bluuebunny/crossref_metadata_2025_split huggingface dataset:
XPD Lys751Gln Polymorphism and Etiology and Outcome of Childhood Acute Myeloid Leukemia.
Authors: Mehta Parinda A. , Alonzo Todd A. , Gerbing Robert B. , Perentesis John P. , Lange Beverly J. , Davies Stella M. 
Published: October 2019

Abstract
Genetic polymorphism results in inter-individual variation in DNA repair capacity, and may in part account for susceptibility of a cell to genotoxic agents, and to malignancy. The DNA repair protein xeroderma pigmentosum complementation group D (XPD) is a major participant in the neucleotide excision repair pathway and is also involved in transcription initiation and in the control of cell cycle and apoptosis. Several studies have found associations between ineffective DNA repair and cancer risk. It is also thought that ineffective DNA repair may lead to additional genomic instability and tumors that are more aggressive. Several single nucleotide polymorphisms including an adenine to cytosine polymorphism leading to Lys751Gln in exon 23 of XPD have been shown to be associated with elevated frequency of chromosomal aberrations and variety of environmentally induced cancers in adults. We hypothesized that XPD polymorphism may play a role in causation of childhood AML. In addition, there are data that XPD polymorphism influences outcome of chemotherapy in adults with solid tumors. Therefore, we also evaluated its effect on outcome of AML therapy. Methods: 457 children treated for AML on CCG studies 2941 and 2961 (intensive induction with daunorubicin, idarubicin, Ara-C, 6-thioguanine, etoposide, dexamethasone, +/− fludarabine, Ara-C, idarubicin; consolidation with high-dose Ara-C and L-asparaginase or HLA-matched sibling BMT) were genotyped for XPD exon 23 polymorphism. Genotype frequencies were compared with published normal control frequencies. In addition, patient outcomes were analyzed according to genotype. Results: Comparison of gene frequencies in AML patients and reported normal controls showed similar frequencies (42.5% AA, 44.2% AC, 13.3% CC in patients vs. 44.2% AA, 45% AC, 10.8% CC in controls; p=0.54). There were no significant difference in OS (p=0.56), EFS (p=0.61), TRM (p=0.5) or relapse rate (p=0.88) between patients with 751AA genotype vs. 751AC/751CC genotypes, in contrast to reports in adult malignancies. Stratification of cases by age at diagnosis, white blood count at diagnosis, AML subtype, or cytogenetics revealed no difference in genotype frequencies. Conclusion: These data, representing the only data in pediatric AML, suggest that XPD genotype does not affect the etiology or outcome of childhood AML.
Requirement for CD4 Help for Optimal GVL Effects of Alloreactive T Cells Given to Established Mixed Chimeras but Not Freshly Irradiated Mice.
Authors: Eom Hyeon-Seok , Chakraverty Ronjon , Sachs Jessica , Zhao Guiling , Sykes Megan 
Published: October 2019

Abstract
Donor lymphocyte infusion (DLI) may lead to lymphohematopoietic graft-versus-host (GVH) reactions without graft-versus-host-disease (GVHD). The graft-versus-leukemia (GVL) effect of DLI is greater in mixed chimeras than in full chimeras following fully MHC-mismatched bone marrow transplantation (BMT). Some studies showed, following MHC-mismatched BMT, that only CD8+ T cells are involved in GVL effects of DLI against MHC class I+ class II− tumors, but others showed that the GVL effect of DLI is dependent on both CD8+ and CD4+ T cells. Previously, we have observed that GVL against EL4 is mediated by CD8+ T cells but not CD4+ T cells following DLI in freshly irradiated mice treated with cytokines to reduce GVHD mortality in fully MHC-mismatched BMT. The exact contribution of CD4+ and CD8+ T cells to the GVL effects of DLI in established mixed chimeras is not known. We hypothesized that lethal conditioning leads to the production of many proinflammatory cytokines which may help to generate a CD4 cell-independent, CD8 cell-mediated anti-tumor effect. However, in delayed DLI recipients, CD4+ helper T cells might be needed to induce CD8+ anti-tumor effector cells. We evaluated the role of T-cell subsets in GVL effects of DLI following fully major histocompatibility complex (MHC)-mismatched BMT in freshly irradiated mice and mixed chimeric delayed DLI recipients. While GVL effects of delayed DLI given to established mixed chimeras were dependent on both CD4+ and CD8+ T cells, CD4+ T cells did not contribute to GVL effects in freshly irradiated mice. Consistent with this, MHC class II expression on host antigen-presenting cells (APCs) was needed to optimize GVL effects of DLI in established mixed chimeras. To address whether cross-presentation of tumor antigens (Ag) via class I would permit GVL responses in full chimeras, we generated full chimeras in which donor and recipient shared a class I locus. However, there were no GVL effects of delayed DLI in full chimeras, providing no evidence that cross-presentation of tumor Ag through class I molecules shared by donor and the tumor led to anti-tumor effects in this model. We conclude that following delayed DLI to established mixed chimeras, the GVL response requires extensive MHC disparity, MHC class II expression on host APCs and the presence of CD4+ T cells. In contrast, the requirement for CD4+ T cells can be bypassed in freshly irradiated recipients, but this occurs at the expense of a greater risk of GVHD. Administration of delayed DLI to mixed chimeras permits achievement of optimal GVL effects because large numbers of GVH-reactive T cells can be administered without inducing GVHD.
The Role of Age at First Exposure and Therapy Regimen on the Development of Neutralizing FVIII Antibodies in Hemophilia A.
Authors: Ettingshausen Carmen Escuriola , Zyschka Alexandra , Saguer Inmaculada Martinez , Heller Christine , Klingebiel Thomas , Kreuz Wolfhart 
Published: October 2019

Abstract
In order to assess the impact of age at first exposure to F VIII and therapy regimen on neutralizing FVIII-antibodies in previously untreated patients (PUP) with hemophilia A a prospective study was performed.
Over a 23-years study period a total of 74 severely affected hemophilia A -PUPs have been consecutively recruited, treated with F VIII and investigated for inhibitor development. The patients were divided into two groups according to their treatment regimen: Group 1 (n=23) started prophylaxis at the age of 1 year (before or immediately after the first relevant bleed). Group 2 (n=43) was treated on-demand or prophylaxis was started after more than 2 bleeds. The following parameters were equally distributed among both groups: caucasian ethnicity, intron-22-inversion, age at 1st ED >0.5 years.
Out of 74 hemophilia A patients 23 developed inhibitors (31%). Inhibitor incidence was 0% (1 transient inhibitor out of 23 patients) in those patients who received early prophylaxis (group 1) and 42% (18/43 patients) in case of delayed prophylaxis or on-demand treatment (group 2) (p=0.002).
No linear correlation was found between the age at first exposure and inhibitor formation. However, patients treated before the age of 0.5 years showed a significantly higher inhibitor incidence (62%) than those treated at an more advanced age. Our data confirm that very early age at first exposure is a risk factor for inhibitor development in severe hemophilia A patients. Early prophylaxis might be protective against inhibitor development. To confirm the data a larger patient cohort has to be investigated.
F VIII Inhibitors in Haemophilia A Patients after Continuous Infusion of Factor VIII Concentrates.
Authors: von Auer Ch. , Oldenburg J. , von Depka M. , Escuriola-Ettinghausen C. , Kreuz W. , Kurnik K. , Lenk H. , Varvenne M. , Scharrer I. 
Published: October 2019

Abstract
Continuous infusion (CI) of coagulation factor concentrates has been used since the early 1990s. Recent reports of the occurrence of an inhibitor (inh) after CI have raised concerns about this method of treatment. We conduct a retrospective study to investigate the development of inh after CI of FVIII concentrates in Germany. 99 haemophilia treating physicians in Germany were contacted and asked to answer a questionnaire. So far data of 13 departments have been reported and analyzed.
Three of these 13 centers never conducted a CI, in 5 no inh were detected and in 5 haemophilia centers 10 patients with inh development after CI were registered.
5 of these patients were suffering from severe, 1 from moderate and 4 from mild haemophilia (age between 7 months and 57 years). Indications for treatment were major bleeds and surgical procedures. Plasma derived (6) and recombinant (4) factor concentrates were given in various infusion sets. Data concerning infused amount (4300 to >100000 IE), exposure days (1 to >100) and inh characteristic (alloantibodies, 3 LR, 7 HR) were collected.
Regarding the genotype, we found 4 missense-mutations, 2 intron-22-inversions, 1 small deletion, 3 were unknown. In our own center we found no inh in 81 patients with major orthopaedic surgery and bolus infusion of factor VIII concentrate compared to 2 inh in 8 patients with major orthopaedic surgery and CI of FVIII.
In conclusion we found only in 2 patients the typical gene mutation for inh development. Strikingly the inh developed very often in patients with mild haemophilia. These findings agree with published results.
There might be an uncommon inh-pathomechanism due to CI or patients with mild haemophilia might exhibit a much higher prevalence of inhibitor development when treated with an “intensive FVIII-treatment” such as CI.
HIV-1 Tat Mediated Effects on Focal Adhesion Assembly and Permeability in Brain Microvascular Endothelial Cells.
Authors: Avraham Shalom , Jiang Shuxian , Lee Tae-Hee , Prakash O. , Avraham Hava Karsenty 
Published: October 2019

Abstract
The blood-brain barrier (BBB) is a network formed mainly by brain microvascular endothelial cells. The integrity of the BBB is critical for brain function. Breakdown of the BBB is commonly seen in AIDS patients with HIV-1-associated dementia (HAD), despite the lack of productive HIV-infection of the brain endothelium. The processes by which HIV causes these pathological conditions are not well understood. Here, we characterized the molecular mechanisms by which Tat mediates its pathogenic effects in-vitro on primary human brain microvascular endothelial cells (HBMECs). Tat treatment of HBMECs stimulated cytoskeletal organization and increased focal adhesion sites as compared to control cells or cells treated with heat-inactivated Tat. Pretreatment with Tat antibodies or with the specific inhibitor SU-1498, which interferes with VEGFR-2 (Flk-1/KDR) receptor phosphorylation, blocked the ability of Tat to stimulate focal adhesion assembly and the migration of HBMECs. Focal adhesion kinase (FAK) was tyrosine-phosphorylated by Tat and found to be an important component of focal adhesion sites. Inhibition of FAK by the dominant-interfering mutant form FRNK (FAK-related non-kinase) significantly blocked HBMEC migration and disrupted focal adhesions upon Tat activation. Furthermore, HIV-Tat induced permeability changes in HBMECs in a time dependent manner. Tat also impaired BBB permeability as observed in HIV-1 Tat transgenic mice. These studies define a mechanism for HIV-1 Tat in focal adhesion complex assembly in HBMECs, via activation of FAK, leading to cytoskeletal reorganization and permeability changes.
Identical Clonal Origin in Three Cases of Hodgkin’s Lymphoma Variant of Richter’s Syndrome Associated with EBV Infection.
Authors: Feugier Pierre , Monhoven Nathalie , Legres Luc , Saout Louis , Martin Laurent , Patey Martine , Janin Anne , Labouyrie Eric 
Published: October 2019

Abstract
Occurrence of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL), clinically referred to as Richter’s syndrome, occasionally manifests as a lymphoproliferation resembling Hodgkin’s lymphoma (HL) and often containing the Epstein-Barr virus (EBV). Only a limited number of HL variants have been subject to informative analysis regarding EBV status and their clonal relation-ship to the CLL, with evidence of an identical clonal origin in some cases and of clonally unrelated neoplasms in most cases. We reported a clinical, pathological and molecular analysis of three new cases of Richter’s syndrome with HL features. The three patients (two males, one female), aged of 67, 70 and 74, have 4, 8 and 15-year history of CLL, respectively. At HL, clinical stages (CS) were IIIAa, IIBb and IIIBb, at HL diagnosis. All the three patients responded to HL specific chemotherapy but two of them died from infectious and cardiac complications and the last one died from HL relapse. Histologically the lesions were composite comprising areas of CLL, areas of CLL with Hodgkin Reed-Sternberg (HRS) cells and areas of HL. The HRS cells were CD45RC−/CD20−/CD79a−/CD30+/CD15+/J-chain-(all cases), Oct-2+ (case 2) and Pax-5+ (cases1 and 3). In all cases, HRS cells were positive for EBV with a latence 2 profile. Using single cell laser microdissection and PEP-PCR amplification of the immunoglobulin heavy chain gene (IgH) FR3A region of each cell type, we demonstrated a same clonal origin for the CLL cells and the HRS cells in all cases. These data were confirmed in two cases by Genescan reamplification with fluorescent FR3A primer and sequenced with BigDye Terminator chemistry. Clinicopathological presentation was similar to classical HL but persistent EBV infection is probably related to an underlined immunosuppression due to CLL and chemotherapy. Seven other cases have been reported in the literature using similar single cell techniques, four of them, EBV +, were clonally unrelated while the three other one, EBV−, were of same clonal origin. At the opposite and although our three cases are EBV+, we show that the HRS cells and CLL cells belong to the same clonal population. Our data do not support the hypothesis that EBV+ HL in CLL patients occurs as unrelated secondary neoplasm in immunocompromised patients.
Pinkie, the First Viable Germline Hypomorph Allele of Retinoid X Receptor Alpha, Reveals an Important Role for RXRa in Th2 Development.
Authors: Du Xin , Bigby Timothy , Tabeta Koichi , Janssen Edith , Crozat Karine , Navjiwan Mann , Beutler Bruce 
Published: October 2019

Abstract
Pinkie is a recessive ENU-induced mutation, homozygotes develop premature graying and subsequently, progressive alopecia. Histologically, the skin is characterized by the destruction of hair follicle architecture, formation of dermal cysts and appearance of black papules throughout the ventral skin late in life. The Pinkie mutation was mapped to the retinoid X receptor alpha (Rxra) locus (chromosome 2) on 700 meioses and positionally cloned. As a component of the nuclear receptors for retinoic acid and other bioactive molecular ligands, RXRa plays an irreplaceable role during embryogenesis and a null allele of RXRa invariably causes embryonic lethality. Pinkie, which results from the amino acid substitution N273I in the ligand-binding domain, is the first viable germline hypomorphic mutation of RXRa. Transfection studies suggest that the abnormal protein retains only 10 to 20% of the activity of the wild type receptor. Pinkie homozygotes develop a progressive phenotype, part of which entails a severe, age-dependent imbalance of Th1/Th2 differentiation upon antigenic challenge. When immunized with ovalbumin (OVA), pinkie homozygotes displayed markedly decreased IgG1 levels in serum as compared with normal C57BL/6 mice; in vitro OVA re-stimulation of pinkie splenocytes causes greatly enhanced IFN-g production and decreased IL-4 production. Upon MCMV infection, pinkie homozygotes showed significantly higher type I interferon levels in serum than normal C57BL/6 mice. The in vitro differentiation of naïve CD4 T cells demonstrated skewed Th1 development in pinkie mouse compared to that of C57BL/6 control animal. However, real-time PCR didn’t reveal significant difference in mRNA level of GATA-3 and T-bet, which are believed to be critical transcription factors in Th1/Th2 development. These data collectively imply that RXRa is required for Th2 development. This requirement might reflect an influence of RXRa on the expression of pertinent transcription factors (e.g., GATA-3, T-bet), cytokines (IL-4, IFN-gamma) and/or cytokine receptors that are involved in Th1/Th2 differentiation. RXRa represents a likely interface between the nutritional environment and the immune status of the host. Consumption of retinoids and vitamin D may therefore be expected to influence the development of the allergic/atopic (Th2) phenotype, and provide a plausible explanation for the increasing frequency of atopic disease observed in developed countries.
Acute Myeloid Leukemia in the Elderly: Longitudinal Outcomes and Hospital Charges in Chemotherapy and Non-Chemotherapy Patients.
Authors: Katz Laura M. , Stern Lee S. , Fastenau John M. , Piech Catherine T. , Doyle John J. 
Published: October 2019

Abstract
Background: Patients with acute myeloid leukemia (AML) have an estimated median age of 65 to 70 years (J Clin Oncol1999;17:3569–76). The overall incidence of the disease increases with increasing age. The five-year survival rate for AML is 2% among elderly patients (Arch Intern Med2002;162:1597–1603). Treatment includes cytotoxic chemotherapy [e.g., the “7+3” regimen consisting of cytarabine and daunorubicin or idarubicin (Leukemia1996;10:389–95)], which can be associated with serious morbidity and is often not tolerated by older patients. Over 80% of Medicare payments for treating AML are attributable to hospitalization costs (Arch Intern Med2002;162:1597–1603).
Methods: A longitudinal cohort design was employed using an inpatient database containing information on over three million individuals from 28 hospitals in the US. The study population included patients aged 60 years and older with initial AML diagnosis between January 2000 and June 2003. Patients were followed across multiple admissions, from first inpatient encounter through last discharge from hospital. Descriptive statistics (demographics and hospital characteristics), comorbidities, chemotherapies, outcomes, resource utilization, and charges were examined; multivariate linear regressions were performed.
Results: 275 patients were identified and included in these analyses. The mean age upon first AML admission was 74.3 years (SD=8.1) and 46.6% of patients were female. On first admission, the mean length of stay (LOS) was 14.7 days (SD=14.3), 37.8% of patients received chemotherapy, and one quarter of all patients (25.3%) died. Patients incurred a mean total charge of $70,305 on first admission, while the median was $17,640; patients on chemotherapy had mean and median total charges of $113,118 and $74,689, respectively, versus $43,999 and $9,784, respectively, for non-chemotherapy patients. Chemotherapy patients also had a higher mean LOS than non-chemotherapy patients (23.0 vs. 6.7 days, respectively). 44.4% of patients had a least one re-admission with a mean of 36.4 days (SD=62.1) between the first and second admissions. For re-admissions, the mean LOS and charges were 8.9 days (SD=15.3) and $38,785 (median $13,936), respectively. Across all admissions, 41.4% of patients received chemotherapy and 40.7% of patients died in-hospital. Over the entire study period, patients incurred a mean total charge of $115,471 with a median charge of $49,168. In multivariate analyses, after adjustment for covariates, chemotherapy was found to be a significant predictor (p<0.0001) of admission charges, LOS, and total days of stay.
Conclusion: Elderly patients with AML incurred substantial charges and inpatient mortality. The highest charges and the majority of deaths occurred during first admission. Current chemotherapy regimens in these patients were associated with substantially increased charges.
Targeted Gene Therapy Vectors for Acute Myeloid Leukemia Cells Selected from Random AAV-Displayed Peptide Libraries.
Authors: Trepel Martin , Lee Mi-Kyung , Kaul Felix , Kleinschmidt Jurgen 
Published: October 2019

Abstract
For acute myeloid leukemia, gene therapy may be a valuable tool to treat patients refractory to conventional chemotherapy regimens. However, there are no vectors available that sufficiently and specifically transduce this cell type. Cell type specific receptors can be used to target gene therapy vectors to the cells of interest (Trepel et al., Hum. Gene Ther., 2001). We have developed a screening system based on random peptide libraries displayed on adeno-associated virus type 2 (AAV) (Muller et al., Nat. Biotechnology, 2003). Such libraries consist of up to 108 different viruses that display a targeting peptide with random sequence in a capsid region that mediates binding of the virus particle to cell surface receptors. Targeted AAV gene therapy vectors that specifically transduce the cell types of interest can be selected from such a library. Here we report the selection of a random AAV display peptide library on a panel of acute myeloid leukemia cell lines (Kasumi-1, U937, HL 60). An X7 (X = any amino acid) oligonucleotide insert was cloned in to the AAV-library plasmid followed by the production of AAV library transfer shuttle AAV. To produce the final library, AAV producer cells were infected with shuttle AAV at an MOI of 1 to ensure encoding of displayed peptides by the packaged DNA. The target cells were then infected with the AAV library. Bound particles were internalized and amplified either by superfinfection of the cells with wild type adenovirus type 5 or by a high-sensitivity PCR-system of the random oligonucleotide followed by cloning of the insert and making a preselected library as above. Amplified clones were recovered and subjected to two more rounds of selection. Enriched peptide inserts were analyzed indirectly by DNA sequencing of recovered clones. After three rounds of selection, enrichment of a peptide motif within the selected AAV capsids was observed. The selected viruses were used for production of recombinant AAV vectors harboring a GFP reporter gene. Such recombinant targeted vectors transduced the target leukemia cells they have been selected on (e.g., Kasumi-1 cells) up to 60 times more efficient compared to a random clone of the initial, unselected library. We conclude that our novel targeting strategy can be applied to a great variety of cell types. The clones selected here may be used as valuable tools to target therapeutic genes to acute myeloid leukemia cells.