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Y Gruel

Publications and source records attributed to Y Gruel.

At least 73 records · Page 4Linked to original sources
PubMed1992

Methodological approach for the detection of IgM anticardiolipin antibodies.

The effects of 10% fetal calf serum (10% FCS), 10% adult bovine serum (10% ABS) and 1% bovine serum albumin (1% BSA) buffers on the reactivity of samples with or without IgM anticardiolipin antibodies (ACA IgM) were studied on cardiolipin-coated wells (target wells) and cardiolipin-free wells (control wells) in an ELISA test. With 1% BSA, target well reactivity was very low for samples containing ACA IgM. The 10% FCS induced a moderate but significant binding of polyclonal IgM on target wells particularly in the case of IgM hypergammaglobulinemia. With 10% ABS, whatever the IgM serum level, this non-specific binding did not occur on the solid phase either in the presence or in the absence of cardiolipin. Using 10% ABS, the study of 35 SLE sera showed that non-specific binding of IgM on control-wells occurred only with ACA IgM positive samples. Thus with the use of 10% ABS, we propose that subtraction of control well from target well values must not be performed for the detection of ACA IgM. The significance of cardiolipin-free well IgM reactivity of ACA IgM positive sera is discussed.

Adult↗
PubMed1992

Immunological study of platelet glycoproteins and alloantigens in families of patients with Glanzmann's thrombasthenia.

To explore the genetic transmission of Glanzmann's thrombasthenia (GT) we conducted a study of platelet glycoproteins and antigens using monoclonal and polyclonal antibodies and cytofluorometry. Twenty-one members of 4 different families in which at least one member was affected with GT were explored. The reactivity with AP2 (anti-GP IIb-IIIa complex, CD41a), AP3 (anti-GP IIIa) and antibodies against HPA-1a (PLA1) and HPA-3a (Leka) was lower than 5% in the platelets of 5 patients with GT type I. Nine obligatory carriers of the GT trait were tested by the same technique. The mean values of reactivity expressed as per cent of normal with AP2 (anti-CD41a) and AP3 (anti-GPIIIa) were 58.3 +/- 3.6% and 58.6 +/- 3.6% respectively, while the frequencies of HPA-1a (PLA1) and HPA-3a (Leka) negativity were 0/9 and 4/9 respectively. When both antigens were expressed they were detected at reduced levels. These results indicate that cytofluorometry is a simple technique for GT detection, but this method would nevertheless not appear to be sufficiently accurate to identify obligatory carriers in a general population.

Antibodies, Monoclonal↗
PubMed1991

Specific quantification of heparin-dependent antibodies for the diagnosis of heparin-associated thrombocytopenia using an enzyme-linked immunosorbent assay.

In order to specifically detect heparin-dependent antibodies in patients with suspected heparin-associated thrombocytopenia (HAT), an adapted ELISA test was developed. Serum-platelet bindable IgG (SPb-IgG) were measured in the absence and in the presence of heparin in the sera from a/ 25 normal controls, 25 patients treated by heparin without thrombocytopenia, 29 thrombocytopenic patients not receiving heparin and b/ 12 patients with confirmed HAT. In the absence of heparin, the 12 HAT sera showed normal or elevated SPb-IgG levels (range = 10.4-36 Arbitrary Units or AU) as compared to healthy controls (8-17.1 AU). After coincubation of HAT sera with heparin (0.25, 0.50, 0.75, and 1 IU/ml), SPb-IgG levels were consistently elevated (range = 22.8-150 AU), and this increase in IgG binding (equal in mean to 200%) was always inhibited with 5 IU/ml of heparin. In contrast, a mean maximum increase in SPblgG levels of only 20% was registered in all control groups whatever the tested heparin concentration. Thus, this ELISA allows the specific diagnosis of HAT by demonstrating a serum IgG binding on platelets only in the presence of therapeutic concentrations of heparin.

Aged↗
PubMed1991

ELISA for the detection of anticardiolipin antibodies. High specificity based on the use of adult bovine serum as buffer and systematic subtraction of non-specific binding.

We have used an ELISA procedure to compare the reactivity of samples with or without IgG anticardiolipin antibodies (ACA) on cardiolipin-coated wells (target wells) and cardiolipin-free wells (control wells), using 10% fetal calf serum (10% FCS), 10% adult bovine serum (10% ABS) or 1% bovine serum albumin (1% BSA) as buffer. With 1% BSA, ACA reactivity was very low which suggests that this buffer would be inappropriate for use in ELISA procedures for ACA. 10% FCS induced non-specific binding of normal IgG only on target wells, particularly in the case of IgG hypergammaglobulinemia. With 10% ABS, this non-specific binding occurred on the solid phase with and without cardiolipin and could be accurately evaluated by subtracting the absorbance of control wells. Results of assays on 35 systemic lupus erythematosus sera using 10% ABS as buffer showed that highly specific results-could be obtained only if non-specific binding was systematically subtracted.

Adult↗
PubMed1991

Usefulness of antiplatelet drugs in the management of heparin-associated thrombocytopenia and thrombosis.

Heparin-associated thrombocytopenia and thrombosis is a severe complication of systemic heparin therapy. Its treatment is mainly based upon discontinuation of heparin therapy. However in some patients requiring emergency cardiac or vascular surgery, reexposure to heparin may be unavoidable. We report the management of two such patients by use of antiplatelet drugs for a vascular procedure. In the two cases, a combination of iloprost, a stable prostacyclin analogue (1 to 2 ng/kg/mn) with aspirin and dipyridamole was shown to inhibit ex vivo the heparin-induced platelet aggregation. These antiplatelet agents were continued during the perioperative period. A successful vascular procedure was achieved with full heparinization without subsequent thrombocytopenia or thrombotic or hemorrhagic complications. This experience supports the hypothesis that heparin can be readministered early to patients with heparin-associated thrombocytopenia and thrombosis, provided antiplatelet therapy is given.

Aged↗
PubMed1991

Comparative study of the fibrinolytic system in human fetuses and in pregnant women.

Levels of major parameters of fibrinolysis were measured in 50 normal human fetuses between 19 and 39 weeks of gestation and compared to those of 50 healthy normal pregnant women and 30 adult controls. In fetuses, euglobulin clot lysis time (ECLT) was significantly shortened, plasminogen level was low and histidine-rich glycoprotein undetectable. While t-PA and u-PA levels were slightly lower than in adult controls, a significant decrease in PAI activity was demonstrated and no PAI-2 could be detected in fetal plasma. In contrast with these findings, the fibrinolytic equilibrium of pregnant women exhibited a prolonged ECLT and a strong increase in both PAI activity and PAI-2 antigen levels, while only a moderate elevation in u-PA and t-PA levels was measured.

Adult↗
PubMed1990

Thrombocytopenia in systemic lupus erythematosus: association with antiplatelet and anticardiolipin antibodies.

Serum platelet bindable immunoglobulin G (SPbIgG) and anticardiolipin antibodies (ACA) have been assayed in SLE patients with (group A, n = 8) and without thrombocytopenia (group B, n = 8). Moreover, we studied the binding of serum IgG on platelet proteins using a Western blotting procedure. Increased levels of SPbIgG were found in all thrombocytopenic patients and in five cases of group B. A binding of serum IgG on platelet proteins (80 and 53 kDa) was seen in seven of eight thrombocytopenic patients and in only one case of group B. ACA were present in the serum of four patients in each group and a significant inhibition of ACA IgG by entire washed platelets was achieved in only two severe thrombocytopenic cases. These data suggest that participation of ACA to the platelet destruction can be evoked for a few SLE patients, whereas recognition of platelet protein determinants by lupus autoantibodies is necessary to the thrombocytopenia.

Adolescent↗
PubMed1990

[Livedo reticularis, cerebrovascular disorders and mitral disease: a new cause of Sneddon's syndrome?].

Sneddon's syndrome consists of livedo reticularis and cerebral vascular accidents with no evidence of systemic disease responsible for the livedo. The syndrome has been assimilated to a subgroup of systemic lupus erythematosus (SLE) with presence of antibodies directed against phospholipids. Recently, a significant increase in the frequency of cardiac valve diseases has been demonstrated in some SLE patients with livedo reticularis, cerebral vascular accidents and antiphospholipid antibodies. We report the case of a 26-year old woman who had been presenting for 6 years with idiopathic livedo reticularis. Her history was remarkable for the occurrence of 2 cerebral ischaemic accidents at the ages of 23 and 26 years, generalized convulsive seizures at 22 years, and hypertension of pregnancy with 2 miscarriages. Biopsy of the livedo showed normal histological patterns, but electron microscopy detected an obliterating endothelial proliferation and endothelial cells with numerous Weibel-Palade bodies. Laboratory signs of SLE, as well as antiphospholipid antibodies were absent. At the age of 26 years, cardiac abnormalities were heard at auscultation for the first time, and echocardiography showed that they were due to a fairly loose mitral stenosis. According to Burton's criteria our patient had all the typical features of Sneddon's syndrome. The finding of mitral stenosis--an emboligenic cardiopathy that is potentially responsible for cerebral vascular accidents--raises the problem of its relationship with Sneddon's syndrome. The association does not seem to be fortuitous, since our case is very similar to the cases of SLE or antiphospholipid antibody syndrome associated with cardiac valve lesions. However, this case is particular in that 6 years after the onset of the disease there was still no sign of SLE and of antiphospholipid antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Comparative double-blind study of two dosage regimens of low-molecular weight heparin in elderly patients with a fracture of the neck of the femur.

A randomized double-blind study comparing the efficacy and safety of two different dosage regimens of a low-MW heparin, Enoxaparin (Lovenox) 20 mg twice (group A) or 40 mg once (group B), was carried out in 103 elderly patients with a fracture of the neck of the femur. Distal and proximal thrombosis occurred in 18.3% of patients in group A and in 10.4% in group B. No major hemorrhagic complication was observed, except for two hematomas in each group. This trial suggests that a total daily dose of 40 mg of Enoxaparin can be effective in the prevention of deep vein thrombosis in elderly surgically treated patients and does not involve a major risk of bleeding.

Aged↗