| 1. |
- Aspholm-Hurtig, Marina, et al.
(author)
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Functional adaptation of BabA, the H. pylori ABO blood group antigen binding adhesin.
- 2004
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In: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 305:5683, s. 519-22
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Journal article (peer-reviewed)abstract
- Adherence by Helicobacter pylori increases the risk of gastric disease. Here, we report that more than 95% of strains that bind fucosylated blood group antigen bind A, B, and O antigens (generalists), whereas 60% of adherent South American Amerindian strains bind blood group O antigens best (specialists). This specialization coincides with the unique predominance of blood group O in these Amerindians. Strains differed about 1500-fold in binding affinities, and diversifying selection was evident in babA sequences. We propose that cycles of selection for increased and decreased bacterial adherence contribute to babA diversity and that these cycles have led to gradual replacement of generalist binding by specialist binding in blood group O-dominant human populations.
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| 2. |
- James, Stefan K., et al.
(author)
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A rapid troponin I assay is not optimal for determination of troponin status and prediction of subsequent cardiac events at suspicion of unstable coronary syndromes.
- 2004
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In: International Journal of Cardiology. - 0167-5273 .- 1874-1754. ; 93:2-3, s. 113-120
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Journal article (peer-reviewed)abstract
- BACKGROUND: Troponin is a specific marker of myocardial damage. For early prediction of coronary events in patients with suspicion of acute coronary syndromes the assay also needs to be highly sensitive. METHODS AND RESULTS: A rapid troponin I assay was performed prior to inclusion in 4447 acute coronary syndrome patients in the GUSTO-IV trial. A quantitative troponin T analysis was later performed on blood samples obtained at randomization by a central laboratory. There was an agreement between the rapid troponin I assay and troponin T (< or =/>0.1 microg/l) in 3596 (80.9%) patients. A positive rapid troponin I was identifying any elevation of troponin T (>0.01 microg/l) in 1990 patients (90.4%) whereas a negative rapid troponin I was corresponding to negative troponin T (< or =0.01 microg/l) in only 1217 patients (54.2%). Patients with a positive versus negative rapid troponin I had an increased risk of death or myocardial infarction at 30 days (9.3 vs. 5.9%; odds ratio, O.R. 1.64; 95% confidence interval, 1.31-2.06). Troponin T elevation (>0.1 microg/l) provided a better (10.5 v. 4.9%, O.R. 2.26; C.I. 1.79-2.85) risk stratification. Regardless of a positive or a negative rapid troponin I, the troponin T result (>0.1 vs. < or =0.1 microg/l) stratified the patients into high and low risk of events at 30 days, (10.3 vs. 5.7%, P=0.002) and (11.5 vs. 4.8%, P<0.001), respectively. CONCLUSION: In a population with non-ST elevation acute coronary syndrome a positive rapid troponin I assay is a specific indicator of troponin elevation and a predictor of early outcome. However, a negative rapid troponin I is not a reliable indicator of the absence of myocardial damage and does not indicate a low risk of subsequent cardiac events. A rapid troponin I assay was performed prior to inclusion in 4447 acute coronary syndrome patients in the GUSTO-IV trial and related to a centrally analyzed quantitative troponin T test. A positive rapid troponin I was well corresponding to any elevation of troponin T (>0.01 microg/l) and predicted an unfavorable outcome at 30 days. However, a negative rapid troponin I was corresponding to troponin T < or =0.01 microg/l in only half of the patients. Troponin T >0.1 microg/l vs. < or =0.1 microg/l provided a better risk stratification than the rapid troponin I result. For patients with troponin T elevation (>0.1 microg/l) the 30 day event rate was high regardless of the rapid troponin I result.
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| 3. |
- James, Stefan K., et al.
(author)
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Activation of the inflammation, coagulation, and fibrinolysis systems, without influence of abciximab infusion in patients with non-ST–elevation acute coronary syndromes treated with dalteparin : a GUSTO IV substudy
- 2004
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In: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 147:2, s. 267-274
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Journal article (peer-reviewed)abstract
- BackgroundIn acute coronary syndromes, the inflammation and the coagulation systems are activated, implying an impaired outcome. In addition to platelet inhibition, recent evidence suggests that the glycoprotein IIb/IIIa receptor inhibitor abciximab attenuates inflammation and coagulation activity.MethodsThe Swedish Global Utilization of Strategies To open Occluded arteries-IV (GUSTO-IV) substudy included 404 patients with non-ST–elevation acute coronary syndromes. In addition to aspirin and dalteparin, all patients were randomized to receive abciximab infusion for 24 hours or 48 hours or corresponding placebo without early coronary revascularization. Plasma samples were obtained at baseline and 24, 48, and 72 hours.ResultsThe median levels of the coagulation markers thrombin/antithrombin complex and soluble fibrin increased significantly from 3.1 to 3.7 ug/L (baseline to peak; P <.001) and from 20 to 23 nmol/L (P <.001), respectively. The fibrinolysis marker, tissue plasminogen-activator, also increased its median levels, from 11.7 to 17.5 ug/L (P <.001), whereas the median level of plasminogen-activator-inhibitor was unchanged. The inflammatory markers interleukin-6, C-reactive protein, and fibrinogen also increased their median levels (5.4–7.8 ng/L, P <.001; 4.4–8.7 mg/L, P <.001; 3.3–3.9 g/L, P <.001). However, there were no differences in median levels or in changes of median levels of any marker at any point between the placebo group and any of the abciximab groups.ConclusionsIn non-ST–elevation acute coronary syndrome, there was a simultaneous activation of the inflammation, coagulation, and fibrinolysis systems, despite aspirin and dalteparin treatment. Prolonged treatment with abciximab had no influence of the activation of these systems.Unstable coronary artery disease (CAD) intricately involves inflammatory mediators in the development of an atherosclerotic plaque and in thrombus formation by platelet aggregation.1 Acute phase elevation of inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and fibrinogen are important predictors of the short- and long-term prognosis in unstable CAD.2, 3 and 4 Activation of the coagulation and fibrinolysis systems, as demonstrated with elevated markers of thrombin generation, thrombin activity, and fibrin turnover, also have been found in the acute phase of unstable CAD and are associated with an adverse outcome.5, 6 and 7 Glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors potently inhibit platelet aggregation and reduce the incidence of ischemic events in patients undergoing percutaneuos coronary interventions8, 9 and 10 and in patients with unstable CAD.11 The GP IIb/IIIa inhibitor abciximab, in addition to its antithrombotic effect, also suppresses the rise in levels of inflammatory markers after percutaneous coronary interventions.12 This anti-inflammatory effect might be related to abciximab's cross-reaction with other integrin receptors.13 Furthermore, by inhibiting platelet aggregation, abciximab might also attenuate the coagulation and fibrinolysis activation as shown in vitro and in vivo.14 and 15The Global Utilization of Strategies To Open occluded arteries in acute coronary syndromes (GUSTO IV-ACS) trial unexpectedly failed to show any benefit of abciximab treatment in a high risk ACS population not undergoing early coronary revascularization.16 In the GUSTO IV-ACS low-molecular weight heparin substudy,17 dalteparin was used as the anticoagulant. Dalteparin, which is an inhibitor of the coagulation cascade, mainly by inhibition of factor Xa and less of factor IIa, has previously been shown to reduce the generation and activity of thrombin in unstable coronary disease.18 There is evidence that a combination of abciximab and a low-molecular-weight heparin have additive effects on the lag-time to platelet aggregation,19 and there are several theoretical advantages with the combination treatment. There was still no significant reduction in clinical events with abciximab in combination with dalteparin.17 The aim of this Swedish substudy of GUSTO IV-ACS was to evaluate the influence of abciximab infusion on markers on inflammation, coagulation, and fibrinolysis in patients with unstable CAD treated with aspirin and subcutaneous dalteparin.
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