bluuebunny/crossref_metadata_2025_split huggingface dataset:
GS-9219 - A Novel Prodrug of the Acyclic Nucleotide PMEG Has Antitumor Activity Against Naive and Melphalan-Refractory Spontaneous Myeloma in Pet Dogs.
Authors: Thamm Douglas H. , Tumas Daniel B. , Reiser Hans , Wolfgang Grushenka H.I. , Kurzman Ilene D. , Plaza Susan , Anderson Christie , Robat Cecilia , Vail David M. 
Published: October 2019

Abstract
Multiple myeloma is an important hematopoietic cancer in humans and pet dogs. While clinical remission can be achieved using currently available antineoplastic agents, eventual drug resistant relapse is common. GS-9219, a novel double prodrug of the anti-proliferative nucleotide analog 9-(2-phosphonylmethoxyethyl) guanine (PMEG), has been shown to have potent cytotoxic activity in vitro in human lymphoblasts and leukemia cell lines and in vivo in naturally occurring non-Hodgkin’s lymphoma in dogs (naive and refractory). We hypothesized that malignant plasma cells in multiple myeloma similarly would possess the intracellular enzymatic machinery necessary for the activation of GS-9219. To generate proof-of-concept, activity and safety data in multiple myeloma, a pilot study with GS-9219 monotherapy was initiated in pet dogs with naturally occurring chemotherapy-naive or refractory multiple myeloma. Three dogs with spontaneously occurring IgA myeloma (1 naive, 2 melphalan-refractory) have been treated with GS-9219 as a 30-minute intravenous infusion weekly for 2 weeks at 1 mg/kg, then every 3 weeks for another 3 treatments at 0.8 mg/kg (total of five GS-9219 doses). To date, major anti-tumor responses have been observed in all 3 multiple myeloma dogs treated with GS-9219. Two dogs are in complete remission as indicated by normalization of serum paraprotein and complete resolution of hypercalcemia, peripheral cytopenias and bone marrow plasmacytosis. The third currently has a strong partial response (normal marrow and >95% reduction in serum paraprotein). The only significant toxicity noted throughout the study was a single episode of transient neutropenia in one dog which resolved and, after a one week delay, treatment was continued without issue. Assessment of durability of response is currently ongoing, with all dogs remaining in remission to date; one dog has remained in complete remission for more than 5 months following completion of the treatment regimen. In conclusion, GS-9219 has significant anti-tumor activity in spontaneous melphalan-refractory or treatment-naive canine multiple myeloma.
Activated Protein C Inhibits Lipopolysaccharide-Induced Anandamide and 2-Arachidonoylglycerol Generation In Vitro and In Vivo.
Authors: Maruyama Ikuro , Wang Yin , Liu Yan , Kawahara Koichi , Yamakuchi Munekazu , Hashiguchi Teruto , Obata Toru 
Published: October 2019

Abstract
Anandamide(ANA) and 2-arachidonoylglycerol(2-AG), two lipid mediators existing in the central nervous system and various peripheral tissues, have been shown to exert their diverse biological effects through cannabinoid receptors CB1 and CB2, and are therefore defined as endogenous cannabinoids. Recently, ANA and 2-AG have been shown to be generated by macrophages and platelets, respectively, by the stimulation with lipopolysaccharide(LPS) in vitro and in vivo in rats. We showed the endocannabinoids are increased in septic shock patients. Furthermore, the increased endocannabinoids are efficiently adsorbed onto polymyxin B immobilized column resulting the improvement of hypotensive shock. On the other hand it has been showed that activated protein C (APC) can ameliorate endotoxin induced-shock and -disseminated intravascular coagulation in experimental animals and patients, although the mechanisms governing its action are unknown. In the present study we found that APC inhibited the generation of ANA and 2-AG in vitro by lipopolysaccharide (LPS)-activated macrophages and platelets, respectively. Furthermore, APC significantly decreased the levels of ANA and 2-AG in the sera from rats preinfused with APC followed by LPS infusion. Consistent with the decrease of them, diminishment of hypotension and an increase in survival rate were confirmed in the APC pretreatment group. These findings demonstrate that APC can inhibit the generation of ANA and 2-AG in vitro and in vivo, and thereby suppress their induced hypotension. This action of APC may explain its efficiency in the treatment of septic shock in humans and experimental animals.
Unrelated Cord Blood Transplantation Using Myeloablative Regimen for Acute Leukemia Patients Aged between 50 and 55 Years: Single Institutional Retrospective Comparison with Patients Less Than 50 Years of Age.
Authors: Konuma Takaaki , Takahashi Satoshi , Ooi Jun , Tomonari Akira , Tsukada Nobuhiro , Kato Seiko , Oiwa-Monna Maki , Uchimaru Kaoru , Tojo Arinobu , Yamaguchi Takuhiro , Asano Shigetaka 
Published: October 2019

Abstract
Background: Increasing age has been well-known as an obvious risk factor for graft-versus-host disease (GVHD) and transplant-related mortality (TRM) resulting negative impact on allogeneic transplantation including cord blood transplant (CBT). The incidence of sever GVHD after CBT, on the other hand, is lower than that after transplants using graft from adult cells, so we have expected the better results of CBT in older patients.
Objectives and Methods: This study aimed to evaluate safety and efficacy of CBT using myeloablative regimen for older patients with acute leukemia.
Patients and Methods: We retrospectively compared outcomes of older patients with acute leukemia with younger adults in our institute. Nineteen elderly patients (median age 52, range 50–55) and 81 young patients (median 49, range 16–49) received myeloablative conditioning regimen including 12 Gy of total body irradiation. GVHD prophylaxis comprised cyclosporine with (N=96) or without (N=4) methotrexate.
Results: Comparisons of characteristics in the 2 age groups showed similar distributions for weight, gender ratio, diagnosis [de novo acute myeloid leukemia (AML), myelodysplastic syndrome related secondary AML, or acute lymphoblastic leukemia], disease status at transplantation, total nucleated cell dose and CD34+ cell dose in the graft before cryopreservation and proportions of HLA and sex compatibility between donors and recipients. The median period of follow-up for survivors after CBT was 730 days for older group and 1331 days for younger group, respectively. Grade II to IV acute GVHD occurred in 10 of 17 evaluable older patients and 49 of 75 evaluable younger patients (P = 0.61), while no older patients, but 6 younger patients developed grade III to IV acute GVHD. Extensive-type chronic GVHD occurred in 4 of 15 evaluable older patients and 18 of 69 evaluable younger patients (P = 0.96), respectively. The cumulative incidence of TRM at 100 days was 5% versus 6% (P = 0.70), and of relapse at 3 years was 29% versus 20% (P = 0.33) and the estimated disease-free survival at 3 years was 67% and 71% (P = 0.53) for older or younger patients, respectively. There was no significant difference in GVHD, TRM, relapse, and DFS between 2 age groups.
Conclusion: The use of cord blood as a stem cell source might contribute to be decreased in the incidence of acute and chronic GVHD resulting in decreased TRM in older patients. Our results suggest that myeloablative CBT might be as safe and effective in patients with acute leukemia aged between 50 and 55 years as in younger patients.
Human Antibodies with Specificity for the Spacer Domain of ADAMTS13 Are Derived from VH1-69 Germline Genes.
Authors: Pos Wouter , Luken Brenda M. , Kremer-Hovinga Johanna , Turenhout Ellen A.M. , Jefferis Roy , Dong Jing-fei , Fijnheer Rob , Voorberg Jan 
Published: October 2019

Abstract
Acquired thrombotic thrombocytopenic purpura (TTP) is characterized by the presence of circulating antibodies directed towards ADAMTS13. This results in the formation of large platelet aggregates that occlude the microvasculature giving rise to thrombocytopenia and micro-angiopathic hemolytic anemia in patients with TTP who lack functional ADAMTS13. Antibodies directed towards the spacer domain of ADAMTS13 are present in the majority of patients with acquired TTP. We have previously isolated a panel of human monoclonal antibodies directed towards ADAMTS13 from the immunoglobulin repertoire of one patient with acquired TTP employing phage display. To further extend these observations we obtained a panel of human anti-ADAMTS13 antibodies from a second patient with acquired TTP. Sequence analysis revealed that the variable heavy chain domains of the majority of anti-ADAMTS13 antibodies were encoded by germline gene segment VH1–69. The VH1–69 encoded antibody II-1 and the previously described antibody I-9, which was also encoded by VH1–69 were selected for further study. Epitope-mapping studies employing a hybrid ADAMTS13 variant containing the spacer domain of ADAMTS1 showed that both antibodies were directed towards the spacer domain. Both antibodies inhibited ADAMTS13 activity as measured by cleavage of FRETS-VWF73 substrate and also inhibited cleavage of VWF multimers under static conditions as well as under flow on the surface of endothelial cells. We subsequently developed an assay to monitor the presence of VH1-69 encoded antibodies in plasma of patients with acquired TTP using the anti-idiotypic monoclonal antibody G8 which specifically reacts with human antibodies that use the VH1-69 gene segment. Analysis of a large cohort of patients with acquired TTP revealed that antibodies reactive with the spacer domain of ADAMTS13 express the VH1-69 derived idiotype that is recognized by monoclonal antibody G8. These results support the notion that VH1-69 derived human antibodies directed towards the spacer domain of ADAMTS13 develop in the majority of patients with acquired TTP.
Identification of a Stroma-Mediated Wnt Signal Promoting Self-Renewal of Hematopoietic Stem Cells in the Stem Cell Niche.
Authors: Kang Young-Ju , Jho Eek-hoon , Kim Hanjun , Park Gyeongsin , Shim Jae-Seung , Oh Il-Hoan 
Published: October 2019

Abstract
With contrasting results recently reported on the effects of b-catenin on hematopoietic stem cells (HSCs), the precise role of Wnt on HSC regulation remains in question. Here, we show that Wnt-b-catenin signaling triggers distinct biological effects on HSCs depending on the target of activation within the hematopoietic microenvironment. Retroviral transduction of a stable form of b-catenin into HSCs caused a loss of competitive repopulating units (CRUs) in a limiting-dilution assay, whereas stabilized b-catenin in stromal cells CRU frequencies of co-cultured HSCs with higher preservation of undifferentiated state and caused enhanced levels of reconstitution in a manner dependent on direct contact between HSC and stroma. The enhancing effect of b-catenin stabilized stroma on HSC was also observed for human HSCs exhibiting higher frequencies of lympho-myeloid repopulating cells after transplantation into NOD/SCID mice. Interestingly, gene expression patterns of Wnt signaling molecules revealed compartmentalization in a manner that canonical Wnt ligands were preferentially expressed in the hematopoietic cells while molecules for reception of the signal such as Frizzled receptors or their co-receptors are preferentially expressed in stromal component, suggesting the role of stromal component as a target of Wnt signals in the niche. Furthermore, b-catenin accumulated selectively in the endosteal stroma of the trabecule region in “stressed” marrows, but not in “steady-state” marrows. Taken together, these results suggest stroma-mediated Wnt signals may function as microenvironmental cues for HSC self-renewal in the stem cell niche.
Co-Development of Intravital, Laser-Induced Experimental and Computational Models of Thrombogenesis.
Authors: Kamocka Malgorzata , Chen Nan , Xu Xhiliang , Alber Mark , Rosen Elliot D. 
Published: October 2019

Abstract
We have developed modified protocols for confocal intravital monitoring of thrombus development in mouse mesenteric vessels following laser-induced injury. By including tetramethyrhodamine-labeled dextran (70,000 mw) in the blood, unlabeled cells (leukocytes and reticulocytes) form black silhouettes where the red fluorescent dye is excluded in the confocal image. In addition, platelets were labeled with rat monoclonal anti-mouse CD41/61 (Emfret Analytics, Germany) mixed with secondary goat anti-rat IgG antibody labeled with Alexa Fluor 488 and human fibrinogen was labeled with Alexa Fluor 350. Thus, high resolution confocal images of the developing thrombus included platelets in green, fibrin in blue, plasma in red and cellular components in black. Near real-time video recordings indicate the importance of flow parameters on the developing clot. In particular, turbulent flow patterns around the developing thrombus contribute to the incorporation of blood cells in the thrombus leading to the development of thrombi with a heterogeneous domain structure. Conceivably, different mechano-elastic properties of the heterogeneous domains might contribute to thrombus instability as the thrombus is subject to varying stresses and strains. In parallel with the modified experimental vascular injury model, we have begun development of a computational model of thrombus development. The modeling framework consists of a stochastic and discrete Cellular Potts Model (CPM) to describe platelet and cellular interactions and continuous submodels to describe hydrodynamic and biochemical reactions. The components of the computational model include the vessel wall, platelets (in resting and activated states), blood cells, coagulation reactions, fibrin formation, and hydrodynamic parameters. By varying input variables (such as flow rate, blood viscosity, coagulant activities) and monitoring properties of the developing thrombus, one can modify and validate the computational model. While our experimental systems enable us to determine essential components required for thrombus development, a validated model could help identify threshold levels of key components involved in thrombogenesis. This may be particularly useful in identifying hemostatic risk factors if these threshold levels are within the normal range found in the human population.
Functional and Structural Characterization of Factor Xa Dimer in Solution.
Authors: Chattopadhyay Rima , Iacob Roxana , Majumder Rinku , Tomer Kenneth B. , Lentz Barry R. 
Published: October 2019

Abstract
Previous studies of blood coagulation factor Xa (bovine) showed that binding of water soluble phosphatidylserine (C6PS) to factor Xa (FXa) leads to Ca2+ dependent inactive (∼1000-fold inactivation) dimer formation. We show now that human factor Xa activity is also regulated by C6PS-induced dimerization in the presence of 5 mM Ca2+ We also report that the FXa dimer is inactive:
despite the fact dimerization does not block the active site; in part because it does block a substrate exosite; the dimer interface involves lysine residues that boarder the active site and exosites, and the structure of FXa in the dimer is altered relative to the monomer.
We have measured initial rates of prothrombin activation (using synthetic thrombin substrate S-2238) at varying FXa and substrate concentrations to show that the kcat/Km decreased (kcat decreased significantly and Km increased slightly) with an increase in FXa dimer formation. The observed significant decrease in kcat indicates that dimerization affects the alignment of substrate with the active site, perhaps through altering substrate binding or through altering the structure of the active site. Amidolytic activity of monomeric FXa (using synthetic substrate S-2765) decreased in response to C6PS binding, while that of the dimer increased slightly. This indicates that dimerization did not block the active site but may alter its conformation. CD and mass spectrometry showed that both Ca2+ and C6PS binding alter FXa structure and that dimerization further alters structure. Acetylation of exposed lysine residues and analysis of MS patterns obtained under conditions that favor either monomer or dimer FXa revealed that the dimerization buries lysines residues 222 and 224 (chymotrypsin numbering) that boarder the active site and are in putative exocytes. We used MS data, fluorescence energy transfer data for active site labeled FXa, to model the FXa dimer structure based on a FXa monomer model (from Gla-domainless Xa X-ray structure and Gla-EGFn with Ca2+) but the requirement that known membrane binding sites or paired FXa molecules would be located in plane was failed. Our lack of success supports our other measurements suggesting that the structure of FXa in a dimer is very different from that in a monomer.
Supported by grant from the NHBL (HL 072827 to BRL).
Time to Complete Cytogenetic Response (CCyR) Does Not Affect Long-Term Outcomes for Patients on Imatinib Therapy.
Authors: Guilhot Francois , Larson Richard A. , O’Brien Stephen G. , Gathmann Insa , Druker Brian J. 
Published: October 2019

Abstract
Background: Results from the International Randomized Study of Interferon and STI571 (IRIS) trial showed that achievement of a CCyR is prognostically relevant for long-term survival in patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP). With the advent of next generation tyrosine kinase inhibitors (TKIs), there is a need to understand factors that may influence long term outcomes. Here we analyze whether time to achievement of a CCyR affects long term outcomes.
Methods: The relationship between time to CCyR and long-term outcomes was examined for 551 imatinib-treated patients with newly diagnosed CML-CP at the 6-year follow up of the IRIS trial. As evaluations included non-responders, landmark analyses were conducted in which only pts who were treated for ≥1 year were included (n=509). Patients were stratified according to time to achieving a CCyR as follows: ≤6 months (n=265), >6≤12 months (n=99), >12≤18 months (n=34), >18 months (n=49), or no CCyR during imatinib treatment (n=62). In each category patients were assessed for duration of cytogenetic response, event free survival (EFS; any event while on study), freedom from progression to accelerated phase (AP) or blast crisis (BC), and overall survival (OS).
Results: In the 447 patients who were treated for at least 1 year and achieved a CCyR (<1% Ph+) during therapy, the durability of major cytogenetic response (1%–35% Ph+) did not differ significantly regardless of when CCyR was achieved (P=0.76). For the overall population, estimated 6-year rates were 88% for OS, 83% for EFS, and 93% for freedom from progression to AP/BC. No statistically significant difference was observed between the responders when categorized according to time to response. However, patients who did not achieve a CCyR had significantly worse outcomes than those who achieved CCyR (P<0.001). Estimated 6-year OS rates were 94%, 95%, 91% and 98% for patients who first achieved a CCyR within 6, 12, 18 months and after 18 months, respectively (P=0.55 for overall comparison of the response categories), compared with 63% for pts without CCyR during imatinib therapy. Estimated EFS rates at 6 years were 93%, 90%, 87% and 89% (P=0.58) and 33% for patients who do not achieve a CCyR, respectively. At 6 years the estimated rates of freedom from progression to AP/BC were 97%, 97%, 97% and 98% (P=0.98), respectively, but only 63% for pts who do not achieve a CCyR. Overall Survival by Time to CCyR.
Conclusion: Long-term outcomes on imatinib for patients in CML-CP are independent of time to achieve CCyR. Therefore, achievement of a “late” CCyR does not increase the potential for progression or portend a worse overall survival for patients treated with imatinib.
Figure Figure
Factor XI Homodimer Formation Is Mediated by Electrostatic (Lys331 with Glu287) and Hydrophobic (Ile290 with Leu284 and Tyr329 with Tyr329) Interactions in the Apple 4 Domain and Is Essential for Normal Proteolytic Activation of Factor XI by Factor XIIa, Thrombin and Factor XIa.
Authors: Wu Wenman , Sinha Dipali , Lear James D. , Billings Paul C. , Walsh Peter N. 
Published: October 2019

Abstract
Factor XI (FXI), a coagulation protein essential for normal hemostasis, is a homodimer consisting of two identical subunits of 80 KDa linked by a disulfide bond formed by Cys321 within the Apple 4 (A4) domain of each subunit. Prekallikrein (PK), in spite of its high homology with FXI both in amino acid sequence and domain structure, is a monomer. Cys321 in PK forms an intrachain disulfide bond with Cys326. However FXI/C321S (in which interchain disulfide bond formation is precluded) is a noncovalent dimer. Thus, there are interacting residues between the two subunits of FXI that are responsible for mediating its unique homodimeric structure. Examination of the crystal structure of FXI (Papagrigoriou E, McEwan P, Walsh PN, Emsley J. Nature Structural & Molecular Biology. 2006;13:557–8) shows salt bridges between Lys331 of one subunit with Glu287 of the other subunit as well as hydrophobic interactions at the interface of the A4 domains involving Ile290, Leu284 and Tyr329. FXI/C321S, FXI/C321S/K331A, FXI/C321S/E287A, FXI/C321S/I290A, FXI/C321S/Y329A, FXI/C321S/L284A and FXI/C321S/K331R were expressed in HEK293 cells and characterized using size exclusion chromatography (SEC), analytical ultracentrifugation (AUC), and functional assays. Whereas FXI/C321S existed in a monomer/dimer equilibrium (Kd ∼40 nM) all other mutants were predominantly monomers by SEC with impaired dimer formation by AUC (Kd 3.4–38 μM). All the monomeric mutants when converted to the active enzyme, FXIa, were able to hydrolyze the small chromogenic substrate S-2366 with normal values of Km and Vmax and cleaved the macromolecular substrate FIX at both its scissile bonds at rates similar to those observed with wtFXIa strongly suggesting that all mutant proteins were properly folded. However all the monomeric mutants displayed impaired clotting activity in an APTT assay and displayed markedly decreased rates of activation by FXIIa or thrombin and autoactivation in the presence or absence of dextran sulfate. We conclude that salt bridges formed between Lys331 of one subunit and Glu287 of the other together with hydrophobic interactions of residues Ile290 with Leu284 and Tyr329 with Tyr329 and are essential for normal homodimer formation, which is essential for normal proteolytic activation of FXI by FXIIa, thrombin and FXIa either in solution or on an anionic surface.