Kor Miedema - Academia.edu (original) (raw)
Papers by Kor Miedema
Point of Care: The Journal of Near-patient Testing & Technology, 2008
Point of Care: The Journal of Near-Patient Testing & Technology, 2004
... BSc; Creed, Gary BSc; Goerlach-Graw, Ada PhD; Engel, Bernhard DI; Halwachs-Baumann, Garbriele... more ... BSc; Creed, Gary BSc; Goerlach-Graw, Ada PhD; Engel, Bernhard DI; Halwachs-Baumann, Garbriele MD; Holzer, Herwig MD; Katz, Norbert PhD; Kost, Gerald MD, PhD; Kraft, Manfred PhD; Kuester, Helmut MD; Miedema, Kor PhD; Nagel, Dietmar PhD; Normand, Hervé MD ...
![Research paper thumbnail of The impact of glucose-insulin-potassium infusion in acute myocardial infarction on infarct size and left ventricular ejection fraction [ISRCTN56720616]](https://attachments.academia-assets.com/41837864/thumbnails/1.jpg)
](BMC medicine, 2005
Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in a... more Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in acute myocardial infarction (MI). The mechanisms of this beneficial effect have not been delineated clearly. GIK has metabolic, anti-inflammatory and profibrinolytic effects and it may preserve the ischemic myocardium. We sought to assess the effect of GIK infusion on infarct size and left ventricular function, as part of a randomized controlled trial. Patients (n = 940) treated for acute MI by primary percutaneous coronary intervention (PCI) were randomized to GIK infusion or no infusion. Endpoints were the creatinine kinase MB-fraction (CK-MB) and left ventricular ejection fraction (LVEF). CK-MB levels were determined 0, 2, 4, 6, 24, 48, 72 and 96 hours after admission and the LVEF was measured before discharge. There were no differences between the two groups in the time course or magnitude of CK-MB release: the peak CK-MB level was 249 +/- 228 U/L in the GIK group and 240 +/- 200 U/L ...
Clinical chemistry, 1997
A reference method that specifically measures hemoglobin (Hb) A1c is an essential part of the ref... more A reference method that specifically measures hemoglobin (Hb) A1c is an essential part of the reference system for the international standardization of Hb A1c/glycohemoglobin. We have developed a new method for quantification, based on the specific N-terminal residue of the hemoglobin beta-chains. Enzymatic cleavage of the intact hemoglobin molecule with endoproteinase Glu-C has been optimized to obtain the beta-N-terminal hexapeptides of Hb A1c and Hb A0. These peptides have been separated by reversed-phase HPLC and quantitated by electrospray ionization-mass spectrometry (method A) or by capillary electrophoresis (method B). With these peptides and hyphenated separation techniques, it has been possible to overcome the insufficient resolution of currently used protein separation systems for Hb A1c.
Clinical chemistry, 1997
We describe a multinational evaluation of the Menarini-Arkray HA 8140 hemoglobin (Hb) A1c analyze... more We describe a multinational evaluation of the Menarini-Arkray HA 8140 hemoglobin (Hb) A1c analyzer, which utilizes a high degree of automation, including bar code reading, cap piercing, and whole-blood sampling. With-in- and between-batch CVs were < 2%. Linearity was confirmed throughout the working range of the analyzer. Common Hb variants, including Hb S, Hb C, and Hb F, did not interfere with the Hb A1c separation, and the potentially interfering labile Schiff base was effectively removed during the chromatographic procedure. The HA 8140 analyzer displayed good correlation to the Bio-Rad Variant analyzer, Tinaquant immunoassay, affinity chromatography, and an optimized "in-house" HPLC Hb A1c method. The methods when compared by Altman and Bland plots showed bias (upper, lower 95% confidence limits) of: Variant minus HA 8140 = 0.99 (0.23, 1.74), Tinaquant minus HA 8140 = 0.14 (-0.71, 0.98); affinity minus HA 8140 (after log transformation) = 1.13 (0.90, 1.41), and &qu...
Clinical chemistry and laboratory medicine : CCLM / FESCC, 2007
The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patien... more The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patients with diabetes. There are at least 30 different laboratory assays commercially available to measure the proportion of HbA1c in blood. In 1995 the IFCC established a Working Group (IFCC WG-HbA1c) to achieve international standardization of HbA1c measurement. The main achievements can be summarized as follows: a) a reference measurement procedure has been established with purified primary calibrators; b) a network of reference laboratories has been developed worldwide; and c) work has begun on implementation of traceability to the IFCC reference system. The IFCC WG-HbA1c recognizes the recommendation of the IFCC-IUPAC Committee on Nomenclature, Properties and Units that the analyte measured by the IFCC reference measurement procedure has been defined as betaN1-deoxyfructosyl-hemoglobin and that the recommended measurement units are mmol/mol. The IFCC WG-HbA1c recommends maintaining the u...
Thrombosis and Haemostasis, 2006
New England Journal of Medicine, 1999
Journal of Virological Methods, 2003
A simple solid-phase blocking ELISA for the detection of antibodies directed against type O foot-... more A simple solid-phase blocking ELISA for the detection of antibodies directed against type O foot-and-mouth disease virus (FMDV) was developed. The ELISA was validated using field sera collected from cattle, pigs and sheep originating from FMDV infected and non-infected Dutch farms, reference sera obtained from the World Reference Laboratory for foot-and-mouth disease at the Institute for Animal Health, Pirbright Laboratory, UK and sera from experimentally infected animals. Testing 2664 sera collected from non-infected cattle, pigs and sheep resulted in a specificity of 96%. A sensitivity relative to the virus neutralisation test (VNT) of &amp;amp;amp;amp;amp;gt;99% was achieved when testing 148 positive cattle, goat and sheep sera collected from FMDV-infected Dutch farms. All international reference sera scored consistently correct. The ELISA also correctly scored 398 of 409 positive experimentally derived sera. The sensitivity and specificity of this monoclonal antibody-based ELISA for detection of type O FMDV antibodies is sufficient for use as a screening ELISA. During the 2001 epidemic in the Netherlands, 8000 serum samples per day were regularly tested in this ELISA. The samples scoring positive were then tested by neutralisation for confirmation thus making optimum use of the neutralisation testing capacity.
Journal of the American College of Cardiology, 2004
To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation m... more To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), treated with different antiplatelet agents and dosages. BACKGROUND The extent of platelet aggregation inhibition is an independent predictor of major cardiac events after elective PCI. In STEMI patients undergoing PCI, routine dose of antiplatelet agents may be associated with less effective platelet aggregation inhibition.
J Amer Coll Cardiol, 2004
Background: Markers of inflammatory activity are predictors of mortality in patients with non-ST ... more Background: Markers of inflammatory activity are predictors of mortality in patients with non-ST elevation acute coronary syndromes (ACS). Interleukin-6 (Il-6) is the initiator of C-reactive protein (CRP) release from the liver and therefore an earlier inflammatory marker. Methods: The GUSTO-IV trial enrolled 7800 patients with non-ST elevation at a median of 9.5 hours after symptom onset. We analyzed baseline levels of Il-6 in 6857 patients and CRP in 7108 patients. One-year mortality was compared between patients with and without elevation ( 10ng/L for Il-6 and 10mg/L for CRP) of the markers enrolled at different time-intervals after symptom onset. Conclusion: In non-ST elevation ACS, elevation of Il-6 seems to provide the best prediction of high and low long-term mortality in patients admitted within 6 hours after symptom onset. Thereafter, elevation of Il-6 and CRP seem to provide a similar mortality prediction.
European Heart Journal, 2005
European Heart Journal, 2003
Background Only few studies specifically addressed the effect of timing of angiography and/or pre... more Background Only few studies specifically addressed the effect of timing of angiography and/or pre-treatment with a glycoprotein 2b/3a receptor blocker in patients with non-ST elevation acute coronary syndromes (ACS) who undergo invasive treatment. Methods In a 2-year period, 220 patients with non-ST elevation ACS, were randomized to early angiography without tirofiban pre-treatment (Early strategy) or to delayed angiography after 24-48 h pre-treatment with tirofiban (Late strategy). The first 48 h after admission, CKmb levels were measured and enzymatic infarct size (LDHQ 48 ) was assessed by the area under the LDH release curve. When PCI was performed beyond 48 h, CKmb was measured 6 and 12 h afterwards. Results Median time to angiography was 6 (Early) and 50 (Late) hours. PCI was performed in 130 patients (59%). In these patients, a patent (TIMI 2 or 3 flow) culprit vessel was more often present in the Late group compared to the Early group (66% vs 82% p=0.05). In patients with an elevated CKmb (n=96, 44%), LDHQ 48 was significantly lower in patients who underwent angiography after pre-treatment with tirofiban (629±503 U/L (Early) vs 432±441 U/L (Late), p=0.02). No difference in clinical outcome between the groups was observed at 30 days follow-up. Conclusion This pilot study showed that a strategy of delayed angiography with concomitant pre-treatment with tirofiban is associated with improved angiographic outcomes and less initial enzyme release, compared to a strategy of immediate angiography without 2b/3a inhibitor pre-treatment. The use of an end point parameter, which assess total enzyme release over a given period of time, might be of special value in patients with non-ST elevation ACS, who undergo very early invasive treatment.
European Heart Journal, 2004
The role of collateral flow in the first hours of infarction remains unclear. Our aim was to dete... more The role of collateral flow in the first hours of infarction remains unclear. Our aim was to determine whether the presence of coronary collateral flow, as evidenced by angiography, has a beneficial effect on infarct size and left ventricular function in acute myocardial infarction (MI) treated by means of early percutaneous coronary intervention (PCI). Between 1994 and 2001, 1059 patients with acute MI treated with primary PCI, TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow at first contrast injection and technically adequate angiograms for collateral flow detection were analysed. Comparison of collateral flow grades 0, 1, and 2/3 showed that increased collateral flow was associated with a lower incidence of Killip class &amp;gt;/= 2 at presentation (12% vs. 10% vs. 3%, p for trend 0.02), less need for intra-aortic balloon pumping after PCI (17% vs. 13% vs. 5%, p for trend 0.005), better myocardial blush grade (MBG) in infarcts related with the left anterior descending coronary artery (LAD) (MBG3: 14% vs. 18% vs. 34%, p for trend 0.01), and smaller enzymatic infarct size (cumulative lactate dehydrogenase release 36 h after symptom onset [LDHQ(36)]) (1932+/-1531 U/l vs. 1870+/-1458 U/l vs. 1217+/-762 U/l, p for trend 0.041). These beneficial effects were particularly evident in LAD-related infarcts. The presence of angiographically detectable collaterals has a protective effect on enzymatic infarct size and pre- and postintervention haemodynamic conditions in patients with acute MI treated by primary PCI, in particular when Rentrop grade 2/3 is present and the LAD is involved in the infarct.
Critical Care, 1999
Crit Care 1999, 3 3 ( (s su up pp pl l 1 1) ):P1 I In nt tr ro od du uc ct ti io on n: : Critical... more Crit Care 1999, 3 3 ( (s su up pp pl l 1 1) ):P1 I In nt tr ro od du uc ct ti io on n: : Critically ill patients requiring intensive care are at risk of iatrogenic ocular damage. Studies have reported an incidence of eye problems of up to 40% in critically ill ventilated patients. We conducted this study to assess the incidence of ocular complications in our intensive care unit where all patients are cared for according to an eye care standard.
Clinical Chemical Laboratory Medicine, 2000
The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patien... more The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patients with diabetes. There are at least 30 different laboratory assays commercially available to measure the proportion of HbA1c in blood. In 1995 the IFCC established a Working Group (IFCC WG-HbA1c) to achieve international standardization of HbA1c measurement. The main achievements can be summarized as follows: a) a reference measurement procedure has been established with purified primary calibrators; b) a network of reference laboratories has been developed worldwide; and c) work has begun on implementation of traceability to the IFCC reference system. The IFCC WG-HbA1c recognizes the recommendation of the IFCC-IUPAC Committee on Nomenclature, Properties and Units that the analyte measured by the IFCC reference measurement procedure has been defined as betaN1-deoxyfructosyl-hemoglobin and that the recommended measurement units are mmol/mol. The IFCC WG-HbA1c recommends maintaining the use of the name HbA1c in clinical practice.
Clinical Chemistry and Laboratory Medicine, 2000
We prepared a candidate primary reference material for the forthcoming international standardisat... more We prepared a candidate primary reference material for the forthcoming international standardisation of beta-N-terminal glycated hemoglobin A measurements. It consists of well-defined mixtures of purified beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A. First, beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A were isolated, purified to homogeneity, and characterised. The techniques used were cation exchange and affinity chromatography for the purification, and high performance liquid chromatography, capillary isoelectric focusing, electrospray ionisation mass spectrometry, and peptide mapping for the characterisation. Hemoglobins from blood of healthy, non-diabetic volunteers were obtained with a purity of > 99.5% for non-glycated hemoglobin A and of > 98.5% for beta-N-terminal glycated hemoglobin A. However, results from peptide mapping indicate that the beta-N-terminal glycated hemoglobin A preparations still contain some non-beta-N-terminal glycated hemoglobins, co-eluting with beta-N-terminal glycated hemoglobin A. The exact content of beta-N-terminal glycated hemoglobin A in these preparations could be determined by a procedure consisting of standard addition, enzymatic cleavage and quantification of the resulting beta-N-terminal peptides to be in the range from 95-97.5%. Since the beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A content could be exactly determined in the materials prepared, mixtures of both components could be successfully used to calibrate the candidate reference methods.
Clinical Chemistry and Laboratory Medicine, 2000
of the network showed excellent results with intralaboratory CVs of 0.5 to 2% and inter-laborator... more of the network showed excellent results with intralaboratory CVs of 0.5 to 2% and inter-laboratory CVs of 1.4 to 2.3%. Possible interferences have been carefully investigated. Due to the higher specificity of the reference method the results are lower than those generated with most of the present commercial methods which currently are calibrated with unspecific designated comparison methods. The new reference method has been approved by the member societies of the International Federation of Clinical Chemistry and Laboratory Medicine and will be the basis for the future uniform standardization of HbA 1c routine assays worldwide. Clin Chem Lab Med 2002; 40(1):78-89
Clinical Chemistry, 2004
on behalf of the IFCC Working Group on HbA 1c Standardization Background: The national programs f... more on behalf of the IFCC Working Group on HbA 1c Standardization Background: The national programs for the harmonization of hemoglobin (Hb)A 1c measurements in the US [National Glycohemoglobin Standardization Program (NGSP)], Japan [Japanese Diabetes Society (JDS)/Japanese Society of Clinical Chemistry (JSCC)], and Sweden are based on different designated comparison methods (DCMs). The future basis for international standardization will be the reference system developed by the IFCC Working Group on HbA 1c Standardization. The aim of the present study was to determine the relationships between the IFCC Reference Method (RM) and the DCMs. Methods: Four method-comparison studies were performed in 2001-2003. In each study five to eight pooled blood samples were measured by 11 reference laboratories of the IFCC Network of Reference Laboratories, 9 Secondary Reference Laboratories of the NGSP, 3 reference laboratories of the JDS/JSCC program, and a Swedish reference laboratory. Regression equations were determined for the relationship between the IFCC RM and each of the DCMs. Results: Significant differences were observed between the HbA 1c results of the IFCC RM and those of the DCMs. Significant differences were also demonstrated between the three DCMs. However, in all cases the relationship of the DCMs with the RM were linear. There were no statistically significant differences between the regression equations calculated for each of the four studies; therefore, the results could be combined. The relationship is described by the following regression equations: NGSP-HbA 1c ؍ 0.915(IFCC-HbA 1c ) ؉ 2.15% (r 2 ؍ 0.998); JDS/JSCC-HbA 1c ؍ 0.927(IFCC-HbA 1c ) ؉ 1.73% (r 2 ؍ 0.997); Swedish-HbA 1c ؍ 0.989(IFCC-HbA 1c ) ؉ 0.88% (r 2 ؍ 0.996). Conclusion: There is a firm and reproducible link between the IFCC RM and DCM HbA 1c values.
Point of Care: The Journal of Near-patient Testing & Technology, 2008
Point of Care: The Journal of Near-Patient Testing & Technology, 2004
... BSc; Creed, Gary BSc; Goerlach-Graw, Ada PhD; Engel, Bernhard DI; Halwachs-Baumann, Garbriele... more ... BSc; Creed, Gary BSc; Goerlach-Graw, Ada PhD; Engel, Bernhard DI; Halwachs-Baumann, Garbriele MD; Holzer, Herwig MD; Katz, Norbert PhD; Kost, Gerald MD, PhD; Kraft, Manfred PhD; Kuester, Helmut MD; Miedema, Kor PhD; Nagel, Dietmar PhD; Normand, Hervé MD ...
BMC medicine, 2005
Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in a... more Favorable clinical outcomes have been observed with glucose-insulin-potassium infusion (GIK) in acute myocardial infarction (MI). The mechanisms of this beneficial effect have not been delineated clearly. GIK has metabolic, anti-inflammatory and profibrinolytic effects and it may preserve the ischemic myocardium. We sought to assess the effect of GIK infusion on infarct size and left ventricular function, as part of a randomized controlled trial. Patients (n = 940) treated for acute MI by primary percutaneous coronary intervention (PCI) were randomized to GIK infusion or no infusion. Endpoints were the creatinine kinase MB-fraction (CK-MB) and left ventricular ejection fraction (LVEF). CK-MB levels were determined 0, 2, 4, 6, 24, 48, 72 and 96 hours after admission and the LVEF was measured before discharge. There were no differences between the two groups in the time course or magnitude of CK-MB release: the peak CK-MB level was 249 +/- 228 U/L in the GIK group and 240 +/- 200 U/L ...
Clinical chemistry, 1997
A reference method that specifically measures hemoglobin (Hb) A1c is an essential part of the ref... more A reference method that specifically measures hemoglobin (Hb) A1c is an essential part of the reference system for the international standardization of Hb A1c/glycohemoglobin. We have developed a new method for quantification, based on the specific N-terminal residue of the hemoglobin beta-chains. Enzymatic cleavage of the intact hemoglobin molecule with endoproteinase Glu-C has been optimized to obtain the beta-N-terminal hexapeptides of Hb A1c and Hb A0. These peptides have been separated by reversed-phase HPLC and quantitated by electrospray ionization-mass spectrometry (method A) or by capillary electrophoresis (method B). With these peptides and hyphenated separation techniques, it has been possible to overcome the insufficient resolution of currently used protein separation systems for Hb A1c.
Clinical chemistry, 1997
We describe a multinational evaluation of the Menarini-Arkray HA 8140 hemoglobin (Hb) A1c analyze... more We describe a multinational evaluation of the Menarini-Arkray HA 8140 hemoglobin (Hb) A1c analyzer, which utilizes a high degree of automation, including bar code reading, cap piercing, and whole-blood sampling. With-in- and between-batch CVs were < 2%. Linearity was confirmed throughout the working range of the analyzer. Common Hb variants, including Hb S, Hb C, and Hb F, did not interfere with the Hb A1c separation, and the potentially interfering labile Schiff base was effectively removed during the chromatographic procedure. The HA 8140 analyzer displayed good correlation to the Bio-Rad Variant analyzer, Tinaquant immunoassay, affinity chromatography, and an optimized "in-house" HPLC Hb A1c method. The methods when compared by Altman and Bland plots showed bias (upper, lower 95% confidence limits) of: Variant minus HA 8140 = 0.99 (0.23, 1.74), Tinaquant minus HA 8140 = 0.14 (-0.71, 0.98); affinity minus HA 8140 (after log transformation) = 1.13 (0.90, 1.41), and &qu...
Clinical chemistry and laboratory medicine : CCLM / FESCC, 2007
The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patien... more The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patients with diabetes. There are at least 30 different laboratory assays commercially available to measure the proportion of HbA1c in blood. In 1995 the IFCC established a Working Group (IFCC WG-HbA1c) to achieve international standardization of HbA1c measurement. The main achievements can be summarized as follows: a) a reference measurement procedure has been established with purified primary calibrators; b) a network of reference laboratories has been developed worldwide; and c) work has begun on implementation of traceability to the IFCC reference system. The IFCC WG-HbA1c recognizes the recommendation of the IFCC-IUPAC Committee on Nomenclature, Properties and Units that the analyte measured by the IFCC reference measurement procedure has been defined as betaN1-deoxyfructosyl-hemoglobin and that the recommended measurement units are mmol/mol. The IFCC WG-HbA1c recommends maintaining the u...
Thrombosis and Haemostasis, 2006
New England Journal of Medicine, 1999
Journal of Virological Methods, 2003
A simple solid-phase blocking ELISA for the detection of antibodies directed against type O foot-... more A simple solid-phase blocking ELISA for the detection of antibodies directed against type O foot-and-mouth disease virus (FMDV) was developed. The ELISA was validated using field sera collected from cattle, pigs and sheep originating from FMDV infected and non-infected Dutch farms, reference sera obtained from the World Reference Laboratory for foot-and-mouth disease at the Institute for Animal Health, Pirbright Laboratory, UK and sera from experimentally infected animals. Testing 2664 sera collected from non-infected cattle, pigs and sheep resulted in a specificity of 96%. A sensitivity relative to the virus neutralisation test (VNT) of &amp;amp;amp;amp;amp;gt;99% was achieved when testing 148 positive cattle, goat and sheep sera collected from FMDV-infected Dutch farms. All international reference sera scored consistently correct. The ELISA also correctly scored 398 of 409 positive experimentally derived sera. The sensitivity and specificity of this monoclonal antibody-based ELISA for detection of type O FMDV antibodies is sufficient for use as a screening ELISA. During the 2001 epidemic in the Netherlands, 8000 serum samples per day were regularly tested in this ELISA. The samples scoring positive were then tested by neutralisation for confirmation thus making optimum use of the neutralisation testing capacity.
Journal of the American College of Cardiology, 2004
To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation m... more To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), treated with different antiplatelet agents and dosages. BACKGROUND The extent of platelet aggregation inhibition is an independent predictor of major cardiac events after elective PCI. In STEMI patients undergoing PCI, routine dose of antiplatelet agents may be associated with less effective platelet aggregation inhibition.
J Amer Coll Cardiol, 2004
Background: Markers of inflammatory activity are predictors of mortality in patients with non-ST ... more Background: Markers of inflammatory activity are predictors of mortality in patients with non-ST elevation acute coronary syndromes (ACS). Interleukin-6 (Il-6) is the initiator of C-reactive protein (CRP) release from the liver and therefore an earlier inflammatory marker. Methods: The GUSTO-IV trial enrolled 7800 patients with non-ST elevation at a median of 9.5 hours after symptom onset. We analyzed baseline levels of Il-6 in 6857 patients and CRP in 7108 patients. One-year mortality was compared between patients with and without elevation ( 10ng/L for Il-6 and 10mg/L for CRP) of the markers enrolled at different time-intervals after symptom onset. Conclusion: In non-ST elevation ACS, elevation of Il-6 seems to provide the best prediction of high and low long-term mortality in patients admitted within 6 hours after symptom onset. Thereafter, elevation of Il-6 and CRP seem to provide a similar mortality prediction.
European Heart Journal, 2005
European Heart Journal, 2003
Background Only few studies specifically addressed the effect of timing of angiography and/or pre... more Background Only few studies specifically addressed the effect of timing of angiography and/or pre-treatment with a glycoprotein 2b/3a receptor blocker in patients with non-ST elevation acute coronary syndromes (ACS) who undergo invasive treatment. Methods In a 2-year period, 220 patients with non-ST elevation ACS, were randomized to early angiography without tirofiban pre-treatment (Early strategy) or to delayed angiography after 24-48 h pre-treatment with tirofiban (Late strategy). The first 48 h after admission, CKmb levels were measured and enzymatic infarct size (LDHQ 48 ) was assessed by the area under the LDH release curve. When PCI was performed beyond 48 h, CKmb was measured 6 and 12 h afterwards. Results Median time to angiography was 6 (Early) and 50 (Late) hours. PCI was performed in 130 patients (59%). In these patients, a patent (TIMI 2 or 3 flow) culprit vessel was more often present in the Late group compared to the Early group (66% vs 82% p=0.05). In patients with an elevated CKmb (n=96, 44%), LDHQ 48 was significantly lower in patients who underwent angiography after pre-treatment with tirofiban (629±503 U/L (Early) vs 432±441 U/L (Late), p=0.02). No difference in clinical outcome between the groups was observed at 30 days follow-up. Conclusion This pilot study showed that a strategy of delayed angiography with concomitant pre-treatment with tirofiban is associated with improved angiographic outcomes and less initial enzyme release, compared to a strategy of immediate angiography without 2b/3a inhibitor pre-treatment. The use of an end point parameter, which assess total enzyme release over a given period of time, might be of special value in patients with non-ST elevation ACS, who undergo very early invasive treatment.
European Heart Journal, 2004
The role of collateral flow in the first hours of infarction remains unclear. Our aim was to dete... more The role of collateral flow in the first hours of infarction remains unclear. Our aim was to determine whether the presence of coronary collateral flow, as evidenced by angiography, has a beneficial effect on infarct size and left ventricular function in acute myocardial infarction (MI) treated by means of early percutaneous coronary intervention (PCI). Between 1994 and 2001, 1059 patients with acute MI treated with primary PCI, TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow at first contrast injection and technically adequate angiograms for collateral flow detection were analysed. Comparison of collateral flow grades 0, 1, and 2/3 showed that increased collateral flow was associated with a lower incidence of Killip class &amp;gt;/= 2 at presentation (12% vs. 10% vs. 3%, p for trend 0.02), less need for intra-aortic balloon pumping after PCI (17% vs. 13% vs. 5%, p for trend 0.005), better myocardial blush grade (MBG) in infarcts related with the left anterior descending coronary artery (LAD) (MBG3: 14% vs. 18% vs. 34%, p for trend 0.01), and smaller enzymatic infarct size (cumulative lactate dehydrogenase release 36 h after symptom onset [LDHQ(36)]) (1932+/-1531 U/l vs. 1870+/-1458 U/l vs. 1217+/-762 U/l, p for trend 0.041). These beneficial effects were particularly evident in LAD-related infarcts. The presence of angiographically detectable collaterals has a protective effect on enzymatic infarct size and pre- and postintervention haemodynamic conditions in patients with acute MI treated by primary PCI, in particular when Rentrop grade 2/3 is present and the LAD is involved in the infarct.
Critical Care, 1999
Crit Care 1999, 3 3 ( (s su up pp pl l 1 1) ):P1 I In nt tr ro od du uc ct ti io on n: : Critical... more Crit Care 1999, 3 3 ( (s su up pp pl l 1 1) ):P1 I In nt tr ro od du uc ct ti io on n: : Critically ill patients requiring intensive care are at risk of iatrogenic ocular damage. Studies have reported an incidence of eye problems of up to 40% in critically ill ventilated patients. We conducted this study to assess the incidence of ocular complications in our intensive care unit where all patients are cared for according to an eye care standard.
Clinical Chemical Laboratory Medicine, 2000
The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patien... more The measurement of glycated hemoglobin is central in the monitoring of glycemic control in patients with diabetes. There are at least 30 different laboratory assays commercially available to measure the proportion of HbA1c in blood. In 1995 the IFCC established a Working Group (IFCC WG-HbA1c) to achieve international standardization of HbA1c measurement. The main achievements can be summarized as follows: a) a reference measurement procedure has been established with purified primary calibrators; b) a network of reference laboratories has been developed worldwide; and c) work has begun on implementation of traceability to the IFCC reference system. The IFCC WG-HbA1c recognizes the recommendation of the IFCC-IUPAC Committee on Nomenclature, Properties and Units that the analyte measured by the IFCC reference measurement procedure has been defined as betaN1-deoxyfructosyl-hemoglobin and that the recommended measurement units are mmol/mol. The IFCC WG-HbA1c recommends maintaining the use of the name HbA1c in clinical practice.
Clinical Chemistry and Laboratory Medicine, 2000
We prepared a candidate primary reference material for the forthcoming international standardisat... more We prepared a candidate primary reference material for the forthcoming international standardisation of beta-N-terminal glycated hemoglobin A measurements. It consists of well-defined mixtures of purified beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A. First, beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A were isolated, purified to homogeneity, and characterised. The techniques used were cation exchange and affinity chromatography for the purification, and high performance liquid chromatography, capillary isoelectric focusing, electrospray ionisation mass spectrometry, and peptide mapping for the characterisation. Hemoglobins from blood of healthy, non-diabetic volunteers were obtained with a purity of > 99.5% for non-glycated hemoglobin A and of > 98.5% for beta-N-terminal glycated hemoglobin A. However, results from peptide mapping indicate that the beta-N-terminal glycated hemoglobin A preparations still contain some non-beta-N-terminal glycated hemoglobins, co-eluting with beta-N-terminal glycated hemoglobin A. The exact content of beta-N-terminal glycated hemoglobin A in these preparations could be determined by a procedure consisting of standard addition, enzymatic cleavage and quantification of the resulting beta-N-terminal peptides to be in the range from 95-97.5%. Since the beta-N-terminal glycated hemoglobin A and non-glycated hemoglobin A content could be exactly determined in the materials prepared, mixtures of both components could be successfully used to calibrate the candidate reference methods.
Clinical Chemistry and Laboratory Medicine, 2000
of the network showed excellent results with intralaboratory CVs of 0.5 to 2% and inter-laborator... more of the network showed excellent results with intralaboratory CVs of 0.5 to 2% and inter-laboratory CVs of 1.4 to 2.3%. Possible interferences have been carefully investigated. Due to the higher specificity of the reference method the results are lower than those generated with most of the present commercial methods which currently are calibrated with unspecific designated comparison methods. The new reference method has been approved by the member societies of the International Federation of Clinical Chemistry and Laboratory Medicine and will be the basis for the future uniform standardization of HbA 1c routine assays worldwide. Clin Chem Lab Med 2002; 40(1):78-89
Clinical Chemistry, 2004
on behalf of the IFCC Working Group on HbA 1c Standardization Background: The national programs f... more on behalf of the IFCC Working Group on HbA 1c Standardization Background: The national programs for the harmonization of hemoglobin (Hb)A 1c measurements in the US [National Glycohemoglobin Standardization Program (NGSP)], Japan [Japanese Diabetes Society (JDS)/Japanese Society of Clinical Chemistry (JSCC)], and Sweden are based on different designated comparison methods (DCMs). The future basis for international standardization will be the reference system developed by the IFCC Working Group on HbA 1c Standardization. The aim of the present study was to determine the relationships between the IFCC Reference Method (RM) and the DCMs. Methods: Four method-comparison studies were performed in 2001-2003. In each study five to eight pooled blood samples were measured by 11 reference laboratories of the IFCC Network of Reference Laboratories, 9 Secondary Reference Laboratories of the NGSP, 3 reference laboratories of the JDS/JSCC program, and a Swedish reference laboratory. Regression equations were determined for the relationship between the IFCC RM and each of the DCMs. Results: Significant differences were observed between the HbA 1c results of the IFCC RM and those of the DCMs. Significant differences were also demonstrated between the three DCMs. However, in all cases the relationship of the DCMs with the RM were linear. There were no statistically significant differences between the regression equations calculated for each of the four studies; therefore, the results could be combined. The relationship is described by the following regression equations: NGSP-HbA 1c ؍ 0.915(IFCC-HbA 1c ) ؉ 2.15% (r 2 ؍ 0.998); JDS/JSCC-HbA 1c ؍ 0.927(IFCC-HbA 1c ) ؉ 1.73% (r 2 ؍ 0.997); Swedish-HbA 1c ؍ 0.989(IFCC-HbA 1c ) ؉ 0.88% (r 2 ؍ 0.996). Conclusion: There is a firm and reproducible link between the IFCC RM and DCM HbA 1c values.