| 1. |
|
|
| 2. |
- Järemo, Petter, et al.
(författare)
-
Inverse relationship between platelet density and reactivity alterations at coronary angiography
- 2001
-
Ingår i: Haemostasis. - Basel : S. Karger. - 0301-0147 .- 1423-0038. ; 31:1, s. 55-60
-
Tidskriftsartikel (refereegranskat)abstract
- This work investigates relationships between platelet density and reactivity. 21 individuals subject to coronary angiography were studied. Peak platelet density was analyzed using a newly developed electronic device. The apparatus measures light transmission through test tubes containing density-separated platelets, thus allowing an estimation of the platelet distribution in the gradient. A flow cytometry technique was used for determining platelet reactivity after stimulating with ADP. Platelet counts, mean platelet volumes, peak platelet density and platelet reactivity were determined immediately before (day 1) and 24 h after cardiac catheterization (day 2). For all parameters changes during the day of angiography were compared with platelet density alterations. The subjects were divided into two groups according to density changes at angiography. Group 1 individuals showed density alterations (i.e. day 2 – day 1 value) ≥–8 × 10–5 kg/l. In contrast, group 2 subjects either displayed density changes <–8 × 10–5 kg/l or grossly disturbed platelet density patterns on day 2. Before angiography both groups had similar platelet counts and volumes. Then platelet reactivity when stimulating with ADP did not differ significantly between the two groups. After angiography, the number of fibrinogen-positive cells when stimulating with ADP rose by 6 ± 8% for group 2 patients. The corresponding figure for group 1 was –1 ± 6%. The difference was significant (p = 0.01). No such relationships were found when comparing density alterations and changes of platelet counts and volumes. We conclude that in this study platelet density alterations at coronary angiography are inversely related to variations of platelet reactivity.
|
|
| 3. |
- Olivecrona, T, et al.
(författare)
-
New aspects on heparin and lipoprotein metabolism.
- 1993
-
Ingår i: Haemostasis. - 0301-0147 .- 1423-0038. ; 23 Suppl 1, s. 150-60
-
Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein lipase (LPL) and hepatic lipase (HL) are two enzymes which participate in metabolism of plasma lipoproteins. The enzymes are located at vascular surfaces and are released from their binding sites on injection of heparin. In this paper we give a short overview of the structure of the lipases and their role in lipoprotein metabolism. Earlier studies had shown that low molecular weight (LMW) heparin preparations result in lower LPL activities in blood than do corresponding amounts of conventional heparin. Studies with organ perfusion in rats show that the two types of heparin have similar ability to release the lipases from their binding sites in extrahepatic tissues, but that LMW heparin is less effective than conventional heparin in preventing rapid uptake and degradation of LPL by the liver. After injection of heparin the metabolism of triglyceride-rich lipoproteins is initially accelerated, presumably as a result of the high levels of circulating LPL. Then follows a phase when lipoprotein metabolism is slower than normal, perhaps because endothelial LPL has been depleted by accelerated transport to and degradation in the liver.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Bergqvist, David, et al.
(författare)
-
Cost/benefit aspects on thromboprophylaxis
- 1993
-
Ingår i: Haemostasis. - 0301-0147. ; 23:Suppl. 1, s. 15-19
-
Tidskriftsartikel (refereegranskat)abstract
- Several studies have shown thromboprophylaxis of any kind to be more cost-effective than no prophylaxis or general diagnostic surveillance and selective treatment. Little has been written on low molecular weight heparins from the cost-effectiveness point of view. This preliminary study shows low molecular weight heparin to be more cost-effective than standard low-dose heparin in most situations of prophylaxis.
|
|
| 7. |
- Bergqvist, D, et al.
(författare)
-
Thromboprophylaxis in emergency surgery
- 1993
-
Ingår i: Haemostasis. - 0301-0147. ; 23:Suppl. 1, s. 51-56
-
Tidskriftsartikel (refereegranskat)abstract
- Except for hip fracture surgery, emergency surgery has been only exceptionally studied concerning thromboprophylaxis. There are, however, several reasons to believe the frequency to be fairly high and that the patient group would be in need of prophylaxis. This paper discusses various emergency situations and also gives the design for an ongoing controlled study on the effect of postoperative start of thromboprophylaxis with low molecular weight heparin in emergency abdominal surgery.
|
|
| 8. |
- Dahlbäck, Björn, et al.
(författare)
-
Inherited resistance to activated protein C caused by presence of the FV:Q506 allele as a basis of venous thrombosis
- 1996
-
Ingår i: Haemostasis. - 0301-0147. ; 26:SUPPL. 4, s. 301-314
-
Tidskriftsartikel (refereegranskat)abstract
- Inherited resistance to activated protein C (APC) was recently discovered as a cause of familial thrombophilia and is now known to be the most common genetic risk factor for venous thrombosis. In a majority of cases, APC resistance is associated with a single point mutation in the factor V gene, which results in substitution of arginine (R) at position 506 by glutamine (Q) (FV:Q506). The mutation renders factor Va partially resistant to degradation by activated protein C (APC), which leads to a hypercoagulable state and a life-long 5-10-fold increased risk of venous thrombosis. The previously known inherited deficiencies of antithrombin, protein S or protein C, are in western societies together found in less than 10-15% of thrombosis patients, whereas APC resistance is present in 20 to 60% of the patients. A functional APC resistance test, which includes predilution of the patient plasma with factor V deficient plasma, is 100% sensitive and specific for the presence of FV:Q506. The FV:Q506 allele is common in populations of Caucasian origin (prevalence ranging between 1 and 15%), whereas it is not found in certain other ethnic groups such as in Japanese and Chinese. The thrombotic risk in individuals with APC resistant may be further increased by other genetic defects such as protein C or protein S deficiency and by exposure to circumstantial risk factors such as oral contraceptives, pregnancy, immobilisation and surgery.
|
|
| 9. |
- Knobe, Karin, et al.
(författare)
-
Factor VIII inhibitors in two families with mild haemophilia A: structural analysis of the mutations
- 2000
-
Ingår i: Haemostasis. - : S. Karger AG. - 0301-0147. ; 30:5, s. 268-279
-
Tidskriftsartikel (refereegranskat)abstract
- The development of inhibitory antibodies against coagulation factor VIII (FVIII) in patients with mild haemophilia A is uncommon. We describe here two families in which three or two members have developed inhibitors, suggesting a familial predisposition. The mutations found, in the A2 (Arg593Cys) and C1 domains (Tyr2105Cys), have been reported to give rise to inhibitor development in single individuals in addition to the family cluster we describe, strongly suggesting that these amino acid substitutions give rise to a more immunogenic protein. The analysis of structural models of activated factor VIII revealed that Arg593 is solvent-exposed and involved in a network of electrostatic interactions while Tyr2105 is partially buried and has hydrophobic interactions essentially with Ile2144. All these residues are strictly conserved in the FVIII amino acid sequence from man, pig and mouse, suggesting, at least, that they have structural roles. We propose that the two mutations in these families could cause mild haemophilia A because they induce local conformational changes (and possible secretion or intermolecular interaction problems, e.g., with von Willebrand factor) compatible with immunogenicity and production of inhibitors against the infused wild-type FVIII.
|
|
| 10. |
- Mätzsch, Thomas
(författare)
-
Thromboprophylaxis with low-molecular-weight heparin: economic considerations
- 2000
-
Ingår i: Haemostasis. - : S. Karger AG. - 0301-0147. ; 30:Suppl. 2, s. 141-145
-
Tidskriftsartikel (refereegranskat)abstract
- Postoperative thromboembolic events are a major cost factor for every healthcare system. Although thromboprophylaxis carries its own costs, the application of a thromboprophylactic regimen is cost-effective in most instances, at least in high-risk patients. A regimen of general postoperative prevention of deep vein thrombosis is always more cost-effective than surveillance programmes with treatment after diagnosis, and is almost always more cost-effective than no prophylaxis. For patients with a high risk of postoperative thromboembolism, such as after orthopaedic surgery, low-molecular-weight heparins have a rather clear advantage over prophylaxis with unfractionated heparin and warfarin, also in terms of cost- effectiveness. With regard to moderate-risk patients, such as after general surgery, the economic benefits are less clear. However, since the results of economic analyses are heavily dependent on the healthcare system, and since there are methodological difficulties and uncertainties connected with the analyses, the implications are difficult -- if not impossible -- to generalize. There is an urgent need for further prospective studies, which should be performed with defined economic variables a priori and in close cooperation with health economists.
|
|
