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Biomedical subjects

C Fournier

Publications and source records attributed to C Fournier.

At least 181 records · Page 10Linked to original sources
PubMed1987

[Induction of flare-ups of chronic progressive polyarthritis in mice after injection of type II homologous collagen].

Immunization by heterologous type II collagen induces in mice a sudden onset of subacute polyarthritis. In order to form a model of auto-immune pathology, we immunized DBA/1 mice with homologous type II collagen extracted from mice xiphoid process; the induced disease corresponds to a progressive chronic polyarthritis with bouts interspersed with remissions, and predominates especially in males. Type II anti-collagen auto-antibodies are found in the serum, with no correlation between the level of mice type II anti-collagen immunoglobulins G and the clinical manifestations of the disease. The histological study demonstrates signs of hyperplastic villous synovitis, with a discrete and infrequent infiltration with mononuclear cells. The model that is obtained is similar to rheumatoid polyarthritis, but also to spondylo-arthropathies.

Animals↗
PubMed1986

Functional role in self reactivity for Ia antigens on murine synovial cells.

Cultures of synovial cells from normal CBA mice were established after collagenase treatment of synovial tissue collected from the knee joint. Morphological studies using light and electron microscopy have shown that confluent monolayers are composed of 90% triangular or stellate dendritic cells with numerous microvilli and 5% secreting cells containing many dense granules. Less than 5% contaminating cells, such as fibroblasts or macrophages, are present. The class I and class II antigens of the major histocompatibility complex, detected by indirect immunofluorescence or complement-dependent cytotoxicity, are expressed on the cell surface of normal CBA synovial monolayers. Functional Ia antigens borne by synoviocytes are evidenced by the proliferative responses they elicit from syngeneic (or allogeneic) spleen cells after a 3-day co-culture. Similarly, monolayers of Ia+ synovial cells were obtained from both MRL/lpr mice, which spontaneously develop an autoimmune syndrome, and the control MRL/n mice. Spleen cells from young MRL/lpr exhibited significantly higher levels of blastogenesis in syngeneic co-cultures than those from MRL/n mice. Conversely, with advancing age the syngeneic proliferative responses declined minimally for MRL/lpr mice and were unchanged for MRL/n mice. These findings suggest that Ia+ synovial cells can effectively interact with syngeneic lymphocytes and may initiate autoimmune reactivity.

Aging↗
PubMed1986

Human autologous rosette-forming cells. V. Study of MHC control in erythrocyte-lymphocyte interaction.

The role of the major histocompatibility complex (MHC) in human autorosette formation was studied. On a large series of healthy subjects who were typed for HLA antigens, we tested in blind rosette formation with 90 autologous and 295 allogeneic red blood cells (RBC). We found that the mean levels of auto- and allorosettes were similar, being significantly higher in females than in males. However, we failed to find any role for blood group antigens and any involvement of HLA antigens in the interactions between lymphocytes and RBC in rosette formation. Moreover, high or low autorosette levels were not associated with a particular HLA allele. The comparison of individual percentages of auto- and allorosettes indicated that 51% of the subjects displayed identical levels of auto- and allorosettes whereas 29% formed preferentially rosettes with auto- rather than allo-RBC and 20% exhibited lower autorosette than allorosette levels. Among the group of subjects who were better responders for autorosettes than allorosettes, we found an increased frequency of the haplotype A29, B44. Taken together these findings suggest that in contrast to the murine situation, the autorosetting phenomenon in humans is not HLA restricted.

Erythrocytes↗
PubMed1986

[Complete left branch block and electrocardiographic diagnosis of left ventricular hypertrophy].

The electrocardiogrammes of 71 patients (39 men and 32 women) with transient or intermittent complete left bundle branch block (LBBB) were studied. Two tracings, one with and the other without LBBB were analysed in each case. The interval between the two recordings was less than 90 days in all cases (average 10 days). The diagnosis of left ventricular hypertrophy (LVH) was established from the ECG without LBBB. The sensitivity and specificity of the classical criteria or indices of LVA and of different associations of indices of LVH were assessed on the ECGs with LBBB. The best criteria of LVH in the presence of LBBB were the SV2 + RV6 greater than or equal to 32 mm (sensitivity 80%; specificity 81%), Sokolow's index greater than or equal to 33 mm (sensitivity 78%, specificity 81%); followed by SV1 greater than or equal to 23 mm (sensitivity 73%, specificity 86%), SV1 + SV2 + RV6 + RV7 greater than or equal to 65 mm (sensitivity 88%, specificity 63%), SV1 + SV2 greater than or equal to 54 mm (sensitivity 73%, specificity 74%). These six parameters allow correct diagnosis of LVH in 81%, 79%, 78%, 79% and 73% of cases, respectively. The SV1 + SV2 + RV5 + RV7 and the SV1 + SV2 + RV6 + RV7 greater than or equal to 65 mm indices are the most stable (same sensitivity and specificity for several consecutive threshold values, i.e. 62 to 67 mm and 64 to 66 mm respectively); the results obtained with these two indices are therefore more likely to be reproducible than those of the other indices as they seem less dependent on the sampling. The indices of LVH based on the QRS amplitude in the precordial leads remain valid in the presence of LBBB and are sufficiently reliable for the diagnosis of LVH to be clinically useful.

Adult↗
PubMed1986

Defective IL2 production in active rheumatoid arthritis. Regulation by radiosensitive suppressor cells.

The production of interleukin 1 (IL1) and interleukin 2 (IL2) by mononuclear cells (MNC) from untreated rheumatoid arthritis (RA) patients or healthy subjects were examined. After PHA stimulation, patient MNC or T cells produced varying amounts of IL2 that were related to the disease activity: patients suffering from active disease showed a scant production of IL2 while those who had a quiescent disease were high producers. The prior irradiation of unfractionated MNC induced a marked increase of the PHA-stimulated IL2 production in both active and quiescent patients compared to the moderate augmentation observed for controls. On the other hand, irradiation of enriched T cells had an enhancing effect only in the active RA patient group. Concurrently, we found that non T cells from active or quiescent RA patients were fully competent to produce IL1 upon LPS activation. Taken together, these findings suggest that the suppressive activity evidenced by irradiation could be mediated by non T cells in quiescent disease or in absence of illness. On the other hand, both radiosensitive suppressor T and non T cells may interfere in IL2 production by active RA patient lymphocytes.

Adult↗
PubMed1986

[Induction of arthritis in mice by injection of homologous type II collagen].

Immunization with heterologous type II collagen (CII) induces arthritis in DBA/1 mice, a strain genetically susceptible to this disease. In order to develop an experimental model of autoimmunity more adequate for the study of human Rheumatoid Arthritis, DBA/1 mice were injected with homologous native CII. About 6 weeks later, the animals developed a chronic progressive polyarthritis assessed by clinical observations and histologic examination. The incidence of arthritis as well as the severity of the disease are clearly higher in males. Conversely, the secretion of autoantibodies raised against mouse CII is correlated neither with sex nor with activity score of the arthritis.

Acute Disease↗
PubMed1985

Platinum concentration in human tumors of head and neck, uterine cervix, and breast following treatment with cisplatin.

Intratumoral platinum concentrations were measured in three tumor sites (head and neck, uterine cervix, and breast) 48 h after cisplatin administration according to the same protocol. The platinum levels were in the same order of magnitude in all tumors, but the concentration in breast tumors was found to be higher than that in tumors of the head and neck and of the uterine cervix.

Breast Neoplasms↗
PubMed1985

Prospective study of the potentiation of acenocoumarol by amiodarone.

The influence of oral amiodarone on the anticoagulant effect of the coumarin derivative acenocoumarol has been investigated prospectively in 10 patients with normal renal, hepatic and haematological function and who were not in cardiac failure. The daily dose of acenocoumarol was sufficient to produce a prothrombin activity of 25 to 35%. When the prothrombin time had become stable amiodarone 600 mg/d was administered for 1 week followed by 400 mg/d for the next 3 weeks. A decrease in prothrombin activity from 30.5 to 20.2% was observed, associated with a decrease in vitamin K coagulation factors, after a mean of 4 days following commencement of amiodarone. In 6 patients a prothrombin activity less than 20% required a 60% reduction in the dose of acenocoumarol after 1 week of amiodarone 600 mg, and a 33% reduction after 3 weeks of amiodarone 400 mg. There was no correlation between the plasma amiodarone and the decrease in prothrombin activity. Inhibition of acenocoumarol metabolism by amiodarone is the most likely explanation of these findings.

Acenocoumarol↗
PubMed1985

Effect of propranolol on left ventricular relaxation in hypertrophic cardiomyopathy: an echographic study.

Many authors have shown that hypertrophic cardiomyopathy (HCM) is often associated with diastolic abnormalities. The purpose of this study was to determine the effect of propranolol on left ventricular isovolumic relaxation time (IVRT) measured by echocardiography in 20 patients with hypertrophic cardiomyopathy under basal conditions and under increasing doses of propranolol (160 mg, 320 mg, and 480 mg per day) and in two control groups, 10 patients with aortic stenosis, and 10 normal subjects. IVRT was less than 50 msec in all normal subjects, while it was always above this limit in aortic stenosis (77 msec +/- 8, p less than 0.001), and in hypertrophic cardiomyopathy (94 msec +/- 19, p less than 0.001), with also a significant difference between these two last groups (p less than 0.01). Under increasing doses of propranolol, relaxation time often shortens gradually until 50 msec or less. These results show an improvement in left ventricular relaxation dependent on the propranolol dosage and often a normalization at high dosages.

Adult↗
PubMed1985

Human autologous rosette-forming cells. III. Binding of erythrocytes from different species to the T-cell receptors for autologous red blood cells.

Spontaneous rosette formation in humans is restricted to a subpopulation of the circulating T cells. We have previously shown that the interaction between lymphocytes and autologous red blood cells (auto-RBC) is not mediated by a self-recognition mechanism, since allogeneic (allo-) RBC bind to T cells through the same receptors. In this work, we have extended these observations to thymocytes. Using a mixed-rosette assay in which one type of erythrocyte was identified by FITC labeling, we have shown that almost all the thymocytes which attached auto-RBC could also fix allo-RBC. However, as for the peripheral blood lymphocytes (PBL), binding of human RBC to thymocytes occurred with varying affinities according to the erythrocyte's origin. In order to further study the specificity of the erythrocyte to lymphocyte binding in rosette formation, PBL were mixed with auto-RBC and erythrocytes of xenogeneic (xeno-) origin. Although very disparate incidences of rosettes were found according to the species from which the RBC were derived, most of the autorosetting lymphocytes also had receptors for xeno-RBC. In addition, preincubation of PBL with monoclonal antibody OKT11A (directed against the sheep RBC receptors on T cells) completely abrogated rosette formation with all the erythrocytes tested (human auto- and allo-, sheep, pig, and rabbit) except mouse RBC. Taken together these data strongly suggest that human auto- or allo-, as well as sheep or some other xeno-RBC, bind to T lymphocytes by a single receptor and that the combining sites are expressed with different densities or varying affinities depending upon the RBC's origin. Therefore, spontaneous autorosettes may represent T lymphocytes having high-affinity receptors for sheep RBC.

Animals↗
PubMed1985

Human autologous rosette-forming cells. IV. Functional role in T-cell activation.

Human autorosette-forming cells (auto-RFC), which represent a T4/leu 3a+ cell subset, were investigated for their functional role in T-cell activation. Peripheral blood lymphocytes from healthy subjects either remained unfractionated or were separated into recovered or depleted auto-RFC populations. The phytohemagglutinin P stimulation of these three cell suspensions induced normal levels of proliferation, whereas the pokeweed mitogen activation was significantly decreased in the auto-RFC-depleted population compared to the auto-RFC-recovered subset or unfractionated cells. All three cell suspensions produced IL-2 in response to PHA stimulation. However the levels of lymphokine released were significantly lower in the recovered auto-RFC fraction than in the depleted auto-RFC. After activation, using anti-Tac antibodies, the synthesis of IL-2 receptors was evidenced in all the cell fractions regardless of the presence or absence of auto-RFC. In addition, both auto-RFC absorbed IL-2 activity from a reference supernatant. Taken together, these data suggest that auto-RFC can be expanded by T-cell mitogens, and that once activated, they express IL-2 receptors, but represent a minor source of IL-2 production.

Cell Separation↗
PubMed1985

Autorosette formation in humans: study of the specificity of the T cell receptors for autologous erythrocytes.

Spontaneous autorosette formation has been described as being restricted to a subpopulation of the circulating helper/inducer T cell subset. In order to study the specificity of the binding between human lymphocytes and autologous red blood cells (auto-RBC), we have investigated the relationship between autorosette forming cells (auto-RFC) and rosettes formed with allogeneic (allo-) or xenogeneic (xeno-) RBC. Using a mixed rosette assay in which the origin of the erythrocytes was assessed by the FITC labeling of one type of erythrocyte, we have shown that auto-RFC and allo-RFC belong to the same T cell subset, and that the T cells which rosette with auto-RBC can also bind xenogeneic (pig, sheep, rabbit) RBC, although a disparate incidence of rosettes is found depending upon the origin of the erythrocytes. Whether T lymphocytes co-expressed distinct receptors for RBC of different species was then investigated. Preincubation of lymphocytes with monoclonal antibody OKT11A (directed against the T cell receptors for sheep RBC) completely abrogated rosette formation with auto- or allo-RBC, indicating that auto- and allo-RBC interact with the lymphocytes by their receptors for sheep RBC. Therefore, the auto-RFC may represent T lymphocytes having high affinity receptors for sheep RBC.

Antibodies, Monoclonal↗
PubMed1985

[Aminoglutethimide-induced dyslipemia. Clinical study].

Plasma levels of cholesterol, HDL cholesterol (HDL chol), LDL cholesterol (LDL chol), triglycerides, Al apoprotein and B apoprotein were studied in 73 patients receiving 500 mg aminoglutethimide (AG)/day and 40 mg hydrocortisone/day for advanced breast cancer. These dosages were done before treatment and then repeated during AG therapy. When all patients were considered together, a significant increase of cholesterol, HDL chol, LDL chol and Al apoprotein was noted. If one considers two groups of patients: group A (where cholesterol and triglycerides plasma levels were normal before treatment) and group B (where cholesterol and/or triglycerides plasma levels were high before treatment), it appears that variations differ in both groups. In group A patients we found an increase in cholesterol, chol LDL, B apoprotein and to a lesser extent Al apoprotein plasma levels. In group B patients there was an increase in cholesterol, HDL chol and Al apoprotein plasma levels.

Aminoglutethimide↗
PubMed1985

[Outcome of hypertrophic and obstructive myocardiopathies treated with high doses of propranolol].

Twenty-five patients with hypertrophic obstructive cardiomyopathy confirmed by clinical, echocardiographic and haemodynamic investigations were treated with high dose propranolol (320 to 800 mg/day, average 420 mg/day) and assessed after an average follow-up period of 25 months. The effects of treatment were assessed by interrogation in all patients and by exercise testing before and after propranolol in 19 cases. Comparative echocardiographic (21 patients) Holter (20 patients) and catheter studies (14 patients) were also performed. The cardiovascular mortality rate during the study period was nil. All patients were symptomatic before treatment; 9 became asymptomatic and 13 patients were improved, the average functional score decreasing from 5.16 +/- 2.15 to 2.28 +/- 1.49 (p less than 0.001). The persistence of severe symptoms led to withdrawal of the beta-blocker in 2 cases. There was a parallel improvement in maximal work capacity during exercise stress testing (96 +/- 27 watts vs 117 +/- 30 watts, p less than 0.01). A resting intraventricular pressure gradient was recorded in 12 of the 14 patients undergoing repeat catheter study which decreased after propranolol from an average of 66.75 +/- 32.72 mmHg to 42.75 +/- 37.6 mmHg (p less than 0.05). Left ventricular end diastolic pressures remained unchanged. The change in pressure gradient did not correlate with the symptomatology and there were no associated echocardiographic changes. The Holter monitoring did not show any improvement of ventricular hyperexcitability under propranolol: the number of patients with complex ventricular arrhythmias remained unchanged (7 patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Hypertrophic myocardiopathy with isolated obstruction of the right ventricle].

The authors report one case of biventricular hypertrophic cardiomyopathy in a 23 year old female patient with severe localized obstruction of the right ventricle (105 mm Hg gradient, almost complete angiographic disappearance of the middle and apical portions of the right ventricle during systole). Echocardiography, hemodynamic findings, and angiography demonstrated nonobstructive involvement of the left ventricle. Among other family members, only her father was noted to have minimal hypertrophic cardiomyopathy. A favorable response to therapy was obtained over 14 months with 320 mg of propranolol given daily (disappearance of palpitations and ventricular tachycardia which had previously been noted on a continuous 24 hour recording before treatment). Other very rare similar cases in the literature are analyzed. It is not possible to distinguish these cases from those with predominantly left ventricular involvement by clinical and radiological findings alone. However, the ECG can often demonstrate right ventricular involvement (right ventricular hypertrophy and/or right bundle branch block). Lastly, it appears that biventricular hypertrophic cardiomyopathies in young patients can initially be localized to only the right ventricle.

Adult↗