bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration of platelet function in dogs mediated by interleukin-6
Authors: Peng J , Friese P , George JN , Dale GL , Burstein SA 
Published: October 2019

Abstract
To determine if interleukin-6 (IL-6) administration influences platelet function, platelet activation was analyzed sequentially in IL-6-treated (80 micrograms/kg/d) and control dogs. Platelet activation was determined in whole blood by flow cytometry by quantitating the binding of a monoclonal antibody to platelet surface P-selectin after stimulation with graded doses of thrombin. Administration of IL-6 resulted in a twofold decrease in the thrombin concentration required for induction of half-maximal P-selectin expression (ED50) compared with control animals. The ED50 returned to normal after cessation of IL- 6 administration. As measured by P-selectin expression, enhanced responsiveness to the strong agonist platelet activating factor (PAF) was also observed in the IL-6-treated dogs. IL-6 had no effect on the susceptibility of platelets to thrombin activation when incubated with anticoagulated dog blood. The data show that, in addition to augmenting the platelet count in normal dogs, IL-6 enhances the sensitivity of platelets to activation in response to thrombin and PAF.
The macrocyclic lactone protein kinase C activator, bryostatin 1, either alone, or in conjunction with recombinant murine granulocyte- macrophage colony-stimulating factor, protects Balb/c and C3H/HeN mice from the lethal in vivo effects of ionizing radiation
Authors: Grant S , Traylor R , Pettit GR , Lin PS 
Published: October 2019

Abstract
We have examined the in vivo radioprotective effects of the macrocyclic lactone protein kinase C (PK-C) activator, bryostatin 1, administered either alone or in conjunction with recombinant murine granulocyte- macrophage colony-stimulating factor (rmGM-CSF), in Balb/c and C3H/HeN mice subjected to lethal total body irradiation (TBI). When administered alone on a divided dose schedule (24 hours and 30 minutes before TBI), rmGM-CSF (20 micrograms/kg) was ineffective in increasing survival in either strain. However, in Balb/c mice, bryostatin 1 alone (1 microgram) permitted the long-term survival (60 days) of 70% of the animals following TBI, and 80% when administered in conjunction with rmGM-CSF. Bryostatin 1 administered alone according to this schedule exerted minimal radioprotective effects in C3H/HeN mice, but, when combined with a subeffective dose of rmGM-CSF, allowed 50% of the animals to survive. Treatment of Balb/c mice with bryostatin 1 administered as a single dose 4 hours before TBI resulted in a 20% survival rate, and 45% when administered with rmGM-CSF; corresponding values for the C3H/HeN strain were 60% and 40%, respectively. Lastly, the survival rates of Balb/c mice treated with bryostatin 1 administered as a single dose 4 hours following TBI was 20%, and 25% with rmGM-CSF; corresponding values were 50% and 25% for C3H/HeN mice. These findings indicate that the PK-C activator bryostatin 1 exhibits intrinsic in vivo radioprotective effects in lethally irradiated Balb/c and C3H/HeN mice, and may, under some circumstances, augment the radioprotective capacity of rmGM-CSF. They also underscore the critical role that strain differences and scheduling considerations play in determining the in vivo radioprotective capacity of bryostatin 1, as well as its interactions with rmGM-CSF.
Circulating monoclonal B cells expressing P glycoprotein may be a reservoir of multidrug-resistant disease in multiple myeloma
Authors: Pilarski LM , Belch AR 
Published: October 2019

Abstract
Multiple myeloma is basically an incurable cancer. Most patients respond initially to chemotherapy with reduction in bone marrow (BM) plasma cells and monoclonal Ig levels, but the disease nearly always recurs and becomes refractory to therapy. The objective of this study was to characterize the expression of the multidrug transport pump, P- glycoprotein 170 (P-gp), in myeloma. The great majority of B cells from peripheral blood mononuclear cells (PBMCs) in myeloma express P-gp, detected by the monoclonal antibody MRK-16. P-gp+ blood B cells exhibit extensive DNA hyperdiploidy, suggesting replicative abnormality characteristic of malignant growth. We speculate these represent a stem cell population in myeloma. The proportion of B cells expressing P-gp was comparable among untreated myeloma patients and those treated with chemotherapy, biologic response modifiers, or off treatment. Among BM cells, P-gp was absent or low in untreated myeloma patients but was expressed at high levels on BM cells from patients previously treated with chemotherapy. For untreated patients the majority of B/plasma cells expressing P-gp are located in PBMCs, not the BM cells. Flow cytometric analysis of rhodamine 123 dye efflux indicated a functional P-gp that was efficiently blocked by verapamil or cyclosporin A (CsA). Both the CD11bhi CD19+ B cells and the T cells in myeloma PBMCs had active CsA-inhibited dye efflux, but monocytes lacked the ability to efflux dye. Nearly all CD38hi plasma cells from myeloma BM cells retained dye, indicating their lack of a functional transport pump. Thus, PBMC B cells may be the predominant set of drug-resistant tumor cells. Myeloma PBMC B cells were cultured with Adriamycin with or without CsA and drug toxicity evaluated by the induction of apoptosis, using flow cytometry to quantitate DNA disruption. No apoptosis was detectable at 0.01 microgram/mL adriamycin, the in vivo steady-state level, with or without CsA. With 0.1 microgram adriamycin, no apoptosis was detectable in the absence of CsA, but with CsA, 66% of B cells initiated DNA disruption, whereas most T cells were spared. This work suggests that currently used drug dosages are too low to effect P-gp+ B- cell death, even in the presence of CsA. We suggest that blood B cells comprise a highly drug-resistant subset of the myeloma B lineage that escapes conventional chemotherapy and may underlie the almost uniform fatal relapse in myeloma patients.
Glycosyl-phosphatidylinositol anchor synthesis in paroxysmal nocturnal hemoglobinuria: partial or complete defect in an early step
Authors: Norris J , Hall S , Ware RE , Kamitani T , Chang HM , Yeh E , Rosse WF 
Published: October 2019

Abstract
The defect in the biosynthesis of the glycosyl-phosphatidyl inositol (GPI) anchor in paroxysmal nocturnal hemoglobinuria (PNH) appears to be in the initial steps. In biosynthetic studies using [3H]mannose, abnormal granulocytes of eight patients, and B lymphocytes transformed by Epstein-Barr virus of six different patients synthesized dolichyl phosphoryl mannose, but little or no later mannosylated intermediates. When fused with murine cell lines known to be deficient at different biosynthetic steps of the GPI anchor, the GPI-anchor-deficient granulocytes of 21/21 patients and lymphocytes from 6/6 patients complemented all murine cell lines except those of class A; cells of this class are not able to add N-acetylglucosamine to phosphatidylinositol. These studies indicate that the defect in GPI- anchor synthesis in PNH is early in the pathway, and is the same as that of class A mutants, but may be partial in some patients, resulting in the production of small amounts of mannosylated intermediates.
A novel beta-globin mutation, beta Durham-NC [beta 114 Leu-->Pro], produces a dominant thalassemia-like phenotype
Authors: de Castro CM , Devlin B , Fleenor DE , Lee ME , Kaufman RE 
Published: October 2019

Abstract
Mutations within exon 3 of the beta-globin gene are relatively uncommon, and many of these mutations produce a dominant thalassemia- like phenotype. We describe a novel thalassemic hemoglobinopathy caused by a single nucleotide substitution (CTG-->CCG) at codon 114 resulting in a leucine to proline substitution and designate it beta Durham-NC [beta 114 Leu-->Pro]. The mutation producing this thalassemic hemoglobinopathy is located near to the beta Showa-Yakushiji mutation (beta 110 Leu-->Pro). Both of these hemoglobinopathies share similar phenotypic features with moderately severe microcytic anemia. Using computer imaging of the hemoglobin molecule, we examined several reported point mutations within exon 3 of the beta-globin gene. These point mutations cause a single amino acid substitution in the G helix, and result in a thalassemic and/or hemolytic phenotype. Computer imaging of nine separate examples suggests that amino acid substitutions affecting side chains that project into the heme pocket may destabilize the heme moiety within the beta-globin chain, resulting in a thalassemic phenotype. Hemolytic phenotypes may be the result of decreased alpha 1 beta 1 interactions. The beta Durham-NC mutation further characterizes a novel group of thalassemias/hemoglobinopathies that are clinically difficult to identify and require accessory laboratory testing.
Expression and extracellular release of transferrin receptors during peripheral erythroid progenitor cell differentiation in liquid culture
Authors: Shintani N , Kohgo Y , Kato J , Kondo H , Fujikawa K , Miyazaki E , Niitsu Y 
Published: October 2019

Abstract
The expression and extracellular release of transferrin receptor (TR) was investigated by in vitro model system of erythroid differentiation. Human peripheral blood mononuclear cells were cultured with interleukin- 3 (IL-3) for 7 days, and with erythropoietin (EPO) for an additional 8 days. After EPO stimulation, IL-3-stimulated blastic cells were serially differentiated into mature erythrocytes. [3H]-thymidine incorporation of cultured cells increased linearly from day 0 to 5, followed by a decrease. Flow cytometric analysis showed an increase of TR expression from day 0 to 5, followed by a slight decrease. By metabolic labeling with [35S]methionine and immunoprecipitation, the cell lysate exhibited a 95-kD band corresponding to the intact TR on sodium dodecyl sulfate-polyacrylamide gel electrophoresis/autoradiography at day 5, when polychromatic erythroblasts had their peak. The culture supernatant solubilized by tween-20 exhibited a 95-kD and an 85-kD band on days 5 and 8, which corresponded to the intact and the truncated forms of TR, respectively. The 95-kD band was more intense at day 5 than at day 8. The reverse transcriptase-polymerase chain reaction assay showed that the receptor- mRNA expression was parallel to receptor synthesis. Thus, the synthesis and expression of TR on erythrocytes is associated mainly with cell proliferation in the early phase, and with both cell proliferation and hemoglobin production in the middle to late phases of maturation. Concomitantly, the extracellular release of TR from erythrocytes occurs in the middle to late phases of maturation. These data suggest that polychromatic erythroblasts release soluble TR as both intact and truncated forms and may be an important source of serum TR implicated as an index for erythropoietic activity in the marrow.
Venous thromboembolic complications (VTE) in children: first analyses of the Canadian Registry of VTE
Authors: Andrew M , David M , Adams M , Ali K , Anderson R , Barnard D , Bernstein M , Brisson L , Cairney B , DeSai D 
Published: October 2019

Abstract
Deep vein thrombosis (DVT) and pulmonary embolism (PE) occur in pediatric patients; however, the incidence, associated morbidity, and mortality are unknown. A Canadian registry of DVT and PE in children (ages 1 month to 18 years) was established July 1, 1990 in 15 tertiary- care pediatric centers. One-hundred thirty-seven patients were identified prospectively and are the subject of this report. The incidence of DVT/PE was 5.3/10,000 hospital admissions or 0.07/10,000 children in Canada. Infants under 1 year old and teenagers predominated with equal numbers of both sexes. DVT were located in the upper (n = 50) and lower (n = 79) venous system, or as PE alone (n = 8). Central venous lines (CVLs) were present in approximately 33% of children with DVT (n = 45). Associated conditions were present in 96% of children and 90% of children had two or more associated conditions for DVT. DVT was diagnosed by venography (n = 83), duplex ultrasound (n = 37), and other combinations (n = 17). Twenty-two of the 31 ventilation/perfusion scans performed were interpreted as high-probability scans for PE. Therapy consisted of heparin (n = 115), thrombolysis (n = 15), surgical removal of a CVL or thrombus (n = 22), and oral anticoagulant therapy (n = 103). Significant bleeding complications did not occur. However, three (2.2%) children died as a direct consequence of their thromboembolic disease; DVT reoccurred in 23 children and postphlebitic syndrome (PPS) occurred in 26. In conclusion, DVTs occur in a significant number of hospitalized children with a mortality of 2.2%. Complications are not hemorrhagic, but thrombotic, and characterized by PE, recurrent disease, and PPS. In contrast to adults, the upper venous system is frequently affected because of the use of CVLs. The frequency of DVT/PE justifies controlled trials of primary prophylaxis in high-risk groups, and therapeutic trials to determine optimal treatment.
Retention of B-cell-specific monoclonal antibodies by human lymphoma cells
Authors: Press OW , Howell-Clark J , Anderson S , Bernstein I 
Published: October 2019

Abstract
The rates of endocytosis, intracellular degradation, and cell-surface shedding of 125I-labeled monoclonal antibodies (MoAbs) HD-37 (anti- CD19), B1 (anti-CD20), MB-1 (anti-CD37), BC8 (anti-CD45), and DA4–4 (anti-mu) by B-lymphoma cells were compared by cellular radioimmunoassay, ultrastructural autoradiography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and thin layer chromatography using biopsy specimens from 12 patients with non- Hodgkin's lymphomas. 125I-BC8 was stably retained on the surface of lymphoma cells without appreciable internalization or shedding, whereas 125I-DA4–4 underwent rapid endocytosis and degradation. 125I-B1 was not internalized or degraded by tumor cells, but rapidly dissociated from the cell surface in intact form. Moderate rates of endocytosis, intracellular metabolism, and cell-surface shedding were shown by 125I- HD37 and 125I-MB-1. The 3 patients with diffuse, small cleaved-cell lymphomas internalized and degraded antibodies more slowly than did patients with other histologic subtypes. These kinetic differences may be important in the selection of MoAbs for immunotoxin and radioimmunoconjugate therapy of B-cell malignancies.
Granulocyte colony-stimulating factor (G-CSF) production and G-CSF receptor structure in patients with congenital neutropenia
Authors: Guba SC , Sartor CA , Hutchinson R , Boxer LA , Emerson SG 
Published: October 2019

Abstract
Congenital neutropenia (Kostmann's syndrome [KS]) is an autosomal recessive syndrome that is characterized by profound neutropenia, resulting in major clinical infections and death. Since the neutropenia and symptoms in KS improve in response to exogenous administration of granulocyte colony-stimulating factor (G-CSF), we studied bone marrow cytokine (G-CSF, granulocyte-macrophage CSF [GM-CSF], and interleukin- 6) production under both basal and stimulated conditions. No differences in G-CSF, GM-CSF, or IL-6 gene expression were found in bone marrow stromal cells between normal controls and KS patients, and all three cytokines were detected by enzyme-linked immunosorbent assay (ELISA) in medium conditioned by bone marrow stromal cells from normal donors and patients with KS. Each KS patient tested had detectable, functional G-CSF in their own serum before exogenous G-CSF administration. Since G-CSF production appeared normal in KS patients, we then asked whether we could detect structural defects in the signaling portion of G-CSF receptor genes. Polymerase chain reaction (PCR) amplification of the G-CSF receptor transmembrane region alone, and of the transmembrane plus cytosolic portions of the receptor, yielded the size products predicted from the sequences of the normal G- CSF receptor. Single-strand conformational polymorphism (SSCP) analysis of G-CSF receptor PCR products demonstrated no variance in structural conformation between KS patients and normal subjects. These results demonstrate that bone marrow stromal cells in patients with KS secrete normal concentrations of functional G-CSF and suggest that the neutropenia in KS patients is caused by an inability of neutrophilic progenitor and precursor cells to respond to normal, physiologic levels of G-CSF. Such a defect, clinically responsive to pharmacologic doses of G-CSF, might be caused by defects in the post-G-CSF receptor signal transduction pathway.
Expression of bcr-abl abrogates factor-dependent growth of human hematopoietic M07E cells by an autocrine mechanism
Authors: Sirard C , Laneuville P , Dick JE 
Published: October 2019

Abstract
The introduction of a retrovirus vector expressing p210bcr-abl (P210) into the human factor-dependent cell line M07E resulted in the rapid outgrowth of factor-independent cells. Early after infection, four factor-independent clones were isolated and analyzed in greater detail along with mass populations obtained from separate infections. High levels of P210 tyrosine kinase activity were measured in the factor- independent cells. The mass populations and three of the four clones remained responsive to exogenous growth factors. Concentrated conditioned media isolated from the factor-independent populations and from all clones contained biologically active granulocyte-macrophage colony-stimulating factor (GM-CSF); interleukin-3 (IL-3) was detected at low levels in the mass population and in two of the clones. Neutralizing antibodies to IL-3, GM-CSF, and mast cell growth factor inhibited proliferation of the factor responsive clones by 60% to 90%. These results indicate that the growth autonomy of the P210-expressing M07E cells was acquired via an autocrine mechanism. In addition to factor-independent growth, P210-expressing M07E cells readily acquired a more mature megakaryocytic phenotype compared with control M07E cells. These data provide experimental evidence that expression of P210 tyrosine kinase in human hematopoietic cells induced growth factor secretion resulting in a pleiotropic effect on growth factor dependence and differentiation.
Analysis of treatment failure in patients with minimally differentiated acute myeloid leukemia (AML-M0)
Authors: Stasi R , Del Poeta G , Venditti A , Masi M , Stipa E , Dentamaro T , Cox C , Dallapiccola B , Papa G 
Published: October 2019

Abstract
Reports of treatment of patients with minimally differentiated acute myeloid leukemia (AML-M0) are limited, heterogeneous, and controversial. We verified the prognosis of this subtype by analyzing the results of 189 consecutive patients with de novo AML. Fifteen cases fitting the criteria of AML-M0 were identified. No clinical features distinguished them from other patients with AML. The median age was 61 years (range 27 to 70), with a leukocyte count ranging from 0.6 to 185 x 10(9)/L. In all cases the leukemic cells expressed CD34 and reacted with at least one of the antibodies to early myeloid antigens, ie, CD13, CD33, or myeloperoxidase. Immunophenotypic analysis also showed positivity for CD7 in seven samples and the multidrug-resistance P- glycoprotein (P-170) in six. Cytogenetic analysis was abnormal in 12 of the 13 patients in whom an adequate number of mitoses could be evaluated. No single abnormality prevailed, the most common findings being trisomy 8 (three cases) and aberrations of chromosome 7 (two cases). Antileukemic treatment differed according to age, but for remission induction, all patients received a combination of cytosine arabinoside and an anthracycline or mitoxantrone. The prognosis of patients with AML-M0 was remarkably poor as compared with the other French-American-British subtypes. Whereas the overall rate of complete remission (CR) was 58% with a median survival of 63 weeks, only 6 of the 15 patients with AML-M0 achieved a CR, and the median survival of this group was 16 weeks (range 3 to 39). The major determinant of treatment failure was unresponsiveness to chemotherapy, as only one patient died of infection during the hypoplastic phase. The CR duration of responders was short, ranging from 3 to 22 weeks, and no second remissions were observed. We conclude that conventional combination chemotherapy yields disappointing results in AML-M0. The reason for this may be the convergence of various unfavorable prognostic factors, such as (1) the high incidence of cytogenetic abnormalities; (2) the lack of differentiation features and the expression of immaturity markers such as CD34 and CD7; and (3) the frequent expression of P-170. Nonconventional therapeutic approaches should be developed to alter the prognosis of this form of leukemia.
Fc gamma receptor II (CD32) on malignant B cells influences modulation induced by anti-CD19 monoclonal antibody
Authors: Vervoordeldonk SF , Merle PA , van Leeuwen EF , van der Schoot CE , von dem Borne AE , Slaper-Cortenbach IC 
Published: October 2019

Abstract
Antigenic modulation is one of many factors determining the effectiveness of monoclonal antibody (MoAb)-mediated therapy. To select the isotype of a CD19 MoAb most suitable for radioimmunotherapy of patients with B-cell malignancies, we studied the influence of MoAb isotype on modulation, after binding of the MoAb to different cell-line cells. The CD19-IgG1 MoAb was found to induce modulation of CD19 antigens on Daudi cell line cells more rapidly than did its IgG2a switch variant. We provide evidence that this difference in modulation rate is caused by the expression of Fc gamma receptor II (Fc gamma RII) on these cells. Experiments aimed at elucidating the mechanism of Fc gamma RII involvement in modulation induction by CD19-IgG1 showed that Fc gamma RII did not comodulate with CD19 MoAbs. However, cocrosslinking of CD19 and Fc gamma RII with CD19-IgG1 MoAb resulted in enhanced calcium mobilization in Daudi cells. This increased signal induction accompanies the enhanced capping and subsequent modulation of CD19 antigens. Because Fc gamma RII is expressed in varying densities on malignant B cells in all differentiation stages, our results have implications for the MoAb isotype most suitable for use in MoAb-based therapy of patients with B-cell malignancies.
Interleukin-4 induces programmed cell death (apoptosis) in cases of high-risk acute lymphoblastic leukemia
Authors: Manabe A , Coustan-Smith E , Kumagai M , Behm FG , Raimondi SC , Pui CH , Campana D 
Published: October 2019

Abstract
We investigated the effects of interleukin-4 (IL-4) on the survival of leukemic and normal B-cell progenitors cultured on bone marrow stroma. IL-4 (at 100 U/mL) was cytotoxic in 16 of 21 cases of B-lineage acute lymphoblastic leukemia, causing reductions in CD19+ cell numbers that ranged from 50% to greater than 99% (median 83.5%) of those in parallel cultures not exposed to the cytokine. All nine cases with the t(9;22)(q34;q11) or the t(4;11)(q21;q23), chromosomal features that are often associated with multidrug resistance and a fatal outcome, were susceptible to IL-4 toxicity. IL-4 cytotoxicity resulted from induction of programmed cell death (apoptosis); there was no evidence of cell killing mediated by T, natural killer, or stromal cells. IL-4 cytotoxicity extended to a proportion of normal B-cell progenitors. After 7 days of culture with IL-4 at 100 U/mL, fewer CD19+, CD34+ normal lymphoblasts (the most immature subset) survived: in five experiments the mean (+/- SEM) reduction in cell recoveries caused by IL-4 was 60.0% +/- 6.0%. By contrast, reductions in recovery of more differentiated bone marrow B cells (CD19+, CD34-, surface Ig+) were low (6.6% +/- 2.2%; P < .001 by t-test). Our findings indicate that IL-4 is cytotoxic for human B-cell precursors and support clinical testing of IL-4 in cases of high-risk lymphoblastic leukemia resistant to conventional therapy.