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Biomedical subjects

J Conard

Publications and source records attributed to J Conard.

At least 37 records · Page 2Linked to original sources
PubMed1997

A single genetic origin for a common Caucasian risk factor for venous thrombosis.

A common genetic risk factor for venous thrombosis among Caucasoid subpopulations is a polymorphism, nt G1691A, in blood coagulation factor V that replaces Arg506 with Gln and imparts resistance of factor Va to the anticoagulant, activated protein C. Haplotype analyses using six dimorphic sites in the factor V gene for 117 Caucasian subjects of Jewish, Arab, Austrian, and French origin who were homozygous for nt A1691 compared with 167 controls (nt G1691) support a single origin for this polymorphism. The nt G1691A mutation is estimated to have arisen circa 21,000 to 34,000 years ago, ie, after the evolutionary divergence of Africans from non-Africans and of Caucasoid from Mongoloid subpopulations.

Arginine↗
PubMed1997

Fibrinogen and plasminogen modifications during oral estradiol replacement therapy.

OBJECTIVE: To assess the effects of oral E2 replacement therapy on various hemostatic parameters and cardiovascular risk factors in healthy, postmenopausal women. DESIGN: A double-blind, randomized, prospective study comparing the effect of a placebo and of oral micronized E2 (2 mg daily) during a 6-month period. Evaluations were performed before treatment and after 3 and 6 months. SETTING: Departments of Gynecology, Hemostasis, and Nutrition, Hôtel-Dieu, Paris, France. PATIENT(S): Thirty-six healthy women with natural or surgical menopause. RESULT(S): Compared with placebo, oral E2 replacement therapy resulted in a significant decrease in fibrinogen and apo B and a significant increase in plasminogen. CONCLUSION(S): Besides the effects on lipoproteins, oral estrogen replacement therapy modifies parameters involved in coagulation and fibrinolysis.

Administration, Oral↗
PubMed1997

Acute ischemic stroke and heparin treatments.

Several case-control studies have reported enhanced platelet activity, hypercoagulation and/or reduced fibrinolytic activity in patients with acute ischemic stroke. However, results of these studies are conflicting and do not allow to make recommendations regarding heparin treatment. The aim of heparin treatment in stroke patients is to prevent venous thromboembolic complications, to improve patient neurologic outcome, to reduce mortality and to prevent early recurrence. Unfortunately, only the first objective has been confirmed. As far as neurologic outcome and mortality are concerned, only trials performed since the CT era should be taken into account because the former ones did not rule out cerebral haemorrhages. The most recent clinical trials using LMWHs gave better results than the previous trials with UFH, but data are still conflicting and firm recommendations cannot be made until the results of ongoing megatriasl (such as IST) become available. As regards prevention of early recurrence, most authors agree that heparin is indicated in cardioembolic stroke.

Anticoagulants↗
PubMed1997

[Value of plasma D-dimer assays in the diagnosis of venous thromboembolism].

The diagnostic usefulness of measuring plasma D-dimers using the ELISA method and the latex agglutination test has been prospectively evaluated in 117 patients hospitalized for suspicion of acute venous thrombo-embolism (AVTE): pulmonary embolism was suspected in 80 patients and the remaining 37 had a suspicion of deep vein thrombosis of the lower limbs. The diagnosis of AVTE was confirmed in 50% of the patients, all of whom underwent gold standard invasive investigation i.e. pulmonary angiography and/or contrast venography. The sensitivity, specificity, negative predictive value and positive predictive value of a D-dimers plasma concentration exceeding 500 ng/ml for the diagnosis of AVTE were respectively 98, 58, 97 and 70% when using the ELISA method, and 86, 71, 84 and 75% when using the latex assay. In 47 patients whose lung scans yielded abnormalities of indeterminate probability of pulmonary embolism, the sensitivity of the ELISA method was very high (94%), but that of latex assay was low (67%). Our results demonstrate that measuring the plasma D-dimers by the latex assay should not be used in the diagnosis of AVTE. On the other hand, the ELISA method might be of great interest in the diagnostic strategy of AVTE, as a normal concentration of D-dimers rules out almost definitely the diagnosis of AVTE, and hence, spares from performing invasive investigations.

Acute Disease↗
PubMed1997

[Comparison of two groups of 22 women homozygous or heterozygous for factor V Leiden mutation].

Clinical characteristics of thrombophilia associated with heterozygous mutation of factor V are well characterized. In contrast, they are not well documented in homozygous subjects who are rare. Moreover, estroprogestative intake and pregnancy are important precipitating factors of venous thromboembolism in women with factor V mutation. In order to determine difference in clinical expression between homo and heterozygous subjects, two groups of 22 age matched women were compared. A modified technique for the diagnosis of activated protein C resistance has been used, and its great specificity and sensitivity has been confirmed. In these two small series of patients, a greater severity of clinical profile was not clearly evident. However, recurrences and thrombosis during pregnancy were more frequent in homozygous than in heterozygous women. However, the differences did not reach significance. Molecular markers of hypercoagulable states were not regularly increased even in homozygous untreated patients, but they were more often increased in untreated than in treated patients. In contrast, to other varieties of thrombophilia, homozygous mutation of factor V may be associated with a minor clinical severity suggesting the role of environmental factors and/or still unknown molecular alterations.

Factor V↗
PubMed1996

Increased fetal loss in women with heritable thrombophilia.

BACKGROUND: A successful outcome of pregnancy requires an efficient uteroplacental vascular system. Since this system may be compromised by disorders of haemostasis associated with a prothrombotic state, we postulated that maternal thrombophilia might be a risk factor for fetal loss. We studied the relation between heritable thrombophilic defects and fetal loss in a cohort of women with factor V Leiden or deficiency of antithrombin, protein C, or protein S. METHODS: We studied 1384 women enrolled in the European Prospective Cohort on Thrombophilia (EPCOT). Of 843 women with thrombophilia 571 had 1524 pregnancies; of 541 control women 395 had 1019 pregnancies. The controls were partners of male members of the EPCOT cohort or acquaintances of cases. We analysed the frequencies of miscarriage (fetal loss at or before 28 weeks of gestation) and stillbirth (fetal loss after 28 weeks of gestation) jointly and separately. FINDINGS: The risk of fetal loss was increased in women with thrombophilia (168/571 vs 93/395; odds ratio 1.35 [95% Cl 1.01-1.82]). The odds ratio was higher for stillbirth than for miscarriage (3.6 [1.4-9.4] vs 1.27 [0.94-1.71]). The highest odds ratio for stillbirth was in women with combined defects (14.3 [2.4-86.0]) compared with 5.2 (1.5-18.1) in antithrombin deficiency, 2.3 (0.6-8.3) in protein-C deficiency, 3.3 (1.0-11.3) in protein-S deficiency, and 2.0 (0.5-7.7) with factor V Leiden. The corresponding odds ratios for miscarriage in these subgroups were 0.8 (0.2-3.6), 1.7 (1.0-2.8), 1.4 (0.9-2.2), 1.2 (0.7-1.9), and 0.9 (0.5-1.5). Significantly more pregnancy terminations had been done in women with thrombophilia than in controls (odds ratio 2.9 [1.8-4.8]); this discrepancy was apparent in nine of 11 participating centres and for all thrombophilia subgroups. INTERPRETATION: Women with familial thrombophilia, especially those with combined defects or antithrombin deficiency, have an increased risk of fetal loss, particularly stillbirth. Our findings have important implications for therapy and provide a rationale for clinical trials of thromboprophylaxis for affected women with recurrent fetal loss.

Abortion, Spontaneous↗
PubMed1996

An association between precocious puberty and fragile X syndrome?

STUDY OBJECTIVE: To determine the FMR1 gene status in a 10-year, 10-month-old girl with a history of precocious puberty and a family history of fragile X syndrome. DESIGN: Case report. SETTING: The outpatient facility of the Division of Adolescent Medicine and the Division of Genetic and Metabolic Disorders at Children's Hospital of Michigan and the Medical Genetics and Birth Defects Center of Henry Ford Hospital, Detroit, Michigan. PARTICIPANT: A 10-year, 10-month-old girl with a history of precocious puberty. INTERVENTION: Evaluation for menorraghia, DNA extraction, and fragile X gene analysis of blood samples from the patient and her mother. MAIN OUTCOME MEASURES: Identification of a full mutation in the FMR1 gene. RESULTS: Southern blot analysis of the FMR1 gene identified a full mutation in the daughter with approximately 750 repeats of the CGG sequence. Methylation studies showed that the full mutation was completely methylated. FMR1 DNA studies on her mother identified a premutation of approximately 100 repeats. CONCLUSIONS: This report identifies a young girl with a history of precocious puberty and fragile X syndrome. It is also the first report of molecular genetic FMR1 studies in a female with precocious puberty. A possible association between the two conditions is suggested and warrants further investigation.

Blotting, Southern↗
PubMed1996

Diagnosis and clinical characteristics of inherited activated protein C resistance.

The diagnostic strategies and clinical characteristics of thrombophilia associated with heterozygous or homozygous factor V Leiden mutation have been determined according to the literature and to a personal study in 51 families. Factor V mutation was present in the 51 propositi and in 84 out of 125 family members (81 heterozygous, 3 homozygous). Venous thrombosis was observed in all the propositi, in 17 of the 84 family members with the mutation and in 6 of the 41 with a normal APC resistance test and no mutation. An associated protein C or protein S deficiency was present in 5 families (10%). The most frequent clinical manifestations were superficial or deep vein thrombosis and/or pulmonary embolism, but also thrombosis at an unusual site (cerebral, mesenteric or central retinal vein). A causal relationship is frequently difficult to demonstrate. A precipitating factor was observed in 84% of cases and a recurrent thrombotic episode occurred in 50% of propositi. The risk of thrombosis associated with pregnancy was high in the post-partum period, especially in homozygous women. In the 28 homozygous subjects, markers of coagulation activation were frequently elevated in untreated patients. Finally, the efficacy of anticoagulant treatment is suggested but the long period often observed between treatment interruption and a recurrence does not militate in favour of long term treatment.

Anticoagulants↗
PubMed1996

Coagulation studies, factor V Leiden, and anticardiolipin antibodies in 40 cases of cerebral venous thrombosis.

BACKGROUND AND PURPOSE: Cerebral venous thrombosis (CVT) is an infrequent condition with a large variety of causes. However, in 20% to 35% of cases, no cause is found. We studied coagulation parameters, including activated protein C resistance associated with factor V gene mutation (factor V Leiden) and anticardiolipin antibodies, in a large series of patients with CVT with or without identified cause or risk factor. METHODS: Forty patients (30 women and 10 men) aged 19 to 71 years (mean age, 36.2 years) with CVT diagnosed by angiography and/or MRI were studied 1 to 18 years after thrombosis. No known cause was found in 10 idiopathic cases. Coagulation studies included the following tests: fibrinogen, antithrombin, protein C, protein S, plasminogen, anticardiolipin antibodies, activated protein C resistance, and factor V Leiden. RESULTS: Six cases of thrombophilia (15%) were found: 1 protein C deficiency, 1 protein S deficiency, and 4 activated protein C resistance with heterozygous factor V Leiden mutation (10%). Only 1 case (protein S deficiency) was found in the group of 10 patients with idiopathic CVT. In the other 5, there was another cause or risk factor. Three patients (8%) had increased anticardiolipin antibodies: 1 with systemic lupus and 2 with primary antiphospholipid syndrome; 2 of these 3 patients also had factor V Leiden mutation. CONCLUSIONS: Although present in a number of CVT cases, acquired (anticardiolipin) or congenital varieties of thrombophilia (factor V Leiden being the most frequent) are almost invariably associated with other predisposing factors. This suggests that (1) these abnormalities should be looked for in patients with CVT, whether a cause is found or not, and (2) their presence should not deter the search for other potential causes. The detection of such abnormalities has major practical consequences on the long-term management of patients to prevent further thrombotic episodes.

Adult↗
PubMed1996

Factor V Leiden (FV R506Q) in families with inherited antithrombin deficiency.

We investigated the presence of the gene mutation of factor V, FV R506Q or factor V Leiden, responsible for activated protein C resistance, in DNA samples of 127 probands and 188 relatives from 128 families with antithrombin deficiency. The factor V mutation was identified in 18 families. Nine families were available to assess the mode of inheritance and the clinical relevance of combined defects. The factor V and antithrombin genes both map to chromosome 1. Segregation of the defects on opposite chromosomes was observed in three families. Co-segregation with both defects on the same chromosome was demonstrated in four families. In one family a de novo mutation of the antithrombin gene and in another a crossing-over event were the most likely explanations for the observed inheritance patterns. In six families with type I or II antithrombin deficiency (reactive site or pleiotropic effect), 11 of the 12 individuals with both antithrombin deficiency and the factor V mutation developed thrombosis. The median age of their first thrombotic episode was 16 years (range 0-19); this is low compared with a median age of onset of 26 years (range 20-49) in 15 of 30 carriers with only a defect in the antithrombin gene. One of five subjects with only factor V mutation experienced thrombosis at 40 years of age. In three families with type II heparin binding site deficiencies, two of six subjects with combined defects experienced thrombosis; one was homozygous for the heparin binding defect. Our results show that, when thrombosis occurs at a young age in antithrombin deficiency, the factor V mutation is a likely additional risk factor. Co-segregation of mutations in the antithrombin and factor V genes provides a molecular explanation for severe thrombosis in several generations. The findings support that combinations of genetic risk factors underly differences in thrombotic risk in families with thrombophilia.

Adolescent↗
PubMed1995

[Resistance to activated protein C in venous thromboembolic complications. Incidence and clinical manifestations].

OBJECTIVES: The frequency of activated protein C resistance is not well established for patients with venous thromboembolic disease. We studied resistance to activated protein C in patients with a past history of deep vein or superficial vein thrombosis. METHODS: Activated protein C resistance was measured in 175 patients (37 males, 138 females; mean age 40.9 +/- 13.8 years; range 15-77) who had suffered a venous thromboembolic event more than one month earlier. Exclusion criteria were malignancy, known autoimmune disease or known coagulopathy. A control population of 50 healthy subjects were also tested to establish a normal lower limit (mean ratio minus 2 SD). RESULTS: The lower limit was established at 2.14. According to this definition, there were 29 thromboembolic patients who were resistant to activated C protein (17%). Two of the subjects considered healthy in the control group were also resistant (4%). There was no difference for age or sex between resistant and non-resistant subjects. Comparing our findings with those reported in the literature confirmed that 3 to 5% of healthy subjects and 15 to 25% of patients with history of venous thromboembolism are resistant to activated C protein. CONCLUSION: Resistance to activated C protein thus appears as a risk factor for thrombotic events which is comparatively more frequent than other causes of thrombotic disease.

Adolescent↗
PubMed1995

17 beta-Estradiol: oral or parenteral administration in hyperandrogenic women? Metabolic tolerance in association with cyproterone acetate.

OBJECTIVE: To compare the metabolic effects of two different administration routes of estrogen associated with cyproterone acetate (CPA) in young women. DESIGN: Randomized and prospective study. SETTING: University medical and research center. PATIENTS: Sixty-five premenopausal young women with clinical hyperandrogenism. INTERVENTIONS: A high dose of CPA was administered, associated with either transdermal (group T) or oral (group O) 17 beta-E2. MAIN OUTCOME MEASURES: Glucose tolerance, plasma lipid level, coagulation and fibrinolysis parameters, and angiotensinogen, before and at 6 and 12 months during treatment. RESULTS: At 12 months, fasting blood glucose and basal insulin levels were significantly lower in group O than in group T. The increase in angiotensinogen was greater in group O, however, without modification in arterial blood pressure. No significant difference between the two groups was observed in lipids, coagulation, and fibrinolysis. CONCLUSION: Natural estrogens associated with CPA have no patent deleterious metabolic effect. However, the choice of oral estrogen administration seems to be better among patients with disorders such as hyperandrogenism or obesity with potential hyperinsulinism.

Administration, Cutaneous↗
PubMed1995

Cardiovascular risk factors and combined estrogen-progestin replacement therapy: a placebo-controlled study with nomegestrol acetate and estradiol.

OBJECTIVE: To assess the effects of oral E2 replacement therapy combined with nomegestrol acetate, a 19-norprogesterone derivative, on cardiovascular risk factors. DESIGN: A double-blind randomized prospective study comparing the effect of a placebo and two oral E2-nomegestrol acetate combinations (1 mg-2.5 mg and 1.5 mg-3.75 mg) over a three-cycle trial. SETTING: Department of Internal Medicine and Nutrition, Hotel-Dieu, Paris, France. PATIENTS: Fifty-seven nonhysterectomized women with natural menopause. MAIN OUTCOME MEASURES: Blood pressure, renin substrate, glucose, total cholesterol, high-density and low-density lipoprotein cholesterol, triglycerides, apoproteins A1 and B, lipoprotein(a), antithrombin III, fibrinogen, plasminogen, prothrombin fragment 1 + 2, protein C, and total and free protein S. RESULTS: Both treatments significantly reduced menopausal complaints, total cholesterol, low-density lipoprotein cholesterol and lipoprotein(a). Treatment with the 1.5 mg-3.75 mg combination resulted in a significant increase in apolipoprotein A1. No significant change were observed in other parameters. CONCLUSIONS: Sequentially combined with oral E2 in hormone replacement therapy, nomegestrol acetate had favorable effects on plasma lipids and lipoproteins. This nonandrogenic progestin decreased lipoprotein(a) levels as observed previously with medroxyprogesterone acetate combined with conjugated equine estrogens.

Apoproteins↗