bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Endothelial Nitric Oxide Synthase by Tetrahydrobiopterin in Vascular Disease
Authors: Alp Nicholas J. , Channon Keith M.
Published: December 2003

Nitric oxide (NO), produced by endothelial nitric oxide synthase (eNOS), is a key signaling molecule in vascular homeostasis. Loss of NO bioavailability due to reduced synthesis and increased scavenging by reactive oxygen species is a cardinal feature of endothelial dysfunction in vascular disease states. The pteridine cofactor tetrahydrobiopterin (BH4) has emerged as a critical determinant of eNOS activity: when BH4 availability is limiting, eNOS no longer produces NO but instead generates superoxide. In vascular disease states, there is oxidative degradation of BH4 by reactive oxygen species. However, augmentation of BH4 concentrations in vascular disease by pharmacological supplementation, by enhancement of its rate of de novo biosynthesis or by measures to reduce its oxidation, has been shown in experimental studies to enhance NO bioavailability. Thus, BH4 represents a potential therapeutic target in the regulation of eNOS function in vascular disease.
Patterns and Risk Factors for Systemic Calcified Atherosclerosis
Authors: Allison Matthew A. , Criqui Michael H. , Wright C. Michael
Published: December 2003

Objective—

Complex atherosclerotic lesions contain radio-opaque calcium hydroxyapatite deposits with the degree of calcification correlating with the extent of atherosclerosis. In this study, we aim to determine the patterns of systemic atherosclerotic calcification.

Methods and Results—

Whole-body electron beam computed tomography scans were performed on 650 asymptomatic subjects to assess the carotid, coronary, proximal, and distal aorta and iliac vessels for atherosclerotic calcification. The mean age was 57.3 and 53% were male. Correlation patterns were similar in both genders, with the largest interbed correlations between the distal aorta and iliac vessels (
r
=0.51 to 0.60). The average man and woman had calcium earliest in the coronaries (younger than age 50 years) and the distal aorta (age 50 to 60), respectively. The prevalence of calcium was greater than 80% for most beds in men older than age 70 and greater than 60% in all beds for women. Approximately on third of subjects younger than 50 were free of calcified disease, whereas all subjects older than 70 were found to have some calcium. Age and hypertension were the dominant risk factors for systemic calcified atherosclerosis.

Conclusions—

This study confirms that there are significant correlations and risk factor associations for calcified atherosclerosis in different vascular beds.
Impact of Infarct-Related Artery Flow on QT Dynamicity in Patients Undergoing Direct Percutaneous Coronary Intervention for Acute Myocardial Infarction
Authors: Bonnemeier Hendrik , Wiegand Uwe K.H. , Bode Frank , Hartmann Franz , Kurowski Volkhard , Katus Hugo A. , Richardt Gert
Published: December 2003

Background—

Complete coronary artery reperfusion in acute myocardial infarction (AMI) has been shown to significantly improve survival. Electrical stability may be the decisive mechanism for this beneficial effect. Because electrical stability is largely dependent on ventricular repolarization, we sought to determine the impact of a modern reperfusion strategy (ie, direct percutaneous coronary intervention [PCI]) on QT dynamicity in AMI and examined its association with infarct-related artery flow.

Methods and Results—

We prospectively investigated QT dynamicity in 128 patients undergoing direct PCI for a first AMI. Slopes and correlation coefficients of the linear QT/RR regression were determined in the time interval before reperfusion, within the initial hour after reperfusion, and within the remaining recording period from Holter ECG recordings, which were initiated on admission. Subgroup analysis based on TIMI 3 (n=100) and TIMI 2 (n=28) flow after PCI revealed no significant differences in QT/RR slope before PCI (0.145±0.12 versus 0.160±0.19,
P
=NS). After PCI, QT/RR slopes increased only in the TIMI 2 subgroup (
P
<0.05). In TIMI 2 patients, QT/RR slopes were significantly steeper in the hour after PCI and in the remaining recording period, respectively (0.155±0.12 versus 0.192±0.15,
P
<0.05, and 0.159±0.10 versus 0.210±0.17,
P
<0.01).

Conclusions—

Alterations of QT dynamicity in patients with incomplete reperfusion may suggest an altered electrical restitution, potentially providing a substrate for serious ventricular arrhythmias. Thus, our findings offer new insights into mechanisms by which complete reperfusion may affect electrical stability.
Successful Catheter Ablation of Electrical Storm After Myocardial Infarction
Authors: Bänsch Dietmar , Oyang Feifan , Antz Matthias , Arentz Thomas , Weber Reinhold , Val-Mejias Jesus E. , Ernst Sabine , Kuck Karl-Heinz
Published: December 2003

Background—

We report on 4 patients (aged 57 to 77 years; 3 men) who developed drug-refractory, repetitive ventricular tachyarrhythmias after acute myocardial infarction (MI). All episodes of ventricular arrhythmias were triggered by monomorphic ventricular premature beats (VPBs) with a right bundle-branch block morphology (RBBB).

Methods and Results—

Left ventricular (LV) mapping was performed to attempt radiofrequency (RF) ablation of the triggering VPBs. Activation mapping of the clinical VPBs demonstrated the earliest activation in the anteromedial LV in 1 patient and in the inferomedial LV in 2 patients. Short, high-frequency, low-amplitude potentials were recorded that preceded the onset of each extrasystole by a maximum of 126 to 160 ms. At the same site, a Purkinje potential was documented that preceded the onset of the QRS complex by 23 to 26 ms during sinus rhythm. In 1 patient, only pace mapping was attempted to identify areas of interest in the LV. Six to 30 RF applications abolished all local Purkinje potentials at the site of earliest activation and/or perfect pace mapping and suppressed VPBs in all patients. No episode of ventricular tachycardia or fibrillation has recurred for 33, 14, 6, and 5 months in patients 1, 2, 3, and 4, respectively.

Conclusions—

Incessant ventricular tachyarrhythmias after MI may be triggered by VPBs. RF ablation of the triggering VPBs is feasible and can prevent drug-resistant electrical storm, even after acute MI. Catheter ablation of the triggering VPBs may be used as a bailout therapy in these patients.
Genetically Reduced Antioxidative Protection and Increased Ischemic Heart Disease Risk
Authors: Juul Klaus , Tybjærg-Hansen Anne , Marklund Stefan , Heegaard Niels H.H. , Steffensen Rolf , Sillesen Henrik , Jensen Gorm , Nordestgaard Børge G.
Published: December 2003

Background—

Extracellular superoxide dismutase (EC-SOD) is an antioxidative enzyme found in high concentrations in the arterial wall. Two to three percent of all people in Denmark carry an R213G substitution, which increases plasma concentration 10-fold. This may reduce arterial wall EC-SOD concentrations, increase intimal LDL oxidation, and therefore may accelerate atherogenesis. Our primary hypothesis was that EC-SOD-R213G predisposes to ischemic heart disease (IHD). The secondary hypothesis was that EC-SOD-R213G offers predictive ability with respect to IHD beyond that offered by measurements of plasma EC-SOD and autoantibodies against oxidized LDL (oxLDL).

Methods and Results—

The primary hypothesis was tested in a prospective, population-based study of 9188 participants from The Copenhagen City Heart Study with 956 incident IHD events during 23 years of follow-up and retested cross-sectionally with independent case populations of patients with IHD (n=943) or ischemic cerebrovascular disease (ICVD) (n=617). Case populations were compared with unmatched IHD/ICVD-free control subjects from The Copenhagen City Heart Study (n=7992). The secondary hypothesis was tested by using a nested case-control study comparing patients with IHD (n=956) with age- and gender-matched control subjects (n=956). Age- and gender-adjusted relative risk for IHD in heterozygotes (n=221, 2.4%) versus noncarriers (n=8965, 97.6%) was 1.5 (95% CI, 1.1 to 2.1). Retesting confirmed this: Age- and gender-adjusted odds ratios for IHD was 1.4 (1.0 to 2.0) and for ICVD 1.7 (1.1 to 2.7). Additional adjustment for plasma EC-SOD produced an odds ratio for IHD in heterozygotes versus noncarriers of 9.2 (1.2 to 72), whereas adjustment for autoantibodies against oxLDL produced an odds ratio of 2.5 (1.2 to 5.3).

Conclusions—

Heterozygosity for EC-SOD-R213G is associated with increased IHD risk. Genotyping offers predictive ability with respect to IHD beyond that offered by plasma EC-SOD and autoantibodies against oxLDL.
Inhibition of Experimental Abdominal Aortic Aneurysm in the Rat by Use of Decoy Oligodeoxynucleotides Suppressing Activity of Nuclear Factor κB and ets Transcription Factors
Authors: Nakashima Hideki , Aoki Motokuni , Miyake Takashi , Kawasaki Tomio , Iwai Masahiro , Jo Nobuo , Oishi Masako , Kataoka Kazusaburo , Ohgi Shigetsugu , Ogihara Toshio , Kaneda Yasufumi , Morishita Ryuichi
Published: December 2003

Background—

Two phenomena, inflammation and matrix degradation, contribute to the progression of abdominal aortic aneurysm (AAA). Importantly, the inflammation is regulated by the transcription factor nuclear factor (NF)–κB, whereas the destruction and degradation of elastin fibers by matrix metalloproteinases (MMP) are regulated by ets. Thus, we developed a novel strategy to treat AAA by simultaneous inhibition of both NF-κB and ets by using chimeric decoy oligodeoxynucleotides (ODN).

Methods and Results—

AAA was induced in rats by transient aortic perfusion with elastase, whereas transfection of decoy ODN was performed by wrapping a delivery sheet containing decoy ODN around the aorta. Gel-mobility shift assay at 7 days after treatment demonstrated that both NF-κB and ets binding activity were simultaneously inhibited by chimeric decoy ODN. Transfection of chimeric decoy ODN resulted in significant inhibition of the progression of AAA such as aneurysmal dilation at 4 weeks after treatment as compared with control, accompanied by a reduction of MMP expression. Moreover, the destruction of elastin fibers was inhibited in the aorta transfected with chimeric decoy ODN. Importantly, transfection of chimeric decoy ODN demonstrated potent inhibition of aneurysmal dilatation compared with NF-κB decoy ODN alone, whereas scrambled decoy ODN had no effects. Interestingly, the migration of macrophages was significantly inhibited by chimeric decoy ODN.

Conclusions—

We demonstrated that inhibition of the progression of AAA was achieved by a novel strategy with chimeric decoy ODN used against NF-κB and ets in rat model. NF-κB and ets are considered to play an important role in the pathogenesis of AAA.
Inhibition of Cytochrome P450 2C9 Improves Endothelium-Dependent, Nitric Oxide–Mediated Vasodilatation in Patients With Coronary Artery Disease
Authors: Fichtlscherer Stephan , Dimmeler Stefanie , Breuer Susanne , Busse Rudi , Zeiher Andreas M. , Fleming Ingrid
Published: December 2003

Background—

Nitric oxide (NO)– and prostacyclin-independent vasodilatation in several vascular beds has been linked to the activation of cytochrome P450 (CYP) epoxygenases expressed in endothelial cells. However, these enzymes, which generate vasodilator epoxyeicosatrienoic acids, may also produce oxygen-derived free radicals, which attenuate the bioavailability of NO. Here, we studied the involvement of CYP 2C9 in modulating endothelium-dependent and -independent changes in forearm blood flow (FBF) in healthy volunteers and in patients with manifest coronary artery disease.

Methods and Results—

The effects of sulfaphenazole, a selective inhibitor of CYP 2C9, on endothelium-dependent (acetylcholine) and endothelium-independent (sodium nitroprusside, SNP) FBF responses were measured by venous occlusion plethysmography in 5 healthy subjects and in 16 patients with angiographically documented stable coronary artery disease. Sulfaphenazole did not modify FBF responses to acetylcholine or SNP in healthy subjects. In contrast, sulfaphenazole markedly and dose-dependently enhanced the FBF response to acetylcholine without affecting the response to SNP. Vitamin C also increased the FBF response to acetylcholine, but this effect was further potentiated by sulfaphenazole. In the presence of

N
ω

-monomethyl-
l
-arginine, sulfaphenazole failed to significantly improve acetylcholine-induced vasodilatation. The oxidation of serum proteins was enhanced in patients with coronary artery disease, and this effect was significantly attenuated by sulfaphenazole.

Conclusions—

The CYP 2C9 inhibitor sulfaphenazole enhances endothelium-dependent vasodilator responses in patients with manifest coronary artery disease. This effect seems to be related to an increase in the bioavailability of NO, probably as a consequence of an attenuated generation of reactive oxygen species by CYP 2C9 in endothelial cells.
Methoxyestradiols Mediate the Antimitogenic Effects of 17β-Estradiol
Authors: Zacharia Lefteris C. , Gogos Joseph A. , Karayiorgou Maria , Jackson Edwin K. , Gillespie Delbert G. , Barchiesi Federica , Dubey Raghvendra K.
Published: December 2003

Background—

Studies using pharmacological agents suggest but do not prove that the antimitogenic effects of estradiol are caused by conversion of estradiol to hydroxyestradiols (mediated by CYP450s) followed by methylation of hydroxyestradiols to methoxyestradiols (mediated by catechol-
O
-methyltransferase, COMT).

Methods and Results—

To test this hypothesis more rigorously, we used aortic smooth muscle cells (SMCs) from mice lacking COMT (COMT-KO). Wild-type (WT) but not COMT-KO SMCs efficiently converted 2-hydroxyestradiol to 2-methoxyestradiol. Both WT and COMT-KO SMCs expressed estrogen receptors. Estradiol and 2-hydroxyestradiol concentration-dependently inhibited serum-induced DNA synthesis, cell numbers, and collagen synthesis in WT but not COMT-KO SMCs. 2-Methoxyestradiol inhibited DNA synthesis, cell numbers, and collagen synthesis in both WT and COMT-KO SMCs.

Conclusions—

These data provide strong evidence that the vascular antimitogenic effects of estradiol are estrogen receptor–independent and involve the sequential conversion of estradiol to hydroxyestradiols and then to methoxyestradiols.
Percutaneous Endovascular Repair of Aneurysm After Previous Coarctation Surgery
Authors: Ince Hüseyin , Petzsch Michael , Rehders Tim , Kische Stephan , Körber Thomas , Weber Frank , Nienaber Christoph A.
Published: December 2003

Background—

Formation of aortic aneurysm late after surgical repair of coarctation carries a significant risk of rupture and lethal outcome, and repeat surgery is associated with a 14% in-hospital mortality rate and morbidity from paraplegia, injury to the central nervous system, or from bleeding. The potential of nonsurgical endovascular repair by the use of stent-grafts in lieu of repeat surgery for postcoarctation aneurysm is unknown.

Methods and Results—

The concept of postsurgical endovascular stent-graft placement was evaluated with respect to feasibility and safety in 6 consecutive patients with late aneurysm formation after coarctation repair. All patients had aneurysm formation late after patch aortoplasty; placement of an elephant trunk during surgical repair of secondary type I dissection preceded formation of a local aneurysm in 2 cases. Patient age was 49±12 years, ranging from 31 to 68 years. Transluminal placement of customized stent-grafts was successful, with no 30-day or 1-year intervention-related mortality or morbidity. Follow-up survey of 11 to 47 months revealed optimal reconstruction of the thoracic aorta; 1 patient died 11 months after endovascular repair from cancer.

Conclusions—

Nonsurgical aortic reconstruction of postsurgical thoracic aneurysms forming late after coarctation repair is safe and feasible; interventional stent-graft placement has the potential to avoid repeat surgery of postsurgical aortic aneurysm.
Cardiovascular and Renal Phenotype in Mice With One or Two Renin Genes
Authors: Lum Craig , Shesely Edward G. , Potter D’Anna L. , Beierwaltes William H.
Published: December 2003

We compared the phenotype of two common mouse models, C-57BL/6J (C57), which carries only the Ren-1
c
gene, and 129/SvJ (Sv-129), with both Ren 1
d
and Ren-2. We hypothesized two renin gene Sv-129 would have increased blood pressure and the renin-angiotensin system would be more influential in regulating renal function compared with one renin gene mice. Sv-129 consistently had higher blood pressure than C-57, whether conscious (128 versus 108 mm Hg,
P
<0.001) or anesthetized (102 versus 88 mm Hg,
P
<0.001). Plasma renin concentration in both conscious and anesthetized C-57 mice was 3- to 4-fold higher than in Sv-129 (
P
<0.05), whereas renal cortical renin content was 2.5-fold higher (
P
<0.005). Renal blood flow and renal vascular resistance were the same in C-57 and Sv-129. Exogenous angiotensinogen produced identical pressor and renal vasoconstrictor responses in both strains. Blocking AT
1
receptors with losartan reduced blood pressure by 19 mm Hg in both strains. Nitric oxide synthase inhibition by
l
-NAME increased blood pressure by 29 mm Hg in C-57 and 35 mm Hg in Sv-129 mice, but the decrease in renal blood flow was 30% less in C-57 (
P
<0.025). We conclude that Sv-129 mice with two renin genes have higher blood pressure but lower plasma and renal renin than C-57 mice with one renin gene. Renin substrate may limit angiotensin II production in the mouse. In Sv-129, the influence of nitric oxide on renal but not systemic resistance may be exaggerated. Renin from Ren-2 may act independently of normal renin control mechanisms.
Attenuation of Lysophosphatidylcholine-Induced Suppression of ANP Release From Hypertrophied Atria
Authors: Han Jeong Hee , Cao Chunhua , Kim Soo Mi , Piao Feng Lian , Kim Suhn Hee
Published: December 2003

Lysophosphatidylcholine (LPC) is an endogenous phospholipid released from the cell membrane during ischemia, and it has potent cardiac effects, including inhibition of atrial natriuretic peptide (ANP) release. The aim of this study was to investigate the effects of LPC on hemodynamics and ANP release in hypertrophied atria and to define its mechanism. Isolated, perfused, beating, hypertrophied atria from monocrotaline-treated rats were used. LPC (30 μmol/L), a mixture of stearoyl-LPC, palmitoyl-LPC, and oleoyl-LPC, caused suppression of ANP release, which was markedly attenuated in hypertrophied atria compared with nonhypertrophied atria. Suppression of ANP release by stearoyl-LPC, palmitoyl-LPC, or oleoyl-LPC was also attenuated in hypertrophied atria. The potency appeared to be dependent on the species of fatty acid residue of LPC. Changes in ANP release by LPC, palmitoyl-LPC, and oleoyl-LPC were positively correlated with the degree of cardiac hypertrophy, but that by stearoyl-LPC was not. Changes in ANP release by LPC also were negatively correlated with changes in pulse pressure. Stearoyl-LPC caused an increase in intracellular Ca
2+
in single, atrial myocytes in a concentration-dependent manner, which was markedly attenuated in hypertrophied atrial myocytes. These results suggest that attenuation of LPC-induced suppression of ANP release from hypertrophied atria might partly be related to changes in pulse pressure in terms of cardiac hypertrophy and/or disturbance of intracellular Ca
2+
regulation.
Effects of Semantic Treatment on Verbal Communication and Linguistic Processing in Aphasia After Stroke
Authors: Doesborgh Suzanne J.C. , van de Sandt-Koenderman Mieke W.E. , Dippel Diederik W.J. , van Harskamp Frans , Koudstaal Peter J. , Visch-Brink Evy G.
Published: December 2003

Background and Purpose—

Semantic deficits, deficits in word meaning, have a large impact on aphasic patients’ verbal communication. We investigated the effects of semantic treatment on verbal communication in a randomized controlled trial.

Methods—

Fifty-eight patients with a combined semantic and phonological deficit were randomized to receive either semantic treatment or the control treatment focused on word sound (phonology). Fifty-five patients completed pretreatment and posttreatment assessment of verbal communication (Amsterdam Nijmegen Everyday Language Test [ANELT]). In an on-treatment analysis (n=46), treatment-specific effects on semantic and phonological measures were explored.

Results—

Both groups improved on the ANELT, with no difference between groups in overall score (difference, −1.1; 95% confidence interval [CI], −5.3 to 3.1). After semantic treatment, patients improved on a semantic measure (mean improvement, 2.9; 95% CI, 1.2 to 4.6), whereas after phonological treatment, patients improved on phonological measures (mean improvement, 3.0; 95% CI, 1.4 to 4.7, and 3.0; 95% CI, 1.2 to 4.7).

Conclusions—

No differences in primary outcome were noted between the 2 treatments. Our findings challenge the current notion that semantic treatment is more effective than phonological treatment for patients with a combined semantic and phonological deficit. The selective gains on the semantic and phonological measures suggest that improved verbal communication was achieved in a different way for each treatment group.
Low Serum Magnesium Predicts Neurological Events in Patients With Advanced Atherosclerosis
Authors: Amighi Jasmin , Sabeti Schila , Schlager Oliver , Mlekusch Wolfgang , Exner Markus , Lalouschek Wolfgang , Ahmadi Ramazanali , Minar Erich , Schillinger Martin
Published: December 2003

Background and Purpose—

Magnesium (Mg) deficiency is thought to be a risk factor for cerebrovascular atherosclerosis and complications. We investigated the prognostic impact of Mg serum levels with respect to the occurrence of neurological events in patients with advanced atherosclerosis.

Methods—

We prospectively studied 323 patients with symptomatic peripheral artery disease and intermittent claudication (197 men; median age, 68 years). Serum Mg was determined, and patients were followed for a median of 20 months (interquartile range, 12 to 25 months) for the occurrence of neurological events, defined as ischemic stroke and/or carotid revascularization (carotid endarterectomy or carotid stenting). Multivariate Cox proportional hazards analysis was applied to assess the association of serum Mg (in tertiles) and neurological events.

Results—

Neurological events occurred in 35 patients (11%) (15 patients with stroke, 13 with carotid revascularization, and 7 with stroke and subsequent revascularization). Compared with patients in the highest tertile of Mg serum levels (>0.84 mmol/L), patients with Mg serum values <0.76 mmol/L (lowest tertile) exhibited a 3.29-fold increased adjusted risk (95% CI, 1.34 to 7.90; P=0.009) for neurological events, but patients with Mg serum values of 0.76 mmol/L to 0.84 mmol/L (middle tertile) had no increased risk (adjusted hazard ratio, 1.10; 95% CI, 0.35 to 3.33; P=0.88). Mg serum levels were not associated with all-cause mortality (P=0.87) or coronary events (P=0.67) during follow-up.

Conclusions—

Low Mg serum levels indicate an increased risk for neurological events in patients with symptomatic peripheral artery disease, favoring Mg substitution therapy in those patients with advanced atherosclerosis.
Increased Pelvic Vein Thrombi in Cryptogenic Stroke
Authors: Cramer Steven C. , Rordorf Guy , Maki Jeffrey H. , Kramer Larry A. , Grotta James C. , Burgin W. Scott , Hinchey Judith A. , Benesch Curtis , Furie Karen L. , Lutsep Helmi L. , Kelly Ellen , Longstreth W.T.
Published: December 2003

Background and Purpose—

Cryptogenic stroke is associated with an increased prevalence of patent foramen ovale. The Paradoxical Emboli From Large Veins in Ischemic Stroke (PELVIS) study hypothesized that patients with cryptogenic stroke have an increased prevalence of pelvic deep venous thrombosis (DVT).

Methods—

At 5 sites, patients 18 to 60 years of age received an MRI venogram (MRV) of the pelvis within 72 hours of new symptom onset. Clinical data were then determined. Radiologists blinded to clinical data later read the scans.

Results—

The 95 patients who met entry criteria were scanned. Their mean±SD age was 46±10 years, and time from stroke onset to pelvic MRV scan was 49±16 hours. Compared with those with stroke of determined origin (n=49), patients with cryptogenic stroke (n=46) were significantly younger, had a higher prevalence of patent foramen ovale (61% versus 19%), and had less atherosclerosis risk factors. Cryptogenic patients had more MRV scans with a high probability for pelvic DVT (20%) than patients with stroke of determined origin (4%,
P
<0.03), with most having an appearance of a chronic DVT.

Conclusions—

In this study of young stroke patients evaluated early after stroke, patients with cryptogenic stroke showed differences in several clinical features compared with patients with stroke of determined origin, including increased prevalence of pelvic DVT. The results require confirmation but suggest that paradoxical embolus from the pelvic veins may be the cause of stroke in a subset of patients classified as having cryptogenic stroke.
Predictive Value of Inflammatory and Hemostatic Parameters, Atherosclerotic Risk Factors, and Chest X-Ray for Aortic Arch Atheromatosis
Authors: Ehlermann Philipp , Mirau Wladimir , Jahn Jürgen , Remppis Andrew , Sheikhzadeh Abdolhamid
Published: December 2003

Background and Purpose—

Aortic arch atheromatosis (AAA) is a common cause of cerebral embolism. Transesophageal echocardiography (TEE) shows not only the extension of atherosclerotic plaques but also the mobility of superimposed thrombi. In most cases AAA is only detected after the embolic event. This study was therefore designed to identify predictive factors for AAA.

Methods—

One hundred seven consecutive patients referred for routine TEE were included in the study. Patients on warfarin therapy, with a history of recent surgery, or with any signs of infectious, immunological, or malignant diseases were excluded.

Results—

Diabetes mellitus carried the highest risk for AAA (odds ratio, 3.0), followed by hyperlipidemia (2.5) and arterial hypertension (2.3). Age >70 years was accompanied with a 1.8-fold increased risk. Patients with aortic calcifications on standard chest x-ray had a 4.6-fold higher prevalence. Severe AAA was associated with higher levels of C-reactive protein (14.6±14.1 versus 4.9±7.2 mg/L), fibrinogen (4.20±1.22 versus 3.45±1.29 mg/L), plasmin/antiplasmin complexes (728±297 versus 453±243 μg/L), and D-dimers (980±652 versus 444±349 μg/L).

Conclusions—

AAA is accompanied by elevation of inflammatory and hemostatic parameters. Patients with classic cardiovascular risk factors and aortic calcifications on chest x-ray have a higher prevalence. Further prospective studies are now warranted to establish a risk score to identify patients in whom TEE screening should be undertaken.
The Outsider Art of Burning Man
Authors: Bee Lady
Published: December 2003

The author describes art installations featured at the annual Burning Man event in Black Rock City, Nevada. Burning Man is community based, collaborative and interactive and attracts a unique community of artists, performers and free spirits. The goal of the event is to remove the artist from the world of commerce and competition, emphasizing instead collaboration, cooperation and shared experience.
The Growing Brain, The Shrinking Ego: Self and Identity Redefined in the New Media Age
Authors: Wennberg Teresa
Published: December 2003

In this article, the author discusses her virtual reality installation The Parallel Dimension and goes on to explore the loss of identity experienced when a viewer is confronted with VR. She suggests that the dislocations caused by this experience may require us to formulate a more fluid and multivalent concept of the self.
Uncomfortable Proximity: The Tate Invites Mongrel to Hack the Tate's Own Web Site
Authors: Harwood Graham , Fuller Matthew
Published: December 2003

Uncomfortable Proximity is a critical web hack of the Tate Gallery's web site, created by Graham Harwood, a member of the Mongrel collective. Commissioned by Tate National Programmes, it mirrors the Tate's own web site, but offers new images and ideas, collaged from Harwood's own experiences, his readings of Tate works and publicity materials and his interest in the Tate Britain site. A related critical text by Matthew Fuller provides wider cultural context.
The Crying Post Project: A Multi-Part, Multi-Media Artwork to Memorialize Global Sites of Pain
Authors: Summers Dennis
Published: December 2003

The author describes The Crying Post Project, an artwork consisting primarily of wood staffs with solar-powered “cry generators” placed at different sites throughout the globe, at locations of environmental and/or social damage. Its two other components include an interactive 3D web site, which has been created as an alternative, data-rich venue for the project, and a series of digitally created photographic prints designed to capture the artist's emotional response to the sites. The artist also discusses how this artwork has been inspired by his research on the cross-cultural symbolism of trees, the indigenous Australian worldview, mapping theory and the relationship between language extinction and environmental destruction.
The Dilemma of Media Art: Cybernetic Serendipity at the ICA London
Authors: Usselmann Rainer
Published: December 2003

One year after the 1967 Summer of Love and at a time of considerable political unrest throughout the United States and Europe, Cybernetic Serendipity—The Computer and the Arts opened at the Institute of Contemporary Art in London to much critical and popular acclaim. This paper outlines the conceptual framework of this seminal exhibition and looks at some of the accompanying press reception in order to address a key question: how media art deals with its own historicity and the underlying socioeconomic forces that render it possible. Presented 35 years ago and still paradigmatic for the ever-shifting boundaries between art, technology, commerce and entertainment, Cybernetic Serendipity epitomizes some of the complicated dynamics that delineate the gamut of media art today.
Common Neural Substrates for Response Selection across Modalities and Mapping Paradigms
Authors: Jiang Yuhong , Kanwisher Nancy
Published: December 2003

In many situations, people can only compute one stimulus-to-response mapping at a time, suggesting that response selection constitutes a “central processing bottleneck” in human information processing. Using fMRI, we tested whether common or distinct brain regions were involved in response selection across visual and auditory inputs, and across spatial and nonspatial mapping rules. We isolated brain regions involved in response selection by comparing two conditions that were identical in perceptual input and motor output, but differed in the complexity of the mapping rule. In the visual—manual task of Experiment 1, four vertical lines were positioned from left to right, and subjects pressed one of four keys to report which line was unique in length. In the auditory—manual task of Experiment 2, four tones were presented in succession, and subjects pressed one of four keys to report which tone was unique in duration. For both visual and auditory tasks, the mapping between target position and key position was either spatially compatible or incompatible. In the verbal task of Experiment 3, subjects used nonspatial mappings that were either compatible (“same” if colors matched; “different” if they mismatched) or incompatible (the opposite). Extensive activation overlap was observed across all three experiments for incompatible versus compatible mapping in bilateral parietal and frontal regions. Our results indicate that common neural substrates are involved in response selection across input modalities and across spatial and nonspatial domains of stimulus-to-response mapping, consistent with behavioral evidence that response selection is a central process.
Common Neural Mechanisms for Response Selection and Perceptual Processing
Authors: Jiang Yuhong , Kanwisher Nancy
Published: December 2003

Behavioral evidence supports a dissociation between response selection (RS; stimulus-to-response [S—R] mapping) and perceptual discrimination (PD): The former may be subject to a central processing bottleneck, whereas the latter is not (Pashler, 1994). We previously (Jiang & Kanwisher, 2003) identified a set of frontal and parietal regions involved in RS as those that produce a stronger signal when subjects follow a difficult S—R mapping rule than an easy mapping rule. Here, we test whether any of these regions are selectively activated by RS and not perceptual processing, as predicted by the central bottleneck view. In Experiment 1, subjects indicated which of four parallel lines was unique in length; PD was indexed by a higher BOLD response when the discrimination was difficult versus easy. Stimuli and responses were closely matched across conditions. We found that all regions-of-interest (ROIs) engaged by RS were also engaged by perceptual processing, arguing against the existence of mechanisms exclusively involved in RS. In Experiments 2 and 3, we asked what processes might go on in these ROIs, such that they could be recruited by both RS and perceptual processing. Our data argue against an account of this common activation in terms of spatial processing or general task difficulty. Thus, PD may recruit the same central processes that are engaged by RS.
Neural Evidence for Representation-Specific Response Selection
Authors: Schumacher Eric H. , Elston Puni A. , D'Esposito Mark
Published: December 2003

Response selection is the mental process of choosing representations for appropriate motor behaviors given particular environmental stimuli and one's current task situation and goals. Many cognitive theories of response selection postulate a unitary process. That is, one central response-selection mechanism chooses appropriate responses in most, if not all, task situations. However, neuroscience research shows that neural processing is often localized based on the type of information processed. Our current experiments investigate whether response selection is unitary or stimulus specific by manipulating response-selection difficulty in two functional magnetic resonance imaging experiments using spatial and nonspatial stimuli. The same participants were used in both experiments. We found spatial response selection involves the right prefrontal cortex, the bilateral premotor cortex, and the dorsal parietal cortical regions (precuneus and superior parietal lobule). Nonspatial response selection, conversely, involves the left prefrontal cortex and the more ventral posterior cortical regions (left middle temporal gyrus, left inferior parietal lobule, and right extrastriate cortex). Our brain activation data suggest a cognitive model for response selection in which different brain networks mediate the choice of appropriate responses for different types of stimuli. This model is consistent with behavioral research suggesting that responseselection processing may be more flexible and adaptive than originally proposed.
Working Memory for Complex Scenes: Age Differences in Frontal and Hippocampal Activations
Authors: Park Denise C. , Welsh Robert C. , Marshuetz Christy , Gutchess Angela H. , Mikels Joseph , Polk Thad A. , Noll Douglas C. , Taylor Stephan F.
Published: December 2003

Age differences in frontal and hippocampal activations in working memory were investigated during a maintenance and subsequent probe interval in an event-related fMRI design. Younger and older adults either viewed or maintained photographs of real-world scenes (extended visual or maintenance conditions) over a 4-sec interval before responding to a probe fragment from the studied picture. Behavioral accuracy was largely equivalent across age and conditions on the probe task, but underlying neural activations differed. Younger but not older adults showed increased left anterior hippocampal activations in the extended visual compared with the maintenance condition. Onthesubsequent probeinterval, however, older adultsshowed more left and right inferior frontal activations than younger adults. The increased frontal activations at probe in older adults may have been compensatory for the decreased hippocampal activations during maintenance, but alternatively could have reflected the increased difficulty of the probe task for the older subjects. Thus, we demonstrate qualitatively different engagement of both frontal and hippocampal structures in older adults in a working memory task, despite behavioral equivalence.
ERP Evidence for a Sex-Specific Stroop Effect in Emotional Speech
Authors: Schirmer Annett , Kotz Sonja A.
Published: December 2003

The present study investigated the interaction of emotional prosody and word valence during emotional comprehension in men and women. In a prosody-word interference task, participants listened to positive, neutral, and negative words that were spoken with a happy, neutral, and angry prosody. Participants were asked to rate word valence while ignoring emotional prosody, or vice versa. Congruent stimuli were responded faster and more accurately as compared to incongruent emotional stimuli. This behavioral effect was more salient for the word valence task than for the prosodic task and was comparable between men and women. The event-related potentials (ERPs) revealed a smaller N400 amplitude for congruent as compared to emotionally incongruent stimuli. This ERP effect, however, was significant only for the word valence judgment and only for female listeners. The present data suggest that the word valence judgment was more difficult and more easily influenced by task-irrelevant emotional information than the prosodic task in both men and women. Furthermore, although emotional prosody and word valence may have a similar influence on an emotional judgment in both sexes, ERPs indicate sex differences in the underlying processing. Women, but not men, show an interaction between prosody and word valence during a semantic processing stage.
Processing Tonal Modulations: An ERP Study
Authors: Koelsch Stefan , Gunter Thomas , Schröger Erich , Friederici Angela D.
Published: December 2003

A common stylistic element of Western tonal music is the change of key within a musical sequence (known as modulation in musical terms). The aim of the present study was to investigate neural correlates of the cognitive processing of modulations with event-related brain potentials. Participants listened to sequences of chords that were infrequently modulating. Modulating chords elicited distinct effects in the event-related brain potentials: an early right anterior negativity reflecting the processing of a violation of musical regularities and a late frontal negativity taken to reflect processes of harmonic integration. Additionally, modulations elicited a tonic negative potential suggested to reflect cognitive processes characteristic for the processing of tonal modulations, namely, the restructuring of the “hierarchy of harmonic stability” (which specifies musical expectations), presumably entailing working memory operations. Participants were “nonmusicians”; results thus support the hypothesis that nonmusicians have a sophisticated (implicit) knowledge about musical regularities.
An Event-Related fMRI Investigation of Implicit Semantic Priming
Authors: Rissman Jesse , Eliassen James C. , Blumstein Sheila E.
Published: December 2003

The neural basis underlying implicit semantic priming was investigated using event-related fMRI. Prime-target pairs were presented auditorily for lexical decision (LD) on the target stimulus, which was either semantically related or unrelated to the prime, or was a nonword. A tone task was also administered as a control. Behaviorally, all participants demonstrated semantic priming in the LD task. fMRI results showed that for all three conditions of the LD task, activation was seen in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the inferior parietal lobe, with greater activation in the unrelated and nonword conditions than in the related condition. Direct comparisons of the related and unrelated conditions revealed foci in the left STG, left precentral gyrus, left and right MTGs, and right caudate, exhibiting significantly lower activation levels in the related condition. The reduced activity in the temporal lobe suggests that the perception of the prime word activates a lexical— semantic network that shares common elements with the target word, and, thus, the target can be recognized with enhanced neural efficiency. The frontal lobe reductions most likely reflect the increased efficiency in monitoring the activation of lexical representations in the temporal lobe, making a decision, and planning the appropriate motor response.
Orienting Attention to Locations in Internal Representations
Authors: Griffin Ivan C. , Nobre Anna C.
Published: December 2003

Three experiments investigated whether it is possible to orient selective spatial attention to internal representations held in working memory in a similar fashion to orienting to perceptual stimuli. In the first experiment, subjects were either cued to orient to a spatial location before a stimulus array was presented (pre-cue), cued to orient to a spatial location in working memory after the array was presented (retro-cue), or given no cueing information (neutral cue). The stimulus array consisted of four differently colored crosses, one in each quadrant. At the end of a trial, a colored cross (probe) was presented centrally, and subjects responded according to whether it had occurred in the array. There were equivalent patterns of behavioral costs and benefits of cueing for both pre-cues and retro-cues. A follow-up experiment used a peripheral probe stimulus requiring a decision about whether its color matched that of the item presented at the same location in the array. Replication of the behavioral costs and benefits of pre-cues and retro-cues in this experiment ruled out changes in response criteria as the only explanation for the effects. The third experiment used event-related potentials (ERPs) to compare the neural processes involved in orienting attention to a spatial location in an external versus an internal spatial representation. In this task, subjects responded according to whether a central probe stimulus occurred at the cued location in the array. There were both similarities and differences between ERPs to spatial cues toward a perception versus an internal spatial representation. Lateralized early posterior and later frontal negativities were observed for both preand retro-cues. Retro-cues also showed additional neural processes to be involved in orienting to an internal representation, including early effects over frontal electrodes.
Grammar Processing Outside the Focus of Attention: an MEG Study
Authors: Shtyrov Yury , Pulvermüller Friedemann , Näätänen Risto , Ilmoniemi Risto J.
Published: December 2003

To address the cerebral processing of grammar, we used whole-head high-density magnetoencephalography to record the brain's magnetic fields elicited by grammatically correct and incorrect auditory stimuli in the absence of directed attention to the stimulation. The stimuli were minimal short phrases of the Finnish language differing only in one single phoneme (word-final inflectional affix), which rendered them as either grammatical or ungrammatical. Acoustic and lexical differences were controlled for by using an orthogonal design in which the phoneme's effect on grammaticality was inverted. We found that occasional syntactically incorrect stimuli elicited larger mismatch negativity (MMN) responses than correct phrases. The MMN was earlier proposed as an index of preattentive automatic speech processing. Therefore, its modulation by grammaticality under nonattend conditions suggests that early syntax processing in the human brain may take place outside the focus of attention. Source analysis (single—dipole models and minimum-norm current estimates) indicated grammaticality dependent differential activation of the left superior temporal cortex suggesting that this brain structure may play an important role in such automatic grammar processing.
Direct Evidence for a Binding between Cognitive and Motor Functions in Humans: A TMS Study
Authors: Bonnard Mireille , Camus Mickael , de Graaf Jozina , Pailhous Jean
Published: December 2003

During voluntary motor actions, the cortico-spinal (CS) excitability is known to be modulated, on the one hand by cognitive (intention-related) processes and, on the other hand, by motor (performance-related) processes. Here, we studied the way these processes interact in the tuning of CS excitability during voluntary wrist movement. We used transcranial magnetic stimulation (TMS) both as a reliable tool for quantifying the CS excitability, through the motor-evoked potentials (MEPs), and as a central perturbation evoking a movement (because the stimulation intensity was above threshold) with subjects instructed to prepare (without changing their muscle activation) either to “let go” or to “resist” to this evoked movement. We studied the simultaneous evolution of both the motor performance and the MEPs in the wrist flexor and extensor, separately for the successful trials (on average, 66% of the trials whatever the condition) and the unsuccessful trials; this allowed us to dissociate the intentionand performance-related processes. To their great surprise, subjects were found able to cognitively prepare themselves to resist a TMS-induced central perturbation; they all reported an important cognitive effort on the evoked movement. Moreover, because TMS only evoked short-latency MEPs (and no long-latency components), the amplitude of these short-latency MEPs was found to be related in a continuous way to the actual movement whatever the prior intention. These results demonstrate that prior intention allows an anticipatory modulation of the CS excitability, which is not only selective (as already known) but also efficient, giving the intended motor behavior a real chance to be realized. This constitutes a direct evidence of the role of the CS excitability in the binding between cognitive and motor processes in humans.
A Monotonic Code for Sound Azimuth in Primate Inferior Colliculus
Authors: Groh Jennifer M. , Kelly Kristin A. , Underhill Abigail M.
Published: December 2003

We investigated the format of the code for sound location in the inferior colliculi of three awake monkeys (Macaca mulatta). We found that roughly half of our sample of 99 neurons was sensitive to the free-field locations of broadband noise presented in the frontal hemisphere. Such neurons nearly always responded monotonically as a function of sound azimuth, with stronger responses for more contralateral sound locations. Few, if any, neurons had circumscribed receptive fields. Spatial sensitivity was broad: the proportion of the total sample of neurons responding to a sound at a given location ranged from 30% for ipsilateral locations to 80% for contralateral locations. These findings suggest that sound azimuth is represented via a population rate code of very broadly responsive neurons in primate inferior colliculi. This representation differs in format from the place code used for encoding the locations of visual and tactile stimuli and poses problems for the eventual convergence of auditory and visual or somatosensory signals. Accordingly, models for converting this representation into a place code are discussed.