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Biomedical subjects

A Vaillant

Publications and source records attributed to A Vaillant.

At least 19 recordsLinked to original sources
PubMed2005

Genetic diversity and population structure of an insular tree, Santalum austrocaledonicum in New Caledonian archipelago.

We present a study of the genetic diversity and structure of a tropical tree in an insular system. Santalum austrocaledonicum is endemic to the archipelago of New Caledonia and is exploited for oil extraction from heartwood. A total of 431 individuals over 17 populations were analysed for eight polymorphic microsatellite loci. The number of alleles per locus ranged from 3 to 33 and the observed heterozygosity per population ranged from 0.01 in Mare to 0.74 in Ile des Pins. The genetic diversity was lowest in the most recent islands, the Loyautes, and highest in the oldest island, Grande Terre, as well as the nearby small Ile des Pins. Significant departures from panmixia were observed for some loci-population combinations (per population FIS = 0-0.03 on Grande-Terre and Ile des Pins, and 0-0.67 on Loyautes). A strong genetic differentiation among all islands was observed (FST = 0.22), and the amount of differentiation increased with geographic distance in Iles Loyaute and in Grande Terre. At both population and island levels, island age and isolation seem to be the main factors influencing the amount of genetic diversity. In particular, populations from recent islands had large average FIS that could not be entirely explained by null alleles or a Wahlund effect. This result suggests that, at least in some populations, selfing occurred extensively. Conclusively, our results indicate a strong influence of insularity on the genetic diversity and structure of Santalum austrocaledonicum.

Cluster Analysis↗
PubMed1996

[Heart valve prosthesis from autologous pericardium. Preliminary results apropos of 15 patients].

The concept of a heart valve prosthesis made from autologous pericardium is based on the idea of creating and developing a valve with a longer life than heterografts or homografts due to the absence of tissue degeneration causing the deterioration of both of these types of bioprostheses. The first attempts using the fascia lata or the pericardium, implanted in the seventies, were unsuccessful due to problems with pretreatment of the pericardium and other purely technical difficulties. J. Love et al then developed a technique based on Carpentier's earlier work, where a valve is made extemporaneously using the autologous pericardium. We applied this technique in 14 patients from June 1994 to 1995. The mean age of the patients was 68 years (7 males, 7 females). The aortic valve was replaced in all cases. Preoperative findings were: aortic stenosis (n = 7), aortic regurgitation (n = 1), aortic valve disease (n = 6). Two patients also had mitral valve disease and 3 had coronary artery disease. There were no operative deaths and no patients were lost to follow up. Clinical state was satisfactory with a follow-up of 1 to 10 months. Postoperative Doppler echocardiography was performed at 3 and 6 months and showed gradients were very low. This group of patients demonstrated the value and applicability of the concept. The validity of the technique will be evaluated as a function of the long-term results.

Adult↗
PubMed1995

[Myxoma of the mitral valve; apropos of 2 surgically treated cases. Review of the literature].

The authors report two cases of anterior mitral valve myxoma. This is an exceedingly rare localisation and these cases add to the other 8 previously reported cases. Intracardiac tumours and valvular endocarditis may be detected non-invasively by echocardiography but the precise diagnosis may be extremely difficult: mitral valve myxoma is an exceptionally rare condition. Treatment was surgical in both reported cases.

Adult↗
PubMed1994

The molecular basis of microtubule stability in neurons.

Microtubule (Mt) populations show large differences in dynamic properties (i.e., turnover rates) among cell types, and even within the same cell type at different stages of the cell cycle or stages of differentiation. These differences in dynamic properties are correlated with altered sensitivity to Mt-disassembling drugs (e.g. colchicine) which bind specifically to the Mt protein tubulin and to certain toxic metals which also interact with tubulin (e.g. methylmercury) and result in Mt disassembly. Mts in neurons become progressively more stable and more resistant to such compounds during differentiation. We are using the P19 embryonal carcinoma cell line, which can be induced to differentiate along the neural pathway by retinoic acid, as a model system in which to analyze the development of stable Mts. Our results show that during differentiation there is an evolution in the sorting of tubulin isotypes into the stable Mts. This appears related both to the expression of specific Mt-associated proteins and to concomitant posttranslational modifications of tubulin.

Animals↗
PubMed1992

[Acute necrotizing eosinophilic myocarditis. Favorable clinical course after heart transplantation].

A case of acute eosinophilic myocarditis without hypereosinophilia, presenting as hypokinetic dilated cardiomyopathy in a 24-year old man is reported. Sudden worsening of subacute cardiac failure required heart transplantation 3 months after the onset of the disease. Only pathological examination provided the diagnosis of acute necrotizing eosinophilic myocarditis of undetermined origin. Two years after transplantation, the patient had no clinical or histological sign of recurrence. Seldom described in the literature, acute eosinophilic myocarditis is a dangerous form of eosinophilic heart disease which often follows a fulminant course beyond all therapeutic resources. This case, which is particular in its clinical presentation, in the lack of hypereosinophilia and above all in its cure after heart transplantation, enables the authors to discuss the mechanisms and various manifestations of the cardiotoxicity of eosinophils.

Acute Disease↗
PubMed1990

Bilateral bronchial anastomosis in double lung and heart-lung transplantations.

During heart-lung or double lung transplantation, the airway anastomosis is usually made at the tracheal level. Healing of this anastomosis is one source of postoperative complications especially after double lung transplantation (DLT). In this series of 10 patients with cystic fibrosis undergoing DLT, the tracheas of donor and recipient were anastomosed with omental wrapping in 2 cases while the two main stem bronchi were joined without omental wrapping in 8. Endoscopy disclosed no sign of ischaemia in the patients with bilateral bronchial anastomoses. Three patients died on day 20, 21 and 35, respectively, after DLT. Two of these patients (one with a tracheal and the other with bronchial anastomoses) showed no complication at the level of the suture line. The third patient (with bronchial suture) suffered dehiscence of both anastomoses which was attributed to a misdosage of corticosteroids. Of the 6 patients alive after bronchial anastomosis, 3 recovered uneventfully and 3 who had required prolonged postoperative mechanical ventilation developed bronchomalacia. Bronchomalacia was treated by laser resection and stenting. Dehiscence did not occur in any of these six cases. This technique was based on the findings of 12 fresh cadaver dissections showing that collaterals between the bronchial arteries and the pulmonary arteries and veins extend up to the origin of the main stem bronchus. Bronchial suture without omental wrap may be used for double lung and heart-lung transplantation instead of tracheal suture.

Adolescent↗
PubMed1990

[Successful cardiac transplantation after 38 days of circulatory assistance with a heterotopic artificial heart].

The survival of a patient with irreversible cardiac failure on the cardiac transplantation waiting list was assured for 38 days by circulatory assistance with heterotopic Pierce Donachy prosthetic ventricles and followed by successful cardiac transplantation. This method of circulatory assistance is relatively simple to install from the technical point of view and provides a satisfactory haemodynamic result whilst waiting for a compatible donor organ. Several complications, some of them serious, were observed. Some were related to the patient's poor preoperative condition: acute renal failure, disorders of coagulation. These regressed slowly when the patient's haemodynamic status improved. On the other hand, septic problems and local haemorrhage were inherent to this technique. These are the commonest complications reported by other authors. Although the mortality rate during the period of circulatory assistance may appear to be high, this technique remains a valuable method of survival for selected patients and does not affect the chances of success of ulterior cardiac transplantation.

Acute Kidney Injury↗
PubMed1990

[Heart and heart-lung transplantation. 3 years' experience in Timone CHU (Marseilles 1985-1988)].

Since December 1985, we have performed 38 transplantations: cardiac (CT) n: 31, cardiopulmonary (CPT) n: 1, or bipulmonary (BPT) n: 6. There were 31 male and 7 female patients, aged 7 to 62, mean 46. In the cardiac group, the cardiomyopathy was primitive in 13, ischemic in 16, valvular in 2. Five patients had undergone one or more previous operations. Three patients had a biventricular assist device (1,6 and 7 days before transplant) for acute cardiac failure. The indication of CPT or BPT was pulmonary artery hypertension (1), silicosis (1), cystic fibrosis (4). There were 4 post-operative deaths in the CT group (12.9%); failure of graft, low cardiac output, pulmonary artery hypertension by multiple pulmonary thrombosis, and 2 deaths in the CPT and BPT groups (28%). The mean post-operative hospital stay was one month. All patients with CT were treated by an initial maintenance bitherapy protocol (cyclosporine, steroids) and observed by myocardial biopsies and echocardiograms. In 40 per cent of the patients, Azathioprine was subsequently added. The patients had 2.1 rejection episode/patient/year, either spontaneously reversed of treated medically. There were two late deaths (2 and 7 months) by refractory rejection. 78 per cent of the patients were alive one year after transplant. All survivors have recovered a normal life, some of them with full-time work.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Cardiac hydatidosis. Review of recent literature and report of 15 cases].

In the context of a personal series of fifteen cases of hydatid cyst of the heart, the authors present a computerized review of the last one hundred cases published in the literature. The modern features of the disease are discussed together with its severity (mortality of 23.47% in 98 recent cases). Despite the considerable contribution of ultrasonography, computed tomography and magnetic resonance imaging, a certain number of pejorative criteria appear to persist:delayed diagnosis, diagnostic error, acute pulmonary oedema and incomplete surgical cure.

Adolescent↗
PubMed1989

[Septal rupture repaired in the acute stage of myocardial infarction. Clinical, hemodynamic and angio-coronarography findings in the evaluation of surgical risk].

Between 1977 and 1987, 27 consecutive patients (16 men, 11 women, mean age 66 years, range 54 to 75 years) with ventricular septal rupture complicating acute myocardial infarction underwent surgical repair. The purpose of this retrospective study was to analyse the post-operative mortality factors from clinical, haemodynamic and operative data in all patients and also from coronary angiographic data in 23/27 patients whose haemodynamic status allowed this type of exploration. Seventeen patients (63 p. 100) died during the first post-operative month, 10 survived and were discharged. Factors that influenced the prognosis were: (1) inferiorly-located necrosis associated with a 75 p. 100 mortality rate (9 out of 12 patients), as opposed to 53 p. 100 (8 out of 15 patients) with anterior necrosis; (2) right ventricular dysfunction, observed in 83 p. 100 of patients with inferior necrosis and 53 p. 100 with anterior necrosis, which was responsible for 7 out of 9 deaths in the inferior necrosis subgroup and contributed to 3 out of 8 deaths in the anterior necrosis subgroup; this established a cause-effect relationship between right ventricular function and the overmortality of patients with inferior necrosis; (3) independently of the haemodynamic status, two- and three-vessel lesions (56 p. 100 of all lesions) which had an 84 p. 100 mortality rate as opposed to 40 p. 100 with one-vessel lesions; (4) the presence of a state of shock which was associated with a 78 p. 100 mortality rate as opposed to 55 p. 100 in patients without shock. We conclude that when permitted by the patient's haemodynamic status coronary angiography should be part of the pre-operative evaluation to assess the operative risk and guide the surgical procedure.

Acute Disease↗
PubMed1989

[Double lung transplantation. Report of the 1st French case and comments on the 5 subsequent cases].

Using a modified version of the technique described by the Toronto group, the Marseille group has performed 6 double lung transplantation procedures. In 6 cases the underlying disease was cystic fibrosis. Four patients are currently alive. The technique was modified in two ways. First anastomosis was made on the two main stem bronchi in order to rule out the risk of ischemic complications. Second a special postoperative care technique in which the patient is regularly turned from one side to the other was applied to avoid lymph stasis during the first postoperative weeks.

Adolescent↗
PubMed1989

[Giant leiomyoma of the inferior vena cava].

The authors report an uncommon case of giant leiomyoma of the inferior vena cava with intracardiac extension and arising from the external iliac vena. This case report illustrates the diagnostical problems usually encountered with this type of tumour. Indeed, despite ultrasound and transverse CT scan, the diagnosis was only assessed by histopathological analysis following a successful surgical removal of the leiomyoma. Only 7 cases of leiomyoma of the inferior vena cava are already reported in the literature. Relationship with intravenous leiomyomatosis of the uterus is also discussed.

Aged↗
PubMed1988

[Results of cardiac surgery in patients over 70 years of age. Apropos of a retrospective study of 170 patients].

The ever increasing age of the general population and the frequency of coronary and aortic lesions in patients aged 70 or older make cardiac surgery in the elderly a topic of current interest. In a retrospective study of 170 cases the overall mortality rate was 14 p. 100 (4.7 p. 100 in 1986). During the past two years (1985 and 1986), the mortality rates in patients with coronary disease who underwent elective surgery were 10 p. 100 and 4 p. 100 respectively. Emergency surgery (left coronary trunk and unstable angina excluded) and associated operations on the heart made the prognosis worse with overall mortality rates of 13 p. 100 and 15 p. 100 respectively (9 p. 100 in 1985, 10 p. 100 in 1986). In aortic valve surgery, hospital mortality rates were 28 p. 100 in 1985 and 6 p. 100 in 1986. Post-operative morbidity was high (52 p. 100 of patients) and consisted mostly of respiratory and neurological complications (14.7 p. 100 and 9.4 p. 100 respectively of all patients). Only 4 p. 100 of the patients developed peri-operative myocardial infarction. Functional results were satisfactory in both coronary disease and heart valve disease patients. The survival rate at 4 years was 74.5 +/- 10 p. 100 globally and 87.3 +/- 9 p. 100 in coronary patients operated upon electively. Thus, the considerable advances in surgical techniques and post-operative intensive care achieved during the last few years have significantly improved the results obtained in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗