| 1. |
- Aspholm-Hurtig, Marina, et al.
(författare)
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Functional adaptation of BabA, the H. pylori ABO blood group antigen binding adhesin.
- 2004
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Ingår i: 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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Tidskriftsartikel (refereegranskat)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. |
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| 3. |
- James, Stefan
(författare)
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Coagulation, Inflammation and Myocardial Dysfunction in Unstable Coronary Artery Disease and the Influence of Glycoprotein IIb/IIIa Inhibition and Low Molecular Weight Heparin
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hjärt-kärl sjukdom är den vanligaste dödsorsaken i västvärlden. Samtidigt som antalet patienter med hjärtinfarkt har minskat, har antalet patienter med instabil kranskärlsjukdom d.v.s. svår kärlkramp ökat påtagligt. Diagnosen är nu den vanligaste orsaken till vård på hjärtinfarktavdelningar i Sverige. Modern behandling av instabil kranskärlssjukdom består av en kombination av läkemedel för att minska blodproppsbildning och avlasta hjärtarbetet samt, i de flesta fall, s.k. ballongvidning eller operation av hjärtats kranskärl. Trots stora behandlingsframsteg är risken för hjärtinfarkt och död hög, såväl på kort som lång sikt. Det finns därför ett stort behov av ytterligare förbättrad behandling utan att samtidigt erhålla oacceptabelt hög risk för allvarliga biverkningar. För att erbjuda en effektiv behandling till patienter med hög risk och samtidigt undvika dyr och potentiellt riskfylld behandling till patienter med låg risk behövs också bättre instrument för tidig riskbedömning. Syftet med avhandlingen var att undersöka en stor grupp patienter med instabil kranskärlssjukdom avseende säkerhet och effektivitet av en behandlingskombination av två moderna blodproppshämmande läkemedel, dalteparin och abciximab (ca 1000 patienter). Syftet var också att studera hur denna behandling påverkar system för inflammation och koagulation (ca 400 patienter). Dessutom ville vi värdera hur blodnivåer av markörer för inflammation, hjärtmuskelskada och nedsatt hjärtfunktion kan förutsäga risken för framtida komplikationer (ca 7000 patienter). Tillägg av abciximab till dalteparin minskade inte risken för dödsfall eller hjärtinfarkt inom trettio dagar. Däremot ökade antalet blödningskomplikationer. Totala antalet blödningar var emellertid relativt lågt och behandlingen syntes vara lika säker som kombinationen av abciximab och det internationellt mycket använda blodproppshämmande medlet heparin. Trots den kraftfulla behandlingskombinationen skedde en samtidig aktivering av system för såväl inflammation som koagulation. Detta kan vara en orsak till den observerade avsaknaden av behandlingseffekt av abciximab. Att hindra denna aktivering skulle samtidigt kunna innebära möjligheter för nya behandlingsstrategier. Förhöjda nivåer av markörer för hjärtmuskelskada (troponin T), inflammation (CRP), nedsatt hjärtfunktion (proBNP) eller nedsatt njurfunktion (kreatininclearance) ökade risken för dödlig utgång både på kort och lång sikt, oberoende av andra riskfaktorer. En kombination av två av dessa markörer gav den högsta risken för dödlig utgång. Således dog endast 0.3 % av patienter med låga nivåer av proBNP och normal njurfunktion inom ett år, jämfört med 25.7 % av patienter med höga nivåer av proBNP och nedsatt njurfunktion. Förhöjda nivåer av troponin T eller nedsatt kreatininclearance (men inte av CRP eller proBNP) ökade dessutom risken för hjärtinfarkt. Resultaten i avhandlingsarbetet har givit kliniskt tillämpbar kunskap om hur kärlkrampspatienter med hög respektive låg risk kan selekteras tidigt efter inkomst till sjukhus och ny kunskap om behandlingseffekt av abciximab och dalteparin. Resultaten har redovisats på internationella kongresser och i högt rankade medicinska tidskrifter och har citerats i europeiska och amerikanska ”guidelines” för behandling av instabil kranskärlssjukdom.
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| 4. |
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| 5. |
- James, Stefan K., et al.
(författare)
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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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Ingår i: International Journal of Cardiology. - 0167-5273 .- 1874-1754. ; 93:2-3, s. 113-120
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Tidskriftsartikel (refereegranskat)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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| 6. |
- James, Stefan K., et al.
(författare)
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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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Ingår i: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 147:2, s. 267-274
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Tidskriftsartikel (refereegranskat)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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| 7. |
- James, Stefan, et al.
(författare)
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N-Terminal Pro–Brain Natriuretic Peptide and Other Risk Markers for the Separate Prediction of Mortality and Subsequent Myocardial Infarction in Patients With Unstable Coronary Artery Disease : A Global Utilization of Strategies To Open occluded arteries (GUSTO)-IV Substudy
- 2003
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 108:3, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Biochemical markers are useful for prediction of cardiac events in patients with non-ST-segment-elevation acute coronary syndrome (ACS). The associations between N-terminal pro-brain natriuretic peptide (NT-proBNP) and other biochemical and clinical risk indicators, as well as their prognostic value concerning the individual end points of death and myocardial infarction (MI), were elucidated in a large cohort of ACS patients. METHODS AND RESULTS: NT-proBNP, troponin T, and C-reactive protein (CRP) were analyzed in blood samples obtained at a median of 9.5 hours from symptom onset in 6809 of 7800 ACS patients in the Global Utilization of Strategies To Open occluded arteries-IV (GUSTO-IV) trial. Levels of NT-proBNP were correlated independently with age, female gender, low body weight, diabetes, renal dysfunction, history of MI, heart failure, heart rate, ongoing myocardial damage, and time since onset of ischemia. Increasing quartiles of NT-proBNP were related to short- and long-term mortality that reached 1.8%, 3.9%, 7.7%, and 19.2%, (P<0.001), respectively, at 1 year. Levels of troponin T, CRP, heart rate, and creatinine clearance, in addition to ST-segment depression, were also correlated independently with 1-year mortality, but NT-proBNP was the marker with the strongest relation. In contrast, only troponin T, creatinine clearance, and ST-segment depression were independently related to future MI. The combination of NT-proBNP and creatinine clearance provided the best prediction, with a 1-year mortality of 25.7% with both markers in the top quartile vs 0.3% with both markers in the bottom quartile. CONCLUSIONS: The use of NT-proBNP appears to add critical prognostic insight to the assessment of patients with ACS.
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| 8. |
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| 9. |
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| 10. |
- James, Stefan, et al.
(författare)
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Troponin T levels and risk of 30-day outcomes in patients with the acute coronary syndrome : prospective verification in the GUSTO-IV trial
- 2003
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Ingår i: American Journal of Medicine. - 0002-9343 .- 1555-7162. ; 115:3, s. 178-184
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A third-generation troponin T assay with improved precision and a lower detection limit has been developed. However, the appropriate cutoff for identifying patients with the acute coronary syndrome who are at low risk of subsequent mortality has not been established. METHODS: A retrospective evaluation of data from the Fragmin and fast Revascularization during InStability in Coronary artery disease II (FRISC-II) trial suggested that a cutoff below 0.1 microg/L for troponin T levels might be more useful in risk stratification. A prospective validation of two cutoff levels (0.03 microg/L and 0.01 microg/L) was performed in 7115 patients with non-ST-elevation acute coronary syndrome from the Global Utilization of Strategies To open Occluded arteries IV (GUSTO-IV) trial. RESULTS: Patients with troponin T levels >0.1 microg/L had greater 30-day mortality (5.5% [201/3679]) than did those with levels CONCLUSION: Using a cutoff of
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