bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ornithine Transcarbamylase Deficiency: A Possible Risk Factor for Thrombosis
Authors: Venkateswaran Lakshmi , Scaglia Fernando , McLin Valerie A , Hertel Paula M , Shchelochkov Oleg A , Mahoney Donald , Karpen Saul J , Yee Donald L 
Published: April 2020

Abstract
We describe four infants with ornithine transcarbamylase (OTC) deficiency, who developed arterial and venous thromboses prior to undergoing liver transplantation. These patients prompted a retrospective chart review of children with inborn errors of metabolism associated with hyperammonemia seen at our institution between 1998 and 2008; no additional cases with thrombosis were detected. Data abstracted from medical records include patient demographics, details about thrombus, treatment, associated risk factors and metabolic abnormalities. OTC deficiency was diagnosed during the first week of life in all patients (median age – 4 days; age range 1–7 days). Thrombotic complications developed prior to liver transplant in all patients (median age - 63 days; age range 6–71 days). One patient had arterial thrombus; the rest developed venous thromboses. Possible risk factors for thrombosis are summarized in the table below.
Risk factors Patient 1 Patient 2 Patient 3 Patient 4 Indwelling catheter at the site of thrombus Yes Yes Yes Yes Hyperammonemia (&gt;94 mmol/L) Yes No Yes Yes Low plasma arginine (&lt;42 mmol/L) Yes Yes Yes Yes Hypercoagulable risk factors None Elevated factor 8, fibrinogen Elevated fibrinogen, low AT III* Dysfibrinogenemia Infection (positive blood culture) None C albicans Coag neg Staph None
Table 1. Patient characteristics that are potential risk factors for thrombosis * AT III - Anti-thrombin III
Multiple pro-thrombotic risk factors were present. Hyperammonemia was seen in 3 patients and low plasma arginine level was present in all patients around the time of thrombosis. As L-arginine is a substrate for nitric oxide synthesis, arginine deficiency leads to low nitric oxide levels. Recent studies have linked nitric oxide insufficiency to platelet hyperaggregability, thrombosis and endothelial damage. Infants with OTC deficiency, indwelling vascular catheters, hyperammonemia and low plasma arginine may be at increased risk for thrombosis. Further studies in patients with OTC deficiency, to evaluate the role of hyperammonemia and low plasma arginine in thrombogenesis are warranted.
A Rapid Multiplexed Genotyping of Hereditary Thrombophilia by SELDI-TOF Mass Spectrometer
Authors: Yang Shangbin , Xu Lihui , Wu Haifeng 
Published: April 2020

Abstract
It is known that approximately 50% of patients presenting with venous thromboembolism are associated with polymorphic SNPs in the genes for coagulation factor V (factor V Leiden), prothrombin (prothrombin G20210A), and MTHFR (C677T). Genotyping these thrombophiliac SNPs helps clinicians to properly manage patients with thrombotic disorders. In this study, we reported a novel method to rapidly genotype all three thrombophiliac SNPs in a multiplexed fashion. First, patient DNA samples were subjected to PCR reactions to amplify and extend the DNA products with masses corresponding to genotypes for each of the three targeted thrombophiliac SNPs. PCR products were then applied to Q10 anionic Protein Chips, undergoing on-chip sample enrichment and clean-up. Finally, genetic variants were genotyped by Surface-enhanced laser desorption and ionization time-of-flight (SELDI-TOF) mass spectrometry based on their masses. This method offers a rapid turnaround time of less than five hours. The analytical accuracy of each SNP genotyping result has been confirmed by DNA sequencing. Additionally, the genotype results produced by this method were validated by comparing them to the results obtained by the approved method in the clinical reference laboratory. In summary, we have developed a novel approach of multiplex genotyping for known thrombophilic SNPs by SELDI-TOF mass spectrometer. This method is fast, accurate, reproducible, and is ready for immediate application in the clinical laboratory.
Evaluation of the Prothrombotic Risk Factors in Children with Leukemia
Authors: Unuvar Aysegul , Akcay Arzu , Saribeyoglu Ebru T , Tugcu Deniz , Karakas Zeynep , Ozturk Gulyuz , Anak Sema , Agaoglu Leyla , Devecioglu Omer 
Published: April 2020

Abstract
Pediatric patients with malignancy are at high risk of thromboembolic complications due to complex interactions of a variety of factors such as the malignancy, chemotherapy, central venous catheters (CVCs), infections, dehydration, and hereditary thrombophilia. In this study, deficiencies of protein C (PC), protein S (PS), and antithrombin (AT), activated protein C resistance (APCR), the factor V G1691A mutation, the prothrombin G20210A mutation, and increased factor VIII, IX, fasting homocysteine levels were assessed at the diagnosis of leukemia, retrospectively. The aim was to evaluate the role of the thrombophilic risk factors on vascular events during treatment period. Thirty children (11 F, 19 M) with leukemia (24 patients with ALL, 4 AML, one biphenotypic leukemia, one infant leukemia) were enrolled in this study. The median age of the patients was 56 months (range 7–215 months). All patients had CVCs, and thromboprophylaxis was not given to the any patients. We detected main prothrombotic risk factors at the diagnosis of leukemia as following: low PC (8/30), PS (11/30), AT activity (3/25), APCR (5/22), increased FVIII (5/22), FIX (2/22), and homocysteine levels (2/8), and FV Leiden mutation (1/24; heterozygous). The prothrombin G20210A mutation was not detected in any patient. The parents of these patients with abnormal test results were also evaluated to discriminate congenital or acquired deficiencies. In addition; PC, PS, AT levels were followed-up, and MTHFR genotype for the patients with high homocysteine levels was studied, also. In spite of, 24 of these 30 patients had at least one abnormal laboratory test result at the diagnosis of leukemia, venous thrombosis (7 with CVC-related venous thrombosis, one CVC-related jugular vein thrombosis and VOD, one vena saphena parva thrombosis) developed in 9 of 24 patients. In conclusion, leukemic children with at least one prothrombotic risk factor have high venous thrombosis risk. Further trials are needed to clarify the necessarity of screening program for thrombophilia and thromboprophylaxis in children with leukemia and CVCs, and, especially for the patients carrying hereditary prothrombotic risk factors.
The Function of Toll-Like Receptor 4 Expressions on Human Platelet in Platelet Activation
Authors: Ma Liping , Nie Da-Nian , Wang Xiu-Ju , Xie Shuang-Fen , Li Yi-Qing , Wu Yu-Dan , Pei Zhi-Xin , Zhang Cheng , Yin Song-Mei 
Published: April 2020

Abstract
Lipopolysaccsharide (LPS) is a principal outer membrane component of gram-negative bacteria. It initiates an inflammatory response to infection by activating Toll-like receptor-4 (TLR4) in host. Infection increases risk for hemostasis, thrombosis, DIC, and tissue repair. Platelet contributes to the inflammation process through respond to invading pathogens, membrane adhesion molecule (P-selectin) is one of the indexes to determine platelet activation. Experiment was designed to study whether TLR4 is expressed on human platelet, and what is the function of TLR4 in platelet activation induced with LPS. Platelet suspensions from 10 heath people were treated with LPS of different concentrations for 1 hour, which were 0mg/L(control),0.1mg/L,0.5mg/L,1mg/L and 5mg/L, respectively. The expressions of TLR4, P-select on platelets and PAI-1 in platelets were detected through flow cytometry (FCM) and western blot(WB) methods. ADP-induced platelet aggregation was measured by LG-PABER aggregometer. Compared with control, the expressions of TLR4,P-selectin on platelets and PAI-1 in platelets after treated with LPS of 0.5mg/L,1mg/L and 5mg/L were increased (P&lt;0.05). positive correlation was observed between TLR4 and P-selectin on platelets, but between TLR4 and PAI-1 in platelets. LPS of all concentrations did not affected ADP-induced platelet aggregation. Therefore, it is evident that functional TLR4 is expressed on human platelet. TLR4 on platelet might be one of the important intermedia between platelet activation and LPS or bacteria, and contribute to the inflammatory process in host. It is also worthy to study whether LPS affect platelet aggregation induced by other inductors.
Baseline Platelet Reactivity as Determined by TRAP-6 Induced Aggregation in Whole Blood Is Related to the Rate of Non-Responsiveness to Clopidogrel
Authors: Spannagl Michael , Jambor Csilla 
Published: April 2020

AbstractBackground: Platelet inhibition by clopidogrel is often determined using ADP induced aggregometry. TRAP-6 stimulates platelets via the PAR receptors and is influenced to a much lesser extend by aspirin or clopidogrel. The value of the determination of TRAP-6 induced aggregometry in patients treated with clopidogrel is unknown. We evaluated the relation of clopidogrel non-responsiveness as determined by multiple electrode aggregometry (MEA) (1) vs. TRAP-6 induced aggregation. MEA provides a measurement of platelet aggregation in whole blood by monitoring changes in electrical impedance via disposable test cells each containing two pairs of electrodes (1).Methods: Following IRB approval hirudin-anticoagulated blood (Dynabyte, Munich, Germany) was sampled from 993 patients. Aggregation induced by arachidonic acid (0.5 mM), ADP (6.4 μM) or TRAP-6 (32μM) was determined in whole blood using a new generation impedance aggregometer. The device is called Multiplate analyzer (Dynabyte, Munich, Germany), indicating the multiplicity of channels and sensors per channel of the device. After dilution (1:2 with 0.9% NaCl solution) of hirudin-anticoagulated whole blood and stirring for three minutes in the test cuvettes at 37°C, the activator was added and aggregation was continuously recorded for six minutes. The increase of impedance due to the attachment of platelets to the electrodes is detected for each sensor unit separately and transformed to arbitrary aggregation units. The aggregation is quantified as area under the curve (AUC).Results: 618 patients were on chronic therapy with 100 mg aspirin/d, 295 patients on clopidogrel 75 mg/d (237 on dual therapy). Aspirin therapy had no influence on TRAP-6- induced aggregation (112+−260 vs. 110+−25; mean +− sd; aspirin vs. no aspirin, p&gt; 0.05 Mann-Whitney U-test). In contrast clopidogrel induced a minor but significant reduction of TRAP6-induced aggregation (107+− 277 vs. 113+−246; p&lt;0.05). Patients on clopidogrel had a significantly lower ADP induced aggregation (41+−30 vs. 86 +−33) compared to controls (p&lt;0.05), and patients on aspirin had a significantly lower arachidonic acid induced aggregation compared to controls (23+−28 vs. 94 +− 35, p&lt;0.05). 89 of 295 patients (30%) were stratified as clopidogrel non-responders based on the cut-off presented in (2). Patients were divided into 4 quartiles (q1-4) depending on their TRAP-6 induced aggregation. The rate of non-responsiveness in Q1 was 8.1%, in Q2 20%, in Q3 38% and 54% in Q4. ADPinduced aggregation was significantly higher in Q4 than in any other quartile (p&lt;0.05).Conclusion: A high TRAP-6 induced aggregation is associated with an increased rate of clopidogrel non-responsiveness as determined by multiple electrode aggregometry. TRAP-6 induced aggregometry seems to indicate the global platelet potential and might allow a prediction of clopidogrel responsiveness before the induction of therapy.
Agonist and Antagonist Effects of Diadenosine Tetraphosphate, a Platelet Dense Granule Constituent, on Platelet P2Y1, P2Y12 and P2X1 Receptors
Authors: Chang Hung , Yanachkov Ivan B , Michelson Alan D , Li YouFu , Barnard Marc R , Wright George E , Frelinger Andrew L 
Published: April 2020

Abstract
Introduction: Diadenosine 5′,5‴-P1,P4- tetraphosphate (Ap4A) is stored in platelet dense granules, but its effects on platelet function are not well understood. In the current study, we examined the effects of Ap4A on signaling through the human platelet purinergic receptors P2Y1, P2Y12 and P2X1.
Methods: Flow cytometry was used to measure the effects of Ap4A in the presence or absence of ADP on:
P2Y12-mediated decrease in intraplatelet phosphorylated vasodilator stimulated phosphoprotein (VASP), P2Y1- mediated increase in platelet cytosolic Ca2+ (measured with FLUO-4), and c) P2X1- mediated intraplatelet entry of extracellular Ca2+ (measured with FLUO-4) (Figure). ADP-stimulated platelet shape change (P2Y1-mediated) and aggregation (P2Y1- and P2Y12-mediated) were measured optically.
Results: Ap4A inhibited 3 μM ADP-induced:
platelet aggregation (IC50 9.8 ± 2.8 μM, n = 3), P2Y1-mediated shape change, P2Y1-mediated increase in platelet cytosolic Ca2+ (IC50 40.8 ± 12.3 μM, n = 3), and P2Y12-mediated decrease in VASP phosphorylation (IC50 &gt;250 μM, n = 3).
In addition to inhibiting these ADP-induced effects on P2Y1 and P2Y12, Ap4A in the absence of added ADP decreased VASP phosphorylation, albeit with significantly reduced potency compared to ADP. This Ap4A-induced reduction of VASP phosphorylation was reversed by addition of AR-C69931, a selective P2Y12 antagonist. Ap4A, therefore, has partial P2Y12 agonist properties. Ap4A also had agonist effects on platelet P2X1 receptors, as evidenced by intraplatelet entry of extracellular Ca2+. All these effects of Ap4A were significant at pathophysiologic concentrations. Ap4A had no agonist effects on platelet P2Y1 receptors.
Conclusions: Ap4A, a known constituent of platelet dense granules, is
an antagonist of platelet P2Y1 and P2Y12 receptors, where it inhibits the effects of ADP, an agonist of P2X1 receptors, and a partial agonist of P2Y12 receptors (Figure).
Figure Figure
Hyperlipidemia Could Activate Platelet and Induce the Production of Plasma Inflammatory Factors in Rabbits, Which Lead to Atherosclerosis
Authors: Xie Shuangfeng , Yin Songmei , Nie Danian , Li Yiqing , Wang Xiuju , Ma Liping , Xiao Jie 
Published: April 2020

Abstract
Background: It had been proved by epidemiology and clinical trials that hypercholesterolemia (HC) and atherosclerosis (AS) had close relations. Lipid could take part in many pathological processes of the AS. Platelets played an important role in this process as an inflammatory mediator. We Chose Platelet aggregation maximum (PAG(M)) and plasma P-selectin as the index of platelet activation, try to explore the transfer of platelet activation and lymphocyte inflammatory reaction in atherosclerosis.
Design: We set up the rabbit hyperlipidemia atherosclerosis model through 12 weeks’ hyper lipid feeding. PAG(M), concentrations of plasma P-selectin, Interleukin (IL)- 6, IL-1β, tumor necrosis factor (TNF)-α and mRNA expression of these factors in the lymphocyte were measured at 0 week, 6th week and 12th week time point.
Results: At the 6th week time point of the hyper lipid feeding, the rabbit had elevated PAG(M) (68.12%±4.73% vs. 62.67%±3.13%; P=0.002, n=20). The PAG(M) was maintained in the high level at 12th week time point (68.83%±3.35% vs. 62.67%±3.13%; P=0.001, n=20). At the 6th week time point of the hyper lipid feeding, the rabbit had elevated plasma P-selectin, IL-6, IL-1β and TNF-α (6th week vs. 0 week, n=20, P-selectin P=0.005, IL-6 P=0.000, IL-1β P=0.001, TNF-α P=0.001). The expressions of IL-6/mRNA, IL-1β/mRNA and TNF-α/mRNA in lymphocytes were elevated too (6th week vs. 0 week, n=20, IL-6/mRNA P=0.000, IL-1β/mRNA P=0.002, TNF-α/mRNA P=0.000). At the 12th week time point, all of the parameters were maintained in the high level, while there had no significant difference between 12th week time point and 6th week time point.
Conclusion: Hyperlipidemia could activate platelet. Increased PAG(M) and plasma P-selectin represented the platelet activation. Hyperlipidemia could induce the production of plasma IL-6, IL-1β and TNF-α. The increased plasma IL-6, IL-1β and TNF-α were partly from the lymphocyte secretion because The IL-1β/mRNA, IL-6/mRNA and TNF-α/mRNA expression of lymphocyte elevated. So in rabbit hyperlipidemia atherosclerosis model, platelet activation and inflammatory factors increasing was the main mechanism, while the lymphocyte took part in the inflammatory process.
Prevalence, Clinical and Instrumental Correlates of Myocardial Fibrosis and Necrosis by Delayed Contrast Enhancement Cardiovascular Magnetic Resonace in Thalassemia Major Patients
Authors: Pepe Alessia , Favilli Brunella , Positano Vincenzo , Capra Marcello , Maggio Aurelio , Pinto Carmen Lo , Spasiano Anna , Forni Gianluca , Filosa Aldo , Borgna-Pignatti Caterina , Cianciulli Paolo , Giuffrida Gaetano , Casini Tommaso , Derchi Giorgio , Lombardi Massimo 
Published: April 2020

Abstract
Cardiovascular Magnetic Resonance (CMR) by delayed enhancement (DE) has proven to visualize myocardial scarring, but no dedicated studies are available in thalassemia major. Aim of our study was to investigate the prevalence, extent, clinical and instrumental correlates of myocardial fibrosis or necrosis by DE CMR in thalassemia major patients. CMR-DE was performed in 115 thalassemia major patients. Myocardial iron overload was determined by multislice multiecho T2*. Cine images were obtained to evaluate biventricular function. All patients gave written informed consent to the protocol. The project was approved by the institutional ethics committee. DE areas were present in 28 patients (24%). Extent of DE was 3.9±2.4 %. In 26 patients the location of fibrosis was not specific and patchy distribution was prevalent. Two patients showed transmural DE following coronary distribution. The DE group was significantly older (P=0.004). DE correlated with cardiac risk factors (P=0.01), history of cardiac complications (P=0.001), anti-HCV antibodies (P = 0.04) and ECG-changes (P=0.002). We did not find significant relation of DE with heart T2* values and biventricular function. Figure shows a thalassemia major patient with no myocardial iron overload (all 16 segments T2* values &gt; 20 ms) (A) and transmural DE (black arrows) following coronary distribution in the apical region (B,C). In conclusion, in thalassemia major patients the significant presence of myocardial fibrosis/necrosis seems to be a time dependent process correlating with cardiovascular risk factors and cardiac complications. HCV infection could be a causal agent in the pathogenesis of myocardial scarring. ECG-changes showed a good accuracy in predicting myocardial scarring.
Figure Figure
Endothelial Differentiation of Human Embryonic Stem Cell and Functional Blood Vessels Formation in Vivo
Authors: Li Zongjin , Smith Bryan , Huang Mei , Xie Xiaoyan , Gambhir Sanjiv Sam , Wu Joseph 
Published: April 2020

Abstract
Background: Human embryonic stem (hES) cells are distinguished by their capacity for self-renewal and pluripotency. Here we characterize the differentiation of hES cell-derived endothelial cells (hESC-ECs), use molecular imaging techniques to examine their survival and function in vivo.
Methods and Results: Here we introduced two-step procedures to increase endothelial differentiation efficiency of hESCs by subcultured embryoid bodies (EBs) in collagen. Single cell suspensions from EBs sprouting in collagen were obtained by treatment with collagenase and Liberase Blendzyme IV and CD31/CD144 positive cells were isolated by FACScan. After isolation, these hESC-ECs express endothelial cell markers similar to HUVEC, form vascular-like channels, and incorporate DiI-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) in vitro. Real time PCR array described increasing endothelial transcription. Using whole genome microarrays, we investigated the hESCs derived endothelial cells (hESC-ECs) transcriptome that occur among sequenced hESCs differentiation processes and human umbilical vein endothelial cells (HUVECs). We found that hESC-ECs expressed endothelial gene at pattern similar to HUVECs. By intravital microscope, we demonstrated that hESC-ECs can form function vessels with blood flow.
Conclusion: Taken together, two-steps procedures increased the endothelial differentiation efficiency hESCs, and hESC-ECs can form functional vessel in vivo.
Differential Effects of TAK-442, a Factor Xa Inhibitor, and Ximelagatran, a Thrombin Inhibitor, on Bleeding: Possible Role of Differences in Effects on Factor V-Mediated Feedback on Blood Coagulation Cascade
Authors: Konishi Noriko , Hiroe Katsuhiko , Imaeda Yasuhiro , Fujimoto Takuya , Kubo Keiji , Kawamura Masaki 
Published: April 2020

Abstract
Thrombin generation serves to amplify the coagulation cascade via positive feedback activation of factor V (FV) and factor VIII. We hypothesized that factor Xa (FXa) inhibitors, unlike thrombin inhibitors, would not block the feedback activation of the coagulation cascade but would have a favorable anticoagulating profile—sufficient to prevent thrombus formation, yet not interfere with hemostatic plug formation. TAK-442 is a newly synthesized, selective FXa inhibitor that strongly inhibits FXa (with a Ki value of 1.8 nM), and displays more than 440x selectivity toward FXa than other serine proteases. In the present study, we compared the effects of TAK-442 versus ximelagatran on FV-mediated positive feedback in vitro, and on their antithrombotic and hemorrhagic effects in a rat model of venous thrombosis.
In vitro, TAK-442 gradually inhibited thrombin generation and prolonged prothrombin time (PT) in a dose-dependent manner, while melagatran, an active form of ximelagatran, exhibited a steeper effect at higher doses tested. The PT prolonging potency was increased in FV–deficient human plasma, with CT2 values (the concentration that causes 2 times prolongation of clotting times) of 120 nM for TAK-442 and 32 nM for melagatran, compared with 500 nM and 360 nM for TAK-442 and melagatran, respectively in normal plasma. In the rat model of venous thrombosis, TAK-442 (10 mg/kg, po) prevented thrombus formation by 55% and prolonged PT by 1.3 times of control values; a similar effect was observed in ximelagatran-treated (3 mg/kg, po) animals, with 59% inhibition of thrombus formation and 1.2 times prolongation of PT. TAK-442 at 100 mg/kg, prolonged PT by 2.1 times, with no significant change in bleeding time (BT); in contrast, increasing the dose of ximelagatran to 10 mg/kg, po prolonged PT by 3.9 times and significantly (P&lt;0.025) increased BT.
Our data suggest that the differential effects of the two agents on FV-mediated amplification of thrombin generation may underlie the observation of a wider therapeutic window for TAK-442 than for ximelagatran.