bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic contribution to variation in atherothrombotic phenotypes in the Asian Indian population
Authors: Khadrinarasimhaih Natesha , Kanjilal Saikat , Mukerjee Manjari , Kakkar Vijay , Rao Veena 
Published: July 2009

SummaryCoronary artery disease (CAD) is a multifactorial disease, and family history is the best available tool to assess gene-environment interaction. This study addressed the heritability of quantitative traits, namely lipid, coagulation/fibrinolysis and pro-inflammatory markers in the ongoing family-based Indian Atherosclerosis Research Study and assessed the effect of the type/lineage of CAD family history on inheritance patterns in the highrisk Indian population. A total of 518 families comprising 2,305 individuals were recruited in phase I of the IARS; of these, 1,195 individuals from 220 families were included in the heritability analysis. With the exception of leptin, all phenotypes exhibited significant age- and sex-adjusted heritability (p<0.0001). Amongst all the phenotypes analysed after adjustment for confounding factors, the significantly higher heritability estimates of triglycerides (0.53, p<0.0001), lipoprotein (a) (0.83, p<0.0001) and interleukin-6 (0.46, p<0.0001) with low spouse pair correlations identifies them as possible CAD risk factors. Families with parental history of CAD had onset of CAD symptoms at much younger ages with significantly higher heritability of proinflammatory markers, whereas in families with sibling history of CAD, more risk factors were present at significantly higher levels. Triglycerides, lipoprotein (a) and interleukin-6 appear to be promising atherothrombotic candidate phenotypes in this population. Genes controlling these phenotypes are possible candidate genes linked with CAD. An informed understanding and incorporation of ‘family history’ as a screening tool may help in the prevention and pre-emption of CAD.
Cross validation of the Multiple Electrode Aggregometry
Authors: Siller-Matula Jolanta , Gouya Ghazaleh , Wolzt Michael , Jilma Bernd 
Published: July 2009

SummarySeveral test systems exist for assessment of platelet function in patients under clopidogrel or aspirin therapy. The objective was to cross-validate the Multiple Electrode Aggregometry (MEA) with three other methods used for determining platelet reactivity under treatment with clopidogrel and aspirin. Platelet function was assessed by the MEA, Vasodilator Stimulated Phosphoprotein (VASP) phosphorylation assay, Platelet Function Analyzer-100 (PFA-100) and the Cone and Platelet Analyzer. Measurements were performed in blood from nine healthy volunteers at baseline, 2, 4, 6 and 72 hours after clopidogrel and aspirin loading. The apparent effect size for clopidogrel and aspirin was greatest for the MEA: treatment induced a 19-fold difference in the arachidonic acid-induced platelet aggregation and an 11-fold difference in the adenosine diphosphate-induced platelet aggregation before/after treatment. For comparison, aspirin and clopidogrel induced only 2.0– to 2.6 -fold changes in other tests (VASP assay, Cone and Platelet Analyzer and PFA-100). Maximal effects were seen 2 hours after aspirin loading and shorter than 72 hours after clopidogrel loading. In conclusion, aspirin and clopidogrel produce stronger signals in the MEA compared to several other methods.
Prognostic impact of haemostatic derangements in chronic heart failure
Authors: Vene Nina , Salobir Barbara , Šebeštjen Miran , Šabovic Mišo , Keber Irena , Jug Borut 
Published: July 2009

SummaryHeart failure is characterised by activation of haemostasis. We sought to explore the prognostic impact of deranged haemostasis in chronic heart failure. In stable, optimally managed outpatients with chronic heart failure, baseline levels of prothrombin fragment F1+2, D-dimer, and tPA and PAI-1 antigens were determined. Clinical follow-up was obtained and the rate of events (heart failure related deaths or hospitalisations) was recorded. We included 195 patients [32.3% female, NYHA class II (66.2%) or III (33.8%), mean age 71 years]. During a median follow up of 693 (interquartile range [IQR] 574–788) days, 63 (30.9%) patients experienced an event; those with an event had higher levels of tPA antigen (median 11.8 [IQR 8.7–14.0] vs. 9.4 [7.9–12.1] µg/l; p=0.033) and D-dimer (938 [485–1269] vs. 620 [37–1076] µg/l; p=0.018). However, on Cox multivariate analysis, only tPA levels above optimal cut-off value of 10.2 µg/l (but not D-dimer) emerged as an independent predictor of prognosis (HRadjusted 2.695, 95% confidence interval 1.233–5.363; p=0.017). Our findings suggest that elevated tPA antigen levels are an independent prognostic predictor in patients with chronic stable heart failure.
Effects of the cAMP-elevating agents cilostamide, cilostazol and forskolin on the phosphorylation of Akt and GSK-3β in platelets
Authors: Hayashi Hideki , Sudo Toshiki 
Published: July 2009

SummaryElevating intracellular cAMP has been shown to inhibit platelet function. cAMP interferes with platelet-activating signals which lead to aggregation inhibition, but the precise mechanism is unclear.The present study examined if cAMP-elevating agents inhibited phosphatidylinositol 3-kinase (PI3-kinase) signaling in rat platelets by immunoblotting. Akt is one of the key molecules downstream of PI3K, and is phosphorylated by collagen stimulation. The phosphodiesterase-3 (PDE3) inhibitors cilostamide and cilostazol, and the adenylate cyclase activator forskolin, inhibited collagen-induced Akt phosphorylation at Ser473.The inhibitory effects of these cAMP-elevating agents on Akt phosphorylation were unchanged in the presence of the PKA (cyclic AMP-dependent protein kinase) inhibitor H-89. These effects were consistent with inhibition of platelet aggregation. It is known that inhibition of Akt phosphorylation leads to inhibition of phosphorylation of glycogen synthase kinase 3-beta (GSK-3β), which is an effector of Akt, but cAMP-elevating agents stimulated GSK-3βphosphorylation at Ser9.The PKA inhibitor H-89 attenuated GSK-3βphosphorylation.The cAMP-elevating agents cilostamide, cilostazol and forskolin did not directly affect the enzyme activity of PI3-kinase.These results suggested that cAMP-elevating agents have two effects on PI3K signalling: inhibition of Akt phosphorylation independent of PKA; and stimulation of GSK-3β phosphorylation dependent on PKA. Our results provide new insights into the inhibitory effect of cAMPelevating agents on platelet function.
Effect of natural killer T cell activation on initiation of atherosclerosis
Authors: van Puijvelde Gijs , van Wanrooij Eva , Hauer Arnaud , de Vos Paula , van Berkel Theo , Kuiper Johan 
Published: July 2009

SummaryIt has been shown that natural killer T (NKT) cell activation accelerates atherosclerosis in apoE−/− mice. ApoE is,however,an important mediator in the presentation of lipids which may complicate conclusions on the role of NKT cells in atherosclerosis. Treatment of LDLr−/− mice with α-GalCer during Western-type diet feeding is therefore of interest. Atherosclerosis was induced by Western-type diet feeding and collar placement around the carotid arteries in both LDLr−/− and apoE−/− mice. Subsequently, the mice were treated twice a week with α-GalCer. This resulted in an 84% reduction in plaque size in LDLr−/− mice (P<0.05), while no effect was observed in apoE−/− mice. In-vitro incubation of splenocytes with α-GalCer showed that LDLr−/− splenocytes proliferated stronger than apoE−/− splenocytes. This is reflected in a larger increase in production of cytokines and especially IL-10 after in-vitro stimulation with α-GalCer in LDLr−/− mice compared with apoE−/− splenocytes. Additionally, feeding a Western-type diet for 1.5 weeks induced a strong increase in the number of NKT cells in LDLr−/− mice and this increase was slower and less prominent in apoE−/− mice. Administration of α-GalCer to LDLr−/− mice in combination with Western-type diet feeding reduced plaque formation, but this effect was not seen in apoE−/− mice. This may be explained by the decreased presentation of lipids on CD1d molecules due to the lack of apoE. In this study we proved for the first time that NKT cells may also act in an atheroprotective manner.
The vulnerable patient: Refocusing on the plaque?
Authors: Heeneman Sylvia , Daemen Mat , Eijgelaar Wouter 
Published: July 2009

SummaryThe term ‘vulnerable plaque’ is used to refer to the lesions that are prone to rupture and may cause life-threatening events like acute coronary syndrome or stroke.The study of the vulnerable plaque phenotype and its detection has attracted increasing interest over the past decades. During this time, there have been some remarkable transitions in the paradigm on methods to identify patients at risk or patients to treat.Whereas formerly, the key factors used to determine an individual’s risk were primarily population-based traditional risk factors such as age, sex, body mass index, hypertension etc., new approaches are based on conditional risk factors that represent an individual’s current risk of suffering a cardiovascular event.These population based risk factors fall short in predicting near-future events in a high-risk individual. In the early 2000s, the focus of research into surrogate markers for cardiovascular event prediction shifted from the vulnerable plaque to the identification of the vulnerable patient.This new paradigm stimulated a number of new initiatives that aimed to identify vulnerable patients by testing systemic biomarkers that could identify patients at high risk for cardiovascular events. A second research paradigm is refocusing on the plaque by searching for plaque-derived biomarkers and non-invasive imaging modalities to assess characteristics of a plaque that determine its vulnerability.Although both concepts are attractive, they still need proper validation in large multicenter cohorts, while cost-effectiveness arguments also need to be assessed.
Structural analysis of eight novel and 112 previously reported missense mutations in the interactive FXI mutation database reveals new insight on FXI deficiency
Authors: Saunders Rebecca , Shiltagh Nuha , Gomez Keith , Mellars Gillian , Cooper Carolyn , Perry David , Tuddenham Edward , Perkins Stephen 
Published: July 2009

SummaryFactor XI (FXI) functions in blood coagulation. FXI is composed of four apple (Ap) domains and a serine protease (SP) domain. Deficiency of FXI leads to an injury-related bleeding disorder, which is remarkable for the lack of correlation between bleeding symptoms and FXI coagulant activity (FXI:C).The number of mutations previously reported in our interactive web database (http://www.FactorXI.org) is now significantly increased to 183 through our new patient studies and from literature surveys. Eight novel missense mutations give a total of 120 throughout the FXI gene (F11).The most abundant defects in FXI are revealed to be those from low-protein plasma levels (Type I: CRM-) that originate from protein misfolding, rather than from functional defects (Type II: CRM+). A total of 70 Ap missense mutations were analysed using a consensus Ap domain structure generated from the FXI dimer crystal structure. This showed that all parts of the Ap domain were affected.The 47 SP missense mutations were also distributed throughout the SP domain structure.The periphery of the Ap β-sheet structure is sensitive to structural perturbation caused by residue changes throughout the Ap domain, yet this β-sheet is crucial for FXI dimer formation. Residues located at the Ap4:Ap4 interface in the dimer are much less directly involved. We conclude that the abundance of Type I defects in FXI results from the sensitivity of the Ap domain folding to residue changes within this, and discuss how structural knowledge of the mutations improves our understanding of FXI deficiencies.
Interactions of gallic acid, resveratrol, quercetin and aspirin at the platelet cyclooxygenase-1 level Functional and modelling studies
Authors: Crescente Marilena , Jessen Gisela , Momi Stefania , Höltje Hans-Dieter , Gresele Paolo , de Gaetano Giovanni , Cerletti Chiara 
Published: July 2009

SummaryWhile resveratrol and quercetin possess antiplatelet activity, little is known on the effect of gallic acid on platelets.We studied the interactions of these three different polyphenols among themselves and with aspirin, at the level of platelet cyclooxygenase-1 (COX-1). Both functional (in vitro and in vivo) and molecular modelling approaches were used. All three polyphenols showed comparable antioxidant activity (arachidonic acid [AA]-induced intraplatelet ROS production); however, resveratrol and quercetin, but not gallic acid, inhibited AA-induced platelet aggregation. Gallic acid, similarly to salicylic acid, the major aspirin metabolite, prevented inhibition of AA-induced platelet function by aspirin but, at variance with salicylic acid, also prevented inhibition by the other two polyphenols. Molecular modelling studies, performed by in silico docking the polyphenols into the crystal structure of COX-1, suggested that all compounds form stable complexes into the COX-1 channel, with slightly different but functionally relevant interaction geometries. Experiments in mice showed that gallic acid administered before aspirin, resveratrol or quercetin fully prevented their inhibitory effect on serum TxB2. Finally, a mixture of resveratrol, quercetin and gallic acid, at relative concentrations similar to those contained in most red wines, did not inhibit platelet aggregation, but potentiated sub-inhibitory concentrations of aspirin. Gallic acid interactions with other polyphenols or aspirin at the level of platelet COX-1 might partly explain the complex,and possibly contrasting, effects of wine and other components of the Mediterranean diet on platelets and on the pharmacologic effect of lowdose aspirin.
Comparison of recombinant and plasma-derived antithrombin biodistribution in a rabbit model
Authors: Berry Leslie , Thong Bruce , Chan Anthony 
Published: July 2009

SummaryAntithrombin (AT) is a native plasma protein that acts as the main inhibitor of enzymes generated by the coagulation cascade. In extreme thrombotic conditions, consumption of plasma AT can make treatment with AT-associated heparin therapies less effective. Supplementation with recombinant human AT (rhAT) has shown promise but altered pharmacokinetics were observed when comparing stable heparin complexes of the plasma-derived AT (pAT) and rhAT proteins. To understand the differential clearance mechanisms,biodistribution of rhAT and pAT was determined. 125I-labelled ATryn (rhAT) or Kybernin P (pAT) was intravenously injected into rabbits. At various time points, animals were sacrificed and organs analysed for bound radioactivity. 131I-albumin, injected shortly before termination, was used as a marker for trapped blood. Levels of circulating protein + metabolites were significantly less for rhAT than pAT (p < 0.001) and removal of acid soluble fragments confirmed that differences were due to more rapid rhAT clearance. More rhAT (28% dose) than pAT (3% dose) was liver-associated by the earliest time points, corresponding to elevated rhAT degradation products in urine/feces. However, at intermediate times (4 hours), rhAT showed significantly increased arterial and venous uptake over pAT (p ≤0.001).These vessel wall interactions accounted for the primary differences between clearance of rhAT and pAT during these time periods. Overall, circulating rhAT is more rapidly lost to the liver and vessels than pAT. Increased vessel wall binding may facilitate rhAT treatment of vascular thrombosis.
Internal quality control of prothrombin time in primary care: comparing the use of patient split samples with lyophilised control materials
Authors: Petersen Per , Sølvik Una , Sandberg Sverre , Stavelin Anne 
Published: July 2009

SummaryMany primary care laboratories use point-of-care (POC) instruments to monitor patients on anticoagulant treatment. The internal analytical quality control of these instruments is often assessed by analysing lyophilised control materials and/or by sending patient samples to a local hospital laboratory for comparison (split sample).The aim of this study was to evaluate the utility of these two models of prothrombin time quality control. The models were evaluated by power functions created by computer simulations based on empirical data from 18 primary care laboratories using the POC instruments Thrombotrack, CoaguChek S, or Hemochron Jr. Signature. The control rules 12S, 13S, exponential weighted moving average, and the deviation limits of ± 10% and ± 20% were evaluated by their probability of error detection and false rejections. The total within-lab coefficient of variation was 3.8% and 6.9% for Thrombotrack, 8.9% and 10.5% for CoaguChek S, and 9.4% and 14.8% for Hemochron Jr. Signature for the control sample measurements and the split sample measurements, respectively. The probability of error detection was higher using a lyophilised control material than a patient split sample for all three instruments, whereas the probability of false rejection was similar. A higher probability of error detection occurred when lyophilised control material was used compared with the patient split samples; therefore, lyophilised control material should be used for internal analytical quality control of prothrombin time in primary health care.
Variability of INR in patients on stable long-term treatment with phenprocoumon and acenocoumarol and implications for analytical quality requirements
Authors: van Geest-Daalderop Johanna H. H. , Péquériaux Nathalie C. V. , van den Besselaar Anton M. H. P. 
Published: July 2009

SummaryWithin each patient treated with vitamin K antagonist (VKA), variation of the international normalised ratio (INR) occurs over the treatment period. The purpose of the present study was to assess INR variation in selected patients on long-term treatment in whom the dose of VKA was not changed.This type of variation is considered as “biological variation” which is caused by many factors but not VKA dose changes or other medication. Four groups of long-term patients were examined: each group with a different VKA (acenocoumarol or phenprocoumon) or a different target intensity (INR 2.0–3.5 or 2.5–4.0). All patients were monitored with the same PT system (Hepato Quick, STA-R Evolution coagulation instrument) by one laboratory.The variation of the INR within each patient was expressed as coefficient of variation (CV, in %).The CV was corrected for the average imprecision of the INR measurement (CV, 2.4%). The mean corrected CV values for the four groups were: 10.9% (acenocoumarol, target INR 2.0–3.5); 10.5% (acenocoumarol, target INR 2.5–4.0); 10.4% (phenprocoumon, target INR 2.0–3.5); 9.1% (phenprocoumon, target INR 2.5–4.0). The analytical performance goal for the INR measurement (imprecision) can be derived from the within-subject biological variation. Desirable INR imprecision goals are <4.9% and <5.3% CV for monitoring of phenprocoumon and acenocoumarol, respectively. These goals were achieved using the aforesaid PT system.
Recombinant activated factor VII and tranexamic acid are haemostatically effective during major surgery in factor XI-deficient patients with inhibitor antibodies
Authors: Livnat Tami , Tamarin Ilia , Mor Yoram , Winckler Harry , Horowitz Zeev , Korianski Yoseph , Bar-Zakay Barak , Salomon Ophira , Seligsohn Uri 
Published: July 2009

SummaryOne-third of patients with severe factor XI (FXI) deficiency caused by homozygosity for null alleles develop inhibitor antibodies following exposure to plasma. Haemostasis during surgery is achievable in such patients by recombinant activated factor VII (rFVIIa) at doses used in haemophilia A patients with an inhibitor to FVIII. However, thrombosis has occurred in three of 12 such patients. In this study we discerned whether low-dose rFVIIa would secure haemostasis and cause no thrombosis in patients with severe FXI deficiency and an inhibitor during surgery. In vitro, a very low concentration of rFVIIa (0.24 µg/ml) induced thrombin generation in FXI-deficient plasma quite similarly to 1.9 µg/ml (a concentration that is achieved in patients with haemophilia A and inhibitor after infusion of 80 µg/kg). Based on this finding, a protocol was designed for four patients with severe FXI deficiency and an inhibitor or immunoglobulin A deficiency who underwent five major surgical procedures. This included administration of tranexamic acid from two hours before surgery until seven to 14 days after, and single infusion of low-dose rFVIIa. No excessive bleeding or thrombosis were observed. In conclusion, a single low dose of rFVIIa and tranexamic acid secure normal haemostasis in patients with severe FXI deficiency who can not receive blood products.
Identification of cancer stem cells in a Tax-transgenic (Tax-Tg) mouse model of adult T-cell leukemia/lymphoma
Authors: Yamazaki Jumpei , Mizukami Takuo , Takizawa Kazuya , Kuramitsu Madoka , Momose Haruka , Masumi Atsuko , Ami Yasushi , Hasegawa Hideki , Hall William W. , Tsujimoto Hajime , Hamaguchi Isao , Yamaguchi Kazunari 
Published: July 2009

AbstractAdult T-cell leukemia/lymphoma (ATL) is a malignant lymphoproliferative disorder caused by HTLV-I infection. In ATL, chemotherapeutic responses are generally poor, which has suggested the existence of chemotherapy-resistant cancer stem cells (CSCs). To identify CSC candidates in ATL, we have focused on a Tax transgenic mouse (Tax-Tg) model, which reproduces ATL-like disease both in Tax-Tg animals and also after transfer of Tax-Tg splenic lymphomatous cells (SLCs) to nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Using a limiting dilution transplantation, it was estimated that one CSC existed per 104 SLCs (0.01%). In agreement with this, we have successfully identified candidate CSCs in a side population (0.06%), which overlapped with a minor population of CD38−/CD71−/CD117+ cells (0.03%). Whereas lymphoma did not develop after transplantation of 102 SLCs, 102 CSCs could consistently regenerate the original lymphoma. In addition, lymphoma and CSCs could also be demonstrated in the bone marrow and CD117+ CSCs were observed in both osteoblastic and vascular niches. In the CSCs, Tax, Notch1, and Bmi1 expression was down-regulated, suggesting that the CSCs were derived from Pro-T cells or early hematopoietic progenitor cells. Taken together, our data demonstrate that CSCs certainly exist and have the potential to regenerate lymphoma in our mouse model.