The frequency of 844ins68 mutation in the cystathionine beta-synthase gene is not increased in patients with venous thrombosis

Background and Objectives. A frequent mutation in the cystathionine beta-synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we Investigated this mutation as a candidate risk factor for venous thrombosis.Design and Methods. The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes, Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene.Results. The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C GBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co-inheritance of the two mutations.Interpretation and Conclusions. Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis. (C)1998, Ferrata Storti Foundation.

Identification of polymorphisms in the 5 '-untranslated region of the TAFI gene: relationship with plasma TAFI levels and risk of venous thrombosis

Background and Objectives. Thrombin activatable fibrinolysis inhibitor (TAFI) plays an important role in hemostasis, functioning as a potent fibrinolysis inhibitor. TAFI gene variations may contribute to plasma TAFI levels and thrombotic risk.Design and Methods. We sequenced a 2083-bp region of the 5 ' -regulatory region of the TAFI gene in 127 healthy subjects searching for variations, and correlated identified polymorphisms with plasma TAFI levels. TAFI polymorphisms were examined as risk factors for venous thrombosis by determining their prevalence in 388 patients with deep venous thrombosis (DVT) and in 388 controls.Results. Seven novel polymorphisms were identified: -152 A/G, -438 A/G, -530 C/T, -1053 T/C, -1102 T/G, -1690 G/A, and -1925 T/C. -152 A/G, -530 C/T and -1925 T/C were found to be in strong linkage disequilibrium, as were the -438 A/G, -1053 T/C, -1102 T/G and -1690 G/A, Plasma TAFI levels were higher in -43866/-1053CC/-1102GG/-1690AA homozygotes than In -438AG/-1053TC/-1102TG/-1690GA heterozygotes, and -438AA/-1053TT/-1102TT/-1690GG homozygotes had the lowest TAFI levels (p=0.0003). TAFI concentrations in -152AA/-530CC/-1925TT homozygotes were somewhat higher but not significantly different from levels observed for -152AG/-530CT/-1925TC heterozygotes, Taken in combination, -438AG/-1053TC/-1102TG/-1690GA and -438AA/-1053TT/-1102TT/-1690GG yielded an OR for DVT of 0.8 (95%CI: 0.6-1). in subjects aged < 35 years the OR was 0.7 (95%CI: 0.5-1.1), the OR for -152AG/-530CT/-1925TC was 1 (95%CI: 0.5-2.2) in the whole group of patients and controls, whereas in subjects aged <35 years the OR was 0.1 (95%CI: 0.02-0.9).Interpretation and Conclusions. Polymorphisms in the TAFI promoter determine plasma antigen levels and may influence the risk of venous thrombophilia. <(c)>2001, Ferrata Storti Foundation.

Response to Treatment in a Prospective Cohort of Patients with Large Ulcerated Lesions Suspected to Be Buruli Ulcer (Mycobacterium ulcerans Disease)

Background: The World Health Organization (WHO) advises treatment of Mycobacterium ulcerans disease, also called Buruli ulcer'' (BU), with a combination of the antibiotics rifampicin and streptomycin (R+S), whether followed by surgery or not. In endemic areas, a clinical case definition is recommended. We evaluated the effectiveness of this strategy in a series of patients with large ulcers of >= 10 cm in longest diameter in a rural health zone of the Democratic Republic of Congo (DRC).Methods: A cohort of 92 patients with large ulcerated lesions suspected to be BU was enrolled between October 2006 and September 2007 and treated according to WHO recommendations. The following microbiologic data were obtained: Ziehl-Neelsen (ZN) stained smear, culture and PCR. Histopathology was performed on a sub-sample. Directly observed treatment with R+S was administered daily for 12 weeks and surgery was performed after 4 weeks. Patients were followed up for two years after treatment.Findings: Out of 92 treated patients, 61 tested positive for M. ulcerans by PCR. PCR negative patients had better clinical improvement than PCR positive patients after 4 weeks of antibiotics (54.8% versus 14.8%). For PCR positive patients, the outcome after 4 weeks of antibiotic treatment was related to the ZN positivity at the start. Deterioration of the ulcers was observed in 87.8% (36/41) of the ZN positive and in 12.2% (5/41) of the ZN negative patients. Deterioration due to paradoxical reaction seemed unlikely. After surgery and an additional 8 weeks of antibiotics, 98.4% of PCR positive patients and 83.3% of PCR negative patients were considered cured. The overall recurrence rate was very low (1.1%).Interpretation: Positive predictive value of the WHO clinical case definition was low. Low relapse rate confirms the efficacy of antibiotics. However, the need for and the best time for surgery for large Buruli ulcers requires clarification. We recommend confirmation by ZN stain at the rural health centers, since surgical intervention without delay may be necessary on the ZN positive cases to avoid progression of the disease. PCR negative patients were most likely not BU cases. Correct diagnosis and specific management of these non-BU ulcers cases are urgently needed.

Prevention of experimental venous thrombosis induced by contrast medium in the rat

In order to assess experimentally the usefulness of some procedures employed in man to prevent venous thrombosis following phlebography, thrombosis was induced in rats using sodium diatrizoate in a temporarily isolated segment of a jugular vein. The prevention of thrombosis was attempted by washing out the vein with physiologic saline or saline plus heparin or by injecting saline plus heparin in the opposite jugular vein. Thrombosis occurred in all animals in the control group and in the group treated with saline alone. Both treatment schemes with heparin significantly reduced the incidence of thrombosis, the wash out with heparin being more effective than systemic heparin.

Heparin, heparin plus ASA and dipyridamole, and arteriovenous fistula as adjuvant methods to prevent rethrombosis after venous thrombectomy. Experimental study in rabbits

Venous rethrombosis following thrombectomy is a common event. The aim of the present study was to verify the action of heparin, heparin plus acetyl salicylic acid (ASA) and dipyridamole, and of an arteriovenous fistula (AVF) in the prevention of this complication. Thrombosis was induced in 48 male rabbits by the injection of thrombin in a segment of the left jugular vein, in which the blood flow was arrested for 10 minutes. After 48 hours, the animals were randomly allocated into one of 4 groups of treatment: (1) control, (2) subcutaneous heparin (600 S.I. Units/kg - 8/8 hours), (3) heparin, in the same dose, plus ASA (10 mg/kg/once a day), and dipyridamole (0.5 mg/kg thrice a day), (4) an AVF was surgically constructed between the left carotid after and the left maxillar vein. After 30 minutes, thrombectomy was performed. The venous blood flow, the hematocrit, activated partial thromboplastin time and thrombin time tests were performed before, right after the thrombectomy and 48 hours after thrombectomy. Venography was performed after thrombectomy and at the end of the experiment. The animals were killed 48 hours after thrombectomy and the veins were examined macroscopically. Venous rethrombosis was significantly prevented only in the AVF group (9/12), when compared to control group (0/12), heparin group (1/12) and heparin plus antiaggregating agents group (2/12). These results validate further clinical and experimental investigations with the use of AVF to prevent rethrombosis after venous thrombectomy, when a reduction of venous flow is present.

The frequency of 844ins68 mutation in the cystathionine β-synthase gene is not increased in patients with venous thrombosis

Background and Objectives. A frequent mutation in the cystathionine β- synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we investigated this mutation as a candidate risk factor for venous thrombosis. Design and Methods. The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes. Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene. Results. The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C CBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co- inheritance of the two mutations. Interpretation and Conclusions. Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis.

Factor XIII Val34Leu is a genetic factor involved in the aetiology of venous thrombosis

A mutation in the factor XIII gene (FXIII Val34Leu) gene was recently reported to confer protection against myocardial infarction, but its relationship with venous thrombosis is unknown. In addition, a mutation in the 5'-untranslated region of the FXII gene (46 C→T) was identified which is associated with low plasma levels of the protein. Its prevalence in patients with venous thrombosis is also unknown. We investigated the frequency of the FXIII Val34Leu and FXII 46 C→T mutations in 189 patients with deep venous thrombosis and in 187 age-, gender- and race-matched controls. FXIII Val34Leu was detected in 38.6% of the patients and in 41.2% of the controls. Interestingly, homozygosity for the FXIII mutation was found in 1.6% of the patients and in 9.6% of the controls. yielding an odds ratio (OR) for venous thrombosis of 0.16 (95% CI: 0.05-0.5). The OR for heterozygotes was 1.1 (95% CI: 0.7-1.7). The FXII 46 C→T mutation was detected in 46.0% of the patients and in 48.6% of the controls. The OR for heterozygotes was 0.9 (95% CI: 0.6-1.4) and for homozygotes the OR was 0.8 (95% CI: 0.3-1.9). Our data indicate that the FXII 46 C→T mutation is unlikely to be a major risk factor for venous thrombotic disease. In contrast, the homozygous state for FXIII Val34Leu is a strong protective factor against venous thrombosis, which emerges as a novel generic factor involved in the aetiology of thrombophilia.

Genetic alterations in benign lesions: Chronic gastritis and gastric ulcer

Aim: To investigate the occurrence of chromosome 3, 7, 8, 9, and 17 aneuploidies, TP53 gene deletion and p53 protein expression in chronic gastritis, atrophic gastritis and gastric ulcer, and their association with H pylori infection. Methods: Gastric biopsies from normal mucosa (NM, n = 10), chronic gastritis (CG, n = 38), atrophic gastritis (CAG, n = 13) and gastric ulcer (GU, n = 21) were studied using fluorescence in situ hybridization (FISH) and immunohistochemical assay. A modified Giemsa staining technique and PCR were used to detect H pylori. An association of the gastric pathologies and aneuploidies with H pylori infection was assessed. Results: Aneuploidies were increasingly found from CG (21%) to CAG (31%) and to GU (62%), involving mainly monosomy and trisomy 7, trisomies 7 and 8, and trisomies 7, 8 and 17, respectively. A significant association was found between H pylori infection and aneuploidies in CAG (P = 0.0143) and GU (P = 0.0498). No TP53 deletion was found in these gastric lesions, but p53-positive immunoreactivity was detected in 45% (5/11) and 12% (2/17) of CG and GU cases, respectively. However, there was no significant association between p53 expression and H pylori infection. Conclusion: The occurrence of aneuploidies in benign lesions evidences chromosomal instability in early stages of gastric carcinogenesis associated with H pylori infection, which may confer proliferative advantage. The increase of p53 protein expression in CG and GU may be due to overproduction of the wild-type protein related to an inflammatory response in mucosa. © 2006 The WJG Press. All rights reserved.