bluuebunny/crossref_metadata_2025 huggingface dataset:
Mineral/melt partition coefficients of oceanic alkali basalts determined on natural samples using laser ablation-inductively coupled plasma-mass spectrometry (LAM-ICP-MS)
Authors: Thompson G. M. , Malpas J.
Published: July 2002

In order to limit the range of possible differentiation mechanisms and the impact of these processes on the trace element signatures of igneous suites, it is important to be able to predict or model the compositional evolution of the primary and/or parental magmas. Part of the problem in understanding these relationships in basalts from ocean islands is the paucity of reliable trace element mineral/melt partition coefficients, particularly for undersaturated magmas. Consequently, we have measured mineral/groundmass partition coefficients for Rb, Sr, Y, Zr, Nb, Hf, Ta, Th and REE, in situ, in clinopyroxene, Fe-Ti oxides and olivine in primitive basalts from Rarotonga, Cook Islands using LAM-ICP-MS.

Analyses of these mafic rocks show high concentrations of most incompatible trace elements (e.g. Sr, Th, Y, REE, etc.) in pyroxenes relative to the other phases, suggesting that fractionation of pyroxenes was the dominant factor in the distribution of these trace elements during crystal fractionation. In such cases, the highly incompatible elements (D <0.01) are Ba, Cs and Nb. Elements that could also be classified as strongly incompatible (D <0.1) are Rb, Ta and Th. The remaining trace elements have bulk partition coefficient values that range from ∼.0.1 up to ∼.0.8 (Sr, Hf, Zr, Y and REE). Magnetites incorporate greater amounts of Nb and Ta than the titanaugites, and any significant fractionation of magnetite would have affected the bulk distribution of Nb and Ta. The LREE have lower Kd values than other REE, with the HREE having Kd values close to unity. Consequently, with the separation of titanaugite an overall enrichment of REE in the residual liquid with an increase in the La/Yb ratio is produced.
Tectonic setting of the carbonatite-melilitite association of Italy
Authors: Lavecchia G. , Boncio P.
Published: July 2002

In this paper the Late Pleistocene carbonatite-melilitite association (CMA) of Italy is evaluated in terms of the Plio-Quaternary extensional structures in the crust and mantle lithosphere. In particular, we briefly discuss the geometry and stress field of the host geological structures, the tectonic control on the eruptive style, the thickness and composition of the lithosphere. Some implications for a passive rift geodynamic environment are also considered.
Fe-Cu-Au-bearing scapolite skarn in moat sediments of the Taum Sauk Caldera, southeastern Missouri, USA
Authors: Lowell G. R. , Noll P. D.
Published: July 2002

Stromatolitic carbonate in moat-fill of a 1.48 Ga caldera was converted to mineralized calc-silicate skarn by interaction with magma-derived brine at Ketcherside Gap in southeastern Missouri. The skarnrecords early lowfO2conditions similar to those of reduced W and Au skarns. Initial skarn-forming conditions were:PL≤ 221 bar (22.1 MPa),XCO2≤ 0.10,T= 450–;400°C, logfO2≈ –30, and logfS2≤ –13. Late skarn records combined effects of T↓,fO2↑,fS2↑,XCO2↓, and appearance of an immiscible CO2-rich vapour. The absence of a contact aureole indicates that skarn reactions were driven by advective heat transfer from an infiltrating fluid. Elsewhere in the region, hypersaline, synvolcanic fluids produced oxidized endoskarn in rhyolite. Development of carbonate-hosted, reduced skarn in caldera moat sediments is attributed to: (1) the nature of the host rock and reaction along a lengthy flow path; (2) early, but temporary, dilution of brine influx by CO2-producing reactions; and (3) cooling, possibly accompanied by increased brine influx with time.
Parageneses and compositional variations of Sb oxyminerals from Långban-type deposits in Värmland, Sweden
Authors: Holtstam Dan , Nysten Per , Gatedal Kjell
Published: July 2002

The Långban, Nordmark and Jakobsberg Mn-Fe deposits contain the only known occurrences of filipstadite and manganostibite (ideal formulae (Mn, Mg)2(Sb0.55+Fe0.53+)O4and Mn72+SbAsO12, respectively). Filipstadite from Nordmark is newly recognized, and occurs in assemblages with svabite-johnbaumite, calcite, tephroite-forsterite, phlogopite-kinoshitalite, tilasite, ±jacobsite, ±plumbia roméite, ±adelite, ±hedyphane. Manganostibite from Långban and Jakobsberg is reported for the first time, and the mineral is generally associated with katoptrite, tephroite, humite-group minerals, calcite, svabite, allactite, manganosite, hausmannite, jacobsite, spinels.s., etc. Whereas filipstadite is clearly secondary relative to the major part of the matrix components, manganostibite is believed to have formed coevally with the principal ore and skarn minerals at these deposits.

The previously known compositional ranges are extended. Based on electron-microprobe analyses, Nordmark filipstadite contains 4.1–7.3 MgO, 0.0–0.5 Al2O3, 30.5–45.3 MnO, 17.0–40.1 Fe2O3, 0.2–0.9 ZnO, 19.9–29.9 Sb2O5(all in wt.%), corresponding to 58–100 mol.% of a pure filipstadite component. Associated jacobsites show Sb2O5contents of up toc. 5 wt.%. Manganostibites (all three deposits considered) contain 1.0–2.9 MgO, 2.8–3.8 SiO2, 57.4–60.3 MnO, 0.2–3.5 Mn2O3, 0.3–2.0 Fe2O3, 0.0–2.4 ZnO, 21.5–23.0 Sb2O5, 7.7–10.0 As2O5(all in wt.%). Si and trivalent cations are incorporated via a (Mn3+,Fe3+) + Si4+=Mn2++ As5+exchange mechanism, which improves the local charge balance at tetrahedral structural sites dominated by As.
Correlation of abnormal intracranial vessel velocity, measured by transcranial Doppler ultrasonography, with abnormal conjunctival vessel velocity, measured by computer-assisted intravital microscopy, in sickle cell disease
Authors: Cheung Anthony T. W. , Harmatz Paul , Wun Ted , Chen Peter C. Y. , Larkin Edward C. , Adams Robert J. , Vichinsky Elliott P.
Published: July 2002

The Stroke Prevention Trial has confirmed that utilization of transcranial Doppler ultrasonography (TCD), which examines blood flow in large intracranial vessels, can identify children with sickle cell disease (SCD) who are at high risk of developing a premature stroke. It is not known to what extent the vasculopathy in SCD involves small vessels and whether the abnormalities, if present, correlate with large-vessel vasculopathy. Eighteen children with SCD were examined with TCD to determine middle cerebral artery (MCA) velocity and computer-assisted intravital microscopy (CAIM) to determine bulbar conjunctival vessel velocity during the same visit for vasculopathy correlation. High MCA velocity (≥ 200 cm/sec) was found by TCD in 4 patients who also showed abnormal conjunctival velocity (< 0.2 mm/sec or intermittent trickle flow) by CAIM. Three patients had conditional (≥ 170 cm/sec and < 200 cm/sec) MCA velocity: 2 showed abnormal (trickle) and 1 showed normal conjunctival velocity (1.9 mm/sec). One patient with unmeasurable MCA velocity had abnormal (trickle) conjunctival velocity. Of the remaining 10 patients who had normal MCA velocity, 2 showed abnormal (0.05 mm/sec and 0.1 mm/sec) and 8 showed normal conjunctival velocities (1.1-2.4 mm/sec). The MCA velocities correlated significantly with bulbar conjunctival flow velocities (P ≤ .008, Fisher exact test). A correlation exists between MCA (large-vessel) and conjunctival (small-vessel) flow velocities. CAIM is a noninvasive quantitative technique that might contribute to the identification of SCD patients at high risk of stroke. Small-vessel vasculopathy might be an important pathological indicator and should be further explored in a large-scale study.
Cytogenetic analysis and clinical significance in adult T-cell leukemia/lymphoma: a study of 50 cases from the human T-cell leukemia virus type-1 endemic area, Nagasaki
Authors: Itoyama Takahiro , Chaganti R. S. K. , Yamada Yasuaki , Tsukasaki Kunihiro , Atogami Sunao , Nakamura Hideo , Tomonaga Masao , Ohshima Koichi , Kikuchi Masahiro , Sadamori Naoki
Published: July 2002

Identification of cytogenetic abnormalities is an important clue for the elucidation of carcinogenesis. However, the cytogenetic and clinical significance of adult T-cell leukemia/lymphoma (ATLL) is still unclear. To address this point, cytogenetic findings in 50 cases of ATLL were correlated with clinical characteristics. Karyotypes showed a high degree of diversity and complexity. Aneuploidy and multiple breaks (at least 6) were observed frequently in acute and lymphoma subtypes of ATLL. Breakpoints tended to cluster at specific chromosomal regions, although characteristic cytogenetic subgroups of abnormalities were not found. Of these, aberrations of chromosomes 1p, 1q, 1q10-21, 10p, 10p13, 12q, 14q, and 14q32 correlated with one or more of the following clinical features: hepatosplenomegaly, elevated lactate dehydrogenase, hypercalcemia, and unusual immunophenotype, all indicators of clinical severity of ATLL. Multiple breaks (at least 6); abnormalities of chromosomes 1p, 1p22, 1q, 1q10-21, 2q, 3q, 3q10-12, 3q21, 14q, 14q32, and 17q; and partial loss of chromosomes 2q, 9p, 14p, 14q, and 17q regions correlated with shorter survival. These cytogenetic findings are relevant in predicting clinical outcome and provide useful information to identify chromosomal regions responsible for leukemogenesis. This study also indicates that one model of an oncogenic mechanism, activation of a proto-oncogene by translocation of a T-cell–receptor gene, may not be applicable to the main pathway of development of ATLL and that a multistep process of leukemogenesis is required for the development of ATLL.
Biology and outcome of childhood acute megakaryoblastic leukemia: a single institution's experience
Authors: Athale Uma H. , Razzouk Bassem I. , Raimondi Susana C. , Tong Xin , Behm Frederick G. , Head David R. , Srivastava Deo K. , Rubnitz Jeffrey E. , Bowman Laura , Pui Ching-Hon , Ribeiro Raul C.
Published: July 2002

To describe the clinical and biologic features of pediatric acute megakaryoblastic leukemia (AMKL) and to identify prognostic factors, experience at St Jude Children's Research Hospital was reviewed. Of 281 patients with acute myeloid leukemia treated over a 14-year period, 41 (14.6%) had a diagnosis of AMKL. Six patients had Down syndrome and AMKL, 6 had secondary AMKL, and 29 had de novo AMKL. The median age of the 22 boys and 19 girls was 23.9 months (range, 6.7-208.9 months). The rate of remission induction was 60.5%, with a 48% rate of subsequent relapse. Patients with Down syndrome had a significantly higher 2-year event-free survival (EFS) estimate (83%) than did other patients with de novo AMKL (14%) or with secondary AMKL (20%;P ≤ .038). Among patients who had de novo AMKL without Down syndrome, 2-year EFS was significantly higher after allogeneic bone marrow transplantation (26%) than after chemotherapy alone (0%;P = .019) and significantly higher when performed during remission (46%) than when performed during persistent disease (0%;P = .019). The 5-year survival estimates were significantly lower for de novo AMKL (10%) than for other forms of de novo AML (42%; P < .001). Treatment outcome is very poor for patients with AMKL in the absence of Down syndrome. Remission induction is the most important prognostic factor. Allogeneic transplantation during remission offers the best chance of cure; in the absence of remission, transplantation offers no advantage over chemotherapy alone.
Dimeric erythropoietin fusion protein with enhanced erythropoietic activity in vitro and in vivo
Authors: Dalle Bruno , Henri Annie , Rouyer-Fessard Philippe , Bettan Mickaël , Scherman Daniel , Beuzard Yves , Payen Emmanuel
Published: July 2002

High doses of recombinant human erythropoietin (rhEpo) are required for the treatment of chronic anemia. Thus, it is clear that therapy for chronic anemia would greatly benefit from an erythropoietin derivative with increased erythropoietic activity rather than the native endogenous hormone. In this report, the activity of a human Epo-Epo dimer protein, obtained by recombinant technology, is described and compared with its Epo monomer counterpart produced under identical conditions. Although monomer Epo and dimer Epo-Epo had similar pharmacokinetics in normal mice, the increase in hematocrit value was greater with the dimer than with the monomer. Moreover, in clonogenic assays using CD34+ human hematopoietic cells, the human dimer induced a 3- to 4-fold-greater proliferation of erythroid cells than the monomer. Controlled secretion of dimeric erythropoietin was achieved in β-thalassemic mice by in vivo intramuscular electrotransfer of a mouse Epo-Epo plasmid containing the tetO element and of a plasmid encoding the tetracycline controlled transactivator tTA. Administration of tetracycline completely inhibited the expression of the mEpo dimer. On tetracycline withdrawal, expression of the Epo-Epo dimer resumed, thereby resulting in a large and sustained hematocrit increase in β-thalassemic mice. No immunologic response against the dimer was apparent in mice because the duration of the hematocrit increase was similar to that observed with the monomeric form of mouse erythropoietin.
Down-regulation of BOB.1/OBF.1 and Oct2 in classical Hodgkin disease but not in lymphocyte predominant Hodgkin disease correlates with immunoglobulin transcription
Authors: Stein Harald , Marafioti Theresa , Foss Hans-Dieter , Laumen Helmut , Hummel Michael , Anagnostopoulos Ioannis , Wirth Thomas , Demel Gudrun , Falini Brunangelo
Published: July 2002

In contrast to the tumor cells (L&H cells) of lymphocyte predominant Hodgkin disease (LPHD), Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin disease (cHD) are unable to transcribe immunoglobulin, despite the presence of rearranged immunoglobulin genes. Although initial studies have suggested crippling immunoglobulin gene mutations to be the cause of absent immunoglobulin expression in cHD, recent work of our group has demonstrated an impaired activation of the immunoglobulin promoter as a superior mechanism. As immunoglobulin transcription is mainly regulated by the B-cell transcription factors Oct2 and BOB.1/OBF.1, we analyzed 35 cases of LPHD, 32 cases of cHD, and 2 Hodgkin disease cell lines for the expression of these transcription factors and also in parallel for immunoglobulin expression. Our results demonstrate an absence of Oct2 and/or BOB.1/OBF.1 in cHD and a striking overexpression of Oct2 in LPHD. Immunoglobulin expression was lacking in cHD but present in LPHD. Furthermore, the reintroduction of BOB.1/OBF.1 and Oct2 into cultured HRS cells restored the activity of cotransduced immunoglobulin promoter constructs. Our findings dismiss the concept that the different immunoglobulin expression in cHD and LPHD is due to disrupting mutations of immunoglobulin V genes in cHD but is most likely due to a down-regulation of Oct2 and/or BOB.1/OBF.1. This study further revealed Oct2 as a new and valuable marker for the identification of L&H cells and their distinction from HRS cells. The impairment of immunoglobulin transcription with a down-regulated synthesis of Oct2 and BOB.1/OBF.1 is the first established general recurrent defect found in HRS cells.
Chromosome 13 abnormalities identified by FISH analysis and serum β2-microglobulin produce a powerful myeloma staging system for patients receiving high-dose therapy
Authors: Facon Thierry , Avet-Loiseau Hervé , Guillerm Gaëlle , Moreau Philippe , Geneviève Franck , Zandecki Marc , Laı̈ Jean-Luc , Leleu Xavier , Jouet Jean-Pierre , Bauters Francis , Harousseau Jean-Luc , Bataille Régis , Mary Jean-Yves
Published: July 2002

A careful prognostic evaluation of patients referred for high-dose therapy (HDT) is warranted to identify those who maximally benefit from HDT as well as those who clearly fail current HDT and are candidates for more innovative treatments. In a series of 110 patients with myeloma who received HDT as first-line therapy, times to event (disease progression and death) were studied through proportional hazard models, in relation to different prognostic factors, including a chromosome 13 fluorescence in situ hybridization (FISH) analysis using a D13S319 probe. Δ13 was detected in 42 patients (38%). Follow-up time among surviving patients and survival time were 48 ± 3 and 51 ± 7 months, respectively (median ± SE). In the univariate analysis, Δ13 was the most powerful adverse prognostic factor for all times to event, especially for the survival time (P < .0001) and was followed by β2-microglobulin (β2m) levels 2.5 mg/L or higher (P = .0001). The comparison of survival prognostic models including β2m 2.5 mg/L or greater and another factor favored the Δ13/β2m combination. In 22 patients (20%) with no unfavorable factor, the median survival time was not reached at 111 months. In contrast, among 55 patients (50%) with one unfavorable factor and 33 patients (30%) with 2 unfavorable factors, median survival times were 47.3 ± 4.6 months and 25.3 ± 3.2 months, respectively (P < .0001). We conclude that Δ13, adequately detected by FISH analysis, is a very strong factor related to poor survival, especially when associated with a β2m level of 2.5 mg/L or higher. Routine FISH Δ13 assessment is strongly recommended for patients considered for HDT.
Distinct domains of the human granulocyte-macrophage colony-stimulating factor receptor α subunit mediate activation of Jak/Stat signaling and differentiation
Authors: Lilly Michael B. , Zemskova Marina , Frankel Arthur E. , Salo Jonathan , Kraft Andrew S.
Published: July 2002

The α subunit of the human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor has several isoforms that result from alternative splicing events. Two forms, α-1 and α-2, have intracytoplasmic sequences that are identical within a membrane-proximal domain but differ completely distally. Variant and mutated GM-CSF receptor α subunits, along with the β subunit (βc protein) were expressed in M1 murine leukemia cells. and the ability of the receptors to signal for differentiation events and to activate Jak/Stat signaling pathways was examined. All cell lines expressing both α and βc proteins exhibited high-affinity binding of radiolabeled human GM-CSF. Receptor α subunits with intact membrane-proximal intracellular domains could induce expression of the macrophage antigen F4/80 and down-regulate the expression of CD11b. Addition of recombinant human GM-CSF to cells expressing α-1 subunits induced the expression of CD86 and tyrosine phosphorylation of Jak-2 and its putative substrates SHPTP-2, Stat-5, and the GM-CSF receptor βc subunit. Cells containing α subunits that lacked a distal domain (term-3) or had the alternatively spliced α-2 distal domain showed markedly decreased ability to support tyrosine phosphorylation of Jak-2 and its substrates or to up-regulate CD86. Ligand binding induced stable association of the α-1 subunit and βc protein. In contrast, the α-2 subunit did not stably associate with the βc subunit. These data identify potential molecular mechanisms for differential signaling of the α-1 and α-2 proteins. The association of unique signaling events with the 2 active GM-CSF α subunit isoforms offers a model for variable response phenotypes to the same ligand.
Endothelial cell protein C receptor plays an important role in protein C activation in vivo
Authors: Taylor Fletcher B. , Peer Glenn T. , Lockhart Marion S. , Ferrell Gary , Esmon Charles T.
Published: July 2002

Endothelial cell protein C receptor (EPCR) augments protein C activation by the thrombin-thrombomodulin complex about 5-fold in vitro. Augmentation is EPCR concentration dependent even when the EPCR concentration is in excess of the thrombomodulin. EPCR is expressed preferentially on large blood vessel endothelium, raising questions about the importance of protein C-EPCR interaction for augmenting systemic protein C activation. In these studies, this question was addressed directly by infusing thrombin into baboons in the presence or absence of a monoclonal antibody to EPCR that blocks protein C binding. Activated protein C levels were then measured directly by capturing the enzyme on a monoclonal antibody and assaying with chromogenic substrate. Blocking protein C-EPCR interaction resulted in about an 88% decrease in circulating activated protein C levels generated in response to thrombin infusion. Leukocyte changes, fibrinogen consumption, fibrin degradation products, and vital signs were similar between the animals infused with thrombin alone and those infused with thrombin and the anti-EPCR antibody. The results indicate that EPCR plays a major role in protein C activation and suggest that defects in the EPCR gene might contribute to increased risk of thrombosis.
Membrane instability in late-stage erythropoiesis
Authors: Waugh Richard E. , Mantalaris Athanassios , Bauserman Richard G. , Hwang William C. , Wu J. H. David
Published: July 2002

During maturation of the red blood cell (RBC) from the nucleated normoblast stage to the mature biconcave discocyte, both the structure and mechanical properties of the cell undergo radical changes. The development of the mechanical stability of the membrane reflects underlying changes in the organization of membrane-associated cytoskeletal proteins, and so provides an assessment of the time course of the development of membrane structural organization. Membrane stability in maturing erythrocytes was assessed by measuring forces required to form thin, tubular, lipid strands (tethers) from the surfaces of mononuclear cells obtained from fresh human marrow samples, marrow reticulocytes, circulating reticulocytes, and mature erythrocytes. Cells were biotinylated and manipulated with a micropipette to form an adhesive contact with a glass microcantilever, which gave a measure of the tethering force. The cell was withdrawn at controlled velocity and aspiration pressure to form a tether from the cell surface. The mean force required to form tethers from marrow reticulocytes and normoblasts was 27 ± 9 pN, compared to 54 ± 14 pN for mature cells. The energy of dissociation of the bilayer from the underlying skeleton increases 4-fold between the marrow reticulocyte stage and the mature cell, demonstrating that the mechanical stability of the membrane is not completely established until the very last stages of RBC maturation.
New mutations inactivating transferrin receptor 2 in hemochromatosis type 3
Authors: Roetto Antonella , Totaro Angela , Piperno Alberto , Piga Antonio , Longo Filomena , Garozzo Giovanni , Calı̀ Angelita , De Gobbi Marco , Gasparini Paolo , Camaschella Clara
Published: July 2002

Hereditary hemochromatosis usually results from C282Y homozygosity in the HFE gene on chromosome 6p. Recently, a new type of hemochromatosis (HFE3) has been characterized in 2 unrelated Italian families with a disorder linked to 7q. Patients with HFE3 have transferrin receptor 2 (TFR2) inactivated by a homozygous nonsense mutation (Y250X). Here the identification of 2 newTFR2 mutations is reported. In a large inbred family from Campania, a frameshift mutation (84-88 insC) in exon 2 that causes a premature stop codon (E60X) is identified. In a single patient with nonfamilial hemochromatosis, a T→A transversion (T515A), which causes a Methionine→Lysine substitution at position 172 of the protein (M172K), has been characterized. TFR2 gene gives origin to 2 alternatively spliced transcripts—the α-transcript, which may encode a transmembrane protein, and the β-transcript, a shorter, possibly intracellular variant. Based on their positions, the effects of the identified mutations on the 2 TFR2 forms are expected to differ. Y250X inactivates both transcripts, whereas E60X inactivates only the α-form. M172K has a complex effect: it causes a missense in the α-form, but it may also prevent the β-form production because it affects its putative initiation codon. Analysis of the clinical phenotype of 13 HFE3 homozygotes characterized at the molecular level has shown a variable severity, from nonexpressing patients to severe clinical complications. The identification of new mutations of TFR2 confirms that this gene is associated with iron overload and offers a tool for molecular diagnosis in patients without HFE mutations.
Truncated mutant B subunit for factor XIII causes its deficiency due to impaired intracellular transportation
Authors: Koseki Shiori , Souri Masayoshi , Koga Shinichiro , Yamakawa Mitsunori , Shichishima Tsutomu , Maruyama Yukio , Yanai Fumio , Ichinose Akitada
Published: July 2002

Two Japanese patients were newly diagnosed as having B subunit (XIIIB) deficiency of factor XIII (former type I deficiency). Both patients have a previously described one-base deletion at the boundary between intron A/exon II in the XIIIB gene, heterozygously or homozygously. A founder effect was proposed for this mutation because 3 unrelated patients with XIIIB deficiency also share 2 3′-polymorphisms. In one patient heterozygous for the above mutation, a novel mutation was also identified: a deletion of guanosine in exon IX (delG) of the XIIIB gene. To understand the molecular and cellular pathology of the delG mutation, expression studies were performed using a cultured mammalian cell line. Pulse-chase experiments showed that a resultant truncated XIIIB remained inside the cells and could not be secreted into the culture medium. Furthermore, immunocytochemical examinations by epifluorescence, confocal, and electron microscopes indicated impaired intracellular transportation of the truncated XIIIB from the endoplasmic reticulum to the Golgi apparatus. No mutations in the gene for the A subunit (XIIIA) were identified in this patient. Therefore, secretion of the truncated XIIIB must also be impaired in vivo, leading to a secondary XIIIA deficiency. These results support a previous conclusion that genetic defects of XIIIB are the basis for the former type I factor XIII deficiency.
Missense mutation of the interleukin-12 receptor β1 chain–encoding gene is associated with impaired immunity againstMycobacterium avium complex infection
Authors: Sakai Tatsunori , Matsuoka Masao , Aoki Manabu , Nosaka Kisato , Mitsuya Hiroaki
Published: July 2002

Interleukin-12 (IL-12) plays an important role in the production of interferon gamma (IFN-γ) and is essential for protection against intracellular pathogens such as Mycobacterium andSalmonella. A 31-year-old man had disseminatedMycobacterium avium complex (MAC) infection. The production of IFN-γ by peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA-PBMCs) was found severely impaired (40.7 pg/mL compared with 833  ± 289 pg/mL for the patient's and healthy subjects' (n = 3) PHA- PBMCs, respectively), and the patient's PHA-PBMCs completely lacked surface IL-12 receptor β1 (IL-12Rβ1) chain. The IL-12Rβ1 gene transcript in his PHA-PBMCs had an R213W substitution in each allele. Family history showed that both parents were heterozygotes in the R213W substitution. Transfection of a human embryonal kidney cell line 293 (HEKC293) with wild-type IL-12Rβ1wt gene led to cell surface IL-12Rβ1 expression; however, no expression was seen in HEKC293 transfected with the mutated IL-12Rβ1R213W gene. TheIL-12Rβ1 gene transcript, but no IL-12Rβ1 protein, was detected in PHA-PBMCs and T cells, suggesting a post-translational event(s), most likely a shortened turnover of the protein. The R213W substitution was not detected in the cells of 32 healthy persons or of 25 patients with tuberculosis or MAC infection. Six amino acid substitutions (Q214R, M365T, G378R, H438Y, A525T, and G594E) were identified, but the incidences of such substitutions were not significantly different between the groups. The Q214R substitution is reportedly linked to IL-12Rβ1 deficiency; however, the study showed that 19 and 10 of 57 Japanese and 6 and 4 of 33 healthy white persons were heterozygous and homozygous for Arg-214, respectively, suggesting that the Q214R substitution represents a polymorphism and is not related to IL-12Rβ1 deficiency but that the R213W substitution is responsible for IL-12Rβ1 deficiency.
Endogenous CD28 expressed on myeloma cells up-regulates interleukin-8 production: implications for multiple myeloma progression
Authors: Shapiro Virginia Smith , Mollenauer Marianne Newton , Weiss Arthur
Published: July 2002

CD28 is the major costimulatory molecule on T cells. CD28 activation, in conjunction with T-cell receptor engagement, up-regulates transcription of several cytokines, including interleukin-2 (IL-2), through transcriptional activation of the RE/AP composite element. Although CD28 is not normally expressed on B cells or plasma cells, more than 90% of extramedullary myelomas (a late stage B-cell neoplasm) express CD28. The functional significance of this is unknown. The results of this study demonstrate that CD28 stimulates transcriptional activation of RE/AP-based reporters in B cells and myeloma cells. However, CD28 stimulation does not up-regulate IL-2 production in myeloma cell lines, demonstrating that the IL-2 promoter may not be a relevant RE/AP-containing target of CD28 in myelomas. Instead, an RE/AP composite element has been identified within the promoter of the IL-8 gene, a chemokine that promotes angiogenesis. Furthermore, stimulation of endogenous CD28 expressed by 3 myeloma cell lines increased IL-8 production. Therefore, the study demonstrates that CD28 is functional in myelomas to up-regulate transcription of endogenous genes, includingIL-8. The proposal is made that aberrant expression of CD28 may play a role in the progression of multiple myeloma.
Fibrinogen Milano XII: a dysfunctional variant containing 2 amino acid substitutions, Aα R16C and γ G165R
Authors: Bolliger-Stucki Bettina , Lord Susan T. , Furlan Miha
Published: July 2002

Fibrinogen Milano XII was detected in an asymptomatic Italian woman, whose routine coagulation test results revealed a prolonged thrombin time. Fibrinogen levels in functional assays were considerably lower than levels in immunologic assays. Polymerization of purified fibrinogen was strongly impaired in the presence of calcium or ethylenediaminetetraacetic acid (EDTA). Two heterozygous structural defects were detected by DNA analysis: Aα R16C and γ G165R. As seen previously with other heterozygous Aα R16C variants, thrombin-catalyzed release of fibrinopeptide A was 50% of normal. Additionally, the release of fibrinopeptide B was delayed. Immunoblotting analysis with antibodies to human serum albumin indicated that albumin is bound to Aα 16 C. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis of plasmin digests of fibrinogen Milano XII in the presence of calcium or EDTA showed both normal and novel D1 and D3 fragments. Further digestion of abnormal D3 fragments by chymotrypsin resulted in degradation products of the same size as the fragments derived from normal fibrinogen. SDS-PAGE analysis under reducing conditions showed no difference between normal fibrinogen and fibrinogen Milano XII or between their plasmic fragments. Circular dichroism analysis revealed a shift in the mean residual ellipticity and a significant reduction of the α-helix content in the variant D3 fragment. It is concluded that the Aα-chain substitution is mainly responsible for the coagulation abnormalities, whereas the substitution in the γ-chain induced a conformational change in the D3 fragment.
The HIV protease inhibitor Indinavir inhibits cell-cycle progression in vitro in lymphocytes of HIV-infected and uninfected individuals
Authors: Chavan Surendra , Kodoth Sangeetha , Pahwa Rajendra , Pahwa Savita
Published: July 2002

Indinavir (IDV) is a potent and selective human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) widely used in antiretroviral therapy for suppression of HIV, but its effects on the immune system are relatively unknown. Recently, it has been reported that PIs inhibit lymphocyte apoptosis. In the present study we have investigated the effects of ex vivo addition of IDV on lymphocyte activation and apoptosis in cells from HIV-infected children (n = 18) and from healthy uninfected individuals (controls, n = 5) as well as in Jurkat and PM1 T-cell lines. Pretreatment of control peripheral blood mononuclear cell (PBMC) cultures with IDV resulted in a dose-dependent inhibition of lymphoproliferative responses to different activation stimuli. Additionally, this treatment led to cell-cycle arrest in G0/G1 phase in anti-CD3 monoclonal antibody–stimulated PBMC cultures in controls and in 15 of 18 HIV-infected children. Spontaneous- or activation-induced apoptosis of PBMCs from HIV-infected or uninfected individuals or of Fas-induced apoptosis in Jurkat and PM1 T cell lines were not inhibited by IDV. Moreover, IDV did not inhibit activation of caspases-1, -3, -4, -5, -9, and -8 in lysates of Jurkat T cells undergoing Fas-induced apoptosis. The findings indicate that IDV interferes with cell-cycle progression in primary cells but does not directly affect apoptosis. It is concluded that IDV may prolong cell survival indirectly by inhibiting their entry into cell cycle. In individuals on PI therapy, PI-mediated effects could potentially modulate immunologic responses independently of antiviral activity against HIV.
Postremission therapy in older patients with de novo acute myeloid leukemia: a randomized trial comparing mitoxantrone and intermediate-dose cytarabine with standard-dose cytarabine
Authors: Stone Richard M. , Berg Deborah T. , George Stephen L. , Dodge Richard K. , Paciucci Paolo A. , Schulman Philip P. , Lee Edward J. , Moore Joseph O. , Powell Bayard L. , Baer Maria R. , Bloomfield Clara D. , Schiffer Charles A.
Published: July 2002

The treatment of older patients with acute myeloid leukemia (AML) remains unsatisfactory, with complete remission (CR) achieved in only approximately 50% and long-term disease-free survival in 10% to 20%. Three hundred eighty-eight patients (60 years of age and older) with newly diagnosed de novo AML were randomly assigned to receive placebo (P) or granulocyte-macrophage colony-stimulating factor (GM-CSF) or GM in a double-blind manner, beginning 1 day after the completion of 3 days of daunorubicin and 7 days of cytarabine therapy. No differences were found in the rates of leukemic regrowth, CR, or infectious complications in either arm. Of 205 patients who achieved CR, 169 were medically well and were randomized to receive cytarabine alone or a combination of cytarabine and mitoxantrone. With a median follow-up of 7.7 years, the median disease-free survival times were 11 months and 10 months for those randomized to cytarabine or cytarabine/mitoxantrone, respectively. Rates of relapse, excluding deaths in CR, were 77% for cytarabine and 82% for cytarabine/mitoxantrone. Induction randomization had no effect on leukemic relapse rate or remission duration in either postremission arm. Because cytarabine/mitoxantrone was more toxic and no more effective than cytarabine, it was concluded that this higher-dose therapy had no benefit in the postremission management of older patients with de novo AML. These results suggest the need to develop novel therapeutic strategies for these patients.
Differentiation of cytomegalovirus-specific CD8+ T cells in healthy and immunosuppressed virus carriers
Authors: Gamadia Laila E. , Rentenaar Rob J. , Baars Paul A. , Remmerswaal Ester B. M. , Surachno Sugianto , Weel Jan F. L. , Toebes Mireille , Schumacher Ton N. M. , ten Berge Ineke J. M. , van Lier René A. W.
Published: July 2002

During immunosuppression, cytomegalovirus (CMV) can reactivate and cause serious clinical problems. Normally, abundant virus replication is suppressed by immune effector mechanisms. To study the interaction between CD8+ T cells and persisting viruses, frequencies and phenotypes of CMV-specific CD8+ T cells were determined in healthy individuals and compared to those in renal transplant recipients. In healthy donors, function of circulating virus-specific CD8+ T cells, as measured by peptide-induced interferon γ (IFN-γ) production, but not the number of virus-specific T cells enumerated by binding of specific tetrameric peptide/HLA complexes, correlated with the number of CMV-specific IFN-γ–secreting CD4+ helper T cells. Circulating CMV- specific CD8+ T cells did not express CCR7 and may therefore not be able to recirculate through peripheral lymph nodes. Based on coexpression of CD27 and CD45R0 most CMV-specific T cells in healthy donors appeared to be memory-type cells. Remarkably, frequencies of CMV-specific CD8+ T cells were significantly higher in immunosuppressed individuals than in healthy donors. In these patients CMV-specific cells predominantly had an effector phenotype, that is, CD45R0+CD27−CCR7− or CD45RA+CD27−CCR7− and contained both granzyme B and perforin. Our data show that in response to immunosuppressive medication quantitative and qualitative changes occur in the CD8+ T-cell compartment. These adaptations may be instrumental to maintain CMV latency.
Vascular cell adhesion molecule-1 (CD106) is cleaved by neutrophil proteases in the bone marrow following hematopoietic progenitor cell mobilization by granulocyte colony-stimulating factor
Authors: Lévesque Jean-Pierre , Takamatsu Yasushi , Nilsson Susan K. , Haylock David N. , Simmons Paul J.
Published: July 2002

Mobilized progenitor cells currently represent the most commonly used source of hematopoietic progenitor cells (HPCs) to effect hematopoietic reconstitution following myeloablative chemotherapies. Despite their widespread use, the molecular mechanisms responsible for the enforced egress of HPCs from the bone marrow (BM) into the circulation in response to mobilizing agents such as cytokines remain to be determined. Results of this study indicate that expression of vascular cell adhesion molecule-1 (VCAM-1) is strongly reduced in vivo in the BM during HPC mobilization by granulocyte colony-stimulating factor (G-CSF) and stem cell factor. Two serine proteases, namely, neutrophil elastase and cathepsin G, were identified, which cleave VCAM-1 and are released by neutrophils accumulating in the BM during the course of immobilization induced by G-CSF. The proposal is made that an essential step contributing to the mobilization of HPCs is the proteolytic cleavage of VCAM-1 expressed by BM stromal cells, an event triggered by the degranulation of neutrophils accumulating in the BM in response to the administration of G-CSF.
Short survival of phosphatidylserine-exposing red blood cells in murine sickle cell anemia
Authors: de Jong Kitty , Emerson Renee K. , Butler James , Bastacky Jacob , Mohandas Narla , Kuypers Frans A.
Published: July 2002

Several transgenic murine models for sickle cell anemia have been developed that closely reproduce the biochemical and physiological disorders in the human disease. A comprehensive characterization is described of hematologic parameters of mature red blood cells, reticulocytes, and red cell precursors in the bone marrow and spleen of a murine sickle cell model in which erythroid cells expressed exclusively human α, γ, and βS globin. Red cell survival was dramatically decreased in these anemic animals, partially compensated by considerable enhancement in erythropoietic activity. As in humans, these murine sickle cells contain a subpopulation of phosphatidylserine-exposing cells that may play a role in their premature removal. Continuous in vivo generation of this phosphatidylserine-exposing subset may have a significant impact on the pathophysiology of sickle cell disease.
No difference in graft-versus-host disease, relapse, and survival comparing peripheral stem cells to bone marrow using unrelated donors
Authors: Remberger Mats , Ringdén Oolle , Blau Igor-Wolfgang , Ottinger Hellmut , Kremens Bernhard , Kiehl Micheil G. , Aschan Johan , Beelen Dietrich W. , Basara Nadezda , Kumlien Gunilla , Fauser Axel A. , Runde Volker
Published: July 2002

The clinical results in 107 patients receiving a peripheral blood stem cell (PBSC) graft mobilized by granulocyte colony-stimulating factor (G-CSF) from HLA-A, -B, and -DR–compatible unrelated donors were compared to 107 matched controls receiving unrelated bone marrow (BM) transplants. Engraftment was achieved in 94% of the patients in both groups. The PBSC graft contained significantly more nucleated cells, CD34+, CD3+, and CD56+ cells (P < .001), and resulted in a significantly shorter time-to-neutrophil (15 versus 19 days) and platelet engraftment (20 versus 27 days), compared to the BM control group (P < .001). Probabilities of acute graft-versus-host disease (GVHD) grades II to IV were 35% and 32% (not significant [NS]) and of chronic GVHD 61% and 76% (NS) in the PBSC and BM groups, respectively. There was no difference between the 2 groups in bacteremia, cytomegalovirus reactivation or disease, and fungal infection. The 3-year transplant-related mortality (TRM) rates were 42% in the PBSC group and 31% in the BM controls (P = .7) and the survival rates were 46% and 51%, respectively. The probability of relapse was 25% and 31% in both groups (NS), resulting in disease-free survival rates of 43% in the PBSC group and 46% in the BM controls (NS). In the multivariate analysis, early disease, acute GVHD grade 0 to I, and presence of chronic GVHD were independent factors associated with a better disease-free survival in this study. PBSC from HLA-compatible unrelated donors can be used safely as an alternative to BM for stem cell transplantation.
Interleukin-7 and infection itself by human immunodeficiency virus 1 favor virus persistence in mature CD4+CD8−CD3+ thymocytes through sustained induction of Bcl-2
Authors: Guillemard Eric , Nugeyre Marie-Thérèse , Chêne Laurent , Schmitt Nathalie , Jacquemot Catherine , Barré-Sinoussi Françoise , Israël Nicole
Published: July 2002

The sequence of events and the mechanisms leading to the destruction of the thymus during human immunodeficiency virus (HIV) infection are still poorly characterized. Investigated here are the survival capacity on HIV-1 infection of the mature single-positive CD4+CD8−CD3+ (SP CD4+) and the intermediate CD4+ CD8−CD3− thymocytes previously shown to be able to replicate the virus in the thymic microenvironment. It is demonstrated that the mature SP CD4+ thymocytes exhibit a high survival capacity despite the production of a high yield of viruses. Interleukin-7, reported to be a crucial cofactor of tumor necrosis factor (TNF) to promote HIV replication, is shown here to counteract the apoptotic activity of TNF. Resistance to apoptosis of SP CD4+ cells is conferred by a high expression of the IL-7 receptor (IL-7R) associated with the capacity of IL-7 to permanently up-regulate Bcl-2. In addition, this high Bcl-2 level is further enhanced by infection itself. In contrast, intermediate thymocytes, which replicate the virus at a lower level, are more sensitive to apoptosis, and their differentiation into double-positive CD4+CD8+CD3− (DP CD3−) cells strongly increases their death rate on infection. This sensitivity is related to a lower expression of IL-7R and Bcl-2 in intermediate thymocytes, which further decreases at the DP CD3− stage. In addition, a decreased level of Bcl-2 is observed in this subset during infection. Altogether these data suggest that in vivo, HIV infection might create a persistent virus reservoir within the SP CD4+ thymocytes, whereas the later infection of intermediate cells might lead to thymopoiesis failure.
Multipotent hematopoietic cell lines derived from C/EBPα(−/−) knockout mice display granulocyte macrophage–colony-stimulating factor, granulocyte– colony-stimulating factor, and retinoic acid–induced granulocytic differentiation
Authors: Collins Steven J. , Ulmer Jon , Purton Louise E. , Darlington Gretchen
Published: July 2002

The transcription factor C/EBPα is an important mediator of granulocyte differentiation and regulates the expression of multiple granulocyte-specific genes including the granulocyte–colony-stimulating factor (G-CSF) receptor, neutrophil elastase, and myeloperoxidase. Indeed C/EBPα knockout mice display a profound block in granulocyte differentiation. To study this block in granulocytic differentiation in more detail, retroviral vector-mediated transduction of a dominant-negative retinoic acid receptor was used to establish hematopoietic growth factor–dependent, lympho-myeloid progenitor cell lines from the fetal livers of both the C/EBPα knockout animals (C/EBPα(−/−)) and their heterozygous littermates (C/EBPα(+/−)). Surprisingly, the C/EBPα(−/−) cell lines displayed significant spontaneous granulocytic differentiation, and this differentiation was markedly enhanced when the cells were stimulated with granulocyte macrophage (GM)–CSF. This GM-CSF–mediated differentiation was associated with the up-regulation of G-CSF receptor mRNA, and the combination of GM-CSF and G-CSF generated more than 95% mature neutrophils in the C/EBPα(−/−) cultures. The addition of all-transretinoic acid also enhanced this granulocytic differentiation of the cultured C/EBPα(−/−) cells, indicating that the activated retinoic acid receptors can enhance granulocytic differentiation through a molecular pathway that is independent of C/EBPα. These studies clearly indicate that terminal granulocytic differentiation associated with the up-regulation of C/EBPα-responsive genes can occur in the absence of C/EBPα, and they indicate the existence of multiple independent molecular pathways potentially used by primitive hematopoietic precursors that can lead to the development of mature granulocytes.
Mutations in the ELA2 gene encoding neutrophil elastase are present in most patients with sporadic severe congenital neutropenia but only in some patients with the familial form of the disease
Authors: Ancliff Phil J. , Gale Rosemary E. , Liesner Ri , Hann Ian M. , Linch David C.
Published: July 2002

Severe congenital neutropenia (SCN) was originally described as an autosomal recessive disorder. Subsequently, autosomal dominant and sporadic forms of the disease have been recognized. All forms are manifest by persistent severe neutropenia and recurrent bacterial infection. In contrast, cyclical hematopoiesis is characterized by periodic neutropenia inter-spaced with (near) normal neutrophil counts. Recently, linkage analysis on 13 affected pedigrees identified chromosome 19p13.3 as the likely position for mutations in cyclical hematopoiesis. Heterozygous mutations in the ELA2 gene encoding neutrophil elastase were detected in all families studied. Further work also demonstrated mutations in ELA2 in sporadic and autosomal dominant SCN. However, all mutations described to date are heterozygous and thus appear to act in a dominant fashion, which is inconsistent with an autosomal recessive disease. Therefore, the current study investigated whether mutations in ELA2could account for the disease phenotype in classical autosomal recessive SCN and in the sporadic and autosomal dominant types. All 5 exons of ELA2 and their flanking introns were studied in 18 patients (3 autosomal recessive, 5 autosomal dominant [from 3 kindreds], and 10 sporadic) using direct automated sequencing. No mutations were found in the autosomal recessive families. A point mutation was identified in 1 of 3 autosomal dominant families, and a base substitution was identified in 8 of 10 patients with the sporadic form, though 1 was subsequently shown to be a low-frequency polymorphism. These results suggest that mutations in ELA2are not responsible for classical autosomal recessive Kostmann syndrome but provide further evidence for the role of ELA2 in SCN.