bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioimaging of Vascular Microenvironment Reveals Presence of Fli1a, Not VEGFR2, in Acute Lymphoblastic Leukemia Model in Syngeneic Zebrafish
Authors: Revskoy Sergei , Mizgirev Igor , Corey Seth J. 
Published: October 2019

Abstract
Abstract 2551
Despite great advances in the curability of children with acute lymphoblastic leukemia (ALL), outcomes for pediatric and adult patients with relapsed ALL remain poor. This highlights the need for new approaches to ALL treatment and novel tools for screening of potential therapeutics. Dysregulated angiogenesis has been implicated both in the pathogenesis of leukemia and development of chemoresistance. However, the complexity of the bone marrow microenvironment and the precise contributions by the various components cannot be easily dissected in cell lines, tissue blocks, or mouse models. For instance, leukemia-associated angiogenesis was mainly characterized by immunostaining of bone marrow biopsies. High resolution in vivo bioimaging of fluorescence-tagged tumors and their microenvironment has recently become feasible due to establishment of transplantable tumor models in clonal syngeneic zebrafish. We have applied this model to dissection of cellular mechanisms of angiogenesis during stages of progression of T-ALL, This novel animal model enables us to 1) track leukemic cell proliferation and dissemination in vivo in different temperio-spatial and vascular contexts, and 2) follow up on cellular angiogenic events in response to leukemia progression including those occurring in response to chemotherapy for leukemia. In zebrafish, angiogenesis is similar to that of mammals and has been well characterized by using VEGFR2 and Fli1a transgenic reporter systems. In embryos, the fli1a:EGFP expression pattern mirrors that of VEGFR2 fluorescence in vascular endothelial cells. However, later in the development, in larvae and adult fish, the pattern of Fli1a or VEGFR2 expression diverges. This divergence further extends to angiogenesis in areas adjacent to T-ALL with more prominent development of Fli1a vasculature. Leukemic patches are characterized by a microenvironment where Fli1a is predominant and VEGFR2 is absent. We are now using cyclophosphamide treatment of leukemic fish to dissect the role of microenvironment and whether angiogenic factors are modified. These data yield new insights into molecular mechanisms of leukemogenesis in conjunction with angiogenesis. Furthermore, our findings would have predicted the lack of efficacy of VEGFR inhibitors in leukemia therapy. Our model offers an advantage for cost-efficient in vivo large scale screening system for antiangiogenic drugs for acute leukemia.

Disclosures:
No relevant conflicts of interest to declare.
Unresponsiveness to CHOP Is Associated with Activation of the p38 MAPK Pathway in Patients with DLBCL
Authors: Vega Mario I , Aviles-Salas Alejandro , Chalapud J Ramon , Huerta-Yepez Sara , Hernandez-Pando Rogelio , Martinez-Paniagua Melisa , Martinez-Miguel Bernardo , Hernandez-Atenogenes Miriam , Vega Gabriel G , Chen Haiming , Berenson James R. , Mayani Hector , Martinez-Maza Otoniel , Bonavida Benjamin 
Published: October 2019

Abstract
Abstract 2647
We have reported in B-NHL cell lines that the p38 MAPK was constitutively activated and was involved in the regulation of tumor cell resistance to cytotoxic drugs. Further, inhibition of this pathway reversed drug resistance. Based in these findings we hypothesized that the activation of the p38 MAPK pathway in patients with B-NHL may be associated with unresponsiveness to cytotoxic drug therapy. This study was designed to test this hypothesis. Eighty patients with Diffused Large B Cell Lymphoma (DLBCL) were used for analysis. Freshly derived tumor tissues from these patients were obtained from biopsies prior to any treatment. Tissue microarrays were prepared and examined by immunohistochemistry for the expression of both p38 MAPK and phosphorylated p38 MAPK (active). The antibodies were tested for specificity. The frequency of stained cells <30% was considered negative and the frequency ≥30% was considered positive. The frequency of stained cells was recorded only for the tumor cells in the arrays and the patterns of expressions were compared to adjacent normal tissues. Among the 80 patients who were treated with CHOP, and were (57) responders (R) and (23) non-responders (NR) to therapy. The data collected were analyzed and correlated with both the response to CHOP therapy and to event-free survival (EFS). The findings revealed that 66/80 (82%) tumor tissues expressed p38 MAPK and only 24/80 (30%) expressed phosphorylated p38 MAPK. The expression and activation of p38 MAPK correlated with high score performance status (1≥, p= 0.01). There was a significant correlation between the expression and the activity of p38 MAPK and failure to respond to CHOP therapy (p=0.02 and 0.002, respectively). Also, the failure to respond to CHOP therapy correlated with the nuclear expression of phospho-p38 MAPK (p < 0.05). Analysis of different clinical pathological parameters did not show a significant correlation with the expression of p38 MAPK. Further analysis demonstrated that high phospho p38 MAPK in the tumor significantly correlated with poor EFS (p=0.005). These findings established for the first time that a subset of patients with DLBCL and whose tumors expressed high and active p38 MAPK responded poorly to CHOP and had poor EFS. We propose that the activation of p38 MAPK in DLBCL patients at diagnosis may require a different treatment strategy than CHOP. In addition, inhibitors of the activation of p38 MAPK in DLBCL are potential for therapeutic intervention. The findings also suggested that activation of p38 MAPK is a potential prognostic biomarker.

Disclosures:
No relevant conflicts of interest to declare.
Molecular Signature Distinguishes Between Primary Mediastinal B-Cell Lymphoma and Diffuse Large B-Cell Lymphoma with Primary Involvment of Mediastinal Lymph Nodes
Authors: Mangasarova Jana K , Misuyrin Andrew V , Magomedova Aminat U , Kravchenko Sergey K 
Published: October 2019

Abstract
Abstract 2654

Background.
Primary mediastinal (thymic) B-cell lymphoma (PMBL) has been recognized as a subtype of diffuse large B-cell lymphoma (DLBCL). It has its distinctive clinical and morphological features but differs from other types of DLBCL due to peculiar immunophenotype and gene expression profile. PMBL have a distinct gene signature with several highly expressed genes including MAL, JAK2, PDL1, PDL2 and TRAF1. PMBL molecular signature was associated with a more favorable survival compared to DLBCL cases with a non-germinal and germinal-center profile, supporting a distinct natural history for PMBL [A. Rosenwald et al., 2003, G. Lenz et al., 2008].

Aim.
The aim of our study was to determine whether the quantitative expression analysis of JAK2, MAL, PDL1, PDL2 and TRAF1 genes may distinguish PMBL cases from other variants of DLBCL with primary involved of mediastinal lymph nodes.

Patients and methods.
31 patients with DLBCL with primary involvement of mediastinal lymph nodes and 12 patients with DLBCL without involvement of mediastinal lymph nodes were enrolled in the study. The diagnosis was made by morphological and immunophenotypic analysis of lymph nodes biopsy samples. Six healthy donors of lymphocytes constituted control group. The expression of JAK2, MAL, PDL1, PDL2 and TRAF1 genes was analyzed with RQ-PCR TaqMan hydrolyzing probes.

Results.
Normal median value of JAK2, MAL, PDL1, PDL2 and TRAF1 gene expression have been established according the data obtained in the set of normal donors. The gene was considered to be overexpressed if its value was more than normal median value + 3SD. In 12 patients with DLBCL without involvement of mediastinal lymph nodes there was no overexpression of MAL, PDL1 and PDL2 genes. In this group only 1 of 12 (8%) pts has the overexpression of JAK2 and 2 out of 12 (16%) pts the overexpression of TRAF1. In patients with DLBCL with primary involvement of mediastinal lymph nodes JAK2 gene was overexpressed in the 18/31 cases (58%), MAL–in the 6/31 (19%), PDL1–in the 2/31 (6%), PDL2–in the 5/31 (16%) and TRAF1–in the 2/31 (6%). Based on the overexpression of more than 3 genes we have separated from DLBCL group (31 cases) a distinct group with primary mediastinal (thymic) B-cell lymphoma 18/31 (58%) patients. So, in PMBL we revealed significant overexpression of at least 3 genes in 18/18 pts whereas in DLBCL with primary involvement of mediastinal lymph nodes no cases have such expression.

Summary.
Our data suggest that the quantitative molecular analysis of JAK2, MAL, PDL1, PDL2 and TRAF gene expression enables to distinguish PMBL from DLBCL with primary involvement of mediastinal lymph nodes.

Disclosures:
No relevant conflicts of interest to declare.
Intrinsic Survival Capacity of Cord Blood T cells is heterogeneous and Can Be Promoted by Repeated Low-Doses of Recombinant Interleukin-7,
Authors: Deberranger Eva , Pascal Laurent B , Trauet Jacques , Choufi Bachra , Thiant Stephanie , Dessaint jean-Paul , Yakoub-Agha Ibrahim , Labalette Myriam 
Published: October 2019

Abstract
Abstract 3227

Background:
Umbilical cord blood (CB) transplantation is known to be associated with delayed and defective immune reconstitution, in part because recent thymic emigrants (RTEs), the most common subset among CB T cells, have limited intrinsic survival. Interleukin-7 (Il-7) has been reported to increase the initial recovery of the graft-derived T-cells compartment. The aim of this study was to investigate CB-derived T-cell survival and to define a minimal effective dose of recombinant human IL-7 (rIL-7), considering that in addition to its anti-apoptotic effect, IL-7 may enhance immune reactions that occur in the host, including uncontrolled acute GVHD.

Methods:
Fifteen CB were obtained immediately after normal-term delivery, using the same procedure as for CB banking. T cells were isolated within 12 hours by negative magnetic bead sorting and cultured for 2 weeks either directly or after being frozen in order to recapitulate clinical procedures. Unstimulated T cell cultures were conducted in parallel in medium (RPMI supplemented with 10% normal AB serum) alone or supplemented with a range of rIL-7concentrations added either only once at day 0 (100 to 1000 pg/mL) or every day (10 to 100 pg/mL). Cell viability was assessed by flow cytometric scatter analysis and staining with 3,3'-dihexyloxacarbocyanine iodide [DiOC6(3)] and propidium iodide.

Results:
In basic culture conditions, the majority of T cells had died over 2 weeks, but there was a marked heterogeneity in cell survival, as proportions of viable T cells varied from 2% to 50% (median 15%) at day 6 of culture. Interestingly, the same intrinsic characteristics of survival were observed in T cells that underwent beforehand a freezing-thawing procedure.
In cultures supplemented with rIL-7, we confirmed the efficacy of rIL-7 in maintaining CB T cell survival. A minimal dose of 20 to 50 pg/mL of IL-7 added daily was sufficient to induce the prolonged survival of CB T cells, with more than 95% of viable cells at day 6. Noteworthy, these concentrations allowed prolonged survival of CD T cells without inducing any cell proliferation, as shown by the absence of CFSE dilution. Similar results were observed comparing CB cells that had been frozen or not.

Conclusion:
Repeated low-doses of rIL-7 are required to preserve the survival capacity of CB T cells without inducing their proliferation. These results could represent a framework for clinical studies aiming at improving T cell reconstitution following allogeneic CB transplantation. Repeated administration of low-doses of rIL-7 might be especially useful in patients with low serum levels of IL-7 after conditioning.

Disclosures:
No relevant conflicts of interest to declare.
A Multicenter, Open-Label Study of Posaconazole Oral Suspension in Treatment of Patients with Invasive Fungal Infection Refractory to or Intolerant of First-Line Therapy,
Authors: Huang Xiaojun , Wang Fengrong , Chen Yuhong , Liu Ting , Wang Jianxiang , Hu Jianda , Jin Jie , Chen Fangping , Wang Shujie , Shen Zhixiang , Yu Li , Yu Kang , Liang Yingmin 
Published: October 2019

Abstract
Abstract 3241

Background
Invasive fungal infection represents one major health threat for patients with a compromised immune system.

Methods
We performed a multicenter, open-label clinical study of posaconazole oral suspension in the treatment of 63 patients with invasive fungal infection that was refractory to or intolerant of first-line therapy. The primary efficacy end point was the cumulative response rate at the end of posaconazole treatment. The safety end points were adverse events (AEs), laboratory test results, and vital sign measurements, as well as patients' rate of withdrawal because of AEs or laboratory abnormalities.

Results
Of the 63 patients enrolled in the study, 62 (98.4%) were treated with study drug and included in the safety set. From those 62 patients, 59 patients entered the full analysis set for efficacy data assessment. A total of 47 patients were included in the per-protocol set. The cumulative clinical response rates at weeks 4, 8, and 12 of treatment were 69.49% (41/59, 95% confidence interval [CI]: 56.13–80.81), 62.71% (37/59, 95% CI: 49.15–74.96), and 64.41% (38/59, 95% CI: 50.87–76.45), respectively. Cumulative fungal pathogens eradication rates at week 4, week 8, and the end of treatment (week 12) were 47.06% (95% CI: 22.98–72.19), 47.06% (95% CI: 22.98–72.19), and 52.94% (95% CI: 27.81–77.02), respectively. At the end of treatment (week 12), 2 patients had died; the cumulative survival rate was 96.61% (95% CI: 88.29–99.59). The incidences of AEs, adverse reactions, and SAEs were 79.0%, 32.3%, and 8.1%, respectively. None of the serious adverse reactions were related to the study drug.

Conclusions
Posaconazole is effective in treating patients with refractory invasive fungal infection. As a novel broad-spectrum triazole antifungal with a good long-term safety profile, posaconazole can be used to treat patients with fungal infection relapse after antifungal treatment, patients with fungal infection resistant to routine antifungal treatment, patients with fungal infection intolerant of routine antifungal treatment due to side effects, and patients with organ dysfunction (e.g., renal dysfunction). (ClinicalTrials.gov number, NCT00811642)

Disclosures:
No relevant conflicts of interest to declare.
Predictors of Clinically Significant Bleeding in Patients with Aortic Stenosis,
Authors: Blackshear Joseph L , Chen Dong , Thomas Colleen S 
Published: October 2019

Abstract
Abstract 3315

Background:
Acquired von Willebrand syndrome (AVWS) is a frequent cause of bleeding in patients with severe aortic stenosis (AS). The goals of this study were to understand the incidence and patterns of bleeding in patients with various degree of AS and identify predictors for bleeding.

Methods:
Ninety-one patients (59 men, median age 79 years) with mild, moderate or severe aortic stenosis (AS) (n=64) or heart valve replacement (n=27) were studied. Clinically significant bleeding was determined based on the 2008 NHLBI VWD diagnostic guideline (Haemophilia. 2008, 14(2):171–232). We recorded blood counts, vital signs, mean gradient, peak aortic velocity, aortic valve area (AVA) and valve area index (AVAi), time velocity integral ratio (TVI ratio), VWF antigen (VWF:Ag), VWF activity by latex immunoturbidity assay (VWF:Lx), VWF multimer analysis, and closure times of platelet function analysis ADP and epinephrine cartridges (PFA–CADP and –CEPI). VWF high molecular weight multimer (HMWM) losses were graded as normal/mild or severe when compared to pooled plasma samples from normal donors. Associations with bleeding tendency were explored using single variable and multivariable logistic regression models.

Results:
Of the 91 patients, 29 (32%) were taking warfarin, and 55 (60%) were taking aspirin. None received a thienopyridine. Clinically significant bleeding was seen in 27 (30%) patients with gastrointestinal (GI) bleeding being most common (n=13). Nine patients who bled required hospitalization. Bleeding tendency was more common in patients with a severe loss of HMWM (OR=3.18, 95% CI: 1.06–9.71, P=0.039) and in patients with AS-associated symptoms (OR=3.02, 95% CI: 1.14–8.24, P=0.027). No other echocardiographic, laboratory, or clinical features demonstrated a statistically significant association with bleeding tendency.

Conclusion:
The incidence of clinically significant bleeding in this population was about 30% with GI being the most common site. Bleeding tendency was associated with severe HMWM loss and AS-associated symptoms. This study underscores the importance of acquisition of a history of bleeding, cardiac symptoms, and VWF multimer analysis in clinical management of AS patients.

Disclosures:
No relevant conflicts of interest to declare.
Mechanistic Determinants of the Acute Coagulopathy of Trauma (ACoT) in Patients Undergoing Emergency Surgery,
Authors: Cotton Bryan A , Sixta Sherry L , Wade Charles E , Holcomb John B , Matijevic-Aleksic Nena 
Published: October 2019

Abstract
Abstract 3319

Introduction:
Acute coagulopathy of trauma (ACoT) is a highly lethal phenomenon whose mechanisms have yet to be clearly defined. While likely multi-factorial, it has been reported to only occur in the presence of blunt injury. The purpose of this study was to identify variables that might influence or contribute to the early development of ACoT.

Methods:
Retrospective review of all patients admitted to a Level 1 trauma center 01/2004–12/2009 who underwent emergent laparotomy. Emergent laparotomy was defined as laparotomy performed within two hours of admission. ACoT(+) was defined as arrival INR >= 1.5, while ACoT(−) was defined as arrival INR<1.5. Univariate and multivariate analyses performed. Primary outcome was the identification of those factors predicting the presence of ACoT on admission.

Results:
1218 patients were included, 337 (27%) presented with ACoT(+), 881 (73%) did not. The groups had similar demographics and pre-hospital and ED fluids. Arrival base deficit (median 8.5 vs. 4.0) and ISS (25 vs. 16) were higher in ACoT(+) as were intra-operative RBC (median 4 vs. 0 U) and plasma (3 vs. 0 U); all p<0.05. 40% of ACoT(+) patients sustained penetrating injury. Six-hour (12% vs. 1%), 24-hour (15% vs. 1%), and 30-day (23% vs. 4%) mortality were significantly greater in ACoT(+); all p<0.001. Linear regression found INR values independently associated with arrival base deficit (p<0.001) but not ISS. Controlling for age, gender, mechanism of injury, and pre-hospital resuscitation, multiple logistic regression demonstrated that arrival base deficit was an independent predictor of developing ACoT.

Conclusion:
The current study found ACoT independently associated with metabolic (base deficit), physiologic (blood pressure) and anatomic insults (ISS). Attempts to address ACoT should focus on correcting each of these components. Moreover, contrary to prior data, 40% of ACoT(+) patients sustained penetrating mechanism.

Disclosures:
No relevant conflicts of interest to declare.
Preclinical Immunogenicity Assessment of Baxter‘s Recombinant Factor VIIa,
Authors: Horling Frank M , Lenk Christine , Ahmad Rafi Uddin , Weiller Markus , Schuster Maria , Schwarz Hans Peter , Reipert Birgit M 
Published: October 2019

Abstract
Abstract 3327
Baxter has developed a recombinant FVIIa (rFVIIa) product for the treatment of hemophilia patients with factor VIII or factor IX inhibitors. Before entering clinical development we assessed the immunogenic safety profile of the new product candidate BAX 817 using two novel mouse models that mimicked specific aspects of the situation in patients.
Several comparative preclinical immunogenicity studies were conducted to assess the immunogenicity profile of Baxter`s rFVIIa BAX 817 in comparison to a licensed recombinant FVIIa product. Three different mouse models were used for this purpose. The first model expresses specific immune tolerance against human FVIIa and, therefore, mimics the situation in both hemophilia A and hemophilia B patients. Using this model, we asked if Baxter‘s rFVIIa is able to maintain immune tolerance to human FVIIa.
The second model is a hemophilia A model that mimics the situation in an important fraction of hemophilia A patients with FVIII inhibitors. This model expresses a human MHC-class II haplotype (HLA-DRB1*1501) that was previously shown to be associated with an increased risk for the development of FVIII inhibitors.
The third model represents a normal wildtype C57BL/6 mouse.
All mice were treated with 8 weekly doses of either Baxter‘s rFVIIa BAX 817 or a licensed recombinant FVIIa product. Total anti-FVIIa antibodies were analyzed prior to the first dose as well as after the 4th and the 8th dose using ELISA assays.
Baxter`s rFVIIa BAX 817 and a licensed recombinant FVIIa product induced similar titers of anti-FVIIa antibodies in C57BL/6 wildtype mice and in hemophilic HLA-DRB1*1501 mice. In addition, both Baxter`s rFVIIa BAX 817 and a licensed recombinant FVIIa product were able to maintain specific immune tolerance in a novel mouse model that is immunologically tolerant to human FVIIa.
Based on the data obtained we conclude that both Baxter‘s rFVIIa BAX 817 and a licensed recombinant FVIIa product have a comparable immunogenic safety profile.

Disclosures:
Horling: Baxter Innovations GmbH: Employment. Lenk:Baxter BioScience: Employment. Ahmad:Baxter BioScience: Employment. Weiller:Baxter BioScience: Employment. Schuster:Baxter Innovation GmbH: Employment. Schwarz:Baxter Innovations GmbH: Employment. Reipert:Baxter Innovations GmbH: Employment.