bluuebunny/crossref_metadata_2025 huggingface dataset:
Subject control and coreference in Early Modern English free adjuncts and absolutes
Authors: Río-Rey Carmen
Published: October 2002

The clear-cut distinction between free adjuncts and absolutes based on the presence in absolutes of an overt subject different from the subject of the matrix clause, as opposed to the covert subject – controlled by the subject of the matrix clause – of free adjuncts, does not always hold. While it is generally agreed that unrelated free adjuncts are fairly frequent in Present-day English (PE), absolutes whose subject is identical to that of the matrix clause are regarded as obsolete (Jespersen, 1909–49; Kortmann, 1991; Söderlind, 1958; Visser, 1963–73). However, no statistical evidence has been provided on this topic for earlier stages of the history of English. This article quantitatively assesses whether the various degrees of relatedness observed in Early Modern English (EModE) coincide with those attested for PE, and concludes that the boundaries between free adjuncts and absolutes were considerably fuzzier in EModE, a phenomenon to which punctuation decisively contributed.
Article: Contemporary issues in audiology: A hearing scientist's perspective
Authors: Parker David J
Published: October 2002

Audiology has developed significantly over the last 30 years leading to better identification and assessment of hearing loss and better habilitation services for both children and adults with congenital or acquired deafness. Advancement in the profession and its services has been largely dependent on the technological development of key methodologies such as the auditory brainstem response and otoacoustic emissions. These methodologies have been used for the identification and assessment of the severity of hearing loss. As a result, these methodologies have underpinned the emergence of service development initiatives such as hearing screening and provision of hearing aids, particularly for newborn babies and young children. This review identifies, describes and evaluates the key methodologies and services involved and presents a hearing scientist's perspective on the developments to date. The aim is to provide state‐of‐the‐art information to those working with children and adults with communication disorders, particularly speech and language therapists.
Complex language functions and subcortical mechanisms: Evidence from Huntington's disease and patients with non‐thalamic subcortical lesions
Authors: Chenery Helen J. , Copland David A. , Murdoch Bruce E.
Published: October 2002

The neuropathological changes associated with Huntington's disease (HD) are most marked in the head of the caudate nucleus and, to a lesser extent, in the putamen and globus pallidus, suggesting that at least part of the language impairments found in patients with HD may result from non‐thalamic subcortical (NTS) pathology. The present study aimed to test the hypothesis that a signature profile of impaired language functions is found in patients who have sustained damage to the non‐thalamic subcortex, either focally induced or resulting from neurodegenerative pathology. The language abilities of a group of patients with Huntington's disease (n =13) were compared with those of an age‐ and education‐matched group of patients with chronic NTS lesions following stroke (n =13) and a non‐neurologically impaired control group (n =13). The three groups were compared on language tasks that assessed both primary and more complex language abilities. The primary language battery consisted of The Western Aphasia Battery and The Boston Naming Test, whilst the more complex cognitive‐linguistic battery employed selected subtests from The Test of Language Competence ‐ Expanded, The Test of Word Knowledge and The Word Test ‐ Revised. On many of the tests of primary language function from the Western Aphasia Battery, both the HD and NTS participants performed in a similar manner to the control participants. The language performances of the HD participants were significantly more impaired (p<0.05 using modified Bonferroni adjustments) than the control group, however, on various lexico‐semantic tasks (e.g. the Boston Naming Test and providing definitions), on both single‐word and sentence‐level generative tasks (e.g. category fluency and formulating sentences), and on tasks which required interpretation of ambiguous, figurative and inferential meaning. The difficulties that patients with HD experienced with tasks assessing complex language abilities were strikingly similar, both qualitatively and quantitatively, to the language profile produced by NTS participants. The results provide evidence to suggest that a signature language profile is associated with damage to the non‐thalamic subcortex resulting from either focal neurological insult or a degenerative disease.
The Calcium-Binding Activity of a Vacuole-Associated, Dehydrin-Like Protein Is Regulated by Phosphorylation
Authors: Heyen Bruce J. , Alsheikh Muath K. , Smith Elizabeth A. , Torvik Carl F. , Seals Darren F. , Randall Stephen K.
Published: October 2002

A vacuole membrane-associated calcium-binding protein with an apparent mass of 45 kD was purified from celery (Apium graveolens). This protein, VCaB45, is enriched in highly vacuolate tissues and is located within the lumen of vacuoles. Antigenically related proteins are present in many dicotyledonous plants. VCaB45 contains significant amino acid identity with the dehydrin family signature motif, is antigenically related to dehydrins, and has a variety of biochemical properties similar to dehydrins. VCaB45 migrates anomalously in sodium dodecyl sulfate-polyacrylamide gel electrophoresis having an apparent molecular mass of 45 kD. The true mass as determined by matrix-assisted laser-desorption ionization time of flight was 16.45 kD. VCaB45 has two characteristic dissociation constants for calcium of 0.22 ± 0.142 mm and 0.64 ± 0.08 mm, and has an estimated 24.7 ± 11.7 calcium-binding sites per protein. The calcium-binding properties of VCaB45 are modulated by phosphorylation; the phosphorylated protein binds up to 100-fold more calcium than the dephosphorylated protein. VCaB45 is an “in vitro” substrate of casein kinase II (a ubiquitous eukaryotic kinase), the phosphorylation resulting in a partial activation of calcium-binding activity. The vacuole localization, calcium binding, and phosphorylation of VCaB45 suggest potential functions.
Rapid Vapor Deposition of Highly Conformal Silica Nanolaminates
Authors: Hausmann Dennis , Becker Jill , Wang Shenglong , Gordon Roy G.
Published: October 2002

Highly uniform and conformal coatings can be made by the alternating exposures of a surface to vapors of two reactants, in a process commonly called atomic layer deposition (ALD). The application of ALD has, however, been limited because of slow deposition rates, with a theoretical maximum of one monolayer per cycle. We show that alternating exposure of a surface to vapors of trimethylaluminum and tris(
tert
-butoxy)silanol deposits highly conformal layers of amorphous silicon dioxide and aluminum oxide nanolaminates at rates of 12 nanometers (more than 32 monolayers) per cycle. This process allows for the uniform lining or filling of long, narrow holes. We propose that these ALD layers grow by a previously unknown catalytic mechanism that also operates during the rapid ALD of many other metal silicates. This process should allow improved production of many devices, such as trench insulation between transistors in microelectronics, planar waveguides, microelectromechanical structures, multilayer optical filters, and protective layers against diffusion, oxidation, or corrosion.
Synthesis of threeSalmonellaepitopes for biosensor studies of carbohydrateantibody interactions
Authors: Yu Henry N , Ling Chang-Chun , Bundle David R
Published: October 2002

Disaccharides 1-3 corresponding to the antigenic determinants of Salmonella serotypes A, B, and D1were synthesized in a form suited for use in biosensors. The disaccharide determinants each contain a unique 3,6-dideoxyhexose, namely abequose (3,6-dideoxy-D-xylo-hexose), paratose (3,6-dideoxy-D-ribohexose), and tyvelose (3,6-dideoxy-D-arabino-hexose), are α-linked to the 3-position of D-mannopyranose. The disaccharides were further derivatized with a linear aglycon that has a terminal amino group, and can be readily coupled to pertinent chains carrying a terminal thiol for the construction of self-assembled monolayers (SAMs). Efficient routes that employed a single 3,6-dideoxygenation step were developed for the synthesis of paratoside 15 and tyveloside 22.Key words: Salmonella O-antigens, lipopolysaccharide, abequose, paratose, tyvelose, 3,6-dideoxyhexose, deoxygenation, glycoside tethers, immobilization via pentenyl glycosides.
Characterization of some mesogenic alkyl 1-thioglycosides
Authors: Henrissat B , Hamer G K , Taylor M G , Marchessault R H
Published: October 2002

A series of dodecyl 1-thio-β-D-glycosides has been synthesized and characterized (DSC, NMR, CP MAS, X-ray diffraction) as possible new marking materials with liquid-crystalline properties. These compounds undergo solid to liquid crystal phase transitions at various temperatures, which depend on the nature of the carbohydrate part of the structure. Their liquid-crystalline phases show extreme shear thinning behaviour.Key words: liquid crystal, powder X-ray diffraction, phase transition, thioglycoside, solid-state NMR, marking material
A NONADIABATIC QUANTUM MECHANICAL MONTE CARLO METHOD
Authors: MAZZONE A. M.
Published: October 2002

The problem addressed by this study is an efficient solution of the multi-particle time-dependent Schrödinger equation to be used under nonadiabatic conditions. To this purpose a solution combining classical dynamics for the nuclei and a quantum mechanical Monte Carlo method for the electrons is suggested as a practically feasible approach. As a show-case example, the method is applied to the evaluation of the ground state of H, He, H2 and H3 whose energy and structure is also obtained from stationary Hartree–Fock calculations.
NAKED SINGULARITIES AND THE WILSON LOOP
Authors: HUSAIN VIQAR
Published: October 2002

We give observations about dualities where one of the dual theories is geometric. These are illustrated with a duality between the simple harmonic oscillator and a topological field theory. We then discuss the Wilson loop in the context of the AdS/CFT duality. We show that the Wilson loop calculation for certain asymptotically AdS scalar field space–times with naked singularities gives results qualitatively similar to that for the AdS black hole. In particular, it is apparent that (dimensional) metric parameters in the singular space–times permit a "thermal screening" interpretation for the uark potential in the boundary theory, just like black hole mass. This suggests that the Wilson loop calculation merely captures metric parameter information rather than true horizon information.
CONFORMAL TRANSFORMATIONS NEAR NAKED SINGULARITIES: I
Authors: BARVE SUKRATU
Published: October 2002

We show that the behaviour of the outgoing radial null geodesic congruence on the boundary of the trapped region (suitably defined as a four dimensional region) is related to the property of nakedness in spherical dust collapse. The argument involves a conformal transformation which justifies the difference in the Penrose diagrams in the naked and covered dust collapse scenarios.
A New Discriminative Kernel from Probabilistic Models
Authors: Tsuda Koji , Kawanabe Motoaki , Rätsch Gunnar , Sonnenburg Sören , Müller Klaus-Robert
Published: October 2002

Recently, Jaakkola and Haussler (1999) proposed a method for constructing kernel functions from probabilistic models. Their so-called Fisher kernel has been combined with discriminative classifiers such as support vector machines and applied successfully in, for example, DNA and protein analysis. Whereas the Fisher kernel is calculated from the marginal log-likelihood, we propose the TOP kernel derived from tangent vectors of posterior log-odds. Furthermore, we develop a theoretical framework on feature extractors from probabilistic models and use it for analyzing the TOP kernel. In experiments, our new discriminative TOP kernel compares favorably to the Fisher kernel.
Relationship of CD8+ T cell noncytotoxic anti-HIV response to CD4+ T cell number in untreated asymptomatic HIV-infected individuals
Authors: Castelli JoAnn C. , Deeks Steven G. , Shiboski Stephen , Levy Jay A.
Published: October 2002

During chronic HIV infection, asymptomatic individuals demonstrate a strong CD8+ cell noncytotoxic antiviral response (CNAR). With the onset of symptoms or reduction in CD4+ cell counts, CNAR decreases. Presently, it is recommended that infected individuals receive antiretroviral therapy if CD4+ cell counts fall below 350 cells/μL. To determine whether CNAR lends support to this recommendation for initiation of antiretroviral treatment, we examined CNAR in 20 healthy, untreated, HIV-infected men exhibiting a range of CD4+ cell numbers. Our results indicate that the asymptomatic untreated HIV-infected individuals with less than 300 CD4+ cells/μL had a significantly lower CNAR than those with higher CD4+ cell counts. These data on CNAR in untreated, healthy, HIV-infected individuals support the current recommendation for when to initiate antiretroviral therapy.
Differential abilities of central nervous system resident endothelial cells and astrocytes to serve as inducible antigen-presenting cells
Authors: Girvin Ann M. , Gordon Kenneth B. , Welsh C. Jane , Clipstone Neil A. , Miller Stephen D.
Published: October 2002

Microglial cells and astrocytes are capable of processing and presenting antigens for efficient activation of T cells. However, the antigen-presenting function and role of cerebrovascular endothelial cells (CVEs) in central nervous system inflammatory responses remain controversial. We compared the expression of necessary accessory molecules and the functional antigen-presenting capacity of cloned SJL/J CVEs and primary astrocytes in response to the pro-inflammatory cytokines interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). Astrocytes and CVEs up-regulated major histocompatibility complex (MHC) class II, and primarily B7-1 as opposed to B7-2, in response to IFN-γ. TNF-α inhibited the IFN-γ–induced up-regulation of MHC class II on CVEs correlating to a decrease in the mRNA for the class II transactivator (CIITA), whereas CIITA expression in astrocytes was unaffected. Unlike astrocytes, CVEs did not elicit significant MHC class II-restricted T-cell responses. Furthermore, we have found that CVE monolayers are altered following T-cell contact, implicating CVE/T-cell contact in the breakdown of the blood–brain barrier during neuro-inflammatory responses.
Correction of the murine Wiskott-Aldrich syndrome phenotype by hematopoietic stem cell transplantation
Authors: Strom Ted S. , Li Xiuling , Cunningham John M. , Nienhuis Arthur W.
Published: October 2002

Allogeneic hematopoietic stem cell transplantation (HSCT) corrects the Wiskott-Aldrich syndrome (WAS) phenotype. However, the toxicity and mortality frequently associated with this approach warrant the exploration of new therapeutic strategies. Transplantation studies of a murine model of WAS deficiency have been limited by the occurrence of a radiation-induced fatal exacerbation of a pre-existing colitis in the peritransplantation period. Here we demonstrate that when crossed to a C57/B6 background, WAS-deficient males show little if any colitis and reliably survive HSCT. We show that HSCT corrects the hematologic and functional deficiencies of WAS knockout mice. These results strengthen the analogy between murine and human WAS and provide a basis for the use of WAS-deficient mice to explore novel approaches for correction of the disease phenotype.
Down-regulation of DNA repair in human CD34+progenitor cells corresponds to increased drug sensitivity and apoptotic response
Authors: Buschfort-Papewalis Claudia , Moritz Thomas , Liedert Bernd , Thomale Jürgen
Published: October 2002

Although DNA repair processes have been shown to considerably modulate the cytotoxic effects of alkylating agents, little information is available on the role of these mechanisms in chemotherapy-induced myelosuppression. Therefore, we have analyzed in detail the DNA repair capacity of primary human hematopoietic cells from cord blood (CB) or bone marrow (BM) by 2 functional assays, the immunocytologic assay (ICA) and single-cell gel electrophoresis (comet assay). Besides substantial interindividual differences, we consistently observed significantly lower repair capacity of CD34+ cells in comparison to CD34−, CD19+, or CD33+ cells of the same donor. After exposure to the alkylating agent ethylnitrosourea (EtNU), the comet assay displayed on average twice as many DNA single-strand breaks (SSBs) in CD34+ cells and a tripled half-life of these lesions in comparison to corresponding CD34− cells. Similarly, reduced SSB repair activity in CD34+ cells was detected following melphalan or cisplatin application. When specific antibodies were used to monitor DNA reaction products of these drugs, adduct levels were significantly higher and lesions persisted longer in the CD34+ fraction. To assess the contribution of individual pathways to overall DNA repair, modulators blocking defined steps in repair processes were coapplied with alkylating drugs. Similar “modulation pattern” in corresponding CD34+ and CD34− cell fractions indicated a generalized reduction in DNA repair capacity of CD34+ cells, rather than deficiencies in a specific pathway. Because CD34+ cells also displayed higher frequencies of apoptosis in response to melphalan or cisplatin, these findings may help to explain the myelosuppression after exposure to alkylating agents.
Paternal mosaicism proves the pathogenic nature of mutations in neutrophil elastase in severe congenital neutropenia
Authors: Ancliff Phil J. , Gale Rosemary E. , Watts Michael J. , Liesner Ri , Hann Ian M. , Strobel Stephan , Linch David C.
Published: October 2002

Heterozygous mutations in neutrophil elastase have been detected in many sporadic cases of congenital neutropenia. However, a convincing pathogenetic mechanism has not been established, and it is unclear whether the effects of the mutant enzyme occur within the cell of production or are paracrine in nature. The healthy father of a patient was demonstrated to be mosaic for his daughter's Cys42Arg elastase mutation. Using semiquantitative polymerase chain reaction, approximately half of his T cells were shown to carry the mutation in contrast to less than 10% of neutrophils. Individual hematopoietic colonies grown from peripheral blood were heterozygous for the mutation or were homozygous wild type. These results demonstrate that precursors containing the mutation are selectively lost during myelopoiesis or fail to develop into neutrophils. This is the first in vivo confirmation of the pathogenic nature of elastase mutations in humans. The normal neutrophil count in the father suggests that the mutant elastase does not have paracrine effects.
Outcome of adult patients with T-lymphoblastic lymphoma treated according to protocols for acute lymphoblastic leukemia
Authors: Hoelzer Dieter , Gökbuget Nicola , Digel Werner , Faak Thomas , Kneba Michael , Reutzel Regina , Romejko-Jarosinska Joanna , Zwolinski Jacek , Walewski Jan
Published: October 2002

We treated 45 adult patients with T-lymphoblastic lymphoma (T-LBL) (age range 15-61 years) with 2 protocols designed for adult acute lymphoblastic leukemia (ALL). An encouraging cure rate of 90% was recently reported for T-LBL in children treated with a similar approach. In our study, an 8-drug standard induction was administered over 8 weeks including prophylactic cranial (24 Gy) and mediastinal irradiation (24 Gy) followed by consolidation and reinduction therapy. At diagnosis, 91% of the 45 patients showed a mediastinal tumor and 40% had pleural/pericardial effusions; 73% of the patients had stage III/IV disease. Overall, 42 patients (93%) achieved a complete remission (CR), 2 patients (4%) achieved a partial remission, and 1 patient (2%) died during induction. In patients with stage I-III disease (n = 18) the CR rate was 100% compared with 89% in stage IV (n = 27). There were 15 patients who relapsed (36%) within 12 months. The majority of relapses (47%) occurred in the mediastinum (n = 7) despite mediastinal irradiation with 24 Gy in 6 out of 7 patients. The estimates for overall survival, continuous CR, and disease-free survival at 7 years are 51%, 65%, and 62%, respectively. Stage, age, lactate dehydrogenase, and all other parameters had no influence on achievement of CR or outcome. This study demonstrates in a large cohort of patients with adult T-LBL that a high CR rate and a favorable outcome can be achieved with an ALL-type regimen. Mediastinal recurrence was the major obstacle and further improvement by intensification of chemotherapy, increased dose of mediastinal irradiation (36 Gy), and extended indications for stem cell transplantation seem to be required.
Risk factors for evolution of acquired aplastic anemia into myelodysplastic syndrome and acute myeloid leukemia after immunosuppressive therapy in children
Authors: Kojima Seiji , Ohara Akira , Tsuchida Masahiro , Kudoh Toru , Hanada Ryoji , Okimoto Yuri , Kaneko Takashi , Takano Toshikuni , Ikuta Koichiro , Tsukimoto Ichiro
Published: October 2002

Long-term survivors of acquired aplastic anemia (AA) have an increased risk of developing myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) after immunosuppressive therapy (IST). It is uncertain whether the increased survival time simply discloses the natural history of AA as a premalignant disease or whether secondary disease is related to the therapy itself. Between November 1992 and September 1997, 113 AA children with normal cytogenetics at diagnosis were treated with IST using antithymocyte globulin, cyclosporin, and danazol with or without granulocyte colony-stimulating factor (G-CSF). We assessed risk factors for developing MDS/AML by Cox proportional hazards models. Twelve of 113 patients developed MDS between 9 and 81 months following the time of diagnosis, giving a cumulative incidence of 13.7 ± 3.9%. The following cytogenetic abnormalities were observed at the time of diagnosis of MDS: monosomy 7 (6 patients), monosomy7/trisomy21 (1 patient), trisomy 11 (1 patient), del (11) (9?:14) (1 patient), add (9q) (1 patient), add 7 (q 32) (1 patient), and trisomy 9 (1 patient). The number of days of G-CSF therapy and nonresponse to therapy at 6 months were statistically significant risk factors by multivariate analysis. The present study suggests a close relationship between long-term use of G-CSF and secondary MDS in nonresponders to IST.
Evaluation of role of G-CSF in the production, survival, and release of neutrophils from bone marrow into circulation
Authors: Basu Sunanda , Hodgson George , Katz Melissa , Dunn Ashley R.
Published: October 2002

In steady-state hematopoiesis, G-CSF (granulocyte-colony stimulating factor) regulates the level of neutrophils in the bone marrow and blood. In this study, we have exploited the availability of G-CSF–deficient mice to evaluate the role of G-CSF in steady-state granulopoiesis and the release of granulocytes from marrow into circulation. The thymidine analogue bromodeoxyuridine (BrdU) was used to label dividing bone marrow cells, allowing us to follow the release of granulocytes into circulation. Interestingly, the labeling index and the amount of BrdU incorporated by blast cells in bone marrow was greater in G-CSF–deficient mice than in wild-type mice. In blood, 2 different populations of BrdU-positive granulocytes, BrdUbright and BrdUdim, could be detected. The kinetics of release of the BrdUbright granulocytes from bone marrow into blood was similar in wild-type and G-CSF–deficient mice; however, BrdUdim granulocytes peaked earlier in G-CSF–deficient mice. Our findings suggest that the mean transit time of granulocytes through the postmitotic pool is similar in G-CSF–deficient and control mice, although the transit time through the mitotic pool is reduced in G-CSF–deficient mice. Moreover, the reduced numbers of granulocytes that characterize G-CSF–deficient mice is primarily due to increased apoptosis in cells within the granulocytic lineage. Collectively, our data suggest that at steady state, G-CSF is critical for the survival of granulocytic cells; however, it is dispensable for trafficking of granulocytes from bone marrow into circulation.
Characterization of Kaposi sarcoma–associated herpesvirus/human herpesvirus–8 infection of human vascular endothelial cells: early events
Authors: Dezube Bruce J. , Zambela Maria , Sage David R. , Wang Jian-Feng , Fingeroth Joyce D.
Published: October 2002

Kaposi sarcoma–associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) is causally associated with Kaposi sarcoma (KS). The absence of a cell culture system that effectively reproduces the composite mechanisms governing initiation and maintenance of HHV-8 infection (lytic and latent) in KS endothelial cells, however, has left important questions unanswered. Here, we report a culture system in which the earliest events that accompany HHV-8 infection could be surveyed in primary endothelial cells. Binding of HHV-8 to microvascular dermal endothelial cells (MVDECs) was directly compared with other primary target cells implicated in HHV-8–associated diseases. Virus attachment, fusion, internalization and transport within MVDECs was monitored by electron microscopy. Studies of genome configuration revealed that rapid circularization of the viral DNA occurred on entry, though by 72 hours after infection linear DNAs accumulated and early as well as late lytic RNAs (T1.1, K8.1) could be detected. The latency transcripts (LT1/LT2) were first detected on day 8, demonstrating that both lytic and latent infection were initiated. Although most lytic transcripts accrued until passage, open-reading frame–74 RNAs fluctuated with a fixed periodicity, suggesting that early replication after infection of MVDECs was synchronous.
A monoclonal antibody to vascular endothelial–cadherin inhibits tumor angiogenesis without side effects on endothelial permeability
Authors: Corada Monica , Zanetta Lucia , Orsenigo Fabrizio , Breviario Ferruccio , Lampugnani Maria Grazia , Bernasconi Sergio , Liao Fang , Hicklin Daniel J. , Bohlen Peter , Dejana Elisabetta
Published: October 2002

Vascular endothelial cadherin (VE-cadherin) is an endothelial-specific, trans-membrane protein that promotes homophilic cell adhesion. Inhibition of VE-cadherin by the blocking monoclonal antibody (mAb) BV13 inhibited angiogenesis and tumor growth in vivo. However, this effect was accompanied by a marked increase in lung and heart permeability. In the present paper, we characterize a different VE-cadherin mAb (BV14) that is able to inhibit angiogenesis without affecting vascular permeability. In vitro studies show that BV14, in contrast to BV13, did not increase paracellular permeability of endothelial monolayers and did not disrupt VE-cadherin clusters at junctions. However, both antibodies could inhibit formation of vascularlike structures in collagen gels and increase migration of endothelial cells into wounded areas. In vivo, BV14 and BV13 were equally active in inhibiting angiogenesis in the mouse cornea and in reducing the growth of hemangioma and C6 glioma. In contrast to BV13, BV14 did not change vascular permeability in all the organs tested and at any dose used. BV14 and BV13 bind to VE-cadherin extracellular repeats EC4 and EC1, respectively. We propose that, in resting vessels, where junctions are stable and well-structured, antibody binding to EC1 but not EC4 disrupts their organization and increases permeability. In contrast, in growing vessels, where endothelial cells are migrating and junctions are weaker, antibody binding to EC4 may be sufficient to disrupt cell-to-cell adhesion and inhibit assembly of new vascular structures.
Hydroxyurea corrects the dysregulated L-selectin expression and increased H2O2 production of polymorphonuclear neutrophils from patients with sickle cell anemia
Authors: Benkerrou Malika , Delarche Charlotte , Brahimi Lamia , Fay Michèle , Vilmer Etienne , Elion Jacques , Gougerot-Pocidalo Marie-Anne , Elbim Carole
Published: October 2002

Impaired polymorphonuclear neutrophil (PMN) functions during sickle cell anemia (SCA) may have a pathogenic role in the onset of vasoocclusive events. We used flow cytometry to study, in whole blood, the adhesion molecule expression and respiratory burst of PMNs from children with SCA. Three different clinical groups were studied: (1) patients with no history of vasoocclusive events (n = 15); (2) patients with a history of vasoocclusive events (n = 17); and (3) patients receiving hydroxyurea therapy for severe vasoocclusive events (n = 9). Unstimulated PMNs showed decreased L selectin expression and increased H2O2 production whatever the severity of the disease, reflecting PMN activation. This could contribute to endothelial activation reflected by abnormal plasma levels of soluble adhesion molecules (soluble intercellular adhesion molecule-1, sE selectin, and sL selectin). After stimulation with bacterial N-formyl peptides (N-formyl-methionyl-leucyl-phenylalanine [fMLP]), PMNs from untreated patients with a history of vasoocclusive events showed dysregulated L selectin shedding and increased H2O2 production. Furthermore, in these patients, tumor necrosis factor priming followed by fMLP stimulation induced an H2O2 production significantly higher than in the other patient groups and controls. These impairments could immobilize PMNs on the endothelium, thereby inducing reduced blood flow and fostering microvascular occlusion and vascular damage. In contrast, children treated with hydroxyurea showed near-normal basal and poststimulation H2O2 production as well as normal L selectin shedding after stimulation but no change in plasma levels of soluble adhesion molecules. To our knowledge, this is the first report showing major qualitative changes of PMN abnormalities upon hydroxyurea treatment in SCA patients. This strongly suggests that PMNs are a primary target of this drug.
The effects of postponing prophylactic treatment on long-term outcome in patients with severe hemophilia
Authors: Fischer Kathelijn , van der Bom Johanna G. , Mauser-Bunschoten Eveline P. , Roosendaal Goris , Prejs Robert , de Kleijn Piet , Grobbee Diederick E. , van den Berg Marijke
Published: October 2002

To prevent hemophilic arthropathy, prophylactic treatment of children with severe hemophilia should be started before joint damage has occurred. However, treatment is expensive, and the burden of regular venipunctures in young children is high. With the aim of providing information on starting prophylaxis on the basis of individual patient characteristics, the effect of postponing prophylaxis on long-term arthropathy was studied in a cohort of 76 patients with severe hemophilia born between 1965 and 1985. The median age at first joint bleed was 2.2 years (range, 0.2-5.8). Prophylaxis was started at a median age of 6 years (interquartile range [IQR], 4-9), and the median annual clotting factor use on prophylaxis was 1750 IU/kg/y (31 IU/kg/wk). Hemophilic arthropathy was measured by the Pettersson score (maximum, 78 points). At a median age of 19 years, the median Pettersson score was 7 points (IQR, 0-17). After 2 decades of follow-up, the Pettersson score was 8% higher (95% confidence interval, 1%-16%) for every year prophylaxis was postponed after the first joint bleed. This effect was independent of age at Pettersson score, age at first joint bleed, and prophylactic dose used. In conclusion, most patients have their first joint bleed after the age of 2 years. Patients who start prophylaxis soon after the first joint bleed show little arthropathy in adulthood. The longer the start of prophylaxis is postponed after the first joint bleed, the higher the risk of developing arthropathy.
5-Hydroxytryptamine drives apoptosis in biopsylike Burkitt lymphoma cells: reversal by selective serotonin reuptake inhibitors
Authors: Serafeim Adamantios , Grafton Gillian , Chamba Anita , Gregory Christopher D. , Blakely Randy D. , Bowery Norman G. , Barnes Nicholas M. , Gordon John
Published: October 2002

Serotonin (5-HT), a well-known neurotransmitter of the central nervous system, has been implicated in diverse aspects of immune regulation. Here we show that 5-HT can efficiently drive programmed cell death in established Burkitt lymphoma (BL) lines that remain faithful to the original biopsy phenotype (group 1). Group 1 BL cells cultured in the presence of 5-HT exhibited marked suppression of DNA synthesis that was accompanied by extensive apoptosis—serotonin-driven apoptosis was complete within 24 hours, was preceded by early caspase activation, and was accompanied by a decline in mitochondrial membrane potential. BL cells that had drifted to a lymphoblastic group 3 phenotype were relatively resistant to these actions of serotonin, and the forced ectopic expression of either bcl-2 orbcl-xL provided substantial protection from 5-HT–induced apoptosis. 5-HT receptor antagonists (SDZ205-557, granisetron, methysergide) failed to inhibit serotonin-induced apoptosis, whereas the selective serotonin reuptake inhibitors (SSRI)—fluoxetine (Prozac), paroxetine (Paxil), and citalopram (Celexa)—substantially blocked the monoamine actions. Western blot analysis showed that BL cells expressed protein for the 5-HT transporter, and transport assays confirmed active uptake of serotonin by the cells. Unlike what was suggested for neuronal cells, there was no evidence that intracellular oxidative metabolites were responsible for the 5-HT–induced programmed death of BL cells. These data indicate that serotonin drives apoptosis in biopsylike BL cells after its entry through an active transport mechanism, and they suggest a novel therapeutic modality for Burkitt lymphoma.
Dehydration response of sickle cells to sickling-induced Ca++ permeabilization
Authors: Lew Virgilio L. , Etzion Zipora , Bookchin Robert M.
Published: October 2002

Interaction of hemoglobin S polymers with the red blood cell (RBC) membrane induces a reversible increase in permeability (“Psickle”) to (at least) Na+, K+, Ca2+, and Mg2+. Resulting changes in [Ca2+] and [H+] in susceptible cells activate 2 transporters involved in sickle cell dehydration, the Ca2+-sensitive K+ (“Gardos”) channel (KCa) and the acid- and volume-sensitive K:Cl cotransport. We investigated the distribution of Psickle expression among deoxygenated sickle cell anemia (SS) RBCs using new experimental designs in which the RBC Ca2+ pumps were partially inhibited by vanadate, and the cells' dehydration rates were detected as progressive changes in the profiles of osmotic fragility curves and correlated with flow cytometric measurements. The results exposed marked variations in (sickling plus Ca2+)–induced dehydration rates within populations of deoxygenated SS cells, with complex distributions, reflecting a broad heterogeneity of their Psickle values. Psickle-mediated dehydration was inhibited by clotrimazole, verifying the role of KCa, and also by elevated [Ca2+]o, above 2 mM. Very high Psickle values occurred with some SS discocytes, which had a wide initial density (osmotic resistance) distribution. Together with its previously shown stochastic nature, the irregular distribution of Psickle documented here in discocytes is consistent with a mechanism involving low-probability, reversible interactions between sickle polymers and membrane or cytoskeletal components, affecting only a fraction of the RBCs during each deoxygenation event and a small number of activated pathways per RBC. A higher participation of SS reticulocytes in Psickle-triggered dehydration suggests that they form these pathways more efficiently than discocytes despite their lower cell hemoglobin concentrations.
Erythropoietin receptor haploinsufficiency and in vivo interplay with granulocyte-macrophage colony-stimulating factor and interleukin 3
Authors: Jegalian Armin G. , Acurio Adriana , Dranoff Glenn , Wu Hong
Published: October 2002

Erythropoietin (EPO) and its receptor (EPOR) are critical for definitive erythropoiesis, as mice lacking either gene product die during embryogenesis with severe anemia. Here we demonstrate that mice expressing just one functional allele of the EpoR have lower hematocrits and die more frequently than do wild-type littermates on anemia induction. Furthermore, EpoR+/−erythroid colony-forming unit (CFU-E) progenitors are reduced both in frequency and in responsiveness to EPO stimulation. To evaluate the interaction between EPO and granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin 3 (IL-3),GM-CSF−/− orIL-3−/− mice were interbred withEpoR+/− mice. Deletion of either GM-CSF or IL-3 also leads to reduction in CFU-E numbers and hematocrits but does not significantly alter steady-state erythroid burst-forming unit numbers. These results suggest EpoR haploinsufficiency and promotion of in vivo erythropoiesis by GM-CSF and IL-3.
p16INK4a immunocytochemical analysis is an independent prognostic factor in childhood acute lymphoblastic leukemia
Authors: Dalle Jean Hughes , Fournier Martine , Nelken Brigitte , Mazingue Françoise , Laı̈ Jean-Luc , Bauters Francis , Fenaux Pierre , Quesnel Bruno
Published: October 2002

We investigated the prognostic value of p16INK4aimmunocytochemistry (ICC) analysis in 126 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL). The incidence of negative p16INK4a ICC was 38.1% and was more frequent in T-lineage ALL. Overall survival (OS) and event-free survival (EFS) were significantly higher in patients with positive p16INK4a ICC than in patients with negative ICC (6 years OS, 90% versus 63%,P = .0014; 6 years EFS, 77.8% versus 55%,P = .0033). The p16INK4a ICC remained a significant prognostic factor within the subgroup of B-precursor ALL. Multivariate analysis showed that negative p16INK4a ICC was an independent prognostic factor for OS (relative risk [RR], 3.38;P = .02) and EFS (RR, 2.49; P = .018). Sequential study showed that p16INK4a expression remained stable during first relapse in most patients. These findings indicate that p16INK4a ICC is an independent factor of outcome in childhood ALL.
A humanized non–FcR-binding anti-CD3 antibody, visilizumab, for treatment of steroid-refractory acute graft-versus-host disease
Authors: Carpenter Paul A. , Appelbaum Frederick R. , Corey Lawrence , Deeg H. Joachim , Doney Kris , Gooley Theodore , Krueger James , Martin Paul , Pavlovic Sandra , Sanders Jean , Slattery John , Levitt Daniel , Storb Rainer , Woolfrey Ann , Anasetti Claudio
Published: October 2002

Visilizumab is a humanized anti-CD3 monoclonal antibody characterized by a mutated IgG2 isotype, lack of binding to Fcγ-receptors, and ability to induce apoptosis selectively in activated T cells. To test pharmacokinetics, safety, and immunosuppressive activity of visilizumab, 17 patients with glucocorticoid-refractory acute graft-versus-host disease (GVHD) were enrolled in a phase 1 study. Six patients were given 7 doses of visilizumab (0.25 or 1.0 mg/m2) on days 1, 3, 5, 7, 9, 11, and 13. Because multiple doses of 1 mg/m2 caused delayed visilizumab accumulation and prolonged lymphopenia, the next 11 patients received a single dose of 3.0 mg/m2 on day 1. GVHD improved in all patients; 15 were evaluable through day 42. Multiple dosing resulted in 1 of 6 complete responses (CRs) and 5 partial responses (PRs), but all 6 patients died at a median of 87 days after starting visilizumab therapy. Single dosing resulted in 6 of 9 CRs, 3 PRs, and 7 of 11 patients surviving after 260 to 490 days (median, 359 days; P = .03). There were no allergic reactions and 3 grade 1 acute infusional toxicities. Plasma Epstein-Barr virus (EBV) DNA titers more than 1000 copies/mL and posttransplant lymphoproliferative disease (PTLD) developed in 2 of the first 7 patients. Based on rising EBV DNA titers, 5 of the next 10 patients were given the B cell–specific monoclonal antibody, rituximab. EBV DNA became undetectable and no overt PTLD developed. Visilizumab is well tolerated and has activity in advanced GVHD. A phase 2 study incorporating preemptive therapy for PTLD is warranted to determine the efficacy of visilizumab in GVHD.
Plasminogen activator inhibitor type 2: a regulator of monocyte proliferation and differentiation
Authors: Yu Hong , Maurer Fabienne , Medcalf Robert L.
Published: October 2002

We have explored the role of plasminogen activator inhibitor type 2 (PAI-2) in THP-1 monocyte–like cells. These cells possess a mutation in the PAI-2 gene and do not produce an active PAI-2 protein. Transfection of THP-1 cells with plasmids expressing active PAI-2 reduced the cells' inherent adhesive properties and decreased the rate of cell proliferation. THP-1 cells expressing active PAI-2 also displayed an altered phenotype in response to phorbol ester–induced differentiation that was concomitant with a reduction in CD14 expression. THP-1 cells transfected with a variant PAI-2 containing a mutation in the reactive center (PAI-2Ala380) displayed no noticeable change in any of these parameters, suggesting the involvement of a PAI-2–sensitive serine protease(s). The antiproliferative effect of PAI-2 was attenuated by treating the PAI-2–expressing THP-1 cells with recombinant urokinase (u-PA), suggesting that PAI-2 was disruptive of a u-PA/u-PA receptor signaling pathway initiated on the cell surface. Consistent with this, treatment of wild-type THP-1 cells with recombinant PAI-2 also caused a reduction in cellular proliferation. These results implicate endogenous PAI-2 as a modulator of monocyte adhesion, proliferation, and differentiation.
The DBY gene codes for an HLA-DQ5–restricted human male-specific minor histocompatibility antigen involved in graft-versus-host disease
Authors: Vogt Mario H. J. , van den Muijsenberg Joost W. , Goulmy Els , Spierings Eric , Kluck Petra , Kester Michel G. , van Soest Ronald A. , Drijfhout Jan W. , Willemze Roel , Falkenburg J. H. Frederik
Published: October 2002

Graft rejection or graft-versus-host (GVH) disease after HLA-identical stem cell transplantation is the result of recognition of minor histocompatibility antigens (mHags) by immunocompetent T lymphocytes from recipient or donor origin, respectively. Cytolytic T lymphocyte (CTL) clones can be isolated during graft rejection and GVH disease to identify mHags and their corresponding genes. Thus far, all human mHags identified appeared to be HLA class I–restricted. Here, we report the characterization of the first human HLA class II–restricted sex-linked mHag involved in GVH disease. Previously, we isolated an HLA-DQ5–restricted CD4+ CTL clone from a male patient with chronic myeloid leukemia who developed acute GVH disease grade III-IV after transplantation of HLA genotypically identical female stem cells. Using a panel of female HLA-DQ5+ EBV cells that we stably transfected with Y chromosome–specific genes, we determined that the HLA class II male-specific mHag (H-Y) was encoded by the Y chromosome–specific gene DBY. The H-Y epitope was localized in the DBY protein using female HLA-DQ5+peripheral blood mononuclear cells loaded with DBY protein fragments. The minimal peptide sequence leading to maximal recognition by the specific HLA-DQ5–restricted CTL clone was characterized as the 12–amino acid sequence HIENFSDIDMGE. Although the epitope differed by 3 amino acids from its X-homolog DBX, only 2 polymorphisms were shown to be essential for recognition by the CTL clone.
Loss of PU.1 expression is associated with defective immunoglobulin transcription in Hodgkin and Reed-Sternberg cells of classical Hodgkin disease
Authors: Jundt Franziska , Kley Katharina , Anagnostopoulos Ioannis , Schulze Pröbsting Kristina , Greiner Axel , Mathas Stephan , Scheidereit Claus , Wirth Thomas , Stein Harald , Dörken Bernd
Published: October 2002

Immunoglobulin transcription is impaired in Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin disease (cHD). We recently demonstrated that defective immunoglobulin promoter transcription correlates with the down-regulation of the B-cell transcription factors Oct2 and BOB.1/OBF.1. These results prompted us to investigate whether immunoglobulin enhancer activity is also impaired in HRS cells and whether as yet unidentified factors could be necessary for immunoglobulin enhancer activity in HRS cells of cHD. Here we analyzed 30 cases of cHD for expression of the Ets family member PU.1 that is known to collaborate with multiple transcription factors and to regulate expression of immunoglobulin genes. We show that PU.1 is not expressed in primary and cultured HRS cells. Reintroduction of PU.1 and Oct2 in cultured HRS cells restored the activity of cotransduced immunoglobulin enhancer constructs. Our study identifies PU.1 deficiency as a recurrent defect in HRS cells that might contribute to their impairment of immunoglobulin transcription.
Adapting a transforming growth factor β–related tumor protection strategy to enhance antitumor immunity
Authors: Bollard Catherine M. , Rössig Claudia , Calonge M. Julia , Huls M. Helen , Wagner Hans-Joachim , Massague Joan , Brenner Malcolm K. , Heslop Helen E. , Rooney Cliona M.
Published: October 2002

Transforming growth factor β (TGF-β), a pleiotropic cytokine that regulates cell growth and differentiation, is secreted by many human tumors and markedly inhibits tumor-specific cellular immunity. Tumors can avoid the differentiating and apoptotic effects of TGF-β by expressing a nonfunctional TGF-β receptor. We have determined whether this immune evasion strategy can be manipulated to shield tumor-specific cytotoxic T lymphocytes (CTLs) from the inhibitory effects of tumor-derived TGF-β. As our model we used Epstein-Barr virus (EBV)–specific CTLs that are infused as treatment for EBV-positive Hodgkin disease but that are vulnerable to the TGF-β produced by this tumor. CTLs were transduced with a retrovirus vector expressing the dominant-negative TGF-β type II receptor HATGF-βRII-Δcyt. HATGF-βRII-Δcyt– but not green fluorescence protein (eGFP)–transduced CTLs was resistant to the antiproliferative and anticytotoxic effects of exogenous TGF-β. Additionally, receptor-transduced cells continued to secrete cytokines in response to antigenic stimulation. TGF-β receptor ligation results in phosphorylation of Smad2, and this pathway was disrupted in HATGF-βRII-Δcyt–transduced CTLs, confirming blockade of the signal transduction pathway. Long-term expression of TGF-βRII-Δcyt did not affect CTL function, phenotype, or growth characteristics. Tumor-specific CTLs expressing HATGF-βRII-Δcyt should have a selective functional and survival advantage over unmodified CTLs in the presence of TGF-β–secreting tumors and may be of value in treatment of these diseases.