bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increase of Sensitivity to Chemotherapy and NK-Mediated Cytotoxicity of Leukemic Stem Cell by a Farnesyltransferase Inhibitor.
Authors: She Miaorong , Li Jinggao , Chen Xilin , Niu Xingqing , Guo Kunyuan , Du Xin , Zhou Maohua , He Yanjie , Le Yi 
Published: October 2019

Abstract
Abstract 4161
Acute myeloid leukemia (AML) is a serious and often lethal hematopoietic malignant disease arising from stem cells. Leukemic stem cells (LSCs) play the central role in the relapse and refractory of AML and highlight the critical need for the new therapeutic strategies to directly target the LSC population. We previous found that LSC were resistant to chemotherapy and NK-mediated cytotoxicity, which were resulted from the apoptosis defect and NKG2D ligands change. Our previous data also showed that Manumycin induced apoptosis in leukemia cells through mitochondria pathway. Here, we demonstrated that manumycin increased the sensitivity of LSC to chemotherapy and NK cell-mediated cytotoxicity. Manumycin enhanced sensitivity to chemotherapy in LSCs via induced apoptosis. Analysis of signaling pathways revealed that manumycin enhanced mitoxantrone activation of caspase 3 and significantly decreasing Bcl2 protein. These finding indicated that manumycin sensitized mitoxantrone to chemotherapy via down-regulating Bcl2. Importantly, manumycin enhanced the sensitivities of LSCs to NK cells cytotoxicity through up-regulating the expressions of NKG2D ligands MICA/B and ULBP3. Thus, Manumycin present a promising novel therapeutic approach for AML therapy especially when resistant to chemotherapy and NK cell immunotherapy.

Disclosures:
No relevant conflicts of interest to declare.
A Concept for Long-Term Anticoagulation Based On the Individual Risk of Lethal Pulmonary Embolism (PE) and Lethal Bleeding Using Oral Anticoagulants.
Authors: Zotz Rainer B. , Sucker Christoph , Gerhardt Andrea 
Published: October 2019

Abstract
Abstract 4174

Objectives
Indications for an indefinite oral anticoagulation are a matter of debate in patients with a first unprovoked proximal DVT.

Methods
An individual risk-benefit analysis is made using published prospective studies by determining the patient-specific lethal risk of bleeding under oral anticoagulation compared with the estimation of lethal PE-risk by type of initial thrombosis (spontaneous vs. secondarily caused, with or without PE).

Results
According to this risk-benefit analysis, long-term oral anticoagulation is indicated to prevent lethal PE in all patients with low risk of bleeding (1% per year, 0.1 % lethal bleeding per year) in the risk group with lethal PE > 0.2 % per year. This risk group includes patients with idiopathic proximal thrombosis and PE in the initial event (also without thrombophilic risk factors) and patients with an idiopathic initial event without PE, who have relevant thrombophilic risk factors with a relative risk ≥ 2, such as antithrombin deficiency, homozygous factor V Leiden or a combined heterozygous factor V Leiden and prothrombin G20210A mutation. In case of a higher bleeding tendency (0.3% lethal bleeding per year in a patient group with 1-2 bleeding risk factors like age >65 or diabetes) other risk-benefit estimations are present.

Conclusions
Our individual risk stratification is in contrast to current therapy recommendations, which generally consider long-term oral anticoagulation for patients with an idiopathic initial proximal DVT with a low bleeding risk, but do not specify these in individual cases.

Disclosures:
No relevant conflicts of interest to declare.
Thrombin Generation Assessment in Platelet Rich Plasma Offers Additional Criteria for Low Molecular Weight Heparin Antithrombotic Fingerprint Characterization.
Authors: Gerotziafas Grigorios T. , Vasso Galea , Walenga Jeanine M. , Kalodiki Evi , Chaari Mourad , Mohamed Hatmi , Fareed Jawed , Ismail Elalamy 
Published: October 2019

Abstract
Abstract 4177

Introduction
National and international organizations recognize that low molecular weight heparins (LMWHs) are distinct entities and that they should not be used interchangeably in clinical practice. Physicochemical properties, such as molecular weight anti-Xa/anti-IIa ratios, are used by health authorities to establish LMWHs differentiation. LMWHs are multitargeted drugs in which small differences in physicochemical properties may lead to significantly different inhibition of blood coagulation. In the present in vitro study we have investigated if thrombin generation assay, reflecting the overall coagulation process, is a suitable tool for the LMWH variability evalution.

Materials and methods
LMWHs (bemiparin, enoxaparin, nadroparin, dalteparin and tinzaparin) and unfractionated heparin (UFH) were added in vitro in normal citrated platelet rich plasma from 10 healthy individuals, at clinically relevant concentrations (ranging from 0.2 to 1 anti-Xa IU/ml). Thrombin generation was studied with Thrombogram-Thrombinoscope® assay using diluted thromboplastin (Innovin®, 1/1000 final dilution, Siemens France). The concentrations doubling the lag-time, the time to Peak, the IC50 for Peak, the endogenous thrombin potential (ETP) and the mean rate index of propagation phase (MRI) were determined for each compound.

Results
LMWHs compared on their anti-Xa activity basis showed variable inhibitory effect on thrombin generation. At equivalent anti-Xa concentrations tinzaparin was significantly more potent than the other LMWHs, being almost similar to UFH profile. Enoxaparin, nadroparin and dalteparin showed a similar inhibitory activity. Bemiparin had the lesser pronounced inhibitory effect on thrombin generation. The impact of anti-Xa and anti-IIa activities on each phase of thrombin generation process is different. Thrombogram chronometric parameters are mainly influenced by the anti-IIa activity. Similarly, ETP inhibition depends more on anti-IIa rather than anti-Xa activity. The MRI of the propagation phase is more sensitive to the anti-Xa activity of LMWHs.

Conclusion
Thrombin generation assessment in platelet rich plasma allows to evaluate the anticoagulant fingerprint of LMWHs and to differentiate them on global and functional criteria. Each LMWH has a particular inhibitory impact on each phase of thrombin generation process. These functional criteria need to be standardized and probably required for a better characterization of LMWHs heterogeneity by health authorities. They could be used also to evaluate bioequivalence of generic and original LMWHs.

Disclosures:
No relevant conflicts of interest to declare.
Higher Prevalence of Heparin-Induced Thrombocytopenia Antibodies in Asian Indian Population: Is This Due to Contaminated Heparin?
Authors: Kannan Meganathan , Ahmad Firdaus , Saxena Renu , Fareed Jawed 
Published: October 2019

Abstract
Abstract 4182
Heparin treatment may result in an adverse effect because of the formation of antibodies against heparin-platelet factor 4 (H-PF4) complexes, which in turn leads to platelet/endothelial cell activation followed by heparin-induced thrombocytopenia (HIT). Several recent publications have reported a higher incidence of H-PF4 antibodies in patients treated with contaminated heparin. The main contaminant in recalled heparin was identified to be oversulfated chondroitin sulfate (OSCS), the same compound known to have caused several deaths due to generation of bradykinin, a potent vasoactive mediator, and generation of C3a and C5a, potent anaphylatoxins derived from complement proteins. It is known that the quality-control measures in the European community and the United States are stringent; such control measures are not enforced in other countries. In our experience, that was performed prior to the global recall of contaminated heparins and the implementation of new analytical procedures, 11 of 47 cardiovascular surgery patients who have undergone heparin therapy were H-PF4 antibody positive by serotonin release assay. Of the 11 patients who showed positive H-PF4 antibody, only 5 of whom had thrombocytopenia and the remaining 6 patients did not show thrombocytopenia or any adverse effects. Even though a greater prevalence of H-PF4 antibody has also been reported with the bovine heparin preparations, the increase in prevalence of these antibodies may also be due to the quality of heparin used. Our subsequent study in another fifty cardiovascular surgery patients, who underwent heparin therapy, did not show any positive H-PF4 antibody. This demonstrates that the quality of heparin used may play a role in the generation of H-PF4 antibodies. Published reports suggest that the hypersulfated glycosaminoglycans such as the pentosan polysulfate also produces a much higher incidence of H-PF4 antibodies. Several other contaminants, such as the oversulfated derivatives of dermatan sulfate, heparin sulfate and heparin, may also be present in substandard heparin preparations. Thus, the higher generation of H-PF4 antibodies in these patients observed may be due to the heparin used; and heparin needs to be re-evaluated and subject to quality-control measures when a batch of heparin shows higher prevalence of H-PF4 antibodies. Also, to confirm true HIT in heparin treated patients, it is important to identify the functional forms of these H-PF4 antibodies.

Disclosures:
No relevant conflicts of interest to declare.
Effect of the Erythrocyte Apheresis On Immunological Parameters in Sickle Cell Anemia Patients in Crisis Period.
Authors: Kilinc Yurdanur , Tekinturhan Ferda , Guvenc Birol , Burgut Refik , Sasmaz Ilgen , Antmen Bulent 
Published: October 2019

Abstract
Abstract 4191
PURPOSE:
Erythrocyte apheresis is an effective therapy in the acute and chronic treatment of sickle cell anemia (SCA). The main goal of erythrocyte apheresis is to improve blood perfusion through reducing Hemoglobin S (HbS) to < %30 and keeping hemoglobin (Hb) at desired level. The aim of this study was to evaluate the effect of the erythrocyte apheresis on immunological parameters in SCA patients with crisis.

METHODS
Between February 2009 and June 2009, 37 patients (20 female / 17 male) received 44 apheresis treatments at Hemapheresis Unit of Cukurova University School of Medicine, Adana, Turkey. The median age was 22 (Range, 4-56) years and the mean body weight was 51.9±18.6 kilograms. The apheresis procedures were carried out using a Cobe Spectra Cell Separator. A mean of 1.77 body volume calculated red blood cell volumes were exchanged with a mean duration of 125.9±34.9 minutes (Table 1). Sickling negative and leukoreduced packed red cells were used for apheresis treatments. Hemoglobin electrophoreses, complete blood counts, immunoglobins, specific surface markers for T, B and natural killer (NK) cells were performed before and after each procedure. While three patients had a SCA-induced functional asplenia, none of the patients was HIV-seropositive.

RESULTS
The erythrocyte apheresis resulted in a decrease on white blood cell (WBC) counts as expected. Average pre and post apheresis WBC counts were 12883±5775/mm3 and 8506±3331/mm3 (p<0.001) respectively. Accordingly, a decrease in post procedure lymphocyte, monocyte and granulocyte counts was observed. Because small amounts of patient's plasma were removed with red blood cells during apheresis procedures, serum levels of immuglobulins were also decreased. CD3, CD4 and CD8 for T cells, CD11b for monocytes, CD20 for B cells, CD56 as a NK marker and CD45 for leukocytes were analyzed and all of surface markers showed an increase after erythrocyte apheresis. The average pre apheresis HbS level was 78.90±19.20%, whereas the mean post apheresis HbS level was found to be 23.85±13.27% (p<0.001) (Table 2).

CONCLUSIONS
The erythrocyte apheresis is an effective and rapid procedure to reduce HbS concentration without increasing blood viscosity. Apheresis treatments have also been found to be beneficial in decreasing the leukocyte counts and serum immunoglobulins levels in the blood. Flow cytometric analyses revealed that T, B and NK cells were increased after apheresis treatment. Interestingly, the change in CD4/CD8 ratio was not statistically significant (p>0.05). This shows that vascular wall integrity is maintained and apheresis can be safely performed in SCA patients. In our study, blood perfusion was restored and blood chemistry was improved to optimal levels after erythrocyte apheresis. As a result, crisis periods were shortened.

Disclosures:
No relevant conflicts of interest to declare.
Molecular Basis for A Thrombophilic Patient's Combined Deficiencies in Proteins C and S.
Authors: Smith Tyler W , Carter Isis S. R , Carter Cedric John , MacGillivray Ross T.A 
Published: October 2019

Abstract
Abstract 4198

Background/objectives
Proteins C and S (PC and PS) are vitamin K-dependent plasma proteins with anticoagulant properties. Protein S functions as a non-enzymatic cofactor for activated protein C (APC). APC proteolytically degrades coagulation factors Va and VIIIa, thereby diminishing the activities of the prothrombinase and tenase complexes, respectively. The human PC gene (PROC) is located on the long arm of chromosome 2 (2q13-q14) and contains 9 exons which code for 461 amino acid residues. The human PS (PROS1) gene resides on chromosome 3 (3p11.1-q11.2) and contains 15 exons coding for 636 amino acid residues. Hereditary PS and PC deficiencies are both autosomal dominant disorders in which patients have diminished functional levels of the respective protein (usually ∼50% relative to normal controls). Clinically, this results in increased propensity toward thromboembolic disease, also known as thrombophilia. In this study, we describe a unique thrombophilic patient who has combined deficiencies in both proteins C and S. The objective of the study was to elucidate the precise genetic defect(s) causing these deficiencies.

Methods
Following purification of the patient's DNA from peripheral blood leukocytes, PCR amplifications were performed using oligonucleotide primers flanking all exons of the PROS1 and PROC genes. In addition, the 400bp region upstream of the first exon of PROS1 (corresponding to the promoter region) was also amplified by PCR. The PCR products were purified and their DNA sequences determined in both forward and reverse directions using the dye-terminator method. The resultant nucleotide sequences were compared with the PROS1 and PROC reference sequences [web address].

Results
The patient was found to be heterozygous for a novel missense PROC gene mutation in exon 8, which codes in part for the proteolytic domain of protein C. The resulting ValàGly substitution of residue 221 is in close proximity to the catalytic triad, which could abrogate its enzymatic activity. Although no mutations were present in any of the patient's PROS1 exons, there was a novel heterozygous CàG nucleotide substitution in the PROS1 promoter region. This substitution is present within an Sp1 transcription factor binding site that is highly conserved among mammals. Therefore, this mutation could significantly diminish expression of the otherwise normal PROS1 gene, leading to the observed decreased protein S level. Both mutations are unreported in the literature and are not listed in the PROC and PROS1 mutation databases.

Conclusions
We have successfully identified two novel genetic defects leading to deficiencies of the anticoagulant proteins C and S in a patient with thrombophilia. Further studies are underway to confirm the suggested biochemical effects of the mutation on protein C and protein S gene expression.

Disclosures:
No relevant conflicts of interest to declare.
Antithymocyte Rabbit Globulin Is Safe and Effective in Children with Severe Aplastic Anemia Report Polish Pediatric Hematology Group (Warszawa, Krakow, Wroclaw, Bydgoszcz, Poznan, Lodz, Bialystok, Szczecin, Gdansk).
Authors: Pawelec Katarzyna , Matysiak Michal , Salamonowicz Malgorzata , Balwierz Walentyna , Zaleska-Czepko Ewa , Chybicka Alicja , Szmyd Krzysztof , Sonta-Jakimczyk Danuta , Bubala Halina , Wysocki Mariusz , Kurylak Andrzej , Wachowiak Jacek , Grund Grzegorz , Mlynarski Wojciech , Bulas Monika , Krawczuk-Rybak Maryna , Leszczynska Elzbieta , Urasinski Tomasz , Peregud-Pogorzelski Jaroslaw , Kaczorowska Barbara , Balcerska Anna 
Published: October 2019

Abstract
Abstract 4220
Bone marrow transplantation (BMT) is a therapy of choice in children with severe aplastic anemia (SAA), but it is possible only in about 15-20% patients who have family donors, so the majority of them received the immunosuppressive therapy (IST).
We want to present the results of IST obtained in 116 children treated between 1993-2008 years at 11 pediatric hematology centers of the Polish Pediatric Hematology Group (PPHG),, 55 patients (22 girls and 33 boys aged 0,6-17,5 years) received antithymocyte rabbit globulin (ATG) as a first course of therapy. ATG was administered according to PPHG and Working Party SAA Group of EBMT protocol: ATG 3.75mg/kg iv for 5 days, cyclosporin A (CSA) 5mg/kg orally from day 1 to day 180 and granulocyte-stimulating factor during deep neutropenia.
Remission of the disease was assessed on days 112, 180 and 360 from start of therapy on the basis of blood and bone marrow examination. The results on 112 and 180 were similar. The remission was achieved in 28 of 55 children (51%), complete remission (CR) in 5 children (9%), and partial remission (PR) in 23 children (42%). On day 360 remission was obtained in 30 of 55 patients (42 %), CR in 10 children (18%) and PR in 20 children (36%) There was no response to treatment (NR) in 25 patients (45%).
In the group of 55 patients, 15 died (27%). 5 of them died early (day 52 and day 72 of therapy) due to septicemia and central nervous system (CNS) hemorrhage. The other 10 died late (day 99 and day 360 of therapy) due to CNS hemorrhage. Observation time of patients ranged from 1 to 14 years. During this time we noted four relapse. PNH was observed in one patient. The probability of 14 year survival in our group of patients treated initially with rabbit ATG is 72,7%. The results in the last follow up (Jun 2009) are better then earlier. We observed CR in 23/55 children (42%), PR in 10/55 (18%), NR 18/55 (33%). o information about 4 patients.
We conclude that initial treatment with rabbit ATG is safe and effective in children. Further studies are needed, to assess long-term effectiveness of rabbit ATG in IST.

Disclosures:
No relevant conflicts of interest to declare.
A Randomized Trial Evaluating a New Powered Bone Marrow Aspirate and Core Biopsy System Compared to Traditional Manual Devices.
Authors: Berenson James R. , Donahue David J. , Yellin Ori , Upadhyaya Gargi , Nassir Youram , Swift Regina A. 
Published: October 2019

Abstract
Abstract 4234
Traditional bone marrow procedures using a manual device hand-inserted by the clinician may be associated with pain, bleeding and inability to obtain adequate specimens leading to multiple attempts and a prolonged time to complete the procedure. These procedures take from approximately 7 minutes to more than 30 minutes to collect adequate aspirate and core biopsy samples. Notably, it has been shown that the duration of needle insertion is the sole predictor of patient pain during the procedure. In an attempt to overcome these shortcomings of the traditional technique, the OnControl bone marrow aspiration and biopsy system has recently been developed. It is an FDA-cleared device, comprised of the driver, a metal needle set and a connector. The driver is a small battery-powered device for insertion of a single lumen needle into the intraosseous space of the adult iliac crest. This device allows for a minimally-invasive procedure that in a 2007 study showed a substantially faster time for needle insertion into the medullary space of the iliac crest with a mean insertion time of 5 seconds. In an interim analysis of a single-arm validation study for the OnControl system, 36 patient procedures were completed with a mean user satisfaction score of 4.6 (on a scale of 0-5, with 5 indicating high satisfaction), a biopsy core acquisition success rate of 92%, a mean length of biopsy core of 1.22 cm, and a mean time from needle insertion to core extraction of 2 minutes and 9 seconds. Thus, we are currently enrolling patients on a multicenter, prospective, randomized controlled trial in order to directly compare results of using this new powered core biopsy needle to traditional manually inserted needles in terms of patient level of pain, time from needle insertion to removal, insertion success rate, core biopsy capture rate, quality of yield of this device, rate of complications, and operator satisfaction with the device. Patients requiring conscious sedation/narcotics for pain relief or extra bone marrow for research purposes/additional tests beyond that required for routine clinical evaluation will be excluded. Block randomization with blocks of size 4 will be used to prevent unequal treatment-group sizes. Each patient is being randomized to undergo a bone marrow procedure with the standard manual device or the powered device. Patient pain is being assessed using the Visual Analog Scale of 0 to 10; with 0 = no pain and 10 = extreme pain. The pain level will be assessed immediately following needle removal and at days 2 and 8 following the procedure. We plan to enroll 102 patients in this study and expect to have all patients enrolled in the next 3 months. Updated data as part of an interim analysis of this randomized trial will be presented at the time of the ASH meeting.

Disclosures:
Berenson: Vidacare, Inc.: Research Funding.