bluuebunny/crossref_metadata_2025_split huggingface dataset:
Granulocyte Colony-Stimulating Factor Enhances Bone Marrow Stem Cell Damage Caused by Repeated Administration of Cytotoxic Agents
Authors: van Os Ronald , Robinson Simon , Sheridan Tara , Mislow John M.K. , Dawes Donald , Mauch Peter M. 
Published: October 2019

Despite the increasing use of cytokines to circumvent the acute dose-limiting myelotoxicity of cancer treatment, little is known about the combined effects of cytotoxic agents and cytokines on the primitive stem cells responsible for long-term hematopoiesis. In an experimental model, we administered cytotoxic agents that have variable effects on primitive stem cells in C57BL/6 (B6)-mice. Mice received six every-other-week doses of cyclophosphamide (CY, 84 mg/kg), VP-16 (24 mg/kg) + cisplatinum (2.4 mg/kg), carboplatinum (50 mg/kg), chlorambucil (12 mg/kg), BCNU (13.2 mg/kg), or TBI (80 cGy). Granulocyte colony-stimulating factor (G-CSF; 250 μg/kg/day) was administered subcutaneously twice daily on days 3 to 6 after each dose of the cytotoxic agent. Comparison with animals receiving the cytotoxic agent alone was made to investigate the effects of G-CSF on long-term hematopoiesis. Hematopoiesis was measured 20 weeks after the last dose of the cytotoxic agent by assessment of peripheral blood counts, marrow cellularity, progenitor cell content (colony-forming units-spleen; CFU-S), and primitive stem cell number (long-term repopulating ability and day 28 and day 35 cobblestone area-forming cell [CAFC] frequencies). Exposure to cytotoxic agents alone resulted in a significant decrease in primitive stem cells (as measured by repopulating units [RU] and day 28 and day 35 CAFC content) in animals given carboplatinum, chlorambucil, BCNU, and TBI, but not in animals treated with cyclophosphamide or VP-16 and cisplatinum. The addition of G-CSF resulted in a significant decrease in stem cell content when compared with no G-CSF administration in animals treated with chlorambucil, BCNU, or TBI. Thus, G-CSF administered after repeated exposure to cytotoxic agents, appeared to damage the primitive stem cell compartment when used in combination with agents known to damage primitive stem cells. These results, although obtained in an experimental model, should raise concerns for the indiscriminate use of G-CSF in the clinic.
© 1998 by The American Society of Hematology.
Elevated Levels of Serum-Soluble CD14 in Human Immunodeficiency Virus Type 1 (HIV-1) Infection: Correlation to Disease Progression and Clinical Events
Authors: Lien Egil , Aukrust Pål , Sundan Anders , Müller Fredrik , Frøland Stig S. , Espevik Terje 
Published: October 2019

Soluble (s) CD14, a marker for monocyte/macrophage activation and a mediator of bacterial lipopolysaccharide (LPS) action, was elevated in serum from human immunodeficiency virus type 1 (HIV- 1)-infected individuals (n = 92) compared with seronegative controls. The highest levels were found in patients with advanced clinical and immunological disease. Patients with ongoing clinical events had significantly higher sCD14 levels than symptomatic HIV-1-infected individuals without clinical events, with especially elevated levels in patients infected with Mycobacterium avium complex (MAC). On longitudinal testing of patients (n = 26) with less than 100 × 106CD4 lymphocytes/L at baseline, we found that increasing sCD14 serum concentrations per time unit were associated with death, whereas no differences in CD4 cell number decrease were found between survivors and nonsurvivors. In vitro studies showed that HIV-1 glycoprotein 120 and purified protein derivative (PPD) from M avium (MAC-PPD) stimulated normal monocytes to release sCD14. Furthermore, MAC-PPD induced tumor necrosis factor (TNF) release from monocytes through interactions with CD14 and, importantly, the addition of sCD14 enhanced this MAC-PPD stimulatory effect. Our findings suggest that the CD14 molecule may be involved in the immunopathogenesis of HIV-1 infection, and it is conceivable that serial determination of sCD14 may give useful predictive information concerning disease progression and survival in HIV-1-infected patients.© 1998 by The American Society of Hematology.
Is Hemoglobin Instability Important in the Interaction Between Hemoglobin E and β Thalassemia?
Authors: Rees D.C. , Clegg J.B. , Weatherall D.J. 
Published: October 2019

Hemoglobin E (HbE; 2β226glu-lys), globally the commonest hemoglobin variant, is synthesized at a slightly reduced rate and has a homozygous phenotype similar to heterozygous β thalassemia. Yet, when it is inherited together with a β thalassemia allele, the resulting condition, HbE/β thalassemia, is sometimes characterized by a severe, transfusion-dependent thalassemia major. The severity of this interaction has not been explained. We have explored the possibility that it may reflect the instability of HbE consequent upon globin chain imbalance imposed by the β thalassemia allele. Time-course and pulse-chase globin chain synthesis studies at 37°C on peripheral blood and bone marrow suggest that hemoglobin instability is not significant in steady-state HbE/β thalassemia; this is confirmed by density-gradient centrifugation studies that show no decrease in HbE levels relative to HbA as HbE/β+ thalassemia red blood cells age. Globin binding to membranes was assessed and only  globin chains were found, in contrast to other unstable hemoglobins in which both  and β chains were present. However, in experiments performed on blood from HbE/β thalassemics in the temperature range 39°C to 41°C, there was evidence of instability of HbE, a finding that was also observed in homozygous HbE. These findings suggest that the phenotype of HbE/β thalassemia is primarily the result of the interaction of two β thalassemia alleles; however, hemoglobin instability may be important during febrile episodes, contributing to worsening anemia.
© 1998 by The American Society of Hematology.
Involvement of Donor T-Cell Cytotoxic Effector Mechanisms in Preventing Allogeneic Marrow Graft Rejection
Authors: Martin Paul J. , Akatsuka Yoshiki , Hahne Michael , Sale George 
Published: October 2019

Donor CD8 cells play a pivotal role in preventing allogeneic marrow graft rejection, possibly by generating cytotoxic effectors needed to eliminate recipient T cells remaining after the pretransplant conditioning regimen or by producing cytokines needed to support the growth and differentiation of hematopoietic stem cells. In the present study, we assessed the role of donor T-cell cytotoxic effector function as a mechanism for eliminating recipient CD8 cells that cause marrow graft rejection in mice. The ability to prevent rejection was minimally affected by the presence of a defect in Fas ligand binding or by the absence of granzyme B but was severely affected by the absence of perforin. Doubly mutant perforin-deficient, Fas ligand-defective CD8 cells were completely unable to prevent rejection. Our results indicate first that recipient CD8 effectors responsible for causing marrow graft rejection are sensitive to cytotoxicity mediated by both perforin- and Fas-ligand-dependent mechanisms, and second that donor T cells must have at least one functional cytotoxic mechanism to prevent allogeneic marrow graft rejection.© 1998 by The American Society of Hematology.
Cell Cycle-Related Changes in Repopulating Capacity of Human Mobilized Peripheral Blood CD34+ Cells in Non-Obese Diabetic/Severe Combined Immune-Deficient Mice
Authors: Gothot André , van der Loo Johannes C.M. , Clapp D. Wade , Srour Edward F. 
Published: October 2019

Most primitive hematopoietic progenitor cells reside in vivo within the G0/G1 phase of the cell cycle. By simultaneous DNA/RNA staining it is possible to distinguish G0 and G1 states and to isolate cells in defined phases of the cell cycle. We report here the use of cell cycle fractionation to separate human mobilized peripheral blood (MPB) CD34+ cells capable of repopulating the bone marrow (BM) of non-obese diabetic/severe combined immune-deficient (NOD/SCID) mice. In freshly isolated MPB, repopulating cells were predominant within the G0 phase, because transplantation of CD34+cells residing in G0 (G0CD34+) resulted on average in a 16.6- ± 3.2-fold higher BM chimerism than infusion of equal numbers of CD34+ cells isolated in G1. We then investigated the effect of ex vivo cell cycle progression, in the absence of cell division, on engraftment capacity. Freshly isolated G0CD34+ cells were activated by interleukin-3 (IL-3), stem cell factor (SCF), and flt3-ligand (FL) for a 36-hour incubation period during which a fraction of cells progressed from G0 into G1 but did not complete a cell cycle. The repopulating capacity of stimulated cells was markedly diminished compared with that of unmanipulated G0CD34+ cells. Cells that remained in G0 during the 36-hour incubation period and those that traversed into G1 were sorted and assayed separately in NOD/SCID recipients. The repopulating ability of cells remaining in G0 was insignificantly reduced compared with that of unstimulated G0CD34+ cells. On the contrary, CD34+ cells traversing from G0 into G1 were largely depleted of repopulating capacity. Similar results were obtained when G0CD34+ cells were activated by the combination of thrombopoietin-SCF-FL. These studies provide direct evidence of the quiescent nature of cells capable of repopulating the BM of NOD/SCID mice. Furthermore, these data also demonstrate that G0-G1 progression in vitro is associated with a decrease in engraftment capacity.© 1998 by The American Society of Hematology.
Treatment of Acquired von Willebrand Syndrome in Patients With Monoclonal Gammopathy of Uncertain Significance: Comparison of Three Different Therapeutic Approaches
Authors: Federici Augusto B. , Stabile Federica , Castaman Giancarlo , Canciani Maria Teresa , Mannucci Pier Mannuccio 
Published: October 2019

Patients with monoclonal gammopathies of uncertain significance (MGUS) may develop an acquired bleeding disorder similar to congenital von Willebrand disease, called acquired von Willebrand syndrome (AvWS). In these patients, measures to improve hemostasis are required to prevent or treat bleeding episodes. We diagnosed 10 patients with MGUS and AvWS: 8 had IgGκ (3) or λ (5) MGUS and 2 IgM-κ MGUS. Three therapeutic approaches were compared in them: (1) desmopressin (DDAVP), (2) factor VIII/von Willebrand factor (FVIII/vWF) concentrate, and (3) high-dose (1 g/kg/d for 2 days) intravenous Ig (IVIg). In patients with IgG-MGUS, DDAVP and FVIII/vWF concentrate increased factor VIII and von Willebrand factor in plasma, but only transiently. IVIg determined a more sustained improvement of the laboratory abnormalities and prevented bleeding during surgery (short-term therapy). In addition to the standard 2-day infusion protocol, a long-term IVIg therapy was performed in 2 patients with IgG-MGUS: repeated (every 21 days) single infusions of IVIg did improve laboratory abnormalities and stopped chronic gastrointestinal bleeding. On the other hand, IVIg failed to correct laboratories abnormalities in patients with IgM-MGUS. These comparative data obtained in a relative large and homogeneous group of patients with AvWS and MGUS confirm that DDAVP and FVIII/vWF concentrates improve the bleeding time (BT) and FVIII/vWF measurements only transiently, whereas IVIg provides a sustained treatment of AvWS associated with IgG-MGUS, but not with IgM-MGUS.© 1998 by The American Society of Hematology.
The Relationship Between Thiopurine Methyltransferase Activity and Genotype in Blasts From Patients With Acute Leukemia
Authors: Coulthard Sally A. , Howell Christopher , Robson Jill , Hall Andrew G. 
Published: October 2019

The level of expression of the enzyme thiopurine methyltransferase (TPMT) is an important determinant of the metabolism of thiopurines used in the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Studies in red blood cells (RBC) have shown that TPMT expression displays genetic polymorphism with 11% of individuals having intermediate and one in 300 undetectable levels. The genetic basis for this polymorphism has now been elucidated and polymerase chain reaction (PCR)-based assays described for the most common mutations accounting for reduced activity. In previous studies, genotype has been correlated with red blood cell activity. In this report, we describe the relationship between genotype and TPMT activity measured directly in the target of drug action, the leukemic cell. We have demonstrated that the TPMT activity in lymphoblasts from 38 children and adults found by PCR to be homozygotes (*1/*1) was significantly higher than that in the five heterozygotes (*1/*3) detected (median, 0.25 v 0.08, P < .002, Mann-Whitney U). Similar results were obtained when results from children were analyzed separately. However, comparison of activity in blasts from AML and ALL showed a higher level in the former (0.35 v 0.22 nU/mg,P < .002, n = 17, 35), suggesting that factors other than genotype may also influence expression.© 1998 by The American Society of Hematology.
CBFA2(AML1) Translocations With Novel Partner Chromosomes in Myeloid Leukemias: Association With Prior Therapy
Authors: Roulston Diane , Espinosa Rafael , Nucifora Giuseppina , Larson Richard A. , Le Beau Michelle M. , Rowley Janet D. 
Published: October 2019

CBFA2(AML1) has emerged as a gene critical in hematopoiesis; its protein product forms the DNA-binding subunit of the heterodimeric core-binding factor (CBF) that binds to the transcriptional regulatory regions of genes, some of which are active specifically in hematopoiesis. CBFA2 forms a fusion gene with ETO andMDS1/EVI1 in translocations in myeloid leukemia and withETV6(TEL) in the t(12;21) common in childhood pre-B acute lymphoblastic leukemia. We have analyzed samples from 30 leukemia patients who had chromosome rearrangements involving 21q22 by using fluorescence in situ hybridization (FISH). Our analysis showed that 7 of them involved CBFA2 and new translocation partners. Two patients had a t(17;21)(q11.2;q22), whereas the other 5 had translocations involving 1p36, 5q13, 12q24, 14q22, or 15q22. Five of these novel breakpoints in CBFA2 occurred in intron 6; this same intron is involved in the t(3;21). One breakpoint mapped to the t(8;21) breakpoint region in intron 5, and 1 mapped 5′ to that region. All 7 CBFA2 rearrangements resulted from balanced translocations. All 7 patients had myeloid disorders (acute myeloid leukemia or myelodysplastic syndrome); 2 were de novo and 5 had treatment histories that included topoisomerase II targeting agents. The association of therapy-related disorders with translocations involving CBFA2 was significant by Fisher’s exact test (P < .003). These results provide further evidence that this region of CBFA2 is susceptible to breakage in cells exposed to topoisomerase II inhibitors.
© 1998 by The American Society of Hematology.
Fluorescence In Situ Hybridization of Progenitor Cells Obtained by Fluorescence-Activated Cell Sorting for the Detection of Cells Affected by Chromosome Abnormality Trisomy 8 in Patients With Myelodysplastic Syndromes
Authors: Saitoh Kohki , Miura Ikuo , Takahashi Naoto , Miura Akira B. 
Published: October 2019

Myelodysplastic syndrome (MDS) is believed to be a stem-cell disorder involving cytopenia and dysplastic changes in three hematopoietic lineages. However, the involvement of pluripotent stem cells and progenitor cells has not been clarified conclusively. To address this issue, we used fluorescence in situ hybridization (FISH) of blood and bone marrow (BM) smears for mature cells and FISH of cells sorted by fluorescence-activated cell sorting for progenitor cells. Seven patients with MDS associated with trisomy 8 were studied. FISH showed +8 in granulocytes, monocytes, and erythroblasts, but not in lymphocytes. Sorted cells of T (CD3+), B (CD19+), and NK cells (CD3−CD56+) from peripheral blood did not contain +8, nor did CD34+ subpopulations from BM including B (CD34+CD19+), T/NK (CD34+CD7+) progenitors, and pluripotent stem cells (CD34+Thy1+). The +8 chromosome abnormality was identified in stem cells only at the level of colony-forming unit of granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM; CD34+CD33+). It may thus be concluded that cells affected by trisomy 8 in the context of MDS are at the CFU-GEMM level and that cells of lymphoid lineage are not involved. These results provide new insights into the biology of MDS and suggest that intensive chemotherapy and autologous BM transplantation may become important therapeutic strategies.
© 1998 by The American Society of Hematology.
Primary Myeloma Cells Growing in SCID-hu Mice: A Model for Studying the Biology and Treatment of Myeloma and Its Manifestations
Authors: Yaccoby Shmuel , Barlogie Bart , Epstein Joshua 
Published: October 2019

Progress in unraveling the biology of myeloma has suffered from lack of an in vitro or in vivo system for reproducible growth of myeloma cells and development of disease manifestations. The SCID-hu mouse harbors a human microenvironment in the form of human fetal bone. Myeloma cells from the bone marrow of 80% of patients readily grew in the human environment of SCID-hu mice. Engraftment of myeloma cells was followed by detectable human Ig levels in the murine blood. Myeloma-bearing mice had high levels of monotypic human Igs, high blood calcium levels, increased osteoclast activity, and severe resorption of the human bones. The human microenvironment was infiltrated with Epstein-Barr virus-negative monoclonal myeloma cells of the same clonality as the original myeloma cells. Active angiogenesis was apparent in areas of myeloma cell infiltration; the new endothelial cells were of human origin. We conclude that the SCID-hu mouse is a favorable host for studying the biology and therapy of myeloma and that a normal bone marrow environment can support the growth of myeloma cells.
© 1998 by The American Society of Hematology.
Changes in human immunodeficiency virus type 1 virus load during mobilization and harvesting of hemopoietic progenitor cells
Authors: Campbell Thomas B. , Sevin Anne , Coombs Robert W. , Peterson Gregory C. , Rosandich Mary , Kuritzkes Daniel R. , Mladenovic Jeannette , Landay Alan , Wong Roberta , Ambruso Daniel , Miles Steve , Pomerantz Roger J. , Schooley Robert T. ,   the Adult AIDS Clinical Trials Group 285 Study Team
Published: October 2019

Abstract
Genetic modification of hemopoietic progenitor cells ex vivo, followed by the infusion of the genetically modified cells into the human immunodeficiency virus-1 (HIV-1) infected donor, has been proposed as a treatment for HIV-1 infection. The current study was undertaken to evaluate the effect of hemopoietic stem cell mobilization and harvesting on HIV-1 replication in persons with HIV-1 infection. Eighteen HIV-1–infected persons received recombinant granulocyte colony-stimulating factor (G-CSF; Filgrastim) 10 μg/kg per day, for 7 days. On days 4 and 5, peripheral blood mononuclear cells were harvested by leukapheresis. The CD4+ lymphocyte count at entry was &gt;500/μL for 6 subjects, 200 to 500/μL for 6 subjects, and &lt;200/μL for 6 subjects. For 9 of 18 subjects, plasma HIV-1 RNA levels increased 4- to 100-fold (&gt;0.6 log10) above baseline between days 4 and 7 and returned to baseline by day 27. Significant increases of plasma HIV-1 RNA levels occurred in 5 subjects despite 3-drug antiretroviral therapy. Changes in CD4+ and CD34+ cells during mobilization and harvesting were similar in all subjects whether they had or did not have increased plasma HIV-1 RNA levels. Thus, mobilization and harvesting of bone marrow progenitor cells from persons infected with HIV-1 induced a transient increase in viral replication in some patients but was not associated with adverse effects. (Blood. 2000;95: 48-55)
Detection of clonal T-cell receptor gamma-chain gene rearrangements in Reed-Sternberg cells of classic Hodgkin disease
Authors: Seitz Volkhard , Hummel Michael , Marafioti Theresa , Anagnostopoulos Ioannis , Assaf Chalid , Stein Harald 
Published: October 2019

Abstract
Recent molecular single-cell studies have shown that in approximately 95% of cases, Reed-Sternberg cells of classic Hodgkin disease (HD) are derived from B cells of germinal center origin. Attempts to determine the cellular nature of the remaining cases have so far failed. To clarify whether they are derived from T cells, this study examined 791 single CD30+ Hodgkin and Reed-Sternberg (HRS) cells from 13 T-cell marker-positive cases and from 6 cases with null-cell phenotype for rearranged T-cell receptor-gamma (TCR-γ) genes by single copy polymerase chain reaction. Monoclonally rearranged TCR-γ genes were detectable in 2 of the 13 classic HD cases with T-cell marker-positive HRS cells, with none detectable in the null-cell cases. Eight of the T-cell marker-positive cases and all 6 null-cell cases were also studied for rearrangements of immunoglobulin genes. Six of the 8 T-cell marker-positive cases harbored clonal immunoglobulin gene rearrangements. The 2 cases without rearranged immunoglobulin genes were those that contained clonal TCR-γ rearrangements and lacked expression of the B-cell-specific activator protein. From these findings we conclude that cases of classic HD with T-cell-derived HRS cells definitely exist, although their overall incidence at 1% to 2% is very low. Even within the T-cell marker-positive cases only a minority (15%) were derived from T cells. The majority (85%) originated from B cells, indicating that the T-cell antigens expressed by HRS cells are, in contrast to those expressed in non-Hodgkin lymphoma, not lineage specific.
Hypermethylation of E-cadherin in leukemia
Authors: Melki John R. , Vincent Paul C. , Brown Ross D. , Clark Susan J. 
Published: October 2019

Abstract
E-cadherin gene is often termed a “metastasis suppressor” gene because the E-cadherin protein can suppress tumor cell invasion and metastasis. Inactivation of the E-cadherin gene occurs in undifferentiated solid tumors by both genetic and epigenetic mechanisms; however, the role of E-cadherin in hematologic malignancies is only now being recognized. E-cadherin expression is essential for erythroblast and normoblast maturation, yet expression is reduced or absent in leukemic blast cells. This study examined the messenger RNA (mRNA) and protein expression of the E-cadherin gene in bone marrow and blood samples from normal donors and patients with leukemia. We found that all normal donor samples expressed E-cadherin mRNA, whereas both samples of acute myelogenous leukemia and chronic lymphocytic leukemia had a significant reduction or absence of expression. However, normal blast counterparts expressed only a low level of E-cadherin surface protein. Sodium bisulphite genomic sequencing was used to fully characterize the methylation patterns of the CpG island associated with the E-cadherin gene promoter in those samples with matched DNA. All of the normal control samples were essentially unmethylated; however, 14 of 18 (78%) of the leukemia samples had abnormal hypermethylation of the E-cadherin CpG island. In fact both alleles of the E-cadherin gene were often hypermethylated. We conclude the E-cadherin gene is a common target for hypermethylation in hematologic malignancies.