摘要:

Spectrophotometric methods were used to assay the clotting factors II, VII, IX and X in plasma of 33 subjectively healthy human donors and in plasma of 98 patients receiving long-term oral anticoagulant therapy. In 33 normal subjects the interindividual variations in the plasma activities of the clotting factors II, VII, IX and X are respectively 12.2, 21.4, 11.0 and 15.0%. After correction for the assay variations the remaining biological variations are respectively 11.7, 21.2, 9.7 and 14.8%. Plasma from 98 patients receiving long-term anticoagulant therapy was assayed with ‘Thrombotest’, a clotting test in whole blood introduced by Owren and in these plasmas the activity of each of the vitamin K-dependent factors was assayed with spectrophotometric methods. For the clotting factors IX and VII, novel spectrophotometric methods were applied and the plasma activities thus measured were compared to results obtained with factor IX and VII clotting assays. Chromogenic activities of the different factors were correlated among each other and with 1/Thrombotest values. When the therapeutic range for Thrombotest values is set between 5 and 12.5% the corresponding therapeutic ranges for the activity of the factors II, VII, IX and X are respectively 12.6–36.1, 27.0–52.3, 23.1–49.3 and 18.9–36.2% (expressed as a percentage of the activity in normal pool plasma). The chromogenic assays for the factors II, VII, IX and X provide the same information on the therapeutic state of the patients in respectively 86.7, 78.6, 81.6 and 89.8% of the cases. Finally we discuss the suitability of the different assays to monitor oral anticoagul

ISSN:1424-8832    

DOI:10.1159/000214679

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

In a strain of genetically hypercholesterolemic rats (RICO), developed from an albino mutant of Rattus norvegicus (Sprague-Dawley, Tif: RAIf, SPF) by selective breeding, the intimal plasminogen activator activity (PAA) at the nonbranching regions of the aorta was markedly lower than at the nonbranching regions of the aorta in the control strain (Sprague-Dawley). At the branching regions of the aorta the intimal PAA showed no difference between the two strains of rats. In another strain of rats (HBC; hyper-beta-cholesterolemic) with a slightly elevated level of total cholesterol in the blood, a high concentration of LDL-cholesterol and a low concentration of triglycerides, the intimal PAA showed no difference from that in the control strain (Sprague-Dawley) at the branching and nonbranching regions of the aorta. 6 weeks after a single injection of streptozotocin at a diabetogenic dose (45 mg/kg) into RICO rats and the control strain, the intimal PAA was found to be increased by 280% in RICO rats, but only by 140% in controls, compared to that in the corresponding nontreated rats.

ISSN:1424-8832    

DOI:10.1159/000214680

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Under conditions of low shear and in the absence of laminar flow the addition of acetylsalicylic acid (ASA), but not of sodium salicylate, to human platelet-rich plasma (PRP) in vitro significantly inhibited platelet adherence to collagen (p < 0.001). Inhibition was of similar degree (17%) at ASA concentrations of 10 and 1,000 μM, but was less (10% inhibition) in PRP with erythrocytes added to 40% hematocrit. The ingestion of 600 mg ASA had negligible effect on platelet adherence in whole blood or in PRP. There was no correlation between the effects of ASA on adherence and on platelet aggregation in vitro or ex vivo. It is concluded that the effect of ASA on platelet adherence is unlikely to be important in vivo, except perhaps in vascular sites where flow is non-laminar and where shear rates and/or the physical forces on platelets are low

ISSN:1424-8832    

DOI:10.1159/000214681

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The procoagulant activity of activated platelets in a one-stage prothrombinase assay is reevaluated. It is shown that the apparent procoagulant activity of platelets activated by ADP or collagen can be explained by minor cell lysis accompanying platelet activation. The reduction in clotting time observed with thrombin activated platelets can be explained by a combined effect of minor cell lysis and release and activation of factor V from the platelets. Platelets stimulated by ionophore A23187 or by the combined action of collagen plus thrombin show a much shorter clotting time than can be accounted for by minor platelet lysis or release and activation of factor V from the platelets. The results with this clotting assay essentially confirm previous observations [Bevers et al.: Eur. J. Biochem. 122:429–436, 1982] using a spectrophotometric method with highly purified coagulation factors and a chromogenic substrate to measure the rate of thrombin formation with activated platelet

ISSN:1424-8832    

DOI:10.1159/000214682

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Plasma beta thromboglobulin (BTG) and platelet factor 4 (PF4) levels were measured and correlated with plasma lipid and lipoprotein patterns in 20 insulin-independent diabetics, in 10 insulin-dependent diabetics and in 30 healthy controls matched to patients as to age, sex and weight. Increased plama BTG and PF4 levels both in insulin-dependent and in insulin-independent diabetics indicate enhanced in vivo platelet activation and release reaction in these patients. No difference in BTG and PF4 values between these two groups of diabetic patients was observed in our study. A marked correlation between plasma PF4 values and plasma glucose levels was shown in insulin-dependent diabetics only whereas a significant positive correlation with plasma triglycerides and plasma triglyceride VLDL and a negative correlation with cholesterol-HDL was shown in insulin-independent diabetics.

ISSN:1424-8832    

DOI:10.1159/000214683

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A heavy metal impregnation technique revealed that platelets from patients with idiopathic scoliosis (IS) are more frequently ‘metallophilic’ and have a higher surface to volume ratio of the dense tubular system (DTS) than age-matched controls. These findings suggest that the fundamental defects in IS platelets involve membrane abnormalities related to cation binding and transp

ISSN:1424-8832    

DOI:10.1159/000214684

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

In order to assess the negative surface charge on platelets from patients with idiopathic scoliosis (IS) and suitable controls, formalin-fixed cells were examined by the two-phase aqueous polymer separation system and by binding of cationised ferritin. The results show that IS platelets have a higher negative surface charge. This could be responsible for several functional and structural abnormalities observed previously in IS platelets.

ISSN:1424-8832    

DOI:10.1159/000214685

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Platelet volume was measured in 30 healthy controls and 87 diabetic patients, the latter subdivided according to the absence, presence and severity of retinopathy, to investigate if platelet size is related to microangiopathy. The platelet volume of the whole diabetic population was increased (p < 0.05) due to a higher percentage of large elements (p < 0.05). The patients with various degrees of retinopathy had similar increases (p < 0.05) in their platelet size, while those without complications occupied an intermediate position between normal controls and retinopathy patients. It is concluded that: (i) increased platelet size accompanies diabetic retinopathy, irrespective of its severity, and (ii) patients without this complication form a heterogeneous group, some of which already have alterations of platelet volume. The role of these abnormalities in the development and progression of diabetic microangiopathy remains to be established.

ISSN:1424-8832    

DOI:10.1159/000214686

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A significant decrease of plasma antithrombin III (AT III) levels, measured with four different biological and immunological methods, was found in 8 of 11 members of a Sicilian family (family DM) and in 3 of 14 members of a northern Italian family (family A). Different behaviour after oral anticoagulant treatment with acenocoumarin was seen in 2 long-term treated subjects. The propositus of family DM, who had had a long history of recurrent thrombosis, did not show any increase of AT III levels. A significant increase was, on the contrary, observed in the propositus of family A, who had suffered a recent thrombosis in a branch of the inferior mesenteric vein.

ISSN:1424-8832    

DOI:10.1159/000214687

出版商:S. Karger AG    

年代:1982

数据来源: Karger