bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety of Low-Molecular-Weight Heparin in Pregnancy: A Systematic Review
Authors: Sanson Bernd-Jan , Lensing Anthonie , Prins Martin , Ginsberg Jeffrey , Barkagan Zinoviy , Lavenne-Pardonge Edith , Brenner Benjamin , Dulitzky Mordechay , Nielsen Jørn , Boda Zoltan , Mac Gillavry Melvin , Hamulyák Karly , Theunissen Ingrid , Hunt Beverley , Büller Harry , Turi Susanna 
Published: March 2018

SummaryUnfractionated heparin (UFH) remains the anticoagulant of choice during pregnancy. Low-molecular-weight heparins (LMWH) are an attractive alternative to UFH due to their logistic advantages and their association with a lower incidence of osteoporosis and HIT. We reviewed all published clinical reports concerning the use of LMWH during pregnancy. In addition, participants of an international interest group contributed a cohort of pregnant women treated with LMWH. Pregnancies were divided into two groups; those with and those without maternal comorbid conditions. The number of adverse fetal outcomes and the occurrence of maternal complications were evaluated in the two groups. In the group of women with comorbid conditions (n = 290), 13.4% of the pregnancies were associated with an adverse fetal outcome. In contrast, in the group of women without comorbid conditions (n = 196), 3.1% were associated with an adverse outcome, which is comparable to that seen in the normal population. We conclude that LMWH appear to be a safe alternative to unfractionated heparin as an anticoagulant during pregnancy.
Factor V Leiden, Prothrombin 20210 G → A and the MTHFR C677T Mutations in Childhood Stroke
Authors: Chalmers E. A. , Thomas A. , Sproul A. , Healey C. , Rafferty I. , McWilliam R. , Eunson P. , McColl M. D. 
Published: March 2018

SummaryIschaemic stroke is a rare occurrence in children and in a proportion of cases the aetiology remains unknown. We have investigated the role of thrombophilia in the aetiology of this condition. Of 50 cases identified at two centres, 37 were available for detailed haematological analysis. No cases were identified with deficiencies of antithrombin, protein C or protein S. One case had elevated IgG anticardiolipin antibodies at low titre. The prevalence of the prothrombin 20210 G→A mutation, factor V Leiden (FVL) mutation and the C677T mutation in the MTHFR gene was compared in cases to that observed in random unselected cord blood controls. The odds ratio for stroke was not significantly increased in carriers of the prothrombin mutation (OR 1.2; 95% CI 0.1-10.7), FVL (OR 2.5; 95% CI 0.5-13.5), or the C677T mutation (OR 1.7; 95% CI 0.6-4.5). Our findings suggest that thrombophilia may not play a significant role in the aetiology of stroke in children, although a large prospective study is required to investigate this area further.
Factor V Q506 (Resistance to Activated Protein C) and Prognosis after Acute Coronary Syndrome
Authors: Hillarp Andreas , Zöller Bengt , Erhardt Leif , Berntorp Erik , Dahlbäck Björn , Holm Johan 
Published: March 2018

SummaryFactor V:Q506 causing resistance to activated protein C (APC-resistance), is a risk factor for venous thrombosis. Some studies have indicated an association with arterial disease, especially in women. We investigated the prevalence of the FV:Q506 allele prospectively in 295 patients with acute coronary syndrome. Mortality and myocardial infarction rate were evaluated after 30 days and after 2 years. The FV:Q506 allele was found in 38 patients. In a Cox proportional hazards model, smokers carrying FV:Q506 had a higher risk of infarction or death within 30 days, compared to non-smokers with a normal genotype (relative risk 2.9 [95% CI 1.2-7.0]). The difference remained significant after 2 years (relative risk 2.8 [95% CI 1.2-6.5]). The effect of the FV:Q506 allele on clinical outcome in acute coronary syndrome has not previously been described. Our results demonstrate a gene-environment interaction between smoking and the FV:Q506 allele, with an increased risk of early complications after an acute ischemic event.
Long-term Management of Homozygous Protein C Deficiency: Replacement Therapy with Subcutaneous Purified Protein C Concentrate
Authors: Sanz-Rodriguez C. , Gil-Fernández J. J. , Zapater P. , Pinilla I. , Granados E. , de Soria V. Gómez-G. , Cano J. , Sala N. , Fernández-Rañada J. M. , Gómez Gómez N. 
Published: March 2018

SummaryWe present the case of a full-term newborn in whom purpura fulminans developed shortly after birth. A diagnosis of homozygous protein C deficiency was established based upon undetectable plasma protein C activity and antigenemia in the newborn infant, and was later confirmed by protein C gene analysis. Specific replacement therapy with intravenous protein C concentrate was started 9 days after birth. This rapidly led to the complete regression of cutaneous lesions and consumption coagulopathy. After stabilization, oral anticoagulation was initiated in association with prophylactic treatment with intravenous protein C concentrate. However, oral anticoagulation was finally abandoned as the patient presented several thrombotic and hemorrhagic episodes clearly related to difficulties with anticoagulation. Due to the hazards related to prolonged venous access, we are currently using subcutaneous infusion of protein C concentrate for the longterm management of this condition, with satisfactory results.
Case-control Study of the Frequency of Thrombophilic Disorders in Couples with Late Foetal Loss and no Thrombotic Antecedent
Authors: Quéré Isabelle , Monpeyrou Françoise , Mercier Eric , Ripart-Neveu Sylvie , Tailland Marie-Laure , Hoffet Méderic , Berlan Jacques , Daurès Jean-Pierre , Marès Pierre , Gris Jean-Christophe 
Published: March 2018

Summary
Background: Women with familial thrombophilia have an increased risk of still birth. We postulated that the presence of asymptomatic risk factors for venous thrombosis might be a risk factor for late foetal loss. Methods: We performed a case-control study on the prevalence of heritable thrombophilic defects, of antiphospholipid-related markers and of the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in patients with at least one episode of late unexplained foetal loss and in control women with successful pregnancies. Partners of cases and controls were also studied. Written conclusions of the pathological examination of the placentas, when available, were also reviewed. Results: We found at least one positive biological risk factor for venous thrombosis in 21.1% of the patients and in 3.9% of the controls (p <10–4). In women, the crude odds ratio for still birth associated with any positive biological risk factor for venous thrombosis was 5.5, 95% confidence interval (95%CI) [3.4-9.0]. No difference was found between partners of cases and controls (5.2% and 4.7%). Using conditional logistic regression analysis, 4 adjusted risk factors for still birth remained: protein S deficiency, positive anti β2 glycoprotein I IgG antibodies, positive anticardiolipin IgG antibodies and the factor V Leiden mutation. The C677T mutation in the MTHFR gene was not an individual risk factor but an homozygous genotype was strongly associated with the former 4 risk factors (16.8% of patients vs. 0.9% of controls). In women with such associations, still births always occurred in absence of folic acid supplementation during pregnancy. Available conclusions of pathological analysis of placentas were found to have a very high proportion of “maternal vascular disease of the placenta” in patients with at least one positive risk marker for thromboembolism, specially in case of association with the C677T MTHFR homozygous genotype, compared to patients with negative markers (p <10–4). Conclusions: Late foetal loss, through placenta thrombosis, may sometimes be the consequence of a maternal multifactorial prothrombotic state associating traditional heritable or acquired thrombosis risk factors to conditions predisposing to an acute mild hyperhomocysteinaemia (coexistence of a genetic predisposition with late pregnancy-related increased folate needs).
Activated Protein C Resistance and the FV:R506Q Mutation in a Random Population Sample
Authors: Rumley Ann , Woodward Mark , Reid Evan , Rumley Joseph , Lowe Gordon 
Published: March 2018

SummaryActivated protein C (APC) resistance, defined as a low APC ratio, is associated with the factor V mutation R506Q (factor V Leiden). APC ratio may also be influenced by other clinical and coagulation variables, which we studied in 460 men and 495 women aged 25-74 years, from a random population sample (Glasgow MONICA Survey). APC ratio correlated positively with APTT; and inversely with factor VIIIc, factor IXc, antithrombin activity, prothrombin F1+2 fragment, and thrombinantithrombin complexes; but not with other coagulation variables. APC ratio decreased with age, but APTT did not. APC ratio and APTT were significantly lower in women versus men, and were significantly lower in users of oral contraceptives or hormone replacement therapy. The FV:R506Q mutation (prevalence 2.5%) was associated with lower APC ratio and protein C and S activities and with higher factor VIIIc levels; but not with increases in F1+2 fragment or thrombin-antithrombin complexes. APC ratio correlated inversely with total cholesterol and diastolic blood pressure; and in women with triglycerides, systolic blood pressure, and body mass index. Obesity was associated with a significantly lower APC ratio. In contrast, smoking markers correlated positively with APC ratio in men. These associations of APC ratio may be relevant to the increased risks of venous thrombosis with age, female sex, oestrogen use, obesity and high factor VIIIc levels. The association of APC resistance with elevated plasma levels of coagulation markers suggests that this phenotype represents an in vivo hypercoagulable state.Current address: Dr. E. Reid, Department of Medical Genetics, Addenbrooke’s Hospital, Cambridge, UK
The High Prevalence of Thermolabile 5-10 Methylenetetrahydrofolate Reductase (MTHFR) in Italians Is not Associated to an Increased Risk for Coronary Artery Disease (CAD)
Authors: Sardi Iacopo , Pepe Guglielmina , Marcucci Rossella , Brunelli Tamara , Prisco Domenico , Fatini Cinzia , Capanni Monia , Simonetti Ignazio , Gensini Gian Franco , Abbate Rosanna 
Published: March 2018

SummaryMild hyperhomocysteinemia was found to be related to venous thrombosis, cerebrovascular and coronary artery disease (CAD). Some recent studies suggested that a mutation in the gene encoding for 5-10 methylenetetrahydrofolate reductase (MTHFR), due to a transition C→ at nucleotide 677, is a genetic risk factor for vascular disease. However, several further studies could not confirm this association.We investigated 84 patients with CAD who underwent percutaneous transluminal coronary angioplasty (PTCA) and 106 healthy subjects.The prevalence of the mutated homozygous genotype was much higher than in other Italian populations, Europeans or other major human groups, but no excess of the Val/Val homozygotes was found in patients (28.5%) with respect to healthy subjects (30.2%). Mutated homozygous MTHFR genotype (+/+) was not found to be related to the clinical manifestations of CAD, to the prevalence of the common risk factors and to the rate of restenosis.In conclusion, thermolabile MTHFR does not appear to be associated “per se” with the risk for CAD or for restenosis after PTCA. The high frequency of the +/+ genotype in our Italian population (from Tuscany) confirms a wide macroheterogeneity and suggests a microheterogeneity in the genotype frequencies of the different ethnic populations.Preliminary data of this paper were selected for an Oral Communication at the XVIth ISTH Congress.
A New Direct, Fast and Quantitative Enzyme-linked Ligandsorbent Assay for Measurement of Free Protein S Antigen
Authors: Giri Tusar Kanti , Hillarp Andreas , Härdig Ylva , Zöller Bengt , Dahlbäck Björn 
Published: March 2018

SummaryA new method to determine the concentration of free protein S in plasma is described. It is an enzyme-linked ligandsorbent assay (ELSA) which utilises the protein S binding capacity of the natural ligand C4b-binding protein (C4BP) to capture the free protein S from plasma samples. The use of C4BP as ligand in the assay is possible due to the high affinity (Kd = 0.1 nM) of the interaction between protein S and C4BP and to a slow rate of complex dissociation. A monoclonal antibody (HPS 54) was conjugated with horseradish peroxidase and used as target antibody. This antibody recognises a Ca2+ dependent epitope in the first EGF-like domain of protein S and does not interfere with C4BP binding sites of protein S. Addition of calcium in the assay helped prevent dissociation of the C4BP-protein S-HPS 54 complex. Three different experiments demonstrated the assay to be specific for free protein S. First, near-identical dose response curves were obtained with protein S in plasma and with purified protein S. Second, addition of purified C4BP to normal plasma resulted in loss of free protein S. Third, protein S depleted plasma gave zero values and around 80% of purified protein S added to protein S depleted plasma, and approximately 70% of protein S added to protein S deficient plasma samples, was recovered with the assay. The assay is fast (involves only a single incubation step of 30 min), sensitive and the range of measurement is 3% to 200% of free protein S when plasma dilution 1 : 20 represents 100%. Intra- and inter-assay coefficients of variation at two levels were 2.3-4.3% and 5.1-7.4%, respectively. In a large protein S deficient family, the assay showed 100% sensitivity and specifity for the causative mutation. Moreover, free protein S levels in anticoagulated protein S deficient patients were completely separated from those obtained in non-anticoagulated controls. The new assay for free protein S is suitable for automation and it provides a useful means for routine clinical purposes to detect protein S deficiencies.
Association of the Platelet Glycoprotein IIIa PIA1/A2 Gene Polymorphism to Coronary Artery Disease but not to Nonfatal Myocardial Infarction in Low Risk Patients
Authors: Humme Jörg , Stricker Jürgen , Nguyen Quoc , Katz Norbert , Philipp Monika , Tillmanns Harald , Hehrlein Friedrich Wilhelm , Rau Matthias , Haberbosch Werner , Gardemann Andreas 
Published: March 2018

SummaryBackground. The platelet membrane glycoprotein IIb/IIIa functions as a receptor for fibrinogen and von Willebrand factor during platelet aggregation. In a small case-control study, evidence has been presented that the PlA2 allele of the platelet glycoprotein GPIIIa PlA1/A2 gene polymorphism might be an independent risk factor for acute myocardial infarction (MI). Methods and Results. We explored the association of the PlA1A2 to the severity of coronary artery disease (CAD), as assessed angiographically in 2252 male individuals, and to myocardial infarction (MI). The severity of coronary heart disease (CHD) was also estimated by calculating a CHD score according to Gensini. The PlA genotype was determined by allele specific restriction digestion. Relation of the PlA2 allele to CAD: In the total population, the frequency of the PlA2 allele was not associated to the presence or to the extent of CAD. Also the CHD scores of PlA1/PlA2 genotypes were essentially the same. However, after exclusion of individuals with high BMI (≥26.9 kg/m2) and/or low apoAI (<1.43 g/l) PlA2PlA2 carriers had clearly higher CHD scores than PlA1PlA1 genotypes; PlA1PlA2 heterozygotes had intermediate values (p <0.05). After division of the study population into one group of individuals without any angiographic signs of CAD (CHD score = 0) and into another group of patients with severe CAD (CHD score (≥120), a strong association of the PlA2 allele with severe CAD was also found in the same low risk groups; e.g. exclusion of persons with high BMI and low apoAI resulted in an Odds ratio of 5.37 (1.46-19.7) (p <0.02). Relation of the PlA2 allele to MI: No association was found between PlA1/PlA2 genotypes and risk of MI neither in the total population nor in low risk subgroups.Conclusions. Whereas no difference in the distribution of allele and genotype frequencies between controls and survivors of MI could be detected, the PlA2 allele is associated with CHD in low risk patients.
Coronary Thrombosis and the Platelet Glycoprotein IIIA Gene PLA2 Polymorphism
Authors: Durante-Mangoni Emanuele , Ahmed Nabeel , Ruggiero Giuseppe , Tuddenham Edward , Davies Graham 
Published: March 2018

SummaryMyocardial infarction results from a platelet-rich occlusive coronary thrombus. Platelet membrane glycoprotein IIb/IIIa plays an important role in platelet adhesion and aggregation. Two polymorphisms of the gene encoding the IIIa subunit, PLA1 and PLA2, have been identified. We investigated the frequency of these polymorphisms in 114 consecutive patients with a history of angina-like chest pain admitted for coronary arteriography. Forty-three of these patients had previously suffered a myocardial infarction. The PLA2 polymorphism was found in 21% of the patients with previous myocardial infarction and in 27% of the patients with angina-like chest pain but no previous myocardial infarction (p = 0.634). There was also no significant association with the extent of coronary disease. There is no evidence, therefore, from this study of an association between the PLA polymorphisms and the occurrence of myocardial infarction.
Plasma Lp(a) Levels Are Increased in Patients with Chronic Thromboembolic Pulmonary Hypertension
Authors: Ignatescu M. , Zorn G. , Kneussl M. , Maurer G. , Lang I. M. , Huber K. , Kostner K. 
Published: March 2018

SummaryChronic thromboembolic pulmonary hypertension (CTEPH) is a disease resulting from the thromboembolic obstruction of the segmental and/or large size pulmonary arteries, subsequently leading to pulmonary arterial hypertension. Incomplete resolution of acute pulmonary emboli and thrombus organization are believed to be important for the development of the disease. Primary pulmonary hypertension (PPH) is a further disease that at present is poorly understood but shows a clinical picture similar to CTEPH. Since lipoprotein(a) [Lp(a)], a genetically determined risk factor for atherosclerosis and thrombosis, has been found increased in plasma of patients with deep vein thrombosis and pulmonary embolism, we measured plasma Lp(a) levels in 40 patients with CTEPH and 50 patients with PPH and compared them to 50 matched controls. The median for Lp(a) plasma levels was significantly higher in CTEPH patients (26.6 mg/dl) than in PPH patients (9.6 mg/dl) and controls (7.2 mg/dl). Increased plasma Lp(a) could, therefore, play a significant role in the mechanisms of ongoing thrombosis and thrombus organization in CTEPH, while its possible role in PPH can be limited to a small number of patients.
GB Virus C/Hepatitis G Virus Isolates in Japanese Haemophiliacs and their Origins
Authors: Fukuda Yoshihide , Hayakawa Tetsuo , Takamatsu Junki , Saito Hidehiko , Okamoto Hiroaki , Toyoda Hidenori 
Published: March 2018

SummaryJapanese haemophiliacs have been at high risk for infection with parenterally-transmissible viruses through the use of blood products, especially imported ones. Recently, novel transfusion-transmissible virus, GB virus C (GBV-C)/hepatitis G virus (HGV) were isolated. We investigated the origin and route of transmission of GBV-C/HGV isolates in haemophiliacs in Japan. GBV-C/HGV RNA was measured by nested reverse transcription polymerase chain reaction in 91 Japanese haemophiliacs. Phylogenetic analysis and genotypic grouping of GBV-C/HGV isolates in Japanese haemophiliacs were performed based on sequences in the 5’ untranslated region, and the characteristics were compared with those of reported isolates. GBV-C/HGV infection was present in 19 of 91 haemophiliacs (20.9%). Sequence analysis showed that 15 of the 19 isolates (78.9%) showed sequence similarity to a group in which mainly West African isolates have been reported. The other 4 isolates (21.1%) showed sequence similarity to Asian isolates. None of the GBV-C/HGV isolates showed sequences similar to those generally found in isolates from USA and Europe. The majority of GBV-C/HGV isolates found in Japanese haemophiliacs who are considered to have been infected by imported blood products were similar to those detected in West Africa.
Factor Xa Cleavage of Tissue Factor Pathway Inhibitor Is Associated with Loss of Anticoagulant Activity
Authors: Salemink Irene , Franssen Jo , Willems George , Hemker Coenraad , Li Anguo , Wun Tze-Chein , Lindhout Theo 
Published: March 2018

SummaryTissue factor : factor VIIa induced activation of blood coagulation is inhibited by the complex between factor Xa and tissue factor pathway inhibitor (factor Xa : TFPI). We recently reported that phospholipid-bound factor Xa reduces the high binding affinity of factor Xa : TFPI for negatively charged phospholipids by a partial degradation of TFPI (17). The present study was undertaken to elucidate the factor Xa cleavage sites in TFPI and to delineate the consequences of this proteolysis with respect to the inhibitory activity of factor Xa : TFPI. We found that phospholipid-bound factor Xa cleaves in TFPI the peptide bonds between Lys86-Thr87 and Arg199-Ala200. Interestingly, Arg199 is the P1 residue of the third Kunitz-type protease inhibitor domain. The fast cleavage of the Arg199-Ala200 bond results in a 50-70% reduction of the anticoagulant activity of factor Xa : TFPI, as determined with a dilute tissue factor assay, but is not associated with a diminished inhibitory activity of factor Xa : TFPI towards TF : factor VIIa catalyzed activation of factor X. On the other hand, the slower cleavage of the Lys86-Thr87 peptide bond was associated with both a diminished anticoagulant and anti-TF : factor VIIa activity. Dissociation of factor Xa from the cleaved TFPI was not observed. These data provide evidence for a dual role of factor Xa since it is the essential cofactor in the TFPI-controlled regulation of TF-dependent coagulation as well as a catalyst of the inactivation of TFPI.
A Genetic Propensity to High Factor VII Is not Associated with the Risk of Myocardial Infarction in Men
Authors: Doggen C. J. M. , Cats Manger , Bertina R. M. , Vandenbroucke J. P. , Reitsma P. H. , Rosendaal F. R. 
Published: March 2018

SummarySeveral studies have examined the relation between factor VII and coronary artery disease by measuring factor VII levels in plasma and some found an association between high levels and disease. This suffers problems of interpretation concerning the causality of high factor VII levels, because factor VII levels may be affected by atherogenic risk factors and may become elevated as a consequence of atherosclerosis. We investigated the association between a genetic variant (353Arg→Gln), shown to be related to factor VII levels, and myocardial infarction in a large case-control study, including 560 cases and 644 controls. Individuals carrying the 353Arg-Arg genotype seemed to have a lower risk of myocardial infarction (odds ratio 0.80 [95% confidence interval 0.60-1.06]). In this study, we confirmed higher factor VII antigen and activity level in 529 men homozygous for the 353Arg allele compared with 115 men carriers of the 353Gln allele (around 20% higher).Our results indicate that a genetic propensity to high factor VII levels is not associated with the risk of myocardial infarction. Since we confirmed the association of the 353Arg-Arg genotype with higher factor VII levels, we conclude that high levels of factor VII are not a causal determinant of myocardial infarction.