bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Myocardial Damage After Electroconvulsive Therapy: Analyses of High-Sensitive Cardiac Troponin I and N-Terminal pro-B-type Natriuretic Peptide
Authors: Kranaster Laura , Badstübner Johanna , Aksay Suna , Bumb Jan , Suliman Rayan , Neumaier Michael , Sartorius Alexander
Published: July 2018

Electroconvulsive therapy (ECT) is a remarkably safe procedure. However, there might exist a subgroup of patients with an increased risk for cardiovascular events. The cardiac-specific enzymes high-sensitive cardiac troponin I (hscTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured before and after ECT in 23 patients. No relevant increase of hscTnI after ECT was found. Mean NT-proBNP levels were higher after ECT and in three patients a new NT-proBNP elevation after ECT was identified. In conclusion, our small study did not find any evidence for myocardial damage due to ECT by measuring hsTnI, but an increase of NT-proBNP, whose clinical relevance could only be speculated, yet.
Recent Advances in the Applications of Triethylsilane in Organic Synthesis
Authors: Soural Miroslav , Ručilová Veronika
Published: July 2018

The synthesis of pharmacologically relevant scaffolds is an important goal in modern organic chemistry. For this reason, the use of methodologies involving operationally simple procedures and easily handled reagents to chemoselectively and stereoselectively convert different functionalities has gained considerable attention. In this review, we summarize the latest trends in reductive reactions using triethyl­silane as the key reagent that provide synthetically interesting intermediates, coupling products and structures with control of the 3D architecture.

1 Introduction

2 Scenario A: Reduction of C–C Multiple Bonds

3 Scenario B: Reduction of Functional Groups

4 Scenario C: Reductive Coupling

5 Scenario D: Reductive Cyclization

6 Conclusion
Oxidative Coupling–Thionation of Amines Mediated by Iron-Based Imidazolium Salts for the Preparation of Thioamides
Authors: Pastor Isidro , Gisbert Patricia
Published: July 2018

An efficient and selective multicomponent oxidative coupling, involving the use of two different amines, sodium phosphate, and elemental sulfur have been described for the preparation of thioamides, employing microwave irradiation. The use of an iron(III)-based imidazolium salt is essential as catalyst. Indeed, the iron-based catalyst is involved in the oxidative coupling of the two amines and in the subsequent C–S bond formation. The protocol is useful for a wide variety of primary benzylamines and alkylamines, as coupling partners. Thus, various electron-rich and electron-poor substituents in the aromatic rings and also fused piperidine derivatives, are suitable starting materials in this reaction. Some of the obtained products are important synthetic intermediates for natural products.
Effects of Alcohol Withdrawal on Responses of Platelets from Alcoholics - A Study Using Platelet-Rich Plasma from Blood Anticoagulated with D-Phenylalanyl-L-prolyl-L-arginyl Chloromethyl Ketone (FPRCH2CI)
Authors: Rand Margaret L , Neiman Jack , Jakowec Donna M , Packham Marian A
Published: July 2018

Platelet responses stimulated by a range of concentrations of ADP or collagen were studied in platelet-rich plasma (PRP) from alcoholics 24-36 h and 6 days after cessation of drinking, and in PRP from age- and sex-matched controls. The studies were done using plasma from blood anticoagulated with the specific thrombin inhibitor D-pheny1a1any1-T,-prolyl-L-arginyl chloromethyl ketone (FPRCH2Cl, PPACK); the use of this compound permits the study of platelet responses in plasma at physiological concentrations of ionized calcium. Responses of platelets to ADP (primary aggregation) and collagen (aggregation, secretion of [14C]serotonin from prelabelled platelets, and thromboxane formation) were lower in alcoholics 24-36 h after withdrawal of alcohol compared with controls. This inhibition of platelet function was not due to the presence of alcohol in the blood of the alcoholics. Aggregation in response to ADP did not change during the withdrawal period studied, while collagen-induced aggregation and secretion increased significantly and collagen-induced thromboxane formation tended to increase towards control values. The reduced platelet responses observed in alcoholics and the different rates of “recovery” of different pathways of aggregation towards control values must be due to alterations either in the platelets themselves and/or in the plasma brought about by the chronic presence of ethanol, and its withdrawal.
Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors
Authors: Hauptmann J , Kaiser B , Nowak G , Stürzebecher J , Markwardt F
Published: July 2018

The anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas
the opposite was true of thrombin inhibitors.

In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosage

The results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.
Enhanced Effective Fibrinolysis following the Neutralization of Heparin in Open Heart Surgery Increases the Risk of Post-Surgical Bleeding
Authors: Gram Jørgen , Janetzko Thomas , Jespersen Jørgen , Bruhn Hans Dietrich
Published: July 2018

The tissue-type plasminogen activator related fibrinolytic system was studied in 24 patients undergoing cardiopulmonary bypass surgery. The degradation of fibrinogen and fibrin was followed during and after surgery by means of new sensitive and specific assays and the changes were related to the blood loss measured in the chest tube drain during the first 24 postoperative hours. Although tissue-type plasminogen activator was significantly released into the circulation during the period of extracor-poreal circulation (p <0.01), constantly low levels of fibrinogen degradation products indicated that a systemic generation of plasmin could be controlled by the naturally occurring inhibitors. Following extracorporeal circulation heparin was neutralized by protamine chloride, and in relation to the subsequent generation of fibrin, there was a short period with increased concentrations of fibrinogen degradation products (p <0.01) and a prolonged period of degradation of cross-linked fibrin, as detected by increased concentrations of D-Dimer until 24 h after surgery (p <0.01). Patients with a higher than the median blood loss (520 ml) in the chest tube drain had a significantly higher increase of D-Dimer than patients with a lower than the median blood loss (p <0.05).

We conclude that the incorporation of tissue-type plasminogen activator into fibrin and the in situ activation of plasminogen enhance local fibrinolysis, thereby increasing the risk of bleeding in patients undergoing open heart surgery
The Conformation Changes of the Finger Domain of Tissue Type Plasminogen Activator during the Activator-lnhibitor Reaction
Authors: Wilczyńska Malgorzata , Cierniewski Czeslaw S
Published: July 2018

A peptide fragment of tissue plasminogen activator (tPA) corresponding to amino acid residues 4-8 (tPA4−8) was synthesized, coupled to thyroglobulin and injected into rabbits. Antibodies specific to the peptide tPA4−8 were purified immunochemically on the pentapeptide coupled to CNBr-Sepha rose 4B. Anti-tPA4−8 antibodies, reacted with iodinated peptide tPA4−8, showing a relatively high binding affinity (KD = 2.3 × 10−8)

There was no interaction between anti-tPA4 − 8 antibodies and native one- or two-chain tPA. However, reduction of disulfide bonds unmasked the epitope on the heavy chain of tPA which became accessible to anti-tPA4−8 antibodies. Similarly, complex-ing of tPA with Α1arantitrypsin inhibitor resulted in unmasking of the epitope formed by amino acid residues in the positions 4-8.

Presented data suggest that complexing of tPA with inhibitors results in conformational changes occurring in the “finger” domain of tPA molecule and such conformational transition can be detected by antipeptide antibodies. Therefore, anti-tPA4−8 antibodies may be employed as sequence-specific reporter molecules to monitor local conformational changes in tPA molecule.
Internalization of Recombinant Tissue-Type Plasminogen Activator by Isolated Rat Hepatocytes is via Coated Pits
Authors: Marks Gary J , Hart Timothy K , Rush Glenn F , Hoffstein Sylvia T , Fong Kei-Lai L , Bugelski Peter J
Published: July 2018

The uptake and internalization of tissue-type plasminogen activator (t-PA) by freshly isolated rat hepatocytes was investigated. Electron microscopic examination of the uptake of t-PA-colloidal gold conjugates (t-PA-gold) by isolated rat hepatocytes showed that t-PA-gold was internalized via coated pits. This was inhibited with excess t-PA. Uptake of 125I-t-PA by isolated rat hepatocytes was a rapid, saturable, and specific process. The initial rate of specific uptake was 0.1 fmol/106 cells per min. The specific uptake plateaued at 1.4 fmol/106 cells by 30 min and declined to 0.8 fmol/106 cells at 2 h. Depletion of cellular ATP by 85-90% did not affect the initial rate of specific uptake. However, specific uptake by ATP-depleted hepatocytes at 30 min was reduced by 37%. By 2 h specific uptake by ATP-depleted hepatocytes was only 5% lower than by untreated hepatocytes, suggesting that processing of t-PA and/or its receptor is ATP-dependent. Uptake of 125I-t-PA was temperature dependent. Specific uptake was reduced by ∼20% at 22° C and by 70% at temperatures below 16° C. Finally, inhibition of coated pit formation by K+-depletion with nigericin decreased the uptake of 125I-t-PA. This inhibition was shown to be K+-specific since treatment with nigericin in the presence of K+ did not inhibit coated pit formation or 125I-t-PA uptake. A threshold K+-depletion level for inhibition of coated pit formation was also demonstrated since treatment under conditions that reduced cellular K+ by only 54% had no effect on coated pit formation or 125I-t-PA uptake. These data support our hypothesis that internalization of t-PA by isolated rat hepatocytes is via coated pits and suggest that uptake of t-PA is a receptor-mediated process.
Depletion of Dense Granule Nucleotides during Storage of Human Platelets
Authors: de Korte D , Gouwerok C W N , Fijnheer R , Pietersz R N I , Roos D
Published: July 2018

The energy metabolism of human platelets was studied during storage of platelet concentrates. The platelets were prepared from buffy coats in PVC/DEHP bags and stored for 7 days at room temperature at a concentration of 1.0 × 109/ml with horizontal agitation. The total amount of ATP and ADP decreased with 40% during this storage. This decrease correlated with the disc-tosphere transformation associated with the loss of platelet viability. During storage, the ability to incorporate 3H-adenosine into metabolic ATP and ADP (45 min at 37° C) decreased with 50%. Via measurement of the specific activity of actin-bound ADP and the amount of incorporated radioactivity into total ATP and ADP, we calculated the content of the metabolic and storage pools of ATP and ADP. The results indicate that the decrease in adenine nucleotide levels during storage was mainly caused by a depletion of ATP and ADP from the storage pool, whereas the metabolic pool remained nearly intact. After 7 days, the ATP : ADP ratio of the storage pool had decreased from 1.0 to 0.3, indicating hydrolysis of ATP.

Diadenosine-triphosphate and diadenosine-tetraphosphate (present in the storage pool) decreased with only 30%, and the serotonin content remained nearly constant. Therefore, it is unlikely that the storage pool was completely secreted. Probably, the storage pool of nucleotides serves as an internal supply for maintaining the contents of the metabolic pool of ATP and ADP during storage of platelets.
Luminographic Detection of von Willebrand Factor Multimers in Agarose Gels and on Nitrocellulose Membranes
Authors: Budde U , Schneppenheim R , Plendl H , Dent J , Ruggeri Z M , Zimmerman T S
Published: July 2018

Two methods for visualization of vWf multimers were compared with respect to sensitivity and detection of normal vWf and vWd variants IIA, IIB, IIC, IID, HE, and HE Autoradiography and luminography after electrotransfer of vWf multimers onto nitrocellulose showed comparable sensitivity with vWf: Ag detectable after 1:500 dilution of normal plasma. The least sensitive method was luminography in agarose gels with vWf: Ag detectable after 1:300dilution of normal plasma. No difference existed in the banding patterns of plasmas from patients with variant vWd.
Fibrin Affinity and Clearance of t-PA Deletion and Substitution Analogues
Authors: Johannessen M , Diness V , Pingel K , Petersen L C , Rao D , Lioubin P , O’Hara P , Mulvihill E
Published: July 2018

To investigate structure-function relationships in tissue-type plasminogen activator (t-PA) we deleted the following domains in the heavy chain: a) The epidermal growth factor domain (t-PA del. G), b) the finger domain, and the epidermal growth factor domain (t-PA del. FG), and c) the finger, the epidermal growth factor and Kr-ingle 1 (1-PA del, FGK1). To study specificly the function of the growth factor domain we made two substitutions of d) 8 amino acids (consensus sequence) in the growth factor domain (t-PA G-CS) and c) the whole domain with factor IX growth factui doniuin (t-PA G-IX). Finally, f) an analogue with substitution in the finger domain (fibronectin consensus sequence) was constructed (t-PA F-CS).

A reduced fibrin binding of all the analogues was found. The fibrin stimulated activity of all analogues was also reduced and correlated to the fibrin binding. In contrast, the activity of the analogues in the clot lysis assay and the plate assay were only slightly reduced as compared to authentic t-PA. This suggested that at high fibrin concentrations the decreased fibrin affinity was less ciitical for obtaining a high fibrinolytic activity.

All analogues had a prolonged half-life in vivo as compared to authentic t-PA. The assumption of clearance mechanism involving mainly the growth factor region (or Kringlc 1) was not challenged by the observation of a prolonged half-life for the substitution analogue t-PA F-CS.

Our results indicate that a high affinity for fibrin and rapid elimination in vivo of t-PA require a nearly intact conformation of the N-terminal part of the molecule.
Fibrinolytic Activity in Chinese Patients with Diabetes or Hyperlipidemia in Comparison with Healthy Controls
Authors: Ho Chao Hung , Jap Tjin Shing
Published: July 2018

Plasma tissue-type plasminogen activator (tPA), plasminogen activator inhibitor (PAI) and euglobulin lysis time (ELT) were determined before and after the venous occlusion test (VOT) in 3 groups of patients with mean age about 60 years: 29 diabetic patients (D group), 8 hyperlipidemic patients (H group) and 19 healthy controls (C group). In the D and H groups, the mean of morning tPA was significantly higher than that of the C grogp, but the means of PAI were not significantly different among the 3 groups. ELI was significantly shortened and tPA was markedly increased after the VOT in all 3 groups whereas PAI had not significantly changed. In conclusion, high tPA activity and good fibrinolytic response without significant change of PAI .activity were found in the diabetic and hyperlipidemic patients, and no definite impairment of the fibrinolytic activity could be found in the Chinese patients with diabetes and hyperlipidemia. This might be one of the reasons why the Chinese has low incidence of thromboembolic diseases.
Binding of Platelet Agglutinating Protein p 37 from the Plasma of a Patient with Thrombotic Thrombocytopenic Purpura to Human Platelets
Authors: Lian Eric C-Y , Siddiqui Farooq A
Published: July 2018

We have previously reported the purification of a 37 kDa platelet agglutinating protein (PAP p37) from the plasma of a patient with thrombotic thrombocytopenic purpura (TTP) that was shown to be present in a subset of TTP patients. To gain further insight into the interaction between PAP p37 and platelets, we have studied the properties of PAP p37 binding to platelets. Washed human platelets from two normal donors and two TTP patients after recovery were used for the experiments. The PAP p 37 binding to platelets was specific, concentration dependent and saturable. Scatchard analysis demonstrated about 20,564–27,090 PAP p37 binding sites per platelet. Stimulation of platelets with thrombin or ADP did not have any significant effect on its binding.

Thiol- and serine-specific protease inhibitors did not inhibit PAP p37 binding to the platelets. Sugars such as glucose, fructose, mannose, and sialic acid, at 40 mM, inhibited its binding to platelets by 44%, 73%, 79%, and 91% respectively, but galactose and amino sugars did not have any significant effect. At 250 μg/ml, Concanavalin-A inhibited 42% of binding, but other lectins, such as phytohemagglutinin-P, potato lectin and helix pomatia lectin (snail), did not. Pre-incubation of 125I-PAP p37 with the adult human IgG, decreased its binding to the platelets. The monoclonal antibodies to GP Ib (6D1) and GP IIb-IIIa complex (10E5) did not inhibit the binding of 125I-PAP p37 to platelets. Fibrinogen and von Willebrand factor did not affect the binding either. These results suggest that PAP p37 binds to platelets on the sites other than GP lb or GP IIb-IIIa complex.
Protein C, Protein S and c4b-Binding Protein in Severe lnfection and Septic Shock
Authors: Hesselvik J F , Malm J , Dahlbäck B , Blombäck M
Published: July 2018

We measured concentrations of the natural anticoagulant protein C; its cofactor, protein S; and the carrier protein C4bbinding protein (C4BP), in 24 patients with severe infection and 13 with septic shock. Decreased antithrombin III levels were found in 16 of 24 infection patients and all shock patients; high thrombin-antithrombin (TAT) complexes were present in 16 of 24 infection and 12 of 13 shock patients. Protein C concentrations were significantly reduced compared to healthy blood donors, to 60 ± 14% (infection) and 47 ± 20% (septic shock) (mean ± 1 SD). Total protein S levels were not reduced (119 ± 36.7 and 88 ± 20.0%, normal value 96±15%). Free protein S was also normal (27 ± 9.4 and 30 ± 8.7%, normal value 29 ± 9%). The percentage free of total protein S was normal in shock patients (35 ± 8.5%), but significantly reduced in patients without shock (23 ± 5.3%). C4BP was significantly higher than normal in the latter group (135 ± 43%), but not in the shock group (118 ± 40%), possibly due to increased consumption. Thus, no deficiency of total or free protein S was found in these patients, who had evidence of activated coagulation but no clinical DIC.
Factors Affecting the lnteraction of Tissue Factor/Factor Vll with Factor X in a Heterogeneous Tubular Reactor
Authors: Gemmell Cynthia H , Turitto Vincet T , Nemerson Yale
Published: July 2018

A novel reactor recently described for studying phospholipiddependent blood coagulation reactions under flow conditions similar to those occurring in the vasculature has been further charactenzed. The reactor is a capitlary whose inner wall is coated with a stable phospholipid bilayer (or two bilayers) containing tissue factor, a transmembrane protein that is required for the enzymatic activation of factor X by factor VIIa. Perfusion of the capillary at wall shear rates ranging from 25 s−1 to 1,200 s−1 with purified bovine factors X and VIIa led to steady state factor Xa levels at the outlet. Assay were performed using a chromogenic substrate, SpectrozymeTMFXa, or by using a radiometric technique. In the absence of Ca2+ or factor VIIa there was no product formation. No difference was noted in the levels of factor Xa achieved when non-activated factor VII was perfused. Once steady state was achieved further factor Xa production continued in the absence of factor VIIa implying a very strong association of factor VIIa with the tissue factor in the phospholipid membrane. In agreement with static vesicle-type studies the reactor was sensitive to wall tissue factor concentration, temperature and the presence of phosphatidylserine in the bilayer.
An Analysis of the Activators of Single-Chain Urokinase-Type Plasminogen Activator (scu-PA) in the Dextran Sulphate Euglobulin Fraction of Normal Plasma and of Plasmas Deficient in Factor XII and Prekallikrein
Authors: Binnema D J , Dooijewaard G , Turion P N C
Published: July 2018

An analysis was made of the various possible activators of single-chain urokinase-type plasminogen activator (scu-PA) in the dextran sulphate euglobulin fraction (DEF) of human plasma. scu-PA activators were detected in an assay system in which the substrate scu-PA, in physiological concentration (50 pM), was immuno-immobilized. After activation of the immobilized scu-PA for a certain period of time the activity of the generated amount of immuno-immobilized two-chain u-PA was determined with plasminogen and the chromogenic substrate S-2251. The scu-PA activator activity (scuPA-AA) in the DEF of plasmas deficient in factor XII or prekallikrein was about half of that in the DEF of normal plasma. Separation of scuPA-AA in the DEF by gel chromatography showed to major peaks, one eluting with an apparent Mr of 500,000 and the other around Mr 100,000. The former peak, which coincided with the activity peak of the kallikrein-kininogen complex, was absent in the DEF of plasma depleted of prekallikrein and therefore was identified as kalli-krein. The latter peak was still present in the depleted plasma and most likely represents plasmin, because its scuPA-AA coincided with the activity peak of plasmin and could be fully inhibited by antibodies raised against human plasminogen. It is concluded that plasmin and the contact-activation factor kallikrein each contribute for about 50% to the scuPA-AA in the DEF. Compared on a molar basis, however, plasmin was found to be almost 1,000 times more effective than kallikrein, and we conclude, therefore, that in vivo plasmin is the primary activator of scu-PA and the role of the contact system is of secondary importance.
A Synthetic Analog of Fibrinogen α27–50 Is an Inhibitor of Thrombin
Authors: Binnie Cameron G , Lord Susan T
Published: July 2018

Binding of the synthetic peptide AAKDSDWPEASDEDWNYKAPSGAR, a fibrinogen α27–50 analog, to thrombin was studied by inhibition assays and affinity chromatography. Peptide α27–50 corresponds to a segment of human fibrinogen downstream from the thrombin cleavage site, with cysteine residues at positions 28, 36, 45 and 49 replaced by alanine. The peptide inhibited clotting of fibrinogen with an inhibition constant of 190–400 μM. Cleavage of fibrinopeptides A and B was inhibited by the peptide and the peptide was competitive with fibrinogen for thrombin. Inhibition of the small substrate tosyl-Gly-Pro-Arg-p-nitroaniline was not observed indicating that the peptide did not block the active site of the enzyme. Peptide α27–50 that was covalently linked to Sepharose bound active siteinhibited thrombin at low ionic strength and was eluted at higher salt concentration. The peptide was not cleaved on overnight exposure to thrombin as determined by reverse phase HPLC. In summary, the peptide bound to, but was not a substrate for thrombin. These results suggest that this region of fibrinogen contributes to binding of thrombin.
Failure of Computerized Impedance Plethysmography in the Diagnostic Management of Patients with Clinically Suspected Deep-Vein Thrombosis
Authors: Prandoni P , Lensing A W A , Büller H R , Carta M , Vigo M , Cogo A , Cuppini S , ten Cate J W
Published: July 2018

Before a new diagnostic modality can be introduced in clinical medicine, the validity of both a normal and abnormal test result have to be assessed prospectively in an appropriate patient group. We have evaluated the clinical validity of. a new computerized impedance plethysmography (CIP) in the diagnostic management of 381 consecutive patients with clinically suspected venous thrombosis. In patients with serially normal CIP results, the diagnosis of venous thrombosis was refuted and, consequently, they were not treated with anticoagulant therapy and all were followed up for a period of 6 months to estimate the occurrence of symptomatic venous thromboembolism.

The study was prematurely terminated by the safety monitoring committee because of an unacceptably high incidence of confirmed venous thromboembolism (10 patients, 3.2%; 95% confidence interval: 1.6% to 6%), including 4 episodes of fatal pulmonary embolism. In a subsequent explanatory study using ultrasonography in 29 other symptomatic patients who had at least 2 repeated normal CIP test results, the failure of CIP to detect proximal vein thrombosis was confirmed in 4 patients (14%). The reasons for this failure are probably related to the use of a modified device to measure impedance in the CIP apparatus, resulting in a lower ability to separate patients without venous thrombosis from those with the disease.

We concluded that CIP is insensitive for the detection of proximal vein thrombosis and, therefore, not clinically useful in the diagnostic management of patients with suspected venous thrombosis.
Bleeding/Bruising Symptomatology in Children with and without Bleeding Disorders
Authors: Nosek-Cenkowska B , Cheang M S , Pizzi N J , Israels E D , Gerrard J M
Published: July 2018

A questionnaire, designed to assess bleeding/bruising tendencies, was administered to 251 otherwise healthy children undergoing a tonsillectomy and/or adenoidectomy. 23 children with excessive bleeding during or after the operation, with a long bleeding time or who reported taking aspirin recently were excluded, to give a population of 228 non-bleeders. For comparative purposes, 31 patients with bleeding disorders (von Wille-brand’s disease and/or platelet function defects) were studied. A considerable proportion of “non-bleeding” children reported easy bruising (24%), had bruises at least once a week (36%) and suffered from nosebleeds (39%). The respective frequencies (67%, 68% and 69%) for children with bleeding disorders were significantly higher. Occurrence of bruises usually on more than one part of the body, frequent large bruises or hematomas were rare in “non-bleeders” (4.9%, 3.5% and 2.7% respectively), but more common in “bleeders” (38.5%, 29.6% and 21.7% respectively).
The Role of Blood and Platelets in Atherosclerosis and the Complications of Atherosclerosis
Authors: Mustard J. F , Packham M. A
Published: July 2018

There appear to be at least three ways in which the blood, and particularly the platelets, may contribute to the development of atherosclerosis and its complications :

1. In the mechanism causing endothelial injury and the response of the smooth muscle cells to vessel injury.

2. Through the formation of persistent mural thrombi which are organized into intimai thickenings.

3. Through the formation of thrombi in association with advanced atherosclerosis that may be either (a) mural thrombi which fragment and shower the distal circulation with platelet emboli or (b) occlusive thrombi.
Changes of Coagulation and Fat-Metabolism Following Pulmonary Microembolism after Trauma and Hemorrhage
Authors: Saggau W. W , Ulmer H. E , Bleyl U
Published: July 2018

In 16 of 24 anesthetized mongrel dogs a standardized bone trauma was performed to both hind legs by open osteotomy. During the following 6 hours the most important hemodynamic parameters, total platelet count (GTZ) and its separate fractions (NKF, KF) were continously monitored.

Five hours after the trauma 50% of the total blood volume (taken to be 80 ml/kg body weight) was withdrawn from two of the four groups of animals.

The trauma caused no direct effect on the pulmonary hemodynamics.

In the following hours there was a slight decrease of cardiac output (HZV) in the traumatised animals. Besides a moderate increase in mean pulmonary pressure (MPP), pulmonary vascular resistance (PVP) increased by 72% of the pretraumatic values. The application of intravascular catheters diminished the total platelet count markedly in the injured, as in the uninjured animals. The increase in PVR was caused less by a mechanical obstruction of the pulmonary capillary bed than by vasoactive substances released by the platelets. The following hemorrhage led to a more marked hemodynamic reaction in the injured animals. All these animals died before the end of the calculated hemorrhage. All animals without trauma survived. Irreversible aggregation of platelets developed in the pulmonary capillary bed caused by the marked pulmonary hypocirculation.

Histological examination showed a marked disseminated pulmonary microthrom-bosis in all animals with trauma and hemorrhage.

The initial phase of experimental pulmonary microembolism caused by trauma was characterized by pulmonary hypocirculation and an activated coagulation with simultaneously diminished total platelet count.
Plasminogen-Plasmin System IX. Specific Binding of Tranexamic Acid to Plasmin
Authors: Iwamoto Masahiro
Published: July 2018

Interactions between tranexamic acid and protein were studied in respect of the antifibrinolytic actions of tranexamic acid. Tranexamic acid did neither show any interaction with fibrinogen or fibrin, nor was incorporated into cross-linked fibrin structure by the action of factor XIII. On the other hand, tranexamic acid bound to human plasmin with a dissociation constant of 3.5 × 10−5 M, which was very close to the inhibition constant (3.6 × 10−5 M) for this compound in inhibiting plasmin-induced fibrinolysis. The binding site of tranexamic acid on plasmin was not the catalytic site of plasmin, because TLCK-blocked plasmin also showed a similar affinity to tranexamic acid (the dissociation constant, 2.9–4.8 × 10−5 M).

In the binding studies with the highly purified plasminogen and TLCK-plasmin preparations which were obtained by affinity chromatography on lysine-substituted Sepharose, the molar binding ratio was shown to be 1.5–1.6 moles tranexamic acid per one mole protein.

On the basis of these and other findings, a model for the inhibitory mechanism of tranexamic acid is presented.
The Effect of Brinase on Fibrinogen in Vivo
Authors: Nyman D
Published: July 2018

Brinase infusions in man cause, without excessive lowering of the inhibitor capacity, a slowing of the fibrin polymerization. This is combined with a degradation of the A α chain into two major fragments. Both fragments carry crosslinking sites. Brinase infusion also causes positive ethanol gelation. Evidence for the formation of γ dimers was found.
Clinical Correlations
Authors: Moore Sean
Published: July 2018

There are two aspects which are clinically relevant in the relationships among thrombosis and arteriosclerosis. First, the relationship of thrombosis to atherogenesis. Thrombosis is closely related to endothelial injury and there is recent evidence that repeated or continuous endothelial damage leads to the development of all the lesions seen in human atherosclerosis. This occurs in the absence of dietary lipid supplement. The relative importance of the parts played by injury and thrombosis in this process need further delineation. Secondly, established arteriosclerotic disease is associated with thrombosis. This thrombosis is usually mural, seldom occlusive. Embolism by platelet aggregates which has been well described in the retinal and cerebral circulations may affect other vascular territories such as the heart and the kidney. Such a mechanism may explain some cases of otherwise unexplained sudden cardiac death and some cases of hypertension. We need better clinical tools to detect the occurrence of thrombo-embolism and to monitor it’s progress. Measures to modify thrombosis and embolism may be as useful or more useful than those we currently employ in the clinical management of atherosclerotic disease.
Various Prothrombin Complex Concentrates and their Effect on Coagulation and Fibrinolysis In Vivo
Authors: Hedner U , Nilsson I.M , Bergentz S.-E
Published: July 2018

Thromboembolic complications occurring in patients treated with factor IX concentrates have been reported. To study the thrombogenicity various types of factor IX concentrates (50 or 100 units F. IX/kg bodyweight) have been infused in dogs. As control albumin was given. The various components of the coagulation and fibrinolytic system have been assayed before the infusion and at various intervals after the end of infusion (0, 1,4 and 24 hrs). Konyne resulted in marked activation of the coagulation process with decrease of platelets, fibrinogen, F. VIII and appearance of FDP and positive ethanol gelation test. Pro thro mplex and Pre-conativ gave no significant changes. Preconativ is prepared without addition of heparin during the procedure.
Purification of Human Factor IX by Chromatography of a Coagulation Factor Concentrate
Authors: Suomela Hannu
Published: July 2018

A purification procedure for, and some properties of, coagulation factor IX are described. The coagulation factor concentrate used for the treatment of hemophilia B patients was employed as the starting material. The isolation procedure consists of chromatography in DEAE-cellulose, two chromatographies in hydroxyapatite gel and two gel filtrations in Sephadex G-200. Only trace amounts of factors II, VII and X were present in the final preparation and the specific activity of factor IX was 159 corresponding 10,300 times purification from plasma. The molecular weight was estimated to be 76,000 in gel filtration and 86,000 in sodium dodecyl sulfate disc gel electrophoresis. Three activity peaks with pis 4.15, 4.25 and 4.40 were obtained by isoelectric focusing.
Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.
Authors: Principe D. Del , Mancuso G , Menichelli A , Maretto G , Sabetta G
Published: July 2018

The authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.
Aggregation of Platelets and Inert Particles Induced by Thrombin
Authors: Chao Frangis C. , Tullis James L. , Conneely Gail S. , Lawler John W.
Published: July 2018

Thrombin-induced platelet aggregation and release were investigated in washed platelet suspensions and in suspensions of inert particles in order to evaluate the role of fibrinogen-fi-brin transformation in aggregometer tracings. Thrombin (0.25–2.0 U/ml) produced two waves of light transmission increase (LTI) in both platelet and inert particle suspensions containing fibrinogen, and concomittantly aggregates were observed under phase microscopy. Without fibrinogen, thrombin induced rapid release of platelet ADP but failed to cause second wave of LTI. The kinetics of LTI in platelet and inert particle systems were related to both thrombin and fibrinogen concentrations. A rapid second wave of LTI could be produced by direct interaction of thrombin-treated platelets or inert particles with polymerizing fibrin, and was inhibited by sodium sulfite and low pH of 5.1 which prevent fibrin monomer polymerization. No fibrin strands were noted in platelet aggregates fixed at the completion of the second wave of LTI. Apyrase and PGE1 inhibited the rate of first but not that of second wave LTI. The results suggest that the release of platelet ADP induced by thrombin primarily affects the first phase aggregation, and the second phase may result from interaction of thrombin-exposed platelets and polymerizing fibrin. Thus, the blood coagulation mechanism may be directly involved in platelet aggregation.
Lack of Agreement of Chromogenic and Glotting Assays for Factor X and Protein C in Warfarinised Plasma
Authors: Han P , Fung K P , Rahdakrishnan U
Published: July 2018

Coagulation serine proteases can be measured with either a chromogenic substrate assay or a clotting assay using deficient plasmas. It is a concern whether both assays give similar quantitative results, in particular in plasma obtained fiom patients on long term warfarin therapy. If these two assay methods were interchangeable, then the chromogenic substrate assay has the advantages of precision as well as laboratory automation. We used the intraclass correlation coefficient (r1) to assess the agreement between the two methods in measuring factor X and protein C levels in warfarinised plasma. The results indicate that the extent and pattern of agreement of the two methods for the measurement of the two variables in warfarinised plasma are poor, despite high Pearson product moment coefficients of correlation.
Plasma Level of IL-1β in Disseminated Intravascular Goagulation
Authors: Wada Hideo , Tamaki Shigehisa , Tanigawa Motoaki , Takagi Mikio , Mori Yoshitaka , Deguchi Akira , Katayama Naoyuki , Yamamoto Toshihiko , Deguchi Katsumi , Shirakawa Shigeru
Published: July 2018

The plasma level of interleukin-1β (IL-1β) was determined in normal individuals, patients with disseminated intravascular coagulation (DIC), patients in the pre-DIC period (within 7 days before the onset of DIC), and non-DIC patients to examine the relationship between DIC and the plasma ILlp level. The plasma IL-1β level was 0-0.085 ng/ml in normal individuals, with little difference being seen according to related age. It was significantly higher in the DIC group (0.19 ± 0.19 ng/ml) than in the pre-DIC group (0.05 ± 0.08 ng/ml) or the non-DIC group (0.09 ± 0.01 ng/ml). The plasma IL-1β level was not markedly elevated in leukemia patients, even in the DIC group, but it was significantly increased in the DIC group of solid cancer patients and was generally elevated in patients with sepsis. It was markedly elevated to 0.39 ± 0.26 ng/ml in patients with organ failure. When mononuclear cells were incubated with lipopolysaccharide, it was found that IL-1β, tumor necrosis factor, and tissue factor (TF) were released into the medium, and there was an increase of TF release from endothelial cells incubated with this medium. These results suggest that the increase in IL-Iβ reflected the activation of monocytes and may be an important factor in DIC and its associated organ failure.
Western Blot Analyses of Prekallikrein and its Activation Products in Human Plasma
Authors: Veloso Dulce , Colman Robert W
Published: July 2018

Prekallikrein (PK), a zymogen of the contact system, and its activation products, kallikrein (KAL), KAl-inhibitor complexes and fragments containing KAL epitope(s) have been detected in human plasma by immunoblotting with a monoclonal anti-human plasma PK antibody, MAb 13G1L. Detection of antigen-MAb 13G11 complexes with peroxidase-conjugated anti-IgG showed that the two variants of PK (85- and 88-kDa) are the only major antigen species in normal, non-activated plasma. Upon plasma activation with kaolin, the intensity of the PK bands decreased with formation of complexes of KAL with CL inhibitor (C1 INH) and α2-rrtzcroglobulin (α2M) identical to those formed by the purified proteins. Immunoblots of normal plasma showed good correlation between the PK detected and the amount of plasma assayed. Increasing amounts of KAL incubated with a constant volume of PK-deficient plasma showed increasing amounts of KAL and of KAL-C1 INH and KAL-α2M complexes. Complexes of KALantithrombin III (ATIII) and the ratio of KALα2M/ KAL-CL INH were higher in activated CL INH-deficient plasmas than in activated normal plasmas. Protein resolution by 3-12% gradient SDS-PAGE and epitope detection with [125I]MAb 13G11 showed four KALα2M species and a 45-kDa fragment(s) in both surface-activated normal plasma and complexes formed by purified KAL and α2M. Immunoblots of activated plasma also showed bands at the position of KALCL INH and KALATIII complexes. When α1-antitrypsin Pittsburgh (cα1-AT, Pitts) was added to plasma before activation, KAL-α1-ALPitts was the main complex. The non-activated normal plasma revealed only an overloaded PK band. This is the first report of an antibody that recognizes KAL epitope(s) in KAL-α2M, KALATIII and KALa1-α1Pitts complexes and in the 45-kDa fragment(s). Therefore, MAb 13G11 should be useful for studying the structure of these complexes as well as the mechanism of complex formation. In addition, immunoblotting with MAb 13G11 would allow detection of KAl-inhibitor complexes in patient plasmas as indicators of activation of the contact system.
Effect of Plasminogen Activator Inhibitor-1 on Tissue-Type Plasminogen Activator-Induced Fibrinolysis
Authors: Carr Marcus E , Krishnamurti C , Alving B M
Published: July 2018

The effect of fibrin on the interaction of human recombinant single-chain tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) was studied in normal rabbit plasma and in plasma with high levels of native PAI-1. t-PA was added to diluted plasma containing calcium (10 mM) and 125I-fibrinogen at 37° C. Clotting was initiated with human thrombin, and lysis was monitored both turbidimetrically and by release of 125I-fibrin degradation products (fdp). The activity of t-PA (50 IU/ml) was rapidly reduced to 15% of the initial value in plasma containing PAI-1 (23 AU/ml). When thrombin and t-PA were added simultaneously to the plasma, more than 70% of the activity was retained through incorporation of t-PA into the fibrin clot. t-PA-induced fibrinolysis in PAI-1 enriched plasma was further delayed when the temperature was reduced from 37 to 25° C. Turbidimet-ric and 125I-fdp release data provided complementary information. The former technique traced fiber dissolution, while the latter reflected network integrity. These results indicate that t-PA-induced fibrinolysis in PAI-1 enriched plasma is modulated by the presence of fibrin and by temperature.
No Evidence for Short-Term Regulation of Plasminogen Activator Inhibitor Activity by Insulin in Man
Authors: Vuorinen-Markkola Helena , Puhakainen llpo , Yki-Järvinen Hannele
Published: July 2018

In crossectional studies a positive correlation has been found between circulating insulin, triglycerides and plasminogen activator inhibitor (PAI-1) activity. To directly examine the effect of insulin on PAI-1 activity in vivo, we determined the response of PAI-1 activity in 17 normal subjects to acute hyperinsulinemia (serum free insulin 92 ± 8 mU/l) during maintenance of normoglycemia (plasma glucose 5.1 ± 0.1 mmol/l). In 12 matched control subjects PAI-1 activity was measured during infusion of saline (serum free insulin 3.6 ± 0.3 mU/l, plasma glucose 5.2 ± 0.1 mmol/l). Plasma PAI-1 activity decreased during the insulin infusion from 9.0 α 1.4 to 5.6 α 0.8 U/ml (p <0.01), and during saline infusion from 7.0 ± 1.4 to 4.3 ± 0.6 U/ml (p <0.05). Serum triglyceride concentrations decreased from 1.09 ± 0.20 to 0.76 ± 0.09 mmol/l (p < 0.001) during hyperinsulinemia but remained unchanged during the saline infusion (1.04 ± 0.11 vs. 1.02 ± 0.12 mmol/l, NS). We conclude that insulin does not acutely change plasma PAI-1 activity, and that acute insulin-induced changes in serum triglycerides occur independently from those of PAI-1 activity.
The Venous Antithrombotic Effect of LF 1351 in the Rat following Oral Administration
Authors: Millet Jean , Theveniaux Jocelyne , Brown Neil L
Published: July 2018

The venous antithrombotic effects of a novel chemical entity, LF 1351, were investigated in rats following single oral administration, in comparison with i.v. administered heparin. LF 1351 demonstrated a dose-related antithrombotic effect in three models of venous thrombosis. The compound was approximately equipotent in two models involving complete stasis of the vena cava and administration of factor Xa or porcine serum, giving respective ED50 values of 48.7 mg/kg and 36.7 mg/kg. LF 1351 was less effective in a model involving partial stasis in the presence of an endothelial lesion. In this case, the antithrombotic effect did not exceed 60-65%, the ED50 being 150 mg/kg. Heparin (50-300 μg/kg; 7.5-45.0 U/kg) was effective in all three models. At the approximate ED80 value against factor Xa-induced thrombosis (75 mg/kg) the antithrombotic effect of LF 1351 persisted for 6 h. The antithrombotic effect of LF 1351 (300 mg/kg) occurred without significant changes in APTT or thrombin time.
The Predictive Value of the Hemostasis Parameters in the Development of Preeclampsia
Authors: Ho Chao-Hung , Yang Zwa-Ling
Published: July 2018

In order to find out which hemostasis parameters would have the predictive value for the development of preeclampsia, modified antithrombin III (ATM, representative of the antithrombin Ill-serine esterase complex), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), beta-throm-boglobulin (BTG), antithrombin III (AT III), fibrinogen, fibrin(ogen) degradation product (FDP), FDP D-dimer and euglobulin lysis time (ELT) were measured in 20 normal nonpregnant women, 21 normal pregnant women, 6 high-risk pregnant women, 14 preeclampsia pregnant women, and 5 patients with disseminated intravascular coagulation (DIC). Only tPA and AT III were found significantly different between the preeclampsia and the normal or high-risk pregnant women: tPA was found progressively and significantly increased from the normal pregnant, to the high-risk pregnant, then to the preeclampsia women (p <0.05). AT III was significantly lower in the preeclampsia than in the normal pregnant (p = 0.0001) or in the high-risk pregnant women (p = 0.002). In the 2nd trimester, tPA, PAI, fibrinogen and FDP were significantly higher, and AT III was significantly lower in the preeclampsia than in the normal pregnant women, whereas in the 3rd trimester, tPA and AT III were significantly higher or lower, respectively, in the preeclampsia than in the normal pregnant women. No significant difference of ATM could be found between the preeclampsia and the normal or high-risk pregnant women. From the present study, we suggest that tPA and AT III would be used as the main predictors, and FDP and D-dimer as the complementary predictors for the development of preeclampsia and should be detected in the normal or high-risk pregnant women.