[Endothelial mediators regulating vascular tonus].

Vascular endothelium is the unavoidable interface between blood and tissues. Its role as regulator of vascular tone is discussed here. The endothelium possesses different receptors for vasoactive mediators.

[Impaired fibrinolytic response to the venous occlusion test in patients with cryptogenic colitis].

The fibrinolytic response to venous occlusion was studied in 17 patients with inflammatory bowel disease: 7 with Crohn's disease, 10 with ulcerative colitis and compared with those obtained in 20 controls. Patients with inflammatory bowel disease showed decreased tissue-type plasminogen activator antigen release (t-PA Ag), no significant Von Willebrand antigen release (vWF Ag), and a residual plasminogen activator inhibitor activity (PAI activity) after venous occlusion. These modifications were more important in the evolutive colitis group compared with the remission group.

[Fibrinolytic activity in traumatic hemothorax fluids].

Twenty-nine patients, 15 to 85-year-old (mean: 50 years) who presented with a pleural effusion after trauma were studied. The blood content of pleural fluid was confirmed by thoracocentesis. None of the patients had been taking anticoagulant drugs during the fortnight preceding the trauma.

Impact of smoking, physical training and weight reduction on FVII, PAI-1 and hemostatic markers in sedentary men.

The variations of FVII, PAI-1, TAT complexes, fibrinopeptide A, D-Dimers and beta thromboglobulin plasma levels were studied on 30 sedentary men, smokers and non-smokers, who were admitted to a 6 months' program of physical training and smoking cessation. After 3 months of intervention, sustained physical training was associated with the decrease of FVII and PAI-1 levels. Mild exercise performed during a second 3-month period could maintain normal FVII and PAI-1 activities but participants who stopped the training increased their FVII and PAI-1 plasma levels.

Biocompatibility of blood tubings.

We studied hemocompatibility of various blood tubings with C3a anaphylatoxin measurement and comparative electron scanning microscopy. The following tubing materials were tested: polyvinylchloride (PVC) plasticised with phthalate (PVC), pvc plasticised with phthalate coextruded with polyurethane (PIV), and two phthalate-free lines: pvc plasticised with trimellitate coextruded with polyurethane (TRI) and pvc plasticised with LT 360 (LTP). Results of C3a generation rate showed a significant activation by all blood tubings, with a reduced rate with PIV when compared to all others.

Impaired fibrinolytic capacity in patients with inflammatory bowel disease.

The venous occlusion test was applied to 17 patients with inflammatory bowel disease (IBD; 7 cases of Crohn's disease, 10 cases of ulcerative colitis). Results were compared to those obtained in 20 healthy matched control subjects. Patients with IBD had significantly decreased t-PA Ag release (p less than 0.

Study of quantitative modifications of the plasma protein S system components in non-acute inflammatory syndromes.

Thrombosis frequently accompanies inflammatory disease. There are numerous and frequent modifications of haemostasis parameters during inflammatory disease. Deficiencies in protein S, a protein C cofactor, are predisposing factors for thromboses.

[Comparison of thawing of plasma by microwave or water bath: preliminary longitudinal biological study of hemostatic parameters].

Exploration of haemostasis was performed on plasmas thawed in an experimental microwave oven comparatively to a 37 degrees C water bath. Factor VIII:R:Ag, procoagulant and antigenic fibrinogen, and Fg:C/Fg:Ag ratio were found to be significantly, slightly decreased with microwave thawing. Factor VIII:C and VIII:C/VIII:R:Ag ratio were found to be increased with microwaves.

[Treatment of deep venous thrombosis in congenital antithrombin III deficiency with low molecular weight heparin].

A 19-year old male patient with hereditary antithrombin III type I deficiency was admitted for thrombosis of the right iliac, femoral and popliteal veins. Treatment with a low molecular weight heparin resulted in recanalization of the veins confirmed by phlebography. After two weeks of treatment, the drug was replaced by another low molecular weight heparin and this was followed, 3 weeks later, by a documented relapse of thrombosis.

Anti-idiotypic antibodies against anti-phospholipid autoantibodies which suppress lupus-like anticoagulant activity.

We have studied IgG F(ab')2 fractions in the plasma from a patient during spontaneous remission from lupus anticoagulant (LAC). Fractions from the remission period inhibited the LAC activity of preremission fractions, as evaluated by in vitro coagulation tests. Idiotypic/anti-idiotypic interactions were demonstrated by affinity chromatography.

[Is protein C deficiency responsible for portal thrombosis after neonatal exchange transfusion?].

The authors report the case of a 12-year old boy admitted to hospital for cerebral ischaemic accident and in whom laboratory examinations revealed a 40% deficiency of protein C. Other investigations showed that the child, who had undergone exchange transfusion by the umbilical route at birth, had portal vein thrombosis. It is suggested that protein C deficiency might be responsible for some cases of portal vein thrombosis occurring after umbilical catheterization performed in the neonatal period.

Present results of the treatment of myelodysplastic syndromes with low-dose cytosine arabinoside. Preliminary results of a cooperative protocol (38 patients) and review of the literature.

In vitro differentiating agents causing little bone marrow aplasia have been proposed as a specific therapy of myelodysplastic syndromes with excess of blasts. A critical review of the published data is presented. The preliminary results of a cooperative protocol using very low dosage of cytosine arabinoside (3mg/m2/twice daily) with or without androgens are given.