Search PubMed⌕ Search

Biomedical subjects

J Emmerich

Publications and source records attributed to J Emmerich.

At least 37 records · Page 2Linked to original sources

[Subintimal angioplasty. Technique, results and role in the treatment of peripheral arterial occlusive disease].

Subintimal angioplasty consists in entering the subintimal space proximal to the occlusion, traversing the occlusion creating by angioplasty a subintimal channel exiting downstream in the natural lumen. Major complications rarely occur but compromising important collaterals or run-off vessels may be very deleterious. Subintimal angioplasty is indicated in patients with critical limb ischemia, unfit for anesthesia or in the absence of a suitable venous conduit. This technique is mainly effective in long and tibioperoneal occlusions, a location in which transluminal angioplasty usually fails. Further studies are required to determine the modalities of associated anti-thrombotic treatment and if subintimal angioplasty can be used as primary treatment in critical leg ischemia.

Angioplasty↗

[Genetic risk factors of thrombosis].

Genetic risk factors became a frequent predisposing cause of venous thromboembolism (VTE) since the discovery of two mutations: factor V Leiden and G20210A mutation of prothrombin gene. One of these both mutations is associated with around 25% of VTE events. Interaction of genetic risk factors, such as interaction of FV Leiden or G20210A mutation of prothrombin with antithrombin, protein C or protein S deficiencies, as well as interaction with acquired risk factors, have demonstrated that venous thrombosis is a multifactorial disease. The search for thrombophilia must be done in VTE occurring before the age of 45, in case of recurrencies and in case of familial history of VTE.

Adult↗

[The best of 2001. Vascular medicine].

Length of treatment after venous thromboembolism remains a controversial issue. Two studies published in 2001 did not demonstrate a higher benefit of long-term treatment compared to short-term treatment. New antithrombotic drugs, such as pentasaccharid and ximelagatran are beginning to appear in this field. Long-term travel as a risk factor for venous thrombolysis has also been studied and a recent study demonstrates that it is a risk factor of pulmonary embolism for a travel above 5000 km. No major advances occurred in the arterial field, except the absence of major differences between carotid surgery and carotid angioplasty in the CAVATAS study. This study required to continue to compare these two therapeutic options in randomized trials.

Arteriosclerosis↗

[Thrombosis and antithrombotic agents in peripheral artery disease].

Aspirin remains the most useful antithrombotic agent in peripheral arterial disease. In intermittent claudication, there is no indication for oral anticoagulant except in the presence of emboligen cardiopathy (atrial fibrillation, valvular prosthesis). In critical leg ischemia, there is no proof of benefit for anticoagulation. In the prevention of distal bypass of the legs, the same efficacy is observed for aspirin and oral anticoagulant, but in both treatment occlusion remains frequent, 25% of patients after two years of follow-up.

Administration, Oral↗

Factors V leiden and II 20210A in patients with symptomatic pulmonary embolism and deep vein thrombosis.

PURPOSE: Factor V Leiden and factor II 20210A are inherited disorders of the clotting system that occur frequently in patients with deep vein thrombosis. We conducted this study to determine whether these factors are also common in patients with pulmonary embolism. SUBJECTS AND METHODS: We determined the prevalence of factor V Leiden and factor II 20210A in 773 consecutive patients with objectively documented symptomatic deep vein thrombosis or symptomatic pulmonary embolism, or with a combination of these disorders. RESULTS: Isolated symptomatic deep vein thrombosis occurred in 345 patients; isolated symptomatic pulmonary embolism occurred in 236; and both anomalies occurred in 192. Factor V Leiden was present in 21 (9%) of the patients with isolated symptomatic pulmonary embolism, in 30 (16%) with both manifestations, and in 63 (18%) with isolated symptomatic deep vein thrombosis (P = 0.007). Factor V Leiden was more common among patients with deep vein thrombosis (odds ratio [OR] = 2.1; 95% confidence interval [CI]: 1.2 to 3.7; P = 0.006) or both pulmonary embolism and deep vein thrombosis (OR = 1.8; 95% CI: 1.0 to 3.3; P = 0.07) than among patients with isolated pulmonary embolism. Factor V Leiden was less common in massive pulmonary embolism (5% [7 of 127]) than in submassive pulmonary embolism (13% [21 of 155], P = 0.03). We found no significant difference in the prevalence of factor II 20210A among the three groups. CONCLUSION: Factors V Leiden and II 20210A vary in prevalence among patients with pulmonary embolism and deep vein thrombosis, suggesting that the risk of pulmonary embolization may vary among patients who have different causes of venous thromboses.

Adult↗

Looking for deep vein thrombosis in suspected pulmonary embolism.

Pulmonary embolism (PE) and deep vein thrombosis are two facets of the same disease, that is, venous thromboembolism (VTE). In patients with angiographically proven PE, the prevalence of proximal deep vein thrombosis by venography is around 70%. The sensitivity of compression ultrasonography (US) for the diagnosis of acute VTE in patients with a suspicion of PE is between 40 and 60%, with a high specificity (96 to 100%). Taking into account the 20 to 30% prevalence of PE in a population consulting for suspicion of this disease, the first line use of compression US will allow the diagnosis of acute VTE in half of patients with confirmed PE, that is, in 10 to 15% of patients addressed for suspicion of PE. In outpatients, the first line use of D-dimers which will exclude acute VTE in one-third of the initial population will slightly increase the reliability of compression US as a first imaging test. New tools of looking for deep vein thrombosis, such as computed tomographic venography coupled with computed tomographic pulmonary angiography, could become an interesting approach in the diagnostic strategy of PE, but require adequate evaluation in prospective studies.

Biomarkers↗

Thrombomodulin promoter mutations, venous thrombosis, and varicose veins.

We analyzed the distal promoter region of the thrombomodulin (TM) gene (nucleotides -300 to -2052) in subjects from the Paris Thrombosis Study (PATHROS), a French case-control study of venous thrombosis, to identify polymorphisms that might modify TM gene expression. Eight novel mutations were found in the 40 DNA samples initially screened. Two of these mutations (-1748G/C and -1208/-1209 del TT) were frequent. One rare transition (-1166G/A) might have functional consequences owing to its position. These 3 mutations were screened for in the entire study population of 327 patients and 398 controls. None of the 3 was significantly associated with thrombosis. Interestingly, the -1208/-1209 TT deletion was associated with varicose veins in the patients. This mutation was in tight linkage disequilibrium with the +1418 C/T change in the coding sequence, a known polymorphism that predicts an Ala 455 Val substitution in the sixth epidermal growth factor-like TM module, a domain previously implicated in the proliferative functions of TM. This linkage suggests that the Ala 455 Val mutation may promote changes in these functions and thus be involved in varicose vein formation.

Adult↗

[The best in 2000 on angiology].

There were no great innovations in angiology in the year 2000 but there was a number of advances, one of which being the publication of an international consensus on peripheral occlusive arterial disease, the TASC consensus. Each year, the number of risk factors for venous thromboembolic disease increases, and 2000 was no exception with the demonstration that high factor IX and XI concentrations were associated with this condition. On the arterial side, oral anticoagulation and aspirin were shown to be equivalent in the prevention of occlusion of lower limb bypass grafts. Finally, some recent data is in favour of a systemic mechanism in the acute complications of atherosclerosis.

Arterial Occlusive Diseases↗

Combined effect of factor V Leiden and prothrombin 20210A on the risk of venous thromboembolism--pooled analysis of 8 case-control studies including 2310 cases and 3204 controls. Study Group for Pooled-Analysis in Venous Thromboembolism.

Factor V Leiden and factor II G20210A mutations are two frequent genetic risk factors involved in venous thromboembolism (VTE). The goal of this pooled analysis of 8 case-control studies, comprising a total of 2310 cases and 3204 controls, was to precisely estimate the risk of VTE in patients bearing both mutations (double heterozygotes). Odds ratios for VTE were 4.9 (95% CI; 4.1-5.9) for the factor V Leiden and 3.8 (3.0-4.9) for the factor II G20210A mutation. Fifty-one cases (2.2%) and none of the controls were double heterozygotes. The odds ratio for venous thrombosis in double heterozygotes was 20.0 (11.1-36.1). Twelve percent of patients heterozygous for factor V Leiden were also heterozygous for factor II G20210A and conversely 23% of patients heterozygous for factor II G20210A were also heterozygous for factor V Leiden. Furthermore, in this large population we analyzed the effect of oral contraceptive (OC) in women carrying one of these mutations. Odds ratio for VTE associated with OC was 2.29 (1.72-3.04). In factor V Leiden carriers using OC, the odds ratio for VTE was 10.25 (5.69-1 8.45). The odds ratio of the association of factor II mutation and OC use was 7.14 (3.39-15.04). Finally, we also confirmed that the frequency of factor V Leiden was lower in patients with pulmonary embolism than in patients with deep vein thrombosis without PE (odds ratio 0.69). Conversely, factor II G20210A mutation was equally balanced in both patient groups.

3' Untranslated Regions↗

Hypercoagulable states in primary upper-extremity deep vein thrombosis.

BACKGROUND: There are very few data on the prevalence of coagulation abnormalities in primary deep vein thrombosis of the upper limbs. OBJECTIVE: To determine if coagulation abnormalities play a role in effort-related and/or idiopathic (non-effort-related) upper-extremity deep vein thrombosis (UEDVT). METHODS: Fifty-one consecutive patients (21 men and 30 women) who had effort-related (n = 20) or idiopathic (n = 31) UEDVT over an 18-year period (median age at diagnosis, 32 years; age range, 15-86 years) were routinely reexamined. Plasma was screened for antithrombin, protein C, and protein S deficiencies and for antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies). The DNA was screened for factor V Leiden and for prothrombin gene G20210A mutations. RESULTS: The median age (35 vs. 28 years), the proportion of women (81% [25/31] vs. 25% [5/201), the proportion of patients with a personal and/or family history of thromboembolism (42% [13/31] vs. 15% [3/20]), and the proportion of patients with at least 1 coagulation abnormality (42% [13/31] vs. 15% [3/20]) were higher in the idiopathic UEDVT group than in the effort-related UEDVT group. The odds ratio of having a coagulation abnormality was 4.09 (95% confidence interval, 0.99-16.78; P = .06) in the idiopathic UEDVT group compared with the effort-related UEDVT group. CONCLUSION: Hypercoagulable states appear to play a significant role in idiopathic but not in effort-related UEDVT.

Adolescent↗

Molecular bases of antithrombin deficiency in French families: identification of seven novel mutations in the antithrombin gene.

We have investigated the molecular bases of familial antithrombin deficiency in eight French families. Eight mutations in the antithrombin coding exons were identified, seven of which were novel mutations. In all cases, individuals were heterozygous for the mutation. We found two small frameshift deletions in exon 3a, leading to type I deficiency. Five missense mutations in exons 3b or 5 also caused type I deficiency and their potential consequences on the antithrombin three-dimensional structure were analysed. The last mutation in exon 4 was associated with a type II 'reactive site' deficiency: a dysfunctional antithrombin that is affected in its interaction with thrombin was present in circulation.

Antithrombin III Deficiency↗

Protective effect of a thrombin receptor (protease-activated receptor 1) gene polymorphism toward venous thromboembolism.

The human protease-activated receptor 1 (PAR-1) is activated by thrombin at the surface of platelets and endothelial cells, 2 cells that are implicated in hemostasis and thrombosis. We studied the PAR-1 gene in a large case-control study from the Paris Thrombosis Study (PATHROS), and the possible implication of polymorphisms in venous thromboembolism was evaluated. Two polymorphisms were found in the 5' regulatory region. The first is a C to T transition that is 1426 nucleotides upstream from the translation start site (-1426 C/T), and the second is a 13-bp insertion repeating the preceding -506 5'-CGGCCGCGGGAAG-3' sequence (-506 I/D, where I indicates insertion and D indicates deletion), a putative cis-acting element of the Ets family. The third polymorphism is an A to T transversion in the intervening sequence (IVS) that is 14 nucleotides upstream from the exon 2 start site (IVS-14 A/T). The distribution of the 3 polymorphisms was otherwise similar in the 250 cases and the 1214 controls. A noteworthy sex heterogeneity led us to analyze men and women separately with regard to the -506 I/D polymorphism. We found that allele I was less frequent in male cases than in male controls (0.154 versus 0.247, P<0.01), with an odds ratio at 0.52 (95% CI 0. 32 to 0.82, P<0.01). Furthermore, a reduction of prothrombin fragment 1+2 levels was observed in homozygous carriers of allele -506 I (P=0.04). Altogether, these data suggested a protective effect in men of -506 I/D polymorphism for venous thromboembolism.

Adult↗

Polymorphisms in the 5' regulatory region of the tissue factor gene and the risk of myocardial infarction and venous thromboembolism: the ECTIM and PATHROS studies. Etude Cas-Témoins de l'Infarctus du Myocarde. Paris Thrombosis case-control Study.

Tissue factor (TF) is a transmembrane protein considered to be responsible for the initiation of coagulation. TF gene expression may be induced in monocytes and endothelial cells and is present in atherosclerotic plaque to initiate thrombus formation. To investigate whether individual differences in TF gene expression could predispose subjects to thrombosis, we sequenced the 5' domain of the gene up to nucleotide 2732 and found 6 different polymorphisms: 4 of them were completely concordant and defined 2 haplotypes with similar frequencies, designated as 1208 D and 1208 I. Genotyping of patients with myocardial infarction in a case-control study involving 2354 subjects showed no association between the polymorphisms and nonfatal coronary thrombosis. In another study involving 255 patients with venous thromboembolism and 1204 controls, allele D was less common in the cases (P=0.022). The odds ratio associated with the presence of at least 1 D allele was 0.72 (P=0. 031). Comparison of subgroups of control subjects who were homozygous for the D or I allele demonstrated a lower plasma TF concentration in DD homozygotes. These results indicate that the TF gene promoter exists in 2 major forms differing at 4 sites. The 1208 D haplotype is not associated with coronary thrombosis but is associated with reduced plasma TF levels and a lower risk of venous thrombosis.

5' Untranslated Regions↗

[The best of vascular pathology in 1999].

In vascular pathology, the discovery of the ABC1 receptor (ATP-binding-cassette transporter 1), the deficit of which is responsible for Tangier disease and familial hypoalphalipoproteinaemias, has opened the greatest perspectives with the possibility of new active treatments in the prevention of atherosclerosis. Other advances were more expected. A large British trial convincingly demonstrated that the follow-up of small abdominal aortic aneurysms is reliable. The MEDENOX trial showed the value of prophylaxis of thromboembolic disease in a medical setting and the reduced incidence of phlebographic events. The ICAI study, on the other hand, showed the difficulty of treatment of critical ischaemia of the lower limbs: alprostadil (PGE1) was ineffective with a 6 month follow-up in this pathology. Finally, low dose aspirin is at least as effective as high doses.

ATP-Binding Cassette Transporters↗

Demonstration of an association between Chlamydia pneumoniae infection and venous thromboembolic disease.

Chlamydia pneumoniae infection has been linked to atherosclerosis, but a possible relationship with venous thromboembolism (VTE) has not been sought. We determined circulating anti-C. pneumoniae antibody levels in patients with VTE. We studied 176 case patients with objectively diagnosed VTE and 197 age- and sex-matched healthy controls, in a retrospective study. Acquired risk factors for VTE and frequent predisposing genetic factors (factor V Arg 506 Gln and factor II G 20210 A mutations) were assessed in all the subjects. Anti-C. pneumoniae IgG antibodies were determined by microimmunofluorescence. All positive plasma samples (titer > or =128) were precisely quantified and tested for the presence of specific IgM antibodies. Fifty-four percent of the cases and 15.9% of the controls had specific IgG titers of at least 256 (p <0.0001). The crude odds ratio for VTE was 6.2 (95% CI, 3.8-10.1), and rose to 7.7 (4.5-13.2) after excluding subjects carrying the factor V Arg 506 Gln or factor II G 20210 A mutations. The odds ratio for VTE increased with the IgG titer: the adjusted odds ratios were 2.1 (95% CI, 1.1-4.1), 5.3 (2.7-10.6) and 33.0 (4.4-248.4) for titers of 256, 512 and 1024, respectively. Only one subject (a case patient) with a high IgG titer (> or =256) also had specific IgM. High titers of anti-C. pneumoniae IgG antibodies are frequently found in patients with previous venous thromboembolism. This association deserves to be confirmed in other case-control studies and prospective studies.

Adult↗