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Biomedical subjects

J Ingerslev

Publications and source records attributed to J Ingerslev.

At least 19 recordsLinked to original sources
PubMed2003

Potential role of the dynamic properties of whole blood coagulation in assessment of dosage requirements in haemophilia.

In the clinical setting, patients suffering from haemophilia are classified according to the residual level of the deficient coagulation factor. Patients suffering from the severe form of haemophilia (critical factor level <0.01 IU mL-1) display some heterogeneity in their tendency to bleeding despite the uniform factor level. Utilizing a new thrombelastographic method in which coagulation is activated by very small amounts of tissue factor and where resulting data are processed with new software, we studied the whole blood coagulation profile in 11 patients with severe haemophilia A and 11 patients with moderate haemophilia. In both groups of patients, we found a considerable degree of heterogeneity in the coagulation signal. In moderate haemophilia with factor VIII (FVIII):C levels between 0.01 and 0.05 IU mL-1, variance was expected, whereas a quite substantial diversity had not been forecasted in patterns of the whole blood coagulation profiles in patients with the severe form of haemophilia A. Ex vivo substitution to patient's blood to reach various theoretical levels of recombinant factor VIII (rFVIII) revealed that the coagulation response to FVIII supplementation varied substantially. In some severely affected patients levels of FVIII:C close to 0.05 IU mL-1 was sufficient to normalize the coagulation profile, while others required a dose giving >0.50 IU mL-1 of FVIII to achieve a normal whole blood clotting profile. In conclusion, our study revealed that severe haemophilia A seems not to be a single entity, but rather several different clinical and biochemical phenotypes, and that the response to added FVIII varies amongst patients.

Blood Coagulation↗
PubMed2003

Whole blood coagulation thrombelastographic profiles employing minimal tissue factor activation.

We investigated whole blood coagulation by thrombelastography (TEG) employing activation with minute amounts of tissue factor (TF). Continuous raw data captured were transformed into novel parameters, such as the maximum velocity (MaxVel) and the time to maximum velocity (t,MaxVel) of whole blood clot formation. The courses of the whole blood clot development were very similar to thrombin generation curves reported in plasma. In this assay healthy women (n = 30) showed an earlier onset and an increased coagulation velocity compared to healthy men (n = 30). In patients with severe hemophilia, and persons undergoing thromboprophylaxis, distinctly abnormal coagulation profiles were observed with a decrease in the MaxVel, as well as a prolonged t,MaxVel. Changes appeared to be dependent on the nature and severity of the hemostatic deficit. Preliminary studies in patients substituted with recombinant factor VIIa demonstrated a marked change in the coagulation profile, in which the MaxVel and t,MaxVel shifted towards normal in a dose-dependent way. Data suggest that the whole blood coagulation TEG profile, following activation with minute amounts of TF, may reflect the hemostatic potential in patients suspected of impaired hemostasis.

Adult↗
PubMed2002

Insulin resistance is accompanied by increased von Willebrand factor levels in nondiabetic women: a study of offspring of type 2 diabetic subjects compared to offspring of nondiabetic subjects.

OBJECTIVES: To examine whether levels of von Willebrand factor (vWF), fibrinogen and fibronectin are related to a parental history of type 2 diabetes and to determine possible explanatory factors for high versus low vWF and fibrinogen. DESIGN: Cross-sectional study. SUBJECTS, MAIN OUTCOME MEASURES: We compared vWF, fibrinogen and fibronectin in 88 nondiabetic offspring of type 2 diabetic subjects (relatives) and 103 offspring of nondiabetic subjects (controls). Other measurements included urinary albumin excretion rate, blood pressure, lipid profile and insulin resistance using homeostasis model assessment (HOMAIR). RESULTS: There were no significant differences in vWF (1.12 vs. 1.06 IU x mL(-1), P = 0.296), fibrinogen (3.2 vs. 3.1 g x L(-1); P = 0.263) or fibronectin (0.39 vs. 0.40 g x L(-1), P = 0.448) between relatives and controls. With multiple logistic regression we determined explanatory factors for high versus low vWF and fibrinogen. Age (P < 0.01), urinary albumin excretion rate (P < 0.05), ischaemic heart disease (IHD) (P < 0.05) were found to be significant explanatory factors for vWF above the median (1.10 IU x mL(-1)). Interaction between insulin resistance and sex was found. Odds ratio for high versus low insulin resistance was 18.39 (P < 0.001) for women and 1.92 (P = 0.32) for men. Body mass index (BMI) (P < 0.05), sex (P < 0.01), smoking status (P < 0.05) and IHD (P < 0.01) were significant explanatory factors for fibrinogen above the median (3.1 g x L(-1)). CONCLUSIONS: Levels of vWF, fibrinogen and fibronectin were not influenced by a parental history of type 2 diabetes. Insulin resistance was found to be a significant risk indicator for high vWF only in women. This may indicate that insulin resistance is a higher risk factor for women than for men, when the outcome is endothelial dysfunction possibly resulting in overt cardiovascular disease.

Case-Control Studies↗
PubMed2001

Use of recombinant factor VIIa (NovoSeven) in patients with Glanzmann thrombasthenia.

Recombinant factor VIIa (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) appears effective and relatively safe for the treatment of bleeding and for surgical prophylaxis in patients with Glanzmann thrombasthenia as reported to the International Registry on rFVIIa and Congenital Platelet Disorders. One of the shortcomings of the Registry data is the heterogeneity of treatment protocol, including dosage, number of doses used, duration of treatment before declaration of failure, and mode of rFVIIa administration (bolus v continuous infusion). The data are not yet sufficient to define optimal regimens for various indications such as the type of bleeding or the type of procedures. The place of this drug compared to platelet transfusion in the overall management of patients with Glanzmann thrombasthenia will need to be determined in relationship to a number of challenges and unresolved issues in the clinical care of these patients. These issues include: how to improve local measures for patients with mucosal bleeds, optimal management of young women during menarche, optimal platelet transfusion regimens for various indications, the relationship between antiplatelet antibodies detected by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and effectiveness of platelet transfusion, whether there are other biological tests that may correlate with effectiveness of platelet transfusion, and management of pregnancy and delivery regarding antiplatelet immunization.

Coagulants↗
PubMed2001

The pulmonary vasculature in a neonatal porcine model with increased pulmonary blood flow and pressure.

INTRODUCTION: Hypertension and hyperperfusion of the pulmonary vascular bed in the setting of congenital cardiac malformations may lead to progressive pulmonary vascular disease. To improve the understanding of the basic mechanisms of this disease, there is a need for clinically relevant animal models which reflect the disease process. MATERIAL AND RESULTS: We randomly allocated 45 newborn pigs, at the age of 48 hrs, to groups in which there was either construction of a 3 mm central aorto-pulmonary shunt, undertaken in 9, or ligation of the left pulmonary artery, achieved in 13. Controls included sham operations in 13, or no operations in 10 pigs. Follow-up was continued for three months. The interventions were compatible with survival in most pigs. The shunts resulted in an acute 85% increase in systolic pulmonary arterial pressure, and a more than twofold increase in pulmonary blood flow. By three months of age, nearly all shunts had closed spontaneously, and haemodynamics were normal. Ligation of the left pulmonary artery resulted in a normal total pulmonary blood flow, despite only the right lung being perfused, and a 33% increase in systolic pulmonary arterial pressure. These haemodynamic changes were maintained throughout the period of study. In both groups, histomorphometry revealed markedly increased muscularity of the intra-acinar pulmonary arteries. Circulating levels of endothelin were normal in the shunted animals, and elevated in those with ligation of the left pulmonary artery. CONCLUSION: In neonatal porcine models of pulmonary vascular disease, created by construction of 3 mm central aorto-pulmonary shunts and ligation of one pulmonary artery, we observed histopathological changes of the pulmonary vasculature similar to early hypertensive pulmonary vascular disease in humans. Elevated circulating levels of endothelin were associated with abnormal haemodynamics rather than abnormal pathology. These findings could be valuable for future studies on the pathogenesis of hypertensive pulmonary vascular disease associated with congenital cardiac malformations.

Animals↗
PubMed2001

Bedside coagulometry during intravenous heparin therapy after coronary angioplasty.

UNLABELLED: In order to assess the applicability of a bedside coagulometer for measurement of b-APTT, serial blood samples were obtained from 20 patients receiving intravenous heparin treatment following PTCA, and from 5 healthy volunteers. B-APTT was analysed bedside on the Hemochron coagulometer; p-APTT and p-heparin, measured as factor anti-Xa activity, were analysed ex-vivo in the laboratory. B-APTT values, determined by the Hemochron coagulometer, were closely correlated to p-heparin (r=0.83, p<0.001, SD=52 seconds (sec), n=89), and duplicate determinations of b-APTT on the Hemochron coagulometer showed an acceptable repeatability. However, an APTT ratio of 1.5-2.5 was not related to a therapeutic p-heparin level, neither as measured by the Hemochron device nor in the laboratory. BACKGROUND: When administering intravenous heparin during angioplasty procedures, a quick and reliable method for safe and effective monitoring of anticoagulation is necessary. OBJECTIVE: To assess the applicability of a bedside coagulometer, measuring the activated partial thromboplastin time (APTT) in patients receiving intravenous heparin treatment after percutaneous transluminal coronary angioplasty (PTCA). METHODS: In patients with stable angina pectoris, receiving intravenous heparin treatment following PTCA, serial blood samples were obtained by venipuncture and from the arterial sheath for analysis of whole blood APTT (b-APTT), and plasma heparin concentration (p-heparin). Additionally, in healthy volunteers blood samples were obtained after a single bolus injection of heparin. B-APTT was analysed bedside on the Hemochron coagulometer; p-APTT and p-heparin, measured as factor anti-Xa activity, were analysed ex-vivo in the laboratory using conventional analytical methods. RESULTS: In 20 patients a total of 94 venous and 69 arterial blood samples were analysed, and in five healthy volunteers analyses were performed in 20 venous blood samples. B-APTT values, determined by the Hemochron coagulometer, were closely correlated to p-heparin (r=0.83, p<0.001, SD=52 seconds (sec), n=89). An APTT ratio of 1.5-2.5 was not related to a therapeutic p-heparin level, however, neither when using APTT assessed by the Hemochron device nor APTT measured in the laboratory. Duplicate determinations of b-APTT on the Hemochron coagulometer showed an acceptable repeatability; the mean difference between duplicate measurements was 4 sec (coefficient of variation (c.v.)=6%, p<0.05, n=163). CONCLUSIONS: In patients receiving intravenous heparin after PTCA treatment, b-APTT values measured by the Hemochron method showed an acceptable repeatability and were significantly correlated to p-heparin.

Adult↗
PubMed2001

Comparison of intramuscular therapy with Erwinia asparaginase and asparaginase Medac: pharmacokinetics, pharmacodynamics, formation of antibodies and influence on the coagulation system.

Asparaginase comes from different biological sources and the various preparations have different pharmacokinetic properties, and their tendency to induce side-effects is different. Erwinia asparaginase (ASNase) has a shorter half-life than the Escherichia coli preparations, and it has been reported to be less immunogenic than the E. coli preparations and to induce fewer coagulation disorders. Children with newly diagnosed acute lymphoblastic leukaemia (ALL) were included in this study. Twenty-seven patients were treated with Erwinia ASNase (induction therapy 30.000 IU/m2/d i.m. for 10 d, and re-induction therapy 30.000 IU/m2 twice a week for 2 weeks) and 15 were treated with ASNase Medac (induction therapy 1.000 IU/m2/d i.m. for 10 d, and re-induction therapy 5.000 IU/m2 i.m. twice a week for 2 weeks). Blood samples were drawn to determine enzyme activity, l-asparagine, anti-asparaginase antibodies, and coagulation parameters. After i.m. administration, Erwinia ASNase displayed a protracted absorption phase compared to ASNase Medac. The mean bioavailability after i.m. administration was 27% for Erwinia ASNase and 45% for ASNase Medac respectively. Mean trough enzyme activities during induction therapy were Erwinia ASNase 1748 IU/l and ASNase Medac 272 IU/l, and during re-induction therapy Erwinia ASNase 83 IU/l and ASNase Medac 147 IU/l. We conclude that in this setting, therapy with ASNase Medac resulted in sufficient treatment during both phases of therapy, whereas treatment with Erwinia ASNase resulted in unnecessarily intense therapy during the induction phase and insufficient treatment during the re-induction phase. There was no significant difference in the incidence of antibody formation, and therapy with Erwinia ASNase resulted in a more pronounced influence on the coagulation parameters than therapy with ASNase Medac.

Absorption↗
PubMed2001

Recombinant activated factor VII (rFVIIa) acutely normalizes prothrombin time in patients with cirrhosis during bleeding from oesophageal varices.

BACKGROUND: Patients with cirrhosis have low levels of coagulation factors, the most pronounced deficiency being that of FVII. This may compromise haemostasis during bleeding from ruptured oesophageal varices. The objective of this trial was to evaluate the effect of rFVIIa on prothrombin time in cirrhosis patients with ongoing variceal bleeding. Safety, including signs of DIC, was monitored. METHODS: The study is a single centre, open-label trial. Ten consecutive patients with known alcoholic cirrhosis and oesophageal variceal bleeding were included. The patients received routine treatment, including Terlipressin. Each patient received one i.v. injection of rFVIIa (80 microg/kg bw). The study observation time was 12 h per patient. RESULTS: The mean age of the patients was 48 years (8 men and 2 women). The cirrhosis was classified as Child B in 5 patients and Child C in 5. At baseline, all patients had prothrombin time levels above the normal range, and all but one had FVII coagulation activity (FVII:C) levels below the normal range. rFVIIa normalized the prothrombin time in all patients within 30 min. The effect lasted for more than 4 h in 7 patients, and for about 2 h in the remaining 3 patients. Immediate bleeding control was obtained in all patients, and no patient died within the study time. There was no sign of DIC. CONCLUSIONS: rFVIIa is effective in transiently reversing the prolonged prothrombin time in cirrhosis patients with haematemesis from varices. This indicates a potential of improving haemostasis and survival in patients with compromised coagulation due to liver disease.

Adult↗
PubMed2001

Recombinant activated factor VII for adjunctive hemorrhage control in trauma.

BACKGROUND: Recombinant activated factor VII (rFVIIa) was approved for treatment of hemorrhages in patients with hemophilia who develop inhibitors to factors VIII or IX. Conditions with increased thromboembolic risk, including trauma with or without disseminated intravascular coagulation, were considered a contraindication for the drug. The mechanism of action of rFVIIa suggests enhancement of hemostasis limited to the site of injury without systemic activation of the coagulation cascade. Therefore, use of the drug in trauma patients suffering uncontrolled hemorrhage appears to be rational. METHODS: Seven massively bleeding, multitransfused (median, 40 units [range, 25-49 units] of packed cells), coagulopathic trauma patients were treated with rFVIIa (median, 120 microg/kg [range, 120-212 microg/kg]) after failure of conventional measures to achieve hemostasis. RESULTS: Administration of rFVIIa resulted in cessation of the diffuse bleed, with significant decrease of blood requirements to 2 units (range, 1-2 units) of packed cells (p < 0.05); shortening of prothrombin time and activated partial thromboplastin time from 24 seconds (range, 20-31.8 seconds) to 10.1 seconds (range, 8-12 seconds) (p < 0.005) and 79 seconds (range, 46-110 seconds) to 41 seconds (range, 28-46 seconds) (p < 0.05), respectively; and an increase of FVII level from 0.7 IU/mL (range, 0.7-0.92 IU/mL) to 23.7 IU/mL (range, 18-44 IU/mL) (p < 0.05). Three of the seven patients died of reasons other than bleeding or thromboembolism. CONCLUSION: The results of this report suggest that in trauma patients rFVIIa may play a role as an adjunctive hemostatic measure, in addition to surgical hemostatic techniques, and provides the motivation for controlled animal and clinical trials.

Adolescent↗
PubMed2000

[Hereditary antithrombin deficiency resulting in severe neonatal thrombosis].

We report a severe vena cava inferior thrombosis in a mature two day-old boy. Pregnancy and birth were event free. The mother had antithrombin deficiency. During pregnancy she was treated with enoxaparin and just before delivery with 2000 IE antithrombin concentrate. At admission the child had unmeasurable antithrombin and low protein C concentrations. He was treated with antithrombin concentrate and heparin. The thrombus disappeared, and now he is on maintenance treatment with warfarin. Risk factors and treatment of inherited antithrombin deficiency are discussed.

Adult↗
PubMed2000

A novel von Willebrand disease-causing mutation (Arg273Trp) in the von Willebrand factor propeptide that results in defective multimerization and secretion.

In this report we describe the molecular defect underlying partial and severe quantitative von Willebrand factor (VWF) deficiencies in 3 families previously diagnosed with types 1 and 3 Von Willebrand-disease. Analysis of the VWF gene in affected family members revealed a novel C to T transition at nucleotide 1067 of the VWF complemetary DNA (cDNA), predicting substitution of arginine by tryptophan at amino acid position 273 (R273W) of pre-pro-VWF. Two patients, homozygous for the R273W mutation, had a partial VWF deficiency (VWF:Ag levels of 0.06 IU/mL and 0.09 IU/mL) and lacked high-molecular weight VWF multimers in plasma. A third patient, also homozygous for the R273W mutation, had a severe VWF deficiency (VWF:Ag level of less than 0.01 IU/mL) and undetectable VWF multimers in plasma. Recombinant VWF having the R273W mutation was expressed in COS-7 cells. Pulse-chase experiments showed that secretion of rVWFR273W was severely impaired compared with wild-type rVWF. However, the mutation did not affect the ability of VWF to form dimers in the endoplasmic reticulum (ER). Multimer analysis showed that rVWFR273W failed to form high-molecular-weight multimers present in wild-type rVWF. We concluded that the R273W mutation is responsible for the quantitative VWF deficiencies and aberrant multimer patterns observed in the affected family members. To identify factors that may function in the intracellular retention of rVWFR273W, we investigated the interactions of VWF expressed in COS-7 cells with molecular chaperones of the ER. The R273W mutation did not affect the ability of VWF to bind to BiP, Grp94, ERp72, calnexin, and calreticulin in COS-7 cells. (Blood. 2000;96:560-568)

Amino Acid Sequence↗
PubMed2000

Two novel type 2N von Willebrand disease-causing mutations that result in defective factor VIII binding, multimerization, and secretion of von Willebrand factor.

Two novel mutations, a T-to-C transition at nucleotide 2612 and a T-to-G transversion at nucleotide 3923 of the von Willebrand factor (vWF) complementary DNA, were detected by analysis of the vWF gene in DNA from members of 2 families with atypical von Willebrand disease. The T2612C transition predicts substitution of cysteine by arginine at amino acid position 788 (C788R), and the T3923G transversion predicts substitution of cysteine by glycine at position 1225 (C1225G) of pre-pro-vWF. The patients homozygous for the C788R and C1225G mutations both had a partial vWF deficiency (0. 18 IU/mL and 0.07 IU/mL vWF antigen, respectively); vWF in plasma from patients homozygous for either the C788R or the C1225G mutation failed to bind factor VIII and lacked high molecular weight multimers. Recombinant (r) vWF molecules having the C788R or C1225G mutation were expressed in COS-7 cells. Both rvWF C788R and rvWF C1225G exhibited significantly impaired secretion and failed to bind factor VIII. Recombinant vWF C788R in COS-7 culture medium showed a severe reduction in high molecular weight multimers, whereas rvWF C1225G showed a very mild reduction in high molecular weight multimers when compared with wild-type rvWF. (Blood. 2000;95:2000-2007)

Animals↗
PubMed2000

Markers of thrombophilia in retinal vein thrombosis.

PURPOSE: To study the prevalence of risk factors for systemic thromboembolism in patients with retinal vein thrombosis (RVT). METHODS: Fifty-four patients younger than 70 years, diagnosed with a retinal vein thrombosis at the Department of Ophthalmology, Aarhus University Hospital, were examined for the presence of venous thrombosis risk factors. RESULTS: 23 patients had a central RVT, 26 had a branch RVT, and 4 had a macular RVT. Nineteen (35.2%) of the patients displayed increased levels of plasma homocysteine, one patient (1.9%) the Factor V Leiden mutation, and one patient (1.9%) displayed an antiphospholipid antibody. All other tests for thrombophilia rendered normal. In 15 of the patients with hyperhomocysteinemia, folic acid substitution returned plasma homocysteine to a normal value in 12 cases. CONCLUSION: A surprisingly high prevalence of hyperhomocysteinemia was detected in this cohort of RVT patients, clearly superseding the prevalence of around 17% found in patients suffering venous thromboembolism in other vascular compartments. Our finding points to the likelihood that hyperhomocysteinemia may be a significant risk factor for retinal vein thrombosis.

Adult↗