows cardiac and extracardiac evaluation of foetuses with this condition. Therapeutic abortions may be proposed and was the commonest choice of the parents in this study. On the other hand, despite better management of neonates with this prenatal diagnosis, the poor prognosis of the Norwood first stage procedure is unchanged. A systematic search for a restriction of the foramen ovale on foetal echocardiography could optimise neonatal management of this problem.

Abortion, Therapeutic↗

PubMed2002

[Dextrocardia with situ solitus, ventricular loop, double outlet hypoplastic right ventricle and L-malposition of the great arteries. Description and surgical treatment of a rare and complex cardiopathy].

Despite the cardiac surgery improvements allowing the correction of the majority of congenital heart diseases with ventricle-great vessels discontinuity, some abnormalities increase the risk of bi-ventricular reparation. We herein report the case of a patient presenting a rare form of double outlet right ventricle with a ventricular loop, with moderate right ventricle hypoplasia. L-malposition of great vessels and pulmonary artery stenosis, and for whom we opted for a palliative surgical treatment including a systemic-pulmonary anastomosis followed by a upper right bi-directional cavo-pulmonary derivation. The last surgery was followed by recurrent right pleural effusions disappearing after the embolization of the systemic-pulmonary anastomosis by catheterism as it probably obstructed the draining of the cavo-pulmonary anastomosis. The relevance of this clinical case reported is, firstly the description of this ventricle loop resulted from a marked ventricular malposition which is a rare heart disease, and secondly the discussion about the surgical treatment, especially about the choice between palliative and curative surgery. Only comparative studies on long term morbidity and mortality between the bi-ventricular reparation and mono-ventricular palliation will allow the selection of the most appropriate surgical treatment.

Abnormalities, Multiple↗

PubMed2000

Fatal cerebral hemorrhage and severe thrombocytopenia during abciximab treatment.

We describe the case of a fatal cerebral hemorrhage associated with a severe thrombocytopenia (4.0 x 10(9)/l), occurring only 90 min after starting treatment with abciximab, in a patient undergoing primary percutaneous transluminal coronary angioplasty (PTCA) for an acute myocardial infarction. Cathet. Cardiovasc. Intervent. 49:177-180, 2000.

Abciximab↗

PubMed2000

Comparison of metabolic expenditure during CAEP versus a test adapted to aerobic capacity (Harbor test) in elderly healthy individuals.

Cardiopulmonary exercise tests are frequently used to test rate responsive pacemakers. The chronotropic assessment exercise protocol (CAEP) has been specifically proposed for the evaluation of rate responsive pacing systems. A mathematical method, based on CAEP measurements, was developed with a view of normalizing the exercise induced metabolic response. CAEP was compared to a tailored protocol (Harbor), adapted to the metabolic capacity of each patient. Harbor was set to keep the exercise duration within 10 minutes and achieve a workload as linear as possible. Metabolic parameters were continuously recorded by a cardiopulmonary system. Those data were used in the construction of slopes by the normalization method. The results of the tests performed in 16 elderly healthy patients showed no differences in metabolic or functional parameters. Slopes of the mathematical model were comparable (1.09 +/- 0.16 for CAEP vs 1.07 +/- 0.17 for Harbor), though both were higher than the value of 1, defined as normal. In both cases, linearity was confirmed by the coefficient of correlation (0.98 +/- 0.02 for CAEP and Harbor). In conclusion, no significant differences were found in the outcomes of the two protocols. Higher values of the slopes with the normalization method can be explained by the definition of the maximal predicted heart rate as 220--age, which is probably not appropriate for elderly, healthy, active subjects.

Aged↗

PubMed1999

Effects of cadmium on the performance and microbiology of laboratory-scale lagoons treating domestic sewage.

Two experiments were performed to assess the impact of cadmium on the sewage lagoon wastewater treatment process. For each one, three laboratory-scale pilot plants with one tank receiving the same raw effluent were used; one plant served as control and the other two were contaminated once only with cadmium. In the first study, the effects of a shock load of two concentrations of cadmium chloride (60 and 300 micrograms/l) on the plant performance, microbial populations (protists and bacteria) and enzyme activities were determined. Initially, most of the performance parameters were affected concentration-dependently. A reduction in the protist population density and some influence on the total bacterial population were observed, and the potential enzymatic activities were also modified. A second experiment with a lower cadmium concentration (30 micrograms/l), supplied as chloride or sulphate, still perturbed most of the parameters studied, and the effects of the two cadmium salts were identical.

Bacteria↗

PubMed1999

Biological treatment of whey by Tetrahymena pyriformis and impact study on laboratory-scale wastewater lagoon process.

A procedure based on a biological treatment of whey was tested as part of research on waste treatment at the scale of small cheesemaking units. We studied the potential biodegradation of whey by a protozoan ciliate, Tetrahymena pyriformis, and evaluated the functional, microbiological and physiological disturbances caused by crude whey and the biodegraded whey in laboratory-scale pilots mimicking a natural lagoon treatment. The results show that T. pyriformis can strongly reduce the pollutant load of whey. In the lagoon pilots serving as example of receptor media, crude whey gradually but completely arrested operation, whereas with the biodegraded whey adverse effects were only temporary, and normal operation versus a control was gradually recovered in a few days.

Animals↗

PubMed1999

[Detection and surveillance of left atrial thrombosis by transesophageal echocardiography].

Out of 1,141 successive transoesophageal echocardiographic studies performed prospectively between 01/05/1993 and 31/12/1995, 26 cases of left atrial thrombosis were observed (2.2%); 5 were in the left atrium (20%), 19 in the left atrial appendage (73%) and the thrombi were in both atrium and left atrial appendage in 2 cases (7%). The 26 patients included 15 women and 11 men, with an average age of 69 +/- 16 years (range 25-89 years); 22 patients (84%) had permanent atrial fibrillation and 4 were in sinus rhythm. Only 5 of the patients were on oral anticoagulant therapy. All had underlying cardiac disease: 11 mitral valve diseases; 10 dilated cardiomyopathies; 2 hypertrophic cardiomyopathies; 3 other cardiac diseases. The indication for transoesophageal echocardiography was systemic embolism in 13 cases (50%); before D.C. cardioversion in 10 cases (38%) and before percutaneous mitral valvuloplasty in 3 cases. The thrombus was adherent in 18 cases (69%) and mobile in 8 cases (31%). Spontaneous contrast was observed in 23 cases (88%). Intravenous heparin was given as soon as the diagnosis was made. In 4 patients, thrombectomy was indicated in view of the threatening nature of the thrombus and/or the necessity for associated valve replacement. In 22 patients, heparin was relayed by oral anticoagulants on the 10th day of treatment. Control transoesophageal echocardiography was not performed because of the patient's refusal or poor general condition. The other 15 patients were reexamined 1 to 5 times between the 4th day and 12th month: a regression was observed in 13 cases (86%) which was complete in 11 and partial in 2 cases. No cases of embolism occurred during follow-up but six patients died: 1 of the operated cases and 5 of the patients treated medically (3 cardiac failures and 2 cerebral haemorrhages). The authors conclude that left atrial thrombosis is rare in the absence of classical embolic cardiac disease. With the exception of the surgical indication of a life-threatening thrombus and/or associated surgical mitral valve disease, anticoagulant therapy results in complete or partial regression of the thrombus visualised by transoesophageal echocardiography which is essential for follow-up. The prognosis depends on the severity of the underlying heart disease.

Adult↗

PubMed1999

[Prospective study on the mechanism of myocardial infarction without significant coronary stenosis].

The aim of this study was to evaluate prospectively the respective roles of the atheromatous plaque, coronary spasm and abnormalities of haemostasis in patients with myocardial infarction with normal coronary arteries. The study population included 25 patients (19 men and 6 women) with a mean age of 52.1 +/- 11.1 years (34-76 years). The diagnosis of myocardial infarction was made as the finding of 2 out of 3 WHO criteria. It occurred spontaneously and was transmural in 80% of cases, inferior wall infarction in 9 patients (36%), anterior in 12 (48%) and lateral in 4 patients (16%). All patients underwent investigation on average 10 days after infarction (1-42 days) by coronary angiography with quantitative angiography, endocoronary ultrasonography, an ergometrine provocation test for coronary spasm and a blood coagulation study. Coronary angiography was normal in 4 patients but showed wall changes without stenosis > 50% in 20 patients and one case of aneurysmal arterial disease. Intracoronary thrombosis was detected in 6 cases. Endocoronary ultrasonography confirmed the normality of the coronary arteries in 2 cases and showed atheroma in 23 cases (soft atheroma: n = 17 and hard: n = 6). It detected 66% of the coronary thrombi observed at angiography and found 3 other cases. Coronary spasm was verified in 10 patients (40%). The coagulation study was normal in 19 patients and showed increase in Pai-1 in 5 patients and primary thrombocythemia in one case. The authors conclude that coronary angiographic data is less accurate than endo-coronary ultrasonography which best shows the extent and, above all, the nature of the plaques present in 23 of the cases (92%). Coronary spasm may be a contributing factor in 40% of cases, in situ thrombosis in 36% of cases despite usually normal blood clotting studies. None of these abnormalities was observed in one case. The embolic cause of infarction was certain in 2 cases.

Adult↗

PubMed1999

[Acute complications of coronary angioplasty: prevention and management].

The immediate results of transluminal coronary angioplasty (TCA) have improved considerably during recent years. Balloon dilatation of the arterial stenosis is the basis of this technique of revascularisation but new tools may be used to treat specific lesions. Coronary occlusion is the most feared complication of TCA. It may cause myocardial infarction or death of the patient. It is usually secondary to dissection and/or thrombus of the artery. The implantation of a stent successfully treats most cases of dissection. New anti-platelet (GP IIb/IIIa) drugs seem to be very effective in the prevention and treatment of the thrombosis. The systematic use of ticlopidine limits the risk of stent occlusion. Improved features enable satisfactory implantation of stents in the majority of cases. In some patients, the clinical consequences of occlusion may be limited by vascular bypass techniques, especially intra-aortic balloon pumping. In other cases, emergency coronary bypass surgery may be necessary. When TCA is considered to be a very high risk procedure, effective surgical cover is essential.

Angioplasty, Balloon, Coronary↗

PubMed1998

Circadian variations in minute ventilation can be reproduced by a pacemaker sensor.

Special software allowing the memorization of 24-hour minute ventilation can be loaded into the memory of the Chorus RM, a DDDR pacemaker driven by minute ventilation. This feature was tested in the postimplant period in 13 patients. Measurements of minute ventilation, respiratory rate, and respiratory amplitude were analyzed according to prospectively defined diurnal and nocturnal time periods. Minute ventilation decreased by 39% (P < 0.001) from the diurnal to the nocturnal phase, while respiratory rate and amplitude decreased by 18% and 28%, respectively (P < 0.001 each). Thus, minute ventilation allowed discrimination between sleep and waking hours. This information could be utilized to modulate the backup rate of the pacemaker.

Aged↗

PubMed1998

Automatic adaptation of the basic pacing rate in response to minute ventilation. Chorum French Investigational Group.

Rate responsive pacing based on minute ventilation (VE) correlates highly with metabolic demand. This type of sensing also recognizes extended periods of rest. The Chorum pacemaker includes a rate responsive algorithm that modulates the basic rate according to phases of activity versus sleep. Forty-six patients (mean age 78 +/- 15), received a Chorum pacemaker for atrioventricular block in 17 cases, sick sinus syndrome in 25, and mixed disorders in 4. Holter monitoring was performed to analyze to heart rate and to examine the circadian adaptation of the minimal pacing rate. The mean basic rate was programmed at 63 +/- 5 beats/min, and the sleep rate at 52 +/- 4 beats/min. Seventeen patients had spontaneous heart rates consistently above the programmed basic rate, and 6 had sustained supraventricular tachyarrhythmias. One-half of the patients had periods of pacing at the programmed sleep rate. The mean diurnal pacing rate was 68 +/- 5 beats/min compared to a mean nocturnal rate of 60 +/- 4 beats/min (P < 0.0001). The average time spent at the basic rate was 37 +/- 30 min (0-110) during daytime (4%), versus 242 +/- 153 min (20-477) at night (45%, P < 0.0001). No adverse effect was observed in this patient population. VE allows a reliable detection of the sleeping periods as well as an adjustment of the basic rate in accordance. Caution is advised in cases of bradycardia dependent tachyarrhythmias.

Aged↗