bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Magnesium on Platelet Aggregation and Adhesion
Authors: Gawaz M , Ott I , Reininger A J , Neumann F-J 
Published: July 2018

SummaryMagnesium deficiency and its association with platelet hyperreactivity has been well recognised in a variety of diseases including myocardial infarction, preeclampsia, and diabetes. In order to investigate potential effects of intravenous Mg2+ supplementation, platelet function was studied by measurements of in vitro bleeding time (BT) and of fibrinogen (Fg)-mediated aggregation of washed platelets. In addition, the effect of Mg2+ on platelet adhesion onto immobilised Fg, on Fg binding to activated platelets, and on surface expression of GMP-140 or GP53 was evaluated. Mg2+(4 mM) prolonged in vitro BT by 30% and inhibited Fg-mediated aggregation significantly, independent of the agonist used to initiate platelet aggregation (ADP, collagen, epinephrine, thrombin, phorbol ester). Adhesion of resting platelets to immobilised Fg was reduced by 50% in the presence of 2 mM Mg2+. Moreover, Mg2+ reduced Fg binding to ADP- or collagen-stimulated platelets as well as surface expression of GMP-140 with an IC50 of approximately 3 mM. Intravenous administration of Mg2+ to healthy volunteers inhibited both ADP-induced platelet aggregation (p <0.05) by 40% and binding of Fg or surface expression of GMP-140 by 30% (p <0.05). Thus, pharmacological concentrations of Mg2+ effectively inhibit platelet function in vitro and ex vivo.
Protein-tyrosine Kinase p72
syk
Is Activated by Platelet Activating Factor in Platelets
Authors: Rezaul Karim , Yanagi Shigeru , Sada Kiyonao , Taniguchi Takanobu , Yamamura Hirohei 
Published: July 2018

SummaryIt has been demonstrated that activation of platelets by platelet-activating factor (PAF) results in a dramatic increase in tyrosine phosphorylation of several cellular proteins. We report here that p72
syk
is a potential candidate for the protein-tyrosine phosphorylation following PAF stimulation in porcine platelets. Immunoprecipitation kinase assay revealed that PAF stimulation resulted in a rapid activation of p72
syk
which peaked at 10 s. The level of activation was found to be dose dependent and could be completely inhibited by the PAF receptor antagonist, CV3988. Phosphorylation at the tyrosine residues of p72
syk
coincided with activation of yllsyk. Pretreatment of platelets with aspirin and apyrase did not affect PAF induced activation of p72
syk
.Furthermore, genistein, a potent protein-tyrosine-kinase inhibitor, diminished PAF-induced p72
syk
activation and Ca2+ mobilization as well as platelet aggregation. These results suggest that p72
syk
may play a critical role in PAF-induced aggregation, possibly through regulation of Ca2+ mobilization.
Lipopolysaccharide Induced Monocyte Thromboplastin Synthesis and Coagulation Responses in Patients Undergoing Coronary Bypass Surgery after Preoperative Supplementation with n-3 Fatty Acids
Authors: Nilsen D W T , Almdahl S M , Svensson B , Vaage J , Rasmussen K , Østerud B 
Published: July 2018

SummaryTwenty patients with coronary heart disease (CHD) and elevated serum lipids were randomized into 2 groups of 10 to receive encapsulated preparations of either a concentrated ethylester form of eicosapentaenoic acid (EPA) and docosa-hexaenoic acid (DHA) or corn oil in doses of 6 g per day, given double blindly for approximately two months prior to coronary bypass surgery. Lipopolysaccharide (LPS) induced monocyte thromboplastin synthesis was studied during the preoperative period and one week following surgery. The ability of n-3 fatty acids to modify tissue factor pathway inhibitor (TFPI) and tissue plasminogen activator inhibitor (PAI-1) was also evaluated along with fibrinogen and thrombin-antithrombin III (TAT) complexes.No significant changes were noted preoperatively. Monocyte reactivity, PAI-1, fibrinogen and TAT increased significantly after surgery. These changes were not modified by preoperative loading with n-3 fatty acids.
Markers of Hemostatic System Activation in Acute Deep Venous Thrombosis-Evolution during the First Days of Heparin Treatment
Authors:   The DVTENOX Study Group
Published: July 2018

SummaryFibrin D-Dimer (D-Di), prothrombin activation fragment (F 1+2) and thrombin-antithrombin III complexes (TAT) were measured using ELISA procedures in the plasma of patients with an acute deep venous thrombosis (DVT), at presentation and on days 2, 6 and 10 after initiation of heparin treatment. Patients were randomly allocated into two treatment groups: 44 patients received adapted doses of continuous intravenous unfractionated heparin (UH) whereas 47 received 1 mg/kg every twelve hours of a low molecular weight heparin (enoxaparin) subcutaneously. A phlebography and a perfusion lung scan were performed before inclusion and on day 10. Failure of therapy (n = 9) was defined by venogram worsening or confirmed pulmonary embolism. Improvement (n = 44) or stationary state (n = 38) were defined by venogram evolution in the absence of new leg scan defects.At presentation, D-Di, F 1 + 2 and TAT were above cut-off values in 97, 66 and 89% of patients respectively. D-Di levels correlated with the extent of venous thrombosis whereas TAT and F 1 + 2 did not. Mean levels of D-Di decreased sharply during the first days of treatment but were still abnormal on day 10. A secondary increase of D-Di on days 6 or 10 by more than 3 μg/ml occurred in 4 of the 9 patients who developed a thromboembolic recurrence but in none of the 72 patients who had a more favorable outcome. F 1 + 2 and TAT time-courses were not related to clinical evolution. In the Enoxaparin group, there was no relationship between antifactor Xa activities and any biological markers. TAT and F 1 + 2 levels fell on day 2 and remained stable until day 10. In contrast, in the UH group, TAT and F 1 + 2 did not significantly decrease on day 2, probably due to a delay in dose adaptation, but they declined slowly until day 10.In conclusion, D-Di displays a higher sensitivity than F 1 + 2 or TAT for the diagnosis of D\T. D-Di, but not TAT or F 1 + 2, follow-up seems to be of potential value for early detection of recurrency. Hemostatic activation is controlled earlier by fixed doses of a low molecular weight heparin, irrespective of the plasma anti-factor Xa activities, than by unfractionated heparin at adapted doses.
Are Capillary Whole Blood Coagulation Monitors Suitable for the Control of Oral Anticoagulant Treatment by the International Normalized Ratio?
Authors: Tripodi Armando , Arbini Arnaldo A , Chantarangkul Veena , Bettega Donato , Mannucci Pier Mannuccio 
Published: July 2018

SummaryThe 512 Coagulation Monitor is a portable coagulation photometer that uses disposable cartridges containing a lyophilized rabbit brain thromboplastin to measure the PT for capillary whole blood. It has been proposed as a suitable system for patient self monitoring at home, but its performance has never been thoroughly assessed for results expressed as International Normalized Ratio (INR). In particular, there is no available information about the adequacy of the WHO calibration model with the Monitor. The aims of the study were to determine the International Sensitivity Index (ISI) against the secondary International Reference Preparation for rabbit thromboplastin and to assess the precision of the INR. The study demonstrates that the Monitor can be calibrated with the WHO model, because log-transformed PTs for patients stabilized on oral anticoagulants and normal individuals are linearly related and because the same orthogonal regression line describes patient and normal data points adequately. However, the ISI calculated in this study (2.715) is higher than that adopted by the manufacturer (2.036). The between-assay reproducibility of the Monitor is acceptable (CV = 9.7%) with results expressed in seconds, but become unacceptably poor when the results are converted into INR (CV = 18.8%) because of the high ISI value of the thromboplastin used. We think that the Monitor might be suitable for monitoring oral anticoagulant therapy if the manufacturer would provide a more sensitive thromboplastin in the cartridges.
Expression and Localization of Tissue Factor-Based Procoagulant Activity (PCA) in Pigeon Monocyte-Derived Macrophages
Authors: Gupta Madhu , Doellgas George J , Cheng Therese , Lewis Jon C 
Published: July 2018

SummaryMonocyte-derived macrophages, focal to initiation and progression of atherosclerosis, have been implicated in thrombotic complication of this disease. In the present study we demonstrated tissue factor based procoagulant activity in cultured macrophages from the White Carneau pigeon following endotoxin (1-2 μg/ml) stimulation. This macrophage procoagulant activity paralleled activity obtained with pigeon brain homogenate. We used Enzyme-Linked Coagulation Assay (ELCA), an ultrasensitive microtiter plate assay, to measure procoagulant activity in these cells. Through the use of clotting factors purified from pigeon plasma, procoagulant activity could be detected with as few as 1-3 cells. Tissue factor antigen, detected through the use of immunogold labelling in conjunction with a polyclonal antibody which was highly specific to human tissue factor, was distributed uniformly over the plasma membrane of the endotoxin-stimulated cells. These studies suggest that this procoagulant activity might play an important role in the pathobiology of atherosclerosis in White Carneau pigeons by initiating fibrin polymerization and thus leading to thrombotic complications of the disease.
Frangulin B, an Antagonist of Collagen-Induced Platelet Aggregation and Adhesion, Isolated from Rhamnus formosana
Authors: Teng Che-Ming , Lin Chien-Huang , Lin Chun-Nan , Chung Mei-lng , Huang Tur-Fu 
Published: July 2018

SummaryEmodin and its glycoside frangulin B were isolated from the plant Rhamnus formosana. Emodin inhibited the aggregation of rabbit platelets induced by arachidonic acid and collagen, without affecting that by ADP or PAF, while emodin acetate had no any antiplatelet effect. Frangulin B inhibited selectively and concentration-dependently collagen-induced aggregation and ATP release in rabbit platelets, without affecting those induced by arachidonic acid, ADP, PAF and thrombin. Frangulin B also inhibited the platelet aggregation induced by trimucytin which was reported to be a collagen receptor agonist isolated from Trimeresurus muscrosquamatus snake venom. The aggregability of platelets inhibited by frangulin B could be recovered after washing the platelets. Frangulin B also selectively suppressed the thromboxane B2 formation caused by collagen, but not those by arachidonic acid and thrombin. Similarly, the formation of inositol phosphate caused by collagen was also suppressed by frangulin B, while that of PAF or thrombin was not affected. In the presence of PGE1, frangulin B also decreased Mg2+-dependent platelet adhesion to collagen. It is concluded that frangulin B may be an antagonist of collagen receptor in platelet membrane.
Hemophilic Bledding Evaluated by Blood Pool Scanning
Authors: Green D , Spies S M , Rana N A , Milgram J W , Mintzer R 
Published: July 2018

SummaryThe technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.
Effect of Local Urokinase on Arterial Occlusion of Lower Limbs
Authors: Fiessinger J-N , Aiach M , Capron L , Devanlay M , Vayssairat M , Juillet Y 
Published: July 2018

SummarySixty nine patients were treated with local intra-arterial urokinase (37,500 U/CTA. hr-1) for recent severe ischemia of lower limbs: 27 (40%) ultimately required amputation. The difference of amputation rate between the groups with and without thrombolysis was not significant (33% v. 42%). A biological study in 6 patients showed that local arterial plasminemia occurred in only 1 patient. Local urokinase does not strongly stimulate “endogenous” thrombolysis and enhances “exogenous” thrombolysis only very inconstantly. A better adaptation of urokinase dosage or the use of an agent with a higher affinity for fibrin might improve the efficiency of local thrombolytic therapy.
Measurement of Fibrinopeptide A in Patients Treated with Phenoprocoumon
Authors: Harenberg J , Haas R , Zimmermann R 
Published: July 2018

SummaryFibrinopeptide A (FPA), which is considered to be a quantitative indicator for the thrombin activity in vivo, was measured in 136 patients treated with phenprocoumon in order to obtain information on the effectiveness of the inhibition of the coagulation system. The results show a decrease of the FPA concentration in relation to the efficacy of the anticoagulant therapy as measured by the thrombotest coagulation method (p<0.01). However, elevated FPA was observed even under an effective oral anticoagulation.These data indicate that an increased thrombin activity cannot be completely prevented by oral anticoagulants in every patient. Combined measurement of FPA and the thrombotest coagulation method might be used to detect patients with an elevated risk of recurrent thromboembolism despite treatment with phenprocoumon.
Abnormal Aggregation Accompanies Abnormal Platelet Ca2+ Handling in Arterial Thrombosis
Authors: Shanbaky Nabila M , Ahn Yeon , Jy Wenche , Harrington William , Fernandez Luis , Haynes Duncan H 
Published: July 2018

SummaryThe resting levels of cytoplasmic Ca2+ (measured by Quin 2 fluorescence) and dense tubular Ca2+ (measured by chlorotetracycline, CTC, fluorescence) are shown to be higher in platelets from patients with arterial thrombosis than from normal donors. Turbidmetric studies of aggregation of diluted platelet-rich plasma (PRP) at 135 μM Ca2+ showed increased rates of aggregation for patients relative to normal controls. For ADP-stimulated aggregation, increased maximal rates (Vmax) and decreased doses for half-maximal rates were observed. With collagen-stimulated aggregation, patient samples showed only decreased ED50 values relative to normal controls. The changes in these values are linearly correlated with the elevation of resting dense tubular Ca2+ level determined by the calcium-CTC test carried out at 2 mM external Ca2+. For ADP-stimulated aggregation this relationship can be mimicked by pre-incubating normal platelets with subcritical concentrations of the Ca2+ ionophore A23187.These results suggest that elevated cytoplasmic and dense tubular Ca2+ in the “resting state” is a major factor in arterial thrombosis, rendering the platelet more sensitive to the stimulation by physiologic agents.
HIV Antibody Status and Immunological Abnormalities in Polish Haemophiliacs
Authors: Lopaciuk S , Kacperska E , Gloskowska-Moraczewska Z , Maslanka K , Uhrynowska M , Kraj M , Seyfried H 
Published: July 2018

SummarySera of 520 multitransfused haemophiliacs were examined for antibody to HIV; 447 patients had haemophilia A and 73 had haemophilia B. In 382 patients with haemophilia A and in 62 with haemophilia B solely Polish-made blood products were used for replacement therapy. The remaining haemophiliacs had also received imported clotting factor concentrates prior to the investigation. Only 8 patients (haemophilia A - 7, haemophilia B - 1) developed anti-HIV and all of them had been exposed to commercial concentrates. The analysis of T-cell subsets demonstrated an inverted T4/T8 ratio (less than 1.0) in 7 (30%) of the 23 haemophiliacs treated solely with domestic cryoprecipitate and in 3 (37%) of the 8 seropositive recipients of commercial concentrates. The most frequent alteration in both subgroups was a reduced ratio with either normal absolute numbers or an increase in T8 cells. Increased serum IgG levels were found in 82% of the users of cryoprecipitate and in 75% of the seropositive patients. Serum beta-2-microglobulin level was elevated in 69 and 62% of each subgroup, respectively. The observed immunological abnormalities, at least in the cryoprecipitate treated subgroup, may be causally related to factors other than HIV infection.
Testosterone Effects on Biosynthesis of Coagulation Proteins
Authors: Owens Michael R , Cimino Catherine D , Donnelly Joan 
Published: July 2018

SummaryStudies were performed to assess the effects of testosterone on synthesis of selected coagulation proteins using the isolated rat liver perfused in vitro for 10 hours, as well as effects of testosterone on plasma levels of these same proteins. Pretreatment of castrated male rat liver donors for 14 days with pellets containing placebo or testosterone, 0.5 mg, 5.0 mg or 15.0 mg had no significant effects on cumulative biosynthesis of Factor II, Factor VII, anti thrombin III, plasminogen or fibrinogen. Plasma concentrations of these proteins in liver donor animals were also unchanged by such hormonal manipulations. In contrast, biosynthesis of fibronectin was increased significantly by increasing doses of testosterone, and plasma concentrations of fibronectin in liver donor rats showed a similar effect.
Antithrombin III in Full-Term and Pre-Term Newborn Infants : Three Cases of Neonatal Diagnosis of AT III Congenital Defect
Authors: De Stefano V , Leone G , De Carolis M P , Ferrelli R , De Carolis S , Pagano L , Tortorolo G , Bizzi B 
Published: July 2018

SummaryAntithrombin III (AT III) plasma levels were investigated in 18 full term neonates and 14 healthy preterm neonates. A control group of 20 healthy adults was also studied. AT III was measured as antigen concentration (Ag) and antithrombin or anti-factor Xa heparin cofactor (H. C.) activities. Crossed immunoelectrophoresis on heparin-agarose (H-CIE) was carried out on plasma samples; moreover the distribution of isoantithrombins was investigated on whole plasma by a technique of crossed immunoelectrofocusing (CIEF). AT III plasma levels in full term infants were significantly lower as compared to the adult values. The preterm newborns group showed a further significant decrease in AT III levels as compared to the full term neonates. In all infants AT III H-CIE runs displayed a single fast moving anodal peak, so that a normal binding to heparin was demonstrated. The CIEF AT III plasma pattern of the adults as well as of all neonates displayed three major peaks at pH range 5.2-4.9, a small amount of AT III at pH 4.9-4.8 and a minor peak at pH 4.8-4.6, so that it was concluded that the isoantithrombins plasma distribution in neonatal age is identical to that of the adult subjects. Four neonates whose mothers were affected by AT III congenital defect were also investigated: diagnosis of congenital deficiency was established in three cases.
Inhibition of Fibrin Polymerization by Serum Amyloid P Component and Heparin
Authors: Meyer Keith , Smith Robert , Williams Eliot C 
Published: July 2018

SummaryThe effects of serum amyloid P component (SAP) and heparin on the thrombin-catalyzed formation of polymeric fibrin from purified fibrinogen were examined using a turbidometric method to quantify fibrin polymerization. SAP and heparin acted synergistically to inhibit the lateral aggregation of fibrin fibrils, resulting in the formation of fibrils with a smaller mass to length ratio. Heparin did not enhance the incorporation of SAP into fibrin clots, and the effect of heparin and SAP did not seem to be related to inhibition of thrombin or of fibrinopeptide release. The evidence suggests that a soluble complex of SAP and heparin inhibits fibrin polymerization.
The Primary Structure of the Inhibitor of Tissue Plasminogen Activator Found in the Seeds of Erythrina caffra
Authors: Joubert F J , Dowdle E B D 
Published: July 2018

SummaryTrypsin and tissue plasminogen activator inhibitor DE-3 from Erythrina caffra contains 172 amino acids, including 4 half-cystine residues, and resembles the Kunitz-type inhibitors. Limited hydrolysis of DE-3 with trypsin at pH 3.2 produced two fragments, FI and F2, containing 63 and 109 amino acids, respectively. Amino-terminal sequence studies showed that FI was the N-terminal and that F2 was the C-terminal fragment. The complete amino acid sequence of the fragments were then determined on peptides produced by enzymatic digestion with trypsin. The sequence of trypsin and tissue plasminogen activator inhibitor DE-3 from E. caffra seeds shows a high degree of homology to that of trypsin and tissue plasminogen activator inhibitor DE-3 from E. latissima seeds and revealed only four amino acids which were replaced.
Hypertensive Disorders of Pregnancy and Preterm Birth Rates among Black Women
Authors: Baer Rebecca , Jelliffe-Pawlowski Laura , Norton Mary , Premkumar Ashish 
Published: July 2018

Objective The objective of this study was to investigate the role of gestational hypertension (gHTN) and chronic hypertension (cHTN) on rates of preterm birth (PTB) among black women.
Study Design Singleton live births between 20 and 44 weeks' gestation among black women in California from 2007 to 2012 were used for analysis. Risk of PTB by subtype and gestational age among women with cHTN or gHTN, including preeclampsia, was calculated via Poisson's logistic regression modeling. Risks were adjusted for maternal factors associated with increased risk of PTB.
Results A total of 154,950 women met the inclusion criteria. Of the 5,948 women in the sample with cHTN, 26.2% delivered preterm; for the 11,728 women with gHTN, 21.6% delivered preterm. Women with gHTN or cHTN had a higher risk of medically indicated and spontaneous PTB, both at less than 32 and 32 to 36 weeks, when compared with nonhypertensive women (adjusted relative risks [aRRs]: 3.4–11.6). Women with superimposed preeclampsia had higher risks of spontaneous (aRR: 2.8, 95% confidence interval [CI]: 2.3–3.4) and medically indicated PTB (aRR: 2.8, 95% CI: 2.0–3.8), especially PTB < 32 weeks, when compared with women with preeclampsia.
Conclusion Among black women, superimposed preeclampsia increased the risk for spontaneous and medically indicated PTB, especially PTB < 32 weeks.