bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subcutaneous Dosing of CRA-027483, a Small Molecule FVIIa Inhibitor, Prevents Arterial Thrombosis in a Baboon Model.
Authors: Marzec Ulla M. , Sukbuntherng Juthamas , Dalrymple Stacie A. , Young Wendy B. , Vijaykumar Dange , Young Peter R. , Hanson Stephen R. 
Published: October 2019

Abstract
Vessel injury may expose tissue factor leading to the activation of FVII, initiation of coagulation, and thrombosis. A small reversible inhibitor of FVIIa (CRA-027483), dosed by subcutaneous (SC) injection, was investigated in an arterio-venous shunt thrombosis model in non-anticoagulated awake baboons. Drug pharmacokinetics (PK) and pharmacodynamics (PD) were studied in non-shunted baboons; PK and PD results were closely correlated with ~ 100% bioavailability following SC drug administration. Thrombosis was initiated by interposing within the shunt a segment of porous expanded (poly)tetrafluoroethylene vascular graft (ePTFE, 4mm ID), filled with relipidated tissue factor. Upon initiation of blood flow at 100mL/min (wall shear rate =256/sec) thrombus growth was monitored by gamma camera imaging of autologous Indium-111 labeled platelets for 1 hour. Fibrin accumulation was quantified using trace amounts of homologous fibrinogen labeled with I-125. Both bleeding time and prothrombin time (PT), the PD marker, were monitored throughout. Animals were dosed SC 90min prior to the initiation of thrombus formation, a regimen that was predicted from PK/PD to result in a fixed concentration of CRA-027483 during the thrombosis phase. Dosing of baboons with CRA 027483 at 1mg/kg, 2mg/kg and 4mg/kg SC (4–5 animals in each study group) inhibited total platelet deposition on the tissue factor surface by 13±4%, 43±30% and 67±26% respectively, vs. control results. Fibrin accumulation was reduced by 22±9%, 50±34%, and 76±19% respectively for these doses. PT values remained stable throughout the thrombosis phase and increased 1.3-, 1.6- and 2.1-fold over baseline with the escalating doses. Bleeding time measurements were slightly prolonged at the higher doses (7.3±1.6min and 7.1±2.5min for the 2mg/kg and 4mg/kg doses, respectively) as compared to the pre-drug measurement of 3.8±0.7min. We conclude that SC administration of CRA-027483, a reversible small molecule inhibitor of FVIIa, effectively reduces tissue factor-initiated thrombus formation in baboons with minimal hemostatic impairment.
The Oral, Direct Factor Xa Inhibitor BAY 59-7939 Does Not Cross-React with Anti-Heparin/PF4 (Heparin-Induced Thrombocytopenia) Antibodies.
Authors: Walenga Jeanine M. , Hoppensteadt Debra , Iqbal Omer , Neville Brian , Jeske Walter P. , Prechel Margaret , Messmore Harry L. , Misselwitz Frank , Bakhos Mamdouh 
Published: October 2019

Abstract
BAY 59-7939 is an orally bioavailable, small-molecule, direct Factor Xa (FXa) inhibitor in advanced clinical trials for the prevention and treatment of thromboembolic disorders. Unfractionated heparin and the low molecular weight heparins (LMWHs) are the current standards of care for patients requiring anticoagulation. However, their use can be restricted by heparin-induced thrombocytopenia (HIT), which may be associated with severe thrombotic complications. It has been reported previously that fondaparinux, a heparin-derived pentasaccharide that indirectly inhibits FXa, does not cross-react with anti-heparin/PF4 (HIT) antibodies. However, we have shown that increased sulfation of fondaparinux does result in strong cross-reactivity with HIT antibodies, leading to platelet activation/aggregation. Previous studies have shown that direct thrombin inhibitors (DTIs), such as argatroban and lepirudin, do not cross-react with HIT antibodies. Current guidelines for patients who have HIT recommend use of a DTI to prevent or treat associated thrombosis. This study was performed to evaluate whether BAY 59-7939 cross-reacts with HIT antibodies, in order to examine its potential as an alternative anticoagulant for the management of patients with HIT. The effect of BAY 59-7939 on platelet activation mediated by HIT antibodies was examined in sera collected from 63 patients diagnosed with HIT (HIT sera), using platelet aggregation assays, the [14C]serotonin release assay, and flow cytometry for the detection of platelet P-selectin expression and platelet microparticle formation. Heparin, the LMWH enoxaparin, fondaparinux, and the DTI melagatran were included for comparison. BAY 59-7939 did not activate platelets or cause aggregation with any of the HIT sera tested, establishing that there is no interaction between BAY 59-7939 and HIT antibodies. As expected, heparin strongly activated platelets and caused their aggregation, and gave a positive response with 100% of the HIT sera tested. Enoxaparin showed positive responses with 73% of the sera. Of all the HIT sera tested, one exhibited a weak positive response with fondaparinux. As has been observed with other DTIs, melagatran did not cause any platelet activation or aggregation responses with the HIT sera. This study clearly demonstrates that BAY 59-7939, a novel, orally active, direct FXa inhibitor, does not interact with preformed HIT antibodies. Therefore, BAY 59-7939 has potential as a new option for the prevention and treatment of thrombosis in patients with HIT.
TTP889, a Novel Orally Active Partial Inhibitor of FIXa Inhibits Clotting in Two A/V Shunt Models without Prolonging Bleeding Times.
Authors: Rothlein Robert , Shen Jane M. , Naser Najih , Gohimukkula Devi R. , Caligan Thomas B. , Andrews Robert C. , Schmidt Ann Marie , Rose Eric A. , Mjalli Adnan M. M. 
Published: October 2019

Abstract
Based on previous studies showing the efficacy of FactorIXa (FIXa) blockade using an active site-blocked form of this coagulation enzyme, we speculated that partial inhibition of the intrinsic coagulation pathway would offer a novel approach to attenuate intravascular clot formation without promoting untoward bleeding. Here we describe the anticoagulant activity of TTP889, a small molecule partial inhibitor of FIXa activity. TTP889 is orally absorbed with a PK profile that is conducive to once daily dosing. It is selective for FIXa in that it shows little to no activity against several other proteases in the clotting cascade including FXa, FXIa, FXIIa or FVIIa in a unique clotting assay. In vivo, TTP889 inhibited fibrin deposition in a rat arteriovenous (A/V) shunt model. In this model, vehicle treated rats had 104mg ± 43 of fibrin deposited on a silk thread after a 15 minute shunt while TTP889 treated rats had significantly less fibrin deposited (39mg ± 18 p=<0.001). Furthermore, TTP889 inhibited clotting in a porcine A/V shunt model where pressure across a hemodialysis filter that was shunting the carotid artery to the jugular vein was used as an indirect marker of clot formation. In this model, TTP889 at 0.3mg/kg performed as well as 150U/kg of heparin over the 90-minute shunt. Of additional importance, TTP889 has no effect on bleeding times as measured by APTT or ACT assays ex-vivo or by bleeding time and volume from incisions in the skin or spleen in vivo. Together, these data support that TTP889 is a selective partial inhibitor of FIXa activity that offers a novel approach to attenuate clot formation associated with intravascular clotting without promoting untoward bleeding. TTP 889 is currently in Phase II and is being evaluated for the prevention of DVT in hip fracture patients with treatment starting one week post surgery and continued for 3 weeks.
Host Inflammation Increases Alloimmunization to Transfused Red Blood Cells.
Authors: Hendrickson Jeanne E. , Chadwick Traci E. , Roback John D. , Hillyer Christopher D. , Zimring James C. 
Published: October 2019

Abstract
Background: Alloimmunization to RBC is a serious sequelae of transfusion, which can result in hemolytic transfusion reactions and difficulty identifying compatible units for future transfusion. Although any given unit of RBC contains numerous alloantigens, only 6% of transfusion recipients mount a measurable alloantibody response. The factors that determine whether a given transfusion recipient will generate antibodies remains undetermined. Activation of the innate immune system through inflammation is known to have a significant effect on immune responses in other settings. Accordingly, we hypothesized that recipient inflammation would modulate humoral responses to transfused RBC.
Methods: Hen egg lysozyme (HEL) is a well studied antigen. In order to convert HEL into a model blood group antigen, we utilized transgenic mHEL mice, which express HEL on the surface of RBC as a transmembrane protein. Leukoreduced mHEL RBC were transfused into B10. BR recipient mice (H-2k MHC haplotype). To induce host inflammation, recipient mice received an intraperitoneal injection of poly(I:C), which is a double-stranded RNA that mimics inflammation commonly seen with viral infection. The inflammatory effects of poly (I:C) were confirmed by observing activation of macrophages using flow cytometry. Plasma was obtained from recipient mice 7 and 14 days post-transfusion, and anti-HEL antibody titers and isotypes were determined by HEL specific ELISA.
Results: Inflammation of mice with poly (I:C) resulted in a significant increase in the magnitude of anti-HEL IgG synthesis. Whereas mice receiving mHEL RBC alone had only a weak anti-HEL IgG response, treatment with poly (I:C) prior to transfusion resulted in a 15 fold increase in anti-HEL IgG (p value =.0003). In addition, whereas IgG1 and IgG3 were the predominant anti-HEL IgG subtypes in mice receiving mHEL RBC alone, IgG3 and IgG2b predominated in mice treated with poly (I:C) prior to mHEL transfusion. Thus, treatment of transfusion recipients with an agent that mimics inflammation commonly seen in viral infections significantly increased humoral immunity and altered IgG subtype composition.
Discussion: The findings reported here demonstrate that host inflammation with a viral-like agent increases alloimmunization to transfused RBC and suggests that co-existing infections in humans may increase humoral immunization to transfused RBC. In addition, since different IgG subtypes have different hemolytic potentials, the observed deviation may influence the clinical significance of alloantibody formation. These findings provide the rational basis for possible intervention using immunomodulatory agents to prevent alloimmunization or to divert the response to a non-hemolytic IgG subtype.
Mantle Cell Lymphoma: Prognostic Capacity of the Follicular Lymphoma International Prognostic Index.
Authors: Moller Michael B. , Pedersen Niels T. , Christensen Bjarne E. 
Published: October 2019

Abstract
Background: The International Prognostic Index (IPI) is the most commonly used prognostic model in mantle cell lymphoma. However, the prognostic value of IPI is limited. The recently published Follicular Lymphoma International Prognostic Index (FLIPI) is built on variables (age, stage, lactic dehydrogenase, anemia, and nodal disease) which also are pertinent to mantle cell lymphoma. This study was conducted to evaluate the prognostic value of FLIPI in patients with mantle cell lymphoma.
Patients and Methods: A population-based series of 93 patients with mantle cell lymphoma diagnosed in a 7-year period were studied. End points of the study were response to therapy, overall survival, and failure-free survival according to IPI and FLIPI.
Results: Applied to the whole series, FLIPI identified 3 risk groups with markedly different outcome with 5-year overall survival rates of 65%, 42%, and 8%, respectively (P < .0001; log-rank 28.13; figure below). Notably, the high-risk group comprised 53% of patients. In contrast, IPI only allocated 16% of cases to the high-risk group and had a lower overall predictive capacity (log-rank 24.8). When both FLIPI and IPI were included in a multivariate analysis, only FLIPI was related to survival. In patients treated with CHOP-based regimens (n = 45) FLIPI also had superior predictive capacity compared to IPI (log-rank, 18.51 versus 11.37), and again only FLIPI retained significance in multivariate analysis. Multivariate analysis of failure-free survival also identified FLIPI, and not IPI, as independently significant.
Conclusion: FLIPI is the superior prognostic model as compared to IPI and should be the preferred clinical prognostic index in mantle cell lymphoma.
Overall survival according to FLIPI risk groups Overall survival according to FLIPI risk groups
FDG-PET May Be Helpful in the Determination of Transformation to an Aggressive Subtype in Low-Grade Lymphoma.
Authors: Kostakoglu Lale , Goldsmith Stanley J. , Chadburn Amy , Vidan Erez , Schuster Michael , Christos Paul , Coleman Morton 
Published: October 2019

Abstract
The therapeutic management of the patient with transformed low-grade lymphoma is quite different from those with pure indolent disease. In cases of transformation FDG uptake characteristics may help identify an area of transformation in indolent disease and thereby impact management. Our objective was to evaluate the potential of FDG-PET imaging in the determination of transformation
Methods: A total of 60 patients with low-grade lymphoma (48 patients) and those with known transformation to DLCL (12 patients) underwent FDG-PET imaging prior to therapy. In the indolent group, 27 patients were diagnosed with a follicular histology and 11 with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and 10 were with marginal zone lymphoma. A total of 370 lesions were evaluated and SUV’s were obtained for all visualized lesions. Mean values were calculated on a patient and total site basis. Additionally, mean SUV values were calculated for lesions with the highest SUV’s, in groups with indolent and transformation histology.
Results: Results are summarized in the Table. There was a significant difference in the mean SUV’s between the group with transformation and that with indolent lymphoma (7.6 ± 4.6 vs. 4.5 ±2.5). More importantly, the mean values for SUV in the lesions with the highest FDG uptake were significantly different between the two groups (13.8 ±5.3 vs 5.8±2.9). Among the patients who had a biopsy taken from the lesions with the highest SUV’s the range was 8 to 27 and the mean value was 14.9±8.0.
Conclusions: In patients with indolent lymphoma, areas of significant increase in FDG (particularly SUV’s >12) should be considered targets for biopsy.
Differences in SUV’s Between Transformed and Indolent Lesions Patient Number Mean SUV Mean SUV in Hottest Lesions SUV Range in Hottest Lesions SUV: standardized uptake values Patients with Transformation 12 7.6+/−4.6 13.8+/−5.3 8–27 Patients with Indolent Lymphoma 48 4.5+/−2.5 5.8+/−2.9 2–12
Insertional Mutagenesis Identifies Genes That Promote the Immortalization/Self-Renewal of Primary Bone Marrow Progenitor Cells.
Authors: Du Yang , Jenkins Nancy A. , Copeland Neal G. 
Published: October 2019

Abstract
Retroviruses can induce hematopoietic disease via insertional mutagenesis of cancer genes and provide valuable molecular tags for cancer gene discovery. Here we show that insertional mutagenesis can also identify genes that promote the immortalization of primary mouse bone marrow progenitor cells, which normally have only limited self-renewal. Transduction of bone marrow cells with replication-incompetent murine stem cell virus (MSCV) expressing only a neo marker gene, followed by serial passage in liquid culture containing SCF and IL-3, produced immortalized immature myeloid cell lines with neutrophil and macrophage differentiation potential in about 50% of the infected cultures. More than half of the lines have MSCV insertions at Evi1 or Prdm16. These loci encode transcription factor homologues and are validated human myeloid leukemia genes.
Integrations are located in intron 1 or 2 where they promote expression of truncated proteins lacking the PR domain, similar to what is observed in human leukemias with EVI1 or PRDM16 mutations. Evi1 overexpression alone appears sufficient to immortalize immature myeloid cells and does not seem to require any other cooperating mutations. Similarly, immortalized cells that are blocked at a very early hematopoietic progenitor stage can be produced by serially passaging the infected cells in SCF and FLT3L. In this case, viral integration deregulates the expression of Setbp1, a gene that is thought to regulate the activity of SET, which is mutated in acute human undifferentiated leukemia.
Interestingly, recurrent retroviral vector integrations at the Evi1 locus have also been recently identified in blood cells of rhesus monkeys transplanted up to 7 years earlier with retrovirally infected CD34+ bone marrow cells (Calmels et al, Blood. in press), and similar results have also been reported for mice (Kustikova et al, Science 2005 308:1171-4). Our results suggest that these cells were selected in transplant recipients due to their increased self-renewal or engraftment potential, which resulted from insertional mutations at Evi1. These studies highlight a new potential problem for human gene therapy, the selection of immortalized cells in transplant recipients that carry activating mutations in human leukemia oncogenes and a possible concomitant increased propensity for developing hematopoietic cancer as the patients age. Based on these studies, it will be important to assay the safety of other retroviral vectors, such as SIN vectors, that may be less apt to activate the expression of an oncogene following viral integration. The immortalization assay we describe here provides a means for assessing this safety.
Analysis of YY1 and XIAP Expression, Proteins That Regulate Resistance, in AIDS-NHL Tissue Arrays.
Authors: Huerta-Yepez Sara , Vega Mario , Gui Dorina , Said Jonathan , Bonavida Benjamin 
Published: October 2019

Abstract
HIV infection is associated with an increased risk of Non-Hodgkin’s B cell lymphoma (AIDS-NHL). AIDS-NHL may arise, in part, because the patients may be immunocompromised and tumor escape takes place. The standard treatment for NHL is chemotherapy, however, many patients become refractory to such treatments. Alternative treatment modalities include immunotherapy, though, even in the presence of an effective anti-tumor response, the tumor may develop mechanisms of resistance to immune-mediated cytotoxicity (e.g., Fas-ligand, TRAIL) and resistance to apoptosis. We have shown that overexpression of the transcription factor Yin-Yang 1 (YY1) is involved in the regulation of tumor cell resistance to FasL-induced apoptosis. The direct role of YY1 was demonstrated in cells transfected with siRNA YY1 which were sensitized to Fas-induced apoptosis (Vega, et al., 2005, Journal of Immunology (In Press)). In addition, we have also shown that overexpression of YY1 and X-linked inhibitor of apoptosis (XIAP) regulate the resistance of tumor cells to TRAIL-induced apoptosis (Ng and Bonavida, 2002, Molecular Cancer Therapeutics1:1051–1058, Huerta-Yepez, et al., 2004, Oncogene23:4993–5003). Hence, we hypothesized that one mechanism of AIDS-NHL immune escape may be due to overexpression of YY1 and XIAP. Tissue arrays containing formalin fixed, paraffin embedded sections from AIDS lymphoma were obtained from the AIDS and Cancer Specimen Resource (ACSR) of the National Cancer Institute (NCI). These arrays consisted of 21 Burkitt, 29 Large Cell Lymphoma, and 6 Small Cell Lymphoma. Immunohistochemistry was performed for the expression of YY1, and XIAP. The arrays were scored and both the percent of positive cells and the intensity were recorded and the data were analyzed statistically. The findings reveal that YY1 and XIAP were overexpressed in the majority of the AIDS-NHL patient specimens. In addition, there was a significant correlation between YY1 and XIAP expression in all 3 types of lymphoma. These studies and studies based on in vitro findings with AIDS-NHL cell lines suggest that overexpression of YY1 and XIAP may be involved in the pathogenesis of AIDS-NHL and are potential markers for tumor unresponsiveness to immune-mediated cytotoxic therapies. Furthermore, inhibitors of YY1 and XIAP expression/activity may be targets for therapeutic intervention when combined with immunotherapy.
Characterization of Platelet TFPI.
Authors: Maroney Susan A. , Friese Paul , Alliman Sarah , Dale George L. , Mast Alan 
Published: October 2019

Abstract
The accumulation of blood borne tissue factor within a blood clot is thought to be important for normal fibrin generation and may cause propagation of the blood clot into an occlusive thrombus. Tissue factor pathway inhibitor (TFPI), the primary inhibitor of tissue factor activity, is present in platelets where it may have an important role in down regulating the activity of circulating tissue factor. Western blot analysis of gel filtered platelet lysates demonstrates the presence of full-length, 43 kDa TFPI. The lower molecular weight, C-terminally truncated forms of TFPI present in plasma are not present in platelet lysates suggesting that full length TFPI is selectively adsorbed from plasma or that TFPI is synthesized within megakaryocytes. Real time PCR analysis of cDNA produced from highly purified platelet mRNA demonstrates transcripts for both TFPI and TFPI-beta, a truncated form of TFPI produced by alternative splicing. TFPI mRNA is about 3000-fold more abundant than TFPI-beta mRNA. TFPI is not released from platelets following stimulation with the thrombin receptor activating peptide SFLLRN (TRAP) indicating that it is not stored as a soluble alpha-granule protein. Instead, it appears to be associated with platelet membranes. It remains largely insoluble following lysis of platelets by repeated freeze thaw or exposure to hypotonic buffer. There is little to no expression of TFPI on the surface of quiescent platelets as assessed by flow cytometry. TRAP stimulated platelets have surface TFPI that is detected by flow cytometry, but the amount varies between experiments. TFPI is consistently detectable by flow cytometry on the surface of coated-platelets that are produced by stimulation with thrombin/convulxin or thrombin/calcium ionophore. Platelet TFPI activity was measured in eight individuals by determining the rate of factor X activation by factor VIIa/tissue factor. Comparison of quiescent and coated-platelets demonstrates a significant increase in the amount of TFPI activity on the surface the coated-platelets (11.0+/−0.3 vs. 38.7+/−17.2 pmole/10 million platelets; p<0.005), but no significant increase in platelets activated with 20 or 200 micromolar TRAP. Since TFPI associates with the endothelial surface through a GPI-anchor, coated-platelets were treated with phospahtidyl inositol specific phospholipase C (PIPLC) to determine if it would remove TFPI. In experiments where PIPLC removed 56% of the CD59 from the platelet surface, only 22% of the TFPI was removed indicating that if platelet TFPI is GPI-anchored, it is expressed in a manner that is relatively protected from PIPLC. Confocal and electron microscopy studies demonstrate that TFPI is distributed throughout the cytoplasm of quiescent platelets without localization to granules suggesting that it may associate with the platelet cytoskeleton.