bluuebunny/crossref_metadata_2025_split huggingface dataset:
HLA Identical Hematopoietic Stem Cell Transplantation for Acute Leukemia in Children - A Single Center Experience.
Authors: Willemze Annemieke J. , Geskus Ronald B. , Noordijk Evert M. , Vossen Jaak M. 
Published: October 2019

Abstract
Between 1980 and 2002, 132 children and adolescents (median age 8.5 years, range 1.1 to 17.3) got an allogeneic HLA-identical hematopoietic stem cell transplantation (SCT) from a sibling donor for acute leukemia. The patients suffered from ALL in 1st remission (n=24), ALL in 2nd remission (n=53) and AML in 1st remission (n=55). The mean follow-up time after SCT was 11.5 years (range 1.3 to 23.3 years). The source of the stem cells was bone marrow in all but 3 cases of cord blood-derived stem cells. The number of nucleated marrow cells in the graft varied between 0.5 and 6.8x108/kg (median 2.75x108/kg). Most patients, 118 of 132, were pre-treated with a total body irradiation (TBI) and cyclophosphamide-based regimen. TBI doses were 1x 7 Gy for children of 3 and 4 years, 1x 7.5 Gy for >4 and <10 years, and 1x 8 Gy (before 1990) and 2x 6 Gy on two consecutive days (after 1990) for children older than 10 years. Initially, graft-versus-host disease (GvHD) prophylaxis consisted of long-course methotrexate (MTX) only (n=24), later a short-course MTX-Cyclosporine A prophylaxis was given (n=102). All patients were nursed in strict protective isolation, using positive-pressure laminar-air flow cubicles or rooms, and got total gut decontamination with non-absorbable antimicrobials. Engraftment, transplant-related complications, relapse of the disease and survival were evaluated retrospectively in relation to disease- and transplant-related characteristics. None of the patients failed to engraft. The mean 5-year probability of overall survival was 63%, 53% and 74% for ALL1, ALL2 and AML1 patients, respectively. Transplant-related mortality was 6%. The incidence of acute GvHD in evaluable cases was 17% (21/124), of whom 7 (6%) got grade II to IV. Chronic GvHD occurred in 10 patients out of 125 evaluable patients (8%). The mean 5-year probability of relapse was 35%, 49% and 26% for ALL1, ALL2, and AML1 patients, respectively. Most relapses (70%) occurred within the first year post-SCT. The patient age and dose of TBI were significantly related with post-transplant relapse (p=0.007). Overall survival was significantly higher in children that received a higher dose of TBI (see figure). Overall, acute GvHD was not significantly associated with relapse, but none of the AML patients (n=9) with acute GvHD got a relapse (likelihood ratio test, p=0.02), which was not the case for ALL first or second remission patients. This retrospective single-center study on HLA-identical SCT for acute leukemia in 132 consecutively enrolled children confirms the beneficial role of slight to moderate acute GvHD in the suppression of relapse of AML, and draws attention to the potential antileukemia effect of a high (fractionated) dose of TBI in the conditioning.
Figure Figure
Transcriptional Regulation Via GATA Switches: Proteasome-Mediated Exchange of Chromatin-Bound GATA Factors.
Authors: Lurie Louis J. , Boyer Meghan E. , Bresnick Emery H. 
Published: October 2019

Abstract
The transcription factors GATA-1 and GATA-2 confer both shared and unique activities to regulate hematopoiesis. GATA-2 is essential for the survival and proliferation of hematopoietic stem cells and multipotent hematopoietic precursors, whereas GATA-1 is critical for erythropoiesis. GATA-1 and GATA-2 are expressed reciprocally during erythropoiesis, with GATA-2 expression preceding that of GATA-1. Erythroid maturation appears to require GATA-2 repression. We have shown that chromatin-bound GATA-2 is displaced by GATA-1, which instigates a distinct transcriptional output at the respective locus. We hypothesize that such “GATA switches” are an important transcriptional mechanism that drives erythropoiesis. Their distinct transcriptional outputs suggest that GATA-1 and GATA-2 have unique biochemical properties. However, biochemical analyses have primarily identified similarities between the factors. For instance, the two zinc fingers of GATA-1 are highly homologous to those of GATA-2, and therefore both factors interact with the cofactor FOG-1 and bind an identical WGATAR sequence with high affinity. We found that GATA-2 is considerably less stable than GATA-1. Studies using cycloheximide to block protein synthesis in erythroid precursor cell lines derived from embryonic stem cells indicate that the half-life of endogenous GATA-2 is ~45–90 min, whereas that of endogenous GATA-1 is >4 h. Biosynthetic labeling studies to measure the stabilities of endogenous GATA-1 and GATA-2 expressed in the same cell confirmed that GATA-2 is considerably less stable than GATA-1. GATA-2 levels increase in cells treated with the proteasome inhibitors MG132 or clasto-lactacystin β-lactone. Importantly, we have found that rapid GATA-2 proteolysis is essential for the proper temporal control of erythroid-specific gene transcription. Quantitative chromatin immunoprecipitation analysis revealed that proteasomal inhibition attenuated the ability of GATA-1 to displace GATA-2 from target genes, which are regulated by GATA switches. Proteasomal inhibition resulted in impaired GATA-2 displacement from GATA-2, and consequently a significantly lower degree of GATA-2 repression. Proteasomal inhibition also diminished GATA-1-mediated displacement of GATA-2 from GATA-1, α-globin, and ALAS-2, genes at which GATA switches precede transcriptional activation. We have therefore identified the 26S proteasome as a key regulator of GATA factor exchange on chromatin. Our studies indicate that rapid proteasomal degradation of GATA-2 is required for GATA-1 and GATA-2 to establish unique patterns of gene expression during erythropoiesis. Studies are underway to determine whether GATA-2 is similarly unstable in multipotent hematopoietic precursors, or if its instability is established upon commitment to the erythroid lineage.
Normalisation of ADAMTS 13 Activity and Disappearance of ADAMTS 13 Antibody Following Rituximab in Acute Refractory Thrombotic Thrombocytopenic Purpura.
Authors: Scully Marie , Cavenagh Jamie , Hagger Diane , Benjamin Sylvia , Mackie Ian , Mchin Samuel J. , Cohen Hannah 
Published: October 2019

Abstract
Thrombotic thrombocytopenic purpura (TTP) is a life threatening disorder characterised by thrombocytopenia and microangiopathic haemolytic anaemia associated with a deficiency in ADAMTS 13. Plasma exchange (PEX) remains the primary treatment modality in acute TTP, with various immunosuppressive agents (e.g. methylprednisolone, vincristine, ciclosporin (CSA)) and other disease modifying agents(e.g. defibrotide), added in refractory cases. However, mortality remains at 15–20%. Rituximab is a monoclonal CD 20 antibody, which acts specifically to clear peripheral B lymphocytes involved with antibody production. We have treated 15 patients with acute refractory TTP; 12 female and 3 male, with 2–8 weekly Rituximab infusions, 375mg/m2. Fourteen had neurological features and 3 had cardiac TTP at presentation. Patients received Rituximab because of progressive clinical disease or deterioration of laboratory parameters despite intensive therapy. On admission, median haemoglobin was 8.2 (range 5.1–12) g/dl, platelet count 14 (range 3–70) X 109/L, lactate dehydrogenase (LDH) 1620 (range 411–>2832) IU/L. All patients attained normal laboratory parameters and clinical remission within 22 days of starting Rituximab therapy. Three patients proceeded to further Rituximab based on ADAMTS 13 activity following 4 treatments. Twelve patients had initial ADAMTS 13 activities <5% (normal range (NR) 66–126% by collagen binding assay) and thirteen patients had normal ADAMTS 13 activity (median 78%) following Rituximab. IgG antibodies to ADAMTS 13 pre Rituximab were detected in thirteen patients but were undetectable post Rituximab. The median number of PEX pre Rituximab was 14 (1–35) and following the first Rituximab treatment, 6 (1–22), including weaning with an alternate day regime following clinical and laboratory remission. This difference was significant (p=0.042, Wilcoxon signed ranks test). To date (follow-up 1–27 months) there have been no TTP relapses. No significant decrease in CD 19 levels, immunoglobulin levels or infectious complications have been documented. These data suggest that patients with acute refractory TTP respond promptly to Rituximab, associated with a significant reduction in the requirement for PEX. Clinical and haematological remission was demonstrated and maintained within 3 weeks of Rituximab treatment in all patients. Only one patient failed to increment ADAMTS 13 activity. In all patients with IgG antibodies to ADAMTS 13, these disappeared within 28 days of Rituximab treatment. Rituximab therefore appears to be a safe, effective, targeted therapy for acute refractory TTP.
A Rapid Method for Comparing the Oncogenic Potential of Retroviral Vectors.
Authors: Hendrie Paul C. , Russell David W. 
Published: October 2019

Abstract
Retroviral gene transfer has successfully cured patients with X-linked severe combined immunodeficiency (X-SCID). Unfortunately, three of the treated patients developed leukemia at least in part due to insertional activation of a neighboring gene. Further advances of this exciting therapeutic modality will require safer viral vectors. Genotoxicity experiments in animals, although an important preclinical study, are not practical for screening large numbers of vectors. We have developed a rapid plasmid-based assay to compare downstream gene activation by retroviral vectors. We constructed a plasmid, pACT, that contains a minimal CMV promoter, an internal ribosome entry site (IRES) and a luciferase reported gene followed by a polyadenylation site. Four different proviral constructs containing identical internal PGK-EGFP expression cassettes were inserted upstream of the minimal promoter and nucleofected (Amaxa Biosystems) into K562 cells. The relative luciferase activation of each provirus was determined and compared to cells nucleofected with the basic pACT plasmid. The relative luciferase activation by a plasmid containing a Moloney murine leukemia virus (MLV) vector provirus with full length long terminal repeats (LTRs) was 144, 1230, and 4525 at 1, 2 and 4 days post nucleofection, respectively. Changing the orientation of the proviral DNA did not significantly change the results, consistent with an enhancer effect from the proviral LTRs. In comparison, the relative luciferase activation by a plasmid containing a self inactivating (SIN) MLV vector provirus with LTR deletions was only 59, 90 and 170, respectively, and was reduced by greater than 90% with the reverse orientation consistent with residual activation by read-through transcription. For plasmids containing the HIV SIN vector provirus, the relative luciferase activation was 48, 45 and 52, respectively at 1, 2 and 4 days post nucleofection, and decreased by >90% with the inverse orientation. The relative luciferase activation for plasmids containing the Foamy Virus (FV) vector provirus, also a “SIN” vector, was the least, only 3, 2 and 6, respectively, at 1, 2 and 4 days post nucleofection. Therefore, all three SIN vectors (MLV, HIV and FV) produced significantly less downstream gene activation than a conventional MLV vector, with the FV vectors being the lowest. Additional studies comparing various internal promoters and vectors will also be presented. These results demonstrate the usefulness of the pACT assay system to identify safer retroviral vectors.
Defects in Management of Labile Iron and Oxidative Stress Underpin Red Cell Enucleation Defects in Rb Null Mice.
Authors: Macleod Kay F. , Spike Benjamin T. 
Published: October 2019

Abstract
The Rb tumor suppressor is critically required for end-stage red cell maturation under conditions of oxidative stress, including in the developing fetal liver, in the bone marrow of aging mice, in the spleen and bone marrow of young mice treated with phenylhydrazine to induce hemolytic anemia, and in lethally irradiated mice reconstituted with donor tissue [1]. Loss of Rb resulted in a failure of end-stage red cells to enucleate, accumulation of red cells with a 4N DNA content and aberrant chromatin structure [1]. The molecular basis of these defects is not defined nor do we understand the reasons why pRb should be required under stress conditions, but not during normal “steady-state” erythropoiesis. The work presented will address both of these questions.
In determining why pRb is critically required for stress erythropoiesis but not for steady-state erythropoiesis, we have demonstrated increased levels of reactive oxygen species (ROS) and labile iron in Rb null erythroblasts relative to wild-type control erythroblasts derived from E12.5 fetal liver. Furthermore, we show that quenching of ROS in Rb null erythroblasts by treatment of mice with the anti-oxidant N-acetyl cysteine (NAC) rescued aspects of the erythroid defect, including red cell enucleation and also extended the lifespan of Rb null mice. Similarly, chelation of labile iron with desferroxiamine restored enucleation capacity to Rb null erythroblasts. Furthermore, we show that the transferrin receptor (CD71) is transcriptionally repressed by pRb/E2F and examine whether deregulated expression of CD71 contributes to increased labile iron and oxidative stress in Rb null erythroblasts. These results suggest that loss of pRb limits the ability of erythroblasts to manage labile iron and oxidative stress, in part through deregulated expression of CD71, and that this contributes to the enucleation defect observed in Rb null mice. Given that pRb is itself regulated by ROS, we present a model in which the timely induction and repression of the CD71 receptor in differentiating erythroblasts is required to manage labile iron, oxidative stress and to coordinate cell cycle exit with end-stage maturation.
Inhibitory Effect of Monoclonal Antibodies Against CXCR3-B NH2-Terminus on the Proliferation of U937 Cells.
Authors: Gao Yuan , Chen Zhi-Cheng , Liu Li , Yang Jin-Ju , Liu Xiao-Lan , Chen Yong , Gao Jian-En , Liu Chaoyan , Visentin Gian Paolo , Sun Qi-Hong 
Published: October 2019

Abstract
The role of CXCR3 in mediating the angiostatic activity of IFN-inducible ELR−CXC chemokines has been further defined with the finding that CXCR3 exists as two alternatively spliced variants, termed CXCR3A and CXCR3B respectively. The chemokine CXCL4/PF4 shares several activities with CXCL9, CXCL10, and CXCL11, but only binds to its specific receptor CXCR3B for the angiostatic activity. CXCR3B, a novel chemokine receptor, is 51 amino acid residues longer at the NH2-terminus than CXCR3A. Unlike activation of CXCR3A, which is pertussis toxin-sensitive and activates cellular proliferation, activation of CXCR3B is pertussis toxin-resistant and leads to inhibit cellular proliferation. Thus, the 51 amino acid residues at CXCR3B NH2-terminus are very important for the CXCL4/PF4 binding and for the CXCR3B inhibitory effect. In the present studies, a GST-tagged fusion protein of CXCR3B (a.a 1-51) was used as the immunogen for generation of monoclonal antibodies (mAbs) against CXCR3B (a.a. 1–51), and three peptides derived from CXCR3B NH2-terminus (a.a. 1–19, a.a. 17–35, and a.a. 33–51) for epitope mapping of the established mAbs. Nine hybrodoma cell lines secreting mAbs against CXCR3B were established, and we found that two mAbs reacted specifically with the CXCR3B a.a. 1–19, and one antibody with the CXCR3B a.a. 33–51. Three of these antibodies could also bind to CXCR3B on the surface of human intestinal epithelial Caco2 cells, and CXCR3B recognized by the antibodies were localized in the vascular endothelial cells of human fetal heart tissues. The data from Cell proliferation assay showed that three mAbs could inhibit the growth of U937 cells, which were found to express CXCR3B as well. We conclude that the novel panel of CXCR3B mAbs could be useful tools for the CXCR3B functional studies. Meanwhile, CXCR3B may be not only the inhibitory target on endothelial cells, but also the new directly reactive site of CXCR3B-positive tumor cells such as promonocytic U937 cells.
Long-Term Effect of Bleomycin on Respiratory Function Tests in Pediatric Cancer Patients.
Authors: Aydogan Gonul , Bilgic E. , Akici F. , Salcioglu Z. , Turhan P. , Tugcu D. 
Published: October 2019

Abstract
Chemotherapy and radiotherapy which are used in the management of cancer have acute and chronic adverse effects on various organs. Patients develop pulmonary damage due to mantle zone irradiation and bleomycin in the short or long-term. In this study, after the completion of treatment long-term pulmonary complications of the teatment were investigated in 30 pediatric patients (19 male, 11 female) with cancer aged between 72–229 months. Twelve of the patients used also chemotherapy in addition to 1020–3570 rad. of mantle zone irradiation (median 2177 rad.), whereas the remaining 18 had chemotherapy alone. All of the patients had completed their treatment approximately 3,8 years ago, and the total dose of bleomycin they used was 12–180 mg. (median 69,83). All of the patients underwent physical examination, and complete blood count, chest radiograph and spirometric tests to measure lung volumes were also performed. Additionally, in 20 patients single breath technique to measure the diffusing capacity for carbon monoxide was carried out. Physical examination of cardiopulmonary system revealed normal findings and none of our patients had a cardiopulmonary symptom. Chest radiograph was normal in 25 (83,3%) but it was abnormal in 5 patients.
Lung volume measurements were normal in 21 (71%), but were abnormal in 9 (29%) patients. Of these 9 patients 23% had restrictive, 3% had combined and 3% had obstructive disorders. In our study, no correlation could be shown between the impaired respiratory function tests and irradiation and bleomycin doses used. In 3 (10%) out of 20 patients in whom the diffusing capacity test for carbon monoxide was performed, decreases in diffusing capacity for carbon monoxide were found. One of these patients had both high dose bleomycin (156 mg.) and mantle zone irradiation (2160 rad.), whereas the remaining 2 had low dose bleomycin (30–63 mg.) alone and received no radiotherapy.
The diffusing capacity test for carbon monoxide which returns to normal values in short -term is less valuable than the measurement of lung volumes for the long-term follow-up evaluation of respiratory functions in these patients. Generally, in our late phase study (3,8 years after the completion of therapy), there was a low rate of impairment in diffusing capacity test for carbon monoxide, but the rate of impairment in lung volumes was much higher. This finding was compatible with most of the related literature.
In conclusion, in pediatirc cancer patients respiratory function tests should be performed during the treatment and also after the completion of treatment in order to follow the course of pulmonary function impairment.
Patterns of Relapse and Toxicity in Patients of CML (Chronic Phase) on Imatinib Therapy.
Authors: Aggarwal Shyam , Gogia Atul , Lal Meena , Dutt Sarjana , Bhargava Manorama 
Published: October 2019

Abstract
44 patients of CML (in chronic phase) were evaluated for their hematological, cytogenetic and molecular response (by doing quantitative PCR- for bcr-abl/abl), over a period of last 4 years. The toxicity profile of these patients was also evaluated. The mean age of study group was 54.5 years, with a male: female ratio of 1.8:1 (28 males and 16 females). 13/44 (29.3%) patients were treated with interferon prior to imatinib therapy, while the rest (31) were started on imatinib (400mg/day) upfront. 43/44 (97.7%) patients achieved a complete hematological response. 1 patient who did not respond to imatinib therapy had long duration of disease (111 months). 24/44 (54.6%) had complete cytogenetic response, 4 (9.1%) had major and 5 (11.3%) had minor cytogenetic response. 7/44 (15.9%) had hematological relapse while on Imatinib therapy. 3/44 (6.8%) had cytogenetics / molecular relapse only. Out of the 13 patients who had received prior interferon, 4 developed hematological relapse and of these 4 patients, 1 developed blast crisis and other 3 are in accelerated phase. 3/31 (9.7%) patients who received imatinib therapy upfront developed hematological relapse, while 6/31 (19.2%) developed cytogenetic/molecular relapse including the 3 patients who developed hematological relapse. A median of 17 months of imatinib therapy was given in patients who did not receive prior interferon. 36/44 (81%) developed hypopigmentation 19/44 (43%) had fluid retention, 9/44 (20%) had muscle cramps and 3/44 (6.8%) developed myelosupression. The relapse rate in patients of CML in chronic phase is more in those who have received interferon prior to imatinib therapy (37.7%). At a median follow up of 17 months the relapse rate in patients who received imatinib de novo was 19.2%.
The JAK2 V617F Mutation Is Uncommon in Patients with Juvenile Myelomonocytic Leukemia.
Authors: Yoshida Nao , Yagasaki Hiroshi , Xu Yinyan , Yamamoto Tomoko , Kudo Kazuko , Kato Koji , Horibe Keizo , Manabe Atsushi , Kojima Seiji 
Published: October 2019

Abstract
Juvenile myelomonocytic leukemia (JMML) is a rare, clonal myeloproliferative disorder afflicting young children and is characterized by specific hypersensitivity of JMML cells to GM-CSF in vitro. The pathogenesis of JMML seems to arise from dysregulation of GM-CSF signal transduction. Approximately, 75% of patients with JMML exhibit dysregulation due to mutations in RAS, NF1 or PTPN11, all of which are positioned in the GM-CSF pathway. Potential causative mutations in remaining patients are anticipated to be in signaling components downstream of the GM-CSF receptor. Recently, a somatic point mutation (JAK2 V617F) in the JAK2 gene, which plays a major role in the development of hematopoietic cells by transducing signals from growth factor receptors including GM-CSF receptor, was found commonly in polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis. All these myeloproliferative disorders are also characterized by hypersensitivity of hematopoietic progenitor cells to several growth factors and cytokines. Because the frequency of JAK2 V617F mutation in JMML remains unknown, we performed mutational analysis of JAK2 in 39 Japanese children (aged 1 to 69 months) with JMML to assess the pathogenetic relevance of this mutation in JMML, in addition to mutational analysis of PTPN11 and N-RAS. Genomic DNA were prepared from bone marrow or peripheral blood samples taken at initial diagnosis. Mutations of JAK2 (exon 12), PTPN11 (exon 3 and 13) and N-RAS (exon 1 and 2) were screened by direct sequencing. PTPN11 or N-RAS mutations were found in 19 (49%) or 3 (8%) patients respectively, and this is compatible with previous reports. In this study, no JAK2 V617F mutations were detected in any of the 39 JMML patients. In conclusion, we confirmed the presence of PTPN11 and N-RAS mutations in JMML. However, the JAK2 V617F mutation appears to be uncommon in patients with JMML, while it is extraordinarily common in classic MPD. Future investigation should focus on other signaling components in the same signaling pathway as JAK2, or on other parallel signal transduction cascades of the GM-CSF receptor.