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C Biron

Publications and source records attributed to C Biron.

At least 19 recordsLinked to original sources
PubMed1999

Preoperative screening for von Willebrand disease type 1: low yield and limited ability to predict bleeding.

Type 1 von Willebrand disease (vWd) is the most common hereditary bleeding disorder. The objective of this study was to measure the von Willebrand factor antigen (vWf:Ag) in a large cohort of patients who underwent surgery to assess the role of a new rapid immunoassay in a screening procedure for vWd in preoperative conditions. We studied 832 consecutive patients (540 children, 292 adults) referred to the surgical departments. For each patient we determined the vWf:Ag level with two different assays, an enzyme-linked immunosorbent assay (ELISA)(Asserachrom vWf:Ag; Diagnostica Stago, France) and a rapid immunoassay (Liatest vWf:Ag; Diagnostica Stago). Using the reference test, we found 30 of 832 patients with a vWf:Ag value below the lower limits (21 U/dL to 46 U/dL). The coefficient of correlation between the two tests was 0.77 (P = .001). When receiver operating characteristic curves were used, the cutoff value calculated to detect vWf:Ag defect with the rapid assay was 68.5 U/dL, leading to 0.36% false negatives and 9.7% false positives. Thus the rapid immunoassay appears to be a useful and easy method that is adaptable to urgent situations. Among the 30 patients with low values in ELISA, 8 had personal or familial bleeding history. Repeat blood samples confirmed the diagnosis of vWd in 5 cases, leading to a prevalence of vWd type 1 of 0.6%. However, in our series the absence of severe bleeding complications raises the question of the screening and the management of patients bearing a type 1 Willebrand disease during surgery.

Adolescent↗
PubMed1999

The Quebec Adolescent Refugee Project: psychopathology and family variables in a sample from 35 nations.

OBJECTIVE: This study presents the results of a psychiatric epidemiological survey using a sample of adolescents from refugee families. METHOD: The sample included 203 adolescents, aged 13 to 19 years, coming from 35 countries. Psychopathology was assessed with the Diagnostic Interview Schedule for Children Version 2.25 and general functioning with the Children's Global Assessment Scale (CGAS). RESULTS: The total rate of psychopathology excluding simple phobia was 21% compared with 11% in a province-wide survey of young adolescents. Overanxious disorder had a high prevalence of 13%. The rates of major depression and conduct disorders were also high, at 5% and 6%. The rate of 3% of attempted suicide was similar to the rate found in Montreal high schools. Girls had a higher rate of psychopathology than boys, with a gender ratio similar to the one found in the provincial survey. Father's long-term unemployment in the first year of settlement was associated with psychopathology for the whole sample, and family structure was associated with psychopathology for boys only. CONCLUSIONS: The high rate of psychopathology in this group confirmed results from other surveys with similar samples. On the other hand, the CGAS scores indicated that many of the adolescents with a diagnosis had good social adaptation.

Adaptation, Psychological↗
PubMed1998

Prevalence of antiphospholipid antibodies in patients with chronic liver disease related to alcohol or hepatitis C virus: correlation with liver injury.

Antiphospholipid antibodies (APAs) have been reported in various clinical conditions. However, the pathogenesis and clinical significance of these antibodies are still unclear. The objective of this study was to assess the prevalence of APAs in patients with chronic alcohol- or hepatitis C virus (HCV)-related liver disease and to evaluate their relation to the underlying liver disease. We prospectively studied 201 patients referred to an hepato-gastroenterology department, including 77 patients with a history of alcohol abuse (group I) and 124 with chronic HCV infection (group II), and 107 healthy subjects (control population). Liver biopsy was performed in all patients. In cirrhotic patients, the severity of the liver disease was assessed with the use of Child's classification, as modified by Pugh. Several biologic parameters, including lupus anticoagulant and anticardiolipin antibodies, were determined. Forty-eight percent of patients in group I and 33% of those in group II had APAs. Among cirrhotic patients, APAs were more frequent in patients with Child grade B or C than in those with grade A severity. In patients with chronic HCV-related liver disease, a correlation was found between APA levels and liver fibrosis (P = 0.009); no relation was found between APA levels and histologic liver disease activity (P = 0.25). In the control group, one subject was APA-positive. None had lupus anticoagulant. APAs seem to be frequently associated with chronic liver disease of various causes. These results suggest further investigations on the potential role of these antibodies in fibrosis or liver injury.

Adult↗
PubMed1998

Aprotinin decreases blood loss and homologous transfusions in patients undergoing major orthopedic surgery.

BACKGROUND: Major orthopedic surgery can be associated with dramatic blood loss, thereby requiring high-volume homologous transfusions in patients unable to benefit from blood salvage techniques. The effect of aprotinin on blood loss and transfusion requirements during orthopedic surgery for either the resection of malignancies of the removal of infected hardware was prospectively studied. METHODS: Twenty-three patients scheduled for orthopedic surgery of the hip, femur, or pelvis for sepsis or malignant tumors, all under general anesthesia, were randomly allocated to receive during operation, in a blinded manner, either aprotinin administered as a bolus of 1.106 kallikrein inactivation units (KIU) followed by an infusion of 5 x 10(5) KIU/h, or the equivalent volume of saline. The anesthesia and perioperative management, as well as the designated transfusion criteria, were standardized. The total blood loss of each patient was evaluated using intraoperative suction losses, sponge weights, and postoperative volumetric drainage. Homologous transfusion requirements were noted. Hemoglobin and hematocrit measures, as well as coagulation and fibrinolytic pathway explorations, were performed before and after surgery. Deep venous thrombosis prophylaxis was applied, and the incidence of this complication was assessed. RESULTS: Twelve patients received aprotinin. Aprotinin reduced the total blood loss from a median of 5,305 ml (range, 3,000-9,770 ml) to a median of 1,783 ml (range, 1,140-4,955 ml; P < 0.05). A blood loss reduction of 56% during surgery and 68% on discharge from the postanesthesia care unit was observed. Seven units (range, 4-16) of packed erythrocytes were transfused per patient in the placebo group, and 3 (range, 2-5) were transfused in the aprotinin group (P < 0.05). In the aprotinin group, platelet counts were higher, and postoperative prothrombin times and D. Dimer values were lower. The activated partial thromboplastin time values showed no significant difference between the two groups. No side effects were observed in the aprotinin group. A deep venous thrombosis developed in one patient in the placebo group. CONCLUSION: Aprotinin treatment during major orthopedic surgery significantly reduces both blood loss and consequent homologous blood transfusion requirements.

Adult↗
PubMed1998

Vascular complications of diabetes mellitus: what role for phospholipid-binding antibodies?

Vascular complications are the main cause of morbidity in diabetes mellitus. However, the risk factors for vascular disease remain incompletely elucidated. It has been previously suggested that factors other than glycemia may contribute to the development of vasculopathy. In this study we determined the prevalence of phospholipid-binding antibodies in uncomplicated and complicated diabetes. We studied 53 uncomplicated diabetic patients, with type 1 (n = 32) or type 2 (n = 21) diabetes; 23 diabetic patients with proliferative retinopathy; 28 diabetic patients with an overt nephropathy; 37 diabetic patients with macroangiopathy and 22 non diabetic control patients. Both lupus anticoagulant and anticardiolipin antibodies were determined. Other risk factors for macroangiopathy were analysed. The prevalence of phospholipid-binding antibodies was similar in uncomplicated diabetic patients and in controls (type 1 diabetes: 9.4%; type 2 diabetes: 9.5%; control group: 4.6%; P= 0.76). In complicated diabetes, the frequency of these antibodies was increased only in patients with overt nephropathy (32.1%, P=0.01) or with macroangiopathy (32.4%, P=0.01) while patients with isolated retinopathy were comparable with uncomplicated diabetic patients (4.3%, P= 0.66). Uncomplicated diabetes was not associated with phospholipid-binding antibodies. We found a higher prevalence of these antibodies in diabetic patients with macroangiopathy or nephropathy. These results suggest a potential role of phospholipid-binding antibodies in the progression of vascular complications in diabetes mellitus.

Adult↗
PubMed1997

Compound heterozygotes for hemochromatosis gene mutations: may they help to understand the pathophysiology of the disease?

Two mutations have been described on the gene considered to be responsible for genetic hemochromatosis, the HLA-H or HFE gene. The C282Y mutation is a disease-causing mutation in most cases of genetic hemochromatosis, but involvment of the H63D substitution in the pathogenesis of the disease is unclear. Compound heterozygotes for both substitutions could help to determine whether or not the second mutation is a worsening factor when associate in trans with the C282Y mutant. We found twenty nine compound heterozygotes during DNA analysis of patients referred to our laboratory for the screening of those mutations. Clinical and biological data were obtainable for 23 of them. Compound heterozygotes could be divided into two groups: subjects with or without iron overload. Five (22%) individuals had normal ferritin levels, whereas 18 had elevated ferritin concentrations (78%). Among those 18 patients, 7 (30% of the total) had clinical and biological criteria of genetic hemochromatosis. Eleven had iron overload without all the criteria of genetic hemochromatosis. Such a high proportion of genetic hemochromatosis is not found in heterozygotes for the C282Y mutation alone neither in our series nor in the literature. Compound heterozygotes for the C282Y and the H63D mutations may have a higher risk of iron overload or genetic hemochromatosis than single heterozygotes for the C282Y mutation. We propose a schematic theoretical representation that could explain this fact at the protein level. Further fundamental studies on the protein, and clinical follow up of compound heterozygotes could help to ascertain this hypothesis.

Adult↗
PubMed1997

Hemostasis parameters during ovarian stimulation for in vitro fertilization: results of a prospective study.

OBJECTIVE: To evaluate the effect of IVF-ET on the hemostatic system. DESIGN: Prospective clinical study. SETTING: Apparently healthy age-matched women of the hospital staff at various stage of the menstrual cycle. PATIENT(S): Twenty-five women involved in a IVF-ET program at the Department of Obstetrics and Gynecology, Montpellier University Hospital. INTERVENTION(S): Twenty-six hemostasis parameters evaluated repeatedly in patients undergoing IVF-ET. MAIN OUTCOME MEASURE(S): Blood cell-dependent hemostasis parameters and plasmatic coagulation factors, determined at pituitary desensitization, maximal E2 level, and P plateau. RESULT(S): Activation of the hemostatic system is evidenced at the P plateau, when D-dimers and fragments 1 + 2 of the prothrombin levels rose dramatically. At E2 peak, no significant modification of hemostasis markers was noted. CONCLUSION(S): The present results indicate that ovarian hyperstimulation may induce hemostasis activation at the P plateau. The role of supraphysiologic sex hormone levels on the hemostatic system requires further investigation.

Adult↗
PubMed1997

Diagnosis strategies in activated protein C resistance: is genotyping still necessary?

Resistance to activated protein C (APC) is due, in most cases, to a G to A mutation at nucleotide 1691 of factor V (FV) gene (the Leiden mutation). This inherited abnormality is now considered to be the major hereditary cause associated with an elevated risk of thrombosis. For this reason, laboratories are faced with an increasing number of samples referred for APC resistance diagnosis. This could have serious economic consequences and a comprehensive laboratory screening strategy for APC resistance is necessary. An original DNA assay based on denaturing gradient gel electrophoresis (DGGE) was designed in our laboratory. During a first period we systematically performed DNA analysis and compared the results with phenotypic assays. Using the modified functional test with a 1:5 predilution of plasmas, the cut-off value for APC resistance ratio was 2.6 in our sample. Among 94 consecutive patients referred to our laboratory we found a clear cut-off between the APC resistance ratio obtained for normal and abnormal individuals. The modified test had a predictive value of 1.0 found by a cut-off < or = 2.6 for the heterozygote FV Leiden. This obviates the necessity of genotyping subjects with a normal phenotype. Among patients with an abnormal phenotype we were able to fully discriminate between homozygous and heterozygous patients using a cut-off value of 1.5. Nevertheless, our results demonstrate that, because of false-positive results such as lupus anticoagulant, genotyping is still indicated for patients with an abnormal ratio determined with the modified APC resistance test. The strategy described here allows us to safely lower the number of samples analysed by DGGE.

Blood Coagulation Disorders↗
PubMed1997

Respective evaluation of the prevalence of haemostasis abnormalities in unexplained primary early recurrent miscarriages. The Nimes Obstetricians and Haematologists (NOHA) Study.

The prevalence of haemostasis abnormalities was evaluated in 500 consecutive women with unexplained primary recurrent miscarriages. Two matched reference groups with no antecedent of miscarriage were studied: 100 healthy mothers and 50 childless women. In the prospective part of the study, we found 9.4% of the patients (95% C.I.: 6.8-12%) with an isolated factor XII deficiency, 7.4% of the patients (5.0-9.8%) with primary antiphopholipid antibodies, 47% of the patients (42.6-51.4%) with an insufficient response to the venous occlusion test and an isolated hypofibrinolysis was found in 42.6% (38.2-47%) of the patients (reference groups: respectively 0/150, 3/150, 2/150, p < 10(-3)). Willebrand disease, fibrinogen, deficiency, antithrombin, protein C or protein S deficiencies were not more frequent in recurrent aborters than in members of the reference groups. In the retrospective part of the study, cases of plasma resistance to activated protein C were not abnormally frequent. Patients had higher Willebrand factor antigen (vWF), tissue-type plasminogen activator antigen (t-PA), plasminogen activator inhibitor activity (PAI) and D-dimers (D-Di) than the reference women. Values of vWF, t-PA, PAI and D-Di were altogether correlated but were not related to C-reactive protein concentrations. Among patients, those with an antiphospholipid syndrome and those with an insufficient response to the venous occlusion test had higher vWF, t-PA, PAI and D-Di values than the patients with none of the haemostasis-related abnormalities. Thus, factor XII deficiency and hypofibrinolysis (mainly high PAI) are the most frequent haemostasis-related abnormalities found in unexplained primary recurrent aborters. In patients with antiphospholipid antibodies or hypofibrinolysis, there is a non-inflammatory ongoing chronic elevation of markers of endothelial stimulation associated with coagulation activation. This should allow to define subgroups of patients for future therapeutic trials.

Abortion, Habitual↗
PubMed1995

Anticardiolipin antibodies and acute alcoholic intoxication.

Many clinical features have been associated with the antiphospholipid antibodies. In a preliminary prospective study, among 1014 consecutive patients admitted to a Medicine Department, 72 (7.1%) patients were found to be anticardiolipin antibodies (aCL) positive. Eight (11%) of these aCL positive patients had alcoholic intoxication. Chronic alcoholism is known to be associated with a high prevalence of autoimmune disorders. The objective of this study was to determine the prevalence of aCL in patients with acute alcoholic intoxication. Sixty two patients (13 women; 49 men), mean age 35 years (range 17-63 years) referred to the emergency care unit were studied. A control population of 62 apparently healthy subjects, age and sex matched, were also tested. Alcoholaemia, aCL, antinuclear antibodies (ANA), Venereal Disease Research Laboratory (VDRL) and Treponema pallidum immobilisation (TPHA) were determined. The mean alcoholaemia among all patients tested was 2.35 gl-1 (range 0.1-4). aCL were found positive in 10 patients (16%); eight men and two women. Seven patients had aCL IgG level of > or = 15 UG PL/ml while two had IgM level of > or = 12.5 UMPL/ml. One had both elevated aCL IgG and IgM. Statistical analysis confirmed that aCL positivity is more frequently encountered in alcoholic patients compared with an age and sex matched population (P = 0.0298). Among alcoholic patients, 12 (19%) had ANA. Four of them were VDRL positive while all were TPHA negative. Two of the 62 control subjects were found aCL positive. From these data, it can be concluded that increased aCL levels are frequently associated with acute alcoholic abuse.

Adolescent↗
PubMed1995

Direct carrier detection for severe haemophilia A: application to families with no available affected male.

Haemophiliae A is a common hereditary disorder of blood coagulation resulting from deficiency of factor VIII. Mutation analysis is the factor VIII gene has been hampered by the large size of the gene and the heterogeneity of molecular defects. In severe haemophiliae A, the most efficient methods of screening for point mutations can detect the lesions in 50 percent of cases only; this is explained by the recent finding (5) of an intragenic inversion that disrupts the factor VIII gene. Since this anomaly could not be characterized by these methods, Lakich et al. have also described a Southern blotting assay that allows a direct determination of the mutation. The use of this assay should greatly increase the feasibility and accuracy with which carrier detection and prenatal diagnosis can be made, as illustrated by the analysis of families with no available affected male that we present here.

Adult↗
PubMed1994

A block in both early T lymphocyte and natural killer cell development in transgenic mice with high-copy numbers of the human CD3E gene.

A severe immunodeficiency involving a complete loss of T lymphocytes and natural killer cells was observed in independent lines of transgenic mice containing > 30 copies of the human CD3E gene (pL12). T-cell- natural killer (NK)- mice could also be generated by using a gene fragment pL12 delta 1 (without exons 4A and 5) coding for the CD3-epsilon transmembrane region and its 55-amino acid nonenzymatic cytoplasmic tail. The abnormally small thymus gland in the homozygous transgenic animals, which was approximately 1% the size of a wild-type thymus, contained only a few (2-4%) prethymocytes with a Thy-1+Pgp-1+IL-2R alpha- CD3-4-8- phenotype. In mice with lower copy numbers of the transgene thymocyte development was blocked at the Thy-1+Pgp-1-IL-2R alpha+CD3-4-8- stage, and normal NK activity was detected. Mice generated with high-copy numbers of a transgene pL12 delta 2 (pL12 delta 1 minus exons 6), coding for a truncated protein from which the CD3-epsilon extracellular domain, its transmembrane region, and most of its cytoplasmic region were absent, contained normal numbers of T lymphocytes and NK cells. These transgene effects suggested that recruitment of signal-transduction molecules by the cytoplasmic tail of this protein played an important role in the abrogation of both lineages. Taken together these observations support the notion that T lymphocytes and NK cells stemmed from a common precursor.

Animals↗