bluuebunny/crossref_metadata_2025 huggingface dataset:
Internationalism, Regionalism, and National Culture: Music Control in Bavaria, 1945–1948
Authors: Monod David
Published: July 2002

Formany Germans in the immediate postwar period, all that remained of their country was its art. Subjugation, destruction, the pain of unfathomable guilt: these had ripped away at the national psyche, severing nation from nationalism, person from people, the present from the past. “We are,” wrote Wolfgang Borchert in 1946, “a generation without a homecoming, because we have nothing to which we can return.” Nation: what would that word now mean? An occupied state no longer possessing statehood, a conquered people starved even of the moral strength that might come from resisting. Even if the institutions of national governance could be recreated, they could have no historical legitimacy; if Bonn were not to be Weimar, it would equally not be the kaisers' or the Führer's Berlin. For many, refuge from the shaming of the nation lay, as Theodor Heuss reflected, in a “decentralizing of the emotions,” in a “flight” to those fields “where the violence of the great political world shake-up is not felt so directly.” This drove literate Germans back to Goethe and music lovers to the endlessly-performed postwar symphonic cycles of Brahms and Beethoven. And yet, escaping into what Jost Hermand aptly termed “the protective wall of self-absorption” did not completely preclude connection to the national community of Germans. In fact, a powerful communion with the whole might still come through the personal enjoyment of a shared art or culture. In art might reside the essence of the national community, a stateless collectivity, without territories perhaps, but with borders and guardians nonetheless
LDH-derived catalysts for complete oxidation of volatile organic compounds
Authors: Bahranowski K. , Bielańska E. , Janik R. , Machej T. , Serwicka E. M.
Published: July 2002

The Cu,Cr-, Zn,Cr- and Cu,Al-layered double hydroxides have been synthesized by the coprecipitation method and characterized by elemental analysis, PXRD, SEM/EDS and BET. The mixed oxide materials obtained upon calcination at 873 K show very high catalytic activity for the combustion of toluene and ethanol. The best sample is derived from the Cu,Cr-LDH precursor with a Cu:Cr ratio of 2, composed of copper oxide and copper chromite. This catalyst gave 50% conversion of toluene and ethanol at temperatures of 45 and 15 K lower, respectively, than the reference commercial catalyst. Catalytic tests with a mechanical mixture of CuO and CuCr2O4 demonstrate that the use of an LDH precursor is essential for optimum results. The importance of the simultaneous presence of both Cu and Cr, the influence of the Cu:Cr ratio on the catalytic activity and the role of the interface boundaries in the CuO-CuCr2O4 mixed oxide system are discussed.
CL for characterizing quartz and trapped fluid inclusions in mesothermal quartz veins: Muruntau Au ore deposit, Uzbekistan
Authors: Graupner T. , Götze J. , Kempe U. , Wolf D.
Published: July 2002

Combined cathodoluminescence (CL) and transmitted light microscopy were used to characterize quartz from flat and steeply dipping quartz veins and from veinlets in banded host rocks from the giant Muruntau Au quartz vein deposit, Kyzyl Kum Desert, western Uzbekistan. The CL examinations were carried out using a ‘hot-cathode’ CL microscope linked to a highly sensitive digital video camera. The multi-stage deformed flat quartz veins and the steeply dipping hydrothermal formations at Muruntau are characterized by quartz with different CL colours, internal structures and degree of secondary alteration. Primary growth zoning of quartz, indiscernible in conventional polarized light was found to occur only in steeply dipping veins. The bulk of the high-grade Au mineralized ‘central’ quartz veins is dominated by one generation of hydrothermal quartz; intense brecciation of these veins is indicated by the occurrence of fragments of zoned quartz crystals. Primary growth zoning in quartz may be revealed not only by variations in the intensity of blue CL and/or by primary fluid inclusions arranged within the zones, but also by secondary inclusions and recrystallization phenomena developed along boundary surfaces between the zones. Using the results from CL imaging and microstructural analysis of the quartz, fluid inclusions investigated earlier were assigned to genetic types; the evidence of probably primary inclusions is of considerable importance for further studies of the geochemical conditions during vein formation. Considering geological and mineralogical data, CL studies of vein quartz may help to reveal the history of precipitation, deformation and recrystallization processes in the Muruntau Au ore field.
Phase relations in the metal-rich portions of the phase system Pt-Ir-Fe-S at 1000°C and 1100°C
Authors: Makovicky E. , Karup-Møller S.
Published: July 2002

Phase relations in the S-poor portions of the dry condensed Pt-Ir-Fe-S system were determined at 1000° and 1100°C with a particular emphasis on delineation of the solid solubility fields of the Pt-Ir-Fe alloys. At both temperatures, a broad field of γ(Ir,Fe,Pt) alloy coexists with γ-(Pt,Fe), Pt3Fe and PtFe which dissolve respectively at least 5.1, 29.3 and 24.0 at.% Ir at 1100°C (2.2, 23.6 and ≤17.2 at.% Ir at 1000°C). Gaps between the nearly Ir-free Pt-Fe alloys γ(Pt,Fe), Pt3Fe s.s., PtFe s.s. and γ(Fe,Pt) were estimated as 20–23 at.%, 40–42 at.% and 54.2–~57 at.% Fe at 1100°C (18–23, 39.5–42.5 and 59–62 at.% Fe at 1000°C). The first gap agrees with data from natural phases by Cabri et al. (1996). The Fe-rich sulphide melt dissolves only traces of Pt and Ir; Fe1–xS dissolves up to 5.8 at.% Ir at 1100°C and 3.4 at.% Ir at 1000°C. These solubilities and the compositions of coexisting alloys (before low-temperature exsolution) may serve as geothermometers. The S-rich melt dissolves up to 8.2 at.% Pt and 2.5 at.% Ir (measured on a solidified melt) at 1100°C. The Fe-Ir thiospinel dissolves up to 2.2 at.% Pt (for the composition Fe21.6Ir18.9Pt2.2S57.3 at 1100°C). The 25–28 at.% Fe portions of Pt3Fe with <10 at.% Ir partake in all important sulphide (± melt)-alloy assemblages (with PtS, Ir2S3, pyrrhotite, S-rich melt and thiospinel). Therefore, their use in recognizing distinct natural assemblages of genetic importance is of limited value.
Lentivirus-transduced human monocyte-derived dendritic cells efficiently stimulate antigen-specific cytotoxic T lymphocytes
Authors: Dyall Julie , Latouche Jean-Baptiste , Schnell Stefan , Sadelain Michel
Published: July 2002

Dendritic cells (DCs) are professional antigen-presenting cells that are highly effective adjuvants for immunizing against pathogens and tumor antigens. The potential merit of genetic approaches to loading DCs with antigens is to express high and sustained levels of proteins that can be subsequently processed and presented to T lymphocytes. Replication-defective oncoretroviruses are able to efficiently transduce CD34+ progenitor-derived DCs but not monocyte-derived DCs. Here, it is shown that efficient gene transfer is obtained using a human immunodeficiency virus-1–derived lentiviral vector deleted of all structural and accessory genes. Infection of immature DCs with the lentiviral vector at a multiplicity of infection of 20 resulted in stable gene expression in 30% to 40% of the matured DCs. Proviral DNA was detectable by Alu polymerase chain reaction for the lentiviral but not the oncoretroviral vector. Most importantly, it is demonstrated that lentivirus-transduced DCs were fully functional and effectively activated autologous HLA A2.1+ peripheral blood cytotoxic T lymphocytes (CTLs). DCs expressing lentiviral vector-encoded Flu peptide were at least as efficient as DCs pulsed with the same peptide in stimulating specific CTLs. The efficacy of the lentivirus-transduced DCs was further demonstrated by their ability to directly activate freshly harvested peripheral blood Flu-specific CTLs in the absence of CD4+ T-cell help and exogenous cytokines. The availability of a stable gene delivery system based on a multiply attenuated lentivirus that does not encode any viral protein and that allows sustained antigen presentation by DCs derived from blood monocytes will be very useful for the biologic investigation of DCs and the improvement of immunotherapeutic strategies involving DCs.
c-mpl mutations are the cause of congenital amegakaryocytic thrombocytopenia
Authors: Ballmaier Matthias , Germeshausen Manuela , Schulze Harald , Cherkaoui Klara , Lang Sabine , Gaudig Annika , Krukemeier Stephanie , Eilers Martin , Strauß Gabriele , Welte Karl
Published: July 2002

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare disease presenting with isolated thrombocytopenia in infancy and developing into a pancytopenia in later childhood. Thrombopoietin (TPO) is the main regulator of thrombocytopoiesis and has also been demonstrated to be an important factor in early hematopoiesis. We analyzed 9 patients with CAMT for defects in TPO production and reactivity. We found high levels of TPO in the sera of all patients. However, platelets and hematopoietic progenitor cells of patients with CAMT did not show any reactivity to TPO, as measured by testing TPO-synergism to adenosine diphosphate in platelet activation or by megakaryocyte colony assays. Flow cytometric analysis revealed absent surface expression of the TPO receptor c-Mpl in 3 of 3 patients. Sequence analysis of the c-mpl gene revealed point mutations in 8 of 8 patients: We found frameshift or nonsense mutations that are predicted to result in a complete loss of c-Mpl function in 5 patients. Heterozygous or homozygous missense mutations predicted to lead to amino acid exchanges in the extracellular domain of the receptor were found in 3 other patients. The type of mutations correlated with the clinical course of the disease. We propose a defective c-Mpl expression due to c-mpl mutations as the cause for thrombocytopenia and progression into pancytopenia seen in patients with CAMT.
Clinical correlates of splenic histopathology and splenic karyotype in myelofibrosis with myeloid metaplasia
Authors: Mesa Ruben A. , Li Chin-Yang , Schroeder Georgene , Tefferi Ayalew
Published: July 2002

Splenic extramedullary hematopoiesis is an integral component of myelofibrosis with myeloid metaplasia (MMM) and may be classified into 3 distinct histologic patterns of infiltration by myeloid precursors: diffuse, nodular, and a predominance of immature granulocytes. These 3 histologic patterns occurred in 121 (56.8%), 75 (35.2%), and 17 (8%), respectively, of 213 patients with MMM who underwent splenectomy at a single institution. In general, karyotypic findings in splenic tissue (n = 92) were similar to those seen in the bone marrow. The histologic pattern of immature granulocyte predominance, the presence of microscopic splenic infarcts (26 patients), or the detection of an abnormal splenic karyotype (52 patients) was significantly associated with decreased postsplenectomy survival. These adverse features were also associated with characteristics of advanced disease. These observations support the bone marrow origin of the myeloid progenitor pool in the spleen of patients with MMM and suggest a prognostic value for splenic histopathology and karyotype.
Tumor necrosis factor α promoter polymorphisms influence the phenotypic expression of hereditary hemochromatosis
Authors: Fargion Silvia , Valenti Luca , Dongiovanni Paola , Scaccabarozzi Anna , Fracanzani Anna Ludovica , Taioli Emanuela , Mattioli Michela , Sampietro Maurizio , Fiorelli Gemino
Published: July 2002

Severe iron overload usually develops in patients with hereditary hemochromatosis (HHC), but variability in the phenotypic expression of the disease has been reported. This study assessed whether tumor necrosis factor α (TNF-α) plays a role in phenotypic expression of HHC. Sixty-four patients with HHC and 172 healthy volunteers (controls) were studied. Release of TNF-α from stimulated peripheral blood monocytes was measured by enzyme-linked immunosorbent assay, and 308 and 238 TNF-α polymorphisms were detected with polymerase chain reaction and restriction fragment-length polymorphism analysis. The relation between TNF-α polymorphisms and clinical expression of HHC was evaluated. Patients with HHC released less TNF-α than controls, but the difference was significant only in homozygotes for the C282Y mutation. The prevalence of the 308 TNF-α polymorphism was similar in patients and controls, whereas the prevalence of the 238 polymorphic allele was significantly lower in patients (3% versus 16%;P = .002). A lower prevalence of cirrhosis was observed in patients with TNF-α polymorphism than in those without it (4 of 15 [27%] versus 28 of 49 [57%]), but the difference was not significant (P = .07). In nonhomozygotes for the C282Y mutation, severe liver siderosis was less prevalent in patients with the 308 polymorphism than in those without it (P = .05). Alanine aminotransferase (ALT) values were significantly lower in patients with TNF-α polymorphism (P = .006), even when patients with other hepatotoxic factors were excluded. Multivariate analysis showed that TNF-α polymorphism was independently associated with ALT values (P = .0008 and P = .045, respectively, in homozygotes and nonhomozygotes for the C282Y mutation) and siderosis in nonhomozygotes (P = .047). Thus, TNF-α appears to play a role in HHC by modulating the severity of liver damage.
Hoechst 33342 efflux identifies a subpopulation of cytogenetically normal CD34+CD38− progenitor cells from patients with acute myeloid leukemia
Authors: Feuring-Buske Michaela , Hogge Donna E.
Published: July 2002

Efflux of Hoechst 33342 from normal hematopoietic cells identifies a “side population” (SP+) of negatively staining cells that, in the mouse, are largely CD34− and are enriched for primitive progenitors. To further characterize human SP+cells, blood or bone marrow from 16 patients with acute myeloid leukemia (AML) was analyzed for their presence, immunophenotype, and cytogenetic and functional properties, and for the relation between SP phenotype and multidrug resistance-1 (MDR-1) expression. The mean percentages of SP+ and MDR+ cells was 8.1% (range, 0.5%-29.9%) and 12.8% (range, 0%-54.8%), respectively, with no correlation between the 2 values. The percentages of SP+ cells that were CD34+CD38−, CD34+CD38+, or CD34− were 12% (range, 0.4%-50%), 25% (range, 0.5%-96%), and 63% (range, 4%-99%). Cytogenetically abnormal cells were always detected in the SP−CD34+CD38− and SP+CD34− fractions, and abnormal colonies (CFC), long-term culture-initiating cells (LTC-IC), and nonobese diabetic-severe combined immunodeficiency (NOD/SCID) mouse leukemia–IC were detected in the former fraction. No progenitors were detected among SP+CD34− cells in any of these assays from 9 of 10 samples. In contrast, exclusively normal cells were detected in the SP+CD34+CD38−fraction from 9 of 15 samples, and CFC, LTC-IC, and multilineage engraftment in NOD/SCID mice from this subpopulation were also cytogenetically normal in 6 of 8, 6 of 7, and 2 of 2 cases studied, respectively. In contrast to murine studies, primitive progenitors are enriched among SP+CD34+CD38− cells from patients with AML. The molecular basis for Hoechst dye efflux is uncertain because it does not appear to be related to MDR-1 expression.
Chemokine stromal cell-derived factor-1α modulates VLA-4 integrin-mediated multiple myeloma cell adhesion to CS-1/fibronectin and VCAM-1
Authors: Sanz-Rodrı́guez Francisco , Hidalgo Andrés , Teixidó Joaquin
Published: July 2002

The chemokine stromal cell-derived factor-1α (SDF-1α) and its G-protein–linked receptor CXCR4 are involved in hematopoietic progenitor cell and lymphocyte migration. The integrin VLA-4 is a cell adhesion receptor for CS-1/fibronectin and VCAM-1 and constitutes one of the main adhesion receptors mediating myeloma cell adhesion to bone marrow (BM) stroma in multiple myeloma (MM). It is shown here that MM CD38hiCD45RA− BM cells and myeloma-derived cell lines expressed CXCR4 and displayed a moderate chemotactic response to SDF-1α. Because cell migration in response to SDF-1α might require a dynamic regulation of integrin function, it was investigated whether SDF-1α can modulate VLA-4 function on myeloma cells. SDF-1α rapidly and transiently up-regulated VLA-4–mediated myeloma cell adhesion to both CS-1/fibronectin and VCAM-1, which was inhibited by pertussis toxin and cytochalasin D, indicating the involvement of Gi protein downstream signaling and an intact cytoskeleton. Modulation of VLA-4–dependent myeloma cell adhesion by SDF-1α could contribute to the trafficking and localization of these cells in the BM microenvironment.
HIV-1 Tat promotes monocyte chemoattractant protein-1 secretion followed by transmigration of monocytes
Authors: Park In-Woo , Wang Jian-Feng , Groopman Jerome E.
Published: July 2002

The mechanism whereby HIV-infected cells transit from the bloodstream into tissues is not well defined. This phenomenon was addressed by studying the effects of HIV-1 Tat, a protein secreted by infected cells, on human lung microvascular endothelial cells (HMVEC-Ls). It was found that monocyte chemoattractant protein-1 (MCP-1) was released from HMVEC-Ls in a dose- and time-dependent manner after Tat treatment. MCP-1 is a potent β-chemokine that recruits monocytes and T cells and promotes cell adhesion and transmigration across an endothelial monolayer. It was also observed that MCP-1 and the culture medium from Tat-treated HMVEC-Ls were chemotactic for CD14+ monocytes from human peripheral blood and for THP-1, a promonocytic cell line used as a model system. To characterize the signaling pathways underlying the observed induction of MCP-1, HMVEC-Ls were treated with 2 different protein kinase inhibitors: PD98059, a MAP kinase inhibitor, and GF109203X, a protein kinase C (PKC) inhibitor. MCP-1 release was significantly reduced when PKC was inhibited, and slightly decreased when PI3 kinase was blocked; no effect on MCP-1 release was observed on MAP kinase inhibition. Similarly, transmigration of THP-1 cells was significantly impaired by the PKC inhibitor, but not by the other tested inhibitors. These data indicate that the HIV-1 Tat protein may act as a protocytokine by causing the release of MCP-1 from the endothelial monolayer, and thereby facilitating monocyte transmigration into tissues via a PKC signaling pathway.
Requirement of Shp-2 tyrosine phosphatase in lymphoid and hematopoietic cell development
Authors: Qu Cheng-Kui , Nguyen Suzanne , Chen Jianzhu , Feng Gen-Sheng
Published: July 2002

Shp-1 and Shp-2 are cytoplasmic phosphotyrosine phosphatases with similar structures. Mice deficient in Shp-2 die at midgestation with defects in mesodermal patterning, and a hypomorphic mutation at the Shp-1 locus results in the moth-eaten viable (mev) phenotype. Previously, a critical role of Shp-2 in mediating erythroid/myeloid cell development was demonstrated. By using the RAG-2–deficient blastocyst complementation, the role of Shp-2 in lymphopoiesis has been determined. Chimeric mice generated by injecting Shp-2−/− embryonic stem cells into Rag-2–deficient blastocysts had no detectable mature T and B cells, serum immunoglobulin M, or even Thy-1+ and B220+ precursor lymphocytes. Collectively, these results suggest a positive role of Shp-2 in the development of all blood cell lineages, in contrast to the negative effect of Shp-1 in this process. To determine whether Shp-1 and Shp-2 interact in hematopoiesis, Shp-2−/−:mev/mev double-mutant embryos were generated and the hematopoietic cell development in the yolk sacs was examined. More hematopoietic stem/progenitor cells were detected in Shp-2−/−:mev/mevembryos than in Shp-2−/− littermates. The partial rescue by Shp-1 deficiency of the defective hematopoiesis caused by the Shp-2 mutation suggests that Shp-1 and Shp-2 have antagonistic effects in hematopoiesis, possibly through a bidirectional modulation of the same signaling pathway(s).
In utero transplantation of fetal liver cells in the mucopolysaccharidosis type VII mouse results in low-level chimerism, but overexpression of β-glucuronidase can delay onset of clinical signs
Authors: Casal Margret L. , Wolfe John H.
Published: July 2002

Mice with the lysosomal storage disease mucopolysaccharidosis (MPS) VII, caused by a deficiency of β-glucuronidase (GUSB), have signs of disease present at birth. Bone marrow transplantation (BMT) or retroviral vector–mediated gene transfer into hematopoietic stem cells can partially correct the disease in adult mice, and BMT performed at birth results in a better clinical outcome. Thus, treatment in utero may result in further improvement. However, this must be done without cyto-ablation, and the donor cells do not have a competitive repopulating advantage over host cells. Transplantation in utero of either syngeneic fetal liver hematopoietic stem cells marked with a retroviral vector, or allogeneic donor cells that constitutively express high levels of human GUSB from a transgene, resulted in only about 0.1% engraftment in the adult. Immuno-affinity enrichment of stem and progenitor cells of 5- to 10-fold resulted in significantly higher GUSB activities at 2 months of age, but by 6 months engraftment was about 0.1%. Attempts to further increase the number of stem and progenitor cells were deleterious to the recipients. Nevertheless, GUSB expressed during the first 2 months of life in MPS VII fetuses could delay the onset of overt signs of disease. This suggests that the expression of some normal enzyme activity beginning in fetal life may offer the possibility of slowing the progression of the disease until more definitive postnatal transplantation or gene transfer to stem cells could be accomplished.
Core-binding factor β (CBFβ), but not CBFβ–smooth muscle myosin heavy chain, rescues definitive hematopoiesis in CBFβ-deficient embryonic stem cells
Authors: Miller Janelle D. , Stacy Terryl , Liu P. Paul , Speck Nancy A.
Published: July 2002

Core-binding factor β (CBFβ) is the non–DNA-binding subunit of the heterodimeric CBFs. Genes encoding CBFβ (CBFB),and one of the DNA-binding CBFα subunits, Runx1 (also known as CBFα2, AML1, and PEBP2αB), are required for normal hematopoiesis and are also frequent targets of chromosomal translocations in acute leukemias in humans. Homozygous disruption of either the Runx1or Cbfb gene in mice results in embryonic lethality at midgestation due to hemorrhaging in the central nervous system, and severely impairs fetal liver hematopoiesis. Results of this study show that Cbfb-deficient mouse embryonic stem (ES) cells can differentiate into primitive erythroid colonies in vitro, but are impaired in their ability to produce definitive erythroid and myeloid colonies, mimicking the in vivo defect. Definitive hematopoiesis is restored by ectopic expression of full-length Cbfbtransgenes, as well as by a transgene encoding only the heterodimerization domain of CBFβ. In contrast, the CBFβ–smooth muscle myosin heavy chain (SMMHC) fusion protein generated by the inv(16) associated with acute myeloid leukemias (M4Eo) cannot rescue definitive hematopoiesis by Cbfb-deficient ES cells. Sequences responsible for the inability of CBFβ-SMMHC to rescue definitive hematopoiesis reside in the SMMHC portion of the fusion protein. Results also show that the CBFβ-SMMHC fusion protein transdominantly inhibits definitive hematopoiesis, but not to the same extent as homozygous loss of Runx1 orCbfb. CBFβ-SMMHC preferentially inhibits the differentiation of myeloid lineage cells, while increasing the number of blastlike cells in culture.
Echicetin, a GPIb-binding snake C-type lectin from Echis carinatus, also contains a binding site for IgMκ responsible for platelet agglutination in plasma and inducing signal transduction
Authors: Navdaev Alexei , Dörmann Dagmar , Clemetson Jeannine M. , Clemetson Kenneth J.
Published: July 2002

Echicetin, a heterodimeric snake C-type lectin from Echis carinatus, is known to bind specifically to platelet glycoprotein (GP)Ib. We now show that, in addition, it agglutinates platelets in plasma and induces platelet signal transduction. The agglutination is caused by binding to a specific protein in plasma. The protein was isolated from plasma and shown to cause platelet agglutination when added to washed platelets in the presence of echicetin. It was identified as immunoglogulin Mκ (IgMκ) by peptide sequencing and dot blotting with specific heavy and light chain anti-immunoglobulin reagents. Platelet agglutination by clustering echicetin with IgMκ induced P-selectin expression and activation of GPIIb/IIIa as well as tyrosine phosphorylation of several signal transduction molecules, including p53/56LYN, p64, p72SYK, p70 to p90, and p120. However, neither ethylenediaminetetraacetic acid nor specific inhibition of GPIIb/IIIa affected platelet agglutination or activation by echicetin. Platelet agglutination and induction of signal transduction could also be produced by cross-linking biotinylated echicetin with avidin. These data indicate that clustering of GPIb alone is sufficient to activate platelets. In vivo, echicetin probably activates platelets rather than inhibits platelet activation, as previously proposed, accounting for the observed induction of thrombocytopenia.
Survival of leukemic B cells promoted by engagement of the antigen receptor
Authors: Bernal Alejandro , Pastore Raymond D. , Asgary Zahra , Keller Shannon A. , Cesarman Ethel , Liou Hsiou-Chi , Schattner Elaine J.
Published: July 2002

Chronic lymphocytic leukemia (CLL) is an incurable leukemia characterized by the slow but progressive accumulation of cells in a CD5+ B-cell clone. Like the nonmalignant counterparts, B-1 cells, CLL cells often express surface immunoglobulin with the capacity to bind autologous structures. Previously there has been no established link between antigen-receptor binding and inhibition of apoptosis in CLL. In this work, using primary CLL cells from untreated patients with this disease, it is demonstrated that engagement of surface IgM elicits a powerful survival program. The response includes inhibition of caspase activity, activation of NF-κB, and expression of mcl-1, bcl-2, and bfl-1 in the tumor cells. Blocking phosphatidylinositol 3-kinase (PI3-K), a critical mediator of signals through the antigen receptor, completely abrogated mcl-1 induction and impaired survival in the stimulated cells. These data support the contention that CLL cell survival is promoted by antigen for which the malignant clone has affinity, and suggest that pharmacologic interference with antigen-receptor–derived signals has potential for therapy in patients with CLL.
Fetal liver myelopoiesis occurs through distinct, prospectively isolatable progenitor subsets
Authors: Traver David , Miyamoto Toshihiro , Christensen Julie , Iwasaki-Arai Junko , Akashi Koichi , Weissman Irving L.
Published: July 2002

Hematopoietic fate maps in the developing mouse embryo remain imprecise. Definitive, adult-type hematopoiesis first appears in the fetal liver, then progresses to the spleen and bone marrow. Clonogenic common lymphoid progenitors and clonogenic common myeloid progenitors (CMPs) in adult mouse bone marrow that give rise to all lymphoid and myeloid lineages, respectively, have recently been identified. Here it is shown that myelopoiesis in the fetal liver similarly proceeds through a CMP equivalent. Fetal liver CMPs give rise to megakaryocyte–erythrocyte-restricted progenitors (MEPs) and granulocyte–monocyte-restricted progenitors (GMPs) that can also be prospectively isolated by cell surface phenotype. MEPs and GMPs generate mutually exclusive cell types in clonogenic colony assays and in transplantation experiments, suggesting that the lineage restriction observed within each progenitor subset is absolute under normal conditions. Purified progenitor populations were used to analyze expression profiles of various hematopoiesis-related genes. Expression patterns closely matched those of the adult counterpart populations. These results suggest that adult hematopoietic hierarchies are determined early in the development of the definitive immune system and suggest that the molecular mechanisms underlying cell fate decisions within the myeloerythroid lineages are conserved from embryo to adult.
Host marrow stem cell potential and engraftability at varying times after low-dose whole-body irradiation
Authors: Stewart F. Marc , Zhong Suju , Lambert Jean-François , Colvin Gerald A. , Abedi Mehrdad , Dooner Mark S. , McAuliffe Christina I. , Wang Han , Hsieh Chung , Quesenberry Peter J.
Published: July 2002

High levels of chimerism in syngeneic BALB/c transplants were reported when hosts were exposed to 1 Gy (100 cGy) whole body irradiation (WBI) and infused with 40 × 106 marrow cells. The recovery of host stem cells and alterations of enhanced host engraftability at varying times after 1 Gy WBI have now been evaluated in this study. Male BALB/c marrow (40 × 106 cells) was infused into female BALB/c hosts immediately or at 6, 12, and 24 weeks after 1 Gy WBI of host female BALB/c mice; engraftment percentages 8 weeks after cell injection at week 0, 6, 12, or 24 were 68% ± 12%, 45% ± 15%, 51% ± 12%, or 20% ± 8%, respectively. Eight-week engraftment levels in nonirradiated hosts average 7.7%. Conversely, engraftable stem cells measured at 8 weeks postengraftment in 1 Gy– exposed hosts were reduced to 8.6% ± 3% of nonirradiated mice at time 0, 35% ± 12% 6 weeks later, 49% ± 10% at 3 months, and 21% ± 7% at 6 months. Engraftment was still increased and stem cell decreased 1 year after 1 Gy. Furthermore, the primary cells transplanted into 1 Gy hosts can be serially transplanted, and the predominant effect of 1 Gy is directly on engrafting stem cells and not through accessory cells. These data show that transplantation in 1 Gy mice may be delayed until recovery of hematopoiesis, suggesting strategies in allogeneic transplantation to avoid the adverse effects of cytokine storm. The incomplete recovery of engraftable stem cells out to 12 months indicates that stem cell expansion, especially in patients previously treated with radiomimetic drugs, may not be feasible.
Expression of high Km 5′-nucleotidase in leukemic blasts is an independent prognostic factor in adults with acute myeloid leukemia
Authors: Galmarini Carlos M. , Graham Kathryn , Thomas Xavier , Calvo Fabien , Rousselot Philippe , El Jafaari Assia , Cros Emeline , Mackey John R. , Dumontet Charles
Published: July 2002

Cytarabine (ara-C) requires activation into its triphosphorylated form, ara-CTP, to exert cytotoxic activity. Cytoplasmic 5′-nucleotidase (5NT) dephosphorylates ara-CMP, a key intermediate, preventing accumulation of ara-CTP and may reduce cellular sensitivity to the cytotoxic activity of ara-C. To determine whether the level of expression of 5NT is correlated with clinical outcome in patients with acute myeloid leukemia (AML) treated with ara-C, this study analyzed the levels of messenger RNA expression of high Km 5NT by real-time polymerase chain reaction at diagnosis in blast cells of 108 patients with AML. High Km 5NT was expressed at diagnosis in the blast cells of 54% of patients. In univariate analysis, (1) patients whose blast cells contained high levels (values greater than the median value for total population) of high Km 5NT at diagnosis had significantly shorter disease-free survival (DFS) than patients with low levels of high Km 5NT (11 months versus 17.5 months, P = .02) and (2) high levels of high Km 5NT also predicted significantly shorter overall survival (15.7 months versus 39 months, P = .01) in young patients (≤ 57 years; median value for the entire population). In a multivariate analysis taking into account age, karyotype risk, and other factors found to have prognostic significance in univariate analysis, (1) high Km 5NT expression was an independent prognostic factor for DFS and (2) high levels of high Km 5NT also predicted significantly shorter overall survival in young patients. These results demonstrate that the expression of high levels of high Km 5NT in blast cells is correlated with outcome in patients with AML.
Nuclear factor-κB is constitutively activated in primitive human acute myelogenous leukemia cells
Authors: Guzman Monica L. , Neering Sarah J. , Upchurch Donna , Grimes Barry , Howard Dianna S. , Rizzieri David A. , Luger Selina M. , Jordan Craig T.
Published: July 2002

Human acute myelogenous leukemia (AML) is thought to arise from a rare population of malignant stem cells. Cells of this nature, herein referred to as leukemic stem cells (LSCs), have been documented for nearly all AML subtypes and appear to fulfill the criteria for stem cells in that they are self-renewing and give rise to the cells found in many leukemic populations. Because these cells are likely to be critical for the genesis and perpetuation of leukemic disease, the present studies sought to characterize unique molecular properties of the LSC population, with particular emphasis on the transcription factor, nuclear factor-κB (NF-κB). Previous experiments have shown that unstimulated human CD34+ progenitor cells do not express NF-κB. In contrast, primary AML CD34+ cells display readily detectable NF-κB activity as assessed by electrophoretic mobility shift assay and gene expression studies. Furthermore, detailed analyses of enriched AML stem cells (CD34+/CD38−/CD123+) indicate that NF-κB is also active in the LSC population. Given the expression of NF-κB in leukemic, but not normal primitive cells, the hypothesis that inhibition of NF-κB might induce leukemia-specific apoptosis was tested by treating primary cells with the proteasome inhibitor MG-132, a well-known inhibitor of NF-κB. Leukemic CD34+/CD38− cells displayed a rapid induction of cell death in response to MG-132, whereas normal CD34+/CD38− cells showed little if any effect. Taken together, these data indicate that primitive AML cells aberrantly express NF-κB and that the presence of this factor may provide unique opportunities to preferentially ablate LSCs.
Induction of a long-lasting antitumor immunity by a trifunctional bispecific antibody
Authors: Ruf Peter , Lindhofer Horst
Published: July 2002

Bispecific antibodies (bsAbs) can efficiently mediate tumor cell killing by redirecting preactivated or costimulated T cells to disseminated tumor cells, especially in a minimal residual disease situation. This study demonstrates that the trifunctional bsAb BiLu is able to kill tumor cells very efficiently without any additional costimulation of effector cells in vitro and in vivo. Remarkably, this bsAb also induces a long-lasting protective immunity against the targeted syngeneic mouse tumors (B16 melanoma and A20 B-cell lymphoma, respectively). A strong correlation was observed between the induction of a humoral immune response with tumor-reactive antibodies and the survival of mice. This humoral response was at least in part tumor specific as shown in the A20 model by the detection of induced anti-idiotype antibodies. Both the survival of mice and antitumor titers were significantly diminished when F(ab′)2 fragments of the same bsAb were applied, demonstrating the importance of the Fc region in this process. With the use of T-cell depletion, a contribution of a cellular antitumor response could be demonstrated. These results reveal the necessity of the Fc region of the bsAb with its potent immunoglobulin subclass combination mouse immunoglobulin G2a (IgG2a) and rat IgG2b. The antigen-presenting system seems to be crucial for achieving an efficient tumor cell killing and induction of long-lasting antitumor immunity. Hereby, the recruitment and activation of accessory cells by the intact bsAb is essential.
The AML1-ETO fusion protein promotes the expansion of human hematopoietic stem cells
Authors: Mulloy James C. , Cammenga Jörg , MacKenzie Karen L. , Berguido Francisco J. , Moore Malcolm A. S. , Nimer Stephen D.
Published: July 2002

The acute myelogenous leukemia–1 (AML1)–ETO fusion protein is generated by the t(8;21), which is found in 40% of AMLs of the French-American-British M2 subtype. AML1-ETO interferes with the function of the AML1 (RUNX1, CBFA2) transcription factor in a dominant-negative fashion and represses transcription by binding its consensus DNA–binding site and via protein-protein interactions with other transcription factors. AML1 activity is critical for the development of definitive hematopoiesis, and haploinsufficiency of AML1 has been linked to a propensity to develop AML. Murine experiments suggest that AML1-ETO expression may not be sufficient for leukemogenesis; however, like the BCR-ABL isoforms, the cellular background in which these fusion proteins are expressed may be critical to the phenotype observed. Retroviral gene transfer was used to examine the effect of AML1-ETO on the in vitro behavior of human hematopoietic stem and progenitor cells. Following transduction of CD34+ cells, stem and progenitor cells were quantified in clonogenic assays, cytokine-driven expansion cultures, and long-term stromal cocultures. Expression of AML1-ETO inhibited colony formation by committed progenitors, but enhanced the growth of stem cells (cobblestone area-forming cells), resulting in a profound survival advantage of transduced over nontransduced cells. AML1-ETO–expressing cells retained progenitor activity and continued to express CD34 throughout the 5-week long-term culture. Thus, AML1-ETO enhances the self-renewal of pluripotent stem cells, the physiological target of many acute myeloid leukemias.
Constitutive activity of signal transducer and activator of transcription 3 protein in acute myeloid leukemia blasts is associated with short disease-free survival
Authors: Benekli Mustafa , Xia Zheng , Donohue Kathleen A. , Ford Laurie A. , Pixley Lynda A. , Baer Maria R. , Baumann Heinz , Wetzler Meir
Published: July 2002

Signal transducer and activator of transcription (STAT) proteins are involved in hematopoietic cytokine receptor signaling pathways that regulate cell proliferation, differentiation, and survival. STATs are dysregulated in acute myeloid leukemia (AML); mechanisms of dysregulation include constitutive activation and truncation of the C-terminal transactivation domain; the latter results in a β isoform that has a trans-dominant negative effect on gene induction mediated by the full-length STATα form. It was hypothesized that constitutive STAT activity might correlate with unfavorable treatment outcome in AML. Pretreatment bone marrow samples from 63 adult patients with AML were analyzed by electrophoretic mobility shift assay for the presence of STAT DNA-binding activity. Isoforms and relative levels of STAT proteins were determined by immunoblotting. Constitutive STAT3 activity was detected in samples from 28 (44%) patients. Pretreatment clinical characteristics, expression of STATα/β isoforms, and treatment regimens did not differ significantly between patients with and without constitutive STAT3 activity. Disease-free survival (DFS) was significantly shorter in patients with than in patients without constitutive STAT3 activity (median 8.7 vs 20.6 months;P = .01). Overall survival did not differ significantly. The subgroup of patients with constitutive STAT3 activity and the STAT3β isoform had the shortest DFS (P = .006) and shorter overall survival (P = .049) than all other patients. Whether adverse treatment outcome is attributable to constitutive STAT activity itself or to a process that leads to constitutive STAT activity remains to be determined. This is the first demonstration of a prognostic significance for STAT proteins in a malignancy.
The role of CC chemokine receptor 5 in antiviral immunity
Authors: Nansen Anneline , Christensen Jan Pravsgaard , Andreasen Susanne Ørding , Bartholdy Christina , Christensen Jeanette Erbo , Thomsen Allan Randrup
Published: July 2002

The CC chemokine receptor CCR5 is an important coreceptor for human immunodeficiency virus (HIV), and there is a major thrust to develop anti-CCR5–based therapies for HIV-1. However, it is not known whether CCR5 is critical for a normal antiviral T-cell response. This study investigated the immune response to lymphocytic choriomeningitis virus in mice lacking CCR5 (CCR5−/− mice). This infection is a classical model for studying antiviral immunity, and influx of CCR5-expressing CD8+ T cells and macrophages is essential for both virus control and associated immunopathology. Results showed that the virus-induced clonal expansion of antigen-specific T cells was augmented in CCR5−/− mice especially with regard to the CD4+ subset. Despite absence of CCR5, intracerebral infection invariably resulted in lethal T cell-mediated meningitis, and quantitative and qualitative analysis of the inflammatory exudate cells did not reveal any significant differences between gene-targeted mice and wild-type controls. CCR5 was also found to be redundant regarding the ability to eliminate virus from internal organs. Using delayed-type hypersensitivity to evaluate CD8+ T cell-mediated inflammation, no significant influence of CCR5 was found, not even when viral peptide was used as local trigger instead of live virus. Finally, long-term CD8+ T cell-mediated immune surveillance was efficiently sustained in CCR5−/− mice. Taken together, these results indicate that expression of CCR5 is not critical for T cell-mediated antiviral immunity, and this molecule may therefore constitute a logic and safe target for anti-HIV therapies.
High frequency of Ikaros isoform 6 expression in acute myelomonocytic and monocytic leukemias: implications for up-regulation of the antiapoptotic protein Bcl-XL in leukemogenesis
Authors: Yagi Tomohito , Hibi Shigeyoshi , Takanashi Mami , Kano Gen , Tabata Yasuhiro , Imamura Toshihiko , Inaba Tohru , Morimoto Akira , Todo Shinjiro , Imashuku Shinsaku
Published: July 2002

While studying Ikaros proteins in childhood acute myeloid leukemia (AML), Ikaros isoform 6 (Ik6) expression was detected in 7 of 10 cases of M4 and M5 leukemia, but in none of the remaining French-American-British subtypes (M2, 8 cases; M7, 6 cases). The spliced Ikaros isoforms 4 to 8 (Ik4-8) suppress the function of full-length Ik1 or Ik2 in a dominant-negative manner, owing to their reduced numbers of DNA binding sites. Thus, dominant-negative Ikaros isoforms may inhibit the normal transcriptional regulation of hematopoietic cell development. To clarify the function of Ik6 in developing blood cells, this isoform was transiently transfected into an Ik2+, interleukin-3 (IL-3)–dependent 32D murine myeloid precursor cell line and studied the expression of Bcl-2 family proteins in relation to in vitro cell growth, using a tetracycline-inducible TREx system. The possibility of aberrant cell regulation due to Ikaros functional changes was examined by cotransfecting both Ik2 and Ik6 into Ikaros/Aiolos/Helios triple-negative Cos-7 cells. The results demonstrated IL-3–independent growth by Ik6-transfected 32D clones coincident with up-regulation of the antiapoptotic protein Bcl-XL. Up-regulation of Bcl-XL, but not of other Bcl-2 family proteins, was associated with the suppression of functional Ik2 by Ik6 in a dominant-negative fashion. Thus, the pathogenesis of myelomonocytic/monocytic AML may involve aberrant regulation of apoptosis due to unscheduled expression of the Ik6 isoform.
Shortened First-Line High-Dose Chemotherapy for Patients With Poor-Prognosis Aggressive Lymphoma
Authors: Gisselbrecht Christian , Lepage Eric , Molina Thierry , Quesnel Bruno , Fillet Georges , Lederlin Pierre , Coiffier Bertrand , Tilly Hervé , Gabarre Jean , Guilmin Francoise , Hermine Olivier , Reyes Félix
Published: July 2002

PURPOSE: Randomized trial LNH93-3 was conducted on patients who had poor-prognosis aggressive lymphoma and were younger than 60 years with two to three factors of the age-adjusted International Prognostic Index to evaluate the benefit of early high-dose therapy (HDT) with autologous stem-cell transplantation (ASCT).

PATIENTS AND METHODS: Patients were randomized between doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone (ACVBP) chemotherapy followed by sequential consolidation and an experimental shortened treatment consisting of three cycles with escalated doses of cyclophosphamide, epirubicin, vindesine, bleomycin, and prednisone and collection of peripheral-blood stem cells. On day 60, HDT was administered with 1,3-bis(2-chloroethyl)-1-nitrosourea, etoposide, cytarabine, and melphalan followed by ASCT.

RESULTS: Eligible patients (n = 370) with aggressive lymphoma were analyzed. For ACVBP (181 patients) and HDT (189 patients), respective complete remission rates were 64% and 63%. With a median follow-up of 60 months, 5-year overall survival and event-free survival for ACVBP and HDT were 60% ± 8% and 46% ± 8% (P = .007) and 52 ± 8% and 39 ± 8% (P = .01), respectively. Survival was independently affected by age greater than 40 years (P = .0003), T-cell phenotype (P = .009), bone marrow involvement (P = .003), and HDT treatment group (P = .04).

CONCLUSION: Early HDT with ASCT in high-risk patients was inferior to the ACVBP chemotherapy regimen. These results indicate that the received dose-intensity before HDT was too low when compared with ACVBP and HDT and was given too early.
Interferon Alfa Therapy for Malignant Melanoma: A Systematic Review of Randomized Controlled Trials
Authors: Lens Marko B. , Dawes Martin
Published: July 2002

PURPOSE: No standard systemic adjuvant therapy has been proven to increase overall survival in melanoma patients. The effect of interferon alfa (IFNα) as a single agent or in combination has been widely explored in clinical trials. The purpose of this study was to assess the benefit of IFNα therapy in malignant melanoma.

METHODS: We performed a systematic review of randomized controlled trials comparing regimens with or without IFNα adjuvant therapy in melanoma patients. We assessed the effect of IFNα therapy on overall survival (OS), disease-free survival (DFS), melanoma recurrences, and toxicity. The quality of each trial was systematically evaluated.

RESULTS: Nine randomized controlled trials (RCTs) of IFNα therapy in melanoma patients were identified. Eight were published and one was unpublished. Eight trials comprising 3,178 patients fulfilled our inclusion criteria and were analyzed. Quality assessment scores ranged from 22 to 71, with a mean score of 55.4 (95% confidence interval, 53.8 to 57.0). For OS, only one trial reported a statistically significant benefit for IFNα, but our analysis did not confirm it. Two trials reported statistically significant benefit in DFS for the patients treated with IFNα, but our analysis confirmed it in only one trial. There was a wide clinical heterogeneity between included trials, making meta-analysis inappropriate.

CONCLUSION: In our review, results from included RCTs demonstrated no clear benefit of IFNα therapy on OS in melanoma patients. A large RCT is required to answer whether a full regimen of IFNα therapy is effective and to identify the subgroups of patients who might benefit from IFNα treatment.