bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concentration of Neurotransmitter and Neurotrophic Factors in Platelet Rich Plasma.
Authors: Swift Matthew J. , Greene Jesse A. , Welch Zachary R. , Woodell-May Jennifer 
Published: October 2019

Abstract
Use of autologous platelet rich plasma (PRP) is emerging in a variety of clinical settings. Although the desired effects of PRP application vary across indications, the common mechanism of action is the up-regulation of the healing response at the site of application. This effect has largely been attributed to the release of cytokines from alpha-granules during platelet degranulation. Research has demonstrated elevated concentrations of a variety of cytokines in PRP samples when compared to baseline blood. To date, no researchthat quantifies the concentration of neurotransmitter and neurotrophic agents present in activated PRP samples has been reported. A number of these molecules have been reported to be present in the alpha and dense granules of platelets with release occurring upon platelet degranulation. Upon release, these molecules elicit actions related to the hemostatic, inflammatory, and reparative processes during the natural wound healing response. In the current study, a commercially available platelet concentrator (GPS II System, Biomet Biologics, Inc) was used to prepare PRP from whole blood samples obtained from 9 healthy subjects. PRP and whole blood samples from each subject were analyzed using a hematology analyzer (Cell Dyn 3700, Abbot Laboratories) for cellular content and then activated with a bovine thrombin/calcium chloride solution. Following a 10-minute incubation, the activated samples were centrifuged for 5 minutes and the resultant serum was collected and assayed for serotonin, adrenaline, noradrenaline, dopamine, and brain derived neurotrophic factor (BDNF) using commercially available ELISA kits. Platelet concentration averaged 196x103 platelets/ml in the baseline samples and 1230 x103 platelets/ml in the PRP samples, a 6.28 fold increase. Serotonin serum levels increased 4.48 fold (base=201.9 pg/ml, PRP=904.6 pg/ml), noradrenaline serum levels increased 3.02 fold (base=286 pg/ml, PRP=863 pg/ml), and BDNF serum levels increased 3.06 fold (base=3.49ng/ml, PRP=10.6 ng/ml). Adrenaline results were highly inconsistent, a factor attributed to the potential of glandular release in response to the blood draw stick. Dopamine concentrations were not detected in any samples using an ELISA with a sensitivity of 100 pg/ml. This study confirms the presence of elevated neurotransmitter and neurotrophic concentrations in activated PRP samples when compared to corresponding base samples. Further studies are necessary to elucidate the role these elevated concentrations contribute in the up-regulation of the wound repair process reported during the clinical application of PRP.
Platelet ABCA1 Expression Is Normal in Scott Syndrome Dogs.
Authors: Catalfamo James L. , Brooks Marjory B. , Ammersbach Melanie , DeMaster Amanda K. 
Published: October 2019

Abstract
Scott syndrome is a rare platelet function defect characterized by a failure of Ca2+-stimulated phosphatidylserine (PS) externalization and lack of platelet prothrombinase activity. In 2005 Albrecht et al. (Blood 106:542) described low levels of ATP-binding transporter A1 (ABCA1) mRNA in lymphocytes and heterozygosity for a novel ABCA1 missense mutation in a patient with Scott Syndrome. The proband’s expression of platelet ABCA1, however, was not measured. Platelet dysfunction has been described as a feature of Tangier disease, a monogenic disorder caused by ABCA1 mutations (Nofer et al, JBC279:34032, 2004). The disease phenotype results from altered lipid trafficking, with a virtual absence of plasma HDL cholesterol and accumulation of lipid in cells of the RE system. In the current study, we systematically evaluated platelets from Scott syndrome dogs to find evidence of ABCA1 deficiency. Platelets from control dogs and affected German shepherd dogs (GSD) were compared with regard to cholesterol content, ABCA1 protein expression, and reactivity to collagen, convulxin (CVX), and thrombin. All GSD had normal plasma cholesterol and triglyceride levels, with no significant difference in mean platelet cholesterol content from that of control dogs (control cholesterol = 13.4 ug/108 platelets, GSD cholesterol = 12.6 ug/108 platelets; n= 6; p = 0.726). Western blot analysis of platelet extracts from control dogs and GSD using a polyclonal antibody to human ABCA1 revealed comparable levels of a 220 kD protein band, the expected size for human ABCA1. We found no significant differences in maximal platelet aggregation in response to 12 ug/mL collagen stimulation [control dog mean response = 82.9% (n=10), GSD = 75.0 % (n= 7); p = 0.133)]. CVX concentration-response aggregation curves obtained for washed platelets were similar for control dogs (n=4) and GSD (n=3) in the range of 1 to 100 nM CVX, with a plateau of maximal aggregation at 10 nM CVX. In flow cytometry analyses, we found no difference in mean platelet mepacrine uptake between control dogs and GSD (mean positive platelets = 64%, n= 3 control, n=5 GSD). There were no significant differences in mean CD62P expression post-thrombin (0.5 U/mL) or CVX (2 nM) stimulation [control CD62P positive platelets post-thrombin = 57%, post-CVX = 47.5% (n=7); GSD CD62P positive platelets post-thrombin = 49%, post-CVX = 56% (n=4)]. Although ABCA1 has been proposed to play a role in PS transport, we found no evidence of ABCA1 deficiency and none of the characteristic platelet abnormalities associated with Tangier disease in canine Scott syndrome, a model of impaired transmembrane PS movement.
Comparison of Platelet Phenotypes ANALYSIS TANGIER DISEASE SCOTT SYNDROME GSD Ionophore induced PS expression Present Absent Collagen or CVX induced aggregation Decreased Normal CVX or thrombin induced alpha granule release Decreased Normal Platelet ABCA1 expression Absent Present
Deficiency in TDAG51 Decreases Atherosclerotic Lesion Development in ApoE-Deficient Mice.
Authors: Hossain Gazi S. , Zhou Ji , Maclean Kenneth , Lhotak Sarka , Sood Sudesh K. , Patel Hansa , Capone John , Rho J. , Austin Richard C. 
Published: October 2019

Abstract
T-cell death associated gene 51 (TDAG51) is a pro-apoptotic gene that can be induced by endoplasmic reticulum (ER) stress agents, including homocysteine, tunicamycin, thapsigargin or dithiothreitol. Our previous studies have demonstrated that transient overexpression of TDAG51 elicited significant changes in cell morphology, decreased cell adhesion and promoted detachment-induced programmed cell death (PCD). In support of these in vitro findings, we have further shown that TDAG51 expression was increased and correlated with PCD in the atherosclerotic lesions from apolipoprotein E (apoE)-deficient mice fed hyperhomocysteinemic diets, compared to mice fed control diet. We designed the current study to investigate the effect of TDAG51 deficiency in the development and progression of atherosclerosis. To assess in vivo significance of TDAG51 on atherosclerosis, we have crossed TDAG51-deficient mice with apoE-deficient mice to obtain double knockout mice. Our findings have demonstrated that TDAG51/apoE-deficient mice have a significant decrease in atherosclerotic lesion area, compared to age- and sex-matched apoE-deficient mice. Total plasma cholesterol and triglycerides as well as lipoprotein profiles were similar in both groups. However, TDAG51/apoE-deficient mice presented with increased hepatic steatosis. Further, a significant upregulation of peroxisome proliferator-activated receptor γ (PPAR-γ), a transcription factor required for adipose tissue formation, was demonstrated in TDAG51-deficient mouse embryonic fibroblasts (MEFs), compared to control wildtype MEFs. Interestingly, earlier studies in mice have reported that overexpression of PPAR-γ decreases atherosclerotic lesion development and increases hepatic steatosis - a phenotype similar to that observed in the mouse deficient in both apoE and TDAG51. Collectively, these findings provide evidence that TDAG51 mediates atherosclerotic lesion development and hepatic steatosis through a mechanism involving PPAR-γ.
2006 Prevalence Estimate of Idiopathic Thrombocytopenic Purpura (ITP) in the United States.
Authors: Deitz Anne C. , St. Laurent Samantha A. , Kobayashi Monica G. , Hall Susan A. , Feudjo-Tepie Maurille A. 
Published: October 2019

Abstract
ITP is a rare but serious platelet disorder. It has been associated with fatal hemorrhage and reduced life expectancy (Cohen et al., Arch Intern Med, 2000). The incidence of ITP has been reported in two population-based studies in Europe (Neylon et al., Br J Haem, 2003; Frederiksen and Schmidt, Blood, 1999). However, there are no recent high quality studies that we are aware of regarding the burden of this disease (i.e., prevalence) in the US by gender and age group, and so we undertook this study in IHCIS (Integrated Healthcare Information Services), a US managed care database comprised of over 38 million patients from 30 health plans. ICD-9 code 287.3 (primary thrombocytopenia) was used as a proxy for an ITP diagnosis. Patients were required to have at least one diagnosis code in 2004 and a second diagnosis code in 2003, 2004 or 2005 to help minimize rule-out diagnoses. Continuous enrolment for a defined period of time also was required. Projected 2006 cases were obtained by multiplying the 2004 prevalence proportions by July 1, 2006 US population estimates (http://www.census.gov/ipc/www/usinterimproj). The projected number of patients with ITP in the US in 2006 was estimated to be 85,000 to 108,000, depending on the stringency of the inclusion criteria (i.e., whether the second occurrence of 287.3 in a patient record had to be within six months of the first). Slightly more of these cases were among women (56%) compared to men, and adults were diagnosed more frequently than those aged 0–15. This is the first study to estimate US prevalence counts using a managed care population, which includes both inpatients and outpatients. However, there are several limitations: ICD-9 code 287.3 is not exclusive to ITP. Segal et al. (Am J Hem, 2004) reported that sensitivity and specificity based on a single occurrence of this code was 100% and 89%, respectively, among inpatients, and 84% and 66%, respectively, among outpatients; our study required two code occurrences. Our estimate also assumes that the prevalence rate has remained constant from 2004 to present. Lastly, Frederiksen and Schmidt reported that the incidence of ITP was higher among older individuals. Therefore, we may be under-estimating the true prevalence of this disease in the general population because the elderly are somewhat under-represented in the IHCIS database.
Antibodies Against Platelet Glycoprotein Target Antigens in Antiphospholipid Syndrome (APS).
Authors: Bidot Carlos J. , Jy Wenche , Bidot Carlos , Horstman Lawrence L. , Fontana Vincenzo , Yaniz Miriam , Gonzalez Martha , Ahn Yeon S. 
Published: October 2019

Abstract
Introduction: Antiphospholipid syndrome (APS) is characterized clinically by thrombotic events and the presence of antiphospholipid antibodies (aPLA) and/or lupus anticoagulant (LA). It is frequently associated with thrombocytopenia and anti-platelet antibodies have been implicated by some. However the roles of anti-platelet antibodies in APS have not been elucidated. We previously reported that platelet activation, but not endothelial activation, was associated with thrombosis in aPLA+ patients [Blood, 104:143a, 2004] but the cause of platelet activation was not addressed. In the present study, we investigated the prevalence of anti-platelet antibodies in APS patients, as well as platelet and endothelial activation.
Material and Methods: We evaluated 47 patients with primary APS. Anti-platelet antibodies against GP IIb/IIIa (CD41b), GP Ib/IX (CD 42b) and GP IV (CD36) for IgG and IgM class were measured by PAICA assay [Thromb Haemost76:1820, 1996]. We also measured platelet and endothelial activation markers by flow cytometry: CD62P on platelets, CD31+/CD42+ platelet microparticles (PMP), and CD31+/CD42- endothelial microparticles (EMP).
Results: Of the 47 patients, 34 (72%) were positive for at least one anti-platelet antibody. Looking first at IgG, 18/34 (53%) were positive for GP IV; 17/34 (50%) for GP IIb/IIIa; and 16/34 (47%) for GP Ib/IX. IgM antibodies were 47% (14/30) for GP Ib/IX, 38%(13/34) for GP IIb/IIIa, and 24% (8/33) for GP IV. Platelet and endothelial markers were significantly more common in the anti-platelet antibodies positive group: 40% vs. 21% for CD62P, 40% vs. 28.5% for EMP, and 23% vs. 5% for PMP, respectively. We found that CD62P associated significantly with IgM anti-GP IIb/IIIa (p< 0.05), and PMP with IgM anti-GP IIb/IIIa (p< 0.05), and IgM anti-GP IV (p< 0.05).
Conclusions: Anti-platelet antibodies are common in APS, confirming previous reports. We found that anti-platelet antibodies IgM anti-GP IIb/IIIa, and IgM anti-GP IV were often associated with platelet activation, suggesting that these antibodies may activate platelets to play an important role in the thrombogenesis of APS. These antibodies were also associated with endothelial activation. It remains to be determined which antibodies, APLA and/or anti-platelet antibodies, play a dominant role in the activation of platelet or endothelial cells and contibute most to the pathogenesis of thrombosis in APS.
Platelet and Red Blood Cell Indices in Harris Platelet Syndrome.
Authors: Naina Harris V.K. , Harris Samar 
Published: October 2019

Abstract
Inherited giant platelet disorders are a group of rare disorders characterized by thrombocytopenia, giant platelets and variable bleeding symptoms. Naina et al., described a new giant platelet disorder called Harris Platelet Syndrome (HPS), the most common inherited giant platelet disorder occurring in up to one third of blood donors from north eastern part of Indian subcontinent. HPS is characterized by an autosomal dominant mode of inheritance with normal to severe thrombocytopenia (less than 50x109/L), giant platelets (mean platelet volume more than 10fL) and absent bleeding symptoms with normal platelet aggregation studies. Occasionally abnormalities in red blood cell morphology have been associated with certain giant platelet disorders such as stomatocytosis in Mediterranean Macrothrmboctopenia, dyserythropoiesis in GATA 1 associated macrothrombocytopenia and thalassemia, in X Linked Thrombocytopenia Thalassemia (XLTT).
This study was undertaken to analyze the platelet and red blood cell indices in blood donors with Harris Platelet syndrome. A total of 203 blood donors were included in this study, 101 blood donors from northeaster part of India with MPV more than 12fl (normal 7–10fl) and 102 blood donors from southern part of India. Before blood donation, all donors were questioned about a history of bleeding conditions, in either themselves or their relatives. Blood samples were collected in ethylenediaminetetraacetic acid (EDTA). Automated platelet counts were performed using a Coulter STKS (Coulter, Hialeah, Florida) within 2 hours of collection.
Peripheral blood smears were examined to confirm thrombocytopenia, giant platelets and red blood cell morphology. There was a significant difference between platelet count (Mean ±SD) 136± 40 Vs 262 ± 53 in southern India (p<0.000). Thirty three donors with HPS had a normal platelet count with MPV more than 12fL. MPV was 13.6±0.13 (range 12 to21.9fL) in donors with HPS and 7.3 ±0.6 (range 6–9.2fl) in southern Indian blood donors. The platelet distribution width (PDW) was 17.4±0.8 in donors with HPS and was 16.38±0.5 in southern India blood donors(p<0.000). Though there was a significant difference between hemoglobin, 13.8 ± 1.0 vs and 14.7± 1.1 (P<0.00), there was no significant difference between RDW, MCV, MCH, MCHC. Peripheral blood smear did not show any obvious red blood cell abnormality, but showed giant platelets and thrombocytopenia.
Harris platelet syndrome is associated with normal to severe thrombocytopenia, giant platelets and significant platelet anisocytosis. There was no associated red blood cell abnormalities observed with HPS.
PEGylation of Factor VIII Reduces the Inhibitory Effects of Human Antibody Inhibitors on the Factor VIII Molecule.
Authors: Tang Liang , Pan Clark , Atwal Harpartap , Nixon Jennifer , Barnett Thomas , Murphy John E. , Mei Baisong , Fournel Michael 
Published: October 2019

Abstract
Replacement therapy with plasma-derived or recombinant Factor VIII (FVIII) has successfully reduced mortality and morbidity and improved the quality of life for patients with hemophilia A. However, up to 30% of patients develop antibody inhibitors to the FVIII molecule. Inhibitors reduce the efficacy of FVIII, increase the cost of treatment, and greatly increase the risk for life-threatening bleeding events in these patients. In the hopes of developing a more efficacious FVIII therapeutic for hemophilia A patients with inhibitors, we initiated studies on the PEGylation of B-region deleted FVIII (FVIII-BDD) with different sizes of polyethylene glycol (PEG) and investigated the inhibitory effects of anti-FVIII inhibitors on the activity of PEGylated FVIII-BDDs. Applying a site-specific mutagenesis technique to the FVIII-BDD molecule, an amino-acid residue at the inhibitor binding site was changed to cysteine. Mutated FVIII-BDD was purified and PEG molecules of different sizes were added at the mutation sites through a chemical reaction with the maleimide group on the activated PEG. PEGylated FVIII-BDD molecules were further purified and tested for FVIII activity using the chromogenic assay. To investigate the effects of antibody inhibitors on the PEGylated FVIII-BDD, studies were carried out utilizing inhibitory plasmas collected from 8 hemophilia A patients with confirmed inhibitors and different monoclonal antibodies as controls. Of the 8 patient plasmas tested, 43 kD PEGylated FVIII-BDD was more resistant to antibody inhibitors in 4 patient plasma samples than unmodified FVIII-BDD. In one sample, pre-incubation of FVIII-BDD with inhibitor patient plasma (1:15 dilution) reduced FVIII activity to 5% of the originally activity added, according to the chromogenic assay. By contrast, approximately 20% of original activity was retained for monoPEGylated FVIII-BDD and >40% activity was retained for diPEGylated FVIII-BDD. Overall, the results suggest that PEGylated FVIII-BDDs may retain more FVIII activity in the presence of some FVIII antibody inhibitors compared to FVIII-BDD. It is important to note that there was a positive correlation between the size of PEG added to FVIII-BDD and the amount of FVIII activity retained. This study indicates that the addition of PEG to FVIII molecules through site-specific PEGylation has the potential to increase the resistance of FVIII to the effects of some antibody inhibitors in patients with hemophilia A.
Single-Dose Pharmacokinetics of Murine and Human Recombinant Activated FVII in Mice.
Authors: Steinoe Anne , Karpf Ditte M. , Stennicke Henning R. , Ezban Mirella , Sorensen Brit B. 
Published: October 2019

Abstract
The practical advantages of using the mouse in pharmacokinetic (PK) studies of human recombinant proteins are many and obvious. However, the relevance of studying human proteins in a mouse model is always questionable. The aims of the present study were i) to investigate if the mouse can be used as a model for PK studies of human FVIIa and FVIIa analogues by comparing the clearance of human recombinant FVIIa (hFVIIa) and murine recombinant FVIIa (mFVIIa), and ii) to study the roles of tissue factor (TF) in clearance of FVIIa.
Eighteen NMRI mice were given a single intravenous 1 mg/kg dose of FVIIa or derivative containing trace amounts of iodinated FVIIa or derivative. Eye blood was sampled from anaesthetized mice in the interval of 0–8 h post administration. A sparse sampling schedule was employed in that three blood samples were taken pr. time point and three samples were drawn pr. mouse. The FVIIa plasma concentration was determined from the radioactivity measured by a γ-counter. The PK parameters were calculated by a 2-compartmental method using the WinNonlin software (Pharsight Corporation, USA), and the data was analyzed in one-way ANOVA test.
The pharmacokinetic profile for both proteins was best determined by a 2-compartment analysis. The PK parameters obtained for the two proteins were statistically indistinguishable and showed a rapid distribution phase followed by a slower terminal half-life. The following values were obtained for hFVIIa and mFVIIa: T½ (distribution) was 0.38 h for hFVIIa and 0.71 h for mFVIIa, while a T½ (elimination) of 4.85 h was found for hFVIIa and 5.53 h for mFVIIa. Total clearance values of 34.7 ml/kg/h and 32.8 ml/kg/h were obtained for hFVIIa for mFVIIa, respectively. The volumes of distribution for the two proteins were also statistically indistinguishable, being 220.1 ml/kg for hFVIIa and 203.9 ml/kg for mFVIIa. No significant difference was thus observed between hFVIIa and mFVIIa in terms of the PK parameters including the terminal half-lives. These data might indicate that human FVIIa and murine FVIIa are cleared by the same mechanism(s) in mice, suggesting that the mouse is a valid model for PK studies of human FVIIa and derivatives thereof.
The similar PK profiles for hFVIIa and mFVIIa observed further indicated a TF-independent clearance mechanism of FVIIa. Relative to mFVIIa the affinity of hFVIIa for mTF is known to be markedly decreased (Petersen LC et. al. Thromb Res.2005;116:75–85). Involvement of TF binding in clearance was therefore expected to result in different PK profiles for the two proteins; hence in a mouse model one would expect hFVIIa to be cleared at a much slower rate than mFVIIa. Since this was not the case, this study suggests a TF-independent mechanism of FVIIa clearance in mice.
Our studies suggest that the mice can be used as a model to evaluate the PK profile of human FVIIa, and that TF is not involved in the clearance mechanisms of FVIIa.
Allosteric Disulfide Bonds in Thrombosis and Thrombolysis.
Authors: Hogg Philip J. 
Published: October 2019

Abstract
Allosteric disulfide bonds control protein function by mediating conformational change when they undergo reduction or oxidation. The known allosteric disulfides are characterized by a particular bond geometry, the -RHStaple. A number of thrombosis and thrombolysis proteins contain one or more disulfide bonds of this type. Tissue factor (TF) is the first haemostasis protein shown to be controlled by an allosteric disulfide, the Cys186-Cys209 bond in the membrane-proximal fibronectin type III domain. TF exists in three forms on the cell surface; a cryptic form that is inert, a coagulant form that binds factor VIIa to initiate coagulation, or a signaling form that binds VIIa and cleaves protease activated receptor 2 that functions in inflammation, tumor progression and angiogenesis. Reduction and oxidation of the Cys186-Cys209 bond is central to the transition between the three activities of TF. The redox state of the bond appears to be controlled by protein disulphide isomerase and NO. Plasmin(ogen), vitronectin, glycoprotein 1balpha, integrin beta3 and thrombomodulin also contain -RHStaple disulfides and there is circumstantial evidence that the function of these proteins may involve redox change of these disulfide bonds.