51
|
Koestenberger M, Nagel B, Ravekes W, Avian A, Burmas A, Grangl G, Cvirn G, Gamillscheg A. Reference values and calculation of z-scores of echocardiographic measurements of the normal pediatric right ventricle. Am J Cardiol 2014; 114:1590-8. [PMID: 25248810 DOI: 10.1016/j.amjcard.2014.08.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/05/2014] [Accepted: 08/05/2014] [Indexed: 11/18/2022]
Abstract
Determination of right ventricular (RV) size and function has gained more interest in recent years in adults and children, especially in patients with congenital heart disease. Data on normal RV size parameters in children are scant. The aim of this study was to investigate growth-related changes in RV internal dimensions in a healthy pediatric cohort and the predictive value of RV parameters in identifying enlarged right ventricles in children with secundum-type atrial septal defects (ASD). A prospective study was conducted in a group of 576 healthy children (aged 1 day to 18 years) and 37 children (aged 1.4 to 17.7 years) with moderate-sized to large ASDs. The effects of age, body length, body weight, and body surface area were determined on the following RV parameters: end-diastolic basal diameter, end-diastolic midcavity diameter, end-diastolic length, end-systolic length, end-diastolic area, and end-systolic area. The predictive value of normal values stratified for age, body weight, body length, and body surface area was tested in children with ASDs. RV end-diastolic basal diameter, end-diastolic midcavity diameter, end-diastolic length, end-systolic length, end-diastolic area, and end-systolic area showed positive correlations with age, body length, body surface area, and body weight. In this population, RV z scores showed high specificity for detecting patients with ASDs, with sensitivity up to 89%, especially in children <8 years of age. In conclusion, the normal ranges of pediatric RV internal dimensions are provided. The z scores of these RV parameters were also calculated. Normal RV z scores might be important predictors in identifying enlarged right ventricles in patients with ASDs.
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria.
| | - Bert Nagel
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria
| | - William Ravekes
- Division of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alexander Avian
- Institute for Medical Informatics, Statistics and Documentation, Medical University Graz, Graz, Austria
| | - Ante Burmas
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria
| | - Gernot Grangl
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University Graz, Graz, Austria
| | - Andreas Gamillscheg
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria
| |
Collapse
|
52
|
Hoerl G, Ledinski G, Kager G, Thalhammer M, Koestenberger M, Juergens G, Gary T, Cvirn G. Virtually same oxidizability of LDL but higher Lp(a) levels in arterial compared to venous plasma. Chem Phys Lipids 2014; 184:38-41. [PMID: 25240239 DOI: 10.1016/j.chemphyslip.2014.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/02/2014] [Accepted: 09/15/2014] [Indexed: 10/24/2022]
Abstract
Plaque formation is confined to the arterial trunk. We assumed that due to the higher aeration of arterial compared to venous blood, higher levels of the atherogenic agent oxidized LDL might be present in arteries, contributing to plaque formation. We aimed to compare (i) the basal oxidative status of LDL in arterial and venous blood and (ii) the susceptibility of arterial and venous LDL to oxidation. The basal oxidative status of LDL was determined by measuring lipid hydroperoxide (LPO) concentrations, plasma levels of auto-antibodies against oxidized LDL, and by measuring oxidation-specific epitopes on LDL particles. The oxidizability of arterial vs. venous LDL (catalyzed by copper) was estimated by monitoring the time-course of conjugated dienes formation. Interestingly, we found the same basal oxidative status of LDL in arterial and venous plasma. LPO concentrations and levels of auto-antibodies against oxidized LDL were similar in arterial and venous plasma and amounts of oxidation-specific epitopes were similar on the respective LDL particles. Moreover, we found similar susceptibilities of arterial and venous LDL to (copper-mediated) oxidation. Lag-times until the onset of conjugated diene formation were slightly shorter in arterial compared to venous LDL in the presence of 5 μM, but not in the presence of 1 μM CuCl2. Additionally, we found significantly higher levels of the atherogenic lipoprotein(a) in arterial plasma. We conclude that not higher oxidizability of arterial LDL but higher arterial lipoprotein(a) levels might help to explain why sclerosis is confined to the arterial trunk.
Collapse
Affiliation(s)
- Gerd Hoerl
- Institute of Physiological Chemistry, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria
| | - Gerd Kager
- Institute of Physiological Chemistry, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria
| | | | | | - Guenther Juergens
- Institute of Physiological Chemistry, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria
| | - Thomas Gary
- Department of Angiology, Medical University of Graz, Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria.
| |
Collapse
|
53
|
Hörl G, Ledinski G, Kager G, Hallström S, Tafeit E, Koestenberger M, Jürgens G, Cvirn G. In vitro oxidation of LDL by ozone. Chem Phys Lipids 2014; 183:18-21. [PMID: 24835738 DOI: 10.1016/j.chemphyslip.2014.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 10/25/2022]
Abstract
Recent studies suggest that ozone is present in atherosclerotic lesions. Since these lesions are characterized by a dramatic accumulation of low-density lipoprotein (LDL), we aimed to investigate whether ozone is capable of oxidizing LDL, thereby rendering this lipoprotein atherogenic. Lipid hydroperoxide (LPO) concentrations and thiobarbituric acid reactive substances (TBARS) were measured to assess the oxidative status of the lipid part of LDL. Relative electrophoretic mobility (REM) and oxidation-specific immune epitopes were measured to assess the oxidative status of the protein part (apoB) of the LDL particle. Ozone turned out to be a potent oxidant of LDL. LPO concentrations, TBARS, REM, and oxidation-specific immune epitopes significantly increased upon ozonization. Our results suggest that ozonization of LDL may be a novel pathway which supports atherogenesis. Ozone is capable of oxidizing the lipid part of LDL, followed by immediate oxidation of the protein part of LDL, rendering the lipoprotein atherogenic.
Collapse
Affiliation(s)
- Gerd Hörl
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | - Gerd Kager
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | - Seth Hallström
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | - Erwin Tafeit
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | | | - Günther Jürgens
- Institute of Physiological Chemistry, Medical University of Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Austria.
| |
Collapse
|
54
|
Koestenberger M, Ravekes W, Nagel B, Avian A, Heinzl B, Cvirn G, Fritsch P, Fandl A, Rehak T, Gamillscheg A. Reference values of the right ventricular outflow tract systolic excursion in 711 healthy children and calculation of z-score values. Eur Heart J Cardiovasc Imaging 2014; 15:980-6. [DOI: 10.1093/ehjci/jeu041] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
|
55
|
Koestenberger M, Nagel B, Ravekes W, Avian A, Cvirn G, Rehak T, Gamillscheg A. Reference values of the mitral annular peak systolic velocity (Sm) in 690 healthy pediatric patients, calculation of Z-score values, and comparison to the mitral annular Plane systolic excursion (MAPSE). Echocardiography 2014; 31:1122-30. [PMID: 25271547 DOI: 10.1111/echo.12541] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The mitral annular peak systolic velocity (Sm) is an echocardiographic measurement using tissue Doppler imaging to assess longitudinal left ventricular (LV) systolic function in children and adults. We determined growth-related changes in Sm to establish reference values for the entire pediatric age group. METHODS AND RESULTS A prospective study was conducted in a group of 690 healthy pediatric patients (age: 1 day-18 years). We determined the effects of age, sex, and body surface area (BSA) on the Sm values. Regression analysis was used to estimate Sm from age, BSA, and sex. In addition, a correlation of normal Sm with normal age-matched values of the M-mode parameter mitral annular plane systolic excursion (MAPSE) was measured. The Sm ranged from a mean of 5.8 cm/sec (Z-score ±2: 3.6-8.0 cm/sec) in the newborn to 11.8 cm/sec (Z-score ±2: 8.5-15.1 cm/sec) in the 18-year-old adolescent. The Sm values showed a positive correlation with age and BSA with a nonlinear course. There was no significant difference in Sm values between females and males. A significant correlation was found between Sm and MAPSE values. CONCLUSION Z-scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Austria
| | | | | | | | | | | | | |
Collapse
|
56
|
Lamprecht M, Obermayer G, Steinbauer K, Cvirn G, Hofmann L, Ledinski G, Greilberger JF, Hallstroem S. Supplementation with a juice powder concentrate and exercise decrease oxidation and inflammation, and improve the microcirculation in obese women: randomised controlled trial data. Br J Nutr 2013; 110:1685-95. [PMID: 23591157 PMCID: PMC3821373 DOI: 10.1017/s0007114513001001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/05/2013] [Accepted: 03/05/2013] [Indexed: 01/03/2023]
Abstract
Obesity and sedentary lifestyle are associated with increased oxidative stress, inflammation and vessel dysfunction. Previous research has shown that an encapsulated fruit/berry/vegetable juice powder (FBV) supplement or controlled exercise training improve the markers of redox biology, low-grade inflammation and circulation. The aim of the present study was to assess the effects of 8 weeks of supplementation with FBV or placebo, and a single bout of controlled walking on the markers of oxidation, inflammation and skin capillary microcirculation in forty-two obese pre-menopausal women (41 (SD 5) years, non-smokers and BMI 34·5 (SD 3·8) kg/m(2)) using a randomised, double-blind, placebo-controlled design. All assessments were made before and after 8 weeks of capsule supplementation, and pre- and post-30 min of controlled treadmill walking at 70 % of VO2max. Venous blood was collected for the determination of carbonyl proteins (CP), oxidised LDL (ox-LDL), total oxidation status (TOS) of lipids, malondialdehyde, TNF-α and IL-6. Capillary blood flow, O2 saturation of Hb (SO2Hb) and the relative concentration of Hb (rHb) were assessed at a 2 mm skin depth. Following 8 weeks of supplementation, compared with placebo, the FBV group had a significant (P< 0·05) reduction in CP, ox-LDL, TOS and TNF-α, and a significant increase in blood flow, SO2Hb and rHb. Independent of supplementation, moderate exercise significantly increased blood flow and rHb, with a trend towards increased SO2Hb. Compared with placebo, 8 weeks of supplementation with FBV decreased the markers of systemic oxidation and inflammation. Both FBV supplementation and a single walking bout improved the markers of the microcirculation in these obese women.
Collapse
Affiliation(s)
- Manfred Lamprecht
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
- Institute of Nutrient Research and Sport Nutrition, Petersbergenstrasse 95b, 8042Graz, Austria
| | - Georg Obermayer
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
- Institute of Nutrient Research and Sport Nutrition, Petersbergenstrasse 95b, 8042Graz, Austria
| | - Kurt Steinbauer
- SportchirurgiePlus, Centre for Individual Sport Medicine and Surgery, Berthold Linderweg 15, 8047Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
| | - Lidija Hofmann
- FH JOANNEUM, University of Applied Sciences, Eggenberger Allee 11, 8020Graz, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
| | - Joachim F. Greilberger
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
- Institute of Laboratory Sciences, Dr Greilberger GmbH, Hauptstrasse 140, 8301Laßnitzhöhe, Austria
| | - Seth Hallstroem
- Institute of Physiological Chemistry, Centre for Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010 Graz, Austria
| |
Collapse
|
57
|
Koestenberger M, Ravekes W, Nagel B, Avian A, Heinzl B, Fritsch P, Sorantin E, Cvirn G, Rehak T, Gamillscheg A. Longitudinal systolic ventricular interaction in pediatric and young adult patients with TOF: a cardiac magnetic resonance and M-mode echocardiographic study. Int J Cardiovasc Imaging 2013; 29:1707-15. [DOI: 10.1007/s10554-013-0261-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/18/2013] [Indexed: 11/30/2022]
|
58
|
Lamprecht M, Moussalli H, Ledinski G, Leschnik B, Schlagenhauf A, Koestenberger M, Polt G, Cvirn G. Effects of a single bout of walking exercise on blood coagulation parameters in obese women. J Appl Physiol (1985) 2013; 115:57-63. [DOI: 10.1152/japplphysiol.00187.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obesity is associated with increased prevalence of thromboembolic events. We aimed to investigate whether obese women might benefit from vigorous aerobic exercise. Forty-two overweight and obese women performed a 30-min walking exercise test (treadmill ergometer) at an intensity of 70% of individual peak oxygen uptake. Blood samples were collected before and immediately after exercise. Thrombelastometry and platelet function measurements were performed on whole blood. Standard coagulation times, thrombin generation curves, markers of thrombin generation, fibrinolytic parameters, plasma levels of pro- and anticoagulatory factors, and microparticle procoagulant activity were determined in platelet-poor plasma samples. Thrombelastometry revealed a significant prolongation of clot formation time ( P = 0.037) and a significant deceleration of fibrin build up (alpha angle, P = 0.034) after exercise. Calibrated automated thrombography revealed a significant exercise-induced decrease in endogenous thrombin potential ( P = 0.039). Moreover, thrombin formation stopped earlier postexercise, reflected in shortened StartTail ( P = 0.046). Significantly elevated tissue-plasminogen activator levels ( P = 0.001) indicate an exercise-induced activation of the fibrinolytic system. White blood cell count increased significantly from pre- to postexercise ( P = 0.045), indicating a mild exercise-induced leukocytosis. The results of this study demonstrate that vigorous aerobic exercise might be a suitable tool to protect obese women from thrombotic events. We show that a single bout of vigorous aerobic exercise is clearly associated with an activation of the fibrinolytic system and a decreased readiness of the postexercise samples to form a clot and to generate thrombin, the pivotal enzyme of hemostasis.
Collapse
Affiliation(s)
- Manfred Lamprecht
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
- Green Beat-Institute of Nutrient Research and Sport Nutrition, Graz, Austria; and
| | - Herve Moussalli
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Bettina Leschnik
- Department of Pediatrics, Medical University of Graz, Graz, Austria
| | | | | | - Guenter Polt
- Green Beat-Institute of Nutrient Research and Sport Nutrition, Graz, Austria; and
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| |
Collapse
|
59
|
Koestenberger M, Nagel B, Ravekes W, Gamillscheg A, Pichler G, Avian A, Heinzl B, Binder C, Cvirn G, Urlesberger B. Right ventricular performance in preterm and term neonates: reference values of the tricuspid annular peak systolic velocity measured by tissue Doppler imaging. Neonatology 2013; 103:281-6. [PMID: 23548493 DOI: 10.1159/000348521] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/29/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND The tricuspid annular peak systolic velocity (S') is an echocardiographic measurement to assess systolic right ventricular function in adults and children. OBJECTIVE We determined growth and birth weight-related changes of S' to establish reference values in preterm and term neonates. METHODS A prospective study was conducted in a group of 290 preterm and term neonates (gestational age 26 + 0 to 40 + 6 weeks of gestation; birth weight 660-4,460 g). A correlation of S' values with established tricuspid annular plane systolic excursion (TAPSE) values was performed. RESULTS The S' ranged from a mean of 4.5 cm/s (Z-score ± 2 SD: 3.6-5.5 cm/s) in preterm neonates in week 26(0-6) of gestation to 7.8 cm/s (Z-score ± 2 SD: 5.5-10.1 cm/s) in term neonates in week 40(0-6) of gestation. The S' values increased from 26 to 40 weeks of gestation. S' and week of gestation are strongly correlated: Pearson's correlation coefficient was 0.66 for week of gestation - S' (p < 0.001). A significant correlation was found between S' and TAPSE values (r = 0.67; p < 0.001). CONCLUSION Z-scores of S' values were calculated and percentile charts were established to serve as reference data for preterm and term neonates with structurally normal hearts.
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Graz, Austria.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
60
|
Cvirn G, Schlagenhauf A, Leschnik B, Koestenberger M, Roessler A, Jantscher A, Vrecko K, Juergens G, Hinghofer-Szalkay H, Goswami N. Coagulation changes during presyncope and recovery. PLoS One 2012; 7:e42221. [PMID: 22876309 PMCID: PMC3410921 DOI: 10.1371/journal.pone.0042221] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/02/2012] [Indexed: 02/02/2023] Open
Abstract
Orthostatic stress activates the coagulation system. The extent of coagulation activation with full orthostatic load leading to presyncope is unknown. We examined in 7 healthy males whether presyncope, using a combination of head up tilt (HUT) and lower body negative pressure (LBNP), leads to coagulation changes as well as in the return to baseline during recovery. Coagulation responses (whole blood thrombelastometry, whole blood platelet aggregation, endogenous thrombin potential, markers of endothelial activation and thrombin generation), blood cell counts and plasma mass density (for volume changes) were measured before, during, and 20 min after the orthostatic stress. Maximum orthostatic load led to a 25% plasma volume loss. Blood cell counts, prothrombin levels, thrombin peak, endogenous thrombin potential, and tissue factor pathway inhibitor levels increased during the protocol, commensurable with hemoconcentration. The markers of endothelial activation (tissue factor, tissue plasminogen activator), and thrombin generation (F1+2, prothrombin fragments 1 and 2, and TAT, thrombin-antithrombin complex) increased to an extent far beyond the hemoconcentration effect. During recovery, the markers of endothelial activation returned to initial supine values, but F1+2 and TAT remained elevated, suggestive of increased coagulability. Our findings of increased coagulability at 20 min of recovery from presyncope may have greater clinical significance than short-term procoagulant changes observed during standing. While our experiments were conducted in healthy subjects, the observed hypercoagulability during graded orthostatic challenge, at presyncope and in recovery may be an important risk factor particularly for patients already at high risk for thromboembolic events (e.g. those with coronary heart disease, atherosclerosis or hypertensives).
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Axel Schlagenhauf
- Department of Paediatrics, Medical University of Graz, Graz, Austria
| | - Bettina Leschnik
- Department of Paediatrics, Medical University of Graz, Graz, Austria
| | | | - Andreas Roessler
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | | | - Karoline Vrecko
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Guenther Juergens
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | | | - Nandu Goswami
- Institute of Physiology, Medical University of Graz, Graz, Austria
- * E-mail:
| |
Collapse
|
61
|
Koestenberger M, Nagel B, Ravekes W, Avian A, Heinzl B, Fandl A, Rehak T, Sorantin E, Cvirn G, Gamillscheg A. Tricuspid annular peak systolic velocity (S') in children and young adults with pulmonary artery hypertension secondary to congenital heart diseases, and in those with repaired tetralogy of Fallot: echocardiography and MRI data. J Am Soc Echocardiogr 2012; 25:1041-9. [PMID: 22763086 DOI: 10.1016/j.echo.2012.06.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Tricuspid annular peak systolic velocity (S'), as an echocardiographic index to assess right ventricular (RV) systolic function, has not been investigated thoroughly in children and young adults with repaired tetralogy of Fallot (TOF) and pulmonary artery hypertension secondary to congenital heart disease (PAH-CHD). METHODS S' values in patients with TOF (n = 183) and PAH-CHD (n = 55) were compared with those in normal subjects. S' values were compared with RV ejection fraction and RV end-diastolic volume index (RVEDVi) determined by magnetic resonance imaging. RESULTS S' values became significantly reduced in PAH-CHD patients after 10.4 years of age and after 13.6 years of age in patients with TOF compared with the lower boundary of the ±2-SD interval of normal subjects. Significant positive correlations between S' and RV ejection fraction were seen in patients with TOF (r = 0.66, P < .001) and those with PAH-CHD (r = 0.82, P < .001). Significant negative correlations between S' and RVEDVi were also seen in patients with repaired TOF (r = -0.29, P = .002) and in those with PAH-CHD (r = -0.59, P < .001). CONCLUSIONS Although initially preserved, in this prospective study, impaired S' values with increasing age were found in patients with repaired TOF and PAH-CHD. Persistent pressure overload in patients with PAH-CHD as well as volume overload in those with repaired TOF might lead to systolic RV functional impairment and increased RVEDVi. The validity of S' data was supported by magnetic resonance imaging data (RVEDVi and RV ejection fraction).
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Auenbruggerplatz 34/2, Graz, Austria.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
62
|
Koestenberger M, Nagel B, Avian A, Ravekes W, Sorantin E, Cvirn G, Beran E, Halb V, Gamillscheg A. Systolic right ventricular function in children and young adults with pulmonary artery hypertension secondary to congenital heart disease and tetralogy of Fallot: tricuspid annular plane systolic excursion (TAPSE) and magnetic resonance imaging data. CONGENIT HEART DIS 2012; 7:250-8. [PMID: 22494699 DOI: 10.1111/j.1747-0803.2012.00655.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The tricuspid annular plane systolic excursion (TAPSE), as echocardiographic index to assess right ventricular (RV) systolic function, has not been investigated thoroughly in children and young adults with tetralogy of Fallot (TOF) and pulmonary artery hypertension secondary to congenital heart disease (PAH-CHD). PATIENTS TAPSE values of 49 patients with PAH-CHD and 156 patients with TOF were compared with age-matched normal subjects. TAPSE values were also compared with RV ejection fraction (RVEF) and RV indexed end-diastolic volume (RVEDVi) determined by magnetic resonance imaging in PAH-CHD and TOF patients. RESULTS Patients with a PAH-CHD showed a positive correlation between TAPSE with RVEF (r= 0.81; P < 0.001) and a negative correlation between TAPSE with RVEDVi (r=-0.67; P < 0.001). Similarly, in our TOF patients, a positive correlation between TAPSE with RVEF (r= 0.65; P < 0.001) and a negative correlation between TAPSE with RVEDVi (r=-0.42; P < 0.001) was seen. CONCLUSIONS Significant pressure overload in PAH-CHD patients and volume overload in TOF patients lead to a decreased systolic RV function, determined by TAPSE and magnetic resonance imaging and to increased RVEDVi values, determined by MRI, with time.
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Auenbruggerplatz 34/2, Graz, Austria.
| | | | | | | | | | | | | | | | | |
Collapse
|
63
|
Koestenberger M, Nagel B, Ravekes W, Urlesberger B, Raith W, Avian A, Halb V, Cvirn G, Fritsch P, Gamillscheg A. Systolic right ventricular function in preterm and term neonates: reference values of the tricuspid annular plane systolic excursion (TAPSE) in 258 patients and calculation of Z-score values. Neonatology 2011; 100:85-92. [PMID: 21273793 DOI: 10.1159/000322006] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 10/11/2010] [Indexed: 11/19/2022]
Abstract
BACKGROUND The tricuspid annular plane systolic excursion (TAPSE) is an echocardiographic measurement to assess right ventricular systolic function in adults and children. OBJECTIVE We determined growth- and birth weight-related changes of TAPSE to establish reference values in preterm and term neonates. METHODS A prospective study was conducted in a group of 258 preterm and term neonates (age: 25+0 to 40+6 weeks of gestation, birth weight: 530-4200 g). RESULTS The TAPSE ranged from a mean of 0.44 cm (Z-score ±2: 0.30-0.59 cm) in preterm neonates in the 26th week of gestation to 1.03 cm (Z-score ±2: 0.85-1.21 cm) in term neonates in the 41st week of gestation. The TAPSE values increased in a linear way from the 26th to 41st week of gestation. TAPSE, week of gestation and weight are strongly correlated: Pearson's correlation coefficient was 0.93 for week of gestation - TAPSE (p < 0.001), 0.93 for week of gestation - birth weight (p < 0.001), and 0.89 for birth weight - TAPSE (p < 0.001). There was no statistically significant difference of normal TAPSE values between female and male patients (p = 0.987). CONCLUSION Z-scores of TAPSE values were calculated and percentile charts were established to serve as reference data for ready application in preterm and term neonates with structurally normal hearts and with congenital heart disease in the future.
Collapse
|
64
|
Cvirn G, Hoerl G, Tafeit E, Heinl N, Wodrig K, Wagner T, Koestenberger M, Juergens G. Effects of nadroparin, enoxaparin, and unfractionated heparin on endogenous formation of factor Xa and IIa and on thrombelastometry profiles in cord versus adult blood. Neonatology 2011; 100:23-31. [PMID: 21150227 DOI: 10.1159/000320164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 08/03/2010] [Indexed: 11/19/2022]
Abstract
BACKGROUND To date, only few pharmacokinetic studies on low-molecular-weight heparins (LMWHs) in neonates exist not allowing to formally assess pharmacodynamics of LMWHs in neonates. OBJECTIVE To evaluate the anticoagulant effects of the two LMWHs nadroparin and enoxaparin on endogenous formation of FXa or FIIa in cord versus adult platelet-poor plasma (PPP) and on thrombelastometry profiles in cord versus adult whole blood (WB). Unfractionated heparin (UH) was the reference antithrombotic drug. METHODS The effects of nadroparin, enoxaparin, or UH on endogenous formation of FXa or FIIa was investigated in tissue factor-activated PPP using a subsampling technique and chromogenic substrates. The anticoagulant efficacy of these drugs was also investigated in WB triggered by the physiological relevant activator collagen/endogenous thrombin using thrombelastometry. RESULTS The major findings are (i) nadroparin is as efficient as enoxaparin concerning inhibition of the endogenous formation of FXa and FIIa, (ii) cord PPP and WB are significantly more susceptible to the addition of LMWHs or UH than adult PPP or WB, and (iii) compared by equivalent anti-FXa activity, the anticoagulant action of UH is markedly higher than that of the LMWHs in PPP and WB of neonatal or adult origin. CONCLUSIONS Administration of LMWHs in neonates has to be performed carefully to avoid bleeding side effects due to their high anticoagulant efficacy in cord PPP and WB.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
65
|
Koestenberger M, Nagel B, Ravekes W, Everett AD, Stueger HP, Heinzl B, Sorantin E, Cvirn G, Gamillscheg A. Tricuspid annular plane systolic excursion and right ventricular ejection fraction in pediatric and adolescent patients with tetralogy of Fallot, patients with atrial septal defect, and age-matched normal subjects. Clin Res Cardiol 2010; 100:67-75. [DOI: 10.1007/s00392-010-0213-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Accepted: 08/19/2010] [Indexed: 11/24/2022]
|
66
|
Cvirn G, Tafeit E, Hoerl G, Janschitz M, Wagner T, Juergens G, Koestenberger M. Heparinase-modified thrombelastometry: inactivation of heparin in plasma samples. Clin Lab 2010; 56:585-589. [PMID: 21141445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND The heparinase-modified thrombelastometry (HEPTEM) assay is a promising tool to assess the coagulation status of heparinised patients. The aim of our study was to examine the heparin neutralizing capability of the HEPTEM assay in plasma samples. METHODS In the HEPTEM assay, blood or plasma samples become activated via the intrinsic pathway in the presence of a heparin processing enzyme. RESULTS We examined coagulation times (CTs) in the presence of increasing amounts (0-4 IU/mL) of heparin. We found that up to a concentration of 0.5 IU/mL, heparin is completely neutralized. However, CTs increased linearly in the presence of heparin concentrations higher than 0.5 IU/mL, indicating incomplete heparin neutralization in the standard HEPTEM assay. CONCLUSIONS We provide herein a mathematical procedure to correct the misleadingly prolonged CTs (for heparin > 0.5 IU/mL) for the HEPTEM assay performed in plasma samples to allow better estimation of the coagulation status in patients requiring intense anticoagulation (e.g., patients undergoing cardiac surgery).
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Austria.
| | | | | | | | | | | | | |
Collapse
|
67
|
Tafeit E, Greilberger J, Cvirn G, Lipp RW, Schnedl WJ, Jürimäe T, Jürimäe J, Wallner-Liebmann SJ. Estimating DXA total body fat percentage by lipometer subcutaneous adipose tissue thicknesses. Coll Antropol 2009; 33:391-396. [PMID: 19662755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
DXA is an accepted reference method to estimate body composition. However several difficulties in the applicability exist. The equipment is rather expensive, not portable, impractical for measurement of big study populations and it provides a minimal amount of ionizing radiation exposure. The optical device Lipometer (EU Pat.No. 0516251) provides non-invasive, quick, precise and safe measurements of subcutaneous adipose tissue (SAT) layer thicknesses at any site of the human body. Compared to DXA there are some advantages in the Lipometer approach, because this device is portable, quick, not expensive and no radiation is involved. To use these advantages in the field of total body fat% (TBF%) assessment, an acceptable estimation of DXA TBF% by Lipometer SAT thicknesses is necessary, which was the aim of this study. Height, weight, waist and hip circumferences, DXA TBF% and Lipometer SAT thicknesses at fifteen defined body sites were measured in 28 healthy men (age: 33.9 +/- 16.6 years) and 52 healthy women (age: 40.1 +/- 10.7 years). To estimate Lipometer TBF% stepwise multiple regression analysis was applied, using DXA TBF% as dependent variable. Using the fifteen Lipometer SAT thicknesses together with age, height, weight and BMI as independent variables provided the best estimations of Lipometer TBF% for both genders with strong correlations to DXA TBF% (R = 0.985 for males and R = 0.953 for females). The limits of agreement were -2.48% to +2.48% for males and -4.28% to + 4.28% for females. For both genders we received a bias of 0.00%. The results of this paper extend the abilities of the Lipometer by a precise estimation of TBF% using DXA as golden standard.
Collapse
Affiliation(s)
- Erwin Tafeit
- Institute of Physiological Chemistry, Center for Physiological Medicine, Medical University Graz, Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
68
|
Koestenberger M, Ravekes W, Everett AD, Stueger HP, Heinzl B, Gamillscheg A, Cvirn G, Boysen A, Fandl A, Nagel B. Right Ventricular Function in Infants, Children and Adolescents: Reference Values of the Tricuspid Annular Plane Systolic Excursion (TAPSE) in 640 Healthy Patients and Calculation of z Score Values. J Am Soc Echocardiogr 2009; 22:715-9. [DOI: 10.1016/j.echo.2009.03.026] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Indexed: 02/08/2023]
|
69
|
Cvirn G, Kutschera J, Wagner T, Ferstl U, Vrecko K, Hallstrom S, Juergens G, Koestenberger M. Collagen/endogenous thrombin-induced platelet aggregation in cord versus adult whole blood. Neonatology 2009; 95:187-92. [PMID: 18797172 DOI: 10.1159/000155613] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Accepted: 04/17/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND In previous studies, neonatal platelets have been shown to be hypoaggregable to various agonists when compared with adult platelets. OBJECTIVES It was the aim of this study to investigate the aggregability of neonatal versus adult platelets when the physiological relevant agonist collagen/endogenous thrombin is used. METHODS AND RESULTS Whole blood (WB) aggregation experiments employing the impedance method revealed the same responsiveness of neonatal and adult platelets to collagen/endogenous thrombin. Maximum aggregation (13.5 +/- 3.2 vs. 13.6 +/- 3.2 Omega; p = 0.94), slope (5.8 +/- 1.8 vs. 6.2 +/- 2.6 Omega/min; p = 0.79) and lag time until the onset of platelet aggregation (38.7 +/- 8.9 vs. 42.6 +/- 16.5 s; p = 0.59) were similar in cord and adult WB. However, the rise in serotonin plasma levels due to platelet activation was significantly lower in neonates versus adults (227.57 +/- 57.65 vs. 473.34 +/- 155.75 ng/ml; p = 0.0001). Furthermore, we found a fast capability of cord plasma to generate (the efficient platelet agonist) endogenous thrombin: thrombin generation started significantly earlier in cord compared with adult plasma (215 +/- 19 vs. 247 +/- 21 s; p = 0.01). Moreover, thrombelastometry revealed significantly shorter coagulation times in cord versus adult WB activated with collagen/endogenous thrombin (229.8 +/- 12.5 vs. 256.3 +/- 25.3 s; p = 0.003). CONCLUSIONS The efficient platelet aggregation in cord WB provoked by collagen/endogenous thrombin might help to explain the clinically observed well-functioning primary hemostasis of neonates.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
70
|
Koestenberger M, Cvirn G, Rosenkranz A, Leschnik B, Raith W, Muntean W. Thrombin generation in paediatric patients with congenital heart disease. Determination by calibrated automated thrombography. Hamostaseologie 2008; 28 Suppl 1:S61-S66. [PMID: 18958342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
UNLABELLED Thrombin generation was studied in paediatric patients with congenital heart disease (CHD) undergoing cardiac surgery using the calibrated automated thrombography (CAT) in terms of the lag time until the onset of thrombin formation, time to thrombin peak maximum (TTP), endogenous thrombin potential (ETP), and thrombin peak height. The suitability to determine the coagulation status of these patients was investigated. PATIENTS, MATERIAL, METHODS CAT data of 40 patients with CHD (age range from newborn to 18 years) were compared to data using standard coagulation parameters such as prothrombin (FII), antithrombin (AT), tissue factor pathway inhibitor (TFPI), prothrombin fragment 1.2 (F 1.2), thrombin-antithrombin (TAT), activated partial thromboplastin time (aPTT), and prothrombin time (PT). RESULTS A significant positive correlation was seen between ETP and FII (p < 0.01; r = 0.369), as well as between peak height and FII (p < 0.01; r = 0.483). A significant negative correlation was seen between ETP and TFPI values (p < 0.05; r = -0.225) while no significant correlation was seen between peak height and TFPI. A significant negative correlation was seen between F 1.2 generation and ETP (p < 0.05; r = -0.254) and between F 1.2 generation and peak height (p < 0.05; r = -0.236). No correlation was seen between AT and ETP or peak. CONCLUSIONS CAT is a good global test reflecting procoagulatory and inhibitory factors of the haemostatic system in paediatric patients with CHD.
Collapse
Affiliation(s)
- M Koestenberger
- Department of Paediatrics, Medical University Graz, Auenbruggerplatz 30, 8036 Graz, Austria.
| | | | | | | | | | | |
Collapse
|
71
|
Koestenberger M, Nagel B, Cvirn G, Beitzke A. Aortopulmonary window, critical pulmonary stenosis, and hypoplastic right ventricle. Clin Res Cardiol 2008; 97:467-9. [PMID: 18454275 DOI: 10.1007/s00392-008-0666-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Accepted: 04/11/2008] [Indexed: 10/22/2022]
|
72
|
Cvirn G, Gallistl S, Kutschera J, Wagner T, Ferstl U, Jurgens G, Koestenberger M. Clot strength: a comparison between cord and adult blood by means of thrombelastometry. J Pediatr Hematol Oncol 2008; 30:210-3. [PMID: 18376283 DOI: 10.1097/mph.0b013e318162bd2c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To evaluate the clot strength in cord versus adult blood. METHOD Thrombelastometry (TEM) was the method of choice as it provides information on the clot strength in terms of the maximum clot firmness (MCF) and on the fibrin polymerization process in terms of the clot formation time and the alpha angle. RESULTS The MCFs were significantly lower in cord versus adult platelet rich plasma (PRP, 63.0+/-3.8 vs. 67.0+/-3.9 mm, P=0.006) and in cord versus adult whole blood (WB, 55.3+/-3.8 vs. 59.3+/-3.6 mm, P=0.001) employing the thrombelastometry with extrinsic activator assay. We suggest that the diminished clot strength in cord versus adult blood and plasma samples is attributable to an impaired polymerization of neonatal fibrin: (i) the thrombelastometry with extrinsic activator and inactivated platelets (FIBTEM) assay revealed significantly lower MCFs in cord versus adult PRP (23.0+/-3.1 mm vs. 27.3+/-3.9 mm, P=0.002) and in cord versus adult WB (11.6+/-2.3 mm vs. 15.3+/-3.3 mm, P<0.001); (ii) the alpha angle in the FIBTEM assay was significantly lower in cord versus adult WB (39.0+/-12.8 degrees vs. 55.5+/-12.3 degrees, P=0.02); (iii) the clot formation times in the FIBTEM assay were significantly longer in cord versus adult PRP (248.0+/-143.5 s vs. 81.5+/-39.8 s, P=0.001). CONCLUSIONS Neonatal fibrin shows impaired polymerization properties under our experimental conditions resulting in reduced clot strength compared with fibrin of adult origin.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Department of Pediatrics, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | | | |
Collapse
|
73
|
Koestenberger M, Cvirn G, Nagel B, Rosenkranz A, Leschnik B, Gamillscheg A, Beitzke A, Muntean W. Thrombin generation determined by calibrated automated thrombography (CAT) in pediatric patients with congenital heart disease. Thromb Res 2008; 122:13-9. [PMID: 17915295 DOI: 10.1016/j.thromres.2007.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 07/09/2007] [Accepted: 08/20/2007] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Thrombin generation was studied in pediatric patients with congenital heart disease (CHD) undergoing cardiac surgery using the calibrated automated thrombography (CAT) in terms of the lag time until the onset of thrombin formation, time to thrombin peak maximum (TTP), endogenous thrombin potential (ETP), and thrombin peak height. The possible suitability to determine the coagulation status of these patients was investigated. MATERIALS AND METHODS CAT data of 40 patients with CHD (age range from newborn to 18 years) were compared to data using standard coagulation parameters such as prothrombin (FII), antithrombin (AT), tissue factor pathway inhibitor (TFPI), prothrombin fragment 1.2 (F 1.2), thrombin-antithrombin (TAT), activated partial thromboplastin time (aPTT), and prothrombin time (PT). RESULTS A significant positive correlation was seen between ETP and FII (p<0.01; r=0.369), as well as between peak height and F II (p<0.01; r=0.483). A significant negative correlation was seen between ETP and TFPI values (p<0.05; r=-0.225) while no significant correlation was seen between peak height and TFPI. A significant negative correlation was seen between F 1.2 generation and ETP (p<0.05; r=-0.254) and between F 1.2 generation and peak height (p<0.05; r=-0.236). No correlation was seen between AT and ETP or peak. CONCLUSIONS Our data indicate that CAT is a good global test reflecting procoagulatory and inhibitory factors of the hemostatic system in pediatric patients with CHD.
Collapse
Affiliation(s)
- Martin Koestenberger
- Division of Pediatric Cardiology, Department of Pediatrics, Medical University Graz, Auenbruggerplatz 30, A-8036 Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
74
|
Cvirn G, Gallistl S, Kutschera J, Wagner T, Ferstl U, Jurgens G, Koestenberger M. Collagen/endogenous thrombin-induced platelet aggregation in whole blood samples. Blood Coagul Fibrinolysis 2007; 18:585-8. [PMID: 17762538 DOI: 10.1097/mbc.0b013e328285d832] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of the study was to investigate the individual and combined effects of collagen (3.5 microg/ml) and endogenously generated thrombin (due to addition of 0.35 pmol/l tissue factor) on platelet aggregation in the physiological environment of whole blood by means of the impedance method. Lag times were significantly shorter when a combination of collagen and endogenous thrombin was used to provoke platelet aggregation (41.9 +/- 16.3 s) compared with collagen (173.8 +/- 52.1 s, P < 0.0001) or endogenous thrombin (94.3 +/- 43.6 s, P < 0.001). Amplitudes and slopes were the lowest in collagen-induced experiments (2.83 +/- 1.59 Omega and 1.79 +/- 0.45 Omega/min, respectively), whereas they were approximately the same in endogenous thrombin-induced experiments whether collagen was present or not (13.7 +/- 3.1 versus 11.2 +/- 4.0 Omega and 6.3 +/- 2.8 versus 5.6 +/- 2.3 Omega/min, respectively). No synergistic effect of collagen and endogenous thrombin on the clot formation process was observed by means of thrombelastometry. Moreover, thrombin potentials in tissue factor-activated plasma samples were approximately the same whether collagen was present or not (834 +/- 67 versus 809 +/- 63 nmol/l.min). In conclusion, endogenously generated thrombin is a potent platelet agonist in whole blood, and a combination of collagen and endogenous thrombin synergistically shortens the lag time until the onset of platelet aggregation.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | | | |
Collapse
|
75
|
Koestenberger M, Nagel B, Gamillscheg A, Temmel W, Cvirn G, Beitzke A. Myocardial infarction in an adolescent: anomalous origin of the left main coronary artery from the right coronary sinus in association with combined prothrombotic defects. Pediatrics 2007; 120:e424-7. [PMID: 17671046 DOI: 10.1542/peds.2006-3181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We present the case of a 15-year-old boy with clinical features of an acute myocardial infarction. Angiography revealed a complete obstruction of the left main coronary artery. A coronary-aorto-bypass graft was undertaken immediately. Cardiac computed tomography demonstrated an anomalous origin of the left main coronary artery from the right coronary sinus of the aorta. A thrombophilic state with a heterozygote genotype for prothrombin G20210 mutation, a C677T methylenetetrahydrofolate reductase gene mutation, and a protein C type 1 deficiency was detected. No other embolic source could be identified. The patient recovered with persistent left ventricular dysfunction. He is now taking the anticoagulant warfarin. Combined prothrombotic defects in combination with additional risk factors such as coronary anomalies can lead to myocardial infarction even in children and adolescents.
Collapse
Affiliation(s)
- Martin Koestenberger
- Department of Pediatrics, Medical University Graz, Auenbruggerplatz 30, A-8036 Graz, Austria.
| | | | | | | | | | | |
Collapse
|
76
|
Cvirn G, Gallistl S, Koestenberger M, Kutschera J, Ferstl U, Kellner J, Jurgens G, Gries A. Effects of beta2-glycoprotein-I on platelet aggregation in cord versus adult whole blood. Platelets 2007; 18:24-8. [PMID: 17365850 DOI: 10.1080/09537100600800529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We present a peculiarity of the neonatal hemostatic system that might contribute to establish a procoagulant readiness in neonatal blood by sensitizing neonatal platelets for ADP stimulation. beta2-glycoprotein-I (beta2-GP-I) is a plasma constituent capable of suppressing ADP-induced platelet aggregation. We found significant lower levels of beta2-GP-I in cord vs. adult plasma (120 +/- 27 vs. 180 +/- 37 microg/mL, P<0.001). We demonstrate dose-dependent inhibition of ADP-induced platelet aggregation in cord whole blood (WB) in the presence of increasing amounts of beta2-GP-I, evaluated by means of WB aggregometry employing the impedance method. Particularly, raising the beta2-GP-I concentration in cord WB from neonatal level up to the respective adult value caused significant reduction of amplitude (from 9.5 +/- 2.7 to 2.8 +/- 0.9 Omega, P<0.001) and of slope (from 5.9 +/- 2.4 to 1.89 +/- 0.9 Omega/min, P<0.001), and a significant prolongation of the aggregation time (from 51.8 +/- 22.9 to 110.8 +/- 60.3 s, P<0.001). In conclusion, physiological low levels of beta2-GP-I in cord WB cause enhanced responsiveness of neonatal platelets to ADP stimulation. This mechanism might help to explain the clinically observed well-functioning hemostasis in neonates.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
77
|
Cvirn G, Cimenti C, Kutschera J, Ferstl U, Wagner T, Muntean W, Jurgens G, Gallistl S, Koestenberger M. Anticoagulant action of melagatran: a comparison between neonates and adults using calibrated automated thrombography (CAT). Eur J Pediatr 2007; 166:427-31. [PMID: 17047995 DOI: 10.1007/s00431-006-0253-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Accepted: 07/13/2006] [Indexed: 11/29/2022]
Abstract
In the present study, we comparatively evaluated the anticoagulant efficacy of the new direct thrombin inhibitor melagatran in cord vs. adult plasma. In contrast to heparin, melagatran does not require antithrombin as a cofactor. Thus, anticoagulant treatment with melagatran is of special interest in neonatal patients, whose plasma is relatively deficient in antithrombin. We evaluated the anticoagulant action of increasing amounts of melagatran (0.1-2.0 micromol/l) in both cord and adult plasma by means of calibrated automated thrombography (CAT) with respect to the lag time until the onset of thrombin formation, time to thrombin peak maximum (TTP), endogenous thrombin potential (ETP), and thrombin peak height. Melagatran exhibited approximately the same ability to prolong lag times or TTPs in both cord and adult plasma. Similar concentrations (IC(50)) of melagatran were required to double the lag times (0.44+/-0.04 micromol/l vs. 0.52+/-0.05 micromol/l) or to double the TTPs (0.91+/-0.08 micromol/l vs. 1.06+/-0.09 micromol/l) in cord vs. adult plasma. Melagatran exhibited a higher ability to suppress ETPs or thrombin peak heights in cord vs. adult plasma. Markedly lower concentrations (IC(50)) of melagatran were required to suppress ETPs (0.27+/-0.03 micromol/l vs. 0.70+/-0.06 micromol/l) or thrombin peak heights by 50% (0.29+/-0.03 micromol/l vs. 0.53+/-0.04 micromol/l) in cord vs. adult plasma. We conclude that our results suggest a higher ability of melagatran to suppress thrombin formation in cord vs. adult plasma. Thus, lower amounts of melagatran might be required in neonates undergoing antithrombotic therapy.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, 8010, Graz, Austria.
| | | | | | | | | | | | | | | | | |
Collapse
|
78
|
Cvirn G, Gruber HJ, Koestenberger M, Kutschera J, Wagner T, Ferstl U, Sedlmayr P, Juergens G, Gallistl S. High availability of intravascular tissue factor in neonates. J Pediatr Hematol Oncol 2007; 29:279-83. [PMID: 17483700 DOI: 10.1097/mph.0b013e31804bdb12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the present study, we compared the levels of intravascular tissue factor (TF) present in cord versus adult whole blood (WB) prior and after lipopolysaccharide (LPS) stimulation. High levels of intravascular TF might help to explain the clinically observed efficient clotting of cord blood despite low levels of procoagulatory factors. Quantitative reverse transcription-polymerase chain reaction revealed same (basal) TF mRNA expression levels in both native cord and adult WB, and approximately same increase in TF mRNA expression owing to LPS incubation in both cord and adult WB (normalized to the housekeeping gene beta-actin). Flow-cytometric (fluorescence activated cell sorting) analysis revealed significantly higher surface TF antigen exposure on the neonatal monocyte membrane in native WB samples, and approximately same ability of neonatal and adult monocytes to express TF upon LPS-stimulation. Thrombelastography revealed significantly shorter clotting times of native cord versus adult WB (527+/-41 vs. 592+/-23 s, P<0.05). Moreover, shortening of clotting times owing to LPS-stimulation was significantly more pronounced in cord versus adult WB (29.65+/-3.35% vs. 12.03+/-6.23%, P<0.05). Because both quantitative reverse transcription-polymerase chain reaction and fluorescence activated cell sorting analysis revealed same capability of both neonatal and adult monocytes to express TF upon LPS-stimulation, this efficient shortening effect in cord WB might be explained by the constitutively high number of monocytes present in neonates. We suggest that the high levels of intravascular TF present in neonates (prior and after LPS-stimulation) might help to explain the clinically observed efficient clotting of cord blood despite low levels of procoagulatory factors.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Department of Pediatrics, Medical University of Graz, Austria.
| | | | | | | | | | | | | | | | | |
Collapse
|
79
|
Koestenberger M, Gallistl S, Bettina L, Cimenti C, Kutschera J, Cvirn G. Effects of melagatran on activated partial thromboplastin time and on ecarin clotting time in cord versus adult plasma. Blood Coagul Fibrinolysis 2006; 17:677-80. [PMID: 17102656 DOI: 10.1097/01.mbc.0000252604.63142.e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Melagatran is the active form of the oral direct thrombin inhibitor ximelagatran. Melagatran does not require antithrombin as a cofactor. Its administration is therefore of special interest in neonatal patients, whose plasma is relatively deficient in antithrombin. We investigated the effects of increasing amounts of melagatran (0.05-1 micromol/l) on the activated partial thromboplastin time (APTT) and ecarin clotting time (ECT) in cord versus adult plasma. Both the APTT and ECT were dose-dependently prolonged in the presence of increasing amounts of melagatran. Furthermore, the ECT revealed a higher susceptibility of cord plasma to addition of melagatran than adult plasma. Whereas similar amounts of melagatran were required in cord and adult plasma samples to double the APTT (IC(50), 0.47 vs 0.46 micromol/l), significantly less melagatran was required in cord versus adult plasma to double the ECT (IC(50), 0.26 vs 0.56 micromol/l). Based on APTT measurements, similar plasma levels of melagatran might be required in neonates and in adults to treat thromboembolic complications. The APTT, however, is relatively insensitive to plasma melagatran concentrations. When the sensitive indicator ECT is used, results suggest that lower amounts of melagatran might be required in neonates than in adults. This has to be scrutinized in future clinical studies.
Collapse
|
80
|
Cvirn G, Koestenberger M, Leschnik B, Male C, Kutschera J, Ferstl U, Muntean W, Juergens G, Gallistl S. Protein S modulates the anticoagulant action of recombinant human activated protein C: a comparison between neonates and adults. Br J Pharmacol 2006; 146:1082-6. [PMID: 16273121 PMCID: PMC1751238 DOI: 10.1038/sj.bjp.0706436] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Recombinant human-activated protein C (rhAPC, Drotrecogin alpha (activated), Xigris) has been shown to reduce organ damage and decrease mortality in severe sepsis. Since protein S (PS) serves as a potentiating cofactor of activated protein C and since PS levels are low in neonatal plasma, we hypothesized that the anticoagulant effect of rhAPC would be decreased in cord plasma compared to adult plasma. We demonstrate that the anticoagulant action of 0.3 microg ml(-1) rhAPC (5 nmol l(-1)) was decreased in cord plasma compared to adult plasma, and dose dependently increased in cord plasma in the presence of increasing activities of PS. Correspondingly, the anticoagulant action of rhAPC decreased in adult plasma in the presence of decreasing activities of PS. The low anticoagulant action of rhAPC in cord compared to adult plasma is attributable to low neonatal levels of PS, and as previously shown, to low neonatal levels of TFPI and AT. Our laboratory experiments do not allow definite conclusions for clinical situations. However, we speculate that the anticoagulant efficacy of rhAPC is impaired in neonates and in clinical situations associated with consumption and/or inhibition of PS, AT, and TFPI, such as severe sepsis.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Harrachgasse 21/II, Graz A-8010, Austria.
| | | | | | | | | | | | | | | | | |
Collapse
|
81
|
Fritsch P, Cvirn G, Cimenti C, Baier K, Gallistl S, Koestenberger M, Roschitz B, Leschnik B, Muntean W. Thrombin generation in factor VIII-depleted neonatal plasma: nearly normal because of physiologically low antithrombin and tissue factor pathway inhibitor. J Thromb Haemost 2006; 4:1071-7. [PMID: 16689761 DOI: 10.1111/j.1538-7836.2006.01947.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Bleeding in hemophilic neonates has a low incidence. A possible explanation for this could be the peculiarities of the neonatal hemostatic system, especially low levels of the inhibitors tissue factor pathway inhibitor (TFPI) and antithrombin (AT). OBJECTIVE We investigated the influence of an elevation of these inhibitors to adult levels on the thrombin generation (TG) in normal neonatal plasma and factor (F) VIII-depleted neonatal plasma by means of incubation with anti-FVIII-antibodies. PATIENTS/METHODS TG was measured after activation with low amounts of tissue factor (TF) by using Calibrated Automated Thrombography. RESULTS TG in FVIII-depleted neonatal plasma was nearly as high as in normal neonatal plasma. TG decreased after elevation of AT in both neonatal plasmas. After elevation of TFPI TG decreased much more in FVIII-depleted neonatal plasma than in normal neonatal plasma. After elevation of both inhibitors their synergistic effect led to a stronger decrease of TG in FVIII-depleted neonatal plasma. TG measured in plasma of one hemophilic newborn showed the same pattern as in FVIII-depleted neonatal plasma. CONCLUSION Our observation provides a biochemical basis for the rare bleeding in hemophilic neonates and shows the important role of the natural inhibitors in the hemostatic system of hemophilic patients.
Collapse
Affiliation(s)
- P Fritsch
- Department of Pediatrics, Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Medical University of Graz, Auenbruggerplatz 30, 8036 Graz, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
82
|
Koestenberger M, Gallistl S, Muntean W, Ferstl U, Kutschera J, Cvirn G. An evaluation of the procoagulant action of recombinant activated factor VII in cord whole blood versus adult whole blood using thromboelastography. Blood Coagul Fibrinolysis 2005; 16:613-7. [PMID: 16269937 DOI: 10.1097/01.mbc.0000191523.79682.15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recombinant activated factor VII (rFVIIa) has been reported to be effective in adult patients in various clinical situations and might be beneficial in neonates with bleeding tendency. In the present study we compared the procoagulant action of increasing amounts of rFVIIa in both cord whole blood and adult whole blood with respect to changes in the values of the clotting time, clot formation time, and maximum clot firmness by means of thromboelastography. Thromboelastography allows evaluation of the effects of rFVIIa on haemostasis in whole blood. When increasing amounts of rFVIIa were added in vitro to whole blood samples, significant decreases in the values of the clotting time and clot formation time and a significant increase in the maximum clot firmness were observed. Cord whole blood was significantly more sensitive to rFVIIa addition than adult whole blood, an effect probably attributable to the low anticoagulant capacity of the neonatal plasma. Maximum clot firmness values were significantly lower in cord whole blood than in adult whole blood, an effect mainly attributable to the hypofunctional state of neonatal platelets. Since cord whole blood exerted a significantly higher sensitivity to addition of rFVIIa, we speculate that lower doses of rFVIIa might be required to treat neonates with bleeding tendency compared with the adult rFVIIa administration strategy.
Collapse
|
83
|
Koestenberger M, Gallistl S, Muntean W, Leschnik B, Fritsch P, Cvirn G. Additive effects of anticoagulants: recombinant human activated protein C and heparin or melagatran, in tissue factor-activated umbilical-cord plasma. Thromb Haemost 2005; 94:69-74. [PMID: 16113786 DOI: 10.1160/th05-01-0041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Severe sepsis in children or adults may cause a life-threatening coagulopathy, with widespread consumption of activated protein C (APC); recombinant human APC (rhAPC) is a promising candidate anticoagulant treatment. We investigated the effects of rhAPC and other anticoagulants on coagulation triggered by adding small quantities of lipidated tissue factor to human umbilical-cord plasma in vitro. rhAPC, unfractionated heparin (UH), and melagatran (a direct thrombin inhibitor) were studied individually, and in combinations of rhAPC with either UH or melagatran. rhAPC alone dose-dependently prolonged the activated partial-thromboplastin time (aPTT) but not the prothrombin time (PT), and dose-dependently suppressed two indices of thrombin generation, namely prothrombin fragment F 1.2 (F 1.2) generation and thrombin-antithrombin (TAT) complex formation. UH alone dose-dependently prolonged the aPTT but not the PT, while melagatran alone dose-dependently prolonged both the aPTT and the PT. Adding either UH or melagatran dose-dependently augmented the capacity of rhAPC to suppress F 1.2 generation (with addition of UH showing a greater effect) and TAT formation (with addition of melagatran showing a greater effect). Both the capacity of UH to prolong the aPTT and the capacity of melagatran to prolong the aPTT and the PT were augmented by adding rhAPC. In our in-vitro study, adding either UH or melagatran augmented the capacity of rhAPC to suppress thrombin generation in human umbilical-cord plasma, with the anticoagulant effect of melagatran being more predictable than that of UH. Hence, combining rhAPC with melagatran might be a valuable therapeutic option in patients with severe sepsis.
Collapse
Affiliation(s)
- Martin Koestenberger
- Department of Pediatrics, and The Ludwig Boltzmann Research, Institute for Pediatric Haemostasis and Thrombosis, Medizinische Universität Graz, Auenbruggerplatz 30, 8036 Graz, Austria.
| | | | | | | | | | | |
Collapse
|
84
|
Koestenberger M, Cvirn G, Gallistl S, Kutschera J, Muntean W. Recombinant human activated protein C, heparin and melagatran in umbilical cord versus adult plasma. Acta Paediatr 2005; 94:884-9. [PMID: 16188810 DOI: 10.1111/j.1651-2227.2005.tb02006.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM We investigated the anticoagulant effects of recombinant human activated protein C (rhAPC), unfractionated heparin (UH) and melagatran (a new direct thrombin inhibitor [DTI]), when administered individually and in combinations of rhAPC with either UH or melagatran, in umbilical cord and adult plasma. rhAPC is a promising candidate treatment to improve the outcome of severe sepsis in neonates and adults; the DTI melagatran represents a potential advance in antithrombotic therapy. METHODS The anticoagulant efficacy of these drugs was measured using the standard coagulation assays activated partial thromboplastin time (aPTT) and prothrombin time (PT). RESULTS Administered individually, rhAPC, UH and melagatran dose-dependently prolonged aPTT to a significantly greater extent in umbilical cord than in adult plasma. Melagatran alone, but not rhAPC or UH alone, dose-dependently prolonged the PT in both umbilical cord and adult plasma. Combining rhAPC with either UH or melagatran significantly augmented aPTT prolongation in both umbilical cord and adult plasma. CONCLUSION Our results, which facilitate estimation of rhAPC and melagatran dose requirements in umbilical cord plasma, may be of benefit in critically sick newborns with severe sepsis.
Collapse
Affiliation(s)
- Martin Koestenberger
- Department of Paediatrics, Ludwig Boltzmann Research Institute for Paediatric Haemostasis and Thrombosis, Medical University of Graz, Auenbruggerplatz 30, A-8036 Graz, Austria.
| | | | | | | | | |
Collapse
|
85
|
Rehak T, Cvirn G, Gallistl S, Leschnik B, Köstenberger M, Katzer H, Ribitsch V, Muntean W. Increased shear stress- and ristocetin-induced binding of von Willebrand factor to platelets in cord compared with adult plasma. Thromb Haemost 2005; 92:682-7. [PMID: 15467896 DOI: 10.1160/th04-05-0270] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Multiple indications do exist that the extensive neonatal platelet adhesion and aggregation, and the shorter closure time of neonatal compared with adult whole blood in the platelet function analyzer 100 are attributable to the physiological high plasma concentrations and high concentrations of unusually large von Willebrand factor (vWf) multimers in neonates. However, to date the direct experimental evidence is lacking. Therefore, we compared in the present study the ability of neonatal vWf to bind to platelets to that of adult vWf. Platelet-poor plasma of neonatal or adult origin, containing antibody-stained vWf, was incubated with neonatal or adult platelet suspension. Subsequently, vWf-platelet interaction was induced by exposing the mixture to shear stress by means of a cone/plate measuring system or by incubating the mixture with ristocetin. Finally, samples were analyzed in a FACScan flow cytometer. Detected fluorescence intensities directly correlate with the amount of vWf attached to the platelet surface. We found that significantly higher amounts of neonatal vWf were attached to platelets in the presence of shear stress or ristocetin. This efficient neonatal vWf-platelet interaction is an effect intrinsic to the neonatal vWf, and not to the neonatal platelet: the amount of neonatal vWf attached to neonatal platelets was not different from the amount of neonatal vWf attached to adult platelets. Furthermore, decreasing the vWf content in cord plasma to adult level resulted in significantly suppressed vWf-platelet attachment in the presence of ristocetin, indicating that the high neonatal vWf level contributes to the efficient vWf-platelet binding in neonates.
Collapse
Affiliation(s)
- Thomas Rehak
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Graz, Austria
| | | | | | | | | | | | | | | |
Collapse
|
86
|
Baier K, Cvirn G, Fritsch P, Köstenberger M, Gallistl S, Leschnik B, Muntean W. Higher concentrations of heparin and hirudin are required to inhibit thrombin generation in tissue factor-activated cord plasma than in adult plasma. Pediatr Res 2005; 57:685-9. [PMID: 15718352 DOI: 10.1203/01.pdr.0000156515.49293.f8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Neonatal plasma clots slower than adult plasma, and only 30-50% of peak adult thrombin activity can be produced in neonatal plasma when high amounts of tissue factor (TF) are added to trigger clotting, as used in standard clotting assays. Plasma activation by addition of low amounts of TF probably better reflects conditions in vivo. Under these conditions, cord plasma clots faster than adult plasma. In the present study, we show that after activation with low amounts of TF, higher amounts of the anticoagulants heparin and hirudin are required in cord plasma for effective inhibition of thrombin generation compared with adult plasma. After strong activation with high amounts of TF (30 microM), the thrombin potential was significantly more suppressed in cord plasma compared with adult plasma in the presence of 0.4 IE/mL heparin (-92 versus -75%; p < 0.01) and in the presence of 2 IE/mL hirudin (-18 versus -8%; p < 0.01). In contrast, after weak activation with low amounts of TF (30 pM), the thrombin potential was significantly more suppressed in adult plasma compared with neonatal plasma in the presence of 0.025 IE/mL heparin (-93 versus -8%; p < 0.01) and in the presence of 2 IE/mL hirudin (-89 versus -48%; p < 0.01). Our results show that in neonates, effects of anticoagulants very much depend on the type of activation used to initiate clotting, and doses of anticoagulants should not be derived from studies done in adults, because potentially higher doses of anticoagulants may be required.
Collapse
Affiliation(s)
- Katrin Baier
- Ludwig Boltzmann Researrch Institute for Pediatric Hemostasis and Thrombosis, Medical University of Graz, Graz, Australia
| | | | | | | | | | | | | |
Collapse
|
87
|
Koestenberger M, Gallistl S, Cvirn G, Baier K, Leschnik B, Muntean W. Anticoagulant action of melagatran, the active form of the oral direct thrombin inhibitor ximelagatran, in umbilical cord and adult plasma: an in vitro examination. Thromb Res 2005; 115:135-42. [PMID: 15567465 DOI: 10.1016/j.thromres.2004.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Revised: 06/16/2004] [Accepted: 07/07/2004] [Indexed: 11/21/2022]
Abstract
INTRODUCTION This study was performed to compare the anticoagulant activity of melagatran, the active form of the oral direct thrombin inhibitor ximelagatran, in umbilical cord plasma with that in adult plasma. In contrast with the most frequently administered anticoagulants, the heparins, melagatran acts independently of antithrombin (AT). As a consequence, administration of melagatran is of special interest in neonates, who have physiologically low levels of AT. MATERIALS AND METHODS Plasma samples were activated under high (as used in standard clotting assays) and low (more comparable with the physiological milieu) coagulant challenge. In the absence of melagatran, adult plasma clotted significantly faster than umbilical cord plasma under high coagulant challenge. Conversely, under low coagulant challenge, clotting of adult plasma was significantly delayed compared with umbilical cord plasma. For both high and low coagulant challenges, clotting times increased and prothrombin fragment 1.2 and thrombin-antithrombin (TAT) formation decreased with melagatran in a concentration-dependent fashion in umbilical cord and adult plasma. With increasing melagatran concentrations, the quotient between prothrombin fragment 1.2 and TAT formation increased in adult and umbilical cord plasma under both high and low coagulant challenges. RESULTS AND CONCLUSIONS Our in vitro results cannot be directly extrapolated to clinical efficacy, but assessing the degree of inhibition of thrombin generation may be a useful surrogate for selecting effective doses of ximelagatran for in vivo studies in neonates with thromboembolic complications.
Collapse
Affiliation(s)
- Martin Koestenberger
- Department of Pediatrics, Karl Franzens University of Graz, Auenbruggerplatz, A-8036 Graz, Austria.
| | | | | | | | | | | |
Collapse
|
88
|
Cvirn G, Gallistl S, Koestenberger M, Baier K, Fritsch P, Greilberger J, Jürgens G, Muntean W. The anticoagulant action of recombinant human activated protein C (rhAPC, Drotrecogin alpha activated): comparison between cord and adult plasma. Thromb Haemost 2004; 91:912-8. [PMID: 15116251 DOI: 10.1160/th03-12-0739] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The present study was performed to compare the anti-coagulant efficiency of recombinant human activated protein C (rhAPC) in cord with that in adult plasma. RhAPC is a promising candidate to improve the outcome of severe sepsis. However, different anticoagulant efficiency of rhAPC in cord compared with adult plasma has to be expected due to physiological low plasma levels of tissue factor pathway inhibitor (TFPI) and antithrombin (AT) present in neonates, two inhibitors known to markedly influence the anticoagulant action of APC. Clot formation was induced in our experiments by addition of high (30 micro M) or low (20 pM) amounts of lipidated tissue factor (TF). High amounts of TF are conventionally applied in standard clotting assays, whereas plasma activation with low amounts of TF probably better matches the conditions in vivo. We demonstrate that under low coagulant challenge increasing amounts of rhAPC (0.1-0.5 micro g/ml final plasma concentration) dose-dependently prolonged clotting time and suppressed thrombin potential and prothrombin fragment 1+2 generation in both cord and adult plasma. The same was true for experiments performed under high coagulant challenge when 4-16 micro g/ml of rhAPC were added. Whereby, cord plasma was significantly more susceptible to addition of rhAPC in the presence of high amounts of TF and adult plasma was significantly more susceptible to addition of rhAPC in the presence of low amounts of TF. We demonstrate that increased anticoagulant efficiency of rhAPC in adult plasma under low coagulant challenge is attributable to the physiological high levels of TFPI and AT present in adults.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Institute of Medical Chemistry and Pregl Laboratory, Karl Franzens University of Graz, Harrachgasse 21/II, A-8010 Graz, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
89
|
Koestenberger M, Cvirn G, Gallistl S, Muntean W. Drotrecogin alfa activated (recombinant human activated protein C) in combination with heparin or melagatran. Blood Coagul Fibrinolysis 2004; 15:693-7. [PMID: 15613925 DOI: 10.1097/00001721-200412000-00010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recombinant human activated protein C (rhAPC) has recently been demonstrated to be a promising candidate to improve the outcome for patients with severe sepsis. Plasma-derived activated protein C and unfractionated heparin (UH) exert anticoagulant synergy due to mechanisms that simultaneously decrease thrombin generation. Melagatran, a new direct thrombin inhibitor, does not bind to plasma proteins or requires antithrombin as a cofactor. The latter is often consumed in patients with severe sepsis. We investigated the anticoagulant efficiency in combined administration of rhAPC and UH or melagatran in terms of prolongation of the standard clotting assays activated partial thromboplastin time (aPTT) and prothrombin time (PT) in pooled plasma samples in vitro. RhAPC dose-dependently prolonged the aPTT but not the PT. The ability of UH and melagatran to prolong the aPTT was significantly enhanced in combination with rhAPC. The combined administration of rhAPC and melagatran, but not UH, resulted in additive prolongation of the PT. In control measurements the capability of rhAPC to suppress prothrombin fragment 1.2 generation dose-dependently increased in combination with heparin and melagatran. Our study demonstrates the respective effects of rhAPC, UH, melagatran and further different additive effects in combined administration of rhAPC and UH or melagatran on the prolongation of the aPTT and PT clotting assays usually used to monitor anticoagulant treatment.
Collapse
Affiliation(s)
- Martin Koestenberger
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Medical University of Graz, Graz, Austria.
| | | | | | | |
Collapse
|
90
|
|
91
|
Abstract
Human macrophages stimulated with interferon-gamma generate neopterin and 7,8-dihydroneopterin which interfere with reactive species involved in LDL oxidation. While neopterin was found to have pro-oxidative effects on copper-mediated LDL oxidation, the influence of 7,8-dihydroneopterin is more complex. This study provides detailed information that 7,8-dihydroneopterin reveals both pro-oxidative and anti-oxidative effects on copper mediated LDL oxidation. 7,8-dihydroneopterin inhibited the oxidation of native LDL effectively monitored by (i) formation of conjugated dienes, (ii) relative electrophoretic mobility (EM) and (iii) specific oxidized epitopes. Using minimally oxidized LDL (mi-LDL) or moderately oxidized LDL (mo-LDL) 7,8-dihydroneopterin changed its antioxidative behavior to a strongly pro-oxidative. Incubation of 7,8-dihydroneopterin with native LDL, mi-LDL or mo-LDL in the absence of copper ions showed that formation of conjugated dienes was more increased in mo-LDL than in mi-LDL while no diene formation was observed with native LDL. We suggest that 7,8-dihydroneopterin is a modulator for LDL oxidation in the presence of copper ions depending on the "oxidative status" of this lipoprotein.
Collapse
Affiliation(s)
- Joachim Greilberger
- Institute for Medical Chemistry and Pregl-Labratory, University of Graz, Harrachgasse 21/2, A-8010, Graz, Austria.
| | | | | | | | | |
Collapse
|
92
|
Koestenberger M, Cvirn G, Gallistl S, Baier K, Leschnik B, Muntean W. Drotrecogin Alfa (activated, Xigris�) in Combination with Heparin or Melagatran: An In vitro Investigation. J Thromb Thrombolysis 2004; 18:5-10. [PMID: 15744547 DOI: 10.1007/s11239-004-0167-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The present in vitro study of human plasma investigated the anticoagulant effects of recombinant human activated protein C (rhAPC; drotrecogin alfa [activated, Xigris]), combined with either unfractionated heparin (UH) or the direct thrombin inhibitor melagatran. METHODS Prolongation of clotting time and generation of prothrombin fragments 1 and 2 (F1 + 2) and of thrombin-antithrombin (TAT) complex were measured in vitro. Clot formation was induced by adding low levels (final concentration, 20 pmol/L) of lipidated tissue factor (TF) to citrated venous plasma samples from healthy human volunteers (n = 16). It has been suggested that experimental activation of plasma with low levels of TF more closely simulates conditions in vivo. RESULTS rhAPC, melagatran, or UH alone concentration-dependently prolonged the clotting time and suppressed F1 + 2 and TAT generation. rhAPC-mediated prolongation of clotting time concentration-dependently increased with the addition of either UH or melagatran, the effect being more pronounced with the addition of melagatran. Similarly, rhAPC-mediated generation of F1 + 2 and TAT also increased concentration-dependently with the addition of either UH or melagatran; the effect being, in this case, more pronounced with the addition of UH. CONCLUSIONS This study demonstrated the effects of rhAPC, alone and combined with either UH or melagatran, on clotting time and markers of thrombin generation in human plasma. These results may guide facilitate estimation of appropriate doses of rhAPC and melagatran in future clinical trials.
Collapse
Affiliation(s)
- Martin Koestenberger
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Medical University of Graz, Auenbruggerplatz 30, A-8036 Graz, Austria.
| | | | | | | | | | | |
Collapse
|
93
|
Koestenberger M, Gallistl S, Cvirn G, Roschitz B, Rehak T, Leschnik B, Muntean W. Combined effects of melagatran and eptifibatide on platelet aggregation inhibition but not thrombin generation inhibition. Blood Coagul Fibrinolysis 2004; 15:131-7. [PMID: 15091000 DOI: 10.1097/00001721-200403000-00004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The aim of our study was to investigate the combined in vitro effects of melagatran and eptifibatide on platelet aggregation and thrombin generation under low and high coagulant challenge in tissue-factor-activated, platelet-rich plasma. Increasing amounts of melagatran dose-dependently decreased prothrombin fragment 1.2 and activated factor X values, and dose-dependently prolonged the lag phase until the onset of platelet aggregation. Eptifibatide exerted a dose-dependent anti-aggregating effect under both high and low coagulant challenge. The combination of melagatran and eptifibatide resulted in significant additive prolongation of the lag phase until the onset of platelet aggregation, which was more pronounced under low coagulant challenge. Under low, but not under high, coagulant challenge, the combination of melagatran and eptifibatide had a significant additive inhibitory effect on platelet aggregation. No additive effects on decreasing prothrombin fragment 1.2 and activated factor X values were observed with combined administration of the drugs. The present study demonstrates the additive effect of melagatran and eptifibatide on platelet aggregation inhibition and on prolongation of the lag phase until the onset of platelet aggregation.
Collapse
Affiliation(s)
- Martin Koestenberger
- Department of Pediatrics, Ludwig Boltzmann Research Institute for Pediatric Haemostasis and Thrombosis and Institute of Medical Chemistry and Pregl Laboratory, University of Graz, Austria.
| | | | | | | | | | | | | |
Collapse
|
94
|
Köstenberger M, Gallistl S, Cvirn G, Muntean W. A laboratory method for parallel determination of platelet aggregation and thrombin generation. Clin Lab 2004; 50:41-8. [PMID: 15000219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Optimal use of combinations of antiaggregating and antithrombotic drugs in vivo requires improved methods for testing of possible synergistic drug effects. Therefore, we developed an in vitro model that allows parallel evaluation of the influence of drugs on the time course of platelet aggregation inhibition and on thrombin generation inhibition. Platelet rich plasma samples were incubated with different amounts of antiaggregating and/or antithrombotic agents and the effects on thrombin generation, lag phase until the onset of platelet aggregation, and on inhibition of platelet aggregation were detected. Plasma activation was performed by addition of high (29 nM final concentration, "high coagulant challenge") or low (5 pM final concentration, "low coagulant challenge") amounts of tissue factor. Thus, platelet activation is initiated in our model by endogenously generated thrombin and not by exogenously added agonists, as usual in conventional evaluation of platelet aggregation. The combination of glycoprotein IIb/IIIa inhibitors (eptifibatide or abciximab) and anticoagulants (unfractionated heparin, low molecular weight heparin, or recombinant hirudin) used in this study exhibited an additive effect on prolongation of the lag phase until the onset of platelet aggregation. Under high but not under low coagulant challenge the combination of eptifibatide and anticoagulants had a synergistic inhibitory effect on platelet aggregation. Combination of abciximab and anticoagulants had no additive inhibitory effects on platelet aggregation under both high and low coagulant challenge. Under low coagulant challenge combination of eptifibatide but not abciximab with low molecular weight heparin significantly reduced the thrombin generation. We suggest that our laboratory method might be useful for pre-clinical testing of in vitro effects of glycoprotein IIb/IIIa inhibitors and anticoagulants.
Collapse
|
95
|
Abstract
Clinically observed excellent hemostasis in neonates despite low levels of clotting factors is not completely understood so far. Therefore, we investigated whether physiological low levels of the inhibitor protein C (PC) facilitate thrombin formation in tissue factor (TF)-activated plasma samples. PC was activated by endogenously generated thrombin after addition of soluble thrombomodulin (TM). The capability of activated PC (APC) to suppress thrombin formation was significantly more pronounced in adult than in cord plasma. Addition of 4 nm of TM decreased the thrombin potential (TP) in cord plasma by 10%, and in adult plasma by 52% in the presence of 5 pm TF. We demonstrate that this low anticoagulant action of PC is attributable to the low levels of tissue factor pathway inhibitor (TFPI) and antithrombin (AT) physiologically present in cord plasma. Addition of 4 nm TM decreased the TP by 58% in cord plasma adjusted to contain TFPI and AT at adult levels in the presence of 5 pm TF. Thus, the combined low anticoagulant action of the three inhibitors APC, TFPI, and AT in cord plasma allows enhanced thrombin formation associated with shorter clotting times compared with adult plasma when low amounts of TF are applied to initiate clot formation. Although our laboratory experiments do not allow definite conclusions for various clinical situations, our data might contribute to explain excellent hemostasis in neonates despite low levels of procoagulants.
Collapse
Affiliation(s)
- G Cvirn
- Institute of Medical Chemistry and Pregl Laboratory and Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis at the Department of Pediatrics, Karl Franzens University of Graz, Graz, Austria.
| | | | | | | | | |
Collapse
|
96
|
Cvirn G, Gallistl S, Leschnik B, Muntean W. Low tissue factor pathway inhibitor (TFPI) together with low antithrombin allows sufficient thrombin generation in neonates. J Thromb Haemost 2003; 1:263-8. [PMID: 12871499 DOI: 10.1046/j.1538-7836.2003.00081.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neonates have an excellent hemostasis despite, in comparison to adults, markedly decreased and delayed ability to generate thrombin. Only 30-50% of peak adult thrombin activity can be produced in neonatal plasma by means of conventional in vitro assays. We show that in contrast to conventional activation, activation with small amounts of lipidated tissue factor (<10 pmol L(-1)) results in shorter clotting times and faster activated factor X- and thrombin generation in neonates compared with adults due to the concomitant action of low tissue factor pathway inhibitor and antithrombin. The concentrations of both inhibitors in cord plasma are approximately 50% of the respective adult values. After addition of 2.5 pmol L(-1) lipidated tissue factor, cord plasma clotted approximately 90 s earlier than adult plasma and the amount of free thrombin generated was approximately 90% of adult value (291 +/- 14 vs. 329 +/- 16 nmol L(-1) min(-1), P < 0.01). Our results might help to explain the clinically observed excellent hemostasis of neonates despite low levels of procoagulant factors.
Collapse
Affiliation(s)
- G Cvirn
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Department of Pediatrics, University of Graz, Austria.
| | | | | | | |
Collapse
|
97
|
Koestenberger M, Gallistl S, Cvirn G, Roschitz B, Petritsch M, Leschnik B, Muntean W. Combined effects of eptifibatide and anticoagulants: differences between LMWH and UH or rH in thrombin generation inhibition but not in platelet aggregation inhibition. Thromb Haemost 2002; 88:1012-9. [PMID: 12529753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Aim of our study was to investigate effects of eptifibatide and anticoagulants on platelet aggregation and thrombin generation under low and high coagulant challenge in tissue factor-activated platelet rich plasma using a model allowing simultaneous determination of the time course of platelet aggregation and thrombin generation. Eptifibatide exerted a dose-dependent anti-aggregating effect under both high and significantly stronger under low coagulant challenge. Combination of eptifibatide and anticoagulants resulted in significant additive prolongation of the lag phase until the onset of platelet aggregation, more pronounced under low coagulant challenge. Under high, but not under low coagulant challenge combination of eptifibatide and anticoagulants had a significant synergistic inhibitory effect on platelet aggregation. Under low coagulant challenge combination of eptifibatide with LMWH, but not with UH, or rH, resulted in significantly reduced thrombin potential, F 1+2 generation, and FXa formation compared to measurements in the absence of eptifibatide. We demonstrate a synergistic effect of eptifibatide and anticoagulants on platelet aggregation inhibition and an additional inhibitory effect of LMWH and eptifibatide on thrombin generation. Our results support the notion that combination of eptifibatide and anticoagulants might be beneficial in atherosclerotic disease to palliate the thrombogenic potency of ruptured atherosclerotic plaques.
Collapse
|
98
|
Abstract
Activated prothrombin complex concentrates (APCCs) are effective in the therapy of bleeding episodes in hemophilic patients with inhibitors. We investigated the respective roles of factor II, factor VII, factor IX, and factor X in the procoagulant activity of the APCC FEIBA. Factor II, factor VII, factor IX, and factor X were reduced in platelet-poor plasma, and the thrombin potential (TP) was determined using a chromogenic substrate in the absence or presence of FEIBA. Reduction of factor II resulted in a significant decrease of the TP without influencing the lag phase until the onset of thrombin generation. The reduction of factor VII showed no effect on the TP, but resulted in a prolongation of the lag phase. Changes of factor IX or factor X concentrations showed neither an effect on the TP nor on lag phases. Our study demonstrates that thrombin generation in the presence of FEIBA mainly depends on prothrombin.
Collapse
Affiliation(s)
- S Gallistl
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, University of Graz, Austria.
| | | | | | | |
Collapse
|
99
|
Cvirn G, Gallistl S, Koestenberger M, Kutschera J, Leschnik B, Muntean W. Alpha 2-macroglobulin enhances prothrombin activation and thrombin potential by inhibiting the anticoagulant protein C/protein S system in cord and adult plasma. Thromb Res 2002; 105:433-9. [PMID: 12062545 DOI: 10.1016/s0049-3848(02)00042-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Protein S (PS) is a vitamin K-dependent plasma protein and serves as a cofactor for the anticoagulant activities of activated protein C (APC). We investigated the effects of different PS concentrations on prothrombin activation and thrombin generation in cord and adult plasma containing APC and different amounts of alpha 2-macroglobulin (a2-M). Prothrombin activation was assessed by monitoring the time-course of prothrombin fragment 1+2 (F1+2) generation. Thrombin generation curves were determined by means of a subsampling technique using the chromogenic substrate S-2238. We demonstrate a dose-dependent inhibition of the anticoagulant action of PS by a2-M: suppression of F1+2 and thrombin generation due to addition of PS was stronger in plasma containing low amounts of a2-M than in plasma with elevated a2-M levels. Since no complex formation between a2-M and PS was observed by means of SDS-PAGE, we attribute decreased anticoagulant action of PS at high a2-M levels to enhanced complex formation between APC and a2-M. Thereby, APC is subtracted from its cofactor PS, resulting in suppressed formation of the anticoagulant APC/PS complex. Thus, our data suggest that a2-M, besides its well-known anticoagulant effects, also acts as a procoagulant by suppressing the formation of the anticoagulant APC/PS complex. Our findings have implications particularly on thrombin generation and inhibition in cord plasma, since a2-M levels in newborns are elevated over adult values and the antithrombotic APC/PS pathway is up-regulated at birth. Therefore, elevated levels of a2-M might restrict the up-regulation of the APC/PS pathway.
Collapse
Affiliation(s)
- Gerhard Cvirn
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Graz, Austria.
| | | | | | | | | | | |
Collapse
|
100
|
Gallistl S, Sudi KM, Cvirn G, Muntean W, Borkenstein M. Effects of short-term energy restriction and physical training on haemostatic risk factors for coronary heart disease in obese children and adolescents. Int J Obes (Lond) 2001; 25:529-32. [PMID: 11319657 DOI: 10.1038/sj.ijo.0801573] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2000] [Revised: 10/13/2000] [Accepted: 11/02/2000] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To study the changes of haemostatic risk factors for coronary heart disease during a weight reduction programme in obese children and adolescents. DESIGN A short-term longitudinal study. SUBJECTS Thirty-seven obese white girls (age, 12+/-1.8 y; body mass index (BMI), 26.9+/-5.25) and 19 obese white boys (age, 11.9+/-1.7 y; BMI, 26.2+/-5.2). MEASUREMENTS Fibrinogen, factor VII coagulant activity, von Willebrand factor antigen, and soluble P-selectin were determined before and after a 3 week programme including energy restriction and physical activities. RESULTS All determined haemostatic risk factors decreased significantly during the programme. Changes in risk factors were correlated to changes in body composition. Children and adolescents with the highest initial concentrations showed the greatest decreases. CONCLUSION Energy restriction combined with physical activity improves the haemostatic risk profile in obese children and adolescents.
Collapse
Affiliation(s)
- S Gallistl
- Ludwig Boltzmann Research Institute for Pediatric Hemostasis and Thrombosis, Graz, Austria.
| | | | | | | | | |
Collapse
|