bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective uptake of [3H]arachidonic acid into the dense tubular system of human platelets
Authors: Laposata M , Krueger CM , Saffitz JE 
Published: October 2019

Abstract
We have used quantitative electron microscopic autoradiography to characterize the subcellular distribution of arachidonoyl phospholipids following brief (5 minutes) exposure of unstimulated human platelets to [3H]arachidonic acid. Labeled arachidonate was taken up rapidly and incorporated into phospholipids. Phospholipid radioactivity was preserved and spatially fixed during tissue processing for electron microscopy. Analysis of autoradiographs showed that following a brief exposure to 750 nmol/L [3H]arachidonate, there is selective labeling of an internal membrane compartment composed of the dense tubular system and the open canalicular system. The plasma membrane, platelet granules, and nonmembranous cytoplasm were not labeled. Since the open canalicular system is continuous with the plasma membrane and since phospholipids in continuous membranes are freely diffusible, our observations indicate that [3H]arachidonate was incorporated into phospholipids within the dense tubular system and not the open canalicular system. Thus, the dense tubular system, known to contain cyclooxygenase activity, incorporates arachidonate selectively following brief exposure to this fatty acid, presumably to concentrate it in proximity to enzymes for icosanoid synthesis.
Regulation of transferrin receptor expression in myeloid leukemia cells
Authors: Taetle R , Ralph S , Smedsrud S , Trowbridge I 
Published: October 2019

Abstract
Surface transferrin (Tf) receptors are displayed by cultured human hematopoietic cells and provide Fe required for cell growth. Cell cycle status, cell density in culture, exposure to Fe, and differentiation alter Tf receptor display by myeloid leukemia cells. To investigate mechanisms controlling Tf receptor expression, rates of receptor synthesis and steady-state mRNA levels were measured in HL60 promyelocytic cells grown in serum and serum-free media or after differentiation in response to dimethylsulfoxide (DMSO). Although surface binding sites were unchanged during the first three days in culture with serum or in serum-free media containing Tf, by the third day, rates of receptor biosynthesis and steady-state mRNA levels declined, consistent with cell density-dependent, receptor regulation. Cells grown with soluble Fe instead of Tf showed reduced Tf binding sites, rates of receptor synthesis, and Tf receptor mRNA. When cells grown with Fe were subcultured, Tf receptor mRNA levels increased within 15 minutes and peaked by 24 hours. This was followed by a decline in receptor and gene expression so that by three days cells grown in the presence of Fe expressed approximately four times fewer receptors and had half the rates of Tf receptor synthesis and mRNA levels of cells grown in serum or Tf. Cells treated with DMSO showed a rapid decline in surface receptors, receptor synthesis, and steady- state mRNA levels. Modulation of Tf receptor expression was not due to redistribution between the cell surface and an internal receptor pool. In each instance, concurrent assessment of N-ras transcripts showed that changes in Tf receptor mRNA levels were not due to generalized alterations in protein synthesis. Exposure of cells grown in Fe or treated with DMSO to cycloheximide did not alter Tf receptor mRNA levels, thereby suggesting that receptor expression was not regulated by posttranscriptional processes dependent on protein synthesis. Actinomycin D inhibition of Tf receptor mRNA was compatible with a transcript half-life of approximately 2.2 hours. Nuclear transcription studies showed reduced rates of Tf receptor transcription after culture with Fe or exposure to DMSO. The present studies show complex patterns of Tf receptor gene regulation in cultured myeloid leukemia cells and demonstrate that transcriptional regulation is a major mechanism controlling Tf receptor gene expression in response to Fe and differentiation.
Carrier testing in hemophilia B with an immunoassay that distinguishes a prevalent factor IX dimorphism
Authors: Smith KJ , Thompson AR , McMullen BA , Frazier D , Lin SW , Stafford D , Kisiel W , Thibodeau SN , Chen SH , Smith LF 
Published: October 2019

Abstract
with a monoclonal antibody (A-1) detect a prevalent dimorphism in plasma coagulation factor IX. The antibody was shown to react with a dimorphic segment of the normal factor IX sequence as follows. First, A-1 bound to isolated activation peptide (residues 146 through 180) prepared from activated factor IX from a normal plasma pool. Second, binding of recombinant factor IXs with A-1 or factor IX from normal individuals was strong only when they had Threonine (Thr) at position 148; factor IXs with the Alanine (Ala) allele at that position were far less reactive. Third, immunoblot reactivity of Escherichia coli fusion proteins containing known segments of the factor IX sequence restricted the epitope to residues 147 through 153. In 120 hemophilia B pedigrees, the Ala immunoassay allele frequency was 0.19 and did not differ from the Ala frequency in normal males. In 22 of 49 families, immunoassay testing was informative for classification of obligate or possible carriers. In one large family, 4 obligate carriers were heterozygous for the dimorphism and 3 of their 7 daughters were classified as carriers. In other families, when the affected member had less than 1 nmol/L factor IX antigen, heterozygosity for Thr/Ala alleles excluded the carrier state even when DNA studies were not informative. Strong linkage disequilibrium of Thr/Ala alleles with the common TaqI DNA polymorphism was found. Nineteen of 75 normal and hemophilic factor IX genes had the 1.3- kilobase (kb) fragment and coded for the Ala allele; the rest had the 1.8-kb fragment and coded for Thr. In selected families, the A-1 immunoassay is an inexpensive and rapid method to confirm and supplement restriction fragment length polymorphism analyses of DNA for carrier testing.
B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells
Authors: Uckun FM , Fauci AS , Heerema NA , Song CW , Mehta SR , Gajl-Peczalska K , Chandan M , Ambrus JL 
Published: October 2019

Abstract
The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11–13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.
Survival after antilymphocyte globulin therapy for aplastic anemia depends on disease severity
Authors: Marsh JC , Hows JM , Bryett KA , Al-Hashimi S , Fairhead SM , Gordon-Smith EC 
Published: October 2019

Abstract
Sixty-four patients with aplastic anemia were treated with antilymphocyte globulin (ALG Merieux) between 1980 and 1985. The actuarial survival for all patients was 53% at 6 years, with 79% survival for nonsevere aplastic anemia (NSAA) and 36% for severe aplastic anemia (SAA). The neutrophil and platelet counts before treatment with ALG were highly predictive of survival, whereas sex, age, and etiology were not. Duration of disease prior to ALG treatment was inversely related to survival, although this was not statistically significant. Survival was closely associated with response to ALG, especially for patients with SAA. The response to one course of ALG was 33%. Eighteen patients who did not respond to an initial course of ALG received a second course; of these, four (22%) responded. The overall response to one or two courses of ALG was 40%. The mean RBC volume (MCV) measured after ALG treatment was a useful early indicator of response. Both the minimum lymphocyte count during ALG therapy and the mean lymphocyte count after therapy, however, were not significantly different between responders and nonresponders. The disappointing survival of patients with SAA in this study may reflect the poor clinical condition of severely affected patients referred to us and/or the presence of longstanding aplasia. The importance of studying a large series of patients with long-term follow-up to assess ALG in the treatment of aplastic anemia is shown by this investigation.
Analyses of phenotype and genotype in acute lymphoblastic leukemias at first presentation and in relapse
Authors: Raghavachar A , Thiel E , Bartram CR 
Published: October 2019

Abstract
As a clue to the cellular origin of leukemic populations in relapse we analyzed 11 cases of acute lymphoblastic leukemia (ALL) by immunological and molecular genetic approaches. Blast cells obtained from both initial diagnosis and relapse were immunophenotyped using a variety of monoclonal antibodies; simultaneously we hybridized Southern blots of respective cell samples to immunoglobulin (Ig) heavy and light chain as well as to T-cell receptor beta-chain (T beta) sequences. While similar phenotypes were observed in both states of nine cases, comparison of Ig gene rearrangements revealed clonal variations, ie, appearance of an evoluted or novel leukemic cell clone in relapse beside identical leukemic populations in both states. One pre-T (ALL) patient, presenting with germline configuration of T beta gene sequences at diagnosis, exhibited a rearrangement of T beta gene sequences in recurrent disease. Another patient displayed T-ALL phenotype and T beta gene rearrangement at diagnosis but relapsed with a very immature phenotype and germline configuration for T beta sequences. Our results emphasize the value of molecular analyses in order to unravel the nature of leukemic relapse.
Genetic differences in hemoglobin influence on erythrocyte oxidative stress hemolysis
Authors: Kruckeberg WC , Doorenbos DI , Brown PO 
Published: October 2019

Abstract
The RBC from mice of certain inbred strains hemolyzed under oxidative stress (2.0 mmol/L hydrogen peroxide), whereas red cells from mice of other strains did not. In the experimental system human erythrocytes did not hemolyze. The rate of formation of malonyldialdehyde (a fatty acid oxidative breakdown product) was fourfold higher in hemolytic v nonhemolytic red cells. There was insufficient variation in the levels of glutathione, peroxidase activity or its substrate, reduced glutathione, to explain these hemolysis differences. On the other hand, the antioxidants butylated hydroxyanisole and hydroxytoluene, and histidine protected the hemolysis-prone red cells from breaking open. The hemolysis trait demonstrated autosomal recessive Mendelian inheritance. When using inbred, recombinant inbred, and congenic inbred mice, this hemolysis/nonhemolysis trait correlated 1:1 with the type of hemoglobin beta chain in the RBC. This experimental system is a potential model for investigating the role of hemoglobin in prehemolytic events.
Localization of surface vWF on resting and stimulated platelets
Authors: Rand JH , Gordon RE , Uson RR , Potter BJ 
Published: October 2019

Abstract
We used immunoelectron microscopic localization techniques to investigate whether platelets stimulated by ADP or ristocetin in the plasma milieu bind von Willebrand factor (vWF) to their surfaces. We found by both peroxidase- and ferritin-based methods that unstimulated platelets lack vWF on their surfaces, whereas platelets that are stimulated with ADP or ristocetin have vWF associated with their surfaces. The specificity of the findings was confirmed by absorption studies using severe von Willebrand disease (vWD) and hemophilic plasmas. The anti-vWF antibodies were blocked by incubation with hemophilic plasma but not by incubation with severe vWD plasma. Thus, in the plasma environment, in the presence of fibrinogen, vWF becomes associated with the platelet surface subsequent to stimulation with ADP or ristocetin.
Therapy of severe aplastic anemia in young adults and children with allogeneic bone marrow transplantation
Authors: McGlave PB , Haake R , Miller W , Kim T , Kersey J , Ramsay NK 
Published: October 2019

Abstract
During an 8-year period, 28 young adults (median age 27 years) and 30 children (median age 10 years) with severe aplastic anemia have received allogeneic bone marrow transplantation (BMT) from major histocompatibility locimatched sibling donors after preparation with cyclophosphamide and total lymphoid irradiation (TLI). All recipients were previously transfused. Comparison of post-bone marrow transplantation events in adults and children reveals equivalent median time to engraftment, median duration of hospitalization, median Karnofsky assessment of activity, and equivalent low rejection rate. Although the incidence of moderate and severe acute graft-v-host disease (GVHD) and of extensive chronic GVHD was greater in adults than in children, the projected survival at 4 years of adults (67%; 95% confidence interval [CI] 49% to 85%) and of children (73%; 95% CI 57% to 89%) was equivalent. All survivors are transfusion-free and have normal peripheral blood counts. One of 28 adults and 2 of 30 children have experienced rejection, and 1 of these patients survives after a second transplant. No malignancies have been identified following transplantation. An unexpectedly high incidence of hypothyroidism has been detected and may be attributable to preparation of recipients with TLI. Therapy of severe aplastic anemia with allogeneic BMT after preparation with cyclophosphamide and TLI offers a high rate of transfusion-free survival and a low rejection rate in previously transfused young adults and children.
von Willebrand factor is present on the surface of platelets stimulated in plasma by ADP
Authors: Adelman B , Carlson P , Powers P 
Published: October 2019

Abstract
von Willebrand factor (vWf) can bind to glycoprotein (GP) IIb/IIIa on activated platelets. The significance of this interaction is unclear, however, because it has not been possible to detect vWf binding to GPIIb/IIIa on platelets stimulated in plasma. We have developed an indirect, flow cytometry assay that uses fluorescein-labeled antibodies to detect vWf and fibrinogen on platelets. Using this assay, we found vWf on the surface of platelets stimulated in plasma by ADP. The number of platelets that bound vWf increased in proportion to ADP concentration and incubation time. Washed platelets in a protein-free buffer activated by 1 mumol/L calcium ionophore A23187 or 10 mumol/L ADP also bound vWf, suggesting that we were detecting surface binding of alpha-granule-derived vWf. Monoclonal antibodies against the vWf binding site on GPIb (6D1) and the vWf and fibrinogen binding sites on GPIIb/IIIa (LJP5 and LJ-CP8, respectively) were used to characterize the mechanism of vWf binding to stimulated platelets. Ristocetin- induced binding of vWf was inhibited by 6D1, and ADP-induced binding of fibrinogen was inhibited by LJ-CP8. None of these antibodies inhibited ADP-induced vWf binding. Aspirin and prostaglandin E1 also inhibited ADP-induced binding of vWf in platelet-rich plasma. During platelet activation in plasma, vWf derived from alpha-granules becomes bound to the platelet surface possibly being transferred already associated with a binding site.
Effect of oxalate and malonate on red cell metabolism
Authors: Beutler E , Forman L , West C 
Published: October 2019

Abstract
The addition of oxalate to blood stored in Citrate-phosphate-dextrose (CPD) produces a marked improvement in 2,3-diphosphoglycerate (2,3-DPG) preservation; an increase in 2,3-DPG levels can also be documented in short-term incubation studies. Oxalate is a potent in vitro inhibitor of red cell lactate dehydrogenase, monophosphoglycerate mutase, and pyruvate kinase (PK). In the presence of fructose 1,6-diphosphate the latter inhibitory effect is competitive with phospho(enol)pyruvate (PEP). Determination of the levels of intermediate compounds in red cells incubated with oxalate suggest the presence of inhibition at the PK step, indicating that this is the site of oxalate action. Apparent inhibition at the glyceraldehyde phosphate dehydrogenase step is apparently due to an increase in the NADH/NAD ratio. Oxalate had no effect on the in vivo viability of rabbit red cells stored in CPD preservatives for 21 days. Greater understanding of the toxicity of oxalate is required before it can be considered suitable as a component of preservative media, but appreciation of the mechanism by which it affects 2,3-DPG levels may be important in design of other blood additives. Malonate, the 3-carbon dicarboxylic acid analogue of oxalate late did not inhibit pyruvate kinase nor affect 2,3-DPG levels.
Acute nonlymphocytic leukemia following etoposide and cisplatin combination chemotherapy for advanced non-small-cell carcinoma of the lung
Authors: Ratain MJ , Kaminer LS , Bitran JD , Larson RA , Le Beau MM , Skosey C , Purl S , Hoffman PC , Wade J , Vardiman JW 
Published: October 2019

Abstract
Combination chemotherapy is frequently used in the therapy of advanced non-small-cell lung cancer (NSCLC), but late complications are rarely recognized because of the short survival of most patients. Of 119 patients with advanced NSCLC treated with cisplatin and other drugs, four patients developed acute nonlymphocytic leukemia (ANLL). All four patients received etoposide and cisplatin with or without vindesine. Leukemia was diagnosed at 13, 19, 28, and 35 months after start of treatment. Three patients had morphologic and/or cytogenetic features of acute leukemia with significant monoblastic involvement; the fourth patient had trilineage dysplasia and cytogenetic abnormalities more commonly associated with therapy-related leukemia. Detailed analysis of the subgroup who survived longer than 1 year (24 patients) suggests that high cumulative doses of etoposide are leukemogenic; the median etoposide dose was 6,795 mg/m2 (first year only) in the four leukemic patients compared with 3,025 mg/m2 in the 20 nonleukemic patients (P less than .01). The rate of ANLL was 0.30 per person-year after the first year (95% confidence limits 0.11 to 0.90), with a cumulative risk of 15% +/- 11% at 2 years, and 44% +/- 24% at 2.5 years. We conclude that high doses of etoposide are potentially leukemogenic, and can induce a syndrome with features of acute monoblastic leukemia de novo that is distinct from other secondary leukemias.
c-fos oncogene expression in human hematopoietic malignancies is restricted to acute leukemias with monocytic phenotype and to subsets of B cell leukemias
Authors: Pinto A , Colletta G , Del Vecchio L , Rosati R , Attadia V , Cimino R , Colombatti A 
Published: October 2019

Abstract
To evaluate relationships between c-fos proto-oncogene expression and specific lineages of hematopoietic differentiation we analyzed the constitutive and TPA-induced expression of the c-fos gene in a wide variety of fresh human leukemic cells. High constitutive c-fos expression was detected in acute leukemias with monocytic phenotype (FAB M4/M5) and in subsets of B lymphoid leukemias, some of which coexpressed B lymphocytic and monocytic markers. Conversely, low basal levels of c-fos transcripts were found in pure acute granulocytic leukemias (FAB M1/M2/M3), in erythroleukemias (FAB M6), in the great majority of B, and in all T lymphoid leukemias. TPA-induced c-fos expression seems to correlate with monocytoid differentiation only when sustained levels of transcripts (ie, detectable for at least 24 hours) were detected. Sustained c-fos expression was in fact observed only in those myeloid or lymphoid cells that acquired a stable monocyte-like phenotype in response to the phorbol ester. These results indicate that high constitutive c-fos expression may identify myelomonocytic-oriented forms of leukemia, specific subsets of B lymphoid malignancies, and at least some cells terminally differentiated in vitro to a monocyte-like phenotype. c-fos oncogene expression can therefore be regarded as an additional marker for the subclassification of human leukemias.
Evidence for a multipotential stem cell disease in some childhood Philadelphia chromosome-positive acute lymphoblastic leukemia
Authors: Tachibana N , Raimondi SC , Lauer SJ , Sartain P , Dow LW 
Published: October 2019

Abstract
Children with Philadelphia chromosome (Ph+) acute lymphoblastic leukemia (ALL) have a poorer prognosis than do most pediatric patients with ALL. Because of this poor prognosis and the presence of the Ph chromosome, we have asked whether or not Ph + ALL involves a multipotential stem cell. We cultured hematopoietic progenitors from two children with Ph+ ALL and examined individual BFU-E and CFU-GM colonies for the Ph chromosome. We studied cells from two patients after 18 to 34 months of first complete clinical remission; direct cytogenetic analyses showed 26% and 13% Ph+ metaphases in these patients' marrow cells. BFU-E colonies were obtained from light density marrow cells cultured in methylcellulose supplemented with erythropoietin and CFU-GM colonies from agar or methylcellulose cultures stimulated with leukocyte feeder layers. Fifty-seven G-banded metaphases were recovered from 33 colonies. Ten metaphases from seven colonies were Ph+. Ph+ metaphases were found in three of 12 and three of five BFU-E colonies from the two patients. One of 16 CFU-GM colonies from one patient had the Ph+ chromosome; analyzable metaphases were not obtained from CFU-GM of the other patient. No colonies contained both Ph+ and Ph- cells. These results indicate that Ph+ ALL with persistence of Ph+ cells in remission involves a multipotential stem cell for erythroid and granulocyte/macrophage as well as lymphoid lineages. Multipotential stem cell involvement in the pathogenesis of some childhood Ph+ ALL suggests similarities to Ph+ chronic myelocytic leukemia and may contribute to the poor prognosis of these patients.