bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Platelet Adhesion by Rigidity Sensing at the Surface of Fibrin Clot.
Authors: Podolnikova Nataly P. , Bowen Benjamin , Lishko Valeryi K. , Podolnikov Andriy V. , Ugarova Tatiana 
Published: April 2020

Abstract
Thrombus formation at sites of vascular injury must occur quickly to reduce blood loss, but is carefully controlled to limit vessel occlusion. Arrest of bleeding is mediated by adhesion and aggregation of platelets and the formation of the fibrin clot. While the interactions responsible for platelet adhesion and thrombus growth have been extensively researched, the mechanisms that limit platelet adhesion are not clear. We have previously demonstrated that plasma fibrinogen is a potent inhibitor of integrin-mediated leukocyte adhesion to fibrin clots and surface-bound fibrinogen, and have provided evidence that fibrinogen reduces cell adhesion by binding to the surface of fibrin rather than blocking leukocyte integrins. Accordingly, cells that engage fibrinogen molecules loosely bound to fibrin (soft substrate) are not able to consolidate their grip on the surface; subsequently, cells detach. Conversely, cells that adhere to the naked fibrin clot (rigid substrate) adhere firmly. Since fibrin and immobilized fibrinogen support platelet adhesion, we examined the effect of soluble fibrinogen on integrin αIIbβ3-mediated adhesion. We show that the anti-adhesive fibrinogen layer formed on the surface of fibrin inhibits platelet adhesion. We also demonstrate that fibrinogen immobilized on plastic at high densities (&gt;20 μg/ml) supports weak platelet adhesion whereas at low concentrations (∼2 μg/ml) it is highly adhesive. An investigation of the mechanism underlying differential platelet adhesion indicates that platelet adhesion to rigid substrates (low-density fibrinogen and naked fibrin gel) induces much stronger phosphorylation of FAK and Syk kinases than that to soft substrates (high-density fibrinogen and fibrin exposed to soluble fibrinogen). Furthermore, the rigid, but not the soft substrates induce recruitment of signaling molecules talin and skelemin to αIIbβ3-containing focal adhesions. Consistent with their limited ability to induce sufficient signaling, soft substrates do not support platelet spreading. These data suggest that circulating fibrinogen prevents stable platelet adhesion by modifying the mechanical properties of the fibrin clot’s surface which results in reduced force generation and insufficient signaling.
Paracrine Suppression of VEGF Secretion by Erythropoietin Inhibits Tumor Growth.
Authors: Smith Carroll R. , Salleng Kenneth J. , Sigounas Vaia Y. , Asch Adam , Sigounas George 
Published: April 2020

Abstract
Several studies have reported that erythropoietin (Epo) is a pleiotropic cytokine with biological properties in addition to its primary function in regulating maturation, growth and survival along the erythroid lineage. Recently, a number of investigators have reported that various neoplastic tissues and human cancer cell lines express Epo and the Epo receptor (EpoR), raising suspicion for the presence of an autocrine-paracrine Epo-EpoR system. It has been shown that inhibition of vascular endothelial growth factor (VEGF) results in an increase of Epo secretion and increased hematocrit in vivo. In this study, we used an in vivo Lewis lung carcinoma model to examine a converse Epo effect on VEGF production and metastasis. Lewis lung carcinoma (LLC) cells were injected subcutaneously into C57BL mice. The plasma levels of VEGF, the tumor vessel formation, the size of the primary tumors and the extent of lung metastatic disease were determined. In addition, intravenously injected LLC cells seeded in the lungs were assessed. Tumor-bearing animals treated with Epo had 23.6% less VEGF in the plasma compared to saline treated mice (p&lt;0.04). There was no correlation between VEGF concentration and hemoglobin levels in either group of animals. Tumor sections indicated that the number of blood vessels was higher (10.7% for inner and 23.8% for outer, respectively) in tumors obtained from animals treated with saline compared to Epo-treated mice (p&gt;0.05). Using non-parametric analysis, we found that there was a statistically significant difference in tumor growth between saline-treated and Epo-treated animals (p&lt;0.05). However, the number of lung metastases derived from primary tumors was similar in both groups. In assessing size of the metastatic tumors, we found that the average volume of lung nodules was 24.2% higher in saline-injected animals compared to Epo-treated mice. The number of tumors seeded in the lungs following intravenous injection of LLC cells was similar in animals treated with a high dosage of Epo, low dosage of Epo or saline. In addition, the average volume of the nodules was reduced by 42% in animals treated with high and low concentrations of Epo compared to the control group (p = 0.03). In conclusion, Epo exerts a paracrine suppressive effect on VEGF secretion resulting in slower tumor growth in this model.
Less Chronic ITP after IVIG for Acute Childhood ITP? A Matched Pairs Analysis from Registry I of the Intercontinental ITP Study Group (ICIS).
Authors: Tamminga Rienk Y.J. , Berchtold Willi , Bruin Marrie C.A. , Buchanan George R. , Kuehne Thomas 
Published: April 2020

Abstract
Introduction: Childhood immune thrombocytopenic purpura (ITP) is a bleeding disorder caused by destruction of platelets with a very small risk of a life threatening bleeding. ICIS Registry I was initiated in 1997 to obtain worldwide prospective data on the natural history of ITP in children. The first analyses of ICIS data showed that 25–47% of the children developed chronic ITP (defined as a platelet count &lt; 150 × 109/l 6 months after diagnosis) depending on age. Previous studies in small numbers of patients suggested that intravenous immunoglobulin (IVIG) treatment at diagnosis might reduce the risk of chronic ITP. Therefore, the ICIS Registry I (with data on &gt;2000 patients) was used to examine prognostic factors related to chronic ITP.
Results: Of the 2605 children with newly diagnosed ITP, between 3 months and 16 years of age, in 1984 the platelet count 6 months after diagnosis was known; 630 (32%) had a platelet count &lt;150 × 109/l. Patient and clinical characteristics associated with a significantly (univariate analysis, p&lt;0.001) higher risk of chronic ITP were: age (&lt;2 yrs: 22%; 2–10: 30%; &gt;10: 49%), platelet count at diagnosis (&lt;10 × 109/l: 25%; 10–20: 37%; 20–50: 40%; &gt;50: 50%) and previous infection (yes: 27%; no 38%). Gender was not of prognostic significance. Investigating the effect of treatment, we performed a matched pairs analysis: two groups were composed, one with platelets ≥150 × 109/l (’controls’) and one with platelets &lt;150 × 109/l (’cases’) at six months from diagnosis, but matched with regard to gender, age, previous infection, platelet count at diagnosis and country of origin. We identified 449 matched pairs. The group with chronic ITP had been more often treated at diagnosis with steroids and less often with IVIG than the controls; the difference between IVIG and steroid treatment was highly significant (p=0.003); patients who were treated with both IVIG and steroids behaved like those with steroids alone; patients without any initial drug treatment behaved in between. Odds ratio (OR) for not having chronic ITP was for IVIG: 1.8 (95% confidence interval: 1.25–2.64) and for steroids 0.60 (0.42–0.87).
Conclusion: Data from the worldwide ICIS Registry I also suggest that IVIG treatment of acute childhood ITP might reduce the risk for chronic ITP while steroids might increase that risk. However, caution is warranted because this study was not a randomized controlled trial, and a considerable number of patients could not be included in the final analyses. A prospective randomised study is needed to confirm these results.
Influences of High-Dose Dexamethasone on Regulatory T Cells, Transforming Growth Factor-β1 and Interleukin-10 of Patients with Chronic ITP.
Authors: Ling Yun , Cao Xiangshan , Yu Ziqiang , Ruan Changgeng 
Published: April 2020

Abstract
Immune thrombocytopenic purpura (ITP) is an autoimmune disorder and high-dose dexamethasone (HD-DXM) has been used as a first-line therapy for patients with ITP. However, little is known about the role of CD4+CD25 + regulatory T (Treg) cells, interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) in the pathogenesis of chronic ITP and the effects of HD-DXM on them contained Treg cells, IL-10 and TGF-β1. In this study, we investigated the expressions of Treg cells, IL-10 and TGF-β1 in 26 untreated adult patients with chronic ITP. All patients had thrombocytopenia (platelet count &lt;50 × 109/L) for more than 6 months. We also observed short time changes of Treg cells, IL-10 and TGF-β1 after treatment with HD-DXM in these patients. The results showed that a good initial response to HD-DXM occurred in 24 of the 26 patients with chronic ITP (92.3%): the mean platelet count was (84.9±30.4)×109/L [range, (20∼150) ×109/L] one week after the initiation of treatment. The proportion of CD4+CD25+ T cells in the peripheral blood of patients with chronic ITP was significantly higher than that in normal controls(P&lt;0.001); there was no significant difference in the percentage of CD4+CD25high T cells between patients and controls ( P=0.317); but the number of CD4+ FOXP3+ T cells in patients was significantly lower than that in controls (P&lt;0.001). After 4-days treatment with HD-DXM, the numbers of CD4+ CD25+ T cells (P&lt;0.001), CD4+CD25high T cells ( P&lt;0.001), and CD4+FOXP3+ T cells ( P&lt;0.001) in patients were all significantly increased. In the serum of chronic ITP patients, the expression level of TGF-β1 was lower than that of healthy controls (P&lt;0.0001) and HD-DXM could significantly increase it; there was no significant difference in the expression level of IL-10 between patients and controls ( P&gt;0.05) and there was no remarkable change of IL-10 in patients after HD-DXM treatment (P&gt;0.05). The mRNA levels of Foxp3 and TGF-β1 gene in patients were lower than those of controls (P&lt;0.05 and P&lt;0.05); HD-DXM administration significantly increased the expressions of Foxp3 and TGF-β1 gene(P&lt;0.05 and P&lt;0.0001), which were even higher than those of controls(P&lt;0.05 and P&lt;0.05); There was a positive correlation between the Foxp3 mRNA expression and TGF-β1 after treatment with HD-DXM (r =0.403, P=0.041). These results suggest that Foxp3 and TGF-β1 gene are deficient in chronic ITP and the immunosuppressive therapy of glucocorticoids could improve the expression levels of these genes.
Idiopathic Thrombotic Microangiopathies: Antinuclear Antibodies, Platelet Count and Creatinin Level Can Predict a Severe ADAMTS13 Deficiency.
Authors: Coppo Paul , Wynckel Alain , Clabault Karine , Schwarzinger Mickael , Monge Matthieu , Poullin Pascale , Azoulay Elie , Galicier Lionel , Mira Jean-Paul , Bordessoule Dominique , Gorin Norbert C. , Vernant Jean-Paul , Veyradier Agnès 
Published: April 2020

Abstract
Severe ADAMTS13 deficiency in thrombotic microangiopathies (TMA) was reported with a variable frequency, which ranges from 13% to 50%. Whether clinical presentation allows to predict accurately severe ADAMTS13 deficiency remains a matter of controversy. To assess this question, we considered all adult (≥ 18 year-old) patients with idiopathic TMA and ADAMTS13 deficiency (&lt; 15% of normal activity) of our Registry, whose clinical characteristics were compared with those of patients with idiopathic TMA and a detectable (≥ 15% normal activity) ADAMTS13 activity. Inclusion criteria were the association of a microangiopathic hemolytic anemia (&lt; 12 g/dL) with a thrombocytopenia (&lt; 150 × 109/L), and no other identifiable cause for cytopenias (transplantation, cancer and chemotherapy, or HIV infection). Patients were included prospectively from October, 2000, to January, 2007, from 17 National centers. One hundred and thirty-five patients were consecutively included. One hundred and two had a severe ADAMTS13 deficiency (58/96 had a plasma inhibitor), and 33 had a detectable ADAMTS13 activity (mean ADAMTS13 activity: 52.7± 29%). Patients with a severe ADAMTS13 deficiency were younger, displayed a lower platelet count and creatinin level, and presented more frequently antinuclear antibodies (ANA) at diagnosis (39.9± 15 versus 49.6± 17.9 year-old, 20± 19.2 versus 56.6± 42.9 × 109/L, 127± 106 versus 425± 335 μmol/L, and 61.8% versus 24.4%, respectively, p&lt;0.001 in all cases). Chronic renal failure occurred more frequently among patients with a detectable ADAMTS13 activity (19.2% versus 1.1%, p&lt;0.001). In a multivariate logistic analysis, patients with severe ADAMTS13 deficiency were more likely to have ANA (Estimated Odds ratio [OR] 4.81, 95% confidence interval [CI] 1.5–15.4), a lower platelet count (OR 0.98, 95% CI 0.96–1), and a lower creatinin level (OR 0.99, 95% CI 0.98–0.99) than patients with detectable ADAMTS13 activity (p&lt; 0.01, 0.14, and &lt; 0.01, respectively). Positive ANA with a platelet count &lt;31 × 109/L and a creatinin level &lt;194 μmol/L represented a set of criteria that allowed to identify patients with a severe ADAMTS13 deficiency with 52% sensitivity, but with a high specificity, at 97%. These criteria had a high positive predictive value for a severe ADAMTS13 deficiency, at 98.2%, and a negative predictive value of 39.5%. ANA, platelet count and creatinin level can predict accurately a severe acquired ADAMTS13 deficiency in idiopathic TMA. This set of criteria may be helpful in the management of patients that require targeted therapies, in association with plasma exchanges.
Primary Fibrinolysis as the Presenting Sign of Metastatic Prostate Cancer: One Case Report and Literature Review.
Authors: Zhou Rongfu , Ouyang Jian , Chen Bing , Zhou Ming , Xu Yong , Ruan Changgeng 
Published: April 2020

Abstract
Primary fibrinolysis revealing a prostatic adenocarcinoma is rare. Most of the case are limited to biological abnormalities. Here, we describe an unusual case of hematuria and primary fibriolysis as the presenting manifestation of metastatic prostate cancer in a 52-year-old man. The patient consulted for hematuria, ecchymosis and bleeding gums for a month. B-type ultrasound examination showed normal image of prostate. Peripheral blood test showed that the counts of white blood cell, red blood cell and platelet were all in normal range. APTT, prothrombin time and thrombin time were normal. But fibrinogen levels continued to lower than 1.1g/l despite infusions of cryoprecipitate and fresh frozen plasma. Further tests suggested that D-dimer was 9.58 mg/l (normal range: &lt;0.5mg/L), FDP 45 μg/ml, t-PA 90.30 ng/ml (1.00∼12.00 ng/ml), PAI-1 38.3 ng/ml (5.00∼45 ng/ml), α2-PI 118.00% (96.8∼118.8%), PLG 43.30% (57.8∼113.4%), prostate-specific antigen (PSA) 640.2 ng/ml (0∼4 ng/ml), Free PSA 64.2 ng/ml (0∼0.93 ng/ml). PET-CT revealed enhanced metabolizing rate of prostate with enlargement of lymph node in abdomen and multiple bone lesions including rib, vertebration and pelvis. Treatment with a luteinizing hormone-releasing hormone (LHRH) agonist (Diphereline) and a short course of an antiandrogen, led to normalization of all coagulation parameters within 2 weeks, and to clinical improvement and decline in the serum levels of PSA and fPSA. Three months later, the serum levels of PSA and fPSA were normal. We discuss the pathogenesis, differential diagnosis, and association of primary fibrinolysis with prostate cancer along with the management of this condition.
Successful Orthotopic Liver Transplantation in Severe Hemophilia A with High Responding Inhibitor.
Authors: Chen Robert , Paul Seligman , Call Justin , Riske Brenda , Kirschman Ruth Ann , Geraghty Sue , Sally Stabler 
Published: April 2020

Abstract
Orthotopic liver transplantation (OLT) is an effective treatment for both hepatitis C associated cirrhosis, hepatocellular carcinoma, and hemophilia A. Factor VIII activity usually increases into the normal range. Only a few patients with hemophilia complicated by an inhibitor have undergone OLT with both successful outcomes and uncontrolled bleeding being reported. We report early results of OLT in a middle-aged white male severe hemophilia A patient with a history of a high responding inhibitor (historical high - 70 Bethesda units) who had been on immune tolerance for greater than 10 years prior to transplant. A regimen of 40 u/kg of Factor VIII three times per week successfully suppressed inhibitor titers to less than 2 Bethesda units in the previous years. Hand surgery was managed with Factor VII infusions in the year prior to OLT with good results. At the time of transplantation, his inhibitor titer was 0.7 B.U. Due to his history of non-linear kinetics with factor VIII infusion, (5% of a dose remaining at 24 hours), frequent bolus dosing during surgery was employed. He received 10,500 units (116 units/kg) prior to the incision with smaller doses repeated every 2–4 hours. During the operation and the 24 hr immediately post op he required another 27,300 units (300 units/kg) of factor VIII infusion to maintain activity between 61–122%. On post op day 1 he required 46 units/kg to keep activity between 60.2–108%. On post op day 2 he required 35 units/kg to keep activity between 36.8–68.4%. His immunosuppresion included tacrolimus, mycophenolate, and solumedrol taper of 120 mg on day 2, 80 mg on day 3, 40 mg on day 4, and 20 mg day 5. From day 6 to day 8, his total bilirubin increased to 15 and his requirement for Factor VIII also increased to 70 units/kg daily for 3 days to keep his activity between 33.1% to 71.2%. His immunosuppression was increased because of possible acute rejection and solumedrol 500 mg IV was given daily for 3 days. On day 9 his requirement for factor decreased to 11.6 units/kg daily for 4 additional days. Solumedrol was tapered off to prednisone 10 mg po daily. On day 13 post operation, Factor VIII replacement was stopped and his activity was 56.8%, which gradually rose to 81% on day 25. We conclude:
Orthotopic liver transplantation was successful in a hemophilia A inhibitor patient on long term immune tolerance. Factor VIII production by the transplanted liver suppressed the inhibitor and normalized Factor VIII activity up to 4 weeks post transplant. Close follow-up will be required.
Temporal Variation in Intensity of Laboratory Response to DDAVP.
Authors: Tran Minh H. , Hassett Andrea L. Cortese 
Published: April 2020

Abstract
Introduction 1-Desamino-8-D-Arginine Vasopressin (DDAVP) is the mainstay of treatment for mild Type I von Willebrand Disease (vWD). The use of a DDAVP challenge is standard practice in the management of newly diagnosed patients. Pre- and Post- DDAVP administration laboratory studies for vWF: RCoF, vWF: Ag and FVIII:C are expected to rise 2–5 fold from baseline. PTT and Closure Time values would be expected to correct. In a subset of our patients, pre- and post- Platelet Function studies were also tested. We sought to retrospectively study responses in our vWD patient population in terms of time-related and intensity of incremental response to DDAVP.
Results Closure Time prolongation was noted in over 55% of patients with vWD. The Collagen/Epi time appears to be more sensitive for the vWD defect (Collagen/Epi was more frequently prolonged than Collagen/ADP). In vWD patients with Closure Time defects at baseline, 86% were corrected following DDAVP administration, and this correction appears stable over all time points evaluated. Post-DDAVP laboratory responses for vWF: RCoF, vWF: Ag and FVIII:C, respectively: 9.1%, 31.2%, and 16.9% incremented by &lt;50%; 24.7%, 33.8%, and 45.5% incremented by 50–99%; 36.4%, 33.8%, and 28.6% incremented by 100–199%; 18.2%, 0%, and 5.2% incremented by 200–299%; and 11.7%, 1.3% and 3.9% incremented by ≥300%. Peak responses occurred in the 60–89 minute post-DDAVP sampling period (see Figure 1). More than 92% of individuals tested achieved a post-DDAVP vWF: RCoF value of &gt;0.80 U/mL. About 30% and 47.8% of individuals had a prolonged APTT and APTT Mix prior to DDAVP; only 7.8% and 16.7%, respectively, remained prolonged afterwards. There was a trend toward improvement in platelet aggregation variables over time (see Figure 2).
Conclusions Baseline Closure Time abnormalities occurred in over half of the patients and were reliably corrected in most following DDAVP administration. Consistent with established experience, DDAVP produces reliable vWF: RCoF, vWF: Ag and FVIII:C responses in patients with mild Type 1 vWD. Platelet function studies trended toward improvement at greater than 45 minutes post-DDAVP challenge, however, very few patients were studied pre- and post- for platelet function studies and therefore statistical significance was not achieved. Although all patients undergoing DDAVP challenge are asked to avoid antiplatelet drugs, inadvertent use may explain residual Closure Time and Platelet Function test abnormalities.
Post DDAVP Delta Post DDAVP Delta Change in platelet aggregation Following DDAVP Change in platelet aggregation Following DDAVP
Plasma Procofactor Activation by Factor Xla
Authors: Whelihan Matthew F , Mann Kenneth G. 
Published: April 2020

Abstract
The procofactors FV and FVIII are activated by thrombin, FXa and plasmin. During contact pathway-initiated thrombin generation, FXIa activates FIX thus feeding into the coagulation cascade; however, the procofactors FVIII and FV must be activated to achieve a robust level of thrombin generation. We tested the hypothesis that FXIa can activate FV and FVIII. FV (1uM) was subjected to FXIa (100nM) proteolysis. During the reaction the relative activity and integrity were measured at selected time points using a one stage PT clotting assay and SDS-PAGE. Over the 60 minute time course, FV showed a transient 50% activation followed by a reduction in activity to 20%. SDS-PAGE analyses showed that proteolysis of FV by FXIa initially generated fragments with mobilities similar to those produced by α-thrombin. This activation and inactivation pattern suggested that FXIa makes the required activation cleavages at R709, R1018 and R1545 coincidently with inactivating proteolyses. FV was activated with α-thrombin and the reaction quenched by the addition of hirudin prior to FXIa proteolysis. FVa’s cofactor activity was reduced by 50% after 30 min and 80% after 60 min. Analysis of the FXIa cleavage process by SDS-PAGE under reducing conditions showed no intact heavy chain and significant proteolysis of the light chain after 30 minutes. In addition to the Mr = 105000 (HC) and Mr = 75000 (LC), six new products were identified by SDS-PAGE under reducing conditions: Mr = 54000, 50000, 48000, 30000, 22000 and 20000. NH2-terminal sequence analysis indicated a single cleavage in the light chain at R1765 yielding the products Mr = 50000, 48000: (1766à2196) and the Mr = 30000 (1546à1764), also seen with plasmin and FXa. A cleavage in the heavy chain represented by the Mr = 22000, 20000 (R511à709) fragments is also observed. Sequence analysis determined that the Mr = 54000 fragment represented the NH2-terminus of the heavy chain. Western analysis using a heavy chain antibody showed a transient band Mr = 75000 lying under the light chain that is consistent with an initial cleavage R510. A subsequent cleavage, which is coincident with a decrease in the cofactor’s activity, results in a Mr = 30000 product which is consistent with a cleavage somewhere COOH-terminal to R306(R316?). Activity analyses suggest that the initial cleavage in the heavy chain at R510 leads to a FVaXla 1 molecule with similar activity (50%) to that seen in FVa cleaved by APC in the absence of phospholipid. The FVaXla 1 was treated with APC resulting in complete inactivation of the cofactor. We have also observed an analogous FXIa cleavage pattern in FVIII; however sequencing analysis has not yet been attempted. These data suggest that factor XIa may play a role in procofactor activation and inactivation of FV and FVIII in the context of contact pathway-initiated blood coagulation.
Figure Figure