22 Fibrinolysis

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57. D ie t a ry in f luence o n f ibr in network structure properties in human subjects

F. J. Veldman, H. H. Vorster, J. C. Jerling, W. Oosthuizen, C. S. Ventner, W. J. H. Vermaak ~ Nutrition Research Group, Department of Nutrition, Potchefstroomse Universiteit vir Christelike Hoer Onderwys, Potchefstroom, South Africa, 1Department of Chemical Pathology, University of Pretoria, Pretoria, South Africa Plasma fibrinogen is accepted as an important risk factor for atherosclerosis, stroke, coronary heart disease (CHD) and the cardiovascular complications of some diseases such as diabetes mellitus and hyperlipidaemia. However, it is sus- pected that not only fibrinogen concentration, but also the quality of fibrin clots may contribute to CHD risk. Very little is known about the contribution of diet to plasma fibrinogen concentration in human subjects and no data are available on the effect of diet on fibrin clot structure properties. The main aim of these studies was to investigate the possible effect of diet on fibrin clot network properties in vivo. Firstly, fibrin clot structure properties were measured in two paired/ matched non-insulin dependent diabetes mellitus subject groups (n=8 per group), following an energy restricted high- fibre, low-fat, high-carbohydrate diet, supplemented with either 150g dry beans (cooked weight), containing plant protein and soluble fibre, or 50 g soy beans (raw weight), containing plant protein without fibre, per day. Supplemen- tation was sustained for 10 weeks. A significant increase in the mass to length ratio of fibrin fibres (roT) (from 13.15_+ 1.08 to 14.58+_2.14 daltons/cm x 1012) were measured in the subject group receiving the plant protein supplement. Improvement of diabetes management was also shown by signifcant reduction of glycosylated haemoglobin (from 10.83_+2.36 to 8.23_+1.42%) in the same group. From the results of this study it is suspected that the observed changes in fibrin clot structure properties were mainly mediated by improvement in diabetes management. Secondly, the effect of the soluble dietary fibre pectin, known for its hypocholes- terolaelniC properties, on fibrin clot structure properties were measured in hyperlipidaemic subjects. Effects of the pectin supplement (15 g per day for 4 weeks) were measured against a corn flour placebo. Pectin supplementation caused significant decreases in both the clot fibrin content (from 2.22+_0.47 to 1.90+_0.17 g/L) and clot lysis time (from 285.6+_16.1 to 232.9___17.9 nlin). Clot compaction was signifi- candy increased (from 21.51_+3.65 to 30.16+_4.41%), as well as mT (from 19.94+_6.27 to 24.80+_4.22 daltons/cm x 1012) and clot permeability (from 279.6+_101.2 to 336.3_+119.1 × 1011 cm2). A significant decrease in total cholesterol (TC) (from 6.50+_0.27 to 5.67_+0.48 retool/L) was also observed. The results of this study suggest that changes in fibrin dot structure properties may be concomitant with changes in other CHD risk variables, such as TC.

Conclusion: From results of both intervention studies, it is evident that fibrin clot structure can be modified by dietary intervention. It is known that fibrin clot structure properties are partially determined during the clotting process by the characteristics of the direct surrounding. Diet may alter the direct surrounding of the fibrinogen molecule, and thus alter fibrin clot structure by indirect mechanisms.

Fibrinolysis (1996) 10, Suppl. 4, 1-26

58. Fibrin sealing in oral surgery with hemorrhagic complications

H. Vinazzer Blood Coagulation Laboratory, Linz, Austria Hemorrhagic complications after oral surgery can be caused by local reasons or by alterations of the hemostatic mecha- nism. In a study which extended over 4 years, all patients with abnormal postoperative hemorrhage received fibrin sealing. The system TISSUCOL by Immuno (Vienna) was used. It consists of a highly concentrated fibrinogen solution containing aprotinine and factor XIII, and of a weak throm- bin solution as a second component. By mixing, a firm fibrin clot is formed within about 60 s which strongly adheres to the wound. This system was used in 155 patients with a total of 517 wounds. The results of detailed coagulation studies permitted the formation of 3 groups. Group 1 was under anticoagulant therapy, group 2 had congenital or acquired hemorrhagic disorders, and in group 3 there was normal co- agulation. In group 1, sealing was carried out in 376 bleed- ing wounds. In only 8 of the wounds resealing or suturing was necessary. In group 2 there were 128 sealings and reseal- ing was necessary in 11 wounds. These patients suffered from hemophilia A or B or from an impaired platelet func- tion. The group with normal coagulation had 13 bleeding wounds. No resealing was necessary in these cases who had undergone major oral surgery and who had bleedings for local reasons. There was primary wound healing in all patients. Examinations for hepatitis after 2 and 6 months were negative with the exception of 4 cases who had abnor- mal results prior to oral surgery.

59. Diet and haemostasis

H. H. Vorster, C. S. Venter, N. Silvis, H. S. Kruger, A. Kruger, J. C. Jerling, F. J. Veldlnan, W. Oosthuizen, W. J. H. Vermaak ~ Nutrition Research Group, Potchefstroomse Universiteit vir Christelike Hoer Onderwys, Potchefstroom, South Africa, 1Department of Chemical Pathology, University of Pretoria, Pretoria, South Africa Diet is one of the environmental factors which protects against chronic diseases of lifestyle in genetically suscepti- ble individuals. We examined the possiblity that some of these protective effects may be mediated through effects on haemostasis (mainly clottable fibrinogen concentra- tion, fibrin networks and fibrinolytic enzymes) in a series of clinical trials in which the effects of energy and specific nutrients (total fat, fatty acids, dietary fibre, cholesterol, antioxidant vitamins) and foods (dry b.eans, eggs, sorghum, maize, tea) were examined in normo- and hyper- fibrinogenaemic subjects. These studies showed inter alia that elderly subjects who regularly took a multi-vitamin supplement had significantly lower fibrinogen levels than those who did not, but that supplementation of the diet of hypercholesterolaemic patients with antioxidants did not influence fibrinogen concentration. Africans following a western type of diet had higher fibrinogen than those who followed a balanced prudent diet. An increased egg intake from 2 to 14 per week, had no effect on fibrinogen concen-

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