bluuebunny/crossref_metadata_2025 huggingface dataset:
Report of the Association Internationale pour l'Etude des Argiles (AIPEA) Nomenclature Committee for 2001: Order, disorder and crystallinity in phyllosilicates and the use of the ‘Crystallinity Index’
Authors: Guggenheim S. , Bain D. C. , F. Bergaya  , Brigatti M. F. , Drits V. A. , Eberl D. D. , Formoso M. L. L. , Galán E. , Merriman R. J . , Peacor D. R. , Stanjek H. , Watanabe T.
Published: October 2002

The purpose of this report is to describe the appropriate use of indices relating to crystallinity, such as the ‘crystallinity index’, the ‘Hinckley index’, the ‘Kü bler index’, and the ‘Árkai index’. A ‘crystalline’ solid is defined as a solid consisting of atoms, ions, or molecules packed together in a periodic arrangement. A ‘crystallinity index’ is purported to be a measure of crystallinity, although there is uncertainty about what this means (see below). This report discusses briefly the nature of order, disorder and crystallinity in phyllosilicates and discusses why the use of a ‘crystallinity index’ should be avoided. If possible, it is suggested that indices be referred to using the name of the author who originally described the parameter, as in ‘Hinckley index’ or ‘Kübler index’, or in honour of a researcher who investigated the importance of the parameter extensively, as in ‘Árkai index’.
Subset of DC-SIGN+ dendritic cells in human blood transmits HIV-1 to T lymphocytes
Authors: Engering Anneke , van Vliet Sandra J. , Geijtenbeek Teunis B. H. , van Kooyk Yvette
Published: October 2002

The dendritic cell (DC)–specific molecule DC-SIGN is a receptor for the HIV-1 envelope glycoprotein gp120 and is essential for the dissemination of HIV-1. DC-SIGN is expressed by DCs, both monocyte-derived DCs and DCs in several tissues, including mucosa and lymph nodes. To identify a DC-SIGN+ DC in blood that may be involved in HIV-1 infection through blood, we have analyzed the expression of DC-SIGN in human blood cells. Here we describe the characterization of a subset of DCs in human blood, isolated from T-/NK-/B-cell–depleted peripheral blood mononuclear cells (PBMCs) on the basis of expression of DC-SIGN. This subset coexpresses CD14, CD16, and CD33 and is thus of myeloid origin. In contrast to CD14+ monocytes, DC-SIGN+ blood cells display a DC-like morphology and express markers of antigen-presenting cells, including CD1c, CD11b, CD11c, CD86, and high levels of major histocompatibility complex (MHC) class I and II molecules. This DC population differs from other described CD14−blood DC subsets. Functionally, DC-SIGN+ blood DCs are able to stimulate proliferation of allogeneic T cells and can produce tumor necrosis factor–α (TNF-α) and interleukin-6 (IL-6) upon activation with lipopolysaccharide (LPS). When they encounter HIV-1, low amounts of these blood DC-SIGN+ DCs enhance infection of T lymphocytes in trans, whereas blood monocytes and CD14−blood DCs are not capable of transmitting HIV-1. Therefore DC-SIGN+ blood DCs can be the first target for HIV-1 upon transmission via blood; they can capture minute amounts of HIV-1 through DC-SIGN and transfer HIV-1 to infect target T cells in trans.
A subject with a novel type I bare lymphocyte syndrome has tapasin deficiency due to deletion of 4 exons by Alu-mediated recombination
Authors: Yabe Toshio , Kawamura Sumiyo , Sato Masako , Kashiwase Koichi , Tanaka Hidenori , Ishikawa Yoshihide , Asao Yoji , Oyama Junko , Tsuruta Kazuma , Tokunaga Katsushi , Tadokoro Kenji , Juji Takeo
Published: October 2002

HLA class I expression depends on the formation of a peptide-loading complex composed of class I heavy chain; β2-microglobulin; the transporter associated with antigen processing (TAP); and tapasin, which links TAP to the heavy chain. Defects in TAP result in a class I deficiency called the type I bare lymphocyte syndrome (BLS). In the present study, we examined a subject with a novel type I BLS who does not exhibit apparent TAP abnormalities but who has a tapasin defect. The subject's TAPASIN gene has a 7.4-kilobase deletion between introns 3 and 7; an Alu repeat–mediated unequal homologous recombination may be the cause of the deletion. No tapasin polypeptide was detected in the subject's cells. The cell surface class I expression level in tapasin-deficient cells was markedly reduced but the reduction was not as profound as in TAP-deficient cells. These results suggest that tapasin deficiency is another cause of type I BLS.
The impact of clonal evolution on response to imatinib mesylate (STI571) in accelerated phase CML
Authors: O'Dwyer Michael E. , Mauro Michael J. , Kurilik Gwen , Mori Motomi , Balleisen Suzanne , Olson Susan , Magenis Ellen , Capdeville Renaud , Druker Brian J.
Published: October 2002

In chronic myelogenous leukemia (CML), the development of chromosomal abnormalities in addition to the Philadelphia chromosome (clonal evolution) is considered by many to be a feature of accelerated phase (AP). Imatinib mesylate (STI571), a selective inhibitor of the Bcr-Abl tyrosine kinase, has significant activity in AP CML. As clonal evolution could allow Bcr-Abl independent proliferation, we analyzed its impact on the outcome of 71 AP patients treated with 600 mg of imatinib mesylate. Fifteen patients had clonal evolution alone (AP-CE), 32 had AP features but no evidence of clonal evolution (HEM-AP), and 24 had AP features plus clonal evolution (HEM-AP + CE). Of the AP-CE patients, 73% had a major cytogenetic response, compared with 31% of the HEM-AP patients (P = .043) and 12.5% of the HEM-AP + CE patients (P = .007). Complete cytogenetic responses were seen in 60% of AP-CE patients, compared with 31% of HEM-AP patients (P = .19) and 8% of HEM-AP + CE patients (P < .001). With mean follow-up of 11.2 months, 35% of all patients failed treatment. The lowest estimated rate of treatment failure at 1 year, 0%, was seen in AP-CE patients, compared with rates of 31% for HEM-AP patients and 69% for HEM-AP + CE patients (P = .0004). After 1 year, 100% of AP-CE patients were still alive, compared with 85% of HEM-AP patients and 67.5% of HEM-AP + CE patients (P = .01). In conclusion, in patients with clonal evolution as the sole criterion of disease acceleration, good responses to imatinib are still possible. Once patients have other signs of acceleration, clonal evolution predicts lower response rates and a shorter time to treatment failure.
Thrombin functions during tissue factor–induced blood coagulation
Authors: Brummel Kathleen E. , Paradis Sara G. , Butenas Saulius , Mann Kenneth G.
Published: October 2002

Tissue factor–induced blood coagulation was studied in 20 individuals, for varying periods of time during 54 months, in contact pathway–inhibited whole blood at 37°C and evaluated in terms of the activation of various substrates. After quenching over time with inhibitors, the soluble phases were analyzed for thrombin–antithrombin III (TAT) complex formation, prothrombin fragments, platelet activation (osteonectin release), factor Va generation, fibrinopeptide (FP) A and FPB release, and factor XIII activation. TAT complex formation, for 35 experiments, showed an initiation phase (up to 4.6 ± 0.6 minutes) in which thrombin was generated at an average rate of 0.93 ± 0.3 nM/min catalyzed by about 1.3 pM prothrombinase yielding approximately 26 nM thrombin. During a subsequent propagation phase, thrombin was generated at a rate of 83.9 ± 3.8 nM/min by about 120 pM prothrombinase, reaching ultimate levels of 851 ± 53 nM. Clot time, determined subjectively, occurred at 4.7 ± 0.2 minutes and correlated with the inception of the propagation phase. The thrombin concentrations associated with the transitions to rapid product formation are 510 ± 180 pM for platelet activation (1.9 ± 0.2 minutes), 840 ± 280 pM for factor XIII activation and factor Va generation (2.2 ± 0.6 minutes), 1.3 ± 0.4 nM for FPA release (2.5 ± 0.7 minutes), 1.7 ± 0.5 nM for FPB release and prethrombin 2 (2.8 ± 0.8 minutes), 7.0 ± 2.2 nM for thrombin B chain (3.6 ± 0.2 minutes), and 26 ± 6.2 nM for the propagation phase of TAT formation (4.6 ± 0.6 minutes). These results illustrate that the initial activation of thrombin substrates occurs during the initiation phase at less than 2 nM thrombin (0.2%). Most thrombin (96%) is formed well after clotting occurs.
Transgenic expression of CD40 ligand produces an in vivo antitumor immune response against both CD40+ and CD40− plasmacytoma cells
Authors: Dotti Gianpietro , Savoldo Barbara , Yotnda Patricia , Rill Donna , Brenner Malcolm K.
Published: October 2002

Because tumor-specific antigens have been identified in multiple myeloma (MM), immunotherapy might provide an additional treatment modality for the disease. Expression of CD40 ligand (CD40L) proximate to the MM cells might serve this purpose, either by increasing their capacity to present self-antigens by activation through their CD40 receptor or by the recruitment of professional antigen-presenting cells (APCs) able to take up and present tumor-associated antigens. To distinguish between these possibilities and predict whether human CD40− myeloma might respond to this approach, we examined 3 murine plasmacytoma cell lines, 2 (MPC-11 and S107) expressing the CD40 molecule and 1 (X-24) lacking such expression. Syngeneic BALB/CBYJ mice were inoculated subcutaneously with tumor cells mixed with CL7.1 fibroblasts, retrovirally transduced to express either the mCD40L or the neo gene. For all 3 plasmacytoma cell lines, coinjection with CL7.1/mCD40L significantly reduced local tumor growth compared with controls. This effect was mediated by a systemic antitumor immune response, since mice immunized with tumor and CL7.1/mCD40L were resistant to subsequent challenge with tumor, and tumor growth inhibition was abolished when CD8+or CD4+ lymphocytes were depleted. Because expression of CD40L gave equivalent protection from CD40+ and CD40− tumors and transgenic-CD40L failed to up-regulate costimulatory molecules in either tumor, the protective effects of CD40L probably resulted from recruitment/activation of professional APCs rather than from CD40 activation of plasmacytoma cells. As further support of this concept, we found that mice were also well protected if CL7.1 and CD40L were injected together with apoptotic plasmacytoma cells from these tumors. Hence, transgenic CD40L expression may produce an antimyeloma immune response against either CD40+ or CD40− tumors and may be of therapeutic value for both types of myeloma in humans.
Impact of trisomy 8 (+8) on clinical presentation, treatment response, and survival in acute myeloid leukemia: a Southwest Oncology Group study
Authors: Wolman Sandra R. , Gundacker Holly , Appelbaum Frederick R. , Slovak Marilyn L.
Published: October 2002

The prognostic impact of trisomy 8, alone or with other clonal aberrations, was evaluated in 849 patients with previously untreated acute myeloid leukemia (AML) who were registered to 5 Southwest Oncology Group trials. At presentation, 108 (12.7%) patients had +8 in their karyotypes, including 43 (5.1%) patients with +8 as the sole aberration; 307 (36.2%) were normal, and 434 (51.1%) had other cytogenetic abnormalities. Patients with +8 were slightly older (P = .033), had lower WBC (P = .011), and had lower percentages of peripheral blasts (P = .0004) than the patients without +8. Median survival time for all patients with +8 was 9.9 months (95% CI, 6.5-12.5), similar to that of “unfavorable” cytogenetics risk groups (8.3 months; 95% CI, 6.8-9.5.) Patients with +8 had significantly lower peripheral blasts (P = .0002), WBC (P < .0001) counts, and decreased overall survival (OS) than patients with normal cytogenetics (9.9 months vs 15.4 months; P = .006). However, survival of patients with +8 as the sole aberration did not differ significantly from those with normal cytogenetics (P = .36). Thus, the trisomy 8 group as a whole had poor survival, which was largely attributable to worsened outcomes among patients whose trisomy 8 was associated with other unfavorable cytogenetic abnormalities.
Activated platelets of patients with paroxysmal nocturnal hemoglobinuria express cellular prion protein
Authors: Holada Karel , Simak Jan , Risitano Antonio M. , Maciejewski Jaroslaw , Young Neal S. , Vostal Jaroslav G.
Published: October 2002

Cellular prion protein (PrPc) is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein that contains a putative membrane-spanning section. Patients with paroxysmal nocturnal hemoglobinuria (PNH) lack GPI proteins on the surface of somatically mutated hematopoietic stem cell and its progeny. Platelet expression of PrPc was studied in 8 PNH patients. Resting PNH (CD55−) platelets were devoid of surface PrPc, but activation of platelets resulted in the surface expression of PrPc. Expressed PrPc was detected by 2 monoclonal antibodies (mAbs) against the N-terminal part of the molecule but not by mAb 6H4, which binds at the C-terminus beyond the membrane-spanning section. However, 6H4 detected PrPc on Western blots of PNH platelets, demonstrating that the lack of 6H4 binding was not caused by PrPc truncation. Our results indicate that in the absence of GPI anchor, PrPc can be expressed intracellularly and up-regulated on the platelet membrane, likely in a transmembrane form with the C-terminal part of the molecule inserted into the cytoplasm.
Lamivudine therapy for prevention of immunosuppressive-induced hepatitis B virus reactivation in hepatitis B surface antigen carriers
Authors: Shibolet Oren , Ilan Yaron , Gillis Shmuel , Hubert Ayala , Shouval Daniel , Safadi Rifaat
Published: October 2002

Viral reactivation in hepatitis B surface antigen (HBsAg) carriers undergoing immunosuppressive therapy is well documented. To evaluate the role of lamivudine prophylaxis in Hepatitis B virus (HBV) carriers treated with immunosuppression for nonhepatic disorders, we reviewed our experience between 1997 and 2000 at Hadassah University Hospital (Jerusalem, Israel). Controls were patients who were HBV carriers and who, between 1990 and 1995, were treated for hematological malignancies but were not treated with lamivudine. Eighteen HBsAg-positive patients were treated with immunosuppression. Fourteen were males, with a mean age of 48 years. Eleven patients had lymphoma; 2 had colonic adenocarcinoma; and 5 had cryoglobulinemia, enophthalmitis, vasculitis, malignant histocytosis, or ulcerative colitis. Fourteen patients were treated with chemotherapy, and 4 with prolonged high-dose corticosteroids. All patients were HBsAg-positive; 4 had hepatitis B e antigen, and 10 had HBV DNA by polymerase chain reaction. Lamivudine was administered to 13 patients in the treatment group 1 to 60 days (mean, 15 days) before immunosuppressive treatment and continued 0.5 to 24 months (mean, 7 months) following initiation of immunosuppression. Mean follow-up after lamivudine administration was 21 months. Three patients died of lymphoma complications and 10 (77%) survived. None of the patients had clinical or serological evidence of HBV reactivation during or after lamivudine prophylaxis. Of 6 patients who presented with liver function test disturbances, 5 improved during combined lamivudine and immunosuppression treatment. At the end of follow-up, HBV DNA became undetectable in 2 of 10 patients. In 2 patients, seroconversion from HBsAg to anti-HBs was observed. In contrast, 2 of 5 control patients had HBV reactivation. Lamivudine prophylaxis in HBsAg carriers receiving immunosuppressive therapy may prevent HBV reactivation and hepatic failure.
Hematopathologic and cytogenetic findings in imatinib mesylate–treated chronic myelogenous leukemia patients: 14 months' experience
Authors: Braziel Rita M. , Launder Teresa M. , Druker Brian J. , Olson Susan B. , Magenis R. Ellen , Mauro Michael J. , Sawyers Charles L. , Paquette Ronald L. , O'Dwyer Michael E.
Published: October 2002

Imatinib mesylate, an Abl kinase inhibitor, produces sustained complete hematologic responses (CHRs) in chronic myelogenous leukemia (CML) patients, but the sequence and timing of morphologic and cytogenetic changes in CML patients during prolonged imatinib mesylate treatment has not been described. In this report, we document sequential hematologic and bone marrow findings in 19 interferon-refractory/interferon-intolerant chronic phase CML patients on imatinib mesylate for at least 14 months. Patients treated at an effective oral dose (300 to 600 mg per day) were followed with peripheral blood (PB) counts, marrow examination, and cytogenetic studies at 0, 2, 5, 8, 11, and 14 months. By 2 months, 17 of 19 patients achieved CHR; 1 reached CHR by 5 months, and 1 at 11 months. Five of 19 patients developed cytopenias requiring treatment interruption and/or dose reduction, but all were able to continue in CHR on study. In contrast to interferon-alfa treatment, imatinib mesylate–treated CML patients achieved not only CHR but complete morphologic marrow response. Normalization of marrow lagged behind PB response; however, by 8 months, all marrows showed normal or reduced cellularity without morphologic evidence of CML. Eighteen of 19 patients continued in CHR and morphologic marrow remission at 14 months; 1 patient relapsed with chronic phase CML. Although hematologic and marrow responses were uniform, cytogenetic responses were variable. Complete cytogenetic responses occurred in 6 patients, with 4 also in remission by fluorescent in situ hybridization and/or reverse-transcription–polymerase chain reaction. Six of 19 had partial and 7 of 19 no cytogenetic response. Several patients acquired additional clonal cytogenetic abnormalities during therapy, a finding with significant implications for prognosis and laboratory monitoring in imatinib mesylate–treated CML patients.
Low-dose total body irradiation followed by allogeneic lymphocyte infusion may induce remission in patients with refractory hematologic malignancy
Authors: Ballen Karen K. , Becker Pamela S. , Emmons Robert V. B. , Fitzgerald Thomas J. , Hsieh Chung C. , Liu Qin , Heyes Christine , Clark Yeteive , Levy William , Lambert Jean Francois , Chiafari Frank , Szymanski Irma , Rososhansky Sarah , Popovsky Mark A. , Stewart F. Marc , Quesenberry Peter J.
Published: October 2002

Allogeneic stem cell transplantation is curative for certain cancers, but the high doses of chemotherapy/radiotherapy lead to toxicity. Here, we treat patients with refractory cancer with 100 cGy total body irradiation (TBI) followed by infusion of nonmobilized pheresed allogeneic peripheral blood cells. Twenty-five patients, with a median age of 47 years, with refractory cancers were enrolled. Eighteen patients received sibling and 7 received unrelated cord blood cells. Donor chimerism was assessed at weeks 1, 2, 3, 4, and 8 after transplantation. Seven patients with solid tumors received a sibling transplant and 6 received a cord blood transplant; none achieved donor chimerism, but 1 treated at the higher dose level of 1 × 108 CD3+ cells/kg had a transient nodal response. Twelve patients with hematologic malignancies were treated; 1 received a cord blood transplant and 11 received sibling donor cells. Nine of these 11 patients achieved donor chimerism, ranging from 5% to 100%. Four patients had sustained complete remission of their cancers, including one patient with transient 5% donor chimerism. The development of chimerism correlated with hematologic malignancy (P < .001), total previous myelotoxic chemotherapy (P < .001), T-cell dose (P = .03), and graft-versus-host disease (P = .01). Tumor response correlated with donor chimerism (P = .01). Engraftment was achieved in patients with hematologic malignancies who had been heavily pretreated, suggesting the degree of immunosuppression may be a determinant of engraftment. Low-dose TBI and allogeneic lymphocyte infusion may induce remission in patients with refractory hematologic malignancy.
Prostaglandin-E2 enhances EPO-mediated STAT5 transcriptional activity by serine phosphorylation of CREB
Authors: Boer Arjen-Kars , Drayer A. Lyndsay , Rui Hallgeir , Vellenga Edo
Published: October 2002

Erythroid colony formation in response to erythropoietin (EPO) stimulation is enhanced by costimulating the cells with prostaglandin-E2 (PGE2). The present study further analyzed the underlying mechanisms and demonstrated that EPO-mediated STAT5 transactivation in the erythroid AS-E2 cell line was enhanced 6-fold by PGE2 (10 μM), without affecting the STAT5 tyrosine phosphorylation or STAT5-DNA binding. Moreover, the PGE2-enhancing effect was independent of STAT5 serine phosphorylation. In AS-E2 cells STAT5 is constitutively phosphorylated on Ser780 (STAT5A) and EPO-dependently phosphorylated on Ser726/731 (STAT5A/STAT5B), but overexpression of STAT5 serine mutants did not affect STAT5 transactivation. In addition, PGE2 did not affect STAT5 serine phosphorylation. Instead, the stimulatory effect of PGE2 on STAT5 signaling could be mimicked by dibutyryl-cyclic adenosine monophosphate (cAMP) and the phosphodiesterase inhibitor IBMX, suggesting that the effect was mediated by cAMP. Activation of the cAMP pathway resulted in cAMP-response element binding protein (CREB) phosphorylation, which was sustained in the presence of EPO plus PGE2 and transient on EPO stimulation alone. The costimulatory effect of PGE2 on EPO-mediated STAT5 transactivation was inhibited by overexpression of serine-dead CREB or protein kinase A (PKA) inhibitor (PKI), in contrast to EPO-mediated transactivation, which was PKA independent. Furthermore, CREB-binding protein (CBP)/p300 was shown to be involved in EPO-mediated STAT5 transactivation, and a CBP mutant with increased affinity for CREB resulted in an additional enhancement of the PGE2 effect. Finally, we demonstrated that the STAT5 target genes Bcl-X, SOCS2, andSOCS3 were up-regulated by costimulation with PGE2. In summary, these studies demonstrate that PGE2 enhancement of EPO-induced STAT5 transactivation is mediated by the cAMP/PKA/CREB pathway.
A role for glycoprotein Ib in Streptococcus sanguis–induced platelet aggregation
Authors: Kerrigan Steven W. , Douglas Ian , Wray Ann , Heath Jason , Byrne Michael F. , Fitzgerald Desmond , Cox Dermot
Published: October 2002

Numerous studies have implicated bacteria in cardiovascular disease, but there is a paucity of information on the mechanism involved. In this study we show how the common oral bacteriumStreptococcus sanguis can directly interact with platelets, resulting in activation and aggregate formation. Platelet aggregation was dependent on glycoprotein IIb/IIIa (GPIIb/IIIa) and thromboxane. Platelets could also directly bind to S sanguis, but this interaction was not inhibited by GPIIb/IIIa antagonists. Antibodies to GPIb could inhibit both platelet aggregation and platelet adhesion to bacteria. This suggested a direct interaction between GPIb and S sanguis; however, this interaction did not require von Willebrand factor, the normal ligand for GPIb. By use of a range of monoclonal antibodies to GPIb and the enzyme mocharagin, which cleaves GPIb at amino acid 282, the interaction was localized to a region within the N-terminal 1-225 portion of GPIbα. Furthermore S sanguisfailed to induce aggregation of platelets from a patient with Bernard-Soulier disease, the organism bound to Chinese hamster ovary cells transfected with the GPIbα gene but did not bind to mock-transfected cells and biotin-labeled S sanguis cells bound to purified GPIb in ligand blots. It is suggested that the interaction between S sanguis and GPIb is important in the pathogenesis of infective endocarditis and may also play a contributory role in some cases of myocardial infarction.
C5a stimulates production of plasminogen activator inhibitor-1 in human mast cells and basophils
Authors: Wojta Johann , Kaun Christoph , Zorn Gerlinde , Ghannadan Minoo , Hauswirth Alexander W. , Sperr Wolfgang R. , Fritsch Gerhard , Printz Dieter , Binder Bernd R. , Schatzl Georg , Zwirner Joerg , Maurer Gerald , Huber Kurt , Valent Peter
Published: October 2002

We have recently shown that resting human mast cells (MCs) produce tissue-type plasminogen activator (t-PA) without simultaneously expressing plasminogen activator inhibitor 1 (PAI-1). In the present study we have identified the anaphylatoxin rhC5a as a potent inducer of PAI-1 expression in human MCs and basophils. In primary human skin MCs and primary blood basophils, exposure to rhC5a was followed by an increase from undetectable to significant levels of PAI-1. In addition, rhC5a induced a concentration- and time-dependent increase in PAI-1 antigen in the MC line HMC-1 and the basophil cell line KU-812 and increased the expression of PAI-1 mRNA in HMC-1. In conditioned media of HMC-1 treated with rhC5a, active PAI-1 could be detected. A simultaneous loss of t-PA activity in conditioned media from the same cells indicated that rhC5a-induced PAI-1 was capable of inhibiting the enzymatic activity of coproduced t-PA. Correspondingly, the levels of t-PA–PAI-1 complexes increased in rhC5a-treated cells. When HMC-1 cells were incubated with pertussis toxin or anti-C5a receptor antibodies, the effect of rhC5a on PAI-1 production was completely abolished. Treatment of C5a with plasmin resulted in loss of its ability to induce PAI-1 production in MCs. Considering the suggested role for MCs and components of the complement system in the development of cardiovascular diseases, we hypothesize that MCs, by producing t-PA in a resting state and by expressing PAI-1 when activated by C5a, might participate in the modulation of the balance between proteases and protease inhibitors regulating tissue injury and repair in such disease processes.
Soluble syndecan-1 promotes growth of myeloma tumors in vivo
Authors: Yang Yang , Yaccoby Shmuel , Liu Wei , Langford J. Kevin , Pumphrey Carla Y. , Theus Allison , Epstein Joshua , Sanderson Ralph D.
Published: October 2002

Syndecan-1 (CD138) is a transmembrane heparan sulfate–bearing proteoglycan expressed by most myeloma plasma cells that regulates adhesion, migration, and growth factor activity. In patients with myeloma, shed syndecan-1 accumulates in the bone marrow, and high levels of syndecan-1 in the serum are an indicator of poor prognosis. To test the effect of soluble syndecan-1 on tumor cell growth and dissemination, ARH-77 B-lymphoid cells were engineered to produce a soluble form of syndecan-1. Controls included vector only (neo)–transfected cells and cells transfected with full-length syndecan-1 complementary DNA that codes for the cell surface form of syndecan-1. Assays reveal that all 3 transfectants have similar growth rates in vitro, but cells expressing soluble syndecan-1 are hyperinvasive in collagen gels relative to controls. When injected into the marrow of human bones that were implanted in severe combined immunodeficient mice, tumors formed by cells expressing soluble syndecan-1 grow faster than tumors formed by neo-transfected cells or by cells expressing cell surface syndecan-1. In addition, cells bearing cell surface syndecan-1 exhibit a diminished capacity to establish tumors within the mice as compared with both neo- and soluble syndecan-1–transfected cells. Tumor cell dissemination to a contralateral human bone is detected significantly more often in the tumors producing soluble syndecan-1 than in controls. Thus, high levels of soluble syndecan-1 present in patients with myeloma may contribute directly to the growth and dissemination of the malignant cells and thus to poor prognosis.
Protease-activated receptors 1 and 4 do not stimulate Gi signaling pathways in the absence of secreted ADP and cause human platelet aggregation independently of Gisignaling
Authors: Kim Soochong , Foster Carolyn , Lecchi Anna , Quinton Todd M. , Prosser Dina M. , Jin Jianguo , Cattaneo Marco , Kunapuli Satya P.
Published: October 2002

Thrombin is an important agonist for platelet activation and plays a major role in hemostasis and thrombosis. Thrombin activates platelets mainly through protease-activated receptor 1 (PAR1), PAR4, and glycoprotein Ib. Because adenosine diphosphate and thromboxane A2 have been shown to cause platelet aggregation by concomitant signaling through Gq and Gipathways, we investigated whether coactivation of Gq and Gi signaling pathways is the general mechanism by which PAR1 and PAR4 agonists also activate platelet fibrinogen receptor (αIIbβ3).  A PAR1-activating peptide, SFLLRN, and PAR4-activating peptides GYPGKF and AYPGKF, caused inhibition of stimulated adenylyl cyclase in human platelets but not in the presence of either Ro 31-8220, a protein kinase C selective inhibitor that abolishes secretion, or AR-C66096, a P2Y12 receptor–selective antagonist; α-thrombin–induced inhibition of adenylyl cyclase was also blocked by Ro 31-8220 or AR-C66096. In platelets from a P2Y12 receptor–defective patient, α-thrombin, SFLLRN, and GYPGKF also failed to inhibit adenylyl cyclase. In platelets from mice lacking the P2Y12 receptor, neither α-thrombin nor AYPGKF caused inhibition of adenylyl cyclase. Furthermore, AR-C66096 caused a rightward shift of human platelet aggregation induced by the lower concentrations of α-thrombin and AYPGKF but had no effect at higher concentrations. Similar results were obtained with platelets from mice deficient in the P2Y12. We conclude that (1)thrombin- and thrombin receptor-activating peptide–induced inhibition of adenylyl cyclase in platelets depends exclusively on secreted adenosine diphosphate that stimulates Gi signaling pathways and (2) thrombin and thrombin receptor-activating peptides cause platelet aggregation independently of Gi signaling.
Tissue-type plasminogen activator (t-PA) is stored in Weibel-Palade bodies in human endothelial cells both in vitro and in vivo
Authors: Huber Denise , Cramer Elisabeth M. , Kaufmann Jocelyne E. , Meda Paolo , Massé Jean-Marc , Kruithof Egbert K. O. , Vischer Ulrich M.
Published: October 2002

Vascular endothelial cells are thought to be the main source of plasma tissue-type plasminogen activator (t-PA) and von Willebrand factor (VWF). Previous studies have suggested that both t-PA and VWF are acutely released in response to the same stimuli, both in cultured endothelial cells and in vivo. However, the subcellular storage compartment in endothelial cells has not been definitively established. We tested the hypothesis that t-PA is localized in Weibel-Palade (WP) bodies, the specialized endothelial storage granules for VWF. In cultured human umbilical vein endothelial cells (HUVECs), t-PA was expressed in a minority of cells and found in WP bodies by immunofluorescence. After up-regulation of t-PA synthesis either by vascular endothelial growth factor (VEGF) and retinoic acid or by sodium butyrate, there was a large increase in t-PA–positive cells. t-PA was exclusively located to WP bodies, an observation confirmed by immunoelectron microscopy. Incubation with histamine, forskolin, and epinephrine induced the rapid, coordinate release of both t-PA and VWF, consistent with a single storage compartment. In native human skeletal muscle, t-PA was expressed in endothelial cells from arterioles and venules, along with VWF. The 2 proteins were found to be colocalized in WP bodies by immunoelectron microscopy. These data indicate that t-PA and VWF are colocalized in WP bodies, both in HUVECs and in vivo. Release of both t-PA and VWF from the same storage pool likely accounts for the coordinate increase in the plasma level of the 2 proteins in response to numerous stimuli, such as physical activity, β-adrenergic agents, and 1-deamino-8d-arginine vasopressin (DDAVP) among others.
Crry, but not CD59 and DAF, is indispensable for murine erythrocyte protection in vivo from spontaneous complement attack
Authors: Miwa Takashi , Zhou Lin , Hilliard Brendan , Molina Hector , Song Wen-Chao
Published: October 2002

Decay-accelerating factor (DAF) and CD59 are 2 glycosylphosphatidylinositol-anchored membrane proteins that inhibit complement activation at the C3 and C5b-9 step, respectively. CD59 is considered critical for protecting erythrocytes from spontaneous complement attack, as deficiency of CD59 or CD59/DAF, but not of DAF alone, on human erythrocytes renders them sensitive to complement lysis in paroxysmal nocturnal hemoglobinuria syndrome. To evaluate the relative roles of CD59 and DAF in vivo, we have generated and studied a CD59 knockout and a CD59/DAF double-knockout mouse. CD59-deficient and CD59/DAF–double-deficient mouse erythrocytes were highly sensitive to antibody-induced complement lysis in vitro, yet neither CD59 knockout nor CD59/DAF double-knockout mouse developed spontaneous hemolytic anemia. Consistent with the latter observation, erythrocytes from the 2 strains of mutant mice were shown to have a normal lifespan in vivo. In contrast, mouse erythrocytes deficient in complement receptor 1 (CR1)–related gene y (Crry), a membrane C3 inhibitor with DAF and membrane cofactor protein activities, were rapidly eliminated from the circulation by a complement-dependent mechanism. Compared with DAF-deficient erythrocytes, Crry-deficient erythrocytes incurred higher levels of spontaneous C3 deposition in vivo. These findings demonstrate that CD59 and DAF are not indispensable on murine erythrocytes. Rather, effective C3 regulation on the cell surface, provided by Crry rather than DAF, is necessary for mouse erythrocytes to resist spontaneous complement attack. Our results raise the possibility that proper control of C3 activation may also be critical on human erythrocytes, where CR1 but not DAF could be the principal regulator of spontaneous C3 activation.
Presentation of a major histocompatibility complex class 1–binding peptide by monocyte-derived dendritic cells incorporating hydrophobized polysaccharide–truncated HER2 protein complex: implications for a polyvalent immuno-cell therapy
Authors: Ikuta Yasushi , Katayama Naoyuki , Wang Lijie , Okugawa Toshiharu , Takahashi Yoshiyuki , Schmitt Michael , Gu Xiaogang , Watanabe Masato , Akiyoshi Kazunari , Nakamura Hideo , Kuribayashi Kagemasa , Sunamoto Junzo , Shiku Hiroshi
Published: October 2002

Recognition of the essential role of dendritic cells (DCs) as professional antigen-presenting cells has prompted investigators to search for methods to use DCs as natural adjuvants in immunotherapy. A number of antigenic oligopeptides, recognized by CD8+cytotoxic T lymphocytes (CTLs) specific for cancer cells, have been applied in clinical trials using DCs. Such a monovalent vaccine with a single epitope for a particular type of HLA class 1 molecule would be effective. However, a polyvalent vaccine might be more potent. We designed a novel protein delivery system consisting of hydrophobized polysaccharides complexed with target proteins. The truncated HER2 protein encompassing 147 N-terminal amino acids, including the 9-mer HER2p63-71 peptide (HER2p63), TYLPTNASL, the human homologue of an antigenic murine tumor rejection peptide, was prepared. We report here that HLA-A2402+ DCs could incorporate hydrophobized polysaccharide–truncated HER2 protein complexes and process the protein to present major histocompatibility complex class 1-binding HER2p63 peptide. The complexes enter DCs by phagocytosis, and then the truncated protein is processed through a pathway similar to that for endogenous proteins. DCs sensitized by these complexes primed and boosted HER2p63-specific CD8+T cells in the context of HLA-A2402. Vaccination with DCs incorporating these complexes completely suppressed lung metastases in a HER2-expressing murine tumor model. We also generated 3 CD4+ clones reactive with different HER2- derived 25-mer peptides from lymph node cells in mice treated with CHP/HER2-147. Thus, hydrophobized polysaccharide–protein complexes are promising candidates for the construction of polyvalent vaccines.
Notch2 is involved in the overexpression of CD23 in B-cell chronic lymphocytic leukemia
Authors: Hubmann Rainer , Schwarzmeier Josef D. , Shehata Medhat , Hilgarth Martin , Duechler Markus , Dettke Markus , Berger Rudolf
Published: October 2002

Members of the Notch family encode transmembrane receptors that modulate differentiation, proliferation, and apoptotic programs of many precursor cells, including hematopoietic progenitors. Stimulation of Notch causes cleavage followed by translocation of the intracellular domain (NotchIC) to the nucleus, where it activates transcription of CBF1 responsive genes. The aim of this study was to elucidate the mechanisms leading to the overexpression of CD23, a striking feature of B-cell chronic lymphocytic leukemia (B-CLL) cells. By electrophoretic mobility shift assays, we identified a transcription factor complex (C1) that binds sequence specific to one known and 4 newly identified putative CBF1 recognition sites in the CD23a core promoter region. With the use of Epstein-Barr virus (EBV)–infected B cells as a model for CBF1 mediated CD23a expression, C1 was found to be EBV inducible. Supershift assays revealed that the nuclear form of Notch2 is a component of C1 in B-CLL cells, supporting a model in which NotchIC activates transcription by binding to CBF1 tethered to DNA. Transient transfection of REH pre–B cells with an activated form of Notch2 induced endogenous CD23a, confirming thatCD23a is a target gene of Notch2 signaling. Finally, reverse transcription-polymerase chain reaction and kinetic analysis demonstrated that the Notch2 oncogene is not only overexpressed in B-CLL cells but might also be related to the failure of apoptosis characteristic for this disease. In conclusion, these data suggest that deregulation of Notch2 signaling is involved in the aberrant expression of CD23 in B-CLL.
Expression and activity of breast cancer resistance protein (BCRP) in de novo and relapsed acute myeloid leukemia
Authors: van der Kolk Dorina M. , Vellenga Edo , Scheffer George L. , Müller Michael , Bates Susan E. , Scheper Rik J. , de Vries Elisabeth G. E.
Published: October 2002

Overexpression of the breast cancer resistance protein (BCRP) efflux pump in human cancer cell lines results in resistance to a variety of cytostatic agents. The aim of this study was to analyze BCRP protein expression and activity in acute myeloid leukemia (AML) samples and to determine whether it is up-regulated due to clonal selection at relapse/refractory disease. BCRP protein expression was measured flow cytometrically with the monoclonal antibodies BXP-34 and BXP-21 in 20 paired samples of de novo and relapsed/refractory AML. BXP-34/immunoglobulin G1 ratios were observed of 1.6 ± 0.5 (mean ± SD, range 0.8-2.7) and BXP-21/immunoglobulin G2a ratios of 4.9 ± 3.0 (range 1.1-14.5) in the patient samples versus 9.8 ± 6.8 and 6.5 ± 2.4, respectively, in the MCF-7 cell line. BCRP activity was determined flow cytometrically by measuring mitoxantrone accumulation in absence and presence of the inhibitor fumitremorgin C. Mitoxantrone accumulation, expressed as mean fluorescence intensity (MFI), varied between 44 and 761 MFI (227 ± 146 MFI) and correlated inversely with BCRP expression (r = −0.58, P < .001). Addition of fumitremorgin C showed a small increase in mitoxantrone accumulation (11 ± 29 MFI, n = 40) apart from the effect of PSC833 and MK-571. No consistent up-regulation of BCRP expression or activity was observed at relapse/refractory disease; some cases showed an increase and other cases a decrease at relapse. Relatively high BCRP expression correlated with immature immunophenotype, as determined by expression of the surface marker CD34 (r = 0.54, P = .001). In conclusion, this study shows that BCRP protein is expressed at low but variable levels in AML, especially in immature CD34+cells. BCRP was not consistently up-regulated in relapsed/refractory AML.
NUP98 is fused to the NSD3 gene in acute myeloid leukemia associated with t(8;11)(p11.2;p15)
Authors: Rosati Roberto , La Starza Roberta , Veronese Angelo , Aventin Ana , Schwienbacher Christine , Vallespi Teresa , Negrini Massimo , Martelli Massimo F. , Mecucci Cristina
Published: October 2002

Fusion between the NUP98 and NSD3genes in a patient with acute myeloid leukemia associated with t(8;11)(p11.2;p15), is reported for the first time. The t(8;11)(p11.2;p15) was identified by classical cytogenetics. Fluorescence in situ hybridization (FISH) analysis revealed a split signal with a mix of BAC 118H17 and 290A12, indicating the translocation disrupted NUP98. FISH restriction at 8p11-12 showed a split of BAC 350N15. Molecular investigations into candidate genes in this BAC showed the NUP98 fusion partner at 8p11.2 was the NSD3 gene. To date the NSD3 gene has never been implicated in hematologic malignancies.
Imatinib mesylate (STI571) in the treatment of relapse of chronic myeloid leukemia after allogeneic stem cell transplantation
Authors: Olavarria Eduardo , Craddock Charles , Dazzi Francesco , Marin David , Marktel Sarah , Apperley Jane F. , Goldman John M.
Published: October 2002

Donor lymphocyte infusion (DLI) can restore durable molecular remission in a high percentage of patients with chronic myeloid leukemia (CML) who have relapses after allogeneic stem cell transplantation, but for patients who do not respond survival is poor. Imatinib mesylate (STI571) is a specific inhibitor of BCR-ABL tyrosine kinase that can induce hematologic and cytogenetic remissions in patients with CML. We report here a male patient who had a relapse to chronic phase after stem cell transplantation for CML, did not benefit from treatment with DLI, and then was administered STI571 at a dose of 400 mg daily. There was a rapid, complete hematologic response, and complete restoration of donor-type hematopoiesis (100% 46, XX marrow metaphases) was achieved after 6 months of therapy, though RT-PCR studies still detected BCR-ABL transcripts in the blood at low level. This case demonstrates that imatinib mesylate can be highly effective in the management of patients who have relapses after allograft for CML.
A FLT3-targeted tyrosine kinase inhibitor is cytotoxic to leukemia cells in vitro and in vivo
Authors: Levis Mark , Allebach Jeffrey , Tse Kam-Fai , Zheng Rui , Baldwin Brenda R. , Smith B. Douglas , Jones-Bolin Susan , Ruggeri Bruce , Dionne Craig , Small Donald
Published: October 2002

Constitutively activating internal tandem duplication (ITD) and point mutations of the receptor tyrosine kinase FLT3 are present in up to 41% of patients with acute myeloid leukemia (AML). These FLT3/ITD mutations are likely to be important because their presence is associated with a poor prognosis. Both types of mutations appear to activate the tyrosine kinase activity of FLT3. We describe here the identification and characterization of the indolocarbazole derivative CEP-701 as a FLT3 inhibitor. This drug potently and selectively inhibits autophosphorylation of wild-type and constitutively activated mutant FLT3 in vitro in FLT3/ITD-transfected cells and in human FLT3-expressing myeloid leukemia–derived cell lines. We demonstrate that CEP-701 induces a cytotoxic effect on cells in a dose-responsive fashion that parallels the inhibition of FLT3. STAT5 and ERK1/2, downstream targets of FLT3 in the signaling pathway, are inhibited in response to FLT3 inhibition. In primary leukemia blasts from AML patients harboring FLT3/ITD mutations, FLT3 is also inhibited, with an associated cytotoxic response. Finally, using a mouse model of FLT3/ITD leukemia, we demonstrate that the drug inhibits FLT3 phosphorylation in vivo and prolongs survival. These findings form the basis for a planned clinical trial of CEP-701 in patients with AML harboring FLT3- activating mutations.
Infusion of cytomegalovirus (CMV)–specific T cells for the treatment of CMV infection not responding to antiviral chemotherapy
Authors: Einsele Hermann , Roosnek Eddy , Rufer Nathalie , Sinzger Christian , Riegler Susanne , Löffler Jürgen , Grigoleit Ulrich , Moris Arnaud , Rammensee Hans-Georg , Kanz Lothar , Kleihauer Annette , Frank Friederike , Jahn Gerhard , Hebart Holger
Published: October 2002

We adoptively transferred donor-derived cytomegalovirus (CMV)-specific T-cell lines into 8 stem cell transplant recipients lacking CMV-specific T-cell proliferation. All patients, of whom one was infected by a CMV strain that was genotypically ganciclovir resistant, had received unsuccessful antiviral chemotherapy for more than 4 weeks. CMV-specific lines had been prepared by repetitive stimulation with CMV antigen, which increased the percentage of CMV-specific T cells and ablated alloreactivity completely even against patients mismatched for 1 to 3 HLA antigens. After transfer of 107 T cells/m2 at a median of 120 days (range, 79-479 days) after transplantation, no side effects were noticed. Despite cessation of antiviral chemotherapy, the CMV load dropped significantly in all 7 evaluable patients, with a maximal reduction after a median of 20 days (range, 5-31 days). In 2 patients with high virus load, the antiviral effect was only transient. One of these patients received a second T-cell infusion, which cleared the virus completely. At a median of 11 days after transfer, CMV-specific T-cell proliferation was demonstrated in 6 patients, and an increase in CMV-specific CD4+ T cells was demonstrated in 5 patients. In 6 patients, 1.12 to 41 CMV-specific CD8+ T cells/μL blood were detected at a median of 13 days after transfer, with an increase in all patients lacking CMV-specific CD8+ T cells prior to transfer. Hence, anti-CMV cellular therapy was successful in 5 of 7 patients, whereas in 2 of 7 patients, who received an intensified immune suppression at the time of or after T-cell therapy, only transient reductions in virus load were obtained.
Isolation and characterization of an antifactor V antibody causing activated protein C resistance from a patient with severe thrombotic manifestations
Authors: Kalafatis Michael , Simioni Paolo , Tormene Daniela , Beck Daniel O. , Luni Sonia , Girolami Antonio
Published: October 2002

A 44-year-old woman with a history of severe thrombotic manifestations presented with a markedly reduced activated protein C–sensitivity ratio (APC-SR). DNA sequencing of and around the regions encoding the APC cleavage sites in the factor Va molecule excluded the presence of the factor VLeiden mutation and of other known genetic mutations. No antiphospholipid antibodies were present in the patient's plasma and both prothrombin time and activated partial thromboplastin time were normal. The total immunoglobulin fraction was isolated from the patient's plasma and found to induce severe APC resistance when added to normal plasma and to factor V–deficient plasma supplemented with increasing concentrations of factor V. Immunoblotting and immunoprecipitation experiments with the total immunoglobulin fraction purified from the patient's plasma demonstrated that the antibody recognizes factor V, is polyclonal, and has conformational epitopes on the entire factor V molecule (heavy and light chains, and B region). Thus, the immunoglobulin fraction interferes with the anticoagulant pathway involving factor V. The inhibitor was isolated by sequential affinity chromatography on protein G–Sepharose and factor V–Sepharose. The isolated immunoglobulin fraction inhibited factor Va inactivation by APC because of impaired cleavage at Arg306 and Arg506 of the heavy chain of the cofactor. The isolated immunoglobulin fraction was also found to inhibit the cofactor effect of factor V for the inactivation of factor VIII by the APC/protein S complex. Our data provide for the first time the demonstration of an antifactor V antibody not related to the presence of antiphospholipid antibodies, which is responsible for thrombotic rather than hemorrhagic symptoms.