bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Organisational Structures of Self-help Groups in the Field of Paediatric Orthopaedics
Authors: Peterlein Christian-Dominik , Friedrich Sinja , Daniel Hanna , Malcherczyk Dominik , Ruden Janine , El Zayat Bilal
Published: July 2018

Hintergrund Studien über Selbsthilfegruppen zu Krankheitsbildern auf kinderorthopädischem Fachgebiet und deren Organisationsformen liegen im deutschsprachigen und internationalen Raum bisher noch nicht vor.

Material und Methoden Mittels eines auf postalischem Weg verschickten, standardisierten Fragebogens wurden gezielt Organisationsstruktur, Kommunikationsplattformen und Art der Finanzierung von dem Anforderungsprofil entsprechenden Selbsthilfegruppen ermittelt.

Ergebnisse Die zahlenmäßig häufigsten Rückmeldungen kamen von Selbsthilfegruppen zum Krankheitsbild Kleinwuchs, infantile Zerebralparese und Trisomie 21. Die Mehrzahl der befragten Selbsthilfegruppen hatte den Status eines eingetragenen Vereins und war einem Dachverband angeschlossen. Das Gründungsjahr war primär in der Dekade 1990 – 2000 (n = 15); Gründer waren überwiegend Eltern (n = 28; 77,8%), Betroffene (n = 11; 30,6%) und nur in 2 Fällen (5,6%) Ärzte. 80,6% der ausgewerteten Selbsthilfegruppen (n = 29) finanzierte sich auch über Spenden. Die Darstellung der Ziele, der Aktivitäten und der Möglichkeit einer ersten Kontaktaufnahme erfolgt primär über die eigene Homepage (n = 35; 97,2%). Nicht wenige Selbsthilfegruppen zu kinderorthopädischen Grunderkrankungen arbeiten mit Ärzten unterschiedlicher Disziplinen zusammen und lassen sich von diesen beraten.

Schlussfolgerung Diese Studie liefert erste Daten über Organisationsstrukturen kinderorthopädischer Selbsthilfegruppen und verdeutlicht die Interdisziplinarität des Fachs Kinderorthopädie. Eine enge Zusammenarbeit zwischen Kinderorthopäden und lokalen Selbsthilfegruppen könnte helfen, Ängste und Unsicherheiten abzubauen und die Qualität der medizinischen Versorgung vor Ort zu verbessern.
Prediction of Human Pharmacokinetics of Bendamustine from Preclinical Species Pharmacokinetics Based on Normalizing Time Course Profiles
Authors: Srinivas Nuggehally , Jairam Ravi , Mallurwar Sadanand , Sulochana Suresh , Chandrasekar Devaraj , Bhamidipati Ravi , Richter Wolfgang , Mullangi Ramesh
Published: July 2018

Bendamustine, an alkylating anticancer agent, is used to treat chronic lymphocytic leukemia by intravenous infusion alone or in combination. The work aimed to develop a method to predict time vs. concentration profile for humans based on preclinical pharmacokinetics using the assumption of superimposability of normalized time course profiles of animals and humans. Standard allometric equations with/without correction factors (CF) were also used in prediction. The Vss was predicted by simple allometry of 0.312W0.871 (r2=0.987), where W is body weight; predicted Vss (19.71 L) was similar to the reported value (20.10 L). However, CL prediction involved both simple and CF allometry. Best proximity CL (543 vs. 598 mL/min) was obtained with maximum life span correction (MLP) [2.46W1.215 (r2=0.988)]. Normalized curves were obtained by normalizing the time (with mean residence time) vs. concentration (with dose/Vss) in animal species. The concentration vs. time profile in humans after intravenous infusion was then simulated using normalized curve for each animal species and the values of CL and Vss were predicted for humans. In summary the findings indicate that normalized time course approach could predict the bendamustine human pharmacokinetics and such an approach could be prospectively applied for analog drugs of this class.
Cascade Radical Cyclization to Vinylogous Carbonates/Carbamates for the Synthesis of Oxa- and Aza-Angular Triquinanes: Diastereoselectivity Depends on the Ring Size of Radical Precursor
Authors: Gharpure Santosh , Niranjana P. , Porwal Suheel
Published: July 2018

An efficient strategy was developed for the stereoselective construction of oxa- and aza-angular triquinanes employing a cascade 5-exo-trig radical cyclization to vinylogous carbonates and carbamates. The radical precursors are readily prepared from 2-(hydroxymethyl)cyclopentenone/cyclohexenones. High diastereoselectivity is observed for the formation of angular oxa- and azatriquinanes. Diastereoselectivity drops when six-membered radical precursors are used. The strategy is found to be useful to incorporate synthetically challenging moieties such as spiroindoline, lactone-bearing, and uracil-fused angular triquinanes in a concise manner.
First Case of Sporadic Protein S Deficiency due to a Novel Candidate Mutation, Ala 484 → Pro, in the Protein S Active Gene (PROSl)
Authors: Borgel D , Jude B , Alach M , Gandrille S
Published: July 2018

In a series of 16 propositi with symptomatic protein S deficiency and a protein S gene mutation, we identified a sporadic case of a novel mutation that probably affects gene expression. The mutation, a G to C transversion leading to the substitution of Ala 484 by Pro, was not found in the protein S gene of the patient’s parents. Transmission of the paternal and maternal protein S alleles was apparently normal, on the basis of the frequent polymorphism in exon XV. We also checked the transmission of chromosomal material by analysing protein C gene polymorphisms, Β-globin gene frameworks and four variable number of tandem repeats (VNTRs). By combining the results of these analyses, we were able to rule out nonpaternity and to confirm the de novo nature of the mutation.
Elevated Levels of Markers of Endothelial Cell Damage and Markers of Activated Coagulation in Patients with Systemic Necrotizing Vasculitis
Authors: Hergesell Olaf , Andrassy Konard , Nawroth Peter
Published: July 2018

Activation of coagulation and endothelial cell damage was studied in 47 patients with small vessel vasculitis [Wegener’s granulomatosis (WG) and microscopic polyangiitis (MP)] by measurement of throm-bin-antithrombin III complexes (TAT), fibrin-D-dimers (D-dimers), von Willebrand-factor (vWF) concentration and plasma thrombomodulin (TM) levels. There was a close correlation between disease activity (DA) in patients with WG or MP and markers of endothelial cell damage (correlation TM/DA r = 0.46 for WG and r = 0.43 for MP) and activated coagulation (correlation TAT/DA r = 0.58 for WG and r = 0.55 for MP).

Elevation of the markers of activated haemostasis and endothelial cell damage was reversed when remission was obtained by specific treatment. The markers studied were particularly helpful in cases where measurement of antineutrophil cytoplasmatic antibodies (ANCA) did fail to assess disease activity.
Localization of Fibrinolytic Activators and Inhibitors in Normal and Atherosclerotic Vessels
Authors: Fålkenberg Marten , Tjärnstrom Johan , Örtenwall Per , Olausson Michael , Risberg Bo
Published: July 2018

Local fibrinolytic changes in atherosclerotic arteries have been suggested to influence plaque growth and promote mural thrombosis on ruptured or ulcerated plaques. Increased levels of plasminogen activator inhibitor (PAI-1) have been found in atherosclerotic arteries. In this study tissue plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA) and PAI-1 were localized in arterial biopsies of healthy and atherosclerotic vessels by immunohistochemis-try. The expression of fibrinolytic regulators was related to the distribution of endothelial cells (EC) and macrophages. Results: t-PA was expressed in vasa vasorum. PAI-1 was positive in endothelial cells, in the media and in the adventitia. Increased expression of t-PA, u-PA and PAI-1 was found in atherosclerotic vessels. t-PA, u-PA, PAI-1 and macrophages were co-localized in plaques. These results support the concept that macrophages can be important in the local regulation of fibrinolysis in atherosclerotic vessels.
The Potential Thrombogenic Action of a Nonionic Radiographic Contrast Medium Used during Coronary Angiography Is Offset by Heparin during Coronary Angioplasty
Authors: Mukherjee Manjari , Scully Michael F , Thomas Martin , Jewitt David , Kakkar Vijay V
Published: July 2018

Iohexol sodium, a nonionic radiographic contrast medium, used in invasive imaging techniques has been shown to be potentially thrombogenic. In the present study, the effect of iohexol sodium on haemostatic factors was evaluated in 20 patients, 16 male and 4 female, 10 undergoing coronary angiography and another 10 undergoing coronary angioplasty. All the patients had angiographically-assessed coronary artery disease. The patients undergoing coronary angioplasty received a significantly larger quantity of the dye as compared with the patients undergoing coronary angiography. The former group of patients also received a bolus of 20,000 units of standard heparin in addition. The levels of thrombin-antithrombin-III complex (TAT), prothrombin fragments 1 and 2 (F1F2), D-dimer and the functional activity of tissue factor pathway inhibitor (TFPI) were assayed. While the baseline and 30-min post-dye levels of TAT and F1F2 were comparable in patients undergoing coronary angioplasty, the 30 min levels were significantly elevated in patients undergoing coronary angiography. The post-dye levels of TFPI activity were significantly increased in the former group due to the heparin-induced release of TFPI. It is concluded that the thrombogenic potential of iohexol sodium was overcome by heparin used routinely during coronary angioplasty.
Free Protein S Deficiency May Be Found in Patients with Antiphospholipid Antibodies who Do not Have Systemic Lupus Erythematosus
Authors: Crowther M A , Johnston M , Weitz J , Ginsberg J S
Published: July 2018

In order to determine if there is a relationship between antiphospholipid antibodies and reduced free protein S levels, we evaluated 21 patients who had an antiphospholipid antibody but had neither a history of venous thromboembolism nor systemic lupus erythematosus (cases) and 55 matched controls, who did not have an antiphospholipid antibody, a history of thrombosis or systemic lupus erythematosus. Cases and controls had similar protein C and antithrombin levels. Six of 21 cases had reduced free protein S antigen levels, compared to 5 of 55 controls (x
2 = 5.823 p <0.025). In addition, the mean free protein S level was significantly lower in cases than in controls (0.30 ± 0.09 units vs 0.39 ± 0.13 units, p <0.01, two-tailed Student’s t-test). We conclude that antiphospholipid antibodies are associated with a significant decrease in free protein S levels, and that this acquired free protein S deficiency may contribute to the thrombotic diathesis seen in patients with antiphospholipid antibodies.
Interleukin-6 Stimulates Coagulation, not Fibrinolysis, in Humans
Authors: Stouthard Jacqueline M L , Levi Marcel , Hack C Erik , Veenhof Cees H N , Romijn Hans A , Sauerwein Hans P , Poll Tom van der
Published: July 2018

The role of IL-6 as a mediator of haemostatic changes during severe inflammation is controversial. To assess the effect of IL-6 on haemostasis we conducted a controlled cross-over study in eight patients with metastatic renal cell cancer. In all subjects coagulation and fibrinolysis were monitored during and after a 4-h infusion of either 150 μg recombinant human (rh) IL-6, or during infusion of saline (control study). Mean maximum IL-6 concentrations were 1418.0 ± 755.8 pg/ml. Compared to the control study, rhIL-6 induced activation of coagulation as reflected by a 190 ± 55% increase in the plasma levels of thrombin-antithrombin III complexes (p <0.001) and by a 24 ± 11% increase in the plasma levels of in the prothrombin activation fragment F1 + 2 (p <0.001). In contrast, fibrinolysis was not affected. We conclude that in severe inflammation IL-6 may contribute to the activation of coagulation, whereas other factors mediate changes in fibrinolysis.
Decreased Expression of PAI-2 mRNA and Protein in Pregnancies Complicated with Intrauterine Fetal Growth Retardation
Authors: Grancha Salvador , Estellés Amparo , Gilabert Juan , Chirivella Melitina , España Francisco , Aznar Justo
Published: July 2018

An increase in plasma plasminogen activator inhibitors (PAIs), fundamentally PAI type 2 (PAI-2), has been described in normal pregnancy probably because the placenta is the main source of the high plasma levels of this protein. Although we have previously described plasmatic alterations of these inhibitors in pregnancies complicated with intrauterine fetal growth retardation (IUGR), no reports have been published about placental PAI-2 mRNA expression. In the present study, the placental PAI-2 expression determined in pregnancies complicated with IUGR and in severe preeclamptic patients was compared with that of normal pregnancies in order to identify the placental cell types expressing PAI-2 and to determine whether the production of PAI-2 is altered in placentas from IUGR. In situ hybridization analyses show that the syncytiotrophoblasts are the cells with the greatest PAI-2 expression in placenta. We report that the significant decrease in plasma and placental PAI-2 levels in IUGR groups is fundamentally due to a diminished expression of PAI-2 mRNA in placenta.
Inhibitory Effect of a Novel Orally Active GP IIb/IIIa Inhibitor, SC-54684A on Intimal Thickening in the Guinea Pig Femoral Artery
Authors: Umemura Kazuo , Nishiyama Hiroshi , Kikuchi Shinji , Kondo Kazunao , Nakashima Mitsuyoshi
Published: July 2018

The inhibitory effect of a novel orally active platelet membrane glycoprotein receptor complex IIb/IIIa (GP IIb/IIIa) inhibitor, SC-54684A is studied on intimal thickening in the guinea pig femoral artery. A segment of the femoral artery was occluded by a platelet-rich thrombus induced by photochemical reaction between systemically administered Rose Bengal and transluminal green light which causes endothelial injury followed by platelet adhesion and aggregation at the site of photochemical reaction. Three weeks after successful thrombolysis by tissue-type plasminogen activator, intimal thickening occurred at the irradiated site. SC-54684A (30 mg/kg), administered 2 h before photochemical reaction, significantly (P <0.05) prolonged the time to occlusion of the femoral artery; in this respect aspirin (100 mg/kg) was ineffective. A combination of SC-54684A and recombinant tissue-type plasminogen activator (rt-PA) increased the frequency of reopening and significantly (P <0.05) prolonged the duration of reflow compared with rt-PA alone. Further, SC-54684A administered orally twice a day for 3 weeks significantly (P <0.05) inhibited intimal thickening but aspirin, administered orally once a day for 3 weeks, was ineffective. Scanning electron microscopy revealed extensive platelet adhesion and aggregation on the denuded vessel walls in the untreated group 24 h after successful thrombolysis. In separate experiments, SC-54684A markedly inhibited platelet aggregation ex-vivo. Inhibition of platelet adhesion and aggregation at the site of endothelial injury by SC-54684A (via GPIIb/IIIa inhibition) may account for its inhibitory effect on intimal thickening
Procoagulant Properties of Intravenous Staphylokinase Versus Tissue-Type Plasminogen Activator
Authors: Okada K , Lijnen H R , Moreau H , Vanderschuere S , Collen D
Published: July 2018

The fibrin-specificity and procoagulant effects of recombinant staphylokinase (Sak42D) were compared with those of recombinant tissue-type plasminogen activator (rt-PA) in patients with acute myocardial infarction. Plasma samples were obtained at baseline and at 25 and 90 min, from 24 patients who were randomly assigned to a double bolus (15 mg each, 30 min apart) administration of Sak42D or to accelerated weight-adjusted rt-PA (maximum of 100 mg over 90 min). Baseline levels of fibrinopeptide A (FPA), prothrombin fragment 1+2 and thrombin-antithrombin III complex (TAT) were comparable in the Sak42D and rt-PA groups (p ≥ 0.6). In patients treated with Sak42D, plasma levels of FPA, prothrombin fragment 1+2 and TAT did not markedly increase during treatment (p = 0.06, p = 0.4 and p = 0.03, respectively). In contrast, during administration of rt-PA the levels of FPA, prothrombin fragment 1+2 and TAT increased significantly over baseline (p = 0.003, p < 0.0001 and p = 0.001, respectively). As a result, the levels of all three procoagulant parameters were significantly lower during treatment with Sak42D as compared to rt-PA. Thus, FPA levels in the Sak42D group (median values) were 40 ng/ml at 25 min and 11 ng/ml at 90 min, as compared to 88 ng/ml and 50 ng/ml in the rt-PA group (p = 0.0007 and p = 0.009, respectively). Prothrombin fragment 1+2 levels in the Sak42D group were 1.3 nM at 25 min and 1.2 nM at 20 min, as compared to 11 nM and 5.3 nM in the rt-PA group (both p < 0.0001). TAT levels were 4.7 ng/ml at 25 min and 6.2 ng/ml at 90 min in the Sak42D group, with corresponding values of 16 ng/ml and 9.6 ng/ml in the rt-PA group (p = 0.02 and p = 0.03, respectively).

In the patients treated with Sak42D, no significant systemic fibrinolytic activation was observed, as revealed by unaltered levels of clotta-ble fibrinogen, plasminogen and a2-antiplasmin up to 90 min after the start of therapy. In contrast, the corresponding residual levels at 90 min in patients treated with rt-PA decreased to (mean ± SEM; n = 12) 62 ± 6%, 45 ± 5% and 52 ± 10%, respectively (all p < 0.01 versus the Sak42D group)

These data confirm the high degree of fibrin-specificity of Sak42D and demonstrate that this is associated with significantly less generation of procoagulant activity in plasma after intravenous administration in patients with acute myocardial infarction
Gene Mutations in 21 Unrelated Cases of Phenotypic Heterozygous Protein C Deficiency and Thrombosis
Authors: Ireland H , Thompson E , Lane D A ,   Protein C Study Group
Published: July 2018

Mutations have been identified in the protein C gene in 21 patients with venous thromboembolism and phenotypic heterozygous protein C deficiency. In 20 probands, single mutations were the only abnormalities identified by sequencing all coding regions, intron exon boundaries and the promoter region back to -1540. In one proband 2 mutations were identified and in another family 2 mutations were identified (but not both in the proband). Of the 23 mutations, 18 resulted in predicted amino acid substitutions, 3 were mutations resulting in stop codons, one was a mutation within a consensus splice sequence and another a 9 base pair insertion within exon 5 (this region within exon 5 is proposed as a deletion/insertion hot spot). A novel polymorphism was also, uniquely, identified in the propeptide region of the molecule (Pro-21 Pro; CCT to CCC) in a kindred from Hong Kong. Cosegregation of the protein C gene mutation with protein C deficiency could be determined in 13 families. In a further family, phenotypic protein C deficiency and the genetic mutation cosegregated in only 4/5 members.

The first thrombotic incident occurred in the probands between the ages of 11 and 59 years and 12 individuals suffered recurrent thrombosis. Thrombosis occurred in at least one other family member in 9/21 families, but in 2 of these it was inconsistently associated with protein C deficiency. An independent genetic risk factor, factor V Arg506Gln (FV Leiden) was identified in 2 probands (and 3 family members) and in 4 protein C deficient members of a third family but not in the proband. The results suggest that in the majority of probands with thrombosis and phenotypic protein C deficiency, a single protein C gene mutation is associated with thrombosis. However, it is also possible that additional unknown genetic risk factors contribute to the thrombotic risk. An added, acquired, risk factor leads to thrombosis at an early age (< 25 years).
A Point Mutation in Glycoprotein IX Coding Sequence (Cys73(TGT) to Tyr(TAT)) Causes Impaired Surface Expression of GPIb/IX/V Complex in Two Families with Bernard-Souiier Syndrome
Authors: Noda Masaaki , Fujimura Kingo , Takafuta Toshiro , Shimomura Takeshi , Fujii Teruhisa , Katsutani Shinya , Fujimoto Tetsuro , Kuramoto Atsushi , Yamazaki Tomio , Mochizuki Toshihiro , Matsuzaki Miwako , Sano Masayuki
Published: July 2018

Bernard-Soulier syndrome (BSS) is a rare inherited bleeding disorder which is caused by abnormal expression or function of the glycoprotein (GP) Ib/IX/V complex, a platelet major receptor for von Wille-brand factor. We studied four BSS patients in two unrelated families in which the same and novel mutation was found. Flow cytometric analysis showed that GPIX was completely absent but residual amounts of GPIbα and GPV were detectable in these patients. We analyzed all coding regions of GPIbα, GPIbβ, GPV and GPIX which were amplified from the patients’ genomic DNA by the polymerase chain reaction (PCR). In all four cases, we identified a point mutation in the GPIX coding region that changes the codon for cysteine 73 (TGT) to a codon for tyrosine (TAT). Furthermore, we confirmed by a transient expression study that the mutation caused the loss of adequate surface expression of GPIX. Since cysteine might be important for the secondary structure, this mutation of GPIX gene would lead to a dramatic conformational change of GPIX protein, resulting in the reduced surface expression. We concluded that this novel point mutation of the GPIX gene was responsible for BSS in these families
Activation of Coagulation and Fibrinolysis in Heatstroke
Authors: Bouchama Abderrezak , Bridey Françoise , Hammami Muhammad M , Lacombe Catherine , Al-Shail Essam , Al-Ohali Yazid , Combe Frédéric , Al-Sedairy Sultan , Prost Dominique de
Published: July 2018

Hemorrhagic diathesis and widespread microthrombosis are common in heatstroke. To assess the early stages of coagulopathy in heatstroke, thrombin-antithrombin III (TAT), fibrin monomers, plasmin-a2-antiplasmin (PAP), plasminogen and D-Dimer were measured in 16 heatstroke patients (means ± SE rectal temperature 42.3 ± 0.2° C) pre- and postcooling and compared with 8 heatstressed and 23 normal controls.

Comparing heatstroke patients with normal controls, TAT, fibrin monomers, PAP and D-Dimer were elevated to (median (range)) 16.5 (4-1000) versus 3.5 (2-7.2) Μg/l p<0.001,16 (4-113) versus 2 (2-9) nM p<0.001; 3300 (1000-36500) versus 255 (136-462) Μg/l p<0.001 and 0.72 (0.22-64.8) versus 0.15 (0.05-0.25) Μg/ml p<0.01 respectively. Plasminogen decreased to 81% (34-106); PAP, TAT and D-Dimer correlated significantly with hyperthermia (r = 0.577, p = 0.02; r = 0.635, p = 0.01; r = 0.76, p = 0.003). Postcooling PAP decreased to 545 (260-850) Μg/1 p<0.005, TAT 10 (6-70) |ig/l, and fibrin monomers 22 (18-86) nM remained unchanged. Heatstressed controls showed mild but significant increase in all markers.

Activation of coagulation and fibrinolysis occurs early and is profound and sustained in heatstroke. Cooling seems to attenuate the activation of fibrinolysis only, however, this requires confirmation in a larger study population.
Age-related Differences in Outcome and Severity of DIC in Children with Septic Shock and Purpura
Authors: Hazelzet Jan A , Risseeuw-Appe Inge M , Kornelisse René F , Hop Wim C J , Dekker Ina , Joosten Koen F M , Groot Ronald de , Erik Hack C
Published: July 2018

We studied the influence of age on mortality and severity of clotting abnormalities in 79 children (median age: 3.1 years) with meningococcal sepsis. Parameters of coagulation and fibrinolysis and plasma levels of cytokines were prospectively measured on admission. The mortality rate was 27%. The age of survivors was significantly different from that of non-survivors (p = 0.013). With the exception of FVII, vWF and t-PA, parameters of coagulation and fibrinolysis, as well as plasma cytokine levels were related to outcome. Patients were divided in two groups: younger and older than median age. The mortality in children ≤3.1 years was 40% versus 13% in children >3.1 years (p = 0.006). In contrast to cytokine levels, which were not different between the two age groups, fibrinogen, prothrombin, factors V, VII, VIII, vWF, protein C, antithrombin, FDP, and the ratio PAI-l/t-PA were related to age, indicating a more severe coagulopathy in children ≤ 3.1 years despite a similar degree of inflammatory response. A relative deficiency of coagulation factors due to an immature state of the clotting system, as well as an inadequate fibrinolytic response, both related to age may have caused this more severe coagulative response in younger children, and may have contributed to the higher mortality rate.
Influence of Sialic Acid on Erythrocyte Aggregation in Hypercholesterolemi
Authors: Hadengue A , Razavian S M , Del-Pino M , Simon A , Levenson J
Published: July 2018

The respective role of adhesive forces induced by fibrinogen and repulsive forces induced by erythrocyte sialic acid content on erythrocyte aggregation, was investigated in hypercholesterolemic and control subjects. Aggregation index (AI) and disaggregation shear rate threshold (³t) were determined in the presence of either autologous plasma or dextran. Compared with controls, fibrinogen (p <0.001) and aggregation parameters (AI p <0.01; ³t p <0.01) were higher in hypercholester-olemics while erythrocyte sialic acid content (p <0.001) was lower; in addition total serum sialic acid was increased (p <0.01). The aggregation properties of erythrocytes, independent of plasma environment using dextran as a bridging macromolecule, showed an enhanced disaggregation shear rate threshold and an inverse relationship with erythrocyte sialic acid content. We conclude that decreased erythrocyte sialic acid content may intensify the effect of fibrinogen on aggregation and disaggregation of erythrocytes and participate in the development of atherothrombotic complications.
Purification and Characterization of Lupus Anticoagulant Like Protein from Agkistrodon Halys Brevicaudus Venom
Authors: Li Zhao-Yan , Wu Xiao-Wei , Yu Tie-Fu , Lian Eric C-Y
Published: July 2018

By means of CM-Sephadex C-25, DEAE-Sephadex A-50, Sephadex G-200, and Sephadex G-75 chromatographies, a lupus anticoagulant like protein (LALP) from Agkistrodon halys brevicaudus was purified. On SDS-PAGE, the purified LALP had a molecular weight of 25,500 daltons under non-reducing condition and 15,000 daltons under reducing condition. The isoelectric point was pH 5.6. Its N terminal amino acid sequencing revealed a mixture of 2 sequences: DCP(P/S)(D/G)WSSYEGH(C/R)Q(Q/K). It was devoid of phospho-lipaseA, fibrino(geno)lytic, 5′-nucleotidase, L-amino acid oxidase, phosphomonoesterase, phosphodiesterase and thrombin-like activities, which were found in crude venom. In the presence of LALP, PT, aPTT, and dRVVT of human plasma were markedly prolonged and its effects were concentration-dependent but time-independent. The inhibitory effect of LALP on the plasma clotting time was enhanced by decreasing phospholipid concentration in TTI test. The individual clotting factor activity was not affected by LALP when higher dilutions of LALP-plasma mixture were used for assay. Russell’s viper venom time was shortened when high phospholipid confirmatory reagent was used. Therefore, the protein has lupus anticoagulant property.
Systemic Thrombin Generation and Activity Resistant to Low Molecular Weight Heparin Administered Prior to Streptokinase in Patients with Acute Myocardial Infarction
Authors: Nilsen Dennis W T , Gøransson Lasse , Larsen Alf-Inge , Hetland Øyvind , Kierulf Peter
Published: July 2018

One hundred patients were included in a randomized open trial to assess the systemic factor Xa (FXa) and thrombin inhibitory effect as well as the safety profile of low molecular weight heparin (LMWH) given subcutaneously in conjunction with streptokinase (SK) in patients with acute myocardial infarction (MI). The treatment was initiated prior to SK, followed by repeated injections every 12 h for 7 days, using a dose of 150 anti-Xa units per kg body weight. The control group received unfractionated heparin (UFH) 12,500 IU subcutaneously every 12 h for 7 days, initiated 4 h after start of SK infusion. All patients received acetylsalicylic acid (ASA) initiated prior to SK.

Serial blood samples were collected prior to and during the first 24 h after initiation of SK infusion for determination of prothrombin fragment 1+2 (Fl+2), thrombin-antithrombin III (TAT) complexes, fibrinopeptide A (FPA) and cardiac enzymes. Bleeding complications and adverse events were carefully accounted for.

Infarct characteristics, as judged by creatine kinase MB isoenzyme (CK-MB) and cardiac troponin T (cTnT), were similar in both groups of patients.

A comparable transient increase in Fl+2, TAT and FPA was noted irrespective of heparin regimen. Increased anti-Xa activity in patients given LMWH prior to thrombolytic treatment had no impact on indices of systemic thrombin activation.

The incidence of major bleedings was significantly higher in patients receiving LMWH as compared to patients receiving UFH. However, the occurrence of bleedings was modified after reduction of the initial LMWH dose to 100 anti-Xa units per kg body weight.

In conclusion, systemic FXa- and thrombin activity following SK-infusion in patients with acute MI was uninfluenced by conjunctive LMWH treatment.
Modulation of Plasma Fibrinogen Levels by Ciprofibrate and Gemfibrozil in Primary Hyperlipidaemia
Authors: de Maat M P M , Knipscheer H C , Kastelein J J P , Kluft C
Published: July 2018

An elevated plasma fibrinogen level is increasingly accepted as an independent risk indicator of cardiovascular disease. This has enhanced the interest in identifying agents that can normalize elevated plasma fibrinogen levels. One group of agents with this capacity are the fibric acid derivatives, e.g. ciprofibrate and gemfibrozil.

We studied fibrinogen levels after 12 weeks of treatment with ciprofibrate (n = 48) and gemfibrozil (n = 51) in hypercholesterolemic patients. The correlation of the decrease in fibrinogen with lipid lowering and the contribution of the acute phase and genetic polymorphisms to this decrease were also evaluated.

After 12 weeks of treatment, the fibrinogen levels were significantly decreased (p<0.0005) with both drugs, although the decrease in the ciprofibrate group (mean 3.4 g/1 pre-treatment to 2.4 g/1 after 12 weeks) was larger than in the gemfibrozil group (mean 3.4 g/1 to 3.0 g/1.). The lipid lowering effect was comparable for the two drugs but there was no correlation for either ciprofibrate or gemfibrozil between the lipid lowering and the magnitude or the velocity of the fibrinogen lowering effect. An attenuation of the major regulatory mechanism of plasma fibrinogen levels, the acute phase reaction, was invoked as the underlying mechanism. However, pre-treatment C-reactive protein levels were not increased and did not change after treatment. Moreover, no effects of the polymorphisms of the fibrinogen β-gene on the decrease of the plasma fibrinogen levels were observed. This suggests that a new, as yet unknown, mechanism is involved in fibrinogen lowering by fibrates.
Factor VIII Inhibitors in Previously Treated Haemophilia A Patients with a Double Virus-inactivated Plasma Derived Factor VIII Concentrate
Authors: Peerlinck K , Arnout J , Di Giambattista M , Gilles J G , Laub R , Jacquemin M , Saint-Remy J M R , Vermylen J
Published: July 2018

Antibodies to factor VIII (inhibitors) are usually produced at the beginning of treatment with factor VIII and are rare in multitransfused patients. Such antibodies are deemed to be patient-related, as supported by the description of a number of associated risk factors. However, a second category of inhibitors has recently been identified, namely antibodies occurring in multitransfused patients as a result of exposure to a particular factor VIII concentrate. A first outbreak of product-related inhibitors was recently described. The present paper describes the second well-documented occurrence of such inhibitors.

Eight out of 140 multitransfused patients with severe haemophilia A developed an inhibitor to factor VIII shortly after changing treatment to a double-virus inactivated plasma-derived factor VIII concentrate. In addition to solvent-detergent treatment, this concentrate was pasteurised at 63° C for 10 hours. Exposure to the pasteurised product before inhibitor detection ranged from 9 to 45 days. Inhibitor titers varied between 2.2 and 60 Bethesda Units and recovery of transfused factor VIII ranged from 0.21 to 0.68 (expressed as IU/dl factor VIII rise per IU/kg administered). In contrast to usual inhibitors in haemophilia A patients, these product-related inhibitors showed complex inhibition kinetics. They were found specific for the factor VIII light chain. The inhibitors gradually declined when exposure to the pasteurised product was stopped, despite further treatment with other factor VIII concentrates. The present data stress the importance of carefully monitored clinical studies, both in previously treated and previously untreated patients, before introduction of a new or modified clotting factor concentrate.
Detection of Polymorphisms in the Human Urokinase-type Plasminogen Activator Gene
Authors: Conne B , Berczy M , Belin D
Published: July 2018

Expressed polymorphisms in the genes encoding components of the fibrinolytic cascade could have implications for the predisposition to thrombolytic disorders and/or for tumor metastasis. The occurrence of published two amino acid sequences at position 194 of the human urokinase-type plasminogen activator prompted us to search by SSCP for frequent polymorphisms in several exons of the gene. Surprisingly, only one sequence was detected in codon 194 (>200 alleles). Two polymorphisms were observed in this study: the most frequent one, a C to T change near the beginning of exon 8, is probably silent; a less frequent polymorphism results in the replacement of a Leu residue by a Pro, in the kringle domain.
Emergency Oral Anticoagulant Reversal: The Relative Efficacy of Infusions of Fresh Frozen Plasma and Clotting Factor Concentrate on Correction of the Coagulopathy
Authors: Makris Mike , Greaves Mike , Phillips Wendy S , Kitchen Steve , Rosendaal Frits R , Preston F Eric
Published: July 2018

Haemorrhage, including intracranial bleeding, is a common, potentially lethal complication of warfarin therapy and rapid and complete reversal of anticoagulation may be life-saving. Fresh frozen plasma (FFP) and vitamin K are most frequently administered. Because of the variable content of vitamin K-dependent clotting factors in FFP, and the effects of dilution, the efficacy of this approach is open to doubt. We have therefore compared the effects of FFP and clotting factor concentrates on the INRs and clotting factor levels of orally anticoagulated subjects requiring rapid correction of their haemostatic defect. In many, the pre-treatment INR was considered to be dangerously above the target therapeutic range. In the 12 patients given FFP, the INR did not completely correct (range 1.6-3.8, mean 2.3) indicating an ongoing anticoagulated state in all. In contrast, the INR in 29 subjects given clotting factor concentrates was completely corrected in 28 (range 0.9-3.8, mean 1.3). Following treatment, marked differences were observed in clotting factor IX levels between the two groups. The median factor IX level was 19 u/dl (range 10-63) following FFP infusion and 68.5 u/dl (range 31-111) following concentrate. In FFP treated patients, poorer responses were also observed for each of the other vitamin K-depen- dent clotting factors but these were less marked than for factor IX, which was present in low concentrations in some batches of FFP. Thus, haemostatically effective levels of factor IX cannot be achieved, in most instances, by the conventional use of FFP in patients requiring reversal of their anticoagulant therapy. Clotting factor concentrates are the only effective option where complete and immediate correction of the coagulation defect is indicated in orally anticoagulated patients with life or limb-threatening haemorrhage.
Reliability of a Modified Tissue Factor-Dependent Factor V Assay for Activated Protein C Resistant Factor Va Using a Calcium-Containing Thromboplastin
Authors: The Le Dzung , Donnelly Kathleen J , Wu Ning , Sevilla Barbara K , Rapaport Samuel I
Published: July 2018

The original tissue factor-dependent factor V assay for activated protein C resistant factor Va (Blood 1995; 85: 1704-1711) has been modified to use a calcium containing thromboplastin and to express results as an observed to expected ratio (Obs./Exp.). The latter permits establishing a normal range independent of variations due to differences in reagents. Comparing Obs/Exp ratios with DNA analysis in 72 persons revealed that an Obs/Exp ratio of 0.6 distinguished without overlap normals from heterozygotes for FV R506Q. Three homozygotes had a ratio of <0.1. Application of this Obs/Exp cut-off ratio of 0.6 to a total of 226 plasma samples tested to date discriminated without overlap between normals and heterozygotes. We conclude that this assay – readily adaptable to any dedicated coagulation laboratory and capable of yielding reliable results in all clinical circumstances in which testing is indicated – can distinguish between normals and heterozygotes for the FV R506Q mutation without the need for confirmatory DNA analysis.
The Importance of the Binding of Factor Xa to Phospholipids in the Inhibitory Mechanism of Tissue Factor Pathway Inhibitor: The Transmembrane and Cytoplasmic Domains of Tissue Factor Are not Essential for the Inhibitory Action of Tissue Factor Pathway Inhibitor
Authors: Kazama Yoshiaki
Published: July 2018

To investigate the inhibitory mechanism of tissue factor pathway inhibitor (TFPI), an attempt was made to examine the inhibitory activity of TFPI toward the factor Vila-truncated tissue factor (TF1-219) complex, which lacks its transmembrane and cytoplasmic domains. Factor VIIa-TF1-219 activity was significantly inhibited by TFPI-factor Xa complex in the presence of phospholipids, but was not in the absence of phospholipids. In addition, TFPI did not inhibit factor VIIa-TF1-219activity in the presence of γ-carboxyglutamic acid-domainless factor Xa. The ability of TFPI-factor Xa complex to inhibit factor VIIa-TF1-219 activity was totally dependent on the presence of phospholipids and was neutralized by prothrombin fragment 1 in a dose-dependent manner. These results indicate that the transmembrane and cytoplasmic domains of tissue factor are not essential for the inhibitory mechanism of TFPI and confirm that the binding of factor Xa to phospholipids through its γ-carboxyglutamic acid domain is essential for this reaction.
The Composition of Complexes between Plasminogen Activator Inhibitor 1, Vitronectin and either Thrombin or Tissue-type Plasminogen Activator
Authors: van Meijer Marja , Stoop Allart , Smilde Annelies , Preissner Klaus T , van Zonneveld Anton-Jan , Pannekoek Hans
Published: July 2018

Vitronectin (VN) is an obligatory cofactor for the inhibition of thrombin by plasminogen activator inhibitor 1 (PAI-1). It accelerates the rate of association between thrombin and PAI-1 more than two orders of magnitude. In contrast, VN does not accelerate the association between tissue-type plasminogen activator (t-PA) and PAI-1. Previously, we reported that the anti-PAI-1 monoclonal antibody (MoAb) CLB-2C8 binds to a short stretch of amino acids of PAI-1, located between residues 128 and 145, and prevents PAI-1 binding to VN. Furthermore, MoAb CLB-2C8 fully blocks the inhibitory activity of PAI-1 towards t-PA, emphasizing the importance of this area for the interaction with t-PA. Here, we show that this area is also required for the interaction between thrombin and PAI-1, since MoAb CLB-2C8 fully prevents inhibition of thrombin by PAI-1. In spite of similar structural requirements for the interaction between t-PA, PAI-1 and VN and between thrombin, PAI-1 and VN, the intermediate reaction products are clearly distinct. By employing surface plasmon resonance (SPR), using the BIAcore equipment, and by immunoprecipitation we demonstrate that, in the presence of VN, t-PA and PAI-1 form exclusively equimolar binary t-PA/PAI-1 complexes. Thrombin, PAI-1 and VN generate equimolar, binary thrombin/PAI-1 complexes and in addition equimolar, ternary complexes and multimers.
Antiplatelet Effect of FK633, a Platelet Glycoprotein Ilb/IIIa Antagonist, on Thrombus Formation and Vascular Patency after Thrombolysis in the Injured Hamster Carotid Artery
Authors: Kaida Takehiro , Matsuno Hiroyuki , Niwa Masayuki , Kozawa Osamu , Miyata Hideo , Uematsu Toshihiko
Published: July 2018

The antithrombotic and restenosis-preventing effects of FK633, an inhibitor of platelet aggregation via binding to the glycoprotein (GP) Ilb/IIIa receptor, were studied. IC50 value of FK633 against platelet aggregation ex vivo induced by 2.5 |iM adenosine diphosphate (ADP) was 5.4 X 10"7 M as determined using hamster platelet rich plasma. The inhibitory effect was also investigated in vivo on thrombus formation at the carotid arterial wall injured by a modified catheter. As a control, the left carotid artery was injured and the time required to develop a thrombotic occlusion (3.9 ±1.1 min, mean ± S.E.M., n = 18) was determined. Then, the right carotid artery of the same animal was injured while a continuous intravenous (i.v.) infusion of FK633 was administered at doses of 0 (saline), 0.1,0.3 or 1.0 mg/kg/h. The time to occlusion was dose-dependently prolonged. In a separate experiment, 10% of the total tPA dose (0.52 mg/kg) was injected into the injured artery as a bolus and the remaining was infused i.v. at a constant rate for 30 min. When FK633 (0.3 or 1.0 mg/kg/h) was infused together with tPA, late patency of the reperfused artery was much improved as compared with that of treatment with tPA alone. Bleeding time, measured at the end of the tPA infusion, was markedly prolonged when the higher dose of FK633 (1.0 mg/kg/h) was coadministered, however coadministration of the lower dose of FK633 (0.3 mg/kg/h) was almost without prolongation on the bleeding time, despite a significant effect on the vascular patency after thrombolysis. Next, neointima formation was evaluated 2 weeks after the vascular injury. When FK633 (0.3 mg/kg/h) was continuously infused i. v. by an implanted osmotic pump for 3,7 or 14 days after the vascular injury, the neointimal area formation was significantly suppressed in the treatment groups for 7 or 14 days. These findings suggest that FK633 inhibits platelet activation in the injured artery and improves vascular patency after thrombolysis with tPA with a concomitant suppression of neointima formation.
Genetic Analysis in Japanese Kindreds of Congenital Type I Antithrombin Deficiency Causing Thrombosis
Authors: Nakahara Yoshifumi , Tsuji Hajime , Nakagawa Katsumi , Masuda Haruchika , Kitamura Hidetsugu , Nishimura Hiromi , Kasahara Teruhisa , Sugano Tatsuya , Sawada Shohei , Nakagawa Masao
Published: July 2018

We have identified two novel minor deletions (case 1; -TA or -AT at nucleotide 9831-3 in exon 5 and case 2; -A at nucleotide 7640-1 in exon 4), one novel nonsense mutation (case 3; TAT to TAA at nucleotide 7491 in exon 4), and one recurrent nonsense mutation (case 4; CGA to TGA at nucleotide 5381 in exon 3A) in Japanease kindreds with congenital type I antithrombin deficiency. The deletion detected in case 1 represented a symmetric element (CTCTGTCTC) and possessed a direct repeat (CTCTATGTCTC). The deletion in case 2 was recognized in a consensus sequence (TGAAT) and possessed a direct repeat (GATGAA). The nonsense mutation in case 3 formed a palindrome (CCGTTAACGG) and that in case 4 was caused hy a CpG dinucleotide mutation. These results confirm that the mutations of congenital type I antithrombin deficiency are not random events but are influenced strongly by DNA sequences.
Pharmacokinetics of Recombinant Hirudin in Hemodialyzed End-stage Renal Failure Patients
Authors: Vanholder R , Camez A , Veys N , Loo A Van , Dhondt A M , Ringoir S
Published: July 2018

Recently, hirudin was used for the first time as an anticoagulant during hemodialysis in men. Pharmacokinetic data of this compound in end-stage renal failure are however not available. In this study, the pharmacokinetics of recombinant hirudin (HBW 023) was evaluated in hemodialysis-treated end-stage renal failure patients. HBW 023 was administered as a bolus at the start of a single dialysis (0.02 to 0.08 mg/kg) in 20 patients, and plasma hirudin levels were followed during this and the 5 following dialyses, without additional hirudin administration. The initial dialysis (HDj) was performed with a low flux polysulfone dialyzer; the following dialyses (up to HD6) with a high flux polysulfone dialyzer and regular heparin. Hirudin levels averaged 504.0 ± 214.0 and 527.7 ± 217.1 ng/ml in the middle and at the end of HDj, and then gradually decreased to 15.2 ± 15.2 ng/ml at the end of HD6. Pharmacokinetic data were compared to those obtained in healthy controls (n = 5), receiving the same dose, and reaching the same peak hirudin level. Hirudin half-life was >30 times longer in hemodialysis patients (51.8 ± 15.6 vs. 1.7 ± 1.5 h, p <0.001), whereas area under the curve was >60 times higher (34,669 ± 14,898 vs. 545 ± 205 ng/ml X h, p <0.001). Distribution volume was lower in hemodialysis patients (11.0 ± 3.1 vs. 14.1 ± 2.0 1, p <0.05). Hirudin disappearance rate was the same during high flux polysulfone dialysis as during interdialytic periods. Hirudin removal was markedly higher in those patients still maintaining some residual renal function and parameters of hirudin removal were significantly correlated to residual creatinine clearance. It is concluded that hirudin removal from the body is markedly depressed in hemodialyzed end-stage renal failure patients and that even minor residual renal function may increase this removal rate.
Anti-factor VIII Inhibitors and Lupus Anticoagulants in Haemophilia A Patients
Authors: Blanco Alicia N , Cardozo María A , Candela Miguel , Santarelli María T , Bianco Raúl Pérez , Lazzari María A
Published: July 2018

In a study of 170 haemophilia A patients, 43 were found to have an inhibitory effect; seven had anti-factor VIII inhibitors (a-fVIII) (A), 18 had lupus anticoagulants (LAs) with a strong (B: 12) or weak (C: 6) time-dependent effect and 18 had no time-dependent LAs (D). The a-fVIII showed a neutralizing effect only against factor VIII and negative diluted Russell viper venom time (dRVVT). The LAs were diagnosed by dRVVT; the Staclot® LA agreed with the dRVVT. During the study, three patients changed from an a-fVIII to an LA pattern; they also modified their clinical response.

Our prevalence of a-fVIII was low (4%) and we found 21% of LA, with a high (50%) prevalence of time-dependent inhibition. This pattern raises the possibility of the coexistence of LA and a-fVIII, stressing the need to develop specific tests to identify a-fVIII and LA.