bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical and structural studies on soluble and conducting polymer from o‐phenylenediamine
Authors: Yano Jun
Published: April 2003

A conducting polymer, poly(o‐phenylenediamine) (PoPD), has been obtained as stable film onto an electrode surface by the electropolymerization of o‐phenylenediamine in 0.1 mol dm−3 H2SO4. The film thickness did not exceed 0.85 μm because of its low electrical con‐ductivity. The virgin “doped” polymer film was soluble in dimethylsulfoxide N, N‐dimeth‐ylformamide, acetone, and tetrahydrofuran without any pretreatment. The highest solubility obtained was 17 g dm−3 in dimethylsufoxide. A cast film of PoPD on a substrate was prepared from its dimethylsulfoxide solution. The mean molecular weight of PoPD was found to be 11,000 with the gel permeation chromatography. The STM observation exhibited that the cast film was considerably uniform compared to the electrodeposited film. The cyclic voltammogram of such film showed a reversible redox property accompanied with excellent electrochromism between transparent yellow and brown. It was suggested from the 1H‐FTNMR and FTIR spectra and the elemental analysis that the polymeric backbone has 1, 4‐substituted benezenoid‐quinoid structure. © 1995 John Wiley & Sons, Inc.
The synthesis and study of the photoinitiated cationic polymerization of novel cycloaliphatic epoxides
Authors: Crivello James V. , Varlemann Ulrike
Published: April 2003

The synthesis of a series of difunctional epoxides bearing two epoxycyclohexyl groups linked together by an alkylene ether group has been carried out. Subsequently, the reactivities of these novel monomers was investigated and compared to the reactivity of the cycloali‐phatic epoxide, 3,4‐epoxycyclohexylmethyl 3′,4′‐epoxycyclohexane carboxylate (I) in pho‐toinitiated cationic polymerization. It was observed that alkylene oxide linking the two epoxycyclohexyl groups was short and the monomers are more reactive than I. The effects of the photoinitiator structure and the experimental conditions of the cationic photopo‐lymerization on the rates was also studied using real‐time infrared spectroscopy. © 1995 John Wiley & Sons, Inc.
Fundamental studies of grafting reactions in free radical copolymerization. II. Grafting of styrene, acrylate, and methacrylate monomers onto cis‐polybutadiene using AIBN initiator in solution polymerization
Authors: Huang Nai‐Jen , Sundberg Donald C.
Published: April 2003

Grafting can be initiated by primary and/ or polymer radical attack on the backbone polymer and it is well known that AIBN does not readily promote grafting, even when using poly‐butadiene. We have studied the grafting of several different monomers onto cis‐polybuta‐diene using AIBN initiator and find dramatically different results among the monomers. As expected, styrene grafts at very low levels due to the inactivity of the initiator radicals and the polystyryl radicals. Methacrylate monomer grafts at a slightly higher level due to its more reactive polymer radical, while acrylate monomer readily grafts onto the poly‐butadiene because polyacrylate radicals are quite reactive. The use of a kinetic model allowed the evaluation of rate coefficients for graft site initiation to be in the relative order of 0.1 : 1.0 : 10.0 (L/mol/s) for styrene:methacrylate:acrylate monomers. The model also pro‐vided successful interpretations of the grafting data and its dependence upon the concen‐trations of monomer, initiator, and backbone polymer. Due to the relatively higher reactivity of the polyacrylate radicals, the benzene solvent acted as a chain transfer agent in this system. This affected the molecular weight of both free and grafted acrylate polymer and also surpressed the graft level. Polyacrylate radicals attack the cis‐polybutadiene backbone by abstracting an allylic hydrogen and also adding across the residual double bond. The latter mechanism is responsible for the majority of the grafting; the hydrogen abstraction leads to relatively inactive radicals which cause a retardation in the overall reaction rate. © 1995 John Wiley & Sons, Inc.
Fundamental studies of grafting reactions in free radical copolymerization. IV. Grafting of styrene, acrylate, and methacrylate monomers onto vinyl‐polybutadiene using benzoyl peroxide and AIBN initiators in solution polymerization.
Authors: Huang Nai‐Jen , Sundberg Donald C.
Published: April 2003

Vinyl‐1,2 polybutadiene (vinyl‐PBD) was used as the backbone polymer for the grafting of styrene, methacrylate, and acrylate monomers using both benzoyl peroxide and AIBN initiators. Radical attack on the backbone can occur through the pendant vinyl group or at the tertiary, allylic hydrogen site. Effective graft sites are formed via double bond addition of either primary (initiator) or polymer radicals. The production of tertiary allylic radicals on the backbone chain also occurs and results in moderate to dramatic reaction rate re‐tardation in every monomer system. The type of initiator is only important when the polymer radicals are not very reactive, as in the case of styrene, and to a lesser extent for methacrylate monomer. Graft efficiencies are generally higher when using vinyl‐PBD than when using cis‐PBD. © 1995 John Wiley & Sons, Inc.
Synthesis of a novel naphthalene‐based poly(arylene ether‐ketone) by polycondensation of 1,5‐bis(4‐fluorobenzoyl)‐2,6‐dimethylnaphthalene with bisphenol a
Authors: Ohno Mami , Takata Toshikazu , Endo Takeshi
Published: April 2003

Synthesis of 1,5‐bis(4‐fluorobenzoyl)‐2,6‐dimethylnaphthalene (1), polycondensation of 1 with Bisphenol A, and properties of the obtained polymer were studied. Friedel–Crafts acylation of 2,6‐dimethylnaphthalene with 4‐fluorobenzoyl chloride in nitrobenzene selectivity afforded 1 in 82% yield. X‐ray single crystal structural analysis of 1 confirmed that the dibenzoylation proceeded regioselectively and two methyl groups sterically inhibited the coplanarity of the two aromatic planes. The polycondensation of 1 with Bisphenol A in toluene/N‐methyl‐2‐pyrrolidone (NMP) mixed solvent in the presence of excess potassium carbonate as a condensation reagent was carried out at 180°C for 4 h to quantitatively afford the corresponding poly(arylene ether‐ketone) (PEK) 3 with high molecular weight (M̄n∼30,000) as a slightly yellow powder. As the reaction time was prolonged, both M̄n and MWD of 3 increased and the solubility of 3 in chloroform clearly decreased. By GPC‐LALLS, M̄n of 3 obtained by the polycondensation for 16 h, was 85,000. The PEK 3 with high molecular weight was produced in a quantitative yield in a variety of solvents such as sulfolane. Water formed during the polycondensation hardly affected the yield and molecular weight of 3, although a small molecular weight decrease took place. To evaluate the special effect of the methyl groups of 3, polycondensation of 2,6‐bis(4‐fluorobenzoyl)naphthalene 2 with bisphenol A was carried out for comparison and the corresponding PEK 4 was quantitatively obtained. Whereas 3 was soluble in ordinary organic solvents such as tet‐rahydrofuran (THF), chloroform, and NMP at room temperature, 4 was insoluble in most solvents except for strong acids such as conc. sulfonic acid. The polymer 3 showed high glass transition temperature (238°C) and 5% weight loss temperature (457°C). Casting of the polymer from THF solution gave a transparent, tough, flexible, and amorphous film. © 1995 John Wiley & Sons, Inc.
Cyclopolymerization. XXI. Radical cyclopolymerization of n,n‐diallylmethacrylamide
Authors: Kodaira Toshiyuki , Liu Quing‐Quing , Urushisaki Michio
Published: April 2003

N,N‐Diallylmethacrylamide (DAMA) was synthesized and its radical cyclopolymerizability was investigated. Polymerizations of DAMA were found to proceed according to the standard kinetic equation for radical polymerization except for the diffusion controlled termination reactions owing to higher viscosity of DAMA, in spite of the fact that it contains two allyl groups. DAMA yields polymers with slightly higher degree of cyclization than 50% in dilute solution polymerization. With increasing monomer concentration, the degree of cyclization decreases gradually and it becomes slightly lower value than 50% in concentrated solution polymerizations. It was found that about 86% of pendant unsaturations is allyl group and the rest is methacryloyl group. Structural studies on repeating units showed that possibility for the presence of bicyclic structures (those formed with consumption of three double bonds involved in DAMA) and structural units with two pendant unsaturations (those formed with one double bond in DAMA participated in polymerization) is extremely small. Main repeating cyclic unit was assigned to five‐membered monocyclic lactam with an allyl group on its nitrogen, the content of which is estimated to be approximately 86% based on the allyl content. The main fraction of the rest of repeating cyclic structures was attributed to monocyclic pirolidine ring with a methacryloyl group on its nitrogen. These structural investigations and ESR studies of DAMA revealed that the methacryloyl group of DAMA is less reactive than its allyl group as in the case of N‐methyl‐N‐allylmethacrylamide which has already been reported. © 1995 John Wiley & Sons, Inc.
Diene‐functional macromonomers by a single‐step free radical addition–fragmentation reaction. Syntheses and kinetics
Authors: Reghunadhan Nair C. P. , Chaumont P. , Charmot D.
Published: April 2003

A new chain transfer agent, 5‐tert‐butylthio‐1,3‐pentadiene (TBPD or 7, 7‐dimethyl‐6‐thia‐1,3‐octadiene) was used in the free radical polymerization of methyl methacrylate and styrene to produce conjugated diene‐end capped macromonomers by a free radical addition–fragmentation mechanism. The chain transfer was found to be degradative. A new kinetic model was proposed to describe the retarded polymerization. The kinetic parameters per‐taining to transfer, reinitiation, primary radical termination, and mutual termination of the primary radicals were evaluated at different temperatures permitting precise theoretical prediction of the functionalities. The chain transfer constants, calculated using a modified Mayo's equation revealed better transfer properties for MMA. The macromonomers were synthesized by high conversion polymerization. Characterizations of the macromonomers revealed that copolymerization predominated over the fragmentation following 1,4‐addition, although the former reaction is not detrimental for the chain‐end functionalization. © 1995 John Wiley & Sons, Inc.
Heterogeneity of molecular targets on clonal cancer lines derived from a novel hormone‐refractory prostate cancer tumor system
Authors: Freedland Stephen J. , Pantuck Allan J. , Paik Sun H. , Zisman Amnon , Graeber Thomas G. , Eisenberg David , McBride William H. , Nguyen David , Tso Cho‐Lea , Belldegrun Arie S.
Published: April 2003

OBJECTIVE

We recently described a new hormone refractory prostate cancer cell line, CL1, derived from LNCaP via in vitro androgen deprivation. To study gene expression during prostate cancer progression and to identify molecular targets for therapy, a pure clonal tumor system was generated.

METHODS

Limiting dilution of CL1 stably transfected with a green fluorescent protein, generated 35 single‐cell clones, which were expanded into stable cell lines. In vitro responses to various therapeutic modalities were assessed in each clone. Gene expression was determined using reverse transcriptase‐polymerase chain reaction and oligonucleotide microarrays. In vivo biology was assessed following orthotopic injection into intact and castrated severe combined immunodeficient mice.

RESULTS

In vitro, all clones demonstrated similar resistance to traditional therapeutic efforts including chemotherapy and radiation therapy, but differential sensitivity to cell‐mediated cytotoxicity. The clones demonstrated differential gene expression relative to each other and to the parental CL1 and LNCaP cell lines. Following orthotopic injection into mice, three distinct growth patterns were observed: fast growth with widespread metastasis; slower grower with widespread metastasis; and no tumor formation. Using oligonucleotide microarrays, several genes were identified as differentially expressed between the most aggressive and the nontumorigenic clone.

CONCLUSIONS

We have described a novel fluorescent‐labeled clonal hormone refractory prostate cancer tumor system that exhibited marked heterogeneity in its response to various therapeutic modalities, gene expression, and in vivo biology. Our data suggests that given the marked clonal heterogeneity, multi‐modality approaches directed against multiple molecular targets rather than single agent therapy will be necessary to adequately eradicate the entire malignant cell population. Clonal tumor lines may allow more accurate examination of molecular pathways involved in tumor progression and resistance to treatment. Prostate 55: 299–307, 2003. © 2003 Wiley‐Liss, Inc.
Dendritic cells transfected with interleukin‐12 and pulsed with tumor extract inhibit growth of murine prostatic carcinoma in vivo
Authors: Zhang Shaobo , Zeng Guangyuan , Wilkes David S. , Reed Gerry E. , McGarry Ronald C. , Eble John N. , Cheng Liang
Published: April 2003

BACKGROUND

The induction of anti‐tumor immune response by injection of dendritic cells loaded with specific antigen or transduced with genes encoding tumor‐specific antigens have been studied in animal models and have shown promising anti‐tumor effects. The impact of different routes of administration of dendritic cells on their anti‐tumor effects is uncertain.

METHODS

We examined the effect of injection of cloned dendritic cells, which were stably transfected with IL‐12 and exposed to an extract of murine RM‐9 prostate carcinoma cell antigens on tumor growth in vivo. The cloned dendritic cells were injected intramuscularly, subcutaneously, or intraperitoneally into C57BL/6 mice. Seven days later, the mice were inoculated subcutaneously with 100,000 RM‐9 cells. The sizes of the resulting tumors were measured every 3 days.

RESULTS

Compared with the wild type dendritic cells, the IL‐12‐transfected dendritic cells delayed tumor engraftment by 7 days (P = 0.04), and reduced tumor growth by up to 80% (P = 0.02). Among the three routes of injection, intramuscular injection was most effective. In contrast to wild type dendritic cells, IL‐12‐transfected dendritic cells induced infiltration of mononuclear cells into the tumors, and induced apoptosis and necrosis of tumor cells. Injection of IL‐12‐transfected dendritic cells also significantly delays tumor growth in the preexisting RM‐9 tumors.

CONCLUSIONS

We conclude that antigen‐exposed, IL‐12‐transfected dendritic cells have potential as an immunotherapy for prostate carcinoma. Routes of administration of dendritic cells are critical for maximal anti‐tumor effect. Prostate 55: 292–298, 2003. © 2003 Wiley‐Liss, Inc.
Nuclear matrix proteins changes in cancerous prostate tissues and their prognostic value in clinically localized prostate cancer
Authors: Boccardo Francesco , Rubagotti Alessandra , Carmignani Giorgio , Romagnoli Andrea , Nicolò Guido , Barboro Paola , Parodi Silvio , Patrone Eligio , Balbi Cecilia
Published: April 2003

BACKGROUND

After the discovery that nuclear matrix (NM) directs the spatial organization of DNA transcription and replication, there has been an increasing interest in studying NM changes associated with malignant transformation and their potential usefulness in the clinical setting.

METHODS

High‐resolution two‐dimensional gel electrophoresis was used to analyze the NM proteins (NMP) of specimens of prostate cancer tissue obtained from the prostates of 75 patients undergoing retropubic prostatectomy.

RESULTS

Nine NMP with different molecular weights and isoelectric points have been identified. They were expressed differently by prostate cancer tissues. An increasing trend toward the expression of such proteins like NMP 6–8 was evident with increasing tumor stage and dedifferentiation. NMP 6–8 were also significantly correlated with the risk of biochemical progression. However, Gleason score was the only significant discriminant in this regard in multiparametric models.

CONCLUSIONS

This study confirms that prostate cancer progression is related to profound changes in NMP expression patterns. However, due to the complexity of the methods required to define these latter, the clinical relevance of NMP appears to be still limited. Prostate 55: 259–264, 2003. © 2003 Wiley‐Liss, Inc.
Complementary Role of CD4+ T Cells and Secondary Lymphoid Tissues for Cross-presentation of Tumor Antigen to CD8+ T Cells
Authors: Yu Ping , Spiotto Michael T. , Lee Youjin , Schreiber Hans , Fu Yang-Xin
Published: April 2003

MHC class I–restricted tumor antigens can be presented to CD8+ T cells by two distinct pathways: via direct and indirect presentation. The relative contribution of these two pathways toward the initial activation of tumor antigen–specific CD8+ T cells and their subsequent tumor rejection is still vigorously debated. Using a tumor model able to dissect the relative contributions of direct and indirect presentation, we show unequivocally the inefficiency of direct presentation and the essential requirement of indirect presentation for the priming of naive tumor antigen–specific T cells leading to tumor rejection. Moreover, we characterize the essential environment under which indirect presentation occurs, and find efficient cross-priming of tumor-specific CD8+ T cells in the complete absence of secondary lymphoid tissues. The independence of this process from local lymph nodes is compromised, however, in the absence of CD4+ T cell help. Therefore, our paper demonstrates that effective immune protection against tumors requires the cross-priming of CD8+ T cells under conditions that require either CD4+ T cell help, or draining lymph nodes.
Improved Bell-in-a-Bell-Jar Demonstration
Authors: Han Dejun
Published: April 2003

It is well understood in acoustics that a medium is required to conduct sound. Stated in another way, sound is not transmitted through a vacuum. The earliest person to test this experimentally was the Irish physicist Robert Boyle (1627–1691).1 In his experiment, he put a ringing bell under a glass cover called a bell jar. After the air was pumped out, the ringing disappeared. This convinced him that sound cannot be conducted in vacuum. Here we describe an improved version of this demonstration.
BEREZIN QUANTIZATION OF THE SCHRÖDINGER ALGEBRA
Authors: FEINSILVER PHILIP , KOCIK JERZY , SCHOTT RENÉ
Published: April 2003

We examine the Schrödinger algebra in the framework of Berezin quantization. First, the Heisenberg–Weyl and sl(2) algebras are studied. Then the Berezin representation of the Schrödinger algebra is computed. In fact, the sl(2) piece of the Schrödinger algebra can be decoupled from the Heisenberg component. This is accomplished using a special realization of the sl(2) component that is built from the Heisenberg piece as the quadratic elements in the Heisenberg–Weyl enveloping algebra. The structure of the Schrödinger algebra is revealed in a lucid way by the form of the Berezin representation.
ON THE SOLVABILITY OF HAMILTON'S EQUATIONS IN HILBERT SPACES
Authors: SHKARIN S. A.
Published: April 2003

We construct a bounded function H : l2 × l2 → ℝ with continuous Fréchet derivative such that for any q0 ∈ l2 the Cauchy problem [Formula: see text] has no solutions in any neighborhood of zero in ℝ.
Lower Incidence of Thrombus Formation With Cryoenergy Versus Radiofrequency Catheter Ablation
Authors: Khairy Paul , Chauvet Patrick , Lehmann John , Lambert Jean , Macle Laurent , Tanguay Jean-François , Sirois Martin G. , Santoianni Domenic , Dubuc Marc
Published: April 2003

Background—

Radiofrequency (RF) catheter ablation is limited by thromboembolic complications. The objective of this study was to compare the incidence and characteristics of thrombi complicating RF and cryoenergy ablation, a novel technology for the catheter-based treatment of arrhythmias.

Methods and Results—

Ablation lesions (n=197) were performed in 22 mongrel dogs at right atrial, right ventricular, and left ventricular sites preselected by a randomized factorial design devised to compare RF ablation with cryocatheter configurations of varying sizes (7F and 9F), cooling rates (−1°C/s, −5°C/s, and −20°C/s) and target temperatures (−55°C and −75°C). Animals were pretreated with acetylsalicylic acid and received intraprocedural intravenous unfractionated heparin. Seven days after ablation, the incidence of thrombus formation was significantly higher with RF than with cryoablation (75.8% versus 30.1%,
P
=0.0005). In a multiple regression model, RF energy remained an independent predictor of thrombus formation compared with cryoenergy (OR, 5.6; 95% CI, 1.7, 18.1;
P
=0.0042). Thrombus volume was also significantly greater with RF than with cryoablation (median, 2.8 versus 0.0 mm
3
;
P
<0.0001). More voluminous thrombi were associated with larger RF lesions, but cryolesion dimensions were not predictive of thrombus size.

Conclusions—

RF energy is significantly more thrombogenic than cryoenergy, with a higher incidence of thrombus formation and larger thrombus volumes. The extent of hyperthermic tissue injury is positively correlated with thrombus bulk, whereas cryoenergy lesion size does not predict thrombus volume, most likely reflecting intact tissue ultrastructure with endothelial cell preservation.
Early Detection of Fabry Cardiomyopathy by Tissue Doppler Imaging
Authors: Pieroni Maurizio , Chimenti Cristina , Ricci Roberta , Sale Patrizio , Russo Matteo Antonio , Frustaci Andrea
Published: April 2003

Background—

Fabry cardiomyopathy is diagnosed by detection of left ventricular hypertrophy (LVH) in patients with α-Galactosidase A deficiency. Conventional noninvasive tools are unable to provide a preclinical diagnosis allowing prompt institution of enzymatic therapy.

Methods and Results—

We studied three groups of patients: 10 patients with causal mutations for Fabry disease and LVH, 10 mutation-positive patients without LV, and 10 healthy relatives without causal mutations and no LVH. All patients with LVH and 6 patients with Fabry disease without LVH with complex repetitive ventricular arrhythmias underwent biventricular endomyocardial biopsy to assess cardiac involvement. In all patients 2-dimensional echocardiography with tissue Doppler analysis in the pulsed Doppler mode was performed: systolic (Sa), early diastolic (Ea), and late diastolic (Aa) velocities were measured, and the Ea/Aa ratio and the dimensionless parameter E/Ea were computed at both corners of the mitral annulus. Histology and electron microscopy studies showed glycosphingolipid deposits in all cases. All mutation-positive patients had significant reduction of Sa, Ea, and Aa velocities at both corners of the mitral annulus compared with normal control subjects. Ea/Aa ratio was significantly lower and E/Ea ratio significantly higher in mutation-positive patients than in control subjects. Patients with LVH showed significantly lower contraction and relaxation tissue Doppler velocities, lower Ea/Aa ratio, and higher E/Ea ratio in comparison with mutation-positive patients with no LVH.

Conclusions—

Fabry cardiomyopathy is characterized by reduced myocardial contraction and relaxation tissue Doppler velocities, detectable even before development of LVH. Tissue Doppler imaging can provide a preclinical diagnosis of Fabry cardiomyopathy, allowing early institution of enzyme replacement therapy.
Absence of Association Between Infectious Agents and Endothelial Function in Healthy Young Men
Authors: Khairy Paul , Rinfret Stéphane , Tardif Jean-Claude , Marchand Richard , Shapiro Stan , Brophy James , Dupuis Jocelyn
Published: April 2003

Background—

Although several studies have reported correlations between infections and coronary artery disease, associations with endothelial dysfunction, its precursor, have not been established. This study assessed whether infection with
Chlamydia pneumoniae
(CP), cytomegalovirus (CMV), Epstein-Barr virus (EBV), or
Helicobacter pylori
(HP) is associated with decreased endothelial function.

Methods and Results—

Sixty-five male subjects, aged 20 to 45 years, with no risk factors or known coronary artery disease were enrolled in a seroepidemiological cross-sectional study. Endothelial function was determined by flow-mediated brachial vasodilation. Serum antibodies consisting of anti-CP IgG and IgM, anti-CMV IgG, anti-EBV nuclear antigen, and anti-HP IgG and markers of inflammation including high-sensitivity C-reactive protein were measured. Average age was 29.3±5.5 years. Seroprevalence values were 65.1%, 34.9%, 88.9%, and 14.3% for CP, CMV, EBV, and HP, respectively. Average values for endothelium-dependent and -independent vasodilation were 9.4±4.5% and 12.6±5.0%. Despite adequate statistical power (82% for the primary end point), no association between endothelial function and seropositivity to individual infectious agents, infectious burden, or C-reactive protein was observed in regression analyses controlling for variables including age, blood pressure, and lipid parameters. Moreover, no dose-response trends between serum titers and endothelial function were found.

Conclusions—

Lack of association between chronic infection with CP, CMV, EBV, HP, or pathogen burden and endothelial function was observed, suggesting that these agents are not implicated as early etiologic triggers in the genesis of coronary artery disease. These results do not preclude active involvement at later stages of the pathophysiological process, such as acceleration of existing atherosclerosis and acute plaque rupture.
Enhanced Ventilatory Response to Exercise in Patients With Chronic Heart Failure and Central Sleep Apnea
Authors: Arzt Michael , Harth Martina , Luchner Andreas , Muders Frank , Holmer Stephan R. , Blumberg Friedrich C. , Riegger Günter A.J. , Pfeifer Michael
Published: April 2003

Background—

In patients with chronic heart failure (CHF), central sleep apnea (CSA) and enhanced ventilatory response (V̇
e
/V̇
co
2
slope) to exercise are common. Both breathing disorders alone indicate poor prognosis in CHF. Although augmented chemosensitivity to
co
2
is thought to be one important underlying mechanism for both breathing disorders, it is unclear whether both breathing disorders are related closely in patients with CHF.

Methods and Results—

We investigated 20 CHF patients with clinically important CSA (apnea-hypopnea-index (AHI), number of episodes per hour ≥15) and 10 CHF patients without CSA. Patients with and without CSA did not differ with respect to exercise capacity (peak V̇
o
2
, 63.4±3.4% versus 60.8±4.4% of predicted value;
P
=0.746) and left ventricular ejection fraction (LVEF, 31±2% versus 31±3%;
P
=0.948). The AHI was not correlated with exercise capacity (peak V̇
o
2
, percent of predicted value;
P
=0.260) and LVEF (percent,
P
=0.886). In contrast, the positive correlation of the V̇
e
/V̇
co
2
slope, determined by cardiopulmonary exercise testing, with the AHI was highly significant (
P
<0.001). The V̇
e
/V̇
co
2
slope was significantly increased in patients with CSA compared with those without CSA (29.7 versus 24.9;
P
<0.001).

Conclusions—

The ventilatory response to exercise is significantly augmented in CHF patients with CSA compared with those without. In contrast to peak V̇
o
2
and LVEF, the V̇
e
/V̇
co
2
slope is strongly related to the severity of CSA in patients with CHF, which underscores an augmented chemosensitivity to
co
2
as a common underlying pathophysiological mechanism.
Interaction between von Willebrand factor and glycoprotein Ib activates Src kinase in human platelets: role of phosphoinositide 3–kinase
Authors: Wu Yi , Asazuma Naoki , Satoh Kaneo , Yatomi Yutaka , Takafuta Toshiro , Berndt Michael C. , Ozaki Yukio
Published: April 2003

The binding of von Willebrand factor (VWF) to glycoprotein (GP) Ib-IX-V stimulates transmembrane signaling events that lead to platelet adhesion and aggregation. Recent studies have implied that activation of Src family kinases is involved in GPIb-mediated platelet activation, although the related signal transduction pathway remains poorly defined. This study presents evidence for an important role of Src and GPIb association. In platelet lysates containing Complete, a broad-spectrum protease inhibitor mixture, Src and Lyn dynamically associated with GPIb on VWF-botrocetin stimulation. Cytochalasin D, which inhibits translocation of Src kinases to the cytoskeleton, further increased Src and GPIb association. Similar results were obtained with botrocetin and monomeric A1 domain, instead of intact VWF, with induction of both Src activation and association between GPIb and Src. These findings suggest that ligand binding of GPIb, without receptor clustering, is sufficient to activate Src. Immunoprecipitation studies demonstrated that Src, phosphoinositide 3– kinase (PI 3–kinase), and GPIb form a complex in GPIb-stimulated platelets. When the p85 subunit of PI 3–kinase was immunodepleted, association of Src with GPIb was abrogated. However, wortmannin, a specific PI 3–kinase inhibitor, failed to block complex formation between Src and GPIb. The Src-SH3 domain as a glutathione S-transferase (GST)–fusion protein coprecipitated the p85 subunit of PI 3–kinase and GPIb. These findings taken together suggest that the p85 subunit of PI 3–kinase mediates GPIb-related activation signals and activates Src independently of the enzymatic activity of PI 3– kinase.
A novel myeloid-like NK cell progenitor in human umbilical cord blood
Authors: Perez Sonia A. , Sotiropoulou Panagiota A. , Gkika Dimitra G. , Mahaira Louisa G. , Niarchos Dimitrios K. , Gritzapis Angelos D. , Kavalakis Yiannis G. , Antsaklis Aris I. , Baxevanis Constantin N. , Papamichail Michael
Published: April 2003

Natural killer (NK) cell differentiation from pluripotent CD34+ human hematopoietic stem cells or oligopotent lymphoid progenitors has already been reported. In the present study, long-term cultures of the CD56−/CD34−myeloid-like adherent cell fraction (ACF) from umbilical cord blood (UCB), characterized by the expression of CD14+ as well as other myeloid markers, were set up with flt3 ligand (FL) and interleukin-15 (IL-15). The UCB/ACF gradually expressed the CD56 marker, which reached fairly high levels (approximately 90% of the cells were CD56+) by day 15. FL plus IL-15–driven ACF/CD56+ cells progressively expressed a mature NK functional program lysing both NK- and lymphokine-activate killer (LAK)–sensitive tumor targets and producing high levels of interferon-γ (IFN-γ), granulocyte-macrophage colony-stimulating factor, tumor necrosis factor α, and IL-10 upon stimulation with IL-12 and IL-18. Similar results were obtained when highly purified CD14+ cells from UCB were cultured with FL and IL-15. In contrast, UCB/CD34+ cells cultured under the same conditions showed a delayed expression of CD56 and behaved functionally differently in that they exhibited NK but not LAK cytotoxicity and produced significantly fewer cytokines. Kinetic studies on the phenotype of UCB/ACF or UCB/CD14+ cells cultured in the presence of FL and IL-15 showed a rapid decrease in CD14 expression after day 5, which reached levels of zero by day 20. Approximately 60% of the CD56+ derived from the UCB/ACF or the UCB/CD14+ cells coexpressed CD14 by day 5. Taken together, our data support the role of CD14+ myeloid-like cells within UCB as a novel progenitor for lymphoid NK cells.
Dendritic cells from CML patients have altered actin organization, reduced antigen processing, and impaired migration
Authors: Dong Rong , Cwynarski Kate , Entwistle Alan , Marelli-Berg Federica , Dazzi Francesco , Simpson Elizabeth , Goldman John M. , Melo Junia V. , Lechler Robert I. , Bellantuono Ilaria , Ridley Anne , Lombardi Giovanna
Published: April 2003

Chronic myeloid leukemia (CML) is characterized by expression of the BCR-ABL fusion gene that encodes a 210-kDa protein, which is a constitutively active tyrosine kinase. At least 70% of the oncoprotein is localized to the cytoskeleton, and several of the most prominent tyrosine kinase substrates for p210BCR-ABLare cytoskeletal proteins. Dendritic cells (DCs) are bone marrow–derived antigen-presenting cells responsible for the initiation of immune responses. In CML patients, up to 98% of myeloid DCs generated from peripheral blood mononuclear cells areBCR-ABL positive. In this study we have compared the morphology and behavior of myeloid DCs derived from CML patients with control DCs from healthy individuals. We show that the actin cytoskeleton and shape of CML-DCs of myeloid origin adherent to fibronectin differ significantly from those of normal DCs. CML-DCs are also defective in processing and presentation of exogenous antigens such as tetanous toxoid. The antigen-processing defect may be a consequence of the reduced capacity of CML-DCs to capture antigen via macropinocytosis or via mannose receptors when compared with DCs generated from healthy individuals. Furthermore, chemokine-induced migration of CML-DCs in vitro was significantly reduced. These observations cannot be explained by a difference in the maturation status of CML and normal DCs, because phenotypic analysis by flow cytometry showed a similar surface expression of maturation makers. Taken together, these results suggest that the defects in antigen processing and migration we have observed in CML-DCs may be related to underlying cytoskeletal changes induced by the p210BCR-ABLfusion protein.
Experience with alemtuzumab plus rituximab in patients with relapsed and refractory lymphoid malignancies
Authors: Faderl Stefan , Thomas Deborah A. , O'Brien Susan , Garcia-Manero Guillermo , Kantarjian Hagop M. , Giles Francis J. , Koller Charles , Ferrajoli Alessandra , Verstovsek Srdan , Pro Barbara , Andreeff Michael , Beran Miloslav , Cortes Jorge , Wierda William , Tran Ngoc , Keating Michael J.
Published: April 2003

We explored the safety and efficacy of rituximab plus alemtuzumab in patients with relapsed or refractory lymphoid malignancies. Forty-eight patients were treated and were assessable for response (32 with chronic lymphocytic leukemia [CLL], 9 with CLL/prolymphocytic leukemia [PLL], 1 with PLL, 4 with mantle cell leukemia/lymphoma, 2 with Richter transformation). The overall response rate was 52% (complete remission, 8%; nodular partial response, 4%; partial response, 40%). With a median follow-up of 6.5 months (range, 1-20 months), the median time to progression was 6 months (range, 1-20 months); median survival, 11 months (11+ months for responders vs 6 months for nonresponders). Most toxicities were grade 2 or lower and infusion-related. Infections occurred in 52% of the patients. Cytomegalovirus (CMV) antigenemia assays were positive in 27% of the patients, but only 15% were symptomatic and required therapy. The combination of rituximab and alemtuzumab is feasible, has an acceptable safety profile, and has clinical activity with a short course in a group of patients with poor prognoses.
Human cord blood CD34+Pax-5+ B-cell progenitors: single-cell analyses of their gene expression profiles
Authors: Sanz Eva , Alvarez-Mon Melchor , Martı́nez-A Carlos , de la Hera Antonio
Published: April 2003

Circulating CD34+ cells are used in reparative medicine as a stem cell source, but they contain cells already committed to different lineages. Many think that B-cell progenitors (BCPs) are confined to bone marrow (BM) niches until they differentiate into B cells and that they do not circulate in blood. The prevailing convention is that BCP transit a CD34+CD19−10+early-B→CD34+CD19+CD10+B-cell progenitor (pro-B)→CD34−CD19+CD10+ B-cell precursor (pre-B) differentiation pathway within BM. However, populations of CD34+CD10+ and CD34+CD19+ cells circulate in adult peripheral blood and neonatal umbilical cord blood (CB) that are operationally taken as BCPs on the basis of their phenotypes, although they have not been submitted to a systematic characterization of their gene expression profiles. Here, conventional CD34+CD19+CD10+ and novel CD34+CD19+CD10− BCP populations are characterized in CB by single-cell sorting and multiplex analyses of gene expression patterns. Circulating BCP are Pax-5+cells that span the early-B, pro-B, and pre-B developmental stages, defined by the profiles of rearranged V-D-JH, CD79, VpreB, recombination activating gene (RAG), and terminal deoxynucleotidyl transferase (TdT) expression. Contrary to the expectation, circulating CD34+CD19−CD10+ cells are essentially devoid of Pax-5+ BCP. Interestingly, the novel CD34+CD19+CD10− BCP appears to be the normal counterpart of circulating preleukemic BCPs that undergo chromosomal translocations in utero months or years before their promotion into infant acute lymphoblastic B-cell leukemia after secondary postnatal mutations. The results underscore the power of single-cell analyses to characterize the gene expression profiles in a minor population of rare cells, which has broad implications in biomedicine.
Generation and genetic modification of dendritic cells derived from mouse embryonic stem cells
Authors: Senju Satoru , Hirata Shinya , Matsuyoshi Hidetake , Masuda Masako , Uemura Yasushi , Araki Kimi , Yamamura Ken-ichi , Nishimura Yasuharu
Published: April 2003

We developed a method to generate dendritic cells (DCs) from mouse embryonic stem (ES) cells. We cultured ES cells for 10 days on feeder cell layers of OP9, in the presence of granulocyte-macrophage colony-stimulating factor in the latter 5 days. The resultant ES cell–derived cells were transferred to bacteriologic Petri dishes without feeder cells and further cultured. In about 7 days, irregularly shaped floating cells with protrusions appeared and these expressed major histocompatibility complex class II, CD11c, CD80, and CD86, with the capacity to stimulate primary mixed lymphocyte reaction (MLR) and to process and present protein antigen to T cells. We designated them ES-DCs (ES cell–derived dendritic cells), and the functions of ES-DCs were comparable with those of DCs generated from bone marrow cells. Upon transfer to new dishes and stimulation with interleukin-4 plus tumor necrosis factor α, combined with anti-CD40 monoclonal antibody or lipopolysaccharide, ES-DCs completely became mature DCs, characterized by a typical morphology and higher capacity to stimulate MLR. Using an expression vector containing the internal ribosomal entry site–puromycinN-acetyltransferase gene or a Cre-lox–mediated exchangeable gene-trap system, we could efficiently generate ES cell transfectants expressing the products of introduced genes after their differentiation to DCs. ES-DCs expressing invariant chain fused to a pigeon cytochrome C epitope presented the epitope efficiently in the context of Ek. We primed ovalbumin (OVA)–specific cytotoxic T lymphocytes in vivo by injecting mice with ES-DCs expressing OVA, thus demonstrating immunization with ES-DCs genetically engineered to express antigenic protein. The methods may be applicable to immunomodulation therapy and gene-trap investigations of DCs.
Transactivation of the fucosyltransferase VII gene by human T-cell leukemia virus type 1 Tax through a variant cAMP-responsive element
Authors: Hiraiwa Nozomu , Yabuta Tomonori , Yoritomi Keijiro , Hiraiwa Miki , Tanaka Yuetsu , Suzuki Takeshi , Yoshida Mitsuaki , Kannagi Reiji
Published: April 2003

Human T-cell leukemic virus type 1 (HTLV-1)–infected T cells express the fucosyltransferase (Fuc-T) VIIgene involved in the biosynthesis of the leukocyte sialyl Lewis X, which may be related to tissue infiltration in patients with malignant adult T-cell leukemia. HTLV-1 induces Fuc-T VIItranscription through the viral transactivator Tax, although the underlying molecular mechanism remains unknown. In the present study, we analyzed the role of the cis-activating element in Tax activation using reporter constructs bearing the 5′-regulatory region of Fuc-T VII in Jurkat T cells. A sequence (GGCTGTGGGGGCGTCATATTGCCCTGG) covering a half-palindromic cyclic adenosine monophosphate (cAMP)–responsive element (CRE) was found to be required for Tax activation of the Fuc-T VII promoter. We further demonstrated that transcription factors of the CRE-binding protein (CREB)/activating transcription factor (ATF) family bind to this CRE-like sequence and that Tax binds in association with CREB and the coactivator CREB-binding protein (CBP) in Jurkat T cells. This element, containing the G+C–rich flanking sequences, is homologous to the Tax-responsive viral CREs in the HTLV-1 long terminal repeat (LTR)–promoter. Furthermore, CREMα, an isoform of CREB deficient in the glutamine-rich domains, was found to activate the Fuc-T VII promoter in a phosphorylation-independent manner, similar to the viral CRE in HTLV-1 LTR but in contrast to the phosphorylation-dependent activation of the cellular CREs by Tax. These findings indicate that the Fuc-T VII promoter is transactivated by Tax in concert with CBP through a CRE-like sequence in a manner similar to that of viral CRE in HTLV-1 LTR.
CD28 loss in senescent CD4+ T cells: reversal by interleukin-12 stimulation
Authors: Warrington Kenneth J. , Vallejo Abbe N. , Weyand Cornelia M. , Goronzy Jörg J.
Published: April 2003

CD28 is the quintessential costimulatory molecule expressed on CD4+ and CD8+ T cells. During chronic infections and the normal aging process, CD28 expression is lost, compromising the functional activity of T cells. CD28 loss is promoted by replicative stress, particularly in the presence of tumor necrosis factor–α, owing to an inoperative CD28 initiator element. It is currently unknown whether CD28 loss is irreversible. The present study examined cytokines for their ability to reinduce CD28 expression. CD4+CD28null T cells constitutively expressed interleukin-12 (IL-12) α and β receptors, which were functional and allowed for the up-regulation of the signal transducer and activator of transcription–4 (STAT-4)–dependent gene CD161. Costimulation of the T-cell and IL-12 receptors induced the transcription of CD28 in approximately 50% of CD4+CD28null T-cell clones and lines. IL-12 by itself did not restore CD28 expression. Up-regulation of CD28 after IL-12 exposure correlated with the reassembly of the CD28–initiator protein complex. The re-expressed CD28 was functional and restored the ability of CD4+CD28null T cells to express CD25 and CD40 ligand. Our data suggest that IL-12 may, in part, functionally rescue senescent CD4+ T cells.
Gains of 2p involving the REL locus correlate with nuclear c-Rel protein accumulation in neoplastic cells of classical Hodgkin lymphoma
Authors: Barth Thomas F. E. , Martin-Subero José I. , Joos Stefan , Menz Christiane K. , Hasel Cornelia , Mechtersheimer Gunhild , Parwaresch Reza M. , Lichter Peter , Siebert Reiner , Möller Peter
Published: April 2003

Structural aberrations of the short arm of chromosome 2, mostly resulting in gains of 2p13∼16, have recently been described as being highly recurrent in Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL). As these gains consistently lead to increased copy numbers of the REL oncogene locus, we investigated the expression of the c-Rel protein in a series of 30 cHL cases with known genomic REL status as determined by comparative genomic hybridization and interphase cytogenetics. Expression of the c-Rel protein was investigated in 26 biopsies by immunohistochemistry. Distinct patterns were observed in HRS cells with no staining, cytoplasmic, and/or nuclear staining for c-Rel. All 13 samples with additional copies of the REL locus displayed nuclear staining for c-Rel, while 13 cHL samples lacking chromosome 2 (2p) gains displayed a significantly lower proportion or complete absence of HRS cells with nuclear c-Rel expression. Detailed analysis using combined immunophenotyping and interphase cytogenetics of individual HRS cells demonstrated that REL gains correlated with the presence of nuclear c-Rel staining. Additionally, in 2 cHL samples with translocation breakpoints in 2p13∼16, nuclear staining of c-Rel was observed; in one of them the staining pattern was indicative of a truncated c-Rel protein. The correlation between structural aberrations involving the REL locus and nuclear c-Rel accumulation in HRS cells qualifies REL as a target gene of the frequent gains in 2p in cHL. The data suggest thatREL aberrations are a genetic mechanism contributing to constitutive nuclear factor (NF)–κB/Rel activation in cHL.
Anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of90Y-DOTA-peptide-Lym-1 in lymphoma xenografts
Authors: Tuscano Joseph M. , O'Donnell Robert T. , Miers Laird A. , Kroger Linda A. , Kukis David L. , Lamborn Kathleen R. , Tedder Thomas F. , DeNardo Gerald L.
Published: April 2003

CD22 is a membrane glycophosphoprotein found on nearly all healthy B-lymphocytes and most B-cell lymphomas. Recent in vitro studies have identified several anti-CD22 monoclonal antibodies (mAbs) that block the interaction of CD22 with its ligand. One of these mAbs, HB22.7, has been shown to effectively induce apoptosis in several B-cell lymphoma cell lines. Lymphoma xenograft studies with Raji-xenograft mice were used to assess the toxicity and efficacy of HB22.7 alone and with combined modality immunotherapy (CMIT) with yttrium 90Y-DOTA-peptide-Lym-1 radioimmunotherapy (RIT). The effect of the sequence of these agents on the combined treatment was assessed by administering HB22.7 24 hours before, simultaneously with, or 24 hours after RIT. Within the groups treated with RIT alone or with RIT and HB22.7 (CMIT), the reduction in tumor volume was the greatest when HB22.7 was administered simultaneously with and 24 hours after RIT, and in the RIT treatment groups, this translated into the greatest overall response and survival, respectively. Overall survival rates at the end of the 84-day CMIT trial were 67% and 50% in the groups treated with HB22.7 simultaneously and 24 hours after RIT, respectively. This compared favorably with the untreated and the RIT alone groups, which had survival rates of 38% and 43% at the end of the trial. Surprisingly, when compared with untreated controls and all other treatment groups, the greatest cure and overall survival rates were observed in the group treated with HB22.7 alone, with 47% cured and 76% surviving at the end of the 84-day trial. RIT clearance was not affected by treatment with HB22.7. When compared with RIT alone, there was no significant additional hematologic (white blood cell, red blood cell, or platelet count) toxicity when HB22.7 was added to RIT. Nonhematologic toxicity (assessed as change in body weight) was also unchanged when HB22.7 was added to RIT. Thus the anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of90Y-DOTA-peptide-Lym-1 in lymphoma xenografts without significant toxicity.