bluuebunny/crossref_metadata_2025_split huggingface dataset:
Venous Thromboembolism and High Grade Gliomas
Authors: Dhami Mandeep S , Bona Robert D , Calogero John A , Hellman Richard M 
Published: July 2018

SummaryA retrospective study was done to determine the incidence of and the risk factors predisposing to clinical venous thromboembolism (VTE) in patients treated for high grade gliomas. Medical records of 68 consecutive patients diagnosed and treated at Saint Francis Hospital and Medical Center from January 1986 to June 1991 were reviewed. The follow up was to time of death or at least 6 months (up to December 1991). All clinically suspected episodes of VTE were confirmed by objective tests. Sixteen episodes of VTE were detected in 13 patients for an overall episode rate of 23.5%. Administration of chemotherapy (p = 0.027, two tailed Fisher exact test) and presence of paresis (p = 0.031, two tailed Fisher exact test) were statistically significant risk factors for the development of VTE. Thrombotic events were more likely to occur in the paretic limb and this difference was statistically significant (p = 0.00049, chi square test, with Yates correction). No major bleeding complications were seen in the nine episodes treated with long term anticoagulation.We conclude that venous thromboembolic complications are frequently encountered in patients being treated for high grade gliomas and the presence of paresis and the administration of chemotherapy increases the risk of such complications.
Comparison of Real-Time B-Mode Ultrasonography and Doppler Ultrasound with Contrast Venography in the Diagnosis of Venous Thrombosis in Symptomatic Outpatients
Authors: Cogo Alberto , Lensing Anthonie W A , Prandoni Paolo , Büller Harry R , Girolami Antonio , ten Cate Jan Wouter 
Published: July 2018

SummaryIn a prospective study, we compared real-time B-mode ultrasonography, using the simple criteria of common femoral and popliteal vein compressibility (Compression US), and Doppler ultrasound, using a standardized technique (Doppler US), with contrast venography in 158 consecutive outpatients symptomatic for deep-vein thrombosis of the lower limbs (DVT). For proximal vein thrombosis, the sensitivities documented for Compression US and Doppler US were 100% (95% CI: 90% to 100%) and 89% (95% CI: 76% to 96%), respectively. This difference is not statistically significant (p = 0.056). For all thrombi (including isolated calf-vein thrombosis), however, the sensitivity of Compression US was significantly higher than that of Doppler US (95% and 76%, respectively; p <0.04). Compression US was normal in all patients with normal venogram (specificity, 100%; 95% CI: 95% to 100%), while Doppler US was abnormal in two patients with normal venogram (specificity, 98%; 95% CI: 92% to 100%). The specificities of the two tests did not differ significantly. The results of our comparison suggest that Compression US is superior to Doppler US in the detection of DVT in symptomatic outpatients.
Functional Characterization of a Variant Prekallikrein (PK Zürich)
Authors: Wuillemin W A , Furlan M , von Felten A , Lämmle B 
Published: July 2018

SummaryThe plasma of a 68-year-old man with cross reacting material (CRM)-positive prekallikrein (PK) deficiency was studied. PK clotting activity was <0.01 U/ml, and PK antigen was 0.1 U/ml. No circulating anticoagulant against PK was detectable. The abnormal PK molecule, denoted as prekallikrein Zürich, was partially characterized by immunological and functional studies on the propositus’ plasma. Immunobiotting analysis showed the abnormal PK being a single chain molecule of the same M
r (80 kDa) as normal PK. Dextran sulfate activation of the propositus’ plasma did not lead to proteolytic cleavage of the variant PK molecule, in contrast to dextran sulfate activation of a mixture of 1 volume normal plasma and 9 volumes CRM-negative PK deficient plasma. Agarose gel electrophoresis followed by immunoblotting demonstrated that PK Zürich was complexed with high molecular weight kininogen similarly to PK in normal plasma. Incubation of the propositus’ plasma with purified β-FXIIa resulted in impaired cleavage of PK Zürich when compared with PK hydrolysis in a mixture of 10% normal plasma and 90% CRM-negative PK deficient plasma. Moreover, proteolytically cleaved PK Zürich showed no enzymatic activity against factor XII and high molecular weight kininogen.These studies show that the functional defect of prekallikrein Zürich is due to an impaired cleavage by activated factor XII and probably the lack of enzymatic activity of the cleaved variant molecule.
Antigens of Tissue Plasminogen Activator and Plasminogen Activator Inhibitor 1: Correlates in Nonsmoking Japanese and Caucasian Men and Women
Authors: Iso Hiroyasu , Folsom Aaron R , Koike Kazuko A , Sato Shinichi , Wu Kenneth K , Shimamoto Takashi , Iida Minoru , Komachi Yoshio 
Published: July 2018

SummaryWe reported in a 1987 preliminary study that tissue plasminogen activator antigen was significantly higher in American Caucasian men than in Japanese men. To further examine possible differences in fibrinolytic activity between the two races, an expanded study was conducted in a total of 300 nonsmoking men and women aged 47-69 years in two population-based samples: rural Japanese living in Akita and Caucasians living in Minneapolis-St. Paul, MN. Antigens of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) were measured. Mean t-PA antigen was 2.3 ng/ml higher in Caucasian men than in Japanese men (P <0.001), but no race difference was seen for women (P = 0.59). Mean PAI-1 was higher in Caucasians than in Japanese for both sexes, and the race difference in mean was 1.8 ng/ml for men (P = 0.07) and 4.4 ng/ml for women (P <0.001). Both t-PA and PAI-1 were associated positively with body mass index and blood triglycerides for all sex-race groups, and positively with alcohol intake for Japanese and Caucasian men. Compared to Japanese, Caucasians of both sexes had higher levels of body mass index and blood triglycerides, and lower average intake of alcohol among men. Even when adjusted for body mass index, triglycerides, alcohol and other cardiovascular risk factors, the race difference in mean t-PA antigen persisted for men (P <0.001), as did the difference in mean PAI-1 for men (P = 0.03) and women (P = 0.001). If PAI-1 is a risk factor for coronary heart disease, a higher level in Caucasians than Japanese would correspond to the higher mortality rate from coronary heart disease in the United States than in Japan.
Tissue-Type Plasminogen Activator after Venous Occlusion in Pregnancy and Puerperium
Authors: Stegnar Mojca , Zore Andrej , Novak-Antolič Živa , Vovk Neva , Kruithof Egbert K O 
Published: July 2018

SummaryPregnancy is associated with depressed fibrinolysis as judged from the decreased fibrinolytic response to venous occlusion. In order to elucidate if this decreased response is due to an increase in plasminogen activator inhibitors 1 and 2 (PAI-1, PAI-2), and/or to decreased release of tissue-type plasminogen activator (t-PA) antigen during venous occlusion, 36 women (18 women with normal pregnancy and 18 with gestational hypertension without proteinuria) were followed during pregnancy and puerperium. In each woman a 20 min venous occlusion was performed in the second and in the third trimester of pregnancy and 3 days after delivery. The increase in t-PA antigen after venous occlusion relative to basal value was in the second trimester of pregnancy on average 3.7 fold, in the third trimester 4.4 fold, and so not reduced compared to non-pregnant women (3.7 fold increase). After delivery the increase in t-PA antigen was significantly enhanced (8.5 fold, p <0.005). The fibrinolytic response to venous occlusion measured by euglobulin and t-PA activity was significantly decreased in the third trimester compared to non-pregnant values (both p <0.005) and returned to somewhat higher (euglobulin clot lysis) or significantly higher (t-PA activity, p <0.01) values 3 days after delivery. Decreased euglobulin and t-PA activity after venous occlusion in the third trimester coincided with significant increases in basal PAI activity, PAI-1 antigen and PAI-2 antigen (2.9, 2.5 and >30 fold increase relative to non-pregnant values, respectively, all p <0.001). No significant differences in fibrinolytic variables were observed between nor-motensive and hypertensive pregnant women. It was concluded that t-PA antigen release during venous occlusion is not decreased during pregnancy and puerperium, and that decreased fibrinolytic response measured by global methods should be attributed to increased t-PA inhibitors. Gestational hypertension without proteinuria is not characterized by changes in fibrinolytic responses different from those observed in normal pregnancy.
Cloning of the cDNA Encoding Human Platelet CD36: Comparison to PCR Amplified Fragments of Monocyte, Endothelial and HEL Cells
Authors: Wyler B , Daviet L , Bortkiewicz H , Bordet J-C , McGregor J L 
Published: July 2018

SummaryGlycoprotein CD36, also known as GPIIIb or GPIV, is a major platelet glycoprotein that bears the newly identified Naka alloantigen. The aim of this study was to clone platelet CD36 and investigate other forms of CD36-cDNA present in monocytes, endothelial and HEL cells. RNA from above mentioned cells were reverse transcribed (RT), using specific primers for CD36, and amplified by the polymerase chain reaction (PCR) technique. Sequencing the different amplified platelet derived cDNA fragments, spanning the whole coding and flanking regions, showed the near identity between platelet and CD36-placenta cDNA. Platelet CD36-cDNA cross-hybridized, in Southern blots, with RT-PCR amplified cDNA originating from monocytes, endothelial and HEL cells. However, monocytes showed a RT-PCR amplified cDNA fragment (561 bp) that was present in platelets and placenta but not on endothelial on HEL-cells. Northern blot analysis of platelet RNA hybridized with placenta CD36 indicated the presence of a major (1.95 kb) and a minor (0.95 kb) transcript. The 1.95 kb transcript was the only one observed on Northern blots of monocytes, endothelial and HEL cells. These results indicate that the structure of CD36 expressed in platelets is similar, with the exception of the 3’ flanking region, to that of placenta. Differences in apparent molecular weight between CD36 and CD36-like glycoproteins may be due to post-translational modifications.
Complexes of Nitric Oxide with Nucleophiles as Agents for the Controlled Biological Release of Nitric Oxide: Antiplatelet Effect
Authors: Diodati Jean G , Quyyumi Arshed A , Hussain Nabeen , Keefer Larry K 
Published: July 2018

SummaryNitric oxide (NO) inhibits platelet aggregation. Accordingly, we hypothesized that complexes of diethylamine and spermine with NO (DEA/NO and SPER/NO, respectively), two vasodilators previously shown to release NO spontaneously in aqueous solution, may also be useful antiplatelet agents. Platelet aggregation was measured in whole blood or platelet-rich plasma by impedance aggregometry after addition of collagen. In whole blood, the dose response curve for DEA/NO added 1 min before collagen was similar to that for aspirin (60% inhibition at 10-4 M), while SPER/NO and sodium nitroprusside were less potent by an order of magnitude. In platelet-rich plasma, 10-6 M DEA/NO caused 60% inhibition, while SPER/NO and sodium nitroprusside were as active only at 10-5 M; aspirin’s potency was unchanged from that in whole blood. In vivo, DEA/NO and sodium nitroprusside produced significant platelet inhibition 1 min after intravenous injection in the rabbit at 50 nmol/kg. Similar in vivo platelet inhibition was observed with SPER/NO and aspirin, but only at higher dose. The effects of DEA/NO and sodium nitroprusside were transient, lasting less than 30 min after treatment, while the activity of SPER/NO and aspirin was sustained throughout the 30 min experiment. The magnitude and duration of the antiplatelet effects of DEA/NO and SPER/NO correlate with the rates at which they release nitric oxide spontaneously in aqueous solution. Thus, NO/nucleophile complexes merit further exploration both as research tools and as potential antiplatelet agents.
Buccal Mucosa Bleeding Time Is Prolonged in Canine Models of Primary Hemostatic Disorders
Authors: Brooks Marjory , Catalfamo James 
Published: July 2018

SummaryBleeding times are reported in many studies using canine models, with a variety of techniques employed to adapt these tests for dogs. We evaluated a canine model of template bleeding time, the buccal mucosa bleeding time (BMBT), by examining the test’s sensitivity and specificity for defects of primary hemostasis. We examined thirty-five dogs having defined defects of either primary hemostasis (Types I, II, III von Willebrand’s disease, thrombasthenia, thrombopathia) or secondary hemostasis (hemophilia A and B, Factor VII deficiency). Comparisons of BMBT and cuticle bleeding time were made in a subset of these dogs.All dogs having primary hemostatic disorders had long BMBT, and all factor deficient dogs had BMBT within normal range. The BMBT in canine models appears to be a specific and sensitive test of primary hemostasis; suitable for evaluating factors affecting template bleeding time and potential efficacy and thrombogenicity of treatment regimens.
A Hexagonal (II) Phase Phospholipid Neutralization Assay for Lupus Anticoagulant Identification
Authors: Triplett Douglas A , Barna Linda K , Unger Gail A 
Published: July 2018

SummaryLupus anticoagulants (LAs) are immunoglobulins (IgG, IgM, or both) which interfere with in vitro phospholipid (PL) dependent tests of coagulation (e.g. APTT, dilute PT, dilute Russell Viper Venom Time). These antibodies may be identified in a wide variety of clinical settings. With the exception of heparinized patient samples, the presence of LAs is often the most common cause of an unexplained APTT in a routine clinical laboratory. The diagnosis of LAs is difficult due to variable screening reagent sensitivity and intrinsic heterogeneity of LAs. Recently, Rauch and colleagues have shown human monoclonal hybridoma LAs were inhibited by hexagonal (II) phase PLs. In contrast, lamellar phase PLs had no effect. We have evaluated a new assay system, Staclot LA®, which utilizes a hexagonal (II) phase PL (egg phosphatidylethanolamine [EPE]) as a confirmatory test for LAs. Plasma samples from the following patient populations were studied: LA positive, heparinized, oral anticoagulated, hemophilia A and B, and specific factor inhibitors (factors V, VIII, IX). Unlike previous studies, the LA positive patients were a mixed population including: autoimmune diseases, drug-induced, and post-infection. Our findings confirm the specificity of hexagonal (II) phase PL neutralization of LAs.
Effect of Various Antiplatelet Agents on Acute Arterial Thrombosis in the Rat
Authors: Bernat A , Mares A M , Defreyn G , Maffrand J P , Herbert J M 
Published: July 2018

SummaryElectrical stimulation of the rat carotid artery causes a deep medial injury and the formation of a platelet-rich thrombus.Occlusive thrombosis at sites of vessel wall injury was significantly reduced after the oral administration of clopidogrel, a potent analogue of ticlopidine, which showed dose-dependent inhibition of the thrombus formation (ED50 = 1.0 ±0.2 mg/kg, p.o.). Accumulation of thrombotic material was also considerably reduced after the i. v. administration of SR 27417, a highly potent and selective platelet activating factor receptor antagonist (ED50 = μg/kg, i.v.), nafagrel, a thromboxane A2 synthetase inhibitor (ED50 = 1.3 mg/kg, i.v.) and hirudin (ED50 = 140 μg/ kg, i.v.). A high dose (20 mg/kg, i.v.) of the anti-adhesive tetrapeptide Arg-Gly-Asp-Ser (RGDS) showed only a slight effect on thrombus formation whereas aspirin was ineffective.These results confirm that ADP and thromboxane A2 play key roles in the initiation and progression of arterial thrombus formation and suggest that platelet activating factor may also modulate thrombosis in this experimental model.
Multicenter Evaluation of Commercially Available Methods for the Immunological Determination of Plasminogen Activator Inhibitor-1 (PAI-1)
Authors: Declerck P J , Moreau H , Jespersen J , Gram J , Kluft C 
Published: July 2018

SummaryIn order to evaluate the comparability of data obtained with various available kits for the immunological determination of PAI-1 antigen in plasma and in order to investigate the underlying cause of observed differences, e. g. problems of specificity or of proper calibration of the provided standard, a multicenter study was organised in the framework of the Subcommittee of Fibrinolysis of the Scientific and Standardization Committee.Eight different plasma samples were distributed among 16 laboratories: a pooled normal plasma, NIBSC 87/512, PAI-1 antigen depleted plasma, PAI-1 depleted plasma supplemented with 59 ng/ml active PAI-1 and four different individual plasma samples. A considerable variation in absolute values is observed between the various kits, e.g. in pooled normal plasma a value is found ranging between 7.4 and 28 ng/ml. Harmonization of all data relative to the PAI-l-depleted plasma supplemented with an exact amount of active PAI-1 (59 ng/ml), followed by a statistical analysis using a two way analysis of variance, revealed that 6 out of 7 kits yielded values that were not significantly different with coefficients of variation around 30%. Correlations between the values obtained with these kits yielded slopes between 0.75 and 1.44 with correlation coefficients between 0.973 and 0.999. Values obtained with one kit appeared to be significantly different (even after harmonization) from the other kits (p <0.001 to p <0.05). Comparison of PAI-1 antigen with the PAI activity values in the analysed samples suggests that one kit may deal with a problem of a difference in reactivity between active and latent PAI-1.In conclusion 6 different kits yield results that, only after harmonization, are comparable and do correlate very well. Thus proper calibration of the provided standards may solve the majority of the problems observed with PAI-1 antigen kits. Differential specificity towards different conformational forms of PAI-1, as a consequence of the use of different monoclonal antibodies, is a minor, but a potential problem, that needs to be considered when comparing data obtained with various methods.
Interaction of Plasminogen Activators and Plasminogen with Heparin: Effect of Ionic Strength
Authors: Rijken Dingeman C , de Munk Gerard A W , Jie Annie F H 
Published: July 2018

SummaryIn order to define the possible effects of heparin on the fibrinolytic system under physiological conditions, we studied the interactions of this drug with plasminogen and its activators at various ionic strengths. As reported in recent literature, heparin stimulated the activation of Lys-plasminogen by high molecular weight (HMW) and low molecular weight (LMW) two-chain urokinase-type plasminogen activator (u-PA) and two-chain tissue-type plasminogen activator (t-PA) 10- to 17-fold. Our results showed, however, that this stimulation only occurred at low ionic strength and was negligible at a physiological salt concentration. Direct binding studies were performed using heparin-agarose column chromatography. The interaction between heparin and Lys-plasminogen appeared to be salt sensitive, which explains at least in part why heparin did not stimulate plasminogen activation at 0.15 M NaCl. The binding of u-PA and t-PA to heparinagarose was less salt sensitive. Results were consistent with heparin binding sites on both LMW u-PA and the amino-terminal part of HMW u-PA. Single-chain t-PA bound more avidly than two-chain t-PA. The interactions between heparin and plasminogen activators can occur under physiological conditions and may modulate the fibrinolytic system.
Synoviorthesis Versus Synovectomy in the Treatment of Recurrent Haemophilic Haemarthrosis: Long-Term Evaluation
Authors: Gamba G , Grignani G , Ascari E 
Published: July 2018

SummaryThe authors report a long-term evaluation of the effects of chemical and surgical synovectomies performed in two groups of patients which were comparable as regards number of haemarthrosis per year and joint mobility. The results obtained indicated that both synovectomy and synoviorthesis were effective in reducing the bleeding episodes; however, while synovectomy stopped almost completely the recurrence of haemarthrosis, synoviorthesis in 3 patients younger than 12 years did not modify it and in one case it even increased the bleeding tendency.Moreover, the occurrence of arthritic pain was observed in 6 knees treated by synoviorthesis and only in 3 knees treated by synovectomy. Finally, the joint function was significantly reduced in the synoviorthesis group as compared to the synovectomy group.In conclusion, synovectomy gave better results than synoviorthesis but the latter treatment has a number of economical and technical advantages and should therefore be considered in patients older than 12 years of age with good joint function and without evident radiological changes, in whom fulldose replacement therapy has had no effect on the recurrence of haemarthrosis.
Effect of Aspirin and Dipyridamole on the Interaction of Human Platelets with Sub-Endothelium: Studies Using Citrated and Native Blood
Authors: Weiss Harvey J , Turitto Vincent T , Vicic William J , Baumgartner Hans R 
Published: July 2018

SummaryThe effect of aspirin and dipyridamole ingestion on the interaction of platelets with the subendothelium was studied using both citrated blood and directly sampled (native) blood. After obtained control studies, normal human subjects ingested 0.6 g of aspirin, 150 mg of dipyridamole, or a placebo and studies were repeated 1½ hrs later. Subjects continued on placebo, aspirin (0.6 g b.i.d.) or dipyridamole (100 mg q.i.d.) for 6 days and studies were obtained 1½ hrs after the last dose. Blood was circulated through an annular chamber on whose inner core were mounted everted segments of de-endothelialized rabbit aorta. The wall shear rate was 2,600 sec-1. Surface coverage with adherent platelets and platelet thrombi, as well as several parameters of thrombus dimensions, were evaluated morphometrically. Aspirin ingestion markedly reduced platelet thrombi in citrated blood, – but had a much lesser inhibitory effect in native blood. Platelet adhesion was unaffected in native blood; it was slightly decreased in citrated blood, in contrast to previous findings in which a lower shear rate (800 sec-1) was used. Ingestion of dipyridamole did not inhibit platelet adhesion or thrombi in either citrated or native blood. The studies indicate that, with the flow conditions used, aspirin is a relatively weak inhibitor of platelet thrombus formation in directly sampled human blood.
Heparin Excretion in Intact and Hepatectomized Rats
Authors: Losito Ray , Gattiker Harry , Bilodeau Ginette 
Published: July 2018

SummaryMetabolism and kinetics of 3H-heparin were compared in intact and hepatectomized rats. Rats were divided into three groups: 1) intact rats with biliary fistulas and cystostomies 2) intact rats with only cystostomies and 3) hepatectomized rats with cystostomies. Radioactivity in blood, bile and urine besides anticoagulant activity in blood and urine were examined. In addition, column chromatography of urine was used to isolate possible metabolites. Seventy percent and 80% of the radioactive dose was found in the urine of intact rats at 24 hr and 48 hr. Close to 5% of the radioactivity was found in bile or rats with a biliary fistula after 48 hr. The APTT declined to near normal values at 1 hr whether rats had a biliary fistula or not. In contrast, only 25 % of the radioactivity could be excreted into the urine of hepatectomized rats in 24 hr; the APTT did not decline as fast and at 5 hr, it was still 100 seconds. Only one radioactive component could be isolated on chromatography from all urines of these animals and appears to be similar to the original heparin. Thus, the liver has an important role to play in regulating the anticoagulant effects and excretion of heparin.