bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serological and Virological Markers of Human Parvovirus B19 Infection in Sera of Hemophiliacs
Authors: Große-Bley A , Eis-Hübinger A M , Kaiser R , Oldenburg J , Brackmann H H , Schwarz T F , Schneweis K E 
Published: July 2018

SummaryIt is known that parvovirus B19 (B19) is transmitted to hemophiliacs by clotting factors prepared from human plasma. However, it is not clear whether B19 is also transmitted by the more recently used inactivated clotting factor preparations. Therefore, we investigated 69 hemophiliacs, mostly children, receiving only virus-inactivated clotting factors. 49 of them (71%) were B19 IgG-positive and 18 of the IgG-positive hemophiliacs (37%) were also B19 IgM-positive. In contrast, out of 73 age-matched controls only 10 (14%) were IgG-positive, two of them being also IgM-positive. In hemophiliacs treated before 1984 with noninactivated clotting factors, seroprevalence was very similar: 94/136 (69%) presented B19 IgG antibodies as compared to their age-matched controls with 16/50 (32%). Out of the 94 IgG-positive patients 24 (26%) were IgM-positive, whereas IgM antibodies were never found in 16 sera of 16 IgG-positive controls. In 4 out of 24 IgM positive hemophiliacs, B19 DNA was detected in the sera by using the polymerase chain reaction. However, B19 DNA was also found in 3/69 anti-B19 IgM-negative, HIV-infected hemophiliacs (all three patients in CDC stage IV). Since it seems unlikely that the results only represent passive acquisition of B19 DNA from blood products and induction of antibodies by immunization with inactivated antigen, the observations rather suggest that infection with B19 is transmitted by clotting factors, including those treated for virus inactivation.
Patterns of Immunogenicity of an Inactivated Hepatitis A Vaccine in Anti-HIV Positive and Negative Hemophilic Patients
Authors: Santagostino E , Gringeri A , Rocino A , Zanetti A , de Biasi R , Mannucci P M 
Published: July 2018

SummaryHepatitis A vaccination has been recommended to patients with hemophilia since they are exposed to potentially infectious clotting factor concentrates. Aim of this study was to assess the immunogenicity of vaccination in hemophiliacs, infected or not with the human immunodeficiency virus (HIV). A formalin-inactivated hepatitis A vaccine was injected subcutaneously to 113 susceptible adults and children and repeated after 1 and 6 months. 47 vaccinees were anti-HIV positive (28 asymptomatic, 15 with CD4 cell counts of less than 200/pl and 4 with symptomatic disease). The first dose of vaccine induced seroconversion, with antibody titers of at least 20 mlU/ml, in 89% of the 66 anti-HIV negative patients, 100% of them responding after the second injection. In anti-HIV positive hemophiliacs seroconversion rates and antibody titers were significantly lower than in non-infected patients. After 12 months, only 76% of anti-HIV positive vaccinees and 40% of those with signs of HIV disease progression maintained the antibody, whereas all anti-HIV negative patients had titers of 20 mlU/ml or more. Our results indicate that there is an association between defective response to hepatitis A vaccine and stage of progression of HIV disease.
Macroaggregation of Platelets in Plasma, as Distinct from Microaggregation in Whole Blood (and Plasma), as Determined Using Optical Aggregometry and Platelet Counting respectively, is Specifically Impaired following Cardiopulmonary Bypass in Man
Authors: Menys Valentine C , Belcher Philip R , Noble Mark I M , Evans Rhys D , Drossos George E , Pillai Ravi , Westaby Steve 
Published: July 2018

SummaryWe determined changes in platelet aggregability following cardiopulmonary bypass, using optical aggregometry to assess macroaggregation in platelet-rich plasma (PRP), and platelet counting to assess microaggregation both in whole blood and PRP. Hirudin was used as the anticoagulant to maintain normocalcaemia.Microaggregation (%, median and interquartile range) in blood stirred with collagen (0.6 µg/ml) was only marginally impaired following bypass (91 [88, 93] at 10 min postbypass v 95 (92, 96] prebypass; n = 22), whereas macroaggregation (amplitude of response; cm) in PRP stirred with collagen (1.0µg/ml) was markedly impaired (9.5 [8.0, 10.8], n = 41 v 13.4 [12.7,14.3], n = 10; p <0.0001). However, in PRP, despite impairment of macroaggregation (9.1 [8.5, 10.1], n = 12), microaggregation was near-maximal (93 [91, 94]), as in whole blood stirred with collagen. In contrast, in aspirin-treated patients (n = 14), both collagen-induced microaggregation in whole blood (49 [47, 52]) and macroaggregation in PRP (5.1 [3.8, 6.6]) were more markedly impaired, compared with control (both p <0.001).Similarly, in PRP, macroaggregation with ristocetin (1.5 mg/ml) was also impaired following bypass (9.4 [7.2, 10.7], n = 38 v 12.4 [10.0, 13.4]; p <0.0002, n = 20), but as found with collagen, despite impairment of macroaggregation (7.2 [3.5,10.9], n = 12), microaggregation was again near-maximal (96 [93,97]). The response to ristocetin was more markedly impared after bypass in succinylated gelatin (Gelo-fusine) treated patients (5.6 [2.8, 8.6], n = 17; p <0.005 v control), whereas the response to collagen was little different (9.3 v 9.5). In contrast to findings with collagen in aspirin-treated patients, the response to ristocetin was little different to that in controls (8.0 v 8.3). Impairment of macroaggregation with collagen or ristocetin did not correlate with the duration of bypass or the platelet count, indicating that haemodilution is not a contributory factor.In conclusion: (1) Macroaggregation in PRP, as determined using optical aggregometry, is specifically impaired following bypass, and this probably reflects impairment of the build-up of small aggregates into larger aggregates. (2) Impairment of aggregate growth and consolidation could contribute to the haemostatic defect following cardiac surgery.
Urokinase versus Recombinant Tissue Plasminogen Activator in Thrombosed Central Venous Catheters:
Authors: Haire William D , Atkinsonn James B , Stephens Lana C , Kotulak Gall D 
Published: July 2018

SummaryFifty dysfunctional central venous catheters proven radiographically to be occluded by thrombus were blindly randomized to be injected with either 2 mg recombinant tissue plasminogen activator (t-PA) or 10,000 units of urokinase (UK) and allowed to incubate for 2 h. A second dose was allowed if catheter function was not restored with the first injection. Repeat radiograph contrast injection was done when catheter function was restored or after 2 doses of study drug were administered, whichever occurred first. Thirteen of 22 catheters randomized to UK had full function restored compared to 25 of 28 randomized to t-PA (p = 0.013). Radiographic contrast injection showed 7 catheters randomized to UK had complete resolution of the thrombus compared to 17 randomized to t-PA (p = 0.042). Four catheters randomized to UK had complete resolution of the thrombus after a single dose compared to 13 randomized to t-PA (p = 0.036). A novel dose of 2 mg of t-PA restored catheter function more reliably and dissolved thrombi faster than twice the standard, FDA-approved dose of UK
Antithrombin III: Associations with Age, Race, Sex and Cardiovascular Disease Risk Factors
Authors: Conlan Maureen G , Folsom Aaron R , Finch Andrea , Davis C E , Marcucci Gretchen , Sorlie Paul , Wu Kenneth K 
Published: July 2018

SummaryAntithrombin III (AT III) is a major inhibitor of blood coagulation, and hereditary deficiency is associated with venous thrombotic disease. The Atherosclerosis Risk in Communities (ARIC) Study, a prospective study of 15,800 middle-aged men and women, measured AT III in its baseline examination. AT III levels were significantly higher in women than men, and in blacks than whites. AT III decreased with age in men but increased with age in women. In age- and race-adjusted analyses, AT III was positively associated with smoking, HDL-cholesterol, triglycerides (men only), and in women, with diabetes and lipoprotein^). AT III was negatively associated with educational level, body mass index in men, and use of female hormones in women. Most of these associations were confirmed in multivariate analysis. These correlations between AT III and other risk factors must be considered when evaluating AT III as a risk factor for venous or arterial thrombosis.
The Platelet Adhesion Capacity to Subendothelial Matrix and Collagen in a Flow Model during Storage of Platelet Concentrates for 7 Days
Authors: Boomgaard M N , Gouwerok C W N , Homburg C H E , de Groot Ph G , IJsseldijk M J W , de Korte D 
Published: July 2018

SummaryThe influence of storage of platelet concentrates (PC) on the adhesion capacity of platelets was studied. Twenty-four PC, 12 prepared by the buffy coat (BC) method and 12 by the platelet-rich plasma (PRP) method, were stored for 7 days at room temperature. On days 1,3 and 7 of storage, the platelet adhesion capacity to subendothelial matrix (SEM) and collagen was studied in a rectangular perfusion system under flow conditions in conjunction with the platelet aggregation capacity after stimulation and the adenine nucleotide content. The platelet adhesion capacity to collagen was constant until day 3 of storage and decreased to about 80% of the starting value on day 7 of storage. The adhesion capacity to SEM, however, had already decreased on day 3 to about 75% of the value of day 1 and was even more decreased on day 7 to about 45% of the starting value. On day 1, platelets prepared by the BC method displayed a higher adhesion capacity to collagen and a higher aggregation capacity after stimulation by collagen alone or in combination with ADP, compared to platelets prepared by the PRP method. No other significant differences in adhesion or aggregation capacity were observed between the PC prepared by the two different methods. Both platelet adhesion and aggregation response decreased during storage, as did the total adenine nucleotide content. This study shows that platelet function, as measured by the aggregation and adhesion capacity, of platelets prepared by the PRP method is more severely impaired during the first 3 days of storage as compared to the function of platelets prepared by the BC method.
In Vivo Antithrombotic Effect of Triflavin, an Arg-Gly-Asp Containing Peptide on Platelet Plug Formation in Mesenteric Microvessels of Mice
Authors: Sheu Joen-Rong , Chao Seh-Huang , Yen Mao-Hsiung , Huang Tur-Fu 
Published: July 2018

SummaryTriflavin, an Arg-Gly-Asp-containing snake venom peptide, inhibits platelet aggregation through the blockade of fibrinogen binding to the activated platelets. In this study, platelet thrombus formation was induced by irradiation of the mesenteric venules with filtered light in mice pretreated intravenously with fluorescein sodium. Electron microscopy reveals moderately damaged endothelial cells, as well as aggregates consisting almost exclusively of platelets with pseudopod formation, and degranulated appearance. Triflavin (10-20 µg/g) significantly prolonged the lag period of inducing platelet plug formation in mesenteric venules when it was intravenously infused. Triflavin (20 µg/g) prolonged the occlusion time about 2-fold (from control 112 ± 23 to 240 ± 47 s). Furthermore, PGE, briefly prolonged the occlusion time about 1.5-fold (from 105 ± 21 to 168 ± 20 s) when it was given by continuous infusion (40 µg/kg/min). On the other hand, triflavin was also effective in reducing the mortality of ADP-induced acute pulmonary thromboembolism in mice when administered intravenously at dose of 2-4 µg/g. Heparin (1.5 U/g) and indomethacin (200 µg/g) had no significant effect in prolonging the occlusion time or in reducing ADP-induced pulmonary embolism in mice. Therefore, triflavin is an effective antithrombotic agent in preventing the thromboembolism in these two in vivo models.
Oral Anticoagulation in the Prevention of One-Year Vein Graft Occlusion after Aortocoronary Bypass Surgery: Optimal Therapeutic Range and Practical Limitations
Authors: van der Meer J , Hillege H L , Dunselman P H J M , Mulder B J M , Michels H R , Buser P T , van Gilst W H , Lie K I ,   the CABADAS Research Group of the Interuniversity Cardiology Institute of The Netherlands
Published: July 2018

SummaryTo assess the optimal level of oral anticoagulation to prevent occlusion of vein coronary bypass grafts, 318 patients from a graft patency trial were analysed retrospectively. Oral anticoagulant therapy was started one day before surgery and continued for one year, after which graft occlusion was assessed by angiography. The aimed level of anticoagulation was 2.8-1.8 International Normalized Ratio (INR). Clinical outcome was assessed by the incidence of myocardial infarction, thrombosis and major bleeding.The observed anticoagulation level was 2.8-4.8 INR for 54%, and 1.8-3.8 INR for 75% of time per patient. Occlusion rates in patients who spent <35, 35-70, and ≥70% of time within INR range 2.8-1.8 were 10.5%, 10.8% and 11.8%, respectively (differences not statistically significant). Patients who spent ≥70% of time within INR range 1.8-3.8 versus 2.8-4.8 showed comparable occlusion rates. The risk of graft occlusion was not related to quality of anticoagulation early (0-3 months) or late (3-12 months) after surgery. Myocardial infarction, thrombosis and major bleeding occurred in 1.3%, 2.0% and 2.9% of patients.To maintain vein graft patency in the first postoperative year by oral anticoagulation, a level within INR range 1.8-3.8 for ≥70% of time seems to be sufficient.
Elevated Levels of Factor VII Activity in the Postprandial State: Effect of the Factor VII Arg-GIn Polymorphism
Authors: Silveira Angela , Green Fiona , Karpe Fredrik , Blombäck Margareta , Humphries Steve , Hamsten Anders 
Published: July 2018

SummaryA genetic polymorphism (Arg/Gln353) of coagulation factor VII was recently identified and shown to be associated with differences in basal factor VII coagulant activity. Postprandial lipaemia seems to exert an acute but evanescent effect on the activity of factor VII, and the influence of the Arg/Gln353 polymorphism on factor VII activation during postprandial lipaemia was therefore studied in male post-infarction patients [age 48.8 ± 3.3 years (mean ± SD)] with Arg/Arg (n = 23) and Arg/Gln (n = 8) genotypes. Factor VII antigen (VIlag) and activity along with plasma lipoproteins were determined before and after intake of a mixed meal-type of oral fat load. Patients with the Arg/Gln genotype had basal VIlag and activated factor VII (Vila) levels 75% and 48%, respectively, of those of patients homozygous for the Arg allele. In absolute terms, Vila increased more in homozygotes for the Arg allele (AO-6 h Vila 1.76 ± 1.48 ng/ml) than in heterozygotes (0.60 ± 0.27 ng/ml) in response to fat intake, but the percentage increase in Vila molecules did not differ significantly between subjects with Arg/Arg and Arg/Gln genotypes (37 ± 32% versus 27 ± 15%). This suggests that the influence of the Arg/Gln polymorphism on factor VII activity is mainly accounted for by differences in the basal factor VII protein level between genotypes. Since most of our lives are spent in the postprandial state, possession of the factor VII-Gln353 allele is likely to confer protection against coronary heart disease by reducing the amount of Vila produced in response to fat intake.
Heparin Enhances Endothelial Cell von Willebrand Factor Content by Growth Factor Dependent Mechanisms
Authors: Tannenbaum Susan H , Chao Elizabeth S , Gralnick Harvey R 
Published: July 2018

SummaryVon Willebrand factor (vWf), a multimeric adhesive glycoprotein synthesized, stored, and secreted in megakaryocytes and endothelial cells, is normally found in plasma, platelets and subendothelium. While many substances mediate the release of vWf from endothelial cells, factors that enhance vWf synthesis and partitioning to its regulated pathway are currently unknown. We studied the effect of pharmacologic doses of heparin on the vWf content of endothelial cells. After a lag of 8 h and in the presence of crude or purified growth factor, heparin at doses between 0.25 and 2 U (1.4-11 μg)/ml, increased the content of high moleculr weight vWf. The increased amounts of vWf were localized to Weibel-Palade bodies and extracellular matrix. Lower molecular weight highly sulfated heparin or heparin-like compounds were most active in growth factor dependent endothelial cell vWf expression. There was no clear importance of polysaccharide sequence or protein core.
Epidemiology of Haemophilia in Greece: An Overview
Authors: Koumbarelis Emmanuil , Rosendaal Frits R , Gialeraki Argyri , Karafoulidou Anastasia , Noteboom Willy M P , Loizou Calliopi , Panayotopoulou Catherine , Markakis Constantine , Mandalaki Titica 
Published: July 2018

SummaryDemographic data of the Greek haemophilia A and B population for the period 1972-1993 were analyzed. Prevalence at birth including known not-registered patients was calculated at 23.1 per 100,000 male births. However, the observed prevalence in 1993 was only 61% of the expected. Since 1975 the proportion of mild cases had significantly increased. Adjusted by age, severity and HIV status reproductive fitness of haemophiliacs was 0.62. Overall mortality was 2.6 times higher than in the general population, but 7.9 times among patients with severe haemophilia and 16.4 among HIV(+) haemophiliacs. Fifty out of 78 deaths occurred among HIV(+) patients and 28 of these were caused by AIDS. Inhibitor patients did not show excess mortality due to bleeding. Cancer mortality was equal to normal, but the number of deaths from ischaemic heart disease was 0.25 of the expected. Risk of death due to cerebral haemorrhage was 3.8 times higher in HIV(+) haemophiliacs than in HIV(-).
The Venous Antithrombotic Profile of Naroparcil in the Rabbit
Authors: Millet Jean , Theveniaux Jocelyne , Brown Neil L 
Published: July 2018

SummaryThe venous antithrombotic profile of naroparcil or (4-[4-cyanoben-zoyl]-phenyl)-1.5-dithio-β-D-xylopyranoside was investigated in the rabbit following single i. v. and oral administration. Naroparcil attenuated thrombus development in a Wessler stasis model of venous thrombosis (jugular vein) employing bovine factor Xa as a thrombogenic stimulus giving ED50 values of 21.9 mg/kg and 36.0 mg/kg after respectively i. v. and oral administration. Venous antithrombotic activity was maximal 2-3 h after i. v. administration and 4-8 h after oral administration. Four hours after the oral administration of maximal antithrombotic (Wessler model, factor Xa) doses (100 and 400 mg/kg), naroparcil had no significant effect on bleeding time. In platelet poor plasma obtained from animals treated 4 h previously with various doses (25 to 400 mg/kg) of naroparcil, there was no detectable anti-factor Xa nor antithrombin activity. Similarly, naroparcil had no effect on APTT nor on thrombin time. A sensitized thrombin time (to about 35 s) was modestly but significantly increased following oral administration of the compound at 400 mg/kg. However, thrombin generation by the intrinsic pathway was reduced in a dose-related manner, maximal reduction being 65% at 400 mg/kg. The same doses of naroparcil enhanced the formation of thrombin/heparin cofactor II complexes at the expense of thrombin/antithrombin III complexes in plasma incubated with (125I)-human a-thrombin and induced the appearance of dermatan sulfate-like material in the plasma of treated rabbits, as measured by a heparin cofactor II-mediated thrombin inhibition assay. The results suggest that naroparcil could have a safe venous antithrombotic profile following oral administration (antithrombotic effect compared to bleeding risk). It is probable that part of the mechanism of action of the β-D-xyloside, naroparcil, is due to the induction of chondroitin sulfate-like glycosaminoglycan biosynthesis, this material being detectable in the plasma.
Laboratory Diagnosis of APC-Resistance: A Critical Evaluation of the Test and the Development of Diagnostic Criteria
Authors: de Ronde Hans , Bertina Rogier M 
Published: July 2018

SummaryThe APC-resistance test consists of two APTT’s, one in the presence and one in the absence of a fixed amount of Activated Protein C (APC), and is a simple and reliable method to detect a reduced sensitivity to the anticoagulant action of APC (APC-resistance). At a fixed concentration of APC the prolongation of the APTT is dependent on the activator, the CaCl2 concentration, the citrate concentration in the sample, and on sample handling. The effect of sample handling can be reduced by calculating the APC-Sensitivity Ratio (APC-SR). The actual prolongation of the APTT is also influenced by low protein S levels (reduction of APC-SR) and by reduced levels of factors V, VIII and IX (increase of APC-SR). The APC-SR is most dramaticly effected by reduced levels of factors II and X, which result often in “unmeasurable” APC-SR’s in plasmas of patients on oral anticoagulant treatment. So at present no reliable APC-SR’s can be measured in these patients. Patients treated with heparin can be tested after treatment of their plasma with Hepzym®. The inter- and intra-assay variation in the APC-SR is 4% and 2%, respectively, when using the same batches of activator and APC. The variation which is introduced in the APC-SR by use of different batches of activator or APC, or by the use of different APC or CaCl2 concentrations, can effectively be avoided by expressing the result of the test in normalized-APC-SR (n-APC-SR).The diagnosis of APC-resistance is defined by a n-APC-SR < 0.84. Patients who are heterozygous for the Factor V Leiden mutation have a n-APC-SR of 0.45-0.70, while patients who are homozygous for the mutation have a n-APC-SR <0.45.
Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”
Authors: Landolfi Raffaele , De Candia Erica , Rocca Bianca , Ciabattoni Giovanni , Antinori Armando , Masetti Riccardo , Patrono Carlo 
Published: July 2018

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.