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Biomedical subjects

C Fournier

Publications and source records attributed to C Fournier.

At least 199 records · Page 11Linked to original sources
PubMed1984

Human autologous rosette-forming cells. II. Specificity of the binding between lymphocytes and erythrocytes.

The relationship between autorosettes and allorosettes was investigated using a mixed rosette assay in which the origin of the erythrocytes was assessed by the fluorescein isothiocyanate (FITC) labeling of one type of erythrocyte. The data show that auto- and allorosettes belong to the same T-cell subset: in most of the subjects, the percentages of T cells binding autologous red blood cells (auto-RBC) are equivalent to those binding allogeneic RBC (allo-RBC); the percentage of rosettes formed after the simultaneous addition of auto- and allo-RBC is similar to that of autorosettes alone or allorosettes alone; and nearly 80% of the rosetting cells bind both types of RBC as directly visualized in the mixed rosette assay. The experiments in which the lymphocytes are rosetted first with one type of RBC, and then with the other type support the finding that auto- and allo-RBC may bind to the lymphocytes through a single receptor which exhibits a varying affinity for RBC according to their origin.

Erythrocytes↗
PubMed1984

Admission criteria for immunogerontological studies in man: the SENIEUR protocol.

Immunogerontological studies in man have often led to conflicting results. One of the main reasons is the selection of the subjects to be studied. Admission criteria such as "apparently healthy" or "without overt disease" seem insufficient to exclude underlying disease which might influence the immune system and thereby the results. In an attempt to solve this problem, the SENIEUR protocol described in this paper was developed by a working party in the framework of the EURAGE Concerted Action Programme on Ageing of the European Community. This protocol establishes strict admission criteria for immunogerontological studies in man based on clinical information and laboratory data, and it sets limits to pharmacological interference. The use of this protocol will lead to standardization between centers and also to a closer study of the influence of age as such on the immune system. These findings in the immunologically "optimally aged" can also serve as reference values for immunogerontological studies in subjects who do not meet the SENIEUR criteria. In this way the use of this protocol can contribute to the dissection of the influence of disease versus ageing on the immune system.

Adult↗
PubMed1984

Preparation and release kinetics of microencapsulated cisplatin with ethylcellulose.

Several kinds of microcapsules containing cisplatin were prepared by the ethylcellulose coacervation process in an attempt to administer cisplatin with chemoembolization. Microcapsules made either with mechanical stirring or with sonication showed similar properties; the chemical structure of cisplatin was not affected by the micro-encapsulation process. The release kinetics of cisplatin from ethylcellulose-walled microcapsules followed different patterns, according to the wall thickness. In each case, the release kinetics did not depend on the stirring rate of the surrounding medium. Only microcapsules with a cisplatin release ratio from 80 to 100% within 24 h were selected for later clinical use.

Capsules↗
PubMed1983

[Ventricular arrhythmias in obstructive hypertrophic cardiomyopathy. Continuous electrocardiographic study].

Ventricular arrhythmias are thought to be responsible for the high incidence of sudden death among patients with hypertrophic obstructive cardiomyopathy (HOC). 24-h ECG recording was applied to 27 HOC patients before any treatment and repeated under beta-blockade with propranolol in doses not lower than 320 mg/day (mean dose : 354 mg/day). ECG tracings showed that 26/27 patients (96%) had ventricular arrhythmia; the arrhythmia was repetitive in 15 patients (55%), 3 of whom (11%) had bouts of ventricular tachycardia. These figures are very different from those found in normal subjects, i.e. : 40-50% ventricular arrhythmia and less than 5% repetitive arrhythmia. The most severe forms of ventricular arrhythmia (categories IVA and IVB in the Ryan, Lown and Horn classification) were exclusively seen in patients who had one or several syncopes. Statistically, the only positive correlations of arrhythmias were with age and left ventricular end-diastolic pressure on the one hand, and age and left ventricular systolic pressure gradient on the other hand. Propranolol had no effect on arrhythmia, which seems to contradict studies suggesting that high doses of propranolol play a substantial role in the prevention of sudden death among patients with HOC. Beta-blockers might act by preventing the transformation of arrhythmia into ventricular fibrillation.

Adult↗
PubMed1983

Human autologous rosette-forming cells. I. Expression of cell surface antigens in relation to age and lymphoid organ distribution.

Autologous rosette-forming cells (auto-RFC) were characterized with monoclonal antibodies to various cell surface antigens using a technique combining immunofluorescence and rosette formation. In peripheral blood, auto-RFC were T cells (Leu 1+/OKT3+) the majority being derived from the helper/inducer subset (Leu 3a+/OKT4+). A small proportion of the circulating auto-RFC were Leu 2a+/OKT8+ and virtually none of them bore T10, T6, and DR antigens or peanut agglutinin (PNA) receptors. In the elderly, the percentages of Leu 3a+ auto-RFC increased significantly along with the augmentation of the Leu 3a+ circulating pool. After Con A stimulation of peripheral blood lymphocytes the autorosette population was expanded and therefore their phenotype was again that of helper cells. In the thymus, high levels of autorosettes are found (30 to 50%). Simple or double labeling of the rosetting cells with various monoclonal antibodies permitted the confirmation of the existence of distinct thymocyte subpopulations and moreover to identify the location of the auto-RFC in the intrathymic differentiation scheme. Nearly 70% of the rosetting cells were derived from common thymocytes, those cells defined by the coexpression of T10, T6, T4, and T8 antigens whether or not they were also stained by OKT3 antibodies. The remaining auto-RFC were found with similar frequency among the T4+ and T8+ mature thymocytes. In the spleen low percentages of auto-RFC were found and the majority resided in the Leu 3a+/OKT4+ population, similarly to peripheral blood autorosettes. Taken together, these data suggest that the expression of autologous erythrocyte receptors is acquired in the thymus and is gradually lost during T-cell maturation.

Adult↗
PubMed1983

Immunological studies of autoimmune thyroid disorders: abnormalities in the inducer T cell subset and proliferative responses to autologous and allogeneic stimulation.

Various immunological parameters were investigated in patients with Hashimoto's thyroiditis (HT) and Graves' disease (GD). The total T cell numbers were significantly decreased in both diseases whether they were enumerated by E rosetting or by pan-T cell monoclonal antibodies (OKT3 and anti-Leu 1). This diminution was due to a loss in the inducer T cell subset (OKT4+/Leu 3a+) whereas the cytotoxic/suppressor T cells (OKT8+/Leu 2a+) were present at normal levels in both diseases. The B cells were significantly higher in GD patients than in controls but were not modified in HT patients. Monocyte percentages remained unchanged and DR+ cells were slightly increased in the two diseases. On the other hand, T lymphocyte responses to stimulation by autologous or allogeneic cells were significantly impaired in GD but not in HT whether cultures were performed in autologous plasma or AB serum. In addition, lymphocytes from normal subjects were unable to proliferate in auto- or allo-MLR in the presence of plasma from GD patients but they were reactive in the presence of HT plasma or AB serum. Taken together, these results suggest that the patients with autoimmune thyroid disorders exhibit a T cell imbalance within the OKT4+/Leu 3a+ subset. Moreover, this abnormality is correlated with the observation that autoreactive and alloreactive cells are defective in GD.

Adult↗
PubMed1983

Autorosette forming cells: phenotypic analysis, specificity and role in the autologous mixed lymphocyte reaction.

The phenotype of autorosette forming cells (A-RFC) in the peripheral blood of normal subjects was analyzed. Using a fluorescent technique in which the rosetting cells are labeled with different monoclonal antibodies directed against various cell surface antigens, we demonstrated that A-RFC are T cells, the majority of which belong to the helper/inducer subset. Nevertheless, about 10% of the A-RFC bear the Leu 2a antigens, which are specific for cytotoxic/suppressor T cells. On the other hand, no autorosettes were identified by OKT6 or anti-DR antibodies. When autologous and allogeneic red blood cells were added simultaneously to lymphocytes, 78% mixed rosettes were formed, suggesting a lack of specificity in autorosette formation. A functional role for A-RFC in the autologous mixed lymphocyte reaction (A-MLR) is demonstrated by the fact that the removal of A-RFC from the responder population abrogated the proliferative response in A-MLR. Therefore, despite their non restriction, A-RFC may represent an autoreactive T cell subset.

Antibodies, Monoclonal↗
PubMed1982

[Coronary arteriovenous fistula. Apropos of a case with thallium myocardial scintigraphy and study of pre- and postoperative myocardial metabolism].

Coronary angiography performed in a 62 year old man with spontaneous chest pain revealed a congenital fistula in the form of a vascular network arising from the proximal part of the left anterior descending artery and draining into the main pulmonary artery. A single severe atheromatous stenosis of the right coronary artery was observed. Thallium 201 myocardial scintigraphy at rest showed a large area of hypofixation in the artero-septo-apical zone. Myocardial and aorto-right coronary bypass, myocardial scintigraphy became almost normal, leaving a small antero-septal and apical deficit: myocardial metabolism returned to normal. The fact that lactate metabolism is a particularly sensitive index of myocardial hypoxia in the territory of the left coronary artery suggests a probable coronary steal syndrome induced by the fistula; this is probably also the cause of the isotopic hypofixation in the territory of the left anterior descending artery which emphasizes the value of Thallium myocardial scintigraphy in the study of congenital malformations of the coronary artery.

Arteriovenous Malformations↗
PubMed1982

[Obstructive hypertrophic myocardiopathy and Osler's endocarditis].

Four cases of bacterial endocarditis (BE) complicating hypertrophic obstructive cardiomyopathy (HOCM) were observed between 1978 and 1980. The causal organism was a streptococcus in all cases and the portal of entry, dental. The mitral regurgitation (MR) observed in HOCM as an epiphenomenon of the obstruction became autonomous in 2 patients as shown by phonocardiography with methoxamine. In one case, the MR became severe and justified mitral valve replacement; at surgery, the chordal rupture suspected on echocardiography was confirmed. Antibiotic therapy was effective on the infectious process in all cases. However, 2 of the 4 patients died, one of thrombosis of the mitral prosthesis on the 15th postoperative day, and the other of a cerebrovascular accident. None of the patients had a detectable aortic or septal infectious lesion. Eight of 27 reported cases (30 p 100) of HOCM complicated by BE were operated; 10 (37 p. 100) died as a result of the endocarditis. These cases underline the incidence of BE in HOCM (5 p. 100) its gravity and the necessity for systematic antibiotic prophylaxis, especially before dental treatment.

Adult↗
PubMed1981

[The clinical diagnosis of aorto-coronary bypass occlusion (author's transl)].

The clinical profile of aorto-coronary bypass occlusion was drawn from a study of 49 patients with 56 occluded bypasses and 69 patients with 123 patent bypasses. All patients had undergone postoperative coronary arteriography or post-mortem examination. An anatomical cause of occlusion was retrospectively detected on the basis of pre-operative arteriographic findings or operation records in 82% of the cases, and on account of post-operative myocardial infraction (particularly significant when of late occurrence), residual angina and positive exercise tolerance test in 35%, 55% and 40% respectively of the cases. The last three criteria are of absolute diagnostic value when the arterial defects have been fully corrected by surgery.

Angina Pectoris↗
PubMed1981

Immunological studies in human ageing. II. Associated increase in anti-RNA and anti-DNA antibodies.

Antibodies against nucleic acids have been studied by counter-immunoelectrophoresis in 95 aged subjects. Increased levels of anti-DNA and/or anti-RNA antibodies were found in 74% of the cases, and immune complexes were detected in 21% of the cases. The increase of anti-DNA antibodies was correlated with that of rheumatoid factor and increased serum IgG levels, whereas the increase of anti-RNA antibodies was associated with decreased serum IgM level and decreased lymphocyte response to PHA.

Adolescent↗