bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antithrombotic Properties of DU-176b, a Novel, Potent and Orally Active Direct Factor Xa Inhibitor in Rat Models of Arterial and Venous Thrombosis: Comparison with Fondaparinux, an Antithrombin Dependent Factor Xa Inhibitor.
Authors: Fukuda Toshio , Matsumoto Chikako , Honda Yuko , Sugiyama Nobutoshi , Morishima Yoshiyuki , Shibano Toshiro 
Published: October 2019

Abstract
Factor Xa (FXa) is an attractive target for the treatment of thrombosis due to its crucial role in the blood coagulation cascade. Fondaparinux, a selective FXa inhibitor, has been approved for clinical use to prevent deep vein thrombosis after orthopedic surgery; however, it requires antithrombin (AT) to exert its antithrombotic effect. It is reported that AT dependent anticoagulants such as heparin are less effective to suppress platelet-rich arterial-type thrombus due to its inaccessibility to thrombus-bound FXa/thrombin. We have developed a potent direct (i.e. AT independent) FXa inhibitor, DU-176b. The objective of this study is to compare the antithrombotic properties of a direct selective FXa inhibitor, DU-176b, with an AT dependent selective FXa inhibitor, fondaparinux. We evaluated the antithrombotic effects of DU-176b and fondaparinux in rat models of arterial and venous thrombosis. The arterial and venous thrombosis was induced by topical application of ferric chloride to the carotid artery and by insertion of a platinum wire into the inferior vena cava, respectively. DU-176b (0.05 – 1.25 mg/kg/h) and fondaparinux (1 – 10 mg/kg/h for arterial thrombosis and 0.03 – 1 mg/kg/h for venous thrombosis) were intravenously administered as continuous infusions. DU-176b prevented both arterial and venous thrombosis in the same dose range. In contrast, the effective doses of fondaparinux markedly differed between these models. A higher dose of fondaparinux more than 100 times was required to inhibit arterial thrombosis compared with venous thrombosis. These results suggest that direct inhibition of FXa is a preferable strategy to AT dependent inhibition for the prevention of thrombus formation in the arteries.
In Vitro Characteristics, Anticoagulant Effects and In Vivo Antithrombotic Efficacy of a Novel, Potent and Orally Active Direct Factor Xa Inhibitor, DU-176b.
Authors: Morishima Yoshiyuki , Furugohri Taketoshi , Isobe Koji , Honda Yuko , Matsumoto Chikako , Shiozaki Yoko , Muramatsu Sumie , Sugiyama Nobutoshi , Shibano Toshiro 
Published: October 2019

Abstract
Factor Xa (FXa) is a key serine protease in the coagulation cascade and is a promising target enzyme for developing a new antithrombotic agent. Our first clinical candidate for a small molecular direct FXa inhibitor DX-9065a potently inhibits FXa (Ki = 41 nM) and exerts antithrombotic effects in animal models. However, due to its poor bioavailability (10% in monkeys) the compound is used only as an injectable formulation in clinical studies. Here we report in vitro characteristics of serine proteases inhibition, anticoagulant effects and in vivo antithrombotic efficacy of DU-176b, a novel, potent and orally active direct FXa inhibitor. DU-176b competitively inhibited human FXa with a Ki value of 0.561 nM, indicating 70-fold increase in FXa inhibitory activity compared with DX-9065a. DU-176b demonstrated 10,000-fold selectivity relative to inhibition of thrombin (Ki = 6.00 μM), and had no effects on the enzymatic activities of factor VIIa, t-PA, plasmin, trypsin and chymotrypsin. In human plasma, DU-176b prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT) in a concentration-dependent manner. Its concentrations for doubling these clotting times were 0.256 and 0.508 μM, respectively. After oral administration of DU-176b to rats, significant anti-Xa activity was observed in plasma over 4 h. The oral bioavailability of DU-176b (approximately 50%) was significantly higher than that of DX-9065a (10%) in monkeys. The antithrombotic efficacy of DU-176b was examined by oral administration to rats 30 minutes prior to thrombogenic stimuli. In a venous stasis thrombosis model, DU-176b (0.5 – 12.5 mg/kg, p.o.) dose-dependently inhibited thrombus formation, prolonged PT, and revealed plasma anti-Xa activity. DU-176b also exerted significant anticoagulant effect in a rat model of tissue factor-induced disseminated intravascular coagulation at doses of 0.1 – 2.5 mg/kg, p.o. These results demonstrate that DU-176b is a potent and selective factor Xa inhibitor that possesses antithrombotic effect after oral administration. DU-176b has the potential to be clinically useful for prophylaxis and treatment of several thrombotic diseases.
Supplemental Alpha-2-Antiplasmin Prevents Plasmin-Induced Hemorrhage.
Authors: Stewart Daphne , Marder Victor J. , Kong Mansze , Quon Doris , Cook Scott A. , Jesmok Gary , Radtke Peter , Baumbach George A. 
Published: October 2019

Abstract
Plasmin is a direct-acting thrombolytic agent with an impressive safety margin in experimental models, as it is tolerated without bleeding at a 6-fold greater dose than needed for thrombolysis. At higher plasmin dosages, above a reproducible dose threshold, alpha-2-antiplasmin (AP) is consumed, accompanied by complete depletion of fibrinogen and factor VIII. As a result of clotting factor exhaustion, the primary bleeding time is prolonged. We assessed whether supplemental AP could prevent bleeding induced by a purposefully toxic dosage of plasmin, and whether AP could arrest such bleeding once it occurs. Using the rabbit ear puncture model, plasmin (8 mg/kg) alone was compared with plasmin plus supplemental AP (5 mg/kg), injected either prior to or after plasmin infusion. We dosed plasmin 8-fold higher than that required for thrombolytic efficacy, based upon our previous observations of its capacity to prolong primary bleeding in greater than 80% of treated animals. Parameters for comparison between treatment groups were: primary bleeding time at timepoints prior to, during, and after experimental infusion, incidence of rebleeding at previously stable hemostatic sites, and quantification of AP, fibrinogen, and factor VIII. Pre-treatment AP doubled the plasma concentration, preserved circulating fibrinogen and factor VIII, and prevented bleeding. Post-plasmin AP corrected the plasmin-associated depletion of AP, but fibrinogen and factor VIII concentrations remained very low, and prolonged bleeding was uncorrected. To test whether AP could be supplemented with coagulation factors in order to arrest bleeding following high dose plasmin, human cryoprecipitate was co-administered. While the fibrinogen and factor VIII levels increased to 200% and 50% of baseline values, respectively, prolonged bleeding persisted. Unexpectedly, administration of human cryoprecipitate led to excess bleeding in association with acute thrombocytopenia and gross hemolysis, presumably mediated by xenographic antibody present in the product. Thus, we find that supplemental AP administered prior to a toxic dose of plasmin prevents coagulation factor consumption and preserves normal hemostasis. Once coagulation factor depletion occurs, AP alone is insufficient to correct the hemorrhagic state that ensues. Clinically, plasmin may be useful as a regional thombolytic agent, and AP supplementation may permit higher dosing as well as protect against accidental overdose. Further studies are needed to determine whether combined AP and coagulation factor repletion may correct the prolonged bleeding induced by massive plasmin infusion.
Respiratory Synctial Virus (RSV) Infection in Hematopoietic Stem Cell Transplant (HCT) Recipients: Risk Factors for Acquisition and Lower Respiratory Tract Disease, and Impact on Mortality.
Authors: Boeckh Michael J. , Gooley Ted , Englund Janet , Chien Jason W. , Crawford Stephen W. , Bowden Raleigh , Lawrence Corey 
Published: October 2019

Abstract
RSV lower respiratory tract disease (LRTD) is a serious complication after HCT. Risk factors for virus acquisition and progression from RSV upper respiratory tract infection (URI) to RSV LRTD are poorly defined. A targeted surveillance system consisting of routine virologic evaluation for RSV (DFA, shell vial assay, culture) in HCT recipients with URI symptoms was instituted in 10/89. We retrospectively analyzed risk factors of RSV acquisition and the development of RSV-LRTD among patients with RSV-URI between 10/89 and 7/02. From 10/94 to 7/97, patients with RSV-URI received preemptive aerosolized ribavirin (2g/day) for 5–7 d; some patients received full-dose preemptive ribavirin (6g/day). All results are from multivariable models. One hundred forty-seven of 4717 (3.1%) patients were diagnosed with RSV URI and/or LRTD during the first 100 days after HCT. Risk factors for RSV acquisition included bone marrow vs. peripheral blood stem cell (PBSC) (1.7, P=0.01), winter season (P<0.0001), the years 1993 and 1997 when 2 outbreaks occurred (HR 1.7, P=0.01), male sex (HR 1.4, P=0.06). Laminar airflow rooms (HR 0.5, P=0.004) and the period after 1997 (HR 0.65, P=0.09) were protective against acquisition (after 1997, we started to restrict patient contact with staff and caretakers who had an URI with uncontrolled secretions). Risk factors for RSV-LRTD among infected patients included age > 20 year (OR 3.2, P=0.02) and lymphocytopenia < 100/mm3 (OR 4.7, P=0.0005). To assess risk factors for progression from RSV-URI to LRTD, patients who presented with RSV-URI were examined. Lymphocytopenia < 100/mm3 was the only statistically significant factor (OR 14, P<0.001) associated with progression; use of preemptive ribavirin (low- or high-dose) was not statistically significantly associated with a lower progression rate. The development of RSV LRTD as a time-dependent variable was associated with increased mortality after HCT (HR 2.2, p < 0.001), after controlling for age, underlying disease status, donor match and type, conditioning regimen, stem cell source, and CMV serostatus. Thus, RSV acquisition is less common with PBSC transplantation and in a strict isolation setting. Restricting recipients’ contact to people with uncontrolled respiratory secretions in the outpatient setting may be beneficial; further studies are needed to confirm this. Lymphocytopenia is an important risk factor for progression from URI to LRTD and RSV-LRTD is independently associated with mortality after HCT.
AMP Deaminase Activation Contributes to Accelerated Adenine Nucleotide Pool Depletion during Periods of Energy Imbalance in Sickle Cell Erythrocytes.
Authors: Sabina Richard L. , Wandersee Nancy J. , Hillery Cheryl A. 
Published: October 2019

Abstract
Mature erythrocytes are unable to synthesize AMP from IMP due to the developmental loss of adenylosuccinate synthetase, which also effectively prevents the synthesis of adenine nucleotides from circulating hypoxanthine, the major salvageable purine compound. Consequently, AMP deaminase (AMPD) activity must be tightly regulated in order to avoid irreversible depletion of the erythrocyte adenine nucleotide pool during periods of energy imbalance. However, increased intracellular calcium promotes activation of erythrocyte AMPD (AMPD3) through a protein-protein interaction with calmodulin (Mahnke and Sabina, Biochemistry44:5551, 2005). Therefore, we hypothesized that Sickle Cell Disease (SCD) erythrocytes would more rapidly accumulate IMP and deplete the adenine nucleotide pool during periods of energy imbalance. In order to test this hypothesis, acid-soluble pools of these metabolites were quantified by anion-exchange HPLC in SCD and control erythrocytes during autoincubation and glucose starvation, both at 37C. Data in the table show that SCD erythrocytes accumulate more IMP during a 6-hour autoincubation compared to control cells, and this is accompanied by a decrease in AMP.
Effect of Autoincubation on Erythrocyte AMP and IMP Pools GROUP HOURS AMPa IMP IMP/AMP a, metabolite concentrations reported as μmol/g Hb; †, p<.05 when compared to 0 time in a paired student’s t-test; ‡, p<.05 when compared to control in an unpaired student’s t-test Control (N=4) 0 .29±.08 .15±.06 .58±.28 6 .29±.01 .33±.11† 1.15±.35† SCD (N=5) 0 .22±.04 .08±.03 .36±.10 6 .14±.03† .74±.24†‡ 5.15±1.25†‡
Data in the figure show an accelerated depletion of ATP and increased accumulation of IMP in glucose-starved SCD erythrocytes compared to control cells (*, p<.05 when compared to control in an unpaired student’s t-test).
Figure Figure
These combined results demonstrate AMPD3 enzyme activation and accelerated adenine nucleotide pool depletion during periods of energy imbalance in SCD erythrocytes. This metabolic imbalance in SCD erythrocytes could contribute to 1) an increased rate of hemolysis, 2) cation channel dysregulation, 3) modulation of adhesive membrane components, and 4) diminished protein phosphorylation. Furthermore, strategies directed against this metabolic imbalance, e.g., diffusible AMPD inhibitors and adenine supplementation, may have a therapeutic benefit in SCD.
Hsp90 Is Critical for the Regulation of Phenotype and Functionality of Human Dendritic Cells.
Authors: Bae Jooeun , Mitsiades Constantine , Yu-Tzu Tai , Martinson Jeff , Batchu Ramesh Babu , Bertheau Robert , Li Cheng , Prabhala Rao , Masood Shammas , Hideshima Teru , Catley Lawrence , Anderson Kenneth , Munshi Nikhil 
Published: October 2019

Abstract
Hsp90, a molecular chaperone, plays a critical role in protein folding and transport, and thereby it modulates cellular activity. Pre-clinical data shows over-expression of Hsp90 in multiple myeloma (MM) and efficacy of Hsp90 inhibitor in myeloma has been determined in vitro. Based on these results, phase I/II trial evaluating clinical efficacy of the Hsp90 inhibitor is underway in MM. Although Hsp90 inhibitor shows significant effects on tumor cells, there is limited information concerning its effects on the immune system. The objective of this study was to evaluate the effects of Geldanamycin on activity of antigen-presenting cells. Immature and mature monocyte derived dendritic cells (DC) from normal human donors were used as the source of antigen-presenting cells in this study. Geldanamycin treatment of DC for 24 hours had no effect on cell viability (>90%), however, it led to a significant down-regulation of surface antigens associated with activation (CD86, CD80), maturation (CD83) and antigen presentation (HLA-ABC, HLA-DPQR). This decline was associated with changes in gene expression levels of these antigens, however the protein expression analyzed by % positive cells was not down-regulated with the treatment. Exposure to Hsp90 inhibitor was associated with significant decreases in IL-12 secretion (untrt vs. trt = 135 vs. 21 pg/ml), antigen uptake (MFI untrt 798 vs. MFI trt 449, Dextran-FITC), and antigen processing. These changes were associated with decline in DC function, which were demonstrated by significant decrease in Hsp90-treated DC compared to untreated DC in presentation of Tetanus Toxoid to autologous T lymphocytes (untrt vs. trt = 73 % vs. 47 %, CFSE proliferation), allogeneic T lymphocytes stimulation (untrt vs. trt = 232795 cpm vs. 116876 cpm, 3H-thymidine incorporation), and induction of IFN-g secretion from allogenic T lymphocytes (untrt vs. trt = 500 vs. 30 pg/ml). Taken together, these results show significant decline in DC function following Hsp90 inhibitor treatment. Further studies are underway using MM patient samples pre- and post-Hsp90 inhibitor treatment to understand in vivo effects on the immune system. Our pre-clinical data suggests the need to consider proper sequence of various therapeutic modalities, including immunotherapy, to optimize and improve clinical outcome.
Targeting MLL-AF4 with Short Interfering RNAs (siRNAs) Induces Apoptosis Related Genes APAF-1 and SEPT4 in t(4;11)-Positive Human Leukemic Cells.
Authors: Greil Johann , Thomas Maria , Gessner Andreas , Heidenreich Olaf 
Published: October 2019

Abstract
The chromosomal translocation t(4;11) marks infant acute lymphoblastic leukemia associated with a particularly dismal prognosis. We have recently shown that transfection of leukemic cells with MLL-AF4 siRNAs reduces leukemia-associated morbidity and mortality in xenotransplanted SCID mice suggesting that MLL-AF4 depletion negatively affects leukemia-initiating cells. In cell culture, transient suppression of MLL-AF4 expression impairs the proliferation of both t(4;11) cell lines SEM and RS4;11 more than tenfold. Clonogenicity of SEM cells was reduced fivefold and of RS4;11 cells more than twofold. One major reason for the antiproliferative consequences is the induction of apoptosis associated with caspase-3 activation and diminished BCL-XL expression. Caspase-3 was induced 3-fold and BCL-xL showed a 60% reduction after siRNA treatment compared to Mock-transfected controls in SEM cells. Analysis of intrinsic signaling pathways of apoptosis showed that MLL-AF4 depletion induces the expression of the proapoptotic genes APAF-1 and SEPT4 (ARTS). In both cell lines APAF-1 was induced more than twofold and SEPT4 more than fourfold. Our findings demonstrate that MLL-AF4 negatively interferes with an intrinsic apoptotic response and is, thus, important for the survival of these highly aggressive and chemoresistant leukemic cells. SiRNA-mediated MLL-AF4 inhibition may sensitize these cells for apoptosis-inducing agents. Therefore, complementing existing treatment strategies with a targeted inhibition of MLL-AF4 expression may lead to an improved and more specific treatment of this therapy-resistant leukemia.
Are Statistically Non-Significant Findings Necessarily Negative? A Review of All Phase III Randomized Controlled Trials in Hematology Conducted by NCI Sponsored Cooperative Groups.
Authors: Kumar Ambuj , Soares Heloisa , Djulbegovic Benjamin 
Published: October 2019

Abstract
Background: Randomized clinical trials (RCT) remain the primary mean for advancement of new treatments for the prevention and cure of hematological malignancies. However, if a RCT fails to show a significant difference between the treatment and the control group, is it because treatment is not effective (evidence of absence of treatment effect) or the results were inconclusive (absence of evidence of treatment effect).
Methods: We identified 143 studies related to hematological malignancies out of 566 trials conducted by 6 NCI sponsored cooperative groups (RTOG, COG, GOG, ECOG, NSABP and NCCTG). Data were extracted from the original research articles and protocols. Quality of trials was high. To determine whether non-significant trial findings were true negatives or inconclusive, we compared the a priori effect size used in the power calculation for the trial’s pre-defined primary outcome to the confidence intervals (CIs) of the non-significant trial results. Trial results were construed as true negative if the effect size and the 95%CIs were entirely outside the limits of equivalence and inconclusive if the 95%CIs crossed the line of no effect and one or both limits of equivalence (BMJ2004;328:476–477).
Results: 71% of studies resulted in non significant outcome (102/143, missing data for 11 studies). Comparing the calculated CI to the a priori specified effect size 48% (44/91) of studies resulted in true negative results (evidence of no effect) and 52% (47/91) were inconclusive (no evidence of effect). Most of the studies (73%, 66/91) had conducted a power analysis before the commencement of trials. The range of expected effect size for experimental treatments in this set of trials ranged from as low as 9% to high as 200% (improvement in survival).
Conclusion: High-quality RCTs conducted by the most prestigious institutions often result in inconclusive or negative findings. Unrealistic expectation in treatment effect size appears to be a major culprit for continuing conduct of underpowered trials.
Oral Mucositis (OM) and Outcomes of Allogeneic (AL) Hematopoietic Stem Cell Transplantation (HSCT) in Patients with Hematologic Malignancies.
Authors: Vera-Llonch Montserrat , Oster Gerry , Ford Colleen , Lu John , Khazanov Irina , Sonis Stephen 
Published: October 2019

Abstract
Background. OM is a common toxicity of conditioning regimens for HSCT that has been associated with adverse clinical and economic outcomes.
Methods. A retrospective chart review study of ~400 consecutive HSCT recipients with hematologic malignancies was undertaken at a single academic center. OM severity was assessed across eight oropharyngeal sites using a validated scale which was scored as follows: no erythema/ulceration = 0; erythema only = I; ulceration one site = II; two sites = III; three sites= IV; and four or more sites = V. OM assessments began on the day of conditioning and continued bi-weekly until hospital discharge. Outcomes of interest included number of days of fever, total parenteral nutrition (TPN), and parenteral narcotic therapy, incidence of Grade III or IV (Common Toxicity Criteria) infection, and inpatient days and charges. We report data here for the 281 AL HSCT recipients in the study cohort.
Results. Mean age was 41 yrs. Most common diagnoses were acute (33%) and chronic (19%) myeloid leukemia. Most patients (96%) received total body irradiation. Fifty-one percent of grafts were from unrelated donors. Seventy-six percent of patients experienced OM ≥ grade II. The relationship between worst recorded grade of OM and each of the outcomes of interest is reported below.
Conclusions. OM is associated with worse clinical and economic outcomes in patients with hematologic malignancies undergoing AL HSCT.
Outcomes of AL HSCT in patients with hematologic malignancies, by worst recorded grade of OM Worst Grade of OM (N=281) 0 I II III IV V Outcome n=34 n=33 n=70 n=60 n=43 n=41 -value p *mean, SD; **test for linear trend; Cochran-Armitage for dichotomous measures, GLM for continuous measures Fever days* 3.1 (3.0) 4.8 (4.4) 5.3 (4.9) 5.7 (4.7) 5.9 (4.7) 7.3 (4.6) <0.001 TPN days* 6.7 (7.2) 7.7 (7.8) 8.8 (7.8) 10.2 (7.8) 13.2 (7.2) 14.0 (6.2) <0.001 Narcotic days* 7.6 (6.3) 10.8 (5.0) 10.7 (7.4) 11.5 (5.1) 14.0 (6.8) 17.2 (5.0) <0.001 Infection (%) 85.3 90.9 92.9 93.3 100.0 100.0 0.002 Mortality (%) 8.8 3.0 8.6 15.0 7.0 22.0 0.042 Inpatient days* 28.1 (8.8) 30.3 (10.6) 34.5 (15.1) 32.7 (14.5) 35.9 (10.4) 42.4 (15.1) <0.001 Inpatient charges* (x 1,000 USD) 214 (102) 252 (156) 313 (251) 280 (198) 305 (140) 437 (233) <0.001