bluuebunny/crossref_metadata_2025 huggingface dataset:
Dimethylarginine Dimethylaminohydrolase Regulates Nitric Oxide Synthesis
Authors: Dayoub Hayan , Achan Vinod , Adimoolam Shanthi , Jacobi Johannes , Stuehlinger Marcus C. , Wang Bing-yin , Tsao Philip S. , Kimoto M. , Vallance Patrick , Patterson Andrew J. , Cooke John P.
Published: November 2003

Background—

NO is a major regulator of cardiovascular physiology that reduces vascular and cardiac contractility. Accumulating evidence indicates that endogenous inhibitors may regulate NOS. The NOS inhibitors asymmetric dimethylarginine (ADMA) and
N
-monomethylarginine are metabolized by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). This study was designed to determine if increased expression of DDAH could reduce tissue and plasma levels of the NOS inhibitors and thereby increase NO synthesis.

Methods and Results—

We used gene transfer and transgenic approaches to overexpress human DDAH I in vitro and in vivo. The overexpression of DDAH in cultured endothelial cells in vitro induced a 2-fold increase in NOS activity and NO production. In the hDDAH-1 transgenic mice, we observed ≈2-fold increases in tissue NOS activity and urinary nitrogen oxides, associated with a 2-fold reduction in plasma ADMA. The systolic blood pressure of transgenic mice was 13 mm Hg lower than that of wild-type controls (
P
<0.05). The systemic vascular resistance and cardiac contractility were decreased in response to the increase in NO production.

Conclusions—

DDAH I overexpression increases NOS activity in vitro and in vivo. The hDDAH-1 transgenic animal exhibits a reduced systolic blood pressure, systemic vascular resistance, and cardiac stroke volume. This study provides compelling evidence that the elaboration and metabolism of endogenous ADMA plays an important role in regulation of NOS activity.
Implantable Cardioverter-Defibrillator Therapy for Prevention of Sudden Death in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia
Authors: Corrado Domenico , Leoni Loira , Link Mark S. , Bella Paolo Della , Gaita Fiorenzo , Curnis Antonio , Salerno Jorge Uriarte , Igidbashian Diran , Raviele Antonio , Disertori Marcello , Zanotto Gabriele , Verlato Roberto , Vergara Giuseppe , Delise Pietro , Turrini Pietro , Basso Cristina , Naccarella Franco , Maddalena Francesco , Estes N.A. Mark , Buja Gianfranco , Thiene Gaetano
Published: November 2003

Background—

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a condition associated with the risk of sudden death (SD).

Methods and Results—

We conducted a multicenter study of the impact of the implantable cardioverter-defibrillator (ICD) for prevention of SD in 132 patients (93 males and 39 females, age 40±15 years) with ARVC/D. Implant indications were a history of cardiac arrest in 13 patients (10%), sustained ventricular tachycardia in 82 (62%), syncope in 21 (16%), and other in 16 (12%). During a mean follow-up of 39±25 months, 64 patients (48%) had appropriate ICD interventions, 21 (16%) had inappropriate interventions, and 19 (14%) had ICD-related complications. Fifty-three (83%) of the 64 patients with appropriate interventions received antiarrhythmic drug therapy at the time of first ICD discharge. Programmed ventricular stimulation was of limited value in identifying patients at risk of tachyarrhythmias during the follow-up (positive predictive value 49%, negative predictive value 54%). Four patients (3%) died, and 32 (24%) experienced ventricular fibrillation/flutter that in all likelihood would have been fatal in the absence of the device. At 36 months, the actual patient survival rate was 96% compared with the ventricular fibrillation/flutter-free survival rate of 72% (
P
<0.001). Patients who received implants because of ventricular tachycardia without hemodynamic compromise had a significantly lower incidence of ventricular fibrillation/flutter (log rank=0.01). History of cardiac arrest or ventricular tachycardia with hemodynamic compromise, younger age, and left ventricular involvement were independent predictors of ventricular fibrillation/flutter.

Conclusions—

In patients with ARVC/D, ICD therapy provided life-saving protection by effectively terminating life-threatening ventricular arrhythmias. Patients who were prone to ventricular fibrillation/flutter could be identified on the basis of clinical presentation, irrespective of programmed ventricular stimulation outcome.
Cyclooxygenase Isoforms and Platelet Vessel Wall Interactions in the Apolipoprotein E Knockout Mouse Model of Atherosclerosis
Authors: Belton Orina A. , Duffy Angela , Toomey Sinead , Fitzgerald Desmond J.
Published: November 2003

Background—

Cyclooxygenase (COX) activity is induced in human atherosclerosis, and the products formed may modify the disease directly or through an effect on platelets. We examined the role of COX-1 and -2 on platelet vessel wall interactions and development of atherosclerosis in a murine model.

Methods and Results—

Apolipoprotein E–deficient (apoE
−/−
) mice fed a 1% cholesterol diet were treated with a selective COX-1 inhibitor (SC-560), a selective COX-2 inhibitor (SC-236), or vehicle. Urinary prostacyclin and thromboxane metabolites (2,3-dinor-6-keto-PGF
1α
and 2,3-dinor-TXB
2
) were increased in the apoE
−/−
knockout mouse. There was also induction of both COX isoforms in the vascular lesions formed, which stained for CD41, a platelet-specific marker, and for CD40L. Selective inhibition of COX-2 had no effect on lesion formation and, despite selective reduction in prostacyclin generation, had no effect on platelet activity, as measured by thromboxane formation or platelet deposition. Selective inhibition of COX-1 reduced 2,3-dinor-TXB
2
generation and lesion formation. However, platelet deposition on the vessel wall persisted, with well-defined monolayers seen. There was also persistent expression of the macrophage marker CD68 and increased expression of the cell death protein Bax. In contrast to lesion development, the selective COX-1 inhibitor had no effect on the regression of evolving lesions.

Conclusions—

COX-1 plays an important role in the early stages of lesion development in the apoE
−/−
knockout model of atherosclerosis, preventing gross lesion formation in the face of continued vascular injury and inflammation. Despite the inhibition of prostacyclin, COX-2 inhibition had no effect on lesion development or platelet–vessel wall interactions.
Pioglitazone Prevents Hypertension and Reduces Oxidative Stress in Diet-Induced Obesity
Authors: Dobrian Anca D. , Schriver Suzanne D. , Khraibi Ali A. , Prewitt Russell L.
Published: November 2003

The objective of this study was to determine the effect of pioglitazone on blood pressure (BP) and oxidative balance in obese, hypertensive, Sprague-Dawley rats and to identify some of the molecular mechanisms involved. After 12 weeks of a moderately high-fat diet, rats diverged into obesity-prone (OP) and obesity-resistant (OR) groups (n=6 per group). At the end of the diet, peroxisome proliferator activated receptor-γ (PPARγ) mRNA expression and activity in the renal cortex and medulla of OP rats were significantly lower compared with that in OR rats. Pioglitazone treatment increased PPARγ expression and activity in OP rats, suggesting a possible direct ligand-related effect of pioglitazone. As opposed to the untreated OP group, which showed moderate hypertension (systolic BP=159±5.3 mm Hg) after 12 weeks, pioglitazone-treated rats were normotensive (systolic BP=123.9±2.7 mm Hg). Insulin production was reduced by 2-fold in the OP group treated with pioglitazone. Urinary isoprostanes and renal lipid peroxides were also reduced in OP rats treated with pioglitazone compared with untreated counterparts. Also, expression of p47
phox
and gp91
phox
, both increased in OP versus OR rats, was reduced in the former by pioglitazone treatment. In addition, pioglitazone treatment increased nitrate/nitrite excretion and expression of renal endothelial and neuronal nitric oxide synthase. Collectively, the results show that pioglitazone treatment prevented hypertension and renal oxidative stress both by reducing free-radical production and by increasing nitric oxide production/availability.
Hypertension Treatment and Control in Five European Countries, Canada, and the United States
Authors: Wolf-Maier Katharina , Cooper Richard S. , Kramer Holly , Banegas José R. , Giampaoli Simona , Joffres Michel R. , Poulter Neil , Primatesta Paola , Stegmayr Birgitta , Thamm Michael
Published: November 2003

Levels of hypertension treatment and control have been noted to vary between Europe and North America, although direct comparisons with similar methods have not been undertaken. In this study, we sought to estimate the relative impact of hypertension treatment strategies in Germany, Sweden, England, Spain, Italy, Canada, and the United States by using sample surveys conducted in the 1990s. Hypertension was defined as a blood pressure of 160/95 mm Hg or 140/90 mm Hg, plus persons taking antihypertensive medication. “Controlled hypertension” was defined as a blood pressure less than threshold among persons taking antihypertensive medications. Among persons 35 to 64 years, 66% of hypertensives in the United States had their blood pressure controlled at 160/95 mm Hg, compared with 49% in Canada and 23% to 38% in Europe. Similar discrepancies were apparent at the 140/90 mm Hg threshold, at which 29% of hypertensives in the United States, 17% in Canada, and ≤10% in European countries had their blood pressure controlled. At the 140/90 mm Hg cutpoint, two thirds to three quarters of the hypertensives in Canada and Europe were untreated compared with slightly less than half in the United States. Although guidelines vary among countries, resulting in different case definitions, this does not account entirely for the varying success of different national control efforts. Low treatment and control rates in Europe, combined with a higher prevalence of hypertension, could contribute to a higher burden of cardiovascular disease risk attributable to elevated blood pressure compared with that in North America.
Hydrochlorothiazide Versus Chlorthalidone
Authors: Carter Barry L. , Ernst Michael E. , Cohen Jerome D.
Published: November 2003

Thiazide diuretics are one of the preferred pharmacologic treatments for hypertension. Hydrochlorothiazide and chlorthalidone have been the 2 most commonly used diuretics in major clinical trials. Treatment guidelines and compendia often consider these 2 drugs interchangeable agents within the class of thiazide or thiazide-like diuretics. Many sources list them as equipotent. Despite these beliefs, there is some suggestion that cardiovascular outcomes are not necessarily the same with these 2 drugs. We conducted a literature search from 1960 to 2003 to identify studies that evaluated the pharmacokinetic and blood pressure–lowering effects of these 2 agents. There are significant pharmacokinetic and pharmacodynamic differences between these diuretics. Chlorthalidone is ≈1.5 to 2.0 times as potent as hydrochlorothiazide, and the former has a much longer duration of action. Whether these pharmacokinetic and pharmacodynamic features cause differences in outcomes is not known.
Different Growth Factor Activation in the Right and Left Ventricles in Experimental Volume Overload
Authors: Modesti Pietro Amedeo , Vanni Simone , Bertolozzi Iacopo , Cecioni Ilaria , Lumachi Camilla , Perna Avio Maria , Boddi Maria , Gensini Gian Franco
Published: November 2003

Mechanical factors play a key role in activation of cardiac growth factor response in hemodynamic overload, and both cooperate in myocardial remodeling. The present study was performed to investigate whether a different growth factor response is activated in the right and left ventricles in aortocaval fistula and its effects on regional myocardial adaptation. Relations between regional growth factor expression (angiotensin II, insulin-like growth factor-I, and endothelin-1), myocyte shape changes, and collagen deposition were investigated at mRNA and peptide levels in adult pigs after the creation of an aortocaval fistula distal to the renal arteries (n=15) and in sham-operated animals (n=15). The role of angiotensin II was investigated by the administration of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist. In the left ventricle, pure volume overload was accompanied by persistent increase of insulin-like growth factor-I mRNA expression, peptide concentration (2.2-fold versus sham at 3 months,
P
<0.05), and significant increase of myocyte length (+29% at 3 months,
P
<0.05). Conversely, the mixed pressure-volume overload faced by the right ventricle resulted in significant regional overexpression of all growth factors investigated (angiotensin II, insulin-like growth factor-I, and endothelin-1), with corresponding increase of myocyte diameter and length and collagen deposition (+117% at 3 months). Collagen accumulation in the right ventricle as well as the increase in right ventricular end-diastolic pressure at the 3-month observation were inhibited by angiotensin II antagonism. The left and right ventricles respond differently to aortocaval fistula, and local growth factor expression is closely related to the regional myocardial adaptation.
ROS During the Acute Phase of Ang II Hypertension Participates in Cardiovascular MAPK Activation But Not Vasoconstriction
Authors: Zhang Guo-Xing , Kimura Shoji , Nishiyama Akira , Shokoji Takaomi , Rahman Matlubur , Abe Youichi
Published: November 2003

The relations among hypertensive response, oxidative stress, and mitogen-activated protein kinase (MAPK) in cardiovascular tissues have not been fully established. We investigated the involvement of reactive oxygen species on changes in the hemodynamics and cardiovascular MAPKs activities induced by acutely administered angiotensin II (Ang II) in conscious normotensive rats with or without treatment with a superoxide dismutase mimetic, 4-hydroxy-2,2,6,6-tetramethyl piperidinoxyl (tempol). Intravenous infusion of a pressor dose of Ang II rapidly increased mean arterial blood pressure (MBP) by 53±5 mm Hg. After a 30-minute treatment with Ang II, phosphorylated MAPKs (ERK1/2, JNK, p38) as well as thiobarbital reactive substances (T-BARS) were increased in the aorta and cardiac left ventricle. Tempol had no significant effect on the elevation of MBP elicited by Ang II; however, it dose-dependently suppressed the augmented phosphorylation of cardiovascular MAPKs and increased T-BARS levels in plasma and tissues induced by Ang II. An acutely administered pressor dose of phenylephrine, an α-adrenoceptor agonist, also showed tempol-sensitive cardiovascular MAPK activation and tempol-insensitive blood pressure elevation. These in vivo data indicate that acute administration of Ang II or phenylephrine provoked an increase in oxidative stress in the cardiovascular tissues leading to the activation of MAPKs, whether it was mediated by pressure overload or the direct action of these vasoconstrictors, and that oxidative stress might not have a major contribution to the acute hypertensive responses elicited by the vasoconstrictors.
Aldosterone Antagonism Attenuates Obesity-Induced Hypertension and Glomerular Hyperfiltration
Authors: de Paula Rogerio B. , da Silva Alexandre A. , Hall John E.
Published: November 2003

This study examined the importance of aldosterone (ALDO) in mediating changes in renal function and increased mean arterial pressure (MAP) during the development of dietary-induced obesity in chronically instrumented dogs. Mean arterial pressure, heart rate (HR), and cardiac output (CO) were recorded 24 hours per day in lean dogs (n=7) before and after administration of an ALDO antagonist, eplerenone (EP) (10 mg/kg twice daily), for 10 days. After 10 days of EP treatment, the dogs (n=7) were given a supplement of cooked beef fat for 5 weeks while EP was continued. An untreated group (n=6) was fed a high fat diet for 5 weeks and used as control (C). In lean dogs, EP decreased MAP from 89±4 to 84±4 mm Hg and glomerular filtration rate from 67.4±6.8 to 53.2±4.9 mL/min while inducing a small negative Na
+
balance (−42±12 mEq). Plasma renin activity increased from 0.4±0.1 to 2.7±0.7 ng AI/mL per hour and plasma K
+
increased from 4.8±0.1 to 6.1±0.3 mEq/L. After 5 weeks of a high fat diet, body weight increased 45% to 53% in EP and C obese dogs. In C dogs, MAP increased by 16±3 mm Hg, compared with only 7±1 mm Hg in EPLE dogs. Compared with untreated dogs, the EP dogs had smaller increases in CO (18±4.6% versus 43±1.5%), HR (33±5% versus 60±3%), glomerular filtration rate (19±5% versus 38±6%), and cumulative Na
+
balance (138±35 mEq versus 472±110 mEq) after 5 weeks of a high fat diet. Thus, EP markedly attenuated glomerular hyperfiltration, sodium retention, and hypertension associated with chronic dietary-induced obesity. These observations indicate that ALDO plays an important role in the pathogenesis of obesity hypertension.
Mice With a Deletion in the First Intron of the
Col1a1
Gene Develop Age-Dependent Aortic Dissection and Rupture
Authors: Rahkonen Otto , Su Ming , Hakovirta Harri , Koskivirta Ilpo , Hormuzdi Sheriar G. , Vuorio Eero , Bornstein Paul , Penttinen Risto
Published: November 2003

The functional significance of the first intron of the
Col1a1
gene in regulation of type I collagen synthesis remains uncertain. A previous study in mice established that a mutated
Col1a1
allele that lacked a large fraction of the first intron, but retained the sequences required for normal splicing, was subject to an age- and tissue-dependent decrease in expression. In this study, we report that mice homozygous for this deletion are predisposed to dissection and rupture of the aorta during their adult life. Aortic dissection was not detected in autopsies of heterozygous animals or their littermate controls. Electron micrographs revealed fewer collagen fibrils and less compacted, irregular elastic lamellae in the aortic walls of homozygous mutant animals. Northern analysis of aortic RNA from 2.5- and 12-month-old homozygous mutant mice revealed that
Col1a1
mRNA levels were decreased by 29% and 42%, respectively, relative to those of control littermates. In 12-month-old heterozygotes, the decrease was 32%. Allele-specific amplification of heterozygous cDNAs demonstrated that this reduction was limited to transcripts from the mutant allele. The collagen content of the aortas of homozygous mutant mice was also significantly lower in comparison to that of age-matched, control animals. These data establish that the integrity of the aortic wall depends on an adequate content of type I collagen, and that continued synthesis of collagen in the aorta as a function of age is critically dependent on sequences in the first intron of the
Col1a1
gene.
Hyperhomocysteinemia Activates Nuclear Factor-κB in Endothelial Cells via Oxidative Stress
Authors: Au-Yeung Kathy K.W. , Woo Connie W.H. , Sung Fion L. , Yip Johnny C.W. , Siow Yaw L. , O Karmin
Published: November 2003

Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. Our previous studies demonstrated an important interaction between nuclear factor-κB (NF-κB) activation and homocysteine (Hcy)-induced chemokine expression in vascular smooth muscle cells and macrophages. The objective of the present study was to investigate the in vivo effect of hyperhomocysteinemia on NF-κB activation and the underlying mechanism of Hcy-induced NF-κB activation in endothelial cells. Hyperhomocysteinemia was induced in Sprague-Dawley rats after 4 weeks of a high-methionine diet. The activated form of NF-κB and increased level of superoxide anions were detected in the endothelium of aortas isolated from hyperhomocysteinemic rats. The underlying mechanism of Hcy-induced NF-κB activation was investigated in human umbilical cord vein endothelial cells and in human aortic endothelial cells. Incubation of cells with Hcy (100 μmol/L) activated IκB kinases (IKKα and IKKβ), leading to phosphorylation and subsequent degradation of IκBα. As a consequence, NF-κB nuclear translocation, enhanced NF-κB/DNA binding activity, and increased transcriptional activity occurred. Additional analysis revealed a marked elevation of superoxide anion levels in Hcy-treated cells. Treatment of cells with a superoxide anion scavenger (polyethylene glycol-superoxide dismutase) or IκB kinase inhibitor (prostaglandin A
1
) could prevent Hcy-induced activation of IKK kinases and NF-κB in endothelial cells. In conclusion, these results suggest that Hcy-induced superoxide anion production may play a potential role for NF-κB activation in the early stages of atherosclerosis in the vascular wall via activation of IκB kinases.
Teleneurology to Improve Stroke Care in Rural Areas
Authors: Wiborg Andreas , Widder Bernhard
Published: November 2003

Background and Purpose—

Assessing both stroke patients and their CT scans by using a conventional videoconference system offers an interesting opportunity to improve stroke care in rural areas. However, until now there have been no studies to suggest whether this method is feasible in routine stroke management.

Methods—

Seven rural hospitals in the southern part of Germany in Swabia were connected to the stroke unit of Günzburg with the use of a videoconference link (Telemedicine in Stroke in Swabia [TESS] Project). The local physicians are free to present every admitted stroke patient to the Günzburg stroke expert, who can assess the clinical status and CT images, thereafter giving therapeutic recommendations. All teleconsultations are rated concerning transmission quality and relevance of telemedicine for stroke management.

Results—

A total of 153 stroke patients were examined by teleconsultation. Mean age was 67.5 years. Eighty-seven patients had suffered an ischemic stroke, 9 had an intracerebral hemorrhage, and 17 suffered a transient ischemic attack. Forty patients were revealed to have a diagnosis other than stroke. Duration of teleconsultation was 15 minutes on average. User satisfaction was good concerning imaging and audio quality, and patient satisfaction was very good or good in all cases. Relevant contributions could be made in >75% of the cases concerning diagnostic workup, CT assessment, and therapeutic recommendations.

Conclusions—

Teleconsultation using a videoconference system seems to be a feasible and promising method to improve stroke care in rural areas where management in a stroke unit is hindered by long transportation distances.
'Job the Dog': Hélène Cixous on Wounds, Scars and the Biblical Text
Authors: Pyper Hugh
Published: November 2003

Hélène Cixous' engagement with biblical texts is a significant but neglected aspect of her work. In this essay, the biblical allusions in several of her works are traced, particularly centring around the theme of the dog and the bite or wound. The Bible represents for Cixous both an example of the unbounded writing she sees as feminine, and a text that is confined by masculine authority and taboo. These two aspects come together in her engagement with the writings of Clarice Lispector whose grammatically paradoxical phrase in Portuguese eles a biblia—'those he-bible', as translations inadequately represent it—embodies that tension. The tension between these styles of writing in the Bible opens up as a wound in the text which allows a penetration below the surface. The power of the Bible is in the way that this opening lets the reader see 'the meat we are' in an encounter with the 'root' of being.
Stabat Mater? Re-birth at the Foot of the Cross
Authors: Kitzberger Ingrid Rosa
Published: November 2003

This paper offers a fresh look at the mother of Jesus at the foot of the cross in John's account of the crucifixion. By reading John 19:25-27 intertextually/interfigurally at the crossroads between John and the Synoptics, in particular Mark 15:34 (= Ps. 22:1), Luke 2:22-38, and Luke 7:11-17, and at the crossroads between text and self, new dimensions are added to the characterization of Jesus' mother (and the beloved disciple) in John's story. Reader response criticism and autobiographical biblical criticism have informed this paper.
Loitering with Intent: Biblical Texts in Public Places
Authors:   Sugirtharajah
Published: November 2003

This essay is about the effect of the Bible in the public arena. It explores the fate of biblical texts as they find themselves in the popular press. Secular newspapers are not the natural place to look for biblical citations but now and then they make appearances either to support or subvert issues ranging from asylumseekers to the use of corporal punishment for children. At a time when biblical allusions and imagery have all but evaporated from the Western consciousness, the intermittent showing up of sacred texts in the secular print media is a sign that the scriptures still have some hermeneutical hold. The essay looks at four areas—international conflict, sexual orientation, law and order and bringing-up children—where biblical texts are being summoned either to endorse or to repudiate. The essay raises hermeneutical issues such as how biblical texts are used in print media, the nature of the texts employed, the interface between popular and professional reading, the role of the common reader as a biblical commentator, and concludes with an examination of the standing and sway of the Bible as it moves outside its own natural habitat.
Discoursing Old Testament Theology
Authors: Ollenburger Ben
Published: November 2003

Stephen Fowl has argued that biblical (so Old Testament) theology is too beholden to academic biblical studies, and too far removed from settings in particular communities of faith, to nurture theological interpretation of scripture. Philip Davies has argued that Old Testament theology is inevitably (Christian) confessional and has no place in academic biblical studies, which should practice a self-consciously non-confessional and only "etic" discourse. Traversing Davies's argument and his use of "discourse," this essay makes brief and unassuming reference to Pierre Bourdieu and Michel de Certeau in moving toward Charles Taylor's definition of "self-defining" social theories. It argues that such practices and convictions of certain communities provide the context and purpose of Old Testament theology.
Alternative promoters regulate transcription of the gene that encodes stem cell surface protein AC133
Authors: Shmelkov Sergey V. , Jun Lin , St Clair Ryan , McGarrigle Deirdre , Derderian Christopher A. , Usenko Jaroslav K. , Costa Carla , Zhang Fan , Guo Xinzheng , Rafii Shahin
Published: November 2003

AC133 is a member of a novel family of cell surface proteins with 5 transmembrane domains. The function of AC133 is unknown. Although AC133 mRNA is detected in different tissues, its expression in the hematopoietic system is restricted to CD34+ stem cells. AC133 is also expressed on stem cells of other tissues, including endothelial progenitor cells. However, despite the potential importance of AC133 to the field of stem cell biology, nothing is known about the transcriptional regulation of AC133 expression. In this report we showed that the human AC133 gene has at least 9 distinctive 5′–untranslated region (UTR) exons, resulting in the formation of at least 7 alternatively spliced 5′-UTR isoforms of AC133 mRNA, which are expressed in a tissue-dependent manner. We found that transcription of these AC133 isoforms is controlled by 5 alternative promoters, and we demonstrated their activity on AC133-expressing cell lines using a luciferase reporter system. We also showed that in vitro methylation of 2 of these AC133 promoters completely suppresses their activity, suggesting that methylation plays a role in their regulation. Identification of tissue-specific AC133 promoters may provide a novel method to isolate tissue-specific stem and progenitor cells.
RNA-transfected CD40-activated B cells induce functional T-cell responses against viral and tumor antigen targets: implications for pediatric immunotherapy
Authors: Coughlin Christina M. , Vance Barbara A. , Grupp Stephan A. , Vonderheide Robert H.
Published: November 2003

Vaccination with antigen-presenting cells (APCs) engineered to mimic mechanisms of immune stimulation represents a promising approach for cancer immunotherapy. Dendritic cell vaccines have entered phase 3 testing in adult malignancies, but such vaccines in children have been limited. We demonstrate that CD40-activated B cells (CD40-B) transfected with RNA may serve as an alternative vaccine that can be generated from small blood volumes regardless of patient age. CD40-B from pediatric patients are efficient APCs and can be loaded with RNA as an antigenic payload, permitting simultaneous targeting of multiple antigenic epitopes without the necessity of HLA matching. For viral and tumor antigens, CD40-B/RNA technology induced cytotoxic T lymphocytes (CTLs) from adults and children, which could be identified with peptide/major histocompatibility complex (MHC) tetramers. These CTLs secreted interferon-γ (IFN-γ) and killed targets in an MHC-restricted fashion. For pooled neuroblastoma RNA and autologous neuroblastoma RNA, CTLs that lysed neuroblastoma cell lines, including CTLs specific against the widely expressed tumor-antigen survivin, were generated. These findings support a novel platform for tumor-specific vaccine or adoptive immunotherapies in pediatric malignancies.
Role of RUNX1 in adult hematopoiesis: analysis of RUNX1-IRES-GFP knock-in mice reveals differential lineage expression
Authors: Lorsbach Robert B. , Moore Jennifer , Ang Sonny O. , Sun Weili , Lenny Noel , Downing James R.
Published: November 2003

The Runx1/core binding factor-β (CBFβ) transcriptional complex is required for the establishment of hematopoiesis during development. Despite its critical role during development, a detailed analysis of Runx1 expression within specific lineages and developmental stages of the adult hematopoietic system is lacking. To address this, we have developed a Runx1—green fluorescent protein (GFP) knock-in mouse. We show that Runx1 is expressed in several hematopoietic lineages, including myeloid, B-lymphoid, and T-lymphoid cells. By contrast, Runx1 is weakly expressed in early erythroid cells, and its expression is rapidly extinguished during later stages of erythropoiesis. Runx1 expression is induced during early B-cell development and is expressed at a uniform level during all subsequent stages of B-cell development. Within the thymus, Runx1 is expressed at the highest level in CD4-CD8- double-negative thymocytes. In peripheral T cells, Runx1 is differentially expressed, with CD4+ T cells expressing 2- to 3-fold higher levels of Runx1 than CD8+ cells. Taken together, these findings indicate that although widely expressed in the hematopoietic system, the expression of Runx1 is regulated in a cell type— and maturation stage—specific manner. In addition, the Runx1-IRES-GFP knock-in mouse strain should prove valuable for investigation of Runx1 function in adult hematopoiesis.
Sustained long-term hematologic efficacy of hydroxyurea at maximum tolerated dose in children with sickle cell disease
Authors: Zimmerman Sherri A. , Schultz William H. , Davis Jacqueline S. , Pickens Chrisley V. , Mortier Nicole A. , Howard Thad A. , Ware Russell E.
Published: November 2003

Hydroxyurea improves hematologic parameters for children with sickle cell disease (SCD), but its long-term efficacy at maximum tolerated dose (MTD) has not been determined. Between 1995 and 2002, hydroxyurea therapy was initiated for 122 pediatric patients with SCD including 106 with homozygous sickle cell anemia (HbSS), 7 with sickle hemoglobin C (HbSC), 7 with sickle/β-thalassemia (HbS/ β-thalassemia [6 HbS/β0, 1 HbS/β+]), and 2 with sickle hemoglobin OArab (HbS/OArab). Median age at initiation of therapy was 11.1 years. Hydroxyurea was escalated to MTD, with an average dose of 25.4 ± 5.4 mg/kg per day; the average duration of hydroxyurea therapy has been 45 ± 24 months (range, 6-101 months). Hydroxyurea was discontinued for 15 (12%) children with poor compliance. Mild transient neutropenia occurred, but no hepatic or renal toxicity was noted. Hydroxyurea therapy led to significant increases in hemoglobin level, mean corpuscular volume, and fetal hemoglobin (HbF) level, whereas significant decreases occurred in reticulocyte, white blood cell, and platelet counts and serum bilirubin levels. Children with variant SCD genotypes also had hematologic responses to hydroxyurea. HbF induction has been sustained for up to 8 years without adverse effects on growth or increased numbers of acquired DNA mutations. Long-term hydroxyurea therapy at MTD is well tolerated by pediatric patients with SCD and has sustained hematologic efficacy with apparent long-term safety.
Migration of Vδ1 and Vδ2 T cells in response to CXCR3 and CXCR4 ligands in healthy donors and HIV-1–infected patients: competition by HIV-1 Tat
Authors: Poggi Alessandro , Carosio Roberta , Fenoglio Daniela , Brenci Sabrina , Murdaca Giuseppe , Setti Maurizio , Indiveri Francesco , Scabini Silvia , Ferrero Elisabetta , Zocchi Maria Raffaella
Published: November 2003

We show that HIV-1–infected patients have increased concentrations of circulating Vδ1 T cells (2.2%-9.0% of T lymphocytes; healthy donors, 1.0%-2%) and, in some instances, Vδ2 T cells (3.5%-4.8% vs 2.0%-3.3%). In these patients, both Vδ1 and Vδ2 T cells are CXCR3+CXCR4+, whereas in healthy donors CXCR4 was preferentially expressed on Vδ1 T lymphocytes. γδ T cells transmigrated across endothelial monolayers, in response to interferon-γ–inducing protein-10 (IP-10/CXCL10), stromal cell–derived factor-1 (SDF-1/CXCL12), or both, according to the expression of the specific receptors CXCR3 and CXCR4. Interestingly, 6Ckine/SLC/CCL21 was more effective than IP-10/CXCL10 on Vδ1 CXCR3+ cells, whereas Vδ2 CXCR3+ cells were driven more efficiently by IP-10/CXCL10. IP-10/CXCL10– and SDF-1/CXCL12–induced transmigration was dependent on phosphoinositide-3 kinase (PI-3K), as demonstrated by the use of the specific blockers wortmannin and LY294002 and by the activation of the downstream serine kinase Akt/PKB on ligation of CXCR3 and CXCR4. Occupancy of CXCR3, but not of CXCR4, led to CAMKII activation; accordingly, the CAMKII inhibitors KN62 and KN93 decreased IP-10/CXCL10– but not SDF-1/CXCL12–driven transmigration. Finally, HIV-1 Tat, which is present in the serum of HIV-1–infected patients, interferes with the chemotactic activity of these chemokines because of the cysteine-rich domain of the protein, which contains CXC and CC chemokine–like sequences.
P-selectin anchors newly released ultralarge von Willebrand factor multimers to the endothelial cell surface
Authors: Padilla Arnoldo , Moake Joel L. , Bernardo Aubrey , Ball Chalmette , Wang Yongtao , Arya Maneesh , Nolasco Leticia , Turner Nancy , Berndt Michael C. , Anvari Bahman , López José A. , Dong Jing-Fei
Published: November 2003

von Willebrand factor (VWF) released from endothelium is ultralarge (UL) and hyperreactive. If released directly into plasma, it can spontaneously aggregate platelets, resulting in systemic thrombosis. This disastrous consequence is prevented by the ADAMTS13 (ADisintegrin and Metalloprotease with ThromboSpondin motif) cleavage of ULVWF into smaller, less active forms. We previously showed that ULVWF, on release, forms extremely long stringlike structures. ADAMTS13 cleaves these strings under flow significantly faster than it does under static conditions. As ULVWF tethering to endothelium is important for its rapid proteolysis, we investigated 2 molecules for their potential to anchor the ULVWF strings: P-selectin and integrin αvβ3. We demonstrated that P-selectin anchors ULVWF to endothelium by several means. First, Chinese hamster ovary (CHO) cells expressing P-selectin specifically adhered to immobilized ULVWF and ULVWF-coated beads to immobilized P-selectin. Second, an anti-VWF antibody coimmunoprecipitates P-selectin from the histamine-activated endothelial cells. Third, P-selectin antibody or soluble P-selectin, but not a αvβ3 antibody, RGDS peptide, or heparin, blocked the formation of ULVWF strings. Fourth, P-selectin expression was in clusters predominantly along the ULVWF strings. Finally, the strength of the minimal ULVWF–P-selectin bond was measured to be 7.2 pN. We, therefore, conclude that P-selectin may anchor ULVWF strings to endothelial cells and facilitate their cleavage by ADAMTS13.
Characterization of clonogenic multiple myeloma cells
Authors: Matsui William , Huff Carol Ann , Wang Qiuju , Malehorn Matthew T. , Barber James , Tanhehco Yvette , Smith B. Douglas , Civin Curt I. , Jones Richard J.
Published: November 2003

The identity of the cells responsible for the initiation and maintenance of multiple myeloma (MM) remains unclear largely because of the difficulty growing MM cells in vitro and in vivo. MM cell lines and clinical specimens are characterized by malignant plasma cells that express the cell surface antigen syndecan-1 (CD138); however, CD138 expression is limited to terminally differentiated plasma cells during B-cell development. Moreover, circulating B cells that are clonally related to MM plasma cells have been reported in some patients with MM. We found that human MM cell lines contained small (< 5%) subpopulations that lacked CD138 expression and had greater clonogenic potential in vitro than corresponding CD138+ plasma cells. CD138- cells from clinical MM samples were similarly clonogenic both in vitro and in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, whereas CD138+ cells were not. Furthermore, CD138- cells from both cell lines and clinical samples phenotypically resembled postgerminal center B cells, and their clonogenic growth was inhibited by the anti-CD20 monoclonal antibody rituximab. These data suggest that MM “stem cells” are CD138- B cells with the ability to replicate and subsequently differentiate into malignant CD138+ plasma cells.
Bone loss following hematopoietic stem cell transplantation: a long-term follow-up
Authors: Schulte Claudia M. S. , Beelen Dietrich W.
Published: November 2003

Transplantation-associated bone loss is a well-known phenomenon, however, effects of hematopoietic stem cell transplantation are insufficiently characterized. We conducted a prospective, unicentric, long-term follow-up in 280 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Bone mineral density (BMD) was measured before transplantation and then yearly for at least 4 years. Patients received vitamin D plus calcium until steroid withdrawal. Mean baseline BMD was normal. We demonstrated significant bone loss with nadir BMD at month 6 for the spine and at month 24 for total body and femoral neck. Average annual bone loss was 0.6% for spine, 0.4% for total body, 2.3% for femoral neck, and 3.5% for Ward triangle. While spine and total body BMD returned to baseline, bone loss at femoral neck sites was attenuated, but BMD did not return to baseline until month 48 (P < .0001 for femoral neck and Ward triangle). Univariate factor analysis of 15 potential risk factors for rapid bone loss revealed a positive correlation of bone loss with steroid and cyclosporine A use, baseline BMD, and loss of muscle mass (overwhelming power of steroid use in multifactor analysis). Such rapid BMD changes probably increase fracture risk consecutive to irreversible microarchitectural changes even if osteodensitometry shows long-term recovery.
Role of p300 and PCAF in regulating cyclooxygenase-2 promoter activation by inflammatory mediators
Authors: Deng Wu-Guo , Zhu Ying , Wu Kenneth K.
Published: November 2003

Coactivators p300 and CREB (cyclic adenosine monophosphate [cAMP]–response element binding protein)–binding protein (CBP) serve as an integrator for gene transcription. Their relative involvement in regulating cyclooxygenase-2 (COX-2) promoter activity had not been characterized. Using fibroblast and macrophage COX-2 transcription as a model, we determined p300 and CBP levels in nuclear extracts and their binding to a COX-2 promoter probe. CBP level was barely detectable and there was little CBP binding. In contrast, p300 was detectable in nucleus and its binding to a COX-2 promoter probe was enhanced by phorbol 12-myristate 13-acetate (PMA), interleukin-1β (IL-1β), or lipopolysaccharide (LPS). Binding of p300/CBP-associated factor (PCAF) was also up-regulated. COX-2 proteins and promoter activities induced by these agonists were augmented by p300 overexpression. Early region 1A (E1A), but not its deletion mutant, abrogated COX-2 expression induced by inflammatory mediators and with or without p300 overexpression. Molecular analysis of p300 revealed the requirement of multiple domains, including histone acetyltransferase (HAT) for COX-2 transactivation. Furthermore, roscovitine, an indirect inhibitor of p300 HAT, and histone deacetylase-1 transfection completely abolished COX-2 promoter activity. We conclude that p300 is the predominant coactivator that is essential for COX-2 transcriptional activation by proinflammatory mediators.
Immunomodulatory effect of decoy receptor 3 on the differentiation and function of bone marrow-derived dendritic cells in nonobese diabetic mice: from regulatory mechanism to clinical implication
Authors: Wu Shu-Fen , Liu Tan-Mei , Lin Yu-Chun , Sytwu Huey-Kang , Juan Hsueh-Fen , Chen Shui-Tein , Shen Kuo-Liang , Hsi Sheng-Chuan , Hsieh Shie-Liang
Published: November 2003

To investigate the regulatory effects of decoy receptor 3 (DcR3) on the differentiation and function of dendritic cells (DCs), bone marrow-derived DCs (BM-DCs) from nonobese diabetic (NOD) mice were cultured with recombinant DcR3.Fc protein. Their differentiating phenotypes and T cell-stimulating functions were then evaluated. Expression of CD11c, CD40, CD54, and major histocompatibility complex I-Ag7 was reduced in cells cultured with additional DcR3.Fc, compared with DCs incubated with granulocyte macrophage-colony stimulating factor and interleukin (IL)-4, indicating that DcR3 interferes with the differentiation and maturation of BM-DCs. One of the most striking effects of DcR3.Fc on the differentiation of DCs was the up-regulation of CD86 and down-regulation of CD80, suggesting a modulatory potential to skew the T cell response toward the T helper cell type 2 (Th2) phenotype. Consistent with this, the proliferation of CD4+ T cells cocultured with DcR3.Fc-treated DCs was significantly reduced compared with that of T cells stimulated by normal DCs. Moreover, the secretion of interferon-γ from T cells cocultured with DcR3.Fc-treated DCs was profoundly suppressed, indicating that DcR3 exerts a Th1-suppressing effect on differentiating DCs. Furthermore, adoptive transfer experiments revealed that NOD/severe combined immunodeficiency mice received DcR3.Fc-treated DCs, and subsequently, autoreactive T cells showed delayed onset of diabetes and a decrease in diabetic severity compared with mice that received normal DCs and T cells, suggesting a future therapeutic potential in autoimmune diabetes. Data from two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight analysis show an up-regulation of some proteins—such as mitogen-activated protein kinase p38 β, cyclin-dependent kinase 6, and signal-induced proliferation-associated gene 1—and a down-regulation of the IL-17 precursor; tumor necrosis factor-related apoptosis-inducing ligand family member-associated nuclear factor-κB activator-binding kinase 1; and Golgi S-nitroso-N-acetylpenicillamine in cells treated with DcR3, further demonstrating its effect on DC differentiation and function.
Age-dependent decrease in Toll-like receptor 4-mediated proinflammatory cytokine production and mitogen-activated protein kinase expression
Authors: Boehmer Eric D , Goral Joanna , Faunce Douglas E , Kovacs Elizabeth J
Published: November 2003

Age-related changes in immunity render elderly individuals more susceptible to infections than the young. Previous work by our laboratory and others showed that macrophages from aged mice are functionally impaired. Macrophages produce proinflammatory cytokines, tumor necrosis factor α (TNF-α) and interleukin (IL)-6, when stimulated with lipopolysaccharide (LPS), which signals through Toll-like receptor-4 (TLR4) and requires activation of mitogen-activated protein kinases (MAPKs). We investigated whether aging is associated with alterations in TNF-α and IL-6 production and MAPK expression and activation in thioglycollate-elicited peritoneal macrophages from mice. Kinetics and LPS dose-responsiveness of macrophage TNF-α production did not differ by age. Unstimulated macrophages did not differ by age in their cytokine production. However, LPS-stimulated (100 ng/mL) cultures from aged mice produced 100 ± 30 pg/mL TNF-α and 6000 ± 2000 pg/mL IL-6, and those from young mice produced 280 ± 50 pg/mL and 10,650 ± 10 pg/mL, respectively (P<0.05). Likewise, levels of activated MAPKs did not differ by age in unstimulated macrophages, and LPS-stimulated macrophages from aged mice had <70% activated p38 and c-jun NH2-terminal kinase (JNK) than those of young controls. Of particular interest, we observed >25% reduction of total p38 and JNK in macrophages from aged mice relative to young. In addition, surface TLR4 levels did not vary with age. We conclude that macrophages from aged mice exhibited suppressed proinflammatory cytokine production, which correlated with diminished total levels and LPS-stimulated activation of p38 and JNK. These observations suggest that decreased MAPK expression could be a mechanism responsible for age-related deterioration of the immune system.
Phase II Trial of Gefitinib in Recurrent Glioblastoma
Authors: Rich Jeremy N. , Reardon David A. , Peery Terry , Dowell Jeannette M. , Quinn Jennifer A. , Penne Kara L. , Wikstrand Carol J. , Van Duyn Lauren B. , Dancey Janet E. , McLendon Roger E. , Kao James C. , Stenzel Timothy T. , Ahmed Rasheed B.K. , Tourt-Uhlig Sandra E. , Herndon James E. , Vredenburgh James J. , Sampson John H. , Friedman Allan H. , Bigner Darell D. , Friedman Henry S.
Published: November 2003

Purpose

To evaluate the efficacy and tolerability of gefitinib (ZD1839, Iressa; AstraZeneca, Wilmington, DE), a novel epidermal growth factor receptor tyrosine kinase inhibitor, in patients with recurrent glioblastoma.

Patients and Methods

This was an open-label, single-center phase II trial. Fifty-seven patients with first recurrence of a glioblastoma who were previously treated with surgical resection, radiation, and usually chemotherapy underwent an open biopsy or resection at evaluation for confirmation of tumor recurrence. Each patient initially received 500 mg of gefitinib orally once daily; dose escalation to 750 mg then 1,000 mg, if a patient received enzyme-inducing antiepileptic drugs or dexamethasone, was allowed within each patient.

Results

Although no objective tumor responses were seen among the 53 assessable patients, only 21% of patients (11 of 53 patients) had measurable disease at treatment initiation. Seventeen percent of patients (nine of 53 patients) underwent at least six 4-week cycles, and the 6-month event-free survival (EFS) was 13% (seven of 53 patients). The median EFS time was 8.1 weeks, and the median overall survival (OS) time from treatment initiation was 39.4 weeks. Adverse events were generally mild (grade 1 or 2) and consisted mainly of skin reactions and diarrhea. Drug-related toxicities were more frequent at higher doses. Withdrawal caused by drug-related adverse events occurred in 6% of patients (three of 53 patients). Although the presence of diarrhea positively predicted favorable OS from treatment initiation, epidermal growth factor receptor expression did not correlate with either EFS or OS.

Conclusion

Gefitinib is well tolerated and has activity in patients with recurrent glioblastoma. Further study of this agent at higher doses is warranted.