bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of Low Levels of Glucose-6-Phosphate Dehydrogenase Levels in Pregnancy
Authors: Chintapatla Rangaswamy , Melinscak Hrvoje , Varma Mala 
Published: October 2019

Abstract
Abstract 5165

Purpose of the study:
To characterize the significance of Glucose-6- Phosphate Dehydrogenase (G6PD) levels measured in pregnancy.

Case series and results:
We saw 3 patients referred to Hematology clinic over the past 1 year. The G6PD levels were measured in pregnancy by the obstetrician while working up the anemia (Table 1). They did not have any evidence of hemolysis during the time of workup and it is unclear as to why the G6PD levels were sent. The G6PD levels were found to be low and all 3 patients had iron deficiency anemia, that improved with iron supplementation. There was no evidence of pregnancy induced hypertension, urinary tract infections, or infections during pregnancy. All the pregnancies were uneventful resulting in healthy babies and the G6PD levels normalized after the delivery in all the patients. We did a literature search to see the significance of such an association and if there were any recommendations for further testing in these individuals.

Discussion:
G6PD deficiency is one of the most common inherited red cell disorders transmitted in an X-linked recessive fashion affecting approximately 400 million people worldwide. In the United States, black males are most commonly affected, with a prevalence of approximately 10 percent. Acute hemolysis is caused by infection, ingestion of fava beans, or exposure to an oxidative drug. G6PD catalyzes nicotinamide adenine dinucleotide phosphate (NADP) to its reduced form, NADPH, in the pentose phosphate pathway. NADPH protects cells from oxidative damage. G6pd deficiency predisposes cells to increased oxidative damage predisposing to hemolysis. G6PD deficiency in pregnancy may manifest as increased urinary tract infections, preeclamsia, neonatal jaundice, hydrops fetalis and still birth. Vergnes et al. [Lancet 1968] reported that low erythrocyte G6PD levels were found in 25% of women in early pregnancy and in up to 65% of women in late pregnancy. In their study G6PD levels normalized after delivery. The reason for this decrease is unclear. Pregnancy is shown to cause increased oxidative stress, alteration in neutrophil G6PD trafficking [ Kindzelskii et al. J Clin Invest 2002] though it is unclear if any of these mechanisms are implicated in the decreased levels of G6PD during pregnancy.

Conclusions:
There are no clear guidelines for the subsequent testing and management of low levels of G6PD diagnosed in the setting of pregnancy. Evidence based guidelines would be helpful towards identifying the subset of patients with true G6PD deficiency.

Disclosures:
No relevant conflicts of interest to declare.
Chronic Iron Deficiency Anemia and Cancer Risk
Authors: Liu Chia-Jen , Chen Kuo-Wei , Hu Yu-Wen , Hong Ying-Chung , Huang Yu-Chung , Chiou Tzeon-Jye , Tzeng Cheng-Hwai 
Published: October 2019

Abstract
Abstract 5172

Background
Iron deficiency anemia (IDA) is a common initial manifestation of gastrointestinal malignancies, but the relationship between chronic IDA and further cancer development is not established.

Aims
We would like to investigate the cancer risk of chronic IDA over a 10-year period in Taiwan.

Methods
We enrolled patients with iron deficiency anemia from a nationwide health registry in Taiwan during the period 2000–2009. All patients received at least 2 related examinations and were treated with iron supplement. Since IDA is an initial manifestation of many underlying malignancies, we excluded patients whose cancer developed within 1 year after IDA diagnosis. Standardized incidence ratios (SIRs) of cancers were calculated to compare the cancer incidence of chronic IDA patients to general population. The specific types of cancer were addressed.

Results
A total of 4, 373 patient with IDA were identified, and 132 (3. 02%) IDA patients developed cancer 1 year after enrollment (SIR 1. 52; 95% confidence interval [CI] 1. 27 – 1. 80, p < 0. 001). The risks of kidney (SIR 5. 47, 95% CI 2. 73 – 9. 78), bladder (SIR 3. 6, 95% CI 1. 64 – 6. 83), liver (SIR 2. 80, 95% CI 1. 82 – 4. 13), and colorectal malignancies (SIR 1. 93, 95% CI 1. 22 – 2. 90) elevated. The risk of hematological malignancies were not increased in current study (SIR 1. 13, 95% CI 0. 31 – 2. 89, p = 0. 758).

Conclusions
After exclusion of cancer development within the first year, IDA patients still had increased risk of cancer, especially kidney, bladder, liver, and colorectal malignancies.

Disclosures:
No relevant conflicts of interest to declare.
Effect of Vitamin D Supplements On Hemoglobin Concentration in Patients with Iron Deficiency Anemia and Concurrent Vitamin D Deficiency:A Randomized Single Blind Placebo Controlled Trial
Authors: Malhotra Pankaj , GS Basavaraj , Sachdeva Naresh , Ahluwalia Jasmina , Bhadada Sanjay 
Published: October 2019

Abstract
Abstract 5173

Background:
The effect of vitamin D replacement on hemoglobin concentration in subjects with concurrent iron deficiency anemia and vitamin D deficiency is not known.

Methods:
In a single blinded randomized placebo controlled study, thirty subjects with iron deficiency anemia (serum ferritin < 15 ug/dl) were randomized to intervention arm (vitamin D 6 lakh IU IM once) or placebo. In all subjects, iron deficiency was corrected with parental iron. All the causes other than iron deficiency were excluded with appropriate investigation. The primary end point was rise in hemoglobin concentration.

Results:
Baseline age, BMI, hemogram, levels of serum ferritin, 25(OH)D and PTH were similar in both the arms. Twelve weeks after vitamin D replacement, there was significant increase in 25 (OH) D levels and decrease in PTH levels in subjects with intervention arm compared to placebo arm (p<0. 01). The increment in serum ferritin in both the group was similar. There was no further increase in hemoglobin concentration in intervention arm compared to placebo arm.

Conclusion:
Vitamin D replacement in subjects with iron deficiency anemia after iron correction does not improve hemoglobin concentration further.

Disclosures:
No relevant conflicts of interest to declare.
Regulation of Mesenchymal Progenitor Cell-Induced Neo-Vascularization by Endothelial Progenitor Cell-Derived Exosomes
Authors: Lener Thomas , Peckl-Schmid Doris , Gimona Mario , Oeller Michaela , Rohde Eva 
Published: October 2019

Abstract
Abstract 5188

Background and rationale
Despite advances in the application of autologous mesenchymal stem/progenitor cells (MSPCs) and endothelial colony forming cells (ECFCs) for novel regenerative therapies, our understanding of the basic mechanisms involved in therapeutic neovascularization remains incomplete. Specifically, the individual contribution of the cell types to vessel formation and maintenance is poorly understood. Here we investigate if MSPC-derived exosomes (small vesicles that are secreted into the extracellular space and fuse with other cells to deliver mRNAs, regulatory miRNAs and proteins) can promote ECFC proliferation, migration and differentiation.

Results
We have generated exosome-enriched fractions from conditioned culture media of human umbilical cord or bone marrow-derived MSCPs propagated in human platelet lysate. These purified fractions were added to the culture media of ECFCs for 48 – 72 hours. Employing FACS analysis, microscopy, and the automated xCELLigence system (ROCHE) we uncovered that MSPC exosomes significantly alter the morphology and the proliferative index of ECFCs, as well as their specific marker profile. Moreover we identified that exosome enriched fractions are sufficient for modifying the expression pattern of the collagen sensor DDR1 at the mRNA level and also influence the levels of the DDR1 regulatory miRNA 199. Significantly, exosome-enriched fractions from ECFCs did not elicit any detectable alterations in ECFCs themselves, whereas we could see changes in morphology, migratory potential, proliferative activity and marker expression in MSPCs.

Conclusions
Taken together our data suggest that progenitor cell-derived exosomes contribute to the neo-vascularization process induced by pairwise injection of ECFCs and MSPCs, and that at least part of the role executed by MSPCs could be delivered in a cell-free manner through exosome-enriched preparations.

Disclosures:
No relevant conflicts of interest to declare.
Anti-Human VWF Monoclonal Antibody SZ-123 Prevents Arterial Thrombus Formation by Inhibiting VWF–collagen and VWF-Platelet Interactions in Rhesus Monkeys
Authors: Zhao Yiming , Ruan Changgeng 
Published: October 2019

Abstract
Abstract 5194

Objective:
To investigate the in vivo antithrombotic efficacy of an anti-VWF monoclonal antibody SZ-123, and its potential underlying mechanism.

Methods and Results:
Cyclic flow reductions (CFRs) were measured in the femoral artery of monkeys before and after intravenous administration of SZ-123. Ex vivo VWF binding to collagen, platelet aggregation, platelet count and template bleeding time were performed as measurements of antithrombotic activity. In addition, plasma VWF, SZ-123 levels, and VWF occupancy were measured by ELISA. Administration of 0. 1, 0. 3, and 0. 6 mg/kg SZ-123 resulted in 45. 3%, 78. 2%, and 100% reduction in CFRs, respectively. When 0. 3 and 0. 6 mg/kg SZ-123 were administrated, 100% of VWF was occupied by the antibody. Moreover, 100% ex vivo inhibition of VWF-collagen binding and 60–95% inhibition of platelet aggregation were observed from 15 min to 1h. None of the doses resulted in significant prolongation of bleeding time. In vitro experiment also revealed that SZ-123 not only blocks collagen-VWF A3 interaction but also inhibits indirectly VWF A1 binding to GPIba induced by ristocetin.

Conclusions:
SZ-123 prevents in vivo arterial thrombus formation under high shear conditions by inhibiting VWF A3–collagen and VWF A1-platelet interactions and does not prolong bleeding time.

Disclosures:
No relevant conflicts of interest to declare.
Gas6 and TAM Receptors in Mouse Platelets
Authors: Kucuk Bahadir , Bingol-Ozakpinar Ozlem , Demir Muzaffer , Uras Fikriye 
Published: October 2019

Abstract
Abstract 5199

Objective:
Growth Arrest Specific-6 (Gas6) is a new vitamin K-dependent protein and is a ligand for TAM receptors, three receptors (Tyro, Axl and Mer) belonging to the receptor tyrosine kinase subfamily. The number of publications concerning the physiological importance of the new vitamin-K dependent proteins, which are not members of the coagulation cascade, is growing. Gas6 has a structural homology to natural anticoagulant of protein S, but has no anticoagulant activity. Some research groups have reported contradictory results concerning the presence of Gas6 and its receptors in mouse platelets. The purpose of this study is to investigate the presence of Gas6 and its receptors in mouse platelets as mRNA and protein levels.

Material and Methods:
25 specific pathogen-free, 8–10 week old, 25–30 g in weight, race of Balb-C male/female mice were anesthetized under light ether anesthesia and blood samples were taken from their hearts. Total RNAs were isolated from platelets, then mRNAs encoding Gas6 and TAM receptors were detected by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Protein concentrations of Gas6 and TAM receptors in platelets were measured by ELISA. We were unable to measure the Mer protein level because of the absence of any commercial ELISA kit for mouse Mer.

Results:
RT-PCR results indicated the presence of mRNAs encoding to Gas6 and Mer in mouse platelets. However, although RT-PCR reactions were performed at various temperatures and cycles, we could not detect the presence of mRNAs encoding Axl and Tyro. Receptor levels of Axl and Tyro were below the detection limits of the ELISA method. Plasma Gas6 concentration was found to be 26 ng/ml.

Conclusion:
We found the presence of mRNAs encoding Gas6 and only receptor Mer in mouse platelets but not Axl and Tyro. Protein Gas6, Axl and Tyro levels were below the detection limits of the ELISA methods. The presence of mRNA is not evidence of protein expression in platelets because they have no DNA. Further studies are required to clarify the presence of Gas6 and TAM receptors in platelets using Real Time PCR, and more sensitive immunological methods, and then, as studies of their effects on mechanisms. Original results from these further studies will provide reliable information as to whether Gas6 and its TAM receptors may be a pharmacological target in thrombosis, hemostasis, restenosis and atherosclerosis.

Disclosures:
No relevant conflicts of interest to declare.
The Leukemic Fusion Gene NUP98-HOXD13 Suppresses Non-Homologous End Joining Factors and Impairs DNA Double Strand Break Repair
Authors: Caudell David L. , Puthiyaveetil Abdul Gafoor A. 
Published: October 2019

Abstract
Abstract 521
Chromosomal translocations are hallmark features of hematologic malignancies that often require collaborating mutations for malignant transformation. These secondary mutations can occur spontaneously, or rather, be induced by the primary translocation. Mutations can occur as a result of DNA damage and misrepair with DNA double strand breaks being one of the most serious types of cell damage. Double strand breaks are classically repaired by the non-homologous end joining (NHEJ) mechanism and impaired NHEJ has been shown to promote mutagenesis. Transgenic mice expressing the myeloid leukemic fusion gene NUP98-HOXD13 (NHD13) develop Myelodysplastic syndrome and progress to acute leukemia after acquiring secondary mutations. Our studies have shown that B lymphocyte development and class switch recombination are impaired in stimulated B lymphocytes from NHD13 mice. Based on this, we used in vitro class switch recombination (CSR) to delineate the DNA break induction and repair mechanisms in NHD13 B lymphocytes. Naïve B lymphocytes were harvested from wild type (WT) and NHD13 spleens and cultured in the presence of E.coli Lipopolysaccharide (LPS) and IL-4 to induce CSR. The DNA break induction pattern was determined using phosphorylated H2AX labeling combined with confocal microscopy and flow cytometry. Our results showed that NHD13 B lymphocytes had a comparable break induction pattern, but significantly reduced DNA repair. Analysis of the cell cycle pattern of stimulated B cells at 24 hour intervals showed cell cycle arrest at the G2/M phase at 72 hours following stimulation—a hallmark feature of impaired DNA break repair. We analyzed the expression of classical NHEJ and alternative end joining factors including Ku70, Ku80, DNA Protein Kinase catalytic subunit (DNAPKcs), Xrcc4, DNA ligase 4, Ligase 1, and Ligase 3. Our results showed reduced expression of DNAPKcs, Ligase 4 and Xrcc4 in NHD13 B lymphocytes at 72 hours following stimulation, suggesting that cells failed to initiate NHEJ-mediated DNA repair. Our results suggest that a myeloid leukemic gene can impair the DNA repair mechanism and may indirectly promote mutations necessary for malignant transformation.

Disclosures:
No relevant conflicts of interest to declare.
Up-Regulation of Heme Oxygenase-1 Is Induced by the Leukemia Stroma-Cell Interaction and Rescues Acute Myeloid Leukaemia (AML) Cells From Cytarabin Induced Cell Death
Authors: Brendel Cornelia A. , Wang Xiaonan , Henkenius Katharina , Pali Mihaela , Haferlach Torsten , Stiewe Thorsten , Neubauer Andreas 
Published: October 2019

Abstract
Abstract 533
Although the majority of patients achieve a complete remission after induction chemotherapy with cytarabine and antracyclines relapse is still the major cause of death in acute myeloid leukemia (AML). In order to address the question of resistance mechanisms in residual leukemic cells we employed a murine leukemia model system. We transplanted Rag2−/−gc−/− mice with human KG1a leukemia cells and treated them with four doses of cytarabine at the onset of AML. Residual human leukemic cells were collected from murine marrow and spleen and RNA was further subjected to whole genome microarray analysis. Heme Oxygenase-1 (HO-1) was found to be highly up-regulated in the persistent cell fraction that had survived cytarabine chemotherapy in vivo. The clinical relevance of HO-1 up-regulation was confirmed with two AML data sets. In a small set of 31 unselected AML patients treated in one institution, overall survival (OS) was significantly worse in patients with high HO-1 expression as determined by qPCR analysis (log rank: p < 0.0001). A second patient cohort of 286 patients was therefore retrospectively analyzed for HO-1 expression based on whole genome expression profiling. Again, OS was inferior in patients expressing HO-1 at high levels (p<0.005).
HO-1 is a well-known stress-response protein also termed heat-shock protein 32 (hsp32) that catalyzes the enzymatic cleavage of heme into biliverdin, carbon monoxide and iron, but also decreases cellular levels of reactive oxygen species (ROS). Employing an in vitro co-culture system we show that mesenchymal stem cells (MSC) increase HO-1 expression in leukemic cells causing a decrease in ROS levels and protection from apoptosis particularly in the adherent fraction of leukemic cells. The cytoprotective effect induced by leukemia stromal cell interaction can be overcome by concomitant treatment of cytarabin together with zinc protophoryrin (ZnPP), a specific competitive inhibitor of HO-1. Taken together we demonstrate that expression of HO-1 may play a critical role for chemotherapy resistance in AML in particular with regard to the leukemia stromal cell interaction. ZnPP is a specific HO-1 inhibitor that has already proven anti-tumor activity in vivo and might therefore be a promising candidate for further targeted drug therapy strategies that intend to eradicate persistent leukemic cells.

Disclosures:
No relevant conflicts of interest to declare.
A Novel Rat Model of Hereditary Hemochromatosis Due to a Mutation in Transferrin Receptor 2
Authors: Bartnikas Thomas Benedict , Wildt Sheryl , Wineinger Amy , Schmitz-Abe Klaus , Markianos Kyriacos , Cooper Dale , Fleming Mark D. 
Published: October 2019

Abstract
Abstract 612
Sporadic iron overload has been reported previously in rats but the underlying cause has not been ascertained. In this study, phenotypic analysis of a subpopulation of Wistar rats designated Hsd:HHCL revealed a low incidence of histologically detected liver iron overload. One rat out of 132 screened animals exhibited liver iron accumulation in a predominantly periportal, hepatocellular distribution; this male rat expressed low RNA levels of the iron regulatory hormone hepcidin and low protein levels of transferrin receptor 2, a membrane protein essential for hepcidin expression in humans and mice and mutated in forms of hereditary hemochromatosis, a disease of excessive intestinal iron absorption and progressive tissue iron overload. Sequencing of the transferrin receptor 2 gene in the iron-overloaded rat revealed a novel Ala679Gly polymorphism affecting a highly conserved residue. Quantitative trait locus mapping revealed that a transferrin receptor 2 polymorphism correlated strongly with serum iron and transferrin saturations in male rats. Transfection of Tfr2 expression constructs into tissue culture cell lines revealed that the Gly679 Tfr2 variant is expressed at a lower level than the Ala679 variant. Selective breeding of rats carrying this polymorphism and characterization of iron metabolism in the resulting progeny indicated that homozygosity for the Ala679Gly allele leads to a hemochromatosis phenotype. The Hsd:HHCL rat is the first genetic rat model of hereditary hemochromatosis and may prove useful for understanding the molecular mechanisms underlying the regulation of iron metabolism and the pathogenesis of hereditary hemochromatosis.

Disclosures:
No relevant conflicts of interest to declare.
IRAK4 Kinase As A Novel Therapeutic Target in the ABC Subtype of Diffuse Large B Cell Lymphoma
Authors: Lim Kian-Huat , Romero Donna L. , Chaudhary Divya , Robinson Shaughnessy D. , Staudt Louis M. 
Published: October 2019

Abstract
Abstract 62
Activating mutations of MyD88, particularly L265P, occur in about 30% of activated B cell-like diffuse large B cell lymphomas (ABC DLBCLs), the more malignant molecular subtype of DLBCL that responds poorly to standard chemotherapy. We found that the oncogenic signal of mutant MyD88 is transduced predominantly through the Interleukin-1 Receptor-Associated Kinase (IRAK) cascade consisting of IRAK4 and IRAK1, resulting in constitutive activation of classical NF-κB signaling. Importantly, using knockdown-rescue experiments, we found that the kinase activity of IRAK4, but not IRAK1, is required for the oncogenic effect of mutant MyD88 in the survival of ABC DLBCL cell lines. As such, we have proposed that inhibitors of IRAK4 kinase activity could have a therapeutic impact in lymphomas with MyD88 mutations. We have identified two potent small molecule IRAK4 inhibitors, ND-2158 and ND-2110, that are highly selective across a panel of more than 300 kinases. When administered to rodents, both compounds lead to >90% suppression of LPS-induced TNF-α release in serum. Both inhibitors are universally toxic towards ABC DLBCL but not GCB DLBCL cell lines, consistent with the highly specific mechanism of action. The molecules demonstrate good pharmacologic drug-like properties and are expected to have a suitable safety profile for clinical evaluation. Mechanistic studies indicate that both inhibitors potently abrogate IRAK4-mediated phosphorylation of IRAK1 and NF-κB activity resulting from the MyD88 (L265P) mutation in ABC DLBCL. Additionally, these agents suppress secretion of the pro-inflammatory cytokines IL-6 and IL-10 by ABC DLBCL cells. A second, parallel survival pathway in ABC DLBCL is engaged by “chronic active” B cell receptor signaling, which can be blocked by inhibiting Bruton's tyrosine kinase (BTK) either genetically or pharmacologically. Notably, the IRAK4 inhibitors strongly synergized with BTK knockdown in killing multiple ABC DLBCL cell lines. Our results provide a solid rationale for the further development of IRAK4 inhibitors for the therapy of ABC DLBCL and suggest that simultaneous inhibition of B cell receptor signaling may provide superior clinical responses.

Disclosures:
Romero: NIMBUS Discovery: Employment. Chaudhary:NIMBUS Discovery: Employment. Robinson:NIMBUS Discovery: Consultancy, Employment.