bluuebunny/crossref_metadata_2025 huggingface dataset:
Acetaminophen for Altering Body Temperature in Acute Stroke
Authors: Kasner Scott E. , Wein Theodore , Piriyawat Paisith , Villar-Cordova Carlos E. , Chalela Julio A. , Krieger Derk W. , Morgenstern Lewis B. , Kimmel Stephen E. , Grotta James C.
Published: July 2002

Background and Purpose

—

Mild alterations in temperature have prominent effects on ischemic cell injury and stroke outcome. Elevated core body temperature (CBT), even if mild, may exacerbate neuronal injury and worsen outcome, whereas hypothermia is potentially neuroprotective. The antipyretic effects of acetaminophen were hypothesized to reduce CBT.

Methods

—

This was a randomized, controlled clinical trial at 2 university hospitals. Patients were included if they had stroke within 24 hours of onset of symptoms, National Institutes of Health Stroke Scale (NIHSS) score ≥5, initial CBT <38.5°C, and white blood cell count <12 600 cells/mm
3
; they were excluded if they had signs of infection, severe medical illness, or contraindication to acetaminophen. CBT was measured every 30 minutes. Patients were randomized to receive acetaminophen 650 mg or placebo every 4 hours for 24 hours. The primary outcome measure was mean CBT during the 24-hour study period; the secondary outcome measure was the change in NIHSS.

Results

—

Thirty-nine patients were randomized. Baseline CBT was the same: 36.96°C for acetaminophen versus 36.95°C for placebo (
P
=0.96). During the study period, CBT tended to be lower in the acetaminophen group (37.13°C versus 37.35°C), a difference of 0.22°C (95% CI, −0.08°C to 0.51°C;
P
=0.14). Patients given acetaminophen tended to be more often hypothermic <36.5°C (OR, 3.4; 95% CI, 0.83 to 14.2;
P
=0.09) and less often hyperthermic >37.5°C (OR, 0.52; 95% CI, 0.19 to 1.44;
P
=0.22). The change in NIHSS scores from baseline to 48 hours did not differ between the groups (
P
=0.93).

Conclusions

—

Early administration of acetaminophen (3900 mg/d) to afebrile patients with acute stroke may result in a small reduction in CBT. Acetaminophen may also modestly promote hypothermia <36.5°C or prevent hyperthermia >37.5°C. These effects are unlikely to have robust clinical impact, and alternative or additional methods are needed to achieve effective thermoregulation in stroke patients.
Reduced Risk of Intracerebral Hemorrhage With Dynamic Recreational Exercise but Not With Heavy Work Activity
Authors: Thrift Amanda G. , Donnan Geoffrey A. , McNeil John J.
Published: July 2002

Background and Purpose

—

It is unclear whether intracerebral hemorrhage (ICH) is associated with dynamic or static exercise. Our aim was to assess whether such an association exists.

Methods

—

A case-control study was undertaken involving 331 consecutive cases of primary ICH and 331 age- and sex-matched community-based neighborhood controls. Cases, verified by CT or autopsy, were identified from 13 major hospitals in Melbourne, Australia. A questionnaire was used to elicit information about lifetime physical activity at leisure and work and other potentially confounding factors.

Results

—

Individuals undertaking recent regular dynamic exercise exhibited an odds ratio (OR) for ICH of 0.63 (95% CI 0.39 to 1.01) when adjustment was made for all potential confounding factors, except hypertension, cholesterol, and body mass index. Among men and women separately, the ORs were 0.51 (95% CI 0.27 to 0.97) and 1.22 (95% CI 0.52 to 2.87), respectively. When hypertension, cholesterol, and body mass index were also included in the multivariate model, the OR among men was 0.57 (95% CI 0.28 to 1.14). There was no association between physical activity at work and ICH (OR 1.14, 95% CI 0.58 to 2.25).

Conclusions

—

These results provide preliminary evidence for a role of exercise in reducing the likelihood of ICH among men. In women, the CI was wide, and the association was not statistically significant. There was further support that factors other than blood pressure status, cholesterol, and body mass index may play a role in the observed inverse association between dynamic exercise and ICH among men.
In Situ Beta Radiation to Prevent Recanalization After Coil Embolization of Cerebral Aneurysms
Authors: Raymond Jean , Leblanc Philippe , Desfaits Anne-Cécile , Salazkin Igor , Morel François , Janicki Christian , Roorda Sjoerd
Published: July 2002

Background and Purpose

—

Endovascular treatment of cerebral aneurysms, a minimally invasive alternative to surgery, is too often followed by recanalization and recurrences. The purpose of this work was to assess if in situ beta radiation can inhibit recanalization after coil embolization.

Methods

—

Radioactive platinum coils (
32
P-coils) were produced by ion implantation of
32
P. A single-coil arterial occlusion model was used to compare angiographic and pathological results at 1 to 12 weeks after nonradioactive and
32
P-coil embolization of maxillary, cervical, and vertebral arteries in 26 dogs. Coils of varying activities were used and results compared to define the minimal activity required to inhibit recanalization. Similar experiments were performed in 16 porcine maxillary and lingual and 8 rabbit axillary arteries. Results of
32
P-coil embolization of bifurcation aneurysms were then compared with embolization with nonradioactive coils in 12 dogs at 3 months.

Results

—

Nonradioactive coil embolization of canine arteries led to occlusion at 1 week, followed by recanalization at 2 weeks, which persisted at 3 months in all cases.
32
P-coils, ion-implanted with activities above 0.13 μCi/cm, led to persistent occlusion at 3 months in 80% of arteries.
32
P-coils ion-implanted with the same activity inhibited recanalization in porcine and rabbit arteries. Bifurcation aneurysms treated with
32
P-coils had better angiographic results at 3 months (
P
=0.006) than aneurysms treated with nonradioactive coils. Arteries occluded were filled with fibrous tissue at 3 months. Aneurysms embolized with
32
P-coils showed more complete neointimal coverage of the neck, without recanalization, as compared with aneurysms treated with nonradioactive coils.

Conclusion

—

In situ low-dose beta radiation inhibits recanalization after coil embolization and may improve long-term results of endovascular treatment of aneurysms.
Ca
2+
Sparks and Their Function in Human Cerebral Arteries
Authors: Wellman George C. , Nathan David J. , Saundry Christine M. , Perez Guillermo , Bonev Adrian D. , Penar Paul L. , Tranmer Bruce I. , Nelson Mark T.
Published: July 2002

Background and Purpose

—

Local Ca
2+
release events (Ca
2+
sparks) caused by the opening of ryanodine-sensitive Ca
2+
channels in the sarcoplasmic reticulum have been suggested to oppose constriction in cerebral arteries through the activation of large-conductance Ca
2+
-activated K
+
(BK) channels. We report the first identification and characterization of Ca
2+
sparks and associated BK channel currents in smooth muscle cells isolated from human cerebral arteries.

Methods

—

Membrane currents and intracellular Ca
2+
were measured with the use of the patch-clamp technique and laser scanning confocal microscopy.

Results

—

Ca
2+
sparks with a peak fractional fluorescence change (F/F
0
) of 2.02±0.04 and size of 8.2±0.5 μm
2
(n=108) occurred at a frequency of approximately 1 Hz in freshly isolated, cerebral artery myocytes from humans. At a holding potential of −40 mV, the majority of, but not all, Ca
2+
sparks (61 of 85 sparks) were associated with transient BK currents. Consistent with a role for Ca
2+
sparks in the control of cerebral artery diameter, agents that block Ca
2+
sparks (ryanodine) or BK channels (iberiotoxin) were found to contract human cerebral arteries.

Conclusions

—

This study provides evidence for local Ca
2+
signaling in human arterial myocytes and suggests that these events may play an important role in control of cerebral artery diameter in humans.
Characteristics of Brain Arteriovenous Malformations With Coexisting Aneurysms
Authors: Halim Alexander X. , Singh Vineeta , Johnston S. Claiborne , Higashida Randall T. , Dowd Christopher F. , Halbach Van V. , Lawton Michael T. , Gress Daryl R. , McCulloch Charles E. , Young William L.
Published: July 2002

Background

—

Patients harboring a brain arteriovenous malformation (BAVM) often have coexisting arterial aneurysms. Experts have argued about the clinical significance of these aneurysms, which may be important for risk stratification in patient management and clinical trials. We studied the association between coexisting aneurysms and initial presentation with intracranial hemorrhage (ICH) in patients with BAVM evaluated at two tertiary-care centers.

Methods

—

Demographic and clinical data were collected from a prospective series of patients evaluated for BAVM at the University of California, San Francisco (UCSF; n=82), and Columbia-Presbyterian Medical Center, New York (CPMC; n=254). Using multivariate logistic regression, we examined the independent association between ICH presentation and the presence of a coexisting aneurysm, and compared the association at the two hospitals.

Results

—

Aneurysms were associated with 28 BAVMs at UCSF (34%) and 74 at CPMC (29%;
P
=0.39). Initial presentation with ICH was associated with the presence of a coexisting aneurysm at CPMC (odds ratio 1.8, 95% confidence interval 1.0 to 3.0,
P
=0.044). The opposite trend was observed at UCSF (odds ratio 0.4, 95% confidence interval 0.2 to 1.1,
P
=0.085). We observed an interaction by site involving the association between ICH presentation and aneurysm (
P
=0.016).

Conclusion

—

Although many BAVM characteristics were similar at the referral centers studied, the association between initial presentation with ICH and coexisting aneurysms was not. This heterogeneity between populations undermines the validity of inferences on the role of aneurysms from any single referral series, and emphasizes the complexity in creating BAVM risk-stratification models that incorporate aneurysms.
Venous Stasis Retinopathy in Symptomatic Carotid Artery Occlusion
Authors: Klijn Catharina J.M. , Kappelle L. Jaap , van Schooneveld Mary J. , Hoppenreijs Vincent P.T. , Algra Ale , Tulleken Cornelis A.F. , van Gijn Jan
Published: July 2002

Background and Purpose

—

Chronic ocular ischemia is a rare form of ischemia of the eye in patients with carotid artery occlusion (CAO). The early and often asymptomatic stage of chronic ocular ischemia is referred to as venous stasis retinopathy (VSR). The aim of this study was to gain insight into the prevalence, cause, and outcome of VSR in patients with symptomatic CAO.

Methods

—

In 110 patients with symptomatic CAO, we prospectively investigated the frequency of VSR, the association between the presence of VSR and impaired cerebral blood flow, and the proportion of patients who developed clinically manifest chronic ocular ischemia with ischemia of the anterior eye segment or blindness.

Results

—

At study entry, VSR was found in 32 patients (29%; 95% CI, 21 to 38), particularly in those with symptoms classically associated with a hemodynamic cause, such as limb shaking (relative risk, 2.4; 95% CI, 1.0 to 5.9). Patients with VSR had lower pulsatility indexes in the ophthalmic artery in case of reversed flow, lower cerebral CO
2
reactivity, and lower cerebropetal blood flow than patients without VSR. On follow-up (mean, 29 months), clinically manifest chronic ocular ischemia developed in 4 patients (annual rate, 1.5%; 95% CI, 0.4 to 3.8); it tended to occur more often in patients in whom VSR was present at study entry (relative risk, 7.3; 95% CI, 0.8 to 68).

Conclusions

—

One third of patients with symptomatic CAO has VSR on ophthalmoscopy. VSR is associated with an impaired flow state of the brain. Development of clinically manifest chronic ocular ischemia is rare.
Carotid Stenting and Endarterectomy
Authors: Gray William A. , White Harvey J. , Barrett Douglas M. , Chandran George , Turner Roxann , Reisman Mark
Published: July 2002

Background and Purpose

—

Investigational carotid stenting for extracranial carotid stenosis has demonstrated procedural results approaching those reported with endarterectomy, but with limited cost and long-term data. This study compared the in-hospital outcomes and costs of these 2 revascularization strategies at a single institution and the long-term effectiveness of carotid stenting.

Methods

—

Data for 136 endarterectomies and 136 carotid stent procedures at a tertiary-care community hospital were obtained. The primary clinical outcome measures were in-hospital major ipsilateral stroke and death. In-hospital direct variable costs and length of stay were the primary economic measures. Information on restenosis and late ipsilateral stroke for the stent group was available at 2-year follow-up.

Results

—

These nonrandomized groups were similar, but the endarterectomy group had more symptomatic patients (42% versus 31%;
P
=0.0004), and the stent group had more NASCET-excluded patients (68% versus 35%;
P
<0.0001). In-hospital major ipsilateral stroke and death occurred more frequently in the surgical group, but the difference was not significant (2.9% versus 0%;
P
=0.1). Minor ipsilateral strokes were similar (2.2% versus 2.9%;
P
=NS). Cost ($5409 versus $3417;
P
<0.0001) and length of stay (3.0 versus 1.4 days;
P
<0.0001) were significantly greater for the surgical group. In the stent group, 6-month angiographic restenosis was 3.1%, and 2-year ipsilateral major stroke rate was 0%.

Conclusions

—

In-hospital outcomes with carotid stenting were similar to those with endarterectomy but were achieved in patients with significantly more comorbidities. Cost and resource utilization with stenting were substantially less than those with endarterectomy. At 2 years, carotid stenting appeared not only durable but also effective in stroke prevention.
Aortic Stiffness Is an Independent Predictor of Primary Coronary Events in Hypertensive Patients
Authors: Boutouyrie Pierre , Tropeano Anne Isabelle , Asmar Roland , Gautier Isabelle , Benetos Athanase , Lacolley Patrick , Laurent Stéphane
Published: July 2002

Arterial stiffness may predict coronary heart disease beyond classic risk factors. In a longitudinal study, we assessed the predictive value of arterial stiffness on coronary heart disease in patients with essential hypertension and without known clinical cardiovascular disease. Aortic stiffness was determined from carotid-femoral pulse wave velocity at baseline in 1045 hypertensives. The risk assessment of coronary heart disease was made by calculating the Framingham risk score according to the categories of gender, age, blood pressure, cholesterol, diabetes, and smoking. Mean age at entry was 51 years, and mean follow-up was 5.7 years. Coronary events (fatal and nonfatal myocardial infarction, coronary revascularization, and angina pectoris) and all cardiovascular events served as outcome variables in Cox proportional-hazard regression models. Fifty-three coronary events and 97 total cardiovascular events occurred. In univariate analysis, the relative risk of follow-up coronary event or any cardiovascular event increased with increasing level of pulse wave velocity; for 1 SD, ie, 3.5 m/s, relatives risks were 1.42 (95% confidence interval [CI], 1.10 to 1.82;
P
<0.01) and 1.41 (95% CI, 1.17 to 1.70;
P
<0.001), respectively. Framingham score significantly predicted the occurrence of coronary and all cardiovascular events in this population (
P
<0.01 and
P
<0.0001, respectively). In multivariate analysis, pulse wave velocity remained significantly associated with the occurrence of coronary event after adjustment either of Framingham score (for 3.5 m/s: relative risk, 1.34; 95% CI, 1.01 to 1.79;
P
=0.039) or classic risk factors (for 3.5 m/s: relative risk, 1.39; 95% CI, 1.08 to 1.79;
P
=0.01). Parallel results were observed for all cardiovascular events. This study provides the first direct evidence in a longitudinal study that aortic stiffness is an independent predictor of primary coronary events in patients with essential hypertension.
Combined Endopeptidase Inhibition and Adrenomedullin in Sheep With Experimental Heart Failure
Authors: Rademaker Miriam T. , Charles Chris J. , Cooper Garth J.S. , Coy David H. , Espiner Eric A. , Lewis Lynley K. , Nicholls M. Gary , Richards A. Mark
Published: July 2002

Adrenomedullin and the natriuretic peptides exert vasodilator, natriuretic, and aldosterone-inhibitory actions, making augmentation of both systems potential therapeutic strategies in heart failure. Adrenomedullin and an endopeptidase inhibitor (SCH32615) were administered separately and in combination in 8 sheep with heart failure. Compared with the control condition, SCH32615 (5 mg bolus+1 mg/kg per hour infusion for 3 hours) reduced arterial pressure, left atrial pressure, and peripheral resistance and increased cardiac output, urinary volume, sodium, creatinine, and cAMP excretion. Plasma atrial and brain natriuretic peptide and cGMP concentrations were increased, whereas aldosterone tended to fall. Adrenomedullin (50 ng/kg per minute infusion for 3 hours) induced directionally similar but significantly greater changes in all hemodynamic variables compared with SCH32615. Urinary cAMP, sodium, and creatinine excretion rose, whereas urinary volume was maintained. Circulating adrenomedullin, cAMP, renin, and angiotensin II levels were increased, aldosterone was reduced, and natriuretic peptide levels were unchanged. Coadministration of adrenomedullin and SCH32615 produced hemodynamic effects greater than those achieved during adrenomedullin administration alone. Despite the larger falls in blood pressure, renal function (urinary volume, sodium excretion, and creatinine clearance) was improved to a level similar to that during SCH32615 administration. Elevations in plasma adrenomedullin and cAMP were greater than those during adrenomedullin administration alone, whereas increments in natriuretic peptides were similar to those during SCH32615 alone. Plasma renin and angiotensin II were increased and aldosterone levels were reduced. In conclusion, cotreatment with adrenomedullin and an endopeptidase inhibitor has beneficial hemodynamic and renal effects in heart failure beyond those of either agent separately.
Associations Between Birth Weight and Antihypertensive Medication in Black and White Medicaid Recipients
Authors: Lackland Daniel T. , Egan Brent M. , Syddall Holly E. , Barker David J.P.
Published: July 2002

The blood pressures of hypertensive patients living in the southeastern region of the United States are less responsive to several classes of antihypertensive medications. Birth weights are lower among blacks and those living in the Southeast, and evidence suggests that this developmental difference increases blood pressure. As an initial step in addressing the possibility that birth weight influences response to antihypertensive therapy, we examined the relationship between birth weight and class of antihypertensive medication among 3236 Medicaid beneficiaries in South Carolina with high blood pressure. Birth weight, obtained from birth certificates, was not related to use of either diuretics or beta blockers. However, among black women, there was an inverse association between birth weight and use of calcium channel antagonists (
P
=0.03), which persisted after adjustment for the number of antihypertensive medications. Among white men, low and high birth weights were associated with greater use of angiotensin converting enzyme inhibitors than in men of normal birth weight (
P
=0.002 for quadratic trend [U-shaped]). This association remained after adjustment for comorbid conditions, including congestive heart failure and diabetes mellitus, which were associated with birth weight and for which angiotensin converting enzyme inhibitors are recommended. The findings indicate that birth weight is associated with use of calcium channel antagonists in black women and angiotensin converting enzyme inhibitors in white men. These observations suggest that further study of the relationship between birth weight and blood pressure responses to various antihypertensive medications may help elucidate pathophysiological factors contributing to geographic and racial disparities in therapeutic efficacy.
Effect of TNF-α–Converting Enzyme Inhibitor on Insulin Resistance in Fructose-Fed Rats
Authors: Togashi Nobuhiko , Ura Nobuyuki , Higashiura Katsuhiro , Murakami Hideyuki , Shimamoto Kazuaki
Published: July 2002

Insulin resistance is associated with hypertension, obesity, dyslipidemia, and type 2 diabetes. It is well known that tumor necrosis factor (TNF)-α is one of the factors linked to obesity-induced insulin resistance; however, there have been no reports on the role of TNF-α in insulin resistance in nonobese insulin-resistant hypertensives. We tested the hypothesis that TNF-α affects insulin resistance in nonobese insulin-resistant hypertensive fructose-fed rats (FFR) and that a TNF-α–converting enzyme (TACE) inhibitor that blocks TNF-α secretion improves insulin resistance in FFR. Six-week-old male Sprague-Dawley rats were fed either standard chow (control) or fructose-rich chow (FFR) for 6 weeks. For the last two weeks of a six-week period of either diet, the rats were treated with a vehicle (control or FFR) or a TACE inhibitor (100 mg/kg/d of KB-R7785; FFR+TACE-I) in peritoneal injection. At the age of 12 weeks, insulin sensitivity was assessed in all conscious rats by the euglycemic hyperinsulinemic glucose clamp technique. While FFR had higher blood pressure than the control rats (
P
<0.01), the TACE inhibitor did not change blood pressure. Insulin sensitivity (M-value) was reduced in FFR compared with that in the control rats (16.7±1.1 mg/kg per min and 10.3±0.6 mg/kg per min in the control rats and FFR, respectively,
P
<0.001), and the TACE inhibitor improved insulin sensitivity to the level of the control rats (14.3±1.2 mg/kg per min in FFR+TACE-I,
P
<0.01). These data indicate that TNF-α plays a major role in insulin resistance in nonobese insulin-resistant models and also suggest that TACE would be a good target for controlling insulin resistance not only in obese models but also in nonobese insulin-resistant models.
Angiotensinogen and Its Cleaved Derivatives Inhibit Angiogenesis
Authors: Célérier Jérôme , Cruz Amauri , Lamandé Noël , Gasc Jean-Marie , Corvol Pierre
Published: July 2002

The members of the serine protease inhibitor (serpin) family, which share a common tertiary structure and a role as serin protease inhibitors, are involved in a variety of newly discovered functions. For example, antithrombin III exerts a strong antiangiogenic activity. Angiotensinogen, the renin substrate, has a folded structure and is a member of the noninhibitory serpin subfamily. Two other noninhibitory serpins, maspin and pigment epithelium-derived factor, have antiangiogenic properties. We investigated the antiangiogenic effect of angiotensinogen and 2 related compounds: (1) des(angiotensin I)angiotensinogen, the product of angiotensinogen cleavage by renin, and (2) the reactive center loop-cleaved angiotensinogen, which is produced after selective and limited proteolysis by the protease V8. We used well-established in vitro (endothelial cell proliferation and migration, and capillary-like tube formation on Matrigel) and in vivo (the chick chorioallantoic membrane assay) models of angiogenesis to evaluate the antiangiogenic activities of these 3 related molecules. Our data demonstrated that these compounds exerted a clear and equipotent antiangiogenic effect, thus attributing a novel function to angiotensinogen and des(angiotensin I)angiotensinogen, for which no function was previously known.
Native LDL Induces Proliferation of Human Vascular Smooth Muscle Cells via Redox-Mediated Activation of ERK 1/2 Mitogen-Activated Protein Kinases
Authors: Locher Rudolf , Brandes Ralf P. , Vetter Wilhelm , Barton Matthias
Published: July 2002

This study investigated mechanisms underlying native low-density lipoprotein (LDL)-stimulated proliferation of human vascular smooth muscle cells (VSMC). Experiments were performed to determine whether native LDL affects reactive oxygen species (ROS) formation and activity of extracellular signal-regulated kinase 1/2 (ERK1/2), and whether redox-sensitive pathways contribute to LDL-induced cell proliferation. Native LDL (100 μg/mL, 24 hours) increased cell proliferation (to 303 to 388% of control,
P
<0.0001) as determined by [methyl-
3
H] thymidine incorporation. This effect was completely blocked either by the antioxidants N-acetylcysteine, Tiron, or nordihydroguaiaretic acid; the flavin-inhibitor diphenylene iodonium; or superoxide dismutase (all
P
<0.0001), and partly blocked by ERK-inhibitor PD98059 or meclofenamate (
P
<0.01). Exposure of VSMC to native LDL for 20 minutes stimulated ROS formation, measured by dichlorodihydrofluorescein oxidation, and increased ERK1/2 activity by 3.1-fold (
P
<0.001). The latter effect was sensitive to MEK1/2 inhibitor PD98059 and Tiron (
P
<0.001), and in part to N-acetylcysteine or diphenylene iodonium (
P
<0.05). These results demonstrate that native LDL induces acute formation of ROS and subsequent activation of redox-sensitive ERK 1/2 mitogen-activated protein kinases, pathways that appear to be important for mitogenic signaling of native LDL in human vascular smooth muscle cells.
Physiological Genomics: Implications In Hypertension Research
Authors: Glueck Susan B. , Dzau Victor J.
Published: July 2002

In this article we delineate the directions in which the study of physiology will take as it becomes integrated with genomics. We also provide specific examples of the ways in which physiological genomics may be applied to study the complex genetics of hypertension and cardiovascular disease.
Excess Norepinephrine Impairs Both Endothelium-Dependent and -Independent Vasodilation in Patients With Pheochromocytoma
Authors: Higashi Yukihito , Sasaki Shota , Nakagawa Keigo , Kimura Masashi , Sasaki Satoshi , Noma Kensuke , Matsuura Hideo , Hara Keiko , Goto Chikara , Oshima Tetsuya , Chayama Kazuaki
Published: July 2002

Abstract—

There is little information concerning the interaction of nitric oxide and norepinephrine (NE) on endothelial function in humans. The purpose of this study was to determine whether endothelial function is impaired by NE secreted from patients with pheochromocytoma (pheo) and whether surgical resection of the tumor improves endothelial function in these patients. We evaluated the forearm blood flow (FBF) response to acetylcholine (ACh), an endothelium-dependent vasodilator, and isosorbide dinitrate (ISDN), an endothelium-independent vasodilator, before and after adrenalectomy in 8 pheo patients, 20 normotensive subjects, and 20 patients with essential hypertension. FBF was measured using a mercury-filled silastic strain-gauge plethysmograph. The FBF response to ACh was the greatest in normotensive subjects and the least in pheo patients. The FBF response to ISDN was significantly less in pheo patients than in the other 2 groups, which had similar responses to ISDN. Adrenalectomy significantly decreased plasma and urinary NE, systolic and diastolic blood pressures, heart rate, and forearm vascular resistance. After adrenalectomy, FBF responses to both ACh and ISDN were enhanced in all pheo patients. The ratio of maximal ACh-stimulated FBF to maximal ISDN-stimulated FBF was significantly higher after adrenalectomy than before adrenalectomy (2.1±0.4 versus 1.1±0.1;

P

<0.05). The increase in maximal FBF response to ACh correlated significantly with the decrease in urinary excretion of NE (

r

=−0.62,

P

<0.01). These findings suggest that excess NE from pheo may predominately impair endothelium-dependent vasodilation in humans.
Renin-Angiotensin System Genetic Polymorphisms and Cerebral White Matter Lesions in Essential Hypertension
Authors: Sierra Cristina , Coca Antonio , Gómez-Angelats Elisenda , Poch Esteban , Sobrino Javier , de la Sierra Alejandro
Published: July 2002

It has been reported that both the DD genotype of the angiotensin converting enzyme (ACE) gene and the presence of cerebral white matter lesions (WML) may represent risk factors for the development of stroke. The present study investigates a possible association between 3 different genetic polymorphisms of the renin-angiotensin system and the presence of WML in 60 never-treated essential hypertensive patients (36 men, 24 women), aged 50 to 60 years, without clinical evidence of target organ damage. All patients underwent brain magnetic resonance imaging to establish the presence or absence of WML. The insertion/deletion (I/D) ACE gene, the M235T angiotensinogen (AGT) gene, and the A1166C angiotensin II type 1 receptor gene polymorphisms were determined by standard polymerase chain reaction. Twenty-five hypertensive patients (41.6%) were found to have WML on brain magnetic resonance imaging. No significant association between the M235T angiotensinogen or A1166C angiotensin II type 1 receptor genotypes and the presence of WML was found. However, the frequency of the DD genotype in patients with WML (64%) was significantly higher than that observed in patients without WML (28.6%;
P
=0.022). The DD genotype odds ratio for the presence of WML was 4.44 (95% confidence interval: 1.48 to 13.3). Likewise, the proportion of the D allele in patients with WML (74%) was significantly higher (
P
=0.014) than that observed in patients without WML (51.4%). We conclude that the presence of the DD genotype and/or the D allele of the ACE gene may be a predisposing factor for developing WML in essential hypertensive patients. However, because of the small sample size, these results require confirmation in a larger study.
Serotonin-Induced Contraction in Mesenteric Resistance Arteries
Authors: Watts Stephanie W.
Published: July 2002

Large arteries from hypertensive subjects are hyperresponsiveness to 5-hydroxytryptamine (5-HT). We tested the hypothesis that small arteries (225 μ ID) have a profile similar to conduit arteries, including signal transduction mechanisms and the 5-HT receptor subtype(s) mediating arterial contraction in normal and high blood pressure. Aorta and mesenteric arteries from Sprague-Dawley (232±6 μ ID), sham (229±7 μ ID; systolic blood pressure, 120±2 mm Hg), or deoxycorticosterone acetate (DOCA)–salt rats (255±11 μ ID, 192±8 mm Hg) were mounted in a wire-based myograph. In resistance arteries from Sprague-Dawley rats, the 5-HT
2A
receptor mediated contraction; agonists of the 5-HT
1B
, 5-HT
1D
, 5-HT
1F
, and 5-HT
2B
receptor were inactive. The tyrosine kinase inhibitor genistein (5 μmol/L, 4.8-fold rightward shift), PD 098,059 (10 μmol/L, 3.2-fold shift), phospholipase C inhibitor NCDC (100 μmol/L), and nifedipine (50 nmol/L) reduced maximum 5-HT–induced contraction in small arteries (4.5% and 53% control, respectively). As in aorta, 5-HT had a decrease in threshold (100-fold lower), increase in potency (11.6-fold leftward shift), and increase in efficacy (140% sham response) in small arteries from DOCA-salt rats compared with sham. Unlike in aorta, 5-HT–induced contraction in DOCA-salt small arteries was shifted competitively by the 5-HT
2A
receptor antagonist ketanserin (−log K
B
[mol/L] for both sham and DOCA-salt, 9.25±0.1), and contraction to the 5-HT
2B
agonist BW723C86 was not observed. Thus, the 5-HT
2A
receptor remains the contractile receptor in hypertension in small arteries. Although similarities were observed for large and small arteries, differences under the condition of DOCA-salt hypertension exist that may determine serotonergic compounds effective in lowering blood pressure.
Reduced Reactivity of Renal Microvessels to Pressure and Angiotensin II in Fawn-Hooded Rats
Authors: van Rodijnen William F. , van Lambalgen Ton A. , Tangelder Geert-Jan , van Dokkum Richard P.E. , Provoost Abraham P. , ter Wee Piet M.
Published: July 2002

Fawn-Hooded rats possess an increased risk to develop glomerular damage. Both an impaired control of preglomerular resistance and an elevated postglomerular resistance have been implicated. In the present study, we directly assessed the myogenic reactivity of distal interlobular arteries and afferent arterioles from hypertensive and normotensive Fawn-Hooded rats compared with Sprague-Dawley and Wistar rats, which are known to be resistant for developing renal disease. Pressure-response curves were made in isolated perfused hydronephrotic kidneys from these rats. In addition, increasing concentrations of angiotensin II were added to the perfusate to determine the reactivity of interlobular arteries, afferent arterioles, and efferent arterioles to this peptide. Preglomerular vessels from hypertensive and normotensive Fawn-Hooded rats exhibited an impaired reactivity to both pressure and angiotensin II compared with that of Sprague-Dawley and Wistar rats. Basal efferent arteriolar diameters were similar among the 4 strains of rat. In addition, efferent arterioles from hypertensive and normotensive Fawn-Hooded rats displayed a reduced sensitivity to angiotensin II. Our observations demonstrate that in Fawn-Hooded rats, 2 components of preglomerular resistance control are impaired: the myogenic and the angiotensin II response. In addition, efferent arteriolar reactivity to angiotensin II is not elevated but lowered in these rats. Therefore, a deficit in preglomerular resistance control is the most important intrinsic factor involved in the increased susceptibility of Fawn-hooded rats to develop renal disease.
Angiotensin II and Catecholamines Increase Plasma Levels of 8-Epi-Prostaglandin F
2α
With Different Pressor Dependencies in Rats
Authors: Aizawa Toru , Ishizaka Nobukazu , Usui Shin-Ichi , Ohashi Noriko , Ohno Minoru , Nagai Ryozo
Published: July 2002

We investigated the extent of oxidative stress evoked in the hypertensive rat by measuring plasma levels of 8-epi-prostaglandin F
2α
(8-epi-PGF
2α
), a marker of in vivo oxidative stress. Administration of angiotensin (Ang) II and norepinephrine at doses of 0.7 and 2.8 mg · kg
−1
· d
−1
, respectively, resulted in similar significant elevations in plasma levels of 8-epi-PGF
2α
. A 7-day infusion of Ang II at a nonpressor dose, but not norepinephrine at a nonpressor dose, also increased plasma levels of 8-epi-PGF
2α
. The norepinephrine-induced increase in 8-epi-PGF
2α
levels could be completely normalized by 3 different classes of antihypertensive drugs: prazosin, an α-adrenergic receptor blocker; hydralazine, a nonspecific vasodilator; and losartan, a specific angiotensin type 1 (AT
1
) receptor antagonist. This finding suggests that the norepinephrine-induced increase is a pressor-dependent event. In contrast, among these antihypertensive drugs, only losartan was effective in inhibiting the Ang II–induced increase in plasma 8-epi-PGF
2α
, suggesting that Ang II increases plasma levels of 8-epi-PGF
2α
in both a pressor-independent and an AT
1
receptor–dependent manner. In summary, continuous infusion of both Ang II and norepinephrine potently increases plasma levels of 8-epi-PGF
2α
and thus in vivo oxidative stress. Ang II and norepinephrine seem to induce this increase in 8-epi-PGF
2α
via mechanisms with different pressor dependencies.
Multi-Center Genetic Study of Hypertension
Authors:   The FBPP Investigators
Published: July 2002

The Family Blood Pressure Program (FBPP) consists of 4 independently established multicenter networks of investigators who have complementary approaches to the genetics of blood pressure levels and hypertension. The program has recruited participants from the African American, Mexican American, Asian, and non-Hispanic white populations. Each network utilized study designs, laboratory measurements, and analytic methods that made efficient use of the unique characteristics of their populations and the investigators’ expertise. The individual networks subsequently unified core study components into a single cohesive program. The unified FBPP includes (1) standardized clinic and laboratory protocols for core variables to facilitate direct comparison of results among networks, (2) coordination among laboratories to avoid unnecessary duplication of effort, (3) utilization of a single laboratory for genome-wide marker typing, and (4) a pooled data set containing phenotype and genotype information from >11 000 individuals.
The Neural Correlates of Grammatical Gender: An fMRI Investigation
Authors: Miceli Gabriele , Turriziani Patrizia , Caltagirone Carlo , Capasso Rita , Tomaiuolo Francesco , Caramazza Alfonso
Published: July 2002

In an fMRI experiment, subjects saw a written noun and made three distinct decisions in separate sessions: Is its grammatical gender masculine or feminine (grammatical feature task)? Is it an animal or an artifact (semantic task)? Does it contain a /tch/ or a /k/ sound (phonological task)? Relative to the other experimental conditions, the grammatical feature task activated areas of the left middle and inferior frontal gyrus and of the left middle and inferior temporal gyrus. These activations fit in well with neuropsychological studies that document the correlation between left frontal lesions and damage to morphological processes in agrammatism, and the correlation between left temporal lesions and failure to access lexical representations in anomia. Taken together, these data suggest that grammatical gender is processed in a left fronto-temporal network. In addition, the observation that the grammatical feature task and the phonology task activated neighboring but distinct regions of the left frontal lobe provides a plausible neuroanatomical basis for the systematic occurrence of phonological errors in aphasic subjects with morphological deficits.
Are Visual Cortex Maps Optimized for Coverage?
Authors: Carreira-Perpiñán Miguel Á. , Goodhill Geoffrey J.
Published: July 2002

The elegant regularity of maps of variables such as ocular dominance, orientation, and spatial frequency in primary visual cortex has prompted many people to suggest that their structure could be explained by an optimization principle. Up to now, the standard way to test this hypothesis has been to generate artificial maps by optimizing a hypothesized objective function and then to compare these artificial maps with real maps using a variety of quantitative criteria. If the artificial maps are similar to the real maps, this provides some evidence that the real cortex may be optimizing a similar function to the one hypothesized. Recently, a more direct method has been proposed for testing whether real maps represent local optima of an objective function (Swindale, Shoham, Grinvald, Bonhoeffer, & Hübener, 2000). In this approach, the value of the hypothesized function is calculated for a real map, and then the real map is perturbed in certain ways and the function recalculated. If each of these perturbations leads to a worsening of the function, it is tempting to conclude that the real map is quite likely to represent a local optimum of that function. In this article, we argue that such perturbation results provide only weak evidence in favor of the optimization hypothesis.
Post-Stroke Rehabilitation with the Rutgers Ankle System: A Case Study
Authors: Deutsch Judith E. , Latonio Jason , Burdea Grigore C. , Boian Rares
Published: July 2002

The “Rutgers Ankle” is a Stewart platform-type haptic interface designed for use in rehabilitation. The system supplies six-degree-of-freedom (DOF) resistive forces on the patient's foot, in response to virtual reality-based exercises. The Rutgers Ankle controller contains an embedded Pentium board, pneumatic solenoid valves, valve controllers, and associated signal conditioning electronics. The rehabilitation exercise used in our case study consists of piloting a virtual airplane through loops. The exercise difficulty can be selected based on the number and placement of loops, the airplane speed in the virtual environment, and the degree of resistance provided by the haptic interface. Exercise data is stored transparently, in real time, in an Oracle database. These data consist of ankle position, forces, and mechanical work during an exercise, and over subsequent rehabilitation sessions. The number of loops completed and the time it took to do that are also stored online. A case study is presented of a patient nine months post-stroke using this system. Results showed that, over six rehabilitation sessions, the patient improved on clinical measures of strength and endurance, which corresponded well with torque and power output increases measured by the Rutgers Ankle. There were also substantial improvements in task accuracy and coordination during the simulation and the patient's walking and stair-climbing ability.
Materials Flows in Finland: Resource Use in a Small Open Economy
Authors: Mäenpaää Ilmo , Juutinen Artti
Published: July 2002

In this article, the development of natural resource use in Finland during the period 1970‐1997 is analyzed. In measuring natural resource use, the concept of total material requirement (TMR) is applied. The focus is on the linkages of resource use with the changing structures of the economy. The linkages are studied using input‐output analysis.

Using input‐output analysis, the TMR is further partitioned into resources used for domestic final use or for total material consumption (TMC) and total material requirement of exports (TME). The analysis shows that TMR has the problem of double accounting: if the TMRs of all countries of the world are summed, then international trade would be accounted for twice in the world TMR, once in imports and once in exports of each country.

The TMC concept does not have this kind of defect. In a small, open economy like that of Finland, where the share of foreign trade is large, the difference between the TMR and the TMC is also large. We show that by 1997, the TME comprised about half of Finland's TMR and that the growth of the TMR over the study period has been due to the TME only as the TMC has stayed rather constant.
Comparison of Plastic Packaging Waste Management Options: Feedstock Recycling versus Energy Recovery in Germany
Authors: Wollny Volrad , Dehoust Günter , Fritsche Uwe R. , Weinem Peter
Published: July 2002

Plastics recycling, especially as prescribed by the German Ordinance on Packaging Waste (Verpackungsverordnung), is a conspicuous example of closing material loops on a large scale. In Germany, an industry‐financed system (Duales System Deutschland) was established in 1991 to collect and recycle packaging waste from households. To cope with mixed plastics, various “feedstock‐recycling” processes were developed. We discuss the environmental benefits and the cost‐benefit ratio of the system relative to municipal solid waste (MSW) incineration, based on previously published life‐cycle assessment (LCA) studies. Included is a first‐time investigation of energy recovery in all German incinerators, the optimization opportunities, the impact on energy production and substitution processes, an estimation of the costs, and a cost‐benefit assessment.

In an LCA, the total environmental impact of MSW incineration is mainly determined by the energy recovery ratio, which was found on average to reach 39% in current German incineration plants. Due to low revenues from additional energy generation, it is not cost‐effective to optimize the plants energetically. Energy from plastic incineration substitutes for a specific mixture of electric base‐load power, district heating, and process steam generation. Any additional energy from waste incineration will replace, in the long term, mainly natural gas, rather than coal.

Incineration of plastic is compared with feedstock recycling methods in different scenarios. In all scenarios, the incineration of plastic leads to an increase of CO2 emissions compared to landfill, whereas feedstock recycling reduces CO2 emissions and saves energy resources.

The costs of waste incineration are assumed to decrease by about 30% in the medium term. Today, the calculated costs of CO2 reduction in feedstock recycling are very high, but are ex‐pected to decline in the near future. Relative to incineration, the costs for conserving energy via feedstock recycling are 50% higher, but this gap will close in the near future if automatic sorting and processing are implemented in Germany.
Horizontal Politics: Transnational Environmental Activism and Global Cultural Change
Authors: Wapner Paul
Published: July 2002

Nongovernmental organizations (NGOs) engage in a host of activities to influence world political affairs. They lobby states, pressure economic actors and alter cultural frames to shape widespread thought and behavior. Most scholars of international relations ignore the cultural dimension of NGO work either because it seemingly lacks clear political significance or because alterations in cultural life are difficult to gauge. In this article I demonstrate that, while less direct and obvious, NGO cultural challenges may have, ironically, more political relevance than conventional forms of activism and engagement. Additionally, I show that, notwithstanding formidable methodological challenges, there are ways to measure shifts in broad ideational frameworks—even across borders—and scholars can adopt these in productive ways. I develop both these points through a study of environmental NGOs. The article's findings, however, can be generalized beyond environmental organizations to all types of NGOs.
L'ORGANISATION SOCIALE DE L'AGRICULTURE DANS L'EGYPTE PHARAONIQUE PENDANT L'ANCIEN EMPIRE (2650-2150 AVANT J.-C.)
Authors: García Juan Carlos Moreno
Published: July 2002

The author analyses the social background of agriculture in Old Kingdom Egypt as well as the interaction of its main constituents : institutions, peasants and the royal taxes. The impact of the foundation of royal farms and temples on peasant communities enhanced the position of the local elite, which became gradually incorporated into the State administration as the local representative of the Pharaoh. Social inequalities also increased on the long term, as some peasants became heavily indebted whereas rural potentates acquired land, serfs and flocks. The final result was the weakening of the State and the struggle for power by the members of the rural elite enriched during this process. L'auteur analyse l'organisation sociale de l'agriculture égyptienne pendant l'Ancien Empire, ainsi que les rapports existant entre ses éléments les plus importants : d'une part les institutions, d'autre part les paysans et, finalement, les impôts et les taxes prélevés par l'Etat. La fondation de temples et d'exploitations agricoles de la couronne contribua à renforcer la condition sociale des élites locales, de plus en plus intégrées dans l'appareil de l'Etat en tant que représentantes locales du Pharaon. Des inégalités sociales apparurent aussi au cours du temps, puisque certains secteurs de la paysannerie devinrent endettés en même temps que les potentats ruraux cumulaient des terres, des serfs et des troupeaux. Ce processus aboutit à l'affaiblissement du pouvoir de l'Etat et à des luttes pour le pouvoir entre les membres des élites rurales, enrichies grâce à ce processus.