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During the last decade interesting data have been collected on the epidemiological significance of some coagulation factors as risk indices for major cardiovascular events and, also, for the prognosis of atherothrombotic disease. The factors for which evidence is most convincing include: plasma fibrinogen, coagulation factor VII, and an inhibitor of fibrinolysis, namely the plasminogen activator inhibitor PAI-1. These data have been provided by studies of primary predictivity, in which the said parameters were measured in healthy subjects whose cardiovascular outcome was followed. Studies of secondary predictivity, or prevalence studies have also been extremely helpful. In these, the coagulation factors measured in patients already suffering from atherothrombotic disease were correlated with its severity, extension and outcome. From these data, the plasma fibrinogen level emerges as the coagulation parameter best correlated with cardiovascular events, that is, as both a primary and a secondary predictor. The predictive power of plasma fibrinogen level appears to be no less significant than that of blood cholesterol. Although a few methodological problems must still be overcome, hyperfibrinogenemia is gaining increasing consideration as a new, important risk factor for cardiovascular events. It is however premature to consider the said parameters not only as risk indices but also as causal factors of atherothrombotic disease. In fact, their pathogenic and causal role, although supported by high biological plausibility, has not yet been confirmed by interventional studies aimed at assessing whether or not therapeutic lowering of these values is associated with reduced cardiovascular risk.

Acute intravenous administration in man of defibrotide (CAS 83712-60-1), a polynucleotide derivative, induces increase of 6-keto-PGF1 alpha and PGE2 production from appropriately stimulated whole blood. In the present study including acute and chronic experiments, defibrotide (Prociclide) orally administered during two weeks to healthy volunteers significantly increased the amounts of 6-keto-PGF1 alpha generated after appropriate stimulation in whole blood and in a neutrophilic leukocytes-platelet suspension. Similar effects were observed for PGE2, while TXB2 production was unchanged. Furthermore, platelet aggregation induced by calcium ionophore A23817 and production of leukotriene B4 from whole blood and isolated polymorphonuclear neutrophils were inhibited. The observed results suggest that defibrotide is biochemically active also by the oral route although the pharmacological and clinical value of the observed changes needs to be assessed.

Thirty-seven patients affected by polycythaemia rubra vera (PRV) and with at least one additional thrombotic risk factor (overt vascular disease, diabetes mellitus, treated hypertension, smoking habit, plasma hyperviscosity, hyperfibrinogenemia) were enrolled in a double-blind randomized placebo-controlled study, and 18 were given ticlopidine 250 mg, b.i.d., for 60 days. All the patients had previously been submitted to cytoreduction, and PRV was under control in all cases at the start of the study. During the study, the haematological parameters were controlled every 15 days, and venesection was performed if haematocrit was greater than 46%. Whole blood viscosity, at low and high shear rates, plasma viscosity, and fibrinogen were measured on days 0 and 60. In the ticlopidine group, we recorded a significant 13.14% reduction of the mean fibrinogen level after treatment (390 +/- 63 vs. 449 +/- 97 mg/dl, p less than 0.01). All the other haemorheological parameters were not significantly modified by ticlopidine treatment, nor were there significant modifications recorded in the placebo group. Our study shows that ticlopidine may reduce a probable thrombotic risk factor (hyperfibrinogenemia) in PRV patients.

In this study we report the data obtained from extensive haemostatic testing of 25 patients undergoing orthotopic liver transplantation and the results of an open randomized pilot trial of antithrombin III concentrate administration during surgery. Marked differences in transfusional needs and in pre- and intraoperative blood coagulation and fibrinolytic changes were observed between recipients with liver cirrhosis and those with primary biliary cirrhosis. In the former, the increases in tissue-type plasminogen activator activity, total euglobulin fibrinolytic activity, and fibrin-derived degradation products occurred earlier and were more marked, as were the signs of increased thrombin formation. Supplementation of antithrombin III concentrate during surgery failed to induce significant changes in the main parameters studied and in the transfusional needs.

Introduction Buflomedil hydrochloride is a vasoactive agent widely used, since 1976, for the treatment of peripheral circulatory insufficiency, with good results in cases of chronic occlusive peripheral arterial diseases (Desandre & Coudrec 1980, Galley & De Boysson 1981, Cloarec 1976, Balas & Pagratis 1981, Trubestein & Duong 1981) and of microcirculatory disorders (Fagrell & Hermansson 1980, Courlier, Bergeron & Fouque 1981). Its mechanism of action has not yet been completely elucidated; recently, however, Dormandy and Ernst (1981) have reported that individual venous infusion with Buflomedil caused a marked improvement in red blood cell deform ability, studied with a filtration method, in ten patients with lower limb ischaemia. This suggests that Buflomedil also has an haemorheologic effect. It is a known fact that patients with diabetes are often affected by vascular diseases, both macroand microcirculatory, and it is also known that one of the pathogenetic processes of vascular complications in diabetes consists in complex alterations of the blood flow properties (McMillan 1975, Calwell et al 1979), comprising mainly an increase in blood and plasma viscosity and alterations in the deformability and aggregability of the red cells (McMillan 1976, McMillan, Utterback & La Puma 1978, Juhan et al 1978, SchmidSchonbein & Volger 1976). The purpose of this study was to investigate the effect of the administration of Buflomedil on the rheologic properties of blood in a group of diabetic patients.

A family with a new congenital dysprothrombinemia is described. The propositus was a 36-yr-old female from the Molise region of Italy who presented with epistaxis, easy bruising, and menometrorrhagia. The main laboratory features of the defect included slight prolongation of prothrombin time, Thrombotest, Normotest, PP test, and partial thromboplastin time. Prothrombin activity was approximately 10% in several one- and two-stage systems employing tissue thromboplastins as activating agents. Using several viper venoms as activating agents low prothrombin levels were also obtained. However, the staphylocoagulase-complexed prothrombin level and immunologic methods yielded levels of about 50%. A line of identity between normal and abnormal prothrombin was seen on immunodiffusion. The migration of the abnormal prothrombin was normal in single and bidimensional immunoelectrophoresis systems. A single abnormal serum fragment was seen on bidimensional immunoelectrophoresis. The brother of the propositus was also affected and presented a similar pattern. Family studies revealed that the mother had approximately 50% prothrombin activity and antigen, whereas the father had 65% prothrombin activity and 100% prothrombin antigen. The propositus's first son showed approximately 50% prothrombin activity and antigen. A second child showed approximately 50% prothrombin activity but normal antigen. We suggest that the propositi are heterozygous for an abnormal prothrombin and heterozygous for “true” prothrombin deficiency. The father and the second child are heterozygous for abnormal prothrombin. The mother and the first child are heterozygous for “true” prothrombin deficiency. The term prothrombin Molise is proposed for this peculiar prothrombin abnormality.

SummaryPregnant mice are more susceptible to the intravenous injection of tissue thromboplastin than nonpregnant mice. This was true whether death of the animal, or the appearance of neurological symptoms, was used as indicator of toxicity. Increase of fibrinogen concentration or prior injection of plasmin or of a protease inhibitor (trypsin inhibitor from bovine lung) did not influence the immediate toxic effects. The reason for the increased sensitivity of pregnant mice to tissue thromboplastin remains undisclosed. Inhibition of tissue thromboplastin by serum is a slow process. The reported increase in inhibition of tissue thromboplastin by serum from pregnant individuals could not be confirmed.

Inpaired vascular synthesis of prostacyclin (PGI2) has been described in pro-thrombotic states,including recurrent venous thrombosis. As varicosis predisposes to local thrombogenesis, we measured in this study the generation of PGI2 and thromboxane A2 (TXA2) in segnents of human varicose veins. Samples of saphena magna were obtained after surgical stripping performed for varicosis in 20 patients (pts), or on preparation for coronary by-pass in 7 non-varicose subjects (controls). Segments (length - 2 cm, weight 200 mg) were dissected from macroscopically varicose areas in the pts and from correspondjmg zones in the controls. Varicose changes were confirmed by microscopic and histochemical studies. Vascular PGI2 production was measured both by bioassay (supernatant of 40 mg fresh tissue per ml TRIS buffer) on ADP platelet aggregation (PA), and by RIA assay of 6keto-PGFlalpha; TXA2 by RIA as TXB2. Bioassay showed that PGI2-like material production by varicose segments was lower than by control veins (% PA inhibition: 77+/19 vs 11+/6; p

It is known that the composition of plasma can influence the results of blood cell filtration tests by a direct effect of plasma viscosity on the filtration time and by the effect of plasma proteins on the aggregation of red cells. This concept is especially relevant when testing blood samples from patients with chronic vascular disease, who frequently have quantitatively and/or qualitatively altered fibrinogen, increased α2-macroglobulin and factor VIII, and raised plasma viscosity. We have therefore studied the influence of different suspension media on red cell filtration in patients with peripheral arterial obliterative disease (PAOD) and intermittent claudication, excluding those with diabetes.

A series of 40 patients with TIA (25 males and 15 females) was thoroughly investigated by means of angiography and computerized tomography, and divided into a group (A) of 15 “sine materia”, and a group (B) of 25 with direct or indirect evidence of vascular occlusive or stenotic changes. Blood viscosity at 230 sec-1 37° was cp 4.2 ± 0.3 in the controls, cp 4.7 ± 0.7 in all patients (p < 0.05) cp 4.98 ± 0.7 in all male patients (p < 0.01 versus male controls), and cp 4.75 ± 0.8 in group B (p < 0.02). Haematocrit and Fibrinogen were also significantly increased in all male patients and in group B. Circulating platelet aggregates (CPA) were increased in 40% of the patients. Almost all patients with elevated CPA were males, with a slight prevalence in group B. Changes in blood viscosity parameters and in platelet aggregation in TIA patients were therefore related both to evidence of vascular lesions, and to sex, since they were found to prevail in male patients of both groups.

Twenty-one thyroprival patients, previously submitted to total thyroidectomy for tumours, were investigated during stabilized L-thyroxine supplementation and at the end of a 20-25 day "no-therapy" period, necessary for a 131I total body scintigraphy. During supplementation therapy a lower than normal mean beta-thromboglobulin (beta-TG) release level was found, the other blood clotting and platelet function tests being normal. After substitution therapy withdrawal, platelet function tests showed reduced adrenalin aggregation, increased collagen threshold aggregating concentrations, decreased beta-TG release values and reduced aggregation to ristocetin, whereas blood clotting tests showed prolonged aPTT values and reduced levels of factor VIII:C and vWf:Ag. We conclude that in acquired hypothyroidism the lowering of factor VIII:C and vWf:Ag (acquired von Willebrand disease) is associated with impaired platelet reactivity not only to ristocetin but also to collagen and especially adrenalin. In the patients investigated these changes were almost completely corrected by substitutive therapy with L-thyroxine at clinically effective doses.

The morphologic evolution of traumatic brain lacerations (TBL) in man has been the object of electron microscopic studies by Testa and Giovanelli (1967) and Testa et al. (1970, 1974). Acute TBL and chronic cerebral traumatic scars were examined on a series of microbiopsies performed during surgical operations. The interest of the authors was mainly focused on the role of the cerebral capillaries in the evolution of TBL.

A pilot open controlled study of FOY was performed in 20 intensive care patients (pts, age 18-63) with DIC diagnosed with standard laboratory criteria (at least 3 of the following: Normotest 70%, fibrinogen 150 mg%, AT III 80%, FDP 20 ug/ml, platelets 150000). Besides the usual treatments, FOY was given to 10 pts (FOY G.) by continuous i.v. infusion (1mg/kg/h) for up to 7 days, while in 10 control pts (Hep.G.) the treatment included low dose s.c. heparin. Blood clotting tests were performed at admission to the study and daily for 7 days; we consider here results obtained at baseline and at the 4th (7 survivors in FOY G. and 10 in Hep.G.) and the 7th day (6 surv. in FOY G. and 9 in Hep. G.). Statistical evaluation was made by means of the twotailed Wilcoxon test for non parametric paired data. In the FOY G. depressed baseline AT III and plasminogen (Plgn) activities (61.8+/-5.3% and 57+/-5.5% respectively) significantly increased at 4th day (92+/-11.2% and 83+/-3.1% p

In the present review some aspects related to platelets in the pathogenesis and evolution of atherosclerotic and thrombotic vascular disease are discussed.

In a group of patients with Traumatic Brain Laceration (TBL) studies on blood coagulation and platelet function were performed in blood samples obtained during angiography from the omolateral carotid artery and jugular vein. Intraoperatory microbiopsies were also performed during neurosurgical operations in patients with TBL at different stages of evolution. In the acute stages of TBL necrosis of the endothelium and extensive micro-thrombosis with platelet material occurs in the capillaries around the damaged area. In the blood obtained from the jugular vein a fall in platelet count, platelet materials and positive paracoagulation tests can be observed.These data suggest that a process of regional intravascular coagulation occurs after TBL around the damaged area. Resulting microthrombosis may be regarded as a significant factor in the pathogenesis of acute ischemic intracellular edema in neurotraumatology.

The rationale of the hemorheologic approach to the pathophysiological knowledge and to the treatment of obstructive arterial diseases of the limbs is discussed in this paper. Indeed, the hemodynamic concepts are the natural frame in which the hemorheologic phenomena have to be considered. Proceeding from this background, it seems evident that the viscosity of blood and its major determinants have a limited role in the regulation of blood flow and pressure gradient through a stenotic artery. On the contrary, viscosity factors are of outstanding significance in the regulation of blood flow in the microcirculation, especially in presence of a reduced perfusion pressure and of exhausted arteriolar vasodilation capacity. Consequently, therapeutic measures capable of modifying one or more viscosity determinants may improve blood flow in the microcirculation of territories related to a stenotic artery. Baseline alterations of viscosity or viscosity determinants may be found in patients with obstructive arterial disease, being classified as primary, associated or secondary to arterial obstruction and ischemic damage. However, the presence of such baseline changes is not relevant to the indication of hemorheologic treatments.

A series of 102 cerebrovascular patients (CVP) investigated with aortic arch angiography, carotidography and CAT scan, were classified clinically in STROKE (55) and TIA (47) and pathologically as having (IAL, 51) or having no (NIAL, 51) identifiable arterial lesions. Coagulation and hemorheologic tests were performed at least 3 months after STROKE or 1 month after a TIA episode. All CVP as compared to controls (84) had significantly higher fibrinogen (Fg), F VIII AHF and RAg, blood (BV) and plasma (PV) viscosity, and poorer erythrocyte deformability (ED, as filtered erythrocyte volume, FEV), but no differences in euglobulin lysis time (ELT) even after venostasis (ELTV) and in circulating platelet aggregates (CPA, as 1/PAR). IAL vs NIAL CVP had higher Fg (mg% 285±74 vs 241±64; p

Obesity in adults is an important risk factor for cardiovascular diseases. An important role among these factors is played by some alterations in the mechanisms of coagulation. Changes in the fibrinolytic process are significant in obesity, although not always correlated with metabolic disorders involving lipid and glucose regulation (1, 2, 3, 4).

The aims of the present study were: 1) interlaboratory normalization of prothrombin time (PT) testing for anticoagulant therapy control through calibration of customary thromboplastins against international reference materials, and 2) "on field" validation of the advantages offered by expression of results as International Normalized Ratio (INR) as opposed to percentage activity. PT tests were carried out over 8 days on the same normal subjects (16) and patients on oral anticoagulants (48) in the 9 laboratories of the Bologna area. The use of customary thromboplastins and coagulometers was maintained in all labs throughout the study. The main results were: 1) the interlaboratory CV of the prothrombin ratios obtained for each sample with all customary thromboplastins (5 different brands) was 15%, but was reduced to levels of 5.8 to 8.9 when using constant thromboplastin brands and batches; 2) the International Sensitivity Index (ISI) values obtained in the different labs were only slightly influenced by the use of different coagulometers; 3) comparable ISI values were obtained through direct calibration with the international reference material and through intermediate calibration with a locally selected standard; 4) use of INR values instead of percentage activity greatly reduced interlaboratory variability and significantly improved uniformity of anticoagulation level measurements, thus reducing the possibility of erroneous prescriptions. The Bologna exercise is therefore of educational value for laboratory and community doctors of the area in understanding and accepting the INR system.

In 20 patients with liver cirrhosis and prolongation of thrombin (Th) and/or thrombin coagulase (ThC) times, fibrin polymerisation was followed at 350 nm after adjustment of fibrinogen concentration. The optical-density values at 10’ (OD 10) were grossly abnormal both with Th and with ThC, but no correlation was found between OD 10 and Th or ThC times. Polymerisation was re-tested after fibrinogen purification with 6 alanine and glycine. ThC time was generally shortened (p < 0.005) although in no case restored to normal. The OD 10 values improved (p < 0.001), but became normal in only a half of the cases, while remaining totally abnormal in 2 cases: PAA gel electrophoresis showed an abnormal band of very low m.w. fibrinogen in 2 out of 10 cases investigated. These results suggest that defective fibrin polymerisation in liver cirrhosis cannot be attributed only to acquired dysfibrinogenaemia. Other features like partially degraded fibrinogen and, especially, still unknown antipolymerizing factor(s)in plasma contribute to the disorder of iibrin formation.

In this collaborative study we have investigated the coexistence of two different markers of fibrinogen to fibrin conversion in 19 patients with liver cirrhosis, confirmed with liver biopsy, and classified according to standardized criteria into 11 moderate and 8 severe cases. Sepharose gel filtration of plasma allowed separation of fibrinogen-like material (FLM) into high m.w. (HMWF), peak, and low m.w. (LMWF) fractions, quantitated as percent (w/w) of the total FLM eluted. FPA was assayed radioimmunologically.HMWF was markedly increased in the whole group of cirrhotics (av ± SD 10.4% ± 2.77) , and in both moderate and severe patients, vs controls (6.9% ± 1.39; n=16; p < 0.01 for each comparison). LMWF was moderately increased in patients (6.8% ± l.84) vs controls (5.3% ± 1.35; p < 0.05).FPA levels (controls: median (m) ng/ml 2.2; m confidence limits (mcl) 1.4-2.5; range (r) < 0.6 to 4.1) showed an increase in cirrhotics (m 2.8; mcl 2.64-3.35, rThe lack of correlation between FPA and HMWF although possibly related to half-life differences, suggests that, besides thrombin effect, other mechanisms for excess formation and/or accumulation of HMWF, as dysproteinaemia, dys- fibrinogenaemia, or impaired clearance, should be considered.

Positivity of paracoagulation tests in a previously studied group of 80 patients with chronic active liver disease did not exceed 5-10% of the cases. In the present study, plasma samples from 20 cases of decompensated liver cirrhosis, assessed by liver biopsy, were investigated by means of agarose cromatography. Fibrinogen related materials were measured immunologically and by Staphylococcal Clumping Test.First appearance of fibrinogen-like materials occurred at earlier fractions in cirrhotic patients in comparison with normal controls. The relative amount of soluble fibrin monomer complexes (SFMC) as referred to total fibrinogen was significantly increased. No correlation was found between the amount of SFMC and the severity of fibrinogen polymerisation defect.Circulating SFMC are therefore present in severe liver cirrhosis. However, DIC may not be the only proposed explanation for this finding.

An increased content in sialic acid in the carbohydrate moiety of fibrinogen (fibrinogen sialic acid, FSA) as described in a number of different liver patients has been accounted for the polymerization defect often found in conditions of liver damage.In 22 cases of liver cirrhosis divided into “moderate” (n = 11) and “severe” (n = 11) according to standardized criteria, FSA was measured with the method of Warren after purification of fibrinogen with β-alanine and glycine, and expressed in mg per 100 mg of fibrinogen.In the whole group of cirrhotics FSA was 0.79 mg ± 0.17 (controls n = 10, FSA 0.70 mg ± 0.13, p > 0.05). However, FSA was markedly increased in “severe” cases (0.90 mg ± 0.16) both vs controls (p < 0.001) and vs “moderate” cases (0.69 mg ± 0.10, p < 0.005). Thrombin time (TT) although prolonged in cirrhotics (p < 0.001) was not significantly different between the subgroups. FSA correlated inversely with fibrinogen level (p < 0.01) but did not correlate with TT.These results show that the increase in FSA is a feature of severe liver cirrhosis especially in presence of a low fibrinogen level. Although probably involved in the polymerization defect, this increase alone cannot properly explain the prolongation of TT which is known to occur also in absence of serum FDP.

A comparison of different methods for AT III was performed in 65 patients. Of these, 45 affected by thrombotic diseases (TD) or under oral contraceptives (0C) were selected on the basis of the finding of low values of “serum” AT III (von Kaulla, AT III S), while 20, under oral anticoagulants, (AC) had abnormally high values of AT III S. The methods used were: AT III S, Xa I, reptilase defibrination (RD), immunologic (Imm), Coatest S 2238 (Chr).In the 45 cases (TD+OC) with low AT III S (≤ 70%), a low AT III level was confirmed with Imm in 20% of the cases, RD also in 20%, XaI in 15,5%, and Chr in 4,4%. Imm values were correlated (p < 0.05) with RD values. The variability of AT III S was completely different from that of all other methods. In AC patients with increased values of AT III S, there was no significant change in AT III with any other method.In conclusion, our results show a marked discrepancy between AT III S and the other methods used, suggesting heterogeneity of AT III S method. AT III S values are in fact related not only to AT III “in vivo”, but also to its “in vitro” consumption rate and possibly to other clotting inhibitors. However, the clinical usefulness of AT III S as an index of “hypercoagulability” remains to be investigated.

The haemorheologic condition was evaluated in 43 obese children and 35 controls. In 18 of the obese children and in 21 controls the euglobulin lysis time (ELT) was also studied. Blood viscosity at 94.5 and at 0.204 s-1 shear rates, plasma viscosity, fibrinogen and erythrocyte filtration time were significantly higher in obese than in control children. No significant differences were observed in haematocrit levels. Triglycerides, non-esterified fatty acids (NEFA), pre-beta-lipoprotein and insulin rates were all significantly higher in obese than in control children. There were no significant differences in glycaemia and in haemoglobin A1 values. ELT, both basal and after stimulation with 1-deamino-8-D-arginine-vasopressin (DDAVP), was significantly higher in the obese than in control children. The haemorheologic disturbances together with alterations of the haemostatic balance and fibrinolysis may be an important risk factor for the development of vascular changes at paediatric age.