bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of age on the performance of single detector helical computed tomography in suspected pulmonary embolism
Authors: Bounameaux Henri , Perrier Arnaud , Righini Marc 
Published: January 2004

SummaryThe prevalence of pulmonary embolism increases with age, but reduces the diagnostic yield of ventilation-perfusion lung scan age. Helical computed tomography (hCT) is widely used to diagnose pulmonary embolism, and should be less susceptible to the influence of age. We studied the influence of age on the performance of hCT to verify that hypothesis. We analyzed a database of 299 consecutive outpatients suspected of pulmonary embolism, in whom pulmonary embolism was diagnosed according to accepted criteria, and who were all submitted to a helical CT. We divided the patient population into tertiles, corresponding to the following age categories: less than 59 years (group 1), 60 to 75 years (group 2), and over 75 years (group 3). Sensitivity and specificity of hCT were calculated in each age category. Overall sensitivity was 70% (95% CI: 62 to 78) and specificity was 91% (95% CI: 86 to 95). Sensitivity was 81% (95% CI: 64 to 93) in group 1, 63% (95% CI: 46 to 78) in group 2, and 67 % (95% CI: 52 to 80) in group 3.The corresponding values for specificity were 92% (95% CI: 82 to 97) in group 1, 86% (95% CI: 75 to 94) in group 2 and 96% (95% CI: 87 to 100) in group 3. Positive predictive values ranged from 75% to 94% and negative predictive values from 77% to 94%. Our data suggest that age does not have a marked influence on the diagnostic performances of hCT in clinically suspected pulmonary embolism.
Epitope mapping of polyclonal clotting factor VIII-inhibitory antibodies using phage display
Authors: Mühle Christiane , Schulz-Drost Stefan , Khrenov Alexey , Saenko Evgueni , Klinge Jens , Schneider Holm 
Published: January 2004

SummaryClotting factor VIII (fVIII)-inhibitory antibodies represent a major problem in the treatment of haemophilia A. To understand the inactivation mechanisms and to pave the way towards modifications of recombinant clotting factors that reduce their immunogenicity, the exact localization of immunodominant epitopes is required. Here, a random peptide phage display library was employed to identify epitopes of polyclonal fVIII antibodies isolated from patient’s plasma by affinity chromatography. FVIIIbinding specificity and inhibitory activity of the isolated fVIII antibodies were confirmed by ELISA and Bethesda assays. Phage selection on the individual samples yielded several phages which were displaced from binding to the respective antibody preparation by fVIII. Their homology with amino acid motifs of human fVIII and immunoprecipitation results with radioactively labelled fVIII fragments suggested putative epitopes in the A1, A2 and C1 domains of fVIII for one and in the C2 domain for another patient. Synthetic peptides corresponding to the A2, C1 and C2 domain epitopes blocked antibody binding to fVIII and partially neutralized the inhibitory activity of the respective plasma in Bethesda assays. These results provide the proof of principle that random peptide libraries can be used for the mapping of epitopes in a polyclonal antibody preparation.
Is prolonged immobilization a risk factor for symptomatic venous thromboembolism in elderly bedridden patients?
Authors: Paltiel Ora , Bursztyn Michael , Gatt Moshe 
Published: January 2004

SummaryProlonged immobilization and advanced age are considered to be important risk factors for venous thromboembolism (VTE). Nevertheless, the need for VTE prophylaxis in long-term bedridden patients is not known. To assess whether very prolonged immobilization (i.e. over three months) carries an increased risk for clinically apparent VTE, we performed a historical-cohort study of nursing home residents during a ten-year period. Data concerning patient’s mobility and incidence of overt deep vein thrombosis or pulmonary embolism were registered. The mean resident age was 85 ± 8.4 years. Eighteen mobile and eight immobile patients were diagnosed with clinically significant thromboembolic events, during 1137 and 573 patient-years of follow up, respectively. The incidence of venous thromboembolic events was similar in both chronically immobilized and mobile patient groups, 13.9 and 15.8 per thousand patient years, respectively (p = 0.77). The rate ratio for having a VTE event in the immobilized patient group as compared with the mobile group was 0.88 (95% Confidence Interval (CI) 0.33 to 2.13). When taking into account baseline characteristics, risk factors and death rates by various causes, no differences were found between the two groups. In conclusion, chronically immobile bedridden patients are no more prone to clinically overt venous thromboembolic events than institutionalized mobile patients. Until further studies are performed concerning the impact of very prolonged immobilization on the risk of VTE, there is no evidence to support primary prevention after the first three months of immobilization. Evidence for efficacy or cost effectiveness beyond this early period is not available.
Endothelial microparticles: a potential contribution to the thrombotic complications of the antiphospholipid syndrome
Authors: Camoin-Jau Laurence , Sabatier Florence , Arnoux Dominique , Anfosso Francine , Bardin Nathalie , Veit Véronique , Combes Valéry , Gentile Stéphanie , Moal Valérie , Sanmarco Marielle , Sampol José , Dignat-George Françoise 
Published: January 2004

SummaryThe antiphospholipid syndrome (APS) refers to persistent antiphospholipid antibodies (aPL) associated with thrombotic and/or obstetrical complications. The endothelial cell is a target of aPL which can induce a procoagulant and proinflammatory endothelial phenotype, as reported both in vivo and in vitro. Microparticle production is a hallmark of cell activation. In the present study, the presence of endothelial microparticles (EMP) in the plasma of APS patients was investigated. To determine if there is a correlation with certain biological and clinical features, EMP levels were measured in thrombosis-free patients with systemic lupus erythematosus (SLE) patients, with and without aPL, in patients with non aPL-related thrombosis, as well as in healthy controls. Compared to healthy subjects, elevated plasma levels of EMP were found in patients with APS and in SLE patients with aPL, but not in SLE patients without aPL or in non aPL-related thrombosis. EMP levels were also associated with Lupus Anticoagulant (LA) detected by a positive Dilute Russell’s Viper Venom time (DRVVT). In parallel, we analyzed the capacity of these plasma to induce vesiculation of cultured endothelial cells. We demonstrated an increase of EMP generated in response to plasma from patients with autoimmune diseases. Interestingly, only APS plasma induced the release of EMP with procoagulant activity. These ex vivo and in vitro observations indicate that generation of EMP in APS and SLE patients results from an autoimmune process involving aPL. Production of procoagulant microparticles in APS patients may represent a new pathogenic mechanism for the thrombotic complications of this disease.
Anti-prothrombin antibodies as a potential risk factor of recurrent venous thromboembolism
Authors: Zanon Ezio , Saggiorato Graziella , Ramon Roberto , Girolami Antonio , Pagnan Antonio , Prandoni Paolo 
Published: January 2004

SummaryThe role of antiprothrombin (aPT) antibodies in the development of venous thromboembolism (VTE) is still uncertain. The aim of this study was to evaluate the potential role of aPT antibodies in the development of recurrent thromboembolism. Out of 236 consecutive symptomatic patients with an episode of acute VTE, antiphospholipid antibodies were found in 85 (36.0%), of whom 24 were carriers of aPT antibodies (10.2% of the entire cohort). A history of previous thromboembolism was identified in 56 patients (23.7%). The prevalence of previous thromboembolism was significantly higher in carriers than in non-carriers of antiphospholipid antibodies (OR=2.4; 95% CI, 1.3 to 4.4). Of the 24 patients with aPT antibodies, 12 had a history of previous thromboembolism. In a multivariate logistic regression analysis, in which the other categories of antiphospholipid antibodies were taken into account, as well as the patient’s age, sex, and the modality of clinical presentation, it was found that the presence of aPT antibodies was significantly associated with the prevalence of prior thromboembolism (OR=3.3; 95% CI, 1.3 to 8.6). Since aPT antibodies are more commonly identifiable in patients with multiple thrombotic episodes, they are a likely risk factor for recurrent thromboembolism.
Enhancement of endogenous fibrinolysis does not reduce local fibrin deposition, but modulates inflammation upon intestinal ischemia and reperfusion
Authors: Levi Marcel , van Vliet Arlène , Declerck Paul , Maas Adrie , van Gulik Thomas , Schoots Ivo 
Published: January 2004

SummaryThis study investigated the contribution of endogenous suppression of fibrinolysis and increased fibrin deposition to intestinal dysfunction and injury in a rat model of intestinal ischemia/ reperfusion (I/R), as fibrinolytic inhibition may lead to thrombotic obstructions that compromise microcirculation and promote intestinal injury. Circulatory fibrinolysis was enhanced by intravenous administration of recombinant tissue plasminogen activator (rt-PA) or by inhibition of PAI-1 by administration of MA-33H1F7. Coagulation and fibrinolysis parameters obtained from portal blood were correlated to fibrin deposition (determined by anti-rat fibrin antibody staining), intestinal function (glucose/water clearance) and intestinal injury (histological evaluation by Park/Chiu score).Enhanced circulatory fibrinolytic activity, as evidenced by increased portal plasma plasminogen activator activity, elevated fibrin degradation products and decreased levels of PAI-1, did not reduce mucosal fibrin deposition and microthrombosis in postischemic intestinal tissue. Furthermore, rt-PA or anti-PAI-1 antibody administration did not attenuate I/R-induced intestinal injury or dysfunction, as demonstrated by intestinal histopathology scores of 4.8±0.2 and 4.7±0.3 (control I/R group 4.7±0.2) and glucose clearances of 47±6 and 46±9 µL/min · g (control I/R group 30±8 µL/min · g) after 40 minutes of intestinal ischemia and 3 hours of reperfusion, respectively. However, both interventions resulted in decreased levels of interleukin-6, which may indicate fibrin-induced modulation of inflammation. Attempts to enhance the fibrinolytic activity (either by rt-PA or by anti-PAI-1 administration), indicated by increased portal plasma levels of released FDP, failed to decrease mucosal fibrin deposition and to attenuate intestinal I/R injury. Based on our observations and previous reports, the contribution of suppressed endogenous fibrinolysis to microcirculatory fibrin deposition and I/R-injury may be of limited importance.
Acquired hypercoagulable state in renal transplant recipients
Authors: Ducloux Didier , Kazory Amir 
Published: January 2004

SummaryStable renal transplant recipients manifest a chronic hypercoagulable state with an increased risk of thromboembolic complications, which appears to be multifactorial. While this group of patients could present the known risk factors for thromboembolism in the general population (e.g. diabetes, cancer, pregnancy), they may also suffer from other situations which are mostly related to transplantation and are consequently specific to them. Here, we review briefly the clinical aspects and controversies of the most important of these factors including immunosuppressive agents, antiphospholipid antibodies, hyperhomocysteinemia, pre-transplant dialysis modality, and posttransplant erythrocytosis. In addition, other more recent topics including hypercysteinemia, recurrent proteinuria, and acute CMV infection are discussed.
Maternal thrombophilias are not associated with early pregnancy loss
Authors: Paidas Michael , Funai Edmund , Kuczynski Edward , Lockwood Charles , Roqué Henry 
Published: January 2004

SummaryWe investigated the association between inherited and acquired maternal thrombophilias and adverse pregnancy events. A cohort of 491 patients with a history of adverse pregnancy outcomes was evaluated for activated protein C resistance, factor V Leiden and prothrombin G20210A mutations, hyperhomocysteinemia, deficiencies of antithrombin, protein C and S and both anticardiolipin antibodies and lupus anticoagulants. The study had an 80% power to detect a 15% difference in the prevalence of thrombophilia for 1st trimester loss. In our high-risk cohort the presence of 1 maternal thrombophilia or more than one thrombophilia were found to be protective of recurrent losses at < 10 weeks (1 thrombophilia: OR: 0.55, 95% CI: 0.33–0.92; >1 thrombophilia: OR: 0.48, 95%CI:0.29–0.78). In contrast, the presence of maternal thrombophilia(s) was modestly associated with an increased risk of losses ≥ 10 weeks (1 thrombophilia: OR:1.76, 95%CI: 1.05–2.94, >1 thrombophilia: OR:1.66, 95%CI:1.03–2.68). Women who experienced only euploid losses were not more likely to have an identified thrombophilia than women who experienced only aneuploid losses (OR 1.03; 0.38–2.75). The presence of maternal thrombophilia was associated with an increased risk of fetal loss after 14 weeks, fetal growth restriction, abruption and preeclampsia. There was a significant “dose-dependent” increase in the risk of abruption (OR:3.60, 95%CI: 1.43–9.09) and preeclampsia (OR:3.21, 95%CI:1.20–8.58). In conclusion, these data indicate maternal thrombophilias are not associated with pregnancy wastage prior to 10 weeks of gestation.
Systematic review of studies of self-management of oral anticoagulation
Authors: Berghold Andrea , Sawicki Peter , Siebenhofer Andrea 
Published: January 2004

SummaryThis work is aimed at assessing the evidence for the possible improvement of therapeutic control of anticoagulation, reduction of major bleedings, thromboembolism and improvement of treatment-related quality of life in patients with self-managed oral anticoagulation therapy versus oral anticoagulation patients on routine care. Randomised controlled trials (RCTs) were identified using the COCHRANE LIBRARY, MEDLINE and EMBASE from 1966 to 2003. RCTs were selected involving patients with oral anticoagulation, which were designed to compare a self-management group to a routine care group. Abstracts and keywords were screened and, in the case of potential inclusion, evaluated. We identified nine potentially relevant trials. Five were excluded for the following reasons: double publication, the patients involved performed only selftesting, or the results of the trial were only published as an abstract. Ultimately, four randomised controlled studies fulfilled the criteria for inclusion. Anticoagulation control: Statistical analysis was not possible because of the great variety of international normalised ratio measurements per patient between the different studies. Comparing the four studies, there was no difference in oral anticoagulation control between self-management care and management by a specialised anticoagulation clinic. In comparison with routine care by general practitioners, self-management care was found to be better. Major bleeding, arterial and venous thromboembolism: Data were available for all studies; however, the studies were either underpowered or obviously not valid and therefore not suitable for statistical analysis. Treatment-related quality of life: Data were available for two studies, which showed that self-management could clearly improve treatment-related quality of life. Patients’ self-management can improve the quality of oral anticoagulation as an indirect parameter of a reduced risk for thromboembolic and bleeding complications. Self-management oral anticoagulation treatment is safe and improves treatment-related quality of life. Patients’ self-management is safe and can improve the quality of anticoagulation control, however, no valid long term study has yet actually demonstrated reduction of bleeding and thromboembolic events.
Moderate-intensity exercise suppresses platelet activation and polymorphonuclear leukocyte interaction with surface-adherent platelets under shear flow in men
Authors: Liao Chang-Hui , Wang Jong-Shyan 
Published: January 2004

SummaryThe reciprocal modulation of platelet and polymorphonuclear leukocyte (PMN) activities is important in the pathogenesis of thrombosis and inflammation. This study investigated how moderate exercise affects shear-induced platelet activation and subsequent PMNs interaction with platelet-related thrombi under shear flow. Sixteen sedentary healthy men engaged in moderate exercise (about 60% V·O2max) on a bicycle ergometer. Platelet activation, PMNs interaction with surface-adherent platelets, and PMN-dependent inhibition of platelet activation under shear flow were measured both before and immediately after exercise. The results of this study can be summarized as follows: (1) moderate exercise was associated with lower extents of shear-induced platelet adhesion and aggregation, binding of von Willbrand factor (vWF) to platelets, and glycoprotein IIb/IIIa activation and P-selectin expression on platelet than at rest; (2) the velocity and percentage of rolling PMNs increased while the number of PMNs remaining bound to surface-adherent platelets decreased after moderate exercise; (3) although treating the PMNs with oxidized-low density lipoprotein (Ox-LDL) enhanced PMNs interaction with surface-adherent platelets, moderate exercise suppressed the enhancement of platelet-PMN interaction by Ox-LDL; (4) moderate exercise decreased platelet [Ca2+]i
elevation induced by ADP and platelet [Ca2+]i
levels mediated by PMN and Ox-LDL-treated PMN; and (5) plasma and PMN-derived nitric oxide metabolites and plasma vWF antigen and activity increased after moderate exercise, whereas plasma and platelet-derived soluble P-selectin levels remained unchanged in response to exercise. Therefore, we conclude that moderate-intensity exercise suppresses shear-induced platelet activation and subsequent PMNs adhesion to platelets deposited at sites of vascular injury under flow, thereby reducing the risks of vascular thrombosis and inflammation.
Two's Company, Three's a Crowd: Differences in Dominance Relationships in Isolated Versus Socially Embedded Pairs of Fish
Authors: Chase Ivan , Tovey Craig , Murch Peter 
Published: January 2004

Abstract
We performed experiments with cichlid fish to test whether several basic aspects of dominance were the same in isolated pairs as in pairs within a social group of three or four. We found that the social context, whether a pair was isolated or within a group, strongly affected the basic properties of dominance relationships. In particular, the stability of relationships over time, the replication of relationships in successive meetings, and the extent of the loser effect were all significantly less in socially embedded pairs than in isolated pairs. We found no significant winner effect in either isolated or socially embedded pairs. These findings call into question many current approaches to dominance that do not consider social context as an important factor in dominance behavior. These findings also cast serious doubt on the validity of empirical and theoretical approaches based on dyadic interactions. Among these approaches are game theoretic models for the evolution of aggressive behavior, experimental designs evaluating how asymmetries in attributes influence the outcome of dominance
Regulation of Worker Activity in the Primitively Eusocial Wasp Ropalidia Cyathiformis
Authors: Gadagkar Raghavendra , Kardile Sujata 
Published: January 2004

Abstract
Ropalidia marginata, traditionally regarded as a primitively eusocial wasp species appears to have acquired some features reminiscent of highly eusocial species. Queens are behaviorally passive individuals, yet maintain complete reproductive monopoly and probably use pheromones to achieve this. Regulation of worker foraging is achieved by the workers themselves in a decentralized, self-organized manner. If there are other species in the genus Ropalidia that do not show such relatively 'advanced' features, this genus can provide an attractive model system to investigate the evolutionary transition from the primitively eusocial to the highly eusocial state. Here, we therefore investigate the congeneric Ropalidia cyathiformis and demonstrate that in contrast to R. marginata, it appears to be a typical primitively eusocial species. As expected therefore, and in striking contrast with R. marginata, R. cyathiformis queens are the most, or among the most, dominant, active and interactive individuals and their behavior is consistent with the possibility that they suppress worker reproduction and regulate worker foraging in a relatively centralized manner. Upon removal of the queen, a potential queen with levels of aggression even higher than that of the queen, becomes apparent immediately. Such a potential queen appears to take over inhibition of worker reproduction and regulation of worker foraging by mechanisms similar to that used by the queen so that, there is no disruption in foraging and brood care. We suggest that comparative studies of
Female Dominance and Social Structure in Alaotran Gentle Lemurs
Authors: Waeber  , Hemelrijk  
Published: January 2004

AbstractLemur social systems have the striking social feature, that adult females consistently evoke submissive behaviour of adult males. In the Alaotran gentle lemur, Hapalemur griseus alaotrensis, however, female dominance has not been studied yet. Here we confirm female dominance over males on the basis of a 5-month field study of the social behaviour of four groups, in the Lake Alaotra marshland of eastern Madagascar. Further, we found that dominant individuals initiated aggressive interactions significantly more often than lowerranking ones, they initiated group movements more often and higher-ranking individuals were groomed more often. The spatial configuration was remarkable, since individuals were closer in space to those more distant in rank.
Female Co-Dominance in a Virtual World: Ecological, Cognitive, Social and Sexual Causes
Authors: Wantia Jan , Dätwyler Marc , Hemelrijk Charlotte 
Published: January 2004

AbstractIn male-dominant primate species, females are sometimes dominant to some or all males of a group. In this paper, we show a number of variables that increase female dominance over males in a model called DomWorld. This model is relevant, because its results have shown to resemble those of typical egalitarian and despotic macaques. Variables that increase female co-dominance are intensity of aggression, group cohesion, a clumped distribution of food, a similar diet for the sexes and sexual attraction (by one sex to the other, but not mutually). We explain that in these cases female co-dominance increases due to more interactions between the sexes (under certain conditions), and as a consequence of all factors that increase the development of the hierarchy (i.e. a higher number of interactions, more interactions per sex, a higher intensity of aggression and a clearer spatial structure). We suggest model-guided studies of female dominance in real animals.