bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing Doses of Anticoagulation Are Associated with Improved Survival in Hospitalized COVID-19 Patients
Authors: Ionescu Filip , Nair Girish B , Petrescu Ioana , Konde Anish S , Zimmer Markie Sue , Anusim Nwabundo , Jindal Vishal , Gaikazian Susanna , Anderson Joseph , Stender Michael , Huben Marianne Terese , Jaiyesimi Ishmael 
Published: February 2021

Background: Hypercoagulability may contribute to COVID-19 pathogenicity. Evidence comparing clinical outcomes among patients with COVID-19 receiving therapeutic compared to prophylactic dose anticoagulation is limited. We evaluated whether therapeutic anticoagulation (tAC) is associated with improved survival compared to prophylactic (pAC) and no anticoagulation (AC) in hospitalized COVID-19 patients.
Methods: This was a retrospective, multi-center cohort study of consecutive COVID-19 patients admitted between March 13th, 2020 and May 5th, 2020 to eight hospitals within a large academic system in Southeast Michigan, USA. Participants were assigned to three groups based on whether they received no AC, pAC throughout most of their hospitalization, or at least 3 days of tAC. Major bleeding was defined as transfusion of five or more units of packed red blood cells within 48 hours regardless of hemoglobin level, hemoglobin &lt; 7g/dL and any red blood cell transfusion or a diagnosis code for major bleeding during the hospitalization or radiological evidence of intracranial hemorrhage
Results: A total of 3480 patients were included (mean age, 64.5 years [17.0]; 51.5% female; 52.1% black and 40.6% white). 18.5% (n=642) were treated in the intensive care unit (ICU). 60.9% received pAC (n=2121), 28.7% received at least 3 days of tAC (n=998), and 10.4% (n=361) did not receive AC. Propensity score (PS) weighted Kaplan-Meier plot demonstrated a statistical difference in the 25-day survival probability in the tAC group compared to the pAC group (57.5% vs 50.7%, Figure). In a PS weighted multivariate proportional hazards model adjusting for age, body mass index and ICU status, AC was associated with a reduced risk of death at both prophylactic (hazard ratio [HR] 0.35 [95% confidence interval {CI} 0.22-0.54]) and therapeutic doses (HR 0.14 [95% CI 0.05-0.23]) compared to no AC. Major bleeding occurred more frequently among tAC patients (81 [8.1%]) compared to those who received no AC (20 [5.5%]) or pAC (46 [2.2%]).
Conclusions : Higher doses of AC are associated with lower mortality in hospitalized COVID-19 patients. The lowest hazard ratio was observed in ICU patients, but risk was also significantly lower in non-ICU hospitalized patients. Bleeding occurred more frequently with higher doses of anticoagulation. Ongoing randomized trials are warranted to prospectively evaluate efficacy and risk of tAC in patients with COVID-19.
Figure

Disclosures
No relevant conflicts of interest to declare.
Role of Hypercoagulable Studies in Cryptogenic Stroke: A Retrospective Study
Authors: Prakash Amulya , Korem Sindhuja , Inkollu Sindhura , Gandhi Haresh , Iqbal Farrukh , Abaskhroun Peter , Pernia Julio , Rojas Juan , Singh Vinit , Du Doantrang T. 
Published: February 2021

Introduction:
Hypercoagulable states are recognized, although uncommon, etiology of ischemic stroke especially in young adults under the age of 40 and children. Currently, there are no specific guidelines related to screening patients for inherited thrombophilia who are diagnosed with ischemic stroke without any identifiable risk factors. Typically, patients to be screened for thrombophilia will have prior unexplained thromboembolic events. We evaluated the association between thrombophilia and cryptogenic stroke and the role of serologic and genetic testing to establish the diagnosis.
Material and methods:
We performed a retrospective study through a review of EHR of patients diagnosed with ischemic stroke at our hospital between 2015- 2019 with laboratory testing for thrombophilia. The primary outcome was to identify any positive association between thrombophilia and cryptogenic stroke. The secondary outcome was to identify any change in clinical management based on thrombophilia testing results.
Results:
Among 35 patients included, who had an average age of 58.5 years ± 16.37 years with 36.6% under the age of 55 and 63.3% above the age of 55. Sex distribution was 40% female and 60%, male. Of 35 patients who had thrombophilia studies ordered, 9 patients had at least one positive thrombophilia test identified but none of them had any resultant change in management. 2 patients had protein C deficiency, 3 patients had protein S deficiency and 4 patients had antithrombin III deficiency, however, they were measured during the acute phase and were not repeated as an outpatient. None of the patients were found to have any Factor V and PT gene G20210A gene mutation. Lupus anticoagulant, antiphospholipid antibodies, homocysteine level were not uniformly tested.
Conclusion:
Only 8% of all patients who had thrombophilia testing had at least one positive study with no change in clinical management. We concluded that there is a poor correlation between inherited thrombophilia and cryptogenic stroke. The majority of our patients who had worked up done were above the age of 55 years who didn't display any symptom of thrombophilia previously. It raises a question of reflexive and inappropriate testing in the absence of clear guidelines for thrombophilia workup in the setting of cryptogenic stroke.

Disclosures
No relevant conflicts of interest to declare.
Obesity-Driven Acceleration of Acute Promyelocytic Leukemia Development in Mice with Inserted PML-RARa
Authors: Kincaid John W.R. , Ribeiro Susan Pereira , Sanchez Gabriela , Hill-Baskin Anne , Berger Nathan A. 
Published: February 2021

While a number of solid tumors are identified as obesity-associated cancers, multiple myeloma and acute promyelocytic leukemia (APL) are the only hematologic malignancies included in this category. APL is a highly treatable form of AML characterized by maturation arrest at the promyelocyte stage, and frequent cures with combined ATRA and Arsenic Trioxide therapy. APL is initiated by a chromosomal translocation that causes the fusion of thePMLandRARAgenes, leading to the production of PML-RARA protein. To determine if obesity accelerates the development of APL, we used a genetically-engineered knock-in model in which human PML-RARA cDNA was inserted into the 5' untranslated region of the murine cathepsin G gene (Ctsg), which targets expression to early myeloid progenitor cells. This knock-in transgene was extensively backcrossed (&gt;20 generations) into the C57BL/6J (B6) genetic background, which has been consistently shown to render mice susceptible to diet-induced obesity.Ctsg-PML-RARA mice developed on the B6 background generate a lethal APL-like leukemia with a latency of 8-12 months, and a penetrance of about 60%, as cooperating mutations occur and cause clinical disease.
We placed cohorts of B6.Ctsg-PML-RARA heterozygous (mCG+/PR) and wild-type (WT) mice, genotyped by PCR, on high-fat (HFD) [57% coconut oil fat] and low-fat (LFD) [10% coconut oil fat] diets, collecting peripheral blood via the retro- orbital sinus at 30 day intervals and performing automated blood counts to observe temporal associations in disease development. HFD feeding significantly accelerated the development of APL in mCG+/PR mice, leading to anemia, thrombocytopenia, leukocytosis of the granulocyte series, and splenomegaly. Survival rate reduction demonstrated sexual-dimorphism, with male HFD-fed mCG+/PR mice displaying a median leukemia-free survival time of 211 days compared to 266 days in the female HFD-fed mCG+/PR cohort. In contrast, LFD-fed mCG+/PR male mice showed a median survival time of 318 days, whereas none of LFD-fed mCG+/PR female group nor any of the WT groups on HFD or LFD have reached median survival as of 325 days. Moreover, no signs of leukemia were observed in either HFD- and LFD-fed WT groups, indicating that adiposity alone had no leukemogenic effect. These studies clearly demonstrate that obesity accelerates leukemogenesis in theCtsg-PML-RARA mouse model of acute promyelocytic leukemia.
High density flow cytometry will be applied in the bone marrow of the different groups to evaluate the modulation of multiple hematopoietic cell lineages and cell surface markers.

Disclosures
No relevant conflicts of interest to declare.
Prdm16 Is a Critical Regulator of Adult Long-Term Hematopoietic Stem Cell Quiescence
Authors: Gudmundsson Kristbjorn Orri , Du Yang , Nguyen Nhu , Oakley Kevin , Han Yufen , Gudmundsdottir Bjorg , Liu Pentao , Tessarollo Lino , Jenkins Nancy , Copeland Neal 
Published: February 2021

Regulation of quiescence is critical for the maintenance of adult hematopoietic stem cells (HSCs). PRDM16 encodes a zinc-finger transcription factor homologous to MECOM and was first cloned from chromosome translocations in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) patients. Disruption of Prdm16 during mouse embryonic development has been shown to cause a profound loss of fetal liver HSCs; however, the underlying mechanisms and the function of Prdm16 in adult HSCs remain unclear. Using a novel Prdm16 conditional knockout mouse model, we show that Prdm16 deletion in adult mouse hematopoietic system have a less severe effect on HSCs, causing a gradual decline in adult HSC numbers and a concomitant increase in the multipotent progenitor (MPP) compartment. Prdm16 deletion in the hematopoietic system following transplantation produced the same phenotype indicating that the defect is intrinsic to adult HSCs. This HSC loss was also exacerbated by stress induced by 5-FU injections. Annexin V staining showed no difference in apoptosis between wild type and knockout adult long-term HSCs (LT-HSCs). In contrast, BrdU analysis revealed that loss of Prdm16 significantly increases cycling of LT-HSCs with majority of the cells found in the S to G2/M phase. Consistently, RNA-seq analysis of mouse LT-HSCs with and without Prdm16 deletion showed that Prdm16 loss induced a significant decrease in the expression of several known cell cycle regulators of HSCs. Two such genes were further identified as direct targets of Prdm16. Our results suggest that Prdm16 preserves the function of adult LT-HSCs by promoting their quiescence.

Disclosures
No relevant conflicts of interest to declare.
Single-Cell Transcriptome of Early Hematopoiesis Guides Arterial Endothelium-Promoted Functional T Cell Generation from Human Pluripotent Stem Cells
Authors: Shen Jun , Xu Yingxi , Zhang Shuo , Lyu Shuzhen , Wang Zack , Wang Min , Li Xin , Cheng Tao 
Published: February 2021

Human pluripotent stem cells (hPSCs) provide a powerful platform for generating functional hematopoietic cells for blood disease modeling and therapeutic testing. However, the quantity and quality of hPSC-derived blood cells remain to be improved. Here, by performing extensive single-cell transcriptomic analyses to map fate choices and gene expression programs during hematopoietic differentiation of hPSCs, we construct the first hematopoietic landscape of hPSCs at the single-cell level and identify strategies to promote hematopoietic progenitor (HP) generation from hPSCs with functional T cell potential.
By focusing specifically on cell populations and molecular events involved in endothelial-to-hematopoietic transition (EHT), we compared the difference of early hematopoiesis between hPSCs and human embryos (Yang Zeng et al. Cell Research. 2019) and found aerobic metabolism was dysregulated during in-vitro-directed differentiation. The decreased oxygen metabolism program was further deciphered as a key molecular event occurred during the EHT. Providing hypoxia at the stage of EHT enhanced hematopoietic differentiation of hPSCs via specifying arterial programs, including arterial hemogenic endothelium (AHE) and arterial endothelium cells (AE).
To further determine the effect of AE on hematopoietic development, we isolated AE, venous endothelium and mesenchymal cells identified in our single-cell transcriptomic analyses and cocultured them with AHE respectively for HP generation. AE were finally validated as a critical regulator of definitive HP specification with more T cell potential. T cells generated from AE-primed HPs (AE-T) were highly functional and exhibited polyfunctional production of interferon (IFN)-γ, tumor necrosis factor alpha (TNF-α), and IL-2 in response to phorbol 12-myristate 13-acetate (PMA) and ionomycin. To further evaluate the function of AE-T, we engineered T cells with CD19-CAR. The in vitro cytotoxicity of CAR-engineered AE-T was performed both in CD19+ cell lines (Nalm-6 and Raji) and human primary B-ALL samples. The efficacy of CAR-engineered AE-T in vivo was evaluated in a mouse xenograft model inoculated intravenously with luciferase-expressing Nalm-6 cells. Similar to CD19 CAR-transduced peripheral blood T cells, the AE-T potently inhibited tumor growth both in vitro and in vivo.
Collectively, our study provides benchmark datasets to understand the origins of human hematopoiesis and presents an advance for guiding the generation of functional T cells in vitro for clinical applications.

Disclosures
No relevant conflicts of interest to declare.
Anti-Acute Monocytic Leukemia Activities of Selenium Nanoparticles Embedded in Nanotube Consisted of Triple-Helix β-D-Glucan
Authors: Chen Yanling , Lv Fengzhi , Luo Ziyi , Zhang Dongdong , Zhou Fuling 
Published: February 2021

Acute monocytic leukemia (AML-M5) is a subtype of acute myeloid leukemia (AML) which has the characteristics of high degree of malignancy, prone to extramedullary infiltration, poor efficacy of conventional chemotherapy, easy recurrence, etc. Besides, chemotherapy has large side effects and high cost. Therefore, it is urgent to find natural, non-toxic and cheap drugs for the treatment of AML-M5.
Polysaccharide is a class of natural macromolecular substances with biological activities such as immune regulation, anti-tumor, anti-oxidation, anti-virus, and hypoglycemic activity. Selenium is a component of human erythrocyte glutathione peroxidase, it participates in the metabolism of peroxide and iodine in the body, regulates the level of iodine and free radicals in the organism, and can enhance the body's ability to prevent and resist diseases. LNT-Se has the activity of SeNPs and the physiological function of polysaccharide.Due to the self-assembly behavior of rigid triple helix β-glucan (LNT) extracted from Lentinus edodes in aqueous solution, Selenium nanoparticles (SeNPs) could be encapsulated in the cavities of hollow nanotubes consisted of LNT to form stable complexes (LNT-Se) with high dispersity and biocompatibility. It could significantly improve the safety, biocompatibility and anti-tumor activity of SeNPs, and had powerful applications in the field of nanomaterials.
In this study, we found that LNT-Se could inhibit the proliferation of AML-M5 cell lines such as THP-1, Molm-13, MV-4-11 and greatly promote the apoptosis of AML-M5 cell lines and M5 patient cells, and obviously block cells in the G2/M phase. It had little toxicity to normal cell lines, hematopoietic stem cells (HSC) and healthy human peripheral blood mononuclear cells (PBMC). Besides, we used a novel optofluidics chips wth diffused total internal reflection (TIR) method to capture single Molm-13 GFP + cell, and at the same time detected the signal intensity changes of GFP at different drug concentrations. At the single-cell level, We also observed the swelling, lysis and fluorescence intensity of the cells after treatment.
Therefore, it's a promising drug for the treatment of AML-M5. These findings indicate that LNT-Se inhibit theproliferation of leukemia cell and it can be a natural inducer for therapy of AML.

Disclosures
No relevant conflicts of interest to declare.
Opposing Evolutionary Pressures Drive Clonal Evolution and Health Outcomes in the Aging Blood System
Authors: Skead Kimberly , Ang Houle Armande , Abelson Sagi , Fave Marie-Julie , Lin Boxi , Soave David , Wright Stephen , Dick John E. , Morris Quaid , Awadalla Phillip 
Published: February 2021

The age-associated accumulation of somatic mutations and large-scale structural variants (SVs) in the early hematopoietic hierarchy have been linked to premalignant stages for cancer and cardiovascular disease (CVD). However, only a small proportion of individuals harboring these mutations progress to disease, and mechanisms driving the transformation to malignancy remains unclear. Hematopoietic evolution, and cancer evolution more broadly, has largely been studied through a lens of adaptive evolution and the contribution of functionally neutral or mildly damaging mutations to early disease-associated clonal expansions has not been well characterised despite comprising the majority of the mutational burden in healthy or tumoural tissues. Through combining deep learning with population genetics, we interrogate the hematopoietic system to capture signatures of selection acting in healthy and pre-cancerous blood populations. Here, we leverage high-coverage sequencing data from healthy and pre-cancerous individuals from the European Prospective Investigation into Cancer and Nutrition Study (n=477) and dense genotyping from the Canadian Partnership for Tomorrow's Health (n=5,000) to show that blood rejects the paradigm of strictly adaptive or neutral evolution and is subject to pervasive negative selection. We observe clear age associations across hematopoietic populations and the dominant class of selection driving evolutionary dynamics acting at an individual level. We find that both the location and ratio of passenger to driver mutations are critical in determining if positive selection acting on driver mutations is able to overwhelm regulated hematopoiesis and allow clones harbouring disease-predisposing mutations to rise to dominance. Certain genes are enriched for passenger mutations in healthy individuals fitting purifying models of evolution, suggesting that the presence of passenger mutations in a subset of genes might confer a protective role against disease-predisposing clonal expansions. Finally, we find that the density of gene disruption events with known pathogenic associations in somatic SVs impacts the frequency at which the SV segregates in the population with variants displaying higher gene disruption density segregating at lower frequencies. Understanding how blood evolves towards malignancy will allow us to capture cancer in its earliest stages and identify events initiating departures from healthy blood evolution. Further, as the majority of mutations are passengers, studying their contribution to tumorigenesis, will unveil novel therapeutic targets thus enabling us to better understand patterns of clonal evolution in order to diagnose and treat disease in its infancy.

Disclosures
Dick: Bristol-Myers Squibb/Celgene: Research Funding.
Integration of EHR and Cancer Registry Data to Construct a Childhood Cancer Survivorship Cohort to Improve Long-Term Follow-up Care for Leukemia and Lymphoma Survivors
Authors: Noyd David H. , Neely Nigel B. , Howell Claire , Oeffinger Kevin C , Kreissman Susan 
Published: February 2021

Background and aims:
Marked improvements in pediatric oncology care for children with acute lymphoblastic leukemia (ALL) and leukemia emphasize the importance of appropriate follow-up care for childhood cancer survivors (CCS) to monitor for late effects. The electronic health record (EHR) sparks unique approaches to construct, maintain, and leverage CCS cohorts to improve care. The primary purpose of this study is to utilize a novel approach to integrate EHR and cancer registry data to construct a CCS cohort for ALL and lymphoma survivors. Data mining in the EHR facilitates stratification of patients into risk cohorts and identification of high risk patients with inadequate subspecialty survivorship care
Methods
Cancer registry data from January 1, 1994 to November 30, 2012 provided a base cohort from which pediatric oncology clinic visits were extracted from the EHR. Explanatory variables included gender, race/ethnicity, risk stratification, distance to the medical center, rural-urban commuting area code, and area deprivation index as a measure of socioeconomic status. Primary outcomes included date of last clinic visit to determine appropriate follow-up, defined as being seen in a subspecialty clinic between five and seven years after initial diagnosis. Patients who died or relapsed during the seven year follow-up period were excluded from the analysis.
Results
Between January 1, 1994 and November 30, 2012, there were 262 pediatric oncology patients evaluated at our institution and reported in the cancer registry who were alive and without evidence of recurrence seven years after initial diagnosis. Of these patients, 22% of patients (n=57) were considered to have inadequate follow-up care. In univariate analysis, younger age (p&lt;0.001), primary diagnosis of ALL compared to lymphoma (p=0.007), low risk strata (p=0.014) and closer proximity to primary treatment center or Children's Oncology Group-affiliate site (p=0.013 and 0.026, respectively) were associated with a higher likelihood of follow-up care. Multivariable logistic regression modeling is currently ongoing.
Conclusions
Integration of EHR and cancer registry data represents a feasible and novel approach to construct a cohort of childhood ALL and lymphoma survivors, risk stratify patients based on treatment exposures, and assess adequate subspecialty survivorship care. Future applications include refinement of treatment exposures through the EHR, adherence to guideline recommendations, and other late effects outcomes.

Disclosures
No relevant conflicts of interest to declare.