bluuebunny/crossref_metadata_2025 huggingface dataset:
Transgenic Model of Aldosterone-Driven Cardiac Hypertrophy and Heart Failure
Authors: Qin Wenning , Rudolph Amy E. , Bond Brian R. , Rocha Ricardo , Blomme Eric A.G. , Goellner Joseph J. , Funder John W. , McMahon Ellen G.
Published: June 2003

Aldosterone classically promotes unidirectional transepithelial sodium transport, thereby regulating blood volume and blood pressure. Recently, both clinical and experimental studies have suggested additional, direct roles for aldosterone in the cardiovascular system. To evaluate aldosterone activation of cardiomyocyte mineralocorticoid receptors, transgenic mice overexpressing 11β-hydroxysteroid dehydrogenase type 2 in cardiomyocytes were generated using the mouse α-myosin heavy chain promoter. This enzyme converts glucocorticoids to receptor-inactive metabolites, allowing aldosterone occupancy of cardiomyocyte mineralocorticoid receptors. Transgenic mice were normotensive but spontaneously developed cardiac hypertrophy, fibrosis, and heart failure and died prematurely on a normal salt diet. Eplerenone, a selective aldosterone blocker, ameliorated this phenotype. These studies confirm the deleterious consequences of inappropriate activation of cardiomyocyte mineralocorticoid receptors by aldosterone and reveal a tonic inhibitory role of glucocorticoids in preventing such outcomes under physiological conditions. In addition, these data support the hypothesis that aldosterone blockade may provide additional therapeutic benefit in the treatment of heart failure.
Creatine Phosphate Consumption and the Actomyosin Crossbridge Cycle in Cardiac Muscles
Authors: Ogut Ozgur , Brozovich Frank V.
Published: June 2003

To investigate the regulation of the actomyosin crossbridge cycle in cardiac muscles, the effects of ATP, ADP, Pi, and creatine phosphate (CP) on the rate of force redevelopment (ktr) were measured. We report that CP is a primary determinant in controlling the actomyosin crossbridge cycling kinetics of cardiac muscles, because a reduction of CP from 25 to 2.5 mmol/L decreased ktr by 51% despite the presence of 5 mmol/L MgATP. The effects of CP on ktr were not a reflection of reduced ATP or accumulated ADP, because lowering ATP to 1 mmol/L or increasing ADP to 1 mmol/L did not significantly decrease ktr. Therefore, the effect of CP on the actomyosin crossbridge cycle is proposed to occur through a functional link between ADP release from myosin and its rephosphorylation by CP–creatine kinase to regenerate ATP. In activated fibers, the functional link influenced the kinetics of activated crossbridges without affecting the aggregate number of force-generating crossbridges. This was demonstrated by the ability of CP to affect ktr in maximally and submaximally activated fibers without altering the force per cross-sectional area. The data also confirm the important contribution of strong binding crossbridges to cardiac muscle activation, likely mediated by cooperative recruitment of adjacent crossbridges to maximize force redevelopment against external load. These data provide additional insight into the role of CP during pathophysiological conditions such as ischemia, suggesting that decreased CP may serve as a primary determinant in the observed decline of dP/dt.
Stroke Associated With Sympathomimetics Contained in Over-the-Counter Cough and Cold Drugs
Authors: Cantu Carlos , Arauz Antonio , Murillo-Bonilla Luis M. , López Mario , Barinagarrementeria Fernando
Published: June 2003

Background and Purpose—

Phenylpropanolamine (PPA) and pseudoephedrine are sympathomimetics contained in over-the-counter cold preparations. A case-control study linked PPA use with hemorrhagic stroke in women. Twenty-two patients with stroke associated with use of these drugs are described.

Methods—

In a consecutive stroke registry since 1988, 22 patients had stroke associated with over-the-counter sympathomimetics. Sympathomimetic dosage and type, time interval until stroke onset, and neuroimaging findings are described.

Results—

Ten male and 12 female patients were included. Intracerebral hemorrhage occurred in 17 patients, subarachnoid hemorrhage in 4, and ischemic stroke in 1. Stroke was associated with PPA use in 16 patients (dose 75 to 675 mg), with pseudoephedrine in 4 (dose 60 to 300 mg), and with others administered by the nasal route in 2 (oxymetazoline and phenylephrine). Stroke occurred after a single dose in 17 patients and after daily use during several days in 5. The interval between drug exposure and clinical onset varied from 30 minutes to 24 hours. Stroke occurred after recommended doses of PPA (50 to 75 mg) in 32% and pseudoephedrine (60 mg) in 50% of patients. Eight patients had acute hypertension at stroke onset. Cerebral angiography was normal in 8 cases and showed diffuse vasospasm or beading in 10 patients.

Conclusions—

Stroke related to over-the-counter sympathomimetics was associated with acute hypertension and/or vasospasm or angiitis mechanisms, most related to the use of PPA; however, stroke also occurred with the use of other sympathomimetics, particularly pseudoephedrine. Although stroke complications occurred when doses were used that were higher than recommended doses, apparently there is also a stroke risk when these agents are taken properly.
Polymorphism in the Promoter Region of the Insulin-like Growth Factor I Gene Is Related to Carotid Intima-Media Thickness and Aortic Pulse Wave Velocity in Subjects With Hypertension
Authors: Schut A.F.C. , Janssen J.A.M.J.L. , Deinum J. , Vergeer J.M. , Hofman A. , Lamberts S.W.J. , Oostra B.A. , Pols H.A.P. , Witteman J.C.M. , van Duijn C.M.
Published: June 2003

Background and Purpose—

Low circulating levels of insulin-like growth factor I (IGF-I) have been associated with an increased risk for atherosclerosis. Absence of the 192-bp (wild-type) allele in the promoter region of the IGF-I gene has been associated with low circulating IGF-I levels. We examined the role of this polymorphism in relation to blood pressure and 2 early markers of atherosclerosis: carotid intima-media thickness (IMT) and aortic pulse wave velocity (PWV).

Methods—

A total of 5132 subjects of the Rotterdam Study, aged 55 to 75 years, were included in this study. In 3769 subjects who did not use blood pressure–lowering medication, the association between the IGF-I polymorphism and blood pressure was examined. In the total population, and in 3484 normotensive subjects, 1648 hypertensive and 462 untreated hypertensive subjects, the association between this polymorphism and IMT and PWV was examined.

Results—

Mean systolic and diastolic blood pressure did not differ between genotypes. In hypertensive subjects IMT was significantly increased in noncarriers of the 192-bp allele (0.83 mm) compared with heterozygous or homozygous carriers (0.80 mm) (
P
=0.04). PWV was also significantly higher in hypertensive subjects who were noncarriers of the 192-bp allele (14.3 m/s) compared with heterozygous (14.1 m/s) or homozygous carriers (13.7 m/s) (
P
=0.02). Findings were more pronounced in hypertensive subjects without medication use. In normotensive subjects, no association between this polymorphism, IMT, and PWV was observed.

Conclusions—

Our study suggests that hypertensive subjects who have low IGF-I levels because of a genetic polymorphism in the IGF-I gene are at increased risk of developing atherosclerosis.
Cerebral Hemodynamic Evaluation Using Perfusion-Weighted Magnetic Resonance Imaging
Authors: Kajimoto Katsufumi , Moriwaki Hiroshi , Yamada Naoaki , Hayashida Kohei , Kobayashi Junya , Miyashita Kotaro , Naritomi Hiroaki
Published: June 2003

Background and Purpose—

Perfusion-weighted magnetic resonance imaging (PWI) is a reliable and semiquantitative method for estimating cerebral hemodynamics. We sought to evaluate the potential of PWI for assessing cerebral blood flow (CBF) and metabolism compared with positron emission tomography (PET) in patients with chronic occlusive carotid disease.

Methods—

In 24 patients with chronic unilateral occlusive carotid disease, time-to-peak (TTP) delay (TTP-D) measured by PWI was compared with CBF, cerebral blood volume (CBV), and oxygen extraction fraction (OEF) obtained by PET. TTP indicates the time from the start of PWI to the bolus peak. TTP-D indicates the difference in TTP values between the occlusive and contralateral hemispheres. TTP-D was compared between patients with normal and reduced CBF/CBV and also between patients with normal and elevated OEF.

Results—

TTP-D in patients with reduced CBF/CBV was significantly longer than that in patients with normal CBF/CBV (3.4±1.8 versus 1.4±0.7 seconds;
P
<0.001). In the patients with reduced CBF/CBV, TTP-D correlated with OEF significantly (
r
=0.710,
P
<0.0001). TTP-D in patients with elevated OEF was significantly longer than that in patients with normal OEF (4.8±2.2 versus 2.0±0.9 seconds;
P
<0.01). In all 5 patients with TTP-D ≥4 seconds, OEF was elevated markedly.

Conclusions—

TTP-D ≥4 seconds is considered to indicate a high risk of hemodynamic failure. The measurement of TTP-D by PWI appears to provide important clinical information for evaluating cerebral hemodynamics in chronic occlusive carotid disease.
Mitochondrial ATP-Sensitive Potassium Channel Activation Protects Cerebellar Granule Neurons From Apoptosis Induced by Oxidative Stress
Authors: Teshima Yasushi , Akao Masaharu , Li Ronald A. , Chong Tae H. , Baumgartner William A. , Johnston Michael V. , Marbán Eduardo
Published: June 2003

Background and Purpose—

Mitochondrial ATP-sensitive potassium (mitoK
ATP
) channels are present in the brain, and several reports have shown that mitoK
ATP
channel openers protect the brain against ischemic injury. However, the precise mechanisms of this protection are not well established. We hypothesized that mitoK
ATP
channel openers prevent apoptosis by preserving mitochondrial membrane potential.

Methods—

We investigated the effect of mitoK
ATP
channel openers on apoptosis induced by oxidative stress using cultured cerebellar granule neurons.

Results—

The mitoK
ATP
channel opener diazoxide (100 μmol/L) significantly suppressed the number of cells with terminal deoxynucleotidyl transferase–mediated dUTP nick end-labeling (TUNEL)–positive nuclei and the increase in caspase-3 activity induced by 20 μmol/L H
2
O
2
. Diazoxide and another opener, pinacidil, prevented the loss of mitochondrial inner membrane potential (ΔΨ
m
) induced by H
2
O
2
. These effects were abolished by 5-hydroxydecanoate (500 μmol/L), a mitoK
ATP
channel blocker. Cyclosporin A and bongkrekic acid, inhibitors of the mitochondrial permeability transition pore, also prevented ΔΨ
m
loss, confirming the involvement of the mitochondrial permeability transition in the apoptotic cascade in neurons. Furthermore, diazoxide prevented the increase in extracellular glutamate concentration induced by H
2
O
2
, but this effect was not attributable to activation of surface K
ATP
channels.

Conclusions—

MitoK
ATP
channel openers inhibited apoptosis by preserving mitochondrial inner membrane potential. These beneficial effects may suggest a possible new target for neuroprotection.
Adoptive Transfer of Myelin Basic Protein–Tolerized Splenocytes to Naive Animals Reduces Infarct Size
Authors: Becker Kyra , Kindrick Darin , McCarron Richard , Hallenbeck John , Winn Robert
Published: June 2003

Background and Purpose—

Breakdown of the blood-brain barrier during stroke allows central nervous system antigens to leak into the systemic circulation and allows circulating leukocytes access to the brain. Encounter of central nervous system antigens by the peripheral immune system can be capitalized on to modulate the postischemic inflammatory response and potentially improve outcome from stroke.

Methods—

Male Lewis rats were tolerized to myelin basic protein (MBP) or ovalbumin (OVA) and subjected to 3 hours of middle cerebral artery occlusion (MCAO) or used as splenocyte donors for immunologically naive animals undergoing MCAO. Infarct size was determined at 24 hours by 2,3,5-triphenyltetrazolium chloride staining. In separate studies, mononuclear cells were removed from the brains of animals after MCAO for enzyme-linked immunospot (ELISPOT) assay and flow cytometry.

Results—

Median infarct volume in animals tolerized to MBP and those receiving splenocytes from MBP-tolerized donors was less than in animals tolerized to OVA and those receiving splenocytes from OVA-tolerized donors (87.7±54.9 versus 148±61.6 mm
3
[
P
=0.01] and 89.2±77.5 versus 153±77.1 mm
3
[
P
=0.05], respectively). There was an increase in the number of transforming growth factor-β1–secreting mononuclear cells in MBP-tolerized animals undergoing sham surgery (
P
=0.001) as well as in ischemic animals 48 hours (
P
=0.02) and 336 hours (
P
=0.04) after stroke. A distinct subset of γδ T cells was present in the brains of MBP-tolerized but not control animals after stroke.

Conclusions—

Immunologic tolerance and its neuroprotective effects can be transferred to naive animals and appear to be related to antigen-specific induction of transforming growth factor-β1.
Of Story and Place: Communicating Ecological Principles through Art
Authors: Wallen Ruth
Published: June 2003

The author argues for the importance of art in the exploration of ecological interrelationships. Art can help engender an understanding of and connection to the natural world, illuminate values and illustrate the myriad of ecological processes. Various artistic strategies used by the artist are discussed, including performances that document close observation of place, site-specific artwork that offers the opportunity to look at the natural and cultural environment in a new way, and digital imaging and web design that encourage a careful reading of representation through juxtaposition of imagery.
Synthetics: A History of the Electronically Generated Image in Australia
Authors: Jones Stephen
Published: June 2003

This paper takes a brief look at the early years of computer-graphic and video-synthesizer–driven image production in Australia. It begins with the first (known) Australian data visualization, in 1957, and proceeds through the compositing of computer graphics and video effects in the music videos of the late 1980s. The author surveys the types of work produced by workers on the computer graphics and video synthesis systems of the early period and draws out some indications of the influences and interactions among artists and engineers and the technical systems they had available, which guided the evolution of the field for artistic production.
Polarization Microscopy as an Art Tool: Border Crossing between Art and Nature
Authors: Friedrich Manfred
Published: June 2003

Until recently, polarization microscopy has been little developed as an art tool. It holds, however, an enormous aesthetic potential. The author first reviews the theoretical and technical background of polarization microscopy and then discusses how selected microscopic structures imaged via polarization microscopy can be represented according to the artist's individual aesthetic choices, the most important of which is color design by interference. The conscious perception of the pictures by the observer is discussed on the basis of our present knowledge of cognitive neurosciences. Polarization microscopy leads to a crossing of the boundaries between nature and the forms of non-representational painting.
Intelligent Bathroom Fixtures and Systems: EXISTech Corporation's Safebath Project
Authors: Mann Steve
Published: June 2003

EXISTech Corporation's computer networks, control systems and image-sensor technology facilitate hygienic touchless control of plumbing fixtures. Two of EXISTech's sensors are described here in detail: an active infrared faucet sensor and a passive infrared autoflush sensor. These devices allow internetworked plumbing systems to help facility managers and law-enforcement personnel remotely monitor the operation of bathroom fixtures. Intelligent fixtures and systems based on quantimetric sensing technology enhance the privacy of law-abiding users by eliminating the need for invasive policing of restrooms. New computer-vision algorithms also automatically detect accidents, as well as vandalism and contraband disposal, to assist remote monitoring by law enforcement.
Augmented Sculpture: Computer Ghosts of Physical Artifacts
Authors: Adzhiev Valery , Comninos Peter , Pasko Alexander
Published: June 2003

This paper describes an approach to computer-based sculpting concerned with the creation and modification of digital models based on physical abstract sculptures. The authors begin by presenting a survey of current methods for the creation of computer-based sculpted artifacts. They proceed to present some original methods and tools based on the Function Representation of geometric models. They introduce a specialized computer language, called Hyper Fun, that facilitates the modeling of complex objects. In addition to presenting computer-generated textured and animated models of pre-existing sculptures, they also show how novel shapes can be generated using the Hyper-Fun system. Finally they outline two advanced projects concerned with creating a sculpture-based augmented reality that allows for the interactive participation of the observer.
Cognitive Dance Improvisation: How Study of the Motor System Can Inspire Dance (and Vice Versa)
Authors: Hagendoorn Ivar
Published: June 2003

This paper describes several dance improvisation techniques inspired by the study of the motor system. One technique takes experiments on interlimb coordination from the laboratory to the dance studio. Another technique, termed fixed-point technique, makes use of the fact that one can change which part of the body is fixed in space. A third technique is based on the idea that one can maintain the action, as it were, by “reversing the acting limb.” All techniques target a specific capacity of the motor system and as such may inspire new psychophysical experiments. The present approach to generating movements, which merges dance improvisation with insights from cognitive neuroscience and biokinesiology, may also be fruitfully extended to robotics.
Lloyd Richards Reflections from the Playwrights' Champion
Authors: Raymond Caroline R.
Published: June 2003

In this far-reaching conversation, Lloyd Richards, one of the premiere directors and educators of the epoch, discusses his long career, which includes being the first black director on Broadway, the Dean of the Yale School of Drama and artistic director of the Yale Repertory Theatre, artistic director of the National Playwrights Conference, and director of the world premieres of six August Wilson plays.
History As Theme Park: Reconfiguring the Human Journey in the Art of Theodora Skipitares
Authors: Stanley N.J.
Published: June 2003

For over 25 years, Theodora Skipitares has been the art world's investigative reporter turned sociocultural critic—conceiving, designing, and directing productions that materialize her passionate and critical interest in history. Although in recent years Skipitares has used actors, puppets and performing objects remain her main artistic vehicles. Skipitares fluctuates between the miniature and the monumental. She continues to use unexpected media to convey very vital messages that use the past to illuminate the present.
Majestic Drag: Monarchical Performativity and the King's Body Theatrical
Authors: Franko Mark
Published: June 2003

Two Bourbon kings, Louis XIII and XIV, were ballet dancers. What were the aesthetic, political, and ritual functions of court ballet? Did the monarch's stage appearances sustain his political identity? Franko argues that dance and music, rather than reinforcing, in their blatant magnificence, the political message of power's presence, were actually the formally subversive means through which the performance sustained the ambiguity and contradiction of personal sovereignty.
Strange Fruit: A Performance about Identity Politics
Authors: Johnson E. Patrick
Published: June 2003

Each of the eight movements of Johnson's performance reflects a different aspect of his identity around which his queerness pivots. The movements range from drag to black masculinity to how Johnson negotiated race, gender, and sexuality in Ghana. Johnson's performance—utilizing slides, music, voice-overs, and dance— encouraged audience participation.
CD8+ T cells that express CD4 on their surface (CD4dimCD8bright T cells) recognize an antigen-specific target, are detected in vivo, and can be productively infected by T-tropic HIV
Authors: Zloza Andrew , Sullivan Yvonne B. , Connick Elizabeth , Landay Alan L. , Al-Harthi Lena
Published: June 2003

CD4 can be up-regulated on CD8+ T cells generating a CD4dimCD8bright phenotype. We previously demonstrated that the CD4dimCD8bright phenotype constitutes an activated phenotype of CD8+ T cells. We demonstrate here that the activated CD4dimCD8bright T cells are not undergoing apoptosis and do not produce significant intracellular levels of interferon γ (IFNγ), interleukin 2 (IL-2), or IL-10 but express elevated levels of intracellular IL-4 in comparison to CD8+CD4– and CD4+ T cells. In response to cytomegalovirus (CMV) peptide (pp65) priming, CD4dimCD8bright cells recognized CMV pp65 tetramer approximately 19-fold higher than CD4–CD8+ T cells, indicating that these cells are capable of antigen-specific recognition to a far greater extent than CD4–CD8+ T cells. CD4dimCD8bright T cells also express both CXCR4 and CCR5 but are susceptible to T-tropic and not M-tropic HIV infection. A soluble factor believed to be β-chemokine is responsible for the inhibition of M-tropic HIV infection in CD4dimCD8bright T cells. CD8+ T cells from HIV+ patients were capable of up-regulating CD4 on CD8+ T cells. We also provide evidence of the presence of peripheral blood CD4dimCD8bright T cells in HIV+ patients, albeit at low frequency. Collectively, these data suggest a role of CD4dimCD8bright T cells in both normal T-cell biology and HIV pathogenesis.
A new xenograft model for graft-versus-host disease by intravenous transfer of human peripheral blood mononuclear cells in RAG2-/- γc-/- double-mutant mice
Authors: van Rijn Rozemarijn S. , Simonetti Elles R. , Hagenbeek Anton , Hogenes Marieke C. H. , de Weger Roel A. , Canninga-van Dijk Marijke R. , Weijer Kees , Spits Hergen , Storm Gert , van Bloois Louis , Rijkers Ger , Martens Anton C. M. , Ebeling Saskia B.
Published: June 2003

The safe application of new strategies for the treatment of graft-versus-host disease (GVHD) is hampered by the lack of a clinically relevant model for preclinical testing. Current models are based on intraperitoneal transfer of human peripheral blood mononuclear cells (huPBMCs) into NOD-SCID (nonobese diabetic-severe combined immunodeficient)/SCID mice. Intravenous transfer would be preferred but this has always been ineffective. We developed a new model for xenogeneic GVHD (X-GVHD) by intravenous transfer of huPBMCs into RAG2-/- γc-/-mice. Our results show a high human T-cell chimerism of more than 20% (up to 98%) in more than 90% of mice, associated with a consistent development of XGVHD within 14 to 28 days and a total mortality rate of 85% shorter than 2 months. After murine macrophage depletion, engraftment was earlier and equally high with lower doses of huPBMCs. Human macrophages were also absent in these mice. Purified huCD3+ cells showed a similar X-GVH effect with contribution of both CD4 and CD8 phenotypes. Human immunoglobulins and cytokines were produced in diseased mice. One of 30 mice developed chronic X-GVHD with skin histology similar to human GVHD. In conclusion, we present a new model for X-GVHD by intravenous transfer of huPBMCs in RAG2-/- γc-/- mice. Murine and human macrophages do not seem to be necessary for acute X-GVHD in this model. (Blood. 2003;102:2522-2531)
Angiogenic effects of prostaglandin E2 are mediated by up-regulation of CXCR4 on human microvascular endothelial cells
Authors: Salcedo Rosalba , Zhang Xia , Young Howard A. , Michael Nelson , Wasserman Ken , Ma Wei-Hong , Martins-Green Manuela , Murphy William J. , Oppenheim Joost J.
Published: June 2003

Stimulation of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) increases the expression of CXCR4 on endothelial cells, rendering these cells more responsive to stromal-derived factor 1 (SDF-1), an angiogenic CXC chemokine and unique ligand for CXCR4. Here, we show that prostaglandin E2 (PGE2) mediates the effects of bFGF and VEGF in up-regulating CXCR4 expression on human microvascular endothelial cells (HMECs). Forskolin or 3-isobutyl-1-methyl xanthine (IBMX), 2 inducers of adenylate cyclase, markedly enhanced, whereas cyclooxygenase (COX) inhibitors including aspirin, piroxicam, and NS398 markedly inhibited CXCR4 expression on HMECs. Furthermore, the ability of PGE2 to augment in vitro tubular formation in SDF-1α containing matrigel was inhibited completely by blocking CXCR4. Treatment of bFGF- or VEGF-stimulated HMECs with COX inhibitors blocked tubular formation by about 50% to 70%. Prostaglandin-induced human endothelial cell organization and subsequent vascularization can be inhibited to a greater extent by a neutralizing antibody to human CXCR4 in severe combined immunodeficient mice. Additionally, VEGF- and bFGF-induced angiogenesis in vivo was also inhibited by about 50% by NS-398 or piroxicam, and this inhibitory effect was accompanied by decreased expression of CXCR4 on murine endothelial cells. Consequently, by inducing CXCR4 expression, prostaglandin accounts for about 50% of the tubular formation in vitro and in vivo angiogenic effects of VEGF and bFGF. Moreover, augmentation of CXCR4 expression by VEGF, bFGF, and PGE2 involves stimulation of transcription factors binding to the Sp1-binding sites within the promoter region of the CXCR4 gene. These findings indicate that PGE2 is a mediator of VEGF- and bFGF-induced CXCR4-dependent neovessel assembly in vivo and show that angiogenic effects of PGE2 require CXCR4 expression.
T-cell developmental blockage by tachykinin antagonists and the role of hemokinin 1 in T lymphopoiesis
Authors: Zhang Yu , Paige Christopher J.
Published: June 2003

Hemokinin 1 (HK-1) is a new member of the tachykinin peptide family that is expressed in hematopoietic cells. Recent reports studying mouse, rat, and human orthologs of HK-1 demonstrate a broader distribution than originally reported. Our previous studies demonstrated that HK-1, by promoting proliferation, survival, and possibly maturation of B-cell precursors, plays an important role in B lymphopoiesis. Here we present data showing that HK-1 also influences T-cell development at a similar stage of differentiation. This peptide enhanced the proliferation of T-cell precursors and increased the number of thymocytes in fetal thymus organ cultures (FTOCs). Tachykinin antagonists, on the other hand, greatly reduced the cellularity of thymi both in vivo and in vitro. The major reduction occurred in the CD4/CD8 double-positive (DP) cells and the CD44–CD25+ subset of the CD4/CD8 double-negative (DN) cells. Of note, these populations also express HK-1, raising the possibility of autocrine or paracrine pathways influencing T-cell development as we previously reported for B-cell development. Consistent with this, the detrimental effect of tachykinin antagonists could be partially overcome with exogenous HK-1 peptide.
Filamin A binding to the cytoplasmic tail of glycoprotein Ibα regulates von Willebrand factor–induced platelet activation
Authors: Feng Shuju , Reséndiz Julio C. , Lu Xin , Kroll Michael H.
Published: June 2003

We examined the hypothesis that filamin A binding to the cytoplasmic tail of platelet glycoprotein Ibα (GpIbα) is regulated by pathologic shear stress and modulates von Willebrand factor (VWF)–induced platelet activation. To begin, we examined filamin binding to GpIbα in Chinese hamster ovary cells coexpressing mutant human GpIb-IX and wild-type human filamin A. We observed that many different deletions and truncations N-terminal to GpIbα's cytoplasmic domain residue 594 disrupted filamin A binding, but that binding was unaffected by 14 different point mutations in hydrophilic residues between amino acids 557 and 593. To try to narrow GpIbα's filamin A–binding domain, we next measured the effect of several cytoplasmic domain peptides on human filamin A binding to a GST-GpIbα cytoplasmic domain fusion protein. One peptide (residues 557-575; designated “A4 peptide”) inhibited filamin A binding to the GST-GpIbα cytoplasmic domain fusion protein and competed with GpIbα for binding to filamin A. When the A4 peptide was delivered to intact human platelets using a carrier peptide, we observed the dose-dependent inhibition of VWF-induced platelet aggregation in response to both ristocetin and shear stress. The effect of the A4 peptide on shear-induced platelet aggregation was accompanied by the attenuation of shear-induced filamin A binding to GpIbα and diminished shear-dependent protein tyrosine phosphorylation. These results suggest that shear-dependent VWF-induced platelet activation affects filamin A binding to GpIb-IX-V, and that filamin A binding to the cytoplasmic tail of GpIbα regulates proaggregatory tyrosine kinase signaling.
A novel strategy using single-chain antibody to show the importance of Bcl-2 in mast cell survival
Authors: Cohen-Saidon Cellina , Nechushtan Hovav , Kahlon Shira , Livni Nadav , Nissim Ahuva , Razin Ehud
Published: June 2003

Apoptosis or programmed cell death plays an important role in a wide variety of physiologic processes and is regulated by proteins of the Bcl-2 family consisting of both antiapoptotic and proapoptotic factors. The direct involvement of the Bcl-2 protein family in the process of mast cell apoptosis has not been clarified. In the present work we have used a single-chain antibody (scFv) raised against Bcl-2 derived from a semisynthetic human phage-display antibody library. The addition of TAT sequence, which is responsible for translocation through the membrane, endows the anti-Bcl-2-scFv with the ability to penetrate living cells. Moreover, it specifically neutralizes Bcl-2 intracellularly by binding to the BH1 domain and eradicates its antiapoptotic activity in 2 types of mast cells and in a human breast cancer cell line. (Blood. 2003;102:2506-2512)
FLT3 and MLL intragenic abnormalities in AML reflect a common category of genotoxic stress
Authors: Libura Marta , Asnafi Vahid , Tu Angela , Delabesse Eric , Tigaud Isabelle , Cymbalista Florence , Bennaceur-Griscelli Annelise , Villarese Patrick , Solbu Gabriel , Hagemeijer Anne , Beldjord Kheira , Hermine Olivier , Macintyre Elizabeth
Published: June 2003

MLL rearrangements in acute myeloid leukemia (AML) include translocations and intragenic abnormalities such as internal duplication and breakage induced by topoisomerase II inhibitors. In adult AML, FLT3 internal tandem duplications (ITDs) are more common in cases with MLL intragenic abnormalities (33%) than those with MLL translocation (8%). Mutation/deletion involving FLT3 D835 are found in more than 20% of cases with MLL intragenic abnormalities compared with 10% of AML with MLL translocation and 5% of adult AML with normal MLL status. Real-time quantification of FLT3 in 141 cases of AML showed that all cases with FLT3 D835 express high level transcripts, whereas FLT3-ITD AML can be divided into cases with high-level FLT3 expression, which belong essentially to the monocytic lineage, and those with relatively low-level expression, which predominantly demonstrate PML-RARA and DEK-CAN. FLT3 abnormalities in CBF leukemias with AML1-ETO or CBFβ-MYH11 were virtually restricted to cases with variant CBFβ-MYH11 fusion transcripts and/or atypical morphology. These data suggest that the FLT3 and MLL loci demonstrate similar susceptibility to agents that modify chromatin configuration, including topoisomerase II inhibitors and abnormalities involving PML and DEK, with consequent errors in DNA repair. Variant CBFβ-MYH11 fusions and bcr3 PML-RARA may also be initiated by similar mechanisms.
NF-Y cooperates with USF1/2 to induce the hematopoietic expression of HOXB4
Authors: Zhu Jiang , Giannola Diane M. , Zhang Yi , Rivera Adam J. , Emerson Stephen G.
Published: June 2003

The transcription factor homeobox B4 (HOXB4) is preferentially expressed in immature hematopoietic cells and implicated in the transition from primitive hematopoiesis to definitive hematopoiesis as well as in immature hematopoietic cell proliferation and differentiation. We previously identified Hox response element 1 (HxRE-1) and HxRE-2/E-box as 2 critical DNA-binding sites of the HOXB4 promoter active in hematopoietic cells and demonstrated that upstream stimulating factor 1 and 2 (USF1/2) activate HOXB4 transcription through their binding to the E-box site. Here we report that the trimeric regulatory complex nuclear factor Y (NF-Y) is the factor that recognizes HxRE-1 and activates the HOXB4 promoter in hematopoietic cells. We further show that NF-Y interacts biochemically with USF1/2 on the HOXB4 promoter, and that the formation of this NF-Y/USF1/2 complex is required for the full activity of the HOXB4 promoter. Most important, NF-Ya subunit protein levels are found to be lower in c-Kit-Gr-1+ granulocytic bone marrow (BM) cells than in c-Kit+ immature BM cells, in parallel with a reduction of NF-Y occupancy on the HOXB4 promoter as shown by chromatin immunoprecipitation (ChIP) assay. These results suggest that NF-Y is a developmentally regulated inducer of the HOXB4 gene in hematopoietic cells. (Blood. 2003;102:2420-2427)
Polymorphic variation in GSTP1 modulates outcome following therapy for multiple myeloma
Authors: Dasgupta Ranjit K. , Adamson Peter J. , Davies Faith E. , Rollinson Sara , Roddam Philippa L. , Ashcroft A. John , Dring Ann M. , Fenton James A. L. , Child J. Anthony , Allan James M. , Morgan Gareth J.
Published: June 2003

Glutathione S-transferase P1 (GSTP1) is a phase 2 drug metabolism enzyme involved in the metabolism and detoxification of a range of chemotherapeutic agents. A single nucleotide polymorphism (Ile105Val) results in a variant enzyme with lower thermal stability and altered catalytic activity. We hypothesized that patients with the less stable variant have a decreased ability to detoxify chemotherapeutic substrates, including melphalan, and have an altered outcome following treatment for multiple myeloma. We have assessed the impact of GSTP1 codon 105 polymorphisms in 222 patients entered into the Medical Research Council (MRC) myeloma VII trial (comparing standard-dose chemotherapy with high-dose therapy). In the standard-dose arm, patients with the variant allele (105Val) had an improved progression-free survival (PFS) (adjusted hazard ratios for PFS were 0.55 for heterozygotes and 0.52 for 105Val homozygotes, compared with 105Ile homozygotes; P for trend = .04); this was supported by a trend to improved overall survival, greater likelihood of entering plateau and shorter time to reach plateau in patients with the 105Val allele. No difference in outcome by genotype was found for patients treated with high-dose therapy. However, the progression-free survival advantage of the high-dose arm was seen only in patients homozygous for 105Ile (P = .008). (Blood. 2003;102:2345-2350)
HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative conditioning for patients with hematologic malignancies
Authors: Maris Michael B. , Niederwieser Dietger , Sandmaier Brenda M. , Storer Barry , Stuart Monic , Maloney David , Petersdorf Effie , McSweeney Peter , Pulsipher Michael , Woolfrey Ann , Chauncey Thomas , Agura Ed , Heimfeld Shelly , Slattery John , Hegenbart Ute , Anasetti Claudio , Blume Karl , Storb Rainer
Published: June 2003

A hematopoietic cell transplantation (HCT) approach was developed for elderly or ill patients with hematologic malignancies that employed nonmyeloablative conditioning to avoid common regimen-related toxicities and relied on graft-versus-tumor effects for control of malignancy. Eighty-nine patients, median age 53 years, were given fludarabine (90 mg/m2) and 2 Gy total body irradiation. Marrow (n = 18) or granulocyte colony-stimulating factor (G-CSF)–stimulated peripheral blood mononuclear cells (G-PBMCs; n = 71) were transplanted from unrelated donors matched for human leukocyte antigen A (HLA-A), -B, -C antigens and -DRB1 and -DQB1 alleles. Postgrafting immunosuppression included mycophenolate mofetil and cyclosporine. Donor T-cell chimerism was higher for G-PBMCs compared with marrow recipients. Durable engraftment was observed in 85% of G-PBMCs and 56% of marrow recipients. Cumulative probabilities of grade II, III, and IV acute graft-versus-host disease (GVHD) were 42%, 8%, and 2%, respectively. Nonrelapse mortality at day 100 and at 1 year was 11% and 16%, respectively. One-year overall survivals and progression-free survivals were 52% and 38%, respectively. G-PBMC recipients had improved survival (57% vs 33%) and progression-free survival (44% vs 17%) compared with marrow recipients. HLA-matched unrelated donor HCT after nonmyeloablative conditioning is feasible in patients ineligible for conventional HCT. G-PBMCs conferred higher donor T-cell chimerism, greater durable engraftment, and better progression-free and overall survivals compared with marrow.
Preclinical in vivo evaluation of pseudotyped adeno-associated virus vectors for liver gene therapy
Authors: Grimm Dirk , Zhou Shangzhen , Nakai Hiroyuki , Thomas Clare E. , Storm Theresa A. , Fuess Sally , Matsushita Takashi , Allen James , Surosky Richard , Lochrie Michael , Meuse Leonard , McClelland Alan , Colosi Peter , Kay Mark A.
Published: June 2003

We report the generation and use of pseudotyped adeno-associated viral (AAV) vectors for the liver-specific expression of human blood coagulation factor IX (hFIX). Therefore, an AAV-2 genome encoding the hfIX gene was cross-packaged into capsids of AAV types 1 to 6 using efficient, large-scale technology for particle production and purification. In immunocompetent mice, the resultant vector particles expressed high hFIX levels ranging from 36% (AAV-4) to more than 2000% of normal (AAV-1, -2, and -6), which would exceed curative levels in patients with hemophilia. Expression was dose- and time-dependent, with AAV-6 directing the fastest and strongest onset of hFIX expression at all doses. Interestingly, systemic administration of 2 × 1012 vector particles of AAV-1, -4, or -6 resulted in hFIX levels similar to those achieved by portal vein delivery. For all other serotypes and particle doses, hepatic vector administration yielded up to 84-fold more hFIX protein than tail vein delivery, corroborated by similarly increased vector DNA copy numbers in the liver, and elicited a reduced immune response against the viral capsids. Finally, neutralization assays showed variable immunologic cross-reactions between most of the AAV serotypes. Our technology and findings should facilitate the development of AAV pseudotype-based gene therapies for hemophilia B and other liver-related diseases. (Blood. 2003;102:2412-2419)
The homeoprotein Hex is required for hemangioblast differentiation
Authors: Guo Ying , Chan Rebecca , Ramsey Heather , Li Weiming , Xie Xiaodong , Shelley William C. , Martinez-Barbera Juan Pedro , Bort Bernardo , Zaret Kenneth , Yoder Mervin , Hromas Robert
Published: June 2003

The first hematopoietic and endothelial progenitors are derived from a common embryonic precursor termed the hemangioblast. The genetic cascades that regulate the differentiation of the hemangioblast to hematopoietic and endothelial cells are largely unknown. In general, much of embryonic development is coordinately regulated by temporal and spatial expression of transcription factors, such as the Homeobox (Hox) gene family. We and others isolated a divergent homeobox gene termed Hex (or Prh) that is preferentially expressed in hematopoietic and endothelial cells. Using in vitro Hex-/- embryonic stem (ES) cell differentiation, in vivo yolk sac hematopoietic progenitor assays, and chimeric mouse analysis, we found that Hex is required for differentiation of the hemangioblast to definitive embryonic hematopoietic progenitors and to a lesser extent endothelial cells. Therefore, Hex is a novel regulator of hemangioblast differentiation to hematopoietic and endothelial cells. (Blood. 2003;102:2428-2435)
Sex-specific alterations in neutrophil apoptosis: the role of estradiol and progesterone
Authors: Molloy Eleanor J. , O'Neill Amanda J. , Grantham Julie J. , Sheridan-Pereira Margaret , Fitzpatrick John M. , Webb David W. , Watson R. William G.
Published: June 2003

Women are conferred with greater immunologic and survival benefits compared to men. Female sex steroids contribute to this sexual dimorphism. Furthermore, during human pregnancy when female sex hormones are elevated, neutrophil apoptosis is delayed. This study examines the specific effects of estradiol and progesterone on neutrophil apoptosis and function in healthy adult men and women. We also examined the contribution of these hormones to the persistence and resolution of an inflammatory response. Spontaneous apoptosis was significantly decreased in women compared with men. Physiologic doses of estradiol and progesterone caused a further delay in spontaneous apoptosis in both men and women but did not diminish Fas antibody-induced apoptosis. The delay in apoptosis was mediated at the level of the mitochondria with decreased release of cytochrome c, which may alter caspase cleavage and activity. There were no associated alterations in neutrophil CD11b, but production of reactive oxygen intermediates (ROIs) in women was increased. Thus, female sex hormones mediate delayed neutrophil apoptosis in both sexes and enhance female intracellular production of ROIs. Modulating hormonal responses may be an effective therapeutic tool in combating inflammatory diseases. (Blood. 2003;102:2653-2659)
Phase 2 clinical and pharmacologic study of clofarabine in patients with refractory or relapsed acute leukemia
Authors: Kantarjian Hagop , Gandhi Varsha , Cortes Jorge , Verstovsek Srdan , Du Min , Garcia-Manero Guillermo , Giles Francis , Faderl Stefan , O'Brien Susan , Jeha Sima , Davis Jan , Shaked Zeev , Craig Adam , Keating Michael , Plunkett William , Freireich Emil J
Published: June 2003

In a phase 2 study, 62 patients with relapsed and refractory acute myeloid leukemia (AML; n = 31), myelodysplastic syndrome (MDS; n = 8), chronic myeloid leukemia in blastic phase (CMLBP; n = 11), and acute lymphocytic leukemia (ALL; n = 12) received 40 mg/m2 clofarabine intravenously over 1 hour daily for 5 days, every 3 to 6 weeks. Twenty patients (32%) achieved complete response (CR), 1 had a partial response (PR), and 9 (15%) achieved CR but without platelet recovery (CRp), for an overall response rate of 48%. In AML, responses were noted in 2 (18%) of 11 patients in first salvage with short first CR (≤ 12 months), in 7 (87%) of 8 patients with longer first CR, and in 8 (67%) of 12 patients in second or subsequent salvage. Responses were observed in 4 of 8 patients with high-risk MDS (50%), in 7 (64%) of 11 with CML-BP, and in 2 (17%) of 12 with ALL. Severe reversible liver dysfunction was noted in 15% to 25%. After the first clofarabine infusion, responders accumulated more clofarabine triphosphate in blasts compared with nonresponders (median 18 vs 10 μM; P = .03). This increased only in responders (median, 1.8-fold; P = .008) after the second clofarabine infusion. In summary, clofarabine is active in acute leukemias and MDS; cellular pharmacokinetics may have prognostic significance. (Blood. 2003;102:2379-2386)
The costs of asthma
Authors: Barnes PJ , Jonsson B , Klim JB
Published: June 2003

At present, asthma represents a substantial burden on health care resources in all countries so far studied. The costs of asthma are largely due to uncontrolled disease, and are likely to rise as its prevalence and severity increase. Costs could be significantly reduced if disease control is improved. A large proportion of the total cost of illness is derived from treating the consequences of poor asthma control-direct costs, such as emergency room use and hospitalizations. Indirect costs, which include time off work or school and early retirement, are incurred when the disease is not fully controlled and becomes severe enough to have an effect on daily life. In addition, quality of life assessments show that asthma has a significant socioeconomic impact, not only on the patients themselves, but on the whole family. Underuse of prescribed therapy, which includes poor compliance, significantly contributes towards the poor control of asthma. The consequences of poor compliance in asthma include increased morbidity and sometimes mortality, and increased health care expenditure. To improve asthma management, international guidelines have been introduced which recommend an increase in the use of prophylactic therapy. The resulting improvements in the control of asthma will reduce the number of hospitalizations associated with asthma, and may ultimately produce a shift within direct costs, with subsequent reductions in indirect costs. In addition, costs may be reduced by improving therapeutic interventions and through effective patient education programmes. This paper reviews current literature on the costs of asthma to assess how effectively money is spent and, by estimating the proportion of the cost attributable to uncontrolled disease, will identify where financial savings might be made.
Prospective study of the value of transbronchial lung biopsy after lung transplantation
Authors: Boehler A , Vogt P , Zollinger A , Weder W , Speich R
Published: June 2003

Transbronchial lung biopsy (TBB) has become the gold standard for the diagnosis of acute rejection and cytomegalovirus (CMV) pneumonia in lung transplant recipients. The aim of this study was to assess the value of regular surveillance TBB in stable asymptomatic patients and to establish the role of TBB as a follow-up procedure 1 month after a previous pathological biopsy result. We prospectively evaluated 76 TBBs performed in 17 lung transplant recipients. A definite pathological results was found in 14 of 15 TBBs performed for clinical indications: CMV pneumonia (5), acute rejection grade > or = A2 according to the criteria of the International Society for Heart and Lung Transplantation (ISHLT) (4), bronchiolitis obliterans (3), and desquamative interstitial pneumonitis (2). Fifteen of 45 surveillance TBBs performed in asymptomatic patients revealed significant abnormalities. Ten episodes of acute rejection ISHLT grade > or = A2 and three episodes of CMV pneumonia detected by TBB had direct therapeutic consequences. Nine of 16 follow-up TBBs performed 1 month after a pathological biopsy result again showed relevant pathological findings. With the exception of one severe haemorrhage, no life-threatening complications occurred. Our results suggest that transbronchial lung biopsies performed on a regular basis after lung transplantation are important for the detection of asymptomatic and/or persistent acute rejection or injection. In the long-term, this strategy might be the most effective tool in reducing the incidence of bronchiolitis obliterans, which is still the main obstacle for further improvement of long-term survival after lung transplantation.