bluuebunny/crossref_metadata_2025 huggingface dataset:
REGULATION OF GROWTH FACTOR PRODUCTION BY ENDOTHELIAL CELLS IN RESPONSE TO COAGULATION AND INFLAMATORY FACTORS
Authors: Bowen-Pope D F , Gajdusek C , Harlan J , Nawroth P , Ross R , Sakariassen K S , Stern D
Published: August 2018

Platelet-derived growth factor (PDGF) is a polypeptide growth factor first discovered in, and purified from, human blood platelets. As assayed by its ability to stimulate proliferation of cultured vascular smooth muscle cells, PDGF is the major mitogen in human whole blood serum. PDGF has also been reported to be chemotactic for fibroblasts, vascular smooth muscle cells, and leukocytes, and to be able to stimulate contraction of arterial smooth muscle. This, spectrum of activities suggests that PDGF could play a significant role in several vascular processes, including wound repair and the formation of atherosclerotic lesions (reviewed in Ross et al., 1986 Cell 46:155). Several cell types in addition to the platelet have now been shown to be capable of secreting PDGF-like molecules. In culture, vascular endothelial cells from many sources secrete significant levels of PDGF (DiCorleto and Bowen-Pope, 1983 PNAS 80:1919). Rates of secretion can be increased four fold and more bythe activated procoagulants thrombin (Harlan et al 1986 J. Cell Biol. 103:1129) and factor Xa (Gajdusek et al 1986 J. Cell Biol. 103:419). Thrombin stimulates secretion by the earliest times measurable (about 1.5hr) and this early response is not diminished by inhibitors of protein and RNA synthesis. Nevertheless, unlike secretion from the platelet, stimulated secretion does not represent release of sequestered active PDGF since no reservoir of active PDGF can be detected within the cells prior to stimulation. It is likely therefore that stimulation of secrtion involves the activation or unmasking of an inactive form of PDGF. The proteolytic activities of thrombin and Xa are necessary for activation of secretion but the mechanism does not seem to to involve direct proteolytic activation by thrombin of a precursor since thrombin treatment does not generate active PDGF in freeze-thawed preparations of endothelial cells. We have recently found that tumor necrosis factor alpha (TNF) and gamma interferon (IFN) can stimulate increased rates of secretion of PDGF by cultured human saphenous vein and umbilical vein endothelial cells. Stimulation by a combination of the two is more than additive. In contrast to the rapid kinetics of stimulation by thrombin and Xa, TNF and IFN do not measurably increase secretion for at lease four hrs. This delayed kinetics is paralleled by increases in mRNA encoding the two subunit chains of PDGF ("A" and "B") and it seems likely that in this case stimulation of secretion results from increased rates of mRNA and protein synthesis. Since evidence is accumulating that TNF and IFN are both present in human atherosclerotic lesions, it is possible that they help stimulate production of endothelial cell-derived mitogens, including PDGF and thus contribute to the development of the lesion.
PEAKING TIME OF CK-MB IN PATIENTS TREATED WITH THROMBOLYTIC AGENTS DURING MYOCARDIAL INFARCTION: IS IT REALLY A CLUE TO REPERFUSION?
Authors: Brunelli C , Spallarossa P , Ghigliotti G , lannetti M , Caponneto S
Published: August 2018

Aim of the study is to evaluate the relevance of CK-MB peaking time as a marker of reperfusion in patients (pts) treated with thrombolytic agent. 150 pts were recruited in 4 centers and randomized into two treatment groups: Group A = conventional therapy + urokinase (2.000.000 U i.v.),Group B = conventional therapy. Inter val between onset of symptoms and beginning of therapy was 3.50 ± 1.25 hrs in group A and 3.45±1.20 hrs in group B. Serum cardiac en zyme determination was performed every 4 hrs for 48 hrs. On day 20 all pts underwent coronary angiography and ventriculography. Cl ini. cal and angiographic data were not significantly different in the two groups. Patency of infart related artery (IRA) was evident in 51% of pts of group A vs 38% of pts in group B (p<0.05). In 119 pts both IRA status and complete CK-MB curve were known. Mean time to peak CK-MB in pts with patent and occluded IRA was 18.7±1.6 hrs and 24.4±1.4 hrs respectively (p<0.02); 15 hrs from onset of symptoms was considered as the boundary between early and late peak.

11 pts died in hospital: 3 in group A and 8 in group B.

Conclusion: 1) CK-MB peak time is significantly different in pts with patent and occluded vessels. 2) From a clinical point of view in conventionally treated pts IRA status is not predicted by CK-4'B peaking time, while in urokinase treated pts IRA status is predicted only by early peaking.
FIBRINOGEN DOSAGE AS A SYSTEMIC MARKER OF UNSUCCESSFUL INTRAVENOUS STREPTOKINASE IN ACUTE MYOCARDIAL INFARCTION
Authors: Col-De Beys Ch , Lavenne-Pardonge E , Moriau M , Renkin J , Col J
Published: August 2018

Whether failure to timely recanalize coronary artery with intravenous streptokinase (SK) is related to inadequate fibrinolysis remains controversial. Since coagulation might also interfere with the course of clot lysis, this relation was investigated in 27 patients (pts) pretreated with heparin (10.000 IU bolus). 500.000 to 1.500.000 IU SK were infused in 45 min, 160 ± 60 min after the onset of infarct.

Angiographic control, performed 219 ± 199 min after SK, showed persistent coronary occlusion in 5 pts (0CC) and patency in 22 (PAT), unrelated to SK dosage. One to 3 hours post SK, fibrinogen (Fg) (Clauss Method) was undetectable in all 22 PAT and 4/5 0CC. However, Fg (and clottable breakdown products) assessed by Gram's method* was detected in all 5 OCC and 3/22 PAT (164 ± 89 VS 13 ± 38 mg %, p < 0.005). Prolongation of thrombin time (neutralized with protamine) was limited in OCC, compared to PAT (59 ± 6 VS 96 ± 11 sec, p < 0.005), supporting the hypothesis of the presence of clottable material in OCC. These results were accompanied by slight differences of ELT (< 20 min in 2/5 OCC VS 21/22 PAT) and non significant differences in plasminogen (1.78 ± 1 VS 2.18 ± 1.1 mg/dl ; NS), α2 antiplasmin (1.7 ± 1.7 VS 3.9 ± 6.9 % ; NS), plasmin (12 ± 4 VS 16 ± 11 mm2 ; NS) and plasminogen activators (95 ± 41 VS 105 ± 23 mm2 ; NS).

Conclusion : at similar systemic lytic activity induced by SK, failure of arterial recanalization was associated wih an apparent incomplete fibrinogenolysis (and fibrinolysis) in 20 % of the patients.

*Gram H.C. - A new method of determination of the fibrin percent in blood and plasma - J Biol Chem 49 : 279 - 295 (1921)

mean ± SD
COAGULATION STUDIES IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION DURING THROMBOLYTIC TREATMENT WITH APSAC (BRL-26921) OR STREPTOKINASE
Authors: Hoffmann J , Bonnier J , de Swart J
Published: August 2018

We studied 70 patients with acute myocardial infarction in a multicenter trial comparing intravenous anisoylated plasminogen-streptokinase activator complex (APSAC or BRL-26921; 30 U in 2-4 min) with intracoronary streptokinase (SK; 250,000 U in 1 hour). Blood for coagulation and fibrinolytic determinations was taken before and 1 1/2,12,24 and 48 h after thrombolytic treatment. There were 65 patients in whom fibrinogen decreased by more than 10% of pretreatment; this was defined as a systemic lytic state. Of these patients,33 were treated with APSAC and 32 with SK. The lowest fibrinogen was found at 1 1/2 h : about 15% and 22% of baseline, respectively. Also plasminogen and α2-antiplasmin reached low levels at 1 1/2h hour. Plasminogen mean 32 ± 11 % and 34 ± 9% of pretreatment for APSAC and SK , respectively and a2-antiplasmin to less than 5% and 6 + 9 %. Fibrin(ogen) degradation products peaked at lh h,too. The mean FDP was significantly higher in the APSAC group than in the SK group (739 vs. 355 mg/L). The global coagulation assays APTT, PT, TT and reptilase time all yielded comparable results: peak values at l^h and no difference between both groups. After 24 to 48 hours all parameters had returned to their baseline levels, except FDP which was still elevated.

The euglobilin clot lysis time(ECLT) showed a different picture: after a very rapid decrease in both groups, ECLT quickly rose to normal in the SK group, but it remained shortened in the APSAC group at 24 and even 48 h. This sustained fibrinolytic activity was significantly different from SK.

In the 5 patients without systemic lytic state (3 APSAC; 2 SK), only minor changes in the parameters measured were found, except a decrease in ECLT at 1 1/2h in three of them and a slight drop in α2-antiplasmin in 2 patients. Two of these patients had a very high SK-resistance titer before treatment.

It is concluded that both APSAC and SK cause a profound systemic lytic state in the majority of patients, but the degree of this systemic lysis did not significantly differ between both groups. The total fibrinolytic activity, measured as ECLT, sustained for a significantly longer period in the APSAC group than in the SK group, which probably explains the low reocclusion rate of APSAC.
THE PROTECTIVE EFFECT OF ACYLATI0N ON THE STABILITY OF EMINASE (APSAC) IN HUMAN PLASMA
Authors: Fears R , Ferres H , Standring R
Published: August 2018

Clinical and animal studies indicate that APSAC (anisoylated plasminogen.streptokinase activator complex, Eminase) circulates longer in the bloodstream in an active form than the other thrombolytics. In the present studies in vitro u/e have found that functional activity of APSAC is maintained in human plasma longer than that of SK.plasmin(ogen): the relative stability half-lives are similar to the plasma clearance haif-lives in patients. Some of the loss of activity of SK at early times can be attributed to neutralisation by inhibitors. Thus, the survival of fibrinolytically-active SK was promoted in plasma depleted in α2-antiplasmin (α2AP) and α2AP-SK.plasmin complexes (detected by immunoblotting) formed rapidly in normal plasma. Corresponding studies with α2 macroglobulin-depleted plasma suggested a slight, late influence on SK activity but the inhibitor complex has not been detected unequivocally. In addition, loss of SK activity can be attributed, in part, to. rapid degradation to low molecular products. The degradation of SK in APSAC was much slower. In other comparative studies, the stability of APSAC was found to be similar to the stability of prourokinase and much superior to that of SK which is similar to UK; t-PA is intermediate in stability.

Maintenance of fibrinolytic activity vivo depends on the stability of the thrombolytic, its rate of clearance and mode of administration. The protective effect of acylation, demonstrated in these experiments, explains why the objective of maintaining a high level of fibrinolytic activity after intravenous bolus injection of APSAC is less compromised by opposing inactivation processes.
INDICATORS OF INCREASED RISK FOR EXCESSIVE BLEEDING AFTER CARDIOPULMONARY BYPASS SURGERY
Authors: Rock W A , Pearce C W , Weichert R F , Johnson W
Published: August 2018

A prospective study of 565 consecutive cases of cardiopulmonary (CP) bypass surgery (in 26 months) wasmade to identify indicators for excessive postoperative bleeding ("bleeders" defined as greater than 400 ml from 1st to 3rd hours in recovery). Patients were studied before, during, and after surgery, with datarecorded on a computerized format for analysis (Table). preoperative indicators of increased postop bleeding risk included surgical complexity; complex-valve or coronary artery bypass graft (CABG) (X2,p<.01), preop use of any antibiotic (P<.05), and use of aorticballonpump (P<<.001). Previous myocardialinfarction diabetes mellitus, hypertension, obesity, smoking history,use of verapamil, digoxin, antihypertensive drugs, preophematocrit, platelet count, and fibrinogen did notpredict bleeders. Intraoperative indicators for increased risk included poor tissue strength (P<.01) and blood added to pump (P<.001). Intraoperative pump run time, cross-clamp time. hematocrit, platelet count,and fibirinogen were not indicators for increased risk for bleeding. Postoperative indicators included bleeding into leg and chest bandages (P<.005), chest tube drainage with clots (P<.001), platelet count (t-test, P<.05); and fibrinogen (t-test, P<.05). The postop hematocrit and prolongation of aPTT did notcharacterize bleeders. This analysis suggests that the intrinsic health of the patient, the strength of the heart, the complexity or the surgery, and the use of certain medications may be better indicators of a risk for bleeding tha are factors relatedonly to CP bypass surgery.
A COMPARISON OF TOPICAL HAEMOSTATIC AGENTS IN EXPERIMENTAL LIVER RESECTION
Authors: Blaire S D , Backhouse C M , Matthews J L , McCollum C N
Published: August 2018

Bleeding from lacerated paranchymal organs such as the liver and spleen may be profuse and difficult to control. The haemostatic agent, calcium alginate (Kaltostat), which acts as a source of chelateable calcium ions has been compared with oxidised cellulose (Surgicel) and porcine collagen (Medistat) in experimental liver resection.

Under general anaesthesia, a standard 3cm2 piece of liver was excised in 42 NZW rabbits and the haemostatic agent immediately applied. Bleeding was assessed at 3-minute intervals and blood loss precisely measured by haemolysis and a haemoglobinometer. Macroscopic and histological examinations of the liver were performed at 2 and 6 weeks.

Calcium alginate stopped bleeding within 3 minutes with minimal blood loss in every animal and was significantly better than the other materials by both criteria. At 2 weeks the macroscopic appearances were similar for the 3 implants with inflammation on microscopy. Oxidised cellulose had absorbed by 6 weeks with calcium alginate having only minimal residual material surrounded by a fibrous reaction. Porcine collagen remained intact with a vigorous foreign body reaction and granuloma formation.

Calcium alginate is significantly more effective than the haemostatic materials currently used in surgical practice.
HAEMOSTASEOLOGICAL CHANGES IN DIABETIC CHILDREN (HUMAN INSULIN VERSUS PORCINE INSULIN
Authors: Nowak-Göttl U , Kreuz W D , John M , Krackhardt B , Grüttner H-P , Breddin H K , kollmann F
Published: August 2018

Changes of haemostaseological parameters are involved in pathogenesis of diabetic angiopathy. However it is not yet clear whether they are cause or consequence of the endothelial damage. We investigated coagulation parameters in 84 children with type I diabetes mellitus without clinical signs of vascular disease.

Compared to the control group no significant changes could be seen in fibrinogen, plasminogen, protein C, α 1 antichymotrypsin, β-thrombo-globulin and ristocetin - induced aggregation.Additionally we could observe significant differences in patients treated with human insulin to those treated with porcine insulin. Spontaneous platelet aggregation (PAT III) and factor VIII C correlated to the duration of diabetes. Also to the mean metabolic equilibrium (HBA1) correlations could be found. Spontaneous platelet aggregation seems to be a useful parameter to assess the onset of atherosclerotic diseases in diabetic children. High values of von Willebrand factor may indicate reversible and/or irreversible damage of vascular endothelium.
FUNCTIONAL CHANGES IN ANTITHROMBIN III IN INSULIN-DEPENDENT DIABETES MELLITUS
Authors: Sandbjerg Hansen M , Milner Jørgensen B
Published: August 2018

The thrombin neutralizing activity of Antithrombin III (AT) was measured in a group of patients with insulin-dependent diabetes mellitus. All patients evaluated had diabetes of several years duration. Their blood glucose control was unsatisfactory as evidenced by relative concentrations of glycated hemoglobin (HbA1c) of 9.6-14.0% determined by polyacrylamide gel electrophoresis. The plasma AT-activity was estimated as thrombin neutralizing activity using the chromogenic substrate Th-1.

The group of diabetic patients had a higher AT-activity than a reference group, but normal AT-concentrations by electro-immunoassay. The treatment of the patient samples with neuraminidase caused a greater fall in the AT-activity than did the treatment of normal samples. The patient samples had a slower mobility in crossed affino-immunoelectrophoresis using immobilized helix pomatia lectin in the first dimension and specific antibodies against AT in the second dimension. The mobility of patient AT, also in complex with thrombin, was indistinguishable from normal AT in crossed immunoelectrophoresis in the presence or absence of heparin.

It is concluded that long-term dysregulation of diabetes mellitus may induce functional changes in the plasma antithrombin activity.
CLINICAL RELEVANCE OF PLASMA FIBRIN DEGRADATION PRODUCTS DETERMINATION IN PATIENTS WITH DEEP VEIN THROMBOSIS (DVT)
Authors: Aillaud M F , Roul C , Elias A , Bouvier J L , Serradimigni A , Juhan-Vague I
Published: August 2018

We have studied fibrin degradation products, D-dimer, in citrated plasma with an ELISA assay using monoclonal antibodies (Asserachrom D-Di Stago).

35 patients with DVT< 7 days were studied at day O (DO) that is upon admission before treatment with streptokinase (n=6), heparin (n=5) or LMWH CY222 Choay (n=24). Phlebographies were scored by Marder’s index (MI).

At DO, MI = 24.28 ± 10.85 (m ± SD), the mean (± SD) of D-dimer was : 4056 ± 5545 ng/ml (range 950-19000) (normal values < 500 ng/ml). No correlation was found between D-dimer and MI and between D-dimer and clinical delay of DVT.

The evolution of D-dimer was studied during 7 days in patients treated with heparin or LMWH (n=29). Blood sampling was undertaken at DO and at 8 h AM, 1 hour before injection at Dl, D3, D5, D7. The evolution of thrombolysis was evaluated by comparing MI at DO and D7. Among patients with MI at DO < 10 (n=25) two groups were compared : - successful group : 8 patients with decrease of MI at D7 < 80% ; - failure group : 11 patients with decrease of MI at D7< 20% : D-dimer at DO were higher in successful group (p< 0.05) ; these results could be explained by better endogenous thrombolysis in this group. The percentages of the decrease of D-dimer at D3 and at D7 compared to DO were higher in the successful group : Successful group versus Failure group (m ± SD) = % decrease at D3 : 46.4 ± 29.2/ 13.4 ± 11 (p< 0.05) ; % decrease at D7 : 52.3 ± 31.5/ 24.2 ± 26.3 (p<0.05) (in agreement with Soria and al, -IX th International Congress of Phlebology, September 1986, Kyoto) ; these results could be explained by a smaller clot mass to be lysed in successful group.

In conclusion the level of D-dimer at DO and the intensity of the decrease of D-dimer during 7 days (as from D3) may have a predictive value for in vivo thrombolysis.
MONITORING OF DEEP VEIN THROMBOSIS BY D DIMER DETERMINATION. INFLUENCE OF HEPARIN REGIMEN
Authors: Soria C , Mirshahi Mc , Soria J , Mirshahi M , Faivre R , Neuhart D , Kieffer Y , Maurat J P , Caen J P
Published: August 2018

In 49 patients the level of plasma fibrin degradation products (FbDP) was measured during the first ten days of deep vein thrombosis (DVT) in order to determine whether FbDP may be used as a non invasive marker to follow the evolution of DVT. Plasma FbDP was measured precisely and reliably by Elisa using a personal anti D neo monoclonal antibody. Thrombus size was determined angiographically on day 0 and day 10 and expressed according to Marder score. Patients were treated by standard or by a very low molecular weight heparin (CY 222 from Choay Laboratory, Paris France).

It is shown that before treatment, in 45 cases of DVT the level of FbDP was dramatically increased as compared to control and remained normal or slightly elevated in 4 cases of DVT. The correlation between thrombus size and FbDP level at day 0 was poor (p = 0.3). During the 10 days of treatment, FbDP determination may give some informations about the evolution of DVT. Three groups were defined :

1 There was no reduction of thrombus size in patients who presented a normal or only slightly elevated FbDP level, leading to the evidence that thrombolysis was almost inexistant in these patients.

2 Thrombolysis was almost complete in 10 days in patients presented both a high FbDP level before treatment and a dramatic decrease of FbDP after 10 days treatment. Taking into account the half life of FbDP, the decrease in FbDP level is related to the reduction in thrombus size.

3 A partial or absence of recanalization was evidenced in patients presenting a high FbDP level throughout the 10 days on therapy. In cases without recanalization we have to assume that thrombolysis evidenced by plasma FbDP level was continuously counteract by a clotting process.

Similar results were observed in patient treated by standard and CY 222.
EFFECTS OF DEFIBROTIDE TREATMENT ON THE PLASMA AND SERUM INDUCED CONTRACTION OF RABBIT AORTIC STRIP IN RELATION TO THE PATHOPHYSIOLOGY OF MYOCARDIAL INFARCTION
Authors: Kindel G , Fareed J , Cornelli U
Published: August 2018

Several clinical and experimental studies have demonstrated the efficacy of a polydeoxyribonucleotide (Defibrotide) in myocardial ischemic disorders and peripheral arterial diseases. In attempts to investigate the mechanisms of action of this agent, we used a modified rabbit model of hemodynamics and an isolated rabbit aortic strip preparation. Intravenous bolus administration of Defibrotide at 5-50 mg/kg did not produce any changes in the mean arterial blood pressure up to 3 hours. Defibrotide treated rabbits also resisted human serum-stasis and stasis alone induced venous and arterial thrombus formation. Serum and plasma from Defibrotide treated animals were tested for their direct contractile and procontractile (synergistic with an epinephrine stimulus) activities on rabbit aortic strips. In contrast to plasma and serum from saline treated rabbits, both serum and plasma produced relatively weak or no effects. The dose-contrac-tion responses were shifted to the right suggesting that serum from Defibrotide treated animals contained much lesser amounts of contractile substances. This data indicates blood from Defibrotide treated rabbits is compositionally different than normal, either due to lack of cellular product formation (thromboxane B 2, serotonin) or due to the generation of endothelial products which are inhibitory to the contractile effects of substances generated during the formation of a thrombus. Plasma thromboxane B2/6 keto-PGFia ratios were also found to be much higher in Defibrotide treated groups when compared to the saline groups. The observed therapeutic effect of Defibrotide in acute myocardial infarction may be linked with the inhibition of the formation of thrombus and with the mediation of vascular spasm due to the generation of inhibitory substances or the lack of generation of spasmogenic substances.
PRQOOAGULANT ACTIVITY OF HUMAN T LYMPHOCYTES IN INTRINSIC AND EXTRINSIC SYSTEMS
Authors: Barrowcliffe T W , Marshall D A , Trickett L P , Hubbard A R , Thorpe R
Published: August 2018

Cells of the monocyte/macrophage series develop thromboplastin procoagulant activity (PCA) when activated. This activity may be enhanced by T lymphocytes, but there have been few studies of the PCA of T lymphocytes themselves. In the present study, we have measured the PCA of four T lymphoma cell lines (JURKAT, CEM, HSB2 and MQLT4) as well as normal peripheral blood T lymphocytes, before and after stimulation with phyto-haemag-glutinin (PHA), using clotting and amidolytic methods.

Of the four cell lines only one, JURKAT, gave enhanced PCA. after stimulation with PHA., with recalcification times in plastic tubes being shortened from 200 secs, to 90 secs, at a cell concentration of 4 × 106 ml. This activity was shown to be thromboplastin-like by its dependence on Factor VII in plasma and in an amidolytic assay with purified Factors VII and × . JURKAT was also the only one of the four cell lines to secrete interleukin-2. All four cell lines promoted the generation of large amounts of thrombin in platelet-free plasma in glass tubes; the peak thrombin concentration of 25 iu/ml was equivalent to that generated by a procoagulant phospholipid reagent. This activity was dependent on the presence of plasma Factor VIII, and was shown to be due to phospholipids in the cell membranes by its inhibition with phospholipase A2 and C and its activity in a purified system with Factors VIII, IXa and X. Normal T lynphocytes generated similar thromboplastin PCA to JURKAT after PHA stimulation, but their intrinsic PCA in the thrombin generation test was only 15% of that of the lymphoma cells.

These results show that some T lymphocytes can develop PCA in both intrinsic and extrinsic systems and this should be taken into account in studies of the PCA of mixed leucocyte populations. The difference in intrinsic PCA between normal and lymphoma cells could be an interesting marker for malignant transformation.
MECHANISMS OF PROCOAGULANT GENERATION BY ALVEOLAR MACROPHAGES DURING MATURATION
Authors: McGee Maria , Rothberger Henry
Published: August 2018

During maturation in vivo and in vitro alveolar macrophages generate procoagulant(s) capable of activating the extrinsic pathway. It is generally agreed that at least part of the activity is due to TF (tissue factor). However, whether or not macrophages also generate functional factor VII or X is controversial. To characterize procoagulant activity increases, we measured kinetic parameters defining interactions between components of the TF-VII complex on membranes of alveolar macrophages either freshly isolated or cultured in serum free medium. In incubation mixtures with fixed concentrations of macrophages and added factor VII, the rate of factor Xa formation (measured by S-2222 hydrolysis) approached a maximum as factor X concentration was increased. Estimated concentrations of factor X yielding 1/2 maximal activation rates, (apparent Km) were 127.1±26 nM and 99.7±34 nM for fresh and cultured cells, respectively. Vmax (maximal velocities) were 1.21±0.24 and 8.9±5 nM Xa/min/106 cells. When concentrations of added factor X were kept constant, the rate of factor X activation increased as the added factor VII concentration was increased. For fresh and cultured cells, the respective apparent Kd were 1.810.7 and 1.410.25 nM. Maximal rates observed with X concentration fixed at 108 nM were 0.46±10.06 and 5.7±1.6 nM Xa/min/106 cells. In the absence of either added factor X or added factor VII, no factor Xa generation was detected in fresh or cultured cells, during 10-20 min incubation periods used for kinetic studies. The observed increase in Vmax without changes in apparent Km and Kd indicate that gains in procoagulant activity during macrophage maturation are due to increases in the number of functional binding sites for factor VII, without significant generation of functional vitamin K dependent factors (VII and X) by the cells. The data also indicate that maturation does not alter the rate behaviour of the TF-VII enzymatic complex on macrophage membranes. Mechanisms of complex assembly that we observed on macrophage membranes are similar to those described for the TF-VII complex assembly on purified systems.
IN VIVO CHANGES IN SYSTEMIC PCO2 AND PO2 INFLUENCE THE THROMBOEMBOLIC REACTION FOLLOWING WALL PUNCTURE IN VENULES BUT NOT IN ARTERIOLES
Authors: oude Egbrink Mirjam G A , Jan Tangelder Geert , Slaaf Dick W , Reneman Robert S
Published: August 2018

Changes in pH and PCO2 influence the aggregation of blood platelets in response to various agents in vitro. In the present study intravital video-microscopy was used to investigate whether changes in systemic blood gas values influence the thromboembolic reaction in vivo as induced by vessel wall injury.

The microtrauma was induced by puncturing the walls of microvessels in the rabbit mesentery (diameter range: 20-40 μm) with glass micropipets (tip diameters: 6-8 μm). The thromboembolic reactions were compared in two groups of anesthetized rabbits. The control group was ventilated to keep the blood gas values within normal ranges (means: pH=7.40, pCO2=32.9 mmHg, pO2=104.7 mmHg). The experimental group breathed spontaneously (mean blood gas values: pH=7.34, pCO2=50.5 mmHg, pO2=48.1 mmHg). The pCO2 and pO2 values were significantly different between both groups.

In arterioles and venules of both groups bleeding and thrombus formation started immediately following wall puncture. Bleeding times were short (medians between 1.0 and 2.6 s). Parts of the thrombi started to embolize between 11.4 and 18.2 s following wall puncture (medians). In the control group embolization continued for 101 s in the arterioles and 17 s in the venules; during these periods 6 and 1 emboli were produced, respectively (all median values). In the experimental group the duration of embolization in the arterioles was 143 s in which period 7.5 emboli were produced, values not significantly different from control. In the venules of the experimental group embolization and hence platelet reaction went on uninhibited during the whole observation period of 600 s and 30 emboli were produced. Fluid dynamic factors cannot explain the differences in thromboembolic reaction between the control and experimental venules; vessel diameters and red blood cell velocities were not significantly different between both groups. Therefore, it is likely that the change in thromboembolic reaction in the venules results from the changes in systemic PCO2 and/or pO2. The different reactions in arterioles and venules in response to the altered systemic blood gas values might arise from different reactions in the vessel walls.
IDENTIFICATION AND PURIFICATION OF AN INHIBITOR TO PLASMINOGEN ACTIVATORS FROM PROSTATE ADENOCARCINOMA CELLS
Authors: Gargan P E , Ploplis V A
Published: August 2018

The rat prostate adencarcinoma cell line (PA-III), derived from qerm-free Lobund Wistar rats has served as a unique model for prostatic cancer. The supernatant from confluent cultures of the cell line was shown by zymographic analysis to contain three molecular forms of plasminogen activator. One of the activators was characterized in a previous study and has been classified as a tissue type plasminogen activator(Mr=30,000). In the same study the activator with a Mr=45,000 was shown to be of the urokinase class. The high molecular weight(Mr=120, 000) activator, which has not been described previously, was identified as a complex between the tissue plasminogen activator and an inhibitor. Dissociation of the activator and its inhibitor was achieved by incubation of the complex with ammonium hydroxide (1.5M) in the presence of NaDodGO4 (2%). Treatment with NaDodSO4 alone did not dissociate the complex but did however enhance its fibrinolytic activity, suggesting disruption of hydropnotic interactions leading to exposure of the activators active site.

A scheme for the purification of the two plasminogen activators, the activator-inhibitor complex, and the free inhibitor was developed. The various components were purified approximately 1000 fold by hydrophobic interaction chromatography on Phenyl-Sepharose, affinity chromatography on Con A Sepharose and by gel filtration on Sephacryl S-200. The purified inhibitor was capable of inhibiting the fibrinolytic activity of both the urokinase type and tissue type plasminogen activators produced by the PAIII cells.
INTERFERENCE OF MONOCLONAL IMMUNOGLOBULINS ON PLATELETS AND WHOLE BLOOD AGGREGATION
Authors: Schinco P C , Fusaro A , Bazzan M , Pannocchia A , Pileri A , Tamponi G
Published: August 2018

We studied 31 patients with monoclonal gammopathy (MG), 10 of them secreting monoclonal antibodies (MoAb) of the G class, 13 of them IgM and 8 IgA. We also studied 15 healthy age- and sex-matched control subjects. On each subject we evaluated whole blood aggregation (WBA) in response to ADP, collagen, epinephrine and arachidonic acid in parallel with PRP aggregation according to the method of Born. We wondered whether WBA could provide us further information on the interference of MoAb on platelet function. Agonists and concentrations which yielded statistically significant results in comparison with controls will be reported.

IgM MG: Increased WBA to epinephrine 5 and 10 μM (p < 0.01) and ADP 4 and 6 μM (p < 0.001). Increased PRP aggregation to ADP 1 μM (p < 0.001) and collagen 1 μg/ml (p < 0.001).

IgA MG: increased WBA to ADP 1 μM (p < 0.001). No difference in PRP aggregation.

IgG MG: no difference in WBA. Reduced PRP aggregation in response to ADP 1 μM (p < 0.01) and arachidonic acid 0.5 mM (p < 0.01).

We conclude that high molecular weight Ig (IgM pentamers and IgA dimers) seem to play a role in WBA, causing an increased aggregatory response when measured as impedance variation; on the other hand, low molecular weight Ig (IgG) seem to interfere directly with platelet function, causing a decreased aggregation. The mechanism underlying this phenomenon is still unclear.

Supported by Grant n° 13 by Regione Piemonte.
PLATELET MEMBRANE GLYCOPROTEINS ABNORMALITIES IN PATIENTS WITH ACUTE LEUKEMIAS AND MALIGNANT LYMPHOMAS
Authors: Gorski J , Van Hove L , Vanlangendonck F , Boogaerts M A , Verwilghen R L , Vermylen J
Published: August 2018

Membrane glycoproteins are implicated in platelet functions.In myeloproliferative disorders some of the platelet functions are known to be perturbated and an abnormal glycoproteins pattern was demonstrated ear-lier.In this study flow cytometry analysis of human platelet membrane glycoproteins IIa and IIIa in patients with acute leukemias and malignant lymphomas has been performed using monoclonal antibodies against these glycoproteins.

A reduction in number of glycoproteins receptors on platelet membrane was demonstrated in patients with acute leukemias and malignant lymphomas in comparison with platelets of healthy donors.In patients with leukemias the positive correlation of percentage of platelets recovered in various density receptor regions to bleeding time and negative correlation to platelet number for both glycoproteins have been found.The study demonstrated that flow cytometry can be a useful method of analysis of platelet membrane glycoproteins, and that the patients with acute leukemias and malignant lymphomas have the number of glycoproteins reduced.
MODIFICATIONS OF BIOLOGICAL PARAMETERS DURING TREATMENT OF PULMONARY EMBOLISM BY A VERY LOW MOLECULAR HEPARIN FRAGMENT (CY 222)
Authors: DELAHOUSSE B , GRUEL Y , MOALIC P , QUILLIET L , TOULEMONDE F , LEROY J
Published: August 2018

45 patients with pulmonary embolism (PE) were treated by a very low molecular weight heparin fragment (CY 222, Institut CHOAY - France) in an open range dose study. Patients were included into three groups (I, II and III) and received respectively 500, 750 or 1000 IC (Institut Choay) antiXa units/ kg/day by continuous intravenous infusion for ten days. The laboratory screen carried out at Day 0 and at 2 - 8 - 12 - 24 - 36, 48 hours and then every day until Day 10, included : Platelet count, Thromboelastography (TEG) on platelet rich plasma (PRP), Amidolytic assays for anti Xa (CBS 3139 STAGO) and anti Ila (S2238 KABI) activities (Calibration with Hepanorm STAGO), Heptest (Diamed, France), Amidolytic assay for tissue plasminogen activator (t-PA) and its inhibitor (PAI, Verheijen's method). Results showed no modification of platelet count and t-PA or PAI levels; An hypocoagulabi 1 ity was demonstrated with TEG on PRP (r+k > 35 mm) in 20 cases (3 patients from group III with haemorrhagic manifestations and 17 cases from groups II and III without complication). Anti-IIa activities were always lower than 0.15 U/ml. Anti-Xa activities and Heptest (Control adult values = 12.75 sec + 1.15) were (Mean + SD):

Any significant biological difference between patients who have good or poor clinical results was observed, excepted for 1 patient who had a high level of PAI at Day 0 and recurrence of PE.
MODIFICATION OF COAGULATION AND FIBRINOLYSIS DURING TRANSLUMINAL ANGIOPLASTY IN PATIENTS RECEIVING HEPARIN OR PENTOSAN POLYSULFATE (HEMOCLAR)
Authors: Bel Lakhal N , Pernes J M , Lichtenstein D , Roncato M , Gaux J C , Nieuwenhuizen W , Aiach M
Published: August 2018

Twenty patients with high stenosis of iliac or femoral artery were randomely allocated to receive by intra arterial route (IA) either 5,000 IU heparin or 50 mg Hemoclar immediately before starting the angioplasty. Those receiving Hemoclar were given a second IA 50 mg bolus at the end of the dilatation.

Two blood samples were obtained by venous punction 1) after an initial 30 min resting (V1), 2) at the end of the procedure (V2)- Arterial punction by the dilatation catheter was also performed immediately before and after the dilatation leading to two other samples A1 and A2

The coagulation studies include activated partial thromboplastin time (APTT), thrombin time (TT), hep test (Hemachem, St-Louis, USA), anti Xa activity (Stachrom heparin, Diagnostica-Stago Asnieres, France). There was a significant increase in APTT, TT, and hep test between A1 and A2 as well as V1 and V2 in both groups of patients. However, the prolongation was significantly higher for heparin. Anti Xa activity significantly increased only in heparin group.

Fibrinolysis was studied by measuring tPA by the SOFIA assay described by Angles-Cano (Anal. Biochem. 1985, 153, 201), euglobulin lysis time (ELT) and a new plasma ELISA assay specific for fibrinogen degradation products (FDPs) using monoclonal antibody described at the Gaubius Institute (Blood 1985, 66, 503). A significant increase in tPA was observed during the dilatation (A2/A1) and V2/V1) only in the patients receiving Hemoclar. The slight increase of the fibrinolytic activity was further corroborated by a significant increase in FDPs (A2/A1). In both groups, but only in the venous samples (V2/V1), ELT was shortened (p<0.05) and fibrinogen was decreased (p<0.05)

No thrombotic complications were observed during the procedure in both groups

Conclusion: This study confirms that Hemoclar has an inhibiting effect on coagulation by inhibiting thrombin and thrombin generation, but no anti Xa activity. However, the anticoagulant potency is much reduced when compared to heparin. The profibrinolytic effect seems to be related to the release of free tPA.
INCREASED SULFATION IMPROVES THE ABILITY OF VESSEL WALL GLYCOSA-MINOGLYCANS TO REGULATE THROMBIN ACTIVITY AND PROTHROMBIN ACTIVATION IN PLASMA
Authors: Ofosu F A , Modi G J , Blajchman M A , Buchanan M R , Johnson E A
Published: August 2018

Studies have shown that dermatan sulfate (DS), heparan sulfate (HS) and chondroitin-4-sulfate (C4S), have antithrombotic properties. The sulfate to carboxylate ratios of these three glycosaminoglycans (GAGs) are approximately half that of heparin (HEP) and the gravimetric dose of each of the three GAGs required to achieve antithrombotic effects in vivo comparable to HEP can be 10 times or more than that of HEPT Since antithrombotic effects depend on the ability of a GAG to catalyse thrombin inhibition and/or to inhibit prothrombin activation, we determined the relationship between the extent of sulfation of various GAGs and their effects on these two reactions in normal plasma. In addition to the three GAGs, DS, HS and C4S were resulfated in vitro to yield DS-S, HS-S and C4S-S, each with a sulfate to carboxylate ratio comparable to that of heparin. As summarized below, increased sulfation improved the ability of a GAG to catalyse thrombin inhibition and to inhibit prothrombin activation. Increasing the degree of sulfation primarily improved the ability of a GAG to accelerate the inhibition of thrombin by heparin cofactor II. The degree of sulfation, therefore, appears to be an important functional attribute of the ability of vessel wall GAGs to regulate the formation and activity of thrombin in plasma.
APPLICATION OF THE ROUTINE PHOTOMETRIC COAGULATION ASSAYS PT, APTT AND FIBRINOGEN TO A CENTRIFUGAL ANALYZER
Authors: Bartl K , Lill H , Dessauer A
Published: August 2018

The vast majority of coagulation tests in the routine laboratory are the global assays PT, APTT and the single factor determination of fibrinogen. We developed a convenient ilystem consisting of these photometric assays and the Cobas® Bio equipped with an external calculator. By use of this system all three determinations are possible from the same sample cup. For a profile of all 3 parameters, a sample through-put of about 60 per hours is possible. For PT and APTT determinations, the photometric assays on basis of chromogenic substrates are used. The time is measured, until defined amounts of p-nitroani1ine are split off from the substrate by the thrombin formed. Fibrinogen is measured in a kinetic turbidimetric reaction during fibrin formation by batroxobin. The performance data are as follows: The coefficients of variation for the PT assay (25 μl of sample and 225 μl of reagent) are 0.5-1 % (X = 31,9 sec or 115,0 sec respectively, n = 20). The normal range is 70-120 %, the therapeutic range 12-27 %. The assay is extremely sensitive for the factors VII, V, X and II. It is both suited for the control of oral anticoagulant therapy and the screening of factor deficiencies. The CV values for the APTT assay (20 μl of sample, 200 μl of reagent and 20 μl of starting reagent) are 0,5-1,3 % for normal plasma samples. The normal value ranges from 36-58 sec. Plasma with 0.3 USP units heparin/ml yields 80 sec (ratio = 1,6). Factor VIII and IX levels of 50 % prolong the APTT ratio for about 1,3 or 1,2 respectively. The data of the clinical evaluation proved the assay suitable for the control of the heparin therapy and the screening of the endogeneous coagulation system. The fibrinogen assay (20 μl of undiluted sample and 300 μl of reagent) shows a linear relationship between measuring signal and concentration from 50-800 mg/dl. The correlation with the functional clotting assay to Clauss is rather good (r = 0,98). There is only a slight interference due to fibrin(ogen) degradation products compared to the clotting test. The performance data and the clinical data make the system Cobas® Bio and the sensitive photometric assays an interesting alternative to the conventional clotting tests in the routine laboratory.
PROTHROMBIN TIME MONITORING OF ORAL ANTICOAGULANT TREATMENT: COMPARISON OF INSTRUMENTS AND THROMBOPLASTINS
Authors: Seveso M P , Macagni A , Viganò D'Angelo S , Manotti C , Bonini P A , D'Angelo A
Published: August 2018

The prothrombin time (PT) is the most widely used assay to monitor oral anticoagulation (OA). Although it has been established that both thromboplastin and instrumentation significantly affect the results, major standardization attempts have been devoted to the calibration of reagents rather than of instruments. To provide safe laboratory monitoring of OA, an International Sen sitivity Index (ISI) for thromboplastin has been introduced. We have compared two automatic coagulometers, the ACL (Instrumentation Laboratory), a laser-nephelometer centrifugal analyzer which measures the intensity of the light scattered by a plasma sample before, during and after clot formation and the KOAGULAB 40A (Ortho Diagnostics), an optical automatic coagulometer, with the till tube technique for the performance ofPT. Five calibrated commercial thromboplastins have been used for replicate determinations in 30 normals, 30 liver disease patients and 30 patients on stabilized OA. The overall observed imprecision (C.V.) was 1.1% for ACL, 2.9% for the KOAGULAB 40A and 3.0% for the till tube technique. The F test for the two-way interaction of ratios was statistically significant (p< O.OOl) for the large majority of reagent/technique combinations in normals and in liver disease patients. Internatio nal normalized ratios were also significantly different (p< O.OOl) in most instances in patients on OA. Inadequate anticoagulation (INR<2.0)was observed in 18% of patients with the ACL , in 31% with the KOAGULAB 40A and in 33% with the till tube technique. Excessive anticoagulation (INR> 4.5) was observed in 19% of the patients with the ACL, in 7% with KOAGULAB 40A and in 3% with the till tube tech nique. These data highlight the need for standardization of both instrumentations and reagents to improve monitoring of OA.
THROMBOEMBOLISM IN PROSTHETIC VALVE ENDOCARDITIS AND ANTICOAGULANT THERAPY
Authors: Fukui T , Aosaki M , Uetsuka Y , Iwade K , Nirei T , Hirosawa K
Published: August 2018

The clinical results of thromboembolism (TE) in Patients with prosthetic valVe endocarditis (PVE) and anticoagulant therapy were studied. 22 PVE patients (ll males and females each from 4 to 59 years old, average 32.7) were selected from 1939 patients who had undergone valve replacement at this hospital from 1964 and 1985. The complication frequency of TE and its clinical results, anticoagulant therapy and coagulation tests were investigated. Diagnostic criterion was determined in either of the following two: l) those patients who experienced valve replacement, with at least gradual pyrogenic symptons and inflammation factors such as a large increase in white blood cells, the progress of ESR and positive CRP, also with the same bacterium found more than twice in blood culture, also with the same bacterium found more than twice in blood culture, or 2) those patients who experienced valve replacement, with bacterial verruca found at re-valve replacement or at pathological anatomy. PVE onset took 2 days to 6.5 years (average 407 days) to appear after valve replacement. 8 out of the 22 PVE patients (36.3%) showed complications at TE onset, and 5 out of the 8 patients repeated. Embolism was found in 6 cases of brain, 4 cases of kidney, 2 cases of lung, 2 cases of limbs and 1 case of spleen, and 8 patients all died. On the other hand, 5 complications (22.7%) at bleeding were found in 3 cases of brain, 1 case of duodenum and 1 case of site of replaced aortic valve, and 4 patients died. Anticoagulant therapy was given to 21 out of the 22 PVE patients, and thrombotest (TT) values at TE onset were all less than 30%. Warfarin was administered as anticoagulant. 2 patients were administered with aspirin, but one was given with 250mg aspirin per day together with warfarin, and the other with 330mg aspirin per day alone. TT values at the onset of bleeding were from 10 to 56%. Anticoagulant therapy had been performed to the PVE patients since PVE onset did not yet appear, but complications coagulability by TT values, and all the patients died. In addition to this, complications at bleeding were found many and most of patients died even when the TT values were not so low. Therefore, we believe that the anticoagulant therapy that had been performed after PVE onset still needs further studies.
LONG-TERM COUMAROL PLUS SMALL DOSE ASA THERAPY IN PATIENTS WITH PROSTHETIC HEART VALVE. SOME QUESTIONS OF LABORATORY CONTROL
Authors: Boda Z , Pfliegler G , Tornai I , Udvardy M , Hársfalvi J , Rak K
Published: August 2018

Thromboembolism in patients with prosthetic heart valves remains a major time-related problem (Sullivan 1971, Dale 1976, Chesebro 1983). Patients receiving anticoagulant plus antiplatelet agent have the lowest incidence of thromboembolism but the risk of bleeding is not negligible. The laboratory control of combined therapy is unsolved.

This study considers the thromboembolic prophylaxis of 38 patients with prosthetic heart valve. Cou-marol treatment was combined with ASA (1 000 mg/week, 36 months follow up).

Prothrombin ratio was used in control of the oral anticoagulant therapy. Malondialdehyde production was measured parallel with the so-called malondialdehyde-ratio (MDA-ratio = malondialdehyde level of patient/ control plasma). MDA-ratio, platelet aggregation, thromboxane and prostacycline metabolites were studied 48 hours after 500 mg ASA intake. The average of MDA-ratio was 0.42 ± 0.23 (from 137 measurements). The therapeutic range of MDA-ratio is 0.7 - 0.2. Value below 0.2 means overdosed, over 0.7 means an ineffective ASA therapy. Normal first and second phase platelet aggregation was observed in 23 % of cases when MDA-ratio was below 0.5. Only in 4 % of patients with MDA-ratio over 0.7 was found an abnormal platelet aggregation. The mean prothrombin ratio was 1.59 ± 0.22.

No gastrointestinal bleeding or thromboembolism was observed during the 36 months follow up. Contrary to the literary data (Chesebro 1983) coumarol plus small dose ASA did not result excessive bleeding and can be suggested for patients with prosthetic heart valve. Examination of both the prothrombin and the malondialdehyde ratio with study of platelet aggregation is recommended as laboratory control.