| 1. |
- Jern, Christina, 1962, et al.
(författare)
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Changes of plasma coagulation and fibrinolysis in response to mental stress.
- 1989
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Ingår i: Thrombosis and haemostasis. - 0340-6245. ; 62:2, s. 767-71
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Tidskriftsartikel (refereegranskat)abstract
- To study the effects of standardized mental stress (arithmetic and the Stroop color word test) on plasma coagulation and fibrinolysis, blood samples were obtained before, during, and after 20 minutes of mental stress from 10 healthy, non-smoking young males aged 22 to 30 years. Reactions were compared with those observed during physical exercise and infusion of adrenaline. Both von Willebrand factor antigen and factor VIII coagulant activity increased significantly in response to mental stress (95 +/- 28 vs 123 +/- 56%; p less than 0.05 and 125 +/- 54 vs 217 +/- 170%; p less than 0.05, respectively). There was also a significant increase of factor VII coagulant activity (86 +/- 31 vs 108 +/- 51%; p less than 0.05). Furthermore, mental stress caused an activation of the fibrinolytic system with an elevation of tissue plasminogen activator activity and tissue plasminogen activator antigen (0.80 +/- 0.48 vs 1.23 +/- 0.96 IU/ml; p = 0.076 and 4.38 +/- 1.87 vs 5.78 +/- 2.58 IU/ml; p less than 0.01). Fibrinogen concentration increased during stress (1.95 +/- 0.29 vs 2.11 +/- 0.27 g/l; p less than 0.05). Similar but more pronounced responses were observed during exercise and adrenaline infusion. Parallel to the increases in coagulation and fibrinolytic factors there were significant increases in heart rate, and systolic and diastolic blood pressure. It is concluded that mental stress has significant effects on plasma coagulation and fibrinolysis, and that it could thus affect important risk factors for cardiovascular disease.
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| 2. |
- Kutti, Jack, et al.
(författare)
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The relation between platelet reactivity and coronary angiographic findings in young female survivors of acute myocardial infarction.
- 1986
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Ingår i: Thrombosis and haemostasis. - 0340-6245. ; 56:2, s. 207-10
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Tidskriftsartikel (refereegranskat)abstract
- In 31 women who had survived their first acute myocardial infarction (MI) studies of platelet reactivity were related to coronary angiographic findings. The results were compared to those obtained from 38 age-matched control women. According to the cardioangiographic findings the group of MI was subdivided into: 9 patients with 1-vessel disease (VD), 10 patients with 2-VD, and 5 patients with 3-VD; 7 subjects did not reveal significant coronary stenosis. When each of these 4 subgroups of MI-patients were compared with the control material significant difference with respect to PF4 was found only for subjects with 1-VD (20.0 +/- 4.8 vs. 10.3 +/- 0.6 ng/ml). As regards BTG the difference was significant for 1-VD and 2-VD patients (69 +/- 12 and 59 +/- 3, respectively vs. 40 +/- 2 ng/ml). The cumulative frequency for secondary aggregation differed only as regards 1-VD patients (78 vs 40%).
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| 3. |
- Mätzsch, Thomas, et al.
(författare)
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Effects of an enzymatically depolymerized heparin as compared with conventional heparin in healthy volunteers
- 1987
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 57:1, s. 97-101
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Tidskriftsartikel (refereegranskat)abstract
- A low molecular weight heparin (LMW-heparin) with a mean molecular weight of 4900 dalton was prepared by controlled enzymatic depolymerization of conventional porcine mucosal heparin. The effects of 2,500, 5,000 and 10,000 U (XaI; 29, 58 and 116 mg) on factor Xa inhibition (XaI), factor IIa inhibition (IIaI), APTT, AT III and platelet count were compared to those of 5,000 U (XaI; 26 mg) of conventional heparin given s.c. to 6 healthy volunteers. 5,000 U (XaI; 58 mg) of LMW-heparin was given i.v. A dose related response with regard to the XaI and the IIa-inhibitory activities with peak values at 4 hours after the s.c. injections was obtained. An increase of the XaI/IIaI ratio over the time after injection was seen only after i.v. administration of the LMW-heparin. The APTT was only slightly prolonged and remained within normal range after s.c. injection. AT III and platelet counts were unaffected. The biological half life of the LMW-heparin was 111 minutes if assayed by Xa inhibition, 76 minutes if assayed by IIa inhibition and 40 minutes if assayed by APTT. A strong correlation between the XaI activities obtained and body weight was seen, indicating that LMW-heparin should be administered individually according to body weight.
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| 4. |
- Mätzsch, Thomas, et al.
(författare)
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Heparin-induced osteoporosis in rats
- 1986
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 56:3, s. 293-294
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Tidskriftsartikel (refereegranskat)abstract
- In order to study the effect of heparin in inducing osteoporosis, 30 female rats were divided in two groups and treated with daily injections of 2 IU heparin/g body weight for 33 and 65 days and compared with the same number of rats acting as controls. The mineral bone mass in the femora of the animals was measured quantitatively. A significant (p less than 0.001) reduction in bone mineral mass was found in the heparin-treated animals. This effect was present to the same degree after 33 days as after 65 days of treatment. It is concluded that heparin in this dose causes osteoporosis in rats after 33 days and that the described method can be used as an experimental model for further studies on this topic.
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| 5. |
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| 6. |
- Vilén, Lars, et al.
(författare)
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ADP-induced platelet aggregation as a function of age in healthy humans.
- 1989
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Ingår i: Thrombosis and haemostasis. - 0340-6245. ; 61:3, s. 490-2
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Tidskriftsartikel (refereegranskat)abstract
- In 120 healthy humans (58 males and 62 females) possible differences in platelet aggregability were investigated with respect to age and sex. By using a narrow range of final ADP concentrations (0.2-1.0 microM) primary and secondary aggregation were evaluated. The rate of primary aggregation was shown to be significantly related to increasing age and this was true for both sexes. As regards secondary aggregation the same pattern was seen in the group of male subjects. Thus, among the youngest (less than 34 years) the frequency of secondary waves was only one third of that encountered among the oldest (greater than 50 years). No similar association was detectable among the female subjects. The present study calls attention to some important issues which should be considered in platelet aggregation studies; the interpretation of data obtained from such studies invariably requires a careful selection of appropriate age- as well as sex-matched control groups.
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