bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free radical stress in chronic lymphocytic leukemia cells and its role in cellular sensitivity to ROS-generating anticancer agents
Authors: Zhou Yan , Hileman Elizabeth O. , Plunkett William , Keating Michael J. , Huang Peng 
Published: May 2003

Abstract
2-Methoxyestradiol (2-ME), a new anticancer agent currently in clinical trials, has been demonstrated to inhibit superoxide dismutase (SOD) and to induce apoptosis in leukemia cells through a free radical–mediated mechanism. Because the accumulation of superoxide (O2−) by inhibition of SOD depends on the cellular generation of O2−, we hypothesized that the endogenous production of superoxide may be a critical factor that affects the antileukemia activity of 2-ME. In the present study, we investigated the relationship between cellular O2− contents and the cytotoxic activity of 2-ME in primary leukemia cells from 50 patients with chronic lymphocytic leukemia (CLL). Quantitation of O2− revealed that the basal cellular O2− contents are heterogeneous among patients with CLL. The O2− levels were significantly higher in CLL cells from patients with prior chemotherapy. CLL cells with higher basal O2− contents were more sensitive to 2-ME in vitro than those with lower O2− contents. There was a significant correlation between the 2-ME–induced O2−increase and the loss of cell viability. Importantly, addition of arsenic trioxide, a compound capable of causing reactive oxygen species (ROS) generation, significantly enhanced the activity of 2-ME, even in the CLL cells that were resistant to 2-ME alone. These results suggest that the cellular generation of O2− plays an important role in the cytotoxic action of 2-ME and that it is possible to use exogenous ROS-producing agents such as arsenic trioxide in combination with 2-ME to enhance the antileukemia activity and to overcome drug resistance. Such a combination strategy may have potential clinical applications.
Hyperhomocysteinemia accelerates atherosclerosis in cystathionine β-synthase and apolipoprotein E double knock-out mice with and without dietary perturbation
Authors: Wang Hong , Jiang XiaoHua , Yang Fan , Gaubatz John W. , Ma Lang , Magera Mark J. , Yang XiaoFeng , Berger Peter B. , Durante William , Pownall Henry J. , Schafer Andrew I. 
Published: May 2003

AbstractAlthough hyperhomocysteinemia is an independent risk factor for cardiovascular disease, a direct role for homocysteine (Hcy) in this disease remains to be shown. Whereas diet-induced hyperhomocysteinemia promotes atherosclerosis in animal models, the effects of Hcy on atherogenesis in the absence of dietary perturbations is not known. We have generated double knock-out mice with targeted deletions of the genes for apolipoprotein E (apoE) and cystathionine β-synthase (CBS), which converts Hcy to cystathionine. ApoE−/−/CBS−/− mice developed aortic lesions even in the absence of dietary manipulation; lesion area and lesion cholesteryl ester (CE) and triglyceride (TG) contents increased with animal age and plasma Hcy levels. Plasma total cholesterol was significantly increased, whereas high density lipoprotein (HDL) cholesterol and TG concentrations of apoE−/−/CBS−/− mice were decreased. Cholesterol esterification and activities of enzymes catalyzing CE or TG formation in the vessel wall and in peritoneal macrophages were not changed by hyperhomocysteinemia. However, uptake of human acetyl-LDL, but not native low density lipoprotein (LDL), by mouse peritoneal macrophages was higher in the presence of hyperhomocysteinemia. These results suggest that isolated hyperhomocysteinemia is atherogenic and alters hepatic and macrophage lipoprotein metabolism, in part, by enhancing uptake of modified LDL.
Induction of heme oxygenase-1 and stimulation of cGMP production by hemin in aortic tissues from hypertensive rats
Authors: Ndisang Joseph Fomusi , Wu Lingyun , Zhao Weimin , Wang Rui 
Published: May 2003

AbstractHeme oxygenase (HO) and carbon monoxide (CO) have been implicated in the modulation of various cardiovascular functions including blood pressure (BP) regulation. Up-regulating the HO/CO system lowers BP in young (8-week-old) but not in adult (20-week-old) spontaneously hypertensive rats (SHRs). The mechanisms for this selective effect are largely unknown. We investigated the effects of HO-1 inducer, hemin, on the HO/CO-soluble gyanylyl cyclase (sGC)/cGMP system in the aorta of prehypertensive (4-week-old) young and adult SHRs as well as age-matched Wistar-Kyoto rats (WKYs). Reduced expressions of HO-1, HO-2, and sGC proteins associated with depressed HO activity and cGMP levels were detected in young SHRs. These deficiencies were significantly reversed by hemin treatment. Macrophage infiltration of vascular tissues was more significant in adult SHRs than adult WKYs, but invisible in young SHRs and WKYs. Hemin treatment did not alter macrophage infiltration of vascular tissues in young SHRs. The same hemin administration resulted in a significant decrease in BP (from 148.6 ± 3.2 to 125.8 ± 2.6 mmHg, P < .01) in young SHRs, but not in prehypertensive or adult SHRs or WKYs of all ages. The HO inhibitor zinc protoporphyrin abrogated the hemin effect in young SHRs. Aortic tissues became desensitized to YC-1, an activator sGC, in adult SHRs. Thus, in young SHRs the expression and function of the HO/CO-sGC/cGMP system were suppressed, constituting a pathogenic mechanism for the development of hypertension. In adult SHRs, the HO/CO-sGC/cGMP system appeared normal, but desensitization of the sGC/cGMP pathway caused hypertension to prevail.
AML-1A and AML-1B regulation of MIP-1α expression in multiple myeloma
Authors: Choi Sun J. , Oba Tomoko , Callander Natalie S. , Jelinek Diane F. , Roodman G. David 
Published: May 2003

Abstract
Macrophage inflammatory protein-1α (MIP-1α) is produced in high concentration by multiple myeloma (MM) cells in about 70% of patients, and MIP-1α levels correlate with their disease activity. Patients who have high levels of MIP-1α have a poor prognosis. Furthermore, blocking MIP-1α expression in an in vivo model of human MM profoundly decreases both tumor burden and bone destruction, suggesting that MIP-1α is an important mediator of MM bone disease. Therefore, to analyze the regulation of MIP-1α production in MM, we cloned the human MIP-1α promoter and characterized the transcription factor (TF) motifs that control MIP-1α expression in MM cells. The proximal region of MIP-1α promoter was composed of 2 sets of identical transcription regulatory regions consisting of GATA-2+ AML-1+ C/EBPα motifs. Since 2 alternatively spliced variants of the acute myeloid leukemia-1 (AML-1) class of TFs can bind the AML-1 region, AML-1A and AML-1B, the relationship between the expression levels of AML-1A or AML-1B in MM cells and their capacity to express MIP-1α was examined. AML-1A mRNA was relatively overexpressed compared with AML-1B in MM cell lines that produced high levels of MIP-1α (> 1 ng/mL per 106 cells per 72 hours), but AML-1A was not increased in MM cell lines that expressed less than 200 pg/mL MIP-1α. More importantly, the ratio of AML-1A to AML-1B mRNA levels was also increased in 3 of 3 highly purified myeloma cells from patients with MM who expressed increased amounts of MIP-1α. The ratio of AML-1A to AML-1B mRNA in patients with MM was 8-fold higher than in healthy controls. Transduction of AML-1B into the MM-derived MM.1S and ARH-77 cells totally blocked MIP-1α production, while AML-1A did not further increase the already high levels of MIP-1α produced by these cells. Taken together, these data demonstrate that in patients with MM who produce increased concentrations of MIP-1α, the relative level of AML-1B is significantly decreased compared with healthy controls. The data suggest that strategies that enhance AML-1B expression or decrease AML-1A in MM cells may be beneficial therapeutically.
Excess hemoglobin digestion and the osmotic stability ofPlasmodium falciparum–infected red blood cells
Authors: Lew Virgilio L. , Tiffert Teresa , Ginsburg Hagai 
Published: May 2003

AbstractDuring their asexual reproduction cycle (about 48 hours) in human red cells, Plasmodium falciparum parasites consume most of the host cell hemoglobin, far more than they require for protein biosynthesis. They also induce a large increase in the permeability of the host cell plasma membrane to allow for an increased traffic of nutrients and waste products. Why do the parasites digest hemoglobin in such excess? And how can infected red cells retain their integrity for the duration of the asexual cycle when comparably permeabilized uninfected cells hemolyse earlier? To address these questions we encoded the multiplicity of factors known to influence host cell volume in a mathematical model of the homeostasis of a parasitized red cell. The predicted volume changes were subjected to thorough experimental tests by monitoring the stage-related changes in the osmotic fragility of infected red cell populations. The results supported the model predictions of biphasic volume changes comprising transient shrinkage of infected cells with young trophozoites followed by continuous volume increase to about 10% lower than the critical hemolytic volume of approximately 150 fL by the end of the asexual cycle. Analysis of these results and of additional model predictions demonstrated that the osmotic stability of infected red cells can be preserved only by a large reduction in impermeant solute concentration within the host cell compartment. Thus, excess hemoglobin consumption represents an essential evolutionary strategy to prevent the premature hemolysis of the highly permeabilized infected red cell.
Interleukin-7 improves CD4 T-cell reconstitution after autologous CD34 cell transplantation in monkeys
Authors: Storek Jan , Gillespy Thurman , Lu Hailing , Joseph Ansamma , Dawson Monja A. , Gough Michael , Morris Julia , Hackman Robert C. , Horn Peter A. , Sale George E. , Andrews Robert G. , Maloney David G. , Kiem Hans-Peter 
Published: May 2003

AbstractIn mice, interleukin-7 (IL-7) hastens T-cell reconstitution and might cause autoimmune diseases, lymphoma, and osteoporosis. We assessed the effect of IL-7 on T-cell reconstitution and toxicity in baboons that underwent total body irradiation followed by autologous transplantation of marrow CD34 cells. Three baboons received placebo and 3 baboons received recombinant human IL-7 (rhIL-7, 75 μg/kg twice a day subcutaneously) between 6 and 10 weeks after transplantation. The mean increase in blood absolute CD4 T-cell counts was 0.9-fold in the placebo-treated animals versus 9.0-fold in those treated with IL-7 (P = .02). The increase observed in the IL-7–treated animals appeared attributable to peripheral expansion rather than de novo generation. The IL-7–treated animals had greater mean increases in the volumes of the spleen (2.0-fold with placebo versus 4.5-fold with IL-7, P = .02) and lymph nodes (1.8-fold with placebo versus 4.1-fold with IL-7,P = .10) but not the thymus (3.4-fold with placebo versus 1.1-fold with IL-7, P = .18). Side effects of IL-7 included thrombocytopenia and possibly neutropenia and hemolytic anemia. One IL-7–treated animal failed to thrive due to a disease resembling graft-versus-host disease. No animals developed lymphoma. Bone density was not decreased. In conclusion, IL-7 raises CD4 T-cell counts in irradiated primates. It remains to be determined whether this is associated with clinical benefit.
Gene expression profiling reveals a highly specialized genetic program of plasma cells
Authors: Underhill Gregory H. , George David , Bremer Eric G. , Kansas Geoffrey S. 
Published: May 2003

AbstractThe formation of terminally differentiated plasma cells represents the critical final step in B-cell differentiation. In this study, utilizing oligonucleotide microarray analysis, we describe the highly specialized genetic profile exhibited by terminally differentiated plasma cells. A total of 1476 known genes were differentially expressed by plasma cells compared with B cells. Plasma cells displayed an up-regulation, induction, or a selective retention of a unique constellation of transcription factors, including members of the AP-1, nuclear factor–κB (NF-κB), nuclear factor of activated T cells (NFAT), and octamer binding factor families. Interestingly, plasma cells also displayed a down-regulation of several RNA polymerase I– related factors, consistent with terminal differentiation, and exhibited a down-regulation of the TATA box binding protein. Furthermore, plasma cells displayed alterations in multiple components of the Wnt and Notch signaling pathways and showed a unique pattern of apoptosis and proliferation-associated genes. Unexpectedly, plasma cells displayed an up-regulation of 2 factors normally associated with microenvironmental positioning of neuronal cells, reelin and neuropilin-1. These results supply insight into the developmental genetics of plasma cell differentiation and provide a foundation for further analysis of plasma cell biology.
Immunoglobulin light chain variable (V) region genes influence clinical presentation and outcome in light chain–associated amyloidosis (AL)
Authors: Abraham Roshini S. , Geyer Susan M. , Price-Troska Tammy L. , Allmer Cristine , Kyle Robert A. , Gertz Morie A. , Fonseca Rafael 
Published: May 2003

AbstractLight chain–associated amyloidosis (AL) is a plasma cell dyscrasia in which the secreted monoclonal immunoglobulin (Ig) light chains form amyloid fibrils. There is considerable heterogeneity in clinical presentation, and prognosis of the disease relates to the severity of organ dysfunction induced by amyloid deposits. The mechanisms by which the amyloid fibrils are deposited as well as the predilection for specific organ sites have not been clearly elucidated. This study characterizes the repertoire of immunoglobulin light chain variable genes used by the clonal B cell in AL amyloid patients, and the association of light chain variable region (VL) genes with clinical presentation and outcome is assessed in 58 (32 λ and 26 κ) patients. A preferential use of VL germ-line genes was noted for both AL κ and λ patients. There was a significant correlation between the use of the Vλ VI germ-line donor, 6a, and renal involvement as well as the Vλ III gene, 3r, with soft-tissue AL. The use of a biased VL gene repertoire also correlated with clinical outcome, revealing important trends for predicting prognosis. The use of Vλ II germ-line genes was associated with cardiac amyloidosis and affected survival adversely. The presence of multiple myeloma also correlated with a poor prognosis. The presence of renal disease, on the other hand, was associated with improved survival. Therefore, identification of the clonal VL gene in AL has important implications in determining clinical outcome.
Utility of FDG-PET scanning in lymphoma by WHO classification
Authors: Elstrom Rebecca , Guan Liang , Baker Gary , Nakhoda Khozaim , Vergilio Jo-Anne , Zhuang Hongming , Pitsilos Stephanie , Bagg Adam , Downs Lisa , Mehrotra Amit , Kim Scott , Alavi Abass , Schuster Stephen J. 
Published: May 2003

Abstract
We retrospectively evaluated 18fluoro-2-deoxyglucose positron emission tomography (FDG-PET) scans in 172 patients with lymphoma and correlated results with pathologic diagnosis using the World Health Organization (WHO) classification system. In total, FDG-PET detected disease in at least one site in 161 patients (94%) and failed to detect disease in 11 patients (6%). The most frequent lymphoma diagnoses were diffuse large B-cell lymphoma (LBCL; n = 51), Hodgkin lymphoma (HL; n = 47), follicular lymphoma (FL; n = 42), marginal zone lymphoma (MZL; n = 12), mantle cell lymphoma (MCL; n = 7), and peripheral T-cell lymphoma (PTCL; n = 5). FDG-PET detected disease in 100% of patients with LBCL and MCL and in 98% of patients with HL and FL. In contrast, FDG-PET detected disease in only 67% of MZL and 40% of PTCL. Comparison with bone marrow biopsies showed that FDG-PET was not reliable for detection of bone marrow involvement in any lymphoma subtype.
Prognostic significance of cytogenetic clonal evolution in patients with chronic myelogenous leukemia on imatinib mesylate therapy
Authors: Cortes Jorge E. , Talpaz Moshe , Giles Francis , O'Brien Susan , Rios Mary Beth , Shan Jianqin , Garcia-Manero Guillermo , Faderl Stefan , Thomas Deborah A. , Wierda William , Ferrajoli Allessandra , Jeha Sima , Kantarjian Hagop M. 
Published: May 2003

Abstract
Cytogenetic clonal evolution (CE) is a known poor prognostic factor in Philadelphia chromosome–positive chronic myelogenous leukemia (Ph-positive CML). However, its prognostic relevance in the era of imatinib therapy is unknown. We investigated the independent prognostic relevance of CE in 498 patients with Ph-positive CML treated with imatinib for chronic or accelerated phases. One hundred twenty-one patients had CE alone (n = 70) or with other accelerated phase criteria (n = 51). Patients were compared in 4 categories: chronic phase (n = 295), CE only (n = 70), accelerated phase without CE (n = 82), and accelerated phase with CE (n = 51). Statistical methods used established methodologies for univariate and multivariate analyses. In chronic and accelerated phases of CML, CE was not associated with significant differences in major or complete cytogenetic response rates, but it was an independent poor prognostic factor for survival by multivariate analyses in both chronic (P = .005) and accelerated phase (P = .03). Multivariate analyses conducted at the 3-month landmark (including the 3-month cytogenetic response) identified the lack of cytogenetic response at 3 months to be a stronger independent poor prognostic factor for survival than CE for both chronic (major cytogenetic response versus other) and accelerated phase (any cytogenetic response versus other). We conclude that cytogenetic CE is not an important factor for achieving major or complete cytogenetic response with imatinib mesylate therapy, but it is an independent poor prognostic factor for survival in both chronic and accelerated phases of CML. The 3-month cytogenetic response to imatinib mesylate refined the prognostic relevance of such studies in patients on imatinib mesylate therapy.
Patterns of somatic mutations in VH genes reveal pathways of clonal transformation from MGUS to multiple myeloma
Authors: Zojer Niklas , Ludwig Heinz , Fiegl Michael , Stevenson Freda K. , Sahota Surinder S. 
Published: May 2003

AbstractMonoclonal gammopathy of undetermined significance (MGUS) can transform to multiple myeloma (MM). In myeloma, mutated VHgenes with sequence homogeneity reveal a postfollicular origin. Previously, some MGUS cases showed mutated VH genes with intraclonal variation, indicating an earlier stage of arrest. We investigated progression from 2 of 2 MGUS to MM, in which VH genes confirmed clonal evolution. In one MGUS case, intraclonal heterogeneity was evident, and transformation to myeloma occurred rapidly with apparent homogeneity in the emergent clone. However, residual MGUS-derived sequences were detectable at this time. Heterogeneity in MGUS does not associate with benign disease, but it indicates an origin from a tumorigenic cell, most likely surface immunoglobulin+, undergoing somatic mutation. The remaining case displayed intraclonal homogeneity at the MGUS stage, conceivably resulting from a self-cloning outgrowth from MGUS with heterogeneity. Transformation can occur at either MGUS stage, but it involves a single cell in which somatic mutation is then silent.
ICAM-directed vascular immunotargeting of antithrombotic agents to the endothelial luminal surface
Authors: Murciano Juan-Carlos , Muro Silvia , Koniaris Lauren , Christofidou-Solomidou Melpo , Harshaw David W. , Albelda Steven M. , Granger D. Neil , Cines Douglas B. , Muzykantov Vladimir R. 
Published: May 2003

AbstractDrug targeting to a highly expressed, noninternalizable determinant up-regulated on the perturbed endothelium may help to manage inflammation and thrombosis. We tested whether inter-cellular adhesion molecule-1 (ICAM-1) targeting is suitable to deliver antithrombotic drugs to the pulmonary vascular lumen. ICAM-1 antibodies bind to the surface of endothelial cells in culture, in perfused lungs, and in vivo. Proinflammatory cytokines enhance anti-ICAM binding to the endothelium without inducing internalization. 125I-labeled anti-ICAM and a reporter enzyme (β-Gal) conjugated to anti-ICAM bind to endothelium and accumulate in the lungs after intravenous administration in rats and mice. Anti-ICAM is seen to localize predominantly on the luminal surface of the pulmonary endothelium by electron microscopy. We studied the pharmacological effect of ICAM-directed targeting of tissue-type plasminogen activator (tPA). Anti-ICAM/tPA, but not control IgG/tPA, conjugate accumulates in the rat lungs, where it exerts plasminogen activator activity and dissolves fibrin microemboli. Therefore, ICAM may serve as a target for drug delivery to endothelium, for example, for pulmonary thromboprophylaxis. Enhanced drug delivery to sites of inflammation and the potential anti-inflammatory effect of blocking ICAM-1 may enhance the benefit of this targeting strategy.
Efficacy and safety of rituximab in type II mixed cryoglobulinemia
Authors: Zaja Francesco , De Vita Salvatore , Mazzaro Cesare , Sacco Stefania , Damiani Daniela , De Marchi Ginevra , Michelutti Angela , Baccarani Michele , Fanin Renato , Ferraccioli Gianfranco 
Published: May 2003

Abstract
The best treatment of type II mixed cryoglobulinemia (MC) has still to be defined. Antiviral treatment for the frequent underlying infectious trigger hepatitis C virus (HCV) may be ineffective, contraindicated, or not tolerated in a fraction of cases, whereas current immunosuppressive treatments may lead to relevant complications. Selective B-cell blockade with rituximab was used in this study, based on favorable results in preliminary experience. Fifteen consecutive patients with type II MC (HCV-related in 12 of 15) were treated with rituximab, 375 mg/m2 intravenously weekly for 4 weeks. Only medium- to low-dose steroids were allowed, if already administered at the time of recruitment. All patients had active disease, poorly controlled or difficult to manage with previous treatments, including corticosteroids in all. Efficacy and safety of rituximab therapy were evaluated in the following 6 months. The overall follow-up after rituximab treatment ranged from 9 to 31 months. Rituximab proved effective on skin vasculitis manifestations (ulcers, purpura, or urticaria), subjective symptoms of peripheral neuropathy, low-grade B-cell lymphoma, arthralgias, and fever. Nephritis of recent onset went into remission in one case. Laboratory features, that is, significantly decreased serum rheumatoid factor and cryoglobulins and increased C4, were consistent with the clinical efficacy. Treatment was well tolerated, with no infectious complications. Thrombosis of retinal artery or self-limiting panniculitis occurred in one patient each. Rituximab may represent a safe and effective alternative to standard immunosuppression in type II MC. Controlled studies are needed to better define drug indications and the cost-efficacy profile in the different systemic manifestations.